KR20040000227A - Image forming apparatus having pre-transfer lamp - Google Patents

Abstract

PURPOSE: An image forming apparatus with a pre-transfer lamp is provided to reduce the material cost by reducing the number of parts such as an auxiliary printed circuit board, a connection line, and a connector. CONSTITUTION: A developer develops an electrostatic latent image formed on a photo conductor drum(11) by an exposure(13). A transfer roller(15) transfers a picture on the photo conductor drum to the paper. A plurality of pre-transfer lamps(130) which are light emitting diodes apply predetermined light to the photo conductor drum before transfer to make a transfer process easy. The pre-transfer lamps are directly connected to a main printed circuit board(140), and include a light induction(132) arranged between the pre-transfer lamps with the photo conductor drum for guiding light of the pre-transfer lamps to a surface of the photo conductor drum.

Description

Image forming apparatus having pre-transfer lamp

The present invention relates to an image forming apparatus having a transfer auxiliary lamp, and more particularly, to an image forming apparatus in which a pre-transfer lamp is directly connected to a main printed circuit board.

The image forming apparatus includes an image forming portion for forming a toner image, which is transferred by a predetermined transfer apparatus onto a recording sheet fed from a paper cassette of the main body of the apparatus. The image forming unit includes a photosensitive drum, and a toner image formed on the photosensitive drum is transferred onto a recording paper. The recording paper on which the toner image is fixed is passed through the fixing unit while the toner image is fixed on the recording paper and then discharged by the discharge unit.

1 is a view schematically showing the configuration of a part of a conventional image forming apparatus. Referring to the drawings, the charging roller 12, the exposure machine 13, the developing roller 14, and the transfer roller 15 are sequentially arranged in the downstream direction in the rotational direction of the photosensitive drum 11. The charging roller 12 uniformly charges the surface of the photosensitive drum 11 at a high voltage. The exposure machine 13 forms an electrostatic latent image on the surface of the charged photosensitive drum 11. The developing roller 14 develops the latent electrostatic image with toner to form a toner image on the photosensitive drum 11. The developing roller 14 receives the toner 17 serving as the developer from the supply roller 19 of the toner loading part 16. The transfer roller 15 transfers the toner image onto the paper fed from the paper cassette (not shown) to the paper transfer path 20. Subsequently, the transferred toner image is fused to the recording paper 50 and fixed by the pressure and temperature of the fixing unit (not shown).

On the other hand, a number of pre-transfer lamps (PTL) 31 for lowering the potential on the photosensitive drum 11 are disposed between the developing roller 14 and the transfer roller 15. A transparent cover 32 that protects the transfer auxiliary lamp 31 is disposed between the transfer auxiliary lamp 31 and the photosensitive drum 11. The transfer auxiliary lamp 31 emits light to lower the potential of the photosensitive drum 11, thereby alleviating the adhesion between the toner 17 and the photosensitive drum 11, thereby facilitating the fixing process. The transfer auxiliary lamp 31 is located on the auxiliary printed circuit board 30, which is connected to the main printed circuit board 40 through the connecting line 34 and the connector 36. . Reference numeral 22 is a paper guide for guiding the paper from the paper cassette.

However, since the image forming apparatus having the above configuration uses the auxiliary printed circuit board 30 to supply power to the transfer auxiliary lamp 31, it requires a separate space for the auxiliary printed circuit board 30. In addition, since the connection line 34 and the connector 36 for connecting between the auxiliary printed circuit board 30 and the main printed circuit board 40 are additionally needed, the cause of the cost increase due to the increase in the material cost and the number of assembly parts There is a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an image forming apparatus having a transfer auxiliary lamp which reduces the number of additional parts by directly connecting the main printed circuit board and the electronic auxiliary lamp. .

1 is a view schematically showing the configuration of a part of a conventional image forming apparatus.

2 is a diagram schematically showing the configuration of an image forming apparatus having a transfer assist lamp according to a preferred embodiment of the present invention.

FIG. 3 is a perspective view illustrating some components of FIG. 2. FIG.

* Description of Signs of Major Parts of Drawings *

11: photosensitive drum 12: charging roller

13: Exposure machine 14: Developing roller

15: transfer roller 20: paper feed path

130: transfer auxiliary lamp 132: light guide

140: main printed circuit board

In order to achieve the above object, an image forming apparatus having a transfer assist lamp of the present invention includes a developing machine for developing an electrostatic latent image formed on a photosensitive drum by an exposure machine, a transfer roller for transferring an image on the photosensitive drum onto a paper; In the image forming apparatus comprising a transfer auxiliary lamp for facilitating the transfer process by irradiating a predetermined light to the photosensitive drum before the transfer,

The transfer auxiliary lamp is directly connected to the main printed circuit board,

And a photoconductor disposed between the transfer auxiliary lamp and the photosensitive drum to guide the light of the transfer auxiliary lamp to the surface of the photosensitive drum.

The transfer auxiliary lamp is preferably a plurality of light emitting diodes disposed corresponding to the longitudinal direction of the photosensitive drum.

In addition, the photoconductor is preferably formed so that its end is convex so that the light from the transfer auxiliary lamp is focused and irradiated to the photosensitive drum surface.

On the other hand, the photoconductor is preferably a transparent acrylic or transparent poly carbonate.

The gap between the transfer auxiliary lamp and the photoconductor is preferably 1 to 2 mm.

Hereinafter, an image forming apparatus having a transfer assist lamp according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of layers or regions illustrated in the drawings are exaggerated for clarity.

FIG. 2 is a view schematically showing a configuration of an image forming apparatus having a transfer assist lamp according to a preferred embodiment of the present invention. FIG. 3 is a perspective view of a partial configuration of FIG. 2 and has the same structure as a conventional invention. The same reference numerals are used for the objects in the drawings, and detailed descriptions are omitted.

Referring to the drawings, referring to the drawings, the charging roller 12, the exposure machine 13, the developing roller 14, and the transfer roller 15 are sequentially arranged in the downstream direction in the rotational direction of the photosensitive drum 11. . The charging roller 12 uniformly charges the surface of the photosensitive drum 11 at a high voltage. The exposure machine 13 forms an electrostatic latent image on the surface of the charged photosensitive drum 11. The developing roller 14 develops the latent electrostatic image with toner to form a toner image on the photosensitive drum 11. The developing roller 14 receives the toner 17 serving as the developer from the supply roller 19 of the toner loading part 16. The transfer roller 15 transfers the toner image onto the paper fed from the paper cassette (not shown) to the paper transfer path 20. Subsequently, the transferred toner image is fused to the recording paper 50 and fixed by the pressure and temperature of the fixing unit (not shown).

On the other hand, between the developing roller 14 and the transfer roller 15, a pre-transfer lamp (PTL) which facilitates a transfer process by irradiating a predetermined light onto the photosensitive drum 11 before transfer. 130 is disposed between the transfer auxiliary lamp 130 and the photosensitive drum 11 to guide the light of the transfer auxiliary lamp 130 to the surface of the photosensitive drum 11. It is. The main printed circuit board 140 for supplying electricity to the lower portion of the transfer subsidiary lamp 130 is directly connected.

The transfer auxiliary lamp 130 is a light emitting diode (LED) in which approximately 12 to 18 are arranged at equal intervals to correspond to the longitudinal direction of the photosensitive drum 11.

The photoconductor 132 is made of transparent acrylic or transparent polycarbonate. The light guide 132 is preferably closer to the transfer-assistance auxiliary lamp 130 adjacent to the transfer aid lamp 130 so as to efficiently receive light from the transfer aid lamp 130 and irradiate the photosensitive drum 11. In this embodiment, in consideration of the assembly play, it is preferable to be disposed about 1 to 2 mm apart. In addition, it is preferable that the shape of one end adjacent to the photosensitive drum is convex so that the light incident from the transfer assist lamp 130 is efficiently irradiated onto the photosensitive drum.

The operation of the image forming apparatus having the above structure will be described in detail with reference to the drawings. First, the charging roller 12 is engaged with the photosensitive drum 11 to rotate to charge the surface of the photosensitive drum 11 to a predetermined potential with a high voltage applied to the charging roller 12. The exposure machine 13 then forms an electrostatic latent image on the surface of the charged photosensitive drum 11. That is, by lowering the potential of the portion where the image is formed, a potential distinct from the potential of the non-image region is formed. The electrostatic latent image is then developed while encountering the developing roller 14 to which the toner 17 having a predetermined electric potential is attached, thereby forming a toner image.

Subsequently, the light irradiated from the transfer auxiliary lamp 130 passes through the light guide 132 and is concentrated at the convex portion 132a formed at one end of the light guide 132 and irradiated to the photosensitive drum 11. This light simultaneously lowers the non-image portion and the image region, which are the surface potentials of the photosensitive drum 11, and at the same time, greatly lowers the potential difference between the non-image portion and the image region. That is, the adhesion between the toner image and the photosensitive drum 11 is reduced, so that the subsequent transfer process is made easy and uniform. Then, the transfer roller 15 is transferred to the sheet 50 passing through the sheet conveying path 20, and the transferred toner image is fixed by pressing and heat at the fixing unit.

As described above, the image forming apparatus having the transfer auxiliary lamp according to the present invention has an advantage of reducing material costs and shortening the assembly process by removing the number of parts such as an auxiliary printed circuit board, a connecting line, and a connector.

Although the present invention has been described with reference to the embodiments with reference to the drawings, this is merely exemplary, it will be understood by those skilled in the art that various modifications and equivalent embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined only by the appended claims.

Claims (5)

A developing aid for developing an electrostatic latent image formed on the photosensitive drum by an exposure machine, a transfer roller for transferring the image on the photosensitive drum onto a paper, and a transfer aid for facilitating a transfer process by irradiating predetermined light onto the photosensitive drum before the transfer. An image forming apparatus comprising a lamp, The transfer auxiliary lamp is directly connected to the main printed circuit board, And a photoconductor disposed between the transfer auxiliary lamp and the photosensitive drum to guide the light of the transfer auxiliary lamp to the surface of the photosensitive drum. The method of claim 1, And the transfer assist lamp is a plurality of light emitting diodes disposed corresponding to the longitudinal direction of the photosensitive drum. The method of claim 1, And the photoconductor is formed so that its end is convex so that light from the transfer auxiliary lamp is focused and irradiated onto the photosensitive drum surface. The method of claim 1, And the photoconductor is a transparent acrylic or a transparent poly carbonate. The method of claim 2, The gap between the transfer auxiliary lamp and the light guide is an image forming apparatus having a transfer auxiliary lamp, characterized in that 1 ~ 2 mm.