JPH06273265A - Lens centering device - Google Patents

Abstract

PURPOSE:To obtain a centering device for a lens and a lens frame which can carry out the automatic position adjustment of a centering jig by allowing the lens and the centering jig to be adjusted free from separation. CONSTITUTION:A lens centering device is equipped with a lens frame supporting shaft 2 which is shaped so that a lens frame 1 loading a lens 3 is placed and a holding tool 5 inside which a lens centering jig 4 which contacts the upper surface of the lens 3 are installed at the upper position of the lens 3 so as to be vertically shiftable. At the same time, each desired gap 18, 19, 20 is formed between the holding tool 5 for holding the centering jig 4, and suction plates 10 and 11 are installed at least at three places in an equal interval on the undersurface of the centering jig 4 so that the centering jig 4 is held in a noncontact form, in each gap 18, 19, 20, and electromagnets 13 and 14 are arranged on a frame 16 opposed to the suction plates 10 and 11, and the centering position is finely adjusted on the basis of the measurement value obtained by an eccentricity measuring means 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centering device for mounting a lens on a lens frame.

[0002]

2. Description of the Related Art A centering device for aligning an optical axis of a lens with a reference axis coaxially arranged with a lens fixing frame for fixing the lens is already known. For example, there is Japanese Utility Model Laid-Open No. 59-172355. The technique described in this publication will be described with reference to FIGS. 4 and 5 are FIGS. 2 and 3 described in the above publication. That is, FIG. 4 is a sectional view showing a conventional lens centering device, and FIG. 5 is a perspective view showing the substrate and the lens retainer shown in FIG.

As shown in FIG. 4, a cylindrical lens fixing frame 31 is coaxially connected to form a cylindrical base shaft 33, and an upper surface of a lens 32 mounted on an upper end surface 31a of the lens fixing frame 31. Has a ring-shaped substrate 35 that presses the upper surface thereof, and has a ring-shaped substrate of the same diameter that holds a cylindrical lens holder 34 that is formed by projecting the lower surface center downward.
It is connected to a bed (not shown) together with the base shaft 33. Further, the substrate 35 is configured to be movable in the axial direction along the dovetail groove provided in the bed. The base shaft 33 is configured to be rotatable with respect to the outer frame of the bed. Further, each member arranged in a series as described above,
That is, the lens fixing frame 31, the base shaft 33, the lens retainer 3
4, a through hole is provided at the center of each of the substrates 35, and it is configured to allow a light beam to pass through the optical axis detection device (not shown).

As described above, around the inner diameter of the hole 4a formed in the center of the lower surface of the lens retainer 34, the cylindrical portion 34b projecting toward the lens fixing frame 31 (downward) is formed and its circular shape. A lens pressing rubber 36 having a semicircular cross section is integrally attached to the tip of the. Further, three screw holes 34c are formed in the vicinity of the outer peripheral edge of the lens retainer 34 at equal intervals on the circumferential surface, and adjustment is made so as to penetrate a loose hole 45b provided on the surface of the substrate 35 at a position corresponding to this. Screws 37 are screwed together. A knurl is applied to the head portion of the adjusting screw 37 formed to have a large diameter so that the adjusting screw 37 can be easily rotated manually.

The operation of the conventional example having the above configuration will be described. First, the lens 32 is placed on the upper surface of the lens fixing frame 31 placed on the upper end of the base shaft 33. Subsequently, the substrate 35 is moved in the direction of the centered lens 32 along the dovetail groove of the bed (not shown) in which the base shaft 33 and the base 35 are connected, and the lens pressing rubber at the tip of the cylindrical portion 34b of the lens pressing member 34 is moved. At 36, the upper surface of the lens 32 is pressed. In this case, the lens 32 has a bell portion 31 on the upper surface of the lens fixing frame 31 with an appropriate pressing force due to the elasticity of the lens pressing rubber 36.
Press against a. In this state, by rotating the three adjusting screws 37 while observing with an optical axis detecting device (not shown), the base 35 and the lens holder 34 are partially rotated.
By tilting the lens retainer 34 in an arbitrary direction with respect to the reference axis 33 by changing the interval between the lens retainer rubber 36 and the lens 32, the lens retainer rubber 36 and the lens 32 do not slip due to the frictional force between the lens retainer rubber 36 and the lens 32. The lens 32 moves integrally with the lens 32, and the lower surface of the lens 32 slides while being in full contact with the bell portion at the tip of the lens fixing frame 31.
Can be fine-tuned.

[0006]

However, in the lens centering device described in the above publication, the position of the lens retainer is constrained by the adjusting screw, and therefore the lens fixing frame and the lens are adjusted when the lens position is adjusted. There is a problem in that a gap is created in the center, which prevents accurate alignment. In addition, when adjusting the lens position, it is necessary to rotate the adjustment screw with human power (finger tip) to perform the adjustment, which causes a problem that it is difficult to improve work efficiency.

The present invention has been made in view of the above-mentioned problems, and eliminates the generation of a gap between the lens fixing frame and the lens at the time of adjusting the lens position, which enables high-precision centering and adjustment. It is an object of the present invention to provide a lens centering device that is excellent in terms of quality and production such that work can be performed efficiently.

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided a lens frame supporting shaft which supports and rotates a lens frame, and a centered centering member which is disposed so as to face the lens frame supporting shaft and is arranged in the lens frame. An eccentricity measuring means for measuring the amount of eccentricity between the optical axis of the lens and the lens frame, a centering jig arranged on a holder so as to move while being in contact with the eccentric lens, and the eccentricity measurement for the centering jig. The lens centering device is provided with an adjusting unit that adjusts without contact based on eccentricity information from the unit.

[0009]

Embodiment 1 A specific example of the lens centering device of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing a main part of a lens centering device according to a first embodiment of the present invention and showing the main part in section. The cylindrical member 2 shown in the figure is a lens frame support shaft which has a base end portion connected to a driving means (not shown) and is rotatably mounted on the base 16. The lens frame support shaft 2 is provided on the upper end surface of the lens frame support shaft 2.
A cylindrical lens frame 1 having a smaller diameter is coaxially supported. The inner peripheral wall surface of the upper end surface of the lens frame 1 is provided with a step portion formed to have a diameter slightly larger than the outer diameter dimension of the lens 3 for mounting the lens 3 which is a centered lens. At the upper position of the lens 3 placed on the stepped portion of the lens frame 1, a disc-shaped centering for adjusting the position of the lens by abutting the tip of the cylindrical portion at the time of adjusting the positions of the lens 3 and the lens frame 2. A jig 4 is provided. That is, the restraining passage hole 5 is formed in the center of the disc, and the tip end surface of the cylindrical portion 6 extending downward from the peripheral portion of the light flux passage hole 5 is formed so as to contact the upper surface of the lens 3. A centering jig 4 is provided.

On the upper surface of the centering jig 4, at a position corresponding to the light beam passing hole 5 provided at the center of the centering jig 4, there is a slight distance from the light beam passing hole 5 formed in the centering jig 4. A large-diameter light flux passage hole 7 is formed, and a bent portion 9 is provided so that a holder 8 configured to hold the centering jig 4 surrounds an outer peripheral edge of the centering jig 4. Are arranged. That is, desired gaps 18, 19, 20 are formed between the outer peripheral edge portion of the upper surface of the centering jig 4 and the outer peripheral surface, and the centering jig 4 is radially arranged in the gaps 18, 19, 20. ，
A holder 8 configured to be movable in the sliding direction is provided.

The holder 8 is supported by guide means (not shown), and is vertically movable by a driving means such as a motor. Further, on the lower surface of the centering jig 4, the attraction plates 10 and 11 (reference numeral 12) made of a magnetic material are provided.
(Not shown) are fixed at equal intervals. This suction plate 1
As shown in the drawing, electromagnets 13 and 14 (reference numeral 15 not shown) are fixedly provided on the frame 16 at positions facing the 0, 11, and 12 downwards. In addition, an eccentricity measuring means 17 for measuring the eccentricity of the lens 3 mounted on the lens frame 1 is provided at an upward position where the axis of the lens support shaft 2 is extended.
Are arranged so that they can move up and down. This eccentricity measuring means 17
Is configured to measure the amount of eccentricity between the lens 3 and the reference axis through the light flux from the light flux passage holes provided in each of the lens frame support shaft 2, the lens frame 1, the centering jig 4, and the holder 8. ing.

The operation of this embodiment having the above configuration will be described. First, in the state before the centering action, that is, before the tip of the cylindrical portion 6 of the centering jig 4 contacts the upper surface of the lens 3, the centering jig 4 has its disc-shaped lower surface. The outer peripheral edge of the holder is in contact with the upper edge surface of the bent portion 9 of the holder 8 and is held. The lens frame 1 is mounted and supported on the upper surface of the lens frame support shaft 2, and the lens 3 which is the lens to be measured is mounted in the step portion at the upper end of the lens frame 1. Next, the drive means is operated to operate the holder 8 and the centering jig 4.
Move and along the guide (not shown) downwards,
When the tip of the cylindrical portion 6 of the centering jig 4 comes into contact with the upper surface of the lens 3, the lowering operation of the holder 8 and the centering jig 4 is stopped.

When the descending holder 8 and centering jig 4 are stopped, the centering jig 4 does not contact the holder 8 and the tip of the cylindrical portion 6 at the center thereof is the lens 3
Familiar with the shape of the top surface of, the entire surface is in contact. That is, the centering jig 4 abuts on the upper surface of the lens 3, and the centering jig 4 makes the gaps 18, 19,
Since the centering jig 4 has a degree of freedom because it is not in contact with the inside 20, the optical function surface of the lens 3 that is in contact with the lens frame 1 only when the centering jig 4 contacts the lens 3. The (lower surface of the lens 3) coincides with the axis of the lens frame 1.

In the above case, when the optical axis of the upper surface of the lens 3 is deviated from the axis of the lens frame 1 (optical axis of the lower surface of the lens 3), that is, when it is tilted, a centering jig is used. 4 is in a state of being inclined with respect to the axis of the lens frame 1. Therefore, the centering jig 4 includes the gap 18 of the holding tool 8,
It is tilted within 19 and 20.

Next, the eccentricity measuring means measures the amount of eccentricity between the reference axis (lens frame supporting axis) 2 of the lens frame 1 and the optical axis of the lens 3, and the electromagnets 13, 14, 15 are based on this value. The position of the centering jig 4 (the centering jig 4 is set in the gap 18, 19, 20 formed by supplying electric current and controlling the respective electromagnets 13, 14, 15 with the holder 8). When it is tilted with respect to the axis of the lens frame 1,
The optical axis of the lens 3 and the reference axis of the lens frame 1 are made to coincide with each other while moving vertically in the inclined direction. The method of performing the centering action is not limited to the above method, but the attraction force of the electromagnets 13, 14, 15 is used to perform the centering jig 4.
May be moved. Alternatively, the repulsive force may be used for movement.

[0016]

Second Embodiment Next, a second embodiment of the lens centering device of the present invention will be described with reference to the drawings. FIG. 2 is a front view showing a part of a lens centering device according to a second embodiment of the present invention in section. In the drawings, the same members, shapes and configurations as those of FIG. 1 used in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The difference between the present embodiment and the above-described first embodiment is that, as shown in FIG. 2, the holder 32 for holding the disc-shaped centering jig 4 is different from the first embodiment. And electromagnets 30, 31, 32 (reference numeral 3) for operating the centering jig 4.
2 is not shown) and the electromagnets 30, 3
1, 32 are different from the mounting positions of the suction plates 22, 23, 24 (reference numeral 24 is not shown) arranged on the centering jig 4 arranged so as to oppose to 1, 32.

The different structure between the present embodiment and the first embodiment will be described in detail. The configuration up to the lens frame 1 placed on the upper end surface of the lens support shaft 2 and the lens 3 which is the object to be measured placed on the stepped portion of the upper end portion of the lens frame 1 is the same as in the first embodiment.
Is the same as A cylindrical portion which is disposed on the upper surface of the lens 3 and has a disc shape that is in contact with the light flux passage hole 5 in the center and the upper surface of the lens 3 that projects downward from the inner peripheral edge of the lower surface of the light flux passage hole 5. Attracting plates 22, 23 made of a magnetic material at equal intervals on the outer peripheral surface of the upper surface of the centering jig 4 provided with
24 is attached. Further, a holding tool 32 having a shape like a circular dish is placed on the upper surface of the centering jig 4 is arranged so as to surround the upper surface of the centering jig 4. That is, the holder 3
A groove 25, into which the outer diameter of the centering jig 4 can be inserted, fitted and mounted, is formed on the entire circumference of the dish-shaped inner diameter lower end edge peripheral wall surface of the plate 2. When the disc-shaped centering jig 4 is inserted and mounted in the groove 25, desired outer circumferential ends are provided with desired gaps 26, 27, 28 between the centering jig 4 and the outer diameter thereof. The degree of freedom is obtained.

At the center position of the circular shape of the holder 32,
A light beam passing hole 29 having a diameter slightly larger than that of the light beam passing hole 5 of the centering jig 4 is formed at a position corresponding to the light beam passing hole 5 formed in the centering jig 4. Further, in the vicinity of the inner peripheral surface of the ceiling surface in the holder 32, that is, at the position facing the attraction plates 22, 23, 24 arranged on the upper surface of the centering jig 4, the electromagnets 30, 31 are disposed. , 32 are mounted on a hanging rack so that the centering jig 4 can be moved.

The operation of this embodiment having the above structure will be described. First, the lens frame 1 is placed on the upper end surface of the lens support shaft 2.
Subsequently, the lens 3 is placed on the upper surface of the lens frame 1. Next, the holder 32 and the centering jig 4 were moved downward along a guide (not shown), and the tip surface of the cylindrical portion 9 of the centering jig 4 was placed on the tip portion of the lens frame 1. It contacts the upper surface of the lens 3. At this time, the centering jig 4 is attached to the holder 32.
The tip end surface of the cylindrical portion 9 and the surface of the lens 3 intervene in the middle of the gaps 26, 27, and 28 provided between the lens holder 3 and the holder 32 and move to fit the curved surface of the lens 3. Then, they are in complete contact.

Next, the eccentricity measuring means 17 located above the holder 32 measures the amount of eccentricity between the reference axis of the lens frame 1 and the optical axis of the lens 3, and the measurement results in eccentricity. In this case, based on the eccentricity value, electromagnets 30, 31, 32
Centering is performed so that the positions of the centering jigs 4 are moved up and down so as to be completely coincident with each other. Note that this embodiment is not limited to the above-described centering method using the electromagnet, but may be performed by moving the centering jig by using the attraction force of the electromagnet, or by using the repulsive force. The jig may be moved.

According to this embodiment having the above-mentioned configuration and operation,
By disposing the electromagnet in the holder, there is an advantage that the positional relationship between the electromagnet and the suction plate is constant, and setting of the centering jig to the lens can be performed reliably and quickly.

[0023]

Third Embodiment A third embodiment of the lens centering device of the present invention will be described with reference to the drawings. FIG. 3 is a front view showing a part of a lens centering device according to a third embodiment of the present invention in section. In the drawings, the same members, shapes and configurations as those in FIGS. 1 and 2 used in the first and second embodiments described above are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 3, the difference between the present embodiment and the above-described first embodiment is that the vicinity of the outer diameter edge of the holder 33 and its edge are bent by 180 ° with respect to the first embodiment. Air blow-out holes 34, 3 penetrating through and penetrating vertically to a desired position where the formed bent portion 9 overlaps.
5, 36, 37, 38, 39 (reference numerals 36, 39 are not shown) are formed at three locations at equal intervals so as to face each other. Further, on the surfaces of the holder 33 and the bent portion 9, air supply holes 40, 41, 4 for supplying the air blown out from the air discharge holes 34, 35, 36, 37, 38.
2, 43, 44, 45 (reference numerals 42 and 45 are not shown)
Are formed in three places at equal intervals. Further, although not shown, a voltage regulator capable of changing the pressure of air by an electric signal is connected to the tip of the air supply holes 40, 41, 42, 43, 44, 45, respectively. Air outlets 34, 35, 3
The pressure of the air blown from 6, 37, 38, 39 can be adjusted. Also, the air blowing hole 3
The pressure of the air blown from one of the upper and lower sides of 4, 35, 36, 37, 38, 39 is constant and blown out, and only the air from the other side can be varied. For example, the air from the blowing holes 34, 35, 36 is variably blown, and the blowing holes 37, 3
The air from 8, 39 is constructed so as to always blow out at a constant pressure.

The operation of this embodiment having the above structure will be described. First, the lens frame 1 is placed on the upper end surface of the lens frame support shaft 2, and then the lens 3 is placed on the upper end surface of the lens frame 1.
Next, the holder 33 and the centering jig 4 are lowered from above along the guide, and the tip end surface of the cylindrical portion 6 of the centering jig 4 is brought into contact with the upper surface of the lens 3. When the tip end surface of the cylindrical portion 6 comes into contact with the lens 3, the centering jig 4 is previously held by the holder 33.
The holder 3 so that it does not come into contact with the inner wall surface of the
3 air blowing holes 34, 35, 36, 37, 38,
The air blown from 39 causes the centering tool 4 to be in a non-contact state, that is, to float in the gaps 26, 27, 28 formed on the inner peripheral surface of the holding tool 33 and the outer peripheral surface of the centering jig 4. The lens 3 is held in the closed state.

The operation of this embodiment having the above structure will be described. First, the lens frame 1 is placed on the upper end surface of the lens support shaft 2.
Subsequently, the lens 3 is placed on the upper surface of the lens frame 1. Next, the holder 33 and the centering jig 4 are moved downward along a guide (not shown), and the tip surface of the cylindrical portion 6 of the centering jig 4 is placed on the tip portion of the lens frame 1. Lens 3
Abut the upper surface of. At this time, the centering jig 4 has the blowing holes 34, 35, 36, 37, 38, 39 of the holder 33.
It is interposed in the middle of the gaps 26, 27, 28 provided between the holder 33 and the holder 33 by the air pressure blown out from the holder 33. The front end surface and the surface of the lens 3 are in conformity with the curved shape of the surface of the lens 3 and move to be in a state of being completely in contact with each other.

In the above state, the eccentricity measuring means 17 measures the amount of eccentricity between the reference axis of the lens frame 1 and the optical axis of the lens 3, and based on this value, the air blowing holes 34, 35, 3
By controlling the pressure of the air blown out from 6, 37, 38, 39 respectively, centering can be performed while moving the position of the centering jig 4 up and down. As in the above-described embodiment, the fact that the lens and the lens frame can be centered by a simple configuration and action of pressure control by air has a great advantage of cost reduction in terms of production.

[0028]

According to the present invention having the above-described structure, since a desired gap is provided between the holder and the holder for holding the centering jig, the centering contact with the lens is performed without contact. Since the lens and the lens frame are not forcibly centered, there is no gap between the lens and the lens frame during centering adjustment, and it is also necessary to manually finely move the lens. The great effect is that it is possible to provide highly accurate lenses that are eliminated and have excellent productivity, cost efficiency, and quality.

[Brief description of drawings]

FIG. 1 is a front view showing a main part relating to a first embodiment of a lens centering device of the present invention and showing a main part in section.

FIG. 2 is a front view showing a main part of a lens centering device according to a second embodiment of the present invention and showing the main part in section.

FIG. 3 is a front view showing a main part of a lens centering device according to a third embodiment of the present invention and showing the main part in section.

FIG. 4 is a front view showing a main part of a conventional lens centering device.

5 is a perspective view of the lens pressing unit shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Lens frame 2 Lens frame support shaft 3 Lens 4 Centering jig 5,7,29 Light flux passage hole 6 Cylindrical part 8,32,33 Holding device 9 Bending part 10,11,12,22,23,24 Adsorption plate 13 , 14, 15, 30, 31, 31, 32 Electromagnet 16 Frame 17 Eccentricity measuring means 18, 19, 20, 26, 27, 28 Gap 25 Groove 34, 35, 36, 37, 38, 39 Air blowing hole 40, 41, 42 , 43, 44, 45 Air supply holes

Claims (1)

[Claims] 1. A lens frame support shaft that supports and rotates a lens frame, and an eccentricity between the lens frame support shaft and an optical axis of a centered lens disposed inside the lens frame and the lens frame. An eccentricity measuring means for measuring the amount, a centering jig arranged on a holder so as to move in contact with the centered lens without contact, and eccentricity information from the eccentricity measuring means for the centering jig. A lens centering device, which is provided with an adjusting means for making non-contact adjustment based on the above.