JPS61205970A - Plate photosensitive body copying machine - Google Patents

Abstract

PURPOSE:To make a titled copying machine small in size and thin by unifying both a photosensitive body and an original platen which move horizontally at the time of a copying process, on the upper face of the copying machine body, and an exposure optical system is constituted of an electric circuit containing a CCD and a light emitting element. CONSTITUTION:In case of an unused state, a photosensitive body 2 and an original platen 3 are placed on a copying machine body 1. When an original is set onto the original platen 3 and a copy button is pushed, the photosensitive body 2 and the origi nal platen 3 move to the left and preliminary electrification is executed by an electrify ing device 4. When the photosensitive body 2 and the original platen 3 move to the right from this state, the photosensitive body 2 is electrified uniformly again by the electrifying device 4. Subsequently, the original on the original platen 3 is read by an image sensor constituted of a CCD, an image exposure is executed onto the photosen sitive body 2 by a light emitting element 6, and its latent image is developed by a developing device 7. Next when a form is joined by a transfer roller 8, a toner image of the photosensitive surface is transferred. The form which has passed through the transfer roller 8 is peeled off by a peeling belt 19, fixed by a fixing roller 9, and discharged to a discharge paper tray. In this way, the conversion to small and thin copying machine is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field This invention relates to improving the operability of a copying machine having a flat photoreceptor.

<Prior art and its drawbacks> In general, a copying machine that performs copying using the so-called Carlson method, which includes charging, exposure, development, transfer, and fixing steps, has a device that uses a photoreceptor drum to carry out the process from charging to transfer. There are two types: and a device that uses a belt-shaped photoreceptor.

However, in devices that use a photoreceptor drum to process everything from charging to transferring, the size of the photoreceptor drum cannot be reduced below a certain level in order to obtain a good copy image; Determined the size of the copier body and made the copier more compact.

The drawback was that it could not be made thinner. Furthermore, even in devices with a belt-shaped photoreceptor, at least two drums are required to rotate the belt-shaped photoreceptor, and these two drums must also have a curvature that prevents the photoreceptor applied to the belt from peeling off. Therefore, there was a drawback that copying machines could not be made smaller and thinner.

Therefore, in order to solve this problem, the present applicant has already filed Japanese Patent Application No. 59-149233 and Japanese Patent Application No. 59499013.
In this issue, the copying machine main body is miniaturized by arranging the document table, which moves horizontally relative to the top and bottom, and the flat photoreceptor facing each other, eliminating the need for parts that require large storage space, such as drums, inside the machine. proposed a thinner copying machine.

However, in both proposals, a document table and a flat photoreceptor are placed at the top and bottom of the device, and both move left and right during the copying operation, so the entire device expands and contracts during operation, making it unstable. . Furthermore, since there is a movable part at the bottom of the device, the space inside the device is extremely limited and the size of the paper cassette etc. is also limited, making it impossible to set a large number of sheets at once. Further, when the document table is installed on the lower side, it is necessary to pull out the document table from the bottom of the apparatus when taking out the set 8 of originals, resulting in poor workability.

<Object of the Invention> In view of the above-mentioned drawbacks, it is an object of the present invention to provide a flat plate photoreceptor copying machine in which moving parts are concentrated on the upper side of the apparatus.

<Structure and Effects of the Invention> The present invention provides a copying machine having a horizontally movable flat photoreceptor on the main body of the apparatus, which includes a document table that moves horizontally in synchronization with the photoreceptor above the photoreceptor. In addition to providing
an image sensor disposed in a direction perpendicular to the moving direction of the document table at a position facing the lower surface of the document table; a light emitting device disposed in a line at the exposure section; The device is characterized by further comprising means for exposing the photoreceptor to light using light emitted from the element.

With the above configuration, according to the present invention, the following effects can be achieved.

Since the photoreceptor and document table, which are moving parts during the copying process, are integrated on the top surface of the copying machine main body, the entire device does not expand or contract during the copying process, making it stable. In addition, the exposure optical system commonly used in conventional copying machines has been replaced with a CCD.
Since the copying machine is replaced with an electric circuit including a light-emitting element and a light-emitting element, the exposure lamp, exposure lens, etc., which required a large space and large amount of power in a conventional copying machine, are no longer necessary, thereby achieving a reduction in size, thickness, and weight. I can do it.

<Embodiment> FIG. 1 is a schematic structural diagram of a flat photoreceptor copying machine which is an embodiment of the present invention. A flat photoreceptor 2 that moves in the horizontal direction (in the direction of the arrow in the figure) is installed above the main body 1 of the copying machine. Above it, a document table 3 is installed which moves in synchronization with the photoreceptor 2. The document table 3 is a glass plate housed in a frame, and an image sensor 5 is installed directly below the left side of the document table 3 to convert the density of the document placed face down on the document table 3 into an electrical signal. The image sensor 5 is composed of a CCD (charge coupled device). Inside the copying machine main body 1, there is a charger 4 for the copying process at a position facing the photoreceptor 2. A light emitting element 6 for exposing the image of the original onto the photoreceptor 2. A developing device 7 and a transfer roller 8 are provided. At the top of both sides of the copying machine body l, there are shielding curtains 10 for shielding external light when the photoreceptor 2 moves to the left or right.
is installed. This shielding curtain 10 is a shielding curtain roller IO
One end is locked to the tip of the photoreceptor 2, and as the photoreceptor 2 moves, it covers the lower surface (photoreceptor surface) of the photoreceptor 2 and blocks light. FIG. 2 shows an enlarged view of the vicinity of the shielding curtain 10. A cleaner 12 is installed on the left side of the developing device 7 to remove residual toner on the photoreceptor 2 that has been transferred to the copy paper. This cleaner 12 is composed of a blade and scrapes off residual toner on the photoreceptor 2. In order not to damage the surface of the photoreceptor 2, the cleaner 12 is kept away from the surface of the photoreceptor 2 by a solenoid (not shown) except during the cleaning process. A charge eliminating lamp 11 is provided between the charger 4 and the light emitting element 6 to remove residual charges on the photoreceptor 2.

Further, a paper feed cassette 13 for storing desired paper is installed from the right side of the copying machine main body 1.

A paper feed cam 14 for peeling off one sheet of paper stacked on the paper feed cassette 13 is disposed at a position facing the tip of the attached paper feed cassette 13. Between the paper feed cam 14 and the transfer roller 8, there is a paper guide 16, as shown in an enlarged view in FIG. A paper transport path is formed by a transport roller l5 and a paper sensor 17. The paper sensor 17 is used to align the right end of the photoreceptor 2 with the leading edge of the paper, and the paper feed cam 14 and conveyance roller 15 are driven and stopped by the control unit based on the detection output of the paper sensor 17. I do. The transfer roller 8 includes rollers 18a and 18b.
A peeling belt 9 driven by is in contact with the peeling belt 9. The peeling bell 1-19 is for peeling the paper conveyed in contact with the photoreceptor 2 by the transfer roller 8 from the photoreceptor 2. Here, the flat photoreceptor 2 is a flat plate fitted in a frame. The photosensitive surface is formed by depositing or coating a conductive thin film on an insulator such as glass, or the photosensitive surface is formed on another flat plate with strength such as glass, resin, metal, etc. It is formed by adhering it to a flat plate surface with no irregularities.

The copying process of the flat photoreceptor copying machine having the above configuration will be explained.

When the flat photoreceptor copying machine is not in use, the photoreceptor 2 and document table 3 are located on the copying machine main body 1 as shown in FIG. When a document is set on the document table 3 and a copy button (not shown) is pressed, the photoconductor 2 and document table 3 move horizontally from the state shown in FIG. 1 to the state shown in FIG. 4, and the photoconductor 2 becomes charged. It is uniformly charged by the container 4. in this case,
The polarity of the charge on the photoreceptor 2 is the same as that used when residual charges are removed in the eighth step, which will be described later. In the state shown in FIG. 1, the left end α of the photoreceptor 2 is located on the right side of the charger 4, but when the photoreceptor 2 moves to the left and the right end β faces the charger 4, the charger The photoreceptor 2 is uniformly charged by the corona discharge of step 4. The photoreceptor 2 is moved so that the photoreceptor surface, which is uniformly charged due to the above movement, is not exposed to the outside.
A shielding curtain 10 is sequentially rewound from a shielding curtain roller 10a to shield the surface of the photoreceptor. Further, the cleaner I2 also operates during the above operation. This is because there is a possibility that toner in the developing device 7 may be attracted when transitioning from the state shown in FIG. 1 to the state shown in FIG. 4. As shown in FIG. 4, when the right end β of the photoconductor 2 moves to a position opposite to the charger 4 and the preliminary charging process is completed, the cleaner 12 moves to the fifth step to prevent damage to the photoconductor 2. The photoconductor 2 and document table 3 are tilted downward until the charging process is completed so that the leading edge does not come into contact with the surface of the photoconductor 2. The photoconductor 2 and document table 3, which are in the state shown in FIG. The photoreceptor 2 is reversed and returns to the state shown in FIG. 1, and further moves to the right to the state shown in FIG. ), transfer (fourth step) and peeling (fifth step) are performed.

In the state shown in FIG. 4, the right end portion β of the photoreceptor 2 is located to the left of the light emitting element 6. When the photoreceptor 2 and document table 3 start moving rightward from this state, the photoreceptor 2 is uniformly charged again by the charger 4 (first step). in this case,
The charging polarity is determined by the characteristics of the photoreceptor 2 and may be positive or negative. As the document table 3 moves, the document placed on the document table 3 is read by an image sensor 5 composed of a COD. The read image of the original is once converted into an electrical signal and then subjected to processing such as amplification, and image exposure is performed onto the photoreceptor 2 by the light emitting element 6 (second step). As it moves to the right, the right end β of the photoreceptor 2, which has formed a latent image corresponding to the image of the document by the light emitting element 6, moves directly above the developing device 7, and toner adheres to the latent image. A developing step is performed (third step). For development, any method such as a cascade development method or a magnetic brush development method may be used, and an appropriate developer and toner are determined depending on the development method. Furthermore, as the photoconductor 2 moves to the right, the right end portion β, which has undergone toner development, is positioned directly below the transfer roller 8, and at the same time, the paper that has been transported to the paper sensor 17 position by the transport roller 15 reaches the paper feed timing. Together, they are conveyed to the transfer position. When the paper is joined by the transfer roller 8 to the photosensitive surface that has been processed in the third step, the toner image on the photosensitive surface is transferred (fourth step).

In this embodiment, the transfer roller 8 is used in this fourth process.
is used, but this may also be a transfer charger. When the photoreceptor 2 and the paper pass the position of the transfer roller 8, the transfer process is completed, and the paper is peeled off from the photoreceptor 2 by the peeling belt 19 from the leading end where the transfer has been completed (fifth step). That is, as shown in FIG. 3, the paper sent out by the conveyance roller 15 is guided on both sides by the peeling belt 19 driven by the roller 18 and led to the transfer roller 8, but after passing the transfer roller 8, Peeling belt 1
It is peeled off from the photoreceptor 2 by 9.

This peeling process is completed when the photoreceptor 2 is removed as shown in FIG.
This is when the left end portion α of is located directly below the transfer roller 8.

In this embodiment, the paper is separated from the photoreceptor 2 by the separation belt 19, but a separation charger may also be used. The sheet of paper peeled off from the photoreceptor 2 by the peeling belt 19 is guided to the fixing roller 9, where it is sequentially subjected to a fixing process starting from the leading edge and is discharged onto the paper output tray 20 (
Step 6).

As shown in FIG. 5, when the left end α of the photoreceptor 2 is located directly below the transfer roller 8 and the fifth process is completed, the photoreceptor 2 moves to the left again and removes the remaining toner on the photoreceptor 2. A seventh step of removing residual charges and an eighth step of removing residual charges are performed. Fifth
When the photoreceptor 2 starts to move leftward from the state shown in the figure, the cleaner 12 shown in FIG. 1 is brought into contact with the photoreceptor 2, and residual toner is removed sequentially from the left end α. Starting from the left end α after the seventh step, residual charges are sequentially removed by the charger 4 and the neutralization lamp 11, which discharge to a polarity opposite to that at the time of charging (eighth step). The eighth process is completed when the right end β of the photoreceptor 2 is located on the charger 4. In addition, No. 7. When performing the eighth step, the transfer roller 8 is lowered so that the toner on the photoreceptor 2 does not adhere. In this embodiment, the charger 4 is used for both charging and neutralizing processes, but a charger exclusively for static neutralizing may be provided. In addition, the static elimination lamp 11 is connected to the cleaner 12.
The copying process for one sheet is completed with the completion of the eighth step, and the photoreceptor 2 is positioned on the main body 1 manually or automatically, but! When copying continues, the document table 3 is placed on the photoreceptor 2 which is undergoing the seventh and eighth steps.
When it returns to the copying machine main body 1, it simultaneously starts moving to the left and restarts the copying process from the above-mentioned first step.

[Brief explanation of drawings]

FIG. 1 is a schematic structural diagram of a flat plate photoconductor copying machine which is an embodiment of the present invention, FIGS. 2 and 3 are partially enlarged views of the vicinity of the shielding curtain and the vicinity of the transfer roller, respectively, and FIG. 4 and FIG. FIG. 3 is a side view showing the positions of a photoreceptor and a document table during a copying process. 2-Photoconductor, 3-Original table, 5-Image sensor (COD), 6-Light emitter element.

Claims (1)

[Claims] (1) In a copying machine in which a horizontally movable flat photoconductor is provided on the device body, and a charger, an exposure section, a developing device, a transfer device, etc. are arranged in the order of the copying process inside the device body facing the photoconductor. , a document table that moves horizontally in synchronization with the photoconductor is provided above the photoconductor, an image sensor is arranged in a direction perpendicular to the movement direction of the document table at a position opposite to the lower surface of the document table, and the exposure section A flat plate photoconductor copying machine characterized by comprising: light emitting elements arranged in a line at the positions of , and means for exposing an image of a document received by the image sensor onto the photoconductor by light emission from the light emitting elements. .