JPS63177183A - Transfer device - Google Patents

Abstract

PURPOSE:To prevent picture quality from being deteriorated at the time of the superposition transfer of toner images of many colors by providing a detecting means which detects the movement position of a transfer material support body and abutting the transfer image nonholding area of the transfer material support body against an image carrier according to a signal obtained when the transfer material support body stops. CONSTITUTION:Stopping operation is performed synchronously when a light shielding member 17 provided to the metallic frame 7 of a transfer drum 2 crosses a light shield sensor 8. Then the movement position of the transfer drum 2 is detected by the light shield sensor 8. The transfer image nonholding area of the transfer drum 2 is abutted against the image carrier according to the signal obtained from the light shield sensor 8 when the transfer drum 2 stops, thereby preventing heat on an image carrier from being conducted directly to the support member made of a high polymer material. Therefore, the picture quality does not deteriorate even at the time of the multiple transfer of toner images of many colors. Consequently, a stable transfer image is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Usability Yf of #Also I-) The present invention provides an image forming apparatus, such as an electrophotographic color copying machine, which develops and transfers images of multiple colors in a superimposed manner. The present invention relates to a transfer device that transfers a toner image formed by a carrier 7 onto a transfer material 1-.

(Prior art) ・Competitively, in this type of copying apparatus, as shown in FIG. In order to keep the charged state of the surface of the carrier 21 constant, a drum heater 26 is provided inside the image carrier 21, and the surface of the image carrier 21 is heated to 35°C to 45°C.
I try to keep it that way.

In addition, in order to transfer the toner image formed by the image carrier 21 onto a transfer material, a dielectric support member 23 such as a polymer sheet is attached to the transfer material support 22! - to ensure that the transfer material is supported on the transfer material support 22.

Furthermore, in this type of copying apparatus, a green plate is provided in the transfer image non-holding area 25 so that the primary copying process can be started in a minimum of 115 minutes when the transfer material support 22 stops. , the image carrier 21 is positioned slightly behind the parschy 24.
and the transfer material support 22 are brought into contact with each other.

(Problems to be Solved by the Invention) However, in the conventional example L, the supporting member 23 made of a polymeric material is in direct contact with the heated image carrier 21.
This heat deforms the support member 23 and causes unevenness on its surface, resulting in uneven transfer during image transfer.

Even if this unevenness is very small compared to the designed diameter of the transfer material support 22, which is about 0.5 square centimeters, it will result in poor transfer when a multicolor toner image is transferred in a folded manner, resulting in poor image quality. The problem was that it deteriorated and was no longer usable.

Therefore, the present invention has been made to solve the problems of the above-mentioned conventional methods, and its purpose is to avoid deterioration of image quality even when transferring multicolor toner images in a flat manner.
It is an object of the present invention to provide a transfer device that can always obtain stable transferred images.

(Step F to solve the problem) In order to solve the problem of the conventional example described in 1-1, in the present invention, a transfer material support, in which the transfer material is supported by a support member, is brought into contact with an image carrier. A transfer device for transferring the toner image on the image carrier l2 onto the transfer material by causing the transfer material support to stop; In response to the signal obtained from the detecting means (1), the transfer image non-holding area of the transfer material support is brought into contact with the placement carrier.

(Function) In the present invention having the structure described in 1-1, when the transfer material support is stopped 1, the signal obtained from the detection means is detected ((; the transferred image on the transfer material support is detected) The holding area and the L-arranged supporting member are brought into contact with each other to prevent the heat of the image bearing member from being directly transmitted to the supporting member.

(Example) The present invention will be explained below based on illustrated embodiments.

FIG. 1 shows a schematic configuration diagram of an image forming apparatus according to a first embodiment of the present invention. In FIG. 6, l is a photosensitive drum as an image carrier having a diameter of 80 mm and made of 0PC (organic semiconductor); A heater 6 is provided almost at the center of the interior, and the surface of the photoreceptor drum l is heated by air convection.
It is kept at ±2℃. Around this photoreceptor drum l, there is a primary charger 13 for uniformly charging the surface of the photoreceptor drum l;
A developing device 10 that develops M (magenta), C (cyan), and Y (yellow) in this order, and a cleaner 14 that cleans residual toner are provided. Reference numeral 2 denotes a transfer drum as a transfer material support body with a diameter of 160 cm, which is composed of a metal frame 7, a gripper stay 4 provided in a transfer image non-holding area 5, and a transfer sheet 3 as a support member.
A PVDF (polyvinylidene fluoride) sheet with a thickness of about 150 μm is used as the gripper stay 4, and the gripper stay 4 is made of metal such as aluminum and has a circumference of 60 mm.

9 is a paper feed guide for feeding the transfer paper to the transfer drum 2E;
Reference numeral 17 indicates a light-shielding sensor serving as a detection stage for detecting the moving position of the transfer drum 2, and 17 indicates a light-shielding member that blocks light emitted from the light-shielding sensor.

Reference numeral 11 is inside the transfer drum 3, and the gripper stay 4
A transfer charger provided at L: 12 is a static eliminator (17) for removing electricity from the transfer sheet 3 and the transfer paper after the image transfer process has been completed, and 16 is a separation claw for separating the transfer paper from the transfer sheet 3.

In this embodiment having the above configuration, first.

Simultaneously with the start of the copying process, the photosensitive drum 1 rotates in the direction of the arrow. A document image is formed as a latent image on the photosensitive drum 1 by the primary charger 13, and developed in the order of M (magenta), C (cyan), and Y (yellow) by the developing device IO.

Further, the transfer material passes through the paper feed guide 9, is gripped by the gripper stay 4 provided in the transfer image non-holding area 5 of the transfer drum 2, and is rotated together with the transfer drum 2 in the direction of the arrow in the figure.

The toner image formed on the photoreceptor drum l is sequentially transferred onto the transfer material by the transfer charger 11, and when the three transfer steps are completed, the transfer sheet 3 and the transfer material are neutralized by the charge-eliminating charger 12, and the separation claw 16, the transfer material is peeled off from the transfer drum 2.

When the copying step L is completed, the gripper stay bar provided in the transfer image non-holding area 5 is stopped at a position where it comes into contact with the photosensitive drum 1. Stop + h operation is transfer drum 2
The light shielding member 17 provided on the metal frame 7 is the light shielding sensor 8.
Do this in sync with what is crossed.

Since the gripper stay 4 is made of metal such as aluminum, it does not deform at the surface temperature of the photoreceptor drum 1, which is about 37±2° C., and can also be used for a long time. This embodiment, which has the structure and function described in , is equipped with a light-shielding sensor 8 that detects the moving position of the transfer drum 2, and the transfer drum is stopped based on the signal obtained from the light-shielding sensor 8 at 1 o'clock when the transfer drum 2 is stopped. The transfer image non-retaining area of No. 2 is brought into contact with the image support member to prevent the heat of the image support member from being directly transmitted to the supporting member made of a polymeric material.
Even when multicolor toner images are superimposed and transferred, a stable transferred image can always be obtained without deterioration of image quality.

In addition, the transfer drum 2 is provided with a gripper stay 4 to securely grip the transfer paper. Even when performing the superimposed transfer as described above, the transferred image does not shift, and a stable transferred image can always be obtained.

Furthermore, the unreleased 1N+ is also applied to the transfer device according to the second embodiment in which a belt is used as a transfer material support as shown in FIG. It is a belt, and a PVDF sheet is used here.

Further, as in the first embodiment, a transfer image non-holding area 105 is provided in a part thereof. Since it is difficult to convert a sheet made of a polymeric material as a support member into a complete endless belt, a seam 11 is formed by pasting or the like, but normally this seam is placed in the transfer image non-holding area 1051-.

The fed transfer material is wound onto the transfer bell (103) by the adsorption charger 118, and 118a is the charger 1
This is a conductive rotating roller provided opposite to 1B.

In this embodiment as well, after the transfer paper is fed, the first copying process proceeds in the same manner as in the first embodiment, and at the end of the copying process, the transfer image non-holding area 105 is at a position facing the photoreceptor drum l. I was forced to stop.

Incidentally, in Figure 3, the photosensitive drum l has a diameter of 80 mm.
, the transfer belt 113 has a circumference of 500 layers l, and the transfer image non-holding area 105 has a circumference of 60+u+. The other configurations and operations are the same as those of the first embodiment, so their explanation will be omitted.

(Effects of the Invention) The present invention has the following configuration and operation, and since the heat of the image carrier is prevented from being directly transmitted to the support member made of a polymeric material, multicolor toner images can be superimposed. There is an effect that a stable transferred image can always be obtained without deterioration of image quality during transfer.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a transfer device according to a first embodiment of the present invention, FIG. 2 is a perspective view of a transfer drum in the same embodiment, and FIG. 3 is a transfer device according to a second embodiment of the present invention. FIG. 4 is an explanatory diagram showing an example of a conventional transfer device. Explanation of symbols 1... Photosensitive drum (image carrier) 2... Transfer drum (transfer material support) 3... Transfer sheet (supporting member) 5... Transfer image non-holding area 8. ... Light-blocking sensor (detection means) +1=4+ Figure 1 Figure 2 Figure 4

Claims (2)

[Claims] (1) In a transfer device that transfers a toner image on an image carrier to the transfer material by bringing the transfer material support in which the transfer material is supported by a support member into contact with the image carrier, the transfer material support a detection means for detecting a moving position of the transfer material support, and a transfer image non-holding area of the transfer material support is brought into contact with the image carrier based on a signal obtained from the detection means when the transfer material support is stopped. A transfer device characterized by: (2) The transfer device according to claim 1, wherein the transfer material support is provided with transfer material gripping means for gripping the transfer material.