KR20090013686A - Molding mold for light guide plate and method for molding light guiding plate - Google Patents

Abstract

A metal molding of a light guide panel and a method for molding the panel are provided to improve quality of the light guide panel by preventing any scratch or mark remaining on the panel. A metal molding of light guide panel(11) comprises a moving mold(12) and a fixing mold(13). A cavity(14), whose volume and thickness is changeable, is installed between the connected two molds. The moving mold includes a molding body unit(15), a core unit(16) and an operation frame unit(19). The fixing mold and the core unit is faced each other. A formation surface(16a) and a plurality of cooling medium flow channels(17) are installed in the inside of core unit to be paralleled.

Description

Molding method of light guide plate and molding method of light guide plate {MOLDING MOLD FOR LIGHT GUIDE PLATE AND METHOD FOR MOLDING LIGHT GUIDING PLATE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die of a light guide plate and a method of forming a light guide plate in a cavity formed between a stationary mold and a movable mold by injection molding, and in particular, a light guide plate which can easily take out a light guide plate from a mold. A molding die and a light guide plate are provided.

As the molding die of the light guide plate which shape | molds a light guide plate by injection molding containing injection compression molding, the thing of patent document 1 is already known. In Patent Literature 1, an air passage 26 is formed between the main body portion 24 and the outer wall portion 21 of the movable mold 6, and air is released from the air supply means not shown immediately before or after the mold opening. Air is blown toward the molded product P via the passage 26, and the light guide plate is taken out. However, in patent document 1, since the said air blowing is mainly extended with respect to the side surface part P1 of the light guide plate, it does not reach well between the cavity surface 18 and the light guide plate on the movable mold side, and the effect | action which helps mold release was lacking. As a result, a large suction force is applied to the sucker 43 of the transfer machine 41 to take out the light guide plate P, and since the light guide plate immediately after molding has a high temperature, marks may remain on the surface of the light guide plate and become defective. There was. In addition, in Patent Document 1, since the light guide plate portion is sucked and taken out in a state where the light guide plate and the sprue are integrated, a runner that has dug into the recess (intrusion) formed in the movable mold in order to remove the sprue from the fixed mold. Since the sprues to contain were released, the adsorption force was especially large.

In the case of separating the light guide plate and sprue in the mold during molding, only the light guide plate can be adsorbed and taken out. Therefore, a smaller adsorption force may be obtained than in the case of Patent Literature 1, but it is still necessary to directly adsorb the suction plate directly to the light guide plate. Since there was no change, it was desired to make the light guide plate much easier to release and to take out the light guide plate with a small force.

[Patent Document 1] Japanese Unexamined Patent Publication No. 2003-145593 (0031, Fig. 3)

In view of the above problem, in the present invention, when the light guide plate is molded in a cavity formed between the stationary mold and the movable mold by injection molding, the light guide plate can be easily taken out of the mold, and the marks on the light guide plate when taken out. An object of the present invention is to provide a molding die and a molding method of a light guide plate which can be prevented from remaining well.

The shaping | molding die of the light-guide plate of Claim 1 of this invention is a shaping | molding die of the light-guide plate in which the shaping | molding of a light-guide plate is performed in the cavity formed between a fixed mold and a movable metal mold | die by injection molding, The part other than an effective surface of a light-guide plate or an effective The light guide plate is deformed by exerting a force on the boundary between the portion other than the surface and the effective surface.

The molding die and the molding method of the light guide plate of the present invention, in the molding die of the light guide plate which performs the molding of the light guide plate in the cavity formed between the fixed mold and the movable mold by injection molding, the part or effective surface other than the effective surface of the light guide plate Since the light guide plate is released by exerting a force on the boundary between the other part and the effective surface, the light guide plate can be easily taken out by a relatively simple mold structure.

A molding die of the light guide plate of the present invention will be described with reference to FIGS. 1 to 8. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the injection compression molding metal mold | die of the light guide plate of this embodiment, and is a figure which shows the state before injection start after mold clamping. FIG. 2 is a cross-sectional view of the injection compression molding die of the light guide plate of the present embodiment, in which the volume in the cavity is enlarged during injection. 3 is a cross-sectional view of the injection compression molding die of the light guide plate of the present embodiment, showing a state in which the resin in the cavity is gate-cut after compression. 4 is a front view of the movable die of the injection compression molding die of the light guide plate of the present embodiment. 5 is a chart showing a method of injection compression molding the light guide plate of the present embodiment. FIG. 6 is an enlarged cross-sectional view showing the situation of mold opening and discharging of the A-A line portion of the movable mold of FIG. 4 and the fixed mold portion opposite thereto. FIG. FIG. 7 is an enlarged cross-sectional view showing a situation after the pressure relief of the A-A line portion of the movable mold of FIG. 4 and the fixed mold portion opposite thereto. FIG. 8 is an enlarged cross-sectional view showing a state after the start of mold opening of the A-A line portion of the movable mold of FIG. 4 and the fixed mold portion opposite thereto. 9 is a front view of a light extraction plate of the light guide plate of the present embodiment.

The injection compression molding die 11 of the light guide plate of the present embodiment is a mold for molding a side light type light guide plate for mobile phones having a diagonal dimension of 3 inches and a plate thickness of 0.4 mm by injection compression molding. For the light guide plate, the abbreviation is simply referred to as a light guide plate.) In injection compression molding, the distance between the movable mold 12 and the stationary mold 13 varies from the start of molding to the end of molding. Therefore, it is assumed that a type called an injection press, in which the molten resin is moved and compressed as it is after the injection in the stop position after mold closing, is also included in the injection compression molding. In these injection compression moldings, the cavity is slightly open before injection start or after injection start as compared with the completion of molding, so that no injection apparatus having a high speed injection capability is required, so that molten resin can be injected at a relatively low speed and low pressure. In addition, since the movable mold is moved in the mold clamping direction after the start of injection to compress the molten resin, there is an advantage that the molten resin can be quickly flowed or finely transferred at a position far from the gate portion of the cavity. Further, after cutting the gate, the normal injection molding die cannot exert pressure retention from the injection apparatus, but in the case of injection compression molding, the molten resin in the cavity can be compressed to cope with shrinkage due to cooling solidification. Such injection compression molding is particularly advantageous when forming a light guide plate having a thin plate thickness compared to the area of the light exit surface or the like.

1 to 3 are cross-sectional views of the injection compression molding die 11 of the present invention. The injection compression mold 11 is composed of a movable mold 12 as a first mold and a stationary mold 13 as a second mold, and a cavity having a variable volume and thickness between the two molded molds 12 and 13. 14 is formed. The mold main body part 15, the core part 16, the movable frame part 19, etc. are provided in the movable mold 12 attached to the movable panel of the injection compression molding machine 1. As shown in FIG. The core part 16 is fixedly attached to the substantially center of the surface of the metal mold | die main body part 15 on the fixed mold side. The surface facing the stationary mold 13 of the core part 16 is made of mirror surfaces, and the formation surface 16a1 and its surroundings that form the light exit surface P4a which is an effective surface of the light guide plate P in the cavity 14. It is a main surface formation surface 16a which consists of the formation surface 16a2 which forms the part P4b other than an effective surface in the shape, and it conforms to the shape of the main-body part P4 of the light guide plate P, and has a square shape. In addition, a plurality of cooling medium flow paths 17 are formed inside the core 16 in parallel with the main surface forming surface 16a. In addition, although the light exit surface P4a of the main surface formation surface 16a in the cavity 14 has disclosed the example of a mirror surface, grooves, roughening, etc. may be performed.

Concave portions are formed in four upper and lower portions of the surface of the mold main body portion 15 on the fixed mold side, and a spring 18 is attached to the fixed mold side in the recess. The fixing die side of the spring 18 is attached to a movable frame portion 19 arranged to surround the core portion 16. In other words, the core part 16 is arrange | positioned in the cavity part formed by the movable frame part 19 in other words. And the whole of the movable frame part 19 is movable with respect to the metal mold | die main part 15 and the core part 16 by the said spring 18 to mold opening-closing direction. The surface facing the stationary mold 13 of the movable frame portion 19 is abutting surface 19a (parting surface). On the side opposite to the gate of the movable frame portion 19, a light incident surface forming block 20 for forming a light incident surface is detachably arranged. 1 is a state in which the clamping force is exerted on the movable mold 12, and the spring 18 is in a contracted state. FIG. 2 is a state in which the core portion 16 is retracted at the time of injection and the volume of the cavity 14 is enlarged. Although it was shown the figure, it exaggerated rather than described.

Moreover, the inner peripheral surface adjacent to the light-incident surface formation block 20 of the part of the fixed metal mold | die 13 inside the movable frame part 19 also becomes the cavity formation surface 19b which forms the side surface of the light guide plate P. As shown in FIG. As shown in FIG. 4, the jaw portion forming portion 19c forming the jaw portion P5 of the light guide plate P is provided at two portions adjacent to the contact surface 19a of the cavity forming surface 19b on one side. Formed. The jaw portion forming portion 19c is formed only by the movable frame portion 19, and is formed in a portion on the inner circumferential side of the contact surface 19a in a concave shape one step lower than the contact surface 19a toward the movable half side. It is formed by the stationary die opposing surface 19c1 and the side surface 19c2 around it. In this embodiment, the square jaw part formation part 19c is formed in the four places in the both sides of the movable frame part 19 in total. The jaw portion P5 formed by the jaw portion forming portion 19c is a portion used when attaching the light guide plate P as a display device such as a cellular phone. In the light guide plate P, the jaw portion P5 is a portion other than the effective surface different from the light exit surface P4a (effective surface) or the reflective surface (effective surface). In addition, in this embodiment, as shown in FIG. 6, FIG. 7, and FIG. 8, the jaw part P5 side is formed thin with respect to the main-body part P4, The force acted when releasing the light guide plate P It is formed into a size and thickness to receive. When the thickness of the light guide plate is thin, the main body portion and the jaw portion may have the same thickness, or conversely, the jaw portion may be thickly formed, and the position and the number of the jaw portions are not limited. In addition, it is also possible to roughen and process the mold die opposing surface etc. of a jaw part, and to make it easy to release.

The heat insulating plate 21 is attached to the movable panel side of the mold main body 15, and the protruding pins 23 which are moved back and forth with the ejector plate 22 of the ejector device are arranged in the space and the hole inside. The protruding pins 23 are arranged in a hole formed over the inside of the mold main body 15 and the core 16, and the tip faces the runner forming surface 32, and the sprue P1 and the runner ( Intrusion part 23a is provided in Z shape so that P2) may be easy to hold | maintain. Driving the protruding pins 23 is an ejector driving device arranged in the movable panel (not shown) or from the movable panel to the mold clamping device side.

In addition, a hole 25 and a space 26 for arranging the gate cutter members 24 are formed in the mold main body 15. On the other hand, in the hole 25 of the metal mold | die main part 15, the guide pin 27 is arrange | positioned, and the core is hold | maintained by the ball of the ball guide. And the gate cutter member 24 is engaged in the center of the fixed half side of the disk-shaped plate 29 which the said guide pin 27 in the space part 26 abuts. The gate cutter member 24 is arranged in the hole 31 of the rectangular cross section so as to be elastically biased by the spring 30 so as to be movable forward and backward.

Moreover, in the core part 16, the surface which faces the sprue bush 44 and the insert block 43 of the fixing die 13 mentioned later becomes the runner formation surface 32. As shown in FIG. About the runner formation surface 32, the convex part is formed in the part adjacent to the protruding pin 23 side from the gate cutter member 24, and the part which the protruding pin 23 opposes with the sprue bush 44 is concave. It is wealth. In addition, a cooling medium flow path 33 is formed around the protruding pins 23 near the gate cutter member 24.

A grooved gas flow passage 34 is provided between the core portion 16 and the movable frame portion 19. As shown in FIGS. 1-4, the gas flow path 34 is formed in the inner part of the movable frame part 19 in parallel with the main surface formation surface 16a of the cavity 14 at regular intervals. In this embodiment, although the groove | channel gas flow path 34 is not arrange | positioned between the core part 16 and the gate cutter member 24, you may make it arrange | position. The cavity 14 side is a gas flow passage 34a with a slight gap (for example, 3 to 20 μm) in which resin does not enter the gas flow passage 34 between the core portion 16 and the movable frame portion 19. . And the opening part 34b of the said gas flow path 34a is formed around the main surface formation surface 16a of the core part 16. In addition, a part of the gas flow passage 34a and the opening 34b is arranged in a gap between the core portion 16 and the light incident surface forming block 20. Furthermore, the opening 34b of the gas flow path 34a is similarly formed around the runner formation surface 32. The gas flow passage 34 is connected to a gas flow passage (not shown) formed through the movable frame portion 19 toward the outside of the movable mold 12. In addition, the gas flow path 34 may be formed from the inner side of the core portion toward the outside of the movable mold via the mold body portion. And it is connected to the compressed air supply apparatus and the air suction apparatus from the said gas flow path connected through a flexible hose. An electromagnetic open / close valve (not shown) is arranged between the compressed air supply device, the air suction device, and the movable mold 12. In addition, the gas flow passage may be provided so that the gas is ejected at a right angle or close to a right angle with respect to the rear surface of the jaw portion or other portions other than the effective surface (including the boundary with the effective surface). In that case, a gas flow path may be formed inside the movable frame or inside the core part.

Next, the fixed mold 13 will be described. As shown in FIGS. 1 to 3, the fixed mold 13 attached to the fixed plate 2 of the injection compression molding machine 1 includes a mold main body 41, The cavity forming block 42, the insert block 43, the sprue bush 44, the gate cutter member 45, the abutting block 46, and the like are formed. In addition, a heat insulating plate 47 is attached to the fixing plate side of the mold main body portion 41, and a hole 48 into which a nozzle of an injection apparatus (not shown) is inserted is formed, and a locator ring 49 is attached to the periphery thereof. It is. The cavity forming block 42 is attached to the movable mold side of the mold main body 41, and the surface facing the movable mold 12 of the cavity forming block 42 is the main surface forming surface 42a among the cavity forming surfaces. have. In this embodiment, this main surface formation surface 42a is a part which forms a reflection surface, and the fine dot is engraved. Further, a plurality of cooling medium flow paths 50 are formed inside the cavity forming block 42 in parallel with the main surface forming surface 42a.

A grooved gas flow passage 53 is formed between the cavity forming block 42, the insert block 43, and the abutment block 46. The gas flow passage 53 is formed so as to surround the cavity forming block 42 in parallel with the main surface forming surface 42a of the cavity 14 at regular intervals. And the gas flow path of the clearance gap (for example, 3-20 micrometers) in which the resin 14 does not enter into the cavity 14 side rather than the gas flow path 53 between the cavity formation block 42 and the insert block 43 and the contact block 46 is shown. It is set to 53a. And the opening part 53b of the said gas flow path 53a is formed around the main surface formation surface 42a of the cavity formation block 42. The gas flow passage 53 is connected to a gas flow passage (not shown) which is formed toward the outside of the fixed mold 13 and is compressed air supply apparatus from the gas flow passage through a flexible hose or an electronic opening / closing valve (not shown). And an air suction device.

Moreover, the insert block 43 is arranged in the mold main body 41 together with the cavity forming block 42. As for the insert block 43, the sprue bush 44 provided with the hole diameter-expanded toward the movable plate side is arrange | positioned at the center part. And around the sprue bush 44, the cooling medium flow path 51 which cools the sprue P1 and the runner P2 is formed. Moreover, the runner formation surface 54 which becomes gradually wider toward the cavity 14 is formed in the surface which faces the movable die 12 of the insert block 43 from the tip of the sprue bush 44 toward the cavity formation surface. .

The gate cutter member 45 is fixed between the gate forming surface connected to the runner forming surface 54 of the insert block 43 and the main surface forming surface 42a of the cavity forming block 42. And the front surface of the gate cutter member 45 opposes the main surface formation surface 16a, and forms the gate cutter 45b by which the edge part of the gate part side of the gate cutter member 45 is cut.

Next, the shaping | molding method of this invention is demonstrated with the chart of FIG. In the present embodiment, the light guide plate P having a diagonal dimension of 3 inches and a plate thickness of 0.4 mm was molded by an injection compression molding method with a molding cycle time of 4.4 seconds. Therefore, in this embodiment, the glass transition temperature (Tg) of polycarbonate which is resin shape | molded by a temperature controller in cooling medium flow paths, such as the cooling medium flow path 17 which cools the main surface formation surface 16a of the movable die 12, is carried out. The temperature controlled cooling medium (cooling water) is flowed about 30-100 degreeC low 50-120 degreeC.

A mold clamping device (not shown) is operated, and mold closing is performed by bringing the movable mold 12 attached to the movable plate into contact with the fixed mold 13 attached to the fixed plate 2. The relationship between the core part 16 and the movable frame part 19 of the movable mold 12 at the time of this mold closing is close to the state of FIG. As shown in FIG. 1, by performing the next mold clamping, the elastic main force of the spring 18 is overcome, and the mold main body 15 and the movable frame 19 of the movable mold 12 abut, and the core portion 16 is contacted. It becomes the position which the movable frame part 19 retreated to the last. Then, a runner including a variable thickness gate and a thickness variable cavity 14 connected to the runner are formed between the fixed mold 13 and the movable mold 12.

When the next predetermined delay time elapses, molten resin is injected through the sprue bush 44 from the nozzle of the injection device (not shown). The mold main body 15 and the core 16 of the movable panel and the movable mold 12 are retracted to the position shown in FIG. 2 by the pressure at the time of injection, and the main surface of the cavity forming surface of the fixed mold 13 The spacing between the forming surface 42a and the main surface forming surface 16a of the movable die 12 is wider than the position where the first clamping force is shown in FIG. 1.

When the screw position reaches the predetermined position by the injection apparatus, mold clamping by the high clamping force is performed on the mold clamping device side, so that the mold is opened by the high clamping force or at a distance smaller than the distance. The movable die 12 is moved in the fastening direction. After that, the clamping force is reduced after a certain time or at the same time as the pressure holding. In the present embodiment, at the same time as the mold clamping force is lowered, the gate cutter member 24 of the movable mold 12 is advanced by a gate cutter member driving device (not shown), and the cutting of the gate P3 where the molten resin is not completely solidified is performed. Do it.

After the cutting of the gate P3 is performed by the gate cutter member 24, the movable mold 12 is advanced by the driving of the mold clamping device to compress the molten resin in the cavity 14. Even if there is a shrinkage due to this, no sink mark is generated, so that good transfer molding can be performed. Then, when a predetermined time elapses, the pressurized air for mold release is applied to the cavity 14 through the gas flow paths 34 and 34a and the opening portion 34b between the movable frame portion 19 and the core portion 16 of the movable mold 12. do. At the same time, the boundary portion between the jaw portion P5 and the main body portion P4 through the gas flow passages 34 and 34a and the opening portion 34b between the movable frame portion 19 and the core portion 16 of the movable mold 12 is approximately simultaneously. The mold release air is made to extend to the cavity 14 including P6. In addition, between the cavity forming block 42 and the insert block 43 and the contact block 46 at the same time, the compressed air for release to the cavity 14 through the groove-shaped gas flow passages 53 and 53a and the opening 53b. Drive crazy. In this embodiment, the voltage of a compressed air supply apparatus is 0.5-0.8 MPa, and compressed air which compressed the atmospheric temperature is supplied. However, it does not exclude other gases such as nitrogen gas. However, at this stage, since the mold clamping is still performed, the compressed air is not supplied into the cavity 14, and the gas flow passages 34, 34a, 53, and 53a are in a high pressure state. In addition, the pressurized air is supplied before the pressure is removed so that the pressurized air of the high pressure can be supplied at the same time as the pressure is removed.

Next, the mold clamping device is operated to depressurize and open the mold in order. First, when the pressure is removed to reduce the clamping force to zero or near zero, the mold body portion of the movable mold 12 with respect to the fixed mold 13 as shown in FIG. 6 to the state shown in FIG. 15 and the core portion 16 are retracted. As a result, the spring 18 holding the movable frame 19 is slightly extended, and the movable frame 19 is relatively advanced with respect to the mold main body 15 and the core 16. Then, the fixed mold opposing surface 19c1 of the jaw portion forming portion 19c of the movable frame portion 19 is physically formed on the rear surface P5a (including the boundary portion P6) of the jaw portion P5, which is a portion other than the effective surface. The force F is exerted, and the mold release is performed in a direction in which the light exit surface P4a of the light guide plate P is lifted from the cavity formation surface 16a. In addition, since the jaw portion P5 has a constant width and thickness as described above, and the cooling solidification is advanced than the main body portion P4, it is not deformed at the time of release. In addition, as shown in FIG. 7, most of the compressed air which is the gas which blows out from the opening part 34b which communicates with the gas flow path 34a of the movable die 12 at this time is the light exit surface P4a of the light guide plate P. As shown in FIG. And as a compressed air flow C1 in the space of the cavity formation surface 16a of the core part 16. As shown in FIG. Further, the compressed air C1 further acts as a force for promoting release of the light guide plate P by promoting release of the light exit surface P4a and the cavity forming surface 16a1 and then increasing the internal pressure of the space. do.

When the mold clamping device is operated to open the mold, the light guide plate P, the sprue P1, and the runner P2 are each taken out while being held on the movable mold 12 side. On the fixed mold 13 side, the compressed air supplied to the fixed mold 13 accelerates and releases the release surface of the reflection surface formed by the main surface forming surface 42a of the cavity 14. Shortly after the mold opening starts, the solenoid valves (not shown) are closed to stop the supply of the pressurized air for release to the fixed mold 13, but the pressurized air is continuously supplied to the movable mold 12. In addition, supply of the compressed air to the stationary metal mold | die 13 can also be performed until the light guide plate P is taken out by the extraction robot 61 mentioned later. In this embodiment, since the space | interval of the fixed metal mold | die 13 and the movable metal mold 12 at the time of mold opening is small by 6-15 cm, the reflecting surface of the light guide plate P is further made by continuing to blow out the compressed air of the fixed metal mold | die 13. Can be cooled. And the trace by the sucker 63 of the takeout-out robot 61 can be prevented from generating in the light guide plate P further.

In addition, on the movable mold 12 side, as a state shown in FIG. 8 to the state shown in FIG. 8 by the mold opening, the movable mold 12 whole (mold main-body part 15, core part ( 16) and movable frame part 19) retreat. As a result, the spring 18 of the movable frame 19 is further extended, and the movable frame 19 is relatively advanced with respect to the mold main body 15 and the core 16. As a result, the light guide plate P is supported in the direction in which the jaw portion P5 is supported by the jaw portion forming portion 19c of the movable frame portion 19 and rises further from the main surface forming surface 16a of the core portion 16. do. At this time, a part of the compressed air C2 flows toward the rear surface P5a (including the boundary portion P6) of the jaw portion P5 of the light guide plate P, and the jaw portion P5 of the light guide plate P. Is exerted by exerting a force by the compressed air stream C2 in the direction of rising from the movable frame portion 19. Further, the remaining half of the compressed air is ejected from the part without the jaw portion P5 on the side surface of the light guide plate P and the cavity forming surface 19b forming the side surface, thereby releasing the side surface. In addition, since the compressed air C2 is relatively inferior to the side surface 19c2 of the jaw portion forming portion 19c, the side surface 19c2 and the jaw portion P5 are not immediately released, and the light guide plate P is movable. ) Is not eliminated. In addition, the pressure removal and mold opening are a series of operations, and the mold opening is performed before the light exit surface P4a of the light guide plate P and the cavity forming surface 16a of the movable mold 12 are completely released by the pressure removal. It is also assumed.

In addition, when the movable mold 12 is mold-opened and the mold structure in which the light guide plate P may fall before taking out the light guide plate P by the take-out robot 61, the suction robot 61 is attracted. It is also contemplated that the air is blown out at about the same time (or slightly before and after). Alternatively, from the mold opening discharge, air of low pressure may be supplied, and the pressure may be changed to the strong pressure at the time of ejection after the mold opening is completed.

And the advancement of the protrusion pin 23 of an ejector apparatus is performed simultaneously with mold opening completion, and mold release from the runner formation surface 32 of runner P2 is performed. Also, the robot for taking out is operated simultaneously with the completion of mold opening or during mold opening. As shown in FIG. 9, the take-out robot 61 used in the present embodiment grips the sprues P1 by the chuck 62 and adsorbs the light guide plate P by the suction plate 63. The first take-out robot 61 of the swing arm type which takes out them separately, and the 2nd take-out robot 65 which pass the light guide plate P from the said 1st take-out robot 61, adsorb | suck it, and raise it on the conveyor 64. )

The present invention is not enumerated one by one, but is not limited to the above-described embodiment, and needless to say that the present invention is also applied to changes made based on the spirit of the present invention. In the present embodiment, the movable frame portion 19 is moved relative to the core portion 16 as a portion other than the effective surface to exert a force F on the jaw portion P5, and the light emitting surface which is the effective surface of the main body portion P4. An example of releasing (P4a) and the like has been disclosed, but releases by blowing the gas to a portion other than the effective surface of the main body portion (a portion around the light-emitting surface or the reflective surface) or another portion to be cut off after the runner P2. May be performed.

In the above embodiment, an example in which the jaw portion P5 of the light guide plate P is formed by the movable frame portion 19 of the movable mold 12 is described. However, the core portion has a portion other than the effective surface such as the effective surface and the jaw portion. The light guide plate may be formed by molding both sides of the mold and exerting a force on the boundary portion between the portions other than the effective surface or the portion other than the effective surface and the effective surface with a spring or a cylinder. It is also possible that the jaw and the like are formed as a stationary mold instead of a movable mold. The present invention can also be applied to a type called an inrow mold in which the convex portions of one mold are fitted into the recesses of the other mold, and a volume variable cavity is formed therebetween. In the case of the in-mold mold, the parts for forming parts other than the effective surface such as the jaw portion forming part can be relatively moved by a spring or the like separately from the member for forming the other effective surface, and the mold opening (including pressure relief) is performed. By extension of the spring or the like, the effective surface portion is released. It is also conceivable to carry out the injection press method, which is one of injection molding.

In the present invention, the size or shape of the light guide plate is not limited. Furthermore, suppose that a lens, a light diffusing plate, and other optical thin plates that accompany or receive light from a molded article are included in the scope of the light guide plate in the present invention. Moreover, although the resin used for shaping | molding was described about the example of polycarbonate, other resin may be sufficient as it is resin excellent in optical performance.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the injection compression molding metal mold | die of the light guide plate of this embodiment, and is a figure which shows the state before injection start after mold clamping.

FIG. 2 is a cross-sectional view of the injection compression molding die of the light guide plate of the present embodiment, in which the volume in the cavity is enlarged during injection.

3 is a cross-sectional view of the injection compression molding die of the light guide plate of the present embodiment, showing a state in which the resin in the cavity is gate-cut after compression.

4 is a front view of the movable die of the injection compression molding die of the light guide plate of the present embodiment.

5 is a chart showing a method of injection compression molding the light guide plate of the present embodiment.

FIG. 6 is an enlarged cross-sectional view showing the situation of mold opening and discharging of the A-A line portion of the movable mold of FIG. 4 and the fixed mold portion opposite thereto. FIG.

FIG. 7 is an enlarged cross-sectional view showing a situation after the pressure relief of the A-A line portion of the movable mold of FIG. 4 and the fixed mold portion opposite thereto. FIG.

8 is an enlarged cross-sectional view showing a state after the start of mold opening of the A-A line portion of the movable mold of FIG. 4 and the fixed mold portion opposite thereto.

9 is a front view of a light extraction plate taking out device of the present embodiment.

<Description of the code>

11 injection compression molding mold 12 movable mold

13 fixed mold 14 cavity

15, 41 mold body 16 core

16a, 42a Main surface forming surface 19 Movable frame part

19c jaw forming part 24, 45 gate cutter member

24b, 45b gate cutter 32, 54 runner forming surface

34, 34a, 53, 53a gas flow paths 34b, 53b, 74a openings

43 Insert Block P Light Guide Plate

P1 Sprue P2 Runner

P3 Gate P4 Body

P4a Output surface P4b Parts other than the effective surface

P5 Jaw

Claims (6)

In the shaping | molding die of the light guide plate which shape | molds a light guide plate in the cavity formed between a fixed metal mold | die and a movable metal mold by injection molding, A molding die for a light guide plate, wherein the light guide plate is released by exerting a force on a portion other than the effective surface of the light guide plate or a portion between the non-effective surface and the boundary portion between the effective surface. 2. The light guide plate according to claim 1, wherein a member for forming a portion other than the effective surface of the light guide plate or a portion other than the effective surface and the boundary portion between the effective surface is moved relative to the member for forming the effective surface to exert a force. Molding mould. 2. The molding die of the light guide plate according to claim 1, wherein gas is blown out of the mold to a portion other than the effective surface of the light guide plate or a portion of the boundary between the effective surface and the portion other than the effective surface. In the molding method of the light guide plate which shape | molds a light guide plate in the cavity formed between a fixed metal mold | die and a movable metal mold by injection molding, A method of forming a light guide plate, wherein the light guide plate is released by exerting a force on a portion other than the effective surface of the light guide plate or a portion of the boundary between the non-effective surface and the effective surface. The light guide plate according to claim 4, wherein a member for forming a portion other than the effective surface or a portion other than the effective surface and a boundary portion between the effective surface and the member is moved relative to the member for forming the effective surface to exert a force. Molding method. 5. The method of forming a light guide plate according to claim 4, wherein gas is blown out of the mold with respect to a portion other than the effective surface of the light guide plate, or a boundary portion between the portion other than the effective surface and the effective surface.

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