JP2003018446A - Imaging device and digital still camera employing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device that can obtain image data in matching with the resolution of a lens and enhance a read rate and the S/N. SOLUTION: The imaging device applies photoelectric conversion to an image of an object formed on an image pickup face to generate an image signal, and includes a pixel number change means to change a total number of pixels. The pixel number change means preferably comprises a thinning-out means that controls pixels from which an image is read and pixels from which no image is read depending on a position of an image pickup face and a mixing means that controls mixing of data of the pixels depending on the position of the image pickup face to change number of pixels.

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 a digital still camera using the image pickup device.

[0002]

2. Description of the Related Art Conventionally, when data is read from expensive pixels on the image pickup surface to create image data, the data is read from all the pixels arranged on the image pickup element as the image pickup surface to create image data. It was

For example, the number of pixels of image data obtained from an image pickup device having an image pickup surface of 1 million pixels is 1 million.

As described above, the number of pixels as the image pickup surface and the number of pixels when reading out as image data are the same.

However, in recent years, the price of pixels functioning as an image pickup surface has been reduced, and in an image pickup device having many pixels as an image pickup surface, it is not always necessary to read data from all the pixels actually arranged on the image pickup surface. Satisfactory image data can now be obtained without creating image data.

[0006]

Therefore, the inventor of the present invention
As a result of intensive studies aimed at effective use of pixels not used in a multi-pixel image pickup device, the present invention has been achieved. An object of the present invention is to obtain image data matched with the resolution of a lens and to read it. An object of the present invention is to provide an image sensor capable of improving the rate and the S / N ratio, and a digital camera using the image sensor.

Another object of the present invention is to provide an image pickup device and a digital camera using the image pickup device, which can obtain image data matched with the resolution of a lens and can improve the read rate without image quality deterioration. is there.

Another object of the present invention is to provide an image sensor and a digital camera using the image sensor, which can obtain image data matched with the resolution of a lens and can obtain image data in which other than the main subject is blurred. Especially.

Another object of the present invention is to obtain image data matched to the resolution of the lens, to improve the read rate without image quality deterioration, to change the aperture ratio, and to obtain sensitivity in a high dynamic range. It is an object of the present invention to provide an image sensor capable of freely changing the light intensity and correcting a peripheral light amount drop caused by a lens or a strobe, and a digital camera using the image sensor.

Another object of the present invention is to provide an image pickup device capable of switching between zooming and wide-angle shooting only by the structure of the image pickup device, and a digital camera using the image pickup device.

Another object of the present invention is to provide an image pickup device capable of continuous shooting and capable of obtaining a plurality of images with one exposure, and a digital camera using the image pickup device.

Other objects of the present invention will be clarified by the following description.

[0013]

According to a first aspect of the present invention for solving the above-mentioned problems, there is provided an image pickup device for photoelectrically converting a subject image formed on an image pickup surface to generate an image signal, The image pickup device is provided with a pixel number changing means for changing the total number of pixels.

According to a second aspect of the invention for solving the above-mentioned problems, the pixel number changing means is
2. A thinning means for controlling the pixels to be read out and the pixels not to be read out to change the number of pixels.
The image pickup device described in 1.

According to a third aspect of the invention for solving the above-mentioned problems, the pixel number changing means is
The image pickup device according to claim 1, comprising a mixing unit that controls the mixing of the data of each pixel to change the number of pixels.

According to a fourth aspect of the present invention for solving the above-mentioned problems, there is provided switching means for controlling a change in the number of pixels by the thinning means and a change in the pixel number by the mixing means according to the position of the image pickup surface. It is characterized by Claim 2 or 3
The image pickup device described in 1.

A fifth aspect of the present invention for solving the above-mentioned problems is an image pickup device for photoelectrically converting a subject image formed on an image pickup surface to generate an image signal, wherein
The image pickup device is characterized by having a conversion unit for controlling whether to read from the entire image or only from the central portion of the image.

A sixth aspect of the present invention for solving the above-mentioned problems is an image pickup device for photoelectrically converting an object image formed on an image pickup surface to generate an image signal, wherein pixels on the same image pickup surface are provided. The image pickup device is characterized in that it has a drive switching means capable of separately driving.

A seventh aspect of the present invention for solving the above problems is a digital still camera using the image pickup device according to the first to sixth aspects.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a cross-sectional view of essential parts showing an example of the image pickup device of the present invention. FIG. 1A is a diagram showing an image pickup surface.
(B) is a figure which shows the site | part which photoelectrically converts and transfers corresponding to an imaging surface.

1A and 1B, 1a and 1b
Is an image pickup surface, which receives an imaged object and performs photoelectric conversion. Reference numerals 2a, 2b ... Are charge storage portions provided corresponding to the image pickup surfaces 1a, 1b ..., and temporarily store the photoelectrically converted charges. 3a, 3b ... Are the charge storage portions 2a, 2b.
Is a vertical transfer path for reading out and transferring the electric charge accumulated in the fixed intervals, and 4 is the plurality of vertical transfer paths 3a, 3b ...
It is a horizontal transfer path for transferring the charges transferred from the outside to the outside of the image sensor.

The operation of the image pickup device will be described. The subject images formed on the image pickup surfaces 1a, 1b ... Are photoelectrically converted, and the charges generated by the photoelectric conversion by the image pickup surfaces 1a, 1b. In step 2, the accumulated charge is transferred to the horizontal transfer path 4 by the vertical transfer path 3 provided in parallel in the charge accumulating section at regular time intervals, and the charge transferred to the horizontal transfer path is further transferred horizontally. Image data is generated by being transferred from the path to the outside of the image sensor.

Here, the image data is data before the image of the subject is digitally converted, and is analog data.

A first aspect of the image pickup device according to the present invention is characterized by having a pixel number changing means for changing the total number of pixels, and preferably the pixel number changing means is an image pickup surface position. The thinning means for controlling the pixels to be read out and the pixels not to be read for changing the number of pixels, or the mixing means for controlling to mix the data of each pixel by the position of the imaging surface to change the number of pixels. Preferably, it has a switching means for controlling the change in the number of pixels by the thinning means and the change in the pixel number by the mixing means, depending on the position of the imaging surface.

In the present invention, changing the total number of pixels means that the number of image pickup surfaces 1a, 1b, etc. of the image pickup device does not match the number of pixel signals read from the image pickup device as a result of image pickup. Is.

In the present invention, the image pickup surface position means the position of each image pickup surface in the entire image pickup surface of the image pickup device.

In the present invention, changing the number of pixels means changing the total number of pixels.

The pixel number changing means of the present invention controls so as to create image data having a total number of pixels different from the total number of pixels of the image pickup surface, and reads all data of each pixel of the image pickup surface. It can be controlled by not providing it, or by controlling a plurality of data of each pixel on the imaging surface to be mixed and regarded as data for one pixel.

According to such a pixel number changing means, it is possible to obtain image data matched to the resolution of the lens and improve the read rate and the S / N ratio.

FIG. 2 is a diagram showing an example of a control flow by the thinning means, and FIG. 3 is a diagram for explaining thinning setting by the thinning means.

The thinning means for changing the total number of pixels by controlling the pixels to be read and the pixels not to be read according to the image pickup position will be described in detail below with reference to FIGS. 2 and 3.

In FIG. 2, when the thinning-out means is activated in taking an image, it is first judged whether or not there is an input of the lens setting to be used (S1), and it is judged that there is an input of the lens setting. Sets the lens (S
2).

On the other hand, if it is determined in S1 that the lens setting has not been input, the process proceeds to S3, which will be described later.

After S2, it is judged whether or not there is an input for thinning setting (S3), and if it is judged that there is an input for thinning setting, thinning setting is performed (S4).

On the other hand, if it is determined in S3 that the thinning setting has not been input, the process proceeds to S5, which will be described later.

After S4, it is judged whether or not there is an image pickup trigger (S5). If it is judged that there is an image pickup trigger, data is read out only from the pixel set as the read pixel in S2 and S4, Image data is created from the data (S6).

The lens setting in S2 is based on the data of the unread pixels corresponding to the shooting lens data input by the user from the shooting lens table in which the shooting lens data and the data of the unread pixels are stored in association with each other in advance. This is done by setting the pixels that are not read.

The photographic lens data is data for specifying the photographic lens, and includes, for example, data including the maker name and model number of the photographic lens, but is not particularly limited as long as the photographic lens can be specified. Not done.

By thus setting the lens, it is possible to obtain image data in which the influence of the change in the light amount due to the characteristic of the lens is suppressed.

The thinning setting in S4 is performed, for example, in FIG.
3A, when the user specifies the portion of the image position to be thinned out, the pixels are thinned out as shown in FIG. 3B to become the thinning target input by the user. The setting is such that pixels are not read according to the image position.

Further, according to the present invention, since the reading or non-reading is controlled according to the image pickup position, the obtained image data has a slope in the relationship between the output value and the incident light amount as shown in FIG. 4 (A). It will be. Therefore, when a pixel that is not thinned out and a pixel that is thinned out are adjacent to each other, an unnatural image is formed at the joint.

Therefore, it is preferable to add an offset to the output value. By doing so, as shown in FIG. 4 (B), the continuity of the output value with respect to the amount of incident light is maintained,
It is possible to prevent an unnatural image from appearing in an adjacent portion between pixels that are thinned out and pixels that are not thinned out.

By performing the thinning-out setting in this manner, the user can obtain the thinned-out images only by inputting the image positions to be thinned-out, which has the effect of simplifying the user's input. .

In the present invention, the input of the imaging trigger is
It is an input by some operation of the user indicating that shooting is performed, and examples thereof include input by an operation of pressing the shutter, but are not particularly limited.

According to such a thinning-out means, it is possible to obtain image data matched to the resolution of the lens and improve the reading rate without deterioration of the image quality.

FIG. 5 is a diagram showing an example of the flow of control by the mixing means, and FIG. 6 is a diagram for explaining the mixing setting by the mixing means.

The mixing means for changing the number of pixels by controlling the mixing of the data of each pixel according to the position of the image pickup surface will be described in detail below with reference to FIGS. 5 and 6.

In FIG. 5, when the mixing means is activated in taking an image, it is first determined whether or not there is an input of the lens setting to be used (S10), and it is determined that the lens setting is input. Sets the lens (S
11).

On the other hand, if it is determined in S10 that the lens setting has not been input, the process proceeds to S12, which will be described later.

After S11, it is judged whether or not there is an input for mixing setting (S12), and if it is judged that there is an input for mixing setting, the mixing setting is carried out (S13).

On the other hand, if it is determined in S12 that the mixed setting has not been input, the process proceeds to S14 described later.

After S13, it is judged whether or not there is an image pickup trigger (S14), and if it is judged that there is an image pickup trigger, the pixels set as the mixed pixels in S11 and S13 are pixel-mixed to obtain data. Read out and create image data from the data (S15).

In the pixel mixing of the present invention, the electric potentials of the image pickup surfaces 1a, 1b, ... (See FIG. 1) of the respective pixels to be pixel mixed are opened and the charges of the image pickup surfaces 1 are mixed in advance on the image pickup surface 1. It is possible to use a method of performing pixel mixing when transferring in a vertical transfer path, a method of performing pixel mixing when transferring in a vertical transfer path, or a method of performing pixel mixing when transferring in a horizontal transfer path like a vertical transfer path. The method is not particularly limited as long as it is a method that can obtain the data in which the data of the target pixel are mixed.

With reference to FIG. 7, an example of a method of performing pixel mixing when transferring in the vertical transfer path will be described.

FIG. 7A is a diagram showing the relationship between the photoelectric conversion portion and the vertical transfer path, and FIG. 7B is a diagram showing the state of charge transfer in the vertical transfer path. In the illustrated example, the photoelectrically converted charges are stored in the photoelectric conversion unit 2a at the position 2 of the vertical transfer path, and the photoelectric conversion unit 2b at the position 5 of the vertical transfer path.
An example is shown in which c is transferred to 8 parts of the vertical transfer path and photoelectric conversion part 2d is transferred to 11 parts of the vertical transfer path. As shown in FIG. 7B, the charges are transferred while the charges from the adjacent photoelectric conversion units are mixed as time passes.

The lens setting in S11 is performed by setting the pixel to be mixed corresponding to the photographing lens data input by the user from the photographing lens table in which the photographing lens data and the data of the pixel to be mixed are associated and stored in advance. This is done by setting pixels to be pixel-mixed based on the data.

Pixel mixing in S13 is performed by, for example, FIG.
When the user specifies a portion of the image position to be pixel-mixed as shown in a, the pixel-mixing target input by the user is set by setting the pixel to be pixel-mixed as shown in FIG. 6b. The pixel corresponding to the image position is set to be mixed.

Further, according to the present invention, the setting of whether or not the pixels are mixed is performed according to the image pickup position. Therefore, the obtained image data has a relationship between the output value and the incident light amount as shown in FIG. 4 (A). Will have a slope. For this reason, when a pixel that is not set to mix pixels is set to be adjacent to a pixel that is set to mix pixels, an unnatural image is formed at the joint.

Therefore, it is preferable to add an offset to the output value. By doing so, as shown in FIG. 4 (B), the continuity of the output value with respect to the amount of incident light is maintained,
It is possible to prevent an unnatural image from appearing in an adjacent portion between a pixel that is set to mix pixels and a pixel that is not set to mix pixels.

According to such a mixing means, it is possible to obtain image data that matches the resolution of the lens, and also obtain image data that blurs other than the main subject.

FIG. 8 is a diagram showing an example of the flow of control by the switching means.

The switching means for controlling the change in the number of pixels by the thinning means and the change in the pixel number by the mixing means according to the position of the image pickup surface will be described in detail with reference to FIG.

In FIG. 8, when the switching means is activated in taking an image, it is first determined whether or not there is an input of the lens setting to be used (S20), and it is determined that the lens setting is input. Sets the lens (S
21).

On the other hand, if it is determined in S20 that the lens setting has not been input, the process proceeds to S22 described later.

After S21, data is read from each pixel in the same manner as during image pickup (also referred to as preimage pickup) to create preimage pickup data (S22). It is determined whether or not there is (S23),
If it is determined that there is a deviation in the light amount, thinning-out setting by the thinning-out means or pixel mixing setting by the mixing means is performed as necessary (S24), and the process returns to the pre-imaging processing in S22.

On the other hand, if it is determined in S23 that there is no deviation in the light amount, it is determined whether or not there is an image pickup trigger (S25), and the data reflecting the setting in S24 is read out to obtain an image pickup image. Data is obtained (S26).

The thinning-out setting or the pixel mixing setting in S24 is performed by setting the thinning-out position by the method of setting to read out at the pixel pitch of the resolution limit of the lens and the mode setting.
There are a method of setting a mixing position, a method of recognizing an object and thinning it out, a method of setting a mixing position, and the like.
Explaining the method example of, as the characteristics of the lens,
The central resolution is higher than the peripheral resolution. If the lens is designed to match the central resolution, the surroundings will be over-spec. Therefore, this setting method is significant because it is meaningless to read many pixels in the periphery. Explaining the example of the method (1), for example, when the landscape mode is set, the upper side is empty, and therefore it is not necessary to read many pixels in the upper side, so this setting method is significant.
An example of the method will be described. For example, when a portrait is set, a process of increasing the resolution only in the center and blurring the periphery can be mentioned. As an example of the method (1), for example, thinning out a bright subject portion without contrast and performing pixel mixing for a dark subject portion without contrast.

Further, according to the present invention, since the setting for pixel mixing or the setting for thinning is controlled according to the image pickup position, the obtained image data has a relationship between the output value and the incident light amount as shown in FIG. 4 (A). Will have a slope. Therefore, when a pixel for which pixel mixing is set, a pixel for which thinning is performed, or a pixel for which normal reading is set is adjacent to each other, an unnatural image is formed at the joint.

Therefore, it is preferable to add an offset to the output value. By doing so, as shown in FIG. 4 (B), the continuity of the output value with respect to the amount of incident light is maintained,
It is possible to avoid an unnatural image in a portion adjacent to a pixel for which pixel mixing is set, thinning-out setting, or normal reading setting is performed.

According to such a switching means, another object of the present invention is to obtain image data matched to the resolution of the lens, improve the read rate without image quality deterioration, and change the aperture ratio. It is possible to change the sensitivity freely with a high dynamic range, and it is possible to correct the peripheral light falloff caused by the lens or strobe.

The second aspect of the image pickup device of the present invention is
An image pickup device for photoelectrically converting a subject image formed on an image pickup surface to generate an image signal, and a conversion means for controlling whether to read the same number of pixels from the entire image or only from the central portion of the image. It is characterized by having.

FIG. 9 is a diagram showing an example of the flow of control by the conversion means, and the switching means will be described in detail below with reference to FIG.

In FIG. 9, when the conversion means is activated in taking an image, it is judged whether an input for designating the wide angle or the zoom and an input of the magnification thereof are made (S30), and when all the inputs are made. Then, pixels to be thinned out are thinned out (S31).

After S31, it is judged whether or not there is an image pickup trigger input (S32). If it is judged that there is an image pickup trigger, an image is picked up from the data of only the pixels to be read based on the thinning setting in S32. Image data is created (S33).

The thinning setting in S31 determines whether to read the same number of pixels from the entire image or only from the central portion of the image depending on whether the image pickup is wide-angle image pickup or zoom image pickup. Such S31
The thinning-out setting is, for example, as shown in FIG. 10 when wide-angle shooting is designated when image data of 9 pixels is obtained in an image pickup device having 81 pixels on the image pickup surface as shown in FIGS. A process of deciding to read out 9 pixels from the entire image is performed, and when zoom photographing is designated, a process of deciding to read out 9 pixels only from the central portion of the image is performed as shown in FIG. In addition, at this time,
When 9 pixels are read from the pixel position between 0 and FIG. 10,
Continuous zoom photography is possible.

According to such a converting means, it is possible to switch between zooming and wide-angle shooting only by the construction of the image pickup device.

A third aspect of the image pickup device of the present invention is an image pickup device which photoelectrically converts a subject image formed on an image pickup surface to generate an image signal, and separately drives pixels on the same image pickup surface. It is characterized by having a drive switching means capable of performing the above.

FIG. 11 is a partial sectional view showing an example of an image pickup device having a drive switching means.

The drive switching means will be described in detail below with reference to FIG. 11. Reference numerals 4a, 4b ... Are image pickup surfaces and charge storage portions, 5a, 5b ... are vertical transfer paths, and 6
.. are horizontal transfer paths, and 7a, 7b, 7c are output amplifiers.

In the conventional image pickup device, one vertical transfer path is provided for one row of the image pickup surface and the charge storage section, and the charges from the one row of the image pickup surface and the charge storage section are sequentially passed through the vertical transfer path. However, the drive switching means of the present invention provides a plurality of vertical transfer paths for one row of the image pickup surface and the charge storage section to store the charges of the one row of the image pickup surface and the charge storage section. The control is performed so that the plurality of vertical transfer paths are sequentially transferred separately.

The drive switching means, for example, as shown in FIG. 11, sequentially transfers the image data obtained on the imaging surface and charge storage section 4a and the imaging surface and charge storage section 4d to the vertical transfer path 5a and the horizontal transfer path 6a. To output to the output amplifier 7a
Drive, and second drive for sequentially transferring the charges of the imaging surface and charge storage section 4b and the imaging surface and charge storage section 4e through the vertical transfer path 5b and the horizontal transfer path 6b, and outputting them by the output amplifier 7b.
Imaging surface and charge storage unit 4c and imaging surface and charge storage unit 4
The charge of f is sequentially transferred through the vertical transfer path 5c and the horizontal transfer path 6c, and is separately driven by the third drive for output by the output amplifier 7c, so that three types of image data are obtained almost at the same time.

For example, by obtaining three types of images with different exposure times and synthesizing the three types of images, high dynamic range photography is possible. Such image composition is based on image data taken at intermediate exposure times of images taken at three types of exposure times, based on data of images taken at the longest exposure time for a portion with insufficient light intensity. This is done by adopting the data of the image taken with the shortest exposure time for the part where the amount of light is very large.

At this time, since control is performed to synthesize images of three types of exposure, the obtained image data has a slope in the relationship between the output value and the incident light amount, as shown in FIG. 4 (A). Become. Therefore, when pixels having different exposure times are adjacent to each other, an unnatural image is formed at the joint.

Therefore, it is preferable to add an offset to the output value. By doing so, as shown in FIG. 4 (B), the continuity of the output value with respect to the amount of incident light is maintained,
It is possible to avoid an unnatural image in a portion adjacent to pixels having different exposure times.

According to the drive switching means, image data can be obtained by a plurality of drives, for example, three drives of the first drive, the second drive and the third drive, so that the plurality of drives can be obtained. Continuous shooting is possible by performing the steps with a slight time difference, and a plurality of images can be obtained with one exposure.

Further, it is preferable to produce a digital still camera by using the image pickup device of the first to third aspects, in order to obtain the above effects as a digital still camera.

[Brief description of drawings]

1A and 1B are cross-sectional views of a main part of an image sensor according to the present invention.

FIG. 2 is a diagram showing an example of a control flow by a thinning means.

3A and 3B are diagrams for explaining thinning setting by thinning means.

4A and 4B are diagrams showing a relationship between an incident light amount and an output value of an image sensor.

FIG. 5 is a diagram showing an example of a flow of control by a mixing means,

6A and 6B are views for explaining mixing setting by a mixing unit.

FIG. 7 is a diagram for explaining pixel mixing in a vertical transfer path.

FIG. 8 is a diagram showing an example of a control flow by a switching unit.

FIG. 9 is a diagram showing an example of a control flow by a conversion unit.

FIG. 10 is a diagram showing an example of pixels to be read when wide-angle shooting is designated.

FIG. 11 is a diagram showing an example of pixels to be read when zoom shooting is designated.

FIG. 12 is a partial cross-sectional view showing an example of an image sensor having drive switching means.

[Explanation of symbols]

1: Imaging surface 2a, 2b ...: Charge storage unit 3a, 3b ...: Vertical transfer path 4a, 4b ...: Horizontal transfer path 5a, 5b ...: Imaging surface and charge storage section 6a, 6b ...: Vertical transfer path 7a, 7b ...: Horizontal transfer path 8a, 8b ...: Output amplifier

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) H04N 1/387 101 H04N 1/387 101 5C076 5/335 5/335 F P // H04N 101: 00 101: 00 (72) Inventor Yasutsugu Nakagawa 2970 Ishikawa-cho, Hachioji, Tokyo Konica stock company (72) Inventor Hiroshi Hasegawa 2970 Ishikawa-cho, Hachioji, Tokyo Konica stock company (72) Inventor Koichi Yamaguchi Tokyo 2970 Ishikawa-cho, Hachioji City Konica Stock Company F-term (Reference) 2H054 AA01 5B047 AB02 BA03 BB04 BC15 CA05 CA07 CA14 CB05 CB09 DC13 5C022 AA13 AB31 AC42 5C024 BX01 CX39 GZ27 5C051 AA01 BA02 DA06 DB07 DB07 DB03 DB07 DB08 DB03 DB08 BB07

Claims (7)

[Claims] 1. An image pickup device for photoelectrically converting a subject image formed on an image pickup surface to generate an image signal, the image pickup device comprising pixel number changing means for changing the total number of pixels. 2. The image pickup device according to claim 1, wherein the pixel number changing means comprises thinning means for changing the number of pixels by controlling pixels to be read and pixels not to be read according to the position of the image pickup surface. 3. The image pickup device according to claim 1, wherein the pixel number changing means comprises a mixing means for changing the number of pixels by controlling the data of each pixel to be mixed according to the position of the image pickup surface. . 4. The image pickup device according to claim 2, further comprising a switching unit that controls a change in the number of pixels by the thinning unit and a change in the number of pixels by the mixing unit according to the position of the image pickup surface. 5. An image pickup device for photoelectrically converting a subject image formed on an image pickup surface to generate an image signal, wherein the same number of pixels is read out from the entire image or only from the central portion of the image. An image pickup device comprising a conversion unit for controlling. 6. An image pickup device for photoelectrically converting a subject image formed on an image pickup surface to generate an image signal, comprising drive switching means capable of separately driving pixels on the same image pickup surface. Characteristic image sensor. 7. A digital still camera using the image pickup device according to claim 1.