JPH11225284A - Image input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the image input device from which an image with high image quality and high resolution is obtained regardless of only a few pixel number of a CCD by simultaneously conducting shake correction and pixel deviation. SOLUTION: A digital camera capable of pixel deviation and consecutive shots is made up of an image pickup element 23 that converts an image of a subject formed on a face of photographing pixels into an electric signal and outputs image data, a laminated piezoelectric element 24 that shifts the image pickup element 23 by a prescribed amount, a shake direction detection section 7 that detects a vertical shake of the subject image, a shake correction pixel shift direction decision section 8 that decides the shake correcting direction and the pixel shift direction based on the detection result by the shake direction detection section 7, and a system controller 30 that controls the laminated piezoelectric element 24 to shift the image pickup element 23 in the decided shake correcting direction and pixel shift direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image input device, and more particularly, to a digital still which inputs image data obtained by imaging a subject using a solid-state image sensor such as a CCD (Charge Coupled Device) image sensor. The present invention relates to an image input device such as a camera and a digital video camera.

[0002]

2. Description of the Related Art In this type of image input device, in order to perform continuous imaging, it is necessary to read out image data for each exposure and store it in a memory, and it is necessary to read out the image data in accordance with the number of pixels given to a solid-state imaging device. Times are different.

In particular, when a high-quality image is obtained, the number of pixels of the solid-state imaging device is set to be large, so that the readout time becomes long. For this reason, in recent years, a pixel shifting technique for achieving high image quality with a small number of pixels has been proposed.

Here, a conventional image quality improving method will be described. FIG. 6 is a timing chart for explaining the pixel shift timing according to the conventional example.

At the pixel shift timing shown in FIG.
Since the read time (TR) for reading image data from the CCD image pickup device is set, for example, in the range of 1/60 to 1/15 seconds, the time for releasing the electronic shutter when the first and second exposure times are constant. The interval, that is, the time interval of the timing to start reading the image data is a time obtained by adding the pixel shift time (TS) to the read time (TR). This pixel shift time (TS) is performed after the time (TF) for transferring charges from the photodiode to the vertical CCD.

On the other hand, in image input devices, miniaturization has become remarkable, and with the background of miniaturization of the imaging pixel surface size, development of high-density mounting technology, and development of a small recorder mechanical chassis, etc. Even models are appearing.

[0007] For example, when a small video camera is used, harmful shake of the screen due to camera shake of the photographer is likely to occur. Therefore, various anti-shake devices have been proposed in order to remove the shake and obtain a stable screen. If this kind of shake prevention device is used, not only harmful shake of the screen due to such shake, but also in situations where harmful shake cannot be removed using a tripod when shooting from a ship or a car, Needless to say, it has a great effect.

The shake preventing apparatus includes at least a shake detecting means for detecting a shake and a shake correcting means for performing some kind of correction so as to prevent a shake from occurring on the screen in accordance with the information on the detected shake. Is done.

As the shake detecting means, for example, an angular accelerometer, an angular velocity meter, an angular displacement meter and the like are known. In addition, as a shake correction unit, one using a variable apex angle prism,
A video camera configured to cut out an area actually used as a screen from the obtained imaging pixel plane information,
A method of sequentially changing the cutout position is known.

[0010]

However, in the conventional image input device, the prevention of image quality deterioration due to the blur correction and the high image quality due to the pixel shift are not performed at the same time. There is a problem that image quality and high resolution cannot be achieved.

In view of the above problems, the present invention provides an image input device capable of obtaining a high-quality and high-resolution image with a small number of CCD pixels by simultaneously performing blur correction and pixel shift. The purpose is to:

[0012]

Means for Solving the Problems The above-mentioned problems are solved,
In order to achieve the object, an image input device according to the present invention is an image input device capable of performing pixel shift and continuous image pickup, wherein an image of a subject formed on an image pickup pixel surface is converted into an electric signal to generate image data. An image sensor, an image sensor moving means for moving the image sensor by a predetermined amount, a blur detecting means for detecting a blur direction of the subject image, a blur correction direction and a pixel based on a detection result of the blur detecting means. A blur correction / pixel shift direction determining means for determining a shift direction;
In the determined blur correction direction and pixel shift direction,
Control means for controlling the image sensor moving means to move the image sensor.

An image input device according to a second aspect of the present invention is an image input device capable of performing pixel shift and continuous image pickup, wherein a subject image formed on an image pickup pixel surface is converted into an electric signal to output image data. An image sensor, an image sensor moving unit that moves the image sensor by a predetermined amount, a blur detecting unit that detects vertical blur of the subject image, and a blur correction direction and a pixel shift based on a detection result of the blur detecting unit. A device comprising: a shake correction / pixel shift direction determining means for determining a direction; and a control means for controlling the image sensor moving means to move the image sensor in the determined shake correction direction and pixel shift direction. It is.

According to a third aspect of the present invention, there is provided the image input apparatus according to the first or second aspect, wherein the blur correction direction and the pixel shift direction are the same, and the image pickup device moving means includes one of The blur correction and the pixel shift are performed simultaneously by the single movement operation.

According to a fourth aspect of the present invention, there is provided the image input apparatus according to any one of the first to third aspects, wherein the image pickup device moving means is a stacked piezoelectric element. is there.

According to a fifth aspect of the present invention, in the image input device according to any one of the first to fourth aspects, the moving amount of the image sensor due to the pixel shift is one pixel. Things.

[0017]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of an image input device according to the present invention. In FIG. 1, reference numeral 1 denotes a digital still camera (hereinafter referred to as a digital camera) which is an example of the image input device. Is shown.

The digital camera 1 shown in FIG. 1 can be roughly classified into an imaging block 2 for obtaining an analog image data by imaging a subject, and a digitalization of the analog image data obtained by the imaging block 2. And a signal processing block 3 for processing the converted digital image data and outputting the processed digital image data to the outside.

In the digital camera 1, an A / D converter 5 for converting image data from analog to digital is provided between the imaging block 2 and the signal processing block 3, and the signal processing block 3 has a mode (not shown). A signal generator 6 that generates a signal in response to an operation of a switch or the like and outputs the signal to the signal processing block 3 is connected.

The image pickup block 2 includes an image pickup lens 20 and an image pickup section 21 movably provided under the control of the signal processing block 3. The imaging unit 21 includes the imaging lens 2
A shutter mechanism (mechanical shutter) 22 for blocking light incident on the imaging lens 20 with an optical mechanism; a CCD (imaging element) 23 for receiving light incident on the imaging lens 20;
3 and a stacked piezoelectric element 24 that moves the light receiving surface of the CCD 23 in parallel with the image forming surface to change the image pickup range of the same subject to shift pixels and correct blur. The output of the CCD 23 is supplied to the A / D converter 5.

The signal processing block 3 includes, for example, a system controller 30, a sensor data output unit 31, a memory group 32 composed of a plurality of memories, and a pixel shift processing unit 33.
Etc.

The system controller 30 is connected to each unit of the image pickup block 2, such as the image pickup unit 21, the A / D converter 5, the sensor data output unit 31, the memory group 32, the pixel shift processing unit 33, and the signal generator 6. , An imaging operation, a strobe light emission operation, an A / D conversion, a memory read / write, a pixel shift, an operation according to a key input, and the like.

The system controller 30 is constituted by a microcomputer or the like, and controls the respective units and executes arithmetic processing by operating the microcomputer according to various programs stored in the ROM in advance.

The sensor data output section 31 is coupled to the output of the A / D conversion section 5 to input digital image data, and input digital data to any one of the memory groups 32 in the subsequent stage under the control of the system controller 30. Output image data.

The memory group 32 has a plurality of memories.
Under the control of the system controller 30, one memory is used for storing image data at one time of imaging, or digital image data is read from one memory and supplied to the pixel shift processing unit 33 at the subsequent stage.

The pixel shift processing section 33 performs a pixel shift process based on the digital image data supplied from the memory group 32. Specifically, the pixel shift processing section 33 performs a pixel shift when the imaging range is changed by the piezoelectric element 24. The image quality of the same subject is improved in accordance with the amount (for example, one pixel pitch), and finally one image data is obtained.

The output of the pixel shift processing section 33 is connected to an external terminal (not shown) and can be transmitted by connecting to an external device such as a personal computer.

The blur direction detector 7 is a circuit for detecting the vertical (up and down) blur of the image pickup pixel surface, and can use known means. For example, an angular velocity sensor or an angular acceleration sensor And so on. The blur correction / pixel shift direction determining unit 8 determines the direction of blur correction and one-pixel shift based on the detection result of the blur direction detection unit 7,
The result is output to the system controller 30. For example, when the blur direction is the upward direction, the blur correction / one-pixel shift direction is defined as the upward direction, and when the blur direction is the downward direction, the blur correction / one-pixel shift direction is defined as the downward direction.
That is, the blur correction direction and the pixel shift direction are set to the same direction.

The signal generator 6 includes a switch for operating the electronic shutter and the shutter mechanism 22 to perform imaging, a mode switch for setting various modes, and the like.

Next, the CCD (image pickup device) 23 will be described. FIG. 2 is a circuit diagram illustrating a configuration example of the imaging element 23 in the imaging block 2.

The image sensor 23 has a CCD 231 and a signal detector 232. The CCD units 231 are arranged in a matrix. The photodiodes PD ..., the VCCDs that transfer the charges in the vertical direction of the photodiodes PD ..., and the Hs that transfer the charges in the horizontal direction of the photodiodes PD ...
It has a CCD.

The photodiodes PD are optical lenses 20
Receives the light incident on it, performs photoelectric conversion,
Transfer charge to HCCD. The VCCD and HCCD output the transferred charges to the signal detection unit 232. The signal detection unit 232 converts the input charge into a voltage and outputs the voltage to the A / D conversion unit 5 as an image signal (analog image signal). In the present embodiment, all-pixel reading is adopted as the pixel reading type of the image sensor 23.

Next, the laminated piezoelectric element 24 will be described. FIG. 3 is a schematic configuration diagram showing a mounting structure of the laminated piezoelectric element 24 in the imaging block 2.

One end of the laminated piezoelectric element 24 has a substrate 26A.
And the other end supports an element holder 25 to which the imaging element 23 is attached. The element holder 25 is a piezoelectric element 24
Moves in the direction of arrow M, that is, in the vertical direction (vertical direction). The multilayer piezoelectric element 24 moves the image sensor in the vertical direction according to the mounting angle in the image pickup block 2 to perform blur correction and pixel shift (change of the image pickup range). By changing the mounting angle of the piezoelectric imaging device, it is possible to move the piezoelectric imaging device in a horizontal direction or a diagonal direction. In this case, the shake direction detection unit may detect shake in the horizontal direction or diagonal direction, and the multilayer piezoelectric element may perform shake correction and pixel shift in the horizontal direction or diagonal direction.

FIG. 4 is a schematic layout diagram showing the layout of main parts of the digital camera. In FIG. 4, reference numeral 40 denotes an exterior (housing) of the digital camera, reference numeral 41 denotes a release key for instructing imaging, reference numeral 20 denotes an imaging lens for forming a subject image, and reference numeral 42 denotes a finder objective lens. , 23 indicate an image sensor for outputting the formed subject image to image data, 24 indicates a stacked piezoelectric element for moving the image sensor up and down, and 43 indicates a finder eyepiece.

Next, a description will be given of the blur correction / pixel shift operation of the digital camera. First, a schematic operation of blur correction and pixel shift will be described. Prior to the exposure of the image sensor 23, the blur direction detector 7 detects the upper and lower blur directions of the subject image of the image sensor 23, and outputs the detection result to the blur correction / pixel shift direction determiner 8. Subsequently, based on the detection result of the blur direction detection unit 7, the blur correction / pixel shift direction determination unit 8 determines the blur correction direction of the image sensor and its correction amount and the pixel shift direction (the blur correction direction and the pixel shift direction are the same direction). ) And outputs the result to the system controller 30. The system controller and the roller 30 control the driving of the multilayer piezoelectric element 24 at the time of imaging based on the blur correction direction, the correction amount and the pixel shift direction, and
Is moved upward or downward. This operation is shown in FIG.
This will be described in detail based on the timing chart of FIG.

FIG. 5 is a timing chart for explaining the blur correction / pixel shifting operation. In the figure,
(A) is an opening / closing operation of a mechanical shutter and an exposure operation of an electronic shutter, (B) is a blur detection operation of a blur direction detection unit,
(C) shows an operation example 1 of the multilayer piezoelectric element, and (D) shows an operation example 2 of the multilayer piezoelectric element.

In FIG. 5, TR is a read time for reading image data from the image sensor, TS is a pixel shift time, TF is a time for transferring charges from the photodiode to the vertical CCD, and T is an exposure time by the electronic shutter. .

In this operation example, first, the continuous shooting timing is shortened by a combination of a mechanical shutter and an electronic shutter. In addition, by moving the image pickup device by operating the multi-layer piezoelectric element, camera shake correction and pixel The shift shooting is performed at the same time.

Prior to the exposure of the image sensor 23, the mechanical direction shutter is opened by the blur direction detector 7 (FIG. 5).
(See FIG. 5A), a blur detection operation is performed (see FIG. 5B), the upper and lower blur directions of the imaging pixel surface are detected, and the detection result is output to the blur correction / pixel shift direction determining unit 8. .
Subsequently, based on the detection result of the blur direction detection unit 7, the blur correction / pixel shift direction determination unit 8 determines the blur correction direction of the image sensor and its correction amount and the pixel shift direction (the blur correction direction and the pixel shift direction are the same direction). ) And outputs the result to the system controller 30.

At the same time that the exposure by the first imaging starts (see FIG. 5A), the system controller 30
Based on the determined blur correction direction and the correction amount, the imaging element 23 is moved by a predetermined amount during the first exposure period T in order to control the multilayer piezoelectric element 24 and correct the blur.
Then, after the first exposure is completed after the elapse of the exposure time T, the transfer in the image sensor 23 is performed. At the transfer timing, the pixel of the image sensor 23 is shifted by the piezoelectric element 24 under the control of the system controller 30 (one pixel).
(See FIGS. 5C and 5D).

After the transfer, the image data is written into the first imaging memory in the memory group 32 under the control of the system controller 30.

Then, after the completion of the pixel shift, the exposure by the second imaging is started. At this time, the time from the completion of the first exposure to the completion of the second exposure is 1 to 3 msec.
c. Also in the case of the second imaging, the exposure time is T, and the same exposure amount is obtained with the same exposure time as the first imaging. Simultaneously with the start of the exposure by the second imaging, the system controller 30 controls the multilayer piezoelectric element 24 to correct the blur by controlling the image sensor 23 based on the determined blur correction direction and the correction amount. The second exposure period T is moved by a predetermined amount. Then, after the second exposure is completed after the elapse of the exposure time T, the operation of the multilayer piezoelectric element 24 is stopped. When the second exposure time T elapses,
At that timing, the shutter mechanism 22 operates and closes (see FIG. 5A). The image sensor 23 is shielded from light by the optical mechanism of the shutter mechanism 22. Thereafter, the blur detection operation ends (see FIG. 5B).

The image data obtained in the second imaging is transferred in the same manner as in the first imaging when the next read signal is generated. Is controlled to write to different memories.

For example, as a result of the shake detection performed by the shake direction detection unit 7, when the shake from the top to the bottom of the subject image is predicted, as shown in FIG.
No. 4 performs shake correction and pixel shift in the direction of the 0 displacement state from the maximum variable state. On the other hand, when the shake is predicted from the bottom to the top as a result of the shake detection, as shown in FIG. 5D, the shake correction and the pixel shift are performed from the zero displacement to the maximum displacement direction.

As described above, in this embodiment, the blur direction detector 7 detects the vertical blur of the subject image, and the blur correction / pixel shift direction determiner 8
The system controller 3 determines a blur correction direction and a pixel shift direction based on the detection result of the blur direction detection unit 7.
0 indicates that the stacked piezoelectric element 24 is to move the image sensor 23 in the determined blur correction direction and the pixel shift direction.
Therefore, by simultaneously performing vertical camera shake correction and pixel shift, it is possible to obtain a high-quality and high-resolution image with a small number of CCD pixels and a simple mechanism.

Further, since the blur correction direction and the pixel shift direction are set to the same direction, and the blur correction and the pixel shift are simultaneously performed by one movement operation by the laminated piezoelectric element 24, the driving range of the image pickup element is minimized. And it is possible to perform pixel shift and blur correction in a short time.

Further, since the stacked type piezoelectric element is used as a means for moving the image pickup element, the apparatus can be reduced in size and responsiveness can be improved.
It becomes possible to drive with a small current and to cope with a high load.

Further, since the moving amount of the image pickup device due to the pixel shift is set to one pixel, an image shifted by one pixel can be obtained.

In the above-described embodiment, the moving direction (M) of the laminated piezoelectric element 24 is only one direction. However, the moving direction (M) is not limited to this. A plurality of stacked piezoelectric elements may be used.

Although the same exposure time is used for the first and second imagings, the present invention is not limited to this, and the second exposure time may be set longer than the first.

As described above, by using different exposure times between the first imaging and the second imaging, a plurality of images having different exposure amounts can be obtained by the same imaging a plurality of times. By combining the plurality of images, it is possible to obtain a high-resolution image with a high resolution and a wide dynamic range.

The present invention is not limited to the above-described embodiment, but can be implemented with appropriate modifications without departing from the spirit of the invention.

[0055]

As described above, according to the image input apparatus according to the first aspect, in an image input apparatus capable of performing pixel shift and continuous image pickup, a subject image formed on an image pickup pixel surface is converted into an electric signal. An image sensor that converts and outputs image data, an image sensor moving unit that moves the image sensor by a predetermined amount,
A blur detecting means for detecting a blur direction of a subject image; a blur correction / pixel shifting direction determining means for determining a blur correcting direction and a pixel shifting direction based on a detection result of the blur detecting means; and a determined blur correcting direction and pixel. In the shifting direction,
And control means for controlling the image sensor moving means to move the image sensor. By simultaneously performing camera shake correction and pixel shift, a high image quality can be obtained with a small number of CCD pixels and a simple mechanism. -A high-resolution image can be obtained.

According to a second aspect of the present invention, in the image input apparatus capable of performing pixel shift and continuous image pickup, the image of the subject formed on the image pickup pixel surface is converted into an electric signal to output image data. An image sensor, an image sensor moving unit that moves the image sensor by a predetermined amount, a shake detecting unit that detects a vertical shake of a subject image, and a shake correction direction and a pixel shift direction are determined based on the detection result of the shake detection unit. Since the blur correction / pixel shift direction determining means and the determined blur correction direction and the pixel shift direction are determined, the control means controls the image sensor moving means to move the image sensor. By simultaneously performing vertical camera shake correction and pixel shift, it is possible to obtain a high-quality and high-resolution image with a small number of CCD pixels and a simple mechanism.

According to a third aspect of the present invention, there is provided the image input apparatus according to the first or second aspect, wherein the blur correction direction and the pixel shift direction are the same, and the image pickup device moving means is provided in one time. Since the blur correction and the pixel shift are simultaneously performed by the moving operation, the driving range of the image sensor can be minimized, and the pixel shift and the blur correction can be performed in a short time.

According to a fourth aspect of the present invention, there is provided the image input apparatus according to any one of the first to third aspects, wherein the imaging element moving means is a stacked piezoelectric element. The element moving means can be miniaturized, responsiveness can be improved, and small current drive can be performed.
Further, it is possible to cope with a high load.

According to a fifth aspect of the present invention, in the image input device according to any one of the first to fourth aspects, the moving amount of the image pickup device due to the pixel shift is one pixel. Therefore, an image shifted by one pixel can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a digital camera according to the present embodiment.

FIG. 2 is a circuit diagram illustrating a configuration example of an image sensor according to the present embodiment.

FIG. 3 is a schematic configuration diagram showing a mounting structure of a piezoelectric element according to the present embodiment.

FIG. 4 is a schematic layout diagram showing an arrangement of main parts of the digital camera according to the present embodiment.

FIG. 5 is a timing chart for explaining a blur correction / pixel shifting operation.

FIG. 6 is a timing chart illustrating pixel shift timing according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Digital camera 2 Imaging block 3 Signal processing block 4 Strobe circuit 5 A / D converter 6 Signal generator 7 Blur direction detector 8 Blur correction / pixel shift direction determiner 21 Imager 22 Shutter mechanism 23 Imager 24 Piezoelectric element 25 Element folder 26A Substrate 30 System controller 31 Sensor data output unit 32 Memory group 33 Pixel shift processing unit

Claims (5)

[Claims] An image input device capable of performing pixel shift and continuous imaging, comprising: an imaging element that converts a subject image formed on an imaging pixel surface into an electric signal and outputs image data; An image sensor moving means for moving; a blur detecting means for detecting a blur direction of the subject image; a blur correction / pixel shifting direction determining means for determining a blur correction direction and a pixel shifting direction based on a detection result of the blur detecting means. In the determined blur correction direction and pixel shift direction,
Control means for controlling the image pickup device moving means to move the image pickup device. 2. An image input device capable of performing pixel shift and continuous imaging, comprising: an image sensor that converts a subject image formed on an image pixel surface into an electric signal and outputs image data; An image sensor moving means for moving; a shake detecting means for detecting a vertical shake of the subject image; and a shake correction / pixel shift direction for determining a shake correction direction and a pixel shift direction based on a detection result of the shake detection means. Determining means, in the determined blur correction direction and the pixel shift direction,
Control means for controlling the image pickup device moving means to move the image pickup device. 3. The apparatus according to claim 1, wherein the blur correction direction and the pixel shift direction are the same direction, and the image pickup device moving means simultaneously performs the blur correction and the pixel shift by one movement operation. 3. The image input device according to 2. 4. The image input device according to claim 1, wherein said image pickup device moving means is a stacked piezoelectric device. 5. The image input device according to claim 1, wherein an amount of movement of the image sensor due to the pixel shift is one pixel.