+

WO2019031479A1 - Dispositif d'affichage - Google Patents

Dispositif d'affichage Download PDF

Info

Publication number
WO2019031479A1
WO2019031479A1 PCT/JP2018/029536 JP2018029536W WO2019031479A1 WO 2019031479 A1 WO2019031479 A1 WO 2019031479A1 JP 2018029536 W JP2018029536 W JP 2018029536W WO 2019031479 A1 WO2019031479 A1 WO 2019031479A1
Authority
WO
WIPO (PCT)
Prior art keywords
display
light
light sources
lighting
display device
Prior art date
Application number
PCT/JP2018/029536
Other languages
English (en)
Japanese (ja)
Inventor
正史 屋鋪
Original Assignee
シャープ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by シャープ株式会社 filed Critical シャープ株式会社
Publication of WO2019031479A1 publication Critical patent/WO2019031479A1/fr

Links

Images

Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3406—Control of illumination source
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals

Definitions

  • the present invention relates to a display device, and more particularly to a display device that displays an image by a field sequential method.
  • a display device that displays a color image without using a color filter a display device that displays a color image by a field sequential method is known.
  • Japanese Patent Application Laid-Open No. 2003-60944 discloses such a field-sequential liquid crystal display device.
  • a color image is displayed by sequentially turning on three color light sources of RGB sequentially in synchronization with the display of each image data of red (R), green (G) and blue (B). .
  • the lighting states of the light sources of three colors are controlled to perform white balance adjustment, and a color image is displayed based on the white balance adjustment result.
  • white balance adjustment when there is a difference in the lighting time of the three color light sources, a predetermined constant current for lighting control is input to the light sources for each light source at the start of lighting for color image display The timing of transition to the state varies. This is because the timing of transition from the transient state to the steady state varies when the constant current source is activated. As a result, the color balance of the three colors at the start of lighting may be lost, and an unintended color may be displayed.
  • An object of the present invention is to provide a technique for preventing display in an unintended color at the start of lighting for color image display in a field sequential display device.
  • the display device includes a plurality of light sources emitting light in different colors, and displays an image according to a field sequential method in which each of the plurality of light sources is sequentially lit in each subfield obtained by dividing one frame.
  • a light emission control unit that controls lighting of each of the plurality of light sources based on an input video signal, and the light emission control unit is configured to display a color image from the extinguished state of the plurality of light sources
  • the plurality of light sources are turned on such that the lighting time is equal for each of the subfields in the predetermined period until the lighting start for lighting, and after the predetermined period has elapsed, the result of the white balance adjustment made in advance
  • the lighting time of the plurality of light sources is controlled in accordance with.
  • display in an unintended display color can be prevented at the start of lighting for displaying a color image.
  • FIG. 1 is a schematic view showing a schematic configuration of a liquid crystal display device in the embodiment.
  • FIG. 2A is a cross-sectional view of a plane perpendicular to the display surface of the display shown in FIG.
  • FIG. 2B is a cross-sectional view of a surface perpendicular to the display surface of the display shown in FIG.
  • FIG. 3 is a functional block diagram showing a configuration example of the image processing unit shown in FIG.
  • FIG. 4 is an example of a pulse signal waveform used for lighting control of the light source shown in FIG.
  • FIG. 5 is an example of the pulse signal waveform used for lighting control of the light source which concerns on a modification.
  • the display device includes a plurality of light sources emitting light in different colors, and displays an image according to a field sequential method in which each of the plurality of light sources is sequentially lit in each subfield obtained by dividing one frame.
  • a light emission control unit that controls lighting of each of the plurality of light sources based on an input video signal, and the light emission control unit is configured to display a color image from the extinguished state of the plurality of light sources
  • the plurality of light sources are turned on such that the lighting time is equal for each of the subfields in the predetermined period until the lighting start for lighting, and after the predetermined period has elapsed, the result of the white balance adjustment made in advance
  • the lighting time of the plurality of light sources is controlled according to (first configuration).
  • the lighting time of all the light sources is made equal in each subfield in a predetermined period from the extinguished state of the plurality of light sources to the lighting start for color image display, and all the light sources are lit. Therefore, at the start of lighting at the time of color image display, the timing of transition to a steady state where a predetermined constant current is input is unlikely to vary for each light source, and display in an unintended color can be prevented.
  • the display control unit further includes: a display panel having a plurality of pixels; and a display control unit configured to control the transmittance of the pixels in the display panel based on the video signal.
  • the transmittance of the pixel may be controlled so as to display black during a period (second configuration). According to the second configuration, by displaying in black during a predetermined period before the start of lighting for displaying a color image, it is possible to further prevent display in an unintended color when displaying a color image.
  • the lighting time of the plurality of light sources in the predetermined period may be longer than the lighting time of the plurality of light sources after the lapse of the predetermined period (third configuration).
  • the lighting time of each light source in a predetermined period before lighting start for color image display is shorter than the lighting time of each light source after the predetermined time period, each light source in a short time Can be transitioned to a steady state in which a predetermined constant current is input.
  • the plurality of light sources include light sources that emit light in respective colors of red (R), green (G), and blue (B), and one frame is divided.
  • the sub-fields may be four sub-fields in which image data corresponding to each color of white (W), red (R), green (G) and blue (B) are sequentially displayed (fourth configuration) .
  • the plurality of light sources include light sources that emit light in respective colors of red (R), green (G), and blue (B), and one frame is divided.
  • the sub-frame may be three subfields in which image data corresponding to each color of red (R), green (G) and blue (B) are sequentially displayed (fifth configuration).
  • FIG. 1 is a schematic view showing a schematic configuration of a display device 1 in the present embodiment.
  • the display device 1 is a liquid crystal display device that displays a color image by a field sequential method.
  • a color image is displayed by displaying screens of different colors for each of a plurality of sub-fields that can be created by dividing a display period of one screen, that is, one frame period.
  • the display device 1 includes a display panel 11, a gate driver 12, a source driver 13, a display control circuit 14, a backlight 15, a backlight control circuit 16, and an image processing unit 17.
  • the display panel 11 is a display panel using liquid crystal, and a plurality of pixels formed by a plurality of gate lines 110 and a plurality of source lines 111 are formed in a matrix.
  • the pixel includes a thin film transistor (TFT) 113 connected to the gate line 110 and the source line 111, and a pixel electrode 114 connected to the TFT 113.
  • TFT thin film transistor
  • the gate line 110 is connected to the gate driver 12, and the source line 111 is connected to the source driver 13.
  • the gate driver 12 and the source driver 13 are connected to the display control circuit 14.
  • the gate driver 12 sequentially scans the gate lines 110 based on control signals such as timing signals and clock signals from the display control circuit 14.
  • the source driver 13 applies a voltage corresponding to the image signal to each source line 111 based on the timing signal and the image signal from the display control circuit 14.
  • the TFT 113 connected to the gate line 110 is turned on, a voltage supplied to the source line 111 is applied to the pixel electrode 114, and the alignment of liquid crystal molecules in the pixel is controlled.
  • the backlight 15 includes a light source 150 and a light guide plate 151.
  • the light source 150 includes LEDs (Light Emitting Diodes) 15R, 15G, and 15B that emit light of each color of red (R), green (G), and blue (B).
  • LEDs Light Emitting Diodes
  • the light guide plate 151 is provided on the back side of the display panel 1.
  • the light guide plate 151 is formed of a transparent material.
  • a portion of the backlight 15 overlapping the display screen of the display panel 11, that is, the display area where the pixels are arranged is transparent.
  • the light source 150 is disposed at a position facing one side surface of the light guide plate 151 in FIG. 1, the light source 150 may be disposed at a position facing a plurality of side surfaces of the light guide plate 151.
  • FIG. 2A and 2B are cross-sectional views of a plane perpendicular to the display surface of the display device 1.
  • FIG. 2A shows an example of a state in which the backlight 15 is turned off to display a transmitted light image including a transmission area seen behind the display device 1.
  • FIG. 2B shows an example of a state in which the backlight 15 is turned on to display a color image.
  • the display panel 11 is provided at a position where the backlight 15 overlaps with the display screen in a direction perpendicular to the display screen.
  • the display panel 11 includes two first and second substrates 25 and 22 and a liquid crystal 24 provided therebetween.
  • the gate line 110, the source line 111, the switching element 113, the pixel electrode 114, and the like are provided on one surface of the first substrate 25 (for example, the surface opposite to the backlight 15).
  • a polarizing plate 26 is provided on the other surface of the first substrate 25.
  • a common electrode (not shown) is formed on one surface of the second substrate 22 (for example, the surface on the backlight 15 side).
  • a polarizing plate 21 is provided on the other surface of the second substrate 22.
  • the first substrate 25 and the second substrate 22 can be formed of, for example, glass or resin.
  • the light guide plate 151 of the backlight 15 has an incident surface 15a of the light from the light source 150, and an emission surface 15b for emitting the light of the light source 150 that has entered from the incident surface 15a.
  • the display panel 11 is provided so as to overlap the emission surface 15 b of the light guide plate 151. That is, the backlight 15 is an illumination unit that emits light to one surface of the display panel 11.
  • the back surface 15c which is a surface facing the exit surface 15b of the light guide plate 151
  • light can be transmitted through the display area where the image of the display panel 11 is displayed, ie, the area overlapping the display screen.
  • the backlight 15 is configured such that light can be transmitted through a portion overlapping the display screen of the display panel 11.
  • a member provided at a position overlapping the display area of the display panel 11 in the direction perpendicular to the display screen is formed of a transparent material.
  • a light guide plate 151 capable of transmitting light in the direction perpendicular to the display screen is disposed. That is, a member that shields light is not disposed on the back surface of the display panel 11.
  • a transparent material such as an acrylic plate may be used as a member on the back side of the light guide plate 151, or nothing may be arranged on the back side of the light guide plate 151.
  • the light guide plate 151 is configured such that the light from the light source 150 propagating through the light guide plate 151 can be easily emitted toward the display panel 11 from the emission surface 15 b facing the display panel 11.
  • dots that reflect incident light can be formed at predetermined intervals on the emission surface 15 b and the back surface 15 c of the light guide plate 151.
  • the light of the light source 150 that has entered from the incident surface 15 a of the light guide plate 151 travels while being totally reflected in the light guide plate 151.
  • the light from the light source 150 that has entered the dots on the back surface 15 c of the light guide plate 151 is reflected by the dots and emitted from the emission surface 15 b of the light guide plate 151 toward the display panel 11.
  • the dots are formed, for example, by printing of a white opaque ink (organic UV curable ink or the like) or a metal ink (aluminum or gold or the like).
  • the surface of the light guide plate 151 can be processed into a shape that allows light to be easily reflected by die pressing or laser processing instead of dots by printing.
  • the light guide plate 151 may be formed of a material that easily reflects light without being limited to a form that utilizes reflection by the shape of the surface of the light guide plate 151.
  • the light guide plate 151 can include a reflection structure that reflects light traveling inside and emits the light to the outside.
  • the backlight 15 when the backlight 15 is lit, the amount of light emitted from the light source 150 through the light guide plate 151 to the display panel 11 passes through the back surface 15 c of the light guide plate 151 and reaches the display panel 11 Compared to Therefore, when the backlight 15 is lit, the color by the light of the backlight 15 is displayed on the display panel 11, and the rear of the display device 1 is not seen through.
  • the display device 1 has a color display mode and a transmitted light image display mode.
  • the backlight 15 is turned on, and the display panel 11 displays a color image that does not include a transmissive area that can be seen behind the display device 1.
  • the transmitted light image display mode the backlight 15 is turned off, and the display panel 11 displays a monotone image (transmitted light image) including the transmitted area.
  • the display panel 11 displays an image by controlling the transmittance of light incident on the display panel 11 for each pixel based on the signal of the panel drive unit in any of the color display mode and the transmitted light image display mode.
  • the display panel 11 In the case of the color display mode, that is, when the backlight 15 is turned on when displaying an image, the display panel 11 transmits the light from the light source 150 propagating in the light guide plate 151 and entering the display panel 11 through the emission surface 15 b. Will control the rate.
  • the transmitted light image display mode that is, when the backlight 15 is turned off when displaying an image, the display panel 11 penetrates the back surface 15 c of the light guide plate 151 from the outside of the display device 1 and enters the display panel 11. Control the light transmission rate. Thereby, a transmitted light image including the transmission area can be displayed. In the transmissive region, the rear of the display device 1 can be seen through.
  • the LEDs 15 ⁇ / b> R, 15 ⁇ / b> G, and 15 ⁇ / b> B are disposed, for example, at positions facing one side surface of the light guide plate 151.
  • the LEDs 15 R, 15 G, 15 B are connected to the backlight control circuit 16.
  • the backlight control circuit 16 includes a backlight drive circuit (not shown) that drives the LEDs 15R, 15G, and 15B. Each of the LEDs 15R, 15G, and 15B lights on the basis of a pulse signal indicating a lighting time input from the corresponding backlight drive circuit.
  • the display control circuit 14 and the backlight control circuit 16 are connected to the image processing unit 17.
  • the configuration of the image processing unit 17 will be described.
  • FIG. 3 is a functional block diagram showing a configuration example of the image processing unit 17.
  • the image processing unit 17 includes a coordinate generation unit 171, a determination unit 172, a separation unit 173, an image data generation unit 174, a backlight data generation unit 175, and a timing control unit 176.
  • the image processing unit 17 receives, for example, a video signal for each frame (60 Hz).
  • the coordinate generation unit 171 can be externally rewritten to hold the total number of horizontal pixels in the extending direction of the gate lines 110 (see FIG. 1) of the display panel 11 and the total number of vertical lines in the extending direction of the source lines 111. It has a register.
  • the coordinate generation unit 171 increments the horizontal counter value by one each time a pixel value (for example, a gradation value of RGB) included in the video signal is input. When the horizontal counter value becomes equal to M, the vertical counter value is incremented by one at the input of the next pixel value, and the horizontal counter value is returned to 1.
  • the coordinate generation unit 171 sets the upper left pixel in the image represented by the video signal as the origin (0, 0), the horizontal direction as the X direction, and the vertical direction as the Y direction, and coordinates (x, y) of the input pixel value.
  • the determination unit 172 determines whether the pixel value included in the input video signal is a pixel value of a predetermined coordinate, and outputs the determination result to the separation unit 173. In the present embodiment, the determination unit 172 determines whether the coordinates (x, y) of the pixel value included in the input video signal are, for example, (0, 0). That is, the determination unit 172 uses the pixel value of the coordinate (0, 0) among the pixel values included in the video signal for the on / off control of the LEDs 15R, 15G, and 15B.
  • the data included in the video signal may have a portion corresponding to the display period of the image and a portion corresponding to the blanking period.
  • data for controlling turning on / off of the LEDs 15R, 15G, and 15B can be included in a portion corresponding to the blanking period.
  • One frame period is divided into an image display period and a blanking period.
  • the pixel value of one frame period has a portion corresponding to the image display period and a portion for the blanking period.
  • the portion corresponding to the image display period includes data such as the gradation value of each pixel corresponding to each TFT 113.
  • the portion corresponding to the blanking period includes control data indicating whether to turn on the LEDs 15R, 15G, and 15B in the frame period.
  • the determination unit 172 outputs, as a determination result, to the separation unit 173, information indicating whether the pixel value of each coordinate is the gradation value of the image to be displayed or the control data representing the on / off of the LED. .
  • the separating unit 173 separates the image data indicating the image to be displayed and the control data of the LED from each pixel value of the input video signal according to the determination result of the determining unit 172.
  • the image data is output to the image data generation unit 174, and the control data of the LED is output to the backlight data generation unit 175.
  • the image data generation unit 174 generates subfield image data to be displayed in each period of a plurality of subfields formed by dividing one frame based on the input image data.
  • image display data for performing field sequential display from image data including gradation values of respective colors of RGB mixed colors W (white) are added to the respective colors of RGB to respective colors of WRGB.
  • W white
  • the generated subfield image is output to the timing control unit 176.
  • the backlight data generation unit 175 generates LED control data for causing the LEDs of the corresponding colors to emit light in the subfield period corresponding to each color of WRGB, and outputs the generated data to the timing control unit 176.
  • the backlight data generation unit 175 and the timing control unit 176 simultaneously cause the LEDs 15R, 15G, and 15B to emit light in the subfield period corresponding to W (white), and correspond to the LEDs 15R and G in the subfield period corresponding to R.
  • the LED 15B is controlled to emit light in the subfield periods corresponding to the LEDs 15G and 15B, respectively.
  • the backlight data generation unit 175 is a backlight that represents lighting / extinguishing of the LEDs 15R, 15G, and 15B for each frame based on control data that represents lighting / extinguishing of the LED when displaying an image indicated by a pixel value.
  • Generate data For example, when each of the RGB gradation values (R, G, B) included in the pixel value of the coordinates (0, 0) is larger than the threshold, the LEDs 15R, 15G, 15B are turned on in the frame period for displaying the image data. Generate backlight data.
  • the backlight data generation unit 175 determines that the gradation value included in the pixel value at the coordinate (0, 0) is (0, 0, 0). If there is, backlight data is generated that instructs the LEDs 15R, 15G, and 15B to turn off.
  • the backlight data generation unit 175 instructs the LED 15R, 15G, 15B to turn on the backlight data Generate
  • the generated backlight data is input to the image data generation unit 174 and the timing control unit 176.
  • the detection process of the control data showing ON / OFF of LED is not restricted to the said example.
  • the input pixel value includes control data indicating whether or not lighting is performed.
  • this control data may be separately input.
  • control data representing lighting / extinguishing may be input simultaneously with the pixel value or in association with the pixel value.
  • the image processing unit 17 inputs the control data to the backlight data generation unit 175 or the timing control unit 176 in synchronization with the pixel value of one frame period or in association with the pixel value of one frame period. .
  • the timing control unit 176 performs timing control for synchronizing the display of subfield images of WRGB with the lighting of the LEDs 15R, 15G, and 15B.
  • the timing control unit 176 controls the timing control signal 14 to synchronize the timing of irradiating each color of RGB and the mixed color W with the timing of displaying each subfield image of WRGB as shown in FIG. And the backlight control circuit 16 (see FIG. 1).
  • the display control circuit 14 displays the display panel 11 for each of the gate driver 12 and the source driver 13 based on each sub-field image of WRGB input from the timing control unit 176 and the timing control signal.
  • a control signal such as a timing signal for driving is input.
  • the backlight control circuit 16 includes an LED drive circuit (not shown) for driving each of the LEDs 15R, 15G, and 15B.
  • the backlight control circuit 16 switches the light emission colors of the LEDs 15R, 15G, and 15B in accordance with the timing when the subfield image of each color of WRGB is displayed on the display panel 11 by the display control circuit 14. That is, the backlight control circuit 16 turns on the LEDs 15R, 15G, and 15B by the LED drive circuits (not shown) corresponding to the LEDs 15R, 15G, and 15B based on the timing control signal input from the timing control unit 176. Control the light off.
  • the backlight control circuit 16 drives each of the LEDs 15R, 15G, and 15B for a certain period of time from when the LEDs 15R, 15G, and 15B are turned off to when lighting for color image display starts (shown in FIG. An adjustment process is performed to bring the output signal into a steady state in which a predetermined constant current is output. Then, after the adjustment processing, each LED drive circuit controls the lighting time of the LEDs 15R, 15G, and 15B according to the result of the white balance adjustment made in advance, and starts lighting for color image display. Each lighting time of LED15R, 15G, 15B is controlled by the pulse signal by which the pulse width was adjusted by the PWM (Pulse Width Modulation) modulation system.
  • PWM Pulse Width Modulation
  • FIG. 4 is an example of waveforms of pulse signals output to the LEDs 15R, 15G, and 15B.
  • a period T1 of the first frame to N-1 (N: an integer of 3 or more) frame indicates the lighting state of the LEDs 15R, 15G, 15B in the adjustment processing period.
  • the adjustment processing period T1 is a period of a transient state before each LED drive circuit enters a steady state.
  • a period T2 after the Nth frame indicates the lighting state of the LEDs 15R, 15G, and 15B after each LED drive circuit has transitioned to the steady state.
  • a video signal is input at 60 Hz for each frame, and one frame period is divided into four subfields F1 to F4 corresponding to WRGB.
  • the frequency of one subfield is 240 Hz, which is four times the frequency of the video signal.
  • subfield images corresponding to each color of WRGB are displayed.
  • each LED drive circuit in the adjustment processing period T1, is in a transient state, and simultaneously turns on the LEDs 15R, 15G, and 15B in all subfields F1 to F4 in each frame.
  • the pulse signals for each of the LEDs 15R, 15G, and 15B have the same pulse width.
  • the LEDs 15R, 15G, and 15B are lighted in substantially the same lighting time in each subfield period of F1 to F4.
  • the pulse widths of the respective pulse signals are adjusted.
  • the pulse width is adjusted so that the lighting time satisfies the relationship of LED15B ⁇ LED15G ⁇ LED15R.
  • the LEDs 15R, 15G, and 15B are turned on in response to pulse signals having pulse widths different from one another, and a W subfield image is displayed.
  • the subfield F2 only the LED 15R is turned on in the lighting time corresponding to the pulse signal of the LED 15R, and the R subfield image is displayed.
  • the sub-field F3 only the LED 15G lights up in the lighting time according to the pulse signal of the LED 15G, and the sub-field image of G is displayed.
  • only the LED 15B lights up in the lighting time according to the pulse signal of the LED 15B, and the sub-field image of B is displayed.
  • the lighting time of each of the LEDs 15R, 15G, and 15B in each subfield of the adjustment processing period T1 of each LED driving circuit is the lighting start time for color image display after each LED driving circuit transitions to the steady state. It makes longer than each lighting time of LED15R, 15G, and 15B in. Thereby, the time until the LED drive circuit (not shown) which drives each of LED15R, 15G, and 15B becomes a steady state which outputs a predetermined
  • each LED driving circuit that drives each of the LEDs 15R, 15G, and 15B at the start of lighting for performing color image display A variation occurs in the time until the steady state (not shown) outputs a predetermined constant current to the corresponding LED.
  • the LEDs 15R, 15G, and 15B are simultaneously lit in the same lighting time in each subfield of each frame. Therefore, at the start of lighting for performing color image display, the time when the LED drive circuits (not shown) of the LEDs 15R, 15G, and 15B (not shown) transition to the steady state does not vary, preventing image display in unintended colors can do.
  • the orientation of liquid crystal molecules in the display panel 11 is controlled by the display control circuit 14 (see FIG. 1) so that a black image is displayed on the display panel 11. It is also good. By displaying the display panel 11 in black, display in an unintended color can be further prevented.
  • a display concerning the present invention is not limited to composition of an embodiment mentioned above, and can be considered as various modification composition.
  • one frame is divided into four subfields corresponding to each color of WRGB
  • one frame may be divided into three subfields corresponding to each color of RGB.
  • one frame period is divided into three subfields F1 to F3.
  • the sub-field is 180 Hz.
  • the pulse width of the pulse signal for each of the LEDs 15R, 15G, and 15B is equal in all subfields F1 to F3 for each frame.
  • the LEDs 15R, 15G, and 15B light up in substantially the same lighting time.
  • the pulse width of each pulse signal is adjusted so as to become the lighting time of the LEDs 15R, 15G, and 15B according to the white balance adjustment after the Nth frame after each LED drive circuit transitions to the steady state.
  • the pulse width is adjusted so that the lighting time becomes longer in the order of the LEDs 15B, 15G, and 15R, as in the above-described embodiment. That is, as shown in FIG. 5, in the subfield F1 of the Nth frame, only the LED 15R lights up in the lighting time according to the white balance adjustment, and the R subfield image is displayed. Further, in the sub-field F2, only the LED 15G is turned on in the lighting time according to the white balance adjustment, and the sub-field image of G is displayed. Further, in the sub-field F3, only the LED 15B lights up in the lighting time according to the white balance adjustment, and the sub-field image of B is displayed.
  • the display device to which the present invention can be applied is not limited to the liquid crystal display device.
  • the present invention may be applied to other display devices (display devices other than liquid crystal display devices) having an illumination unit that emits light on one surface of the display panel and having a function to show through the back of the display screen.
  • the display panel includes a display panel including a plurality of shutter elements arranged two-dimensionally to transmit light, capable of controlling an off state to block light for each pixel, and a backlight, in one frame period.
  • the present invention can also be applied to a display device that switches the on state and the off state of the shutter element a plurality of times in accordance with each bit of the image data.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Theoretical Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical & Material Sciences (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Optics & Photonics (AREA)
  • Liquid Crystal (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Liquid Crystal Display Device Control (AREA)

Abstract

L'invention concerne une technologie pour un dispositif d'affichage séquentiel de champs dans lequel, au début de l'allumage d'une source de lumière telle qu'une lumière d'arrière-plan, un affichage dans une couleur non voulue est empêché. Le dispositif d'affichage est pourvu d'une pluralité de sources de lumière de type DEL 15R, 15G, 15B, qui émettent de la lumière dans différentes couleurs, et réalise un affichage d'image séquentielle de champs dans lequel les sources de lumière sont allumées de manière séquentielle pour chacun des sous-champs F1 à F4 qui sont obtenus par division d'une trame. Le dispositif d'affichage est pourvu d'une unité de commande d'émission de lumière qui commande l'allumage des sources de lumière sur la base d'un signal d'image entré. Dans une période de temps prescrite T1 à partir de l'état éteint des sources de lumière de type DEL 15R, 15G, 15B, jusqu'au démarrage de l'allumage pour un affichage d'image couleur, l'unité de commande d'émission de lumière allume les sources de lumière de type DEL 15R, 15G, 15B, de sorte que les temps d'allumage des sources de lumière de type DEL 15R, 15G, 15B, sont égaux les uns aux autres pour chacun des sous-champs. Dans une période de temps T2 suivant la période de temps prédéterminée T1, l'unité de commande d'émission de lumière commande les temps d'allumage des sources de lumière de type DEL 15R, 15G, 15B en fonction du résultat de l'ajustement préliminaire d'équilibre des blancs.
PCT/JP2018/029536 2017-08-09 2018-08-07 Dispositif d'affichage WO2019031479A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2017-153974 2017-08-09
JP2017153974 2017-08-09

Publications (1)

Publication Number Publication Date
WO2019031479A1 true WO2019031479A1 (fr) 2019-02-14

Family

ID=65272089

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2018/029536 WO2019031479A1 (fr) 2017-08-09 2018-08-07 Dispositif d'affichage

Country Status (1)

Country Link
WO (1) WO2019031479A1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001215466A (ja) * 2000-02-03 2001-08-10 Ichikoh Ind Ltd カラー液晶表示装置用のバックライト
JP2008249998A (ja) * 2007-03-30 2008-10-16 Nec Lcd Technologies Ltd バックライト装置および液晶表示装置
JP2010107579A (ja) * 2008-10-28 2010-05-13 Seiko Epson Corp 駆動方法および電気光学装置
JP2017111165A (ja) * 2015-12-14 2017-06-22 日本精機株式会社 光源装置、表示装置およびヘッドアップディスプレイ装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001215466A (ja) * 2000-02-03 2001-08-10 Ichikoh Ind Ltd カラー液晶表示装置用のバックライト
JP2008249998A (ja) * 2007-03-30 2008-10-16 Nec Lcd Technologies Ltd バックライト装置および液晶表示装置
JP2010107579A (ja) * 2008-10-28 2010-05-13 Seiko Epson Corp 駆動方法および電気光学装置
JP2017111165A (ja) * 2015-12-14 2017-06-22 日本精機株式会社 光源装置、表示装置およびヘッドアップディスプレイ装置

Similar Documents

Publication Publication Date Title
CN101809645B (zh) 视频显示装置及其光源驱动方法
CN101029986B (zh) 液晶显示设备、其中使用的驱动控制电路以及驱动方法
US9922588B2 (en) Image display device
WO2016104340A1 (fr) Dispositif d'affichage et son procédé de pilotage
JP2009163945A (ja) 光源システムおよび表示装置
JP2007122018A (ja) 液晶表示装置
US9548013B2 (en) Image display device and drive method therefor
US9620044B2 (en) Image display device and drive method therefor
WO2003001495A1 (fr) Affichage a cristaux liquides et dispositif electronique
CN110085179B (zh) 显示装置
JP2007206326A (ja) 液晶表示装置、該液晶表示装置に用いられる駆動回路及び駆動方法
JP2006293095A (ja) 液晶表示装置、および液晶表示装置の表示方法
JP7287855B2 (ja) 表示装置
CN102496352A (zh) 场序式液晶显示器
WO2018008720A1 (fr) Dispositif d'affichage
CN100399128C (zh) 液晶显示装置
WO2019031479A1 (fr) Dispositif d'affichage
KR102458604B1 (ko) 액정표시장치 및 그 구동방법
US20230142486A1 (en) Display device and display method
JP2005115139A (ja) 電気光学装置
US20230137916A1 (en) Display device and display method
KR101232616B1 (ko) 액정표시장치와 그의 제어방법
WO2017030033A1 (fr) Dispositif d'affichage et son procédé de commande
US20160104436A1 (en) Display apparatus and method of driving the same
WO2016059847A1 (fr) Dispositif d'affichage

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18844885

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18844885

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载