Image sensor, solid-state imaging device including image sensor, and method for controlling

Abstract

Embodiments relate to an image sensor, a solid-state imaging device including the image sensor, and a control method of the solid-state imaging device. An image sensor according to an embodiment includes a plurality of solid-state imaging elements arranged in a row and performing photoelectric conversion, an accumulation unit provided for each solid-state imaging element and temporarily holding charge accumulated in the solid-state imaging element, and a charge-voltage conversion unit converting the charge into a voltage signal. In addition, the solid-state imaging element includes a first PDSH that transfers charges accumulated in odd pixels in the solid-state imaging element to the accumulation unit, and a second PDSH that transfers charges accumulated in even pixels in the solid-state imaging element to the accumulation unit. And a signal processing section including a first SH that transfers the charges accumulated in the odd pixels from the accumulation section to the charge voltage conversion section, and a second SH that transfers the charges accumulated in the even pixels from the accumulation section to the charge voltage conversion section, the first SH transferring the charges accumulated in the odd pixels from the accumulation section to the charge voltage conversion section, and the second SH transferring the charges accumulated in the even pixels from the accumulation section to the charge voltage conversion section. The signal processing section sequentially outputs voltage signals obtained from odd pixels and even pixels.

Description

Image sensor, solid-state imaging device including image sensor, and control method of solid-state imaging device

[0001] Related application: This application enjoys priority based on Japanese Patent Application No. 2024-190379 (filed on October 30, 2024). This application incorporates the entire contents of the basic application by reference to that basic application. Technical Field

[0002] Embodiments of the present invention relate to an image sensor, a solid-state imaging device including an image sensor, and a control method for the solid-state imaging device. Background Technology

[0003] As a method for image reading using a low-cost monochrome single-line sensor, there is a known method that switches the light from the light source to multiple colors and then performs additive color synthesis on the image signals obtained from the reflected light of each light. In such reading, acquiring the image signals of each light takes time, and there are problems such as color deviation and moiré fringes. Summary of the Invention

[0004] The embodiments provide an image sensor capable of reducing color deviation and the generation of moiré fringes, a solid-state imaging device including the image sensor, and a control method for the solid-state imaging device.

[0005] The image sensor of this embodiment includes a plurality of solid-state imaging elements arranged in a row for photoelectric conversion, an accumulation section for each solid-state imaging element to temporarily hold the charge accumulated therein, and a charge-to-voltage conversion section to convert the charge into a voltage signal. Furthermore, it includes a first PDSH (Power-On-Side Filter) that transfers the charge accumulated in odd-numbered pixels of the solid-state imaging elements to the accumulation section, and a second PDSH that transfers the charge accumulated in even-numbered pixels of the solid-state imaging elements to the accumulation section. Additionally, it includes a signal processing section that transfers the first PDSH (charge accumulated in odd-numbered pixels) from the accumulation section to the charge-to-voltage conversion section, and the second PDSH (charge accumulated in even-numbered pixels) from the accumulation section to the charge-to-voltage conversion section, and sequentially outputs voltage signals obtained from the odd-numbered pixels and even-numbered pixels. Attached Figure Description

[0006] Figure 1 is a block diagram showing the imaging structure of a solid-state imaging device having an image sensor 100 according to the first embodiment.

[0007] Figure 2 is a block diagram showing the schematic structure of the image sensor 100 according to the first embodiment.

[0008] Figure 3 is a diagram showing the monochrome single-line sensor 10 of the image sensor 100 according to the first embodiment.

[0009] Figure 4 is a block diagram showing the control structure of the image sensor 100 according to the first embodiment.

[0010] Figure 5 is a flowchart illustrating the reading operation of a solid-state camera device having the image sensor 100 of the first embodiment.

[0011] Figure 6 is a block diagram showing the control structure of the image sensor 200 in the comparative example.

[0012] Figure 7 is a timing diagram showing the reading operation of the image sensor 200 in the comparative example.

[0013] Figure 8 is a timing diagram showing the reading operation of the image sensor 100 in the first embodiment.

[0014] Figure 9 is a diagram showing the signal pattern of the image sensor 200 in a comparative example.

[0015] Figure 10 is a diagram showing the signal pattern of the image sensor 100 according to the first embodiment.

[0016] Figure 11 is a diagram showing the signal pattern of the image sensor 100 of the first embodiment after the signal has been supplemented.

[0017] Figure 12 is a diagram showing the signal pattern of the image sensor 300 in the first modified example.

[0018] Figure 13 is a diagram showing the signal pattern of the image sensor 300 after the signal has been supplemented in the first modified example.

[0019] Figure 14 is a timing diagram showing the reading operation of the image sensor 400 according to the second embodiment.

[0020] Figure 15 is a diagram showing the signal pattern of the image sensor 400 according to the second embodiment.

[0021] Explanation of reference numerals in the attached figures

[0022] 1. Solid-state imaging device; 10. Monochrome single-line sensor; 11. Imaging unit; 12. Processing unit; 13. Light source unit; 14. Image sensor; 15a. Motion control unit; 15b. Control circuit; 16. Image generation unit; 17. Storage unit; 18. Output unit; 19. Subject; 21. Signal processing unit; 27. Timing generation circuit; 30, 30a, 30b. Solid-state imaging element; 34, 34a, 34b. PDSH; 35. Storage unit; 36, 36a, 36b. SH; 37. OG; 38. FJ; 40. Charge-voltage conversion circuit. Detailed Implementation

[0023] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this description, common parts will be labeled with common reference numerals throughout the drawings. Furthermore, these embodiments do not limit the present invention, and the aspect ratio of the drawings is not limited to the ratio shown in the figures.

[0024] Hereinafter, the solid-state imaging device according to the embodiment will be described in detail with reference to FIG1. ​​However, the present invention is not limited to this embodiment.

[0025] Figure 1 is a block diagram showing a schematic structure of a solid-state imaging device 1 equipped with an image sensor 14 according to an embodiment. As shown in Figure 1, the solid-state imaging device 1 includes an imaging unit 11 and a processing unit 12.

[0026] The camera unit 11 includes a light source unit 13, an image sensor 14, a motion control unit 15a, and a control circuit 15b. The light source unit 13 selectively emits light of multiple colors onto the subject 19, for example. The image sensor 14 reads the reflected light from the subject 19. The image sensor 14 transmits the signal obtained through imaging to the processing unit 12. The motion control unit 15a and the control circuit 15b will be described later.

[0027] The processing unit 12 includes an image generation unit 16 and a storage unit 17. The image generation unit 16 is a processor such as an ISP (Image Signal Processor) that processes the signals input from the image sensor 14. The image generation unit 16 performs high-quality image processing such as color compositing, noise removal, defect pixel correction, and resolution conversion.

[0028] Furthermore, the image generation unit 16 generates an image signal through the color addition and synthesis processing of the signal described later, and stores it in the storage unit 17. The image signal fed back from the image generation unit 16 to the imaging unit 11 is used for the adjustment and control of the image sensor 14.

[0029] The storage unit 17 stores the image signal input from the image generation unit 16 as an image. Furthermore, the storage unit 17 outputs the image signal of the stored image to the output unit 18 according to user operations, etc. The output unit 18 displays the image based on the image signal input from the image generation unit 16 or the storage unit 17. The output unit 18 is, for example, a host computer or a liquid crystal display.

[0030] Next, the image sensor 14 included in the imaging unit 11 will be described with reference to FIG2. FIG2 is a block diagram showing the schematic structure of the image sensor 14 according to an embodiment. The image sensor 14 shown in FIG2 is assembled as an image sensor in a solid-state imaging device. For example, it is mounted on a substrate as an encapsulated electronic component and electrically connected to an external control circuit (not shown).

[0031] Furthermore, the image sensor 14 in this embodiment is not limited to a surface-illuminated CMOS (Complementary Metal-Oxide-Semiconductor) image sensor, but can be any image sensor such as a back-illuminated CMOS image sensor or a CCD (Charge Coupled Device) image sensor.

[0032] The image sensor 14 includes a solid-state imaging element 30, a PDSH (Photo Diode Shift Gate) 34, an accumulation section 35, an SH (Shift Gate) 36, a charge-voltage conversion section 40, a signal processing section 21, and a timing generation circuit 27.

[0033] A solid-state imaging element 30 is disposed in the imaging area of ​​the image sensor 14. This solid-state imaging element 30 is a photodiode that serves as a photoelectric conversion element, and multiple photodiodes are arranged horizontally in a row. Furthermore, each photoelectric conversion element of the solid-state imaging element 30, corresponding to each pixel, generates a charge (e.g., electrons) corresponding to the amount of incident light.

[0034] The charge generated by the solid-state imaging element 30 is stored in the charge storage section 35, which temporarily holds the charge. The stored charge is converted into a voltage signal by the charge-to-voltage converter 40, and then processed by the signal processing section 21. The timing generation circuit 27 is a processing unit that outputs pulse signals, which serve as the reference for the operation timing, to the PDSH34, SH36, charge-to-voltage converter 40, and signal processing section 21. The PDSH34 is responsible for transferring charge from the solid-state imaging element 30 to the charge storage section 35, and the SH36 is responsible for transferring charge from the charge storage section 35 to the charge-to-voltage converter 40. In addition to converting charge into a voltage signal, the charge-to-voltage converter 40 is also responsible for, for example, resetting unwanted charge that is not used for image processing.

[0035] The signal processing unit 21 performs prescribed signal processing and outputs the signal to the processing unit 12. The signal processing unit 21 performs signal processing such as amplification, filtering, and digitization (A / D conversion) of analog signals. The signal processing unit 21 may also include an AFE (Analog Front End).

[0036] In the image sensor 14, multiple photoelectric conversion elements disposed in the solid-state imaging element 30 generate an amount of charge corresponding to the amount of light received, and convert it into a voltage signal, thereby performing image capture. This embodiment uses a monochrome single-line sensor as the solid-state imaging element 30 in the solid-state imaging device.

[0037] Next, the reading operation of the solid-state camera device 1 using a general monochrome single-line sensor will be explained.

[0038] In the solid-state imaging device 1, a monochrome single-row sensor 10 (one-dimensional solid-state imaging element) as shown in FIG3 is assembled as an image sensor for capturing light (transmitted light or reflected light) from the subject 19.

[0039] In Figure 2, the solid-state imaging element 30 is included in the monochrome single-line sensor 10. Furthermore, as shown in Figure 3, the monochrome single-line sensor 10 is formed by a one-dimensional arrangement of multiple solid-state imaging elements 30. In this solid-state imaging device 1, the image of the subject 19 is read in two dimensions by performing parallel readings of the monochrome single-line sensor 10 and movement relative to the subject 19. Here, as shown in Figure 1, a movement control unit 15a is assembled in the imaging unit 11 of the solid-state imaging device 1. The movement control unit 15a is equipped with a sub-scanning mechanism that moves the monochrome single-line sensor 10 and the subject 19 relative to each other in a direction orthogonal to the direction of the one-dimensional arrangement of the solid-state imaging elements 30 (the main scanning direction). The movement control unit 15a also moves the light source unit 13 included in the imaging unit 11 simultaneously. The direction orthogonal to the main scanning direction and in which the monochrome single-line sensor moves is defined as the sub-scanning direction. The main scanning direction is defined as the X-direction, and the sub-scanning direction as the Y-direction.

[0040] When a single reading in the X direction is defined as one line, the amount of movement in the sub-scanning mechanism is represented by the number of lines. Here, reading refers to a series of processes in which the solid-state imaging element 30 receives reflected light from the subject 19, thereby generating a charge, which is then converted into a voltage signal and transmitted from the signal processing unit 21 to the processing unit 12. Additionally, the process of exposing the monochrome one-line sensor 10 to reflected light from the subject 19 and accumulating charge is called exposure. Exposure time refers to the time during which the monochrome one-line sensor 10 is exposed to light due to reflected light from the subject 19.

[0041] When using a monochrome 1-line sensor 10 to read a color image of a subject 19 in two dimensions, the color decomposition of the three colors—R (Red), G (Green), and B (Blue)—is achieved by switching the light emission from the subject 19 to the light source unit 13. Here, R represents red, G represents green, and B represents blue. The monochrome 1-line sensor 10 reads the image color sequentially, for example, by exposing R → G → B. This exposure is performed by moving the sensor in rows in the Y direction. Therefore, by setting the reading of each color as one row, and by reading three rows, the RGB signal used to represent the color of each color pixel can be obtained. In addition, since the reading resolution is determined by the pixel density, when exposing each color sequentially while moving, as with a monochrome 1-line sensor, the pixel density tends to decrease. In such cases, the spatial deviation between rows caused by the movement becomes the cause of color deviation and moiré fringes.

[0042] Here, an example of the control structure of the image sensor 100 according to the first embodiment will be described with reference to FIG4. As shown in FIG4, the image sensor 100 of the first embodiment includes a solid-state imaging element 30, a PDSH 34, an accumulation unit 35, an SH 36, an OG (Output Gate) 37, and an FJ (Floating Junction) 38 for acquiring images. In the first embodiment, as shown in FIG4, the odd-numbered solid-state imaging elements 30 are designated as odd-numbered pixels 30a, and the even-numbered solid-state imaging elements 30 are designated as even-numbered pixels 30b. For example, as shown in FIG3, the first number from the left is used as a natural number for counting. Even-numbered pixels and odd-numbered pixels can be counted from any position, and adjacent pixels are not necessarily odd or even. A PDSH 34a is provided in the odd-numbered pixels 30a. Moreover, a PDSH 34b is provided in the even-numbered pixels 30b. The PDSH 34a is responsible for charge transfer to the odd-numbered pixels 30a, and the PDSH 34b is responsible for charge transfer to the even-numbered pixels 30b. Furthermore, SH36a is responsible for transferring the charge of odd-numbered pixels 30a to the charge-voltage conversion unit 40, and SH36b is responsible for transferring the charge of even-numbered pixels 30b to the charge-voltage conversion unit 40. Additionally, PDSH34a is designated as the first PDSH, PDSH34b as the second PDSH, SH36a as the first SH, and SH36b as the second SH. Furthermore, OG37 and FJ38 are included in the charge-voltage conversion unit 40 shown in FIG2. Moreover, OG37 receives the charge transferred from SH36 and transfers it to FJ38. For example, by setting an appropriate potential barrier between OG37 and SH36, the charge is efficiently transferred to FJ38.

[0043] Next, the image reading operation of the solid-state imaging device 1 equipped with the image sensor 100 of the first embodiment will be described using the flowchart in FIG5. First, the control circuit 15b causes the light source unit 13 to emit light (step S11 in FIG5). At this time, light of one color selected from multiple colors is emitted. Next, the solid-state imaging element 30 receives the reflected light from the subject 19 and generates charge (step S12 in FIG5). Then, the timing generation circuit 27 controls PDSH34 (34a, 34b) to transfer the charge to the storage unit 35 (step S13 in FIG5). In addition, the timing generation circuit 27 controls SH36 to transfer the charge transferred to the storage unit 35 to the charge-voltage conversion unit 40 (step S14 in FIG5). At this time, PDSH34a and SH36a control the charge transfer of odd-numbered pixels 30a, and PDSH34b and SH36b control the charge transfer of even-numbered pixels 30b. The timing generation circuit 27 controls each operation. The charge transmitted to the charge-to-voltage conversion unit 40 is converted into a voltage signal by the FJ38 included in the charge-to-voltage conversion unit 40 (step S15 in FIG. 5). At this time, for example, as shown in step S16(A) of FIG. 5, if the signal is obtained based on odd-numbered pixels 30a, the signal is transmitted to the signal processing unit 21 and processed (step S17 in FIG. 5). It is then transmitted to the image generation unit 16 for image generation (step S18 in FIG. 5). On the other hand, if the signal is obtained based on even-numbered pixels 30b, the signal is discarded (step S19(A) in FIG. 5). This reset process of removing unwanted signals is performed, for example, by the charge-to-voltage conversion unit 40, and the timing of the discard is controlled by the timing generation circuit 27. The action of discarding the signal obtained based on exposure and not using it for image generation is set as a non-exposure action. Image reading is performed by repeating such a series of actions. In addition, in the next exposure action, as shown in step S16(B) of FIG. 5, the signal obtained based on even-numbered pixels is used for image generation, and the signal obtained based on odd-numbered pixels is discarded. Therefore, in the first embodiment, the exposure and non-exposure actions are repeated alternately between odd and even numbers. Furthermore, the operation in S18 is executed by the control circuit 15b at the timing of switching the light source unit 13 to the next emission. The emission timing of the light source unit 13 can be controlled by the light source unit 13 itself or by the control circuit 15b. Similarly, the operation timing of PDSH34, SH36, the charge-voltage conversion unit 40, and the signal processing unit 21 can also be controlled by the timing generation circuit 27 or by the control circuit 15b.

[0044] This action is performed by the movement control unit 15a shown in Figure 2, which moves the camera unit 11 relative to the subject 19 in the Y direction.

[0045] Figure 6 shows the structure of an image sensor 200, a general monochrome image sensor as a comparative example. In the image sensor 200, one PDSH 34 is responsible for the transfer of charge in all pixels. That is, since one PDSH reads out the charge stored in the solid-state imaging element 30 and transfers it to the storage unit 35, the sampling period based on the charge obtained from exposure becomes the same phase in all pixels.

[0046] On the other hand, since the image sensor 100 of this embodiment is equipped with PDSH for both odd and even signals, the phase of the charge sampling period can be staggered according to odd and even signals. Thus, by acquiring the exposure-based signal at different timings according to odd and even signals, spatial deviation can be further prevented, resulting in a clearer image. Furthermore, it can increase the variation in additive color synthesis of color pixels. The proportion and arrangement of each color during additive color synthesis affect color performance and visual quality.

[0047] Here, FIG7 shows a timing diagram of the operation of an image sensor 200, representing a general monochrome image sensor of a comparative example. Furthermore, FIG8 shows a timing diagram of the operation of an image sensor 100 according to a first embodiment.

[0048] According to Figure 7, in the comparative example image sensor 200, the reading of one line is performed sequentially by color, such as R exposure → G exposure → B exposure, through the switching of the color of the light source unit 13. Furthermore, if the signal interval that will be used to time the operation of the PDSH34 is set to time t, then during time t, exposure is performed by emitting light of each color at fixed intervals through the light source unit. By adding color to the RGB signals obtained from sequentially exposing each color, one color pixel is generated. Therefore, the time required to generate one color pixel in the image sensor 200 is given by equation (1).

[0049] t(R)+t(B)+t(G)=3t…(1)

[0050] Furthermore, as shown in Figure 7, the signal (R image signal) generated by the charge accumulated in the solid-state imaging element 30 by the emission of the first color (R) during time t is output in the next B exposure operation. The signal (B image signal) generated by the charge accumulated in the solid-state imaging element 30 by the emission of B is output in the next G exposure operation. The signal (G image signal) generated by the charge accumulated by the emission of G is output in the next R exposure operation. In this way, the timing of the next color emission operation becoming active (high level) is synchronized with the timing of the output operation of the signal generated by the emission of the previous color. In addition, such a series of operations are performed during line movement.

[0051] On the other hand, as shown in FIG8, in the image sensor 100 of this embodiment, the time t corresponding to the driving timing of the PDSH34 of the image sensor 200 of the comparative example is shortened by half and set to 0.5t. Furthermore, the light emission time of the light source unit 13 is also correspondingly shortened by half. This control is controlled by the control circuit 15b or the timing generation circuit 27. Furthermore, the charge transfer timing read by the odd-numbered pixels 30a and even-numbered pixels 30b is staggered by half a cycle in both odd and even positions. Here, when the first green exposure is set to G (first G) and the second green exposure is set to G' (second G), the time required to generate each color pixel displayed by additive color synthesis is, for example, equation (2). In addition, the first and second exposures here are the order within the dataset required to generate one color pixel, independent of the overall number of data acquisitions.

[0052] 0.5t(R)+0.5t(B)+0.5t(G)+0.5t(G')=2t...(2)

[0053] That is, compared with image sensor 200, image sensor 100 of this embodiment can reduce the time required to generate each color pixel to 2 / 3. Here, in the comparative example image sensor 200, 3 RGB signals are acquired in a period of 3t, while in the first embodiment, 4 RGB signals are acquired in a period of 2t. In this way, an additional signal based on exposure can be acquired, thus in the first embodiment, two G signals with high visual sensitivity are acquired. In this way, by increasing the signal of G with the highest visual sensitivity to twice that of R and B, the apparent resolution can be improved, and further, it can also help to improve color deviation and moiré patterns.

[0054] Furthermore, as shown in Figure 8, during the process of the light source unit 13 illuminating the initial color R for a certain period of time, charge accumulation of R occurs in odd-numbered pixels 30a. After the illumination of R becomes inactive (low level), PDSH34a becomes active (high level), transferring charge to the accumulation unit 35. Then, SH36a is driven, and the charge-to-voltage conversion unit 40 converts it into a voltage signal. Then, the output processing of the R signal is performed during the timing of the switching from the light source unit 13 to the illumination of the next color B. That is, the timing of the next color's emission becoming active (high level) is synchronized with the timing of the output of the signal generated by the emission of the previous color. On the other hand, in even-numbered pixels 30b, R is illuminated, and during the exposure of odd-numbered pixels 30a, PDSH36b is active (high level), and charge is transferred to the accumulation unit 35 instead of accumulating within the pixel. Moreover, when PDSH34b becomes inactive (low level), SH36b is driven, and the charge transferred to the charge-to-voltage conversion unit 40 is discarded through a reset process. This operation is defined as a non-exposure operation. In the subsequent exposure operation of B, exposure is performed on even-numbered pixels 30b, and non-exposure is performed on odd-numbered pixels 30a. Signals that are not discarded but output are subjected to color addition synthesis, for example, through post-processing in the image generation unit 16. Alternatively, PDSH34a or PDSH34b can also be driven for pixels undergoing non-exposure, synchronized with the timing of the transfer of charge accumulated during the exposure operation to the accumulation unit 35 via PDSH34a or PDSH34b.

[0055] Figure 9 is an example of a signal pattern of the image sensor 200 in a comparative example. Figure 10 is an example of a signal pattern of the image sensor 100 in the first embodiment. In both figures, the color information acquired by the monochrome sensor 10 in the X direction is shown row by row over time.

[0056] In Figure 9, the area A enclosed by the dashed line, and in Figure 10, the area B enclosed by the dashed line, respectively represent examples of signal configuration patterns during color composite processing in the image generation unit 16. Composite processing is performed using signals containing two pixels in the X direction and each of the colors R, G, and B in the Y direction. When the same composite processing is performed on the image sensor 200 of the comparative example, as shown in Figure 9, signals of two pixels in the X direction and 3t (3 rows) in the Y direction are displayed as one block for one color pixel. In the case of the image sensor 100 of the first embodiment, as shown in Figure 10, signals of two pixels in the X direction and 2t (4 rows) in the Y direction are displayed as one block for one color pixel. In the output unit 18, by continuously arranging this block, a two-dimensional subject 19 is displayed. Furthermore, in the image sensor 100 of the first embodiment, either the odd-numbered pixel 30a or the even-numbered pixel 30b has its charge discarded during a non-exposure operation; therefore, pixels that do not receive a signal during a non-exposure operation are supplemented by signals obtained through the exposure operation of the other pixel. That is, as shown in FIG11, supplementation is performed by placing adjacent signals of the same color in the X direction. Such processing is performed, for example, by the image generation unit 16, but a processor or the like, which is electrically connected to an external source and is not shown, may also be used.

[0057] Thus, according to the first embodiment, without changing the resolution in the X direction, the spacing of the lines in the Y direction is set to 0.5t. That is, by reducing the Y-direction movement distance required to display one color pixel, color deviation and the generation of moiré fringes can be reduced. Furthermore, by setting non-exposure operations in even-numbered pixels and odd-numbered pixels respectively, there are colors that are not exposed in the Y direction in odd and even directions, so no color deviation between them is detected. Therefore, color deviation can be mitigated. For example, in even-numbered pixels in the first embodiment, R and G are exposed, and there is a non-exposure operation of B, so no color deviation occurs between B and R, or between B and G.

[0058] Furthermore, in the first embodiment, since PDSH34 is provided separately for odd and even signals, the phase of the charge sampling period can be staggered. The signals acquired by even pixels and the signals acquired by odd pixels are transmitted sequentially. Therefore, the OS (Output Signal) controlling the transmission of odd and even signals can be unified into one. In this first embodiment, the odd and even signals are serially output from the signal processing unit 21 to the processing unit 12. By serial outputting, the communication lines become one or a few, thus reducing the number of wires. Moreover, noise is easily reduced, and signals can be transmitted efficiently.

[0059] Furthermore, the color assigned to odd and even pixels can be arbitrary. The color is not limited to this embodiment; other colors such as white and IR can also be assigned. Additionally, the color combination synthesized from the additive color of a single colored pixel and the amount of data constituting a block are not limited to this embodiment. All signals after exposure can be used, or unused signals can be included.

[0060] (First variation of the first embodiment)

[0061] Next, a first variation of the first embodiment will be described.

[0062] Figure 12 shows the signal pattern of an image sensor 300, a first variant of the image sensor 100 according to the first embodiment. For convenience, G after exposure of B is referred to as G'. As shown in Figure 12, the image sensor 300 acquires R and B signals through odd-numbered pixels and G and G' signals through even-numbered pixels. The area C enclosed by the dashed line shows an example where one color pixel consists of two pixels in the X direction and four rows in the Y direction. Furthermore, in the image sensor 300 of the first embodiment, either the odd-numbered pixel 30a or the even-numbered pixel 30b has its charge discarded during a non-exposure operation. Therefore, the pixel that did not receive a signal during the non-exposure operation is supplemented by the signal obtained through the exposure operation of the other pixel. That is, as shown in Figure 13, the signal is supplemented by having signals of the same color adjacent in the X direction. Additionally, in the Y direction, B or R is arranged between G and G'. That is, G is discontinuously arranged within a block constituting one color pixel, resulting in a non-biased arrangement pattern. In this way, by configuring more visually sensitive Gs, and setting the patterns where Gs are not adjacent to each other in the Y direction, the overall color bias can be reduced, and higher quality images can be generated.

[0063] As described above, in this embodiment, since the timing of charge sampling can be controlled separately for odd and even numbers, the order of the acquired colors and the pattern of the additive color synthesis can be arbitrarily set.

[0064] (Second Implementation)

[0065] Next, Figure 14 shows a timing diagram of the reading operation of the image sensor 400 according to the second embodiment, and Figure 15 shows an example of the signal pattern of the image sensor 400 according to the second embodiment.

[0066] The sensor structure in the second embodiment is the same as that in the first embodiment, but it differs in that it does not have a non-exposure operation because neither odd nor even signals are discarded. This embodiment does not exhibit a temporary non-exposure state like the first embodiment, therefore the brightness of each block unit displaying one color pixel is not reduced. Furthermore, in the image sensor 400 of the second embodiment, compared to the image sensor 200 of the comparative example, both the PDSH driving time and the exposure time are shortened, thus reducing the signal acquisition time required to display one color image to 2 / 3 of that required for the image sensor 200 of the comparative example.

[0067] That is, it is an image sensor with higher color reproducibility and reduced color deviation and moiré fringes compared to the comparative example image sensor 200.

[0068] Furthermore, as shown in Figure 14, two visually sensitive Gs are obtained in the image sensor 400. Here, the G after exposure B is denoted as G'. The area D enclosed by the dashed line in Figure 15 shows an example of the signal pattern used for additive color synthesis to display one color pixel. The area D enclosed by the dashed line shows an example of one pixel consisting of 2 pixels in the X direction and 2t (4 rows) in the Y direction. According to Figure 15, B or R is arranged between G and G' in the Y direction. That is, G is discontinuously arranged in the Y direction within a block that constitutes one color pixel, forming a non-biased arrangement pattern. In this way, by arranging more visually sensitive Gs, and setting a pattern in which Gs are not adjacent to each other in the Y direction, the overall color bias can be reduced in the same way as the image sensor 300, resulting in a higher quality image.

[0069] Furthermore, by further providing an infrared-emitting unit in the light source unit 13, the image sensors 100, 300, and 400 of this embodiment can convert a portion of the signal obtained based on exposure into an IR (Infrared) signal. Such a solid-state imaging device utilizing infrared light can also be used, for example, in devices for detecting counterfeit banknotes and for reading and inspecting the text of printed materials. By acquiring a signal from the reflected light from the subject 19 that has received infrared light from the light source unit 13, and analyzing its intensity and pattern using the processing unit 12 or an externally connected processor, the aforementioned solid-state imaging device can be realized.

[0070] Embodiments of the invention have been described, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, and are included in the scope of the invention as described in the claims and its equivalents.

Claims

1. An image sensor, wherein, It has: multiple solid-state imaging elements that perform photoelectric conversion and are arranged in a row; and a storage unit provided for each of the solid-state imaging elements to maintain the charge stored in the solid-state imaging elements; The charge-to-voltage conversion unit converts the charge of the storage unit into a voltage signal; the first PDSH transfers the charge stored in the odd-numbered pixels of the solid-state imaging element to the storage unit; the second PDSH transfers the charge stored in the even-numbered pixels of the solid-state imaging element to the storage unit; the first SH transfers the charge stored in the odd-numbered pixels from the storage unit to the charge-to-voltage conversion unit; the second SH transfers the charge stored in the even-numbered pixels from the storage unit to the charge-to-voltage conversion unit. And a signal processing unit that outputs the voltage signal obtained from the odd-numbered pixels and the even-numbered pixels.

2. The image sensor according to claim 1, wherein, It also includes: a timing generation circuit that controls the timing of the operation of the first PDSH, the second PDSH, the first SH, the second SH, the charge-voltage conversion unit and the signal processing unit, wherein the timing generation circuit controls the timing of the operation for the odd or even values ​​of the solid-state imaging element.

3. The image sensor according to claim 1 or 2, wherein, The signal from the signal processing unit is output serially.

4. A solid-state imaging device, wherein, The device comprises: an image sensor as described in claim 2; a light source unit that emits light of multiple colors; a control circuit that controls the timing of the light emission of the light source unit and the timing generation circuit; and an image generation unit that synthesizes signals from the signal processing unit to generate an image.

5. The solid-state imaging device according to claim 4, wherein, The control circuit or the light source unit controls the light source unit to emit light of each color for half the time. The control circuit or the timing generation circuit controls the driving timing of the first PDSH and the second PDSH to be half the time respectively.

6. The solid-state imaging device according to claim 5, wherein, The image generation unit generates a single color pixel by performing color addition synthesis on the voltage signals obtained from four exposures: R, B, the first G, and the second G.

7. The solid-state imaging device according to claim 5, wherein, The control circuit controls the light emission of the light source, so that exposure is performed in a discontinuous order between the first G and the second G.

8. The solid-state imaging device according to claim 4, wherein, The light emitted from the light source is infrared.

9. A control method for a solid-state imaging device, wherein, The control circuit causes the light source to emit light. The first PDSH transfers the charge accumulated in the odd-numbered pixels of the solid-state imaging element that receives the reflected light generated by the emission to the accumulation unit. The second PDSH transfers the charge accumulated in the even-numbered pixels of the solid-state imaging element that receives the reflected light generated by the emission to the accumulation unit. The first PDSH transfers the charge accumulated in the odd-numbered pixels from the accumulation unit to the charge-voltage conversion unit. The second PDSH transfers the charge accumulated in the odd-numbered pixels from the accumulation unit to the charge-voltage conversion unit. The timing generation circuit makes the operation timing staggered according to odd and even numbers. The charge-voltage conversion unit converts the transmitted charge into a voltage signal. The signal processing unit sequentially outputs the voltage signals obtained from the odd-numbered pixels and the even-numbered pixels.

10. The control method for the solid-state imaging device according to claim 9, wherein, In a timing synchronization with the generation of charge by the light emission of the light source unit by either the odd-numbered pixels or the even-numbered pixels, the other pixel transfers charge to the storage unit and discards the charge transferred from the other pixel to the storage unit.

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