JPH05338853A - Controlling device for feed of transfer material - Google Patents

Abstract

PURPOSE:To reduce the rate of occurrence of jams by disposing an auxiliary feed roller for feeding a transfer material toward a main feed roller so as to form a loop, and varying both the attracting position of the transfer material and the time required for jam recognition according to whether an OHP film or other transfer material is used. CONSTITUTION:A transfer device transfers a developed image on an electrostatic latent image carrier 11 to a transfer material S held on a transfer material holder 15. A transfer material feeding device 14 feeds the transfer material S toward the transfer material holder 15. In this case, a main feed roller 31 for feeding the transfer material S toward the transfer material holder 15 and an auxiliary feed roller 32 for feeding the transfer material S toward the main feed roller 31 to form a loop are disposed in the transfer material feeding device 14. A jam recognition timer recognizes the jam of the transfer material S according to a signal indicating detection by a transfer material sensor 35. Further, an OHP film sensor 38 detects an OHP film, and a value set in the jam recognition sensor is made larger when the OHP film is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer material in an image forming apparatus such as an electrophotographic copying machine, a printer, a facsimile, etc., particularly in an image forming apparatus of the type in which multiple transfer is performed to form a color image, a composite image or the like. The present invention relates to a transfer control device.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing an example of a color electrophotographic copying machine as an image forming apparatus of a multiple transfer system, which includes an automatic document feeder 1, an image input section 2, an image output section 3 and a transfer material supply. It consists of part 4. The color original document is placed on the platen glass 5 by the automatic original document feeder 1. The image input unit 2 includes an imaging unit 6, a wire 7 for driving the unit, a drive pulley 9, and the like. By using a CCD line sensor and a color filter in the imaging unit 6, in the case of four-color full color, A color original is read for each of B (blue), G (green), and R (red), which are the primary colors of light, converted into a digital image signal, and then this reflectance information is converted into density information, and further, color and floor In order to enhance reproducibility such as tonality and definition, after various data processing is performed, the toner primary colors Y (yellow), C (cyan), M
(Magenta) and K (black) pixel signals are converted, and the laser on-time is determined for each pixel according to this signal and output to the image output unit 3.

The image output section 3 has an electrostatic latent image carrier such as a scanner 10 and a photosensitive drum 11, and the photosensitive drum 11
Around the area, a charger 12 for uniformly charging the photosensitive drum 11, a developing device 13 for developing the electrostatic latent image into a toner image, and a transfer device 15 for transferring the toner image onto a transfer material. A cleaning device 16 for collecting the untransferred residual toner is arranged,
1 is rotationally driven by an electric motor as shown by an arrow.

In the laser output unit 10a of the scanner 10, for example, a yellow image signal from the image input unit 2 is converted into an optical signal, and the photosensitive drum is passed through a polygon mirror 10b, an f / θ lens 10c and a reflection lens 10d. 1
A latent image corresponding to the original image is formed on the image 1. When this yellow latent image is transferred to the transfer material through development, the photoconductor drum 11 is charged by the charger 12 after the residual toner is removed by the cleaner 16, and the laser output unit 10a.
Outputs a cyan image signal. Hereinafter, latent images of magenta and black image signals are sequentially formed.

The developing device 13 is a yellow developing device 13.
Y, cyan developing device 13C, magenta developing device 13M,
It has a black developing device 13K, and each developing device is arranged around the rotation shaft. Then, for example, when forming a yellow toner image, the yellow developing device 13 is placed at the position shown in the drawing.
When developing with Y to form a cyan toner image, the developing device 13 is rotated and the cyan developing device 13C is disposed at a position in contact with the photoconductor drum 11. The magenta and black developments are similarly operated.

A transfer material carrier made of a dielectric sheet is stretched around the outer periphery of the transfer drum 15 constituting the transfer device, and the transfer drum 15 is connected to a dedicated electric motor or the photosensitive drum 11 by a gear. , Are driven to rotate as shown by arrows. Around the transfer drum 15, a transfer charger 17, a toner charge control static eliminator 19, a peeling claw 20, a static eliminator 21, a cleaner 22, a suction opposite roll 23, and a suction charger 25 are arranged. Then, the transfer material is conveyed from the transfer material supply unit 4 to the transfer drum 15 via the sub-conveying roll 32 and the main conveying roll 31 which constitute the transfer material conveying device 14, and the dielectric sheet is generated by corona discharge of the adsorption charger 25. Is adsorbed on. The transfer drum 15 is the photosensitive drum 1.
The toner image developed by yellow is transferred to the transfer material by the transfer charger 17,
Further, the rotation of the transfer drum 15 causes other colors to be sequentially transferred.

When the transfer drum 15 is rotated four times and the transfer of four colors is completed, the charge is removed by the separating discharger 19 provided inside and outside the transfer drum 15, and the transfer material is peeled off.
The toner image is separated by the conveyance belt 27 and sent to the fixing device 29, and the toner image is melted and fixed by the heat and pressure roller 30, and the copy cycle ends.

By the way, in the transfer material conveying device 14, in order to surely convey the transfer material to the transfer point at a predetermined timing, the on / off timings of the clutches for driving the conveying rolls 31 and 32 are determined, and the transfer material is transferred. The material is attracted to the dielectric sheet of the transfer drum 15. In this case, if the transfer material conveyance direction is deviated, the transfer material is not stably fed to the photoconductor suction surface, so that floating occurs between the photoconductor suction surface and the transfer material, resulting in a transfer failure. There is.

To solve this problem, Japanese Patent Publication No. 60-
In Japanese Patent Publication No. 27979, the sub-conveyance roll 32 is driven before the main conveyance roll 31 is driven to bend the transfer material to form a loop, and if the loop amount is normal, the main conveyance roll 31 is driven. This ensures that the tips of the transfer material are aligned and that the transfer material is discharged from another path if the loop amount is abnormal.

In addition to the above problems, Canon CLC
In the 200 Service Manual, the film for the overhead projector (hereinafter referred to as O
There is disclosed a technique in which an HP film) is conveyed and detected by an OHP detection sensor to control a transfer current value and a fixing condition.

[0011]

By the way, as shown in FIG. 6, the transfer drum 15 has a cylindrical member 15a on both sides.
Are connected by a connecting member 15b, and a transfer material carrying film 15c is fixed to the outer periphery of the cylindrical member 15a and both ends of the connecting member 15b. In the case of ordinary transfer paper, a plurality of transfer papers are transferred. In order to efficiently arrange the transfer paper on the outer periphery of the carrying film 15c, the leading end of the transfer paper is made to adsorb to the position of the transfer material carrying film 15c on the connecting member 15b.
If it is adsorbed on b, the OHP film has a strong elastic force and floats from the transfer material-carrying film 15c to cause transfer failure. Therefore, it is necessary to adsorb it on a position away from the connecting member 15b.

On the other hand, in the case of an OHP film, slipping is likely to occur and conveyance tends to be delayed, so that Japanese Patent Publication No. 60-279.
Even when trying to form an optimum loop as in Japanese Patent No. 79,
There is a problem in that the delay of conveyance must be judged as a jam, and the occurrence rate of jam increases.

The present invention solves the above-mentioned problems by changing the suction position of the transfer material and the jam determination time between the OHP film and the transfer material other than the OHP film and forming the optimum loop amount. An object of the present invention is to provide a transfer material conveyance control device capable of reducing the jam occurrence rate.

[0014]

In order to achieve the above-mentioned object, a transfer material conveying control device of the present invention uses a transfer material held on a transfer material holder to transfer a developed image on the electrostatic latent image carrier. In a multiple transfer type image forming apparatus including a transfer device for transferring and a transfer material transport device for transporting a transfer material toward the transfer material holder, the transfer material transport device is directed toward the transfer material holder. A main transport roll for transporting the transfer material, a sub-transport roll for transporting the transfer material toward the main transport roll to form a loop, a transfer material detection sensor provided in proximity to the main transport roll, A transfer position reference signal for the transfer material holding member, which includes a jam determination timer for determining a transfer material jam based on a detection signal from the transfer material detection sensor, and an OHP film detection sensor provided on the exit side of the sub-conveyance roll. Due to Controls the driving timing of the serial main transport roll and the auxiliary carrier roll, in the case of OHP film is characterized by increasing the set value of the jam determination timer than otherwise of the transfer material.

Further, in the case of an OHP film, the drive timing of the main carrying roll may be delayed as compared with the case of other transfer materials.

[0016]

According to the present invention, the optimum amount of loop is formed after the transfer material detecting sensor for driving the sub-conveying roller from the transfer drum rotation position reference signal to detect that the transfer material has reached the position of the main conveying roller is turned on. After that, the sub-conveyance roll is turned off, and then the main conveyance roll is turned on. Then, in the case of an OHP film, as compared with a transfer material other than the OHP film, the set value of the jam determination timer is increased to relieve the delayed OHP film to form an optimum loop amount, and the main conveyance is performed. The on-timing of the roll driving clutch is increased to delay the transport of the OHP film, and the suction position of the OHP film on the transfer drum is changed to a predetermined position.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a transfer material conveyance control device of the present invention. The present invention is preferably applied to the color electrophotographic copying machine described in FIG. 6, but can also be applied to other multiple transfer type image forming apparatuses.

In FIG. 1, a transfer drum 15 that rotates in synchronism with the photosensitive drum 11 that constitutes the electrostatic latent image carrier is disposed in proximity to the photosensitive drum 11, and inside the transfer drum 15, A transfer charger 17 is provided so that the developed image on the photosensitive drum 11 is transferred to the transfer material S held on the transfer drum 15. In addition, in the transfer drum 15,
A transfer drum rotation position detection sensor 34 that detects the rotation position of the transfer drum 15 is provided.

The transfer material conveying device 14 conveys the transfer material S between the transfer drum 15 and the suction opposing roll 23, and the transfer material S toward the main conveyance roll 31. Sub-transport roll 32 and main transport roll 3
Transfer material detection sensor 35 provided close to the inlet side of No. 1
And the gap 3 is provided above the transfer material transport guide 36.
7 is formed, the leading end of the transfer material S is brought into contact with the main transport roll 31, and when the sub-transport roll 32 is driven, the transfer material S bends and the loop L can be formed. Further, an OHP film detection sensor 38 is provided near the exit side of the sub transport roll 32. The sub-transport roll 32 includes
A transfer material automatic supply transport path 33a and a manual feed transport path 33b are provided, and the OHP film is fed from the manual feed transport path 33b.

FIG. 2 is a block diagram of the control system according to the present invention. The signals from the transfer drum rotational position detection sensor 34, the transfer material detection sensor 35 and the OHP film detection sensor 38 are input to the arithmetic and control unit 40, which will be described later. Depending on the control method, the on / off timing of the main transport roll drive clutch 31a and the sub transport roll drive clutch 32a is controlled. Further, based on the signal from the OHP film detection sensor 38, the arithmetic and control unit 40 performs processing for changing the set value of the jam determination timer 41. The jam determination timer 41 compares the set value with the detection signal of the transfer material detection sensor 35 to determine a jam and displays the jam outside the apparatus.

FIG. 3 is a timing chart of control in the present invention, showing a case of a normal transfer material. Sub-carrier roll driving clutch 32a is a transfer drum rotational position turned by T ₁ from the reference signal from the detection sensor 34, transfer the transfer material material is detected that comes to the position of the main conveyor rolls 31 detection sensor 35 is T ₂ , The sub-conveyance roll clutch 32a is turned off after a time T _L for forming the optimum loop amount, and then the main conveyance roll clutch 31a is turned on by T ₃
Control to turn it on. The auxiliary transport roll clutch 32a is turned on again to assist the transport of the main transport roll 31. In the figure, T ₂
Indicates the set value of the jam judgment timer 40, and when the transfer material detection sensor exceeds T ₂ , it is judged as a jam and the apparatus is stopped and displayed externally.

FIG. 4 shows a control flow in the present invention,
First, in step S1, the OHP film detection sensor 38
If it is not an OHP film, the setting value of the jam determination timer 41 is set to the normal T ₂ in step S2, and it is determined in step S2.
At 3, the on-timing set value of the main transport roll driving clutch 31a is set to the normal T ₃ . OHP in step S1
If it is determined that the film is a film, in step S4, the set value of the jam determination timer 41 is increased to T ₂ + α to rescue the delayed OHP film, and in step S5, the on-timing of the main transport roll drive clutch 31a is determined. The setting value of is increased to T ₃ + β to delay the conveyance of the OHP film, and the suction position of the OHP film on the transfer drum 15 is changed to a predetermined position.

FIG. 5 shows the difference in the transport method between the OHP film and the other transfer material. In the figure, A shows the on-timing of the main transport roll driving clutch 31a in the case of a transfer material other than the OHP film, and B shows the main transport roll driving clutch 31 in the case of the OHP film.
In the case of an OHP film, the on-timing of a is shown. In the case of the OHP film, the on-timing is delayed and the set value of the jam determination timer 41 is lengthened to form the optimum loop amount.

[0024]

As is apparent from the above description, according to the present invention, in the multiple transfer type image forming apparatus, the transfer material conveying device conveys the transfer material toward the transfer material holder. A roll, a sub-conveying roll for conveying the transfer material toward the main conveying roll to form a loop, a transfer material detecting sensor provided in the vicinity of the main conveying roll, and an exit side of the sub-conveying roll. An OHP film detection sensor for controlling the drive timing of the main transport roll by the rotational position reference signal of the transfer material holder, and in the case of an OHP film, the drive timing as compared with the case of other transfer materials. Delay and increase the set value of the jam judgment timer, the transfer material suction position and the jam judgment are detected between the OHP film and the other transfer material. Changed the time, along with the formation of optimal loop amount respectively, it is possible to reduce the jamming occurrence rate.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a transfer material conveyance control device of the present invention.

FIG. 2 is a block diagram of a control system according to the present invention.

FIG. 3 is a diagram showing a timing chart of control in the present invention.

FIG. 4 is a diagram showing a flow of control processing in the present invention.

FIG. 5 is a diagram showing a difference in a transport method between an OHP film and other transfer materials.

FIG. 6 is a perspective view of a transfer drum for explaining the problems of the present invention.

FIG. 7 is a configuration diagram showing an example of an image forming apparatus to which the present invention is applied.

[Explanation of symbols]

11 ... Photosensitive drum (electrostatic latent image carrier), 15 ... Transfer drum (transfer material holder) L ... Loop, 31 ... Main transport roll, 31a ... Main transport roll drive clutch 32 ... Sub transport roll, 32a ... Sub-conveyance roll drive clutch, S ... Transfer material 34 ... Transfer material rotational position sensor, 35 ... Transfer material detection sensor 38 ... OHP film detection sensor, 40 ... Arithmetic control device 41 ... Jam determination timer

Claims (2)

[Claims] 1. A transfer device for transferring a developed image on an electrostatic latent image carrier to a transfer material held on a transfer material holder, and a transfer material carrier for transferring the transfer material toward the transfer material holder. In the image forming apparatus of the multiple transfer system including an apparatus, the transfer material transporting device transports the transfer material toward the transfer material holder, and transports the transfer material toward the main transport roll. A sub-conveying roll for forming a loop, a transfer material detection sensor provided in proximity to the main conveying roll,
A jam determination timer for determining a jam of the transfer material based on the detection signal of the transfer material detection sensor, and an OHP film detection sensor provided on the exit side of the sub-conveyance roll are provided, and the rotational position reference of the transfer material holder is provided. The transfer timing is controlled by a signal, and the set value of the jam determination timer is set to be larger in the case of the OHP film than in the case of other transfer materials in the case of the OHP film. Material transfer control device. 2. The transfer material transport control device according to claim 1, wherein the drive timing of the main transport roll is delayed in the case of an OHP film as compared with the case of other transfer materials.