JPS61262757A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To copy the image of an original surface on normal paper stably with simple constitution without any shift in position by providing a synchronizing signal generating means, a conveyance control means, and an original start end detecting means, and generating a synchronizing signal at desired intervals of time from a start end detection signal outputted by the original start end detecting means. CONSTITUTION:An original 16 moves as shown by an arrow 19 in synchronism with the rotation of a photosensitive body 10 to form an electrostatic latent image on a reflected image on the periphery of the photosensitive body 10 and a developing device 13 sticks toner according to the charge distribution of the electrostatic latent image to form a visual image on the photosensitive body 10. In this case, the original 16 moves as shown by an arrow 19 and when the start end of the original 16 is detected by an original start end detection sensor 20, an original start end signal 22 is inputted to a synchronizing signal generating circuit 27, which drives a normal paper conveyance control solenoid 21 when a movement time corresponding to the difference between distance B and distance A is elapsed, thereby aligning the start end of normal paper 17 with the start end of the visual image on the photosensitive body 10.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electrophotographic apparatus that uses the so-called Carlson process to copy an image of a document surface onto plain paper. The present invention relates to an electrophotographic apparatus that can control the conveyance of a material at desired time intervals and control the position of an image on a document surface and an image on a transfer material.

2. Description of the Related Art A conventional electrophotographic device that controls the conveyance of a transfer material in relation to the position of the original image on a photoreceptor is, for example, our National Panacopy Copying Machine FP-452.
0J, pages 13-15. An example of a conventional electrophotographic apparatus will be described below with reference to the drawings.

FIG. 3 shows an example of a schematic configuration of the main parts of a conventional electrophotographic apparatus using the Carlson process.

In FIGS. 3 and 4, the photoreceptor 10 rotates in the direction of the arrow 11 when copying, and first the charger 14
A uniform charge is imparted to the surface by corona discharge from the The original surface 18 of the original 16 is irradiated with light by a fluorescent lamp 15 serving as an original irradiation means, and the reflected image is formed on the photoreceptor 10 through an imaging optical system such as an optical fiber 12 having a lens effect. The document 16 moves in the direction of the arrow 19 from left to right in the figure in synchronization with the rotation of the photoreceptor 10.
8 original surface images are sequentially exposed.

In the developing device 13, the photoreceptor 10 is exposed by the exposure of the original surface image.
Toner adheres according to the charge distribution of the electrostatic latent image formed thereon, and a developed image is formed on the photoreceptor 1o.

This developed image is transferred onto plain paper 17 by a transfer charger 26 to form a copy image.

By the way, when obtaining a copy image, there is a demand to maintain a constant positional relationship between the original surface image and the transferred image transferred onto the plain paper 17. However, in conventional electrophotographic apparatuses, the photoreceptor 10 Exposure is started when the starting edge of the original passes directly above the optical fiber 12, and the iron at the starting edge of the original surface 18, which is started at that time, is aligned with the starting edge of the plain paper 17 and transferred. In order to do this, it is necessary to align the image of the starting edge of the original surface 18 on the photoreceptor 1o with the starting edge of the plain paper 17. To do this, it is necessary to move the transfer charger from the position of the image of the starting edge of the original surface 18 at the start of exposure. It is necessary to arrange the document start edge detection sensor 20 so that the moving distance A of the image of the start edge up to 25 matches the distance B from directly below the optical fiber 12 to the document start edge detection sensor 20 composed of a reflective photosensor or the like. The plain paper transport control unit 2 detects the starting edge of the original 16 and uses the original starting edge signal 22 output from the original starting edge detection sensor 2o.
1 passes through the plain paper 17, the photoreceptor 1
The image of the starting edge of the original surface 18 on 0 coincides with the starting edge of the plain paper 17, and the images on the original surface 18 are sequentially transferred to the plain paper 17 by the rotation of the photoreceptor 10 in the direction of the arrow 11 and the transfer charger 26. It is what is being transcribed.

Problems to be Solved by the Invention However, in the electrophotographic apparatus configured as described above, it is necessary to maintain the distance A and the distance B equal and constant, and it is difficult to mechanically attach the document start edge detection sensor 2°. Without stability and ease, there was a problem that appropriate image quality could not be obtained after transfer.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides an electrophotographic apparatus that has a simple configuration and is capable of stably copying an image on a document surface onto plain paper without misalignment.

Means for Solving the Problems In order to solve the above problems, the electrophotographic apparatus of the present invention includes:
synchronization signal generating means for generating a synchronization signal for aligning a transfer material for transferring a developed image of the reflected image of the surface of the original on the photoconductor with the position of the developed image; and controlling the conveyance of the transfer material using the synchronization signal. and document start edge detection means for causing the synchronization signal generation means to detect the start edge of the document, and the synchronization signal is generated at a desired time interval from the start edge detection signal output from the document start edge detection means. It can occur.

According to the above-described structure, the synchronizing signal generating means generates a synchronizing signal for controlling the conveyance of the document to the conveyance control means at a desired time interval based on the start edge detection signal outputted from the document start edge detection means. If the position of the document start edge detection means is in the relationship of distance A≧short distance, the position of the image on the document surface and the image on the transfer material can be determined just by the set time interval of the synchronization signal generation means. This makes it possible to maintain a constant value.

Embodiment FIG. 1 is a diagram showing an embodiment of the schematic structure of the main parts of an electrophotographic apparatus according to the present invention. In FIG. 1, 16 is a document to be copied, and 14 is a charger, which uniformly charges the photoreceptor 1o rotating in the direction of arrow 11 by corona discharge. A fluorescent lamp 16 irradiates the document surface 18 with light to form a reflected image of the document surface 18 on the photoreceptor 10 through an imaging optical system such as an optical fiber 12 having a lens effect. The developing device 13 forms a developed image by depositing toner in accordance with the charge distribution of the electrostatic latent image, which is the reflected image on the photoreceptor 10 . The document start edge detection sensor 20 is provided with a document start edge detection sensor 2o at a position that maintains the relationship between distance A and distance B shown in FIG. 22, and the synchronization signal generation circuit 27 generates a transport control signal 28 when a preset time interval has elapsed using a so-called memory IC or the like.
The plain paper conveyance control solenoid 21 is configured to generate
by driving the starting edge of the plain paper 17 to the photoreceptor 10.
This is made to coincide with the beginning of the visible image above.

The operation of the electrophotographic apparatus configured as described above will be described below.

First, the photoreceptor 1o is rotating in the direction of the arrow 11, and is uniformly charged by corona discharge from the charger 14. The document surface 18 of the document 16 moving in the direction of an arrow 19 is irradiated with light by the fluorescent lamp 16, and a reflected image of the document surface 18 is projected onto the photoreceptor 1o through an imaging optical system such as an optical fiber 12. Form an image. The original 16 moves in the direction of the arrow 19 in synchronization with the rotation of the photoreceptor 10, and electrostatic latent images, which are the reflected images, are sequentially formed on the circumference of the photoreceptor 10, and the developing device 13 Toner is attached according to the charge distribution of the electrostatic latent image to form a developed image on the photoreceptor 10. Here, when the original 16 is moving in the direction of the arrow 19 and the original starting edge detection sensor 2o detects the starting edge of the original 16, the original starting edge signal 22 is input to the synchronizing signal generating circuit 27, and the synchronous signal generating circuit 27 Now, when the moving time for the difference between distance B and distance A has elapsed, the starting edge of the plain paper 17 and the starting edge of the developed image on the photoreceptor 1o are brought into alignment by driving the plain paper conveyance control solenoid 21. .

Furthermore, controlling the travel time for the difference between distance B and distance A is achieved by setting the amount of travel time in advance in a circuit such as the memo IJIc of the synchronization signal generation circuit 27. . Plain paper 17 is conveyed to the photosensitive area 10, and the paper 17 moves in the direction of the arrow 23, and the image on the original surface 18 is placed on the plain paper 17 by the transfer charger 26 without shifting its position. transcribed.

As described above, according to this embodiment, the document starting edge detection sensor 2
The position of the image on the document surface 18 on the plain paper 17 can be determined simply by applying a specific condition to the relationship between distance A and distance B, and setting the amount of travel time derived from that relationship in the synchronization signal generation circuit 27. This allows for accurate matching and copying.

Effects of the Invention As described above, the present invention provides a synchronizing signal generating means for generating a synchronizing signal for aligning a transfer material to which a developed image of a reflected image of the surface of a document on a photoreceptor is transferred with the position of the developed image; The apparatus includes a conveyance control means for controlling the conveyance of the transfer material using the synchronization signal, and a document start edge detection means for causing the synchronization signal generation means to detect the start edge of the document; This invention provides a practically extremely useful electrophotographic apparatus which can copy an image of the document surface onto plain paper with the starting edge thereof aligned with the original paper by generating the starting edge detection signal at a desired time interval from the starting edge detection signal. This can be achieved with

[Brief explanation of drawings]

FIG. 1 is a schematic front view of main parts of an electrophotographic apparatus according to an embodiment of the present invention, FIG. 2 is a schematic dimensional view of main parts of an electrophotographic apparatus according to an embodiment of the present invention, and FIGS. 3 and 4 are FIG. 1 is a schematic front view and a schematic dimensional diagram of main parts of a conventional electrophotographic apparatus. 10...Photoreceptor, 12...Optical fiber, 13...Developer, 14...
...Charger, 16...Fluorescent lamp, 16...
・Original, 17... Plain paper, 18... Original surface, 2o... Original start edge detection sensor, 21...
...Plain paper transport control solenoid, 25...
Transfer charger, 27... Synchronization signal generation circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person27
---Double word generation circuit Figure 2 Figure 3/A Figure 4

Claims (1)

[Claims] an original irradiation means for irradiating a document surface with light to obtain a reflected image; an imaging optical system for forming a reflected image of the document surface on a photoreceptor; and a developing optical system for developing the reflected image of the document surface; a developing means for obtaining a developed image on the photoreceptor; a synchronizing signal generating means for generating a synchronizing signal for aligning a transfer material to which the developed image is transferred with the position of the developed image; and conveyance of the transfer material. and a document start edge detection means for causing the synchronization signal generation means to detect the start edge of the document, and the synchronization signal is a start edge detection signal output from the document start edge detection means. 1. An electrophotographic apparatus characterized in that the electrophotographic apparatus is configured to generate images at desired time intervals.