Imaging device

Abstract

This imaging device is miniaturized. The imaging device includes an imaging element, a data length change unit, a processing unit, and a restoration unit. The imaging element includes a pixel array unit in which a plurality of pixels are arranged and configured to generate pixel signals corresponding to incident light, converts the generated pixel signals into digital pixel signals, and outputs the digital pixel signals. The data length change unit changes the data length of the outputted pixel signals. The processing unit processes the pixel signals of which the data length has been changed. The restoration unit restores the data length of the processed pixel signals.

Description

Imaging device

[0001] The present disclosure relates to an imaging device.

[0002] In an imaging device, an imaging device including an imaging element that performs imaging in two imaging modes, a high-sensitivity mode and a low-sensitivity mode, for HDR (High Dynamic Range) and generates two image signals with different sensitivities has been proposed (see, for example, Patent Document 1). In this imaging device, an image processing unit that processes each image signal is arranged. This image processing unit performs demosaicing processing and noise reduction processing.

[0003] International Publication No. 2023 / 037600

[0004] However, in the above conventional technology, since processing is performed on two image signals, there is a problem that the circuit size of the image processing unit becomes large and miniaturization of the imaging device becomes difficult.

[0005] Therefore, the present disclosure proposes an imaging device that can be miniaturized.

[0006] The imaging device according to the present disclosure includes a pixel array unit configured by arranging a plurality of pixels that generate pixel signals according to incident light, an imaging element that converts the generated pixel signals into digital pixel signals and outputs them, a data length changing unit that changes the data length of the output pixel signals, a processing unit that processes the pixel signals with the changed data length, and a restoring unit that restores the data length of the processed pixel signals.

[0007] This figure shows an example configuration of an imaging device according to the first embodiment of this disclosure. This figure shows an example configuration of an image sensor according to the first embodiment of this disclosure. This figure shows an example configuration of a pixel array according to the first embodiment of this disclosure. This figure shows an example configuration of a signal processing unit according to the first embodiment of this disclosure. This figure shows an example configuration of a processing unit according to the first embodiment of this disclosure. This figure shows an example of data length modification according to the first embodiment of this disclosure. This figure shows an example of restoration according to the first embodiment of this disclosure. This figure shows an example configuration of a conventional imaging device. This figure shows an example configuration of a signal processing unit according to the second embodiment of this disclosure. This figure shows an example of data length modification according to the second embodiment of this disclosure. This figure shows an example of restoration according to the second embodiment of this disclosure. This figure shows a comparison with a conventional imaging device.

[0008] Embodiments of the present disclosure will be described in detail below with reference to the drawings. The description will be in the following order. In each of the following embodiments, the same parts will be denoted by the same reference numerals, and redundant descriptions will be omitted. 1. First Embodiment 2. Second Embodiment

[0009] (1. First Embodiment) <Configuration of Imaging Device> Figure 1 is a diagram showing an example configuration of an imaging device according to the first embodiment of the present disclosure. The same figure is a block diagram showing an example configuration of the imaging device 1. The imaging device 1 is a device that captures an image of a subject and generates pixel signals that constitute the image of the subject. The generated pixel signals are output to an external device, etc. The imaging device 1 comprises an image sensor 10 and a signal processing unit 20. The image sensor 10 captures an image of a subject and generates pixel signals. For example, a CMOS (Complementary Metal Oxide Semiconductor) type image sensor can be applied to this image sensor 10. The image sensor 10 also outputs digital pixel signals. The signal processing unit 20 processes the digital pixel signals from the image sensor 10 and outputs the processed pixel signals. As will be described later, the signal processing unit 20 outputs a 12-bit wide pixel signal that supports HDR.

[0010] <Configuration of the Image Sensor> Figure 2 is a diagram showing an example configuration of an image sensor according to the first embodiment of the present disclosure. The same figure is a block diagram showing an example configuration of the image sensor 10. The image sensor 10 is a semiconductor element that generates pixel signals of a subject. The image sensor 10 comprises a pixel array section 11, a vertical drive section 12, a column signal processing section 13, and a control section 14.

[0011] The pixel array section 11 is composed of multiple pixels 100 arranged together. The pixel array section 11 in Figure 2 shows an example in which multiple pixels 100 are arranged in the shape of a two-dimensional matrix. Here, each pixel 100 is equipped with a photoelectric conversion unit that performs photoelectric conversion of incident light and generates a pixel signal of the subject based on the irradiated incident light. For example, a photodiode can be used for this photoelectric conversion unit. Signal lines 15 and 16 are wired to each pixel 100. The pixel 100 generates a pixel signal controlled by a control signal transmitted by the signal line 15 and outputs the generated pixel signal via the signal line 16. The signal lines 15 are arranged in each row of the two-dimensional matrix and are wired in common to multiple pixels 100 arranged in one row. The signal lines 16 are arranged in each column of the two-dimensional matrix and are wired in common to multiple pixels 100 arranged in one column.

[0012] The vertical drive unit 12 generates the control signals for the pixels 100 described above. In Figure 2, the vertical drive unit 12 generates control signals for each row of the two-dimensional matrix of the pixel array unit 11 and outputs them sequentially via the signal line 15.

[0013] The column signal processing unit 13 processes the pixel signals generated by the pixels 100. The column signal processing unit 13 in Figure 2 simultaneously processes pixel signals from multiple pixels 100 arranged in one row of the pixel array unit 11, which are transmitted via the signal line 16. This processing can include, for example, analog-to-digital conversion, which converts the analog pixel signals generated by the pixels 100 into digital pixel signals, and correlated double sampling (CDS), which removes offset errors in the pixel signals. The processed pixel signals are output to external circuits, etc., of the image sensor 10.

[0014] The control unit 14 controls the vertical drive unit 12 and the column signal processing unit 13. In Figure 2, the control unit 14 generates control signals to control the vertical drive unit 12 and the column signal processing unit 13 based on data that commands the clock, operating mode, etc., input from an external circuit. Next, the control unit 14 controls the vertical drive unit 12 and the column signal processing unit 13 by outputting control signals via signal lines 17 and 18, respectively.

[0015] In Figure 2, the column signal processing unit 13 is equipped with an analog-to-digital converter, which outputs a digital pixel signal. The data length of this digital pixel signal can be, for example, 12 bits or 14 bits. By increasing the data length of the pixel signal to 12 bits or more, the dynamic range can be expanded, enabling support for HDR as described above.

[0016] <Configuration of Pixel Array Section> Figure 3 is a diagram showing an example configuration of the pixel array section according to the first embodiment of the present disclosure. The figure is a plan view showing an example configuration of the pixel array section 11. As described above, the pixel array section 11 is configured by arranging pixels 100 in a two-dimensional matrix. The rectangles in the figure represent pixels 100. The "R", "G", and "B" attached to the pixels 100 in the figure represent the types of pixel signals generated by each pixel 100. The "R", "G", and "B" in the figure represent pixel signals corresponding to red light, green light, and blue light, respectively. As shown in the figure, pixels 100 that generate the same type of pixel signal are arranged in a 2x2 grid. In the pixel array section 11 of the figure, the four pixels 100 arranged in this 2x2 grid are arranged in a Bayer array.

[0017] <Configuration of the Signal Processing Unit> Figure 4 is a diagram showing an example configuration of the signal processing unit according to the first embodiment of the present disclosure. The figure is a block diagram showing an example configuration of the signal processing unit 20. The signal processing unit 20 receives a 12-bit pixel signal from the image sensor 10. The signal processing unit 20 in the figure processes this pixel signal and outputs two 12-bit pixel signals, each having undergone different processing. The groups of rectangles labeled "R" etc. in the figure represent the arrangement of the pixel signals in each part. The pixel signals from the image sensor 10 are sequentially input in an arrangement that follows the order of the pixels 100 in the pixel array section 11 shown in Figure 3. One of the pixel signals output from the signal processing unit 20 is output with four pixel signals in a 2x2 arrangement corresponding to the Bayer array. The other pixel signal output from the signal processing unit 20 is output in the same format as the pixel signal output from the image sensor 10.

[0018] The signal processing unit 20 comprises a processing unit 210, a data length modification unit 220, a processing unit 230, a restoration unit 240, and an interface unit 250. In Figure 4, the "interface unit" is abbreviated as "IF".

[0019] The processing unit 210 processes the 12-bit pixel signal. The processing unit 210 outputs the processed pixel signal to the data length modification unit 220 and the interface unit 250. The image based on the pixel signal output to the interface unit 250 is an image that has not undergone the processing (remosaic processing) of the processing unit 230 described later, and is referred to as RAW data. This RAW data can be used, for example, for AI learning. Details of the configuration of the processing unit 210 will be described later. Note that the processing unit 210 is an example of the "second processing unit" of this disclosure.

[0020] The data length modification unit 220 modifies the data length of the input pixel signal. In Figure 4, the data length modification unit 220 modifies a 12-bit wide pixel signal into a 10-bit wide pixel signal. The data length modification unit 220 also generates two 10-bit pixel signals and outputs them to the processing unit 230. Details of the data length modification by the data length modification unit 220 will be described later.

[0021] The processing unit 230 processes pixel signals whose data length has been changed. This processing unit 230 can, for example, perform remosaic processing. This remosaic processing is the process of converting an image consisting of an array of multiple pixel signals into an array of different pixel signals. Specifically, remosaic processing is the process of converting an image in which four 2x2 block pixel signals are arranged in an order corresponding to a Bayer array, as shown in Figure 4, into an image in which four 2x2 pixel signals are arranged in a Bayer array. The processing unit 230 outputs two processed 10-bit pixel signals to the restoration unit 240. Note that if remosaic processing is performed on a 12-bit pixel signal, the circuit size of the processing unit 230 will increase. The processing unit 230 in Figure 4 can be made into a relatively small circuit by configuring it to process 10-bit pixel signals. The processing unit 230 performs the 10-bit pixel signal remosaic processing twice using time division multiplexing.

[0022] The restoration unit 240 restores the data length of the pixel signal. The restoration unit 240 restores the data length of a 10-bit wide pixel signal to its original 12-bit width. In Figure 4, the restoration unit 240 restores the 12-bit wide data length by combining two 10-bit wide pixel signals. The restoration unit 240 outputs the pixel signal with the restored data length to the interface unit 250. Details of the data length restoration by the restoration unit 240 will be described later.

[0023] The interface unit 250 communicates with external devices. Furthermore, this interface unit 250 can convert the input pixel signal into a signal conforming to the MIPI (Mobile Industry Processor Interface) (registered trademark) standard and output it to external devices. The interface unit 250 converts and outputs the 12-bit pixel signal output from the restoration unit 240 and the 12-bit pixel signal (RAW data) output from the processing unit 210.

[0024] The processing unit 210, processing unit 230, and restoration unit 240 each use a working memory to hold one row of pixel signals. The processing unit 210 uses 12-bit memory. The processing unit 230 and restoration unit 240 each use two 10-bit memories.

[0025] <Configuration of the Processing Unit> Figure 5 is a diagram showing an example of the configuration of the processing unit according to the first embodiment of the present disclosure. The same figure is a block diagram showing an example of the configuration of the processing unit 210. The processing unit 210 comprises a sorting processing unit 211, an adjustment unit 212, and a defect correction unit 213.

[0026] The reordering processing unit 211 rearranges the pixel signals. As described above, the image sensor 10 reads out the pixel signals of one row of pixels 100 for each row of the pixel array unit 11, performs analog-to-digital conversion, and outputs them sequentially. However, depending on the image sensor 10, the order in which the pixel signals are read out may differ from the order in which the pixels 100 are arranged in the pixel array unit 11. In such cases, the reordering processing unit 211 rearranges the pixel signals and outputs them in the same order as the arrangement of the pixels 100 in the pixel array unit 11.

[0027] The adjustment unit 212 adjusts the pixel signal. This adjustment includes, for example, black level adjustment and sensitivity adjustment.

[0028] The defect correction unit 213 compensates for pixel signals that have been lost due to defects in the pixel 100.

[0029] <Data Length Modification> Figure 6 is a diagram showing an example of data length modification according to the first embodiment of this disclosure. The diagram shows an example of the data length modification process in the data length modification unit 220. The data length modification unit 220 generates an upper-order pixel signal consisting of multiple bits, excluding at least the least significant bit, that are consecutive from the most significant bit of the 12-bit wide pixel signal in the direction of lower bits. The data length modification unit 220 also generates a lower-order pixel signal consisting of multiple bits, excluding at least the most significant bit, that are consecutive from the least significant bit of the 12-bit wide pixel signal in the direction of higher bits. In the example shown in the diagram, the data length modification unit 220 extracts the upper 10 bits of the 12-bit wide pixel signal to generate a 10-bit wide pixel signal. This pixel signal is a low-sensitivity pixel signal. The data length modification unit 220 also extracts the lower 10 bits of the 12-bit wide pixel signal to generate a 10-bit wide pixel signal. This pixel signal is a high-sensitivity pixel signal. In this way, the data length modification unit 220 generates a low-sensitivity pixel signal and a high-sensitivity pixel signal with shortened data lengths. In the following explanation, the upper-side pixel signal and the lower-side pixel signal may be referred to as the low-sensitivity pixel signal and the high-sensitivity pixel signal, respectively.

[0030] <Restoration> Figure 7 is a diagram showing an example of restoration according to the first embodiment of the present disclosure. The diagram shows the restoration process in the restoration unit 240. The restoration unit 240 extends the data length while combining the low-sensitivity pixel signal and the high-sensitivity pixel signal. Specifically, the restoration unit 240 extends the data length by mixing the low-sensitivity pixel signal and the high-sensitivity pixel signal, which have been shifted by the number of missing bits. As shown in the diagram, the data length of the low-sensitivity pixel signal is extended by shifting it by adding two bits of value "0" to the low-sensitivity pixel signal. Next, this pixel signal and the high-sensitivity pixel signal are mixed according to the formula shown in the diagram to generate a 12-bit wide pixel signal. Here, α in the diagram represents the mixing ratio. This mixing method is called α blending.

[0031] The mixing ratio α can be adjusted according to the pixel signal value. The restoration unit 240 can increase the ratio of the upper pixel signal when the pixel signal value is large, and increase the ratio of the lower pixel signal when the pixel signal value is small.

[0032] <Comparison with Conventional Technology> Figure 8 shows an example of the configuration of a conventional imaging device. The same figure is a block diagram showing an example of the configuration of conventional imaging device 1, which serves as a comparative example. The image sensor 10 in the same figure is assumed to be an image sensor that outputs 10-bit low-sensitivity pixel signals and 10-bit high-sensitivity pixel signals. The signal processing unit 20 outputs a 12-bit wide pixel signal, similar to the signal processing unit 20 in Figure 4.

[0033] The signal processing unit 20 comprises a processing unit 210, a processing unit 230, combining units 290a and 290b, and an interface unit 250. The combining unit 290a combines two 10-bit wide pixel signals output from the processing unit 230 to generate a 12-bit wide pixel signal. The combining unit 290b also combines two 10-bit wide pixel signals output from the processing unit 210 to generate a 12-bit wide pixel signal. The combining units 290a and 290b can perform the same processing as the restoration shown in Figure 7. The processing unit 210, processing unit 230, and combining units 290a and 290b in Figure 8 use two 10-bit working memories.

[0034] The conventional signal processing unit 20 processes the two 10-bit pixel signals as they are, resulting in a larger memory size in each section. Furthermore, a combining unit 290b is required to generate 12-bit wide pixel signals that become RAW data. Therefore, the conventional signal processing unit 20 has a larger circuit size than the signal processing unit 20 shown in Figure 4. However, in the conventional signal processing unit 20, if the 12-bit pixel signals from the image sensor 10 are input to the processing unit 230 for processing, the memory size is reduced compared to the processing unit 230 shown in Figure 4. However, the remosaic processing circuit of the processing unit 230 increases in size proportionally to the data length, leading to increased power consumption.

[0035] The configuration of the imaging device 1 in the embodiment of this disclosure is not limited to this example. For example, an image sensor 10 that generates a pixel signal with a bit width greater than 12, for example, 14 bits wide, can also be used. In this case, the signal processing unit 20 processes the 14-bit wide pixel signal. Specifically, the processing unit 210 of the signal processing unit 20 processes the 14-bit wide pixel signal. The data length changing unit 220 changes the data length of the 14-bit wide pixel signal to two 10-bit wide pixel signals. The restoration unit 240 restores the 14-bit wide pixel signal from the two 10-bit wide pixel signals.

[0036] As described above, the imaging device 1 of the first embodiment of this disclosure uses an image sensor 10 that generates a pixel signal with a data length corresponding to HDR, and includes a signal processing unit 20 that processes the pixel signal. The signal processing unit 20 performs processing that uses the input pixel signal as is, as with the processing unit 210, and also inputs a pixel signal with a modified data length to the processing unit 230, whose processing circuit size increases according to the data length of the pixel signal, and performs processing. This makes it possible to reduce the circuit size of the signal processing unit 20 and make the imaging device 1 more compact.

[0037] (2. Second Embodiment) In the first embodiment described above, the signal processing unit 20 of the imaging device 1 generated the upper pixel signal and the lower pixel signal using the data length changing unit 220. In contrast, the signal processing unit 20 of the imaging device 1 of the second embodiment of this disclosure differs from the first embodiment described above in that it generates either the upper pixel signal or the lower pixel signal.

[0038] <Configuration of the Imaging Device> Figure 9 is a diagram showing an example configuration of a signal processing unit according to the second embodiment of the present disclosure. This figure is a block diagram showing an example configuration of the signal processing unit 20, similar to Figure 4. In this figure, the working memory is omitted. The signal processing unit 20 in this figure differs from the signal processing unit 20 in Figure 4 in that it includes a data length changing unit 260 instead of a data length changing unit 220, and a restoration unit 280 is arranged instead of a restoration unit 240. The processing unit 210 in this figure includes an adjustment unit 212 and a defect correction unit 213, as described in Figure 5, and processes the pixel signal whose data length has been changed by the data length changing unit 260. On the other hand, the sorting processing unit 211, which was included in the processing unit 210 in Figure 5, is arranged before the data length changing unit 260.

[0039] The 12-bit wide pixel signals from the image sensor 10 are input to the reordering processing unit 211. The reordering processing unit 211 inputs the reordered pixel signals to the data length changing unit 260.

[0040] The data length modification unit 260 generates and outputs either a 10-bit wide upper pixel signal or a 10-bit wide lower pixel signal, obtained by modifying the data length from a 12-bit wide pixel signal. At this time, the data length modification unit 260 further outputs identification information to distinguish between the upper and lower pixel signals. "Flg" in Figure 9 represents this identification information. Details of the data length modification in the data length modification unit 260 will be described later.

[0041] Processing unit 210 and processing unit 230 each perform processing on a 10-bit wide pixel signal.

[0042] The restoration unit 280 restores the data length of either the upper-order pixel signal or the lower-order pixel signal of the 10-bit width, and outputs a 12-bit width pixel signal. Details of the restoration process in the restoration unit 280 will be described later.

[0043] The interface unit 250 converts the pixel signals from the restoration unit 280 into signals conforming to the MIPI (registered trademark) standard and outputs them to external devices, etc.

[0044] <Data length change>Figure 10 is a diagram showing an example of data length change according to the second embodiment of the present disclosure. This figure represents the process of data length change in the data length change unit 260. Similar to the process in FIG. 6, the data length change unit 260 generates upper and lower pixel signals from a pixel signal with a 12-bit width. Next, the data length change unit 260 selects and outputs either the upper pixel signal (low-sensitivity pixel signal) or the lower pixel signal (high-sensitivity pixel signal). The data length change unit 260 can perform the selection based on, for example, the pixel signal value. Specifically, when the value of the pixel signal is relatively large, the data length change unit 260 selects the upper pixel signal, and when the value of the pixel signal is relatively small, the data length change unit 260 selects the lower pixel signal. This is because in the pixel signal in a low illuminance environment, the information near the most significant bit is not necessary, and in the pixel signal of a high-luminance subject, the contribution of the information near the least significant bit is not large.

[0045] The data length change unit 260 adds identification information corresponding to the selected pixel signal to the pixel signal and outputs it. In FIG. 10, 1-bit identification information "Flg" is added. In the example of the identification information in FIG. 10, when the value is "0", it represents the upper pixel signal (low-sensitivity pixel signal), and when the value is "1", it represents the lower pixel signal (high-sensitivity pixel signal).

[0046] <Restoration>Figure 11 is a diagram showing an example of restoration according to the second embodiment of the present disclosure. This figure represents the restoration process in the restoration unit 280. The restoration unit 280 determines whether it is the upper pixel signal (low-sensitivity pixel signal) or the lower pixel signal (high-sensitivity pixel signal) based on the identification information. Then, the restoration unit 280 performs restoration by adding data of the missing bits to the upper and lower pixel signals to extend the data length.

[0047] The restoration unit 280 adds the missing 2-bit data to the upper pixel signal on the least significant bit side. The data to be added is such that the values "0" and "1" are randomly selected. Also, the restoration unit 280 adds the missing 2-bit data to the lower pixel signal on the most significant bit side. The data to be added is the value "0". Thus, the restoration unit 280 restores the data length for either the upper pixel signal or the lower pixel signal.

[0048] <Comparison with the Prior Art> Fig. 12 is a diagram showing a comparison example with a conventional imaging device. The upper side of the figure is a timing diagram showing the processing in the signal processing unit 20 described in Fig. 8. The processing of the signal processing unit 20 is performed at a timing based on the synchronization signal. In the signal processing unit 20 of the prior art, the processing of the 10-bit width pixel signal (low sensitivity) and the 12-bit pixel signal and the processing of the 10-bit pixel signal (high sensitivity) are performed in a time-sharing manner.

[0049] The lower side of Fig. 12 is a timing diagram showing the processing in the signal processing unit 20 of Fig. 9. In the signal processing unit 20 of Fig. 9, only the processing of the 10-bit width pixel signal and the identification information is performed. The size of the memory required for the processing can be reduced to 1 / 2. Further, since the processing of the 12-bit pixel signal is unnecessary, in the signal processing unit 20 of Fig. 9, the circuit scale of the processing circuit can be reduced. Also, since the time-sharing operation is unnecessary, the signal processing unit 20 of Fig. 9 can reduce the power consumption and can also improve the frame frequency.

[0050] Since the configuration of the imaging device 1 other than that described above is the same as the configuration of the imaging device 1 in the first embodiment of the present disclosure, the description thereof is omitted.

[0051] Thus, in the imaging device 1 of the second embodiment of the present disclosure, the data length changing unit 260 of the signal processing unit 20 selects either the upper pixel signal or the lower pixel signal and outputs it to the subsequent processing units (processing unit 210 and processing unit 230). Thereby, the circuit scale of the signal processing unit 20 can be further reduced, and the imaging device 1 can be made smaller.

[0052] <Effect> The imaging device comprises a pixel array section composed of multiple pixels arranged to generate pixel signals corresponding to incident light, an image sensor that converts the generated pixel signals into digital pixel signals and outputs them, a data length modification section that changes the data length of the output pixel signals, a processing section that processes the pixel signals whose data length has been modified, and a restoration section that restores the data length of the processed pixel signals. This results in the pixel signals whose data length has been modified being processed by the processing section. The circuit size of the processing section can be reduced.

[0053] Furthermore, the processing unit performs a process to convert an image consisting of multiple arrays of pixel signals into a different array of pixel signals. For processes where the circuit size increases according to the data length, pixel signals with changed data lengths can be applied.

[0054] Furthermore, the system may have a second processing unit that performs a different process on the output pixel signal than the processing unit described above, and the data length changing unit may change the data length of the pixel signal processed by the second processing unit. This allows the pixel signal before the data length change to be applied to the second processing unit.

[0055] Furthermore, the data length changing unit changes the data length of the pixel signal by generating an upper-order pixel signal consisting of multiple bits from the most significant bit of the pixel signal, excluding the least significant bit, and a lower-order pixel signal consisting of multiple bits from the least significant bit of the pixel signal, excluding the most significant bit, and the processing unit performs the above processing on the upper-order pixel signal and the lower-order pixel signal. This makes it possible to maintain the amount of information in the pixel signal before the data length change.

[0056] Alternatively, the restoration unit may restore the data by extending the data length while combining the upper-side pixel signal and the lower-side pixel signal. This makes it possible to maintain the amount of information in the pixel signal before the data length was changed.

[0057] Furthermore, the restoration unit may combine the upper and lower pixel signals by mixing the upper and lower pixel signals, which have been shifted by the missing number of bits. This makes it possible to restore the original data length of the pixel signal.

[0058] Furthermore, the data length modification unit modifies the data length of the pixel signal by generating either an upper-order pixel signal consisting of multiple bits excluding the least significant bit that are consecutive from the most significant bit of the pixel signal downwards, or a lower-order pixel signal consisting of multiple bits excluding the most significant bit that are consecutive from the least significant bit of the pixel signal downwards. The processing unit then performs the above processing on either the upper-order pixel signal or the lower-order pixel signal. This reduces the circuit size of the subsequent processing unit.

[0059] Furthermore, the data length modification unit may generate identification information for identifying the upper-level pixel signal and the lower-level pixel signal. This allows for proper restoration of the data length of the pixel signal.

[0060] Furthermore, the restoration unit may restore the data length for either the upper pixel signal or the lower pixel signal. This allows the processing to be limited to only the necessary steps.

[0061] Furthermore, the restoration unit may restore the data by adding missing bits of data to the upper and lower pixel signals to extend the data length. This allows the original data length of the pixel signal to be restored.

[0062] Furthermore, the effects described herein are merely illustrative and not limiting, and other effects may also occur.

[0063] Furthermore, this technology can also take the following configurations: (1) An imaging device comprising: an image sensor comprising a pixel array section configured with a plurality of pixels arranged to generate pixel signals corresponding to incident light, which converts the generated pixel signals into digital pixel signals and outputs them; a data length changing section which changes the data length of the output pixel signals; a processing section which processes the pixel signals whose data length has been changed; and a restoration section which restores the data length of the processed pixel signals. (2) The imaging device according to (1) above, wherein the processing section performs processing to convert an image consisting of a plurality of the pixel signals into a different array of pixel signals. (3) The imaging device according to (1) or (2) above, further comprising a second processing section which performs processing different from that of the processing section on the output pixel signals, wherein the data length changing section changes the data length of the pixel signals processed by the second processing section. (4) The imaging apparatus according to any one of (1) to (3), wherein the data length changing unit changes the data length of the pixel signal by generating an upper-order pixel signal consisting of a plurality of bits from the most significant bit of the pixel signal in the direction from the most significant bit downwards, excluding at least the least significant bit, and a lower-order pixel signal consisting of a plurality of bits from the least significant bit of the pixel signal in the direction from the least significant bit upwards, and the processing unit performs the above processing on the upper-order pixel signal and the lower-order pixel signal. (5) The imaging apparatus according to (4), wherein the restoration unit restores the data by extending the data length while combining the upper-order pixel signal and the lower-order pixel signal. (6) The imaging apparatus according to (5), wherein the restoration unit synthesizes the upper-order pixel signal and the lower-order pixel signal by mixing the upper-order pixel signal and the lower-order pixel signal which have been shifted by the number of missing bits.(7) The imaging apparatus according to (1), wherein the data length changing unit changes the data length of the pixel signal by generating either an upper-order pixel signal consisting of a plurality of bits from the most significant bit of the pixel signal in a downward direction, excluding at least the least significant bit, or a lower-order pixel signal consisting of a plurality of bits from the least significant bit of the pixel signal in a downward direction, excluding at least the most significant bit, and the processing unit performs the processing on either the upper-order pixel signal or the lower-order pixel signal. (8) The imaging apparatus according to (7), wherein the data length changing unit further generates identification information for identifying the upper-order pixel signal and the lower-order pixel signal. (9) The imaging apparatus according to (7) or (8), wherein the restoration unit restores the data length for either the upper-order pixel signal or the lower-order pixel signal. (10) The imaging apparatus according to (9), wherein the restoration unit restores the data length by adding data for missing bits to the upper-order pixel signal and the lower-order pixel signal to extend the data length.

[0064] 1 Imaging device 10 Image sensor 20 Signal processing unit 100 Pixels 210, 230 Processing units 220, 260 Data length modification unit 240, 280 Restoration unit

Claims

1. An imaging device comprising: an image sensor having a pixel array section configured with a plurality of pixels arranged to generate a pixel signal corresponding to incident light, and which converts the generated pixel signal into a digital pixel signal and outputs it; a data length changing section that changes the data length of the output pixel signal; a processing section that processes the pixel signal whose data length has been changed; and a restoration section that restores the data length of the processed pixel signal.

2. The imaging apparatus according to claim 1, wherein the processing unit performs a process to convert an image consisting of a plurality of the arrays of pixel signals into a different array of pixel signals.

3. The imaging apparatus according to claim 1, further comprising a second processing unit that performs processing on the output pixel signal different from that of the processing unit, wherein the data length changing unit changes the data length of the pixel signal processed by the second processing unit.

4. The imaging apparatus according to claim 1, wherein the data length changing unit changes the data length of the pixel signal by generating an upper-order pixel signal consisting of a plurality of bits from the most significant bit of the pixel signal in the direction of lower order, excluding at least the least significant bit, and a lower-order pixel signal consisting of a plurality of bits from the least significant bit of the pixel signal in the direction of higher order, excluding at least the most significant bit, and the processing unit performs the processing on the upper-order pixel signal and the lower-order pixel signal.

5. The imaging apparatus according to claim 4, wherein the restoration unit restores the image by extending the data length while combining the upper pixel signal and the lower pixel signal.

6. The imaging apparatus according to claim 5, wherein the restoration unit synthesizes the upper pixel signal and the lower pixel signal by mixing the upper pixel signal and the lower pixel signal which have been shifted by the number of missing bits.

7. The imaging apparatus according to claim 1, wherein the data length changing unit changes the data length of the pixel signal by generating either an upper-order pixel signal consisting of a plurality of bits from the most significant bit of the pixel signal in a downward direction, excluding at least the least significant bit, or a lower-order pixel signal consisting of a plurality of bits from the least significant bit of the pixel signal in a downward direction, excluding at least the most significant bit, and the processing unit performs the processing on either the upper-order pixel signal or the lower-order pixel signal.

8. The imaging apparatus according to claim 7, wherein the data length changing unit further generates identification information for identifying the upper pixel signal and the lower pixel signal.

9. The imaging apparatus according to claim 7, wherein the restoration unit restores the data length for either the upper pixel signal or the lower pixel signal.

10. The imaging apparatus according to claim 9, wherein the restoration unit restores the image by adding missing bit data to the upper pixel signal and the lower pixel signal to extend the data length.

Images