JPS62124569A - Image forming device - Google Patents

Abstract

PURPOSE:To shorten the format time of beltlike photosensitive body and to reduce its cost by providing a sensor which outputs a reference output signal, arranging a light transmission window or reflecting member on one side of the photosensitive body, and providing a control circuit which controls an image formation segment position. CONSTITUTION:The belt like photosensitive body 6 is driven to rotate as shown by an arrow at the start of copying operation, the part of a light-transmissible joint 28 is passed through the detection sensor 30 and detected, and when the beltlike photosensitive body 6 further moves, the light transmission window 31 is also detected by the detection sensor 30. The joint 28 and light transmission part 31 differ in detection width, so the outputs of the detection sensor 30 are processed by a control circuit 32 while the detection output corresponding to the joint 28 is regarded as a reference output signal and the detection output corresponding to the light transmission window 31 is used as a control output signal, thereby calculating the interval M between both signals. Namely, the length L of the light transmission window 31 from the joint 28 is set optionally, but the interval M is calculated to know the position relation between the joint 28 and light transmission part 31. The position of the image formation segment to the joint 28 is therefore determined.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to image forming apparatuses such as copying machines, non-impact printers, and facsimile machines that use a belt-like photoreceptor having seams.

2. Description of the Related Art Conventionally, some copying machines use a belt-shaped photoreceptor having a seam as a photoreceptor. In this case, if an image is formed at the seam, the image quality will be degraded due to the difference in level at the seam, so it is necessary to control the position of the image forming segment so that the seam becomes a non-image area. In this regard, there is a conventional method of attaching a detection mark at a certain distance from the seam of the belt and detecting this detection mark. However, in this case, it is necessary to strictly control the mechanical positional accuracy so that the distance from the seam position to the detection mark is constant during the manufacturing process of the belt-shaped photoreceptor, which takes manufacturing time and increases costs. Become.

On the other hand, as shown in Japanese Unexamined Patent Publication No. 58-46353, there is a device in which the seam itself of a belt-shaped photoreceptor is used as a synchronization mark, and control is performed by detecting this seam. but,
Foreign matter such as toner and paper powder easily adheres to the joint, and the surface potential fluctuates greatly, making it impossible to maintain the initial characteristics and making it difficult to perform stable control over a long period of time.

Purpose The present invention has been made in view of the above points, and an object of the present invention is to provide an image forming apparatus that can appropriately control the position of an image forming segment without requiring time for manufacturing a belt-shaped photoreceptor. do.

Structure In order to achieve the above object, the present invention uses a belt-like photoreceptor having a seam, and controls the position of the image forming segment so that the seam portion becomes a non-image area to form an image on the photoreceptor. In the forming apparatus, a sensor is provided on one side of the photoconductor to connect the vfI seam portions with translucency or reflection, and to detect the seam and output a base output signal. A translucent window or a reflective member is provided that is detected as a control output signal with an output state different from the base J signal, and the base □ detected by the sensor is provided.
□□ The present invention is characterized in that a control circuit is provided that calculates the interval from the output signal to the control output signal and controls the position of the imaging segment so that the joint portion becomes a non-image portion.

Hereinafter, one embodiment of the present invention will be described based on the drawings. This embodiment is applied to a copying machine. First, as shown in FIG.
A projected image is formed on a belt-shaped photoreceptor 6 via a lens 4 and a mirror 5. Here, the lamps 2a and 2b are flash lamps, which instantaneously illuminate the entire surface of the document, and are of an entire surface simultaneous exposure system in which the entire image is projected onto the belt-shaped photoreceptor 6 at once. Then, this belt-shaped photoreceptor 6
is rotationally driven in the direction of the arrow while being supported by a driving roller 7, a driven roller 8, etc. The belt-shaped photoreceptor 6 is used as a photoreceptor unit together with the roller 7.degree. 8, etc., and can be freely pulled out from the main body of the copying machine toward the front for replacement of the photoreceptor. Since the surface of the belt-shaped photoreceptor 6 has already been uniformly charged by the charger 9, an electrostatic latent image is formed by projection of the original optical image.

When this latent image reaches the developing device 10, it is developed with toner and becomes a visible image. For such a visible image, the transfer paper 12 fed from the cassette 11 is moved by the registration roller 1.
3, the paper is fed to the belt-shaped photoreceptor 6 at a predetermined timing. Then, this visible image is transferred onto the transfer paper 12 by the action of the transfer charger 14. The transfer paper 12 after transfer is the transfer paper 1 due to the small diameter of the driven roller 8 in that part.
2 is released from the belt-shaped photoreceptor 6 by curvature separation using its own stiffness. However, a separate charger 15 is also provided to improve its reliability. The transfer paper 12 is then discharged onto a paper discharge tray 18 via a conveying device 16 and a fixing device 17. On the other hand, the belt-shaped photoreceptor 6 that has completed the transfer process is neutralized by a static elimination lamp 19, and the remaining a toner after the transfer is cleaned and removed by a cleaning device 20.

Next, a specific configuration of the belt-shaped photoreceptor 6 will be explained. First, the cross-sectional structure of the belt-shaped photoreceptor 6 is as shown in FIG. 4. On a photoreceptor base material 21 made of a polyester film with a thickness of 100 μm, a conductive layer 22 deposited with AQ to a thickness of about 300 to 500 layers is formed. On top of that is a 300μ thick CGL.
020 layer (
An organic semiconductor R4) 25 is formed. A conductive paint layer 2G is formed on both sides in electrical contact with the conductive layer 22, and an earth brush 27 is brought into contact with one side of the conductive paint layer 2G.

The belt-like photoreceptor 6 is a sheet-like member joined by a seam 28 to form a loop, and when it is unfolded, it has an image forming segment as shown in FIG. It is necessary to set the position of 29. This is to prevent an image from being formed at the seam 28 portion. That is, in this embodiment, as shown in FIG. 5, the image forming segment 29A4 for A4 size is for 5 sheets, the image forming segment 29B4 for B4 size is for 3 sheets, and the image forming segment 29A3 for A3 size is for 2 sheets. Each image forming position is determined to be equally spaced from the seam 28 so that the images can be separated.

Therefore, during the copying operation, the seam 2 is
It is necessary to control the position of the imaging segment 29 by detecting the position of the imaging segment 8.

Therefore, in this embodiment, after coating and forming a conductive paint layer 26 on both sides of the belt-shaped photoreceptor 6 in the unfolded state as shown in FIG. 5, it is bent as shown in FIGS. 6(a) and (b). They are joined at the seam 28 to form an endless shape, but the seam 28
The parts are welded by ultrasonic welding as shown in FIG. At this time, in order to improve weldability, the non-transparent conductive paint was not applied to the seam 28, and as a result, the seam 28
The portion is configured as a transparent portion. A light-transmitting type detection sensor 30 for detecting such a light-transmitting seam 28 is provided at a predetermined position so as to sandwich one side of the belt-shaped photoreceptor 6, as shown in FIG. . Therefore, in this embodiment, a transparent window 31 is formed by not applying the conductive paint [26] at an arbitrary position on one side that can be detected by the detection sensor 30. The length of the light-transmitting window 31 (in the moving direction of the belt-shaped photoreceptor 6) is longer than the length of the seam 28.

A detection output signal from the detection sensor 30 is input to a control circuit 32.

In such a configuration, control of the position of the image forming sag men 829 according to this embodiment will be explained. First, at the start of a copying operation, the belt-shaped photoreceptor 6 is rotationally driven in the direction of the arrow by the motor. Due to this.

Since the translucent seam 28 portion passes through the detection sensor 3o, it is detected. Further, when the belt-shaped photoreceptor 6 moves, the light-transmitting window 31 is also detected by the detection sensor 30. The output of the detection sensor 30 at this time differs as shown in FIG. 2 because the detection widths of the seam 28 and the transparent window 31 are different. Therefore, in this embodiment, focusing on the fact that the output states are different, the control circuit 3 uses the output from the detection of the seam 28 as the reference output signal and the output from the detection of the translucent window 31 as the control output signal.
2 to calculate the interval M between both signals. That is, in the manufacturing process of the belt-shaped photoreceptor 6, the length L of the transparent window 31 from the seam 28 is set arbitrarily;
By calculating , the positional relationship between the seam 28 and the transparent window 31 can be determined. This allows the position of the imaging segment 29 relative to the seam 28 to be determined. Then, all the processes start operating at the set timing, and the above-described copying operation is performed.

Here, the detection sensor 30 detects the seam 28 in this way only at the time of initial setting (that is, when the belt-shaped photoreceptor 6 is replaced with a new one), and thereafter the detection sensor 30 detects the transparent window 31. By doing so, the control circuit 32 performs timing control. In other words,
If the distance from the seam 28 to the transparent window 31 is known at the time of initial setting, by storing that value in a non-volatile memory or the like, the transparent window 31 can relatively function as the seam 28.
Thereafter, the position of the imaging sagmen 829 can be determined simply by detecting the position of the transparent window 31 (of course, the detection sensor 30 detects the seam 28 and the transparent window 31 not only at the initial stage but also at all times, The image forming timing may be controlled by calculating the interval M).

2, according to the embodiment, the light-transmitting window 31 can be formed at an appropriate position on the belt-like photoreceptor 6, so that the seam 28 and the light-transmitting window 31 can be formed in the manufacturing process of the belt-like photoreceptor 6. There is no need to consider positional accuracy, and manufacturing time can be shortened and costs can be reduced. Further, in an extreme case, such a light-transmitting window 31 can be formed by a service engineer during machine setting at the customer's site. In addition, controlling the position of the image forming segment 29 is usually not done by detecting the seam 28 itself;
Since the detection is changed to the detection of the transparent window 31, control with high positional accuracy becomes possible.

In this embodiment, the width of the output signal is set to be longer as the length on the transparent window 31 side is longer than the seam 28, but this may be the other way around, as long as the two can be distinguished.

Further, in this embodiment, since the transmission type detection sensor 30 was used, the seam 28 portion was made to have translucency, and the transparent window 31 was also made to have translucency. However, when using a reflection type optical sensor, may be configured to have reflectivity.

Effects Since the present invention is configured as described above, the image forming segment position can be accurately controlled in a certain relationship with the seam by using a detection sensor to detect a transparent window or a reflective member separate from the seam. In this case, it is only necessary to form such a light-transmitting window or a reflective member at an appropriate position on the belt-shaped photoreceptor, thereby reducing the time and cost in the manufacturing process of the belt-shaped photoreceptor. It is also possible to reduce the

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a perspective view, Fig. 2 is a waveform diagram of the output signal of the sensor, Fig. 3 is a schematic side view of the overall configuration, and Fig. 4 is a diagram of the photoreceptor. 5 is a plan view of the photoreceptor in an expanded state, and FIGS. 6(a) and 6(b) are schematic perspective views of the manufacturing process thereof. FIG. 7 is a sectional view of the joint portion. 6... Belt-shaped photoreceptor, 28... Seam, 29... Image forming segment, 30... Detection sensor, 31... Transparent window, 32... Control circuit output 1 person Ri Co., Ltd. Ko
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Claims (1)

[Claims] In an image forming apparatus that uses a belt-shaped photoreceptor having a seam and forms an image on the photoreceptor by controlling the position of an image forming segment so that the seam portion becomes a non-image area, the seam portion is transparent or transparent. A sensor is provided on one side of the photoconductor to detect the joint and output a reference output signal, and the sensor detects the control output signal in an output state different from the reference output signal. A light-transmitting window or a reflective member is provided, and an interval between the reference output signal detected by the sensor and the control output signal is calculated, and the imaging segment position is adjusted so that the joint portion becomes a non-image portion. An image forming apparatus comprising a control circuit for controlling.