JPH0425698Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an optical system fixing device for a copying machine that uses both an optical system movement mode and an original movement mode as methods for scanning an original.

Prior Art Conventionally, this type of optical system fixing device has been placed in the middle of a transmission path that transmits driving force to the optical system. Therefore, in order to stop the optical system at a position corresponding to the document movement mode, it is necessary to set the stop timing while observing the movement of the optical system. In particular, in copying machines that control various operations according to information written in the ROM of a microcomputer, the above-mentioned stop timing must be set at the ROM manufacturing stage.
If the timing is readjusted in response to mechanical accuracy errors, it is impossible to make adjustments, and it is extremely difficult to stop the optical system at the correct position.

Purpose The purpose of this invention is to provide an optical system fixing device for a copying machine that can easily fix the optical system at an appropriate position corresponding to the document movement mode with a simple configuration.

Embodiment An embodiment of this invention will be described below with reference to FIGS. 1 to 7.

The optical system fixing device of this embodiment is applied to a copying machine 3 in which a document feeding device 2 is retractably installed on a document glass 1 as shown in FIG.

The copying machine 3 includes a lamp 4 that illuminates the original placed on the original glass 1, a first scanning mirror 5 that changes the direction of the reflected light from the original by approximately 90 degrees, and a first scanning mirror 5 that changes the direction of the reflected light from the first scanning mirror 5 by approximately 180 degrees. A second scanning mirror 6 to be converted, a projection lens 7 for projecting the original image onto the photosensitive drum 9, projection mirrors 10a and 10b for projecting the light transmitted through the projection lens 7 onto the photosensitive drum 9 via a slit 8, etc. It has an optical system consisting of.

In the optical system movement mode in which the lamp 4 and the first and second scanning mirrors 5 and 6 of this optical system are moved by a scanning system drive mechanism (not shown) to scan the original on the original glass 1, the original is moved by the original feeding device 2. is conveyed to a predetermined position on the original glass 1 and then stopped. The first lamp moves integrally with the lamp 4.
The scanning mirror 5 and the second scanning mirror 6 are moved at a speed of 2:1 to scan the original while keeping the optical path length from the original surface to the photosensitive drum 9 constant.

On the other hand, the lamp 4, the first lamp,
In the document movement mode in which the scanning system consisting of the second scanning mirrors 5 and 6 is stopped and the document is scanned by conveying the document at a constant speed on the document glass 1, the document is fed from the document loading port 2a and is conveyed at a constant speed. By doing so, the original is scanned and the original is delivered from the original discharge port 2b.

Note that the scanning end position here is the position at which scanning of the maximum size original is completed, and therefore the original glass 1 is formed to be slightly longer than the maximum original size.

In FIG. 1, reference numeral 11 denotes a developing device, and the developing device 11 develops an image projected through the optical system and formed into an electrostatic latent image on the surface of the photosensitive drum 9 with toner. 12 is a transfer charger, and the toner image on the surface of the photosensitive drum 9 is transferred to a paper feed cassette 13a or 13b by this transfer charger 12.
The image is then transferred onto a copy sheet fed in synchronization with the rotation of the photosensitive drum 9. 14a and 14b are fixing rollers that fix the transferred image on copy paper, and after fixing,
The copy paper is sent to the discharge section 15. A cleaner 16 cleans residual toner on the surface of the photosensitive drum 9, and the cleaned surface returns to the initial imaging position. Projection lens 7 and projection mirror 10 of the optical system
a and 10b are movable, for example, between the positions shown by imaginary lines and the positions shown by solid lines in FIG. 1, so that the projection magnification can be variably set.

The optical system fixing device in this embodiment is coaxial with pulleys 19, 19 around which wire ropes 18, 18 are wound for pulling the slider 17 on which the first scanning mirror 5 of the optical system is installed in the moving direction in the optical system moving mode. A disc cam 20 having an engaging notch 20a on its peripheral edge and an optical system wound around the rotating shaft 21 of the pulleys 19, 19 on the standby position side (in FIGS. 2 to 7) in the moving mode. A torsion spring 2 that biases the pulleys 19, 19 to rotate in a direction that pulls the slider 17 toward the left side of the paper, that is, in a counterclockwise direction.
2, and an engagement claw portion 2 which is pivotally provided near the outer periphery of the disk cam 20 and can engage with the engagement notch 20a of the disk cam 20 when the pulleys 19, 19 rotate counterclockwise.
3a at the tip and the tip side is biased by a tension spring 24 in a direction away from the disk cam 20, and the tail end is connected to the tail end of the swing lever 23 via a tension spring 25. The tip of the slider 17 that is connected to the slider 17 and moves toward the scanning end position (right side of the page in FIGS. 2 to 7) collides with the slider 17 to rotate clockwise, causing the first swing lever 23 to move toward its end position. The engagement claw portion 23a is the engagement notch 20a of the disc cam 20.
An interlocking lever 26 is connected to the swinging lever 23 and is connected to the swinging lever 23 to move the optical system at least when the slider 17 is near the scanning end position in the optical system movement mode and from the document movement mode. A solenoid 27 that is driven to separate the swing lever 23 from the disk cam 20 when the mode is switched is provided.

The slider 17 is linked to the aforementioned scanning system drive mechanism (not shown) via pulleys 19, 19, and in the optical system movement mode, the slider 17 is moved from the waiting position to the scanning end position by the scanning system drive mechanism. It is moved against the direction torsion spring 22. On the other hand, when the slider 17 returns to the standby position, it is disconnected from the scanning system drive mechanism and returns to the standby position by the restoring force of the torsion spring 22.

A tension spring 24 that urges the swing lever 23 in a clockwise direction such that its engagement claw portion 23a separates from the disc cam 20 pushes the swing lever 23 counterclockwise when the slider 17 does not collide with the interlocking lever 26. Its tensile strength is set so as to overcome the tension spring 25 that biases in the direction. Therefore, when the slider 17 is not approaching the scanning end position, the engaging claw portion 23a of the swing lever 23 is reliably separated from the disc cam 20.

The interlocking lever 26 has a roller 28 pivotally attached to its tip that collides with the slider 17.
Collision with the slider 17 can be performed smoothly. A tension spring 29 is connected to this distal end side, and the interlocking lever 26 is biased toward the counterclockwise rotation side. It has stopped when it hits.

The operation of this optical system fixing device will be explained below based on FIGS. 3 to 7.

When the document moving mode is selected, the slider 17 in the standby position starts moving toward the scanning end position by the action of the scanning system drive mechanism. In this mode, the solenoid 27 is not driven, but until the slider 17 collides with the interlocking lever 26,
Due to the bias of the tension spring 24 that overcomes the tension spring 25, the swing lever 23 is retracted to a swing position where its engaging claw portion 23a is separated from the disc cam 20. As the slider 17 moves, the pulley 19,
19 rotates clockwise, the engagement notch 20a of the disc cam 20 engages the engagement claw 2 of the swing lever 23.
Gradually approach the position facing 3a.

When the tip of the slider 17 begins to come into contact with the contact roller 28 of the interlocking lever 23 as shown in FIG. 3, the interlocking lever 26 rotates clockwise as the slider 17 moves. With this operation, the interlocking lever 26 urges the swing lever 23 counterclockwise via the tension spring 25. Therefore, the swing lever 23 is brought into a state in which its engaging claw portion 23a slides against the circumferential surface of the disc cam 20 against the bias of the tension spring 24. At this time, disc cam 2
The engagement notch 20a of 0 is located slightly in front of the position facing the engagement claw 23a of the swing lever 23.

In the state shown in FIG. 4 in which the slider 17 has advanced to the movement position corresponding to the scanning system stop position in the document movement mode, the slider 17 has moved in a circle until the engagement notch 20a faces the engagement claw 23a of the swing lever 23. Board cam 2
0 continues to rotate, and the engagement claw portion 2 is inserted into the engagement notch 20a.
3a is locked.

The transfer limit position of the slider 17 by the scanning system drive mechanism is set to a position that slightly exceeds the scanning system stop position with some margin. As shown in FIG. 5, when the slider 17 passes the scanning system stop position, the engagement notch 20a of the disc cam 20 passes the position opposite to the engagement claw 23a of the swing lever 23.

When the slider 17 reaches the transfer limit position and is disconnected from the scanning system drive mechanism, the torsion spring 22 of the pulley rotating shaft 21 is released due to the previous transfer operation.
The pulleys 19, 19 begin to rotate counterclockwise due to the restoring force accumulated in the slider 17, and the slider 17 attempts to return to the standby position. However, the sixth
As shown in the figure, when the slider 17 returns to the scanning system stop position, the engaging claw portion 23a of the swing lever 23
is locked in the engagement notch 20a of the disc cam 20,
The slider 17 is fixed at this position.

When copying in the document movement mode is completed and the scanning method is switched to the optical system movement mode, the solenoid 27 is driven. This solenoid 27 has an engaging claw portion 23a that connects the swing lever 23 to the disk cam 2.
0 to the separating side to release the locked state with the engagement notch 20a. The pulleys 19, 19 rotate counterclockwise by the restoring force of the torsion spring 22, and the slider 17 returns to its original standby position.

On the other hand, in the optical system movement mode, the swing lever 23
The engaging claw portion 23a of the disc cam 20 and the engaging notch portion 2 of the disc cam 20
As mentioned above, the engagement with solenoid 27
Since the slider 17 is released by the drive of the torsion spring 22, the slider 17 is moved from the standby position to the scan end position by the scanning system drive mechanism regardless of the presence of the optical system fixing device, and after the scan is completed, the slider 17 is returned to the standby position by the restoring force of the torsion spring 22. Return until.

The solenoid 27 is driven not only when the solenoid 27 is kept in a driven state throughout the optical system movement mode as described above, but also when
In this mode, the slider 17 may be driven only while it is close to the scan end position so as not to be interfered with by the optical system fixing device.

In the embodiment described above, the disc cam 20 provided coaxially with the pulley 19 may be constructed so that its mounting rotational position can be arbitrarily adjusted and reset. Therefore, it is possible to easily adjust the position of the slider 17 when the engagement claw portion 23a of the swing lever 23 is engaged with the engagement notch 20a of the disc cam 20, that is, the stop position of the optical system in the document movement mode. can.

The return motion of the slider 17 can be measured by the restoring force of the torsion spring 22 as in the previous embodiment, or by arranging the compression spring that hits the slider 17 on the scanning end position side so that the return motion is measured as the slider 17 is pushed. However, in the case of the embodiment described above, the restoring force of the torsion spring 22 does not directly act on the slider 17, but is transmitted via the pulleys 19, 19, and the restoring force is transmitted to the disc cam. Since the swing lever 23 also makes sliding contact with the slider 20, the forward movement of the slider 17 is stabilized, and inconveniences such as tilting and deformation can be avoided. The restoring forces of the torsion spring 22 and the compression spring are set to be large enough to return the slider 17 from the state shown in FIG. 5 to the state shown in FIG.
The return operation may be performed by reversing the scanning system drive mechanism.

According to the optical system fixing device of this invention, the pulley 19 is provided at the same time as the pulley 19 around which the cable (wire rope 18) for pulling the optical system (slider 17) is wound, and the engagement portion (engagement notch) is provided in a part of the circumference. A cam member (disc cam 20) having a portion 20a) and an engaging portion (engaging notch 20) of this cam member (disc cam 20).
a) and a swinging lever 23 which has an engaging part (engaging claw part 23a) that can be engaged with the cam member (disc cam 20) and is biased in a direction away from the cam member (disc cam 20), and a moving optical system (slider 17). ) and collides with the swing lever 2.
3 in the direction of engaging with the cam member (disc cam 20); Since it is equipped with a release member (solenoid 27) that separates the optical system (slider 17), the optical system (slider 17) is located at a position corresponding to the document movement mode.
It is easy to fix the optical system properly, and even when applied to a copying machine where various operation controls are performed according to information written in the ROM of a microcomputer, the timing of stopping the optical system must be precisely determined at the ROM manufacturing stage. It has the effect that it can be fixed at an accurate position without having to set it to a certain position, that the precision of the copying machine can be improved, and that adjustments during manufacturing can be made extremely easy.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical sectional view of a copying machine to which this invention is applied, FIG. 2 is a perspective view showing an embodiment of this invention, and FIGS. 3 to 7 are explanatory views showing the operation. 17... Slider, 18... Wire rope (rope), 19... Pulley, 20... Disc cam (cam member), 20a... Engagement notch, 21... Rotating shaft, 22... Torsion spring , 23... Swinging lever, 23a... Engaging claw portion, 24... Tension spring,
25... tension spring, 26... interlocking lever (interlocking member), 27... solenoid (release member).

Claims (1)

[Claim for Utility Model Registration] An optical system movement mode in which an original placed on a document table is scanned by moving an optical system and exposed onto a photoreceptor; An optical system fixing device for a copying machine, which has a document movement mode in which the system is fixed and the document is conveyed at a constant speed on the document table to scan the document and expose the photoreceptor, the device pulling the optical system. A cam member that is provided coaxially with the pulley around which the cable is wound and has an engaging part in a part of its circumference, and has an engaging part that can engage with the engaging part of the cam member and is spaced apart from the cam member. a swinging lever biased in a direction; an interlocking member that collides with a moving optical system to swing the swinging lever in a direction in which it engages with a cam member; and a swinging lever connected to the swinging lever. What is claimed is: 1. An optical system fixing device for a copying machine, comprising a release member that separates the optical system from a cam member, and fixes the optical system at a terminal position in an optical system moving mode during an original moving mode.