JPS5948377B2 - Sequence control device for transfer type electrophotographic copying machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sequence control device for a transfer type electrophotographic copying machine.

Conventionally, as a sequence control device for a transfer type electrophotographic copying machine, as disclosed in Japanese Patent Application Laid-Open No. 50-11443, a detection section detects the rotation of a photosensitive drum in a transfer type electrophotographic copying machine, extracts a pulse, and converts the pulse into a pulse. A system that performs sequence control based on this has been proposed.

Since the sequence control of such a transfer type electrophotographic copying machine can be performed in synchronization with the photosensitive drum, the sequence control can be performed accurately and reliability can be improved. However, since it requires a detection part,
The configuration becomes complicated, and there is also a risk of malfunction due to an error in the detection section. SUMMARY OF THE INVENTION An object of the present invention is to provide a sequence control device for a transfer type electrophotographic copying machine that performs sequence control in synchronization with the rotation of a photoreceptor drum without the detection unit, in order to eliminate the problems caused by the detection unit. .

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

As shown in FIG. 1, a synchronous motor 1 is used as a drive source, and a photosensitive drum 2 is rotationally driven by the synchronous motor 1 at a constant speed.

This photosensitive drum 2 is charged by a charging device 3, an original image is exposed by an exposure device 4, developed by a developing device 5, and then transferred by a transfer device 8 onto a transfer paper T fed from a paper feed device 6. conduct. Thereafter, the transfer paper 7 is fixed by the fixing device 9 and is discharged outside the machine as a copy. In the exposure device 4, the original 10 is illuminated by a lamp 11, and the reflected light is guided onto the photosensitive drum 2 via mirrors 12, 13 and an in-mirror lens 14, and the original 10 is moved to the right. Or the lamp 11 and mirrors 12, 13 are moved to the left. The synchronous motor 1 is supplied with power from a commercial power source and rotates in synchronization with the power. Therefore, in this example, a timing pulse is extracted from a commercial power source and each load is controlled based on this timing pulse, thereby controlling each process in a sequence synchronized with the photosensitive drum 2. FIG. 2 is a block diagram of this example, and FIG. 3 is a timing diagram thereof. In the above-mentioned transfer type electrophotographic copying machine, the output of the commercial power supply 15 is supplied to the synchronous motor 1 and also to the timing pulse generation circuit 16.
A timing pulse synchronized with the output of the commercial power supply 15 is generated and applied to the control section 17. In the control unit 17, the counter CNT receives the timing pulse from the timing pulse generation circuit 16 and repeatedly counts the number, for example, from 0 to 9, and outputs the output terminal 18o according to the counted number.
~18, outputs an output signal. flipflop FF1
~FF3 is provided corresponding to each of the negative loads L1 to L3 to be sequentially controlled, and outputs signals necessary for sequence control of the loads L1 to L3 to each output terminal 18o to 189 of the counter CNT.
It is created by appropriately combining signals from the following sources. For example, flip-flop FF1 is set by a signal from output terminal 181 when the content of counter CNT reaches ``11'', and flip-flop FF1 is set by a signal from output terminal 181, and
When the content of the counter CNT reaches "4", it is reset by a signal from the output terminal 184.The flip-flop FF2 is reset by the signal from the output terminal 184 when the content of the counter CNT reaches "02".
The contents of counter CNT are set by the signal from
It is reset by a signal from the output terminal 186 when it becomes . Flip-flop FF3 is set by a signal from the output terminal 184 when the content of the counter CNT reaches 141, and is reset by a signal from the output terminal 188 when the content of the counter CNT reaches ``8''. Load L1~
L3 includes, for example, a charging device 3, a lamp 11, and a transfer device 8, and is driven by the output signals of flip-flops FF1 to FF3. In this case, the photosensitive drum 2 is rotated once by the synchronous motor 1 while the counter CNT counts from 0 to 9, and the loads L1 to L3 are accurately sequence controlled in synchronization with the photosensitive drum 2. Although not shown in the figure, the motor 1 for rotating the photoreceptor drum 2 is powered on when the print switch is turned on, using the same means as in conventionally used copying machines, such as copying machines having the detection section. 15, the power supply is started, and the power supply is stopped when the copy number counter outputs an output signal when the set number of copies have been completed. Furthermore, the control unit 17 also uses the same conventional means to start operation from the initial state when a set time has elapsed since the print switch was turned on, and when the set number of copies has been completed, an output signal from the copy number counter is output. Become a Fudo Kui. Therefore, when the control section 17 starts sequence control, the rotation of the motor 1 is synchronized with the output frequency of the power source 15, and the sequence control is performed in synchronization with the rotation of the photosensitive drum. As described above, according to the sequence control device for a transfer type electrophotographic copying machine according to the present invention, the synchronous motor is driven four times by the output of the commercial power source, the photosensitive drum is rotated by the synchronous motor, and timing pulses are generated from the output of the commercial power source. Since sequence control is performed based on this timing pulse, there is no need for a detection section like the conventional device described above, which eliminates the possibility of inaccurate sequence control due to malfunction of this detection section, and the configuration is simple. Become.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing an example of a copying machine, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a timing diagram of the same embodiment. DESCRIPTION OF SYMBOLS 1...Synchronous motor, 2...Photosensitive drum, 3...Charging device, 8...Transfer device, 11...Lamp, 15... Commercial power supply, 16... Timing pulse generation circuit, CNT
...Counter, FF1 to FF3...Flip-flop, L1 to L3...Load.

Claims (1)

[Claims] 1 It has a plurality of devices arranged around the photoreceptor drum, and the plurality of devices sequentially perform charging, exposure, development, transfer, and cleaning steps in synchronization with the rotation of the photoreceptor drum. In a transfer-type electrophotographic copying machine that repeatedly copies each rotation of a photoreceptor drum, the synchronous motor is driven by the output of a commercial power source to rotate the photoreceptor drum, and the output of the commercial power source is supplied to operate the copying machine. a timing pulse generation circuit that generates a timing pulse in synchronization with the output of this timing pulse; a counter that counts the timing pulses from the timing pulse generation circuit and repeatedly counts a set number of times each rotation of the photoreceptor drum; A sequence control device for a transfer type electrophotographic copying machine, comprising means for sequentially operating predetermined devices in the plurality of devices in accordance with the contents of the counter.