JP3914420B2 - Optical unit eccentricity adjustment mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of an optical unit provided in an optical apparatus such as a camera, and more particularly to an eccentricity adjustment mechanism for preventing an optical axis shift between a plurality of lenses constituting the optical unit.
[0002]
[Prior art]
An optical system equipped in an optical apparatus such as a camera is adjusted by an observation apparatus as shown in FIG. That is, FIG. 6A shows an apparatus configuration for observing a photographed image formed by the optical system 1, and a photographed image by the optical system 1 is formed on the screen 7. An optical system 1 equipped in this adjusting device includes a light source 2, a condenser lens 3, a chart 4 for forming a projected image, a to-be-adjusted optical unit 5 composed of a plurality of lenses, and other lens groups 6. .
FIG. 6B is a cross-sectional view showing the internal configuration of the adjusted optical unit 5. The adjusted optical unit 5 includes a circular first lens system 11 and the first lens system 11. A first lens unit 13 composed of a cylindrical first lens frame 12 to be held, a circular second lens system 15, and a cylindrical second lens frame 16 that holds the second lens system 15. And a configuration in which the outer peripheral surface of the second lens frame 16 is held by the inner peripheral surface of the first lens frame 12.
In such an optical system 1, when there is an error in each lens constituting the lens group 6 that has been assembled, there is a deviation in the optical axis between the lenses 11, 15, or in the lens barrel (lens frame). If there is an accuracy error, an error occurs on the image plane and aberration occurs.
In order to eliminate such a deviation of the optical axis between the lenses, a relative position of the two lenses 11 and 15 included in the centered optical unit 5 is conventionally a specific lens. Alignment work was performed to offset aberrations by shifting the lens in a direction (shift direction) perpendicular to the optical axis.
In the conventional alignment work, for example, a little (one side) is provided between the outer periphery of the lens frame 16 that holds the lens 15 to be aligned and the inner diameter of the lens frame 12 that holds the other lens 11 serving as a reference for alignment. The structure is such that the lens frame 16 to be aligned can be shifted in a direction perpendicular to the optical axis by providing a gap of about 0.1 mm to 0.15 mm.
At the time of alignment work, the optical system 1 as shown in FIG. 6A is set on a dedicated alignment jig, and the positional relationship between the two lens systems 11 and 15 constituting the alignment optical unit 5 is determined. While adjusting in the shift direction, the second lens system 15 to be aligned is shifted to the position where the most balanced image state is obtained while viewing the image projected on the screen 7 as the alignment state. decide.
In this case, fine adjustment of the position of the lens to be aligned is performed by shifting in the X and Y directions orthogonal to the optical axis using a dedicated alignment jig.
After the alignment, the lens frames 12 and 16 are UV-bonded by an ultraviolet curable adhesive. Conventionally, bonding work including temporary bonding or main bonding is performed on the alignment jig. Temporary adhesion is an adhesion method in which only adhesion at a level that can ensure a minimum strength is performed in order to reduce the number of adhesion processes, and regular adhesion that ensures regular strength is performed in the next step.
[0003]
[Problems to be solved by the invention]
As described above, in the conventional alignment method, the alignment is performed by shifting the second lens system to be aligned with respect to the reference first lens system in the X direction and the Y direction perpendicular to the optical axis. ing.
For example, in the “lens decentering adjustment jig” (Olympus) of Japanese Patent Laid-Open No. 8-334664, the adjustment of the optical system during alignment is performed by moving the lens straightly in a direction perpendicular to the optical axis. It is carried out.
However, in these “straight-shifting” systems, the configuration of the alignment jig for accurately moving in the X direction and the Y direction is complicated, and the development of jigs is costly. Further, since it is necessary to shift and adjust the second lens system in units of microns even in actual alignment work, a certain level of skill is required for the operator.
One object of the present invention is to provide a decentering adjustment mechanism for an optical unit that prevents the configuration of the aligning jig from becoming complicated and costly, and that enables alignment without requiring skill. .
Next, using an adhesive as the fixing means for the lens frames after alignment is an effective means for reducing the size of the optical system unit to be aligned and reducing the number of parts. However, in the bonding work in the alignment process, for example, even when UV bonding is performed, the time until the adhesive is cured is that the alignment optical unit occupies the alignment jig. The productivity of alignment work is reduced.
Another object of the present invention is to cure the adhesive in a state in which the optical alignment unit is removed from the alignment jig even when the adhesive is used as a fixing means for the lens frames after alignment. This is to improve the productivity by increasing the operating rate of the alignment jig.
Next, there is an example in which a holding member that fixes between two lens frames constituting an optical unit requiring alignment without using an adhesive has been commercialized before. This holding member has a configuration that requires screwing, and is used by being assembled into an optical system component without being removed from the lens frame even after the alignment process. However, there are concerns about the complexity of the process due to screwing, the increase in size due to the space occupied by the holding member, and the restriction on the layout. Furthermore, when the holding member is a metal spring, this may cause internal reflection.
[0004]
Another object of the present invention is that when fixing the two lens frames constituting the to-be-adjusted optical unit, the process becomes complicated, the size is increased, the layout is restricted, and a part of the holding member is internally reflected. It is to prevent the occurrence of the occurrence.
Also, in the past, an adhesive application space for bonding between the lens frames constituting the optical core unit to be adjusted was separately provided at the joint between the lens frames, which increased the size and complexity of the lens frame. However, an object of the present invention is to improve the space efficiency by enabling the application of an adhesive without providing a special bonding space.
As described above, the present invention aims to improve the alignment method and the alignment mechanism in the aligned optical unit used for alignment.
[0005]
[Means for Solving the Problems]
  In order to solve the above-mentioned problems, a first lens unit comprising a first lens system, and a cylindrical first lens frame that holds the first lens system, and a second lens unit are provided. A second lens unit comprising a lens system and a cylindrical second lens frame that holds the second lens system, and the second lens frame is formed by an inner peripheral surface of the first lens frame. Each of the optical units having a configuration in which the outer peripheral surface of the first lens system is rotatably held, so that the optical axis of the first lens system and the optical axis of the second lens system are decentered in advance by a predetermined value. When the lens frame is configured and the alignment operation is performed, the second lens unit is rotated with respect to the first lens unit so that the optical axis of the second lens system is the optical axis of the first lens system. Or a position very close to the optical axis of the first lens system. The first lens frame and the second lens frame each have a flange portion at one end edge in the optical axis direction, and after the positioning of the second lens unit with respect to the first lens unit is completed, both lenses It has a holding member that joins each flange part of the unit,A required gap is provided between the inner peripheral surface of the first lens frame and the outer peripheral surface of the second lens frame, and at least one through hole provided in the first lens frame has a ball bearing at the tip. An alignment pin held rotatably is supported, and the outer peripheral surface of the second lens frame can be rotated by the ball bearing of the alignment pin or the ball bearing and the inner peripheral surface of the first lens frame. A decentering amount of the optical axis of the second lens system with respect to the first lens system is set to a predetermined value by the adjustment pin.It is characterized by that.
  In the present invention, the configuration of the alignment jig can be simplified and the alignment operation can be simplified by using the second lens unit used for alignment as an adjustment method only for rotational adjustment. As in the prior art, the workability can be greatly reduced as compared with the fine adjustment work in which the lens unit used for alignment is shifted in the direction orthogonal to the optical axis. Further, by fixing both lens units using the holding member, it is possible to perform the bonding operation in the alignment process in a separate process, and to reduce the man-hour of the alignment process.Also,The alignment of the optical axis between the two lenses is performed using a centering pin, and the outer peripheral surface of the inner lens unit is rotatably supported by the centering pin. Alignment can be performed.
[0006]
  Claim2The invention of claim1In the above, a stopper portion for preventing rotation of the holding member is provided on at least one of the flange portions provided on the first and second lens frames, respectively.
  The attachment workability of the holding member can be improved by stopping the screwing of the holding member, which has been conventionally performed, so that the holding member itself has a spring property and sandwiches the lens frame. In addition, it is possible to effectively utilize the space of the lens unit by making the shape so that the functionally unnecessary holding member can be easily removed after the alignment work, and the optical system caused by the holding member It is possible to prevent image deterioration due to internal reflection of the inside.
  Claim3The invention of claim 1 or claim2The flange portion of the second lens frame is formed with a plurality of jig holes through which a plurality of protrusions provided on a rotating jig for rotating the second lens unit are fitted, respectively. The tool hole is used as a space for applying an adhesive when the second lens frame is bonded to the first lens frame in the bonding step after the alignment operation.
  In order to rotate the entire second lens unit with the rotating jig, a plurality of “rotating jig holes” for receiving the protrusions of the rotating jig are provided in the flange portion of the second lens frame. The “hole” becomes an unnecessary space after alignment. Therefore, by setting this space as a through hole and filling the adhesive from the through hole so that the first lens frame and the second lens frame can be bonded, there is no need to provide a separate bonding space. It can be improved so as not to place a burden on the design freedom and the frame structure.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
The to-be-adjusted optical unit that receives alignment by the adjusting mechanism of the present invention corresponds to the to-be-adjusted optical unit 5 constituting the projection optical system shown in FIG. The image can be confirmed visually. Therefore, the embodiment of the present invention will be described with reference to the configuration of FIG.
The adjusting mechanism according to the present invention adjusts the optical axes of the first and second lens units 13 and 17 constituting the to-be-adjusted optical unit 5 in the direction in which they are aligned, and the lens positioned at the rear stage by this adjustment operation. The optical axis shift caused by the manufacturing error and assembly error of the group 6 is also adjusted.
That is, FIG. 1A is a cross-sectional view for explaining the configuration of the adjustment mechanism of the optical unit of the present invention. The to-be-adjusted optical unit 5 includes a first lens system 11 having a circular planar shape and the first lens system 11. A first lens unit 13 including a cylindrical first lens frame 12 that holds the outer periphery of one lens system 11, a second lens system 15 having a circular planar shape, and a second lens system 15 are held. A second lens unit 17 composed of a cylindrical second lens frame 16, and the outer peripheral surface of the second lens frame 16 is rotatably held by the inner peripheral surface of the first lens frame 12. It has a configuration. The embodiment of the positional relationship between the two lens frames is merely an example, and the present invention includes a configuration in which the second lens frame 16 is disposed on the outer diameter side of the first lens frame 12.
[0008]
The eccentricity adjusting mechanism 30 according to the present invention is provided on the alignment base unit 31 provided with a fitting hole 32 and a support surface 33 for supporting the first and second lens units 13 and 17, and the adjusted optical unit 5 side. And a structure for characteristic adjustment.
The first lens frame 12 has a bilaterally symmetric shape with the optical axis A1 as the center, and the thickness of each part is also uniform in the circumferential direction. A fixed support portion 12a that fixedly supports the first lens system 11 is provided at one end portion of the first lens frame 12, and the outer periphery of the second lens frame 16 is rotatably supported above the fixed support portion 12a. A recessed sliding support portion 12b is provided. The outer peripheral surface of the first lens frame 12 is fitted in the fitting hole 32 of the alignment base 31, and is locked on the support surface 33 by a flange portion 12c provided at the other end.
The second lens frame 16 has an outer periphery of the second lens system 15 at an inner periphery near one end of the main body 16a having an outer peripheral surface in close contact with the inner peripheral surface of the sliding support portion 12b of the first lens frame 12. And a flange portion 16b opposite to the flange portion 12c of the first lens frame 12 is provided. A plurality of jig holes (or recesses) 16c are formed on the end surface of the flange portion 16b at a predetermined circumferential pitch. The jig hole 16c is a through hole or a recess into which a plurality of protrusions 42 provided on a rotation jig 41 for rotating (turning) the second lens unit 17 are fitted, and has a predetermined circumferential pitch. A plurality of jig holes are formed. As will be described later, the jig hole 16c as a through hole is used as a space for applying an adhesive when the second lens frame 16 is bonded to the first lens frame 12 in the bonding step after the alignment operation. Is done.
[0009]
A characteristic configuration of the embodiment of the present invention includes a first lens unit 13 including a circular first lens system 11 and a cylindrical first lens frame 12 that holds the first lens system 11; A second lens unit 17 including a circular second lens system 15 and a cylindrical second lens frame 16 that holds the second lens system 15, and the inner part of the first lens frame 12. In the optical unit 5 having a configuration in which the outer peripheral surface of the second lens frame 16 is rotatably held by the peripheral surface 12b, the optical axis of the first lens system 11 and the optical axis of the second lens system 15 are The configuration of each lens frame is set in advance so as to be decentered by a predetermined value ΔX, and the second lens unit 17 is rotated relative to the first lens unit 13 during the alignment operation. The optical axis of the second lens system 15 is the same as that of the first lens system 11. Position corresponding to the shaft, or in that constructed to reach a position very close to the optical axis of the first lens system.
[0010]
FIGS. 1B and 1C are a longitudinal sectional view and a side view showing the assembled state of the first and second lens units constituting the adjusting mechanism of the present invention, and the optical axis of the second lens system 15. A2 is configured in advance so as to be shifted in the radial direction by a predetermined value ΔX with respect to the optical axis A1 of the first lens system 11.
As described above, as an alignment method for aligning the optical axis of the second lens system 15 with the first lens system 11, the configuration of the conventional lens cell is as shown in FIG. It is assumed that coaxial management is performed on the first lens frame 12 and the second lens frame 16, respectively. However, in the case of an actual optical system, it is difficult to ideally align the optical axis due to decentering of a single lens or stacking of frame coaxial errors. For this purpose, a process called eccentric adjustment is required.
As described above, the conventional eccentric adjustment is referred to as shift adjustment, and is performed by linearly moving the second lens system 15 that is a to-be-adjusted lens in the shift direction, but in the embodiment of the present invention. The second lens frame with respect to the X first lens frame 12 in advance so that the optical axis A2 of the second lens system 15 is decentered by ΔX with respect to the optical axis A1 of the first lens system 11 in advance. 16 is configured to be eccentric. The second lens frame 16 is rotated by a required angle by the lens frame rotation jig 41, and adjustment is performed by finding a position that is most compatible with the first lens system 11.
That is, ΔX is determined from the amount of eccentricity allowed in the lens design and the accumulated tolerance value in the lens frame configuration, and the locus of the locus that draws a circle of radius ΔX with respect to the optical axis A1 of the first lens system. Determine the most balanced position. In determining the position where the adjustment of the optical axis is most balanced, a known method such as observing a chart image projected on the screen 7 can be used.
[0011]
In this example, the thickness of each part of the first lens frame 12 is set constant in the circumferential direction, while the thickness of the side wall of the second lens frame 16 is illustrated in FIGS. 1A and 1B, for example. As shown in the figure, the side wall of one half circumference sandwiching the optical axis is thick, and the other half of the opposite half circumference is thin (for convenience of illustration, the thickness difference between the side walls is the value of ΔX Is overstated). Therefore, the cylindrical outer peripheral shape of the second lens frame 16 is shifted by ΔX with respect to the cylindrical inner peripheral shape of the first lens frame 12, and is supported by the lens frames 12 and 16, respectively. Further, a deviation of ΔX occurs between the optical axes A1 and A2 of the lenses 11 and 15.
At this time, since the optical axis A2 of the second lens 15 rotates so as to draw a circle with a radius ΔX around the optical axis A1 of the first lens 11, the most balanced portion in the movement trajectory is found. The positioning of the second lens unit 17 at the position is effective in preventing the occurrence of aberration due to the optical axis misalignment or the like.
Further, by configuring the second lens frame 16 so that the center of rotation when rotating the second lens unit 17 does not coincide with the optical axis A1 of the first lens 11, the second lens 15 is configured. It is possible to include the optical axis A1 of the first lens 11 in the movement trajectory of the second optical axis A2 when the lens rotates. That is, the first optical axis A1 and the second optical axis A2 can be completely matched. With this configuration, the error component due to the stacking of the optical axis shifts in the lens group 6 positioned at the subsequent stage of the optical axis unit 5 is aligned between the lenses 11 and 15 in the optical axis unit 5. By canceling, it becomes possible to eliminate the aberration.
Regarding the determination of the amount of “ΔX”, for example, when the lens frames 12 and 16 are plastic molded products, the error amount is calculated based on the inspection data of the mold. Further, the amount of eccentricity of a single lens is calculated from the process capability of the lens polishing process. “ΔX” can be determined by accumulating these data.
The specific value of “ΔX” is determined in the range of φ0.02 ± 0.01 because the average lens frame coaxiality error amount in mass production is about φ0.02.
[0012]
Next, a second embodiment of the present invention will be described based on the cross-sectional view of the optical core unit to be adjusted shown in FIGS. 2A and 2B and the enlarged view of the main part. That is, in the first embodiment, the amount “ΔX” for decentering the lenses 11 and 15 is reflected in the dimensions of the second lens frame 16 in advance, but in the present embodiment, the first lens A required gap G between the inner peripheral surface 12b of the frame 12 and the outer peripheral surface of the main body 16a of the second lens frame 16 ("eccentric white" provided at a position to be the radial reference position of both lens frames). The outer diameter of the second lens frame 16 is set to be smaller than the inner diameter of the first lens frame 12 by a predetermined amount. An alignment pin 45 that rotatably supports a ball bearing 47 is supported at the tip of the pin body 46 by at least one through hole 12A provided in the first lens frame 12. A plurality of alignment pins 45 are arranged on the side wall of the first lens frame 12 at a predetermined circumferential pitch, and the second lens frame outer peripheral surface is rotatably supported by ball bearings 47 of the plurality of alignment pins 45. Also good. Alternatively, the first lens frame 12 is provided with a hollow cylindrical lens unit receiving member 18 that rotatably supports the first lens unit 13 (the outer peripheral surface of the first lens frame 12 and the like) by the inner peripheral surface. The outer peripheral surface of the frame may be rotatably supported. Reference numeral 19 denotes a third lens unit positioned in front of the first and second lens units 13 and 17, and the third lens unit 19 includes a third lens system (front group lens) 19a. And a third lens frame 19b for positioning and supporting the outer periphery of the third lens system 19a. The third lens frame 19b is also positioned by the lens unit receiving member 18. In order to make it possible to use the rotating shaft 41 when the first lens unit 13 is rotated with respect to the lens unit receiver 18, a jig hole 12 e is also provided on one axial end surface of the first lens frame 12. Form.
[0013]
The optical axis A1 is an optical axis in which the optical axis of the first lens system 11 and the optical axis of the third lens system 19a coincide with each other. The optical axis is shifted by a predetermined value “ΔX”.
In any case, the amount of protrusion of the adjustment pin 45 in the inner diameter direction is set in advance, and the deviation between the optical axes A1 and A2 of both lenses 11 and 15 is set to a predetermined value “ΔX”. . At this time, the rotation center of the second lens 15 may be set so as to coincide with the optical axis A1 of the first lens 11, or the second lens is placed so that the rotation center comes to other positions. You may make it rotate.
As described above, in the present embodiment, a gap called “eccentric white” is provided at the radial reference position of the first lens frame 12 and the second lens frame 16, and the first pin 45 is used as the first pin. Since the eccentric amount “ΔX” of the second lens frame 16 is adjusted with respect to the lens frame 12, this is an especially effective alignment means when the variation width in the eccentric direction is large.
As a method of determining the amount of eccentricity ΔX, for example, when the coaxiality of the lens frame constituting the lens barrel of the optical unit 5 to be aligned is about φ0.02 (mm), the value of ΔX obtained experimentally As a test, the test is carried out at about φ0.03 to φ0.05 (0.015 to 0.025 on one side), the molding condition improvement of the lens frame in the prototype step, the transition of the optical system eccentricity after assembly, the direction of eccentricity ΔX is reduced to reflect the result when the current becomes stable, such as φ0.02 ± 0.01 (φ0.01 to φ0.03 (one side 0.005 to 0.015)). The steps are determined.
That is, in this embodiment, the eccentric amount ΔX is determined from the eccentric amount allowed in lens design and the tolerance accumulated value in the configuration of the lens frame, and the eccentric amount ΔX is managed by the eccentric pin 45. .
[0014]
Next, FIGS. 3A and 3B are a cross-sectional view and a perspective view showing a configuration of an adjustment mechanism according to another embodiment of the present invention.
In the adjustment mechanism of the present embodiment, each of the first lens frame 12 and the second lens frame 16 includes flange portions 12c and 16b at one end edge in the optical axis direction, and is a second lens for the first lens unit 13. A characteristic feature is that the holding member 50 is provided to connect the flange portions of both lens units after the positioning of the unit 17 is completed.
That is, the to-be-adjusted lens systems 11 and 15 need to be fixed at positions adjusted after the alignment operation. Here, the holding member 50 as a “pressing spring” that does not interfere with the alignment work is used, and after the alignment is completed, the aligned second lens frame 16 does not move from the first lens frame 12. To fix. In this state, the alignment optical unit 5 is removed from the alignment base 31, and the bonding operation is performed in the bonding process. The holding member 50 may be removed after the bonding operation.
The holding member 50 is made of, for example, a metal material such as stainless steel, and two clamping pieces 50a that are elastically pinched and held between two adjacent flange portions 12c and 16b are connected and integrated by an arc-shaped coupling piece 50b. It has a simplified configuration. The holding member 50 can attach each pinching piece 50a from the side surfaces of both flanges. By fixing the lens units 13 and 17 that have been aligned using the two holding members 50, the lens units 13 and 17 can be detached from the alignment base 31, and can be held even after being removed. After the bonding is completed by applying and filling an adhesive in the gap between the flange portions 12c and 16b of the lens units 13 and 17 connected by the holding member 50 and curing, the adjustment can be performed by removing the holding member 50. The tuned optical unit 5 having completed the core is completed. Note that the holding member 50 has a clamping pressure on the outer peripheral surface of the portion 12c ′ that is positioned on the outer diameter side of the flange portion 12b by bending the outer peripheral edge of the flange portion 12c. By providing the stopper groove 12d that stops the rotation by locking the piece 50a or the stopper projection, the pressing piece 50a slips between the flange portion and completes the positioning. It is possible to prevent a problem that the lens units 13 and 17 are displaced. Further, by preventing the holding member 50 from rotating, it is also possible to perform the alignment work by rotating only the inner second lens unit in a state in which both flange portions are held with pressure by the holding member 50. .
[0015]
In this embodiment, by fixing both lens units using the holding member 50, the bonding operation in the alignment process can be performed in a separate process, and the number of steps in the alignment process can be reduced.
In addition, if it is possible to remove the alignment jig (alignment base) 31 and perform bonding, the degree of freedom in the bonding process increases. For example, when UV bonding is considered, it is impossible to bond on the alignment jig where UV light does not rotate. However, if the lens frame that requires bonding is removed from the alignment jig, all Since the site can be irradiated with UV light, there is no such inconvenience. Therefore, the bonding man-hour itself can be improved.
In addition, it is possible to improve the mounting workability of the holding member by stopping the screwing of the holding member, which has been conventionally performed, so that the holding member 50 itself has a spring property and sandwiches the appropriate positions of both lens frames. . Further, by making the holding member 50 functionally unnecessary after the alignment work, the lens unit space can be effectively used and the optical generated by the holding member can be easily removed. It is possible to prevent image deterioration due to internal reflection in the system.
[0016]
Next, FIG. 4 is a perspective view showing a configuration of an adjustment mechanism according to the third embodiment of the present invention. The difference from the embodiment of FIG. 3 is that the outside of the flange portion 12c of the first lens frame 12 is outside. This is a point that uses a holding member 50 that is configured so that the peripheral shape is an oval shape (including an oval shape and an oval shape) and the pressing piece 50a is positioned on the long side portion. Needless to say, a stopper portion 12d made of a stopper groove or a stopper projection may be provided on the outer surface of the long side portion. By providing the stopper portion 12d, it is possible to rotate the second lens frame 16 while preventing the holding member 50 holding both flange portions from rotating. After the alignment and bonding operations are completed, the holding member can be easily removed in the lateral direction.
That is, the inner periphery of the first lens frame 12 is cylindrical, and the outer periphery of the second lens frame 16 can be rotatably supported by the inner periphery. Since the outer shape is an oval shape, the two flange portions 12c and 16b cannot be sufficiently clamped and held by the holding member 50 having the arc-shaped connecting piece 50b as shown in FIG. For this reason, as shown in the figure, by using the holding member 50 in which the two pinching pieces 50a are integrated by the linear connecting piece 50b, the flange portion can be pinched and held.
Next, FIG. 5 is a cross-sectional view of a lens unit assembly (aligned optical unit 5) according to another embodiment of the present invention. In this embodiment, the second lens frame is used as the rotation jig hole 16c. By using the through hole formed in the flange portion 16b as a “rotating jig hole / adhesive application space”, the adhesive 55 is applied from the rotating jig hole 16c to the bonding surface between the flange portions. The first lens frame and the second lens frame are fixed.
[0017]
【The invention's effect】
  As described above, according to the first aspect of the present invention, the configuration of the alignment jig is simplified by making the second lens unit used for alignment only the rotation adjustment, thereby simplifying the alignment operation. can do. That is, the work necessary for the alignment work is only to rotate the second lens frame (second lens unit) integrally provided with the second lens to be aligned. There is no need to shift and adjust the to-be-adjusted lens system in the direction perpendicular to the optical axis. Therefore, alignment work is simplified, workability is improved, and mass productivity is improved. As a result, work man-hours can be reduced and costs can be reduced.
Furthermore, by fixing both lens units using the holding member, it is possible to perform the bonding operation in the alignment process in a separate process, and the man-hours in the alignment process can be reduced. The occupancy time of the alignment jig can be shortened, the alignment man-hours can be reduced, and the capital investment of the alignment device can be held down. Compared with the bonding work on the alignment jig, the bonding workability is improved and the restriction on the bonding position is remarkably improved, so the man-hour of bonding itself is reduced, the mass productivity is improved and the cost is reduced. It becomes possible.
  Claim 1In the invention, the alignment of the optical axis between the two lenses is performed using the alignment pin, the necessary alignment amount can be adjusted in advance, and the adjustment amount can be easily changed in advance. By providing a ball bearing at the tip of the alignment pin, when the second lens system has an eccentric component with respect to the second lens frame, the alignment by the method of rotating the second lens frame is It becomes an effective means. Also, by inserting the first lens frame while rotating it, the sitting of the second lens frame (preventing the generation of components in the tilt direction) can be stabilized. The same rotation as that of claim 1 by rotating the entire first lens unit with reference to the inner peripheral surface of the lens unit receiving member that supports the first lens unit and the outer peripheral surface of the first lens frame. It is possible to perform alignment while making Therefore, it is easy to cope with the variation width of the component accuracy, the number of units that cannot be aligned can be significantly reduced, and the generation of the failer cost can be suppressed.
[0018]
  Claim2According to the present invention, the attaching workability of the holding member can be improved by stopping the screwing of the holding member, which has been conventionally performed, and giving the holding member itself springiness and sandwiching the lens frame. In addition, it is possible to effectively utilize the space of the lens unit by making the shape so that the functionally unnecessary holding member can be easily removed after the alignment work, and the optical system caused by the holding member It is possible to prevent image deterioration due to internal reflection of the inside. Since it is easy to attach and detach the holding member, the burden of the holding member mounting process is less than that of a method such as screwing. Further, since the removal after the alignment work is easy, it is possible to effectively use the space of the holding member which is not directly necessary for ensuring the functional quality for another purpose by removing the holding member after the alignment. Further, when the holding member is made of a metal, it can be prevented in advance that it causes internal reflection.
  Claim3In the present invention, a plurality of “rotating jig holes” for receiving the protrusions of the rotating jig are provided in the flange portion of the second lens frame in order to rotate the entire second lens unit with the rotating jig. The “rotating jig hole” becomes an unnecessary space after alignment. Therefore, by setting this space as a through hole and filling the adhesive from the through hole so that the first lens frame and the second lens frame can be bonded, there is no need to provide a separate bonding space. It can be improved so as not to place a burden on the design freedom and the frame structure. That is, by using both the “rotating jig hole” and the “adhesive application space”, fixing after alignment is possible without providing a new space for applying the adhesive. Therefore, there are advantages such as effective utilization of space, simplification of the mold structure of the lens frame, and improvement in design flexibility.
[Brief description of the drawings]
1A is a cross-sectional view illustrating the configuration of an adjustment mechanism of an optical unit according to the present invention, and FIGS. 1B and 1C are an assembly of first and second lens units that constitute the adjustment mechanism of the present invention. The longitudinal cross-sectional view which shows a state, and a side view.
2A and 2B are a cross-sectional view and an enlarged view of a main part of a to-be-adjusted optical unit according to another embodiment of the present invention.
FIGS. 3A and 3B are a cross-sectional view and an external perspective view of a to-be-adjusted optical unit including an adjustment mechanism according to another embodiment of the present invention.
FIG. 4 is an external perspective view of a to-be-tuned optical unit including an adjustment mechanism according to another embodiment of the present invention.
FIG. 5 is a cross-sectional view of a to-be-adjusted optical unit including an adjustment mechanism according to another embodiment of the present invention.
6A is a schematic diagram illustrating an example of a conventional optical system, and FIG. 6B is a cross-sectional view of an optical unit to be adjusted.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Optical system, 2 Light source, 3 Condenser lens, 4 Chart, 5 Adjustable center optical unit, 6 Lens group, 7 Screen, 11 1st lens system, 12 1st lens frame, 12a Fixed support part, 12b Sliding Support portion (inner peripheral surface), 12c flange portion, 12d stopper portion, 13 first lens unit, 15 second lens system, 16 second lens frame, 16a body, 16b flange portion, 16c jig hole, 17 Second lens unit, 30 adjustment mechanism, 31 alignment base, 32 fitting hole, 33 support surface, 41 rotating jig, 42 protrusion, 45 alignment pin, 46 pin main body, 47 ball bearing, 50 holding member, 50a Clamping side, 50b connecting member

Claims (3)

A first lens unit comprising a first lens system and a cylindrical first lens frame that holds the first lens system;
A second lens unit, and a second lens unit comprising a cylindrical second lens frame that holds the second lens system,
An optical unit having a configuration in which the outer peripheral surface of the second lens frame is rotatably held by the inner peripheral surface of the first lens frame,
Each lens frame is configured such that the optical axis of the first lens system and the optical axis of the second lens system are decentered by a predetermined value in advance,
During the alignment operation, the second lens unit is rotated with respect to the first lens unit so that the optical axis of the second lens system coincides with the optical axis of the first lens system, or Configured to reach a position very close to the optical axis of the first lens system,
Each of the first lens frame and the second lens frame includes a flange portion at one edge in the optical axis direction, and after the positioning of the second lens unit with respect to the first lens unit is completed, Bei give a holding member for coupling the respective flange portions each other,
A required gap is provided between the inner peripheral surface of the first lens frame and the outer peripheral surface of the second lens frame,
A centering pin holding a ball bearing rotatably at the tip is supported by a through-hole provided in at least one of the first lens frame,
The outer peripheral surface of the second lens frame is rotatably supported by the ball bearing of the alignment pin, or the ball bearing and the inner peripheral surface of the first lens frame,
A decentering adjustment mechanism for an optical unit, wherein the decentering amount of the optical axis of the second lens system with respect to the first lens system is set to a predetermined value by the adjusting pin .   2. The eccentricity of the optical unit according to claim 1, wherein a stopper portion for preventing rotation of the holding member is provided on at least one of the flange portions provided on each of the first and second lens frames. Adjustment mechanism. The flange portion of the second lens frame is formed with a plurality of jig holes through which a plurality of protrusions provided on a rotating jig for rotating the second lens unit are respectively fitted. It is regulated by the centering operation after the bonding step, according to claim 1 or 2, characterized in that it is using the second lens frame as a space for adhesive application when bonded to the first lens frame Optical unit eccentricity adjustment mechanism.

Images