JPH0227644B2 - KOGAKUSOCHINOICHIGIMEKIKO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a mechanism for use in optical devices such as copying machines and projectors, and for holding optical elements such as lenses and positioning an optical element holder, which moves in the optical axis direction, at a predetermined position. It is related to.

2. Description of the Related Art In an optical device such as a copying machine, a lens holder holding a lens is movably arranged between an original and an image forming surface, and the lens holder is moved to a predetermined position according to a specified copying magnification. When moving this lens holder, it is required to be correctly positioned at a predetermined position and to be held at a predetermined position without moving even when external forces such as vibrations are applied. Conventionally, a rail with a V-shaped groove formed at the stop position is arranged in the optical axis direction, and a stopper (called a wedge) that is biased in the direction of entering the V-shaped groove is provided on the lens holder. The lens holder is positioned by this stopper and the V-shaped groove. Alternatively, a lace may be provided on the lens holder and the lens holder may be restrained by a fixed stopper.

In this positioning mechanism, in order to prevent the lens holder from easily moving even when an external force is applied, the angle of inclination of the V-shaped groove must be made sharp, or the force of the spring biasing the stopper must be increased. It is necessary. However, in the conventional positioning mechanism, the stopper is pushed up by the V-shaped groove, so if the stopper is used as described above, it becomes difficult to pull out the stopper from the V-shaped groove.

Based on the above background, the present invention provides a positioning mechanism for an optical device that allows the stopper to be easily pulled out from the groove when moving the optical element holder even when the coupling between the stopper and the groove is strengthened. The purpose is to

In order to achieve the above object, the present invention provides a stopper actuating member between an interlocking member, such as a belt, that moves in the optical axis direction in conjunction with the rotation of the motor, and an optical element holder that moves in the optical axis direction, By pulling out the stopper from the groove at the beginning of the belt movement, and connecting the belt and the optical element holder via the pulled out stopper, the optical element holder is moved in the optical axis direction in conjunction with the belt. This is what I did.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, a lens holder 1 is mounted on a pair of guide rods 2 and 3, and is moved between an original and an image forming surface, such as a photosensitive drum, to change the object distance and image forming distance of the lens 4. The copy magnification can be changed by

A recess 1a and a hole 1b are formed in the side of the lens holder 1, and the upper end of a stopper 5 is inserted into the hole 1b and urged downward by a spring 6. This stopper 5 is provided with symmetrical inclined surfaces 5a and 5b that become wider toward the top, and a roller 7 is attached to the lower end. This roller 7 is configured to be able to roll along the upper end surface of a rail 8 disposed in the optical axis direction of the lens 4, but this is not necessarily required. If omitted, set the lower end of the stopper 5 to V
What is necessary is to form it into a V-shaped groove of the rail 8. The V-shaped groove of the race 8 is provided at a predetermined copying magnification position, and in this embodiment, three V-shaped grooves 8a to 8c are provided so that the magnification can be changed in three stages. It is being Note that the V-shaped grooves 8a to 8c are formed by the roller 7.
Since the lens holder 1 is positioned in cooperation with the lens holder 1 and fixed to prevent it from moving unnecessarily, a rectangular groove or a U-shaped groove can be used instead.

Stopper operating members 9 and 10 are arranged adjacent to the slopes 5a and 5b of the stopper 5.
Slopes 9a and 10a corresponding to the slopes 5a and 5b are formed on these stopper actuating members 9 and 10, and the stopper 5 is pushed upward by the connection of these slopes 9a and 10a.

The stopper operating members 9 and 10 are fixed to the side surface of the rack gear 11.
move along the optical axis. This rack gear 1
1 is slidably held by an elongated hole and a pin, as is well known, and meshes with a pinion 13 attached to the rotating shaft of the motor 12.

Next, the operation of the above embodiment will be explained. The motor 12 rotates according to the specified copy magnification.
The rotation of this motor 12 is transmitted to the rack gear 11 via the pinion 13,
move in the optical axis direction. For example, as shown in FIG. 2, when the rack gear 11 moves to the right while the stopper 5 is in the V-shaped groove 8a, the slope 9a of the stopper actuating member 9 comes into pressure contact with the slope 5a of the stopper 5. , the stopper 5 is pushed upward. This stopper 5
moves upward while compressing the spring 6, and pulls out the roller 7 from the V-shaped groove 8a.

When the stopper 5 stops rising, the acting force of the stopper operating member 9 is applied to the lens holder 1 via the stopper 5, so that the lens holder 1 is guided by the guide rods 2 and 3 and moves to the right together with the rack gear 11.

When the lens holder 1 moves to, for example, the position of the V-shaped groove 8c, the rotation of the motor 12 is stopped by a signal from a microswitch or a photo sensor that detects the position of the lens holder 1. The stopper 5 moves downward while pushing the stopper operating member 9 back toward the optical axis in response to the stored force of the spring 6, and the roller 7 enters the V-shaped groove 8c. Note that if the lens holder 1 is stopped with the center line of the stopper 5 slightly deviated from the apex of the V-shaped groove 8c, the roller 7 will move along the slope of the V-shaped groove 8a due to the accumulated force of the spring 6. When the lens holder 1 is moved down, the lens holder 1 is moved somewhat in the optical axis direction.
The deviation is corrected and the groove is positioned at the correct position in the center as shown in FIG. Also, roller 7
Since the lens holder 1 is bitten into the V-shaped groove 8a, the lens holder 1 does not move even if an external force such as vibration is applied to the lens holder 1.

FIG. 4 shows another embodiment of the invention. A pair of pulleys 16,1 on the lens holder 15
7 is attached, and these pulleys 16,
A belt 18 is hung on 17. This belt 18 has both ends fixed to the upper end of a stopper 19, and is hung over a pair of pulleys (not shown) spaced apart in the optical axis direction. One of these pulleys is driven by a motor 12 shown in FIG. The stopper 19 includes an integrally formed flange 19a and a roller 20 attached to its lower end, and moves up and down along the hole 21.

When the belt 18 moves in the optical axis direction due to rotation of the motor, the stopper 19 is pulled up against the spring 22 at the beginning of the movement.
When the flange 19a of the stopper 19 hits the stepped portion 15a of the lens holder 15, the stopper 19
9 stops rising, the tensile force of the belt 18 acts on the lens holder 15, moving it in the optical axis direction.

In the embodiment shown in FIG. 5, a trident-shaped stopper actuating member 25 is used, and this is housed in a recess 26a of a lens holder 26. This stopper operating member 25 has one piece 2
5a is fixed to the belt 27, and the remaining two pieces 25
The tips of b and 25c touch the lens holder 26 and act as a fulcrum. The upper end of the stopper 28 is connected to the stopper actuating member 25 via a pin 29, and the roller 3 is connected by a spring 30.
1 is urged downward so that it enters the V-shaped groove 8a.

In this embodiment, when the belt 27 moves, for example, to the right, the stopper operating member 25 swings using the tip of the piece 25c as a fulcrum, and can pull up the stopper 28 against the spring 30.
This stopper 28 rises and the flange 2
When the lens 8a collides with the lens holder 26, the rotation of the stopper actuating member 25 is stopped. After this,
The tensile force of the belt 27 acts on the lens holder 26 and can move it in the optical axis direction.

In the present invention having the above configuration, the stopper is pulled out from the groove at the beginning of the movement of the interlocking member that moves in the optical axis direction, and then the optical element holder is moved in the optical axis direction, so that the stopper is firmly attached to the groove. The stopper can be bitten to prevent the optical element holder from moving inadvertently, and even if the biting force is strong, the stopper can be pulled out of the groove with a light force when moving the optical element holder. Can be done.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is a sectional view of the main part showing a state in which the stopper has entered the V-shaped groove, FIG. 3 is a sectional view of the main part showing a state in which the stopper is pulled up, and FIGS. FIG. 3 is a cross-sectional view of main parts showing each example. 1... Lens holder, 2, 3... Guide rod, 4
...Lens, 5...Stopper, 5a, 5b...
Slope, 7...Roller, 8...Rail, 8a-8c
... V-shaped groove, 9, 10 ... stopper operating member, 9a, 10a ... slope, 11 ... rack gear, 12 ... motor, 15 ... lens holder,
16, 17...Pulley, 18...Belt, 19...
...Stopper, 25...Stopper operating member, 2
6...Lens holder, 27...Belt, 28...
…stopper.

Claims (1)

[Scope of Claims] 1. An optical device including an optical element holder that holds an optical element such as a lens and is movable in the optical axis direction, and the optical element holder is moved to a predetermined stopping position. a rail that is arranged in the direction and has a groove that opens in a direction perpendicular to the optical axis at a position corresponding to the stop position; and a rail that is attached to the optical element holder and that fits in the groove. A stopper energized by the motor, an interlocking member that moves in the optical axis direction in conjunction with the rotation of the motor, and this interlocking member and the stopper are coupled, and at the beginning of the movement of the interlocking member, the optical axis direction 1. A positioning mechanism comprising: a stopper actuating member that extracts the stopper from the groove by converting an acting force in a direction perpendicular to the acting force into an acting force in a direction perpendicular to the actuating force. 2. The stopper actuating member has a slope and is fixed to the interlocking member, and the stopper has a slope corresponding to the slope of the stopper actuating member. Positioning mechanism. 3 The stopper actuating member has a trifurcated shape, the interlocking member is connected to one piece thereof, and the remaining two pieces act as a fulcrum, and the stopper member is held constant with one piece as the fulcrum depending on the direction of movement of the interlocking member. 2. The positioning mechanism according to claim 1, wherein a stopper connected to the stopper is pulled out of the groove when the positioning mechanism swings by an angle. 4. The interlocking member is a belt, a part of which is fixed to a stopper, and the stopper operating member is a pair of pulleys arranged above the stopper to face each other and change the moving direction of the belt by 90 degrees. A positioning mechanism according to claim 1.