JP4138068B2 - Electronic still camera and mounting surface processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic still camera in which an image sensor that receives a subject image incident on a camera body through a photographing lens is held by a holder, and the image sensor is attached to the camera body via the holder.
[0002]
[Prior art]
In an electronic still camera, in order to obtain a high-quality image, it is necessary to correctly form a subject image from a photographing lens on an image sensor. The image sensor is held in a package, and the image sensor is attached to the camera body by attaching the package to the camera body. However, since the dimensions of the light receiving surface of the image sensor and the mounting surface of the package include manufacturing errors, the desired dimensional accuracy cannot be satisfied simply by mounting the package on the mounting surface of the camera body. Therefore, after the package is attached to the camera body, the position of the image sensor with respect to the photographic lens is adjusted, or conversely, the position of the photographic lens is adjusted.
[0003]
In an interchangeable lens camera, for example, a single-lens reflex camera, the interchangeable lens is mounted on a lens mount surface, and therefore it is necessary to attach and adjust the image sensor at a predetermined position relative to the lens mount surface. Therefore, conventionally, the packaged image sensor is incorporated into the camera body together with the position adjustment mechanism, the reference pattern is projected onto the image sensor and displayed on the monitor, and the position of the image sensor is adjusted with the position adjustment mechanism while watching the monitor. is doing.
[0004]
The position adjustment mechanism has, for example, three screws arranged at each vertex of a triangle and a spring for rattling, and the position of the image sensor is adjusted by screwing and screwing the three screws. To adjust.
[0005]
[Problems to be solved by the invention]
However, when the position adjustment mechanism is housed in the camera body together with the image sensor as in the conventional case, the camera is not only enlarged, but if the image sensor is removed for maintenance and inspection of the camera, readjustment is required during installation, There are problems of poor workability and poor maintainability.
[0006]
An object of the present invention is to provide an electronic still camera that does not require a position adjustment mechanism and has improved workability and maintainability.
Another object of the present invention is to provide a processing method for easily processing a holder side mounting surface of an electronic still camera that does not require a position adjusting mechanism and has improved workability and maintainability.
[0007]
[Means for Solving the Problems]
The present invention will be described with reference to FIGS.
(1) The invention of claim 1 is a camera body 11 in which a photographic lens 13 is replaceably mounted on a lens mounting surface, and an image sensor that receives a subject image incident on the camera body 11 through the replaceable photographic lens 13. 21 and an electronic still camera having a holder-side attachment surface 221 that contacts the camera-body-side attachment surface 111 of the camera body 11 and a holder 22 that holds the image sensor 12. The camera body 11 has the camera body side mounting surface 111 cut in advance so that the dimension up to the lens mounting surface 121 is a predetermined value L2, and the holder 22 has a light receiving surface 21a of the image sensor 12. The holder-side mounting surface 221 is cut in advance so that the dimension up to the predetermined value L3 is obtained, and the dimension from the lens mounting surface 121 of the camera body 11 to the planned imaging surface of the subject image by the photographing lens 13 is predetermined. The predetermined values L2 and L3 are dimensions satisfying L2 + L3 = L1, and the holder 22 holding the image sensor 12 is brought into contact with the camera body side mounting surface 111. It is attached to the camera body 11, and in this state, the light receiving surface 21a of the image pickup device 12 is coincident with the scheduled imaging surface.
The holder side attachment surface processing method according to the present invention includes a step of cutting the holder side attachment surface 221 in advance, and this step includes a step of projecting a predetermined pattern onto the image sensor 21 held by the holder 22; A step of inputting an image signal from the image pickup element 21 on which the pattern is projected, a step of calculating the position of the holder-side attachment surface 221 relative to the cutter based on the input image signal, and a holder according to the calculated position And a step of cutting the holder-side mounting surface 221 with a cutter to obtain the dimension L3 .
(2) The invention of claim 2 is the holder side mounting surface machining method according to claim 1, wherein the lens mounting surface 121 extends in a direction perpendicular to the optical axis, and the camera body side mounting surface 111 extends to the lens mounting surface 121. The holder side mounting surface 221 is parallel to the light receiving surface 21 a of the image sensor 21.
(3) The invention of claim 3 is the holder side mounting surface machining method according to claim 1 or 2, wherein the contact surface 223 defines the position of the holder 22 relative to the camera body 11 in a plane perpendicular to the optical axis. , 225, respectively.
[0008]
In the means for solving the above-described problems and operations for explaining the configuration of the present invention, the drawings of the embodiments are used to make the present invention easier to understand. It is not limited.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a schematic configuration when an electronic still camera according to the present invention is of a single-lens reflex type. As shown in FIG. 1, the camera body 11 is provided with a lens mount 12, and an interchangeable photographing lens 13 is attached to the lens mount 12. The subject light that has passed through the photographing lens 13 is reflected upward by the quick return mirror 14 and forms an image on the screen 15. The subject image formed on the screen 15 is observed from the finder observation window through the eyepiece 17 from the penta roof prism 16.
[0010]
The quick return mirror 14 jumps upward when a release button (not shown) is fully pressed, and the subject image from the photographing lens 13 enters the imaging device 20. The imaging device 20 is a device in which a solid-state imaging device 21 typified by a CCD is fixed to a holder 22. The mounting surface 221 abuts on the mounting surface 111 of the camera body 11 and is fastened to the camera body 11 with screws 18. Yes. In such a single-lens reflex type electronic still camera, the dimensions of the lens mounting surface 121 of the lens mount 12 and the light receiving surface 21a of the image sensor 21 are attached to the predetermined distance L1 with a predetermined accuracy, thereby photographing the light receiving surface 21a. It is necessary to match with the imaging plane of the lens 13. The image sensor 21 is prepackaged with ceramic or the like, and a holder 22 is integrated with the package.
[0011]
Therefore, in this embodiment, in other words, the lens mount surface 121 is used as a reference so that the dimension of the lens mounting surface 121 formed on the lens mount 12 and the camera side mounting surface 111 of the camera body 11 is a predetermined distance L2. The attachment surface 111 is processed using the imaging surface of the photographic lens 13 as a reference. As shown in FIG. 2 when the camera body 11 is viewed from the back of the camera, an opening 112 is formed in the camera body 11 so that the subject luminous flux incident from the photographing lens 13 enters the imaging device 20, and is attached to the lower portion of the opening 112. The surfaces 111a and 111b and the attachment surface 111c are formed on the upper part, respectively. The mounting surfaces 111a to 111c are processed with the lens mounting surface 121 as a reference, as described above, after the lens mount 12 is mounted on the front surface of the camera body 11.
[0012]
Further, lower positioning surfaces 113a and 113b for determining the position around the optical axis of the imaging device 20 extend perpendicularly to the rear of the camera from the mounting surfaces 111a and 111b, and a side positioning surface 113c on the left side of the opening 112. Is extended in a plane parallel to the optical axis direction. The lower positioning surfaces 113a and 113b are processed at a distance L4 from the horizontal reference line HL passing through the optical axis, and the side positioning surface 113c is processed at a distance L5 from the vertical reference line VL passing through the optical axis. The position adjustment around the optical axis of the imaging device 20 will be described later.
[0013]
On the other hand, as shown in FIG. 1, the holder 22 is attached with the light receiving surface 21a of the image sensor 21 as a reference so that the dimension between the light receiving surface 21a of the image sensor 21 and the mounting surface 221 of the holder 22 is a predetermined distance L3. If the surface 221 is processed, when the imaging device 20 is attached to the camera body 11 with the screw 18, the dimensions of the lens mounting surface 121 of the lens mount 12 and the light receiving surface 21a of the imaging element 21 are set to a predetermined distance L1 with a predetermined accuracy. Is set. A method for processing the attachment surface 221 will be described later.
[0014]
FIG. 3 is a view of the attachment state of the imaging device 20 to the camera body as seen from the back of the camera. In the holder 22 of the imaging device 20, two attachment pieces 222a and 222b projecting downward in FIG. 3 and one attachment projecting piece 222c projecting upward are formed. The one side 223 of the two mounting protrusions 222a and 222b is brought into contact with the lower positioning surfaces 113a and 113b of the camera body 11, respectively, and the left side surface 225 of the holder 22 is brought into contact with the side positioning surface 113c. Positioning around the axis is performed.
[0015]
A method for processing the mounting surface 221 and the positioning surfaces 223 and 225 of the imaging device 20 will be described in detail with reference to FIGS. As shown in FIG. 4B, the holder-side attachment surface 221 is formed on the back surface of each projecting piece 222 a to 222 c of the holder 22.
[0016]
4 and FIG. 5, the chucking device 113 that chucks the holder 22 of the image pickup device 20, and the chucking device 113 are moved up and down in the direction of the arrow A1, swung in the direction of the arrow A2, and the direction of the arrow A3. 5, a horizontal movement in the directions of arrows A4 and A5 in FIG. 5 and rotation in the direction A6 in FIG. 4, an illumination light source 103, a test chart 105 irradiated by the illumination light source 103, and a test An optical system 107 that forms an image of the pattern of the chart 105 on the light receiving surface 21 a of the image sensor 21, a cutter 109 A that processes the attachment surface 221 of the holder 22, a cutter 109 B that processes the positioning surface 223 of the holder 22, and the holder 22 A cutter 109C for machining the positioning surface 225, a suction device 111 for sucking cutting powder by the cutter 109A, The analog imaging signal from the element 21 is converted into a digital image signal or various signal processings are performed, and various processes described later are executed based on the image signals from the signal processing apparatus 119 to drive the driving device 115. And a control device 117 for controlling the driving of the motor. The processing surface of the cutter 109 </ b> A is set at a position separated from the imaging surface of the test chart 105 by L <b> 3.
[0017]
The pattern of the test chart 105 is a pattern that can measure the signal intensity of the image signal output from each of the plurality of pixels at least at the center, the left and right ends, and the upper and lower ends of the light receiving surface 21a. With this pattern, the holder side mounting surface 221 is positioned in the optical axis direction. Further, a horizontal reference line and a vertical reference line which are orthogonal to each other on the optical axis of the optical system 107 are also drawn. As will be described later, the positioning surface 223 is positioned by the horizontal reference line, and the positioning surface 225 is positioned by the vertical reference line. Is done.
[0018]
FIG. 6 is a flowchart illustrating an example of a processing procedure of the attachment surface 221 executed by the control device 117. In step S <b> 1, the illumination optical system 103 is turned on to project the pattern of the test chart 105 onto the image sensor 21. In step S2, it is determined whether the image signal at the center of the light receiving surface 21a of the image sensor 21 is equal to or greater than a predetermined value. If it is determined that the image signal at the center of the light receiving surface 21a is not equal to or greater than the predetermined value, the process proceeds to step S3, the chucking device 113 is moved in the A1 direction, the image sensor 21 is moved up and down, and the process returns to step S2. If it is determined in step S2 that the image signal at the center of the light receiving surface 21a is equal to or greater than a predetermined value, that is, if it is determined that the center matches the focal plane of the optical system 107, the process proceeds to step S4. It is determined whether the image signals at the left and right ends of 21a are greater than or equal to a predetermined value. If it is determined that the image signals at the left and right end portions of the light receiving surface 21a are not equal to or larger than the predetermined value, the process proceeds to step S5, the chucking device 113 is swung in the A2 direction, and the image sensor 21 is centered on the center portion of the light receiving surface 21a. And return to step S4.
[0019]
If it is determined in step S4 that the image signals at the left and right ends of the light receiving surface 21a are equal to or greater than a predetermined value, that is, if it is determined that the left and right ends coincide with the focal plane of the optical system 107, the process proceeds to step S6. It is determined whether the image signals at the upper and lower ends of the light receiving surface 21a are equal to or greater than a predetermined value. If it is determined that the image signals at the upper and lower end portions of the light receiving surface 21a are not equal to or greater than the predetermined value, the process proceeds to step S7, the chucking device 113 is swung in the A3 direction, and the image sensor 21 is centered on the central portion of the light receiving surface 21a. And return to step S6. If it is determined in step S6 that the upper and lower end image signals of the light receiving surface 21a are equal to or greater than a predetermined value, that is, if it is determined that the upper and lower end portions coincide with the focal plane of the optical system 107, the process proceeds to step S8. In step S8, the suction device 111 is started, and in step S9, the attachment surface 221 is processed by the cutter 109A.
[0020]
By processing the holder side mounting surface 221 in this manner, the dimension of the holder side mounting surface 221 and the light receiving surface 21a is set to L3 as shown in FIG.
[0021]
FIG. 7 is a flowchart showing an example of a processing procedure of the positioning surfaces 223 and 225 executed by the control device 117. In step S <b> 11, the illumination optical system 103 is turned on to project the pattern of the test chart 105 onto the image sensor 21. In step S12, it is determined whether the horizontal reference line 309 (FIG. 5) projected on the light receiving surface 21a of the image sensor 21 in the test chart 105 is parallel to the horizontal line direction (left and right direction in FIG. 4B) of the image sensor 21. . If negative, the process proceeds to step S13, the chucking device 113 is rotated about the optical axis in the A6 direction (FIG. 4A), and the process returns to step S12. If it is determined in step S12 that the horizontal reference line 309 is parallel to the horizontal line direction of the image sensor 21, the process proceeds to step S14.
[0022]
In step S14, the horizontal reference line 309 projected on the light receiving surface 21a of the image sensor 21 in the test chart 105 matches the center horizontal line of the image sensor 21 (the horizontal pixel arrangement direction passing through the screen center of the image sensor 21). Judge whether to do. If negative, the process proceeds to step S15, the chucking device 113 is moved in the A4 direction (FIG. 5), and the process returns to step S14. If it is determined in step S14 that the horizontal reference line 309 matches the central horizontal line of the image sensor 21, the process proceeds to step S16.
[0023]
In step S <b> 16, the vertical reference line 307 (see FIG. 5) projected on the light receiving surface 21 a of the image sensor 21 in the test chart 105 is a center vertical line of the image sensor 21 (vertical pixel passing through the screen center of the image sensor 21. It is determined whether or not it matches. If negative, the process proceeds to step S17, the chucking device 113 is moved in the A5 direction (FIG. 5), and the process returns to step S16. If it is determined in step S16 that the vertical reference line 307 matches the central vertical line of the image sensor 21, the process proceeds to step S18. In step S18, the suction device 111 is started. In step S19, the positioning surfaces 223 and 225 are processed by the cutters 109B and 109C, respectively.
[0024]
By processing the positioning surfaces 223 and 225 in this way, the dimension between the positioning surface 223 and the horizontal reference line 309 is set to L4 as shown in FIG. 5, and the dimension between the positioning surface 225 and the vertical reference line 307 is set to L5. Set to As shown in FIG. 2, the camera side positioning surfaces 113a and 113b and the horizontal line HL are preliminarily processed to L4, and the camera side positioning surface 113c and the vertical line VL are preprocessed to L5. Therefore, when the imaging device 20 is attached to the camera body 11, the optical axis of the photographing lens 113 and the optical axis of the imaging device 20 are also correctly aligned.
[0025]
FIG. 8 shows another example of the processing apparatus of FIG. Instead of projecting the pattern of the test chart 105, the position up to the light receiving surface 21a is measured by the microscope 203 and the chucking device 113 is driven. Parts similar to those in FIG. 4 are denoted by the same reference numerals for description. In FIG. 8, the microscope 203 is focused on the holder mounting surface 221 before processing. The cutter 109A is also set to process the focal plane position of the microscope 203.
[0026]
The processing procedure will be described with reference to the flowchart of FIG. In step S21, the microscope 203 is moved to the upper left point of the light receiving surface 21a, and in step S22, the microscope 203 is moved up and down to focus on the light receiving surface 21a, and a displacement amount t1 of the light receiving surface 21a from the mounting surface 221 at that time is calculated. To detect. In step S23, the microscope 203 is moved to the upper right point of the light receiving surface 21a, and in step S24, the microscope 203 is moved up and down to focus on the light receiving surface 21a, and the amount of displacement t2 of the light receiving surface 21a from the mounting surface 221 at that time is calculated. To detect. In step S25, the microscope 203 is moved to the lower right point of the light receiving surface 21a. In step S26, the microscope 203 is moved up and down to focus on the light receiving surface 21a. At this time, the shift amount t3 from the mounting surface 221 of the light receiving surface 21a. Is detected.
[0027]
In step S27, the driving amount of the light receiving surface 21a is calculated based on the shift amounts t1 to t3. In step S28, the chucking device 113 is driven based on the calculated amount. In this case, the chucking device 113 is driven in the A1 to A3 directions according to the shift amounts t1 to t3 so that the distance between the light receiving surface 21a and the processed surface of the cutter 109A is L3. In step S29, the suction device 111 is started, and in step S30, the attachment surface 221 is processed by the cutter 109A.
[0028]
In this way, the dimensions of the holder-side mounting surface 221 and the light receiving surface 21a can be processed to L3 using a microscope as shown in FIG. Note that the case where the microscope 203 is provided with an autofocusing function will be described, and the amount of focus adjustment deviation from the mounting surface 221 of the light receiving surface 21a is automatically detected. It is also possible to adjust the focus to 21a and detect the focus adjustment amount at that time as a shift amount.
[0029]
Although the description has been given of the single-lens reflex camera of the photographing lens exchange type, the present invention can be applied to various types of electronic still cameras such as a lens shutter camera including a photographing lens that cannot be exchanged.
[0030]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
(1) According to the first to third aspects of the present invention, the camera body side mounting surface is formed on the camera body with the lens mounting surface as a reference, and the holder side mounting surface on the holder side with the light receiving surface of the image sensor as a reference. Since the image sensor is mounted on the camera body by contacting the camera body side mounting surface and the holder side mounting surface, the light receiving surface of the image sensor is set at the imaging position without the need for a positioning mechanism for the image sensor. They can be matched, contributing to the miniaturization of the camera. In addition, after removing the imaging device for maintenance after shipment, the camera body side mounting surface and the holder side mounting surface are brought into contact with each other to attach the image sensor to the camera body, eliminating the need for position adjustment and improving maintainability. To do.
(2) According to the inventions of claims 4 and 5 , the dimensions of the light receiving surface of the image sensor and the holder side mounting surface can be set with high accuracy and can be easily processed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an electronic still camera according to the present invention. FIG. 2 is a view of an imaging device mounting surface of the camera body of FIG. FIG. 4A is a diagram showing an example of a processing device for the mounting surface of the imaging device viewed from the direction of the aa line in FIG. 4B, and FIG. FIG. 5 is a perspective view showing a surface 221. FIG. 5 is a diagram showing a processing device for a positioning surface of an imaging apparatus. FIG. 6 is a flowchart showing an example of a processing procedure for a mounting surface using a test chart. FIG. 8 is a diagram showing another example of the processing device for the mounting surface of the imaging apparatus. FIG. 9 is a flowchart showing an example of the processing procedure for the mounting surface by the processing device of FIG.
DESCRIPTION OF SYMBOLS 11 Camera body 12 Lens mount 13 Shooting lens 20 Imaging device 21 Image pick-up element 21a Light-receiving surface 22 Holder 111 Camera side attachment surface 112 Opening 113a, 113b, 113c Camera side positioning surface 121 Lens attachment surface 221 Holder side attachment surface 222a-222c Projection piece 223, 225 Holder side positioning surface

Claims (3)

A camera body on which a photographic lens is interchangeably mounted on the lens mounting surface;
An image sensor for receiving a subject image incident on the camera body through the photographing lens;
A holder side mounting surface that comes into contact with the camera body side mounting surface of the camera body, and a holder for holding the imaging device ,
In the camera body, the camera body side mounting surface is cut in advance so that the dimension to the lens mounting surface is a predetermined value L2.
In the holder, the holder side mounting surface is cut in advance so that the dimension to the light receiving surface of the imaging element is a predetermined value L3,
When the distance from the lens mounting surface of the camera body to the planned image formation surface of the subject image by the photographic lens is a predetermined distance L1, the predetermined values L2 and L3 satisfy L2 + L3 = L1,
The holder holding the image sensor is attached to the camera body with the holder-side attachment surface abutting on the camera body-side attachment surface, and in this state, the light-receiving surface of the image sensor coincides with the scheduled imaging surface. An electronic still camera,
The step of cutting the holder side attachment surface in advance,
Projecting a predetermined pattern onto the image sensor held by the holder;
Inputting an image signal from the image sensor onto which the pattern is projected;
Calculating the position of the holder-side mounting surface relative to the cutter based on the input image signal;
Moving the holder according to the calculated position and cutting the holder-side mounting surface with the cutter to obtain the dimension L3. In the holder side attachment surface processing method according to claim 1,
The lens mounting surface extends in a direction perpendicular to the optical axis,
The camera body side mounting surface is parallel to the lens mounting surface,
The holder side mounting surface processing method, wherein the holder side mounting surface is parallel to a light receiving surface of the imaging device. In the holder side attachment surface processing method according to claim 1 or 2,
Wherein the camera body side attachment surface holder side mounting surface, the holder-side mounting surface and having abutment surfaces for defining the position of the holder relative to the camera body in a plane perpendicular to the optical axis, respectively machining Way .

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