JPS6173976A - Transfer device - Google Patents

Abstract

PURPOSE:To improve transfer properties when an image is transferred to the same transfer material repeatedly by providing a gripping means which grips the front end edge of the transfer material, support means which moves the gripping means, and electrostatic attracting means for end edges of the transfer material except the front end edge. CONSTITUTION:A gripper 42 is open when a gripper cam 43 operates and a paper feed guide 71 approaches a transfer device 4 to guide transfer paper P to the grippe 42. The transfer paper P whose front end is gripped by the gripper 42 while wound around the transfer device 4 has both its edge parts attracted to an electrostatic attracting member and is held stably on the transfer device 4. The held transfer paper P contacts a photosensitive drum 1 as the transfer device 4 is driven and a visual image on the photosensitive drum 1 is transferred by a corona electrostatic charger 41. When the transfer is completed, the gripper 42 is opened by a separation cam 41 and the transfer paper P is sent to a fixing device 8 by a separation guide 45. Thus, the transfer material is held stably and securely at a fixed position, so the transfer properties are improved even when transfer to the same transfer material is repeated.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a transfer device that obtains a transferred image on the transfer material by placing a transfer material facing an image carrier carrying a developed image and applying corona discharge from the back side. In particular, the present invention relates to a transfer device suitable for transferring multiple developed images onto the same transfer material to obtain a color image or the like.

[Background of the invention]

For example, after forming an electrostatic latent image on an electrophotographic photoreceptor (photosensitive drum) having a photoconductor layer, this is developed with toner, and the formed toner image is transferred onto a transfer material such as transfer paper. In conventional transfer devices, the above-mentioned transfer is generally performed by either a roller transfer device or a corona transfer device. The former type of roller transfer device makes it relatively easy to regulate the pressure contact position of the transfer paper on the photoconductor surface by providing a part of the roller with a claw or the like that locks the edge of the transfer paper. Multiple transfer is easy, and therefore it is convenient when used in a color electrophotographic device that sequentially forms toner images of different colors on a photoreceptor and transfers them sequentially onto the same transfer paper, but on the other hand, The phenomenon of so-called hollowing, in which the central part of the linear toner image is not transferred, is likely to occur, and when performing multiple transfers, additional transfer efficiency control means such as sequentially increasing the voltage applied to the rollers may be required. In addition, when there is no transfer paper or in areas where there is no transfer paper, the roller comes into direct pressure contact with the photoconductor, which may cause wear and pinball on the photoconductor, causing mechanical damage to the photoconductor. It is easy to be damaged, and toner may adhere to the row 2, which may stain the back side of transfer paper of different sizes.

Such inconveniences of the roller transfer device can be solved by the above-mentioned corona transfer device, but in this corona transfer device, for example, when performing multiple transfer, it is necessary to accurately align the contact surface position of the transfer paper with the photoreceptor. In some cases, special measures are required to support the transfer paper. In addition, this corona transfer device may be a device that grips the leading edge of the transfer paper and controls the movement range of the transfer paper to enable contact alignment with the photoreceptor. There are problems such as a 7-lead gap at the rear end of the paper, inability to accurately align the paper during multiple transfer, and damage to one unfixed image. Therefore, a method has been considered in which a thin dielectric material is used as a support and a corona discharge is applied from the back side of the support to perform the transfer, and the transfer paper is electrostatically adsorbed and supported on the dielectric support. In this method, the dielectric material is charged up each time the transfer is repeated, reducing the transfer efficiency, and furthermore, a device for controlling the dielectric material is required.

[Purpose of the invention]

The present invention has been made to solve these problems, and its first purpose is to provide a transfer device that can perform good and clear transfer without causing registration misalignment or transfer defects. be. The second object of the present invention is to
It is an object of the present invention to provide a simple transfer device that does not require a gluing means such as a dielectric material. A third object of the present invention is to provide a transfer device suitable for transfer paper that provides margins at the edges of the transfer paper for color proofing (color proofing) and the like.

[Embodiments of the invention]

The present invention will be explained in detail below based on embodiments shown in the drawings.

(4) shows a color radar printer, and the interior of this color radar printer is sensitive to V-DEN light (I). It has a photosensitive drum 1 and a corona charger 2 for charging the photosensitive drum 1, and a color developing device 3 is brought into contact with the photosensitive drum 1. This color developing device 3 includes, for example, developing units 31, 32, 33, and 34 for cyan, magenta, yellow, plastic, and shoes.
These developing devices 31, 32, 33, and 34 are provided so as to be able to selectively come into contact with the photosensitive drum 1.

4 is a transfer device installed opposite to the photosensitive drum 1, and this transfer device 4 includes a corona charger 41 and a glyph i4 of the transfer paper.
42 N Gripper cam 43, separation cam 44, separation id 45, current frame 47.4 on both side edges of transfer device 4
It has an electrostatic adsorption member 46 supported via 7'. The structure of the gripper 42 is disclosed in, for example, Japanese Patent Application Laid-open No. 5
A mechanism known in Japanese Patent No. 0-99334 can be employed. The electrostatic attraction member 46 includes a dielectric material 46a, a positive electrode 46b, a negative electrode 46c, and a resistor 46d, and 49 is an electric wire for supplying current to the electrostatic attraction member 46 via a sliding electrode (not shown). It is. 48
indicates grits support. 5 is a cleaning device for the photosensitive drum 1; 6 is a radar scanner optical device; the radar light from this optical device can be irradiated onto the photosensitive drum 1 through a polygon mirror 61, a lens 62, and a mirror 63; It has become. 7 is a paper feeding device, 71 is its paper feeding guide, and 8 is a fixing device.

The structure of this embodiment has been described above. Next, its operation will be described. First, the circumferential surface of the photosensitive drum 1 is uniformly charged by the operation of the corona charger 2. Next, a radar beam modulated by a recording information signal from a semiconductor radar (not shown) and a polygon mirror 61, a lens 62, a mirror 63
An optical device 6 consisting of a photosensitive drum 1 is horizontally scanned with shirede light (I) onto the photosensitive drum 1 to form an electrostatic latent image. Next, on the photosensitive drum 1 on which the electrostatic latent image is formed, one of the color developing devices 31, 32, 33, and 34 of the developing device 3 is designated to be controlled by the recording information signal on which the latent image is formed. Developing devices of a designated color come into contact with each other to develop the image.

Next, the visible image is transferred to the transfer paper by the transfer device 4, which holds the transfer paper e) fed by the paper feeding device 7, contacts the photosensitive drum 1 in a driven relationship, and applies corona discharge from the back side of the transfer paper ψ). feces). To obtain a multicolor print, the transfer paper ψ) is repeatedly brought into contact with the photosensitive drum two to four times to produce multiple or all images of each color such as cyan, magenta, yellow, and black. The images are superimposed and transferred.

Next, the transfer paper ψ) holding the transferred visual image is sent to the fixing device 8, where it is heated and melted and fixed to the transfer paper to obtain a color print. - The photosensitive drum 1 is cleaned by the cleaning device 5 and prepared for reuse.

Next, the operation of the transfer device 4, which is the gist of the present invention, will be explained.

The transfer paper (P) fed by the paper feeding device 7 is gripped by the clipper 42 of the transfer device 4. That is, the gripper 42 is open when the gripper cam 43 operates, and at this time, the paper feed guide 71 approaches the transfer device 14 and guides the transfer paper e) to the grit 442, so that the transfer paper e) is transported by the gripper 42. be grasped.

In this way, the transfer paper (P) whose leading end is gripped by the grip tool 442 is drawn into the transfer device 4 as the transfer device 4 rotates, and the edges of both sides of the transfer paper (P) are electrostatically attracted. The transfer paper e) is electrostatically attracted by the electrostatic force of the member 46, and is stably held on the transfer device 4. The transfer paper (P) held by the transfer device 4 comes into contact with the photosensitive drum 1 as the transfer device 4 is driven, and the corona charger 4
1, a visible image on the photosensitive drum 1 is transferred in the same manner as described above. When the transfer to the transfer paper is completed, the separation cam 44 opens the grid Y/# 42, and the transfer paper (J?) is further separated by the ID 45 and sent to the fixing device 8. According to the embodiment, the leading edge of the transfer paper () supplied to the transfer device 4 is gripped by the grit 42, and both side edges of the transfer paper (ψ) are gripped by the electrostatic adsorption member 4.
Since the transfer paper is electrostatically attracted and held on the transfer device 4 by the action of 6, it is possible to stably hold the transfer paper on the transfer device 4 without shifting the position, and therefore even during multiple transfers such as color copying. This has the effect of making it possible to transfer the resist well.

FIG. 4 shows another embodiment of the transfer device in which the rear end of the transfer paper ψ) can also be electrostatically attracted.
In this embodiment, the gripper support 48 is provided with transfer paper (I)
An electrostatic adsorption member 46' is provided for electrostatic adsorption of the rear end portion. Therefore, according to this embodiment, the transfer paper?
) can be held, which has the effect of further increasing the holding power of the transfer paper ().

Further, the frames 47 and 47' in the above embodiments may be formed into a belt shape such as a timing belt, and an electrostatic attraction portion may be provided on this belt.

[Summary of the invention]

As described above, the present invention provides a transfer device that transfers a developed image carried on the surface of an image carrier onto a transfer material by applying a corona discharge from the back side of the transfer material, in which the leading edge of the transfer material is gripped. It has a gripping means, a support means for supporting the gripping means so as to move along a predetermined movement path, and an electrostatic adsorption member for electrostatically holding at least one end edge of the other four pieces of the transfer material other than the leading edge thereof. This is a transfer device characterized by the following.

〔Effect of the invention〕

Therefore, according to this transfer device, it is possible to hold the transfer material in a fixed position stably and reliably, so even when performing edge-reverse transfer on the same transfer material, such as for color printing, transfer performance and resolution can be improved. This has the effect of allowing good transfer.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing an embodiment of a copying machine equipped with the transfer device of the present invention, FIG. 2 is a perspective view showing an embodiment of the B transfer device, and FIG. FIG. 4 is a perspective view showing another embodiment of the present invention. 1: Photosensitive drum, 2: Corona charger, 3: Developing device, 4: Transfer device, 41: Corona charger,
42: Gripper, 43 Nigri, Nonakam,
44: Separation cam, 45: Separation guide, 46: Electrostatic adsorption member, 47.47': Frame, 48: Glyph/4 support, 49: il! line, 5: cleaner, 6: radar scanner optical device, 7: paper feeding device.

Claims (1)

[Claims] In a transfer device that transfers a developed image carried on the surface of an image carrier onto the transfer material by applying a corona discharge from the back side of the transfer material, the transfer device includes a gripping means for grasping a leading edge of the transfer material; A support means for supporting the gripping means so as to move it along a predetermined movement path, and an electrostatic attraction member for electrostatically holding at least one edge of the transfer material other than the leading edge thereof. A transcription device that uses