JPH03216681A - Optical power varying mechanism for electrophotographic copying machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to an optical variable magnification mechanism for an electrophotographic copying machine.

<Prior Art> In an electrophotographic copying machine using a fixed focus lens, in order to change the copying magnification, it is necessary to move a mirror together with the fixed focus lens.

FIG. 2 is a perspective view showing a schematic configuration of a variable magnification mechanism of such an electrophotographic copying machine.

In response to a drive signal from a drive circuit (not shown), the drive motor 20 rotates by an amount corresponding to the magnification change, thereby rotating the first gear 2l.
The second gear 22 meshing with the second gear 22 and the L-boot 23 coaxial with the second gear 22 rotate, and the driving wire 27 wound around the I-boot 23 and each of the boons 24 to 26 at fixed positions is rotated. The lens base 28 is moved along the movement axis 29 through the lens base 28, and the fixed focus lens 3l held in the lens holder 30 on the lens base 28 is thereby moved to a predetermined position corresponding to variable magnification. 1) Hyperactive.

On the other hand, due to the rotation of the drive motor 20, the worm 3
I and the worm wheel 32 rotate, and the driving force ram 33 integrated with the worm wheel 32 rotates, whereby the mirror holder 34 having a groove (not shown) that engages with the protrusion 33a of the driving force 33 is rotated. is moved along an axis (not shown), and the mirror 35 attached to this mirror holder 34 is moved to a predetermined position corresponding to the magnification change.

<Problem to be solved by the invention> However, in such a conventional optical variable magnification mechanism,
Since the fixed focus lens 31 is moved by the drive wire 27, the drive wire 2
There is a drawback that it takes time to wrap the 7.

The present invention has been made in view of the above-mentioned points, and it is an object of the present invention to provide an optical magnification change mechanism for an electrophotographic copying machine that does not require a drive wire and has a simplified configuration.

<Means for Solving the Problem> In order to achieve the above-mentioned object, the present invention provides an optical magnification mechanism for an electrophotographic copying machine that changes magnification by moving a fixed focus lens and a mirror. A pinion that is rotatably driven, a rack that meshes with the pinion, a moving axis that extends in a predetermined direction and is fixed, and the fixed focus lens is attached and moves along the moving axis integrally with the rack. A mirror base to which the mirror is attached, and a cam mechanism that moves the mirror base along the movement axis in response to movement of the lens base.

<Operation> According to the above configuration, the lens base to which the fixed focus lens is attached is moved along the movement axis by the pinion and rack, so assembly is easier than in the conventional example using a drive wire. Furthermore, since the mirror base is moved along the movement axis by the cam mechanism according to the movement of the lens base, there is no need to use a worm or worm wheel to transmit the power of the drive motor to the mirror base. There is no need for such gear.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing a schematic configuration of an optical variable magnification mechanism according to an embodiment of the present invention.

The electrophotographic copying machine of this embodiment includes a pinion 2 that is rotationally driven by a drive motor 1, a rack 3 that meshes with the pinion 2, and a moving shaft 5 that extends in a predetermined direction and is fixed.
A fixed focus lens 4 is attached and the rack 3
a lens base 6 that moves integrally along the movement axis 5; a mirror base 1 to which a mirror 9 is attached;
The cam mechanism is provided with a cam mechanism that is provided parallel to the movement axis 5 and rotates according to the movement of the lens base 6. 7, a cam 8 that is provided on the camshaft 7 and rotates integrally with the camshaft 7, and an adjustment screw IO as a driven body that is integral with the mirror base I1.

A lens base 6 to which a lens holder I2 holding a fixed focus lens 4 is attached is integrally constructed with a rack 3 and is movable back and forth along a movement axis 5. The moving shaft 5 is supported at a fixed position by a shaft holder 13, and a cam shaft 7 is rotatably supported by the shaft holder 13 parallel to the moving shaft 5.

The camshaft 7 has a spiral protrusion 7a formed on its outer circumference extending along the longitudinal direction, and the lens base 6 has a groove 6a that engages with the protrusion 7a. ing. Therefore, when the lens base 6 moves along the moving shaft 5, the cam shaft 7 having the protrusion 7a that engages with the groove 6a of the lens base 6 rotates. Further, the camshaft 7 is provided with a cam 8 that rotates integrally with the camshaft 7. The cam 8 has a cam surface that changes along the axial direction of the moving shaft 5 in accordance with its rotation.

A mirror holder l4 holding the mirror 9 and a mirror base 1l integral with the mirror holder +4 are connected to the moving axis 5.
The mirror polder 14 has supporting parts 14a and lla through which it is inserted, and an adjusting screw 10 as a driven body is provided on the free end side of the supporting part 14a of the mirror holder 14, and the tip of the adjusting screw 10 is connected to the cam. It is in contact with the 8th cam. Furthermore, a compression spring I5 is interposed between the support rod 14a and the shaft holder l3, which biases the adjustment screw 10 in a direction to bring it into contact with the cam surface.

Next, the operation of the optical variable magnification mechanism having the above configuration will be explained.

In response to a drive signal from a drive circuit (not shown), the drive motor 1 rotates by an amount corresponding to the magnification change, the pinion 2 rotates, and the rack 3 that meshes with the pinion 2 moves along the movement axis 5. The lens base 6, which is integral with this rack 3, is also moved along the movable member 5, so that the fixed focus lens 4 held in the lens holder l2 of this lens base 6-1- is It will be moved to a predetermined position corresponding to.

On the other hand, as the lens base 6 moves, the cam shaft 7 having the protrusion 7a that engages with the groove 6a of the lens base 6 rotates, and the cam 8 provided on the cam shaft 7 also rotates.
The adjustment screw IO as a driven body that contacts the cam surface of the cam 8 by 4 degrees moves along the moving axis 5, and as a result, the mirror base I integrated with the adjustment screw 10 moves.
I will be moved to a predetermined position corresponding to the magnification change.

In this way, the lens base 6 to which the fixed focus lens 4 is attached is moved along the movement axis 5 via the pinion 2 and the rack 3 by the rotational power of the drive motor i, so that the drive wire can be moved. It is easier to assemble than the conventional example used, and the lens base 6
The mirror base 1 has a driven body 10 that rotates the cam shaft 7 to which the cam 8 is attached in accordance with the movement of the cam 8, and contacts the cam 8! is moved along the moving axis 5, so gears such as a worm or worm wheel for transmitting the power of the drive motor I to the mirror base l1 are not required.

In addition, since the lens base 6 and the mirror base It move along the same movement axis 5, the movement axis of the lens base and the movement axis of the mirror base are There is no need to correct the axis misalignment between the two.

Furthermore, in this embodiment, since the adjustment screw 10 is used as a driven body that contacts the cam 8, it is possible to correct the slight distance between the fixed focus lens 4 and the mirror 9 using this adjustment screw IO. It becomes possible.

<Effects of the Invention> As described above, according to the present invention, the lens base to which the fixed focus lens is attached is moved along the movement axis via the pinion and the rack by the rotational power of the drive motor. This makes assembly easier compared to conventional models that use drive wires.Furthermore, a cam mechanism moves the mirror base as the lens base moves.
Since the movement is made along the movement axis, there is no need to transfer the power of the drive motor to the mirror base.
This eliminates the need for gears such as worms and worm wheels, simplifying the configuration.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a schematic configuration of an optical variable magnification mechanism according to an embodiment of the present invention, and FIG. 2 is a perspective view of a conventional example. 4... Fixed focus lens, 5... Moving axis, 6... Lens base, 7... Cam axis, 8... Cam, 9...
Mirror 10...adjustment screw (driven body), 11...mirror base.

Claims (1)

[Claims] (1) An optical magnification mechanism for an electrophotographic copying machine that changes magnification by moving a fixed focus lens and a mirror, which comprises a pinion that is rotationally driven by a drive motor, a rack that meshes with the pinion, and a rack that extends in a predetermined direction. a moving axis to which the fixed focus lens is attached; a lens base that moves along the moving axis integrally with the rack; a mirror base to which the mirror is attached; and the lens base. An optical variable magnification mechanism for an electrophotographic copying machine, comprising: a cam mechanism that moves the mirror base along the movement axis in response to movement of the mirror base.