JPH0335252A - Electrostatic copying device - Google Patents

Abstract

PURPOSE:To carry out proper separation even on a copying condition that a blank part is left on the part of transfer paper by providing a means detecting the setting of the copying condition that the blank part is forcedly left on the transfer paper and a means controlling a pre-transfer exposure lamp based on the detection of the detecting means. CONSTITUTION:The pre-transfer exposure lamp 7 is arranged between a developing device 6 and a transfer pole 8. When one of modes for erasing at the outside of a designated area, erasing at the inside of the designated area, a frame erasing, and reduction shifting is selected by an operation part 31 and fetched into a control part 32, the pre-transfer exposure lamp 7 is forcedly turned on. As a result, since the surface of the photosensitive body 3 is irradiated with the pre-transfer exposure lamp 7 at the time of setting the copying condition that the blank part is forcedly left on the part of the area of the transfer paper, the surface potential of the photosensitive body 3 is lowered and the attraction of the transfer paper is lowered. Therefore, separability at a separating pole 9 is prevented from deteriorating. Thus, deterioration in the separability and picture quality, and paper jamming are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is an electrostatic copying apparatus capable of setting special copying modes such as masking, trimming, frame erasing, or reduction shift copying. The present invention relates to an electrostatic copying device with improved characteristics.

[Conventional technology]

2. Description of the Related Art Conventionally, there have been copying apparatuses that have a function of copying only a portion of a document, for example. As shown in FIG. 4, this method specifies the area 2a of the original 2 placed on the platen glass 1 by, for example, specifying coordinates, and copies only the area 2a within the specified area (erasing outside the specified area). (see, for example, Japanese Patent Laid-Open No. 60-213168).

[Problem to be solved by the invention]

However, this outside designated area erasing function uses a charged erasing lamp to expose and erase charges on the surface of the photoreceptor, excluding the area corresponding to the designated area 2a of the original 2 described above, to prevent toner from adhering. Therefore, when transferring the toner image to the transfer paper after development,
The adhesion between the transfer paper and the toner-free portion of the photoreceptor becomes stronger. As a result, separation is not performed completely in the subsequent separation step, resulting in changes in the toner image and deterioration of image quality, or in the worst case scenario, the transfer paper wraps around the photoreceptor, causing a paper jam.

Such an abnormal situation may also occur during designated area erasure (masking), which reversely erases the designated area 2a of the original document 2, and may also occur when erasing the frame portion, shift copying, binding margin copying, and reduction shift copying. It can also occur in some cases. In other words, when the copying conditions are such that a relatively large area remains as a blank on the transfer paper, the above-mentioned problem is likely to occur, especially when the leading edge remains.

The present invention has been made in view of these points, and its purpose is to enable proper separation even in the case of copying conditions that leave blank areas on a portion of the transfer paper as described above. To provide a copying device.

[Means to solve the problem]

To this end, the electrostatic copying apparatus of the present invention includes a means for detecting that a copying condition that forcibly leaves a blank area on the transfer paper is set, and a means for controlling a pre-transfer exposure lamp based on the detection by the detecting means. It is now equipped with the following.

〔Example〕

Examples of the present invention will be described below. FIG. 3 is a diagram schematically showing the copying apparatus. In the electrostatic recording section A, a charged electrode 4,
Charge erasing lamp 5, developing device 6, pre-transfer exposure lamp 7,
A transfer pole 8, a separation pole 9, and a cleaning device 10 are arranged in this order.

Further, upstream of the transfer pole 8, a registration roller 12 is provided to temporarily stop the transfer paper fed from the paper feed section 11 to adjust the timing, and further downstream of the separation pole 9, a conveyor belt 13 and a heat transfer roller 12 are provided. Fixing devices 14 are sequentially provided.

On the other hand, in the document reading section B, a rod-shaped exposure light source 15 that travels in the direction indicated by the arrow on the lower surface of the platen glass l on which the document 2 is set and exposes the document 2, and a photoreceptor is provided with the reflected image light obtained by exposure. Mirrors 16 to 19, a lens 20, and the like are provided for transmitting information to the 3.

In this copying apparatus, the original 2 on the platen glass l is exposed by scanning the exposure light source 15 in the direction of the arrow. When the image light obtained by this exposure is incident on the photoreceptor 3, the charge on the light irradiated portion of the photoreceptor, which has been previously charged at a high voltage by the charging electrode 4, decreases in accordance with the degree of brightness, and the original is placed there. An electrostatic latent image corresponding to the image is formed. and,
As the photoreceptor 3 rotates, this electrostatic latent image portion is transferred to the developing device 6.
When the image reaches the sleeve 6a, it is developed there with toner, forming a toner image corresponding to the image of the document. Then, this toner image is transferred from the registration roller 12 to a transfer sheet fed at a timing when the leading edge of the image coincides with each other at a transfer pole 8, and further reaches a separation pole 9 where it is separated from the surface of the photoreceptor 1. and,
The transfer paper with the toner image placed on it is then transferred to conveyor bell 1-1.
At step 3, the sheet is sent to the thermal fixing device 14, where it is thermally fixed, and the sheet is discharged. The photoreceptor 3 on which toner remains is cleaned by the blade 10a when it reaches the cleaning device IO, and is prepared for the next cycle.

When copying only the specified area 2a of the document 2 described above, information corresponding to the specified area is transmitted to the charge erasing lamp 5, and the plurality of L's constituting the charge erasing lamp 5 are
By lighting a predetermined one of the EDs at a predetermined timing, the designated area 2 of the document 2 on the photoreceptor 3 is
Charges outside the region corresponding to a are erased. As a result, the adhesion of the transfer paper to the erased portion increases, and the separation performance deteriorates as described above.

Therefore, in this embodiment, the pre-transfer exposure lamp 7 is disposed between the developing device 6 and the transfer pole 8 as described above. This pre-transfer exposure lamp 7 itself is disclosed in Japanese Patent Application Laid-Open No. 58-6267.
5, 5B-62676, Japanese Patent Application No. 16117-1983, etc.

In this embodiment, the pre-transfer exposure lamp 7 is turned on when a copy mode in which a blank area is forcibly formed in a part of the transfer paper is selected as described above.

FIG. 1 is a diagram showing this control system. 31 is an operation unit for setting various copy modes, number of copies, density, etc., 32
Reference numeral 32 denotes a control section consisting of a micro-combiner, etc., and the pre-transfer exposure lamp 7 is controlled to be turned on/off by this control section 32.

FIG. 2 is a diagram showing a flowchart of a control program when the pre-transfer exposure lamp 7 is forcibly turned on. Here, when one of the modes of erase outside the specified area, erase within the specified area, frame erase, and reduction shift is selected in the operation unit 31 described above and the command is taken into the control unit 32, the transfer is performed. ffJ'before g''11 The light lamp 7 is forced to light up.

As a result, when setting a copy mode that forcibly forms a blank area in a part of the transfer paper, the surface of the photoconductor 3 is irradiated by the pre-transfer exposure lamp 7, so the surface potential decreases and the transfer paper adsorption properties are reduced. Therefore, the separation performance of the separation electrode 9 is prevented from deteriorating.

In the above, only the erase outside specified area, erase within specified area, frame erase, and reduction shift are shown as copy modes that forcibly create a blank area in a part of the transfer paper, but there are other copy modes such as shift copy and binding. There are other types such as substitute copies.

Furthermore, in the above embodiment, the pre-transfer exposure lamp was controlled to be turned on during the copy mode in which a blank area was forcibly formed in a part of the transfer paper, but the pre-transfer exposure lamp was turned on at all times. If the light is turned on when other conditions are satisfied, the light may be further strengthened by one step during the copying mode to increase the illuminance on the photoreceptor surface, or the filter may be In the case of a device equipped with a filter, it is also possible to perform control such as replacing the filter or inserting another filter.

〔Effect of the invention〕

As explained above, according to the present invention, since the pre-transfer exposure lamp is controlled when copying conditions are set that forcefully leave blank areas on the transfer paper, deterioration of separation performance can be prevented.
This has the advantage of being able to prevent image quality deterioration and paper jams.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a control unit according to an embodiment of the present invention, FIG. 2 is a flowchart of its control program, FIG. 3 is a schematic configuration diagram of a copying machine, and FIG. 4 is an explanatory diagram of erasing outside a specified area. be. 5... Charge erase lamp, 7... Pre-transfer exposure lamp.

Claims (2)

[Claims] (1) It is characterized by comprising a means for detecting that a copying condition that forcibly leaves a blank area on the transfer paper is set, and a means for controlling a pre-transfer exposure lamp based on the detection by the detecting means. Electrostatographic equipment. (2) The detection means is configured to perform an outside specified area erase mode, an inside specified area erase mode, a frame erase mode, a shift copy mode,
2. The electrostatic copying apparatus according to claim 1, wherein the electrostatic copying apparatus detects the setting of a binding margin production mode or a reduction shift mode.