JPS6068789A - Color television with line transfer type solid image sensor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color television camera having a solid-state imaging device. In order to realize a single imager type color camera, it is necessary to combine a solid-state imager, a mosaic of color filters, and a processing circuit for the video signal from the solid-state imager. In fact, many structures have been proposed for solid-state imaging devices for RP-1 color cameras. However, the invention particularly relates to a single imager color camera combined with a line transfer imager.

In one structure actually used, a line transfer type imaging device is configured as follows. That is, a photosensitive area containing m-p photosites is coupled to two command registers with logical delays that select the even and odd rows of the matrix of photosites. Even-numbered columns are connected to a first line memory, and odd-numbered columns of lines are connected to a second line memory. The two charge transfer delay registers each contain a half line of video.

The operating principle of such an imaging device can be summarized as follows. A line of 11 photosites is selected by the first delay register if the line falls in an even row, and is selected by the first delay register if the line belongs to an odd row. )2 delay registers. -11, When one line is selected, the charges accumulated in that phototite are transferred to the line memory, which means that the charges of even-numbered photosites belonging to the same horizontal scanning line are transferred to the first line. This is because the charges of the odd-numbered rows of photosites are sent toward the second line memory. The contents of the memory are then transferred to the output delay registers and these two registers are read in time with the television to produce one video line.

The reading of the imager is done row by row, and the capacity for each entry in the delay register is equal to half a line of video, so that only a single video line with each line period comes out of the imager. However, these types of imaging devices are not adapted to R-coupling between lines. For this reason, the mosaic of color filters combined with the imaging device preferably has a Bayer type structure, in which the same color filters are combined on two consecutive lines. However, the same color filters are included, alternating green and red for the 100-day group, then blue and green for the second group of lines, and so on.

The processing circuitry that is combined with this imaging device and the color filter can take many forms, but in order to obtain the color and brightness information, the processing circuitry combines two consecutive lines of the same frame. All sample signals of chrominance (green, red and blue) and luminance must be combined (signal).

Therefore, in order to use these sample signals and create a color difference signal, a line having a time delay of the IH of the analysis line is required. By such a combination of two consecutive lines of the same frame (thus these two lines are separated by one line of the other frame),
Vertical resolution is lost and lines in diagonal directions are not well reproduced. Furthermore, such a structure requires a delay line.

SUMMARY OF THE INVENTION The object of the present invention is to realize a new color television camera with a solid-state imaging device that does not have the disadvantages of the prior art described above without affecting the other characteristics of the camera, namely sensitivity and horizontal resolution. This camera, located in
The IJ Fuchs photosensitive elements and the conductive columns connecting these elements to the memory are constructed in two separate structures.

In these free-standing structures, the photosensitive elements are arranged in a quincunx pattern. The special structure described above, which will be described in detail later, allows even points of one line and odd points of the following line to be transferred to the same line memory, and in this special structure, especially A particularly simple combined processing circuit with a color filter is combined.

A color television camera having a line transfer type solid-state imaging device according to the present invention has the following features. That is, in a one-line transfer imaging device, means are included in combination with the photosite matrix for selecting successive lines of the matrix to which stored charges are to be transferred, so that even-numbered columns of one line of the matrix are selected. and the odd rows of photosites are each connected by a conductive column to one of two memories, each of which is combined with a delay register having a storage capacity equal to one line of the matrix; The conductive columns that are associated with the even points of one line are simultaneously associated with the odd points of the next line, and transfer the charge generated from the entire quincunx photosites of the die to the two registers of the output section. forwarded to each. Even rows of photosites in one line and Vc
These charges stored in the odd rows of photosites of the adjacent lines, i.e. the preceding or subsequent lines, are
- 7 tricks of complementary colors, i.e. yellow, cyan and magenta color filters, which are transferred during the retrace period and inserted into the registers of the corresponding outputs, are placed in the matrix of photosites and inserted into the registers of the first dice; The quincunx photolight is covered with a yellow filter, and the quincunx photosites on the other dice are covered with a cyan filter on one line.
The second line is alternately covered with a magenta filter, - the processing circuit is ma) IJ Fuchs directly combines the signals output from the two registers of the output section resulting from the combination of two consecutive lines. The color signal and luminance signal are extracted from there.

The invention will be better understood, and other features of the invention will become clear, from the following description of the embodiments, which refers to the accompanying drawings.

FIG. 1 schematically shows a camera having a solid-state imaging device. These cameras include a single line-transfer 4
It includes a color filter 10 placed in front of the imaging device 2o. The line transfer imaging device used in the camera of the invention includes two line memories connected to a photosensitive matrix, each connected to an output resistor. To this end, the illustrated line transfer imaging device has two output parts emitting signals sl and 82, which are applied to the human part of the processing circuit 3o. The processing circuit processes 3 of the color television signals.
The luminance Y and 2-) are converted into different color difference components D□ and skin.

FIG. 2 is a schematic diagram of a line transfer type imaging device used in the camera of the present invention. This imaging device has 10 cameras (
It includes photosensitive areas 1 forming a matrix of lines, e.g. m = 576), each line consisting of 9 photosites, e.g. is associated with two line selection delay registers 2.3, the first line selection delay register 2 being associated with the lines of the odd-numbered matrix, and the second line selection delay register 2 being associated with the lines of the even-numbered matrix. The charges stored in the photosites are transferred by the conductive columns as follows. That is, the conductive columns C□ connect the photosites of odd lines located in one column on the one hand, and the conductive columns C
The even-numbered photosites in the 1+1 column of IJ Socs are connected. One of the two adjacent conductive columns is connected to a first line memory 4 and the other conductive column is connected to a second line memory 5. These line memories 4 and 5 each have p/2 memory elements. The parallel output parts of the line memories 4 and 5 are connected to p/2 parallel input parts of delay registers 6 and 7 of the charge transfer output. Two independent structures are thus defined, in each structure the pixels are arranged in a quincunx pattern. The line selection performed by either registers 2 and 3 is
Pixels associated with one quincunx structure and pixels associated with the other quincunx structure are simultaneously selected. The number of conductive columns connected to each line memory is equal to half the number p of pixels in one line, but the complete output of the information of delay registers 6 and 7 has a duration of one line. However, these delay registers include, for example, nine stages. In such a configuration Φ, both selection registers 2 and 3 are active during the readout period of one frame, and for each frame, the imaging bag "L" is all read out. That is, in this imaging device is read out every 2(1:IJ seconds) as a whole, which means that the odd lines in and even lines jl of the matrix are
! n' is combined, while the even number water 31 of the statue? - To form scanning line Ln゛) IJ sock even number line! n' and the odd line βg+l are combined.

For this reason, the period of time and α in the photosite is equal to the time period of
The period will be reduced by half compared to the previous period. Thus, if the color filter structure and associated processing circuitry were similar to the processing circuitry described above, a camera using such an imaging device would have half the sensitivity.

In order to avoid these disadvantages, the color filter 1o combined with this line transfer type imaging device has a special configuration. This color filter is made up of a filter mosaic of complementary colors. This color filter is shown in FIG. The color filters include, for example, yellow filters J and cyan (turquoise blue) filters C arranged alternately for odd-numbered lines of the matrix. All odd-numbered lines have a similar alternating arrangement. The color filters on the even-numbered lines are the Masenda filter M and the yellow filter J, which are arranged alternately, and a similar alternating arrangement is made on all the even-numbered lines.

Therefore, the yellow filter J covers the photosites located in the quincunx shape of the psycho IJ. Of course, all sample signals of the yellow filter J correspond to one of the two quincunx structures of the imaging device.

This mosaic is not broken down into frames, as all imaging devices are read to create the television frames. Such a reading method is explained by the waveform of the command signal shown in FIG. During the line retrace period of the video signal, reading of two consecutive lines is commanded. Therefore, selection command signals C52 and C applied to selection registers 2 and 3
S3 is the signal shown on this waveform. The Cs2 pulse transfers the charges stored in the photosites of line n to the two line memories 4 and 5. The C33 pulse then commands the reading of the charge stored in the photosites belonging to column n of the matrix. Both pulses occur during the same retrace interval. Manual part φ for transfer commands in line memories 4 and 5.

By changing the state of the voltage applied to the output register 6
．． The contents of these memories at 7 can then be transferred to each new charge transporter.

As mentioned above, each output register has a length comparable to a video line, so that one half line belongs to line n of the matrix and the other half line belongs to the next line n of the matrix of photosites. The contents of one line are stored in each output register twice as long because they contain quincunx-shaped photosites. Clock signals H1 and H9 for transfer and delay in output registers
commands charge output to output portions S1 and S2 of these output registers.

Thus, after reading out two successive lines n and n', the output registers 6 and 7, together with the sample signals obtained as a result of the filtering performed by the color filters shown in FIG. It has the contents shown in Figure 5. The signal S+ is formed by sample signals that all correspond to the negative components of the image, and the yellow sample signals of two successive lines n and n of the quincunx in the matrix are delivered one after another and delayed. They are combined at the output part of register 6. The signal S2 is formed by sample signals corresponding alternately to the magenta and cyan components of the image, each of these two previously taken on a quincunx sample signal of two successive lines of the matrix of photosites. The two ingredients are combined.

The processing circuit shown in FIG. 6 allows the components of the video signal to be obtained simultaneously by means of these two signals S1 and S2. The output of the register 6 is connected to the input of a sample circuit 31 commanded by the tarlock signal H2. The output part of the delay register 7, which provides the signal s2, is connected to the human parts of two sample circuits 32 and 33, commanded by the clock signals H2 and H, respectively.

Clock signals H1, H2, H3 and sample circuit 31
．． 32.33 output signals S1, Sc, S++) are shown in FIG. These three sample circuits are connected to a filter and matrix circuit 34, which uses three color signals corresponding to yellow, cyan and magenta components to generate a pseudo-luminance 5HIP signal and a red R1 green V and a blue B color signal.

These signals are destroyed in the following manner.

SJ+5)l-8C=2R a S, +10b Sc+ CSi+=S++p (however, a, b, c are equilibrium coefficients) SJ+5C-3N=2
VSM! −Sc Sr= 2 B This must result in a signal R1 resulting from such a combination.
■, B is the cutoff frequency F. Low pass filter with -750 Kllz: filtered at 35.36.37.

For this reason, the luminance signal Y [lF with a low frequency is obtained by the linear summation of the above three signals.

Furthermore, the pseudo luminance signal SHF is set to a cut-off frequency F, ,=7
+17 to 50. The Nyquist frequency FH 72 is then filtered through a high-pass filter 38 and then applied to a shift filter 39 to cancel the noise resulting from the multiplexing of two consecutive lines n and n'. Fill 35.36
．． The 37th and 39th output sections are formed by known matrixing,
It is connected to the corresponding human power section of the encoding and video processing circuit 40, which circuit has components R, B, YBF, J,
C1 After normal processing, that is, white level and black level ijl! j After performing adjustment, constant brightness adjustment, gamma correction, etc., the color difference components D II and Dn and the brightness Y1DR=
l'! YllF, Dn” B Yu+, Y=
Yllp + K YIIF is generated.

The processing described above is not the only processing that can be taken from components S1, SC and SN.

In fact, in this first case, spatial averaging is performed over several pixels to round the signal S1,1, giving priority to camera sensitivity at the expense of horizontal resolution. On the other hand, in the first mode described below, the pseudo luminance is derived exclusively from the yellow sample signal, so horizontal resolution is prioritized at the expense of sensitivity.

In this first aspect, the high frequency luminance signal Yllll+
is derived exclusively from the signal SIIF derived exclusively from the series of yellow samples No. 4.1 by high-pass filtering with a cut-off frequency F C = 750 Kllz.

Other processing circuits are the same as above.

In a second aspect of the invention, the edge components are preserved by dematresizing YllF, R and B, and YBF is obtained by low-pass filtering the pseudo-luminance signal Y at 750 KHz. Signal Y HF is the first on the left as detailed above.
is obtained by filtering the pseudo-luminance signal Y with a 750 KHz high-pass filter, as in the case of .

The invention is not limited to the duplicate embodiments.

In particular, two selection registers 2 and 3 are shown, one selection register connected to the even lines of the matrix and the other selection register connected to the odd lines of the matrix. In fact, since the mosaic is read completely for each frame of the image, the selection means for successive lines of the matrix may consist of only one delay register, which is Contains two delayed pulses of line period, signals C52 and C
commanded by a signal C5 which is equal to the sum of ss.

The camera mentioned above guarantees a good compromise between resolution and sensitivity, and as mentioned above, it allows
A particularly simple processing circuit can be used since no delay line is required for this camera.

Furthermore, the principle adopted to read the imaging device (reading the quincunx of the signal of two consecutive lines)
For example, it is possible to eliminate the miscellaneous spots and smudges (S
It is possible to repair defects such as "

A commonly employed device to reduce these defects consists of storing a single line during retrace time and then processing the information collected on this line into a useful signal.

For this reason, it must be possible to perform such neutralization processing at frequency points, and such work requires
For example, it is necessary to develop extremely high-speed bipolar processing technology. By the way, these techniques present the disadvantages that are very consuming, and these disadvantages make the integration of such modifications extremely difficult, at least in bipolarity. On the contrary, these modifications
2Fsc=8.861Jllz), it is possible to correct these deficiencies with integrated circuits made in MO8 technology.

The applied reading method confirms that such a modification can be made at half the frequency of the above frequency point (Is.-4,43M1lz). In fact, at the output of the imager (S+ and S2) the sample signals can be grouped in pairs. This is because each of the two sample signals passes along the same path and thus undergoes the same changes as the congeners of the same column (but belonging to different selected lines).

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a color television camera having a solid-state imaging device, FIG. 2 is a schematic diagram of a solid-state imaging device having a quincunx structure used in the camera of the present invention, and FIG. 4 is a diagram showing the mosaic of the color filter used in the camera of the present invention, FIG. 4 is a diagram showing the waveform of the command signal applied to the imaging device, and FIG. 5 is a diagram showing the waveform of the command signal applied to the imaging device, and FIG. FIG. 7 is a diagram showing the contents of the delay register of the output section of the circuit, and FIG. 7 is a schematic diagram of the processing circuit, and FIG. (Main reference numbers) 1...Photosensitive area, 2.3...Register, 4.5
...Line memory, 6.7...Register, 10...Color filter, 30.
...Processing circuit patent applicant So/Ete Delectronique de la Légion Pays Deloire Serel agent Patent attorney Masahiko Arai - N ■

Claims (3)

[Claims] (1) A color television camera having a line transfer solid state imager, the one line transfer imager being combined with a photozite matrix to select successive lines of the matrix for transferring stored charges. means, wherein the even and odd columns of photosites of one line of the matrix are each connected by a conductive column to one of two memories, each of which is equal to one line of the matrix. The conductive columns combined with the output delay registers with storage capacity are combined with the even points of one line and the odd points of the next line at the same time, forming a quincunx of the dice. The charge generated from the entire photosites of is transferred to each of the two registers of the output section, and 1
even rows of photosites and adjacent lines of two lines,
That is, those charges stored in the odd rows of photosites of the preceding or following line are transferred during the same retrace period and inserted into the register of the corresponding output to produce the complementary colors, i.e. yellow, cyan and A matrix of magenta color filters is placed in the matrix of photosites, the quincunx of the first die, ) the entire site is covered with a yellow filter, and the quincunx of the other dice. The entire photosites of are covered alternately with a cyan filter on one line and a magenta filter on the next line, and one processing circuit results from the combination of two consecutive lines. 4'! The signals output from the two registers of the output section are directly combined, and the color signal and luminance signal are extracted from them. ? ffi
color television camera. (2) To form an image composed of two combined rows, a pair of consecutive lines (!n. βn') combined to form the first horizontal line of the image is pairs of consecutive lines (βn′1.f!, n+1′) that are combined to form a horizontal line of
2. Color television camera according to claim 1, characterized in that the delay is effected by selection means (2, 3) at the beginning of each horizontal scanning line of the image. (3) The processing circuit includes a sample circuit connected to the output (Sl) of the register associated with the entire photosite covered by the yellow filter, the sample circuit being commanded with a sample frequency of one line; is further connected to the output (S2) of the register associated with all other photosites and commanded at a frequency of half the sample frequency.
The output section of these sample circuits includes a matrix circuit, a filter circuit, and a color difference component (D
3. A color television camera according to claim 1, wherein the color television camera is connected to a human power section of a processing circuit which provides a luminance component (Y) and a luminance component (Y).