JPS5853546Y2 - Rokousouchinokogakukeisadokikou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an optical system operating mechanism of an exposure apparatus that moves movable optical blocks in the same direction at a speed ratio of 2:1.

In an electronic copying machine with a stationary original tank table, it is necessary to employ an exposure optical system having at least two movable mirrors that move in the same direction at a speed ratio of 2:1.

An example of this type of exposure optical system is the one shown in FIG.

That is, reference numeral 1 denotes a light source consisting of a straight tube lamp provided on the lower surface side of the document table 2. A first movable mirror 3 is integrally provided near the light source 1, and a first movable mirror 3 is provided along the document table 2. This constitutes a first movable optical block 4 that moves in parallel.

Further, a second movable optical block 7 having a second movable mirror 5 and a third movable mirror 6 is provided corresponding to the first movable optical block 4.

Further, a projection lens 8 and a fixed mirror 9 are sequentially arranged opposite to the third movable mirror 6 of the second movable optical block 7, and the document surface 3 of the document A is placed on the photosensitive surface 10a of the photosensitive drum 10. It constitutes an exposure optical system 11 that projects an image as an inverted image.

Note that 12 is a reflector that focuses the light emitted from the light source 1 onto the document surface a on the document table 2 in a band-like manner.

The light emitted from the light source 1 illuminates the document surface a on the document table 2, and the light reflected from the document surface a is reflected by the first movable mirror 3, the second movable mirror 5, the third movable mirror 6, The image passes sequentially through a projection lens 8 and is finally projected onto a photosensitive surface 10a by a fixed mirror 9.

At this time, the first movable optical block 4 moves in parallel along the document table 2 at a speed υ equal to the circumferential speed of the photosensitive drum 10 to scan the document surface a, and the second movable optical block 7 moves 1/2 in the same direction. It moves at a speed of 2υ.

The distance from the document table 2 to the projection lens 8 is always kept constant, so that the projection magnification does not change.

On the other hand, as an optical system operating mechanism for operating the first movable optical block 4 and the second movable optical block 7 which mutually move in the same direction at a speed ratio of 2:1, a drive pulley, a driven pulley,
A version using a movable pulley and wire was developed.

This type of optical system operating mechanism has been put into practical use because it has the advantages of a simple configuration and good movement accuracy.

However, in the past, both ends of a single wire that was passed through a driving pulley and a driven pulley that were placed apart from each other were passed to a movable pulley located between these pulleys, and each was folded back and fixed. .

A first movable optical block is connected to a part of the wire between the drive pulley and the movable pulley, and a second movable optical block is coupled to the movable pulley to transmit the driving force of the drive pulley to the wire. According to the above first
．． The second movable optical block is adapted to move in the same direction at a speed ratio of 2:1.

However, it is necessary to wind the wire multiple times around the drive pulley to reliably transmit the driving force to the wire.

Therefore, in this conventional method of operating using one wire, the length of the wire is inevitably long, and it is difficult to determine the relative position of each movable optical block.

Furthermore, when a wire breaks, a long wire must be replaced, which is very troublesome and uneconomical.

The present invention was developed based on the above circumstances, and its purpose is to move the first and second movable optical blocks of the exposure optical system using two wires for driving and positioning. The object of the present invention is to provide an economical optical system operating mechanism for an exposure apparatus that is capable of moving in the same direction at a speed ratio of 2:1, has extremely good workability, and is economical.

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

In the figure, 20 indicates a light source 1, a reflector 12, and a first movable mirror 3.
21 is a first support member that supports a first movable optical block 4 consisting of a second movable mirror 5 and a third movable mirror 6.
This is a second support member that supports the second movable optical block 7 consisting of.

Also, these first. One end of the second support member 20.21 is connected to the first support member 20.21. It is supported by a support rod 22 provided in a direction perpendicular to the moving direction of the second movable optical blocks 4, 7.

Above 1. The second support members 20.21 each have two guide portions 20a, 20b, 21a, 21b.
are provided, and the support rod 22 is connected to these guide portions 2.
0 a , 20 b , 21 a , and 21 b penetrate through the guide holes provided in the first. The attachment angle of the second support member 20° 21 to the support rod 22 is regulated.

Also, 1st. The other end of the second support member 20.21 is placed on a rail (not shown) provided parallel to the support rod 22, and is supported parallel to the document table 2.

In this way, the first . The second support members 20, 21 are moved in the same direction at a speed ratio of 2:1 by an optical system operating mechanism 23, which will be described later.

That is, a pair of grooves 2 are provided at one end of the front side of the support rod 22.
A drive pulley 24 having 4a and 24b also has
A pair of grooves 25a, 25 are provided at the other end of the support rod 22 on the front side.
A driven pulley 25 with b is provided.

Further, a support shaft 26 is provided on the front end surface side of the second support member 21.
A movable pulley 27 having a pair of grooves 27 a and 27 b is rotatably fitted to the tip of the support shaft 26 .

Furthermore, a wire fixing plate 28 as a wire fixing member is screwed to the front end surface of the first support member 20 via screws 29 and 29, and a wire fixing plate 28 is screwed to the front end surface of the first support member 20, and a wire fixing plate 28 is screwed to the front end surface of the first support member 20. Wire fixed shaft 30, 3
1 is provided.

Two wires, a drive wire 32 and a positioning wire 33, are stretched across these members.

That is, as shown in FIG. 3A, the driving wire 32 is fixed at one end to the first fixing portion 28a of the wire fixing plate 28, and then hooked to the driven pulley 25 with the other end and folded back. Further, after being wound several times around the groove 24a of the drive pulley 24, the other end is fixed under tension to the second fixing portion 28b of the wire fixing plate 8.

Further, as shown in FIG. 3, one end of the positioning wire 33 is fixed to the wire fixed shaft 30, and then passed through the groove 27a of the movable pulley 27 and folded back. Pass the hook through the groove 25b and turn it back.

Further, the hook is passed through the groove 24b of the drive pulley 24 and turned back, and then passed through the groove 27b of the movable pulley 27 and turned back, and the other end is fixed to the wire fixing shaft 31 under tension.

Further, in the middle part of the positioning wire 33 stretched in this way, which is located between the drive pulley 24 and the movable boo 1125, at a position that is at a predetermined distance from the movable pulley 27, the drive side wire 32 is It is fixed to the third fixing portion 28C of the wire fixing plate 28, which is moved through the wire fixing plate 28.

Note that 34 shown in FIG. 2 is a reversible motor that rotates the driving pulley 24 forward or reverse.

When the drive pulley 24 rotates clockwise (in the direction of the arrow) at a constant speed, the end of the drive wire 32 fixed to the second fixing part 28b side of the wire fixing plate 28 is wound around the drive pulley 24. At this time, the end portion of the wire fixing plate 28 fixed to the first fixing portion 28a side is let out by the same length.

Therefore, the wire fixing plate 28 moves toward the drive pulley 24 at a speed υ equal to the circumferential speed of the photosensitive drum 10, and the first support member 20, which is integral with the wire fixing plate 28, moves in the same direction.

On the other hand, the positioning wire 33 connected to the driving wire 32 via the wire fixing plate 28 is fed in the same direction and the same length.

Therefore, the movable pulley 27 to which the positioning wire 33 is hooked moves in the same direction as the wire fixing plate 28 at half the speed 1/2υ based on the same principle as the movable pulley.

In this way, when the drive pulley 24 rotates, the first and second support members 20.21 move laterally at a speed ratio of 2:1.

Therefore, these first. The first movable optical block 4 and the second movable optical block 7 fixed to the second support member 20.21 also move in one direction at the same speed, and the projection magnification does not change over the distance from the document table 2 to the projection lens 8. As such, it will always remain constant.

Further, when the exposure operation is completed, the drive pulley 24 rotates in the opposite direction, and the first drive pulley 24 rotates in the opposite direction. The second movable optical block 4.7 returns to its home position and stands by in this state.

As explained above, the present invention uses two wires for the operating mechanism that operates the exposure optical system, a driving wire and a positioning wire, so it is operated using one long wire as in the past. In comparison, the relative position of a movable optical block consisting of a movable mirror etc. can be easily determined.

In addition, since each wire is short, assembly efficiency can be improved, and if the wire breaks, only one wire needs to be replaced, making it easy to replace and economical.

Since the driving wire and the positioning wire are connected to a common driving pulley with a pair of grooves and a driven boot, the configuration is not complicated and the driving force can be directly transmitted to both wires. This has the effect that no excessive force is applied to the drive wire, and the life of the drive wire is not shortened.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of the exposure optical system, Fig. 2 is a partially exploded perspective view showing an embodiment of the optical system operating mechanism of the present invention, and Fig. 3 A-9 shows the wires of the same embodiment. It is a figure explaining a stretched state. 4...First movable optical block, 7...
Second movable optical block, 23... Optical system operating mechanism, 24... Drive pulley, 25... Driven pulley, 27... Movable pulley, 28... ...
... Wire fixing member, 32 ... Drive wire,
33...Positioning wire.

Claims (1)

[Scope of utility model registration request] It is wound several times around one groove of a driving pulley that has a pair of grooves, one end is passed through one groove of a driven pulley that has a pair of grooves, then it is folded back, and both ends are held under tension on a wire fixing member. A fixed driving wire is passed through the other groove of the driving pulley and the other groove of the driven pulley, and the hooks are passed through a pair of grooves on the movable pulley located between these pulleys at both ends. a positioning wire that is folded back and fixed in a tensioned state and connected to the drive wire via the wire fixing member, and connected to the first movable optical block connected to the wire fixing member and the movable pulley. ,
An optical system operating mechanism for an exposure apparatus, characterized in that the second movable optical block is moved in the same direction at a speed ratio of 2:1.