JP3203877B2 - Transfer device for image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer and a facsimile, and more particularly to a transfer apparatus using a transfer image carrier made of a dielectric film.

[0002]

2. Description of the Related Art Conventionally, for example, in a color electrophotographic copying machine, latent images of yellow, cyan, magenta, and black are sequentially formed on a photoreceptor, and each latent image is developed with yellow, cyan, magenta, and black. The developed toner image is transferred to a transfer material on a rotating transfer drum in contact with the photoreceptor, and the transfer drum is rotated four times so that the four color toner images are superimposed on the transfer material and transferred. A method of obtaining a full-color copy of four colors is known.

In the transfer device of the above image forming apparatus,
To superimpose images on a single transfer material with high accuracy,
A transfer image carrier made of a dielectric film is fixed to the outer periphery of the transfer drum, and the transfer material is electrostatically attracted to the transfer image carrier, and the transfer is performed by bringing the transfer material into close contact with the peripheral surface of the photoconductor. After the completion of the transfer, the charge of the transfer material is removed by a charge removing corotron, and the transfer material is peeled off by a peeling claw (for example, JP-A-3-168784).

[0004]

A plurality of transfer material detection sensors are provided around the transfer drum, and the presence or absence of the transfer material on the transfer drum at the sensor position is detected. It detects the jam of the material. However, in a transfer device using the above-described transfer image carrier, the dielectric film contracts or relaxes due to heat conduction and radiant heat from the fixing device, and the transfer image carrier is deformed. There is a problem that a malfunction occurs and a false jam occurs even though the transfer material is normally conveyed. Further, as the number of copies increases, the deformation of the transfer image carrier increases, causing a problem of poor suction of the transfer material, making it impossible to convey the transfer material to the transfer portion in a smooth state, and deteriorating the image quality.

An object of the present invention is to solve the above-mentioned problem, and to surely detect the deformation of the transfer image carrier, prevent the occurrence of false jams, and properly replace the transfer image carrier. It is an object of the present invention to provide a transfer device that can perform the transfer.

[0006]

In order to achieve the above object, a transfer device according to the present invention comprises an image forming means for forming an electrostatic latent image on an image carrier, and developing the electrostatic latent image into a toner image. In an image forming apparatus comprising: a developing unit, a transfer image carrier made of a dielectric film, and a transfer device for transferring the toner image to a transfer material on the transfer image carrier, a dielectric material opposing the transfer image carrier A deformation detection sensor for detecting a deformation state of the film is provided. Note that the deformation detection sensor may also be used as a transfer material detection sensor that detects a jam of the transfer material.

[0007]

In the present invention, when the difference between the maximum value and the minimum value of the output of the film deformation detection sensor at the position of the transfer image carrier is greater than or equal to a predetermined value, or when the difference is less than the minimum value, Inform the operator of the service life.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing one embodiment of a transfer device according to the present invention, and showing an example applied to a color electrophotographic copying machine. The present invention is not limited to such a color electrophotographic copying machine, but can be applied to all image forming apparatuses using a transfer device using a transfer image carrier made of a dielectric film.

The color electrophotographic copying machine includes an automatic document feeder 1, an image input unit 2, an image output unit 3, and a transfer material supply unit 4.
Consists of The color document is placed on the platen glass 5 by the automatic document feeder 1. The image input unit 2 includes an imaging unit 6, a wire 7 for driving the unit 6, a driving pulley 9, and the like. , A color original is read for each of B (blue), G (green), and R (red), which are primary colors of light, and converted into a digital image signal, and this signal is converted to a primary color of toner, K (black), Y ( Yellow), M (magenta), and C (cyan), and further perform various data processing to increase the reproducibility of color, gradation, definition, etc., to turn on / off the color gradation toner signal. The signal is converted into an OFF binary signal and output to the image output unit 3.

The image output unit 3 has a scanner 10 and a drum-shaped photosensitive member 11 made of an organic photosensitive member. A charging device 12 for uniformly charging the photosensitive member 11 is provided around the photosensitive member 11. A rotary developing device 13 for developing the electrostatic latent image into a toner image, a transfer device 14 for transferring the toner image to a transfer material, and a cleaner 15 for collecting untransferred residual toner are arranged. The body 11 is driven to rotate by an electric motor as shown by the arrow in the figure.

At a laser output unit 10a of the scanner 10, for example, a black image signal from the image input unit 2 is converted into an optical signal, and the photoreceptor 11 is converted via a polygon mirror 10b, an f / θ lens 10c and a reflection mirror 10d. A latent image corresponding to the original image is formed thereon. When the black latent image is transferred to the transfer material through development, the photoconductor 11 is charged again by the charger 12 after the residual toner is removed by the cleaner 15, and the laser output unit 10a outputs the yellow image signal. Is output. Hereinafter, latent images of magenta and cyan image signals are sequentially formed.

The rotary developing device 13 includes a black developing device 13K, a yellow developing device 13Y, and a magenta developing device 1Y.
3M, a developing unit 13C for cyan, and each developing unit is disposed around a rotating body 13a, and a rotating shaft 13b of the rotating body 13a is provided.
Are rotatable by a motor (not shown). For example, when a black toner image is formed, development is performed by the black developing device 13K at the position shown in the figure, and when a yellow toner image is formed, the rotary developing machine 13 is rotated and the photoconductor 11 is rotated. The yellow developing device 13Y is arranged at a position in contact with. Magenta and cyan development are operated in the same manner.

The transfer drum 1 constituting the multiple transfer device 14
A transfer image carrier made of a dielectric film is stretched around the outer periphery of the transfer drum 6. The transfer drum 16 is connected to a dedicated electric motor or the photoconductor 11 by a gear, and is driven to rotate as shown by an arrow in the figure. A transfer corotron 17, a pressing member 18, a separating corotron 19, a peeling claw 20, a transfer material detection sensor 21 are provided inside and outside the transfer drum 16.
a, 21b, 21c, film deformation detection sensor 21d,
A cleaning device 22, a suction roll 23, a drum rotation position detection sensor 24, and a suction corotron 25 are arranged. The drum rotation position detection sensor 24 generates a reference signal of a machine clock in order to control the timing of paper conveyance and the timing of image writing.

The paper feed tray 4a of the transfer material supply unit 4
The transfer material conveyed and fed from 4 to 4d through the conveyance roller 26, the paper feed guide 27 and the registration roller 28 is attracted to the transfer image carrier by the pressing action of the suction roll 23 and the corona discharge of the suction corotron 25. . The transfer drum 16 is rotated in synchronization with the photoconductor 11, and, for example, a toner image developed in black is transferred to the transfer corotron 1.
7, the toner image developed by yellow is transferred to the transfer material by the transfer corotron 17 after one rotation of the transfer drum 16, and the toner images developed by magenta and cyan are successively superimposed. Is transcribed. When the transfer of the four colors is completed by the rotation of the transfer drum 16 and the transfer of the four colors is completed, the transfer material is discharged by the separating corotron 19, then separated by the separation claw 20, sent to the fixing device 30 via the transport path 29, and transferred. The toner image is fused and fixed,
Hereinafter, this series of copy cycles is repeated.

FIG. 2A is a perspective view of a transfer drum, and FIG.
2B is a cross-sectional view of the transfer drum, and FIG. 2C is a developed view of the transfer image carrier. The transfer drum 16 includes two cylindrical members 3
1, 32, a connecting member 33 connected and fixed between the two tubular members 31, 32, and a transfer image carrier 3 made of a dielectric film.
4 and a front end plate 35 and a rear end plate 36 fixed to both ends of the transfer image carrier 34, and both side edges of the transfer image carrier 34 are fixed to the outer periphery of the two cylindrical members 31, 32 by a double-sided adhesive tape 37. The front and rear end plates 35 and 36 of the transfer image carrier 34 are fixed by connecting members 33 with screws 38 to form a hollow cylindrical space inside. A driving gear 39 is provided on the outer periphery of one of the cylindrical members 31, and the end plate 35 is provided with a driving gear 39.
A plurality of openings 4 are provided on the back surface of the transfer image
The suction force adjusting plate 40 having Oa is adhered. Further, a black painted portion 4 is provided at the tip of the transfer image carrier 34.
1 is formed.

FIG. 2D shows the transfer material detecting sensors 21a and 21a when there is no transfer material on the transfer image carrier 34.
b, 21c, and the output waveform of the film deformation detection sensor 21d. An optical reflection type sensor is used for each sensor, and the sensor output value at each position of the transfer drum is read based on a reference signal generated from the drum rotation position detection sensor 24. The sensor output value indicates a value that fluctuates in the portion X of the rear end plate 36, the connecting member 33, and the front end plate 35, and indicates a constant high level value in the portion Y of the black paint portion 41. In the part Z, a constant low level value is indicated, and the black painted portion 41 is
The data is read at a, 21b, and 21c, and a jam display is performed when the output level is abnormal.

FIG. 3 shows transfer material detection sensors 21a and 21b,
21A shows an output waveform of the transfer material detection sensors 21a, 21a.
The outputs of b and 21c are output as shown in FIG.
In the case of A4 vertical two-sheet feed, the output is as shown in FIG. FIG. 4 shows the output waveform of the film deformation detection sensor 21d. First, when a new transfer image carrier 34 is mounted, the output of the film deformation detection sensor 21d is shown in FIG.
As shown in (A), the machine confirms that the output of the black coating portion 41 is X or more and the output of the surface of the transfer image carrier 34 is Y or more. It is desirable that the life check of the transfer image carrier 34 be performed in a state where the transfer material is not adsorbed and the toner is not stained unlike the cleaning cycle. Therefore, the life check is performed in the latter half of the cleaning cycle. The output of the film deformation detecting sensor 21d, as shown in FIG. _{4 (B), T 3 ~T} 4 in machine clocks T ₁ through T ₂ is a black painted portion 41 at the machine clock and transfer image bearing member 34 surface . FIG. 4 (C) shows a case of detecting the deformation of the transferred image carrying member 34 in the film deformation detecting sensor 21d, the output machine clock T of the film deformation detecting sensor 21d ₃ through T ₄
When the value between (maximum value Max-minimum value Min) becomes, for example, 1 V or more, the life of the transferred image carrier is notified to the operator. Alternatively, as shown in FIG.
When the output level of the four surfaces becomes equal to or less than the minimum value Min level, the operator is notified of the life of the transfer image carrier.

In the above embodiment, the deformation of the transfer image carrier is detected by the film deformation detection sensor 21d.
It is also possible to use b and 21c. In this case, one of the plurality of transfer material detection sensors 21a, 21b, and 21c may be used, or three of them may be used, and the life may be reached when any one of them is lower than the Min level. In addition to using the output of this sensor to inform the operator of the life of the transfer film, a serviceman or the like performs idle rotation of the transfer drum when replacing the transfer image carrier and checks the deformation of the transfer image carrier. It is also possible.

[0019]

FIG. 5 shows another embodiment of the transfer device of the present invention, in which a transfer image carrier is provided on a transfer belt 51. The transfer belt 51 constituting the transfer device 14 is made of a dielectric sheet in the form of an endless belt, is wound around a drive roll 52 and a driven roll 53, and is rotated in the direction of the arrow.
Opposite to the transfer belt 51, for black, yellow,
Four image forming units K for magenta and cyan
Y, M, and C are provided, and the toner images of four colors are multiplex-transferred one after another by one rotation of the transfer belt 51.

[0021]

As is apparent from the above description, according to the present invention, the deformation of the transfer image carrier is reliably detected, the occurrence of false jam is prevented, and the exchange of the transfer image carrier can be accurately performed. It can be carried out.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an embodiment of a transfer device according to the present invention and an example applied to a color electrophotographic copying machine.

FIG. 2A is a perspective view of a transfer drum, and FIG.
FIG. 2C is a cross-sectional view of the transfer drum, FIG. 2C is a developed view of the transfer image carrier, and FIG. 2D is a diagram illustrating an output waveform of the sensor when there is no transfer material on the transfer image carrier.

FIG. 3 is a diagram illustrating an output waveform of a transfer material detection sensor.

FIG. 4 is a diagram showing an output waveform of a film deformation detection sensor.

FIG. 5 is a configuration diagram showing another embodiment of the transfer device according to the present invention.

[Explanation of symbols]

10, 12 image forming means, 11 image carrier, 13 developing means, 14 transfer device, 16 transfer drums 21a, 21b, 21c transfer material detection sensor, 21d
Deformation detection sensor

Claims (2)

(57) [Claims] An image forming means for forming an electrostatic latent image on an image carrier; a developing means for developing the electrostatic latent image into a toner image; a transfer image carrier comprising a dielectric film; Transcription
An image forming apparatus comprising: a transfer device for transferring a transfer material onto an image carrier; and a transfer detection sensor for detecting a deformation state of the dielectric film facing the transfer image carrier. apparatus. 2. The transfer apparatus according to claim 1, wherein said deformation detecting sensor is a transfer material detecting sensor for detecting a jam of the transfer material.