JPH0143706Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a liquid developing device for supplying a developing solution to photosensitive paper using a developing roller in a diazo copying machine or an electronic copying machine.

(Prior art) A liquid developing device includes a developing roller and a pressure roller disposed in contact with the developing roller, and the pressure roller presses the photosensitive paper against the developing roller to develop the peripheral surface of the developing roller. A method is known in which a film-like developer is supplied to photosensitive paper.

However, in this liquid developing device, when the developing roller is not rotated for a long time, the solvent in the film of developing solution coated on the circumferential surface of the developing roller evaporates, increasing the viscosity of the developing solution. Since the viscosity of the developing solution becomes large in this case, when developing the photosensitive paper with the developing roller, the adhesive force of the developing solution may cause the photosensitive paper to wrap around the developing roller, damaging the developing roller, scooping roller, and pressure roller. There is a drawback.

(Purpose) The purpose of this invention is to detect that the photosensitive paper is wrapped around the developing roller and stop the rotation of the developing roller, lifting roller, and pressure roller. An object of the present invention is to provide a liquid developing device that can effectively prevent damage.

(Structure) Next, the structure of the present invention will be described based on examples.

In FIG. 1, arrow 1 indicates a developer container. A developer 2 is stored inside the developer container 1 . Inside the developer container 1, a pumping roller 3 is disposed with its lower part immersed in the developer 2. This pumping roller 3 is driven by a driving means 4
is rotated in the direction of arrow a.

A developing roller 5 is arranged so as to be in contact with the upper part of the pumping roller 3. This developing roller 5 is rotated in the direction b by the driving means 4. The circumferential speed of this developing roller 5 is
The peripheral speed is set to be the same as, or slightly slower than, the circumferential speed of When the pumping roller 3 is rotated, the developer 2 is drawn up by its circumferential surface and applied to the rotating developing roller 5 in the form of a film.

A pressure roller 6 is arranged so as to be in contact with the upper part of the developing roller 5. This pressure roller 6 is rotated by the drive means 4 in the direction of arrow c. The circumferential speed of the pressure roller 6 is set to be faster than the circumferential speed of the developing roller 5, for example, about 1.5 to 3 times faster.

A pressure means 7 for pressing the pressure roller 6 against the developing roller 5 is arranged above the pressure roller 6 . This pressurizing means 7 includes a rotating lever 7b whose one end is rotatably supported by a support shaft 7a, and an abutment rotatably provided at a portion of the rotating lever 7b near the supporting shaft 7a. A roller 7c, a solenoid 7d disposed below the rotating end of the rotating lever 7b, and a tensioning solenoid 7d connecting the plunger 7e of the solenoid 7d and the rotating end of the rotating lever 7b. It consists of a spring 7f.

When current is supplied to the solenoid 7d by the power supply circuit 7g, the plunger 7e is positioned at the lowest position and the spring 7f urges the rotary lever 7b downward, so that the contact roller 7c comes into pressure contact with the pressure roller 6. A pressure roller 6 as a lever is brought into pressure contact with the developing roller 5.

A micro switch 8a is fixed to the intermediate portion of the rotary lever 7b, and a flexible filler 8b is fixed to the lower part of the micro switch 8a. The lower end of the filler 8b is located near the plunger 7e of the solenoid 7d.
A pin 7h is provided on the plunger 7e so as to project laterally. The lower end of the filler 8b is elastically pressed against a pin 7h that is integral with the plunger 7e.

When the supply of current from the power supply circuit 7g to the solenoid 7d is stopped, as shown in FIG. 2, the plunger 7e is raised and the filler 8b is pushed up, and the rotating lever 7b is accordingly moved upward. Since the abutment roller 7c is rotated, the contact roller 7c is separated from the pressure roller 6, so that the pressing force of the pressure roller 6 on the developing roller 5 is released.

As shown in FIG. 1, the pressure roller 6 is pressed against the developing roller 5 by a pressure means 7,
In addition, while the lifting roller 3, the developing roller 5, and the pressure roller 6 are being rotated in the directions of arrows a, b, and c, the exposed photosensitive paper 9 is pressed against the developing roller 5 by a paper conveying means (not shown). The photosensitive surface is inserted between the pressure roller 6 and the developing roller 5 so that the photosensitive surface is in contact with the developing roller 5. These developing rollers 5
The pressure roller 6 clamps the photosensitive paper 9 and sends it in the direction of arrow d, and at this time, a film of developer on the circumferential surface of the developing roller 5 is supplied to the photosensitive surface of the photosensitive paper 9, making the latent image visible. Ru.

The micro switch 8a constitutes a paper wrapping sensor 8 which detects that the photosensitive paper 9 is wrapped around the developing roller 5 by detecting the displacement of the rotating lever 7b of the pressure means 7 from its normal position.

As shown in FIG. 1, while the pressure roller 6 is in pressure contact with the developing roller 5, a sheet of photosensitive paper 9 is inserted between them.
is not wrapped around the developing roller 5, when the pressure roller 6 is in pressure contact with the development roller 5 and no photosensitive paper is inserted between them, and when the pressure roller 6 is not in pressure contact with the development roller 5. , the filler 8b of the micro switch 8a
is in pressure contact with the actuator 8c, so the microswitch 8a is in the on state.

As shown in FIG. 3, when the pressure roller 6 is in pressure contact with the developing roller 5, the photosensitive paper 9 is wrapped around the developing roller 5, and the developing roller 5
When two or more sheets of photosensitive paper 9 are inserted between the roller and the pressure roller 6, that is, when the developing roller becomes thick, the pressure roller 6 is pushed up and the pressure is applied. Since the lever 7b is pushed up against the tensile force of the spring 7f, the rotating end of the rotating lever 7b and the plunger 7e
The distance between the actuator 8c and the filler 8b increases, and the filler 8b remains in pressure contact with the pin 7h integrated with the plunger 7e due to its elasticity, so the filler 8b is separated from the actuator 8c.
a is in an off state.

The microswitch 8a is connected to an input terminal of a control circuit 10. The output terminal of this control circuit 10 is connected to the drive means 4, the power supply circuit 7g, and the display means 11. The above control circuit 10
In this case, when the micro switch 8a is turned off, that is, the paper wrapping sensor 8 detects the developing roller 5.
When it is detected that the photosensitive paper 9 is wrapped around the photosensitive paper 9, the power supply circuit of the drive means 4 is opened to stop the rotation of the developing roller 5, the lifting roller 3, and the pressure roller 6, and the power supply circuit 7g to the solenoid 7d is opened. The pressing force of the pressing means 7 on the developing roller 5 is released, and the power supply circuit of the display means 11 is closed to display on the display means 11 that the photosensitive paper 9 is wrapped around the developing roller 5.

Note that when the paper wrapping sensor 8 detects that the photosensitive paper 9 is wrapped around the developing roller 5, the rotation of the developing roller 5, the lifting roller 3, and the pressure roller 6 is stopped, and the pressure applied to the developing roller 5 is stopped. It is not necessary to release the pressing force of the means 7 and to display on the display means 11 that the photosensitive paper 9 has been wrapped around the developing roller 5.

FIGS. 4 to 7 show other embodiments of the paper wrapping sensor 8, which will be described next.

The paper wrapped sensor 8 shown in FIGS. 4 to 7 is
It consists of a light emitting element and a light receiving element. A stopper pin 7i and a holding pin 7j are arranged above the rotating lever 7b. A tension spring 7k is attached to the upper part of the rotating lever 7b and the holding pin 7j.
is being worked on. When current is supplied to the solenoid 7d from the power supply circuit 7g, the plunger 7
e is lowered, the rotary lever 7b is rotated downward, and the contact roller 7c applies a pressing force to the pressure roller 6, thereby bringing the pressure roller 6 into pressure contact with the developing roller 5.

When the supply of current from the power supply circuit 7g to the solenoid 7d is stopped, the plunger 7e is raised from the position shown in FIG. Since it is stopped at , the rotation lever 7b
The abutting roller 7c, which is integral with the developing roller 5, is also separated from the pressure roller 6, and the pressing force of the pressure roller 6 against the developing roller 5 is released.

Two detection protrusions 8d and 8e are formed at a predetermined interval at the rotating end of the rotating lever 7b. These detection protrusions 8d and 8e can be arranged between the light emitting element and the light receiving element of the paper wrapping sensor 8 as the rotary lever 7b rotates. The output terminal of the light receiving element of the paper wrapped sensor 8 is connected to a control circuit 10.

When the pressure roller 6 is in pressure contact with the developing roller 5 and no photosensitive paper is inserted between them, the space between the light-emitting element and the light-receiving element of the paper-wrapped sensor 8 is as shown in FIG. The detection protrusion 8d integrated with the rotating lever 7b is positioned to block light from the light emitting element and prevent it from entering the light receiving element.

While the pressure roller 6 is in pressure contact with the developing roller 5, a sheet of photosensitive paper 9 is inserted between them.
If the paper is not wrapped around the sensor 8, the rotating lever 7b is raised slightly above the position shown in FIG. Light from the light emitting element is blocked to prevent it from entering the light receiving element.

When the pressure roller 6 is in pressure contact with the developing roller 5, the photosensitive paper 9 is wrapped around the developing roller 5, and the developing roller 5 and the pressure roller 6
When two or more sheets of photosensitive paper 9 are inserted between the As shown in FIG. 6, the paper wrapped sensor 8 is no longer located between the light emitting element and the light receiving element, and light from the light emitting element is incident on the light receiving element.

When the pressure roller 6 is not pressurized against the developing roller 5 and the photosensitive paper is not wrapped around the developing roller 5, the lower detection protrusion 8e integrated with the rotary lever 7b is connected to the paper wrapping sensor 8. The light-emitting element is located between the light-emitting element and the light-receiving element to block light from the light-emitting element and prevent it from entering the light-receiving element.

If the photosensitive paper 9 is wrapped around the developing roller 5 and the detection protrusions 8d and 8e are not positioned between the light emitting element and the light receiving element of the paper wrapped sensor 8 as shown in FIG. Since light is incident on the light receiving element, the output signal of the light receiving element is transmitted to the control circuit 1.
0, so in this case the control circuit 10
In this case, the power supply circuit of the drive means 4 is opened to stop the rotation of the developing roller 5, the pumping roller 3, and the pressure roller 6, and the power supply circuit 7g of the solenoid 7d is opened to increase the pressing force of the pressure means 7 against the development roller 5. Then, the power supply circuit of the display means 11 is closed to display on the display means 11 that the photosensitive paper 9 is wound around the developing roller 5.

Note that since the rotating lever 7b is rotated only for a predetermined period of time from the time when the supply of current to the solenoid 7d is started or stopped, the detection protrusions 8d and 8e are provided between the light emitting element and the light receiving element of the paper wrapped sensor 8. may not be located, but in this case, the supply of current to the light emitting element of the paper wrapped sensor 8 may be stopped to stop the emission of light from the light emitting element.

Note that the paper-wrapped sensor 8 is not limited to the above-described embodiment, and may be constructed using a reed switch, a Hall element, an ultrasonic sensor, a capacitance switch, or the like. Further, the paper wrapping sensor 8 may be configured to detect the displacement of the pressure roller 6 in addition to detecting the displacement of a predetermined portion of the pressure means 7 as in the above-described embodiment.

(Effects) The liquid developing device of the present invention can detect that photosensitive paper is wrapped around the developing roller and the developing roller becomes thick, and can stop the rotation of the developing roller, scooping roller, and pressure roller. Therefore, damage to the developing roller, scooping roller, pressure roller, etc. can be effectively prevented.

[Brief explanation of the drawing]

1 to 3 are diagrams showing the configuration of the liquid developing device of the present invention, FIG. 4 is a diagram showing the configuration of another embodiment of the liquid developing device of the present invention, and FIGS. 5 to 7 are diagrams showing the configuration of the liquid developing device of the present invention.
This figure is a partially cutaway front view showing the paper wrapping sensor of the liquid developing device shown in FIG. 4. DESCRIPTION OF SYMBOLS 1... Developer container, 2... Developer, 3... Drawing roller, 4... Drive means, 5... Developing roller, 6... Pressure roller, 7... Pressure means, 8...
...Sensor with paper wrap.

Claims (1)

[Scope of utility model registration request] A developer container containing a developer, a pumping roller disposed in the developer container with its lower part immersed in the developer, and a developer that is in contact with the pumping roller and is pumped up by the pumping roller. a developing roller whose circumferential surface is coated with the following: a pressure roller which is placed in contact with the developing roller and presses the photosensitive paper against the developing roller; and a drive means which rotates the scooping roller, the developing roller and the pressure roller. a pressure means for elastically pressing the pressure roller against the development roller; and a paper wrapper for detecting displacement of the pressure roller caused by thickening of the roll of the development roller when the photosensitive paper is wrapped around the development roller. A liquid developing device comprising: a sensor; and a control means for stopping rotation of the developing roller, the scooping roller, and the pressure roller when the paper wrapping sensor detects that photosensitive paper is wrapped around the developing roller.