JPH04249211A - Scanning optical device - Google Patents

Abstract

PURPOSE:To adjust an optical axis in its optical axis direction and to adjust the rotation in a plane of polarization independently when the optical box is fitted to the base of a printer by fitting the optical box to the base through two specific pins. CONSTITUTION:A positioning pin 8 is held in a guiding hole 11 on the optical box 10 movably only in the optical axis direction of an ftheta lens 50 and the tip part is fitted in the guiding hole 11 on the fitting plate of the optical box 10. Thus, the positioning pin 8 is positioned in the vicinity of the center of the irradiation position of a photosensitive body. A positioning pin 9 is movably held by a guiding hole 12 on the optical box 10 at a specific distance from the positioning pin 8 in the optical axis direction of the ftheta lens 50 orthogonal to the optical axis direction of the ftheta lens 50 and the tip part is fitted in the guiding hole on the fitting plate of the optical box 10.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning optical device used in laser beam printers, laser facsimiles, and the like.

0002

2. Description of the Related Art In a scanning optical device used in a laser beam printer, a laser facsimile, etc., a photoreceptor is scanned with a beam of light deflected and scanned by a deflector to form an electrostatic latent image. This electrostatic latent image is visualized into a toner image by a developing device, this toner image is transferred onto recording paper, and then the toner is heated and fixed to the recording paper after the toner image has been transferred by a fixing device. Printing is done.

FIG. 4 is a plan view illustrating the configuration of a conventional scanning optical device used in a laser beam printer to scan a photoreceptor with a beam of light. Figure 4 shows
FIG. 3 is a diagram for explaining functions within a cross section parallel to a deflection surface (a light beam flux surface formed over time by a light beam deflected by a deflection reflection surface of a deflector).

[0004] The scanning optical device includes a scanner body (optical box) 1
FIG. 4 shows a plan view with the lid removed. The scanning optical device is a semiconductor laser device 1
, a collimator lens 2 that converts the light beam generated from the semiconductor laser device 1 into a parallel light beam, and a cylindrical lens 3 that condenses the parallel light beam from the collimator lens 2 into a linear shape.
, a rotating polygon mirror 4 having a deflection reflecting surface 4a near the line image of the light beam condensed by the cylindrical lens 3, an fθ lens 50, and the like. The light beam deflected and reflected by the deflection reflecting surface 4a enters the reflecting mirror 7 via the fθ lens 50, is reflected by the reflecting mirror 7, and illuminates the photoreceptor.

The fθ lens 50 is designed so that the light beam reflected by the deflection reflection surface 4a is focused to form a spot on the photoreceptor, and the scanning speed of the spot is kept constant. There is. In order to obtain such characteristics of the f.theta. lens 50, the f.theta. lens 50 is composed of two lenses, a spherical lens 5 and a toric lens 6.

As the rotating polygon mirror 4 rotates, main scanning is performed on the photoreceptor by the light beam, and sub-scanning is performed by rotationally driving the photoreceptor around its cylindrical axis. In this way, an electrostatic latent image is formed on the surface of the photoreceptor.

Around the photoreceptor, there is a corona discharger for uniformly charging the surface of the photoreceptor, and a developing device for visualizing the electrostatic latent image formed on the surface of the photoreceptor into a toner image. , a transfer corona discharger (both not shown) for transferring the toner image onto the recording paper, etc. are arranged, and by the action of these, recorded information corresponding to the luminous flux generated by the semiconductor laser device 1 is printed on the recording paper. be done.

As shown in FIG. 4, the irradiation position of the scanner body 10 is adjusted using positioning pins 51 and 52 provided on the outside of the scanner body 10. 53 is a guide hole for the positioning pin 51, and 54 is a guide hole for the positioning pin 52. Adjustment of the irradiation position of the scanner body 10 in the x direction is performed by moving both positioning pins 51 and 52 in the same x direction. Further, the adjustment of the scanner body 10 in the θ direction in FIG.
By moving the positioning pin 1 and the positioning pin 52 in directions opposite to x, rotational movement in the θ direction is performed.

[0009]

[Problem to be Solved by the Invention] However, in the configuration shown in FIG. 4, it is necessary to move the two positioning adjustment pins for both the x-direction adjustment and the θ-direction adjustment, so the following steps are required: There are drawbacks. (1) When adjusting the x-direction, it is difficult to accurately move the scanner in the x-direction (optical axis direction). (2) When adjusting in the θ direction, the center of rotation of the scanner body becomes an imaginary point, so the adjustment in the θ direction causes movement in the x direction as a crosstalk component.

[0010] In recent years, there has been an increasing demand for automation of the assembly of optical scanning devices for reasons such as improving productivity and reducing costs, but the above-mentioned drawbacks are an impediment to this.

[0011]

[Means for Solving the Problems] The present invention provides a light source for independently adjusting the optical axis direction and rotating the optical box within the deflection plane when the optical box is mounted on the base of a printer. a deflector that deflects the light beam from the light source section, an optical system that focuses the light beam deflected by the deflector onto a predetermined surface, and an optical box to which the light source section, the deflector, and the optical system are attached. a first pin held movably in the optical axis direction of the optical system on the opposite side of the optical box from the optical system; and a first pin that directs the light of the optical system from the first pin. A second pin is provided at a predetermined distance in the axial direction and is held movably in a direction perpendicular to the optical axis direction of the optical system;
This is a scanning optical device in which the optical box is attached to a base via two pins.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view illustrating the structure of a first embodiment of a scanning optical device according to the present invention. FIG. 1 is a diagram for explaining functions within a cross section parallel to a deflection surface (a light beam surface formed over time by a light beam deflected by a deflection reflection surface of a deflector). Further, FIG. 2 is a diagram showing a cross section along the optical axis of the fθ lens 50 in a direction perpendicular to the deflection surface.

The scanning optical device is housed in an optical box 10. The scanning optical device includes a semiconductor laser device 1, a collimator lens 2 that converts the light beam generated from the semiconductor laser 1 device into a parallel light beam, a cylindrical lens 3 that condenses the parallel light beam from the collimator lens 2 into a linear shape, and the cylindrical lens. 3, a rotating polygon mirror 4 having a deflection reflecting surface 4a near the line image of the light beam formed by condensing the light beam, fθ
It is configured to include a lens 50 and the like. Deflection reflective surface 4a
The light beam deflected and reflected at is incident on the reflecting mirror 7 via the fθ lens 50, and is reflected at the reflecting mirror 7,
The photoreceptor 20 is irradiated. The inside of the optical box 10 is sealed by a lid 10a.

The fθ lens 50 is designed so that the light beam reflected by the deflection reflection surface 4a is focused to form a spot on the photoreceptor 20, and the scanning speed of the spot is kept constant. ing. Such fθ
In order to obtain the characteristics of the lens 50, the fθ lens 50 is composed of two lenses, a spherical lens 5 and a toric lens 6. Due to the rotation of the rotating polygon mirror 4, the photoreceptor 20
Main scanning is performed using the light beam, and the photoreceptor 20
Sub-scanning is performed by rotationally driving the cylinder around its cylindrical axis. In this way, an electrostatic latent image is formed on the surface of the photoreceptor 20. Around the photoreceptor 20, there is a corona discharger for uniformly charging the surface of the photoreceptor 20, a developing device for visualizing the electrostatic latent image formed on the surface of the photoreceptor into a toner image, A transfer corona discharger (none of which is shown) and the like are arranged to transfer the toner image onto recording paper, and as a result of these functions, recording information corresponding to the luminous flux generated by the semiconductor laser device 1 is printed on the recording paper. Ru. As shown in FIG. 1, the irradiation position of the optical box 10 is adjusted using positioning pins 8 and 9 provided on the opposite side of the optical box 10 from the fθ lens 50. 11 is a guide hole for the positioning pin 8, and 12 is a guide hole for the positioning pin 9.

The positioning pin 8 is aligned in the optical axis direction (x direction) of the fθ lens 50 by the guide hole 11 on the optical box 10.
The optical box 10 is held movably only in a movable manner, and its tip is fitted into a guide hole 31 on a mounting plate 30 of the optical box 10. In this way, the positioning pin 8 is located near the center of the photoreceptor irradiation position. The positioning pin 9 is movable in a direction perpendicular to the optical axis direction of the fθ lens 50 (y direction) at a predetermined distance from the positioning pin 8 in the optical axis direction of the fθ lens 50 by means of a guide hole 12 on the optical box 10. is held in
The tip is located in the guide hole 32 on the mounting plate 30 of the optical box 10.
is fitted. In this way, the optical box 10 adjusts the irradiation position of the laser beam on the photosensitive drum, which is the photosensitive member 20, which is attached to the mounting plate 30, which is the base of the printer, through the two pins 8 and 9. When the positioning pin 8 is moved in the x direction, the scanning line of the laser beam on the photosensitive drum also moves in the x direction. At this time, the positioning pin 9 also moves in the x direction with respect to the mounting plate 30, but since the guide hole 32 is a long hole in the x direction, the movement is not hindered. Further, the guide hole 31 is a round hole.

Next, when the positioning pin 9 is moved in the y direction, the scanning line of the laser beam on the photosensitive drum rotates in the θ direction in the figure. At this time, the positioning pin 9 also moves in the x direction with respect to the mounting plate 30, but since the guide hole 32 is a long hole in the x direction, the movement is not hindered.

In this way, the optical box 10 includes the fθ lens 5.
Two positioning pins are provided near the optical axis of 0 (including near the extension line of the optical axis), and the pin (positioning pin 8) near the predetermined surface (photoreceptor) is movable only in the x direction, The pin (positioning pin 9) far from the predetermined surface (photoreceptor) is movable only in the y direction.

Further, when the optical box 10 is attached to the mounting plate 30 which is the base of the printer, the positioning pin 8 is positioned directly above the photoreceptor 20.

Through the operations described above, the irradiation position on the photoreceptor 20 is adjusted (adjustment of the optical axis direction of the optical box) and the inclination of the scanning line is adjusted (rotation adjustment within the deflection plane of the optical box 10). Can be done.

FIG. 3 shows a sectional view illustrating the configuration of a second embodiment of the scanning optical device of the present invention. The basic configuration of the device is the same as the device described above with reference to FIG. 1, so a description thereof will be omitted. In the device shown in FIG. 3, positioning pins 8, 9
By setting the distance L from the optical axis center of the fθ lens 50, the laser beam at the optical axis position is not obstructed during adjustment.

[0021]

As explained above, the present invention provides a light source section, a deflector that deflects a light beam from the light source section, and an optical system that focuses the light beam deflected by the deflector onto a predetermined surface. and,
In the scanning optical device including the light source section, the deflector, and the optical box to which the optical system is attached, a first optical system is provided on a side of the optical box opposite to the optical system, and is held movably in the optical axis direction of the optical system. A second pin is provided at a predetermined distance from the first pin in the optical axis direction of the optical system and is held movably in a direction perpendicular to the optical axis direction of the optical system. This is a scanning optical device in which the optical box is attached to a base via pins. By adopting such a configuration, when the optical box is attached to the base of the printer, the optical axis direction and rotational adjustment within the deflection plane of the optical box can be independently performed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view illustrating the configuration of a first embodiment of a scanning optical device of the present invention.

FIG. 2 is a sectional view illustrating the configuration of a first embodiment of the scanning optical device of the present invention.

FIG. 3 is a sectional view illustrating the configuration of a second embodiment of the scanning optical device of the present invention.

FIG. 4 is a cross-sectional view illustrating the configuration of a conventional scanning optical device.

[Explanation of symbols]

1 Semiconductor laser device 4 Rotating polygon mirror 8 Positioning pin 9 Positioning pin 10 Optical box 20 Photoreceptor 30 Mounting plate 50 fθ lens

Claims (1)

[Claims] 1. A light source section, a deflector that deflects a light beam from the light source section, an optical system that focuses the light beam deflected by the deflector onto a predetermined surface, the light source section, the deflector, and an optical system. a scanning optical device having an optical box to which a system is attached; a first pin held movably in the optical axis direction of the optical system on a side of the optical box opposite to the optical system; a second lens which is held movably in a direction perpendicular to the optical axis direction of the optical system and is spaced a predetermined distance from the optical system in the optical axis direction of the optical system;
A scanning optical device characterized in that the optical box is attached to a base via the two pins.