JPH07222067A - Image input device - Google Patents

Abstract

PURPOSE:To obtain an image with high resolution regardless of employing an inexpensive solid-state image pickup element by moving the solid-state image pickup element within an image pickup area so as to receive the total images of the image pickup area and compositing the all images into one image. CONSTITUTION:A relative position between an object image and a solid-state image pickup element 42 is provided so that a movement nearly equal to one side of a light receiving area of the solid-state image pickup element 42 is provided in horizontal and vertical directions by a drive mechanism 45. An image composition memory 53 has a capacity by image data of one pattern (image pickup area) read when the solid-state image pickup element 42 is moved. When image data in an image buffer memory 50 are transferred to the image compositing memory 53, a control circuit 51 writes the data to an area of the image synthesis memory 53 corresponding to a determined position of one pattern. When the image data by one pattern are stored in the image synthesis memory 53, the content is sequentially read by the control circuit 51 and displayed on a high accuracy monitor 59.

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 for inputting image information, and more particularly to an image input device for inputting a high resolution image using a two-dimensional solid-state image pickup device.

[0002]

2. Description of the Related Art In order to obtain a high resolution image, a two-dimensional solid-state image pickup device has been proposed and provided with a large number of pixels and a large size. An image input device using a plurality of two-dimensional solid-state image pickup devices is disclosed in Japanese Society for Photography, Vol. 56, No. 2, "High-definition image input method for electronic camera", and JP-A-231589. Discloses a pixel shift method.

FIG. 9 is a block diagram showing an example of the configuration of a conventional apparatus, and is a block diagram of the configuration of the image input apparatus described in "High-definition Image Input Method for Electronic Cameras" Vol. is there. The optical image information entered through the imaging lens 1 is composed of two C images arranged at different positions.
It is incident on CDs 2 and 3 (hereinafter abbreviated as CCD 1 and CCD 2). At this time, CCD1 and CCD2 are the controller 10
It is driven by the CCD driver 11 which is controlled by. The outputs of CCD 1 and CCD 2 are amplified by amplifiers 4 and 5, and then enter A / D converters 6 and 7 to be converted into digital image data. The outputs of these A / D converters 6 and 7 are stored in the frame memories 8 and 9, respectively.

The frame memories 8 and 9 are the controller 10
Is read out by the following, and enters the relative position detection unit 12. Then, the relative position detection unit 12 detects the relative positional relationship (translation vector and rotation angle) between the two images. The interpolating unit 13 controlled by the controller 10 receives the output of the second frame memory 9 based on the translation vector and the rotation angle given by the relative position detecting unit 12, and combines the two images. Perform interpolation calculation. This interpolation unit 13
After being subjected to the image enhancement processing by the enhancer 14, the output of is input to the image combining unit 15. Image combiner 15
Combines the output of the frame memory 8 and the output of the frame memory 9. The combined image is displayed on the display 16.

FIG. 10 is a block diagram showing another example of the configuration of the conventional apparatus, which is a block diagram of the image input apparatus described in Japanese Patent Laid-Open No. 231589. An optical image entered from the image pickup lens 21 arranged on the optical axis OA enters the solid-state image pickup element 22, but in this example, a parallel plate glass 25 is arranged between the image pickup lens 21 and the solid-state image pickup element 22. There is. The parallel flat plate glass 25 can be slightly rotated in the X-axis direction and the Y-axis direction by the drive devices 26a and 26b controlled by the control device 34. The solid-state image sensor 22 is a photoelectric conversion pixel (pixel)
Are arranged two-dimensionally, and a color separation filter F having vertical stripes of three primary colors of R, G, B is provided on the surface thereof. The solid-state imaging device 22 is driven by a drive circuit 23 controlled by the control device 34.

The output signal from the solid-state image pickup device 22 is sampled and held by the subsequent color separation circuit 24a and converted into a simultaneous signal of three primary colors. The output of the color separation circuit 24a enters the subsequent process circuit 24b, is subjected to various corrections, and then displayed on the monitor device 28 as a color image. Further, these three primary color signals are converted into digital signals by the A / D converter 29 and then stored in the image buffer memory 30. The image buffer memory 30 is 1 / horizontal in comparison with the pixel array of the solid-state image sensor 22.
The number of pixels is 3, and the number of pixels is the same in the vertical direction.

The data of one screen stored in the image buffer memory 30 is transferred to the image synthesis memory 31 of the next stage before being rewritten to the next screen. The image composition memory 31 is capable of storing data for three colors with the number of pixels doubled in the horizontal and vertical directions as compared with the pixel array of the solid-state image sensor 22. The image stored in the image synthesis memory 31 is scan-converted via the D / A converter 32 and displayed on the high-definition monitor 33 as a color image.

In this example, the parallel flat plate glass 25 is slightly rotated in the X-axis direction and the Y-axis direction to expand the image pickup range in the two-dimensional direction (pixel shift method), and an equivalent high resolution image processing apparatus. Has been realized. In this pixel shift method, a high resolution image can be obtained as necessary by changing the amount of movement equal to 1/2 or 1/4 of the pixel pitch.

[0009]

If the number of pixels and the size of the two-dimensional solid-state image pickup device are increased, the manufacturing yield is low. In addition, since the material cost is high, the two-dimensional solid-state image sensor becomes expensive,
There is a problem that the practical use including peripheral circuits is delayed and the IC used becomes expensive. In addition, in the image input device using the plurality of two-dimensional solid-state image pickup elements shown in FIG. 9, an optical system for providing a portion for distributing light rays is required, which causes an increase in the size of the optical system. The light intensity of is reduced.
Further, each circuit is required as many as the number of two-dimensional solid-state image pickup devices, and it is necessary to make a fine adjustment of the plurality of circuits to obtain an equivalent signal.

Further, in the pixel shift method shown in FIG.
A high-resolution optical system is required, and the subject image and the aperture ratio of the two-dimensional solid-state imaging device (ratio of pixel area to total light receiving area) are affected. When the aperture ratio is high, the sensitivity is high, but the number of divisions is small. When the aperture ratio is low, the sensitivity is low, but the number of divisions is large.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an image input apparatus capable of obtaining a high resolution image by using an inexpensive solid-state image pickup device.

[0012]

According to the present invention for solving the above-mentioned problems, an image pickup optical system for picking up an image of a subject, and a two-dimensional solid-state image pickup device for receiving light in an area smaller than the image pickup area of the image pickup optical system are provided. The solid-state imaging device includes a moving unit that moves in a two-dimensional direction and an image reading unit that reads an output of the solid-state imaging device. The feature is that all images are input and combined into one image.

[0013]

By using a small two-dimensional solid-state image pickup device, the entire image pickup area is moved relatively to read the image in the entire area, and the read image is combined into one image. As a result, the solid-state image sensor can be inexpensive, and a high resolution image can be obtained.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, 41 is an image pickup optical system for picking up a subject image, 42 is a solid-state image pickup device (for example, CCD) in which photoelectric conversion pixels (pixels) are two-dimensionally arranged, and 43 is a timing for reading charges generated in the solid-state image pickup device 42. An image pickup element drive circuit for controlling the above, etc., a preprocessing circuit 44 for performing processing such as amplifying the output of the solid state image pickup element 42, 4
Reference numeral 5 is a drive mechanism for relatively moving the solid-state image pickup element 42 within the image pickup area.

Reference numeral 46 is a synchronizing signal generating circuit for giving a timing signal to the image pickup device driving circuit 43 and the preprocessing circuit 44, and 4
7 is an A / D converter (A / D converter) for converting the output of the preprocessing circuit 44 into digital data, and 48 is the A / D converter.
A digital signal processing circuit for applying various signal processing to the output of the converter 47, a buffer memory interface 49 for receiving the output of the digital signal processing circuit 48, and a digital signal processing circuit 50 sent through the buffer memory interface 49. An image buffer memory for temporarily storing 48 outputs.

Reference numeral 51 is a control circuit for controlling each component, and for example, a CPU is used. 52 is a synthetic memory interface for receiving the output of the image buffer memory 50;
3 is an image composition memory for storing one composite image, 54
Is a D / A converter (D / A converter) that converts the output of the digital signal processing circuit 48 into an analog signal, 55 is an image signal processing circuit that processes the output of the D / A converter 54, and 58 is the image It is a monitor that displays the output of the signal processing circuit 55. Bidirectional transmission of signals is performed between the composition memory interface 52 and the image composition memory 53.

Reference numeral 56 denotes a D / A converter (D / A converter) for converting the output of the image synthesis memory 53 sent through the synthesis memory interface 52 into an analog signal, 5
Reference numeral 7 is an image signal processing circuit that receives the output of the D / A converter 56 and performs signal processing, and 59 is a high-definition monitor that displays the output of the image signal processing circuit 57. The control circuit 51 controls the overall operation of this embodiment. The operation of the apparatus configured as described above will be described below.

The subject image is formed on the light receiving surface of the solid-state image pickup device 42 through the image pickup optical system 41. The relative position between the subject image and the solid-state image sensor 42 is given by the drive mechanism 45 so that the movement is approximately equal to one side of the light-receiving area of the solid-state image sensor 42 in the horizontal and vertical directions. The subject image is photoelectrically converted by the solid-state image pickup device 42 driven by the image pickup device drive circuit 43 that controls charge accumulation and readout scanning, and is output as an image signal.

This image signal passes through a preprocessing circuit 44 including an output amplifier and is sent to an A / D converter 47 to be converted into a digital image signal. This digital image signal is
Various corrections (for example, shading correction, density correction, etc.) are performed by the digital signal processing circuit 48, and are stored in the image buffer memory 50 having a storage capacity of one solid-state image sensor 42 through the buffer memory interface 49. .

On the other hand, from the output of the digital signal processing circuit 48, a digital image signal is sent to the D / A converter 54 for image output and converted into an analog image signal. The converted analog image signal is subjected to predetermined image processing by the subsequent image signal processing circuit 55, and then sent to the monitor 58 and displayed on the monitor.

The image data for one image of the solid-state image pickup device 42 stored in the image buffer memory 50 is transferred to the image synthesis memory 53 through the synthesis memory interface 52 before being rewritten on the next screen. The image synthesizing memory 53 has a capacity of image data for one screen (image capturing area) that the solid-state image sensor 42 moves and reads.
Here, when transferring the image data of the image buffer memory 50 to the image composition memory 53, the control circuit 51 writes the image data in an area of the image composition memory 53 corresponding to a fixed position of one screen (imaging area).

When one screen of image data is stored in the image composition memory 53, the control circuit 51 sequentially reads out the contents of the image composition memory 53 via the composition memory interface 52 and supplies it to the D / A converter 56. The D / A converter 5
Reference numeral 6 converts the input image data into an analog image signal. The analog image signal of the D / A converter 56 is subjected to predetermined image processing by the subsequent image signal processing circuit 57, and then enters the high precision monitor 59 and is displayed on the monitor.

Next, details of the drive mechanism 45 will be described in detail. FIG. 2 is a diagram showing a configuration example of the image pickup element drive mechanism. The same parts as those in FIG. 1 are designated by the same reference numerals.
In the figure, reference numeral 42 denotes a two-dimensional solid-state image pickup element, and a drive mechanism 45 for moving the solid-state image pickup element 42 in the X and Y two-dimensional directions is arranged below the solid-state image pickup element 42. A planar image can be obtained by moving the solid-state image sensor 42 in the X and Y two-dimensional directions. The drive mechanism 45 includes an imaging area 64.
Is controlled by the control circuit 51 so as to sequentially move from to and return to a predetermined reference position.

The solid-state image pickup device 42 mounted on the moving table 60 is moved in the image pickup area 64 which is divided by the two linear actuators 61 and 62 which are moved in the X and Y directions. You can do it. The divided imaging area 64 is a reference position for image reading, and before reading, exposure adjustment, white balance, and white balance are determined based on the output of the solid-state image sensor 42.
The imaging conditions such as focusing are set and the image is read. Note that such image adjustment may be performed not at the reference position but at other positions up to other areas. When the image adjustment is completed, the linear actuator 6
1, 62 to drive the solid-state image sensor 42 →→→
Move to → and read the image at each position. The image information read at these positions is stored in the image buffer memory 50, and moved to a predetermined position in the image synthesis memory 53 before the next image reading position comes.
When the solid-state image sensor 42 finishes reading the image at all positions up to, the image data of the entire area of the image pickup area 64 is stored in the image synthesis memory 53 as one image data. According to this embodiment, the solid-state imaging device 42 having a light receiving area which is 1/9 of the imaging area 64
Therefore, an inexpensive device can be provided.

FIG. 3 is a diagram showing another example of the structure of the image pickup device driving mechanism 45. The same parts as those in FIG. 2 are designated by the same reference numerals. In this embodiment, only one direction is shown. When driving in the two-dimensional direction, two sets of configurations shown in the figure are required. In the figure, when the pulse motor 70 is rotated, the rotational force is transmitted to the gear 72 via the gear 71 directly connected to the motor shaft, and the lead screw 73 directly connected to the gear 72 also rotates. When the lead screw 73 rotates, the moving table 74 moves linearly in the direction of the arrow in the figure. A guide pin 75 for ensuring the linear movement of the solid-state image sensor 42 mounted on the moving table 74 is provided on the opposite side of the moving table 74. That is, the solid-state image sensor 42 moves in the linear direction (the arrow direction in the drawing) along the lead screw 73 and the guide pin 75. When the drive pulse of the pulse motor 70 is changed in the forward and reverse directions, the solid-state imaging device 42 can move linearly in the right and left directions in the figure. The stop position and the moving amount of the moving table 74 are defined by the position detecting sensors 76 and 77 provided at both ends of the moving range.

FIG. 4 is a diagram showing another structural example of the image pickup device driving mechanism 45. The same parts as those in FIG. 2 are designated by the same reference numerals. This embodiment also shows the case of moving in one direction. A protrusion 80 is provided at one end of the solid-state image sensor 42, and a coil portion 82 is provided at the tip of the protrusion 80, and a direct current is applied. A portion 81 indicated by a broken line in the drawing
Constitutes a linear actuator, and when an exciting coil is driven, a magnetic field is generated, and an electromagnetic force acts on the coil portion 82 placed in the magnetic field. As a result, the solid-state image sensor 42
Moves along the guide pins 83 in the direction of the arrow in the figure.
The solid-state image sensor 42 can move to the right or left by changing the direction of the current flowing through the coil portion 82.

FIG. 5 is a diagram showing a main part of another configuration example of the image pickup device driving mechanism 45. In this embodiment, the pulse motor 70 shown in FIG. 3 is replaced with an intermittent feed mechanism, and a ratchet feed mechanism by a plunger 90 is used. The gear 91 is adapted to rotate in the direction of the arrow.
On the other hand, in the gear 91, one end of the spring 92 has a fixing pin 93.
Urging force is applied in the direction of the arrow in the figure. Therefore, when the plunger protrusion enters the plunger, the gear 91 rotates by one tooth. After that, the plunger protrusion comes out and rotation is blocked. Next, when the re-entered plunger protrusion enters the plunger, the gear 91 rotates by one tooth. In this way, the gear 91 is stepwise rotated in one direction.

6A and 6B show the solid-state image pickup device 42.
It is a figure which shows the mode of movement of. The same parts as those in FIG. 2 are designated by the same reference numerals. In (a), 64 is an imaging area, which is divided into 9 divided imaging areas 1
It consists of 01. A portion 100 surrounded by a broken line is a region covered by the actual solid-state image sensor 42, that is, an effective pixel area.

There is a reference position at the center of the image pickup area 64, and the solid-state image pickup element 42 moves in the order of →→→→ ... →. At the time of this movement, a part of the effective pixel area 100 surrounded by the broken line in the figure overlaps. By using this overlapping area, correction calculation of movement error in X and Y directions, rotation deviation, etc. is performed. This correction calculation is performed by the calculation / synthesis unit in the control circuit 51. Since the read image data up to are combined into one image by the correction calculation and the combination calculation of the calculation / combination unit, the drive mechanism 45 does not need to have a high positioning accuracy and is of high quality. Higher images can be combined.
Therefore, the drive mechanism 45 does not require high positioning accuracy, and thus the device can be easily assembled and inexpensive. Before moving the solid-state image sensor 42, for example, the output of the solid-state image sensor 42 is used at the reference position to perform image adjustment such as exposure adjustment, white balance, and focusing. At other positions, the read image is adjusted using the image adjustment value at this time. The position for image adjustment does not necessarily have to be the reference position, and may be another position (any of up to).

The example shown in FIG. 6B shows a case where the movement is performed with high accuracy. In this case, the effective pixel area 100 and the divided imaging area 101 match. When the movement is performed with high accuracy in this way, it is not necessary to perform the interpolation calculation using the overlapping area of the images, so that the image can be read at high speed.

If the moving accuracy of the solid-state image pickup element 42 is provided with an overlapping area of (a) and (b) and maintained at an intermediate accuracy, an overlapping area of the image is generated, but a correction calculation of the overlapping area is performed. It is also possible to combine the read image as it is into one image without performing. The deterioration of the quality of the read image is almost negligible, and high-speed image reading is possible.

FIG. 7 is a diagram showing another movement of the solid-state image pickup device 42. In the figure, 64 is an imaging area, and 11
0 is an effective pixel area, and 111 is a divided imaging area.
In this embodiment, the image pickup area 64 is composed of divided image pickup areas 111 which are vertically divided into two, and shows an embodiment in which a high-definition solid-state image pickup element is used. In high-definition, in consideration of the difference in aspect ratio (aspect ratio), the movement within the imaging area is shown when one screen is composed of two upper and lower screens. The high-definition solid-state image sensor 42 has an aspect ratio of 16: 9 (horizontal: vertical), and when it is formed into a square image, it is read by moving it so that it overlaps by 1/9 in the vertical direction, and image synthesis is performed. I'll do it.

FIG. 8 is a diagram showing another movement of the solid-state image pickup device 42. In the figure, 64 is an imaging area, 12
0 is an effective pixel area, and 121 is a divided imaging area.
In this embodiment, the solid-state image pickup element 42 is rotated within the divided image pickup areas with the point A as the center of rotation, and the image at each position is read. The solid-state image pickup device 42 rotates about a point A in the image pickup area 64 using a drive mechanism (not shown) for each turntable (not shown), reads an image at 90 ° intervals, and performs image composition. is there. That is, the image is read at the first point, and then the solid-state image sensor 42 is rotated by 90 ° in the direction shown in the figure, and brought to the position. Then, the image is read at the position of. Similarly, the solid-state imaging device 42 is sequentially
Rotate by 90 ° to read the image at each position. According to this embodiment, by rotating the solid-state image pickup element 42, it is possible to display the image of the divided image pickup areas 121
It is possible to synthesize images for individual pieces, which simplifies the drive mechanism.

In the above-mentioned embodiments, the case where the CCD is used as the solid-state image pickup element 42 is taken as an example. However, the present invention is not limited to this, and other types of solid-state imaging devices may be used. It goes without saying that the present invention can be applied not only to monochrome images but also to color images.

[0035]

As described in detail above, according to the present invention, an image pickup optical system for picking up an image of a subject, and a two-dimensional solid-state image pickup device for receiving light in an area smaller than the image pickup area of the image pickup optical system, An image pickup device driving mechanism for moving the solid-state image pickup device in a two-dimensional direction, and an image reading means for reading the output of the solid-state image pickup device are provided, and the solid-state image pickup device relatively moves in the image pickup area for image pickup. By inputting all the images of the area and synthesizing them into one image, it is possible to provide an image input device capable of obtaining a high-resolution image using an inexpensive solid-state imaging device.

[Brief description of drawings]

FIG. 1 is a configuration block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of an image sensor driving mechanism.

FIG. 3 is a diagram showing another configuration example of an image pickup element drive mechanism.

FIG. 4 is a diagram showing another configuration example of an image pickup device driving mechanism.

FIG. 5 is a diagram showing a main part of another configuration example of the image pickup device driving mechanism.

FIG. 6 is a diagram showing how the solid-state imaging device moves.

FIG. 7 is a diagram showing another state of movement of the solid-state imaging device.

FIG. 8 is a diagram showing another state of movement of the solid-state imaging device.

FIG. 9 is a block diagram showing a configuration example of a conventional device.

FIG. 10 is a block diagram showing another configuration example of a conventional device.

[Explanation of symbols]

 41 image pickup optical system 42 solid state image pickup device 43 image pickup device drive circuit 44 preprocessing circuit 45 drive mechanism 46 synchronization signal generation circuit 47 A / D converter 48 digital signal processing circuit 49 buffer memory interface 50 image buffer memory 51 control circuit 52 composite memory Interface 53 Image synthesis memory 54 D / A converter 55 Image signal processing circuit 56 D / A converter 57 Image signal processing circuit 58 Monitor 59 High-definition monitor

Claims (6)

[Claims] 1. An imaging optical system for imaging a subject, a two-dimensional solid-state imaging device for receiving light in an area smaller than an imaging area of the imaging optical system, and an imaging device drive for moving the solid-state imaging device in two-dimensional directions. A mechanism and an image reading means for reading the output of the solid-state image sensor, wherein the solid-state image sensor moves relatively in the imaging area,
An image input device, wherein all the images in the imaging area are input and combined into one image. 2. An image buffer memory for temporarily holding an image at each position of the solid-state image sensor, and an image composition memory for holding image data for one screen, and the image buffer memory stores the image data. 2. The image input device according to claim 1, wherein the image is moved to a predetermined position of the image synthesizing memory, and the images at the respective positions are synthesized to obtain one image. 3. A solid-state imaging device is moved relatively twice or more, and an arithmetic / synthesis means for performing arithmetic and synthesis for joining the images read at respective positions is provided, and the image is calculated by the arithmetic / synthesis means. The image input device according to claim 2, wherein one complete image is obtained on the composition memory. 4. The image input device according to claim 1, wherein the moving direction of the relatively moving solid-state imaging device is an X, Y two-dimensional direction. 5. The unit of movement of the relatively moving solid-state image pickup device is approximately 9 with the center of the image pickup area being the rotation axis position.
The image input device according to claim 1, wherein the image input device is 0 °. 6. Image adjustment such as focus adjustment, white balance adjustment, and exposure adjustment is performed with the solid-state image sensor placed in the central portion or its peripheral portion within the image pickup area, and the adjustment values at that time are used to determine other values. The image input device according to claim 1, wherein correction is performed when an image is read in the area.