JPH07333481A - Driving device for projection lens - Google Patents

Abstract

PURPOSE:To accurately change a shift amount and a tilt amount by simple and inexpensive constitution in a driving device for a projection lens capable of shifting and tilting the optical axis of a projection lens barrel. CONSTITUTION:This device is provided with a gear plate 8 having a rack gear 8-3 sliding in a shift direction and straight advance grooves 8-1 and 8-2, a fixed plate 7 having a cam groove 7-1 and a roller shaft 7-2 straight advancing the gear plate 8, and a slide plate 6 having a roller shaft 6-3 abutting on the cam groove 7-1 of the fixed plate 7 and a cam groove 6-2 decreasing the shift amount, and sliding in an optical axis direction. Furthermore, it is provided with a mount part 2 coupling a lens plate 5 having a roller shaft 5-1 abutting on the cam grooves 6-1 and 8-1 of the slide plate 6 and the gear plate 8 and supporting a lens main body, and a pedestal part 3 slidably coupled with the mount part 2 in a circular arc shape and having a roller shaft 3-4 engaging and abutting on the cam groove 6-2 of the slide plate 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for a projection lens such as a projector lens, and particularly NoYAF1.
The present invention relates to a lens barrel structure corresponding to the optical system No. 005.

[0002]

2. Description of the Related Art Conventionally, many companies have proposed a tilt mechanism and a shift mechanism in a driving device for a projection lens, but all of them have a structure in which the tilt shift mechanism operates independently.

[0003]

Since the conventional projection lens driving device is constructed as described above, there are restrictions in use, and the tilt mechanism and the shift mechanism work together when zooming the zoom lens. It was not structured, and it was structurally complicated and was a factor of cost increase.

Further, the tilt mechanism and shift mechanism used in interchangeable lenses and the like have a structure composed of a rack gear and a pinion, and the shape of parts is complicated and the number of parts is large, which causes further cost increase. There was a problem that it has become.

The present invention has been made to solve the above-mentioned conventional problems, and it is an object of the present invention to make it possible to accurately change the shift amount and the tilt amount with a simple and inexpensive structure. To aim.

[0006]

A projection lens driving device according to the present invention includes a gear plate having a rack gear that slides in a shift direction, a fixed plate having a roller shaft for linearly moving the gear plate, and the fixed plate. Roller plate that abuts the cam groove of the above, and a slide plate that has a cam groove that reduces the shift amount and that slides in the optical axis direction; And a mount for supporting the lens body and a pedestal part are connected by an arc to slide, and a roller shaft abutting against the cam groove of the slide plate is arranged from the pedestal part, whereby the lens The shift and tilt of the main body are performed at the same time.

[0007]

【Example】

Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a drawing best showing the features of the present invention, and is an exploded view of the lens body as seen obliquely from the front, and FIG. 2 is a front view thereof.

In FIGS. 1 and 2, reference numeral 1 is a lens barrel for holding an optical system, and 2 is a mount portion connected to the lens barrel 1. The mount portion 2 has an arcuate sliding surface 2-1 on which a concave rail 2-2 that is coupled to the convex rail 3-1 of the pedestal portion 3 is formed. Lens barrel 1
Slides in an arc.

On the focusing surface side of the pedestal portion 3, there is a sliding portion 3-3 for moving the pedestal portion up and down. The sliding portion 3-
A concave rail 3-2, which is coupled to the convex rail 4-1 protruding from the revolving plate 4, is formed on the metal plate 3. The revolving plate 4 has a sliding portion (not shown) for rotating the projection device main body and the lens main body on the focus surface side, and the output gear of the motor gearbox 10 is provided on the outer periphery of the revolving plate 4. A gear for gear coupling is provided,
It is possible to rotate the entire lens body by rotating the motor.

Reference numeral 5 denotes a lens plate screwed to the mount portion 2. The roller shaft 5-1 at the tip of the plate and the roller shaft 3-4 of the pedestal portion 3 are respectively cam grooves 6- of the slide plate 6. 1 and the cam groove 6-2 are fitted and abutted.

The slide plate 6 has a roller shaft 6-3, and the roller shaft 6-3 is in contact with the cam groove 7-1 of the fixed plate 7. The gear plate 8 is fixed to the revolving plate 4 by screws (not shown), and has a rack gear and a cam groove 8-2 that is fitted and abutted on the roller shaft 7-2 of the fixed plate 7.
A roller shaft 5-1 provided on the lens plate 5 is fitted and abutted on the cam groove 8-1 of the gear plate 8. The rack gear portion 8-3 of the gear plate 8 is gear-coupled with the output gear of the gearbox 9.

Next, the operation of the first embodiment will be described. When the motor is driven, the output plate of the gear box 9 and the gear combination of the rack gear portion 8-3 of the gear plate 8 cause the gear plate 8 to move up and down as shown in FIG. Further, the lens moves up and down along each cam groove while interlocking with shift and tilt.

A point P on the lens barrel 1 shown in FIG. 1 is the position of the center of gravity of the lens body, and this point P is the axis of the roller even if the focal length of the lens changes or the focusing lens moves due to focusing. It does not move across 5-1. This point P may be on the front side or the rear side of the lens of the roller shaft 5-1.

Example 2. In the first embodiment, the roller shaft 3-4 and the roller shaft 5-1 are both arranged on the optical axis, but when the gear plate, the fixed plate, the slide plate, and the lens plate cannot be arranged due to outer restrictions. It is also possible to remove the gear plate, the fixed plate, the slide plate, and the lens plate from the distribution of the optical axis centers, and dispose the roller shafts 3-4 and 5-1 offset from the optical axis.

Depending on the relationship of the amount by which the lens is tilt-shifted, the same operation result can be obtained by disposing either the roller shaft 3-4 or the roller shaft 5-1 away from the optical axis.

[0016]

As described above, according to the present invention, the gear plate having the rack gear that slides in the shift direction, the fixed plate having the roller shaft for moving the gear plate straight, and the cam groove of the fixed plate are provided. A slide plate that has a roller shaft that abuts and a cam groove that reduces the shift amount, and slides in the optical axis direction;
A slide plate and a roller shaft abutting against the cam groove of the gear plate are arranged on the lens plate protruding from the lens body, and the mount for supporting the lens body and the pedestal part are connected by an arc to slide, and the pedestal part Since the roller shaft that comes into contact with the cam groove of the slide plate is arranged to shift and tilt the lens body at the same time, the projection lens can be accurately changed by the shift amount and tilt amount according to the optical specifications. In addition, there is an effect that the large projection lens can be efficiently driven.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a projection lens driving device according to the present invention.

2 is a front view of FIG.

[Explanation of symbols]

 1 lens barrel 2 mount part 3 pedestal part 3-4 roller shaft 5 lens plate 5-1 roller shaft 6 slide plate 6-1 and 6-2 cam plate 6-3 roller shaft 7 fixing plate 7-1 cam groove 7- 2 Roller shaft 8 Gear plate 8-1, 8-2 Straight advance groove 8-3 Rack gear

Claims (5)

[Claims] 1. A drive device for a projection lens for shifting and tilting an optical axis of a projection lens barrel, wherein a rack gear sliding in a shift direction and a gear plate having a rectilinear groove, a cam groove and a roller for rectilinearly moving the gear plate. A fixed plate having a shaft, a roller shaft contacting a cam groove of the fixed plate, and a slide plate having a cam groove for decelerating a shift amount and sliding in the optical axis direction; and a cam groove of the slide plate and the gear plate And a mount portion for supporting a lens body by coupling a lens plate having a roller shaft that abuts on the base portion, and a pedestal portion having a roller shaft that slidably couples with the mount portion in an arc shape and fits and abuts a cam groove of the slide plate. A drive device for a projection lens, comprising: 2. When the center of gravity of the lens moves due to the movement of the zoom lens or the movement of the focus adjustment lens,
2. The projection lens driving device according to claim 1, wherein the center of gravity of the lens does not move beyond the roller axis position of the lens plate. 3. The drive device for a projection lens according to claim 1, wherein the roller axis of the lens plate and the roller axis of the pedestal portion are arranged on the optical axis. 4. The drive device for a projection lens according to claim 1, wherein either one of the roller axis of the lens plate and the roller axis of the pedestal portion is arranged at a position apart from the optical axis. 5. The projection lens driving device according to claim 1, wherein both the roller axis of the lens plate and the roller axis of the pedestal portion are arranged at positions apart from the optical axis.