JPS6111771A - Image recorder - Google Patents

Abstract

PURPOSE:To reduce the size of an image recorder by providing image exposing means which expose an image to a photoconductive layer from the inside of a photosensitive drum, erasing the electric charge according to the image, make the electrostatic sticking strength of a toner smaller than the transfer force of the toner and transferring the toner to a recording medium. CONSTITUTION:The photoconductive layer 14 of the photosensitive drum 11 is made conductive in the part irradiated with light and grounds and discharges the charge held on the outside peripheral surface through a transparent electrode 13. The phenomenon is generated by image exposure and the charge on the outside peripheral surface of the layer 14 is erased by the exposed image. The sticking strength of the toner layer 18 to the drum 11 decreases in the part of the layer 18 on the outside peripheral surface of the drum 11 where the charge is erased. The decrease in the sticking strength of the layer 18 to the drum 11 corresponds to the exposed image when the charge is erased by the image exposure. The toner layer 18 is transferred to recording paper 7 adcording to the exposed image when the decreased sticking strength is smaller than the transfer force by the charge for transfer. The need for a cleaning part for removing the toner remaining on the photosensitive drum is thus eliminated and the size of the device is made smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an image recording device, and in particular to a method for electrostatically attaching toner to a photoconductive drum by imagewise exposing the photoconductive drum and controlling the conductivity. The present invention relates to an image recording device that utilizes changes in adhesion force.

[Background of the invention]

Image recording devices that use electrophotographic technology or electrostatic recording technology generally form a charge latent image according to the image on the surface of a recording medium, and then attach toner to this charge latent image to obtain a visible (toner) image. It is. When the recording medium is used repeatedly, the toner image is transferred and fixed onto recording paper, which is a secondary recording medium.

FIG. 4 shows a conventional image recording device using electrophotographic technology. -The photosensitive drum 1 used as a next recording medium is:
It has an outer circumferential surface for image recording, with a photoconductive layer provided on the surface of a substrate such as aluminum. This photosensitive drum 1 is rotated at a constant speed in the direction of arrow (A) by a driving means (not shown), and an electrophotographic process is performed on its outer peripheral surface. First, it is uniformly charged by the charger 2, exposed to image by the image exposure means 3 to form an electrostatic latent image, and this electrostatic latent image is developed by the developing section 4 to become the toner image 5. .

The toner image 5 is transferred by an electrostatic transfer device 6 to a recording paper 7, which is a secondary recording medium, which moves in the direction of the arrow (b), and then fixed. Outside the arbitrary light drum after the toner image 5 has been transferred,
Since residual toner and electrostatic latent images remain on the peripheral surface,
A static eliminating section 8 eliminates static electricity, a cleaning section 9 removes residual toner, and a static eliminating lamp 10 further eliminates static electricity.

Moreover, since all of these elements were arranged outside the photosensitive drum 1, it had the disadvantage of being large in size.

[Purpose of the invention]

An object of the present invention is to reduce the number of elements for carrying out the image recording process and to obtain a compact image recording apparatus by considering the arrangement of the elements.

[Summary of the invention]

In order to achieve this object, the present invention provides a photosensitive drum in which a transparent electrode layer and a photoconductive layer are provided on a transparent support, and a toner adhering device that uniformly adheres toner to the outer peripheral surface of the photosensitive drum using electrostatic force. a transfer means for bringing a recording medium into contact with a photosensitive drum to which toner is uniformly adhered and applying a toner transfer force from the back side of the recording medium; Particularly, it is characterized by being provided with an image exposure means which makes the electrostatic adhesion force of the toner smaller than the toner transfer force and transfers the toner to the recording medium by performing image exposure and causing the charge to disappear according to the image. Eliminating the need for a cleaning section to remove toner remaining on the outer circumferential surface of the photosensitive drum after toner transfer, the number of elements is reduced, and space is effectively utilized by locating the image exposure means inside the photosensitive drum, thereby creating a compact image recording device. [Embodiment of the Invention] An embodiment of the present invention will be described with reference to FIGS. 1 to 3.

In FIG. 1, the photosensitive drum 11 has a transparent electrode 13 made of tin oxide or indium oxide on the outer peripheral surface of a transparent support 12 made of glass or plastic, as detailed in FIG.
The transparent electrode 13 is grounded, and a photoconductive layer 14 made of selenium, oPC, etc. is formed on the surface thereof. The photosensitive drum 11 is rotated at a constant speed in the direction of arrow (A) by a driving means (not shown), and first, the outer circumferential surface of the photosensitive drum 11 is uniformly charged by the charger 2. The toner 16 stored in the toner container 15 is transferred to the photosensitive drum 11 by electrostatic force.
The toner adheres to the toner, and the amount of toner adhering is regulated by the blade 17 to form a uniform toner layer 18. The recording paper 7 moving in the direction of the arrow (B) is pressed against the outer peripheral surface of the photosensitive drum 11 having uniform toner 711B, and an electrostatic transfer charge is applied from the back surface thereof by the electrostatic transfer device 6. Photosensitive drum 1
As it is, the electrostatic adhesion force of the toner layer 18 to the toner layer 18 is larger than the electrostatic transfer force due to the electrostatic transfer charge, so that toner transfer to the recording paper 7 does not occur. The image exposure means 3 is arranged in the internal space of the photosensitive drum 11,
In the area where this electrostatic transfer force acts, the photosensitive drum 1
The photoconductive layer 4 of 1 is imagewise exposed from the inside. As shown in FIG. 3, this image exposure means 3 itself has a structure including a light-emitting gionide array chip 19 and a focusing rod lens array 20, and a photoconductive layer I4 has a light spot corresponding to the light emission of each light-emitting diode. The exposure scanning line 21 is formed.

Each light emitting diode is controlled to blink in accordance with an image signal as the photosensitive drum 11 rotates, thereby realizing matrix image exposure of light spots. The portion of the photoconductive layer 14 of the photosensitive drum 11 that is irradiated (exposed) with light becomes conductive, and the charges held on its outer peripheral surface are discharged to the ground via the transparent electrode 13. Such a phenomenon occurs due to the imagewise exposure, and the charge on the outer peripheral surface of the photoconductive layer 14 disappears according to the exposed image. Since the toner layer 18 on the outer circumferential surface of the photosensitive drum 11 is attached to the outer circumferential surface by electrostatic force due to the electric charge on the outer circumferential surface, the toner layer 18 on the outer circumferential surface of the photosensitive drum 11 is attached to the outer circumferential surface in the portion where the electric charge has disappeared.
The adhesive force of B becomes smaller. Therefore, when the charge is eliminated by image exposure as described above, the reduction in the adhesion force of the toner layer 18 to the photosensitive drum 11 corresponds to the exposed image, and the reduced adhesion force is caused by the transfer force due to the transfer charge. If the size is smaller than , the toner layer 18 is transferred to the recording paper 7 according to the exposed image.

Therefore, the relationship between the electrostatic adhesion force of the toner layer 18 that is uniformly charged and the electrostatic transfer force that is reduced by image exposure to the photosensitive drum 1 is expressed as follows: A toner image 22 is obtained on the recording paper 7 by setting so that the toner image 22 is clearly generated. Since mechanical forces due to viscosity and the like are also added to these adhesion forces and transfer forces, these mechanical forces are also taken into consideration.

The toner image 22 transferred to the recording paper 7 in this manner is fixed and used.

After the toner transfer has been performed, the photosensitive drum 11 is neutralized from the inside by a neutralizing lamp 10, and then enters the next image recording process again.

The image exposure means 3 described above may be modified to a combination of a fluorescent lamp and a liquid crystal shutter or other exposure methods.

Furthermore, if the toner 16 contains a magnetic material, the transfer device 6 can be transformed into a magnetic transfer device.

〔Effect of the invention〕

As described above, the present invention eliminates the need for a cleaning section for removing toner remaining on the photosensitive drum, and also disposes the image exposure means inside the photosensitive drum, which has the effect of providing a compact image recording device. .

[Brief explanation of drawings]

Figures 1 to 3 show one embodiment of the present invention.
The figure is an overall side view, the second figure is a cross-sectional view of the photosensitive drum, and the third figure is a side view of the entire photosensitive drum.
The figure is a perspective view of an image exposure means, and FIG. 4 is a side view of a conventional image recording apparatus. 3... Image exposure means, 6... Electrostatic transfer device, 11...
- Photosensitive drum, 12... Transparent support, 13... Transparent electrode, 14... Photoconductive layer, 15... Toner container, 1
6... Toner, 18... Tona layer. 1st rlA 3m 211A 4th r1! J

Claims (1)

[Claims] 1. Toner is uniformly applied to the outer peripheral surface of a photosensitive drum having a transparent electrode layer and a photoconductive layer provided on a transparent support, and this toner is transferred to the surface of a recording medium according to the image to be recorded to record the image. In an image recording apparatus, a toner adhering device uniformly adheres toner to the outer peripheral surface of the photosensitive drum using electrostatic force, and a toner adhering device contacts the photosensitive drum to which the toner is evenly adhered, and applies toner from the back side of the recording medium. A transfer means for applying a transfer force, and an imagewise exposure of the photoconductive layer from the inside of the photosensitive drum in the toner transfer force action area to cause the charge to disappear according to the image, thereby reducing the electrostatic adhesion force of the toner before toner transfer. 1. An image recording apparatus comprising: an image exposure means that transfers the toner onto a recording medium by applying a force smaller than that of the toner.