JPH0710348Y2 - Copying device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a copying apparatus of a type in which a document table or mirror scanning means is moved.

(Prior Art) In recent years, variable-magnification optical devices in which the image magnification can be changed have been widely used in copying machines. In this variable power optical device, for example, as shown in FIG. 6, when the lens body 104 is changed in magnification by the lens moving means, it is moved to a predetermined position according to the image forming magnification, and the mirror group 103 is a mirror for scanning an original. It is moved by the driving means.

The mirror driving means includes a drive pulley 123 fixed to the output shaft 122 of the drive motor 121, and a driven pulley 125 rotatably attached to the support frame 124 of the mirror group 103, as intermediate pulleys 126, 1.
It is connected by a wire 128 via 27.
A support fitting 129 of the illuminator is connected to the wire 128, and the position of the mirror group 103 is detected by a sensor 131.

The lens moving means attaches a lens holder 133 holding a lens 132 to a rail shaft 134 so as to be reciprocally movable, and a drive pulley fixed to an output shaft 136 of a drive motor 135.
The wire 138 is wound around the wire 137, and the middle of the wire 138 is fixed to the lens holder 133 side via a mounting bracket 139. One side of the lens holder 133 is supported by the roller 141, and the position of the lens holder 133 is detected by the sensor 142. Further, the focal length of the lens 132 is changed at the same time as the movement of the lens holder 133 by the gear 143 attached to the zoom ring engaging with the rack 144.

As described above, in the conventional variable-magnification optical device, the drive source is provided in each of the mirror driving device and the lens moving device, so that the device is expensive.

In order to solve this problem, Japanese Patent Application No. 60-205416 proposes that the scanning driving means of the original scanning optical means such as a mirror and the driving source of the lens moving means are made common.

(Problems to be Solved by the Invention) In such a conventional example, when the driving force for moving the mirror or the platen glass and the driving force for displacing the lens are selectively switched from a common driving source, After displacing the lens, the drive part of the lens is disconnected from the drive source, so the optical system was included due to vibration of mirror movement during copy or movement of platen glass, or during replacement of developer or jam processing. There is a problem that the position of the lens changes when a part of the device is opened and closed, and the set magnification and correct focus position cannot be secured.

Therefore, the present invention has been made to solve the above-mentioned problems of the conventional example, and its purpose is to change the lens position when vibrating during copying or when opening and closing a part of the image forming apparatus. It is another object of the present invention to provide a variable power optical device which can secure a set magnification and a correct focus position without using it.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, a document scanning drive for moving a document table or mirror scanning means for scanning a document placed on a document table. Means, a lens driving means for moving a lens for forming image light from an original on a photoconductor in response to a change in copy magnification, and a drive source for driving both the original scanning drive means and the lens drive means. In the copying apparatus having the above, the driving force from the driving source is transmitted to the lens driving means when the copying magnification is changed, and is movable with the locking member to restrict the driving of the lens driving means when scanning the original. When the copying magnification is changed to the original scanning, the transmission member moves in one direction to block the driving force transmitted from the driving source to the lens driving means and to lock the document. It is constituted by locking with a member to regulate the driving of the lens driving means.

(Operation) In the present invention having the above-described structure, the driving force transmitted from the driving source to the lens driving means is first interrupted and the driving thereof is restricted during scanning of the original.

(Example) Below, this invention is demonstrated based on the Example shown in figure. Fifth
The figure shows an embodiment of a copying apparatus to which the variable power optical apparatus according to the present invention is applied. In the figure, 20 is a document placed on a platen glass 21, which is illuminated by a lamp 24 and
20 is a scanning mirror, that is, the first, second and third mirrors 16, 17, 19
Is scanned in parallel with the original 20, and is scanned and projected onto the photosensitive drum 23 through the lens 2 and the reflection mirror 22. Around the photosensitive drum 5, a charger 30 and a developer 2
5. A transfer corona discharger 26 and a cleaning device 31 are arranged. The transfer sheet P is sent out from a storage cassette (not shown) by a sheet feeding roller, and is conveyed in synchronization with the toner image onto the photosensitive drum 23 by the roller to transfer the image. After that, it is sent to the fixing device 27 by the conveyor belt and sent to the tray through the discharging device.

Next, the variable power optical apparatus of the present embodiment will be described with reference to FIGS. In FIG. 1, 1 is a movable lens barrel holding the lens 2, 3 is a guide member for moving the movable lens barrel 1 along the optical axis AA ', 4 is an auxiliary pulley, 5
Is a lens driving wire, which is wound around a pulley portion 6 provided integrally with the auxiliary pulleys 4, 4 and the lens driving gear 10, and both ends thereof are fixed to the movable lens barrel 1. As a result, the lens drive gear 10 rotates to cause the lens drive wire 5 to rotate.
The movable lens barrel 1 can be moved along the guide member 3 through. Numeral 7 is a switching arm having a substantially "U" shape on a plane,
The lens drive gear 10 is rotatably mounted coaxially with the rotation center of the lens drive gear 10. A lens drive auxiliary gear 11 is rotatably provided at one end of the lens drive gear 10, and the other end is connected to the plunger 8. The movable lens barrel 1, the guide member 3, the auxiliary pulley 4, the lens driving wire 5, the lens driving gear 10, the lens driving auxiliary gear 11 and the like constitute the lens driving means of the present invention. A return spring 9 is attached near the other end of the switching arm 7 and urges the switching arm 7 to rotate counterclockwise. The lens drive auxiliary gear 11 provided at one end of the switching arm 7 is constantly meshed with the lens drive gear 10. Reference numeral 12 is a mirror drive pulley, and 13 is a drive gear, which is attached to a drive motor 14. Reference numeral 15 is a mirror drive wire, 28 is a pulley of the second mirror 17, and 29 is a pulley. The mirror driving wire 15, the pulley 28 and the like constitute the document scanning driving means of the present invention.

Then, the switching arm 7 connecting the other end to the plunger 8 turns clockwise around the pulley portion 6 against the biasing force of the return spring 9 by turning on the plunger 8. As described above, when the switching arm 7 rotates clockwise, the lens drive auxiliary gear 11 rotates integrally with the drive motor 14 as the drive source for mirror scanning.
The drive force of the drive motor 14 is transmitted to the movable lens barrel 1 via the lens drive wire 5 by meshing with 13 to move the lens 2.

That is, in the above configuration, when the magnification is changed, the plunger 8 is actuated and sucked, and when the lens drive auxiliary gear 11 rotates and meshes with the drive gear 13, the drive motor 14 is actuated and the movable lens barrel 1 is moved to a predetermined magnification. Move to the set position. Then, the drive motor 14 is stopped, the power supply to the plunger 8 is also turned off, and the lens drive auxiliary gear 11 is forcibly separated from the drive gear 13 by the return spring 9 attached to the other end of the switching arm 7, and the lens 2 And presses against the locking member 18 that regulates the position of. The locking member 18 is made of an elastic material such as rubber,
The contact surface side with the lens driving auxiliary gear 11 is formed in an uneven shape, whereby the lens driving auxiliary gear 11 is reliably prevented from rotating. Thus, the lens driving auxiliary gear 11 becomes unrotatable due to the frictional force with the convex portion of the locking member 18, and sudden vibration or force is applied to the movable lens barrel 1, and the force for changing the position is applied to the lens driving wire 5. Even if added, the pulley portion 6 meshing with the lens driving auxiliary gear 11 also does not rotate, so that the lens 2 cannot move. The plunger 8, the switching arm 7, the return spring 9, the locking member 18 and the like constitute means for restricting the driving of the lens driving means in the present invention.

Further, in the above embodiment, the driving force from the mirror scanning driving means is transmitted as the moving force of the lens when the image forming magnification is changed, and the transmission path is blocked when the document is scanned.

In the above embodiment, the mirror moving type optical system is used for scanning the original, but the present invention is not limited to this, and the present invention can be applied to a platen glass moving type copying apparatus.

Further, in the above-described embodiment, the locking member 18 may be detachable, and when the locking member 18 is worn out, it may be appropriately replaced with another locking member prepared in advance.

Furthermore, in the above embodiment, the locking member 18 locks the lens driving auxiliary gear 11, but the invention is not limited to this, and the moving lens 2 itself may be locked. However, when the lens 2 is locked in this way, the lens driving auxiliary gear 11 does not stop at the same time, so that a load is applied to the pulleys 4 and 6 and the wire 5, and the wire 5 is distorted and the next lens Since the displacement is adversely affected, it is desirable to lock the lens driving auxiliary gear 11 as in the above embodiment.

Furthermore, in the above-mentioned embodiment, since the driving means has the unevenness of the gear, a more reliable locking effect can be obtained.

(Effect of the Invention) As described above, according to the present invention, the driving force transmitted from the driving source to the lens driving means is first interrupted during the scanning of the original, so that the driving force for scanning the original does not affect the lens. The displacement of the lens due to this driving force can be prevented.

Further, in the present invention, the driving of the lens driving means whose driving force is cut off is regulated next, so that the lens changes its position even if the original table or the mirror scanning means moves due to the original scanning to cause vibration. It is possible to prevent the displacement of the lens more reliably. Therefore, in the case where it is necessary to open or close a part of the device including the optical system due to vibration due to mirror scanning or movement of the document table during normal copying other than lens movement, or replacement of the developing device or jam processing. Since the lens position does not change, there is no need to refocus the image or reset the magnification, and the reliability is improved.

Further, since the movement of the transmission member retracting from the drive source and engaging with the locking member is performed by a series of movements in one direction, the moving mechanism of the transmission member can be made extremely simple and the device configuration can be simplified. Can be converted.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a variable power optical device used in the present invention, FIG. 2 is a plan view showing a lens moving state in the same embodiment, and FIG. 3 is a lens drive auxiliary gear in the same embodiment. FIG. 4 is a plan view showing a state in which it is pressed against the locking member, FIG. 4 is a plan view of the locking member in the same embodiment, FIG. 5 is a schematic configuration diagram of a copying apparatus according to the present invention, and FIG. FIG. 3 is a perspective view of a main part of a variable power optical device. Explanation of reference numerals 1 ... moving lens barrel, 2 ... lens 7 ... switching arm, 8 ... plunger 11 ... lens driving auxiliary gear 13 ... driving gear, 14 ... driving motor 16 ... first mirror, 17 …… Second mirror 18 …… Locking member, 19 …… Third mirror 20 …… Original, 21 …… Original glass 24 …… Lamp

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-57-188067 (JP, A) JP-A-59-140438 (JP, A) JP-A-60-55329 (JP, A) JP-A-57- 188068 (JP, A) Actually open Sho 61-38641 (JP, U) Japanese Patent Sho 60-12617 (JP, B2)

Claims (1)

[Scope of utility model registration request] 1. A copy magnification of a document scanning driving means for moving a document table or a mirror scanning means for scanning a document placed on a document table and a lens for forming an image light from the document on a photoconductor. Lens driving means for moving according to
In a copying machine having a driving source for driving both the original scanning driving means and the lens driving means, the driving force from the driving source is transmitted to the lens driving means when the copying magnification is changed, and the lens is moved when scanning the original. The movable member has a movable transmission member that locks with the locking member for restricting the drive of the driving unit, and when the copying magnification is changed to the scanning of the original, the transmission member is moved in one direction to move from the driving source. A copying machine, characterized in that the driving force transmitted to the lens driving means is shut off and the driving force of the lens driving means is regulated by being locked with the locking member.