JP2001094861A - Method for positioning imaging device and device for aiding positioning of imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reproducible imaging device positioning method removing a personal difference in positioning. SOLUTION: An image signal of a plane subject image uniforming luminance and a color tone is generated by an imaging device temporarily fitted to a prescribed position of a lens barrel, plural partial images arranged at an equal distance from the center of the image of the image signal are extracted, the temporarily fitted position of the imaging device is finely adjusted so that the signal values of plural partial images are balanced and the imaging device is regularly fitted on the balanced position. Since the signal values of plural partial images are balanced while finely adjusting the fitted position of the imaging device, the suitable regular fitting position of the imaging device can be simply and surely detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging device positioning method and an imaging device positioning support device, and more particularly, to an imaging device positioning method and an imaging device positioning support device to be mounted on a lens barrel of a digital camera or the like.

[0002]

2. Description of the Related Art FIG. 6A is a diagram schematically showing the configuration of a lens barrel of a digital camera or the like. Inside a lens barrel (hereinafter simply referred to as a “barrel”) 1, an imaging element 4 housed in a package 3 is mounted together with an optical lens 2. The position of the optical lens 2 can be moved back and forth along the optical axis Z, and by adjusting the position,
The focus of the optical lens 2 is focused on the light receiving surface of the image sensor 4. On the other hand, the position of the image pickup device 4 is fixed, and the package 3 containing the image pickup device 4 is bonded and fixed to a predetermined position of the barrel end of the lens barrel 1 when the image pickup device 4 is assembled. In some cases, the relative positional relationship between the optical lens 2 and the image pickup device 4 becomes inappropriate due to the shift of the optical axis Z of the optical lens 2 or the like.

For example, as shown in FIG. 6B, when the short side direction of the image sensor 4 is the Y axis and the long side direction is the X axis, if the image sensor 4 is displaced in the XY directions, the optical Lens 2
And the center O of the image sensor 4 does not match, and an image of uniform image quality cannot be obtained. Therefore, conventionally, an engaging portion (not shown) having a slightly larger shape than the package 3 is provided at the barrel end of the lens barrel 1, and an output image of the image sensor 4 temporarily fixed to the engaging portion is checked. The XY directions of the package 3 are finely adjusted so as to obtain uniform image quality, and the package 3 is bonded and fixed.

[0004]

However, according to the above-mentioned conventional adjustment method, since the uniformity of the image is visually checked, the individual inspector has large variations and good adjustment with reproducibility. Cannot be performed.
Therefore, an object of the present invention is to provide a method and a device for assisting the positioning of an image sensor with high reproducibility while eliminating individual differences.

[0005]

According to a first aspect of the present invention, there is provided a method for positioning an image sensor, the method comprising: using an image sensor temporarily fixed at a predetermined position of a lens barrel to convert an image signal of a planar subject image having uniform luminance and color tone. Generate and extract a plurality of partial images located equidistant from the center point of the image of the image signal, and fine-tune the temporary fixing position of the image sensor so that the signal values of the plurality of partial images are balanced. The image pickup device is permanently stopped at a balanced position. According to this, while finely adjusting the mounting position of the image sensor,
By balancing the signal values of multiple partial images,
An appropriate final stop position of the image sensor is easily and reliably found. According to a second aspect of the present invention, there is provided an image pickup device positioning assisting apparatus, wherein a planar object having uniform luminance and color tone, a capturing unit for taking in an image signal from the image pickup device, and an image signal of the image signal are located equidistant from a center point of the image. Extracting means for extracting a plurality of partial images, generating means for generating correction information for correcting a positional shift amount of the image sensor based on signal values of the plurality of partial images, and visualizing the correction information Display means for displaying. According to this, the fine adjustment direction and the adjustment amount of the mounting position of the imaging device are quantitatively visualized and displayed by the correction information displayed on the display means. According to a third aspect of the present invention, in the image sensor positioning method according to the first aspect, the plurality of partial images are located on a diagonal line passing through a center point of the image of the image signal, and are located from the same center point. It is characterized by four partial images located at equal distances. According to this, while finely adjusting the mounting position of the imaging element and balancing the signal values of the four partial images, an appropriate final stop position of the imaging element can be easily and reliably found. According to a fourth aspect of the present invention, in the imaging device positioning assisting apparatus according to the second aspect, the plurality of partial images are positioned on a diagonal line passing through a center point of the image image of the image signal and have the same center. It is characterized by four partial images located equidistant from the point. According to this, while finely adjusting the mounting position of the imaging element and balancing the signal values of the four partial images, an appropriate final stop position of the imaging element can be easily and reliably found. According to a fifth aspect of the present invention, there is provided the imaging device positioning method according to the first aspect, wherein the image signal is obtained when the focal point of the optical lens in the lens barrel is set at infinity or near infinity. The image signal is characterized in that: According to this, the unevenness of the brightness or the color tone of the planar object image is leveled. According to a sixth aspect of the present invention, in the imaging device positioning assisting device according to the second aspect, the image signal sets the focal point of the optical lens in the lens barrel at infinity or near infinity. It is characterized by being an image signal at the time. According to this, the unevenness of the brightness or the color tone of the planar object image is leveled.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. In FIG. 1, a CCD housed in a package 3 together with an optical lens (which is generally a lens group including a plurality of optical lenses, but is hereinafter referred to as an optical lens for convenience of explanation) 2 is provided inside a lens barrel 1.
(Charge Coupled Device) or the like. As described above, the position of the optical lens 2 is movable back and forth along the optical axis Z,
By adjusting the position, the optical lens 2 is focused on the light receiving surface of the image sensor 4. The position of the image pickup device 4 is fixed, and when the image pickup device 4 is assembled, the package 3 containing the image pickup device 4 is connected to an engaging portion (not shown) provided at the end of the lens barrel 1. Is temporarily fixed to an engagement portion having a slightly larger shape, and a positioning operation described later is performed. Then, the package 3 is adhesively fixed.

The surface light source (corresponding to the plane object described in the gist of the invention) 10 generates a plane light (corresponding to the plane object image described in the gist of the invention) 10a having uniform luminance and color tone. The plane light 10a is received by the imaging device 4 through the optical lens 2, and is extracted from the imaging device 4 as a CCD image (corresponding to an image signal described in the gist of the invention) 4a. The imaging device positioning support device 20 includes the surface light source 10, a focus driving unit 21, an image input unit (corresponding to a capturing unit described in the gist of the invention) 22, and a reference image extraction unit (extraction described in the gist of the invention). 23, image comparison unit 2
4, an index line generating unit (corresponding to the generating unit described in the gist of the invention) 25, an image output unit 26, and a display device (corresponding to the displaying unit described in the gist of the invention) 27. The focus driving unit 21 moves the position of the optical lens 2 in the direction of the optical axis in order to set the focal point of the optical lens 2 to infinity when positioning the imaging device 4. The reason for setting the distance to infinity will be described later.

The image input section 22 takes in the CCD image 4a output from the image pickup device 4 and stores it in a frame memory (not shown). The reference image extracting unit 23 extracts a predetermined reference image from the CCD image 4a stored in the frame memory. FIG. 2 is a conceptual diagram of the extraction of the reference image. In this example, the reference image is located on two diagonal lines 32 and 33 passing through the center point 31 of the image image 30 of the CCD image 4a, and from the same center point 31. Four partial images 34 to 3 located at equal distances
7 is extracted as a reference image. That is, the first partial image 34 is a partial image near the upper left corner of the image 30 of the CCD image 4a, the second partial image 35 is a partial image near the upper right corner of the image 30 of the CCD image 4a, and the third partial image. Image 36 is a partial image near the lower left corner of image image 30 of CCD image 4a, and fourth partial image 37 is CCD image 4a.
Is a partial image in the vicinity of the lower right corner of the image 30. All of the partial images 34 to 37 have the same area (or the same number of pixels) located equidistant from the center point 31 of the image 30 of the CCD image 4a. It is an image.

[0009] The image comparison unit 24 is provided with the four partial images 3
By comparing the signal values 4 to 37 with each other, the amount of displacement of the image sensor 4 with respect to the optical lens 2 in the XY directions and the direction of the displacement are quantitatively grasped. The index line generating unit 25 generates an alignment image (described later) for visualizing and displaying the amount of displacement of the image sensor 4 with respect to the optical lens 2 in the XY directions and the direction of the displacement, which are grasped by the image comparing unit 24. . Image output unit 26
Outputs the alignment image to the display device 27, and the display device 27 displays the alignment image and presents it to the inspector.

FIG. 3 is a view showing a display state of the display device 27. A screen 40 of the display device 27 displays a positioning target line 43 and an index line along with auxiliary lines such as a horizontal center line 41 and a vertical center line 42. An alignment image including 44 (corresponding to the correction information described in the gist of the invention) is displayed. The target line 43 indicates the ideal position of the image sensor 4, and the index line 44 indicates the current position of the image sensor 4 in consideration of the information grasped by the image comparison unit 24. Incidentally, FIG. 3A shows a display example when the image sensor 4 is slightly displaced in the upper left direction from the ideal position (the target line 43), and FIG. 13 is a display example after the adjustment).

FIG. 4 is a conceptual diagram showing one aberration of the convex lens when the optical lens 2 is regarded as one convex lens. When polychromatic light P (ideally, white light) is incident on the convex lens, this light is refracted twice (see D and D 'or D and D ") on both surfaces of the convex lens, and then converges on the focal point. It changes from F1 to F2 depending on the wavelength included in the polychromatic light P, and the magnitude of this change (the distance between F1 and F2) becomes more remarkable as the incident position of the light becomes farther from the center of the convex lens. Is a phenomenon that is always seen in a convex lens to a certain extent. Chromatic aberration causes unevenness in the surface direction of the convex lens. The brightness of the polychromatic light P depends on the polychromatic light. This is because the wavelength is given by the sum of all the wavelength lights included in P. In a portion where the chromatic aberration is large (especially near the periphery of the convex lens), the distance between F1 and F2 becomes long, and all the wavelength lights included in the polychromatic light P are one Because they will not be able to gather

The present embodiment provides a reproducible imaging device positioning method and an imaging device positioning support apparatus that eliminates individual differences by utilizing the chromatic aberration of the convex lens.

FIG. 5 is a diagram showing a procedure for positioning the image pickup device according to the present embodiment. In this figure, first,
The focus of the optical lens 2 is set to infinity using the focus drive unit 21 (step S1). The reason for setting the distance to infinity is that the plane light 10a generated by the surface light source 10 is not always an ideal surface light source having uniform brightness and color tone. By setting the distance to infinity, some unevenness in brightness and color tone can be made inconspicuous. For example, a surface light source having a simple structure in which a light source such as a fluorescent lamp is provided behind a translucent diffusion plate (eg, : Viewer) can be used. Of course, if an ideal surface light source can be obtained, it is not necessary to set the distance to infinity.

Next, the power of the surface light source 10 is turned on and the plane light 1 is turned on.
0a is generated (step S2). Hereinafter, the surface light source 10
Must be placed at an appropriate position so that the center of the plane light 10a and the vertical line of the plane light 10a can coincide with the optical axis of the optical lens 2. Next, the image sensor 4 is driven to read the CCD image 4a (step S3), and the first to fourth partial images 34 to 37 are extracted as reference images (step S4). Next, first to fourth partial images 34 to 37
Of the image sensor 4 with respect to the optical lens 2 in the XY directions and the direction of the shift (step S).
5).

Now, assume that the signal value of the first partial image 34 is E1,
The signal value of the second partial image 35 is E2, and the third partial image 3 is
6 is E3, and the signal value of the fourth partial image 37 is E4.
In the case where the CCD image 4a has uniform luminance and color tone, if the relationship of E1 = E2 = E3 = E4 is satisfied, the amount of displacement of the imaging device 4 with respect to the optical lens 2 in the X and Y directions is zero. If the relationship of <E2 = E3 <E4 is satisfied, the shift state shown in FIG. 3A, that is, the image sensor 4 is moved in the upper left direction by a predetermined amount (| E1-E2 | or | E3-E4).
│). Therefore, E
The deviation amount can be quantitatively represented by (the absolute value of) the difference value of 1 to E4, and the deviation direction can be represented by the magnitude relationship of E1 to E4.

Next, an alignment image including the index line 44 taking into account the above-described shift direction and shift amount is generated (step S).
6), and output the alignment image to the display device 27 (step S7). Then, the inspector finely adjusts the position of the temporarily fixed imaging element 4 so that the index line 44 of the alignment image is aligned with the alignment target line 43 (Step S8), and as a result, it is determined that there is no shift (Step S8). That is, when the coincidence between the index line 44 of the alignment image and the alignment target line 43 is visually determined), the image sensor 4 is adhered and fixed (Step S10), and the adjustment operation ends.

As described above, according to the present embodiment, the shift amount and the shift direction in the XY directions of the image sensor 4 with respect to the optical lens 2 can be quantitatively indicated by the display position of the index line 44. Therefore, the inspector finely adjusts the position of the image sensor 4 so that the display position of the index line 44 coincides with the target line 43, so that the position of the image sensor 4 in the XY directions with respect to the optical lens 2 is accurately adjusted. Thus, it is possible to provide an image pickup device positioning method and an image pickup device positioning support device with good reproducibility by eliminating variations among inspectors.

In this embodiment, the CCD image 4a
Are extracted as four partial images 34 to 37 near the four corners of the image 30 of the CCD image 4a, but the present invention is not limited to this. In short, it is sufficient that the plurality of partial images are located at the same distance from the center point 31 of the image 30 of the CCD image 4a.

[0019]

According to the image pickup device positioning method of the present invention, an image signal of a flat subject image having uniform luminance and color tone is generated using an image pickup device temporarily fixed at a predetermined position of a lens barrel. Extracting a plurality of partial images located equidistant from the center point of the image of the image signal, fine-adjusting the temporary fixing position of the image sensor so that the signal values of the plurality of partial images are balanced, Since the image sensor is permanently fixed at the removed position, by appropriately adjusting the mounting position of the image sensor and by balancing the signal values of a plurality of partial images, an appropriate final stop position of the image sensor can be easily determined. And it is surely found. Accordingly, since it is only necessary to balance the signal values of the plurality of partial images, it is possible to provide a method for positioning the imaging element with high reproducibility without individual differences. According to the imaging device positioning assisting device of the second aspect, a planar subject having uniform luminance and color tone, capturing means for capturing an image signal from the imaging device, and equidistant from a center point of the image of the image signal. Extracting means for extracting a plurality of partial images located; generating means for generating correction information for correcting a positional shift amount of the image sensor based on signal values of the plurality of partial images; and visualizing the correction information. Since the display information is displayed on the display means, the fine adjustment direction and the adjustment amount of the mounting position of the imaging device are quantitatively visualized and displayed based on the correction information displayed on the display means. Therefore, it is only necessary to finely adjust the mounting position of the image sensor while looking at the correction information. Therefore, it is possible to provide an image sensor positioning support device that can eliminate individual differences and has reproducibility. According to the image pickup device positioning method of the third aspect, in the image pickup device positioning method of the first embodiment, the plurality of partial images are located on a diagonal line passing through a center point of the image image of the image signal and have the same center. Since the four partial images are located at the same distance from the point, the signal value of the four partial images is balanced while finely adjusting the mounting position of the image sensor, so that the proper final stop position of the image sensor can be easily adjusted. And surely found. Therefore, since it is only necessary to balance the signal values of the four partial images, it is possible to provide a method of positioning the imaging element with high reproducibility without individual differences. According to the imaging device positioning assisting device of the fourth aspect, in the imaging device positioning assisting device of the second aspect, the plurality of partial images are positioned on a diagonal line passing through a center point of the image of the image signal, and Since the four partial images are located at the same distance from the same center point, the signal position of the four partial images is balanced while finely adjusting the mounting position of the image sensor, so that the proper final stop position of the image sensor can be obtained. Are easily and reliably found. Therefore, since it is only necessary to balance the signal values of the four partial images, it is possible to provide a reproducible imaging device positioning support device that eliminates individual differences. According to the imaging element positioning method of the fifth aspect, in the imaging element positioning method of the first aspect, the image signal causes the focal point of the optical lens in the lens barrel to be at infinity or a state close to infinity. Since the image signal is obtained when the above-described processing is performed, the unevenness of the brightness or the color tone of the planar object image is equalized. Therefore, a planar light source having a simple structure such as a viewer can be used for a planar subject. According to the image pickup device positioning assisting device of claim 6, in the image pickup device positioning assisting device of claim 2, the image signal is a state where the focal point of the optical lens in the lens barrel is at infinity or near infinity. , The unevenness of the brightness or the color tone of the planar object image is equalized. Therefore, a planar light source having a simple structure such as a viewer can be used for a planar subject.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment.

FIG. 2 is a conceptual diagram of extracting a reference image.

FIG. 3 is a display state diagram of the display device.

FIG. 4 is a conceptual diagram illustrating chromatic aberration of a convex lens.

FIG. 5 is a diagram showing a procedure for positioning an image sensor in the present embodiment.

FIG. 6 is a diagram schematically showing a configuration of a lens barrel.

[Explanation of symbols]

 Reference Signs List 1 lens barrel 4 image sensor 4a CCD image (image signal) 10 plane light source (plane subject) 10a plane light (plane subject image) 20 image sensor positioning support device 22 image input unit (capturing unit) 23 reference image extraction unit (extraction) Means) 25 Index line generator (generation means) 27 Display device (display means) 30 Image image 31 Center point 32, 33 Diagonal line 34-37 Partial image 44 Index line (correction information)

Claims (6)

[Claims] 1. An image signal of a planar subject image having uniform luminance and color tone is generated using an image sensor temporarily fixed at a predetermined position of a lens barrel, and the image signal is equidistant from a center point of the image image of the image signal. Extracting a plurality of partial images located at a position, finely adjusting a temporary fixing position of the image sensor so that signal values of the plurality of partial images are balanced, and permanently stopping the image sensor at a balanced position; An imaging device positioning method, comprising: 2. A flat object having uniform luminance and color tone, a capturing unit for capturing an image signal from an image sensor, and extracting a plurality of partial images located equidistant from a center point of the image of the image signal. Extracting means, generating means for generating correction information for correcting the amount of displacement of the image sensor based on the signal values of the plurality of partial images, and display means for visualizing and displaying the correction information. An imaging device positioning support device, comprising: 3. The plurality of partial images are four partial images located on a diagonal line passing through a center point of the image of the image signal and equidistant from the center point. Item 2. The method for positioning an imaging device according to Item 1. 4. The partial image according to claim 1, wherein the plurality of partial images are four partial images that are located on a diagonal line passing through a center point of the image of the image signal and are equidistant from the center point. Item 3. An imaging device positioning support device according to Item 2. 5. The image pickup device according to claim 1, wherein the image signal is an image signal when a focal point of an optical lens in the lens barrel is set at infinity or near infinity. Method. 6. The image pickup device according to claim 2, wherein the image signal is an image signal when a focal point of an optical lens in the lens barrel is set at infinity or near infinity. Support equipment.