JPH11242177A - Deflecting scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost heat radiation structure for laser deflecting scanner and to prevent electric charging and discharging in an optical box. SOLUTION: In a deflecting scanner where a rotary polygon mirror 4 which deflects laser light and an electric motor which rotates and drives it are provided and the motor M is provided on as metallic substrate 6, a steel plate 3 for heat absorption is joined to the rear face of the substrate 6, and a part of the steel plate 3 is exposed to the outside of the optical box. A heat transmissive adhesive or a conductive adhesive is interposed between the substrate 6 and the steel plate 3. Further, a heat absorption plate 9 is brought into contact with an IC package for motor driving and is partially exposed to the outside of the optical box. A heat transmissive adhesive 10 is interposed between the IC package 5 and the heat absorption plate 9. The heat absorption plate 9 is made short and is stored in the optical box and is brought into contact with the steel plate 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for deflecting and scanning a laser beam. This apparatus is used, for example, in digital copiers, facsimile photoconductor exposure devices, laser printers, laser plotters, and the like.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for high-speed and high-definition image recording with a laser printer or the like. This speedup,
In order to achieve higher definition, it is necessary to rotate a rotary polygon mirror driving motor of a laser deflection scanner at a high speed. When the motor drive current is increased for high-speed rotation, the drive motor and an IC package for driving the drive motor are increased.
The calorific value of di increases.

On the other hand, an optical box in which a rotating polygon mirror is housed is
Due to the intensification of cost competition in recent years, it has become more common to use plastic instead of metal.However, in order to suppress wind noise of the rotating polygon mirror and adhesion of dirt such as dust to the rotating polygon mirror, use a cover or the like. In many cases, the space around the rotating polygon mirror is substantially closed. In this case, heat is stored inside the optical box, and an IC package for supplying electricity to the rotating polygon mirror driving motor is provided.
The temperature around the rotary polygon mirror may significantly increase due to heat generation of the bearing and the bearing portion of the rotary polygon mirror, and the life of the rotary polygon mirror may be reduced. Further, if a fan is provided for the above-described problem, the cost becomes very high.

To solve the above problems, for example,
Japanese Patent Publication No. 230306 discloses that a heat absorbing member having a large heat capacity and / or thermal conductivity, such as aluminum, is provided on the back surface of a mounting portion of an IC package of a metal substrate supporting a driving motor and an IC package. is suggesting.

[0005]

However, an absorbing member made of aluminum or the like having a large heat capacity and / or heat conductivity increases the cost. On the other hand, in general, when a metal member is present in a state where it is not electrically grounded in the machine, when a certain amount of charge accumulates, it is discharged at once, which may cause damage to an electric circuit or the like. For this reason, it is necessary to ground the metal heat absorbing member or the like using a harness or the like,
After all cost becomes high.

An object of the present invention is to eliminate or reduce the above problems.

[0007]

(1) The present invention comprises a rotary polygon mirror (4) for deflecting laser light and an electric motor (M) for rotating the mirror. Metal substrate (6)
In the deflection scanning device equipped above, the metal substrate (6)
Is characterized in that a steel plate (3) for heat absorption is provided on the back surface of the (FIG. 1).

To facilitate understanding, symbols or corresponding items of the corresponding elements of the embodiment shown in the drawings and described later are additionally provided in the parentheses for reference.

According to this deflection scanning device, since the steel plate (3) absorbs the heat of the metal substrate (6), the temperature rise of the metal substrate (6) is suppressed. Steel plates are inexpensive and can reduce the temperature rise around the rotating polygon mirror at low cost.

(2) The deflection in which the steel plate (3) is in contact with the back surface of the metal substrate (6) via a member (7) having a high thermal conductivity or the same thermal conductivity as a steel plate. Scanning device (Figure
2). Since the member (7) makes the steel plate (3) and the back surface of the substrate (6) surely come into contact with each other, the heat absorption efficiency of the steel plate (3) increases.

(3) A deflection scanning device (FIG. 3) in which the steel plate (3) is in contact with the back surface of the metal substrate (6) via a member (8) having high conductivity. The member (8) ensures that the steel plate (3) and the back surface of the drive motor substrate (6) are in contact with each other to increase the heat absorption efficiency, and that the steel plate (3) has substantially the same potential as the drive motor substrate (6). I do. By electrically grounding the drive motor substrate (6), the steel plate (3) is also grounded, so that the steel plate (3) does not accumulate static electricity and does not discharge.

(4) The IC package (5) for driving the electric motor is mounted on the same metal substrate (6) as the electric motor (M), and is mounted on the IC package (5). A deflection scanning device provided with a metal heat absorbing member (9) (FIG. 4). The IC package (5) absorbs heat from the steel plate (3) through the metal substrate (6) on the lower side and heat is absorbed by the metal heat absorbing member (9) on the upper side. Highly effective for suppressing the temperature rise of the package (5).

(5) The metal heat-absorbing member (9) is a member (10) having high thermal conductivity or having thermal conductivity comparable to that of a steel plate.
A deflection scanning device (FIG. 5) that is in contact with the IC package (5) via the IC. Since the member (10) makes the IC package (5) and the metal heat absorbing member (9) surely come into contact with each other, the heat absorbing efficiency of the metal heat absorbing member (9) increases.

(6) A deflection scanning device in which a part of the metal heat absorbing member (9) is in contact with the steel plate (3). Since the heat absorbing member (9) provided above the IC package (5) and the steel plate (3) provided below the motor board (6) are in contact, one of the steel plate (3) and the metal heat absorbing member (9) By extending only the outside of the optical box, there is only one heat radiating portion to the outside, and the internal heat can be effectively radiated to the outside, and a good heat radiating effect can be obtained at low cost. .

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

[0017]

FIG. 1 shows a main part of a first embodiment of the present invention. An electric motor M and an IC package 5 for driving the electric motor M are mounted on a motor board 6 made of a steel plate, and the rotary polygon mirror 4 is fixed to a rotating shaft of the electric motor M. In this embodiment, a steel case 3 bent in a z-shape is placed on a plastic case 1.
However, a part is stored outside the case, and is supported by the case 1 below. The motor substrate 6 is mounted on the upper surface of the inside of the case of the steel plate 3, and the motor substrate 6 is fixed to the case together with the steel plate 3 by screwing the motor substrate 6 to the case 1. . By this screwing, the steel plate 3 is
Then, the steel plate 3 is in close contact with the motor substrate 6. The upper opening of the case 1 is also closed by a plastic cover plate 2 in this embodiment. The case 1 and the cover plate 2 attached thereto constitute an optical box.

The heat generated by the electric motor M, the rotating polygon mirror bearing, the IC package 5, and the like mounted on the substrate 6 is transmitted to the steel plate 3 through the motor substrate 6, and the optical box (1 + 2) Dissipate outside. In addition, optical box (1+
If there is a gas in the inner space of 2), the heat is also radiated out of the optical box through the steel plate 3 according to the temperature difference from the temperature outside the optical box. That is, the heat in the optical box is
Dissipate out of the optical box through.

Second Embodiment FIG. 2 shows a main part of a second embodiment of the present invention. This second
In the embodiment, a heat transfer member 7 having adhesive properties on both sides is interposed between the steel plate 3 and the motor substrate 6. In this embodiment, the heat transfer member 7 is formed by applying an adhesive layer having high thermal conductivity to the front and back surfaces of a thin copper plate. The heat transfer member 7 may be only an adhesive layer having high heat conductivity, or may be a material obtained by applying an adhesive layer having high heat conductivity to a heat conductive metal such as an aluminum thin plate or a steel thin plate. The steel plate 3 is supported below by the case 1, and the motor substrate 6 is screwed to the case 1 to form a heat transfer member 7.
The steel plate 3 is pressed by the motor substrate 6, whereby the heat transfer member 7 is adhered to the motor substrate 6 in close contact, and the steel plate 3 is adhered to the heat transfer member 7 in close contact. Other configurations are the same as those in the first embodiment.

The heat of the motor substrate 6 is transmitted to the steel plate 3 through the heat transfer member 7 and dissipated outside the optical box 1.

Third Embodiment FIG. 3 shows a main part of a third embodiment of the present invention. This third
In the embodiment, between the steel plate 3 and the motor substrate 6, a highly conductive member 8 having adhesive properties on both surfaces is interposed. In this embodiment, the highly conductive member 8 is formed by applying a highly conductive adhesive layer to the front and back surfaces of a copper thin plate. The highly conductive member 8 may be only an adhesive layer having high conductivity.
A conductive metal such as a steel sheet may be coated with a highly conductive adhesive layer. The steel plate 3 is supported below by the case 1, and the motor substrate 6 is screwed to the case 1, whereby the highly conductive member 8 and the steel plate 3 are pressed by the motor substrate 6, thereby forming the highly conductive member. 8 is adhered to the motor substrate 6 in close contact, and the steel plate 3 is adhered to the highly conductive member 8 in close contact. Other configurations are the same as those in the first embodiment.

Since the motor substrate 6 is grounded through a harness (not shown), the steel plate 3 is also grounded through the highly conductive member 8, the motor substrate 6, and the harness. Therefore, since the steel plate 3 is not charged (potential rise),
No discharge occurs. Since the highly conductive member 8 has high thermal conductivity, the heat of the motor substrate 6 is transmitted to the steel plate 3 through the highly conductive member 8 and dissipated outside the optical box 1.

Fourth Embodiment FIG. 4 shows a main part of a fourth embodiment of the present invention. This fourth
In the embodiment, on the IC package 5 for driving the motor,
A z-shaped heat absorbing / dissipating member 9 is provided in contact with a part of the heat absorbing / dissipating member 9 and is out of the optical box (1 + 2). In this example,
The heat absorbing / radiating member 9 is also a steel plate, and the spring force thereof causes
It is in pressure contact with the package 5. The heat absorbing / radiating member 9 may be made of other metal having high heat conductivity, such as an aluminum plate or a steel plate, other than the steel plate. Other configurations are the same as those in the first embodiment.

The steel plate 3 absorbs the heat of the substrate 6 and absorbs the heat of the optical box (1).
+2), while the heat absorbing / radiating member 9 absorbs the heat of the IC package 5 which is one of the heat sources and emits it to the outside of the optical box (1 + 2).

Fifth Embodiment FIG. 5 shows a main part of a fifth embodiment of the present invention. This fifth
In this embodiment, a motor driving IC package 5 and a z-shaped heat absorbing / dissipating member 9 are joined by a heat transfer member 10 having adhesive properties on both surfaces. In this embodiment, the heat transfer member 10
Is a copper thin plate coated with an adhesive layer with high thermal conductivity on the front and back surfaces. The heat transfer member 10 may be only an adhesive layer having high heat conductivity, or may be a material obtained by applying an adhesive layer having high heat conductivity to a heat conductive metal such as an aluminum thin plate or a steel thin plate. Other configurations are the same as in the above-described fourth embodiment.

In this embodiment, since the heat transfer member 10 is in close contact with the IC package 5 and the heat absorbing and radiating member 9 is in close contact with this heat transferring member 10, the heat absorbing and radiating member 9 has a high effect of radiating heat, and a high effect of suppressing the temperature rise of the IC package 5.

Sixth Embodiment FIG. 6 shows a main part of a sixth embodiment of the present invention. This sixth
In the embodiment, the heat absorbing / radiating member 9 is L-shaped, and its short leg is fixed to the steel plate 3 by spot welding by spot welding.
Before the substrate 6 is placed on the steel plate 3, the heat absorbing / radiating member 9 is inclined in a direction closer to the steel plate 3 (downward to the left) than shown in FIG. When the substrate 6 provided with the motor M and the IC package 5 is supported by the steel plate 3, the heat absorbing / radiating member 9 is used.
Is spread in the direction away from the steel plate 3 within the range of its rigidity (within the spring limit), and the substrate 6 is placed between the steel plate 3 and the heat absorbing / radiating member 9.
And the IC package 5 to insert the substrate 6 on the steel plate 3. After the overlapping, the heat absorbing / radiating member 9 is pressed against the IC package 5 by its spring force.
In this state, the substrate 6 is screwed into the case 1 to obtain the shape shown in FIG. Other configurations are the same as in the fourth embodiment.

The heat of the IC package 5 for driving the motor is
The light is transmitted to the steel plate 3 through the substrate 6, is transmitted to the steel plate 3 also through the heat absorbing member 9, and is emitted out of the optical box through the steel plate 3. In this embodiment, similarly to the fifth embodiment shown in FIG. 5, a heat transfer member 10 may be interposed between the IC package 5 and the heat absorbing / radiating member 9.

In any case, in the sixth embodiment, the heat of the IC package 5 is absorbed by the steel plate 3 from above, but the heat absorbing / radiating member 9 does not come out of the optical box. The outer periphery of the optical box is simpler than in the case of the fourth and fifth embodiments. It is easy to assemble to a copier, printer, etc.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a main part of a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a main part of a third embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a main part of a fourth embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing a main part of a fifth embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing a main part of a sixth embodiment of the present invention.

[Explanation of symbols]

 1: Case of optical box 2: Cover plate of optical box 3: Steel plate 4: Rotating polygon mirror 5: IC package 6: Substrate 7: Heat conducting member 8: Highly conductive member 9: Heat absorbing / radiating member 10 ： Heat transfer material

Claims (6)

[Claims] 1. A deflection scanning device having a rotary polygon mirror for deflecting a laser beam and an electric motor for rotating the same, wherein the rear surface of the metal substrate absorbs heat. A deflection scanning device, characterized in that a steel plate is provided. 2. The deflection scanning device according to claim 1, wherein the steel plate is in contact with the rear surface of the metal substrate via a member having high thermal conductivity or a thermal conductivity similar to that of the steel plate. A deflection scanning device. 3. The deflection scanning device according to claim 1, wherein the steel plate is in contact with a back surface of the metal substrate via a member having high conductivity. 4. The deflection scanning apparatus according to claim 1, wherein the IC package for driving the electric motor is mounted on the same metal substrate as the electric motor, and a metal heat sink is provided on the IC package. A deflection scanning device comprising a member. 5. The deflection scanning device according to claim 4, wherein the metal heat absorbing member is in contact with the IC package via a member having high thermal conductivity or a thermal conductivity similar to that of a steel plate. A deflection scanning device, comprising: 6. The deflection scanning device according to claim 4, wherein a part of the metal heat absorbing member is in contact with the steel plate.