JPS5921389Y2 - electronic copying device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an electronic copying apparatus that performs slit exposure by reciprocating a document table or an optical system.

In recent years, many types of electronic copying apparatuses using this type of slit exposure method have been put into practical use because they have the advantage of being faster and more compact.

In this slit exposure method, the original and the photoreceptor are moved at a constant speed, or the original is kept stationary and an optical system including a mirror and the photoreceptor are moved at a constant speed for exposure.

In either case, it is necessary to reciprocate the document table or the optical system in synchronization with the photoreceptor, and to move the photoreceptor only in one direction.

Therefore, conventionally, in order to synchronize the photoreceptor and the document table or optical system, the same motor drives the photoreceptor through a single power transmission system consisting of a chain, belt, etc. It also has a pair of clutch mechanisms for backward motion and an operating mechanism that switches between forward and backward motion.

However, when two clutch mechanisms are provided in one power transmission system, a large load is generated during forward and reverse switching and is transmitted to the power transmission system, which has the disadvantage of causing negative effects such as vibration of the photoreceptor. .

There is also a method of driving the document table or the optical system with a separate motor, but this poses a major obstacle to practical application, as it is difficult to drive the document table or the optical system at the same speed as the photoreceptor.

The present invention was developed based on the above-mentioned circumstances, and its purpose is to prevent load fluctuations that occur during the backward movement of the document table or optical system from being transmitted to the power transmission system and adversely affecting the photoreceptor. An object of the present invention is to provide an electronic copying apparatus that employs the operating mechanism as described above.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows an electronic copying apparatus with a moving optical system (original stationary type). In the figure, 1 is a light source consisting of a straight tube lamp installed on the bottom side of the document table 2. A first movable mirror 3 is integrally provided, and constitutes a first movable optical block 4 that moves in parallel along the document table 2.

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 A is placed on the photosensitive surface 10a of the photosensitive drum 10 as a photosensitive member. An exposure optical system 11 is configured to project an image of the document surface 8 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 light passes sequentially through a projection lens 8 and is finally subjected to slit exposure 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 V equal to the circumferential speed of the photosensitive drum 10 to scan the document surface a, and the second movable optical block 7 moves in the same direction. move at a speed of

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

Furthermore, when the exposure is finished, the first movable optical block 4 and the second
The movable optical block 7 returns to its original position in the direction opposite to the arrow at a speed ratio of 1:+.

On the other hand, the first. As shown in FIG. 2, the second movable optical blocks 4 and 7 are attached at one end to a support rod 13 and at the other end to a first and second support member 14 and 15 supported reciprocally by a rail (not shown). It is being

As described above, the first support member 14, which is attached to the first and second support members 14 and 15, which can freely reciprocate along the document table 2, is attached to the first support member 14, 15. The second movable optical blocks 4 and 7 are moved in synchronization with the photosensitive drum 10 by an actuation mechanism 16.

That is, a fixed pulley 17 is disposed corresponding to one end of the support rod 13, a wire drum 18 as a driving body is disposed corresponding to the other end, and a movable pulley 19 functioning as a movable pulley is disposed between these. has been done.

Then, the middle part of the wire 20 is wound around the wire drum 18 a plurality of times and passed around the fixed pulley 17, and both ends are passed around the movable pulley 19 and then folded back and fixed.

Further, the first movable optical block 4 is connected to a part of the wire 20 between the wire drum 18 and the movable pulley 19, and the second movable optical block 7 is connected to the movable pulley 19.

Further, the wire drum 18 is fitted onto one end of a rotating shaft 22 of an electromagnetic clutch 21 serving as a clutch mechanism.

When the electromagnetic clutch 21 is excited, the rotational force of the sprocket 23 is transmitted to the rotating shaft 22, and when it is not excited, it can rotate freely.

The sprocket 23 is rotated in a predetermined direction by a drive chain 24 serving as a power transmission system for driving the exposure drum 10.

Further, as shown in FIG. 3, a second sprocket 25 is fitted to the other end of the rotating shaft 22, and is attached to a drive shaft 27 of a reversible motor 26 via a one-way clutch 28. It is designed to interlock with a third sprocket 29 as a rotating body via a chain 30.

Next, the operation of the actuation mechanism 16 configured as described above will be explained.

First, when a print button (not shown) is pressed, a drive source (not shown) operates, the drive chain 24 runs endlessly in the direction of arrow A, and the photosensitive drum 10 rotates in the direction of arrow A so that the peripheral speed becomes -.

At this time, the drive chain 24 simultaneously rotates the sprocket 23 of the electromagnetic clutch 21 in the direction of the arrow.

Next, the electromagnetic clutch 21 is excited by the exposure operation signal, that is, the forward movement signal, and the rotating shaft 22 is moved to the sprocket 2.
A wire drum 18 and a second sprocket 25 that rotate in the same direction as the rotation direction of No. 3 and are fitted onto this rotating shaft 22.
rotate in the direction of the solid arrow.

The rotational force of the wire drum 18 is transmitted to the wire 20, and the first optical movable block 4 connected to the wire 20 moves at a speed V equal to the circumferential speed of the photosensitive drum 10, and a movable pulley 19 that functions as a movable pulley. The second optically movable blocks 7 connected to the two start moving simultaneously in the directions of the arrows at a speed of +■.

On the other hand, the rotational force of the second sprocket 25 rotating at the same time is transmitted to the third sprocket 29 via the chain 30.

At this time, the drive shaft 27 of the reversible motor 26 rotates in the same direction (in the direction of the solid line arrow) at the same or higher speed as the rotation speed of the third sprocket 29, and is interposed between the drive shaft 27 and the sprocket 29. Due to the action of the one-way clutch 28, the third sprocket 29 is brought into a state similar to that of idle rotation.

The reversible motor 26 is prevented from becoming a load on the drive chain 24 during the exposure operation by preventing the generation of a force that would try to turn the reversible motor 26.
There is no adverse effect on the exposure drum 10.

Next, when the exposure operation is completed, a backward movement signal is issued, the excitation of the electromagnetic clutch 21 is stopped, the sprocket 23 is in a state of idle rotation, and the wire drum 18, the second... The third sprocket) 25, 29 is released from the drive chain 24.

In this state, the drive shaft 27 of the reversible motor 26 reversely rotates in the direction of the dashed arrow, and the third sprocket 29 rotates in the same direction due to the action of the one-way clutch 28, and this driving force is transferred to the chain 30 and the second The signal is transmitted to the wire drum 18 via the sprocket 25 and the rotating shaft 22, and the wire drum 18 rotates in the reverse direction in the direction of the dashed arrow.

Therefore, the first. The second optically movable blocks 4 and 7 move back and return to their home positions.

At this time, since the electromagnetic clutch 21 is released, the first
．． Load fluctuations that occur when the second optically movable blocks 4 and 7 change direction from forward to backward are not transmitted to the drive chain 24, resulting in extremely smooth movement and no adverse effect on the photosensitive drum.

In addition, although the case where the optical system moves in the above-mentioned embodiment has been described, the present invention is not limited to this, and it goes without saying that the same objective can be achieved in a case where the document is moved.

As explained above, the present invention provides an electronic copying machine in which a document table or an optical system is reciprocated by forward and reverse rotation of a driving body to perform slit exposure, which has a rotating shaft that interlocks with the driving body; A clutch mechanism that transmits the driving force of a power transmission system that operates the photoconductor to a rotating shaft based on a forward motion signal from the document table or the optical system, and cuts off the power transmission based on a backward motion signal, and the rotating shaft of this clutch mechanism. It has a rotating body interlocked with the rotary body, and a drive shaft that pivotally supports this rotating body with a one-way clutch interposed, and when the document table or optical system moves forward, the drive shaft rotates at the same speed as the rotating body. Alternatively, an actuation mechanism is provided that includes a reversible motor that rotates in the same direction at a high speed to bring the rotating body into an idling state, and then reverses the rotation based on a backward motion signal to reversely rotate the driving body.

Therefore, when the document table or the optical system moves forward, the movable motor does not become a load on the power transmission system and does not adversely affect the photoreceptor.

In addition, since the electromagnetic clutch is released when changing direction from forward to backward, the load fluctuations that occur when changing direction are not transmitted to the power transmission system, resulting in extremely smooth movement and no negative impact on the photoreceptor. be effective.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a schematic structural explanatory diagram, FIG. 2 is an exploded perspective view of the main parts, and FIG. 3 is a front view of the clutch section. 2... Document table, 4, 7... Optical system (first and second optical movable blocks), 10... Photoreceptor (photoreceptor drum), 16... ...Operating mechanism, 18
...Motive force (wire drum), 21...
・Clutch mechanism (electromagnetic clutch), 22...rotating shaft, 24...power transmission system (drive chain),
26... Reversible motor, 27...
Drive shaft, 28...One-way clutch, 29...
...Rotating body (third sprocket).

Claims (1)

[Scope of utility model registration request] A document table or an optical system that performs slit exposure by reciprocating by forward and reverse rotation of a prime mover, which has a rotating shaft that interlocks with the prime mover, and is configured to perform slit exposure based on forward movement signals of the document table or optical system. A clutch mechanism that transmits the driving force of the power transmission system that operates the photoreceptor to the rotating shaft and cuts off the transmission of power by a backward motion signal, a rotating body that interlocks with the rotating shaft of this clutch mechanism, and this rotating body are integrated. It has a drive shaft that is pivotally supported with a directional clutch interposed, and when the document table or optical system moves forward, the drive shaft rotates in the same direction at the same or faster speed as the rotating body. What is claimed is: 1. An electronic copying apparatus comprising: a reversible motor that rotates the motor in an idling state and reversely rotates the driving body based on a double-motion signal.