JPS5931073B2 - Developing device of wet copying machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device for a wet-type copying machine, in which a developer is supplied to the developing roller by a supply roller that is in pressure contact with or in contact with the developing roller.

In this type of developing device, if the supply roller is constantly pressed against or in contact with the developing roller, the developing roller will become distorted while the copying machine is stopped. Since the coating is made of a flexible material with good properties, the pressure or contact portion may change in quality, resulting in uneven absorption of the developer, which may result in uneven coating and development.

For this reason, the supply roller can be switched between a state in which it is pressed or in contact with the developing roller and a state in which it is separated from the developing roller, and the above two states are switched in conjunction with the start and stop of the copying machine, and the copying A developing device has been proposed in which the supply roller is kept separated while the machine is stopped.

However, in this conventional device, the supply roller is in pressure contact with or comes into contact with the developing roller when the main switch of the copying machine is turned on and the developing roller is rotationally driven. There were flaws.

In other words, when the copying machine is started, the developing roller, which has already started rotating, and the supply roller, which is stationary, come into pressure contact or contact, which creates unnecessary friction (slip) between the two, which causes wear. It will become.

This is particularly noticeable in the case where the supply roller is freely rotatable and rotates passively in contact with the developing roller, but even in the case where the rotational force is transmitted between the developing roller and the supply roller by means of gears, it is generally Since the meshing of the gears is completed when the surfaces of both rollers are pressed against each other to some extent, there is a considerable possibility that the above phenomenon will occur. Also,
In the latter type, since a rotating gear and a stationary gear mesh, gear noise often occurs when the gears mesh.

The present invention aims to solve the above-mentioned conventional drawbacks with an extremely simple structure.A rotatable operating dial is provided on the outer surface of the aircraft body, and a dial that is rotated by the operating dial is provided inside the aircraft body. In addition to providing a shaft, a lever is provided whose central portion is rotatably supported around a horizontal axis.
A supply roller for supplying developer to the developing roller is attached to one end of the lever, a cam follower is attached to the other end, and a first cam for turning the main switch on and off is attached to the dial shaft. and a second cam for rotating the lever around the horizontal axis b via the cam follower, and by rotating the operation dial), the main switch is operated by the first cam. The present invention is characterized in that, prior to the ON operation, the second cam rotates the lever to press or contact the supply roller with the developing roller.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes the body of a wet-type copying machine, and 2 denotes a table provided at the front of the machine.A stacked document and photosensitive paper are guided by this table 2 and inserted into the machine. 3 is a cylinder glass 5 containing an exposure light source 4 and a conveyance roller 6
a, b, c, d and the conveyor belt 7 wound between them
The inserted original and photosensitive paper are sent between the conveyor belt 7 and the cylinder glass 5, and are printed therein.

After passing through the exposure device 3, the original is separated from the photosensitive paper and discharged onto the sheet tray 8, and the single-strength photosensitive paper is developed while being transported and guided by the transport rollers 9a, 9b1, the transport base 7, and the guide plate 10. It passes between the roller 11 and the pressure blade 12 and is sent out through the discharge port 13. and the developing roller 1
When passing between the photosensitive paper 1 and the pressure blade 12, the photosensitive paper is developed by the developer C applied to the surface of the developing roller 11. 14 is a supply roller that supplies developer to the developing roller 11, and this roller 14 has a developing tank 1.
Developing solution A stored in 5 is constantly replenished by a replenishing member 16.

Reference numeral 17 has five supply roller switching mechanisms, which are attached to an L-shaped lever 18 and a dial 19' that is rotated by a control dial 19 that is rotatable around the vertical axis provided on the outer surface of the machine body 1. It is composed of a disk-shaped second cam 20 and the like.

A central portion 18a of the lever 18 is rotatably supported on the body 1 around four horizontal axes, and the supply roller 14 is rotatably attached to one end, and a cam follower consisting of an idle roller is attached to the other end. The cam follower 18b is rotatably mounted on the upper surface of the peripheral edge of the second cam 20. On the other hand, as shown in FIG. 2, the second cam 20 has an arcuate stepped portion 21 centered around the dial shaft 19' formed on a part of its peripheral edge.
The cam follower 18b is placed on the stepped portion 21 before the copying machine is turned on by rotating the cam follower 9. Here, the switch on and off of the copying machine is dial axis 19.
The switching is performed by a first cam 22 attached to the lower end of the cam 22 and a main switch, for example, a micro switch MS, provided opposite to the first cam 22. The timing at which this switch is turned on and the timing at which the cam follower 18b lands on the stepped portion 21 are illustrated in FIG. 3. Figure A shows the switch-off state, Figure B shows the operation dial 19 being rotated in the switch-on direction (in the direction of arrow P), and Figure C shows the switch-on state. That is, as can be understood from these figures, when the operation dial 19 is rotated, the cam follower 18b first lands on the step 21 and is switched over. and,
By appropriately determining the arrangement of the lever 18 and the second cam 20, when the cam follower 18b does not ride on the stepped portion 21, the supply roller 14 is separated from the developing roller 11 and is in a non-contact stateV) (See FIG. 4), when the cam follower 18b rides on the stepped portion 21, the supply roller 1
4 is pressed against or in contact with the developing roller 11.
(See Figure 1). Therefore, when the switch is turned off, that is, when the copying machine is stopped, the developing roller 11 and the supply roller 14 are kept apart, and when the switch is turned on, that is, when the copying machine is started,
First, the supply roller 14 comes into pressure contact with or comes into contact with the developing roller 11, and then the developing roller 11 and the supply roller 14 are rotationally driven by a switch.

Furthermore, when stopping the copying machine, from the state shown in FIG. The system stops (the supply roller and the developing roller also stop rotating), and then the cam follower 18b, which had been riding on the stepped portion 21, falls onto the second cam 20, and the supply roller 14 separates from the developing roller 11. Therefore, the supply roller 14 and the developing roller 11 can be smoothly brought into contact with each other and separated from each other. Next, 23 is a pressure blade switching mechanism, which includes a solenoid 25 that moves the plunger 24 in and out depending on whether the solenoid is energized or not.
When the solenoid 25 is de-energized, it is composed of a switch 26 that controls de-energization, and a drive lever 27 whose one end is pivotally connected to the plunger 24 and the other end is fixed to the J-shaft 12a that supports the pressure blade 12. When the pressure blade 12 is separated from the developing roller 11 (see Figure 4), when the solenoid 25 is energized, the plunger 24, drive lever 27, and support shaft 1
2a to rotate the pressure blade 112 to release the developing roller 1.
1 (see FIG. 1).

The switch 26 is equipped with a rotatable actuator 26a, as shown in detail in FIG. I'm letting you do it.

This actuator 26a is rotated in the direction shown by arrow B in FIG. 5 by coming into contact with the leading edge of the photosensitive paper being conveyed, and is moved out of the conveyance path 28. The switch 26 is turned on by the rotation of the actuator 26a2, energizing the solenoid 25, and bringing the pressure blade 12 into pressure or contact with the developing roller 11. On the other hand, the tip of the support shaft 12a is connected to the actuator 2.
A bent rod-shaped locking tool 29 is fixedly connected to the lower part of the rod 6a. When the pressure blade 12 is separated from the developing roller 11, this locking tool 29 is operated by the actuator 26a to allow it to protrude into the conveyance path 28, as shown by the chain line in FIG. 5, or by the actuator 26a. Pushed by the photosensitive paper, the switch 26 is turned on to the position shown by the two-dot chain line in FIG. 5, and the solenoid 25 is energized.
2 comes into pressure contact or contact with the developing roller 11, the bent end portion of this locking tool 29 or the actuator 26
A is rotated to the solid line position in FIG. 5 and held in that position. With this configuration, the actuator 26a detects only the photosensitive paper that is conveyed first, and when the pressure blade 12 is brought into contact with the developing roller 11, the fifth Since it is held at the position indicated by the solid line in the figure and does not come into contact with the second and subsequent sheets of photosensitive paper, wrinkles in the photosensitive paper, paper jams, etc. are less likely to occur. Also, when the main switch MS is turned off by turning the control dial 19, the excitation of the solenoid 25 is released and the lever 27 is returned to the position shown in FIG. 4 by the tensile force of the spring 30. At the same time as the pressure blade 12 and the developing roller 11 are released from contact, the locking tool 29 releases the locking of the actuator 26a, and the actuator 26a is moved to the fourth position.
It returns to the position shown in the figure.

According to the developing device configured as described above, when the copying machine is stopped, both the supply roller 14 and the pressure blade 12 are separated from the developing roller 11, causing distortion of the developing roller 11 and damage to the developing roller 11. Deterioration of the contact portion of the supply roller 14 or pressure blade 12
This prevents changes in pressure force over time and prevents curling.

Next, when the copying machine is started, the supply roller 14
Since the developing roller 11 and the developing roller 11 are pressed against or in contact with each other, unnecessary friction is not generated between the developing roller 11 and the developing roller 14 at the time of starting, and the developing roller 11 and the developing roller 14 are started in a state where wear is prevented. Furthermore, even when gears are used to transmit the drive between the developing roller 11 and the supply roller 14, the gears can be smoothly engaged. At the time of starting, the developer is applied and supplied to the developing roller 11 via the developer supply roller 14. After startup, the first photosensitive paper is conveyed to the developing roller 11 position with a slight delay from the time of startup, and during that time, both the developing roller 11 and the supply roller 14 have to rotate at least a few times, so the pressure blade 12 is used to develop the paper. Before pressing or contacting the roller 11, the developing roller 1 is
1 is uniformly coated with developer, and then when the first photosensitive paper is conveyed along the guide plate 10 to the front of the developing device section, the pressure blade 12 is moved to the developing roller 11 by the detection of the switch 26. Since it is pressed or brought into contact with the photosensitive paper, even and clean development can be performed from the initial photosensitive paper. From then on, the pressure blade 12 remains in that state until the copying machine is stopped. As is clear from the above examples),
According to the present invention, by keeping the supply roller separated from the developing roller while the copying machine is stopped, it is possible to prevent distortion of the developing roller, pressure contact between both rollers, or deterioration of the contact portion, and also prevent rotation of the supply roller around the horizontal axis. A supply roller is attached to one end of a freely movable lever, and a cam follower is attached to the other end, and a dial shaft having a first cam for operating the main switch is connected to the horizontal axis via the cam follower. A second cam is provided for rotational operation on the periphery, and these first and second cams are
By using an extremely simple structure in which the phase difference of the cams is appropriately set, the conventional drawbacks mentioned at the beginning can be completely eliminated.

That is, according to the present invention, when starting the copying machine, by rotating the operation dial, the supply roller is brought into pressure contact or contact with the developing roller by the action of the second cam, and then the main switch is turned on by the first cam. Since both rollers rotate, unnecessary friction is not generated between the rollers and wear can be prevented.Also, the rotational force is transmitted between the developing roller and the supply roller using gears. Even when the gears are stationary, they mesh and then rotate, which prevents gear noise from occurring.
Because the structure is extremely simple, it can be manufactured easily and at low cost, and has the advantage of having fewer failures.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention. Fig. 1 is a sectional view showing the overall structure of a wet copying machine, Fig. 2 is a perspective view showing the main parts of the supply roller switching mechanism, and Fig. 3 A, B, and C are diagrams illustrating the supply roller switching mechanism, Figure 4 is a sectional view showing the supply roller and pressure blade separated from the developing roller, and Figure 5 is the pressure blade switching mechanism. FIG. 1... Machine body, 11... Development roller, 1
4... Supply roller, 18... L-shaped lever 18a... Central part, 18b...
Cam follower 1, 19... Operation dial, 19
'... Dial shaft, 22... First cam, 20... Second cam.

Claims (1)

[Claims] 1 A rotatable operation dial is provided on the outer surface of the aircraft body, and a dial shaft rotated by the operation dial is provided inside the aircraft body, and a lever whose central portion is rotatably supported around a horizontal axis. At one end of this lever,
A supply roller for supplying developer to the developing roller is attached to the other end, and a cam follower is attached to the other end, and a first cam for turning on and off the main switch and the cam follower are attached to the dial shaft. a second cam for rotating the lever about the horizontal axis through the second cam;
By rotating the operation dial, the second cam rotates the lever and presses or contacts the supply roller with the developing roller, prior to turning on the main switch by the first cam. A developing device for a wet type copying machine, characterized in that: