JP2019148646A - Lens centering method and device - Google Patents

Abstract

To provide a lens centering method and device in which a centering work is simple and shortened, and work efficiency is excellent.SOLUTION: A lens centering device comprises: lens holding means 2 that holds a reference lens 3 and a driven lens 4 at a prescribed location in a centering location L; a lens drive actuator 5 that has a reciprocal mover 5a made freely retractable toward an optical axis in the centering location; and control means 9 that causes the reciprocal mover of the lens drive actuator to move back and force,and stores a location where a tip end of the reciprocal mover aligns the optical axis and abuts with a circumference of the reference lens held by the lens holding means as a reference circumference location, moves the driven lens held by the lens holding means to the stored reference circumference location, and aligns an optical axis of the driven lens.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lens centering method and apparatus, and more particularly to a lens centering method and apparatus suitable for centering a cemented lens.

  In an optical unit including a camera lens, a cemented lens in which a plurality of lenses are bonded to each other is used in order to remove various aberrations of the optical system and improve characteristics. Since optical glass, which is the material of the lens, is a transparent and easily damaged material, a centering operation for aligning the optical axes of a plurality of lenses is performed manually.

  However, since it is necessary to move the lens with micron-order accuracy for centering, it has been proposed to perform mechanical centering (see Patent Document 1 and Patent Document 2).

JP 11-006945 A JP 2000-352647 A

  In the centering devices shown in Patent Document 1 and Patent Document 2, the optical axes of both lenses coincide when the upper lens and the lower lens that are stacked vertically with the lens surfaces facing each other are joined. The centering is performed by moving the upper lens until the optical axis coincides with the lower lens fixed while optically measuring this.

  However, according to the methods of both Patent Documents 1 and 2, the centering operation is complicated because the movement of the upper lens and the measurement of the optical optical axis coincidence are performed each time the both lenses are centered. As a result, the centering operation takes a long time and the work efficiency is poor.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a lens centering method and apparatus that have a simple and short centering operation and that have a high work efficiency.

  In order to achieve the above-described object, the lens centering method according to the first aspect of the present invention includes a reciprocating slider of a lens driving actuator with respect to the outer periphery of a reference lens that is installed with its optical axis aligned at the centering position. The reference outer periphery in which the position where the tip is moved toward the optical axis and abutted is stored as a reference outer peripheral position, and then the driven lens held at the centering position is stored by the reciprocating mover of the lens driving actuator. And moving the optical axis of the driven lens to the optical axis position of the reference lens.

  A lens centering method according to a second aspect of the present invention is the lens centering method according to the first aspect, wherein the reference lens is an upper lens of a reference cemented lens, and the driven lens is on a lower lens of the centered cemented lens. And the optical axis of the lower lens and the upper lens of the centering cemented lens is aligned with the lens driving actuator as an ultrasonic actuator.

  The lens centering method according to a third aspect of the present invention is the lens centering method according to the first or second aspect, wherein the reciprocating element is advanced and retracted in four directions orthogonal to the optical axis. A drive actuator is provided to align the optical axis.

  The lens centering device according to the first aspect of the present invention includes a lens holding means for holding the reference lens and the driven lens at predetermined positions at the centering position, and can be advanced and retracted toward the optical axis at the centering position. The lens drive actuator having the reciprocating mover and the reciprocating mover of the lens drive actuator are moved forward and backward, and the reference of the tip of the reciprocating mover is held by the lens holding means with the optical axis aligned Control means for storing the position in contact with the outer periphery of the lens as a reference outer peripheral position, moving the driven lens held by the lens holding means to the stored reference outer peripheral position, and aligning the optical axis of the driven lens It is characterized by having.

  The lens centering device according to the second aspect of the present invention is the lens centering device according to the first aspect, wherein the reference lens is an upper lens of a reference cemented lens, and the driven lens is a lower lens of the centered cemented lens. An upper lens placed on the lens, wherein the lens driving actuator is an ultrasonic actuator.

  In the lens centering device according to the third aspect of the present invention, in the first or second aspect, the four lens driving actuators are respectively provided in four directions orthogonal to the optical axis. It is characterized by being.

  According to such a configuration, the lens centering device according to the first aspect of the present invention is operated in accordance with the lens centering method according to the first aspect of the present invention, so that the lens centering operation is simple. It is possible to execute lens centering with a short working time and high work efficiency.

  Further, by operating the lens centering device according to the second aspect of the present invention according to the lens centering method according to the second aspect of the present invention, the centering operation of the cemented lens can be performed easily and in a short time, and the work efficiency can be improved. Good lens centering can be performed.

  Further, by operating the lens centering device according to the third aspect of the present invention in accordance with the lens centering method according to the third aspect of the present invention, the lens centering work can be accurately performed using the four lens driving actuators. This makes it easy and time-consuming, and can perform lens centering with high work efficiency.

  By operating the lens centering device of the present invention according to the lens centering method of the present invention, the centering operation of the lens can be performed easily and in a short time, and the lens centering with high work efficiency can be executed.

1 is an overall block diagram showing an embodiment of a lens centering device according to the present invention. The top view which shows the positional relationship of the lens holding means and lens drive actuator of the lens centering apparatus which concerns on this invention (1) to (6) are diagrams corresponding to FIG. 2 in the lens centering method according to the present invention. The flowchart which shows the process of the lens centering method which concerns on this invention.

  Hereinafter, embodiments of a lens centering method and a lens centering apparatus according to the present invention will be described with reference to FIGS.

  1 and 2 show a lens centering device 1 according to this embodiment.

  In the lens centering device 1, a vertical centering position L (see a chain line in FIG. 1) for matching the optical axes of the respective lenses is set, and the reference lens and the driven lens are respectively set at the centering position L. A holding mount 2 is provided as a lens holding means for holding the position. On the holding mount 2, the reference lens 3 is fixed and held with its optical axis coinciding with the optical axis at the centering position L, and the driven lens 4 is held movably in the XY directions. In the present embodiment, four lens drive actuators 5, 6, 7, and 8 are provided at intervals of 90 degrees around the optical axis at the centering position L, and from four directions orthogonal to the optical axis. It has reciprocating movers 5a, 6a, 7a, 8a that can be moved back and forth toward the optical axis. In the present embodiment, ultrasonic motors that can move the reciprocating movers 5a, 6a, 7a, and 8a forward and backward at a fine pitch in units of microns are used as the lens driving actuators 5, 6, 7, and 8. Of course, other actuators can be used as long as the actuator can move the moving element linearly. The lens driving actuators 5, 6, 7, and 8 are formed so as to be driven and controlled by a control means 9 having a CPU, a memory and the like. The control means 9 transmits a pulse command for moving the reciprocating elements 5a, 6a, 7a, 8a of the lens driving actuators 5, 6, 7, 8 to advance and retreat, and the reciprocating elements 5a, 6a, 7a. The position where the tip of 8a is in contact with the outer periphery of the reference lens 3 held on the holding mount 2 of the lens holding means with the optical axis aligned is stored as the reference outer peripheral position and held on the holding mount 2 of the lens holding means. The driven lens 4 is moved to the stored reference outer peripheral position so as to perform control for adjusting the optical axis of the driven lens 4.

  Next, a lens centering process by the lens centering method according to the present invention will be described with reference to FIGS.

  In the present embodiment, a case where a cemented lens in which an upper convex lens is joined to a lower concave lens with both optical axes joined together will be described as an example.

Step ST1 (see FIG. 3 (1)):
A reference lens 3 in which a lower concave lens 3a and an upper convex lens 3b prepared in advance are joined with their optical axes aligned is made to match the optical axis of the centering position L of the holding mount 2 on the eccentricity measuring instrument. Place.

Step ST2 (see FIG. 3 (2)):
Next, a command is issued by the control means 9, and the reciprocating movers 5a, 6a, 7a, 8a of the lens driving actuators 5, 6, 7, 8 are brought into contact with the outer peripheral surface of the convex lens 3b above the reference lens 3. Then, the position is retracted by 10 μm, and the retracted position is stored in the memory of the control means 9 as the reference outer peripheral position (may be the position before the retracting). When the reciprocating elements 5a, 6a, 7a, and 8a are brought close to the convex lens 3b, they are brought close to the neighboring position that is a minute distance Δ1 away from the outer peripheral surface of the convex lens 3b, and then moved at a fine pitch in units of microns. Good. Thereby, the efficiency can be improved.

Step ST3 (see FIG. 3 (3)):
Next, a command is issued by the control means 9, and the reciprocating movers 5a, 6a, 7a, 8a of the lens driving actuators 5, 6, 7, 8 are retracted outward from the outer peripheral surface of the reference lens 3, and thereafter The reference lens 3 is removed from the holding mount 2.

Step ST4 (see FIG. 3 (4)):
Next, a UV curable adhesive is applied between the lens surfaces of the lower concave lens 4a and the upper convex lens 4b manufactured as the driven lens 4 in the same shape and the same size (jointly) as the reference lens 3. After that, the lower concave lens 4 a is placed so as to match the optical axis of the centering position L of the holding mount 2.

Step ST5 (see FIG. 3 (5)):
Next, a command is issued by the control means 9, and the reciprocating movers 5a, 6a, 7a, 8a of the lens driving actuators 5, 6, 7, 8 are slightly moved from the outer peripheral surface of the convex lens 4b above the driven lens 4. Then, the reciprocating movers 5a, 6a, 7a, 8a are moved 10 μm at a fine pitch in micron units and brought into contact with the outer peripheral surface of the convex lens 4b. In this case, even if the minute movement length of each reciprocating mover 5a, 6a, 7a, 8a is less than 10 μm, the ultrasonic motor idles further movement of each reciprocating mover 5a, 6a, 7a, 8a. Stop and absorb well.

  Here, the convex lens 4b of the driven lens 4 has a manufacturing error with respect to the convex lens 3b of the reference lens 3 and an eccentric error based on the positional relationship between the optical axis of the lens and the outer peripheral surface. To do. Since these errors exist, the centering of the convex lens 4b is not necessarily complete depending on the operation of step ST5, and the reciprocating movers 5a, 6a, 7a, 8a of the lens driving actuators 5, 6, 7, 8 are minute. The moving length may not be 10 μm. Therefore, the error of ± when the reciprocating movers 5a, 6a, 7a, 8a are not 10 μm is stored in the control means 9.

Step ST6 (see FIG. 3 (5)):
Next, the control means 9 sets the length that is excessive or insufficient to 10 μm in the opposite direction for each set in the XY direction, that is, in the X direction of the lens drive actuators 5 and 7 and in the Y direction of the lens drive actuators 6 and 8. For example, the group of the reciprocating movers 5a and 7a and the group of the reciprocating movers 6a and 8a are moved separately, and one is moved first and the other is moved later so as to be divided into ½ lengths. As a result, manufacturing errors are also well absorbed, and the optical axis of the convex lens 4b matches the optical axis of the concave lens 4a.

  In the above operation, a known lens eccentricity measuring device is installed in accordance with the optical axis at the centering position, and the optical axis of the convex lens 4b is included in the centering allowable range with the concave lens 4a and the optical axis. A match can be confirmed. Further, when the optical axis of the convex lens 4b is not included in the allowable centering range, a set in the X direction of the lens drive actuators 5 and 7 made of an ultrasonic motor and a Y direction of the lens drive actuators 6 and 8 are arranged. Depending on the group, as described above, the concave lens 4b may be further finely moved by a necessary distance for centering. In this case, the necessary distance may be automatically calculated by the control means 9 or manually input.

Step ST7:
Next, the UV curable adhesive applied between the lenses 4a and 4b is irradiated and cured, and the lenses 4a and 4b are firmly bonded to finish the driven lens 4 into a regular cemented lens. .

Step ST8:
Next, a command is issued by the control means 9, and the reciprocating movers 5a, 6a, 7a, 8a of the lens driving actuators 5, 6, 7, 8 are retracted outward from the outer peripheral surface of the driven lens 4, and then Then, the driven lens 4 is removed from the holding mount 2.

Step ST9:
Next, the end of the centering is determined, and if not completed, the operation of finishing a new driven lens 4 to a regular cemented lens is executed by repeating Step ST4 to Step ST9, and the processing is completed. Finish the centering operation.

  In addition, this invention is not limited to such a structure, A various change is possible as needed.

  For example, a known lens eccentricity measuring device is installed in accordance with the optical axis of the centering position, and in step ST6, it is formed so that it can be confirmed that the optical axis of the convex lens 4b matches the optical axis of the concave lens 4a. May be.

DESCRIPTION OF SYMBOLS 1 Lens centering apparatus 2 Holding mount 3 Reference lens 4 Driven lens 5-8 Lens drive actuator 5a-8a Reciprocating mover 9 Control means

Claims (6)

The position where the tip of the reciprocating mover of the lens driving actuator is moved toward the optical axis with respect to the outer periphery of the reference lens installed with the optical axis aligned at the centering position is stored as the reference outer peripheral position.
Thereafter, the driven lens held at the centering position is moved to the reference outer peripheral position stored by the reciprocating mover of the lens driving actuator, and the optical axis of the driven lens is adjusted to the optical axis position of the reference lens. And a lens centering method. The reference lens is an upper lens of a reference cemented lens,
The driven lens is an upper lens placed on the lower lens of the centered cemented lens,
The lens drive actuator as an ultrasonic actuator,
The lens centering method according to claim 1, wherein the optical axes of the lower lens and the upper lens of the centered cemented lens are aligned. 3. The lens core according to claim 1, wherein the optical axis is aligned by providing the lens driving actuator so as to move the reciprocating element forward and backward in four directions orthogonal to the optical axis. How to put out. Lens holding means for holding the reference lens and the driven lens at predetermined positions at the centering position;
A lens drive actuator having a reciprocating mover that is movable back and forth toward the optical axis at the centering position;
The reciprocating element of the lens driving actuator is moved forward and backward, and the position where the tip of the reciprocating element contacts the outer periphery of the reference lens held by the lens holding means with the optical axis aligned is set as a reference outer peripheral position. A lens centering device, comprising: a control means for storing and moving the driven lens held by the lens holding means to the stored reference outer peripheral position so as to align the optical axis of the driven lens. apparatus. The reference lens is an upper lens of a reference cemented lens;
The driven lens is an upper lens placed on the lower lens of a centered cemented lens;
The lens centering device according to claim 4, wherein the lens driving actuator is an ultrasonic actuator. The lens centering device according to claim 4 or 5, wherein the four lens driving actuators are respectively provided in four directions orthogonal to the optical axis.

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