JPS6210669A - Copying device provided with original feeding device - Google Patents

Abstract

PURPOSE:To obtain good copy images of no transfer deviation by setting the operation start time of a paper feeding device so that the front end of a transfer paper reaches the transfer position at the same time as the front end of an image. CONSTITUTION:Since a detecting sensor S is arranged just before an exposure light source part 31 and the detection position and the exposure position are close, the time spent on running of the front end of an original from the detection position to the exposure position is not varied. That is, the timing when the front end of the image on an original D formed on a photosensitive body 41 reaches the transfer position after arrival of the front end of the original at the detection position and the timing when the front end of a transfer paper P fed by a resist roll 53 of a paper feeding device 5 which starts the operation after a prescribed time reaches the transfer position are not shifted from each other, and the picture of the original is transferred to a proper position of the transfer paper without transfer deviation thereby.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a copying apparatus equipped with a document feeder such as an automatic document feeder or a semi-automatic document feeder.

Specifically, the copying apparatus includes a document detection means that detects the arrival of the document conveyed by the document feeder and sends a signal to start operation of the transfer paper feeder, thereby preventing transfer misalignment. The present invention relates to an improvement in a copying apparatus that can obtain good copy images.

2. Description of the Related Art Conventionally, it is generally known that the above-mentioned copying apparatus is provided with the above-mentioned document detection means in the guide path of the document feeder. This often results in discrepancies.

For example, a copying apparatus schematically shown in FIG. 3 will be explained. The copying apparatus shown in the figure includes an original storage case 11 that stores original originals, a feed roller 12 that is driven by copy process control and sends out original originals one by one from original storage case 11 at a constant speed, and a platen that transports the original originals. An automatic document feeder 1 includes a guide path consisting of a plurality of guide rollers 13 and a guide plate 14 that guide the glass 2, and a conveyor belt 15 arranged opposite to the platen glass 2 and rotated at a constant speed. , a detection sensor S serving as a document detection means provided in the guide path, a paper feed cassette 51 and a paper feed roller 52.
It is equipped with a paper feeding device i15 for transfer paper P, etc., which has an I registration roller 53, etc., and the copy process is controlled so that the operation of the registration roller 53 is started after a predetermined time after receiving the signal from the detection sensor S. It is. Note that the predetermined time is the time required for the leading edge of the original document to reach the exposure position from the detection position where the detection sensor S is located to the exposure position where the exposure light source section 31 of the exposure optical system 3 is located, and
From the sum of the time it takes for the leading edge of the original image formed by the exposure action to reach the transfer position, which is the placement position of the transfer device 44, the transfer paper P is transferred from the position of the registration roller 53. It is set as the time minus the time it takes to reach the position.

The copying operation of the copying apparatus shown in the figure is as follows.

During a copying operation, a document is sent out from the document storage case 11 at a constant speed by a feed roller 12, and is conveyed onto the platen glass 2 through a guide path.

After being conveyed onto the platen glass 2, it is moved by a conveyor belt 15 that rotates at a constant speed, and after passing the exposure position, it is guided by a discharge guide 6 and discharged from the platen glass 2. While the document is passing through the exposure position, the charger 4
The photoreceptor 41, which has already been charged in step 2, is exposed to light by the exposure optical system 3, and an image of the document is formed on the photoreceptor 41 as an electrostatic latent image. The image on the document is developed by the developing device 43 and formed as a toner image, and then transferred to the photoreceptor 4.
1, the transfer position is eventually reached.

On the other hand, as described above, when the document is sent out from the document storage case 11 and its leading edge reaches the detection position, the detection sensor S is turned on and sends a signal. After a predetermined time, the registration rollers 53 of the paper feeder 5 start operating.

The transfer paper P has already been fed by the paper feed roller 52 from the paper feed force roller 51, and its leading edge is held by the registration rollers 53, so its leading edge is moved at the same speed at the same time as the leading edge of the original image. The paper is fed by registration rollers 53 so that the paper reaches the transfer position at . As described above, since the original image and the leading edge of the transfer paper arrive at the transfer position at the same time and at the same speed, the original image is transferred to an appropriate position without causing transfer misalignment.

If the copying apparatus shown in the figure is operated properly, it is possible to obtain good copy images without transfer misalignment as described above, but in reality, transfer misalignment often occurs, making it difficult to produce good quality copy images. The problem is that it cannot be obtained. In particular, the exposure optical system is selectively set to a moving type or a fixed type, and the document feeder is selectively set to an operating position, which is a position facing the exposure optical system, and a position other than the above, that is, a non-operating position. In a copying apparatus configured to be placed in a fixed position, when the document feeder is placed in the operating position and the exposure optical system is set to a fixed type, transfer misalignment often occurs more often than in the copying apparatus shown in the above figure. There is a problem that this occurs.

OBJECTS OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems. It is an object of the present invention to provide a copying apparatus that can set the timing and obtain good copy images without transfer deviation.

Structure of the Invention The present inventor has obtained the following knowledge as a result of research to achieve the above object. The cause of transfer misalignment in conventional copying devices is that the time it takes for the leading edge of the original to reach the exposure position from the detection position is not constant, so the leading edge of the original image formed on the photoreceptor may not be on the transfer paper. This is due to the fact that it reaches the transcription position at a different time than the tip. In other words, since the detection position and the exposure position are 111L theory, and the moving speed or movement path of the document between the two positions is difficult to be actually constant, the actual time it takes for the leading edge of the document to reach the exposure position from the detection position is The time will be inconsistent and different from the set time.

Therefore, the time it takes for the leading edge of the original image to reach the transfer position after the leading edge of the original reaches the detection position is not constant. The time will be different from the time set as the time it takes for the leading edge to reach the transfer position.

In addition, in a copying machine that has an exposure optical system that can be selectively set to a moving type or a fixed type, it is difficult to properly position the exposure optical system when fixing it, so the distance between the detection position and the exposure position is was not constant, and the actual time taken for the leading edge of the document to reach the exposure position from the detection position was further different from the set time.

From the above, by shortening the distance between the detection position and the exposure position, that is, by placing the document detection means immediately in front of the exposure light source, and in particular by arranging it fixedly to the exposure light source, it is possible to It has been found that the actual time from the detection position to the exposure position can be made constant, and a good copy image without transfer deviation can be obtained.

The present invention was completed based on the above findings, and consists of a document feeder disposed opposite to the exposure optical system, and a transfer paper feeder that detects the arrival of the document and operates the transfer paper feeder. 1. A copying apparatus comprising a document feeding device characterized in that the document detecting means is disposed immediately before an exposure light source section of an exposure optical system, in the copying apparatus equipped with a document detecting means for transmitting a signal for starting. It is a device.

Example The present invention will be explained by examples.

FIG. 1 is a schematic explanatory diagram of a copying machine for explaining an embodiment, and FIG. 2 is a schematic enlarged sectional view taken along the line 1--2 in FIG. In the figure, the same reference numerals as in FIG. 3 indicate the same functional members. In the copying apparatus shown in the figure, the exposure optical system 3 can be selectively set to a moving type or a fixed type, and the automatic document feeder 1 can be placed in a position facing the exposure optical system 3, that is, in an operating position, and in other positions. That is, it is selectively disposed in the non-operating position, and is characterized in that the detection sensor S, which is the document detection means, is fixedly provided to the exposure light source section 31, which is the exposure position of the exposure optical system 3. That is. As shown in FIG. 2, the detection sensor S is a reflective sensor consisting of a light-emitting/light-receiving element S1 provided in the exposure light source section 31 and a reflection plate S2 provided in the guide plate 17 that supports the conveyor belt 15. , detects the change in the amount of light reflected to the light receiving element that occurs when the leading edge of the original document reaches, and transmits a signal to start operation of the paper feeder 5 by turning on the light receiving element.

The copying apparatus shown in the figure is configured as described above and performs the copying operation in the same manner as the conventional copying apparatus, but the detection sensor S is placed immediately in front of the exposure light source section 31, and the detection position and the exposure position are Since these are close to each other, there is no variation in the time it takes for the leading edge of the document to reach the exposure position from the detection position.

That is, after the leading edge of the original reaches the detection position, the registration roller 53 of the paper feeding device 5, which starts operating after a predetermined period of time, determines when the leading edge of the original image formed on the photoreceptor 41 reaches the transfer position. Since there is no timing lag between when the leading edge of the fed transfer paper P reaches the transfer position, the image of the document is transferred to an appropriate position on the transfer paper without any transfer misalignment. In addition, since the detection sensor S is fixedly provided to the exposure light source section 31, 1.
Even if the fixed position of the exposure light source section 31 is not constant, the distance between the exposure light source section 31 and the detection sensor S, that is, the distance between the detection position and the exposure position, remains unchanged, and the leading edge of the document changes from the detection position to the exposure position. There is no variation in the time it takes to reach . Therefore, a good copy image can be obtained without causing transfer misalignment.

Effects of the Invention As explained in the embodiments, the copying apparatus of the present invention has the following features:
The document detection means that sends a signal to start operation of the paper feeding device is provided just before the exposure position, which is the location of the exposure light source of the exposure optical system, so that the leading edge of the document is located at the location of the document detection means. The time from the detection position to the exposure position is constant, and the leading edge of the image on the original and the leading edge of the transfer paper can reach the transfer position at approximately the same time without any timing discrepancy. In addition, in a copying machine having an exposure optical system that can be selectively set to a moving type or a fixed type, the original detection means is fixedly disposed in the exposure light source section, so that the exposure optical system can be set to the fixed type. There is no need to strictly set the fixed positioning of the exposure light source, and the leading edge of the original image and the transfer paper can reach the transfer position at approximately the same time, as described above.

As described above, the copying apparatus of the present invention can obtain a good copy image without causing transfer misalignment.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of an embodiment of the present invention, FIG. 2 is an enlarged sectional view taken along line 1--2 in FIG. 1, and FIG. 3 is a schematic explanatory diagram of a conventional example. l...Automatic document feeder, 2...Platen glass. 3... Exposure optical system, 31... Exposure light source section. 5... Paper feeding device, 53... Registration roller. S... Original detection sensor + Sl... Light emitting-light receiving element. S2...Reflector, D...Document, P...
Transfer paper. Patent applicant: Konishiroku Photo Industry Co., Ltd.j11 Figure 2 Figure 3

Claims (4)

[Claims] (1) In a copying apparatus equipped with a document feeding device disposed opposite to an exposure optical system, and a document detecting means for detecting the arrival of a document and transmitting a signal to start operation of a transfer paper feeding device. 1. A copying apparatus equipped with an original feeding device, characterized in that an original detecting means is disposed immediately in front of an exposure light source section of an exposure optical system. (2) The exposure optical system is selectively set to a moving type or a fixed type, and the document feeder is selectively arranged at a position facing the exposure optical system and at a position other than the above. A copying apparatus comprising the document feeding device according to claim 1. (3) A copying apparatus comprising the document feeding device according to claim 1 or 2, wherein the document detecting means is fixedly disposed in the exposure optical system. (4) A copying apparatus equipped with a document feeding device according to any one of claims 1 to 3, wherein the document detecting means includes a light reflection type sensor.