JPH0774882B2 - Slit exposure optical device - Google Patents

Description

The present invention relates to a slit exposure optical device used in an electrophotographic copying machine or the like.

As is well known, in an electrophotographic copying machine, a document is optically scanned by synchronously operating a plurality of movable tables equipped with exposure slits and mirrors.

By the way, in order to drive such a movable table, the movable table is cyclically driven by a wire pulley device hung between one end of the movable table and the apparatus fixing portion, but in this one-sided driving, the holding span for the guide member is increased. Therefore, the slit exposure optical device becomes very large. Therefore, conventionally, the holding span is reduced by so-called double-sided drive in which wire pulley devices are arranged at both ends of the movable table, and the device is downsized. However, even in this conventional double-sided drive system, since a plurality of movable bases are moved on the same orbital surface, there is a limit to the approach distance between the mirrors mounted on the respective movable bases, and thus the device itself is limited. The miniaturization was not as good as expected.

In consideration of the actual state of the conventional slit exposure optical device as described above, the present invention provides a first movable table on which a first mirror is mounted and a first movable table that reflects incident light from the first mirror at a right angle. A second movable table on which a second mirror and a third mirror that reflects incident light from the second mirror at a constant angle are mounted, and the second movable table corresponds to the first movable table. In a slit exposure optical device for synchronously moving at a speed of 1/2 to optically scan a document, a first track surface for guiding the first movable table and a second track surface for guiding the second movable table. A pair of plate-shaped channels having a pair of guides are provided to guide both end portions of the first and second movable bases, and both end portions of the first and second movable bases are driven in a substantially horizontal direction. , A pair of wire pulley devices for synchronous movement provided at both ends of the first raceway surface, The first movable base and the second movable base are arranged so as to overlap each other in the vertical direction in a part of the movement range, and the first movable base and the second movable base are arranged above the raceway surface. The slit exposure optical device is characterized in that it is guided on one track surface, and both ends of the second movable table are guided on the second track surface. The details of the embodiment of the present invention will be described.

FIG. 1 is an overall view of a slit exposure optical device according to the present invention. The slit exposure optical device includes movable bases 3 and 4 incorporated between a pair of machine body frames 1 and 2 facing each other.
The first movable table 3 includes an exposure lamp 6 that illuminates an original document on the original table glass 5 shown in FIG. 2 and a first mirror 7 that reflects a reflected image of the original document.
It has a slit 8 to be incident on. The second movable table 4 also includes a second mirror 9 that reflects the incident light from the first mirror 7 at a right angle, and a third mirror 11 that causes the incident light from the second mirror 9 to enter the projection lens 10. Have
The first movable table 3 and the second movable table 4 are the body frame.
A pair of horizontal "U" -shaped channels 12 and 13 fixed to the inner surfaces of the guides 1 and 2 are guided at both ends. In other words, the unitary U-shaped channel 1
A resin tape 15 having a small coefficient of friction is adhered to the upper surfaces of the upper side portions 12a, 13a of the 2, 13, and the surface of the resin tape 15 constitutes a first raceway surface 16. The spherical projections 18 of the resin block 17 fixed to both ends of the first movable table 3 are in contact with each other. In addition, “U” shaped channel 1
A resin tape 19 similar to the resin tape 15 is adhered to the lower surfaces of the lower side portions 12b and 13b of the second and third members 13, and the upper surfaces of these resin tapes 19, that is, the second track surfaces 20, of the second movable base 4 are attached. The spherical projections 22 of the resin blocks 21 at both ends are brought into contact with each other.

At both ends of the first movable table 3, joint pieces 24a, 24b fixed to an intermediate portion of a drive wire 23 described later are projected, and
Floating pulleys 25a and 25b are supported at both ends of the second movable table 4.

A pair of wire pulley devices A and B are provided between both ends of the first movable base 3 and the second movable base 4 and the machine body frames 1 and 2 corresponding to these ends, respectively. The first movable table 3 and the second movable table 4 by A and B
Is driven on both sides. That is, these wire pulley devices
A and B are a pair of fixed pulleys 26 and 27 that are installed to face the machine body frame 2 as represented by the wire pulley device A.
And a drive drum 28 and a relay pulley 29 that are rotated at a constant speed, and the second movable table 4 and the first movable table 3 between these members.
A drive wire 23 that is synchronously moved at a speed of 1/2 is hung.

The slit exposure optical device according to the present invention is configured as described above, and since the first and second movable bases 3 and 4 are synchronously driven on both sides by the wire pulley devices A and B, the holding span for the track surface is reduced. Even if it is small, accurate synchronous movement can be performed. Particularly, in the present invention, the first track surface 16 and the second track surface in which both movable bases 3 and 4 are vertically displaced so as to have two guide surfaces by one member. Since it is configured to be guided individually by 20 and 20, it is possible to design so that the first movable table 3 and the second movable table 4 shown in FIG. 3 can overlap with each other, and the entire exposure optical apparatus is small and lightweight. In addition, even if both ends of the first movable base 1 and the second movable base 4 are made slightly wider, they do not abut each other, so that stable running of the raceway surface is possible, and the present invention is Not only can the entire exposure optical system be made smaller and lighter Ku, since it compresses the upper and lower width of the slit exposure optical system, there is an effect of reduction in the overall size of the copier.

Further, in the present invention, since the first raceway surface and the second raceway surface of the channel are integrally formed, stable running of the raceway surface is possible, the number of manufacturing steps is reduced, and the cost can be reduced. .

[Brief description of drawings]

FIG. 1 is an overall perspective view of a slit exposure optical device according to the present invention, FIG. 2 is a sectional view of the same slit exposure optical device, and FIG. 3 is a sectional view when the first and second movable bases are brought close to each other. . A, B …… Wire pulley device, 3,4 …… Movable stand, 7,9,11 …… Mirror, 8 …… Slit, 12,13 …… “U” shaped channel, 16,
20 …… Orbital plane.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-48-47380 (JP, A) JP-A-53-87234 (JP, A) JP-A-56-65163 (JP, A) JP-A-54- 156550 (JP, A) JP 55-138763 (JP, A) JP 58-37670 (JP, A) Actual opening 53-100241 (JP, U) Actual opening 52-51633 (JP, U) Japanese Patent Sho 39-26451 (JP, B1) Japanese Official Sho 52-41391 (JP, Y1)

Claims (2)

[Claims] 1. A first movable table on which a first mirror is mounted, a second mirror which reflects the incident light from the first mirror at a right angle, and a constant incident light from the second mirror. A second movable table having a third mirror that reflects at an angle is provided, and the second movable table is synchronously moved at a speed half that of the first movable table to optically scan a document. In the slit exposure optical device for performing, a plate-shaped channel having a first track surface that guides the first movable table and a second track surface that guides the second movable table has the first and second movable channels. A pair of wire pulley devices provided for pairing both ends of the base, and for driving both ends of the first and second movable bases in substantially horizontal directions for synchronous movement. The first movable base and the first movable base are arranged above the second raceway surface. Of the movable table of the first movable table is configured to overlap in the vertical direction in a part of the moving range, and both end portions of the first movable table are guided on the first track surface, and both ends of the second movable table. The slit exposure optical device, wherein the portion is guided on the second orbital surface. 2. The slit exposure optical device according to claim 1, wherein the first orbital surface and the second orbital surface of the channel are integrally formed.