JPH055850A - Optical device - Google Patents

Abstract

PURPOSE:To easily align the optical axis of an optical device to a target and to constitute each turning-back mirror and each supporting member in common with respect to the optical device used in an image forming device of a laser print or the like. CONSTITUTION:In the optical device where the emitted light from a light source LS is reflected by plural plane mirrors M1 and M2 and is led to the target, plane mirrors M1 and M2 are supported by supporting means S1 and S2 which can be moved in parallel with the optical axis of incident light, and reflection faces of plane mirrors M1 and M2 and moving directions of supporting means S1 and S2 are set to the same angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device used in an image forming apparatus such as a laser printer.

[0002]

2. Description of the Related Art In an optical device using a light source for emitting light such as laser light, for example, a laser printer, laser light emitted radially from a laser diode LD is collimated by a collimator lens G1 as shown in FIG. The light is converted into light, which is then condensed on the polygon mirror PM by the cylindrical lens G2, and the condensed laser light is scanned on the photoconductor by the rotation of the polygon mirror PM. By the way, the optical path length d between the cylindrical lens G2 and the polygon mirror PM is determined by the focal length of the cylindrical lens G2, and if the optical path is secured in a straight line, the entire device becomes large.
It is known that two or more folding mirrors are used to secure a required optical path length d in a narrow space and to downsize the entire apparatus as shown in FIG.

[0003]

However, in order to secure the required optical path length by using the folding mirror as described above, the delicate movement of the folding mirror causes the optical axis of the optical axis at the arrival point (target) of the light to be changed. Since the position changes greatly, it is necessary to carefully set the position and angle of the folding mirror.

By the way, as a conventional method of adjusting the folding mirrors in such an optical device, a method of rotating the folding mirrors M1 and M2 as shown in FIG. 5 or a method of adjusting the folding mirrors M1 and M2 as shown in FIG. A method of sliding in a fixed direction is known, but in the former case, the mirror M
When 1 and M2 are rotated by the angle θ, the respective reflection angles become 2θ, and the optical axis L3 with respect to the target T is largely moved with respect to the rotation of the mirrors M1 and M2. Therefore, it is difficult to adjust the angles of the mirrors M1 and M2. There is a problem. In the latter case, the change in the optical axis L3 with respect to the target T corresponds to the amount of movement of the mirrors M1 and M2, and therefore the position adjustment of the mirrors M1 and M2 is easy, but the mirrors M1 and M2 are easy to adjust.
In the supporting member that movably supports M2, since the angle formed by the moving direction and the reflecting surface of the mirror is different,
There is a problem that the same support member cannot be used.

The present invention has been made in consideration of the above circumstances, and an optical device in which the optical axis can be easily aligned with the target and the folding mirrors and the supporting members can be formed in common. Is provided.

[0006]

According to the present invention, in an optical device constructed so that light emitted from a light source is reflected by a plurality of plane mirrors and guided to a target, each plane mirror is parallel to the optical axis of the incident light. (EN) Provided is an optical device which is supported by movable support means, and wherein the reflecting surface of each plane mirror and the moving direction of each support means are set at the same angle.

FIG. 1 is a principle diagram showing the structure of the present invention, in which light emitted from a light source LS is reflected through plane mirrors M1 and M2 and reaches a target T. The plane mirror M1 is supported by the supporting means S1 which is movable in parallel to the incident optical axis L1, the reflecting surface of the plane mirror M1 and the moving direction of the supporting means S1 are set at an angle α, and the plane mirror M2 is the plane mirror M1. The reflecting surface of the plane mirror M2 and the moving direction of the supporting means S1 are supported by the supporting means S2 which is movable in parallel to the optical axis L2 of the light reflected by, and the angle α is set. The angle α is 0 ° <α
It satisfies <90 °.

[0008]

In FIG. 1, the supporting means S1 is moved in parallel with the optical axis L1 and the supporting means S2 is moved in parallel with the optical axis L2 so that the incident angle and the reflection angle on the plane mirrors M1 and M2 are (90-α). The optical axis of the light emitted from the light source LS can be moved in parallel while being maintained at a high level, and thus the deviation of the optical axis with respect to the target T can be easily corrected. Further, since the supporting means S1 and S2 both move in parallel with the incident optical axis and support the plane mirrors M1 and M2 at an angle α with respect to the moving direction, their structures can be the same.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the embodiments shown in the drawings. This does not limit the present invention.

FIG. 2 is an explanatory view of the main configuration of a laser printer showing an embodiment of the present invention. LD is a laser diode for emitting a laser beam and G1 is a laser diode LD.
Is a collimator lens for converting the light from the collimator into parallel light, and G2 is a cylindrical lens for receiving the parallel light from the collimator lens G1 and converting it into light having an optical axis L1.

M1 is a folding mirror (planar mirror) that reflects light having an optical axis L1, and the mirror M1 has a reflecting surface on the supporting member S1 that slides in parallel with the optical axis L1 in the sliding direction of 60. It is installed to form an angle of degrees. M2
Is a folding mirror (planar mirror) that further reflects the light having the optical axis L2 reflected by the mirror M1, and S2 is the optical axis L
The mirror M2 is a support member that is slidable in parallel with 2, and the mirror M2 is installed on the support member S2 such that the reflection surface forms an angle of 60 degrees with respect to the sliding direction. PM is a polygon mirror, and the light having the optical axis L3 reflected by the mirror M2 is reflected by the polygon mirror PM and becomes light L for scanning a photoconductor (not shown).

In such a structure, when the supporting members S1 and S2 are slid, the incident angles of light and the reflecting surfaces of the mirrors M1 and M2 are maintained at 30 degrees, and the light emitted from the laser diode LD is maintained. The optical axes move in parallel. Therefore, the light emitted from the laser diode LD is
It is easily guided to a desired position of the polygon mirror PM.

The supporting members S1 and S2 slide in parallel with the optical axis of the incident light, and support the mirrors M1 and M2 so that the reflection surfaces are 60 degrees with respect to the sliding direction. Therefore, the same structure is sufficient for both. In addition,
In this embodiment, the folding mirrors M1 and M2 move the cylindrical lens G2 to the polygon mirror PM.
Since the optical path length up to (1) is bent, the space for housing the components is reduced as compared with the conventional example (FIG. 4) that does not use a folding mirror. In addition, the cylindrical lens G2
The required optical path length d from to the polygon mirror PM is d = d
Reserved as 1 + d2 + d3 (FIG. 2).

FIG. 3 is a structural explanatory view showing another embodiment of the present invention. The above-mentioned embodiment has two folding mirrors M.
1, M2 and supporting members S1 and S2 are used, in contrast to this embodiment, a folding mirror (plane mirror) M3 supported by the supporting member S3 is further added, and other components are The description is omitted because it is the same as FIG. The mirror M3 is supported by a support member S3 that is slidable in parallel with the optical axis of the incident light, and the reflecting surface of the mirror M3 and the sliding direction are set to 60 degrees.

In the embodiment of FIG. 3, each support member S
By sliding 1, S2 or S3 for adjustment, the optical axis of the reflected light of the mirror M1, M2 or M3 moves in parallel. As a result, the light emitted from the laser diode LD enters the mirror M1 at an incident angle of 30 degrees, the reflected light enters the mirror M2 at an incident angle of 30 degrees, and the reflected light enters the mirror M3 at 30 degrees. The light enters at an angle, and the reflected light of the mirror M3 enters a desired position of the polygon mirror PM. The mirror M3 and the support member S3 are, as described above, the mirror M3.
1, M2 and their supporting members S1, S2 may have the same structure.

[0016]

According to the present invention, since the light emitted from the light source can be moved in parallel with the target by the folding mirror, it becomes easy to adjust the deviation of the optical axis, and the folding mirror and It is possible to make all the supporting members of the mirror have a common structure.

[Brief description of drawings]

FIG. 1 is a principle diagram showing a configuration of the present invention.

FIG. 2 is a structural explanatory view showing an embodiment of the present invention.

FIG. 3 is a structural explanatory view showing another embodiment of the present invention.

FIG. 4 is an explanatory diagram of a main configuration of a laser printer.

FIG. 5 is an explanatory diagram of a configuration showing a conventional example.

FIG. 6 is a configuration explanatory view showing another conventional example.

[Explanation of symbols]

 LS light source M1, M2 plane mirror S1, S2 support means T target

Claims (1)

Claim: What is claimed is: 1. An optical device configured so that light emitted from a light source (LS) is reflected by a plurality of plane mirrors (M1, M2) and guided to a target.
1, M2) is supported by supporting means (S1, S2) movable parallel to the optical axis of the incident light, and the reflecting surface of each plane mirror (M1, M2) and each supporting means (S1, S2). An optical device characterized in that the moving direction is set to the same angle (α).