JPH04208917A - Optical deflector - Google Patents

Abstract

PURPOSE:To reduce the occupying space of the device and the cost of the device by using a shaft-shaped mirror deflector which can be three-dimensionally positioned and integrally forming plural mounting bases to which device constituting parts are mounted as one housing. CONSTITUTION:A revolving shaft 20 rotates at a specified angle when a plane opposition type motor 18 runs. A light beam is deflected at 90 deg. angle and is rotated at the same angle as the angle of the shaft within the plane perpendicular to the shaft, when the reflection mirror surface 21 formed to incline 45 deg. is irradiated with the light beam from a light source 25 right above this surface. The deflected light beam scans at an equal angular velocity as the revolving shaft 20 revolves. The scanning beam is changed by an optical lens 17 to the scanning speed of an equal linear speed from the angular velocity. A photosensitive body, such as laser printer or digital copying machine, is irradiated at an equal pitch with the light beam. The constituting parts relating to light deflection, particularly the shaft-shaped mirror deflector 12, the light source 25 and the optical lens 17, are stereoscopically disposed in one housing 10 and, therefore, the occupying space of the device is made smaller than the occupying space of a device constituted by using a rotary polygonal mirror and the cost of the device is reduced.

Description

[Detailed description of the invention]

[0001]

[Industrial Application Field] *The invention relates to an optical deflection device that deflects the propagation direction of a light beam, and in particular, it reflects a light beam by a mirror installed on a rotation axis so that the light beam is reflected in a plane perpendicular to the rotation axis. An optical deflection device is used to scan the beam. [0001shi)

2. Description of the Related Art Conventionally, optical deflection devices employing rotating polygonal mirrors have been frequently used in scanning optical systems of printers, digital copying machines, and the like. This rotating polygon mirror has a large number of reflecting surfaces parallel to the rotation axis (P), and deflects a light beam incident from a direction close to perpendicular to the rotation axis by an angle twice the rotation angle. An example of the optical deflection device 1-7 that employs a rotating polygonal mirror is described in Japanese Patent Application Laid-Open No. 62-94814. According to this publication, the rotating body (shaft) has one end A rotating polygon mirror and an evening magnet are fixed on one side, and the other end is supported by a ball @ receiving part.The ball bearing part is connected to the optical deflection system frame of the optical deflection device. In addition to being integrally formed, an oil-scattering prevention sill is provided on the end side where the rotating polygon mirror is attached.Furthermore, the motor that rotates the rotating shaft is connected to a rotor magnet fixed to the rotating shaft. Opposed to each other, a plurality of drive coils are provided in the optical deflection system (optical deflection system), and these rotor magnets and drive coils constitute an L-plane facing type model. [0003]

[Problems to be Solved by the Invention] I, 7 However, in such a conventional optical deflection device, in addition to the rotating polygon mirror, there is also a so-C source that generates optical beam -18, and a polygon mirror. Optical correction pressures (1/lens), etc., are arranged in a plane to correct the deflected light beam at an equal f11 position to a beam with an equal linear velocity of 1'.Therefore, the light The deflection device occupies a large area, making it difficult to miniaturize the L device7.Also, with a rotating polygon mirror, if there is a difference in the reflectance of the multiple reflecting surfaces, the brightness will vary depending on the scanning line. [0004] Therefore, the invention of claim 1 provides an axially shaped structure that can be arranged in three dimensions. In addition to using a mirror deflector, a single housing has multiple mounting stands to which device components can be attached]
The object of the present invention is to provide an optical deflection device which can achieve a reduction in the space occupied by the L device and a reduction in space by integrally forming the L device. A/-1 The invention as claimed in claim 2 reduces the space occupied by the L device and reduces the cost by integrally forming the axial mirror deflector and the mounting base of the light correction means as one housing 7. The purpose of the present invention is to provide an optical deflection device that can achieve the following effects.j2. ing. [0005] Furthermore, the invention according to claim 3 provides a mounting base for the annular mirror deflector, the source, and the light correction means in one unit.
It is an object of the present invention to provide an optical deflection device with two housings (which are integrally formed with two housings) and can achieve a reduction in the space occupied by the L device and a reduction in cost. [0006]

[Means for solving the problem] The invention according to claim 1 is:
Top 2 [To achieve target 1, rotate the end of the rotating shaft by anti-I=I
- an axial mirror deflector serving as a mirror; a light source for directing a light beam toward the reflecting mirror of the 52 axial mirror deflector; A light correcting means for optically correcting the light, and a first one in which the rotation axis of the axial mirror deflector is rotatably taken (-i).
mount and this 1st. A second mount 83 is placed at a position opposite to the mount 83, to which the light source is attached, and a second mount 83 is disposed in the direction of deflection of the light beam by the axial mirror deflector, and to which the light correction means is attached. In the optical deflection device having a mounting base, at least two of the first to third mounting bases are connected to one housing.
[0007] Also, the invention according to claim 2 provides a structure in which the first and third parts are integrated with each other.
The mounting base is integrally formed as one housing, and the cross-sectional shape of the housing including the optical axis is approximately U-shaped. All of the first to third mounts are integrally formed with a single housing, and the cross-sectional shape of the housing including the optical axis is approximately 17-shaped. [0O08]

[Operation]] In the invention described in the claim having two bridge structures, at least two or more of the first...-third mounting bases are integrally formed with one housing 7. The space occupied by the L device can be reduced. Further, in the invention as claimed in claim 2, the first and the third
By integrally forming the mounting base as one housing and making the cross-sectional shape of the housing including the optical axis substantially U-shaped, the number of L parts can be reduced and costs can be reduced. [0009] Furthermore, in the invention according to claim 3, all of the first to third mounting bases are integrally formed as one housing, and the cross-sectional shape of the housing including the optical axis is made into an abbreviated shape. L The number of parts can be reduced and costs can be lowered. [0010]

EXAMPLES The present invention will be explained below based on examples. FIG. 1 is a cross-sectional view showing an embodiment of the optical deflection device according to the first or third aspect of the invention. First, the configuration will be explained. In FIG. 1, a housing 10 of the optical deflection device is molded in one piece, and has a cross-sectional shape that includes the optical axis of the optical system. A bearing 1 of the axial mirror deflector 12 is mounted on a first mount, which is one opposite side inside the housing 10.
A stepped hole 15 is formed for holding 3.14. Further, a light beam source section 16 that generates a light beam is attached to a second mounting base on the other side of the housing 10. A third mount is formed in succession to the first mount in the direction in which the light beam is deflected by the axial mirror deflector 12.The third mount includes a light correction means. An optical lens 17 is attached. Furthermore, an axial mirror deflector 12 and an optical lens 17
A drive coil 19, which is a motor stator of the surface-facing motor 18, is provided on the outer side surface of the housing 10 to which the motor 18 is attached. [0011] In the axial mirror deflector 12, an oblique reflective mirror surface 21 is provided at one end of a rotating shaft 20, and a rotor magnet 22 of the surface facing type motor 18 is fixed to the other end. . Note that the reflective mirror surface 21 is inclined at, for example, 45 degrees with respect to the rotation axis 20. The rotating shaft 20 is mounted on a bearing 13.1 held in the stepped hole 15 of the housing 10.
4 and rotates. Note that the rotating shaft 20 is
When the drive coil 19 is energized, the rotor magnet 22 arranged opposite to the drive coil 19 rotates, thereby rotating. The drive coil 19 is arranged on a substrate 23, and circuit components 24 such as a control circuit for rotating the rotor magnet 22 at a constant angular velocity and a rotation sensor for the rotor magnet 22 are mounted on the substrate 23. [0012] The light beam light source section 16 includes a light source 25 composed of, for example, a semiconductor laser and a collimating lens attached to the semiconductor laser, a circuit component 26 for driving the light source 25, and the light source 25 and the circuit component. 26 is mounted on a substrate 27 and the like. Here, the light source 25
is such that the light beam is incident in the axial direction of the rotating shaft 20,
It is placed directly above the reflective mirror surface 21. [0013] Next, the operation will be explained. Surface facing motor 1
8 rotates, the rotating shaft 20 rotates at a constant angular velocity. At this time, when a light beam is irradiated from the light source 25 directly above onto the reflective mirror surface 21 formed at an angle of 45 degrees with respect to the rotation axis 20, the light beam is deflected at an angle of 90 degrees, and
Rotate by the same angle as the axis in a plane perpendicular to the axis. That is, this deflected light beam is scanned at a constant angular velocity as the rotating shaft 20 rotates. This scanning light beam is changed from a constant angular velocity to a constant linear scanning velocity by an optical lens 16 such as an fθ lens. As a result, the light beam can be irradiated onto a photoreceptor of, for example, a laser printer or a digital copying machine at a uniform pitch. [0014] In this embodiment, components related to optical deflection, particularly the axial mirror changer 12, the light source 25, and the optical lens 17 are three-dimensionally arranged in one housing 10. The space occupied by the device can be reduced compared to the conventional planar light changing device using a rotating polygon mirror. Furthermore, since a rotating polygon mirror, which is difficult and expensive to manufacture, is not used, the cost of the device can be reduced. Furthermore, by configuring the surface-facing motor 18 using the outer surface of the housing 10, the volume of the L housing 10 can be reduced. Additionally, the integral molding of the housing 10 also improves the ease of assembling the L device. [00151 FIG. 2 is a cross-sectional view showing an embodiment of the optical deflection device according to the second aspect of the invention. In this embodiment, the same components as those in the above-mentioned example are designated by the same reference numerals, and detailed explanation thereof will be omitted. First, a configuration different from the above example will be explained. In FIG. 2, the housing 10 is integrally formed with the first and third mounting bases to which the axial mirror deflector 12 and the optical lens 17 are attached, and the cross-sectional shape of the housing 10 including the optical axis is It is said to be abbreviated as U. A substrate (second mount) 27 to which the light source 25 is attached is detachably attached to the housing 10. Further, in this embodiment, since the surface facing type motor 18 is constructed by disposing the drive coil 19 on the inner surface of the housing 10 and fixing the rotor magnet 22 to the rotating shaft 20 so as to face the driving coil 19, the housing 10 internal spaces are utilized effectively. Note that the other configurations and operations are the same as those in the above example, so explanations will be omitted. [0016] In this way, in this embodiment, the first and third mounts are integrally formed as one housing, and the cross-sectional shape of the housing including the optical axis is approximately C. It is possible to reduce the number of parts and achieve lower costs. [0017]

As described above, according to the invention set forth in claim 1, at least two or more of the first to third mounting bases are integrally formed as one housing. Since the space occupied by the device can be reduced and the number of parts can be reduced, manufacturing costs can be reduced. [0018] Furthermore, according to the invention as claimed in claim 2, the first
By integrally forming the and third mounting base as one housing and making the cross-sectional shape of the housing including the optical axis substantially U-shaped, the number of L parts can be reduced and costs can be reduced.
Further, according to the invention as claimed in claim 3, all the first, ..., and third mounts are integrally formed as one housing 7, and the cross-sectional shape of the housing including the optical axis is abbreviated as A. By reducing the number of L parts by 4'' and 7, it is possible to achieve a low = 1 stroke.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of a light deflection device according to the invention according to claim 1 or 3. FIG.

FIG. 2 is a sectional view showing an embodiment of the rotary deflection device according to the invention of claim 2. [Explanation of symbols] 10 Housing 12 Axial mirror deflector 17 Optical lens 1 step of correction) 25 light source

Claims (3)

[Claims] 1. An axial mirror deflector having an end of a rotating shaft as a reflecting mirror; a light source for making a light beam incident on the reflecting mirror of the axial mirror deflector; and a light beam deflected by the axial mirror deflector. a first mount to which the rotating shaft of the axial mirror deflector is rotatably mounted; and a first mount disposed at a position facing the first mount. , a second mount to which the light source is attached; and a third mount, which is arranged in the direction of deflection of the light beam by the axial mirror deflector and to which the light correction means is attached.
In the optical deflection device having a mounting base, the first to
An optical deflection device characterized in that at least two or more of the third mounts are integrally formed as one housing. 2. The optical deflector according to claim 1, wherein the first and third mounts are integrally formed as one housing, and the cross-sectional shape of the housing including the optical axis is approximately U-shaped. Device. 3. The light according to claim 1, wherein all of the first to third mounts are integrally formed as one housing, and the cross-sectional shape of the housing including the optical axis is approximately L-shaped. Deflection device.