JP2004320282A - Mount structure for solid state imaging element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mount structure for a solid state imaging element whereby swing and tilt can easily be adjusted and entire two-dimensional sensor areas can be focused with high accuracy. <P>SOLUTION: The mount structure for the solid-state imaging element includes: a first support plate 1 for supporting the solid-state imaging element 106; a third support plate 3 for fixing an imaging optical section 12 including an imaging lens 102; and a second support plate 2 interposed between the first and third support plates 1, 3, and engaging with a fulcrum provided in a diagonal line direction to any of the respective support plates and an imaging face 106A of the imaging element 106. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an imaging device using a solid-state imaging device represented by a CCD, and more particularly to a mechanical coupling structure between a solid-state imaging device and an imaging lens unit.
[0002]
[Prior art]
2. Description of the Related Art An imaging apparatus that captures an image of a subject through an imaging lens using a solid-state imaging element that is a two-dimensional sensor and obtains an electrical image signal has been more widely used than before.
One example is shown in FIGS. 5, reference numeral 101 denotes a subject, 102 denotes an imaging lens constituted by a lens group, 103 denotes a lens base that supports the imaging lens 102, 104 denotes a base, 105 denotes a ring, 106 denotes a solid-state imaging device, 107 denotes a sensor base, and 108 denotes a solid-state imaging device. Is a spacer.
[0003]
Here, the lens base 103, the base 104, and the ring 105 are all substantially cylindrical, and FIG. 5 shows a cross section obtained by cutting them along the axial direction. The solid-state imaging device 106 is a rectangular parallelepiped, and has a rectangular shape as shown in FIG. 6 when the imaging surface 106A is viewed from the normal direction, that is, from the subject side.
[0004]
6, sensors for the number of pixels (for example, several hundred thousand to several million) are arranged in a plane on an imaging surface 106A of the solid-state imaging device 106. The solid-state imaging element 106 is fixed to a sensor base 107, and a hole 107A for screwing the sensor base 107 to the base 104 via a spacer 108 is formed.
[0005]
Further, as shown in FIG. 5, a plurality of screw holes 105B are formed in the ring 105 in the radial direction, and a screw 109 having a tapered tip is screwed into the screw hole 105B. Further, the tapered tip of the screw 109 is engaged with a groove 104 </ b> A formed in the outer periphery of the base 104.
[0006]
Here, as shown in FIG. 5, the center line direction of the optical axis (the direction of the center axis of the imaging lens 102) is the Z axis, and as shown in FIG. 6, the center point 106B of the imaging surface 106A of the solid-state imaging device 106 is the Z axis. It is assumed to be on the axis. The two-dimensional seat surface including the center point 106B and orthogonal to the Z axis is represented by the X axis and the Y axis.
[0007]
In addition, the base 104 is fixed to a structure of the imaging device (not shown), and the positional relationship between the subject 101 and the base 104 does not change unless the positional relationship between the subject 101 and the imaging device changes.
[0008]
In such a conventional solid-state image sensor mounting structure, first, the ring 105 is rotated around the Z-axis to adjust the position of the imaging lens 102 in the Z-axis direction. Here, since the tip of the screw 109 is engaged with the groove 104A, the ring 105 does not move in the Z-axis direction even when rotated. A female screw 105A is formed on the inner surface of the cylindrical ring 105, and is engaged with a male screw 103B formed at the tip of a flange 103A protruding from the lens base 103.
[0009]
Further, since the protrusion 103C of the lens base 103 is engaged with the groove 104B in the Z-axis direction formed on the inner surface of the base 104, rotation around the Z-axis is prevented. Therefore, by rotating the ring 105 forward and backward, the imaging lens 102 fixed to the ring base 103 moves in the Z-axis direction, and the position of the focal point at which the image of the subject 101 passing through the imaging lens 102 is formed is solid-state imaging. It can be adjusted to the main surface 106A of the element 106.
[0010]
With such a configuration, focusing can be performed in the Z axis direction distance relationship between the solid-state imaging device 106 and the imaging lens 102. However, with the recent increase in definition of images, more accurate focusing is achieved. Since the alignment is required, an adjustment for correcting an angular difference between the actual imaging surface 106A of the solid-state imaging device 106 and the XY plane geometrically limited by the Z axis which is the optical axis center line, So-called tilt adjustment has become necessary.
[0011]
This is because the difference in the degree of parallelism between the imaging surface 106A of the solid-state imaging device 106 and the main surface of the sensor base 107 or the difference in angle between the imaging surface 106A and the XY plane caused by the dimensional variation of other structures. As a cause, even if the center 106B of the imaging surface 106A is in focus, the deviation from the focus near the periphery of the imaging surface 106A cannot be ignored, and this has become a serious problem.
[0012]
Therefore, in the technique disclosed in Patent Document 1, a device for solving the above problem is devised. As shown in FIG. 7, the sensor base 110 is supported at three points, and the positions of the three support points 111 in the Z-axis direction can be independently adjusted. Therefore, solid-state imaging with respect to the optical axis obtained by the lens barrel 112 is performed. The tilt of the element 113 can be adjusted.
[0013]
In the technique disclosed in Patent Document 2, as shown in FIG. 8, a convex hemisphere 121A is formed on the back surface of a sensor base 121 that supports a solid-state imaging device 120, and a concave hemisphere opposing the convex hemisphere 121A. A receiving member 122 on which 122A is formed is provided.
[0014]
FIGS. 8B and 8C show the cross sections of the air shown in FIG. 8A. By turning the angle adjustment knob 123 about the X axis, the sensor base 121 becomes hemispherical. Guided by the contact surfaces 121A and 122A, the angle of the solid-state imaging device 120 around the X axis can be adjusted. By turning the angle adjustment knob 124 about the Y axis, the angle of the solid-state imaging device 120 about the Y axis can be similarly adjusted.
[0015]
At this time, since the center of curvature of the hemispherical contact surfaces 121A and 122A is set to the center of the imaging surface of the solid-state imaging device 120, the centers do not shift even if the above-described angle adjustment is performed. It is basically the same as a so-called goniometer stage.
[0016]
[Patent Document 1] JP-A-2003-69886 [Patent Document 2] JP-A-2002-77699
[Problems to be solved by the invention]
However, the prior art disclosed in Patent Document 1 described above adjusts three support points 111 on the sensor base 110 individually. If one certain point is adjusted, the position of the entire imaging surface in the optical axis direction is adjusted. Is displaced, making the adjustment extremely difficult and not practical.
[0018]
According to the related art disclosed in Patent Document 2, even if the angle adjustment knob 123 around the X axis or the angle adjustment knob 124 around the Y axis is turned, the center position of the main surface of the solid-state imaging device 120 does not deviate. When the corner of the imaging surface of the imaging device 120 is focused, it is necessary to turn both the angle adjustment knob 123 around the X axis and the angle adjustment knob 124 around the Y axis.
[0019]
In particular, in the angle adjustment of the imaging surface of the solid-state imaging device, the position change in the optical axis direction with respect to the angle change increases as the position becomes farther from the center of the imaging surface. Therefore, in order to accurately adjust the corner of the main surface of the solid-state imaging device 120 to the focus as in the related art disclosed in Patent Literature 2, it is necessary to perform adjustment using two knobs each of which affects the same corner. Very difficult. In addition, a structure in which a convex hemispheric surface and a concave hemispheric surface are formed and brought into surface contact requires high-precision processing and increases costs.
[0020]
The present invention has been made in order to solve the above-mentioned problem, and has a tilt adjustment mechanism that can easily adjust a focus even at a corner of an imaging surface of an individual imaging element and does not require a large-scale mechanism. It is an object of the present invention to realize a mounting structure for an image sensor.
[0021]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a first support plate that supports a solid-state imaging device having a quadrangular imaging surface, and a case where two diagonals of the imaging surface are viewed from a center line direction of an optical axis. A second support plate that is provided with a fulcrum on an extension of both ends of one diagonal line and engages with the first support plate, and the other when the two diagonals are viewed from the center line direction of the optical axis. And a third support plate provided with a fulcrum on an extension of both ends of the diagonal of the third support plate and engaged with the second support plate, and the third support plate is fixed to an imaging optical unit including an imaging lens. A mounting structure for a solid-state imaging device is provided.
[0022]
Further, as a second aspect, a fulcrum related to the engagement between the first support plate and the second support plate and a fulcrum related to the engagement between the second support plate and the third support plate are engaged with each other. According to a first aspect, there is provided a mounting structure for a solid-state imaging device, wherein the mounting structure includes a pair of protrusions protruding from any of both supporting plates.
[0023]
Further, as a third aspect, the tip of the projection is substantially semicircular or substantially hemispherical, and a circular opening having a radius smaller than the radius of the semicircle or hemisphere is provided at a position where the tip of the engaging support plate abuts. The mounting structure of the solid-state imaging device according to the first or second aspect, wherein the mounting portion is provided.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a side view of a mounting structure of a solid-state imaging device showing one embodiment of the present invention. In the figure, reference numeral 1 denotes a first support plate, 2 denotes a second support plate, 3 denotes a third support plate, and 12 denotes an imaging optical unit. In this figure, elements having the same structure and function as those used in the description of the related art are denoted by common reference numerals. Here, the center line of the optical axis is defined as the Z axis, as in FIG.
[0025]
FIG. 2 is an exploded perspective view showing one embodiment of the present invention. In this drawing, the imaging optical unit 12 is shown without being disassembled. In this figure, the structure for mounting the imaging optical unit 12 and the third support plate 3 is omitted. Here, 2A is a pair of protrusions related to the engagement between the first support plate 1 and the second support plate 2, and 2B is a pair of protrusions related to the engagement between the second support plate 2 and the third support plate 3. 1A are circular openings where the tips of a pair of projections 2A abut, 3A is a circular opening where a pair of projections 2B abut, 4 and 5 are spacers, and 6 and 7 are compression coil springs.
[0026]
Next, an adjustment method after the individual imaging element 106 is attached will be described. First, focusing is performed on the center 106B of the imaging surface 106A. This focusing is performed by rotating the ring 105 and moving the imaging lens 102 in the Z-axis direction. The details of this operation have been described with reference to FIG.
[0027]
Focusing is generally performed by using a chart for focusing as a subject, actually capturing the image with a solid-state image sensor, and looking at the screen of an output video. Is an effective means. An image pattern suitable for focusing is printed on the chart.
[0028]
When the focusing of the center 106B of the imaging surface 106A is completed, the tilt adjustment is performed next. In the tilt adjustment according to the present invention, the angle adjustment in two directions is performed in order, and the order of adjustment in each of these directions does not matter.
[0029]
To adjust the tilt, first, the adjustment screw 9 shown in FIG. 2 is turned. At this time, the vicinity of the tips of the pair of projections 2B on the second support plate 2 is in contact with the circular opening 3A of the third support plate 3, and the second support is formed by the compression coil spring 6 and the holding screw 8. One end of the plate 2 is biased in the direction of the third support plate 3.
[0030]
Therefore, turning the adjustment screw 9 changes the angle of the second support plate 2 with the vicinity of the tips of the pair of projections 2B as a fulcrum. Explaining this from the Z-axis direction, as shown in FIG. 3, the circular opening 3A with which the pair of protrusions 2B abuts is located on an extension of one diagonal of the imaging surface 106A of the solid-state imaging device 106. .
[0031]
Therefore, turning the adjustment screw 9 can focus on the lower left and upper right regions of the imaging surface 106A as shown in FIG. 3, but at this time, the focus is applied from the upper left corner to the lower right corner of the imaging surface 106A. The Z-axis position of the diagonal portion does not change.
[0032]
Next, the adjustment screw 11 shown in FIGS. 1 and 2 is turned. At this time, the vicinity of the tip of the pair of projections 2A on the second support plate is in contact with the circular opening 1A of the first support plate 1, and the first support plate is compressed by the compression coil spring 7 and the holding screw 10. One end of 1 is urged in the direction of the second support plate 2.
[0033]
Therefore, turning the adjustment screw 11 changes the angle of the first support plate 1 with the vicinity of the tips of the pair of projections 2A as a fulcrum. Explaining this from the Z-axis direction, as shown in FIG. 3, the circular opening 1A with which the pair of projections 2A abuts is located on an extension of the other diagonal of the imaging surface 106A of the solid-state imaging device 106. .
[0034]
Therefore, turning the adjustment screw 11 can focus on the upper left and lower right regions of the imaging surface 106A as shown in FIG. 3, but at this time, the lower left corner to the upper right corner of the already adjusted imaging surface 106A have been adjusted. The Z-axis position of the portion on the diagonal line over the portion does not change.
[0035]
Here, the relationship between the projections 2A and 2B and the circular openings 1A and 3A will be described in detail with reference to FIG. The protrusions 2A and 2B according to the present embodiment are formed by raising the second support plate 2 formed by punching a steel plate. When viewed from the main surface of the raised steel sheet, the tip has a semicircular shape as shown in FIG.
[0036]
At this time, since the radius of the circular openings 1A and 3A is smaller than the radius of the projections 2A and 2B, the tips of the projections do not fit into the openings. When the above-described angle adjustment is performed in this state, the semicircular arc-shaped edge at the tip of the protrusion and the edge at the upper end of the circular openings 1A and 3A rub against each other, and the protrusion is positioned at the center of the radius of the semicircle. Incline with the fulcrum. Therefore, no displacement occurs even if the projection is inclined for angle adjustment.
[0037]
In order to prevent the displacement, a projection having a pointed shape may be used as shown in FIG. 4B. However, since the projection is sharp, the projection is easily crushed, and in that case, the position is shifted. On the other hand, according to the configuration shown in FIG. 4A, there is no risk of displacement even if the edge is slightly worn.
[0038]
In the embodiment shown in FIG. 4 (a), a steel plate is punched to form a semicircular tip, but as shown in FIG. 4 (c), a cylindrical projection having a hemispherical tip is provided. This may be made to abut on a circular opening having a radius smaller than the radius of the hemispherical shape. In addition, in order to form a circular opening, a through-hole may be formed or a recess with a bottom may be formed.
[0039]
【The invention's effect】
According to the present invention, independent angle adjustment in each of two directions based on two diagonal lines of the solid-state imaging device can be performed, and adjustment in one diagonal direction affects adjustment in the other diagonal direction. Since this is not provided, highly accurate focusing over the entire imaging surface can be easily performed.
[0040]
Therefore, it is possible to eliminate the difficulty of focusing on the corners on the rectangular imaging surface, which is particularly bad in the related art. Further, this effect can be easily obtained at low cost, and there is no element that hinders mass productivity.
[Brief description of the drawings]
FIG. 1 is a side view of a mounting structure of a solid-state imaging device showing one embodiment of the present invention. FIG. 2 is an exploded perspective view of a mounting structure of a solid-state imaging device showing one embodiment of the present invention. FIG. 4 is a front view of an imaging surface of a mounting structure of the solid-state imaging device showing one embodiment. FIG. 4 is a detailed view of a projection of a mounting structure of the solid-state imaging device showing one embodiment of the present invention. FIG. 6 is a front view of an imaging surface of a conventional solid-state image sensor mounting structure. FIG. 7 is a perspective view showing another conventional solid-state image sensor mounting structure. FIG. Figure showing the mounting structure of the solid state imaging device
DESCRIPTION OF SYMBOLS 1 1st support plate 2 2nd support plate 3 3rd support plate 4, 5 Spacer 6, 7 Compression coil spring 8, 10 Holding screw 9, 11 Adjustment screw

Claims (3)

An attachment structure of the solid-state imaging device in the imaging device,
A first support plate that supports a solid-state imaging device having a quadrangular imaging surface;
A second support plate that engages with the first support plate by providing a fulcrum on an extension of both ends of one diagonal when two diagonals of the imaging surface are viewed from the center line direction of the optical axis; ,
And a third support plate that engages with the second support plate by providing a fulcrum on an extension of both ends of the other diagonal when the two diagonals are viewed from the center line direction of the optical axis. ,
A mounting structure for a solid-state imaging device, wherein the third support plate is fixed to an imaging optical unit including an imaging lens. The fulcrum related to the engagement between the first support plate and the second support plate and the fulcrum related to the engagement between the second support plate and the third support plate may be any one of the two support plates engaged with each other. The mounting structure of the solid-state imaging device according to claim 1, wherein the mounting structure includes a pair of protrusions protruding from the crab. The tip of the projection has a substantially semicircular or substantially hemispherical shape, and a circular opening having a radius smaller than the radius of the semicircle or hemisphere is provided at a position where the tip of the supporting plate to be engaged is in contact. The mounting structure of the solid-state imaging device according to claim 1 or 2.

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