JP2984437B2 - Imaging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging device, and more particularly to a solid-state imaging device used in a high-sensitivity camera system.

[0002]

2. Description of the Related Art Conventionally, HDT has been used as a high-resolution image.
V (1920 × 1035 pixels), HR (1280 × 10
Standards such as 24 pixels) and SVGA (1204 × 768 pixels) have been proposed. As a high-resolution imaging device corresponding to such a standard, for example, CMD (Charge Modulation)
Device: charge modulation element) is known.

FIG. 8 shows a configuration of a CMD imager. In FIG. 1, a CMD1 serving as a pixel includes a drain, a gate, and a source. The CMD1 is connected in a horizontal direction by a gate selection line 2 of each pixel, and a source portion is connected in a vertical direction by a common source selection line 3. . The drain is a common electrode for all pixels.

The vertical scanning circuit 5 outputs a quaternary voltage corresponding to each operation of accumulation, read, reset and overflow to the gate selection line 2 at a predetermined timing. A potential corresponding to the accumulated charge of the pixel selected by the horizontal scanning circuit 4 and the vertical scanning circuit 5 is transmitted to a source and a vertical signal line, and a source follower circuit, a video signal line, and an amplifier connected to each signal line are transmitted. Is read out to the outside.

As described above, one of the features of the CMD1 is that a pixel from which data is read out can be arbitrarily selected by the horizontal scanning circuit 4 and the vertical scanning circuit 5 (hereinafter, XY addresses are possible). I have.

If an image is to be picked up by changing the number of pixels using an XY-addressable image pickup device such as the CMD described above, for example, a configuration shown in EG & G RETICON catalog RA2568N can be considered. The technique disclosed in this catalog divides a horizontal scanning circuit into a plurality of parts in order to read out data stored in an image sensor at high speed. However, depending on how the horizontal scanning circuit is divided, HDTV and HR may be used. , SVGA, etc., can be used for the purpose of imaging while changing the number of imaging pixels.

Hereinafter, description will be made with reference to FIG. This image sensor includes a plurality of horizontal scanning circuits 6 ₁ , 6 ₂ , 6 ₃ ,
6 _4, ..., it includes a 6 _n-1, 6 _n, the output terminal ₇₁ of the number fraction, 7 _2, 7 _3, 7 _4, ..., 7 _n-1, 7 _n are provided. In the example shown in the figure, the horizontal scanning circuits 6 ₁ and 6 ₂ , 6 ₃ and 6 ₄ ,..., 6 _n−1 and 6 _n are grouped, and the light receiving area is divided into four blocks. Each horizontal scanning circuit can scan at the same time, so that a four-fold frame rate can be obtained.

[0008]

As described above, in the related art, even if the number of imaging pixels can be changed in the related art, the number of pixels is fixed and the HDT is fixed.
The number of pixels of the imaging apparatus cannot be arbitrarily selected according to the number of pixels specified in standards such as V, HR, and SVGA. An object of the present invention is to provide an imaging device capable of selecting the number of imaging pixels according to a standard.

[0009]

That is, the present invention provides an X
Scanning means for scanning a plurality of XY-addressable imaging pixels arranged in the Y and Y directions, signal supply means for supplying a scanning start signal to the scanning means, and corresponding to receive a scanning start signal from the signal supply means. Selecting means for selecting a scanning start position of the scanning means, and scanning inhibiting means for inhibiting the scanning signal from propagating beyond a predetermined range for scanning by the scanning means. .

[0010]

According to the imaging apparatus of the present invention, there are provided a selecting means for selecting a scanning start position and a scanning inhibiting means for inhibiting the transmission of a scanning signal beyond a predetermined range. Since the scan start signal is provided to the scan start position selected by the selection means, the number of imaging pixels can be selected according to the standard.

Further, since a bidirectional buffer is used for the scanning means and the direction in which the scanning signal propagates can be selected by the scanning direction selecting means, a mirror image can be read.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic diagram of a horizontal scanning circuit, and FIG. 2 shows one element of a shift register group constituting the horizontal scanning circuit.

In FIG. 1, when a start pulse as shown in FIG.
The signal is input to the shift register elements 13 ₁ , 13 ₂ , and 13 ₃ via 12. When a start pulse is applied, pixel selection signals are sequentially output from the signal line 14 from the left side to the right side in FIG.

The input terminal 15 is a signal input terminal for inverting the scanning direction, inverter - are connected via the motor 16 and 17 in the shift register elements 13 _1. When a low-level signal is input to the input terminal 15, the switches 12 and 18 are switched to the illustrated side, and the start pulse is supplied from the shift register elements 13 ₁ , 13 ₂ and 13 _3. , The pixel selection signals become active sequentially from left to right. On the other hand, when a high-level signal is input to the input terminal 15, the switch 12 and the switch
18 is switched to the side opposite to the one shown, and the start pulse is applied via switch 18 to the shift register elements 13 ₄ , 1
3 _5, 13 are input to the _6. Then, the pixel selection signals become active sequentially from the right side to the left side in FIG.

Here, 13 ₁ to 13 ₆ and 13 ₂ to 13 ₅
To, from 13 ₃ to 13 _4, the number of each shift register element, HDTV respectively, HR, and corresponds to the number of pixels SVGA. That is, the shift register element 13
It is 1920 from each 13 ₁ 13 to _6, from 13 ₂
13 1280 up to _5, from 13 ₃ to 13 ₄ and a 1024 element.

The decoder 19 activates only the output signal line corresponding to the signal input from the input terminal 21 among the three output signal lines (A, B, C) 20. For example, if “01”, “10”, and “11” are added from the input terminal 21, “0” is output from the output signal line 20.
11 ”,“ 101 ”, and“ 110 ”are output. Three signal lines A, B, C is a shift register, respectively elements 13 ₁
And 13 ₆ , 13 ₂ and 13 ₅ , 13 ₃ and 13 ₄ , and are configured so that only the selected start pulse is valid. For example, when "01" is input to the input terminal 21, "011" is output from the decoder 19, and only the HDTV start pulse becomes valid.

[0017] Figure 2, the shift register element 13 ₂ or 13
₅ shows details. Outputs of the inverters 16 and 17 in FIG. 1 are input to input terminals 22 and 23, respectively. In FIG. 2, when scanning from left to right (hereinafter referred to as a normal mode), a high-level signal is input to the input terminal 22 and a low-level signal is input to the input terminal 23. . On the other hand, when scanning from the right side to the left side (hereinafter, referred to as a mirror image mode), a low-level signal is input to the input terminal 22 and a high-level signal is input to the input terminal 23.

Further, buffers 24, 25, 26 and 27, 28, 29 are connected to the input terminals 22 and 23, respectively. Of these, buffers 24 and 28 have AND gate 30
The signal from the signal line B or C of the output signal line 20 is input from the input terminal 32 via the input terminal 31 and the input terminal 31. Buffer 33 is
A start pulse is input from input terminal 34, and the inverter
Under the control of a control line 36 via 35, an output is supplied to a control line 38 via a buffer 37. In addition, switches 39 and 40
Are turned on and off by signals from the control lines 41 and 42, respectively.

Hereinafter, the normal mode will be described.
In this case, since a low-level signal is input to the input terminal 23, the buffers 27, 28, and 29 are all non-conductive. Now, assuming that the HR standard is selected, a low-level signal is input to the input terminal 32, the control line of the buffer 33 becomes high, and the buffer 33 becomes conductive. At this time, the start pulse is applied from the input terminal 34, is input to the buffer 25 via the buffer 33, and is supplied to each pixel output to the signal line 38 via the buffer 37. The buffers 25 and 26 are conductive because a high-level signal is input to the control line from the input terminal 22.
The switches 39 and 40 are turned on and off at predetermined timing by the control lines 41 and 42.

Next, the operation of shifting the start pulse will be described with reference to FIGS. FIG. 3 is a diagram extracting and showing a main part of the shift register element shown in FIG. 2, and FIG. 4 is a timing chart of the output of each part in FIG. In FIG. 3, 43, 44, 45,
46, 47 and 48 are buffers, 49, 50, 51 and 52 are switches, and a, b and X and Y are signal lines.

The buffers 44 and 45 in FIG. 3 correspond to the buffers 25 and 26 in FIG. 2, respectively, and the signal lines a and b correspond to the control lines in FIG.
The switches are turned on at a high level corresponding to 41 and 42, respectively. When a start pulse is applied, switch 49 turns on and off while the start pulse is high,
45 holds the high level. Next, the switch 50 is controlled to be turned on and off, the buffers 46 and 47 maintain the high level, and the selection signal Y to the adjacent pixel column goes high.

Next, when the switches 49 and 51 are turned on and off, the buffer 45 goes low and the buffer 48 goes high. Subsequently, the switches 50 and 52 are turned on and off, the buffers 46 and 47 go low, and the selection signal Y goes low. Further, when the switch 51 is turned on and off, the output of the buffer 48 becomes low. Thereafter, by repeating this operation, the start pulse supplied to the buffer 44 sequentially moves to the right in FIG.

Returning to FIG. 2, as a result of the AND operation between the high-level signal supplied from the input terminal 22 and the low-level signal supplied from the input terminal 32 by the AND gate 30, the control is performed. Since the line goes low, the buffer 24 is turned off. Therefore, a signal coming from the left side of the buffer 24 does not go to the right side beyond the buffer 24. Therefore, if the shift register element 13 is used as the right end of the 13 ₅ prohibits the pulse for the pixel selection advances to the right beyond the number of effective pixels of the HR.

Next, the case of the mirror image mode will be described. In the mirror image mode, a low-level signal is applied to the input terminal 22 and a high-level signal is applied to the input terminal 23. Therefore, all the buffers 24, 25, and 26 become non-conductive, and the buffers 27, 28, and 29 become effective.
However, when a low-level signal is applied to the input terminal 32 (for example, when HR is selected), a low-level signal is input from the input terminal 32 to the AND gate 31, so that the buffer 28 is turned off. It becomes. Thus, this time the shift register element 13 functions as a 13 _second left, the left side of the number of effective pixels of the HR does not advance pixel selection pulse. Further, when the shift register element 13 functions as the right end of the 13 _5, a start pulse applied from the input terminal 34,
Proceed to the left via buffer 27.

The circuits of the shift register element 13 located at the left end and the right end are configured as shown in FIGS. 5 and 6, respectively. In FIG. 5, the buffer corresponding to the buffer 27 in FIG. 2 is removed, and the input of the buffer corresponding to the buffer 24 is grounded. In FIG. 6, except for buffers corresponding to buffers 25, 26 and 29 of FIG.
In this configuration, the input of the buffer corresponding to the buffer 28 is dropped to the ground. The other configurations of the circuits in FIGS. 5 and 6 are the same as those shown in FIG. 2, and the description is omitted here.

In this embodiment, with the configuration described above,
It is possible to configure an imaging device in which horizontal pixels are scanned by the number of pixels corresponding to the selected standards such as HDTV, HR, and SVGA.

In the above-described embodiment, only the horizontal scanning circuit has been described. However, the vertical scanning circuit can be realized with the completely same circuit configuration.
It is possible to select an imaging pixel according to a standard such as V, HR, or SVGA. Next, a second embodiment of the present invention will be described.

In the first embodiment described above, the image sensor is H
Although the case where the number of pixels corresponds to a high-resolution image such as DTV, HR, and SVGA has been described, the present invention
The present invention is not limited to the above embodiment, and can be effectively applied to an image sensor having a smaller number of pixels.

Hereinafter, a second embodiment of the present invention will be described with reference to FIG. The optical system 53 forms an image of an external object (not shown) on the image sensor 54 according to the embodiment. At the same time, an image having a mirror image relationship with the image formed on the image sensor 54 by the half prism 55 is formed on the image sensor 56. The imaging devices 54 and 56 are arranged shifted by half a pixel, and by combining output signals from both imaging devices, a higher resolution image can be captured. Here, the images on the imaging devices 54 and 56 are in a mirror image relationship, but as described in the first embodiment, according to the present invention, scanning from the opposite direction can be easily realized.

As described above, conventionally, when a high-resolution image is obtained by shifting the pixels, the image is obtained by reflecting twice to avoid a mirror image. However, according to the second embodiment, One reflection is sufficient, and the size of the half prism can be reduced.

[0031]

As described above, according to the present invention, it is possible to provide an imaging apparatus capable of selecting the number of imaging pixels according to a standard.

[Brief description of the drawings]

FIG. 1 is a schematic circuit configuration diagram of a horizontal scanning circuit in a first embodiment of an imaging device according to the present invention.

FIG. 2 is a circuit diagram showing one element of a shift register group constituting the horizontal scanning circuit of FIG. 1;

FIG. 3 is a schematic circuit configuration diagram illustrating a main part of the shift register element illustrated in FIG. 2;

FIG. 4 is a timing chart of the output of each unit in FIG. 3;

FIG. 5 is a circuit configuration diagram of a shift register element located at the left end of FIG. 2;

FIG. 6 is a circuit configuration diagram of a shift register element located at the right end of FIG. 2;

FIG. 7 illustrates a second embodiment of the present invention, and is a diagram illustrating a schematic configuration of an imaging apparatus.

FIG. 8 is a circuit configuration diagram showing a CMD imager as a conventional imaging device.

FIG. 9 is a circuit configuration diagram of an image sensor showing a conventional imaging device.

[Explanation of symbols]

11, 15, 21, 22, 23, 32, 34 ... input terminals, 12, 18, 39,
40 ... switch, 13 (13 ₁ , 13 ₂ , 13 ₃ , ..., 13 ₄ , 1
3 ₅ , 13 ₆ ), 14 ... signal line, 16, 17, 35 ... inverter, 1
9 ... decoder, 20 ... output signal line, 24, 25, 26, 27, 28, 2
9, 33, 37 ... buffer, 30, 31 ... AND gate, 36, 38
... control lines.

Claims (2)

(57) [Claims] A scanning means for scanning a plurality of XY addressable imaging pixels arranged in the X and Y directions; a signal supply means for supplying a scanning start signal to the scanning means; and a scanning start from the signal supply means. Selecting means for selecting a scanning start position of the corresponding scanning means to receive a signal; and scanning inhibiting means for inhibiting the scanning signal from propagating beyond a predetermined range to be scanned by the scanning means. An imaging device characterized by the above-mentioned. 2. The imaging apparatus according to claim 1, wherein said scanning means is constituted by a bidirectional buffer, and further comprising scanning direction control means for controlling a scanning direction of said scanning means.