JPH0683130A - Electrostatic copying machine provided with mechanism for inhibiting attachment/detachment of high voltage unit at the time of turning on power source - Google Patents

Abstract

PURPOSE:To realize a fail-safe mechanism capable of safely executing work such as maintenance and inspection even when a safety mechanism does not act as for an electrostatic copying machine in which a high voltage power source is cut off when a front door is opened. CONSTITUTION:The electrostatic copying machine in which the power source is cut off by opening a protection door is provided with a detection means 13 detecting that voltage is impressed on high voltage unit parts 3, 4 and 5, and a locking mechanism 14 inhibiting the high voltage unit parts 3-5 from being taken out when the detection means 13 detects that the voltage is impressed on the high voltage unit part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic copying machine, and more particularly to a safety mechanism for operating, maintaining and inspecting a unit such as a transfer machine and a developing machine to which a high voltage is applied.

[0002]

2. Description of the Related Art In a copying machine such as an electrostatic copying machine having a high voltage operating unit such as a transfer machine and a developing machine, a voltage remains applied to these high voltage units during maintenance and inspection. The removal of the high voltage unit
Since maintenance and inspection work is dangerous, it is considered that the application of the voltage to the high-voltage unit is cut off by opening the door as shown in FIGS. Also,
In a copier that enables multicolor copying using a sub-developing machine, even an operator who does not have specialized knowledge can easily replace the sub-developing machine. Performing the replacement work while the voltage is still applied may cause a risk of electric shock, and it is necessary to provide the above-mentioned safety mechanism.

FIG. 3 is a conceptual diagram showing the outline of the vicinity of a high voltage unit of a conventional electrostatic copying machine, and FIG. 4 is a diagram showing the concept of its circuit. In the figure, the main body 1 of the copying machine includes a DC high voltage (1.
5 to 5 kV) is applied, and the high voltage unit is protected by the front cover 2 which normally works as a protective door. A safety switch 6 is provided on the main body 1 and is configured to turn on the power supply to the high voltage unit portion by being pushed by the protrusion 7 provided on the front cover. When the front cover 2 is opened during maintenance / inspection of the copying machine, the pressing by the projection 7 is released and the safety switch 6 is cut off, so that the supply of voltage to the high voltage unit and the drive mechanism (not shown) is cut off ( Figure 3 (A)). Next, the transfer machine 3, the main developing machine 4, and the sub-developing machine 5 are pulled out and removed to perform maintenance / inspection or replacement of each mechanism (FIG. 3 (B)).

The circuit of the main body 1 of the electrostatic copying machine includes a high voltage unit section such as a transfer machine 3, a main developing machine 4 and a sub developing machine 5, a power section such as a driving motor 11, a display unit 12 and a control section. The load of the low voltage section such as is connected to the power source section 8 of the copying machine. The copier power supply 8 is connected to a commercial power supply 10 of AC 100V via a main power switch 9, and outputs, for example, DC 24V for high voltage unit, DC 12V for power, and low voltage. The output of DC 5V and the output of AC 100V for the heater of the fixing unit and the like are output. To the output for the high voltage unit and the output for the power unit, a safety switch 6 that is cut off when the door opening detection means 7 detects the opening of the protective door is connected in series. According to this device, the application of the voltage to the high-voltage unit section and the power section is cut off by opening the front door during maintenance / inspection, so that it is possible to avoid the risk of the operator touching the high-voltage source. Such a safety device has already been disclosed in, for example, Japanese Patent Laid-Open No. 62-69277 and is a well-known device. Further, when the output of the copier power source unit 8 or the operation of the high voltage unit unit is controlled by a control device (not shown), it is detected that the high voltage unit unit is taken out, and the high voltage becomes high voltage unit. It is also possible to control so as not to join the department.

[0005]

The above-mentioned conventional means is safe because the application of the voltage to the high voltage unit is cut off when the front door is opened. However, the safety switch 6 is used for some reason. For example, it is conceivable that even if the front door is opened, it will not be interrupted due to seizure of the contacts. In such a case, the operator believes that the device itself has cut off the application of voltage to the high-voltage unit, so that he may not be prepared to deal with the high-voltage and may inadvertently touch the high-voltage unit. Yes, it is extremely dangerous. Further, in the means for controlling the cutoff of the voltage application to the high voltage unit section by the software when the high voltage unit section is taken out, there is a possibility that the cutoff may not be normally performed due to the runaway of the software. In this case, there is the same danger as described above. The present invention is
It is an object of the present invention to provide a fail-safe mechanism that avoids such a danger in an electrostatic copying apparatus.

[0006]

In order to achieve the above object, the present invention relates to an electrostatic copying machine in which a power supply is cut off by opening a protective door, and a voltage is applied to a high voltage unit of the electrostatic copying machine. Is provided, and a lock mechanism for prohibiting removal of the high-voltage unit section when the detection section detects that a voltage is being applied to the high-voltage unit section.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to FIGS. FIG. 1 is a diagram showing the concept of the circuit and the lock mechanism of the present invention, and FIG. 2 is a conceptual diagram showing the concept of the lock mechanism near the high voltage unit. In the figure, a solenoid 13 connected in parallel to a high-voltage unit section voltage terminal and a lock mechanism 14 operated by the solenoid are provided, and the lock mechanism 14 has a locking pawl 15
And a tension spring 16 for returning the locking claw to the unlock position, and lock claw escape portions 31, 41, 5 provided in the transfer machine 3, the main developing device 4, and the sub developing device 5, respectively.
1 is different from the conventional device. The same reference numerals as those in FIGS. 3 and 4 indicate the same configurations as those cases. Transfer machine 3, main developing machine 4, sub developing machine 5
Is provided with a boosting means for receiving a voltage of 24 V DC from the power supply unit 8 and boosting it to a voltage suitable for each device. As described above, the solenoid 13 is connected to the output terminal to the high voltage unit in parallel with the high voltage unit, and when the safety switch 6 is closed and a voltage appears at the output terminal, the solenoid 13 is connected. Is urged to maintain the lock mechanism 14 in the operating state.

The locking mechanism 14 includes a locking pawl 15 attached to a plunger provided on the solenoid 13 and a locking pawl 1 when the voltage applied to the solenoid 13 is turned off.
5 is composed of a tension spring 16 for returning 5 to the unlocked position, and lock claw escape portions 31, 41, 51 provided in the transfer machine 3, the main developing machine 4, and the sub developing machine 5, respectively. In a state where a voltage appears at the high voltage terminal and a voltage is applied to the high voltage unit, the solenoid 13 is energized and the locking claw 15 moves to the position indicated by the broken line from the tension spring 16. It is prohibited to take out the transfer device 3, the main developing device 4, and the sub developing device 5.

When the safety switch 6 operates normally and no voltage appears at the high voltage terminal of the power source 8 of the copying machine, the solenoid 13 is not energized, and the locking claw 15 is transferred by the tension spring 16 to the transfer machine 3. The lock claw escape portions 31, 41, 51 provided on the main developing device 4 and the sub developing device 5 are moved to the positions indicated by the solid lines to release the locks, and the respective devices can be taken out.

According to the above embodiment, the means for shutting off the output voltage to the high voltage unit by opening the front door 2 has a mechanical structure of the safety switch 6 and the door opening detecting means 7. It is needless to say that the present invention can be applied to the one using the method of shutting off the output for the high-voltage unit of the copier power supply unit 8 when the front door is opened by. Further, the lock mechanism 14 is provided with a means for displaying a locked state and a non-locked state, for example, a means for displaying a high voltage caution or the like when the lock claw 15 is at the broken line position so as to alert the operator. You can also do it. Further, the means for prohibiting the removal of the high voltage unit portion when a voltage is applied to the high voltage unit portion is shown by the lock mechanism 14 having the solenoid 13 and the locking claw 15, but the high voltage unit portion is not shown. Various other means for prohibiting the removal of the high voltage unit portion by a detection signal from the means for detecting that a voltage is applied to can be adopted. For example, the lock mechanism 14
Can be provided on a rail on which each high-voltage device is placed and moved, and the device can be prevented from moving when a voltage is applied to prohibit removal. In the above embodiment, an example in which each high voltage unit is provided with the boosting means individually is shown, but it is assumed that the copier power source unit 8 outputs the high voltage for each high voltage unit unit. May be configured to be detected.

[0011]

According to the present invention, the high voltage unit portion of the electrostatic copying machine cannot be taken out unless the power is surely cut off, when the high voltage unit portion of the electrostatic copying machine is taken out. Since a heavy fail-safe mechanism can be provided, safety can be improved. Also, in the case where the inter-image lamp is integrated into the transfer machine, if the transfer machine is reattached with the power turned on, the lighting pattern of the inter-image lamp becomes indeterminate, and it corresponds to the part where the lamp is lit. Although it leads to fatigue of a specific portion of the transfer drum portion, if the configuration is such that the power source is turned off and then reattached as in the present invention, it is possible to start from a reset state and eliminate such inconvenience. .

[Brief description of drawings]

FIG. 1 is a diagram showing a concept of a circuit and a lock mechanism of a device of the present invention.

FIG. 2 is a conceptual diagram showing the concept of a lock mechanism in the vicinity of a high voltage unit section according to the present invention.

FIG. 3 is a conceptual diagram showing an outline of the vicinity of a high voltage unit of a conventional electrostatic copying machine.

FIG. 4 is a diagram showing a concept of a circuit of a conventional device.

[Explanation of symbols]

1 copy machine main body, 2 front cover, 3 transfer machine, 4 main developing machine, 5 sub-developing machine, 6 safety switch, 7 door opening detecting means, protrusion, 8 copier power supply section, 9 main power switch, 10 external power supply, 11
Drive motor, 12 indicators, 13 solenoids,
14 locking mechanism, 15 locking claw, 16 tension spring, 31, 41, 51 locking claw relief part.

Claims (1)

[Claims] 1. An electrostatic copying machine in which power is shut off by opening a protective door, a detection means for detecting that a voltage is applied to a high-voltage unit section, and a voltage to the high-voltage unit section. An electrostatic copying machine, comprising: a lock mechanism for prohibiting removal of the high-voltage unit section when the detection means detects that the voltage is being applied.