JP2005318292A - Single plate color image sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single-plate color image sensor having RGB pixels on a plane of a sensor plate, capable of individually adjusting the gain for each pixel, and capable of preventing image quality deterioration.
A single-plate color image sensor 10 detects light incident on a photoelectric conversion element for each color according to each pixel, and outputs a photocurrent corresponding to each color as a sensor signal. And variable resistors VR1 to VR4 provided on the output side of the pixel and connected to a bias power source, switches SW1 to SW4 for selecting a pixel from which a sensor signal is read out among a plurality of pixels, and the color of the read pixel Correspondingly, a control unit 13 is provided to change the read load by changing the resistance value of the variable resistor.
[Selection] Figure 1

Description

  The present invention relates to a single-plate color image sensor, and more particularly to a single-plate color image sensor that includes three RGB pixels on the plane of a single sensor plate and can individually adjust the gain for each color of each pixel. About.

  In order to capture a color image with a color image sensor made of a solid-state image sensor (sensor plate), each pixel needs to obtain information of three colors of R (red), G (green), and B (blue). There is. There are three methods for obtaining three colors. Therefore, there are three types of color image sensors. The first method is a three-sensor method in which incident light is divided into three colors and received and detected by, for example, three sensor plates, and the second method is the RGB color before each pixel on one sensor plate. One sensor system in which filters are attached alternately, and the third system is an alternate filter system in which an alternating filter that changes to R, G, and B is provided in front of one sensor plate and images are taken at 3 × speed. The three-sensor method is called a three-plate color image sensor or a multi-plate color image sensor, and the one-sensor method is called a single-plate color image sensor.

  Of the various color image sensors described above, the single-plate color image sensor has the advantage that the number of imaging elements is small and generally has a low cost, and is widely used in consumer video cameras. In a single-plate color image sensor, one of R, G, and B filters is provided in front of each pixel on the plane of one sensor plate. Therefore, according to each pixel of the single-plate color image sensor, only one of the necessary three colors can be obtained. The other two colors are obtained by complementing a plurality of pixels arranged in the periphery.

  In general, natural light such as sunlight has a spectrum distribution as shown in FIG. As can be seen from FIG. 9, when visible light is divided into R, G, and B components, the G component is large and the R and B components are small compared to the G component. Therefore, when performing color photographing with a color image sensor using a solid-state image sensor, the gain (amplification factor or readout load) is individually adjusted for each color signal due to the difference in spectral sensitivity between the three colors. It was necessary. In particular, in the case of a single-plate color image sensor, the gain cannot be adjusted for the entire color image sensor, so the gain is adjusted for each color so that the overall white balance is aligned after the output of the color image sensor ( For example, see Patent Document 1).

  However, according to Patent Document 1, since the gain is adjusted for each color so that the white balance is uniform, there is a problem that the image quality deteriorates for the following reason.

Conventionally, information (video signal) of each pixel output from a single-plate color image sensor is first converted into a digital signal by an A / D converter, and then image processing such as white balance adjustment is performed. However, the spectral characteristics of each color are not uniform as described above. For example, only about 1/6 of the G component is input to the A / D converter with respect to the B component. In this case, for example, when an A / D converter having a conversion resolution of 10 bits is used, a signal of 60 dB should theoretically be obtained, but only a signal of 56 dB is actually obtained. The difference of 4 dB is an internal noise of the A / D converter, which causes image quality deterioration. The internal noise of the A / D converter has a constant value regardless of the magnitude of the input signal. As a result, the internal noise of the A / D converter overlapped with the B and R component signals is also amplified when adjusting to the G component signal during white balance adjustment after conversion to a digital signal. As a result, the image quality is degraded.
JP-A-6-165190

  SUMMARY OF THE INVENTION An object of the present invention is to enable a large level signal to be input to an A / D converter by adjusting the gain for each of the three colors R, G, and B in a single-plate color image sensor. It is intended to suppress the influence of internal noise.

  In view of the above problems, an object of the present invention is to provide RGB pixels using a color filter on the plane of one sensor plate, and to adjust the gain for each pixel individually at the sensor output stage. Another object of the present invention is to provide a single-plate color image sensor that can appropriately balance colors and prevent deterioration of image quality.

  In order to achieve the above object, a single-plate color image sensor according to the present invention is configured as follows.

  A single-plate color image sensor according to the first aspect of the present invention (corresponding to claim 1) detects light incident on a photoelectric conversion element for each color according to each pixel, and a photocurrent corresponding to each color is a MOS transistor. A plurality of pixels that convert sensor outputs and output a sensor signal, a variable resistor that is provided on the output side of each of the plurality of pixels and that is connected to a bias power source, and a pixel that reads the sensor signal is selected from the plurality of pixels. A selection unit and a control unit that changes the resistance value of the variable resistor corresponding to the color of the pixel to be read and changes the reading load are configured.

  In the above first aspect of the present invention, a variable resistor as a reference resistor is provided for the bias voltage applied to the output side of each pixel of the pixel group of the single-plate color image sensor, and the color of the pixel to be read out In response to this, the value of the variable resistor is optimally changed based on the control unit. Thus, the gain (reading load) for each pixel is individually adjusted at the output stage of the sensor signal, the color balance is appropriately adjusted, and the deterioration of the image quality is prevented.

  The single-plate color image sensor according to the second aspect of the present invention (corresponding to claim 2) detects the light incident on the photoelectric conversion element for each color according to the pixel, and the photocurrent corresponding to each color is detected by the MOS transistor. A plurality of pixels that convert and output sensor signals, a bias switch that is provided on the output side of each of the plurality of pixels and that is connected to a bias power source and that can switch the input bias voltage, and the input side of the bias switch A plurality of bias lines connected to each other, and a control unit that switches a bias switch corresponding to the color carried by the plurality of pixels to select one of the plurality of bias lines and changes a read load. Is done.

  In the above second aspect of the present invention, a bias switch is provided that allows the bias voltage to be switched with respect to the bias voltage applied to the output side of each pixel of the pixel group of the single-plate color image sensor, and tries to read out. The value of the bias voltage is optimally changed based on the control unit according to the color carried by the pixel. Thus, the gain (reading load) for each pixel is individually adjusted at the output stage of the sensor signal, the color balance is appropriately adjusted, and the deterioration of the image quality is prevented.

    A single-plate color image sensor according to a third aspect of the present invention (corresponding to claim 3) detects light incident on a photoelectric conversion element for each color according to a pixel, and a photocurrent corresponding to each color is detected by a MOS transistor. A plurality of pixels that convert and output sensor signals, an output switch provided on each output side of the plurality of pixels, a plurality of output lines connected to the output side of the output switch, and a color carried by the plurality of pixels And a control unit that switches the output switch to select one of the plurality of output lines and outputs a pixel having specific color information to the specific output line.

  In the second aspect of the present invention, an output switch for changing the reading load is provided on the output side of each pixel of the pixel group of the single-plate color image sensor, and based on the control unit according to the color of the pixel to be read. Change the output load optimally by switching the output switch. Thereby, the gain for each color of each pixel (reading load based on the amplifier in the subsequent stage) is individually adjusted at the output stage of the sensor signal, the color balance is appropriately adjusted, and the deterioration of the image quality is prevented.

  According to the first to third aspects of the present invention, when the sensor signal of each color pixel is read from the pixel group in the single-plate color image sensor, the gain for each color of R, G, and B of each pixel at the output stage of the sensor signal. In other words, since the readout load can be adjusted individually, the response output characteristics (relative sensitivity) of the pixels responsible for each color of R, G, and B can be made to be substantially equal, and each color of R, G, and B can be adjusted. The difference in the corresponding spectral characteristics can be eliminated, the color balance can be appropriately adjusted, and the deterioration of the image quality can be prevented.

  DESCRIPTION OF EMBODIMENTS Preferred embodiments (examples) of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows a main configuration of a first embodiment of a single-plate color image sensor according to the present invention. The single-plate color image sensor 10 shown in FIG. 1 includes a pixel group 10A composed of a large number of pixels arranged in a matrix. In the illustrated example, 16 pixels of 4 × 4 are shown as an example. A detailed circuit structure of each of the plurality of pixels in the pixel group 10A is shown in FIG. Details of the circuit shown in FIG. 2 will be described later.

  In the single-plate color image sensor 10, a pixel group 10A composed of a plurality of pixels D11 to D44 is formed in the matrix-like pixel arrangement shown in FIG. 1 on the plane of one sensor plate made of a solid-state image sensor. ing. Each of the plurality of pixels is provided with a color filter according to each pixel, and each of the large number of pixels has three colors, R (red), G (green), and B (blue). It is configured to perform light detection. The notations “R”, “G”, and “B” shown in the blocks of the pixels D11 to D44 mean colors detected by each pixel.

For the pixel group 10A, in FIG. 1, horizontal pixel selection lines X1, X2, X3, and X4 for selecting horizontal pixels, and vertical pixel selection lines for selecting vertical pixels. Y1, Y2, Y3, and Y4 are provided. Pixels to be read are specified based on read signals supplied to the horizontal pixel selection lines X1 to X4 and the vertical pixel selection lines Y1 to Y4, and the sensor signal output from the specified pixels is a single plate color. Read out as an output signal (voltage V ₀ ) from the output end of the image sensor 10.

  Further, for the pixel group 10 </ b> A, a power supply line 11 connected to a bias power supply (+ V) and a video output line 12 that is an output end of the single-plate color image sensor 10 are provided. Variable resistors VR1, VR2, VR3, and VR4 serving as reference resistors are connected between the power supply line 11 and the pixel output terminals of each column of the pixel group 10A, and the pixels of the video output line 12 and each column of the pixel group 10A are connected. Output switches SW1, SW2, SW3, and SW4 are connected to the output terminals, respectively.

  For the pixel group 10A of the single-plate color image sensor 10, the variable resistors VR1 to VR4 corresponding to each column set the current value flowing through each pixel in each column. Depending on the resistance value set by these variable resistors VR1 to VR4, the gain of each pixel in each column, that is, the magnitude of the read load is set. The magnitude of the sensor signal readout load of each pixel in the pixel group 10A is set to be different depending on the color. The switches SW1 to SW4 are connected / disconnected between the video output line 12 and the output end of each pixel by opening / closing operations thereof. A readout circuit that reads the sensor signal of each pixel of the pixel group 10A is formed by the switches SW1 to SW4.

  The resistance values of the variable resistors VR1 to VR4 are individually set for each color of each pixel based on the command signal Sa given from the control unit 13. The resistance values of the variable resistors VR1 to VR4 are changed and set according to the color of the pixel to be read when the sensor signal of each pixel is sequentially read and scanned in time series. In the present embodiment, preferably, when reading the sensor signal of the G pixel, the resistance value is set so that the gain becomes a predetermined value, and when reading the sensor signal of the R or B pixel, the gain is G. In this case, the resistance value is changed and set so as to be larger than the gain. As a result, the response output characteristics of the pixels carrying the R, G, and B colors can be made uniform, and the difference in spectral characteristics corresponding to the R, G, and B colors can be eliminated.

  The opening / closing operations of the output switches SW1 to SW4 are individually controlled for each output switch based on the command signal Sb given from the control unit 13. When the output switches SW1 to SW4 are turned on, the output terminal of the readout pixel selected by the selection circuit is connected to the video output line 12, and the sensor signal of the pixel is read out.

  In the single-plate color image sensor 10 shown in FIG. 1, the pixels to be read out in the pixel group 10A based on the readout signals supplied to the horizontal direction pixel selection lines X1 to X4 and the vertical direction pixel selection lines Y1 to Y4, respectively. The identification, the change / setting of the resistance values of the variable resistors VR1 to VR4 corresponding to the identified pixel, and the ON operation of the output switches SW1 to SW4 corresponding to the identified pixel are based on the control operation by the control unit 13. It is done with appropriate timing. In this way, when reading the sensor signal of each pixel having a different color in the pixel group 10A of the single-plate color image sensor 10, the gain for reading the sensor signal, that is, the magnitude of the reading load differs according to the color of each pixel. Thus, the difference in spectral characteristics corresponding to each color of R, G, and B is eliminated.

  FIG. 2 shows a spectral group based on varying the magnitude of a read load when reading a sensor signal according to each color of the pixels D11 to D44 in the pixel group 10A of the single-plate color image sensor 10 according to the first embodiment. The change in characteristics is shown. As is clear from the characteristic portions 14 and 15 shown in FIG. 2, the resistance output of the variable resistors VR1 to VR4 (that is, the gain or the read load) is changed for each color, and the response output of the pixels responsible for each color of R, G, and B The characteristics (relative sensitivities) are arranged so as to be substantially equal to each other, thereby eliminating the difference in spectral characteristics corresponding to the R, G, and B colors.

Next, the circuit configuration of each of the pixels D11 to D44 will be described with reference to FIG. FIG. 3 shows the photosensor circuit 20 of the pixel D11 as an example. The optical sensor circuit 20 weakens the photodiode PD as a photoelectric conversion element that generates a sensor current according to the amount of incident light Ls, the capacitor C that stores the charge of the generated sensor current, and the sensor current that flows through the photodiode PD. When the output switch SW1 is turned on with the pulse timing of the read signal VS, the transistor Q1 for converting the voltage signal Vpd into the voltage signal Vpd with the logarithmic output characteristic in the inverted state, the voltage signal Vpd, and the output signal V _0. As a transistor Q3. By using this optical sensor circuit 20 for a pixel and having logarithmic output characteristics, it is possible to expand the dynamic range and detect an optical signal with high sensitivity.

  Next, a second embodiment of the single plate color image sensor according to the present invention will be described with reference to FIG. In FIG. 4, the same elements as those described in the first embodiment are denoted by the same reference numerals. In the single-plate color image sensor 30 according to the second embodiment, the pixel group 10A, the horizontal pixel selection lines X1 to X4 and the vertical pixel selection lines Y1 to Y4 related thereto, the power supply line 11, and the video output line The configuration of 12 is the same as that of the first embodiment.

Next, between the power supply line 11 and the pixel output end of each column (horizontal direction pixel selection lines X1 to X4) of the pixel group 10A, three routes of bias voltage signal lines corresponding to the colors R, G, and B, respectively. 31R, 31G, and 31B are provided. Each of the bias voltage signal lines 31R, 31G, and 31B includes a bias resistor (R _R , R _G , R _B ) and a bias switch (SW _R , SW _G , SW _B ) connected in series. Three bias resistors R _R, R _G, in R _B, their resistance values are determined according to the color, it is set to mutually different values. The opening / closing operation of the bias switches SW _R , SW _G , SW _B is performed based on an opening / closing control command Sc from the control unit 13. In reading out sensor signals from each pixel of the pixel group 10A, when reading out sensor signals of pixels for each color in each column, the corresponding bias switches SW _R , SW _G , and SW _B are turned on according to the color of the read pixels. The optimum bias resistor corresponding to the color in the state is selected, and the optimum gain, that is, the optimum reading load is selected.

  FIG. 5 is a timing chart of a driving example in which sensor signals of each pixel of the pixel group 10 </ b> A of the single-plate color image sensor 30 are read. FIG. 4 shows an example of driving in progressive scanning, in which the initialization cycle for one pixel is 1/30 seconds. In the timing chart shown in FIG. 5, from the upper side, the selection signals on the vertical pixel selection lines Y1 to Y4, the selection signals on the horizontal pixel selection lines X1 to X4, the read additional resistors of the resistors R1 to R4, and to be read The pixel X1-R, G, B, the pixel X2-R, G, B, the pixel X3-R, G, B, the readout operation state of the pixel X4-R, G, B, the time series of the pixel to be read out The order is shown.

In the above, the read operation states of X1-R, G, B, X2-R, G, B, X3-R, G, B, X4-R, G, B are column lines X1, X2, X3. , X4 corresponds to the ON state of the aforementioned bias switches SW _R , SW _G , SW _B provided corresponding to each of X 4, X 4. That is, the above-described bias switches SW _R , SW _G , and SW _B provided corresponding to each of the column lines X1 to X4 are appropriately on-controlled according to the color of the pixel to be read, so that a predetermined value is obtained. Sensor signals of each pixel are read out in order.

  In the driving example of progressive scanning shown in FIG. 5, when scanning the line Y1, in the case of a pixel at a position intersecting with the lines X1 and X3, a read load of G is connected and intersecting with the lines X2 and X4. In the case of the pixel at the position, the R readout load is connected. When scanning the line Y2, in the case of a pixel at a position intersecting with the lines X1 and X3, a B reading load is connected, and in the case of a pixel at a position intersecting with the lines X2 and X4, the G reading load is applied. Connected. When scanning the line Y3, a G reading load is connected in the case of a pixel at a position crossing the lines X1 and X3, and an R reading load is connected in the case of a pixel at a position crossing the lines X2 and X4. Connected. When scanning the line Y4, a B reading load is connected in the case of a pixel at a position crossing the lines X1 and X3, and a G reading load is connected in the case of a pixel at a position crossing the lines X2 and X4. Connected.

  Next, FIG. 6 shows another timing chart of a driving example in which the sensor signal of each pixel of the pixel group 10A of the single-plate color image sensor 30 is read. This is an example of driving in interlace scanning. Also in FIG. 6, as in FIG. 5, from the upper side, the selection signals on the vertical direction pixel selection lines Y1 to Y4, the selection signals on the horizontal direction pixel selection lines X1 to X4, and the read additional resistors of the resistors R1 to R4 are read. The pixel X1-R, G, B, the pixel X2-R, G, B, the pixel X3-R, G, B, the readout operation state of the pixel X4-R, G, B, the time series of the pixel to be read out The order is shown.

Also in the driving example shown in FIG. 6, the bias switches SW _R , SW _G , and SW _B provided corresponding to the respective lines X1 to X4 in the column read out, similarly to the driving example described in FIG. The sensor signal of each pixel is read out in a predetermined order by being appropriately turned on according to the color of the pixel to be processed.

Also in the single-plate color image sensor according to the second embodiment, on / off of the bias switches SW _R , SW _G , and SW _B is controlled so that the R, G, and B have the spectral characteristics shown in FIG. Each time the bias resistors R _R , R _G , and R _B are selected to change the resistance value (that is, gain or readout load), the response output characteristics (relative sensitivity) of the pixels that carry R, G, and B colors become substantially equal. Thus, the difference in spectral characteristics corresponding to each color of R, G, and B is eliminated.

  Next, FIG. 7 shows a third embodiment of a single plate color image sensor according to the present invention. In FIG. 7, the same elements as those described in the first embodiment or the second embodiment are denoted by the same reference numerals. In the single-plate color image sensor 40 according to the third embodiment, the pixel group 10A, the horizontal pixel selection lines X1 to X4 and the vertical pixel selection lines Y1 to Y4 related thereto, the power supply line 11, and the video output line The configuration of 12 is the same as that of the first embodiment.

  The single-plate color image sensor 40 according to the third embodiment is a modification of the second embodiment, and the basic configuration is similar to the single-plate color image sensor 30 according to the second embodiment. Compared to the second embodiment, the characteristics of the single-plate color image sensor 40 of the third embodiment are as follows.

Between the power supply line 11 and the pixel output terminals of the four columns of the pixel group 10A (horizontal direction pixel selection lines X1 to X4), two routes of bias voltage signal lines 41G corresponding to the colors G and B, respectively. , 41B, two routes of bias voltage signal lines 41R, 41G corresponding to colors R, G, two routes of bias voltage signal lines 41G, 41B, colors R, G corresponding to colors G, B, respectively. Corresponding two routes of bias voltage signal lines 41R and 41G are provided. Each of the bias voltage signal lines 41R, 41G, and 41B includes a bias resistor (R _R , R _G , R _B ) and a bias switch (SW _R , SW _G , SW _B ) connected in series. These three bias resistors R _R, R _G, with respect to R _B, as described above, their resistance values are determined according to the color, are set to mutually different values. The opening / closing operation of the bias switches SW _R , SW _G , SW _B is performed based on an opening / closing control command Sc from the control unit 13. In reading out sensor signals from each pixel of the pixel group 10A, when reading out sensor signals of pixels for each color in each column, the corresponding bias switches SW _R , SW _G , and SW _B are turned on according to the color of the read pixels. The optimum bias resistor corresponding to the color is selected in accordance with the state, and the optimum gain, that is, the optimum reading load is selected.

  In the single-plate color image sensor 40 according to the third embodiment, in the configuration of the pixel group 10A, there are no R component pixels in the lines X1 and X3, and no B component pixels in the lines X2 and X4. Paying attention, the number of bias resistors and bias switches in each column is reduced. Accordingly, in addition to the advantages described in the first and second embodiments, the circuit configuration of the bias resistor and the bias switch can be simplified and the number of components can be reduced.

  Next, a fourth embodiment of the single-plate color image sensor according to the present invention will be described with reference to FIG. In FIG. 8, the same elements as those described in the above-described embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  In the single-plate color image sensor 50 according to the fourth embodiment, the configuration of the pixel group 10A is the same as that in the above embodiment. As described above, the bias voltage and the bias switch are not supplied from the power supply line 11 to the pixel group 10A, but are directly connected to the pixel output terminals of the respective columns of the pixel group 10A. As a characteristic configuration of the single-plate color image sensor 50 of the fourth embodiment, the video output lines are provided not in one system but in two systems 12a and 12b as described above. A switch unit 51 is provided between the two video output lines 12a and 12b and the column direction lines X1 and X2, and a switch 52 is provided between the video output lines 12a and 12b and the column direction lines X3 and X4. Is provided.

  The switch units 51 and 52 have a dual-type switch mechanism, and the opening / closing operation of the two-state selection of the switch units 51 and 52 is controlled by the control unit 13 as follows.

  The switch unit 51 for selecting the two states connects the pixel output ends of the lines X1 and X2 to the video output lines 12a and 12b in the first selection state, and the pixel output ends of the lines X1 and X2 in the second selection state. Connect to the output lines 12b and 12a, respectively. Similarly, the switch unit 52 for selecting the two states connects the pixel output terminals of the lines X3 and X4 to the video output lines 12a and 12b in the first selection state, respectively, and the pixel output terminals of the lines X3 and X4 in the second selection state. Are connected to the video output lines 12b and 12a, respectively.

  An amplifier 53 and an A / D converter 54 are provided following the video output line 12a, and the video signal is input to the correction circuit 55 via the amplifier 53 and the A / D converter 54. Further, an amplifier 56 and an A / D converter 57 are provided at the subsequent stage of the video output line 12 b and are input to the correction circuit 55 via the amplifier 56 and the A / D converter 57. The video signal corrected by the correction circuit 55 is input to the color reproduction circuit 58. The gains (amplification factors) of the amplifiers 53 and 56 provided in the subsequent stages of the video output lines 12a and 12b are set to different values, specifically, the gain of the amplifier 53 that amplifies the sensor signal from the G pixel. Is set to a relatively low and fixed value, and the gain of the amplifier 56 that amplifies the sensor signal from the R or B pixel is set higher than the gain of the amplifier 53. As a result, as described above, the response output characteristics (relative sensitivity) of the pixels responsible for the R, G, and B colors are aligned so that the difference in spectral characteristics corresponding to the R, G, and B colors is eliminated.

  According to the configuration of the fourth embodiment, the sensor signal read from the G pixel is taken out only from the video output line 12a, and the sensor signal read from the R or B pixel is taken out only from the video output line 12b. Thus, the gain, that is, the read load is appropriately set and made different, whereby the difference in spectral characteristics corresponding to each of the R, G, and B colors can be eliminated.

  As a modification of the fourth embodiment, three video output lines can be provided, and R, G, and B can be assigned to each line.

  The configurations and the like described in the above embodiments are merely schematically shown to such an extent that the present invention can be understood and implemented. Therefore, the present invention is not limited to the described embodiments and is not limited to patents. Various modifications can be made without departing from the scope of the technical idea shown in the claims.

  The single-plate color image sensor according to the present invention aligns the response output characteristics (relative sensitivity) of the pixels responsible for each color of R, G, and B so as to eliminate the difference in spectral characteristics corresponding to each color. This is used to properly balance the image quality and prevent image quality degradation.

1 is an electric circuit diagram showing a first embodiment of a single-plate color image sensor according to the present invention. It is a characteristic view which shows the spectral characteristics obtained with the single-plate color image sensor which concerns on 1st Embodiment. It is an electric circuit diagram which shows the specific structure of the optical sensor circuit of each pixel. It is an electric circuit diagram which shows 2nd Embodiment of the single-plate color image sensor which concerns on this invention. It is a timing chart which shows the driving example of the progressive scanning in 2nd Embodiment. It is a timing chart which shows the drive example of the interlace scanning in 2nd Embodiment. It is an electric circuit diagram which shows 3rd Embodiment of the single-plate color image sensor which concerns on this invention. It is an electric circuit diagram which shows 4th Embodiment of the single-plate color image sensor which concerns on this invention. It is a characteristic view which shows the spectral characteristic of natural light.

Explanation of symbols

10 single plate color image sensor 10A pixel group 13 control unit 16 storage unit VR1~VR4 variable resistance SW1~SW4 output switch D11~D44 pixels 31R, 31G, 31B bias voltage signal lines _R R, R G, R _B bias resistor SW _R , SW _G , SW _B bias switch

Claims (3)

A plurality of pixels that detect light incident on the photoelectric conversion element for each color according to each pixel, convert a photocurrent corresponding to each color by a MOS transistor, and output a sensor signal;
A variable resistor provided on each output side of the plurality of pixels and connected to a bias power source;
Selecting means for selecting a pixel from which a sensor signal is read out of the plurality of pixels;
Control means for changing the resistance value of the variable resistor corresponding to the color of the pixel to be read and changing the read load;
A single-plate color image sensor comprising: A plurality of pixels that detect light incident on the photoelectric conversion element for each color according to the pixel, convert a photocurrent corresponding to each color by a MOS transistor, and output a sensor signal;
A bias switch provided on the output side of each of the plurality of pixels and connected to a bias power source to enable switching of an input bias voltage;
A plurality of bias lines connected to the input side of the bias switch;
Control means for switching the bias switch corresponding to the color carried by the plurality of pixels to select one of the plurality of bias lines and changing a read load;
A single-plate color image sensor comprising: A plurality of pixels that detect light incident on the photoelectric conversion element for each color according to the pixel, convert a photocurrent corresponding to each color by a MOS transistor, and output a sensor signal;
An output switch provided on each output side of the plurality of pixels;
A plurality of output lines connected to the output side of the output switch;
Control means for switching the output switch corresponding to the color of the plurality of pixels to select one of the plurality of output lines and outputting a pixel having specific color information to a specific output line;
A single-plate color image sensor comprising:

Images