JPS5913246A - Image forming device - Google Patents

Abstract

PURPOSE:To simplify a sequence and to eliminate the need for a control circuit for a photosensitive drum driving motor and a latent image forming electrostatic charger by operating said devices associatively with the on-off operation of an electric power source. CONSTITUTION:The driving motor 20 for a photosensitive drum 1 is driven through a filter circuit 2 with a power source switch 1, and a signal is rectified by a rectifying circuit 3 and turned on and off by a switching circuit 4 to generate the primary side output of a converter transformer 5. The output of the transformer 5 is supplied as a low voltage from a low-voltage power source circuit 7 through high-voltage output circuits 6a and 6b together with a high voltage. When the switch 1 is turned on, the high-voltage output circuits 6a and 6b generate high voltages of 5-8KV as well as the rotation of a motor 20, and a primary electrostatic charger 9 and a transferring electrostatic charger 10 generate high voltages; and the circuit 7 also inputs 12-24V to a sequence controller.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus, and particularly to an image forming apparatus that forms an image by developing a latent image formed on a photosensitive drum using a charger using a toner developer.

Conventionally, such image forming apparatuses have been used in electronic copying machines, and in order to optimize the image formed on the photosensitive drum, the sequence controller that controls the entire system operates first after the power is turned on. The timing of the photosensitive drum and the timing of energization of the charger are controlled, various high voltages are generated, and the charger is controlled accordingly to obtain the optimum image forming conditions. In this case, a motor on/off control circuit and a high voltage on/off control circuit applied to the charger are required to control the speed of the rotating drum and the amount of charge on the charger, making the device complex and expensive. It had become a device.

Accordingly, it is an object of the present invention to provide a lightweight and compact image forming apparatus which eliminates such conventional drawbacks, simplifies the sequence, and simplifies the control circuit.

In order to achieve this object, the present invention is configured so that the drive motor that rotates the photosensitive drum and the charger that forms the latent image are turned on and off in conjunction with the on and off of the power supply.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 shows the configuration of an electronic copying machine which is an embodiment of an image forming apparatus according to the present invention.
1 is a power switch, and by turning this switch on and off, power can be supplied from the power supply 1' to the subsequent circuit.

A filter circuit 2 is connected after the power switch 1, and its output drives a drive motor 20 that rotates a photosensitive drum 12, which will be described later. It is turned on and off to generate an output on the primary side of the converter transformer 5. This converter transformer 5 transforms the output to the high voltage output circuit (Jt) including the rectifier circuit (
A high voltage is generated through high voltage windings 6a and 6b, and is also input to a low voltage power supply circuit (low voltage winding) 7, and low voltage power is supplied through a sequence terminal 8.

The photosensitive drum 12 rotated by the drive motor 20 is neutralized by the front static eliminating lamp 19 and then connected to the high voltage output circuit 6a.
After the entire surface is uniformly charged by the primary streetcar 9 to which high voltage is applied via the original, the charge is removed according to the image by scanning light 15 of the original, forming a latent image corresponding to the original. A blank exposure lamp 18 is placed at this latent image forming position to perform blank exposure.

The latent image formed in this manner is developed by a developing device 13 having a developing roller 14, and then transferred to a paper feed cassette 1 via a transfer charger 10 to which a high voltage is input from a high voltage output circuit 6b.
6 onto a transfer paper 18 that is fed via a paper feed roller 17. The thus transferred image is fixed by a fixing device (not shown) and then discharged from the copying machine.

In such a configuration, when the power is turned on, the drive motor 20 is driven and the photosensitive drum 12 is rotated, and the primary side of the converter transformer 5 is turned on and off via the switching circuit 4, and the energy is supplied to the secondary winding. , high voltage output circuits 6a, 61) are each 5~
A high voltage of 8kV is generated to charge the primary charger 9 and the transfer charger l.
Generates high pressure at O. At the same time, a constant voltage of about 12 to 24 V is supplied from the low voltage power supply circuit 7 to the sequence controller, roller, and clutch lamp (none of which are shown) via the output terminal 8.

Therefore, at the same time as the illumination is turned on, the sequence controller [・roller also operates and the pre-static discharge lamp 19 and blank exposure lamp 18 are turned on]] ~ After the drum has rotated several times, the memory is removed and the photosensitive drum is in a state waiting for the start of copying. become. -Also, after a predetermined period of time has elapsed after the photosensitive drum has been cleaned and the fixing device is ready for fixing, copy reception will start.
1 copy is now possible, and the optical system and paper feed roller 17 are activated to start copying. When a predetermined period of time has elapsed after the completion of copying, sequence: 1 is commanded and switch 1 is shut off.

FIG. 2 shows another embodiment of the present invention, in which the same parts as in FIG. 1 are denoted by the same reference numerals, and their explanation will be omitted.

In the embodiment shown in the figure, a filter circuit 2 and a rectifier circuit 3
A line frequency transformer 21 is connected between the line frequency transformer 21, which lowers the voltage at one end, and then supplies the voltage to the switching circuit 4 for high voltage generation and the low voltage power supply circuit 7 via the rectifier circuit 3.

Another embodiment of the present invention is illustrated in FIG.
In the figure, the output winding of the converter transformer 5 is further divided to supply high voltage to the primary charger 9 and transfer charger 10 via high voltage output circuits 6a, 6b, and at the same time, a separate high voltage output circuit 6C is provided. is supplied to the developing roller 14 as a bias voltage. There are also two low voltage power supply circuits 7a and 71 on the low voltage side.
) 24V supply voltage to loads such as clutches, solenoids, lamps, etc., and 12V supply voltage to sequence controllers.
It is structured to be divided into.

As explained above, according to the present invention, the mold temperature 1 is turned off.

Since the motor that rotates the photosensitive tram and the charger are turned on and off in conjunction with the off state, the photosensitive tram can be rotated at all times when energized, and the charger can be kept energized at all times. Emergency Diagram 2 421'6 Diagram 3

Claims (2)

[Claims] (1) In an image forming device that forms an image by developing a latent image formed on a photosensitive drum, a low-voltage winding for sequence control and a charging winding are installed on the same core of a transformer that is energized at the same time as the power is turned on. An image forming apparatus characterized by having a power transformer wound with a high voltage winding. (2) In an image forming device that develops a latent image formed on a photosensitive drum to form an image, a low-voltage winding for sequence control and a developing bias winding are placed on the same core of a transformer that is energized at the same time as the power is turned on. An image forming device characterized by having a power transformer wound with a winding wire.