阅读说明：本技术 一种应用于激光打印机的双光束激光扫描系统及扫描方法 (Double-beam laser scanning system and scanning method applied to laser printer ) 是由 张俊辉 焦庆玲 王培芳 杜维佳 杨云涛 旷立明 王龙飞 王荣星 吴杰影 于 2019-12-12 设计创作，主要内容包括：本发明涉及一种应用于激光打印机的双光束激光扫描系统,依次包括双光束激光光源,多面旋转棱镜,Fθ系统和光路转折系统,双光束激光光源发射两束激光光束,经过多面旋转棱镜将两束激光光束折射到光路转折系统,两束激光光束到达光路转折系统前会经过Fθ系统。本发明的有益效果是：采用双光束激光扫描的方式,激光光源同时发射两束激光,两路激光光束同时扫描,达到提高激光打印机打印速度的目的,与现有扫描技术相比,速度能够提升两倍,有效提高了激光打印机的速度。(The invention relates to a double-beam laser scanning system applied to a laser printer, which sequentially comprises a double-beam laser light source, a multi-surface rotating prism, an F theta system and a light path turning system, wherein the double-beam laser light source emits two laser beams, the two laser beams are refracted to the light path turning system through the multi-surface rotating prism, and the two laser beams pass through the F theta system before reaching the light path turning system. The invention has the beneficial effects that: adopt two beam laser scanning's mode, laser source launches two bundles of laser simultaneously, and two way laser beam simultaneous scanning reach the purpose that improves laser printer printing speed, compare with current scanning technique, and speed can promote the twice, has effectively improved laser printer's speed.)

1. A double-beam laser scanning system applied to a laser printer is characterized in that: the laser system comprises a double-beam laser source, a multi-surface rotating prism, an F theta system and a light path turning system in sequence, wherein the double-beam laser source emits two laser beams, the two laser beams are refracted to the light path turning system through the multi-surface rotating prism, and the two laser beams pass through the F theta system before reaching the light path turning system.

2. The dual-beam laser scanning system for a laser printer according to claim 1, wherein: the F theta system sequentially comprises a first arc-shaped prism and a second arc-shaped prism, the radian of the first prism is larger than that of the second prism, and the arc length of the first prism is smaller than that of the second prism.

3. The dual-beam laser scanning system for a laser printer according to claim 2, wherein: the light path turning system is a reflector, and a protection window is arranged between the reflector and the light sensing surface.

4. The dual-beam laser scanning system for a laser printer according to claim 3, wherein: and a laser collimating device and a laser shaping device are arranged between the double-beam laser light source and the multi-surface rotating prism.

5. A dual beam laser scanning system for a laser printer as claimed in any one of claims 1 to 4, wherein: still include initial positioning system, initial positioning system includes positioning prism and photosensitive element, initial positioning system sets up F theta system left side edge, the left fringe beam of first prism refraction passes by triggering behind the positioning prism photosensitive element.

6. The dual-beam laser scanning system for a laser printer according to claim 5, wherein: the light beam of the positioning prism enters one surface to form an optical plane, and the light beam exits the other surface to form an optical curved surface.

7. A dual-beam laser scanning method implemented by the dual-beam laser scanning system applied to a laser printer according to any one of claims 1 to 6, characterized in that: the double-beam laser light source emits two beams of laser beams, the beams are deflected by the multi-surface rotating prism, are refracted at multiple angles under the action of the F theta system, and scan two lines of data contents on a photosensitive surface through the light path turning system.

8. The dual beam laser scanning method of claim 7, wherein: after the laser beam is refracted by the first prism, the leftmost end beam penetrates through the positioning prism and is emitted to the photosensitive element, and the photosensitive element receives the beam penetrating through the positioning prism and confirms that the scanning initial position starts to convey data.

Technical Field

The invention belongs to the field of laser printing equipment, and particularly relates to a double-beam laser scanning system and a scanning method applied to a laser printer.

Background

The printing speed of the laser printer mainly depends on the scanning speed of the laser scanning unit, the laser scanning unit of the laser printer in the market at present adopts a single-beam laser scanning unit, and the single-beam laser scanning unit mainly comprises a single-beam laser light source, a laser collimation and shaping system, a rotating multi-surface reflector stacked on a high-speed motor and a scanning lens. The method for improving the scanning speed of the laser scanning printer only improves the rotating speed of the polygon mirror and increases the number of reflecting surfaces of the polygon mirror, when the rotating speed of the polygon mirror reaches a certain value, the motor stability is restricted, and the requirement on the machining precision of the polygon mirror is greatly improved due to the increase of the number of the polygon mirror surfaces, so that the scanning speed of the laser scanning unit is restricted.

Disclosure of Invention

To solve the above technical problems, the present invention provides a dual-beam laser scanning system and a scanning method for a laser printer.

The technical scheme adopted by the invention is as follows: a double-beam laser scanning system applied to a laser printer sequentially comprises a double-beam laser light source, a multi-surface rotating prism, an F theta system and a light path turning system, wherein the double-beam laser light source emits two laser beams, the two laser beams are refracted to the light path turning system through the multi-surface rotating prism, and the two laser beams pass through the F theta system before reaching the light path turning system.

Preferably, the F θ system comprises a first prism and a second prism in an arc shape in sequence, the arc degree of the first prism is larger than that of the second prism, and the arc length of the first prism is smaller than that of the second prism.

Preferably, the light path turning system is a reflector, and a protection window is arranged between the reflector and the light-sensitive surface.

Preferably, a laser collimating device and a laser shaping device are arranged between the double-beam laser light source and the multi-surface rotating prism.

Preferably, the starting positioning system comprises a positioning prism and a photosensitive element, the starting positioning system is arranged at the left edge of the F theta system, and the left edge beam refracted by the first prism passes through the positioning prism and is triggered by the photosensitive element.

Preferably, the light beam entering surface of the positioning prism is an optical plane, and the light beam exiting surface is an optical curved surface.

A double-beam laser scanning method is realized by a double-beam laser scanning system applied to a laser printer, wherein a double-beam laser light source emits two beams of laser beams, the beams are deflected by a multi-surface rotating prism, are refracted at multiple angles under the action of an F theta system, and scan two lines of data contents on a photosensitive surface through a light path turning system.

Preferably, after the laser beam is refracted by the first prism, the leftmost beam passes through the positioning prism and is emitted to the photosensitive element, and the photosensitive element confirms that the scanning starting position starts to convey data after receiving the beam passing through the positioning prism.

The invention has the advantages and positive effects that: adopt two beam laser scanning's mode, laser source launches two bundles of laser simultaneously, and two way laser beam simultaneous scanning reach the purpose that improves laser printer printing speed, compare with current scanning technique, and speed can promote the twice, has effectively improved laser printer's speed.

Drawings

FIG. 1 is a schematic structural diagram of one embodiment of the present invention;

FIG. 2 is a schematic view of a positioning prism structure according to the present invention;

FIG. 3 is a schematic view of a multi-faceted rotating prism structure according to the present invention.

In the figure:

1. double-beam laser light source 2, laser collimator 3 and laser shaping device

4. Multi-face rotary prism 5, first prism 6 and second prism

7. Protective window 8, light-sensing surface 91, optical plane

92. Optical curved surface

Detailed Description

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in fig. 1 to 3, the present invention relates to a dual-beam laser scanning system for a laser printer, which comprises a dual-beam laser source, a multi-surface rotating prism, an F θ system and a light path turning system in sequence; the double-beam laser light source emits two laser beams, the two laser beams are refracted to the light path turning system through the multi-surface rotating prism, and the two laser beams pass through the F theta system before reaching the light path turning system.

Dual beam laser light source: the laser unit can simultaneously emit two laser beams which have the same wavelength, the same divergence angle and the same power, do not interfere with each other, have small distance and can meet the requirement;

multi-face rotating prism: the polygonal prism comprises a plurality of scanning mirror surfaces, rotates at a high speed around a scanning shaft, and reflects two rows of collimated and shaped laser beams to a certain angle space; specifically, the scanning speed may be 5-edge prisms or 6-edge prisms, the number of edges is different, and the scanning speed is faster when the number of edges is larger.

F theta system: the optical system sequentially comprises an arc-shaped first prism and an arc-shaped second prism, wherein the radian of the first prism is larger than that of the second prism, the arc length of the first prism is smaller than that of the second prism, the aberration of an on-axis point and an off-axis point of the system can be combined and corrected, and simultaneously the design requirements of no vignetting and a flat field are met so as to ensure that light spots reaching a photosensitive device of the printer have the same size and quality; and controlling the scanning distortion of the scanning system;

light path turning system: the light path deflecting system mainly comprises a single body and plays a role in deflecting the light path, and is specifically a reflector, a protection window is arranged between the reflector and the light sensing surface, and the protection window plays a role in protecting powder from entering the laser scanning unit.

In addition, a laser collimating device and a laser shaping device are arranged between the double-beam laser light source and the multi-surface rotating prism, and the beam collimating device mainly comprises a single prism and has the function of adjusting the divergence and convergence of light beams; the beam shaping device mainly comprises a single prism, and the shape and the size of the light spot can be adjusted by adjusting the front position and the rear position in the system.

The double-beam laser scanning system also comprises an initial positioning system, the initial positioning system comprises a positioning prism and a photosensitive element, the positioning prism is a polyhedron with curved surfaces, the main function is to fold and converge the light rays which reflect the most edge on the photosensitive element, the scanning initial position is confirmed after the photosensitive element is photosensitive, data transmission is started, the initial positioning system is arranged on the left edge of the F theta system, and the light rays at the left edge refracted by the first prism pass through the positioning prism and then trigger the photosensitive element. The positioning prism is a single prism with a curved surface, one component plays a role in light path turning and converging, and the mounting space is saved on the basis of the same function. The light beam entering surface of the positioning prism is an optical plane, the light beam emitting surface is an optical curved surface, and the optical plane and the optical curved surface form an angle of 45 degrees.

A double-beam laser scanning method realized by a double-beam laser scanning system applied to a laser printer is characterized in that a double-beam laser light source emits two beams of laser beams, the beams are deflected by a multi-surface rotating prism, are refracted at multiple angles under the action of an F theta system, and scan the contents of two lines of data on a photosensitive surface through a light path turning system, after the laser beams are refracted by a first prism, the leftmost end beam penetrates through a positioning prism and is emitted to a photosensitive element, and the photosensitive element confirms that the scanning initial position starts to transmit data after receiving the beams penetrating through the positioning prism. Specifically, the double-beam laser unit emits two modulated laser pulses, the modulated laser pulses are converged on a reflecting surface of the multi-surface rotating prism through the laser collimator and the laser shaper, the multi-surface rotating prism rotates to deflect the direction of laser, the laser beams pass through a preset F theta lens, the light beams have preset angles and scanning ranges, the light beams are converged on a photosensitive unit of a printer through a reflecting mirror and a protection window, and the effect that one surface of the multi-surface rotating prism rotates to scan data for two lines is achieved.