JP3129160B2 - LED printer head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED in which an insulating substrate on which a plurality of LED arrays are mounted is provided on a heat sink and a lens cover is provided on the heat sink so as to cover the insulating substrate. The present invention relates to a print head, and more particularly, to a sealing structure between the lens cover and the heat sink.

[0002]

2. Description of the Related Art Conventional LED printer heads A include those shown in FIGS. 5 and 6, in which an LED array 1 in which a plurality of LED chips are connected and a drive driver IC 2 for driving the LED array 1 are provided in a predetermined manner. A wiring pattern (not shown) is provided, and is linearly mounted on a conductor of an insulating substrate 3 made of, for example, a ceramic material (LED).
The array 1 and the driver IC 2 are wire-bonded by a connection member made of a gold wire or the like.) The insulating substrate 3 is an LED array 1 mounted on the insulating substrate 3.
In consideration of the heat generated by the heat sink, a heat conductor (not shown) made of silicon resin or the like is provided on the heat sink 4 made of a material such as aluminum having a substantially U-shaped cross section. A plurality of LEDs mounted on the insulating substrate 3 are disposed on the heat sink 4.
A lens cover 6 made of an aluminum material or the like having a condenser lens group 5 for condensing light emitted from the array 1 and irradiating the light to a photosensitive drum (not shown) is provided directly above the LED array 1. The heat radiating plate 4 and the lens cover 6 are fixed by screws 7 so as to cover the insulating substrate 3.

The pudding head A having such a configuration is provided with a heat radiating plate 4 or a lens cover 6 in consideration of prevention of printer toner from entering, prevention of deterioration of semiconductor due to entry of ozone generated from a charger (not shown), prevention of moisture entry, and the like. By applying a gel-like sealing agent 8 made of a silicone resin or the like to one of the joining surfaces 4a, 6a, and then fixing the heat sink 4 and the lens cover 6 with screws 7 as described above,
A sealant 8 for hermetically sealing a space a in which the insulating substrate 3 is provided between the heat sink 4 and the lens cover 6 from the outside is hermetically sealed. 6a is formed flat.

[0004]

However, the mounting position of the condenser lens group 5 provided on the lens cover 6 is
After being mounted so as to be at the center of a predetermined distance from the LED array 1 to the photosensitive drum, it is disposed on the heat radiating plate 4. A flat sealant 8 on each of the joining surfaces 4a and 6a.
LED (between several microns)
The distance from the array 1 to the condenser lens group 5 changes (the condenser lens group 5 is positioned above by the film thickness), so that the light emitted from the LED array 1 is transmitted to the condenser lens group 5. However, there is a problem that when irradiating the photosensitive drum through the optical disc, the focal position of the condensed light is shifted, thereby deteriorating the print quality.

In order to solve such a problem, it is conceivable to mount the condenser lens group 5 at a position in consideration of the film thickness of the sealant 8 in advance. However, the work of attaching the condenser lens group 5 in consideration of the film thickness is very complicated, and there is a problem that productivity cannot be improved, and it is not a complete solution.

When the amount of application is large, the heat sink 4
Since the sealant 8 is applied to substantially the entire area of the joint surfaces 4a, 6a between the lens cover 6 and the lens cover 6, the adhesion between the heat radiating plate 4 and the lens cover 6 is strong. A maintenance (for example, LE
D array 1 and drive driver 2 are replaced), heat sink 4
The repair work was very troublesome because the deformation and breakage of the lens and the lens cover 6 had to be considered.

Therefore, without changing the focal position of the light condensed through the condenser lens group, the space for disposing the insulating substrate between the heat radiating plate and the lens cover is airtightly sealed, Another object of the present invention is to provide an LED printer head sealing structure that can be easily maintained.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has an advantage in that a plurality of LED arrays are linearly arranged.
An edge substrate, a heat sink on which the insulating substrate is provided, and the LE
The light emitted from the D array is applied to the photosensitive drum.
A condensing lens group is provided to cover the insulating substrate.
LED with lens cover disposed on heat sink
In the printer head, the heat radiating plate and the lens cover are provided around an outer periphery of a joint between the heat radiating plate and the lens cover.
Taper or step at least one peripheral edge
Forming a sealing groove obtained by forming
It is characterized by being filled with a sealant .

[0009]

[0010]

By forming a sealing groove for sealing with a sealant at the joint between the heat radiating plate and the lens cover, it is possible to change the focal position of the light condensed through the condenser lens group (LED
It is not necessary to consider the distance from the array to the condenser lens group), and the space between the heatsink and the lens cover where the insulating substrate is provided is hermetically sealed from the outside.

When the sealing groove is formed by forming a tapered portion or a stepped portion on at least one peripheral edge of the heat radiating plate and the lens cover, when the sealing agent is filled with a dispenser or the like, the sealing groove is formed. Since the groove can be filled as a guide, the workability of the sealing step in the manufacturing process is reduced, and the filling amount of the sealing agent can be easily controlled. Also,
Since a part of each joint surface between the heat sink and the lens cover is filled with a sealant, the adhesion is weaker than in the past, and
When maintaining the ED printer head,
It is not necessary to consider deformation, breakage, and the like of the heat radiating plate and the lens cover, and the repair work can be reduced.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the embodiments shown in the accompanying drawings, but the same or corresponding parts as those in the conventional example will be denoted by the same reference numerals and detailed description thereof will be omitted.

FIG. 1 is a sectional view of an essential part of an LED printer head of a first embodiment, FIG. 2 is a perspective view of an LED printer head of a first embodiment, FIG. 3 is an enlarged sectional view of an essential part showing a second embodiment,
FIG. 4 is an enlarged sectional view of a main part showing a third embodiment.

The first embodiment will be described with reference to FIGS. 1 and 2. In the LED printer head B, an insulating substrate 3 on which electronic components such as an LED array 1 and a driver IC 2 are mounted is made of a heat conductive material made of silicon resin or the like. A lens cover 6 having a condenser lens group 5 is disposed on a heat radiating plate 9 described later in detail via a body (not shown). The lens group 5 is located so as to cover the insulating substrate 3, and the heat sink 9 and the lens cover 6 are fixed by screws 7.

The heat radiating plate 9 has a joint surface 9 with the lens cover 6.
a taper portion 9b is formed at the peripheral edge of the lens cover 6a, that is, the taper portion 9b is formed at the peripheral edge of each of the joining surfaces (joining portions) 6a, 9a between the lens cover 6 and the heat radiating plate 9. To form a sealing groove 10 for filling. Therefore, after fixing the heat radiating plate 9 and the lens cover 6 with the screw 7, the sealing groove 8 is filled with the sealing agent 8 by a dispenser or the like, so that the insulating substrate between the heat radiating plate 9 and the lens cover 6 is formed. 3 is to hermetically seal the space a where the 3 is disposed from the outside.

Next, second and third embodiments of the sealing groove formed on the joint surface between the heat sink and the lens cover will be described with reference to FIGS.

The second embodiment will be described with reference to FIG. 3. The joint surfaces 11a and 12a of the lens cover 11 and the heat sink 12 will be described.
Each of the tapered portions 11b and 12b is formed at the peripheral edge of a, and a sealing groove 13 for filling the sealing agent 8 at the peripheral edge of each of the joint surfaces 11a and 12a.

Referring to FIG. 4, the third embodiment will be described. The heat radiating plate 14 has a stepped portion 14b formed at the peripheral edge of the joint surface 14a with the lens cover 6 to allow the lens cover 6 and the heat radiating plate 14 to be connected to each other. A sealant 8 is provided on the peripheral edge of each joint surface 6a, 14a.
To form a sealing groove 15 for filling.

In the LED printer head B, a tapered portion 9b (11b, 12b) or a step 14b is formed at the peripheral edge of each joint surface between the lens cover 6 (11) and the heat radiating plate 9 (12, 14). This constitutes the sealing groove 10 (13, 15) for filling the sealing agent 8, and since the sealing agent 8 does not intervene between the joining surfaces as in the related art,
The lens cover 6 (11) and the heat radiating plate 9 (12, 1) are kept without changing the focal position of the light condensed through the condenser lens group.
4), the space a in which the insulating substrate 3 is disposed can be hermetically sealed from the outside. In addition, the sealing groove 10 (1
By configuring (3, 15), the lens cover 6 (11)
After fixing the heat radiation plate 9 (12, 14) with the screw 7, the sealing groove 10 (13, 15) is formed by using a dispenser or the like.
Can be used as a guide to fill the sealing agent 10, so that the sealing operation in the manufacturing process is reduced, and the filling amount can be easily managed. Also, the heat sink 9 (12, 14)
Of the joint surface between the lens and the lens cover 6 (11) (sealing groove)
Only the sealant 8 is filled in the heat sink 9 (12, 1).
4) and the lens cover 6 (11) have weaker adhesion than before (because there is no close contact between the joining surfaces), and even when the lens cover 6 (11) is detached and maintenance is performed, the heat radiating plate 9 (12) is removed. , 14) and the lens cover 6 (11), etc., without the fear of deformation, breakage, etc., and can be easily repaired.

The present invention according to claim 1 is not limited to the shape of the sealing groove described in the above embodiment. For example, the present invention may be applied to the peripheral edge of each joint surface between the heat sink and the lens cover. A step may be formed as shown in FIG. 4 to form a sealing groove.

[0021]

According to the present invention, a plurality of LED arrays are linearly arranged.
Insulating substrate to be disposed on a heat sink
And the light emitted from the LED array is applied to the photosensitive drum.
A condenser lens group for irradiation is provided, and the insulating substrate is
And a lens cover disposed on the heat sink to cover the lens cover.
In the LED printer head provided , the heat radiating plate and the laser
At least one peripheral edge with the lens cover
Or a sealing groove obtained by forming a step portion,
A space formed by the heat radiating plate and the lens cover without changing a focal position of light condensed through a condenser lens group, wherein the sealing groove is filled with a sealing agent. The part can be hermetically sealed from the outside.

[0022] The sealing groove from that obtained by forming a tapered portion or a step portion on at least one perimeter edge of the lens cover and the radiator plate, screws or the like and the lens cover and the heat radiating plate After fixing, the sealing agent can be filled using the sealing groove as a guide using a dispenser or the like, so that the workability of the sealing step in the manufacturing process is reduced and the filling amount is easily managed. In addition, since only a part (sealing groove) of each joint surface between the heat radiating plate and the lens cover is filled with the sealing agent, the adhesion between the two members is weak, and the lens cover is removed for maintenance. In this case, there is an effect that the repair work can be easily performed without worrying about deformation, breakage, and the like of the heat sink and the lens cover.

[Brief description of the drawings]

FIG. 1 is an essential part cross-sectional view showing an LED printer head according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing the LED printer head of the first embodiment.

FIG. 3 is an enlarged sectional view of a main part showing a second embodiment of the present invention.

FIG. 4 is an enlarged sectional view of a main part showing a third embodiment of the present invention.

FIG. 5 is a sectional view of a main part showing a conventional LED printer head.

FIG. 6 is a perspective view showing a conventional LED printer head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 LED array 3 Insulating board 9, 12, 14 Heat sink 9a, 12a, 14a Joining surface (joining part) 5 Condensing lens group 6, 11 Lens cover 6a, 11a Joining surface (joining part) 10, 13, 15 Sealing Groove a Space B LED printer head

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/44 B41J 2/45 B41J 2/455 H04N 1/036

Claims (1)

(57) [Claims] 1. A plurality of LED arrays are arranged in a straight line.
An insulating substrate; a heat sink on which the insulating substrate is disposed;
Irradiate light emitted from ED array to photosensitive drum
And a condenser lens group for covering the insulating substrate.
LE having a lens cover disposed on the heat sink
In D the printer head, the junction periphery of the lens cover and the radiator plate, wherein
At least one peripheral edge of the heat sink and the lens cover
Obtained by forming a tapered part or a step part in the part
Providing a sealing groove and filling the sealing groove with a sealing agent
LED printer head according to claim.