JP2001315001A - Method of manufacturing plate for forming prism face of light guide member, method of manufacturing telescopic plate by using the plate, and die for manufacturing light guide member by using the plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a method of manufacturing a plate or a telescopic plate for forming a prism face, to be used in forming a prism sheet and a prism light guide plate in a very short time while keeping necessary accuracy. SOLUTION: The plate 1 for forming the prism face used in forming a prism master for a light guide plate, is attached to a rotary cylindrical body 2, and a fine irregular pattern 5 is formed on an outer peripheral face 3 of the plate 1 by working the outer peripheral face 3 with a lathe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method and a manufacturing method capable of forming a prism surface forming plate for forming a prism surface of a light guide member requiring a highly precise fine uneven surface, in a very simple manner. The present invention relates to a mold for manufacturing a light guide member using an electroformed nested plate or a mold directly using the plate.

[0002]

2. Description of the Related Art For example, a light guide member such as a prism sheet or a prism light guide plate used for a backlight device of a liquid crystal display is formed of an acrylic resin having excellent light transmittance. A fine saw-tooth pattern is formed to improve the state of the emitted light (for example, the scattering state).

[0003] These prism light guide members are formed by injection molding using a mold, but the fine uneven pattern formed on the prism light guide member is not directly formed on the cavity surface of the mold, and is generally formed. It is formed on a nested plate that is stretched over the cavity surface.

[0004] In the meantime, the fine concavo-convex pattern greatly affects the optical characteristics of the light emitted from the prism light guide member with a small error. Therefore, the fine uneven pattern of such a nested plate needs to be formed extremely precisely, and usually, a thick wall is formed by electroforming using the fine uneven surface of the cut prism-forming plate as a matrix. The nested plate is directly manufactured by casting a nested plate or directly performing a fine unevenness process with a diamond bite on a material plate having excellent machinability such as aluminum, copper, or brass.

In both the former case and the latter case, when the fine unevenness of the plate for forming the prism surface for electroforming or the fine unevenness is directly performed on the nested plate, a very small cutting amount of the diamond bit like a sawer is used. In this method, linear reciprocating movement was performed and the number of reciprocating movements was gradually increased while sequentially increasing the cutting amount, so that linear fine V-grooves were carefully formed one by one on the prism surface forming plate or the nesting plate. , A large amount of time is required for processing the fine V-groove, and the cost increases,
There is a problem that the prism sheet or the prism light guide plate as the final product is expensive. In addition, a special dedicated processing device must be prepared for the special processing, and there is a problem in production that processing destinations are limited.

[0006]

A first problem to be solved by the present invention is that a plate for forming a prism surface or a nesting plate for forming a light guide member such as a prism sheet or a prism light guide plate maintains required accuracy. The second is to develop a method for forming the prism surface in a very short time while applying the prism surface forming plate directly to the mold.

[0007]

A first aspect of the present invention relates to a first method of the present invention, wherein a plate (1) for forming a prism surface of a light guide member (6) is attached to a rotating cylinder (2), and a prism is formed. Turning the outer peripheral surface (3) of the surface forming plate (1) to form a fine uneven pattern (5) on the outer peripheral surface. "

Claim 2 relates to the second method of the present invention,
`` Plate (1) for forming prism surface of light guide member (6)
(4) Attached on the surface of the prism surface forming plate (1)
(3a) is milled to form a fine irregular pattern on the surface (3a).
Form (5) ".

According to the first method, fine V-groove processing can be performed with the accuracy (surface roughness) of the lathe because it is a normal lathe processing, and milling processing is performed according to the second method because it is a normal milling processing. Fine V-groove processing can be performed with the accuracy (surface roughness) possessed.
Since these lathe processing and milling have a processing speed several steps higher than that of the conventional special-purpose precision machine, the processing time can be greatly reduced.
As a result, the manufacturing cost of the prism surface forming plate (1) is greatly reduced, and the cost of the prism light guide member (6) such as a prism sheet or a prism light guide plate as a final product can also be reduced. Also, since lathes and milling machines are not general equipment but very general equipment, they are provided in many processing factories and there is no difficulty in selecting a processing destination.

[0010] Claim 3 is a nesting plate for a light guide member.
Regarding the manufacturing method of (a), "After separating the prism surface forming plate (1) formed in claim 1 from the rotating cylinder (2), the prism surface forming plate (1) is flattened, Electroforming the fine irregular surface of the plate for forming prism surface (1) as a master for electroforming and manufacturing a nested plate (a) arranged in the cavity (7a) ''. I do.

[0011] Claim 4 is a nesting plate for a light guide member.
(A) Another manufacturing method is described as follows: "After separating the planar prism surface forming plate (1) formed in claim 2 from the surface plate (4), the prism surface forming plate (1) Electroforming the fine uneven surface as a matrix for electroforming to manufacture a nested plate (a) disposed in the cavity (7a). "

By doing so, it is possible to manufacture the prism surface forming plate (1) which has the required accuracy and is a master mold for electroforming extremely easily and in large quantities, and a nested plate formed by electroforming. (B) The manufacturing cost can be significantly reduced.

A fifth aspect of the present invention relates to a case where the prism surface forming plate (1) formed in the first or second aspect is directly applied to the mold (7). The surface forming plate (1) is stretched over a mold block (7B) attached to the mold body (7A) so as to be exposed on the cavity surface of the cavity (7a). "

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. Plate for forming prism surface before processing
As (1), in the case of a metal plate, for example, a plated plate or a brass plate in which a machined surface of an aluminum plate, a copper plate, or a stainless steel plate having excellent workability and machinability is subjected to free-cut Ni plating is used. Of course, a resin plate can be used if it is excellent in workability and machinability. In this embodiment, a case where a brass plate is used will be described as a representative example.

The rotating cylindrical body (2) is mounted on a lathe (not shown) and rotates. As shown in FIG. 2, a rotating shaft (8a) is formed in a cylindrical or cylindrical shape on both end faces, and a center is formed at the center thereof. A drum body (8) having a hole (8b) formed therein and two chuck grooves (9) formed along the axial direction on opposite sides of the outer periphery of the drum body (8). A pair of L-shaped chuck members (10), inserted between the chuck member (10) and the chuck groove (9), and the end portion (1a) of the prism surface forming plate (1) before processing. Sandwich, for example, a chuck member
(10) and a pair of chuck blocks (11) fixed by bolts. A balancer (12) for smooth rotation is appropriately fixed to the side surface of the drum body (8).

The method of mounting and processing the prism surface forming plate (1) in the first method of the present invention will be described.
(1) is prepared, its end (1a) is bent, and the whole is bent along the drum body (8). After that, the drum body (8)
An L-shaped chuck member (10) and a chuck block (11) which are arranged along the outer peripheral surface of the prism surface forming plate (1) and are disposed in the chuck groove (9) of the drum body (8). Insert the ends (1a) of the prism surface forming plate (1) into the gaps (14) between them, and attach the chuck block (11) to the chuck member.
(10) Bolt is fixed together with the end (1a).

At this time, the L-shaped chuck member (1)
0) is attached to the groove bottom (9a) of the chuck groove (9) with a fixing bolt (13) through a slight gap, and by tightening the fixing bolt (13), the chuck block is tightened. (11)
At the same time, the chuck member (10) is moved in the direction of the groove bottom (9a), and the prism surface forming plate (1) before processing, which is stretched on the outer peripheral surface of the drum body (8), is stretched.

Next, the drum body (8) on which the prism surface forming plate (1) is attached is mounted on a lathe, rotated at high speed, and moved, for example, with a diamond bite parallel to the center axis of the drum body (8). (15) Plate for forming prism surface
The outer peripheral surface (3) of (1) is cut, and a fine V-groove (5a) is formed on the entire outer peripheral surface (3) of the prism surface forming plate (1) or by a required width. Cutting is performed with great care, and cutting is performed by reciprocating several times while adjusting the cutting depth. Of course, if the cutting conditions are appropriate, it is also possible to perform the fine uneven groove processing by one cutting.

The fine V-groove (5a) is a diamond tool
The accuracy is determined by the shape and cutting depth of the cut portion (15), the feed speed of the diamond bite (15), and the rotation speed of the drum body (8). The higher the rotation speed, the more beautiful the cutting. When the cutting is completed, the fixing bolt (13) is loosened, the cutting is completed, and the curved prism surface forming plate (1) is removed from the drum body (8). Thus, the prism surface forming plate (1) on which the fine uneven grooves are formed by the lathe is completed.

Next, a case where the prism surface forming plate (1) formed by the lathe is used as an electroforming master will be described. The prism surface forming plate (1) formed by the lathe is curved when detached from the drum body (8) and cannot be used as it is. Then, the plate (1) for forming the prism surface which is curved by the correction jig (20) as shown in FIG. 2 is returned to a flat plane.

The correction jig (20) includes a jig body (21) having fixed grooves (22) formed at both ends, a pair of chuck members (23) disposed in the fixed grooves (22), and the chuck. Consists of a chuck block (24) for fixing the end (1a) of the prism surface forming plate (1) to the member (23), and a flat surface plate block (25) fixed to the upper surface of the jig body (21). Have been. The curved prism surface forming plate (1) is placed on a flat surface plate block (25), and both ends (1a) of the prism surface forming plate (1) are attached to a chuck member (23) by a chuck block (24). Bolts,
The fastening bolt (26) of the chuck member (23) is tightened in the direction of the groove bottom (22a).

Thus, the prism surface forming plate (1)
Is pulled from both sides along the flat surface plate block (25),
Flattening is achieved. After that, the plate for forming the prism surface (1) is formed by a standard electroforming method using the flat uneven surface of the plate for forming the prism surface (1) as a matrix.
A relatively thick electroformed material is formed on the substrate, and a nested plate (a) having the required accuracy is formed by peeling the electroformed material. Electroforming can be repeatedly performed, and a plurality of nested plates (a) are formed from one matrix.

In the case of FIG. 3, another correction jig (20) is used. In this case, the upper surface of the platen block (26) is convexly curved in a convex columnar shape, and the prism surface forming plate (1) is used. Used when used in a slightly curved state. It is used for a light guide plate (6) having a concave surface on which a fine uneven surface is formed.
In this case, the "child plate" obtained by electroforming due to the curved surface is again used as a matrix, and the "grandchild plate" obtained by electroforming is used as a nested plate (a). In the two examples of the correction jig (20),
As a method of fixing the prism surface forming plate (1), both ends (1
Although the method of applying the tension from a) has been described, it is needless to say that the method is not limited to this, and an appropriate method such as an electrostatic chuck or a vacuum suction method may be employed as needed.

In the above case, when a resin plate is used as the prism surface forming plate (1) instead of the metal plate, the prism surface forming plate (1) is removed from the drum body (8) to obtain a flat plate. Since it returns to a flat surface, it is easier to handle than a metal plate.

Next, a nested plate formed by electroforming
The case where (a) is used will be described with reference to FIGS. The electroformed material (30) is cut in accordance with the cavity (7a) to obtain a nested plate (a). The nesting plate (a) obtained as shown in FIG. 6 is disposed in the cavity (7a), the mold is clamped in this state, and the resin is injected and filled into the cavity (7a) from the injection cylinder (40). The resin (42) injected and filled into the cavity (7a) passes through the cooling and
The fine concavo-convex pattern (5) formed on the surface of (a) is precisely transferred, and the molded product is taken out when the mold is opened. FIG. 6 shows an example in which the nesting plates (a) are provided on both sides of the cavity (7a), but it is needless to say that the nesting plates (a) may be provided on only one of them.

The prism light guide plate thus formed
(6) is assembled as a backlight device together with a light source (61), a reflection plate (62), a prism sheet (63), and a light diffusion sheet (64) as shown in FIG. 8, and is used together with a liquid crystal display panel (65). You.

Next, a case where the prism surface forming plate (1) is directly applied to the mold (7) will be described with reference to FIGS. Plate for forming a prism surface formed by the lathe
(1) is curved when removed from the drum body (8), and cannot be used as it is as described above.
Then, the curved prism surface forming plate (1) is returned to a flat plane by the correction jig (20) as shown in FIG. The difference from the case where the nesting plate (a) is formed by electroforming is that the straightening jig (20) is applied to the mold (7) “fixed mold in this case” as it is. Of course, it is also possible to apply to the moving mold side. In the case of FIG. 7, an example is shown in which a nesting plate (a) is provided on the movable mold side and a correction jig (20) is provided on the fixed mold side, but it is needless to say that the present invention is not limited to this. is not.

Here, there are two types of correction jigs (20), and the method of fixing the prism surface forming plate (1) to the correction jig (20) is as described above. . In the case of FIG. 7, the runner (41) is the chuck member (23).
Since it passes above, the upper end of the chuck member (23) extends to a position corresponding to the bent end of the prism surface forming plate (1). This part is indicated by (X). "Of course, this is not necessary if the mounting direction of the correction jig (20) is rotated by 90 degrees." In the example of FIG. 7, the mold block (7B) is the correction jig (20) and is fixed. The prism surface forming plate (1) is used by being fitted into the mold body (7A), which is a mold, and the cavity (7a)
Exposed on the cavity surface. And mold clamping as before,
The injection cylinder (40) injects and fills the resin into the cavity (7a), and then cools and maintains the pressure to obtain the fine uneven pattern (5).
Is precisely transferred to the molded article.

Next, the second method of the present invention will be described. In this method, a flat plate (1) for forming a prism surface before flat processing is prepared and fixed on a chuck plate (4) of a milling machine (not shown) by a method such as an electrostatic chuck or vacuum suction. The surface (3) of the prism surface forming plate (1) fixed on the surface plate (4) with a diamond tool (16), which is mounted on a milling machine, moves at a predetermined feed rate in one direction, and is rotating, Milling, fine V-groove (5
Form a).

In this case, since the milling is performed,
The groove (5a) becomes an aggregate of arcs, but the diamond bite (1
By making the diameter of the cutting locus of 6) sufficiently large, a fine V-groove (5a) approximated to a straight line is formed.

Also in this case, the accuracy of the fine V-groove (5a) is determined by the shape and cut amount of the cut portion of the diamond tool (16), the feed speed and the rotation speed of the diamond tool (16). The higher the rotation speed, the more beautiful the cutting. When the cutting is completed, the chuck is released and removed from the surface plate (4), and a necessary portion as a nest (a) is cut out from the prism surface forming plate (1) after the fine unevenness processing. In this case, since it is fixed to the flat surface plate (4), unlike the first method, there is no need to curve or flatten the prism surface forming plate (1), and the prism surface forming plate (1) Can be handled in a flat state. Of course, it is possible to use this as a mold for electroforming as described above.

The use of the prism surface forming plate (1) formed by milling as the nesting plate (a) is the same as described above, and it is also mounted on a correction jig (20) and mounted on a mold block. Since it is the same as that described above by fixing it to the mold body (7A) as (7B), its description is omitted for simplicity.

[Embodiment] Plate for forming prism surface (1)
Prepare a 0.4 mm thick brass plate for
This was set on a 0 mm rotating drum, and a fine V groove was cut with a lathe. The higher the rotation speed of the drum, the more beautiful the mountain was formed.

[0034]

According to the method of the present invention, the plate for forming the prism surface for forming the prism master for the light guide member is formed by lathe processing or milling processing. Since processing can be performed, the processing time can be significantly reduced, and the manufacturing cost of the prism surface forming plate can be significantly reduced. As a result, the cost of the prism sheet or prism light guide plate as the final product can be reduced.

Further, the nested plate is formed by flattening the plate for forming a prism surface formed in claim 1 or by electroforming a fine uneven surface of the plate for forming a prism surface in a flat state as a matrix for electroforming. By manufacturing the light-guiding member or mounting it directly on the mold block and attaching it to the mold body, the manufacturing cost of the light guide member can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state in which a plate for forming a prism surface is manufactured by a first method (lathe) of the present invention.

FIG. 2 is a front view of a jig for correcting a plate for forming a prism surface manufactured by the first method of the present invention.

FIG. 3 is a front view of another correction jig manufactured by the prism surface forming plate manufactured by the first method of the present invention.

4 is a perspective view of an electroformed member obtained by taking out a prism surface forming plate corrected by the correction jig of FIG. 2 as a matrix.

FIG. 5 is a perspective view showing a state in which a plate for forming a prism surface is manufactured by a second method (milling machine) of the present invention.

FIG. 6 is a cross-sectional view of a main part in a state where injection molding is performed using a nesting plate formed by the method of the present invention.

FIG. 7 is a cross-sectional view of a main part in a state where injection molding is performed using a nest plate and a mold block formed by the method of the present invention.

FIG. 8 is an exploded perspective view of a liquid crystal device using a light guide plate produced by the method of the present invention.

[Explanation of symbols]

 (B) Nesting (1) Plate for forming prism surface (1a) Edge (2) Rotating cylinder (3) Outer surface (4) Surface plate (5) Fine uneven pattern

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshimi Yoshizaki 2500-1 Oshihara, Komono-cho, Mie-gun, Mie Prefecture Inside Tortoise Engineering Co., Ltd. (72) Inventor Hiroshi Fujita 2-4-2 Nishiharacho, Niihama-shi, Ehime No. 34 Nissen Chemical Co., Ltd. F-term (reference) 3C045 DA03 4F202 AH76 CA11 CB01 CD12 CD18

Claims (5)

[Claims] 1. A light guide comprising: attaching a plate for forming a prism surface of a light guide member to a rotating cylinder; and lathing the outer peripheral surface of the plate for forming a prism surface to form fine irregularities on the outer peripheral surface. A method for manufacturing a plate for forming a prism surface of a member. 2. A light guide member according to claim 1, wherein the plate for forming the prism surface of the light guide member is stuck on a surface plate, and the surface of the plate for forming the prism surface is milled to form fine irregularities on the surface. A method for manufacturing a plate for forming a prism surface. 3. After the plate for forming a prism surface formed in claim 1 is detached from the rotating cylinder, the plate for forming a prism surface is flattened, and the fine uneven surface of the flattened plate for forming a prism surface is removed. A method for producing a nesting plate for a light guide member, comprising: producing a nesting plate which is electroformed as a matrix for electroforming and disposed in a cavity. 4. After the flat plate for forming a prism surface formed in claim 2 is detached from a surface plate, the fine uneven surface of the plate for forming a prism surface is electroformed as a matrix for electroforming. A method for manufacturing a nesting plate for a light guide member, comprising manufacturing a nesting plate disposed in a cavity. 5. The prism surface forming plate formed in claim 1 or 2 is stretched over a mold block attached to a mold body so as to be exposed on the cavity surface of the cavity. Light guide member manufacturing mold.