RU2621664C1 - Videosignal sensor of primary colours for panoramic television surveillance of colour images - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention relates to the panoramic television surveillance of a colour image, that is performed using three sensors of the primary colour videosignal (R, G, B) in the area similar to a hemisphere, i.e. in the spatial angle of 360 degrees in azimuth and tens of degrees in elevation angle. The method is carried out by implementing a "ring" photodetector of different in size photosensitive elements and controlling the charge reading in the sensor videosignal with the same size of the aperture area.

EFFECT: aligning the sensor image resolution abilities.

3 cl, 6 dwg

Description

The invention relates to panoramic television observation of a color image, which is performed using three primary color video sensors (R, G, B) in a region close to the hemisphere, i.e. in a spatial angle of 360 degrees in azimuth and tens of degrees in elevation.

The closest in technical essence to the claimed invention should be considered the primary color video sensor [1], the optical input of which is located in one of the three outputs of the optical beam splitter installed between the panoramic lens and three of these sensors, each of which contains a “ring” photodetector, the target of which is projected a panoramic optical image in one of three primary colors, i.e. either in red - R, or in green - G, or in blue - B, as well as a photodetector unit sequentially located and connected to the "ring" sensor, the output of which is the output of the sensor video signal, while the "ring" photodetector is made using instrument technology with charge-coupled (CCD), has a target crystal in the form of a circular ring of silicon and consists of successively connected by a charge-coupled photodetector region, a memory section, a “ring” shift register and a charge-voltage converter (CPS), moreover, on the photodetector about The regions of the line of photosensitive elements, alternating with the lines of light-shielded elements, as well as the lines of light-shielded elements of the memory section are located along radial directions from the imaginary center of the circular ring to its outer periphery and the “ring” shift register located there, the number of elements of which is equal to the number of elements in each “annular” line of the photodetector region and in each “annular” line of the memory section, while the photodetector unit provides an “annular” raster image the formation and formation of an analog video signal at the output.

For the prototype, the following is assumed.

Firstly, the OTL of the “ring” photodetector is organized as a “floating diffusion region” [2], and therefore has a control input that provides an elementwise voltage drop of the generated video signal.

Secondly, the photodetector unit contains a “ring” scan unit and a signal processor, while the information input of the signal processor is connected to the output of the CCD of the “ring” photodetector, the first output of the “ring” scan unit is connected to the control inputs of the photodetector area of the “ring” photodetector, the second the output of the “circular” scan unit is to the control inputs of the memory section, the third output of the “circular” scan unit is to the control inputs of the “ring” shift register of the “ring” photodetector, the fourth output of the “ring” block th "scan - to the control input BPZN" ring "of the photodetector, and a fifth output" ring "scanner - to the input of the signal processor synchronization.

The disadvantage of the prototype sensor is a variable image resolution within the frame, decreasing towards the outer periphery of the "ring" photodetector due to the increasing gap (gap) between its photosensitive elements, which have the same geometric area.

The objective of the invention is to equalize the resolution of the image of the sensor by implementing in the "ring" photodetector of different in area of the photosensitive elements and control charge reading in the video signal of the sensor with the same area of the aperture.

The problem in the inventive sensor of the video signal of the primary colors is solved by the fact that in the device of its prototype [1], containing a "ring" photodetector, on the target of which a panoramic optical image is projected in one of the three primary colors (either in red - R, or in green - G, or in blue - B), as well as a “ring” sweep unit and a signal processor, the output of which is the output of the sensor video signal, while the “ring” photodetector made by CCD technology has a target crystal in the form of a silicon circular ring and consists of a photodetector region, a memory section, an “annular” shift register, and an SPS with a “floating diffusion” organization, which are sequentially connected by charge coupling, and on the photodetector region there are lines of photosensitive elements alternating with lines of elements shielded from light, as well as lines of shielded from light elements of the memory section are located along radial directions from the imaginary center of the circular ring to its outer periphery and the “circular” shift register located there, the number of elements of which is equal to the number of elements in each “ring” line of the photodetector region and in each “ring” line of the memory section, while the information input of the signal processor is connected to the output of the SPS of the “ring” photodetector, the first output of the block of the “ring” scan is connected to the control inputs of the photodetector the area of the “circular” photodetector, the second output of the “circular” scan unit - to the control inputs of the memory section, the third output of the “circular” scan unit - to the control inputs of the “circular” shift register of the “circular” photodetector the receiver, the fourth output of the “ring” scan block - to the control input of the CCD of the “ring” photodetector, the fifth output of the block “ring” scan - to the synchronization input of the signal processor, the aperture formation unit (BFA) is introduced, the information input of which is connected to the sixth output of the block “ ring ”sweep, synchronizing the input of the BFA - to the seventh output of the block“ ring ”sweep, and the output of the BFA - to the control input of the block of“ ring ”sweep, while the following design nological changes of a topological nature, namely: the area of photosensitive elements and the equal area of shielded elements are different from row to row, increasing as they move to the outer periphery to a maximum value not exceeding the area of the element of the memory section, and the period of control pulses T _r formed on BPA output is determined by the ratio:

where T _p - the reading period of the element in the "ring"photodetector;

n _m is a coefficient, an integer whose value for the current read line in the "ring" photodetector is equal to the ratio:

where Δ ₁ and Δ _m are, respectively, the area of the photosensitive element for the first and current read lines in the "ring" photodetector, providing, thanks to these features, the implementation in the output video signal of the sensor the same area of the reading aperture.

Comparative analysis with the prototype [1] shows that the inventive primary color video sensor differs in that in its "ring" photodetector, the photosensitive elements have a geometric area that monotonically increases in the radial direction on the way to the outer periphery.

In this case, using the introduced BFA, the same indicator of the area of the reading aperture of the photodetector is realized, which ensures the same sensitivity of the sensor over its entire target and without introducing noise loss for the video signal.

Given that in the new photodetector topology, gaps, i.e. the gaps between the photosensitive elements throughout the target become the same (or close to the same) in magnitude, the image resolution parameter is equalized within the entire “ring” television frame.

The combination of known and new features for the claimed device is not known from the prior art, therefore, the proposed technical solution meets the criterion of novelty.

Image resolution equalization is performed in the “ring” image raster. Therefore, this technical solution meets the criterion of the presence of an inventive step.

In FIG. 1 shows a structural diagram of the inventive sensor of the video signal of the primary colors for panoramic television observation of a color image; in FIG. 2 shows the circuit organization of the “ring” photodetector from this sensor; in FIG. 3 shows a fragment of this photodetector, illustrating the details of its design; in FIG. 4 according to [2, p. 19], a structural diagram of the BPS with the organization of the type "floating diffusion region"; in FIG. 5 shows a plot of the output signal of BFA, which controls the aperture of the inventive "ring" sensor; in FIG. 6, according to [3], a photograph of an image obtained using a domestic panoramic mirror-lens lens is presented.

The inventive video signal sensor of the primary colors (see Fig. 1-3) comprises a “ring” photodetector 1, a “ring” scan unit 2, a signal processor 3, the output of which is the sensor output for an R (G or B) video signal, and also BFA 4, in this case, the “ring” photodetector 1 consists of a photodetector region 1-1 sequentially connected by charge coupling, the memory section 1-2, the “ring” shift register 1-3 and the CPS 1-4, and the control input of the photodetector region 1- 1 “ring” photodetector is connected to the first output of block 2 “ring” p switchers, control sections of memory 1-2 - to the second output of block 2 of the "circular" scan, control input of the "ring" shift register 1-3 of the "ring" photodetector - to the third output of block 2 of the "circular" scan, control input of BPZN 1-4 “Ring” photodetector - to the fourth output of the “ring” scan unit 2, the fifth output of which is connected to the synchronization input of the signal processor 3, while the BFA 4 information input is connected to the sixth output of the “ring” scan unit 2, the synchronizing BFA 4 input - to the seventh block output 2 "ring" sweep, and the output of BFA 4 - to the control input of block 2 of the "ring" sweep.

The presence of a passive (non-informative) region in the center of the optical frame of the panoramic image, see FIG. 6, confirms the advisability of choosing the shape of the photodetector 1, as in the prototype, in favor of a circular ring.

It is important to note that in the crystal of the new “ring” photodetector 1, as with the prototype sensor ['1], an analog memory section is integrated. Due to its presence, an increased signal-to-noise ratio of the video signal is preserved due to a significant weakening of the influence of two parasitic physical factors on the target on the noise level, namely: re-reflection of the light flux and diffusion of charge carriers in the semiconductor.

We add that in the "ring" photodetector 1, the transfer electrodes on the photodetector region 1-1, in the memory section 1-2 and in the "ring" shift register 1-3 can be made with a geometric shape not in the form of a rectangle, but as a part of a circular rings. Undoubtedly, this will provide certain advantages in the manufacture of the “ring” photodetector using CCD technology.

In FIG. Figure 4 shows a possible block diagram of the CCD of a "ring" photodetector with an organization of the type "floating diffusion region", which completely coincides with the scheme currently used in CCD arrays for the implementation of rectangular scanning of a video signal. In this drawing, the following notation: U _f1 , U _f2 , U _f3 - voltage on the tires for three-phase control of the "ring" shift register 1-3; U _out - voltage at the output gate; D _o , D _sbr - output and reset diodes, respectively.

Before reading the next information charge element (pixel) in the process of converting into voltage charge video information of the previous element must be cleared in an erasing diode D _RRF.

This procedure is carried out with the help of control pulses T _r , often referred to in the literature as reset pulses, which are supplied to the corresponding control bus BPS 1-4.

The aperture forming unit (BFA) 4 is designed to control the reading aperture in the “ring” photodetector 1 when the video signal voltage is taken element-wise in BPZN 1-4. As a result, for all the lines of the photodetector, the area of the reading aperture is the same across the field, with the area of the electrodes of the photosensitive elements of the sensor varying from line to line.

The plot of the output signal T _r generated at the output of BFA 4 is shown in FIG. 5. It is assumed that the photodetector 1 contains n "ring" lines. In this diagram, the first row is denoted by T _c1 , and the last row is denoted by T _cn .

The control pulses have a positive polarity, short (short) duration and a different repetition period within each of the "ring" lines.

The period of the control pulses for the first “ring” line is denoted by T _r1 , and the period of the control pulses for the last “ring” line is R _rn . The period T _r1 is the smallest and is equal to the reading period of the element T _p , and the reading period T _{r n.} - the largest, which is equal to nT _r .

In physical terms, the aperture area is controlled by summing the charge packets in the neighboring elements of each current “ring” line of the sensor before performing the charge-voltage conversion procedure. Therefore, this charge addition cannot be an additional source of noise for the video signal at the output of the inventive sensor.

BFA 4 in practice can be implemented using the classic set of hardware (logic elements) of digital electronics. It is obvious that BFA 4 can be performed as part of block 2 "ring" scan.

The remaining blocks of the inventive sensor, namely: block 2 "ring" sweep and signal processor 3, are no different from the blocks of the prototype.

The inventive video sensor of the primary colors for panoramic television viewing of a color image (see Fig. 1-5) works as follows.

Suppose that in a television camera (not shown here) three such video signal sensors that receive an image of R - red, G - green and B - blue as the input optical image, are located at the outputs of the optical beam splitter prism, which is mounted behind the panoramic lens and is connected optically to it. Note that the design of the beam splitting prism is completely similar to that used in three-matrix color cameras of broadcast television, see, for example, [4, p. 154].

Each of the three video sensors R, G, and B implements a “ring” scan of the charge image on the photodetector region 1-1, followed by transfer of charge packets of all the lines of the frame to the memory section 1-2 and the final element-by-stage reading of charges in the “ring” register 1-3 with the formation of the output voltage BPSN 1-4 voltage of the video signal of the corresponding color component in analog form.

At the same time, in the interval of the forward course of the frame, the process of accumulation of charge packets occurs in proportion to the illumination of the panoramic plot in the photosensitive elements (pixels) of the photodetector region 1-1.

During the short period of the subsequent interval of the reverse motion of the frame scan, a photo shutter opens, and the charges of all the “ring” lines involved in the accumulation are transferred (in one rotation step) to the screened from light pixels located in the same region 1-1.

In the same interval of the reverse stroke along the frame, the previously accumulated charge packets in radial directions are transferred from region 1-1 to section 1-2.

Then the shutter closes and in a new frame cycle, another charge “picture” is accumulated on the target, and the charge packets accumulated in the previous frame are transferred in the radial directions to the periphery of the photodetector crystal, loading the “ring” register 1-3 in the interval of the reverse stroke along the line .

But unlike the prototype [1], the process of the current element-by-element conversion “charge - voltage, performed in BPSN 1-4, is carried out with a variable value of the period of discharge of the previous charge packet into the erasing diode.

This period, designated as T _r , within the "ring" frame varies in magnitude from the smallest (T _r1 ) for the first row to the largest (T _cn ) for the last row.

Due to the fact that the area of the photosensitive elements for the "circular" lines on the photodetector region 1-1 a priori varies in this direction proportionally, but in the direction of reduction, the same size of the sensor reading aperture is provided.

The gap between the individual aperture areas (“aperture spots”) due to the new topology of the photodetector provides almost the same across the entire target area and the same gap between the photosensitive elements of the sensor.

Therefore, for each of the three primary color video sensors, equalization of the resolution parameter directly in the photodetector will be achieved.

Further, using the video signals R, G, and B from these three sensors, an analog composite video signal of a color image is formed through the interface of the television camera.

As is known, see for example [4, p. 155], to obtain it, you need to have a brightness signal (Y), a color difference signal red (R-Y) and a color difference signal blue (B-Y). Everything necessary for this is already there.

The brightness signal is determined by the expression:

Red Color Difference Signal:

Blue Color Difference Signal:

These two color difference signals, together with the luminance signal, are mixed into the CVBS signal (CVBS is an abbreviation of the English words: “composite video bar signal”, i.e., the full video signal) in the PAL system.

Then, the analog composite video signal of the color image is digitized, acquiring, like at the output of the prototype television camera [1], a digital form.

Further, as in the prototype computer system device [1], the digital composite video signal of the color image is transmitted to the server, where video information is recorded in its main memory per frame.

In the computer system server, the conversion of the “ring” frame of the color image into the corresponding “rectangular” frames is realized by reading the video signal from the RAM, and the number of “rectangular” frames corresponding to one current “ring” frame satisfies the ratio:

where γ _g is the horizontal angle of the field of view in degrees observed by the operator of the image.

Suppose that when designing a television-computer system, the developer has laid down that the current angle of view (γ _g ) of the panoramic image presented to the operator is 60 ° horizontally.

Then, according to relation (6), the “ring” frame should correspond to six “rectangular” frames (n = 6). This means that we have 6 conditional areas in the space of the "circular" frame.

Therefore, each “ring” frame of the image recording is converted into 6 “rectangular” frames, which can be offered in the form of the current sequence to the operators of this computer system of panoramic television surveillance.

The technical result of the proposed video sensor can be considered to obtain the same indicator of image sharpness R, G and B colors throughout the space of the "ring" frame.

Currently, all the elements of the structural diagram of the primary color video sensor for panoramic television color image monitoring have been mastered or can be mastered by the domestic industry.

Therefore, the alleged invention should be considered as meeting the requirement for industrial applicability.

INFORMATION SOURCES

1. RF patent No. 2552101. IPC H04N 7/00. The device of a computer system for panoramic television surveillance and the organization of a photodetector for its implementation / V.M. Smelkov // B.I. - 2015. - No. 16.

2. Khromov L.I., Lebedev N.V., Tsytsulin A.K., Kulikov A.N. Solid state television. - "Radio and Communications", 1986.

3. RF patent No. 2185645. IPC G02B 13/06, G02B 17/08. Panoramic mirror lens. / A.V. Kurtov, V.A. Solomatin // B.I. - 2002. - No. 20.

4. Vlado Damianowski. CTV. Bible CCTV, Digital and Network Technology. / Translation from English. M .: LLC "IS-ES Press", 2006.

Claims (9)

1. The primary color video signal sensor for panoramic television viewing a color image, comprising a “ring” photodetector, onto the target of which a panoramic optical image is projected in one of the three primary colors (either in red - R, or in green - G, or in blue - B ), as well as a “ring” scan unit and a signal processor, the output of which is the output of the sensor video signal, while the “ring” photodetector made by the technology of charge-coupled devices (CCD) has a target crystal in the form of a circular ring It is made of silicon and consists of a photodetector region, a memory section, an “annular” shift register, and a charge – voltage converter (LPS) sequentially connected by a charge coupling with an organization of the “floating diffusion” type, moreover, on the photodetector region of a line of photosensitive elements, alternating with rulers of light-shielded elements, as well as rulers of light-shielded elements of the memory section are located along radial directions from the imaginary center of the circular ring to its outer periphery and are located the “ring” shift register there, the number of elements of which is equal to the number of elements in each “ring” line of the photodetector region and in each “ring” line of the memory section, while the information input of the signal processor is connected to the output of the OCR of the “ring” photodetector, the first block output “Ring” scan - to the control inputs of the photodetector area of the “ring” photodetector, the second output of the block of “ring” scan - to the control inputs of the memory section, the third output of the block of “ring” scan - to the control inputs I will give a “circular” shift register of the “circular” photodetector, the fourth output of the “circular” scan unit - to the control input of the CPSU of the “circular” photodetector, the fifth output of the “circular” scan unit - to the synchronization input of the signal processor, characterized in that the aperture forming unit is introduced (BFA), the information input of which is connected to the sixth output of the “circular” scan unit, the synchronizing input of the BFA - to the seventh output of the “circular” scan unit, and the output of the BFA - to the control input of the “circular” scan unit, at the volume on the photodetector area of the sensor and the area of shielded elements equal to it are different from row to row, increasing as they move to the outer periphery to a maximum value not exceeding the area of the memory section element, and the period of control pulses T _r generated at the output of the BPA, determined by the ratio

where T _p - the reading period of the element in the "ring"photodetector; n _m is a coefficient, an integer whose value for the current read line in the "ring" photodetector is equal to

where Δ ₁ and Δ _m are, respectively, the area of the photosensitive element for the first and current read lines in the "ring" photodetector, providing the implementation in the output video signal of the photodetector of the same area of the reading aperture. 2. The sensor device according to claim 1, characterized in that in the "ring" photodetector, the charge transfer electrodes on the photodetector region, in the memory section and in the "ring" shift register are made with a geometric shape in the form of a part of a circular ring. 3. The sensor device according to p. 1, characterized in that the BPA is made as part of the block "ring" scan.

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