JPH02282274A - Image forming device - Google Patents

Abstract

PURPOSE:To cut off feed for an exposed electrical equipment at the time of dividing and opening an image forming device by supplying output form DC-DC converter which inputs power-supply voltage through a power source cut-off means to the desired electrical equipment as a control voltage. CONSTITUTION:When the image forming device which can be divided into two, an upper main body and a lower main body, is opened, an interlock switch 3 is interlockingly opened to shut off the feed from an AC-DC converter 6 being a power source unit to a driving system and shut off the feed of the control voltage to the exposed electrical equipment 5 through the DC-DC con verter 8. Meanwhile, the control voltage to the control system of the electrical equipment other than the electrical equipment 5 is not shut off and the power is fed thereto from the converter 6, thereby preventing the loss of data and the occurrence of damage and trouble through the exposed electrical equipment.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image forming apparatus such as a laser printer, a copying machine, or a facsimile machine, and particularly to an image forming apparatus whose main body can be divided and opened into an upper main body and an I-shaped main body. Regarding the power supply of the device. .

[Conventional technology]

2. Description of the Related Art Generally, some image forming apparatuses such as laser printers, copying machines, and facsimile machines have a main body that can be separated into an upper main body and a lower main body to facilitate jam removal and maintenance.

In such an image forming apparatus, when the main body is split open, it is undesirable for exposed electrical components to remain supplied with power.
As described in Publication No. 965, a safety switch is operated in conjunction with the opening mechanism of the main body to cut off the power, but in this case, in order to prevent data in the control circuit from being lost. In this case, only the power supply for the drive system is cut off, and the power supply for the control system is not cut off.

[Problem to be solved by the invention]

However, although it is possible to prevent data loss by not shutting off the control system power when dividing and opening the main unit,
If there are electrical components that are exposed when the power is supplied from the control system power supply and are opened, the power supply may be destroyed due to erroneous contact, etc.
There is a problem of sipping caused by sensor malfunction.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to make it possible to also cut off the power supply to the electrical components exposed when the inner water body of the electrical components to which the control system voltage is supplied is divided and opened.

[Means to solve the problem]

In order to achieve the above object, the present invention generates a control system voltage by inputting the power supply voltage from the drive system power supply through a power cutoff means that cuts off the power supply path of the drive system power supply when the main body is divided and opened. A DC-DC converter is provided to convert the DC-D
The output of the C converter is supplied to electrical components that feed the control system voltage exposed when the main body is split open.

[For production]

When the main body is closed, D (>DC) is connected from the drive system power supply.
Control system voltage is generated by the converter and power is supplied to the electrical components exposed when the main body is split open, but when the main unit is split open, the power supply path from the drive system power source is cut off by the power cutoff means. (2) [C-J] The control system voltage is no longer generated by the C converter, and the power supply to the above-mentioned electrical components is also cut off.

〔Example〕

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

FIG. 2 is a perspective view showing a laser printer as an image forming apparatus embodying the present invention with the main body opened in sections.

The main body of this laser printer can be divided and opened into two main bodies 1 and a lower main body 2, and is equipped with an interlock switch 3, which is a power cutoff means that turns off when the upper main body 1 is released from the pressure when the upper main body 1 and the lower main body 2 are opened. When the image forming case 4 is held up as shown in the figure in the split open state, the electrical components 5 to which the control system voltage is supplied are exposed.

FIG. 1 is a block diagram showing the power supply section of this laser printer.

The AC-DC converter (power supply units 1 to 1) 6 is supplied with power from a commercial power supply via a switch/noise filter unit 7, and generates, for example, a DC5V control system voltage and a DC24V immediate-acting system voltage from the AC voltage. This circuit doubles as a control system power supply and a drive system power supply.

The control system voltage from this AC-DC converter 6 is supplied to a control circuit that controls the sequence control of the image forming process (excluding the electrical components 5 exposed when the main body is split open), and the drive system voltage is supplied to an interlock switch. Power is supplied to various parts of the drive system (not shown) through the power supply terminal 3.

The DC-DC converter 8 generates a control system voltage by inputting the immediate voltage from the A, C-DC converter 6 via the interlock switch 3, and outputs this control system voltage in the divided open state of the main body. It is supplied to the exposed electrical components 5 of the control system.

For example, as shown in FIG. 3, the DC-DC converter 8 can be composed of a three-terminal regulator 10, an input resistor 11, and capacitors 12 and 13. Note that the resistance value and power capacity of the resistor 11 are determined by the potential difference between the input and output.

Further, the DC-DC converter 8 in FIG.
It can also be configured with a resistor 15 and a Zener diode 16 as shown in the figure.

Next, the operation of this embodiment configured as described above will be explained.

First, when the main body is divided and opened into upper main body 1 and lower main body 2 as shown in FIG. 2, the supply of drive system voltage to each part of the drive system (not shown) is cut off.

At the same time, the supply of power system voltage to the DC-DC converter 8 is also cut off, so the supply of control system voltage to the electrical components 5, etc. of the control system exposed when the main body is split open is also cut off, causing malfunctions of the electrical components 5. will no longer occur.

On the other hand, since the power supply to the control circuits and the like to which the control system voltage is directly supplied from the A/C-DC converter 6 is not cut off, data will not be lost.

By the way, when a three-terminal regulator 10 is used as the DC-DC converter 8 as shown in FIG. 3, a power source with a relatively large current capacity that is stable for the load can be obtained.

In this case, the three-terminal regulator 10 is appropriately selected based on current capacity, voltage fluctuation tolerance, and the like.

Further, when a Zener diode 16 is used as shown in FIG. 4, the cost becomes low.

In the above embodiments, an example in which the present invention is applied to a laser printer has been described, but for example, an electrostatic copying machine,
It can also be implemented by facsimile, etc.

〔Effect of the invention〕

As explained above, according to the present invention, the control system voltage for the electrical components exposed when the main body is split open is
Since it is generated from the immediate power supply that is cut off when the main unit is split open, it has a simple configuration and is low cost, ensuring safety when splitting the main unit and preventing malfunctions in the control system. can do. .

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the power supply section of a laser printer embodying the present invention, Fig. 2 is a perspective view showing the main body of the laser printer in a split open state, and Figs. I) C-1) C in the diagram
FIG. 3 is a circuit diagram showing different examples of converters. 1 Upper body 2...Lower body 3 Interlock switch (power cutoff means) 5...Electrical components exposed when the main body is split open B-A C-D C converter (power supply unit) 8...D C-1 ) C converter 10... Three-terminal regulator 16... Zener diode

Claims (1)

[Claims] 1 The main body can be divided and opened into an upper main body and a lower main body, and is equipped with a power cutoff means for cutting off a power supply path from a drive system power source when the main body is divided and opened, and the above-mentioned electrical components to which control system voltage is supplied are provided with In an image forming apparatus in which some parts are exposed when the main body is split open, a DC-DC converter is provided that inputs a power supply voltage from the drive system power supply through the power supply cutoff means to generate the control system voltage, and the DC-DC converter generates the control system voltage. - An image forming apparatus characterized in that the output of the DC converter is supplied to the electrical component.