JP4533602B2 - Lens alignment apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lens alignment apparatus and method for aligning optical axes (axial centers) of lenses, and in particular, in a camera unit in which an imaging element and a plurality of lenses are integrally provided, lens adjustment for aligning lenses is performed. The present invention relates to a core device and method.
[0002]
[Prior art]
As a conventional lens aligning device, in order to align and join a biconvex lens to a biconcave lens, the lower holder that supports the biconcave lens and the outer peripheral surface of the biconcave lens are held around the optical axis. A rotating mechanism for rotating, an annular holding member for holding a biconvex lens placed on the cemented surface of the biconcave lens, a plate spring member for supporting and biasing the holding member to press the biconvex lens from above, and a plate spring member up and down An XYZ axis stage that moves horizontally, a cross chart and light source arranged below the biconcave lens, a CCD camera arranged above the biconvex lens, an image processing personal computer that processes images taken by the CCD camera, etc. What you have is known.
[0003]
In this lens aligning device, with a biconvex lens mounted on a biconcave lens, an image taken by a CCD camera through these lenses is processed by a personal computer, and an optical axis shift is detected from a focus image of light ( And the relative angular position of both lenses is adjusted by driving the rotation mechanism and appropriately rotating the biconcave lens while moving the XYZ axis stage to adjust the tilt of the biconvex lens based on the deviation amount. By adjusting, the optical axes (axis cores) of both lenses are matched (for example, refer to Patent Document 1 and Patent Document 2).
[0004]
[Patent Document 1]
JP 2000-352647 A [Patent Document 2]
Japanese Patent Laid-Open No. 2002-98877
[Problems to be solved by the invention]
By the way, in the conventional lens aligning device, alignment is performed in order to form two cemented lenses to form one cemented lens. Therefore, in a camera unit or the like in which a plurality of lenses are arranged in a case equipped with an image sensor such as a CCD, even if this lens aligning device is applied, the light projected through the cross chart from the light source is Alignment cannot be performed by being blocked by the case or the image sensor.
[0006]
Further, in this lens alignment device, the lower lens (biconcave lens) is rotatably supported by a rotation mechanism. In order to support such a rotation, the outer peripheral surface of the lens is circular. If it is partially missing or not a perfect circle, it is difficult to rotate.
[0007]
Furthermore, in order to hold the upper lens (biconvex lens) and move it in the horizontal direction, the holding member holding the lens and the XYZ axis stage are connected by a leaf spring member. Even if driven in this direction, the leaf spring member is elastically deformed, and the amount of movement according to the drive is not directly transmitted to the holding member (that is, the lens), and there is a possibility that positioning cannot be performed with high accuracy.
[0008]
The present invention has been made in view of the above-described prior art, and the object of the present invention is to facilitate lens alignment in a camera unit or the like that integrally includes a plurality of lenses and an image sensor. It is another object of the present invention to provide a lens alignment apparatus and method that can be performed with high accuracy and simple setup.
[0009]
[Means for Solving the Problems]
The lens aligning device of the present invention is a lens aligning device that aligns lenses with respect to a camera unit including a plurality of lenses arranged in the optical axis direction and an image sensor disposed behind the plurality of lenses. there are, comprises a table for placing as the camera unit is its front facing upward, the flat surface perpendicular to Oite the optical axis direction at least in the outer peripheral edge region of the inner being arranged on the most front end of the camera unit A lens holder having an annular portion for holding the lens so as to be pressed from the outside, and holding the lens holder so that the lens moves along a plane perpendicular to the optical axis direction of the camera unit at least horizontally. A driving mechanism capable of moving in a two-dimensional direction, an alignment subject arranged in front of the camera unit, and an image of the subject taken by the imaging device It has a Shimesuru image display means, and is characterized in that.
According to this configuration, the camera unit including the imaging element and having a plurality of lenses arranged on the front side thereof is placed on the table, the frontmost lens is held from the outside by the lens holder, and the imaging unit of the camera unit is used. By imaging the subject for alignment and displaying it on the image display means, the operator can check the display image while maintaining a predetermined state (a state where the image is in focus or a state where the image blur is uniform). Until then, the lens holder can be moved horizontally to adjust the position of the lens so that the lens is moved along the plane perpendicular to the optical axis direction of the camera unit by operating the drive mechanism. As described above, even in a camera unit including an image sensor, it is possible to easily perform an alignment operation between lenses.
[0010]
In the apparatus configured as described above, a configuration in which the annular portion of the lens holder has a conical contact surface that spreads toward the lens can be adopted.
According to this configuration, since the annular portion of the lens holder is formed on the conical contact surface that widens toward the end, the outer peripheral edge region of the lens can be easily and reliably pressed from the outside. By horizontally moving the lens, the horizontal position of the lens is reliably adjusted according to the movement. Even if the outer peripheral edge region of the lens is missing or has a shape other than a circular shape, the lens is securely held without being detached because it is held by pressing from the outside with a conical contact surface.
[0011]
In the apparatus having the above-described configuration, a configuration in which the table is provided with a connection portion that can detachably connect the terminal wiring led from the imaging device of the camera unit to the image display means can be adopted.
According to this configuration, it is possible to display the captured image on the image display means simply by placing the camera unit on the table and connecting the terminal wiring of the image sensor to the connection portion. Therefore, the lens aligning device can be easily inlined in the assembly line of the camera unit.
[0012]
In the apparatus having the above configuration, the drive mechanism may have a manual operation unit that can be finely adjusted manually in at least a two-dimensional direction.
According to this configuration, the position of the lens in the horizontal plane can be adjusted with high accuracy by appropriately adjusting the manual operation unit (for example, a microhead that can adjust the position in the X-axis direction and the Y-axis direction with high accuracy by rotation adjustment). Can be adjusted.
[0013]
In the apparatus having the above-described configuration, the table may be configured so that the camera unit can be placed and rotated around the optical axis of the lens.
According to this configuration, by rotating the table appropriately, the angular position of the lens arranged behind the lens held by the lens holder can be changed. The characteristics can be adjusted to be in an optimum state.
[0014]
The lens alignment method of the present invention is a lens alignment method for aligning lenses with respect to a camera unit including a plurality of lenses arranged in the optical axis direction and an imaging device arranged behind the plurality of lenses. The camera unit is placed at a predetermined position on the table so that the front of the camera unit faces upward, and the alignment subject placed in front of the camera unit is imaged by the image sensor of the camera unit and monitored. While viewing the image displayed on the monitor, until the image is in a predetermined state, a flat surface perpendicular to the optical axis direction is arranged at the foremost end of the camera unit and at least on the inner peripheral edge area. It is characterized in that fine adjustment is performed by moving a flat surface of a lens including the lens from the outside along a plane perpendicular to the optical axis direction of the camera unit in the horizontal direction while pressing the lens .
According to this configuration, even in a camera unit including an image sensor, the lenses arranged inside the camera unit can be easily and accurately aligned with a simple setup. In particular, the lens arranged at the front end of the camera unit is finely adjusted by pressing the lens from the outside and moving the flat surface horizontally along the plane perpendicular to the optical axis direction of the camera unit. The core can be easily and highly accurately performed with a simple setup.
[0015]
In the method of the above configuration, an ultraviolet curable adhesive is applied to the lens disposed at the foremost end in advance, and after the image displayed on the monitor is in a predetermined state, the adhesive is irradiated with ultraviolet rays. Irradiation configuration can be adopted.
According to this configuration, the lens after the alignment can be securely fixed to the alignment position by irradiating the ultraviolet ray and curing the adhesive simultaneously with the completion of the alignment.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIGS. 1 to 4 show an embodiment of a lens alignment apparatus and method according to the present invention. FIG. 1 is a schematic diagram of the apparatus, and FIGS. 2 and 3 are cameras aligned by this apparatus. FIG. 4 is an enlarged partial view of a part of the apparatus.
[0017]
As shown in FIG. 1, the lens aligning apparatus includes a table 100 on which the camera unit 10 is placed, a lens holder 110 that holds the frontmost lens G1 of the camera unit 10, and a lens holder 110 that holds the lens holder 110 in the horizontal direction. A driving mechanism 120 that can be moved in a three-dimensional direction in the vertical direction, a photographing chart 130 as an alignment subject arranged in front of the camera unit 10, and an image display that displays an image photographed by the image sensor of the camera unit 10. An image display circuit unit 140, a control unit 150, a monitor 160, etc. are provided as means.
[0018]
Here, the camera unit 10 to be aligned will be described. As shown in FIGS. 2 and 3, a cylindrical member 11 extending in the optical axis direction L (having an axis), and the front side of the cylindrical member 11. A lens frame 12 accommodated in the lens, and an annular cam member 13 provided so as to be rotatable with respect to the outer peripheral surface of the cylindrical member 11 and exerting a cam action on the lens frame 12 in the optical axis direction L. Similarly, the cylindrical member 11, a coil spring 14 that urges the lens frame 12 toward the cam member 13, a presser member 15 that compresses and presses the coil spring 14, and an imaging that is disposed on the rear side of the cylindrical member 11. A CCD 16 or the like as an element is provided.
[0019]
2 and 3, the cylindrical member 11 is formed by a cylindrical portion 11a, a rectangular holding portion 11b, etc., and penetrates the cylindrical portion 11a in the radial direction and extends in the optical axis direction L. In addition, three guide holes 11c and the like opening forward are formed. Projection portions 12d of a lens frame 12, which will be described later, are inserted into the three guide holes 11c, and the holding portion 12 holds a CCD 16 having terminal wirings 16a.
[0020]
The lens frame 12 is slidably inserted into the inner peripheral surface of the cylindrical portion 11a, and as shown in FIGS. 2 and 3, the lens G1, the lens G2, and the lens in that order from the front to the rear. G3 is arranged, the rear lenses G2 and G3 are held by the inner wall portion 12a, and the foremost lens G1 is joined to the lens G2 with a partition plate 12b having an opening having a predetermined diameter interposed therebetween. Yes.
[0021]
Further, as shown in FIGS. 2 and 3, the lens G1 is formed by a glass mold so that the outer surface and the inner surface of the outer peripheral edge region are flat surfaces that are parallel to each other and have a hooked shape as a whole. ing. Therefore, the lens G1 can be slid (finely adjusted) within a predetermined range along a plane perpendicular to the optical axis direction L in an unbonded state in which the inner surface of the lens G1 is in contact with the partition plate 12b. Yes.
Then, after the lens G1 is joined, an aperture plate 12c having a predetermined aperture diameter is joined from the front side thereof.
[0022]
In addition, on the outer peripheral surface of the lens frame 12, three protruding portions 12d that protrude outward in the radial direction are formed. That is, in the camera unit 10, when the cam member 13 is rotated, the cam surface 13a exerts a cam action on the protruding portion 12d, and the lens frame 12 is positioned at a desired position in the optical axis direction L. It has become.
[0023]
When the lens unit is used to align the camera unit 10 having the above configuration, the lens G2 and the lens G3 are pre-aligned and assembled, and the optical axes (axis) of the lenses G2 and G3 are assembled. Alignment is performed so that the optical axis (axial core) L1 of the lens G1 disposed at the foremost end coincides with the wick L2.
[0024]
As shown in FIGS. 1 and 4, the table 100 includes a flat mounting unit 101 (which fits the rear end surface of the camera unit 10) on which the camera unit 10 is mounted and positioned, and a drive mechanism 120 (a Z-axis described later). The stage 123) is formed by a guide portion 102 that guides the Z-axis direction (vertical direction), a connection portion 103 that is embedded in the mounting portion 101 and can removably connect the terminal wiring 16a of the CCD 16.
[0025]
Since the mounting portion 101 is formed with the mounting portion 101, simply mounting the camera unit 10 on the table 100 (mounting portion 101) and connecting the terminal wiring 16 a of the CCD 16 to the connecting portion 103 allows the monitor 160 to be connected to the monitor 160. A captured image can be displayed. Therefore, the setup for the alignment work can be easily performed, and this lens alignment apparatus can be easily inlined in the assembly line of the camera unit 10 or the like.
[0026]
As shown in FIGS. 1 and 4, the lens holder 110 is connected to a driving mechanism 120 (an X-axis stage 121 described later) that integrally holds the annular portion 111 that defines a conical opening, and the annular portion 111. The connecting portion 112 is formed.
The annular portion 111 is formed to have a conical abutment surface 111a that extends downward in the vertical direction Z, that is, toward the centered lens G1.
[0027]
Therefore, when the contact surface 111a is brought into contact with the outer peripheral edge region from the outside (above) of the lens G1, the lens G1 is pressed and held by the lens holder 110, and the lens holder 110 is moved horizontally (XY plane). Thus, the horizontal position of the lens G1 is surely performed corresponding to the movement. Further, even when the outer peripheral edge region of the lens G1 is missing or has a shape other than a circle, the lens G1 is securely held because the conical contact surface 111a is pressed from the outside.
[0028]
As shown in FIGS. 1 and 4, the drive mechanism 120 includes an X-axis stage 121 that drives the lens holder 110 so as to be able to move backward in the X-axis direction, a Y-axis stage 122 that drives the lens holder 110 so that it can move backward in the Y-axis direction, It is formed by a Z-axis stage 123 or the like that is driven to move backward in the Z-axis direction.
[0029]
As shown in FIGS. 1 and 4, the X-axis stage 121 directly holds the lens holder 110 and positions it at a desired position in the X-axis direction. The X-axis stage 121 includes a micro head 121a as a manual operation unit so that the operator can finely adjust the movement in the X-axis direction manually. Thereby, the position of the lens G1 in the X-axis direction can be adjusted with high accuracy.
[0030]
As shown in FIGS. 1 and 4, the Y-axis stage 122 carries an X-axis stage 121. By moving the X-axis stage 121 in the Y-axis direction, the lens holder 10 is moved to a desired position in the Y-axis direction. It is positioned at a position. The Y-axis stage 122 includes a micro head 122a as a manual operation unit so that the operator can finely adjust the movement in the Y-axis direction manually. Thereby, the position of the lens G1 in the Y-axis direction can be adjusted with high accuracy.
[0031]
As shown in FIGS. 1 and 4, the Z-axis stage 123 carries the Y-axis stage 122 (and the X-axis stage 121), and the lens holder 10 is moved by moving the Y-axis stage 122 in the Z-axis direction. Is positioned at a desired position in the Z-axis direction. The Z-axis stage 123 includes a micro head 123a as a manual operation unit so that the operator can finely adjust the movement in the Z-axis direction manually. Thereby, the position of the lens holder 110 in the Z-axis direction can be adjusted with high accuracy.
[0032]
The Z-axis stage 123 moves the lens holder 110 in the vertical direction (vertical direction Z) when the camera unit 10 is put in and out (exchanged). Therefore, the Z-axis stage 123 is not necessarily required in this alignment device as long as the camera unit 10 can be replaced and the lens G1 can be held without moving the lens holder 110 up and down.
[0033]
The imaging chart 130 is an alignment subject that is imaged for alignment by the CCD 16, and faces the lens G1 by a support rod 131 and a holding plate 132 fixed to the table 100 as shown in FIG. It is fixed to the front (upper) of the camera unit 10.
Note that the photographing chart 130 may be drawn directly on the surface of a hard plate instead of being held by the holding plate 132.
[0034]
Next, the alignment operation of the camera unit 10 by this lens alignment apparatus will be described. First, on the camera unit 10 in which the lenses G2 and G3 are incorporated, a lens G1 coated with an ultraviolet curable adhesive is placed in front (upper) of the lens G2. Then, the camera unit 10 is placed on the placement unit 101 of the table 100, and the terminal wiring 16 a of the CCD 16 is connected to the connection unit 103.
The lens G1 may be placed above the lens G2 (partition plate 12b) after the camera unit 10 is placed on the table 100.
[0035]
Subsequently, the Z-axis stage 123 is driven to move the lens holder 110 downward, and the contact surface 111a is brought into contact with the outer peripheral edge region of the lens G1. Accordingly, the lens G1 is pressed against the partition plate 12 (lens G2) and is held slidable in the horizontal plane (XY plane) direction. In addition, when there is no partition plate 12b, it presses directly on the lens G2.
[0036]
Subsequently, the imaging chart 130 is photographed by the CCD 16 while irradiating illumination light as necessary, and the photographed image is displayed on the monitor 160 via the image display circuit unit 140 and the control unit 150.
Then, while confirming the display image on the monitor 160, the display image is in a predetermined state (that is, a state where the optical axis L1 of the lens G1 coincides with the optical axis L2 of the lenses G2 and G3, or the image is in focus, or The micro heads 121a and 122a are appropriately rotated until the image blur becomes uniform), the X axis stage 121 and the Y axis stage 122 are driven, and the lens holder 110 (lens G1) is moved in the horizontal plane. Make fine adjustments.
[0037]
Then, when the display image on the monitor 160 is in the predetermined state, the lens G1 is irradiated with a predetermined amount of ultraviolet rays. Then, the adhesive is cured and the lens G1 is firmly fixed to the partition plate 12b (and the lens G2 and the lens frame 12).
[0038]
Thereafter, the Z-axis stage 123 is driven, the lens holder 110 is moved upward to be detached from the lens G1, the camera unit 10 that has been aligned is removed, and then the camera unit 10 that performs alignment is placed. Set. Thereafter, alignment can be performed for the plurality of camera units 10 by the same procedure.
As described above, since the setup for the alignment work can be easily performed, the time required for the entire assembly work can be reduced by installing this lens alignment device in the assembly line of the camera unit 10 or the like. And productivity can be improved.
[0039]
FIG. 5 shows another embodiment of the lens alignment device according to the present invention. The same components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted.
That is, in the lens alignment device in this embodiment, the table on which the camera unit 10 is placed is formed so as to be able to rotate around the optical axis L2 of the lenses G2 and G3 with the camera unit 10 being placed. As shown in FIG. 5, in the table 100 ′, the placement unit 101 ′ on which the camera unit 10 is placed is formed to be rotatable around the Z axis. The mounting portion 101 ′ is provided with a connection portion 103 ′ that can connect the terminal wiring 16 a of the CCD 16.
[0040]
According to this, when the mounting unit 101 ′ is appropriately rotated in a state where the camera unit 10 is mounted, the lens unit 110 is disposed behind the frontmost end (uppermost end) lens G <b> 1 held by the lens holder 110. Since the angular positions of the lenses G2 and G3 thus made can be changed, the angular direction can also be adjusted so that the optical characteristics are in an optimal state.
[0041]
In the above-described embodiment, the lens having a flange shape in which the outer peripheral edge region is formed on a flat surface is shown as the lens G1 for alignment. However, the lens is not limited to this, and lenses having other shapes are used. It can be the target of alignment.
For example, as shown in FIG. 6, even if the lens G1 ′ arranged at the foremost end is a convex flat lens having a spherical surface on the outer side, the annular portion 111 of the lens holder 110 has an abutting contact surface 111a. Therefore, the lens G1 ′ can be reliably held by being pressed, and alignment can be performed with high accuracy as in the above-described embodiment.
[0042]
In the above embodiment, the camera unit to be aligned is shown as incorporating three lenses G1, G2, and G3. However, the present invention is not limited to this, and only the lens G1 and the lens G2 are incorporated. Even so, the lens alignment apparatus and method according to the present invention can be applied.
[0043]
【The invention's effect】
As described above, according to the lens alignment device and method of the present invention, the table on which the camera unit is placed so that the front thereof is upward, and the lens disposed at the foremost end of the camera unit are pressed from the outside. A lens holder that is held in such a manner, a drive mechanism that can move the lens holder in at least a two-dimensional direction, a subject for alignment arranged in front of the camera unit, and an image of the subject photographed by the image sensor of the camera unit By providing image display means, etc., for a camera unit including a plurality of lenses arranged in the optical axis direction and an image sensor, the alignment of the lenses can be performed easily and with high accuracy. Can be done.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a lens alignment device according to the present invention.
FIG. 2 is a front view of a camera unit that can be aligned by the lens alignment apparatus of the present invention.
FIG. 3 is a cross-sectional view of a camera unit that is aligned by the lens alignment device of the present invention.
FIG. 4 is a partially enlarged view in which a part of the lens aligning device according to the present invention is enlarged.
FIG. 5 is a schematic configuration diagram showing another embodiment of the lens aligning device according to the present invention.
FIG. 6 is a cross-sectional view of a camera unit having another configuration that can be aligned by the lens alignment apparatus of the present invention.
[Explanation of symbols]
10 Camera unit G1 Frontmost lens G2, G3 Lens 100, 100 'Table 101, 101' Placement part 103, 103 'Connection part 110 Lens holder 111 Annular part 111a Contact surface 112 Connection part 120 Drive mechanism 121 X-axis stage 121a Micro head (manual operation unit)
122 Y-axis stage 122a Micro head (manual operation unit)
123 Z-axis stage 123a Micro head (manual operation unit)
130 Shooting chart (Subject for alignment)
140 Image display circuit unit (image display means)
150 Control unit (image display means)
160 Monitor (image display means)

Claims (7)

A lens alignment device that aligns lenses with respect to a camera unit including a plurality of lenses arranged in an optical axis direction and an imaging device arranged behind the plurality of lenses,
A table on which the camera unit is placed with its front facing upward;
The lens includes a vertical flat surface Oite the optical axis direction at least in the outer peripheral edge region of the inner being arranged on the most front end of the camera unit, a lens holder having an annular portion for holding so as to press from the outside,
A driving mechanism capable of moving the lens in the horizontal two-dimensional direction by holding the lens holder to move the flat surface along a plane perpendicular to the optical axis direction of the camera unit ;
An alignment subject arranged in front of the camera unit;
Image display means for displaying an image of the subject imaged by the imaging element;
A lens aligning device characterized by that. The annular portion of the lens holder has a conical contact surface that widens toward the lens.
The lens aligning device according to claim 1, wherein: The table is provided with a connecting portion capable of detachably connecting a terminal wiring led from the imaging device of the camera unit to the image display means.
The lens aligning device according to claim 1, wherein the lens aligning device is provided. The drive mechanism has a manual operation unit that can be finely adjusted manually in at least a two-dimensional direction.
The lens aligning device according to claim 1, wherein the lens aligning device is provided. The table is formed so that the camera unit can be placed and rotated around the optical axis of the lens.
The lens aligning device according to claim 1, wherein the lens aligning device is provided. A lens alignment method for aligning lenses with respect to a camera unit including a plurality of lenses arranged in an optical axis direction and an imaging device arranged behind the plurality of lenses,
Place the camera unit at a predetermined position on the table so that the front is upward,
An alignment subject arranged in front of the camera unit is imaged by an image sensor of the camera unit and displayed on a monitor,
While confirming the image displayed on the monitor until the image becomes a predetermined state, the lens comprising a flat surface perpendicular to the optical axis direction at least the outer circumferential edge region of the inner being arranged on the most front end of the camera unit Finely adjusting the flat surface of the camera unit by moving it horizontally along the plane perpendicular to the optical axis direction of the camera unit while pressing from the outside .
A lens alignment method characterized by that. For the lens arranged at the foremost end, an ultraviolet curing adhesive is applied in advance,
After the image displayed on the monitor is in the predetermined state, the adhesive is irradiated with ultraviolet rays.
The lens alignment method according to claim 6.

Images