KR20040000836A - Laser beam printer having stability output of laser beam - Google Patents

Abstract

PURPOSE: A laser printer having stable output of a laser beam is provided to reduce the material cost by regulating supply power to be transmitted to a laser diode and each block of a system by a single switch, and improve the quality of printed images by stabilizing laser diode supply power. CONSTITUTION: A photo conductor drum is provided. A switching mode power supply(SMPS) unit(110) supplies power source to the photo conductor drum for developing an image according to print data and fusing toner. A switch(120) regulates power supplied to the photo conductor drum from the SMPS unit according to opening and closing of a print cover. A light scanning unit receives the power source from the power supply unit for applying light to form a latent image on the photo conductor drum according to the image. A regulator(130) regulates the power transmitted through the switch for supplying the same to the light scanning unit.

Description

Laser beam printer having stability output of laser beam

The present invention relates to a printer, and more particularly, to a laser printer which performs printing by forming an electrostatic latent image using a laser light.

The laser printer charges the photosensitive drum surface on which the photoconductive layer is formed and irradiates the laser light on the surface with the print data. Then, the charge of the portion irradiated with the laser light disappears from the photosensitive drum surface, and the toner is adsorbed to the portion irradiated with the laser light to form an image on the drum surface. Thereafter, the image formed on the surface of the drum is transferred onto the paper, and the print data is printed onto the paper by heating and compressing the toner transferred onto the paper to fix the image onto the printing paper.

However, when the laser light used in the laser printer is exposed to the outside, the eyesight of the user may be degraded. Therefore, various methods for blocking the laser light are being sought according to circumstances.

1 is a view schematically showing a laser beam blocking structure of a conventional laser printer. In the conventional laser printer, the shutter 2 is installed in front of the laser diode 1-1 output of the laser scanning unit (LSU (Laser Scanning Unit) 1). As the cover A opens and closes, a structure is formed so that the shutter 2 can interrupt the laser beam (arrow in the drawing) output from the laser diode 1-1.

Figure 2 is a block diagram schematically showing another laser light blocking structure of a conventional laser printer. The laser printer receives SMPS (Switching Mode Power Supply 11) for supplying commercial power (AC) to each block (developing and fixing circuit unit) of the system, and SMPS ( A laser diode (LSU LD) from the SMPS unit 11 in conjunction with the opening and closing of the first switch 12 and the printer cover A to control the power supply VPP supplied to each block (not shown) of the system. The second switch 13 is provided to interrupt the power supplied to. Each block of the system here includes blocks that utilize high pressure and high temperature for developing and toner fixing of the printed image. The power VCC supplied to the laser diode LSU LD is used to supply the logic circuit of the printer system.

In the above laser printer, as the cover A is opened, the first switch 12 and the second switch 13 are opened together to cut off the power supplied to each block of the system, while the laser diode LSU LD The power supplied to the circuit is cut off to turn off the laser diode LSU LD.

However, the conventional laser printer as described above can prevent the laser light from being exposed to the user according to opening and closing of the printer cover A. However, in the case of using a shutter interlocked with the mechanical structure, the structure of the mechanical shape and the frame, etc. In addition to the difficulty in design, there was a problem that the cost increases, and when the power supplied to the laser diode is designed to be cut off by the switching means, the output power of the SMPS supplied to the laser diode is unstable and the image quality is deteriorated. There was a problem.

An object of the present invention is to provide a laser printer capable of supplying a stable power to the laser diode while being able to cut off the power supplied to the laser diode in conjunction with the opening and closing of the mechanism structure to solve the above problems. .

1 is a view schematically showing a laser beam blocking structure of a conventional laser printer;

2 is a block diagram schematically showing another laser beam blocking structure of a conventional laser printer; and

3 is a block diagram schematically showing a laser beam blocking structure of a laser printer according to the present invention.

* Description of the symbols for the main parts of the drawings *

1: LSU (Laser Scanning Unit) 1-1: Laser Diode

2: shutter

11, 110: switching mode power supply (SMPS)

12, 13, 120: switch 130: regulator

Laser printer of the present invention for achieving the above object is a photosensitive drum; A power supply unit supplying power to the photosensitive drum for developing images and fixing toners according to print data; Switching means for controlling power supplied from the power supply to the photosensitive drum in accordance with opening and closing of a mechanism structure; An optical scanning device for supplying power supplied from the power supply unit to irradiate light to form a latent image according to the image on the photosensitive drum; And a regulator for regulating the power transmitted through the switching means to supply the optical scanning device.

The laser printer as described above can block the laser light according to opening and closing of the printer cover, and can supply stable power to the optical scanning device through a regulator, thereby improving the quality of the printed image.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

3 is a block diagram schematically showing a laser beam blocking structure of a laser printer according to the present invention. The laser printer is supplied with power from a commercial power source (AC) in conjunction with the opening and closing of the SMPS (110) and the printer cover (A) to supply driving power (VPP) to each block (developing and fixing circuit unit) of the system Laser diode (LSU) by regulating the power switch (VPP) transmitted through the first switch 120 and the first switch 120 to control the driving power (VPP) supplied to each block of the system from the SMPS unit 110 Regulator 130 to deliver to LD). Here, the power supply VCC supplied from the SMPS unit 110 to the logic circuit unit is designed so as not to be affected by the opening and closing of the cover A.

In the laser printer as described above, when the cover A is normally covered, when a print command is transmitted from the user and the printing operation is normally performed, the power VPP supplied from the SMPS unit 110 is switched to the first switch ( 120 is transmitted to each block (developing and fixing circuit unit, etc.) of the system, while a stable power is supplied to the laser diode (LSU LD) through the regulator 130. However, when the user opens the cover A, the cover A is opened and the first switch 120 for switching the power supply VPP supplied to each block of the system is opened. Accordingly, power is no longer supplied to each block of the system, and the supply of power VPP is similarly stopped at the regulator 130 and the laser diode LSU LD is turned off. That is, the laser diode LSU LD is turned off with the cover A being opened.

In the laser printer as described above, the switch 120 is installed on the driving power supply path of each block of the system from the SMPS unit 110, and the rear end of the switch 120 is also used to supply stable power to the laser diode (LSU LD). Since the regulator 130 is installed, it is possible to control the operation of each block of the system and the laser diode LSU LD with one switch 120 interlocked with opening and closing of the cover A.

In addition, since the laser diode (LSU LD) is supplied with more stable power through the regulator 130, it is possible to irradiate light more reliably to the drum surface, thereby improving image quality on printing paper. Can be printed.

Here, although the first switch 120 is described as being on / off in conjunction with the opening and closing of the cover (A), the first switch 120 is not necessarily linked to the opening and closing of the cover, the operation of another mechanism structure On / off operation may be performed by. For example, the first switch may be designed to be turned on / off in accordance with the removal of the printing paper tray.

In the laser printer of the present invention as described above, it is possible to interrupt the supply power delivered to each block of the laser diode and the system by one switch, thereby reducing the material cost, and stabilizing the laser diode supply power using the regulator. Through this, the quality of the printed image can be improved.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the general knowledge in the technical field to which the present invention pertains without departing from the gist of the present invention claimed in the claims. Anyone with a variety of variations will be possible.

Claims (1)

Photosensitive drum; A power supply unit supplying power to the photosensitive drum for developing images and fixing toners according to print data; Switching means for controlling power supplied from the power supply to the photosensitive drum in accordance with opening and closing of a mechanism structure; An optical scanning device for supplying power supplied from the power supply unit to irradiate light to form a latent image according to the image on the photosensitive drum; And And a regulator for regulating the power transmitted through the switching means to supply the optical scanning device.