JPH06337365A - Light deflector - Google Patents

Abstract

PURPOSE:To effectively utilize air flow blown out from an opening part of a cover. CONSTITUTION:This deflector is provided with a rotary polygon mirror 1 rotated at high speed and the cover 2 provided with a cylindrical part consisting of a cylindrical wall 3 and the top wall covering the outer periphery of the mirror 1, and the opening part 5 causing a laser beam L1 being a lighting beam outgoing from a light source S1 to pass through is provided on the cylindrical wall 3. The opening part 5 has a nearly square shape having a pair of side edges 5a, 5b prolonging in parallel to the rotary shaft of the rotary polygon mirror 1, and a long-length plate-shaped guide member 6a guiding so as to blow the air flow blown out from the opening part 5 to the light source S1 is projected on one side side edge 5a. Thus, the air flow blown out from the opening part 5 flows as shown by a void arrow and is blown on the light source S1, and the light source S1 is cooled off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical deflector for deflecting and scanning a laser beam or the like at a high speed in a laser printer or the like.

[0002]

2. Description of the Related Art Optical deflectors for laser printers, laser facsimiles and the like have been particularly accelerated in recent years, and rotary polygon mirrors used for these deflectors rotate at high speeds of 10,000 or more revolutions per minute. When the rotary polygon mirror is rotated at such a high speed, the wind noise during rotation is increased and a large noise is generated. Therefore, the periphery of the rotary polygon mirror is covered with a substantially cylindrical cover.

FIG. 4 illustrates a general optical deflector as a whole. A laser oscillator S mounted on an optical box 100 is shown.
_The laser light L ₀ generated from ₀ is condensed into a predetermined beam shape by the cylindrical lens C ₀ , and then is deflected and scanned by the rotary polygon mirror 101 to form an image forming lens system F _0.
Then, an image is formed on the photosensitive drum D ₀ . Rotating polygon mirror 101
A part of the laser light reflected by is introduced into the optical fiber B ₀ by the reflection mirror M ₀ and converted into a scanning start signal.

FIG. 3 shows the rotary polygon mirror 101 and its drive unit. The drive unit of the rotary polygon mirror 101 is a rotary shaft 111.
And the rotor magnet 112 integrally connected to the
The rotary polygon mirror 1 includes a stator coil 114 that is integral with a bearing device 113 that supports the rotary shaft 111, and a circuit board 115 that supplies a drive current to the stator coil 114.
01 is a corrugated washer 116a and a flat washer 116b
A pressing mechanism 116 including a stopper ring 116c presses the flange member 111a, which is integrated with the rotating shaft 111, and thereby is integrated with the rotating shaft 111. The rotary polygon mirror 101 is covered with a substantially cylindrical cover 102, which limits the flow of air accompanying the rotation of the rotary polygon mirror 101, reduces wind noise, and reduces wind noise. To prevent leakage. The cover 10
The second cylindrical portion 102a has a window 10 through which laser light passes.
3 is provided.

[0005]

However, in the above-mentioned conventional technique, the air flow blown from the window of the cover is merely scattered outside the cover, and the blown air flow cannot be effectively used. There was a problem.

An object of the present invention is to realize an optical deflector capable of effectively utilizing the air flow blown from the opening of the cover.

[0007]

In order to achieve the above object, an optical deflector of the present invention comprises a rotary polygon mirror for deflecting and scanning illumination light emitted from a light source, and a cover having a cylindrical portion covering the outer periphery thereof. An opening for passing the illumination light is provided in the cylindrical portion, and a guide member for guiding an air flow blown out from the opening toward the light source is provided. is there.

[0008]

The air flow blown from the opening is guided by the guide member and blown against the light source of the illumination light, so that the light source can be cooled.

[0009]

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

FIG. 1 is a partial schematic sectional view showing a main part of one embodiment, and FIG. 2 is a schematic perspective view of a cover in the embodiment shown in FIG.

The optical deflector of the present embodiment has a rotary polygon mirror 1 which is rotated at a high speed by a drive motor (not shown), and a cover 2 having a cylindrical portion which covers the outer circumference thereof and a cylindrical wall 3 and a top wall 4. The cylindrical wall 3 is provided with an opening 5 for passing the laser light L ₁ which is the illumination light emitted from the light source S ₁ . The cover 2 is attached to a circuit board 7 of a drive motor that drives the rotary polygon mirror 1.

A laser beam L ₁ emitted from a light source S ₁ composed of a semiconductor laser or the like passes through a collimator lens C ₁ to become a parallel light beam, which is applied to the reflecting surface 1 a of the rotary polygon mirror 1. The parallel light flux irradiated on the reflecting surface 1a is deflected and scanned by the rotation of the rotary polygon mirror 1, passes through an imaging lens system F _{1 including} a spherical lens R ₁ and a toric lens T ₁ , and
An image is formed on the photosensitive drum D ₁ .

The opening 5 has a substantially rectangular shape having a pair of side edges 5a and 5b extending parallel to the rotation axis of the rotary polygon mirror 1, and the opening 5 is formed on one side edge 5a. A long plate-shaped guide member 6a for guiding the air flow blown out from the air source toward the light source S ₁ made of a semiconductor laser or the like is projected. In addition, the other side edge 5 of the opening 5
A short plate-shaped guide member 6b that guides the air flow sucked into the cover 2 is provided on b.

In the present embodiment, when the rotary polygon mirror 1 rotates at a high speed, the air inside the cover 2 also flows at a high speed in the circumferential direction along with this, and a part of the opening 5 becomes a high-speed air flow. Is blown out from the blowing side. The blown airflow is guided by the guide member 6a and flows as shown by the white arrow,
The light source S ₁ is cooled by being blown toward the light source S _1.

In the above-mentioned embodiment, when the heat-generating mounted components such as the IC and the resistance of the drive motor (not shown) provided on the circuit board 7 are arranged in the air flow indicated by the white arrow, these components are generated. It can also serve to cool the mounted parts.

In the above-described embodiment, the cover is attached to the circuit board, but the same effect can be expected if the cover is provided integrally with the lid for sealing the inside of the optical box.

[0017]

Since the present invention is configured as described above, it has the following effects.

The airflow blown out from the opening is guided by the guide member and blown against the light source, so that the light source can be cooled. As a result, it is not necessary to separately provide a cooling device for the light source, and the device can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a partial schematic sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is a schematic perspective view of a cover in the embodiment shown in FIG.

FIG. 3 is a partial schematic sectional view of a conventional optical deflector.

FIG. 4 is an explanatory diagram showing an entire conventional optical deflector.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 rotating polygonal mirror 1a reflective surface 2 cover 3 cylindrical wall 4 top wall 5 openings 5a, 5b side edges 6a, 6b guide member 7 circuit board 8 optical box C ₁ collimator lens F ₁ imaging lens system S ₁ light source

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hideyuki Miyamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kenichi Tomita 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Yasuo Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (4)

[Claims] 1. A rotary polygon mirror that deflects and scans illumination light emitted from a light source, and a cover having a cylindrical portion that covers the outer periphery thereof, and an opening that allows the illumination light to pass through is provided in the cylindrical portion. An optical deflector provided with a guide member for guiding the airflow blown from the opening toward the light source. 2. The optical deflector according to claim 1, wherein the guide member is provided so as to project from the cylindrical portion of the cover. 3. The optical deflector according to claim 1, wherein the guide member is provided so as to protrude from the optical box. 4. The optical deflector according to claim 1, wherein the guide member is provided on a lid that seals the inside of the optical box.