JP5090388B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus suitable for high-speed imaging.

  As an image pickup apparatus capable of shooting at a frame rate higher than usual, for example, an apparatus disclosed in Patent Document 1 is known. FIG. 9 shows a schematic configuration diagram of an imaging unit in this imaging apparatus.

  In FIG. 9, the subject image L incident on the prism 901 is separated into a blue light component B, a red light component R, and a green light component G by the reflecting surfaces 902 and 903. The blue light component B is incident on the blue light imaging element 914 and the red light component R is incident on the red light imaging element 913. The green light component G is further separated into a first green light component G1 and a second green light component G2 by the half mirror 904. The first green light component G1 is incident on the first green light imaging element 911, and the second green light component G2 is incident on the second green light imaging element 912. Each of the imaging elements 911 to 914 is configured with 2n lines (n is a natural number) of the imaging surface.

  If the frame rate during normal shooting is 60 frames / second, one frame period is 1/60 seconds. In each of the image sensors 911 to 914, the charge accumulated in each pixel is sequentially read out one line at a time, and 2n lines are read out in one frame period.

  On the other hand, at the time of double speed shooting, the first green light image sensor 911 and the second green light image sensor 912 are imaged with a half-cycle shift of one frame period during normal shooting. That is, assuming that T = 1/60 seconds, the first green light imaging device 911 sequentially reads out 2n lines one line at a time from time t to t + T, thereby obtaining an image of one frame. For the second green light image sensor 912, 2n lines are sequentially read out line by line during the period from time t + T / 2 to t + 3T / 2 to obtain an image of one frame. Thereafter, the same operation is performed to obtain two frames each having a 1/60 second offset and each having a 1/120 second shift, each having 2n lines. As a result, for green, one frame period is equivalently 1/120 second. For the red light image sensor 913 and the blue light image sensor 914, utilizing the fact that the human visual sensitivity to red and blue is lower than green, the line to be read is thinned out in half and from the n line in 1/120 seconds. Get one frame each. In this way, high-speed shooting at a frame rate of 120 frames / second, that is, double speed is possible for all colors.

JP 2000-228775 A

However, when high-speed shooting is realized by the driving method as described above, the two green light image pickup devices 911 and 912 are driven at alternate timings, so that control signals for driving and controlling the respective image pickup devices interfere with each other. Therefore, there is a problem that noise is generated in an image read from the image sensor and the image quality is deteriorated.
In the above driving method, one green frame is obtained from one first green light image sensor 911 and another green frame is obtained from the other second green light image sensor 912. Therefore, when the two image sensors 911 and 912 have, for example, a difference in characteristics of photoelectric conversion efficiency, the green frames are alternately different in brightness level. This level difference between light and dark appears as flicker during reproduction, which causes a deterioration in image quality.

  The present invention has been made in view of the above points, and an object thereof is to provide an imaging apparatus capable of obtaining a high-quality video during high-speed shooting.

The present invention has been made in order to solve the above-described problem. First and second image sensors for green light that capture an image of a green light component, and red light that captures an image of a red light component An image sensor for a blue light, an image sensor for a blue light that captures an image of a component of blue light, and the first green light image sensor. Read one frame image consisting of half-thinned pixels and read one frame image consisting of pixels complementary to the one frame image pixels during the period from the second green light image sensor. Read out one frame image from the red light image sensor, which is a half-thick pixel of the entire pixel during the period, and half the pixel of the total pixel during the period from the blue light image sensor. From the pixels that are thinned out Based on a readout control means for reading out an image of one frame, an image read out from the first green light image sensor and an image read out from the second green light image sensor every time period, A green image generating means for generating a one-frame green image having the image information; an image read from the red light image sensor for each period; an image read from the blue light image sensor; and the green image generator means An image synthesizing unit that synthesizes the green image generated by the step S1 with an image of one frame, and the readout control unit includes an odd-numbered column on an odd-numbered line from the first image sensor for green light. An image of one frame including each pixel and each pixel in the even-numbered column on the even-numbered line is read, and each pixel in the even-numbered column on the odd-numbered line is read from the second image sensor for green light. An imaging apparatus characterized by reading one frame image consisting of odd-numbered column pixels of the even row line.
For example, the reading control means may perform the first green light in the order of the mth pixel of the nth line, the m + 1th pixel of the n + 1th line, the m + 2 pixel of the nth line, the m + 3 pixel of the n + 1th line,. Sequentially read out from the image pickup device, the second green color in the order of the (m + 1) th pixel of the (n + 1) th line, the (m + 1) th pixel of the nth line, the (m + 2) pixel of the (n + 1) th line, the (m + 3) pixel of the nth line,. Reading is sequentially performed from the optical imaging device (where n and m are natural numbers).

In the imaging apparatus according to the aspect of the invention, the readout control unit may be configured to read the red light imaging element and the blue light in the same readout order as the first or second green light imaging element. and performing sequentially read from the image sensor.

  According to the present invention, in reading out images from two green light image sensors, pixels are read out by thinning out pixels in one frame, so that the pixels are shorter in the period than usual (when all pixels are read out). The readout of one frame with a small number is completed to increase the speed, and the two frames of green light are read out in the same period with two green light image sensors, and one image in the period is obtained from two images with pixels thinned out. Thus, an image having the same resolution as that obtained when reading without thinning out pixels is obtained by generating a complete image (that is, pixels not thinned out).

Therefore, since the two green light imaging elements are not driven at alternate timings, noise due to control signal interference does not occur and good image quality can be maintained. In addition, since one green image is generated from two images obtained by thinning pixels, even if the original two images have a characteristic difference, the characteristic difference is within one frame of the generated green image. Since it is distributed, it is difficult to recognize visually and does not appear as flicker, so that deterioration in image quality can be suppressed.
Therefore, according to the present invention, it is possible to obtain a high-quality image during high-speed shooting.

It is a figure which shows the structure of the imaging device by one Embodiment of this invention. FIG. 6 is a diagram illustrating a pixel selection signal for a first green light image sensor and an image signal output from the first green light image sensor in accordance with the pixel selection signal. It is a figure showing the pixel selection signal with respect to the 1st image sensor for green light and the 2nd image sensor for green light at the time of 2x speed photography. It is a figure showing the image signal regarding the green light component G obtained based on the pixel selection signal of FIG. 3 is a diagram illustrating an image signal related to a red light component R. FIG. It is a figure showing the pixel selection signal with respect to the 1st image sensor for green light and the 2nd image sensor for green light in 2nd Embodiment. It is a figure showing the image signal regarding the green light component G obtained based on the pixel selection signal of FIG. It is a figure showing the pixel selection signal with respect to the image sensor for red light and the image sensor for blue light in 2nd Embodiment. It is a schematic block diagram of the imaging part in the conventional imaging device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram illustrating a configuration of an imaging apparatus according to an embodiment of the present invention. The imaging device includes a first green light imaging element 111, a second green light imaging element 112, a red light imaging element 113, a blue light imaging element 114, a prism 104, a readout control unit 101, A green image generation unit 102 and an image composition unit 103 are included.

  The prism 104 is an optical element that has a function of separating the subject image L into red, green, and blue color components and branching the green component into two, and includes reflection surfaces 1041 and 1042 and a half mirror 1043 therein. It has. The subject image L incident on the prism 104 is separated into a blue light component B, a red light component R, and a green light component G by the reflecting surfaces 1041 and 1042. The blue light component B is incident on the blue light image sensor 114, and the red light component R is incident on the red light image sensor 113. The green light component G is further branched into a first green light component G1 and a second green light component G2 by the half mirror 1043. The first green light component G1 is incident on the first green light imaging element 111, and the second green light component G2 is incident on the second green light imaging element 112.

  The first green light imaging element 111 receives and photoelectrically converts the first green light component G1 of the incident subject image L. The second green light image sensor 112 receives and photoelectrically converts the second green light component G2 of the incident subject image L. The red light image sensor 113 receives the red light component R of the incident subject image L and photoelectrically converts it. The blue light imaging element 114 receives the blue light component B of the incident subject image L and photoelectrically converts it. Each of the imaging elements 111 to 114 is, for example, a CMOS image sensor, and the imaging surface is configured with a large number of pixels. Each pixel is arranged to form 2n lines (n is a natural number).

  The read control unit 101 controls the image sensors 111 to 114 to read charges accumulated in the pixels by photoelectric conversion. In this readout control, the readout control unit 101 generates a pixel selection signal for sequentially selecting pixels to be read out of charges from the pixels constituting the imaging surface. The generated pixel selection signal is input to each of the image sensors 111 to 114. In accordance with the pixel selection signal, charges are sequentially read from the selected pixels of the image sensors 111 to 114.

The readout operation from the image sensor by the pixel selection signal will be described in detail.
FIG. 2 is a diagram illustrating a pixel selection signal for the first green light imaging element 111 and an image signal output from the first green light imaging element 111 according to the pixel selection signal. Hereinafter, the frame rate during normal shooting is 60 frames / second, and the frame rate during double-speed shooting is 120 frames / second. In addition, the k-th line on the imaging surface is referred to as a line k (k is a natural number).

  At the time of normal shooting in FIG. 2A, the readout control unit 101 sequentially selects each pixel of the line 1 from the left side to the right side, and then selects each pixel of the line 2 sequentially from the left side to the right side. Next, each pixel in the line 3 is sequentially selected from the left side to the right side, and then each pixel in the line 2n-1 is sequentially selected from the left side to the right side, and then each pixel in the line 2n is sequentially selected from the left side to the right side. A pixel selection signal to be selected is generated every 1/60 seconds, which is one frame period during normal shooting. As a result, a signal based on the charge accumulated in each pixel in line 1, a signal based on the charge accumulated in each pixel in line 2, a signal based on the charge accumulated in each pixel in line 3,..., Line 2n− An image signal representing an image of one frame composed of 2n lines composed of a signal based on the electric charge accumulated in each pixel of 1 and a signal based on the electric charge accumulated in each pixel of the line 2n is one frame period. That is, it is output from the first green light image sensor 111 every 1/60 seconds.

  On the other hand, at the time of double-speed shooting in FIG. 2B, the readout control unit 101 selects pixel selection signals for selecting only pixels on odd-numbered lines, that is, the pixels on line 1 sequentially from left to right. Then select each pixel in line 3 sequentially from left to right, then select each pixel in line 5 sequentially from left to right, and then each pixel in line 2n-3 sequentially left From the left side to the right side, and then a pixel selection signal for selecting each pixel of the line 2n-1 sequentially from the left side to the right side is generated every 1/120 second, which is one frame period during double-speed shooting. As a result, a signal based on the charge accumulated in each pixel of line 1, a signal based on the charge accumulated in each pixel of line 3, a signal based on the charge accumulated in each pixel of line 5,..., Line 2n− 1 frame image composed of n lines of only odd-numbered lines, comprising a signal based on the charge accumulated in each pixel 3 and a signal based on the charge accumulated in each pixel of line 2n-1. Is output from the first green light imaging element 111 every frame period, that is, every 1/120 second. In this way, at the time of double speed shooting, the image of one frame is read out at a speed twice as high as normal by thinning the line of the image sensor in half.

FIG. 3 is a diagram illustrating pixel selection signals for the first green light imaging element 111 and the second green light imaging element 112 during double-speed shooting. The first green light imaging element 111 in FIG. 3A is as shown in FIG. In FIG. 3B, the readout control unit 101 selects a pixel selection signal for selecting only the pixels on the even-numbered line, that is, each pixel on the line 2 as a pixel selection signal for the second green light imaging element 112. Select sequentially from left to right, then select each pixel in line 4 sequentially from left to right, then select each pixel in line 6 sequentially from left to right, ... then line 2n- 2 pixels are sequentially selected from the left side to the right side, and then a pixel selection signal for sequentially selecting each pixel of the line 2n from the left side to the right side is 1/120 second, which is one frame period in double-speed shooting. Generate every time.
Although not shown, the readout control unit 101 uses the odd-numbered lines or even-numbered lines as pixel selection signals for the red-light image sensor 113 and the blue-light image sensor 114 as in FIG. A pixel selection signal for selecting only the pixel (which may be any) is generated every 1/120 second, which is one frame period at the time of double-speed shooting.

  FIG. 4 is a diagram illustrating an image signal related to the green light component G obtained based on the pixel selection signal of FIG. The image signal output from the first green light imaging element 111 in FIG. 4A is as shown in FIG. In FIG. 4B, a signal based on the charge accumulated in each pixel of the line 2, a signal based on the charge accumulated in each pixel of the line 4, a signal based on the charge accumulated in each pixel of the line 6,. 1 frame composed of n lines of only the even-numbered lines consisting of a signal based on the charge accumulated in each pixel of the line 2n-2 and a signal based on the charge accumulated in each pixel of the line 2n The second green light image sensor 112 outputs an image signal representing the first image every frame period, that is, every 1/120 second.

Next, the green image generation unit 102 will be described.
The green image generation unit 102 receives the image signal output from the first green light image sensor 111 and the image signal output from the second green light image sensor 112. The green image generation unit 102 outputs an image signal output from the first green light imaging element 111 for every frame period (1/120 seconds), that is, an image signal including n lines of only odd-numbered lines, From the image signal output from the second green light image sensor 112, that is, the image signal composed of only n lines of even-numbered lines, the green light component G is completely composed of all 2n lines ( An image signal representing an image (green image) of one frame (including all pixels) is generated. This will be specifically described below.

  FIG. 4C is a diagram illustrating an image signal output from the green image generation unit 102. When the green image generation unit 102 receives a signal based on the charge accumulated in each pixel of the line 1 (line 1 signal) and a signal based on the charge accumulated in each pixel of the line 2 (line 2 signal), These two signals are output in the order of line 1 signal and line 2 signal. Next, when a signal based on the charge accumulated in each pixel on line 3 (line 3 signal) and a signal based on the charge accumulated on each pixel on line 4 (line 4 signal) are input, the green image generation unit 102 Outputs these two signals in the order of line 3 signal and line 4 signal. The same applies to the following.

  In this way, an image signal corresponding to a complete green image of one frame, in which each signal is arranged in the order of line 1 signal, line 2 signal, line 3 signal,..., Line 2n-1 signal, line 2n signal. Are output from the green image generation unit 102 every frame period (1/120 seconds).

Next, the image composition unit 103 will be described.
The image composition unit 103 receives the image signal output from the red light image sensor 113, the image signal output from the blue light image sensor 114, and the image signal of the green image output from the green image generation unit 102. Is done. The image composition unit 103 interpolates the image signal from the red light image sensor 113 and the image signal from the blue light image sensor 114 to generate an image signal composed of 2n lines, and becomes 2n lines by interpolation. The red and blue image signals and the green image signal composed of 2n lines from the green image generation unit 102 are combined to perform processing of one frame image.

The interpolation process will be described.
FIG. 5 is a diagram illustrating an image signal related to the red light component R (the same applies to the blue light component B). As shown in FIG. 5A, the image signal from the red light image sensor 113 is the same as the image signal from the first green light image sensor 111 (FIG. 4A), and only the odd-numbered lines. N lines. For example, the image synthesis unit 103 performs interpolation to generate a signal of an even-numbered line sandwiched between two odd-numbered lines based on signals of two adjacent odd-numbered lines. As shown in FIG. 5B, an image signal composed of 2n lines is generated. Note that other methods may be used as the interpolation method.

  Thus, according to the present embodiment, it is possible to perform double-speed shooting with a frame rate of 120 frames / second. In addition, since the method of driving the two green light imaging elements 111 and 112 at alternate timings is not employed, noise due to interference of control signals for performing such driving does not occur, and good image quality is achieved. Can keep. In addition, since the odd-numbered lines from the first green light image sensor 111 and the even-numbered lines from the second green light image sensor 112 generate one frame of the green image, the resolution of the image sensor A green image with the same resolution can be obtained, and even if the two green light image sensors 111 and 112 have a characteristic difference, the characteristic difference is skipped by one line within one frame of the generated green image. Since it is difficult to recognize visually and does not manifest itself as flicker, image quality deterioration can be suppressed.

(Second Embodiment)
The image pickup apparatus of FIG. 1 may be configured to read out from the image pickup device using a pixel selection signal as described below at the time of double speed shooting.

  FIG. 6 is a diagram illustrating pixel selection signals for the first green light imaging element 111 and the second green light imaging element 112. In FIG. 6A, the readout control unit 101 uses, as a pixel selection signal for the first green light imaging device 111, a pixel selection signal for selecting half of all pixels in a zigzag manner, that is, line 1 and line 1 2, the first pixel (A) of line 1, the second pixel (B) of line 2, the third pixel (C) of line 1, the fourth pixel (D) of line 2, the fifth pixel of line 1, .. Are sequentially selected, and then for the lines 3 and 4, the first pixel of the line 3, the second pixel of the line 4, the third pixel of the line 3, the fourth pixel of the line 4, and the fifth pixel of the line 3 ,... Are sequentially selected, and then for the lines 5 and 6, the first pixel of the line 5, the second pixel of the line 6, the third pixel of the line 5, the fourth pixel of the line 6, and the fifth pixel of the line 5. Select pixels, ... and pixels in sequence, then ... line 2 -1 and line 2n, the first pixel of line 2n-1, the second pixel of line 2n, the third pixel of line 2n-1, the fourth pixel of line 2n, the fifth pixel of line 2n-1, ... A pixel selection signal for sequentially selecting pixels is generated every 1/120 second, which is one frame period during double-speed shooting.

  Similarly, in FIG. 6B, the readout control unit 101 uses a half of the pixels complementary to the pixel selected in FIG. 6A among all the pixels as a pixel selection signal for the second green light image sensor 112. A pixel selection signal for selecting a zigzag pattern, that is, for the lines 1 and 2, the first pixel (a) of the line 2, the second pixel (b) of the line 1, the third pixel (c) of the line 2, and the line 1st pixel (d), 5th pixel of line 2,... And pixels are sequentially selected, and then for line 3 and line 4, the first pixel of line 4, the second pixel of line 3, and the 4th pixel of line 4 3 pixels, the fourth pixel on line 3, the fifth pixel on line 4, and so on are sequentially selected, and then for line 5 and line 6, the first pixel on line 6, the second pixel on line 5, and the line 6 3rd pixel, 4th pixel on line 5, 5th pixel on line 6 .. Are sequentially selected, and then, for the lines 2n-1 and 2n, the first pixel of the line 2n, the second pixel of the line 2n-1, the third pixel of the line 2n, and the fourth of the line 2n-1 A pixel selection signal for sequentially selecting the pixels, the fifth pixel of the line 2n,... And the pixels is generated every 1/120 second that is one frame period at the time of double-speed shooting.

Here, the j-th pixel (j is a natural number) refers to the j-th pixel from the left in each line. Further, “complementary” means a complete image of one frame (green) consisting of all pixels by the pixels selected from the first green light image sensor 111 and the pixels selected from the second green light image sensor 112. Image).
In the following description, for the sake of convenience, in FIG. 6A, a set of pixels selected from line 1 and line 2 is a line 1 ′, a set of pixels selected from line 3 and line 4 is a line 3 ′,. In FIG. 6B, a set of pixels selected from line 1 and line 2 is referred to as line 2 ′, a set of pixels selected from line 3 and line 4 is referred to as line 4 ′,. To do.

  FIG. 7 is a diagram illustrating an image signal related to the green light component G obtained based on the pixel selection signal of FIG. In FIG. 7A, a signal based on the charge accumulated in each pixel of the line 1 ′, a signal based on the charge accumulated in each pixel of the line 3 ′, and a charge accumulated in each pixel of the line 5 ′. Corresponds to half of all pixels consisting of a signal, a signal based on the charge accumulated in each pixel of the line 2n-3 ′, and a signal based on the charge accumulated in each pixel of the line 2n-1 ′ An image signal representing an image of one frame composed of the zigzag n lines (a “line” for convenience) is output from the first green light imaging element 111 every one frame period, that is, every 1/120 second. Here, for example, looking at line 1 ′, pixel A (first pixel of line 1), pixel B (second pixel of line 2), pixel C (third pixel of line 1), pixel D (line 2). Signals of the respective pixels are arranged as in the fourth pixel).

  Similarly, in FIG. 7B, a signal based on the charge accumulated in each pixel of the line 2 ′, a signal based on the charge accumulated in each pixel of the line 4 ′, and accumulated in each pixel of the line 6 ′. Complementary to FIG. 7A, comprising a signal based on charges,..., A signal based on charges accumulated in each pixel of line 2n-2 ′, and a signal based on charges accumulated in each pixel of line 2n ′. An image signal representing an image of one frame composed of zigzag n lines (“lines” for convenience) corresponding to a typical pixel is the second green light imaging element 112 every one frame period, that is, every 1/120 second. Is output from. Here, for example, looking at line 2 ′, pixel a (first pixel of line 2), pixel b (second pixel of line 1), pixel c (third pixel of line 2), pixel d (of line 1) Signals of the respective pixels are arranged as in the fourth pixel).

  Based on the image signals from the first green light image sensor 111 and the second green light image sensor 112, the green image generation unit 102 is a complete 1 including all pixels, as in FIG. 4C. An image signal representing a green image of a frame is generated. The specific processing method is as follows.

  FIG. 7C is a diagram illustrating an image signal output from the green image generation unit 102. The green image generation unit 102 receives a signal (line 1 ′ signal) based on the charge accumulated in each pixel of the line 1 ′ and a signal (line 2 ′ signal) based on the charge accumulated in each pixel of the line 2 ′. Then, the signal of each pixel included in the line 1 ′ signal and the signal of each pixel included in the line 2 ′ signal are alternately rearranged, and the signal of each pixel is arranged in the actual line 1 pixel order. The arranged line 1 signal and the line 2 signal in which the signals of the respective pixels are arranged in the actual line 2 pixel order are output in this order. That is, a line 1 ′ signal configured in the order of pixel A, pixel B, pixel C, pixel D,... And a line 2 ′ signal configured in the order of pixel a, pixel b, pixel c, pixel d,. For the input, the line 1 signal configured in the order of pixel A, pixel b, pixel C, pixel d,... And the line 2 signal configured in the order of pixel a, pixel B, pixel c, pixel D,. Output is obtained.

  Similarly, when a signal based on the charge accumulated in each pixel on the line 3 ′ (line 3 ′ signal) and a signal based on the charge accumulated on each pixel on the line 4 ′ (line 4 ′ signal) are input. The green image generation unit 102 alternately rearranges the signal of each pixel included in the line 3 ′ signal and the signal of each pixel included in the line 4 ′ signal, so that each pixel in the actual line 3 is arranged in the order. The line 3 signal in which the pixel signals are arranged and the line 4 signal in which the signals of the respective pixels are arranged in the actual arrangement order of the pixels in the line 4 are output in this order. The same applies to the following.

  In this way, each signal is arranged in the order of line 1 signal, line 2 signal, line 3 signal,..., Line 2n-1 signal, line 2n signal, which is the actual arrangement order of each pixel. An image signal corresponding to a green image of one frame is output from the green image generation unit 102 every one frame period (1/120 seconds).

  FIG. 8 is a diagram illustrating pixel selection signals for the red light imaging element 113 and the blue light imaging element 114. As shown in FIGS. 6A and 6B, the pixel selection signal of the red light image sensor 113 is the same as the pixel selection signal of the first green light image sensor 111 of FIG. The pixel selection signal of the image sensor for image 114 is the same as the pixel selection signal of the image sensor for second green light 112 in FIG.

  FIG. 8C is a diagram illustrating an interpolation process of a pixel selection signal of the red light imaging element 113 illustrated in FIG. As shown in FIG. 8A, for the line 2, there are signals of the second pixel (B), the fourth pixel (D),..., But the first pixel (X), the fourth pixel. A signal of each pixel (Y),... Does not exist. Therefore, the signal of the pixel X is, for example, a signal of three pixels around it, that is, each signal of the pixel A (first pixel of line 1), pixel B, and pixel E (first pixel of line 3). Interpolate. The interpolation formula is, for example, X = (A + B + E) / 3. Similarly, the signal of the pixel Y is, for example, the signals of the four surrounding pixels, that is, the signals of the pixel B, the pixel C (third pixel of the line 1), the pixel D, and the pixel G (third pixel of the line 3). Interpolate using each signal. The interpolation formula is, for example, Y = (B + C + D + G) / 4. However, X, Y, A, B, C, D, E, and G represent values of pixel signals, respectively.

  Also in this embodiment, the same effect as the above-described embodiment can be obtained. In particular, since one frame of a green image is generated by mutually complementary pixels read out in a zigzag manner from the first green light image sensor 111 and the second green light image sensor 112, the resolution of the image sensor is the same. A green image can be obtained and even if the two green light image sensors 111 and 112 have a characteristic difference, the characteristic difference is dispersed by one pixel within one frame of the generated green image. Since it is difficult to recognize visually and does not become apparent as flicker, deterioration of image quality can be suppressed.

  Furthermore, since the red light image sensor 113 and the blue light image sensor 114 are also read out and interpolated in a zigzag manner, the resolution in the direction perpendicular to the lines for red and blue can be improved, and the image quality can be improved. .

  As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the scope of the present invention. It is possible to

  For example, the pixels read out from the first green light image sensor 111 and the pixels read out from the second green light image sensor 112 are pixels in which some pixels are thinned out from all the pixels and are complementary to each other. It suffices that the number of pixels to be read out is not necessarily the same (that is, half of the total number of pixels). Here, “thinning out” means that when two arbitrary regions having a predetermined area on the imaging surface are compared, the same number of pixels are non-selected pixels. For example, the first green light image sensor 111 selects pixels at a rate of 60 pixels per 100 pixels, and the second green light image sensor 112 selects pixels at a rate of 40 pixels per 100 pixels. May be. At this time, one frame period is not half of one frame at the time of normal shooting, but for example, a period corresponding to the image sensor for green light having a larger number of pixels to be read (however, it is longer than one frame at the time of normal shooting) (Short).

  In addition, an optical spatial filter that removes a component having a high spatial frequency may be inserted between the red light imaging element 113 and the blue light imaging element 114 and the prism 104. This is to prevent the high-frequency component from becoming noise because the pixels read out from the red-light image sensor 113 and the blue-light image sensor 114 are thinned out. The spatial filter is arranged so that the direction of the wave number of the high-frequency component to be removed is perpendicular to the direction in which pixels remaining after being thinned out (the horizontal direction in FIG. 3 and the oblique 45 ° direction in the figure). It is preferable that

  In addition, the readout method from the image sensor described as the second embodiment is based on the first green light image sensor 111, the odd-numbered pixels on the odd-numbered lines and the even-numbered lines on the even-numbered lines. An image of one frame made up of each pixel in the column is read out, and each pixel in the even-numbered column on the odd-numbered line and each of the odd-numbered column on the even-numbered line from the second green light image sensor 112 This is an example of a reading method for reading an image of one frame made up of pixels, and is not limited to this.

  DESCRIPTION OF SYMBOLS 101 ... Read-out control part 102 ... Green image production | generation part 103 ... Image composition part 104 ... Prism 111 ... 1st image sensor for green light 112 ... 2nd image sensor for green light 113 ... Image sensor for red light 114 ... Imaging for blue light element

Claims (2)

First and second green light imaging elements that capture green light component images;
An image sensor for red light that captures an image of a red light component;
An image sensor for blue light that captures an image of a component of blue light;
From the first image sensor for green light, an image of one frame consisting of pixels obtained by thinning out half of all the pixels is read out in a half time period when all pixels are read out, and the second green light is read out. One frame image consisting of pixels complementary to the pixels of the one frame image is read from the light image sensor during the period, and half of all the pixels are thinned out from the red light image sensor during the period. A readout control means for reading out one frame image composed of pixels and reading out one frame image composed of pixels obtained by thinning out half of all the pixels during the period from the blue light imaging device;
Based on the image read from the first green light image sensor and the image read from the second green light image element for each period, a one-frame green image having image information for all pixels is obtained. A green image generating means for generating;
Image synthesizing means for synthesizing the image read from the red light image sensor, the image read from the blue light image sensor and the green image generated by the green image generating means into one frame image for each period;
Equipped with a,
The readout control means includes an image of one frame including each pixel in the odd-numbered column on the odd-numbered line and each pixel in the even-numbered column on the even-numbered line from the first green light image sensor. And reading from the second image sensor for green light one frame image composed of each pixel in the even-numbered column on the odd-numbered line and each pixel in the odd-numbered column on the even-numbered line. An imaging apparatus characterized by the above. The readout control means sequentially reads out from the red light imaging device and the blue light imaging device in the same readout order as any one of the first or second green light imaging device. The imaging device according to claim 1 .

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