JP2000134528A - Method for positioning solid-state image pickup element and method for adjusting digital still camera and holding member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for positioning a solid-state image pickup element for improving positioning precision, and a method for adjusting a digital still camera. SOLUTION: A subject passing through a photographic lens is converted into an electric signal by using a CCD 5, and the image of the subject is displayed on a monitor MT based on an electric signal from the CCD 5, and the CCD 5 is moved so that the CCD 5 can be put into a prescribed positional relation with the photographic lens based on the image of the subject, and then the positional relation between the photographic lens and the CCD 5 is fixed. Thus, even when the part precision of the photographic lens or the CCD 5 is deteriorated, positioning precision can be improved in a final assembled state in which error factors are assembled based on the subject image outputted from the CCD 5. Therefore, an image with a further high quality can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting a solid-state imaging device and the like, and more particularly to a method for positioning a solid-state imaging device and the like for a digital still camera.

[0002]

2. Description of the Related Art For example, a digital still camera generally has a solid-state image pickup device for converting a subject image formed on a light receiving surface by an image pickup optical system into an electric signal. By the way, in recent years, the number of pixels of the solid-state imaging device tends to increase due to a demand for higher image quality by users,
Therefore, a digital still camera having a solid-state imaging device having 1,000,000 pixels or more has been developed and is already on the market.

[0003]

However, with the increase in the number of pixels of the solid-state imaging device, the following manufacturing problems have been highlighted. In a digital still camera according to the related art, positioning accuracy between an imaging lens of an imaging optical system and a solid-state imaging device is determined by an imaging lens, a solid-state imaging device, and an imaging unit that integrally holds the imaging lens and the solid-state imaging device. Was determined depending on the accuracy of the parts. Therefore, based on such component precision, a certain degree of positional deviation has occurred between the optical axis of the photographing lens and the center of the solid-state imaging device. Is relatively wide, and such a positional deviation did not cause a serious problem.

However, as the number of pixels of the solid-state image sensor increases, the resolution is improved, so that the allowable range of positional deviation between the optical axis of the photographing lens and the center of the solid-state image sensor decreases. More specifically, when a position shift occurs between the optical axis of the imaging lens and the center of the solid-state imaging device, an optical image is generally received by the solid-state imaging device through a peripheral portion of the imaging lens having poor optical characteristics. There is a possibility that an image is formed on the surface, which causes a reduction in the amount of light of the optical image through the peripheral portion and a reduction in resolution. Such a problem based on the optical characteristics of the photographing lens can be solved to some extent by using a high-performance photographing lens, but this increases the cost of the digital still camera and increases the size of the camera body. The problem arises.

On the other hand, the positional deviation between the optical axis of the photographing lens and the center of the solid-state image pickup device is caused by the accumulation of component shape errors and the like. Such a displacement cannot be drastically reduced. Therefore, some kind of positioning means is required instead of the positioning by improving the component accuracy.

Further, there is a problem that occurs in the solid-state image sensor of the digital still camera and the finder optical system. Specifically, there is usually a deviation between the optical axes of the imaging optical system and the finder optical system. Due to this deviation, the range of the object field visually recognized through the finder optical system is different from the range of the object field formed by the imaging optical system. This phenomenon is called parallax. If the parallax is large, there is a possibility that an image may be captured without a part of the subject visually recognized by the photographer via the finder optical system. In order to prevent parallax from occurring, the optical axes of the imaging optical system and the finder optical system may be made to coincide with each other. However, in a normal digital still camera, it is impossible to make the optical axes coincide with each other due to its structure. Have difficulty. Therefore, it is necessary to make the optical axes of the imaging optical system and the finder optical system parallel in order to keep parallax within an allowable range as a compromise solution.

On the other hand, in the digital still camera according to the prior art, the parallax is set within an allowable range and the finder field ratio is set to be small to some extent based on the accuracy of components such as a finder optical system. The finder field-of-view ratio is the ratio of the range of the object field visually recognized through the finder optical system to the range of the object field imaged by the imaging optical system.
Even if the parallax increases due to the non-parallel optical axes of the photographing optical system and the viewfinder optical system due to poor component accuracy, capture at least the entire subject viewed through the viewfinder optical system. Will be able to

However, when the finder field ratio becomes extremely small, the subject visually recognized through the finder optical system differs greatly from the subject to be imaged, and the photographer feels a sense of discomfort. However, if the parallax is large, the finder field-of-view has to be considerably reduced, so that an unnecessary object to which the photographer does not want to take an image is imaged, and as a result, pixels that image the unnecessary object are wasted. Would be used for Therefore, some means for suppressing parallax is required.

To solve such a problem, it is conceivable to provide a digital still camera with a position adjusting mechanism for a solid-state image sensor or a finder optical system. However, once the adjustment is completed, it is wasteful to provide a mechanism that is hardly used thereafter, and increases the cost of parts in the digital still camera. In addition, the size of the digital still camera may be increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the related art, and has as its object to provide a method of positioning a solid-state image sensor and a method of adjusting a digital still camera, which can further improve the positioning accuracy.

[0011]

In order to achieve the above object, a method for positioning a solid-state imaging device according to the present invention converts an object image passed through an imaging optical system into an electric signal using the solid-state imaging device. A step of displaying an image of a subject based on an electrical signal from the solid-state image sensor; and a step in which the solid-state image sensor has a predetermined positional relationship with respect to the imaging optical system based on the image of the subject. The method includes moving the solid-state imaging device and fixing a positional relationship between the imaging optical system and the imaging solid-state imaging device.

According to the method for adjusting a digital still camera of the present invention, a step of converting a subject image passed through an imaging optical system of the digital still camera into an electric signal using a solid-state image sensor; A step of displaying an image of a subject based on the electrical signal of the subject; and, based on the image of the subject, the finder optical system and the finder optical system so that the solid-state imaging device has a predetermined positional relationship. The method includes a step of moving at least one of the solid-state imaging devices and a step of fixing a positional relationship between the finder optical system and the solid-state imaging devices.

[0013]

According to the solid-state imaging device positioning method of the present invention, a step of converting a subject image passing through the imaging optical system into an electric signal using the solid-state imaging device, and an electric signal from the solid-state imaging device Displaying an image of a subject based on the image of the subject; and moving the solid-state imaging device such that the solid-state imaging device has a predetermined positional relationship with respect to the imaging optical system based on the image of the subject. And fixing the positional relationship between the imaging optical system and the solid-state imaging device, so that even if the accuracy of the components of the imaging optical system or the solid-state imaging device is low, the subject image output from the solid-state imaging device Based on this, the positioning accuracy can be improved in the final assembly state in which the error factors are combined, whereby a higher quality image can be obtained.

According to the adjustment method of the digital still camera of the present invention, the step of converting the subject image passed through the imaging optical system of the digital still camera into an electric signal using a solid-state imaging device; A step of displaying an image of a subject based on the electrical signal of the subject; and, based on the image of the subject, the finder optical system and the finder optical system so that the solid-state imaging device has a predetermined positional relationship. The method includes a step of moving at least one of the solid-state imaging elements and a step of fixing a positional relationship between the finder optical system and the solid-state imaging element. By adjusting the optical system, parallax can be suppressed as much as possible.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an assembly diagram of an imaging unit 10 that is assembled to a digital still camera. In FIG. 1, a unit body 1 provided with a photographic lens 2 as an image pickup optical system has a housing-like mounting portion 1a having open upper and lower surfaces on the back surface (upper surface in the drawing). An optical low-pass filter 3, a filter holder 4, and a CCD 5, which is a solid-state imaging device, are assembled in this order in the mounting portion 1a. The CCD 5 has a plurality of output terminals 5a extending from both sides toward the rear (upward in the figure). Through these output terminals 5a, electric signals obtained by converting an optical image are output. It has become so.

FIG. 2 is a perspective view showing a device for positioning a solid-state imaging device according to the present embodiment. In FIG. 1, the imaging unit 10 is attached to a rigid body (not shown) by attachment fittings 21 and 22. The CCD 5 is held by a holding member 23. More specifically, the holding member 23 has a connector portion (not shown) for receiving each output terminal 5a of the CCD 5 and electrically connecting to the output terminal 5a. By doing so, the CCD 5 is held by the holding member 23 and moves integrally.

The holding member 23 is supported by a driving device 24. The driving device 24 mounts a Y-direction driving body 24a and a Y-direction driving body 24a, which are movable vertically in small steps by a step motor (not shown) on a moving shaft 24b to which a holding member 23 is attached at an upper end. An X-direction driving body 24c and an X-direction driving body 24c that are driven in a horizontal direction (horizontal direction with respect to the imaging unit 10) by minute steps by a step motor (not shown) are mounted, and photographing is performed. Θ is rotated around the optical axis of the lens 2 at a small angle by a step motor (not shown).
And a driving body 24d.

The holding member 23 can output an image signal to the personal computer PC in a state where the CCD 5 is instructed. In the personal computer PC, an image can be displayed on the monitor MT based on the input image signal.

Next, an embodiment will be described in which the positioning of the CCD is performed using the positioning device according to the present embodiment when a digital still camera is manufactured. Note that the imaging unit 10
At the stage when the lens is mounted as shown in FIG. 2 using the mounting brackets 21 and 22, the center CTR of the chart CHT matches the optical axis of the photographing lens 2. In order to match the optical axis of the photographing lens 2 to such a center CTR, a master unit having almost the same design value as that of the master unit may be formed, and the position of the chart CHT with respect to the imaging unit may be determined using the master unit. Accordingly, when the optical axes of the imaging units 10 are fixed by the mounting brackets 21 and 22, the optical axes of the imaging units 10 coincide with the center CTR of the chart CHT.

Next, as shown in FIG.
While the D5 is held by the holding member 23, the personal computer P
The image of the chart CHT is displayed on the monitor MT of C. FIG. 3 is a diagram illustrating an example of an image displayed on the monitor MT. The intersection of the dotted lines displayed on the monitor MT is the center of the monitor MT and can be regarded as the optical axis of the photographing lens 2.

FIG. 3A shows an image based on the image signal from the CCD 5 before the position adjustment. FIG.
From the display shown in (a), it is understood that the position of the CCD 5 needs to be adjusted in the x, y, and θ directions. Therefore, the adjustment is first performed in the y direction. More specifically, when the holding device 23 is moved downward in the vertical direction by the y-direction driving body 24a and the image displayed on the monitor MT becomes as shown in FIG. The drive of 24a is stopped. Thus, the adjustment in the y direction is completed.

Further, according to the display shown in FIG.
As for No. 5, it is understood that position adjustment is necessary in the x and θ directions. Therefore, the adjustment is performed next in the x direction. More specifically, the holding device 23 is driven by the x-direction driving body 24c.
Is moved to the right in the horizontal direction, and when the image displayed on the monitor MT becomes as shown in FIG. 3C, the driving of the x-direction driving body 24c is stopped. This completes the adjustment in the x direction.

Further, from the display shown in FIG.
As for No. 5, it is understood that the position adjustment is required in the θ direction. Therefore, the adjustment is finally performed in the θ direction. More specifically, the holding device 23 is rotated clockwise by the θ-direction driving body 24d, and the positioning of the CCD 5 ends when the solid line of the chart CHT overlaps the dotted line. Note that the operation of the θ driver 24d may cause displacement of the CCD 5 in the x and y directions.
What is necessary is just to operate the 4c or y direction drive body 24a again. When the positioning is completed, an adhesive is injected to fix the CCD 5 to the mounting portion 1a of the imaging unit 1. Thereafter, the digital camera is completed by removing the holding member 23 and assembling necessary circuit components, a body, and the like.

As described above, the positional deviation between the optical axis of the photographing lens and the center of the CCD is suppressed by the accuracy of the conventional parts. On the other hand, according to the present embodiment, the parts errors are combined. Since the position of the CCD can be adjusted while viewing the image, more accurate positioning can be achieved. As a result, in the inspection process after the completion of the digital still camera, the rate of defective digital still cameras is reduced, and the yield is improved. In addition, according to the experimental results, x and x of the CCD adjusted based on the present embodiment are shown.
It was confirmed that the variation width in the y and θ directions was reduced to 1/18, 1/14, and 1/14, respectively, as compared with the conventional technology.

FIG. 4 is a diagram showing a method for adjusting parallax in a digital still camera according to the second embodiment. In FIG. 4, the imaging unit 10 is attached to the front camera body 6. A finder optical system 30 is temporarily assembled on the upper part of the front camera body 6. The CCD 5 of the imaging unit 10 is attached to a holding member 23 having the same connector as in the above-described embodiment. That is, the holding member 23 can output an image signal to the personal computer PC while holding the CCD 5. In the personal computer PC, an image can be displayed on the monitor MT based on the input image signal.

Next, a mode of adjusting parallax at the time of manufacturing a digital still camera will be described. The operator can select an image of the chart CHT displayed on the monitor MT,
The degree of parallax is inspected by comparing the image with the image viewed through the finder optical system 30. If it is determined that the degree of parallax is large, the finder optical system 3
The adjustment is performed so that the optical axis of 0 is parallel to the optical system of the photographing lens.

In some cases, the position of the finder optical system 30 can hardly be adjusted. In such a case, the optical system finder optical system 30 is replaced with another part and the inspection is performed again. If possible, the imaging unit including the CCD may be moved. Therefore, the position adjustment of the finder optical system should be considered as a broad concept including replacement of the finder optical system and movement of the imaging unit. Thus, the finder optical system 3
When the parallax of 0 is within the allowable range, the finder optical system 30 is fixed to the front camera body 6 using an adhesive or the like. Thereafter, the digital camera is completed by removing the holding member 23 and assembling necessary circuit components, a body, and the like.

As described above, the parallax is suppressed by the accuracy of the conventional parts, but according to the present embodiment, the position of the parallax can be adjusted while viewing the image in a state where the parts errors are combined. You can do it. Also,
There is no need to provide position adjustment means in the digital still camera, so that the cost of parts does not increase. In the present embodiment, the position of the finder optical system is adjusted for parallax adjustment. However, the position of the imaging unit itself may be adjusted.

Although the present invention has been described with reference to the embodiment, it should be understood that the present invention should not be construed as being limited to the above-described embodiment, and that modifications and improvements can be made as appropriate. is there. For example, as shown in FIG.
5 is provided on the back surface of the projection 5, and a recess 23 a corresponding to the projection 5 b is provided on the holding member 23, and
When the CCD 5 is driven via the holding member 23, the C
CD5 can be held. Also, monitor MT
The personal computer PC may control the driving device 24 based on the analysis of the chart image displayed in the above-described manner, and thereby the positioning may be automatically performed. The present invention is applicable not only to a digital still camera but also to any apparatus having a photographic lens and a solid-state imaging device.

[0030]

According to the method of positioning a solid-state imaging device of the present invention, a step of converting a subject image passed through an imaging optical system into an electric signal using a solid-state imaging device; Displaying an image of a subject based on a target signal; and moving the solid-state imaging device based on the image of the subject such that the solid-state imaging device has a predetermined positional relationship with respect to the imaging optical system. And the step of fixing the positional relationship between the imaging optical system and the imaging solid-state imaging device. Therefore, even if the accuracy of the components of the imaging optical system or the solid-state imaging device is low, the subject output from the solid-state imaging device Based on the image, the positioning accuracy can be improved in the final assembly state in which the error factors are combined, so that a higher quality image can be obtained.

According to the adjustment method of the digital still camera of the present invention, the step of converting the subject image that has passed through the imaging optical system of the digital still camera into an electric signal by using a solid-state imaging device; A step of displaying an image of a subject based on the electrical signal of the subject; and, based on the image of the subject, the finder optical system and the finder optical system so that the solid-state imaging device has a predetermined positional relationship. The method includes a step of moving at least one of the solid-state imaging elements and a step of fixing a positional relationship between the finder optical system and the solid-state imaging element. By adjusting the optical system, parallax can be suppressed as much as possible.

[Brief description of the drawings]

FIG. 1 is an assembly diagram of an imaging unit 10 to be assembled in a digital still camera.

FIG. 2 is a perspective view showing a solid-state imaging device positioning device according to the present embodiment;

FIG. 3 is a diagram illustrating an example of an image displayed on a monitor MT.

FIG. 4 is a diagram illustrating a parallax adjustment method in a digital still camera according to a second embodiment.

FIG. 5 is a perspective view showing a CCD and a holding member according to another embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 unit body 2 photographing lens 3 optical low-pass filter 4 holding rubber 5 CCD 6 front camera body 10 image pickup unit 21, 22 mounting bracket 23 holding member 24 drive device 30 finder optical system PC personal computer MT monitor

Claims (8)

[Claims] A step of converting a subject image passed through an imaging optical system into an electric signal using a solid-state imaging device; and a step of displaying an image of the subject based on the electric signal from the solid-state imaging device. Based on the image of the subject, such that the solid-state imaging device has a predetermined positional relationship to the imaging optical system,
A method of positioning a solid-state imaging device, comprising: moving the solid-state imaging device; and fixing a positional relationship between the imaging optical system and the imaging solid-state imaging device. 2. The method according to claim 1, wherein the solid-state imaging device is mounted on a digital still camera. 3. The solid-state imaging device according to claim 1, wherein the solid-state imaging device is moved such that a center of the solid-state imaging device coincides with an optical axis of the imaging optical system. Positioning method. 4. The method according to claim 1, wherein the solid-state imaging device is moved in at least one of a vertical direction, a horizontal direction, and a rotation direction. 5. A holding member for holding and moving the solid-state imaging device in order to execute the positioning of the solid-state imaging device according to claim 1. 6. A step of converting a subject image that has passed through an imaging optical system of a digital still camera into an electric signal using a solid-state imaging device, and converting an image of the subject based on the electric signal from the solid-state imaging device. Displaying, based on the image of the subject, such that the solid-state imaging device has a predetermined positional relationship with respect to a finder optical system,
A method for adjusting a digital still camera, comprising: moving at least one of the finder optical system and the solid-state imaging device; and fixing a positional relationship between the finder optical system and the solid-state imaging device. 7. The adjustment method for a digital still camera according to claim 6, wherein at least one of the finder optical system and the solid-state imaging device is moved so that a field rate of the finder becomes maximum. . 8. A holding member for holding and moving the solid-state imaging device in order to execute the digital still camera adjustment method according to claim 6.