TWI438510B - Manufacturing method of light guide plate and light guide plate - Google Patents

Description

Light guide plate manufacturing method and light guide plate

The present invention relates to a method of manufacturing a light guide plate used for a display panel such as a liquid crystal panel provided in a mobile phone, and the like, and more particularly to a surface of a light-transmissive plate formed by an injection molding machine, by attaching a special The manufacturing method of the light guide plate and the light guide plate which can make the film uniformly light on the ground.

In recent years, in a relatively small-sized liquid crystal display monitor, a light guide plate that emits light uniformly on the ground is used. In the light guide plate, a condensed pattern in which light is reflected on one side of a plate made of an acrylic resin is provided, and a diffusion pattern in which the front side is condensed to increase the brightness on the other surface is provided.

However, in the case of manufacturing a light guide plate, an injection molding machine is usually used. However, in recent years, the molding cycle time of one cycle in forming the light guide plate takes about 13 seconds to 15 seconds. Therefore, it is desirable to further shorten the molding cycle time. On the other hand, since the sheet used as a part of the light guide plate formed in the cavity of the mold is formed together with the sheet material when being formed by the injection molding machine, the runner forming portion (which is formed by the forming loss) The portion formed by the corresponding passage or the flow path portion (the portion formed corresponding to the flow path) is taken out in a state of being integrally formed with the plate material, so that removal work must be performed to remove the runner formation which becomes the forming loss. Department and flow path forming unit. Further, in the removal operation or after the removal of the work, it is necessary to perform an inspection operation such as whether it is a defective product, and further, after the inspection operation, the surface of the condensing pattern and the diffusion pattern provided on both sides of the sheet material is attached and protected. The membrane is protected from dirt or scratches. Furthermore, such inspection work or the attachment of the protective film must actually be performed by a skilled operator. Use manual work or visual inspection.

Patent Document 1 which is a related art of the above-described method for producing a light guide plate discloses a method of injection compression molding in which a mold cavity is shortened in order to shorten a molding cycle time when a light guide plate having a relatively small thickness is manufactured. The formation surface is cooled by a cooling medium flowing through the cooling medium flow path, and the other cooling medium flow paths different from the cooling medium flow path are cooled to a lower temperature than the cooling medium flow path of the cooling cavity forming surface A small light guide plate that speeds up the injection speed.

Further, Patent Document 2 discloses a molding die for forming a light guide plate in a cavity forming portion formed between molds, which is a cooling cavity bushing and a cavity forming portion disposed around the cavity. The cooling medium flow paths are independent of each other, and even if the runners are thinned, they can be compressed and formed while maintaining the pressure retention corresponding to the cooling shrinkage of the molten resin in the cavity, and the flow path forming portion or the runner formation which is reduced in forming loss can be reduced. The ratio of the department to increase the yield or to shorten the molding cycle time.

[Patent Document 1] Japanese Patent No. 4044608

[Patent Document 2] Japanese Patent No. 4047917

In the above-mentioned Patent Document 1 and Patent Document 2, both of them are techniques for improving the manufacturing efficiency of the light guide plate. However, if the molding cycle time is shortened, the productivity of the light guide plate is drastically improved. Harder. In other words, the molding cycle time of one cycle usually takes about 15 seconds, and even if the injection speed is increased or decreased to the volume of the runner forming portion of the molding loss, only It is only a matter of shortening the molding cycle time, and it is difficult to achieve the purpose of greatly improving the production efficiency of the light guide plate.

The present invention has been developed to solve the above problems, and an object of the present invention is to provide a method of manufacturing a light guide plate and a light guide plate manufactured by the method, which is not shortened by an injection molding machine or the like when manufacturing a light guide plate. The molding cycle time is automated by a person who has been manually operated by a previously skilled operator, and the productivity in manufacturing the light guide plate is improved.

A method of manufacturing a light guide plate according to claim 1 is characterized in that the screw provided in the heating cylinder is retracted while rotating, and the molten resin is measured. After the measuring step, the screw is advanced and installed. An injection nozzle at a front end of the heating cylinder barrel, the molten resin is ejected to a cavity formed by a fixed mold fixed to the fixed template and a movable mold fixed to the movable mold set to advance and retreat, and Forming a transparent plate by an injection molding machine, and attaching a film to the upper surface of the plate formed by the injection molding machine, and comprising the fixed mold and the movable mold provided in the injection molding machine After forming the plate material by the cavity, discharging the plate adhered in the cavity, and taking out the discharged plate as a take-out device; placing the lower surface of the plate on the bottom film wound from the first film roll in the horizontal direction After the specific placement position on the upper surface, the upper surface of the plate is conveyed in a state of being placed on the bottom film wound from the first film roll. Placing the second film from the unwinding roll The upper film, the upper film and the bottom film are attached to the plate; and the plate to which the upper film and the bottom film are attached in the horizontal direction are attached, and the cutter provided in the cutting device slides in the vertical direction The upper film and the bottom film which are attached to the above-mentioned sheet material are cut.

The method of manufacturing a light guide plate according to claim 2, wherein the take-out device includes a holding device that attracts the plate by generating a negative pressure, and the attraction device is retained by the holding device. The removed sheet material is placed on a specific mounting position on the bottom film.

The method of manufacturing a light guide plate according to claim 2, wherein the film forming apparatus provided in the other embodiment of the injection molding machine includes at least the first film roll and the a second film reel and the cutting device; the film forming processing device is disposed on a side portion of the injection molding machine; and a fetching device is disposed on the virtual line, the imaginary line is connected from the shortest distance in a straight line a cavity of the mold of the molding machine takes out a take-out port in the vicinity of the cavity of the plate material, and a specific mounting position on which the plate material is placed on the bottom film by the film forming processing device; The sheet material taken out at the vicinity of the outlet is conveyed to the specific placement position at the shortest distance.

The method of manufacturing a light guide plate according to claim 4, wherein the injection molding machine and the film forming processing device are interleaved in plural, and corresponding to each of the injection moldings. The machine is provided with one of the above-mentioned film forming processing devices on the side portions thereof, and the above-mentioned shots are The forming machine and the film forming apparatus described above are provided in a one-to-one manner as a unit, and the unit is provided in parallel, and the light guide plate is continuously mass-produced in parallel.

The light guide plate of claim 5, wherein the upper film and the bottom film are used as a protective film in the light guide plate manufacturing method according to claim 3 or 4, and the protective film is attached by a film forming processing device. It is formed on the top of the above plate.

According to the present invention, since the sheet metal is formed by the injection molding machine when the light guide plate is manufactured, it is not manually operated by a skilled operator as before, but the film forming processing apparatus can be automatically carried out under the sheet. The step of manufacturing a light guide plate by attaching a protective film or the like, so that the manufacture of the light guide plate can be performed for a short period of time and can prevent the occurrence of scratches or soiling on the upper surface of the sheet due to manual work by humans, thereby reducing the accompanying Poor workmanship can further increase yield and increase production efficiency.

Furthermore, since the plate taken out from the outlet near the cavity to the specific placement position of the film forming apparatus can be transported at a short distance, before the fine dirt such as dust or worm adheres to the transparent plate, The surface of the sheet is protected with a protective film to further increase the yield. Further, since the protective film attaching step is automatically performed by the film forming processing apparatus, the attaching step time for manufacturing the light guiding plate can be shortened, and the production efficiency can be improved.

In addition, since the injection molding machine for forming a sheet material and the film forming apparatus are provided in a unit of one to one and a plurality of units, the light guide plate can be mass-produced, and can be manufactured by each film forming apparatus. Guide light The plates are discharged from the same direction, so that the operation of the robot or the person using the light guide plate after the discharge can be performed easily and in a short time and efficiently.

Hereinafter, the preferred embodiment will be described with reference to Figs. 1 and 2 for the purpose of carrying out the invention. Of course, the present invention is not limited to the scope of the invention, and the structure other than the ones described in the embodiments can be easily applied.

1 is a schematic view showing a state in which a unit including an injection molding machine, a film forming apparatus, and the like are plurally arranged as viewed from above, and FIG. 2 is a front view showing a configuration of a film forming processing apparatus. As shown in Fig. 1, each of the injection molding machine 1 and the film forming and processing device 2 includes one take-out device 3, and these are arranged as a single unit 4, and the take-out device 3 is connected to the injection molding machine 1 and the film forming processing device 2. Arranged between the ways.

The injection molding machine 1 includes a mold fastening unit 5 and an injection unit 6, and the mold fastening unit 5 includes a movable mold 8 including a movable mold 8 fixed to the movable die plate 7, and a fixed mold 10 fixed to the fixed mold 9. The fixed mold 10 moves the movable mold 8 forward and backward to perform a mold opening and closing switching link mechanism or the like.

The injection unit 6 includes a funnel 11 into which a granular material, that is, a resin (pellet), into which the granular resin is dropped by the funnel 11 and put into a cylindrical heating cylinder 12 provided below it. The molten resin which is supplied to the heating cylinder 12 and which is plasticized by heat is measured by being rotated while being rotated by a screw (not shown) provided in the heating cylinder 12, and after the measuring step, the screw is advanced. Injection from the front end of the heating cylinder 12 The nozzle 13 emits molten resin to a cavity formed by the fixed mold 10 and the movable mold 8 at the time of mold closing, and forms a sheet B as a molded body. Further, in the injection molding machine 1 of the present embodiment, since the plate material B formed by the cavity is used as a transparent body for the light guide plate, a condensed pattern is provided on each side (upper and lower faces) of the transparent plate material B. And a diffusion pattern, and a light guide plate to which a protective film described later is attached is formed on the surface of the condensing pattern and the diffusion pattern.

Next, a film forming processing apparatus will be described with reference to Fig. 2 . The film forming apparatus 2 shown in Fig. 2 attaches the first protective film 20 as a bottom film to the lower surface of the sheet B formed by the injection molding machine 1, and attaches the second protective film as the upper film thereon. The film 21 is thereafter cut by the first protective film 20 and the second protective film 21 attached to the sheet B, and the steps of the steps are automated, and the first protective film 20 is wound. The film roll 22 and the second film roll 23 wound by the second protective film 21 are provided on the upper and lower pairs of the first induction rolls 24, the second induction rolls 25, the conveyance roller group 26, and the first cut. The protective film 20 and the cutting device 27 of the second protective film 21 and the like. In addition, the first and second film reels 22 and 23 and the first induction roller 24, the second induction roller 25, and the conveyance roller group 26 are rotatably supported, and are driven as a motor of a rotation drive mechanism (not shown). The source transports the first protective film 20 (from the left to the right direction as shown in FIG. 2).

The take-out device 3 shown in FIG. 1 can take out the sheet B formed by the cavity of the mold of the injection molding machine 1 from the take-out port a near the cavity, and mount it on the specific placement of the film forming processing apparatus 2. At position b, in the take-out device 3, the sheet B is taken out from the take-out port a near the cavity, and the holding device for sucking the sheet B by the negative pressure is provided to hold the sheet B attracted by the device from the take-out port a. It is conveyed and placed on the specific mounting position b on the upper surface of the first protective film 20 as shown in FIG. Further, in the mold opening state in which the movable mold 8 is retracted as shown in FIG. 1, the take-out port a in the vicinity of the cavity and the specific mounting position b on the upper surface of the first protective film 20 are disposed. On the imaginary line X connected by the shortest distance on the straight line, the sheet material can be conveyed by the take-out device 3 from the take-out port a near the cavity to the specific placement position b at the shortest distance.

Next, the procedure of attaching a protective film to a sheet formed by an injection molding machine and manufacturing a light guide plate will be described. The sheet B which is formed in the vicinity of the cavity of the injection molding machine 1 and which is formed by the injection molding machine 1 is sucked and held by the holding device of the take-up device 3, and is the first from the film forming and processing device 2 The film roll 22 is wound up and placed on a specific mounting position b that passes through the upper surface of the first protective film 20 of the first induction roll 24.

Then, the second protective film 21 that has been wound by the second induction roll 25 from the second film roll 23 is placed on the upper surface of the plate material B placed on the first protective film 20, and then the second induction roller 25 is used. In the conveyance roller group 26 and the like, it is confirmed that the first protective film 20 and the second protective film 21 are surely attached to the respective surfaces of the sheet material B, and are not peeled off.

Then, the sheet material B to which the first protective film 20 and the second protective film 21 are attached is further horizontally oriented by the first induction roller 24, the second induction roller 25, the conveyance roller group 26, and the like (right as shown in FIG. 2). In the direction of the induction, when the specific cutting position c is reached, the rotation driving mechanism is stopped. In this state, the cutter 31 formed by the cutting device 27 is lowered in the vertical direction, and the first protective film 20 and the second protective film are stopped. 21 cutting, that is, the manufacture of the light guide plate is completed. Further, by repeating this operation, the manufacture of the light guide plate can be repeated.

According to the embodiment as described above, the screw provided in the heating cylinder tube 12 is made The rod is rotated while being retracted to measure the molten resin. After the measuring step, the screw is advanced and self-mounted to the injection nozzle 13 at the front end of the heating cylinder 12, and is fixed by the fixing mold 10 fixed to the fixed template 9. The movable mold 8 of the movable template 7 that advances and retracts the molten resin, and ejects the molten resin to a cavity formed during mold closing, and the condensed pattern and the diffusion pattern are formed on the transparent plate B of the surface, and the plate is attached to the cavity. B is discharged by the ejector pin or the like which can be advanced and retracted, and the sheet B discharged from the outlet a near the cavity is sucked and taken out by the take-up device 3, and the lower surface of the removed sheet B is placed on the first film. The reel 22 is unwound, and the first inducing roller 24 is placed on the upper surface of the first protective film (bottom film) 20 which is fed in the horizontal direction, and then placed on the first mounting position b. The upper surface of the sheet B conveyed by the first protective film 20 wound by the film roll 22 is placed on the second protective film which is wound by the second film roll 23 while being sandwiched by the second induction roll 25 ( The upper film 21) is a first protective film 20 coated with a bonding material on one side and (2) The protective film 21 is attached to each surface of the sheet material B, and is attached to the sheet material B to which the first protective film 20 and the second protective film 21 conveyed in the horizontal direction are attached, and is provided in the cutting device 27. The cutter 31 automatically slides in the vertical direction, and the first protective film 20 and the second protective film 21 attached to the sheet B are cut to produce a light guide plate. Therefore, the sheet B is formed by the injection molding machine 1. Thereafter, the step of manufacturing the light guide plate by attaching the first protective film 20 and the second protective film 21 to the upper surface of the sheet B is performed, and the film forming processing device 2 can be automated, so that the manufacturing of the light guide plate can be short. The time is further increased, and further, it is possible to prevent the surface of the sheet B from being scratched or soiled because the work of attaching the protective films 20 and 21 cannot be performed by manual work by humans. Therefore, it is possible to suppress the malfunction accompanying the work of the person and improve the yield, thereby Improve the production efficiency of the light guide plate.

In addition, as shown in FIG. 1, a film forming apparatus 2 is provided separately from the injection molding machine 1, and the film forming apparatus 2 includes a first film roll 22 wound by the first protective film 20, The second film roll 23 and the cutting device 27, which are wound by the second protective film 21, are disposed on the side (lateral side) of the injection molding machine 1 to form the sheet forming apparatus 2, and the sheet is formed by the injection molding machine 1. The take-out port a near the cavity where B is taken out and the specific mounting position b on which the plate material B is placed on the first protective film 20, and the take-up device 3 is disposed on the imaginary line X connected at the shortest distance on the straight line. The sheet B taken out from the outlet a near the cavity can be conveyed to the specific placement position b of the film forming apparatus 2 at the shortest distance, so that the conveyance time can be shortened. Moreover, the first protective film 20 and the second protective film 21 can be quickly attached to the sheet material B conveyed at a short distance, and the dust can be adhered to the transparent sheet B before the fine dirt such as dust or ray is adhered to The attaching step can further improve the yield of the product. Further, since the film forming processing device 2 can automatically perform the attaching operation, the attaching operation can be performed in a short period of time compared with the operation of the user, thereby improving productivity.

Further, the injection molding machine 1 for forming the sheet material B and the film forming processing apparatus 2 are provided in a one-to-one manner and the take-out device 3 is used as the unit unit 4, and the unit is provided in plural, whereby the yield of the light guide plate can be further achieved, and Since the plurality of light guide plates manufactured by the film forming processing apparatus 2 of each unit are discharged to the packing position d in the same direction, the operator or the like bundles the light guide plate to the rear end of the film forming and processing apparatus 2 When the bag position d is moved, the direction of the arrow as shown in FIG. 1 can be moved by the shortest distance on the straight line, so that the packing operation can be performed efficiently and in a short time to bundle the light guide plate.

1‧‧‧Injection molding machine

3‧‧‧Removal device

Unit 4‧‧‧1

7‧‧‧ movable template

8‧‧‧ movable mold

9‧‧‧Fixed template

10‧‧‧Fixed mould

12‧‧‧heating cylinder

13‧‧‧Injection nozzle

20‧‧‧1st protective film (bottom film)

21‧‧‧2nd protective film (upper film)

22‧‧‧1st film reel

23‧‧‧2nd film reel

27‧‧‧cutting device

31‧‧‧Cutter

a‧‧‧Export

b‧‧‧Specific placement position

B‧‧‧ plates

X‧‧‧ imaginary line

1 is a schematic view showing a state in which a unit including an injection molding machine, a film forming apparatus, and the like are plurally arranged as viewed from above; and FIG. 2 is a front view showing a structure of a film forming processing apparatus. .

1‧‧‧Injection molding machine

2‧‧‧Film forming processing device

3‧‧‧Removal device

Unit 4‧‧‧1

5‧‧‧Mold fastening clip unit

6‧‧‧Injection unit

7‧‧‧ movable template

8‧‧‧Make a mold

9‧‧‧Fixed template

10‧‧‧Fixed mould

11‧‧‧ funnel

12‧‧‧heating cylinder

13‧‧‧Injection nozzle

22‧‧‧1st film reel

23‧‧‧2nd film reel

24‧‧‧1st induction roller

25‧‧‧2nd induction roller

27‧‧‧cutting device

a‧‧‧Export

b‧‧‧Specific placement position

C‧‧‧ cut position

d‧‧‧Bundle location

X‧‧‧ imaginary line

Claims (5)

A method for manufacturing a light guide plate, wherein the screw provided in the heating cylinder is rotated while being retracted, and the molten resin is measured, and after the measuring step, the screw is advanced and mounted from the above Heating the injection nozzle at the front end of the cylinder, and ejecting the molten resin to a cavity formed by a fixed mold fixed to the fixed template and a movable mold fixed to the movable mold set to advance and retreat, and being ejected by the injection mold Forming machine for forming a transparent plate and attaching a film to the upper surface of the plate formed by the injection molding machine; and forming the cavity formed by the injection molding machine including the fixed mold and the movable mold After the plate is discharged, the plate adhered to the cavity is discharged, and the discharged plate is taken out by the take-out device; the lower surface of the plate is placed on the bottom film which is wound from the first film roll in the horizontal direction. After the placement position, the upper surface of the above-mentioned plate material conveyed in a state of being placed on the bottom film wound from the first film roll is placed on the second surface. The upper film rolled up by the film roll, the upper film and the bottom film are attached to the plate; and the plate to which the upper film and the bottom film are attached in the horizontal direction are attached to the cutting device The film is slid in the vertical direction and the upper film and the bottom film attached to the sheet are cut. The manufacturing method of the light guide plate of claim 1, wherein the take-out device has a holding device for attracting the sheet by generating a negative pressure, The sheet material taken out by the attraction of the device is placed on a specific mounting position on the bottom film. The method of manufacturing a light guide plate according to claim 2, wherein the film forming apparatus provided in the other embodiment of the injection molding machine includes at least the first film roll, the second film roll, and the cutting device; The film forming apparatus is disposed on a side portion of the injection molding machine; and the extracting device is disposed on a virtual line, and the imaginary line is connected to a cavity of the mold of the injection molding machine at a shortest distance in a straight line to take out the sheet material. a take-out port in the vicinity of the cavity, and a specific mounting position on which the plate material is placed on the bottom surface film by the film forming processing device; and the plate material taken out from the take-out port near the cavity is the shortest The distance is transported to the specific placement position described above. The method of manufacturing a light guide plate according to claim 3, wherein each of the injection molding machine and the film forming processing device are alternately arranged, and one of the side portions is disposed corresponding to each of the injection molding machines. In the film forming apparatus, the injection molding machine and the film forming apparatus are provided in a one-to-one manner as a unit, and the unit is provided in parallel, and the light guide plate is continuously mass-produced in parallel. A light guide plate characterized in that, in the method of manufacturing a light guide plate according to claim 3 or 4, the upper film and the bottom film are used as a protective film, and the protective film is attached to the film forming apparatus by the film forming apparatus. The above plate is formed above and below.