JP2002051351A - Image pickup element and image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the scale and cost of a circuit. SOLUTION: In this image pickup element in which plural image pickup areas 201-204 are arranged on a substrate, the plural image pickup areas are respectively driven in different timings, and signals read from the plural image pickup areas 201-204 are switched and outputted, according to the driving timings.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device and an image pickup apparatus for picking up a subject image to generate a moving image or a still image.

[0002]

2. Description of the Related Art In recent years, with the spread of video cameras and electronic still cameras, there has been an increasing demand for miniaturization of devices. In particular, there has been an increasing demand for thinner devices in consideration of the convenience of carrying. ing. In the past, this problem has been dealt with by reducing the focal length of the photographing lens by downsizing the image sensor.

Here, the details of the conventional image pickup device will be described. FIG. 4 shows an arrangement of a color filter of a conventional ordinary imaging device. In FIG. 4, reference numeral 101 denotes a first color filter that transmits red light, and 102 denotes a second color filter that transmits green light. , 103 are third color filters that transmit blue light. As is clear from FIG. 4, in the ordinary image sensor, the first color filters 101 are arranged in odd rows starting from the first row of the photoelectric conversion elements corresponding to the two-dimensionally arranged photoelectric conversion elements. And the second color filter 102 are arranged alternately, and the second color filter 102 and the third color filter 1 are arranged in even rows starting from the second row of the photoelectric conversion elements.
03 are alternately arranged. Further, the second color filters 102 are arranged so as to be alternated in the odd rows and the even rows.

[0004]

However, in this method, for example, the pixel pitch is 10 μm and the number of pixels is 640 horizontal.
In the case of an image sensor having 480 pixels and 480 pixels vertically, the focal length of the lens that provides the standard angle of view is 8 mm, which is the diagonal length of the image sensor. It is difficult to reduce the thickness of the image pickup device to 8 mm or less because the photographing lens is configured by combining the above lenses. Furthermore, if the focal length is shortened by widening the angle of view, the obtained image tends to be distorted. Even in this case, since a plurality of lenses are combined to correct chromatic aberration and the like, there is a limit to thinning. there were.

[0005]

According to an image pickup device of the present invention, in an image pickup device having a plurality of image pickup areas on a substrate, each of the plurality of image pickup areas is driven at a different timing, and the image pickup element is driven in accordance with the drive timing. It is characterized in that signals read from a plurality of imaging areas are switched and output.

Further, the image pickup device of the present invention divides the image pickup area into a plurality of areas each including a plurality of pixels each outputting a color signal of the same color, and divides the image pickup area into a plurality of areas. And reading means for sequentially reading signals from the imaging area, and forming the reading means on the same substrate.

[0007] An imaging device according to the present invention includes the above-described imaging device according to the present invention, and a signal processing circuit that processes a signal output from the imaging device.

[0008]

In this embodiment, focusing on the arrangement of the color filters described in the conventional example, an image pickup area is divided for each color filter and formed on the same chip, and the divided image pickup areas correspond to the divided image pickup areas. We propose a method to achieve thinner by providing a lenslet array. FIG. 5 is a diagram showing a configuration of the imaging device of such an imaging device as viewed from the front. In FIG. 5, reference numeral 200 denotes an imaging device, 201 denotes a first imaging area, 202 denotes a second imaging area, and 203 denotes a second imaging area.
Is the third imaging area, 204 is the fourth imaging area, 21
Reference numerals 1, 212, 213 and 214 denote first, second, third and fourth imaging areas 201, 202, 203 and 204, respectively.
This is the output terminal from. A first color filter 221 that transmits red light is provided on the first imaging area 201.
However, the second and third color filters 222 transmitting green light are provided on the second and third imaging areas 202 and 203.
And 223, a fourth color filter 224 that transmits blue light is formed on the fourth imaging area 204. Each imaging area of the imaging device 200 has a horizontal 3
It has a photoelectric conversion unit of 20 pixels and 240 vertical pixels,
This output is subjected to pixel shift processing by an image processing circuit at the subsequent stage, thereby obtaining a resolution equivalent to that of a conventional image sensor.

FIG. 6 is a front view of a lenslet array combined with the image pickup device 200. In FIG.
Reference numerals 2, 303, and 304 denote first, second, third, and fourth lenslets, respectively.

FIG. 7 is a diagram showing a configuration of an image pickup unit 400 in which an image pickup device 200 and a lenslet array 300 are combined, and FIG. 7A is a sectional view taken along aa 'of FIG. FIG. 7B is a sectional view taken along line bb 'of FIG. As shown in FIGS. 7A and 7B, the first lenslet 301 is arranged so as to form a subject image in the first imaging area 201. Similarly, the second lenslet 3
02 is arranged in the second imaging area 202, the third lenslet 303 is arranged in the third imaging area 203, and the fourth lenslet 304 is arranged in the fourth imaging area 204 so as to form the subject image. ing.

[0011] The imaging unit 400 configured as described above.
, The red component of the subject image is
1 and output from the first output terminal 211. Similarly, the green component of the subject image is photoelectrically converted in the second and third imaging areas 202 and 203, and the second and third output terminals 212 respectively. And 213, and the blue component of the subject image is
The signal is photoelectrically converted at 04 and output from the fourth output terminal 214.

FIG. 8 is a block diagram showing a configuration of an image pickup apparatus using the image pickup unit 400. In FIG.
1, 402, 403, and 404 are first, second, third, and fourth correlated double sampling circuits, 411, 41, respectively.
2, 413, 414 are first, second, third, and fourth gain control amplifiers, respectively, and 420 is an image processing circuit. In FIG. 8, first, second, third, and fourth correlated double sampling circuits 401, 402, and 4 output image signals of respective primary colors output from the imaging unit 400 in order to reduce noise.
After the correlated double sampling process is performed at 03, 404, the first, second, third, and fourth gain control amplifiers 411, 412, 413, 4, 4 have a predetermined signal amplitude.
At 14, the signal is amplified with a predetermined gain. Further, the image processing circuit 4
In 20, predetermined processing such as gamma conversion and matrix processing is performed and output as a video signal.

In the imaging unit described above, since the diagonal length of each imaging area on the imaging device 200 is 4 mm,
The focal length of each lenslet of the lenslet array 300 is 4 mm even when a standard angle of view is given, which is half that in the case where a normal imaging element is used. Furthermore, in each imaging area, since only the image of a single primary color component is photoelectrically converted, it is not necessary to consider chromatic aberration in the photographing lens, so that it is not necessary to combine lenses for correcting chromatic aberration, and the photographing lens is not required. Therefore, the thickness of the imaging device itself can be reduced.

Here, in the image pickup apparatus described above, the output from each image pickup area on the image pickup device 200 is subjected to correlated double sampling processing by first, second, third, and fourth correlated double sampling circuits. After applying, the first, second, third, and fourth gain control amplifiers amplify them, so they have the effect of gain variation between channels and have the drawback that temperature characteristics vary easily, This may lead to an increase in the number of parts and the number of parts.

Further, since the image processing circuit is also dedicated to the image pickup apparatus, an inexpensive image processing circuit generally used cannot be used as in an image pickup apparatus using a normal image pickup device. It may also increase costs.

Therefore, in the following, the effects of variations in circuit elements and variations in temperature characteristics are reduced without impairing the advantage of thinning by the above-described imaging device, the number of components is reduced, and a normal image processing circuit is also used. A method is proposed in which an inexpensive image processing circuit generally used together with an image sensor can be used.

Hereinafter, a detailed description will be given with reference to the drawings.

FIG. 1 is a block diagram showing the structure of an image pickup device used in the image pickup apparatus according to the present invention. In FIG. 1, the same components as those in FIG. In FIG. 1, reference numeral 500 denotes an image sensor according to the present embodiment, 501 denotes a rearrangement circuit, and 502 denotes an output terminal. FIG. 2 is a timing chart showing a state of driving a pulse for driving the image pickup device 500 in the horizontal direction. In FIG. 2, H1 denotes a horizontal drive pulse of the first image pickup area 201,
H2 is a horizontal drive pulse of the second imaging area 202, H3
Is a driving pulse of the third imaging area 203, H4 is a horizontal driving pulse of the fourth imaging area 204, R is an output signal of the first imaging area 201, and Gr is a second imaging area 202.
Gb is the output signal of the third imaging area 203, B is the output signal of the fourth imaging area 204, Sout
Is an output signal of the image sensor.

The operation will be described with reference to FIG. At the beginning of the odd-numbered column drive period in FIG. 2, a vertical drive pulse V12 for the first and second imaging areas is applied to the image sensor, and the image sensor is driven by one column in the vertical direction. Subsequently, the first horizontal driving pulse H1 and the second horizontal driving pulse H2 are alternately applied, so that the first imaging area 201 and the second imaging area 20 are applied.
2 are alternately read. During the odd-number column driving period, the rearranging circuit 501 alternately switches the output signals R and Gr from the first and second imaging areas to output the output signal 50.
Output from 2.

On the other hand, at the beginning of the even-numbered column drive period, a vertical drive pulse V34 for the third and fourth image pickup areas is applied to the image pickup device to drive one column in the vertical direction. Subsequently, the signals from the third imaging area 203 and the fourth imaging area 204 are alternately read by alternately applying the third horizontal driving pulse H3 and the fourth horizontal driving pulse H4. During the even-number column driving period, the rearranging circuit 501 alternately switches the output signals Gb and B from the third and fourth imaging areas and outputs the signals from the output terminal 502. With the above configuration and driving method, the output signal from the image sensor 500 becomes equivalent to the output signal from the conventional normal image sensor 100.

FIG. 9 is a configuration diagram showing the configuration of the image pickup apparatus of the present invention more specifically, and a timing chart showing the operation thereof.

As shown in FIG. 9, first, pixel signals of the first row of the imaging area G1 and the imaging area B are inputted to the line memories 1 and 2 by the vertical shift register (V shift register) 1, respectively. (H shift register) The pixel signals from the first row of the imaging area G1 and the imaging area B are alternately output from the amplifier (Amp) 1 by alternately operating the H and H shift registers.

Next, the pixel signals of the first row of the imaging area R and the imaging area G2 are input to the line memories 1 and 2 by the vertical shift register (V shift register) 2, respectively. 2 are alternately operated so that the pixel signals from the first row of the imaging area R and the imaging area G2 are alternately amplified (Am).
p) Output from 1.

In this manner, signals on the second and subsequent rows of the imaging area G1 and the imaging area B, and signals on the second and subsequent rows of the imaging area R and the imaging area G2 are alternately output.

FIG. 3 is a block diagram showing the configuration of an image pickup apparatus using the image pickup device of the present invention. In the figure, 60
1 is a correlated double sampling circuit, 602 is a gain control amplifier, and 603 is an image processing circuit. An image signal output from the image sensor 500 is a correlated double sampling circuit 601.
After the noise is reduced by the above, the signal is amplified by the gain control amplifier 602 so as to have a predetermined amplitude, and is input to the image processing circuit 603. The image processing circuit 603 is a normal imaging device 10
This is a general circuit used in combination with 0, and the input image signal is subjected to predetermined processing such as gamma processing and matrix processing, and then output as a video signal.

In the above-described conventional imaging apparatus, the image processing circuit 42
Since the pixel shifting process performed at 0 is performed on the image sensor in this embodiment, no special circuit is required for signal processing.

[0027]

As described above, according to the present invention,
Enables processing using a single circuit element for correlated double sampling processing, etc.
In addition, the circuit scale and the cost of the circuit can be reduced, and an inexpensive imaging device can be obtained by using an inexpensive image processing circuit used in combination with a normal imaging device.

[Brief description of the drawings]

FIG. 1 is a block diagram of an imaging device used in an imaging device of the present invention.

FIG. 2 is a timing chart showing how a pulse for driving an image sensor is driven in the horizontal direction.

FIG. 3 is a block diagram illustrating a configuration of an imaging device according to the present invention.

FIG. 4 is a diagram in which color filters of a conventional ordinary image sensor are arranged.

FIG. 5 is a diagram showing a configuration of an image pickup device of a conventional image pickup apparatus as viewed from the front.

FIG. 6 is a front view of a lenslet array.

FIG. 7 is a diagram illustrating a configuration of a conventional imaging unit.

FIG. 8 is a block diagram illustrating a configuration of a conventional imaging device.

FIG. 9 is a configuration diagram more specifically showing the configuration of the imaging apparatus of the present invention and a timing chart showing its operation.

[Explanation of symbols]

100, 200, 500 Image sensors 101, 221 Color filters 102, 222, 223 that transmit red light Color filters 103, 224 that transmit green light Color filters 201, 202, 203, 204 that transmit blue light Imaging areas 211, 212, 213, 214, 502 Output terminal 300 Lenslet array 301, 302, 303, 304 Lenslet 400 Imaging unit 401, 402, 403, 404, 601 Correlated double sampling circuit 411, 412, 413, 414, 602 Gain control Amplifier 420, 603 Image processing circuit 501 Rearrangement circuit

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04N 1/028 H04N 5/335 F 5C051 5/335 V 5C065 H01L 27/14 BF term (reference) 2H054 AA01 2H083 AA26 4M118 AA10 AB01 BA10 BA13 DD10 FA06 GC08 GC20 GD02 GD07 GD20 5B047 AB04 BB04 BC05 BC07 CA06 CB17 5C024 BX01 CX00 DX01 DX04 EX42 GY11 GZ42 GZ46 GZ49 HX13 HX50 JX41 5C051 AA01 BA02 DA06 DB02 DB01 DB02 DB02 DB01 DB02 DB02 EE20 GG10 GG12 GG15

Claims (5)

[Claims] In an image sensor having a plurality of imaging areas on a substrate, each of the plurality of imaging areas is driven at a different timing, and a signal read from the plurality of imaging areas according to the driving timing is provided. An image pickup device characterized by switching and outputting. 2. A color filter is arranged on each of the imaging areas.
An image sensor according to claim 1. 3. The image sensor according to claim 2, wherein a lens array is arranged on the color filter. 4. An imaging area including a plurality of pixels each outputting a color signal of the same color, a plurality of imaging areas, each of which is divided into a plurality of areas, and a signal is sequentially output from each of the plurality of imaging areas for each area. An image pickup device comprising: reading means; and reading means formed on the same substrate. 5. An imaging apparatus comprising: the imaging device according to claim 1; and a signal processing circuit that processes a signal output from the imaging device.