WO2013018536A1

WO2013018536A1 - Image display device and image display method

Info

Publication number: WO2013018536A1
Application number: PCT/JP2012/068083
Authority: WO
Inventors: 香川　周一; 令奈西谷; 菜美中野
Original assignee: 三菱電機株式会社
Priority date: 2011-07-29
Filing date: 2012-07-17
Publication date: 2013-02-07
Also published as: JP2014197038A

Abstract

In these image display device and image display method, a quantity of illuminating light is corrected corresponding to image data. In the device and method, a light source drive unit generates or acquires a first drive quantity (D₁) in first operation mode (steps (S2, S14, S15)), whether results obtained by comparing a detected light quantity with a correct light quantity (L_R) meet predetermined conditions or not is determined, said detected light quantity being obtained when a light source unit is driven with a light source drive quantity (D₃) generated on the basis of the first drive quantity (steps (S8-S11)), when the predetermined conditions are met, a value of a stored reference drive quantity (D₀) is changed to the value of the first drive quantity (step (S12)), and the mode is switched to second mode (step (S13)), and when the predetermined conditions are not met, the value of the first drive quantity is changed corresponding to the detected light quantity data (L₀) (step (S5)).

Description

Image display device and image display method

The present invention relates to an image display device and an image display method for displaying an image by modulating illumination light from a light source unit with a light modulation unit.

Conventionally, a value (light quantity) related to the chromaticity of illumination light directed from a backlight unit as a light source unit to a liquid crystal panel as a light modulation unit is detected by a color sensor, a temperature in the vicinity of the light source unit is detected by a temperature sensor, There is a proposal of an image display device that controls light emission of a light source unit according to a value and temperature related to detected chromaticity (see, for example, Patent Document 1). Such an image display device can appropriately adjust the chromaticity of a display image displayed on the liquid crystal panel even if the light emission characteristics of the backlight unit change due to temperature or change over time.

On the other hand, in recent years, in order to improve contrast, an image display device that adjusts the intensity of illumination light directed to the liquid crystal panel by adjusting the light emission intensity of the backlight unit in accordance with input image data has also become widespread.

Japanese Patent Laying-Open No. 2010-66465 (paragraphs 0009 to 0016, FIG. 1)

However, in the case of an image display device that adjusts the intensity of illumination light in accordance with input image data, the amount of light incident on the color sensor varies within a certain detection time. There is a problem that it is difficult to appropriately perform light emission control of the light source unit (that is, it is difficult to appropriately compensate for the influence of secular change of the light emission characteristics of the light source unit), and it is difficult to maintain high image quality.

Therefore, the present invention has been made to solve the above-described problems of the prior art, and its purpose is to achieve high image quality even when it has a function of correcting the amount of illumination light according to image data. It is an object to provide an image display device and an image display method capable of maintaining the above.

An image display device according to an aspect of the present invention receives a light source drive amount, emits illumination light with a light amount corresponding to the light source drive amount, and modulates the illumination light according to input image data. A light modulation unit that displays an image, a light amount detection unit that detects a light amount of the illumination light and outputs detected light amount data indicating the detected light amount, and a first storage unit that stores an appropriate light amount of the illumination light A second storage unit that stores a reference drive amount that is a reference value of the light source drive amount, a mode switching process that switches the operation mode to either the first operation mode or the second operation mode, and the first operation The light source driving amount correction process based on the image data is not executed in the mode, and the light source driving amount correction process based on the image data is executed in the second operation mode to generate the light source driving amount. Driving amount And a light source driving unit for executing a process,
The light source driving unit, when the operation mode is the first operation mode,
Executing a process of generating or acquiring the first drive amount;
The light source driving amount having a value corresponding to the first driving amount is generated, and the light amount detected by the light amount detecting unit when the light source unit is driven by the light source driving amount is compared with the appropriate light amount. , Execute a determination process to determine whether or not a predetermined condition is satisfied,
A reference drive amount changing process for changing the value of the reference drive amount stored in the second storage unit to the value of the first drive amount when it is determined that the predetermined condition is satisfied in the determination process; and Executing a second operation mode setting process for switching the operation mode to the second operation mode;
When it is determined in the determination process that the predetermined condition is not satisfied, a drive amount change process for changing the value of the first drive amount is executed in accordance with the detected light amount data. Yes.

In addition, an image display method according to an aspect of the present invention includes a light source unit that receives a light source drive amount and emits illumination light having a light amount corresponding to the light source drive amount, and the illumination light according to input image data. A light modulation unit that modulates and displays an image, a light amount detection unit that detects a light amount of the illumination light and outputs detected light amount data indicating the detected light amount, and a first light amount that stores an appropriate light amount of the illumination light A storage unit; a second storage unit that stores a reference drive amount that is a reference value of the light source drive amount; a mode switching process that switches an operation mode to a first operation mode or a second operation mode; In the first operation mode, the light source drive amount correction process based on the image data is not executed, and in the second operation mode, the light source drive amount correction process is executed based on the image data to generate the light source drive amount. Light source A method of device executes and a light source driving unit for executing amount generation process,
The light source driving unit, when the operation mode is the first operation mode,
Executing a process of generating or acquiring the first drive amount;
The light source driving amount having a value corresponding to the first driving amount is generated, and the light amount detected by the light amount detecting unit when the light source unit is driven by the light source driving amount is compared with the appropriate light amount. , Execute a determination process to determine whether or not a predetermined condition is satisfied,
A reference drive amount changing process for changing the value of the reference drive amount stored in the second storage unit to the value of the first drive amount when it is determined that the predetermined condition is satisfied in the determination process; and Executing a second operation mode setting process for switching the operation mode to the second operation mode;
When it is determined that the predetermined condition is not satisfied in the determination process, a drive amount change process for changing the value of the first drive amount is executed according to the detected light amount data.

According to the image display device or the image display method according to the present invention, even when a function for correcting the amount of illumination light according to image data is provided, the change in the light emission characteristics of the light source unit can be appropriately adjusted. There is an effect that high image quality can be maintained.

1 is a block diagram schematically showing a configuration of an image display device according to Embodiment 1 of the present invention. It is a block diagram which shows roughly an example of a structure of the light source drive part shown by FIG. 4 is a flowchart illustrating an example of an operation performed by a light source driving unit of the image display device according to the first embodiment. It is a block diagram which shows schematically the structure of the image display apparatus which concerns on Embodiment 2 of this invention. It is a block diagram which shows roughly an example of a structure of the light source drive part shown by FIG. 10 is a flowchart illustrating an example of an operation performed by a light source driving unit of the image display device according to the second embodiment. It is a block diagram which shows schematically the structure of the image display apparatus which concerns on Embodiment 3 of this invention. It is a block diagram which shows roughly an example of a structure of the light source drive part shown by FIG. 14 is a flowchart illustrating an example of an operation performed by a light source driving unit of the image display device according to the third embodiment.

<< 1 >> Embodiment 1
<< 1-1 >> Configuration of Embodiment 1 FIG. 1 shows the configuration of an image display apparatus 1 according to Embodiment 1 of the present invention (that is, an apparatus capable of performing the image display method according to Embodiment 1). FIG. As shown in FIG. 1, the image display device 1 includes a display image data generation unit 10, a light modulation unit 11 such as a transmissive liquid crystal panel, a light source unit 12 such as a backlight unit, a light amount detection unit 13, and the like. , the initial used in deriving the temperature detecting section 14, a light source driver 15, a first storage unit 16 for storing the proper amount L _R of the illumination light, the light source driving amount D ₃ to be supplied to the light source unit 12 a second storage unit 17 for storing a reference driving amount D ₀ is a value (reference value), and a third storage unit 18 for storing the maximum drive amount D _M is the maximum value allowed as a reference driving amount D ₀ Have. The first storage unit 16, the second storage unit 17, and the third storage unit 18 may be separate storage devices, or may be different storage areas of the same storage device.

FIG. 2 is a block diagram schematically showing an example of the configuration of the light source driving unit 15 shown in FIG. As illustrated in FIG. 2, the light source driving unit 15 includes a first drive processing unit 151, a second drive processing unit 152, and a third drive processing unit 153. However, the configuration of the light source driving unit 15 is not limited to the example of FIG.

As shown in FIG. 1 or FIG. 2, the display image data generation unit 10 receives image data I ₀ input from the outside, and the display image conforming to the standard of the light modulation unit 11 from the image data I _0. to generate the data _{I 1.} The image processing performed by the display image data generating unit 10 is, for example, the gradation conversion processing for converting tone characteristics of the image data I _0, and a color conversion process for converting the hue or saturation of the image data I ₀ Etc. are included.

The light modulation unit 11 is, for example, a light transmission type liquid crystal panel. Optical modulator 11 receives the display image data I ₁ generated from the image data I _0, in accordance with the contents of the display image data I _1, transmission of the illumination light E ₀ emitted from the light source unit 12 for each pixel modulating the rate, and displays the image E _1.

Light source unit 12 receives a signal indicating a light source driving amount D ₃ from the light source driving unit 15, which emits illumination light E ₀ of the amount of light corresponding to the light source drive amount D _3. The light source unit 12 includes, for example, a plurality of light emitters as the light emitter 121 that emits light. The light source drive amount D ₃ given to the light source unit 12, a plurality of light emitters 121 included in the light source unit 12 (typically a plurality of colors of light emitters) can be individually controlled the amount of light emitted from the. As a result, the color of the illumination light emitted from the light source unit 12 (the color of the illumination light E ₀ changes according to the ratio of the light emitted from the light emitters 121 of each color) and the brightness (the amount of light of the illumination light E ₀ ). Or proportional to the intensity). As the light emitter 121, for example, red, green, and blue light emitting diodes (LEDs) or laser elements can be used. Further, red, green, and blue light emitters 121 (LEDs or laser elements) can be used in combination with other light emitters that emit light of complementary colors. The light source drive amount D ₃ given to the light source unit 12, for example, can employ any of the length of the current amount and the light emission time. Further, as the light source drive amount D _3, may also be used both the length of the current amount and the light emission time. Further, as a light source drive amount D _3, may be a fixed value of one of the current amount and the light emission time, it controls the other as a variable value. As the light emitter 121, other types of light emitters such as a cold cathode ray tube can be used. Further, different types of light emitters such as LEDs and laser elements can be used in combination as the light emitter 121.

The light amount detection unit 13 detects the light amount of the illumination light E ₀ from the light source unit 12 and outputs detected light amount data L ₀ indicating the detected light amount. The light quantity detection unit 13 can be configured by, for example, a color sensor that detects the light quantity of each color of red, green, and blue.

The temperature detection unit 14 detects the temperature of the light source unit 12 or the temperature in the vicinity of the light source unit 12 and outputs detected temperature data T ₀ indicating the detected temperature.

The light source drive unit 15 generates a light source drive amount D ₃ using the reference drive amount D ₀ received from the second storage unit 17, and executes a light source drive amount generation process for supplying this to the light source unit 12. The light source driving unit 15 also performs a mode switching process for switching the operation mode to either the first operation mode or the second operation mode. In the first operation mode (operation mode value = “1”), the light source drive unit 15 corrects the light source drive amount based on the image data I ₀ for improving contrast (correcting the first drive amount D _1). by without performing the processing) of correcting the light source driving amount D _3, detected light quantity data based on L ₀ and the detected temperature data T ₀ and adjust the light source driving amount, a reference driving amount stored in the second storage unit 17 to change the value of D _0. Further, the light source driving unit 15 performs a light source driving amount correction process based on the image data I ₀ in the second operation mode (operation mode value = “0”), but the reference stored in the second storage unit 17 is used. not change the value of the drive amount D _0.

<< 1-2 >> Operation of Embodiment 1 <Processing of Steps S1 to S16>
FIG. 3 is a flowchart showing an example of the operation of the image display device 1 according to the first embodiment (that is, the image display method according to the first embodiment).

In the image display device 1 according to the first embodiment, first, the operation start signal C ₀ is input to the first drive processing unit 151 of the light source drive unit 15 at a predetermined timing. The predetermined timing is, for example, when the image display device 1 is started (for example, when the image display device is turned on), when the image display operation is ended (for example, when the image display device is stopped), when a channel is switched, or the like. Any one of or two or more. However, the input timing of the operation start signal C ₀ is an input operation of a user instruction using a user interface, a predetermined time interval, may be other timing such as a predetermined date. When the input timing of the operation start signal C ₀ is a user-instruction input operation, for example, a microcomputer (not shown) provided in the image display device 1 generates the operation start signal C ₀ and the light source driving unit 15. To supply.

When the operation start signal C ₀ is input, the first drive processing unit 151 enters the first operation mode (the operation mode value is “1”), and this operation mode value is output to the third drive processing unit 153 ( Step S1). The operation mode value is a signal representing the state of the first drive processing unit 151. The operation mode value “1” indicates that the light source driving unit 15 is in the first operation mode, and the operation mode value “0” indicates that the light source driving unit 15 is in the second operation mode. In addition, when the first drive processing unit 151 enters the first operation mode, first, the reference drive amount D ₀ stored in the second storage unit 17 is read, and this reference drive amount D ₀ is directly used as the first drive amount D _1. (Step S2). Here, the case where the value of the reference drive amount D ₀ is equal to the value of the first drive amount D ₁ is exemplified, but between the value of the reference drive amount D _{0 and} the value of the first drive amount D ₁ in advance. to have a certain relationship-determined (a first drive amount D ₁ is a value corresponding to the reference driving amount D _0), the first drive amount D ₁ may be derived by calculation from the reference driving amount D _0.

After step S1, the operation mode is switched to the second operation mode to (step S13), and the first driving unit 151, with reference to the detected light quantity data L ₀ indicating the detected amount of light at a light quantity detecting unit 13, the first and correcting the drive amount _{D 1,} and outputs it as a new first drive amount _{D 1} (step S11 ~ S15). Details of this operation will be described later.

Next, the second drive processing unit 152 receives the detected temperature data T ₀ indicating the temperature of the light source unit 12 or the vicinity thereof from the temperature detection unit 14 (step S3).

Next, the second driving unit 152 by correcting the first drive amount _{D 1} with reference to the detected temperature data _{T 0,} to generate a second drive amount _{D 2} (step S4). Generating the second drive amount D ₂ is, for example, can be implemented using a look-up table stored in a memory (not shown). In general, the amount of light emitted from a light emitting body (light source) such as an LED or a laser element varies depending on the temperature of the light emitting body even if the driving amount (for example, the supply current value or the light emission time) is the same. In general, a light emitting body such as an LED or a laser element tends to decrease in light emission amount as the temperature increases. The change in the amount of light emission accompanying the temperature change varies depending on the type of light source. For this reason, the value of the drive amount for obtaining the same light emission amount at each temperature is measured in advance and stored in the memory as a lookup table, thereby correcting the change in the light emission amount of the light source unit 12 due to the temperature change. be able to. In addition, when the light source unit 12 includes light emitters of a plurality of colors and the light emission amount change characteristics with respect to the temperature change are different for each color light emitter, it is necessary to provide a lookup table for each color light emitter. is there. Also, instead of using the look-up table, the same amount of light emission can also be generated second drive amount D ₂ by the processing using an arithmetic expression that models the change in the driving amount for obtaining a temperature change It is.

Next, the third drive processing unit 153 determines whether the operation mode value received from the first drive processing unit 151 is “1” (that is, the first operation mode) or “0” (that is, the second operation mode). (Step S5), and the operation content is switched based on the determination result.

Third drive processing section 153, when it is determined that the operation mode value is "1", i.e., when a first operation mode, and outputs a second drive amount D ₂ as a light source drive amount D ₃ as it is (step S6). That is, when the first operation mode, the light source drive amount D ₃ has the same value as the second drive quantity.

On the other hand, when the third drive processing unit 153 determines that the operation mode value is “0”, that is, in the second operation mode, the third drive processing unit 153 refers to the input image data I ₀ to determine the second drive amount D ₂ . corrected by (corrected for contrast enhancement), it generates a light source driving amount D ₃ (step S7). Details of this operation will be described later.

Light source unit 12 emits light of an amount corresponding to the light source drive amount _{D 3} (step S8).

Next, the first drive processing unit 151 determines whether the operation mode value is “1” (that is, the first operation mode) or “0” (that is, the second operation mode) (step S9). ), The operation content is switched based on the determination result.

When the first drive processing unit 151 determines that the operation mode value = “1”, the light amount detection unit 13 uses the brightness of the illumination light E ₀ from the light source unit 12 as the light amount of light emitted from the light source unit 12. Detected light amount data L ₀ representing the detected light amount is output. The first driving unit 151 receives the detection light quantity data L ₀ (step S10), and compared with the reference light quantity L _R stored in the first storage unit 16, determines appropriate or not is detected light ( Step S11). Details of this determination processing will be described later. Light source unit 12, when having a plurality of colors of light emitters, the light source unit is detected light amount for each light emitters of each color included in 12, also detected light quantity data L ₀ is generated as data for each light emitter of each color .

When it is determined that the detected light amount indicated by the detected light amount data L ₀ is appropriate, the first drive processing unit 151 sets the value of the first drive amount D ₁ at that time as the reference drive amount D ₀ and the second storage unit 17. In other words, the value of the reference drive amount stored in the second storage unit 17 is updated (step S12), the operation mode value is changed to “0”, and the operation mode is changed from the first operation mode to the first operation mode. It switched to second operation mode with (step S13), and the first drive amount _{D 1} at that time is output to the second driving unit 152 without correcting (step S14).

Detected when the light quantity data L ₀ is detected light indicated is determined not to be appropriate, first driving unit 151, first corrects the drive amount D _1, a new first drive amount D ₁ as the second It outputs to the drive process part 152 (step S15). In this correction operation, also referred to the maximum drive amount D _M, which is stored in the third storage unit 18. Details of this operation will be described later.

On the other hand, in step S9, if the operation mode value "0", the first driving unit 151 outputs without correcting the first drive amount _{D 1} at that time (step S16). Operation after the first drive amount D ₁ is output is similar to the operation described above, the detected temperature data T ₀ from the temperature detecting unit 14 is outputted (step S3), and with reference to the detected temperature data T ₀ second drive amount _{D 2} is generated (step S4), and a second drive amount _{D 2} from the light source drive amount _{D 3} is generated (step S5 ~ S7), the light source unit 12 by the light source drive amount _{D 3} is driven to emit light (Step S8).

<Process of step S11>
The first driving unit 151 will be described in detail the operation determines proper or not the detected light quantity data L ₀ (step S11). The first drive processing unit 151 compares the ratio of each color value in the reference light amount (that is, the appropriate light amount L _R ) with the ratio of each color value in the detected light amount data L ₀ . Here, when the light source unit 12 includes red, green, and blue light emitters, the light source unit 12 emits red, green, and blue light, and the reference light amount and the detected light amount data L ₀ are red, green, The data represents the amount of blue light. For example, the red reference light amount is “40”, the green reference light amount is “45”, the blue reference light amount is “50”, the red detection light amount indicated by the detection light amount data L ₀ is “9”, and the green detection light is detected. When the light amount is “8” and the detected blue light amount is “10”, the reference light amount and the detected light amount are normalized so that the maximum value is “100”. The normalized reference light amount is “80” for the red reference light amount, “90” for the green reference light amount, and “100” for the blue reference light amount. The normalized detected light intensity is “90” for the red detected light intensity, “80” for the green detected light intensity, and “100” for the blue detected light intensity. These values were compared for each color, does not exceed the determination threshold value for the difference or ratio of all colors, the detection light amount indicated by the detected light quantity data L ₀ is determined to be appropriate, or If even one color exceeds the determination threshold, it is determined that the detected light amount data L ₀ is not appropriate. The determination threshold value is set in advance in consideration of the white stability required in the image display device.

<Processing of step S15>
The first driving unit 151 corrects the first drive amount _{D 1,} detailed description will be given of the operation of generating a first drive amount _{D 1} new (Step S15). The first driving unit 151, within the first drive amount D ₁ does not exceed the maximum drive amount D _M that is stored in the third storage unit 18, the ratio of detected light intensities of each color indicated by the detected light quantity data L ₀ , so as to be close to the ratio of each color of the reference light intensity, to correct the first drive amount D _1. For example, as in the above-described example, the reference light amount normalized so that the maximum value is “100” is red reference light amount “80”, green reference light amount “90”, and blue reference light amount “ "and the detected light intensity of the red color indicated by the detected light quantity data _{L 0} is" 100 90 "green detection light quantity is" 80 ", a blue detection light amount" will be described which is 100 ". In such a case, the red, larger than the detection light amount reference amount of light, the green, the detection light quantity is small compared to the reference amount of light, corresponding to the red light emitter of the first drive amount D ₁ First, the driving amount is smaller than the current amount (for example, by a predetermined amount), and the driving amount corresponding to the green light emitter is larger than the current amount (for example, by a predetermined amount). 1 corrects the drive amount _{D 1.} At this time, if the maximum drive amount _DM is exceeded by correcting the green drive amount, the drive amounts corresponding to the red and blue light emitters are reduced. Providing the maximum drive amount D _M has the effect of preventing the life of the light source unit 12 is shortened by giving an excessive driving amount.

<Processing of steps S5 to S16>
Third driving unit 153 operates to generate a light source driving amount _{D 3} at about (Step S5 ~ S16) will be described in detail. If the operation mode value "1" from the first driving unit 151, the third driving unit 153 outputs the second driving amount _{D 2} as a light source drive amount _{D 3} as it is (step S6). On the other hand, when the operation mode value is “0”, the third drive processing unit 153 generates the light source drive amount D ₃ by correcting the second drive amount D ₂ with reference to the input image data I _0. (Step S7). Specifically, it operates as follows. The third drive processing unit 153 detects the average luminance of each frame of the input image data I ₀ and accumulates the detected average luminance of each frame for several frames. The third drive processing unit 153 is a multiplication coefficient that has a small value when the accumulated average luminance is low, and a large value when the accumulated average luminance is high. For example, the third drive processing unit 153 has a value from 0 to 1. A multiplication coefficient within the range of is generated. Third drive processing section 153, the generated multiplication factor, by multiplying the second drive amount D _2, generates a light source driving amount D _3.

By operating in this way, when the average luminance of the input image data I ₀ is high, the light emission of the light source unit 12 becomes even brighter, and when the average luminance of the input image data I ₀ is low, the light source unit The emission of 12 becomes even darker. Thereby, the difference (contrast) between a bright image and a dark image can be improved, and the light emission of the light source unit 12 becomes dark with respect to the image data I _{0 having} a low average luminance, thereby reducing the power consumption. There is.

Note that the average luminance of each frame is accumulated and used for several frames. When the luminance of one frame is used, the image quality may be deteriorated when the brightness of the light source section changes abruptly. This is to prevent such image quality deterioration.

Moreover, when generating the light source drive amount D _3, it is also possible to use the maximum value and the minimum value in each frame of the input image data I ₀ instead of using the average luminance.

The first driving unit 151, when the first operation mode, repeatedly determining the detected light quantity data _{L 0} proper (step S11) is until the first correction driving amount _{D 1} (step S15), and detects after the light quantity data _{L 0} is properly judged (step S11), the first driving unit 151, the second operation mode becomes (step S13), and outputs without correcting the first drive amount _{D 1} (step S14).

Third driving unit 153 between the first driving unit 151 is the first operation mode, and outputs a second drive amount _{D 2} as a light source drive amount _{D 3} as it is (Step S15). As a result, the light quantity detection unit 13 can detect a change in the light quantity of each color due to a long-term characteristic change such as a secular change in the light emission characteristic of the light source part 12 without being affected by the contents of the input image data I _0. It becomes. The third drive processing unit 153 corrects the second drive amount D ₂ in accordance with the input image data I ₀ after the first drive processing unit 151 enters the second operation mode (step S14) (step S14). S7), for generating a light source drive amount D _3, it becomes capable of displaying high quality images contrast, it contributes to reduction in power consumption.

<< 1-3 >> Effects of First Embodiment As described above, in the image display device 1 according to the first embodiment, a high-quality image with high contrast in the second operation mode, which is a normal image display mode. A display can be provided, and in the first operation mode, a change in light emission intensity with respect to the driving amount of the light source unit 12 caused by a long-term change in characteristics such as a change in characteristics over time can be detected with high accuracy. There is an effect that can be corrected.

<< 1-4 >> Modification of Embodiment 1 As the light emitter constituting the light source unit 12, red, green, and blue LEDs or a laser light source can be used. Further, a red, green or blue LED or laser light source and a light source that emits light of a complementary color can be used in combination. As an example, a combination of a red laser light source and a cyan LED that is a complementary color thereof can be used. By providing the light emitters of a plurality of colors, there is an effect that the color reproduction range of the image display device can be expanded, and this effect increases as the color purity of the light emitted from the light emitter increases. In addition, when a combination of a red laser light source and a cyan LED is used, there are two types of light emitters used, compared to the case of using red, green, and blue three-color LEDs and a laser light source. There is an effect that the configuration becomes simple and control of the driving amount of each color light emitter becomes easy.

In the above description, the operation after the operation start signal C ₀ is input has been described. However, when the operation start signal is not input when the image display device is activated, the first drive processing unit 151 is in the second operation mode. The reference drive amount D ₀ stored in the second storage unit 17 is output as the first drive amount D ₁ .

When an operation start signal is input when the image display device is terminated, it is desirable that the display image data I ₁ be data for displaying black after the operation start signal C ₀ is input. By doing so, it is possible to make an impression that the image display device is instantaneously ended without the user being aware of the time until the first drive processing unit 151 changes from the first operation mode to the second operation mode. it can. The first driving unit 151 is a display image data I ₁ when the first operation mode, if the data representing the black, successively illuminates each color of the light-emitting body having the light source unit 12 for each color, it sync Thus, the amount of light can be detected. In this case, the light amount detection unit 13 can be configured by a monochrome optical sensor instead of a color sensor, and the cost can be reduced.

<< 2 >> Embodiment 2
<< 2-1 >> Configuration of Embodiment 2 FIG. 4 shows the configuration of an image display apparatus 2 according to Embodiment 2 of the present invention (that is, an apparatus capable of performing the image display method according to Embodiment 2). FIG. FIG. 5 is a block diagram schematically showing an example of the configuration of the light source driving unit 25 shown in FIG. FIG. 6 is a flowchart illustrating an example of an operation (that is, an image display method according to the second embodiment) by the light source driving unit 25 of the image display apparatus 2 according to the second embodiment. 4, components that are the same as or correspond to those shown in FIG. 1 (Embodiment 1) are assigned the same reference numerals. In FIG. 5, the same reference numerals are given to the same or corresponding components as those shown in FIG. 2 (Embodiment 1). Further, in FIG. 6, the same reference numerals are given to the same or corresponding components as the steps shown in FIG. 3 (Embodiment 1).

As shown in FIG. 4, the image display device 2 according to the second embodiment includes a display image data generation unit 10, a light modulation unit 11, a light source unit 22, a light amount detection unit 13, a temperature detection unit 14, and a light source drive unit. 25, a first storage unit 16, a second storage unit 17, and a third storage unit 18. As shown in FIG. 5, the light source drive unit 25 includes a first drive processing unit 151, a second drive processing unit 152, and a third drive processing unit 253. Regarding points other than the configuration and functions of the light source unit 22 and the third drive processing unit 253, the image display device 2 according to the second embodiment is basically the same as the image display device 1 according to the first embodiment. .

In the light source unit 22, the amount of illumination light for each of a plurality of image display regions in the light modulation unit 11 (for example, a liquid crystal panel) (that is, light emission corresponding to each of the plurality of image display regions of the light modulation unit 11). The amount of light emitted from the body is individually controlled. The third drive processing unit 253 is configured to be able to give a different light source drive amount D ₃ for each of the plurality of image display regions of the light modulation unit 11. In other words, the light modulation unit 11 is divided into a plurality of image display areas, the light source unit 22 includes a plurality of light emitters respectively corresponding to the plurality of image display areas, and the light source driving unit 25 performs the second operation. In the light source drive amount correction process in the mode (step S7), the light source drive amount corresponding to each of the plurality of light emitters is supplied based on the image data of each of the plurality of image display areas.

<< 2-2 >> Operation of Embodiment 2 The third drive processing unit 253, when the operation mode value from the first drive processing unit 151 is “1” (first operation mode), and outputs ₂ as the drive amount of the light emitters corresponding to all of the illumination region as a light source drive amount D ₃ as it is.

On the other hand, when the operation mode value is “0” (second operation mode), the third drive processing unit 253 refers to the input image data I ₀ and corrects the second drive amount D ₂ for each illumination area. it allows to produce a light source drive amount D _3. Specifically, the third drive processing unit 253 detects the average luminance of each frame of the input image data I ₀ for each of a plurality of image display areas set in the screen. The image display area in this screen is determined so as to coincide with the illumination area of the corresponding light source unit. The third drive processing unit 253 accumulates the detected average luminance for each image display area for several frames. For each image display area, the third drive processing unit 253 applies a multiplication coefficient in a range from 0 to 1 which is a small value when the accumulated average luminance is low and a large value when the accumulated average luminance is high. Generate. Third drive processing section 253, the generated multiplication factor, by multiplying the second drive amount D _2, generates a light source driving amount D _3. By operating in this way, the illumination light in the region where the average luminance of the input image data I ₀ is high becomes brighter, and the illumination light in the region where the average luminance of the input image data I ₀ is low becomes darker. As a result, the contrast between bright and dark areas in the image is improved, and the illumination light becomes darker in areas with low average luminance, thereby reducing power consumption.

Also, as in the first embodiment, when the first driving unit 151 is in the first operation mode, the third driving unit 253 outputs the second driving amount D ₂ as a light source drive amount D ₃ as it is Therefore, the light quantity detection unit 13 can detect a change in the light quantity of each color due to a long-term characteristic change such as a secular change in the light emission characteristic of the light source part 22 without being affected by the contents of the input image data I _0. Become. In particular, when the light emission amount of the light source unit 22 changes for each illumination region, the intensity of illumination light in each region influences each other, so that it is very difficult to detect a change in the characteristics of the light source unit 22. In the image display device 2 according to the second embodiment, the light quantity change of each color due to a long-term characteristic change such as a secular change of the light emission characteristic of the light source unit 22 is not affected by the contents of the input image data I _0. It is possible to provide a high-quality display image that can be detected and corrected with high accuracy and has high contrast.

Other than the above operation, the operation of the image display device 2 according to the second embodiment is basically the same as the operation of the image display device 1 according to the first embodiment.

<< 2-3 >> Effects of Second Embodiment As described above, in the image display apparatus 2 according to the second embodiment, a high-quality image with high contrast in the second operation mode, which is a normal image display mode. A display can be provided, and in the first operation mode, a change in light emission intensity with respect to the driving amount of the light source unit 22 due to a long-term change in characteristics such as a change in characteristics over time can be detected with high accuracy. There is an effect that can be corrected.

<< 3 >> Embodiment 3
<< 3-1 >> Configuration of Embodiment 3 FIG. 7 shows the configuration of an image display apparatus 3 according to Embodiment 3 of the present invention (that is, an apparatus capable of performing the image display method according to Embodiment 3). FIG. FIG. 8 is a block diagram schematically showing an example of the configuration of the light source driving unit 35 shown in FIG. Further, FIG. 9 is a flowchart illustrating an example of an operation (that is, an image display method according to the third embodiment) by the light source driving unit 35 of the image display device 3 according to the third embodiment. In FIG. 7, the same or corresponding components as those shown in FIG. 1 (Embodiment 1) are denoted by the same reference numerals. In FIG. 8, the same reference numerals are given to the same or corresponding components as those shown in FIG. 2 (Embodiment 1). Further, in FIG. 9, the same reference numerals are given to the same or corresponding components as the steps shown in FIG. 3 (Embodiment 1).

The image display device 3 according to Embodiment 3 does not include the temperature detection unit 14 (FIG. 1) in Embodiment 1 as shown in FIG. 7, and the light source as shown in FIG. The driving unit 35 is different from the image display device 1 according to the first embodiment in that the driving unit 35 does not include the second driving processing unit 152 (FIG. 2) in the first embodiment. Further, the operation (image display method) of the image display device 3 according to the third embodiment is the same as the first embodiment in that steps S3 and S4 (FIG. 3) in the first embodiment are not provided, as shown in FIG. 1 is different from the operation (image display method) of the image display apparatus 1 according to FIG. In other respects, the image display device 3 according to the third embodiment is basically the same as the image display device 1 according to the first embodiment.

<< 3-2 >> Operation of Embodiment 3 In the image display device 3 according to Embodiment 3, the light source driving unit 35 sets the operation mode to the first operation mode (operation mode value = “1”) or the second operation mode. The mode switching process for switching to any one of (operation mode value = “0”) and the light source driving amount correction process based on the image data I ₀ are not executed in the first operation mode (step S6), and the second operation mode in running the light source driving amount of the correction processing based on the image data I ₀ (the step S7), and executes the light source driving amount generating process (step S6 ~ S8) for generating a light source drive amount D ₃ to be supplied to the light source unit 12 To do.

Light source driving unit 35, when the operation mode is the first operation mode, the first drive amount _{D 1} generated or obtained to process (steps S2 or S14, S15) executes, corresponding to the first drive amount _{D 1} generating a light source drive amount D ₃ whose value. Next, the light source driving unit 35 as a result of the amount of light quantity detection unit 13 has detected when driving the light source unit 12 by the light source drive amount D _3, and compared with appropriate light quantity L _R is, whether a predetermined condition is satisfied A determination process (steps S8 to S11) for determination is executed. When the light source driving unit 35 determines that the predetermined condition is satisfied in the determination processing, the reference driving amount for changing the value of the reference driving amount D ₀ stored in the second storage unit 17 to the value of the first driving amount D _1. When the change process (step S12) and the second operation mode setting process (step S13) for switching the operation mode to the second operation mode are executed and it is determined that the predetermined condition is not satisfied in the determination process, the detected light amount data L ₀ depending on, it executes drive amount changing processing of changing the first value of the drive amount D ₁ a (step S15).

As described above, the operation (image display method) of the image display apparatus 3 according to the third embodiment is basically the same as the first embodiment except that steps S3 and S4 (FIG. 3) in the first embodiment are not provided. 1 is the same as the operation (image display method) of the image display apparatus 1 according to FIG.

<< 3-3 >> Effects of Embodiment 3 As described above, in the image display device 3 according to Embodiment 3, a high-quality image with high contrast is obtained in the second operation mode, which is a normal image display mode. A display can be provided, and in the first operation mode, a change in light emission intensity with respect to the driving amount of the light source unit 12 caused by a long-term change in characteristics such as a change in characteristics over time can be detected with high accuracy. There is an effect that can be corrected.

Further, the image display device 3 according to the third embodiment has a function capable of maintaining the temperature of the light source unit 12 substantially constant when a light emitter having low temperature dependency is used as the light source of the light source unit 12. It is effective in the case of having, and the configuration can be simplified.

Note that the configuration shown in the third embodiment can be applied to the second embodiment.

1, 2, 3 image display device, 10 display image data generation unit, 11 light modulation unit, 12, 22 light source unit, 13 light quantity detection unit, 14 temperature detection unit, 15, 25, 35 light source drive unit, 16 first Storage unit, 17 second storage unit, 18 third storage unit, 121, 221 light emitter, 151 first drive processing unit, 152 second drive processing unit, 153, 253, 353 third drive processing unit.

Claims

A light source unit that receives a light source driving amount and emits illumination light of a light amount corresponding to the light source driving amount;
A light modulator that modulates the illumination light according to input image data and displays an image; and
A light amount detector that detects the light amount of the illumination light and outputs detected light amount data indicating the detected light amount;
A first storage unit that stores an appropriate amount of illumination light;
A second storage unit that stores a reference drive amount that is a reference value of the light source drive amount;
The mode switching process for switching the operation mode to either the first operation mode or the second operation mode, and the correction process of the light source driving amount based on the image data is not performed in the first operation mode, and the second operation is performed. A light source drive unit that executes a light source drive amount generation process for generating the light source drive amount by executing a correction process of the light source drive amount based on the image data in the mode, and
The light source driving unit, when the operation mode is the first operation mode,
Executing a process of generating or acquiring the first drive amount;
The light source driving amount having a value corresponding to the first driving amount is generated, and the light amount detected by the light amount detecting unit when the light source unit is driven by the light source driving amount is compared with the appropriate light amount. , Execute a determination process to determine whether or not a predetermined condition is satisfied,
A reference drive amount changing process for changing the value of the reference drive amount stored in the second storage unit to the value of the first drive amount when it is determined that the predetermined condition is satisfied in the determination process; and Executing a second operation mode setting process for switching the operation mode to the second operation mode;
When it is determined in the determination process that the predetermined condition is not satisfied, a drive amount change process for changing the value of the first drive amount is executed according to the detected light amount data. An image display device.
A temperature detection unit that detects a temperature of the light source unit or a temperature in the vicinity of the light source unit and outputs detection temperature data indicating the detected temperature;
The determination process generates a second drive amount by correcting the first drive amount according to the detected temperature data, and drives the light source unit by the light source drive amount having the same value as the second drive amount. The image display device according to claim 1, wherein the image display device according to claim 1 is a process for determining whether a result of comparing the light amount detected by the light amount detection unit with the appropriate light amount satisfies a predetermined condition. .
The operation mode of the light source driving unit is the first operation mode from when a predetermined first operation mode start signal is received until the second operation mode is switched in the second operation mode setting process. The image display device according to claim 1, wherein the image display device is an image display device.
A third storage unit for storing the maximum drive amount;
The said light source drive part performs the said drive amount change process which changes the value of the said 1st drive amount within the range in which the said 1st drive amount does not exceed the said maximum drive amount. The image display device according to any one of the above.
The light modulation unit is divided into a plurality of image display areas,
The light source unit includes a plurality of light emitters respectively corresponding to the plurality of image display areas,
The light source driving unit, in the correction process of the light source driving amount in the second operation mode, based on the image data of each of the plurality of image display areas, the light source driving amount corresponding to each of the plurality of light emitters. The image display device according to any one of claims 1 to 4, wherein the image display device is supplied.
The light source unit includes a plurality of light emitters,
The light source driving amount is an amount including at least one of a current value of a current supplied to each of the plurality of light emitters and a light emission time of each of the plurality of light emitters. 6. The image display device according to any one of items 1 to 5.
The plurality of light emitters include a red light emitter that emits red light, a green light emitter that emits green light, and a blue light emitter that emits blue light. Image display device.
The image display device according to claim 7, wherein the plurality of light emitters further include a light emitter that emits light of a complementary color of at least one of red, green, and blue.
A light source unit that receives a light source driving amount and emits illumination light of a light amount corresponding to the light source driving amount;
A light modulator that modulates the illumination light according to input image data and displays an image; and
A light amount detector that detects the light amount of the illumination light and outputs detected light amount data indicating the detected light amount;
A first storage unit that stores an appropriate amount of illumination light;
A second storage unit that stores a reference drive amount that is a reference value of the light source drive amount;
The mode switching process for switching the operation mode to either the first operation mode or the second operation mode, and the correction process of the light source driving amount based on the image data is not performed in the first operation mode, and the second operation is performed. A light source driving unit that executes correction processing of the light source driving amount based on the image data in the mode to generate the light source driving amount, and a light source driving unit that executes the light source driving amount generation processing.
The light source driving unit, when the operation mode is the first operation mode,
Executing a process of generating or acquiring the first drive amount;
The light source driving amount having a value corresponding to the first driving amount is generated, and the light amount detected by the light amount detecting unit when the light source unit is driven by the light source driving amount is compared with the appropriate light amount. , Execute a determination process to determine whether or not a predetermined condition is satisfied,
When it is determined in the determination process that the predetermined condition is satisfied, a reference drive amount change process for changing the value of the reference drive amount stored in the second storage unit to the value of the first drive amount; and Executing a second operation mode setting process for switching the operation mode to the second operation mode;
When determining that the predetermined condition is not satisfied in the determination process, an image display method is provided, wherein a drive amount change process for changing a value of the first drive amount is executed according to the detected light amount data.