JP2002055300A - Optical scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a heat resistant structure of a polygon mirror drive assembly of an optical operating device. SOLUTION: A polygon mirror 10 is provided with a revolving shaft, not shown in Figure, at the center of rotation. The revolving shaft is inserted into a rotary bearing 14 and is rotatably held. The revolving shaft 14 is fastened to a case 30. A drive circuit substrate 20 of a motor 12 for rotating the polygon mirror 10 is mounted at the case 30. Further, the prescribed portion of the case in contact with the drive circuit substrate 20 is provided with heat radiation holes 32 formed by penetrating the case 30 so as to allow the easy radiation of the heat generated from an exothermic circuit element 22 mounted at the drive circuit substrate 20 to the outside. The heat radiation holes 32 are preferably disposed in the positions which are the same as the plane direction position of the substrate mounted with the exothermic circuit element 22 and face the surface on the side opposite to the substrate surface mounted with the exothermic circuit element 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device, and more particularly to a heat radiation structure having a polygon mirror structure.

[0002]

2. Description of the Related Art As a heat dissipation structure of a polygon mirror structure, for example, there is one disclosed in Japanese Patent Application Laid-Open No. Hei 10-111467. FIG. 6 shows a structure disclosed in the above-mentioned publication, in which a bearing device 3 of a rotating shaft 2 of a polygon mirror 1 is fixed to a support member 4 attached to a substrate 5 and a heat-generating component as a motor drive circuit element 6. Are provided in contact with the support member 4. A radiating fin 7 is attached near the heat-generating component attachment position of the support member and on the side opposite to the side where the polygon mirror 1 is provided.

FIG. 7 shows a structure in which a cooling device 8 formed of an electronic cooling element is attached to a support member 4. The support member 4 is formed of a material having high thermal conductivity. According to the above configuration, there is an effect that the support member facilitates diffusion of heat generated in the motor drive circuit element 6, the bearing device 3, and the like.

Further, regarding the heat dissipation structure of the polygon mirror, a material having high thermal conductivity such as an aluminum plate is brought into contact with the lower surface of the polygon mirror drive circuit, a heat pipe is attached to the aluminum plate, and the end of the heat pipe is put outside the case. There is known a structure in which the projection is protruded and the tip is attached to a radiation fin. This structure also has an effect of facilitating diffusion of heat generated in the motor drive circuit, the bearing device, and the like.

[0005]

However, in the above-mentioned prior art, the supporting member is limited to a material having a high thermal conductivity, and it is necessary to form a special structure such as a radiation fin or a heat pipe. However, there is a problem that the bulk increases.

Accordingly, the present invention has been made in view of the above problems, and has as its object to provide a heat dissipating structure of a polygon mirror structure which can be manufactured with a simple structure without providing a special member and at a low cost. .

[0007]

An optical scanning device according to the present invention comprises:
As basic means, a polygon mirror that reflects and deflects laser light, a support member that rotatably supports the polygon mirror, a motor that drives the polygon mirror to rotate, and a drive circuit that drives the motor are formed. A motor drive circuit board, the polygon mirror, the support member, the motor and the motor drive circuit board having a polygon mirror structure constituted by a case to isolate from the outside,
The case has a radiating hole for releasing heat generated by the polygon mirror structure to the outside in a region where the motor driving circuit board and the case overlap.

The heat radiation hole is located at a position substantially the same as the surface position of the motor drive circuit board to which the circuit element is mounted and opposed to a surface opposite to the surface of the substrate to which the circuit element is mounted. It is provided in.

In addition, the apparatus may further include a heat radiating device which is provided in the heat radiating hole while being in contact with the motor driving circuit board and radiating heat generated by the circuit element.

The motor drive circuit board is a double-sided mountable board, and the heat radiation hole is provided at a position where the circuit element provided on the substrate surface facing the case is arranged in the heat radiation hole, The apparatus may further include a radiator for radiating heat generated by the circuit element.

The motor drive circuit board further includes a connection member for electrically connecting the motor drive circuit to an external circuit, wherein the connection member is connected to the motor drive circuit and the external circuit via a heat radiation hole. It connects to a circuit.

A seal may be provided between the case and the motor drive circuit board at a portion where the case contacts the motor drive circuit board and between the case and the motor drive circuit board to prevent heat from entering the case. it can.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a heat dissipation structure of a polygon mirror structure according to the present invention will be described below with reference to FIG.

The polygon mirror 10 is provided with a rotating shaft (not shown) at the center of rotation, and the rotating shaft is inserted into a rotating bearing 14 and held rotatably. The rotating bearing 14 is the case 3
0. The case 30 includes a drive circuit board 20 for the motor 12 for rotating the polygon mirror 10.
Is also attached. Further, a heat radiating hole 32 formed through the case 30 is provided in a predetermined portion of the case 30 which comes into contact with the motor drive circuit board 20, and is generated from the heat generating circuit element 22 attached to the motor drive circuit board 20. The heat is easily dissipated to the outside. In addition,
The case 30 and the motor drive circuit board 20 are attached in close contact with each other, thereby isolating the inside of the case from the outside, that is, the outside world, and preventing dust from entering from outside.

The position of the heat radiating hole 32 is the same as the position in the surface direction of the substrate on which the heat generating circuit element 22 is mounted, and is provided at a position facing the surface opposite to the substrate surface on which the heat generating circuit element 22 is mounted. Is preferred.

According to the above configuration, the heat generated from the heat generating circuit element 22 is transmitted to the air near the heat radiating hole 32 via the substrate 20. Therefore, the generated heat is radiated to the outside of the case 30, and the heat generating circuit element 22 and the motor drive circuit board 20 do not overheat, and the ambient temperature inside the case 30 does not rise. Furthermore, the radiation fin like the conventional
The same heat radiation effect can be obtained only by providing the heat radiation holes 32 in the case 30 having the polygon mirror structure without separately providing a special structure such as a heat pipe.

Next, a second embodiment of the heat dissipation structure of the polygon mirror structure of the present invention will be described below with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, the motor drive circuit board 20 is changed to a board that can be mounted on both sides, and only the heat generating circuit element 22 is mounted on the board surface facing the case 30. The heat radiating hole 32 is provided at a position where the heat generating circuit element 22 is disposed in the heat radiating hole 32.

According to the above configuration, the heat generated from the heat generating circuit element 22 is directly transmitted to the air and is radiated to the outside of the case 30. Therefore, a better heat radiation effect can be obtained than in the first embodiment.

Next, a third embodiment of the heat dissipation structure of the polygon mirror structure of the present invention will be described below with reference to FIG. The same components as those in the above embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the present embodiment, the heat-generating circuit element 22 is mounted on a surface substantially the same as the surface direction of the substrate 20 to which the heat-generating circuit element 22 is mounted and opposite to the substrate surface on which the heat-generating circuit element 22 is mounted. The radiating fins 40 are provided in the radiating holes 32 provided facing the surface.

According to the above configuration, the heat generated from the heat generating circuit element 22 is transmitted to the heat radiation fins 40 via the motor drive circuit board 20. The heat conducted to the radiation fins 40 is transmitted to the air near the fin surface and is radiated to the outside of the case 30. Therefore, the heat radiation effect is larger than when the heat generated from the generated heat circuit element is transmitted to the air near the heat radiating hole via the base as in the embodiment described in the first embodiment.

In the above embodiment, the exothermic circuit element 22 is used.
Is the polygon mirror 10 with respect to the motor drive circuit board 20.
Although the aspect provided on the side has been described, the invention is not limited thereto.
In a mode in which the heat-generating circuit element 22 is provided on the substrate surface facing the heat-dissipating hole 32 and is located in the heat-dissipating hole 32, the heat-generating circuit element 22 is provided on the same substrate surface as the heat-generating circuit element 22. A radiating fin 40 may be provided in the radiating hole 32 so as to be in contact with the fin 22.

According to the above configuration, the heat generated from the heat-generating circuit element 22 is transmitted to the radiating fins 40, and the heat is transmitted to the air near the fin surface and is radiated to the outside of the case 30. Therefore, the heat radiation effect is larger than when the heat generated from the heat generating circuit element 22 is transmitted to the air near the heat radiation hole as in the embodiment described in the second embodiment.

Next, a fourth embodiment of the heat dissipation structure of the polygon mirror structure of the present invention will be described below with reference to FIG. The same components as those in the above embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, a packing 50 as a sealing member is provided between the case 30 and the motor drive circuit board 20 at a portion where the case 30 and the motor drive circuit board 20 are in contact with each other. This packing 50
Is preferably formed of, for example, a chloroprene rubber-based foam, particularly neoprene foam.

According to the above configuration, the heat generated from the heat generating circuit element 22 is transmitted to the air in the vicinity of the heat radiating hole 32 and is radiated to the outside of the case 30.
In some cases, the heat may not enter the case through the gap between the substrate and the substrate 20, and the heat may not be sufficiently transmitted. But,
As described above, the packing 5 is provided between the case 30 and the substrate 20.
By providing 0, the case 30 is sealed, so that heat does not enter the case 30 and heat is sufficiently radiated.

In FIG. 4, the mode in which the heat generating circuit element 22 is provided on the polygon mirror 10 side with respect to the motor drive circuit board 20 has been described.
The embodiment described in the embodiment and the third embodiment is also applicable. The packing 5 is added to the embodiment shown in the second and third embodiments.
By providing 0, the heat radiation effect is promoted.

In the above embodiment, the mode in which the heat generated from the heat-generating circuit element 22 is released to the outside of the case 30 has been described. However, the present invention is not limited thereto, and the mode in which the heat generated from other heat-generating members is released can be applied. . As an example, there is a rotary bearing 14. The release of heat generated in the rotary bearing is achieved by providing a heat dissipation hole near the bearing and conducting heat to the case.

Further, in the above-described embodiment, the heat radiating hole 32 penetrating the case 30 is provided only for releasing the heat generated by the heat generating member to the outside. However, the present invention is not limited to this. It goes without saying that the harness 70 to be electrically connected may function to be drawn into the motor drive circuit board 20 in the case 30. As shown in FIG. 5, one of the male connector and the female connector of the connector set 60 is provided on the surface of the motor drive circuit board 20 facing the case, and the other is provided on the harness 70 side.

According to the above configuration, the cover 3 is formed as in the prior art.
As compared with the case where the harness 70 is penetrated into the packing provided to secure the sealing performance inside the harness and draw the harness 70 into the case,
With a simple configuration, there is no need to provide a packing, and the connector 60 can be attached and detached with the hermeticity inside the case 30 secured.
That is, the harness 70 can be replaced.

[0032]

According to the optical scanning device of the present invention having the above-described structure, the heat radiation effect of the polygon mirror structure can be obtained by providing the heat radiation hole in the case. Therefore, it is possible to provide a heat dissipation structure of a polygon mirror structure which can be manufactured at a low cost with a simple structure without providing a special member. That is, the heat generated from the circuit element is transmitted to the air near the heat radiating hole via the substrate.
Therefore, the generated heat is radiated to the outside of the case, and the circuit element and the motor drive circuit board are not heated, and the ambient temperature inside the case does not rise. Further, similar heat radiation effects can be obtained only by providing heat radiation holes in the case of the polygon mirror structure without separately providing special structures such as heat radiation fins and heat pipes as in the related art.

Further, the heat generated from the circuit element is conducted to the heat radiating device via the motor driving circuit board. The heat conducted to the heat radiator is transmitted to the air near the heat radiator and is radiated to the outside of the case. Therefore, the heat radiation effect is larger than when heat generated from the circuit element is transmitted to the air near the heat radiation hole via the substrate.

The heat generated from the circuit element is transmitted to the air in the heat radiating hole and radiated to the outside of the case. Therefore, the generated heat is radiated to the outside of the case, so that the heat generating circuit element and the motor drive circuit board do not overheat, and the ambient temperature inside the case does not rise. Further, similar heat radiation effects can be obtained only by providing heat radiation holes in the case of the polygon mirror structure without separately providing special structures such as heat radiation fins and heat pipes as in the conventional case.

By providing the heat radiator, the heat generated from the circuit element is transmitted to the air near the heat radiator and radiated to the outside of the case. Therefore, compared with the case where the heat generated from the circuit element is transmitted to the air near the heat radiating hole,
Great heat dissipation effect.

The heat generated by the rotary bearings conducts through the case,
The heat is dissipated by being transmitted to the air in the heat dissipation hole.
Therefore, the generated heat is radiated to the outside of the case, so that the heat generating circuit element and the motor drive circuit board do not overheat,
The ambient temperature inside the case does not rise. Further, similar heat radiation effects can be obtained only by providing heat radiation holes in the case of the polygon mirror structure without separately providing special structures such as heat radiation fins and heat pipes as in the related art.

By disposing the connection member in the heat radiation hole, the connection member can be detached, that is, replaced, with a simple configuration, without the need to provide packing, and with the hermeticity inside the case secured.

Further, the case is sealed by providing a sealing member between the case and the substrate, so that heat does not enter the inside of the case and heat is sufficiently radiated.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a first embodiment of the present invention.

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

FIG. 3 is an explanatory view showing a third embodiment of the present invention.

FIG. 4 is an explanatory view showing a fourth embodiment of the present invention.

FIG. 5 is an explanatory view showing a fifth embodiment of the present invention.

FIG. 6 is an explanatory view showing a conventional device.

FIG. 7 is an explanatory view showing a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Polygon mirror 12 Motor 14 Rotating bearing 20 Motor drive circuit board 22 Heat generating circuit element 30 Case 32 Heat dissipation hole 40 Heat dissipation fin 50 Packing 60 Connector 70 Harness

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Masanobu Yamamoto 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Taka Kyosuke 22-22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Within Sharp Co., Ltd. (72) Inventor Seki Manabe 22-22, Nagaikecho, Abeno-ku, Osaka City, Osaka Prefecture Within Sharp Co., Ltd. (72) Toshio Yamanaka 22-22, Nagaikecho, Abeno-ku, Osaka City, Osaka Sharp Stock In-house F term (reference) 2C362 DA33 DA41 2H045 AA13 AA33 AA59 DA02 DA41 5C072 AA03 BA20 HA02 HA13 XA05

Claims (8)

[Claims] A polygon mirror for reflecting and deflecting a laser beam; a support member for rotatably supporting the polygon mirror; a motor for rotating and driving the polygon mirror;
A motor drive circuit board that forms a drive circuit that drives the motor, and a polygon mirror structure including a case that isolates the polygon mirror, the support member, the motor, and the motor drive circuit board from the outside; The optical scanning device according to claim 1, wherein the case has a radiating hole for releasing heat generated by the polygon mirror structure to an outside in a region where the motor driving circuit board and the case overlap. 2. The heat-dissipating hole is substantially the same as the surface direction position of the motor drive circuit board on which the circuit element is mounted, and is located at a position facing the surface opposite to the substrate surface on which the circuit element is mounted. The optical scanning device according to claim 1, wherein the optical scanning device is provided in the optical scanning device. 3. The optical scanning device according to claim 2, further comprising a heat radiating device provided in said heat radiating hole while being in contact with said motor driving circuit board and radiating heat generated by said circuit element. apparatus. 4. The motor drive circuit board is a double-sided mountable board, and the heat radiating hole is provided at a position where the circuit element provided on the board surface facing the case is arranged in the heat radiating hole. The optical scanning device according to claim 1, wherein: 5. The apparatus according to claim 1, further comprising: a heat radiating device provided in the heat radiating hole so as to contact the circuit element provided in the heat radiating hole, and radiating heat generated by the circuit element. Item 5. The optical scanning device according to item 4. 6. The optical scanning device according to claim 1, wherein the heat radiation hole is provided near the support member. 7. The motor drive circuit board further includes a connection member provided on the motor drive circuit board for electrically connecting the motor drive circuit to an external circuit, wherein the connection member is connected to the motor drive circuit via a heat radiation hole. The optical scanning device according to claim 1, wherein the optical scanning device is connected to the external circuit. 8. A sealing member for preventing heat from entering inside the case at a portion where the case and the motor driving circuit board are in contact with each other and between the case and the motor driving circuit board. The optical scanning device according to claim 1, wherein: