WO2011159120A2

WO2011159120A2 - Molding apparatus and method of manufacturing polymer molded article

Info

Publication number: WO2011159120A2
Application number: PCT/KR2011/004431
Authority: WO
Inventors: Chan Kwon Lee
Original assignee: Lg Innotek Co., Ltd.
Priority date: 2010-06-17
Filing date: 2011-06-16
Publication date: 2011-12-22
Also published as: TW201208856A; WO2011159120A3; KR20110137649A; TWI443008B

Abstract

A molding apparatus and a method of manufacturing a polymer molded article are provided. The molding apparatus comprises a mold in which a raw material is injected, a packing part injecting the raw material into the mold through an inlet of the mold, the packing part increasing pressure in the mold through the inlet, a light source emitting light to the raw material within the mold, and a press part increasing pressure in the mold by applying pressure to the mold. The molding apparatus can provide a considerably precise polymer molded article by using the packing part and the press part.

Description

MOLDING APPARATUS AND METHOD OF MANUFACTURING POLYMER MOLDED ARTICLE

The present disclosure relates to a molding apparatus and a method of manufacturing a polymer molded article.

Recently, mobile devices, such as cellular phones, have been equipped with cameras, thus enabling the capture of still images and videos anytime, anywhere.

Furthermore, cameras are being gradually enhanced in performance so as to capture high-definition quality images, and are provided with camera modules having auto-focusing, close-up, optical zooming functions and the like.

Currently, to ensure the performance of the camera modules, the size thereof needs to be increased.

However, considering the design aspects of a mobile device, it is difficult to mount a large-sized camera module on a mobile device. Such a large-sized camera module has limitations in performance.

The camera module needs to include a precise lens formed of polymer such as plastic. Accordingly, various researches have been being conducted to manufacture a polymer molded object with a fine structure.

Embodiments provide molding apparatuses for manufacturing a polymer molded article having improved heat-resisting properties and implementing a desired structure, and methods of manufacturing the same.

In one embodiment, a molding apparatus includes: a mold in which a raw material is injected; a packing part injecting the raw material into the mold through an inlet of the mold, the packing part increasing pressure in the mold through the inlet; a light source emitting light to the raw material within the mold; and a press part increasing pressure in the mold by applying pressure to the mold.

In another embodiment, a method of manufacturing a polymer molded article, includes: injecting a raw material into a mold through an inlet of the mold; primarily increasing pressure of the raw material within the mold through the inlet; irradiating the raw material, having the primarily increased pressure, with light; and secondarily increasing the pressure of the raw material, the pressure of which has been primarily increased.

The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.

As set forth above, according to embodiments, a molding apparatus includes a packing part and a press part for increasing the pressure in a mold. A raw material, when cured, may undergo shrinkage. In this case, the packing part may supplement the raw material. Also, when a polymer molded article is formed by curing the raw material, the press part may calibrate the polymer molded article formed as the raw material is cured.

That is, the molding apparatus may compensate for the shrinkage occurring in the process of curing the raw material through the packing by the packing part and the secondary pressure increase by the press part.

Accordingly, the molding apparatus may provide a polymer molded article having a complicated and fine structure. In particular, the molding apparatus may be used to form a lens requiring a highly precise structure.

Furthermore, a photo-curable resin may be used to form the polymer molded article. Since the photo-curable resin has improved heat-resisting properties, the molding apparatus and the method of manufacturing a polymer molded article according to embodiments may provide a polymer article with improved heat-resisting properties.

Fig. 1 is a view illustrating a lens array substrate molding apparatus according to an embodiment.

Fig. 2 is an exploded perspective view illustrating a mold.

Fig. 3 is a perspective view illustrating a lower mold.

Fig. 4 is a perspective view illustrating an upper mold.

Fig. 5 is a cross-sectional view of the mold.

Fig. 6 is a view illustrating a light source.

Fig. 7 is a plan view illustrating a mask.

Fig. 8 is a view illustrating the positions of a transmission portion, first cores and second cores.

Fig. 9 is a flowchart for explaining the process of forming a lens array substrate.

Fig. 10 is a perspective view illustrating a lens array substrate formed according to an embodiment.

Fig. 11 is a cross-sectional view a lens array substrate, first cores and second cores.

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.

Also, in the descriptions of embodiments, it will be understood that when a lens, a unit, a part, a hole, a protrusion, a recess or a layer (or film) is referred to as being `on’ or ‘under’ another lens, unit, part, hole, protrusion, recess or layer (or film), it can be directly on or under the another lens, unit, part, hole, protrusion, recess or layer (or film), or one or more intervening layers may also be present. Further, the reference for discriminating ‘on’ and ‘under’ will be determined on the basis of drawings. In the drawings, the size of each element may be exaggerated for clarity of illustration, and does not entirely reflect an actual size.

Fig. 1 is a view illustrating a lens array substrate molding apparatus according to an embodiment. Fig. 2 is an exploded perspective view illustrating a mold. Fig. 3 is a perspective view illustrating a lower mold. Fig. 4 is a perspective view illustrating an upper mold. Fig. 5 is a cross-sectional view of the mold. Fig. 6 is a view illustrating a light source. Fig. 7 is a plan view illustrating a mask. Fig. 8 is a view illustrating the positions of a transmission part, first cores and second cores. Fig. 9 is a flowchart for explaining the process of forming a lens array substrate. Fig. 10 is a perspective view illustrating a lens array substrate formed according to an embodiment. Fig. 11 is a cross-sectional view a lens array substrate, first cores and second cores.

Referring to Figs. 1 to 8, a lens array substrate molding apparatus according to an embodiment includes a base 10, a mold 100, a packing part 200, a cooling part 300, a light source 400, a mask 500, and a press part 600.

The base 10 supports the mold 100, the packing part 200, the cooling part 300, and the press part 600. The base 10 has a metal frame structure. The base 10 may further include a mold fixing part 11 fixing the mold 100 by applying pressure thereto in a vertical direction. Furthermore, the base 10 may further include a transfer part 12 transferring the packing part 200 in a horizontal direction.

The mold 100 receives a raw material for forming a lens array substrate 20. The raw material may be a photo-curable resin composition. For example, the resin composition may include a monomer or oligomer which is curable by ultraviolet rays or the like. Furthermore, the resin composition may further include a photo-initiator or the like.

As examples of materials used as the photo-curable monomer, there may be 2-butoxyethyl acrylate, ethylene glycol phenyl ether acrylate, ether methacrylate, 2-hydorxyethyl methacrylate, isodecyl methacrylate, phenyl methacrylate, bisphenol A propoxylate diacrylate, 1,3(1,4)-butandiol diacrylate, 1,6-hexandiol ethoxylate diacrylate, neopenyyl glycol diacrylate, ethylene glycol diacrylate, di(ethylene glycol) diacrylate, tetra(ethylene glycol) diacrylate, 1,3(1,4)-Butanediol dimethacrylate, diurethane dimethacrylate, grycerol dimethacrylate, ethylene glycol dimethacrylate, di(ethylene glycol) dimethacrylate, tri(ethylene glycol) dimethacrylate, 1,6- hexanediol dimethacrylate, glycerol propoxylate triacrylate, pentaerythritol propoxylate triacrylate, ditrimetylolpropane tetra-acrylate, pentaerythritol tetra-acrylate, or the like.

The photo-initiator is a material initiating the cross-linking and curing reactions of the photo-curable resin composition by being decomposed into radicals by light such as ultraviolet rays. The kind and content of photo-initiator is appropriately selected in due consideration of adhesive properties toward a base material, yellowing properties and curing-reaction speed of a resin composition. A mixture of two or more of the photo-initiators may be used as the need arises.

Examples of the photo-initiator may include α-hydroxyketone, phenylglyoxylate, benzildimethyl ketal, α-aminoketone, mono acyl phosphine, bis acyl phosphine), 2,2-dimethoxy-2-phenylacetophenone), and a mixture thereof.

The photo-initiator may be mixed at approximately 0.1 wt% to 0.3 wt% with respect to the resin composition.

The raw material is admitted into the mold 100 through an inlet 103 of the mold 100. The inside of the mold 100 is sealed from the outside. In more detail, the inside of the mold 100 is sealed to stand a very high level pressure. For example, the mold 100 may be designed to bear the pressure of approximately 5000 kgf/㎠.

Furthermore, a portion or the entirety of the mold 100 may be transparent, so that light can be applied into the mold 100. In more detail, the raw material disposed inside the mold 100 may be irradiated by light.

Referring to Figs 2 to 5, the mold 100 includes a lower mold 101 and an upper mold 102. The lower mold 101 and the upper mold 102 face each other. The upper mold 102 is disposed on the lower mold 101. In this case, the lower mold 101 and the upper mold 102 may be joined together. Furthermore, a space into which the raw material can be injected is formed between the lower mold 101 and the upper mold 102.

The lower mold 101 includes a first frame 111, a second frame 112, a plurality of frame guides 121, a plurality of first cores 131, a first core receiving part 130, a support plate 132, a plurality of plate guides 122, a first sealing member 141, and a second sealing member 142.

The first frame 111 supports the second frame 112, the frame guides 121, and the plate guides 122. In particular, the frame guides 121 and the plate guides 122 are fixed to the first frame 111.

Examples of materials used for the first frame 111 may include metal, quartz, glass or the like. Furthermore, the first frame 111 may include a plurality of metal plates coupled with each other.

A first through hole 116 is formed in the first frame 111. The first through hole 116 vertically penetrates the first frame 111 and exposes the bottom of the support plate 132.

The second frame 112 is disposed on the first frame 111. The second frame 112 houses the first core receiving part 130 and the support plate 132. In more detail, the second frame 112 houses the first core receiving part 130 and the support plate 132, and includes a first guide hole 133 guiding the first core receiving part 130 and the support plate 132 in a vertical direction.

The first guide hole 133 penetrates the second frame 112 in a vertical direction. Furthermore, the diameter of the first guide hole 133 corresponds to the diameters of the first core receiving part 130 and the support plate 132. In more detail, the plane shape of the first guide hole 133 is substantially the same as the plane shapes of the first core receiving part 130 and the support plate 132. Furthermore, the outer circumferential surfaces of the first core receiving part 130 and the support plate 132 directly contact the inner circumferential surface of the first guide hole 133.

The second frame 112 has the inlet 103 for injecting the raw material into the space between the lower mold 101 and the upper mold 102. The inlet 103 penetrates the second frame 112 and is connected to the top surface of the first core receiving part 130. Thus, the raw material introduced through the inlet 103 may be injected into the mold 100 through the top surface of the first core receiving part 130.

A plurality of second guide holes 117 for the insertion of the frame guides 121 are formed in the second frame 112. The second guide holes 117 correspond to the frame guides 121, respectively. The plane shape of each second guide hole 117 is substantially the same as the plane shape of a corresponding one of the frame guides 121.

Examples of materials used for the second frame 112 may include metal, quartz, glass and the like. Furthermore, the second frame 112 may include a plurality of metal plates joined together.

The frame guides 121 are fixed to the first frame 111. In more detail, one end of each of the frame guides 121 is fixed to the first frame. Each of the frame guides 121 has a column shape. The frame guides 121 may extend upwardly from the first frame 111.

The frame guides 121 are inserted into the second guide holes 117, respectively, to thus guide the second frame 112. There may be four frame guides 121, and the frame guides 121 may be disposed on the corners of the first frames 121, respectively.

Furthermore, the frame guides 121 also guide the upper mold 102. That is, the frame guides 121 may penetrate the entirety of the second frame 112 and a portion of the upper mold 102. Accordingly, the frame guides 121 serve to guide the second frame 112 and the upper mold 102 so as to prevent them from being separated to the side.

The first cores 131 are received in the first core receiving part 130. In more detail, the first cores 131 are inserted and fixed in the first core receiving part 130. The first cores 131 are molds for forming lens parts 21 of a lens array substrate 20 according to an embodiment.

Referring to Fig. 10, the lens array substrate 20 include a plurality of lens parts 21 each having a curved surface, and a support part 22 extending from the lens parts 21. The lens parts 21 may have concave or convex shapes. The support part 22 may be flat, and the support part 22 and the lens parts 21 are integrally formed.

Referring to Fig. 11, the first cores 131 may have curved surfaces respectively corresponding to the lens parts 121. That is, the first cores 131 serve to control the curvature, size, shape and the like of the lens parts 21.

A material used for the first cores 131 may be, for example, metal, glass, quartz or the like.

The first core receiving part 130 is disposed inside the second frame 112. In more detail, the first core receiving part 130 is received in the second frame 112. In more detail, the first core receiving part 130 is disposed in the first guide hole 133. The first core receiving part 130 is guided in a vertical direction by the first guide hole 133.

The first core receiving part 130 has a plate shape. In more detail, the first core receiving part 130 may have a circular plat shape. A material used for the first core receiving part 130 may be, for example, metal, quartz, glass or the like.

The first core receiving part 130 receives the first cores 131. In more detail, the first core receiving part 130 includes a plurality of first receiving concave portions 134 for receiving the first cores 131, respectively. The first receiving concave portions 134 may penetrate the first core receiving part 130.

The first core receiving part 130 has third guide holes 135. The third guide holes 135 correspond to the plate guides 122, respectively. The plane shape of the guide holes 135 is substantially the same as that of the plate guides 122.

The plate guides 122 are inserted into the third guide holes 135, respectively, thus guiding the first core receiving part 130 in the vertical direction. That is, the third guide holes 135 and the plate guides 122 prevent the first core receiving part 130 from rotating.

Furthermore, the second frame 112 further includes a plurality of spouts connected to the inlet 103 and connected to the top surface of the first core receiving part 130. The raw material injected through the inlet 103 is spurted through the spouts. That is, the raw material is introduced into the mold 100 through the inlet 103 and the spouts.

The support plate 132 is disposed under the first core receiving part 130. The support plate 132 supports the first cores 131 and the first core receiving part 130. The support plate 132 transmits pressure applied from the outside to the first cores 131 and the first core receiving part 130.

The support plate 132 is disposed inside the second frame 112. In more detail, the support plate 132 is received in the second frame 112. In more detail, the support plate 132 is disposed in the first guide hole 133. The support plate 132 is guided vertically by the first guide hole 133.

The support plate 132 has a plate shape. In more detail, the support plate 132 may have a circular plate shape. A material used for the support plate 132 may be, for example, metal, quartz, glass or the like.

The support plate 132 has fourth guide holes 136 therein. The fourth guide holes 136 correspond to the plate guides 122, respectively. The plane shape of the fourth guide holes 136 is substantially the same as that of the plate guides 122.

The plate guides 122 are inserted into the fourth guide holes 136, respectively, thus guiding the support plate 132in the vertical direction. That is, the fourth guide holes 136 and the plate guides 122 serve to prevent the support plate 132 from rotating.

The plate guides 122 are fixed to the first frame 111. In more detail, the plate guides 122 have a column shape, and one end of each of the plate guides 122 is fixed to the first frame 111. That is, the plate guides 122 extend upwardly from the first frame 111.

The plate guides 122 penetrate the support plate 132 and the first core receiving part 130. That is, the plate guides 122 are inserted into the third guide holes 135 and the fourth guide holes 136.

The plate guides 122 serve to guide the support plate 132 and the first core receiving part 130 in the vertical direction. The plate guides 122 serve to prevent the support plate 132 and the first core receiving part 130 from rotating.

Furthermore, the plate guides 122 are disposed inside the second frame 112. In more detail, the plate guides 122 are disposed in the first guide hole 133. The plate guides 122 have a high level of strength, and a material used for the plate guides 122 may be metal or the like, for example.

In the drawings, the plurality of plate guides 122, the plurality of third guides holes 135, and the plurality of fourth guide holes 136 are illustrated. However, the mold 100 may include a single plate guide, a single third guide hole, and a single fourth guide hole.

The first sealing member 141 is disposed on the second frame 112. In more detail, the first sealing member 141 may be inserted inside the groove formed in the top surface of the second frame 112. The first sealing member 141 is disposed between the second frame 112 and the upper mold 102.

The first sealing member 141 extend s along the circumference of the first guide hole 133. The first sealing member 141 may have a closed-loop shape for example. The first sealing member 141 extends along the circumference of the first core receiving part 130.

The first sealing member 141 has elasticity. Furthermore, the first sealing member 141 has an improved adhesive force with respect to the upper mold 102 and the second frame 112. A material used for the first sealing member 141 may be, for example, a rubber-based resin, a silicon-based resin, or the like.

The second sealing member 142 is disposed inside the second frame 112. The second sealing member 142 is disposed in the first guide hole 133. Furthermore, the second sealing member 142 is disposed on the outer circumferential surface of the support plate 132. That is, the second sealing member 142 is disposed between the support plate 132 and the second frame 112.

The second sealing member 142 extends along the outer circumferential surface of the support plate 132. That is, the second sealing member 142 may have a closed-loop shape. The second sealing member 142 extends along the outer circumferential surface of the support plate 132.

The second sealing member 142 has elasticity. Furthermore, the second sealing member 142 has an improved adhesive force with respect to the support plate 132 and the second frame 112. A material used for the second sealing member 142 may be, for example, a rubber-based resin, a silicon-based resin, or the like.

The upper mold 102 includes a third frame 113, a fourth frame 114, a fifth frame 115, a plurality of second cores 151, a second core receiving part 150, and a window 160.

The third frame 113 is disposed on the lower mold 101. The third frame 113 is disposed on the second frame 112. The third frame 113 has a quadrangular frame shape. The third frame 113 surrounds the second receiving part 150.

That is, the third frame 113 guides the outer edge of the second core receiving part 150. Accordingly, the inner side surface of the third frame 113 may substantially coincide with the outer side surface of the second core receiving part 150. That is, the second core receiving part 150 is fixed by the third frame 113 without being separated to the side. A material used for the third frame 113 may be, for example, metal, glass, quartz or the like.

The third frame 113 may have therein fifth guide holes 118 in which the frame guides 121 are inserted, respectively. The plane shape of the fifth guide holes 118 is substantially the same as that of the frame guides 121. The frame guides 121 and the fifth guide holes 118 serve to guide the third frame 113 in the vertical direction.

The fourth frame 114 is disposed on the third frame 113. The fourth frame 114 has a quadrangular frame shape. The fourth frame 114 surrounds the window 160.

That is, the fourth frame 114 guides the outer edge of the window 160. Accordingly, the inner side surface of the fourth frame 114 may substantially coincide with the outer side surface of the window 160. The window 160 is fixed by the fourth frame 114, without being separated to the side. A material used for the fourth frame 114 may be, for example, metal, glass, quartz, or the like.

The fourth frame 114 has therein sixth guide holes 119 in which the frame guides 121 are inserted, respectively. The plane shape of the sixth guide holes 119 is substantially the same as that of the frame guides 121. The frame guides 121 and the sixth guide holes 119 serve to guide the fourth frame 114 in the vertical direction.

The fifth frame 115 is disposed on the fourth frame 114. The fifth frame 115 covers the fourth frame 114. The fifth frame 115 has a transmission hole 161 exposing the top surface of the window 160. The fifth frame 115 may be coupled to the fourth frame 114.

A material used for the fifth frame 115 may be, for example, metal, quartz, glass or the like. The fifth frame 115 may have a plate shape.

The second cores 151 are disposed on the first cores 131. In more detail, the second cores 151 correspond to the first cores 131, respectively. In more detail, each of the second cores 151 is disposed over a corresponding one of the first cores 131 to be spaced apart from the corresponding first core 131.

The second cores 151 are transparent, and a material used for the second cores 151 may be, for example, glass, quartz or the like. As shown in Fig. 11, the second cores 151 may each have a curved surface to form curves on the lens parts 21. For example, the second cores 151 have curved surfaces corresponding to the curved surfaces of the lens parts 21, respectively.

The second core receiving part 150 is disposed on the first core receiving part 130. The second core receiving part 150 and the first core receiving part 130 are spaced apart from each other and face each other. The second core receiving part 150 is disposed inside the third frame 113. In more detail, the outer edge of the second core receiving part 150 is guided by the third frame 113.

The second core receiving part 150 has a plate shape. The outer side surface of the second core receiving part 150 may substantially coincide with the inner side surface of the third frame 113. The second core receiving part 150 has a wider planar area than the first core receiving part 130, and may cover the entirety of the first core receiving part 130.

The second core receiving part 150 has therein a plurality of second receiving concave portions. The second cores 151 are disposed in the second receiving concave portions, respectively. That is, the second cores 151 are inserted into the second receiving concave portions, respectively, and the second cores 151 are thus received in the second core receiving part 150.

The second core receiving part 150 is transparent, and a material used for the second core receiving part 150 may be, for example, quartz, glass or the like. As shown in Fig. 11, the core receiving part is used to form the support part 22 included in the lens array substrate 20. The support part 22 is formed around the lens parts 21 and supports the lens parts 21. The second core receiving part 150 is used to form the support part 22, the flat portion of the lens array substrate 20.

The window 160 is disposed on the second core receiving part 150. The window 160 supports the top surface of the second core receiving part 150. For example, when pressure is upwardly exerted upon the second core receiving part 150, the window 160 on the second core receiving part 150 supports the second core receiving part 150.

Furthermore, the window 160 supports the second cores 151. The window 160 supports the top surfaces of the second cores 151. That is, when pressure is upwardly exerted upon the second cores 151, the window 160 supports the upper portions of the second cores 151.

Furthermore, the window 160 is disposed inside the fourth frame 114. In more detail, the outer edge of the window 160 is guided by the fourth frame 114. For example, the outer side surface of the window 160 may substantially coincide with the inner side surface of the fourth frame 114.

The window 160 may have a plate shape. The window 160 may cover the second core receiving part 150. For example, the planar area of the window 160 is greater than that of the second core receiving part 150.

The window 160 is transparent. A material used for the window may be, for example, glass, quartz, or the like.

A space in which the raw materials can be injected is formed between the lower mold 101 and the upper mold 102. In more detail, the raw material may be injected into the space between the first core receiving part 130 and the second core receiving part 150.

Furthermore, an air bubble outlet 104 through which the air is discharged when the raw material is injected is formed in the upper mold 102. After air bubbles are removed through the air bubble outlet 104, the air bubble outlet 104 is closed by a valve or the like.

Furthermore, the first sealing member 141 is tightly attached to the top surface of the second frame 112 and the bottom surface of the second core receiving part 150. Furthermore, the second sealing member 142 is disposed between the second frame 112 and the support plate 132 such the inner side surface of the first guide hole 133 and the outer circumferential surface of the support plate 132 are tightly attached to each other.

Accordingly, the first sealing member 141, the second frame 112, the second core receiving part 150 and the support plate 132 serve to form a sealed area. That is, the space between the first core receiving part 130 and the second core receiving part 150 substantially corresponds to the sealed area. Thus, the raw material is injected into the sealed area.

Furthermore, through the inlet 103, the pressure inside the mold 100, that is, in the sealed area, may be increased. That is, high pressure is applied through the inlet 103, and the pressure between the first core receiving part 130 and the second core receiving part 150 may be increased.

Also, when pressure is upwardly exerted upon the support plate 132, the pressure in the mold 100, that is, in the sealed region, may be increased. That is, by directly applying force to the support plate 132, the pressure between the first core receiving part 130 and the second core receiving part 150 may be increased.

Furthermore, the mold 100 has a firm structure due to the first to

fifth frames

111, 112, 113, 114 and 115 and the frame guides 121. Also, since pressure is exerted upwardly and downwardly upon the first frame 111 and the fifth frame 115, respectively, the mold 100 is firmly assembled.

Thus, when the pressure inside the mold 100 is increased through the inlet 103 and the support plate 132, the mold 100 can bear even high pressure.

Also, the window 160, the second cores 151, and the second core receiving part 150 are transparent, and the transmission hole 161 is formed to expose the window 160. Accordingly, light such as ultraviolet rays may be applied to the space in the mold 100, that is, the space between the first core receiving part 130 and the second core receiving part 150.

As shown in Fig. 1, the packet part 200 is provided at the base 200. The packing part 200 may be moved horizontally by the transfer unit 12. The packet part 200 injects the raw material into the mold 100.

The packing part 200 includes a hopper 230. The raw material may be introduced into a cylinder 220 of the packet part 200 through the hopper 230.

Also, the packet part 200 increases the pressure in the mold 100 through the inlet 103. For example, the packet part 200 further includes a piston 210 and a screw 211. That is, the rotation of the screw 211 may make the piston 210 move forward within the cylinder 220 of the packing part 200. In such a manner, the packing part 200 transmits the pressure exerted by the piston 210 to the inside of the mold 100.

The packing part 200 may exert a force of approximately 2000 kgf upon the piston 210. Accordingly, the packing part 200 can transmit a pressure of approximately 300kgf/㎠ to the inside of the mold 100.

Also, the packing part 200 injects the raw material into the mold 100. For example, the raw material flows into the cylinder 220 through the inlet 103 by the pressure of the piston 210. That is, the packing part 200 serves to inject the raw material into the mold 100 while increasing the pressure in the mold 100.

The cooling part 300 cools the raw material. For example, a temperature of the raw material may be lowered to approximately 5℃ to approximately 15℃. The raw material cooled by the cooling part 300 in the above manner is injected into the mold 100.

When the temperature of the raw material cooled to the aforementioned temperature by the cooling part 300 is increased to a room temperature, the cooled raw material may be further expanded by approximately 0.065 vol% to approximately 0.13 vol%. This thermal expansion of the raw material, previously cooled to the aforementioned temperature, may compensate for the shrinkage of approximately 0.65% occurring in the process of curing the raw material.

The cooling part 300 is provided in a passage through the raw material flows from the cylinder of the packing part 200 to the inlet 103. The cooling part 30 may be a pipe wound around the passage. In this case, a refrigerant flows through the pipe.

Although not shown, the cooling part 300 may be disposed around the mold 100. For example, a pipe through which a refrigerant flows may be provided around the mold 100, and thus the temperature of the mold 100 may also be decreased.

The light source 400 is disposed on the mold 100. The light source emits light into the mold 100. For example, the light source 40 applies ultraviolet rays to the inside of the mold 100. In more detail, the light source 400 applies ultraviolet rays between the first core receiving part 130 and the second core receiving part 150 through the transmission hole 161, the window 160, the second cores 151 and the second core receiving part 150.

The light source 400 includes a super pressure mercury lamp 410, an ellipse collection mirror 420, a first plane reflective mirror 430, an integrator lens 440, a second plane reflective mirror 450, and a collimator lens 460.

The mercury lamp 410 generates ultraviolet rays, and the ultraviolet rays emitted from the mercury lamp 410 are concentrated by the collection mirror 420. Thereafter, the concentrated ultraviolet rays are reflected by the first plane reflective mirror 430, and the reflected ultraviolet rays is increased in uniformity by the second plane reflective mirror 450, and is made incident upon the collimator lens 460. The collimator lens 460 allows the ultraviolet rays to have further enhanced uniformity, and these ultraviolet rays are applied toward the mold 100.

The mask 500 is disposed between the light source 400 and the mold 100. Alternatively, the mask 500 may be disposed in the mold 100. The mask 500 selectively transmits light from the light source 400. For example, the mask 500 may transmit light to only a region corresponding to the first cores 131 and the second cores 151.

As shown in Figs. 7 and 8, transmission portions 510 of the mask 500 may correspond to the second cores 151, respectively. That is, the mask 500 may allow ultraviolet rays to be applied to only the raw material corresponding to the second cores 151.

Accordingly, the mask 500 may allow the raw material corresponding to the second cores 151 to be cured first. That is, the lens parts 21 may be formed first, and the support part 22 around the lens parts 21 may be formed later. Thus, since the mask 500 allows the lens parts 21, which need to be precisely formed, to be formed first, the quality of the lens array substrate 200 according to this embodiment can be improved.

The pressure part 600 is provided in the base 100. The pressure part 600 is disposed under the mold 100.

The press part 600 increases pressure in the mold 100. In more detail, the press part 600 directly applies pressure to the mold 100, thus increasing the pressure of the raw material injected into the mold 100.

In more detail, the press part 600 may increase pressure in the sealed area by exerting force upon the support plate 132. For example, the press part 600 may exert a force of approximately 5000 kgf upon the support plate 132. Also, the pressure in the mold 100 may be increased up to approximately 1000kgf/㎠ by the press part 600.

The press part 600 includes a hydraulic cylinder 610 and a press bar 620.

The hydraulic cylinder 610 generates force. For example, the hydraulic cylinder 610 exerts force upwardly. In more detail, the hydraulic cylinder 610 may upwardly exert a maximum force of approximately 7000 kgf.

The press bar 620 transmits the force generated from the hydraulic cylinder 610 to the mold 100. The press bar 62 may upwardly exert force upon the support plate 132 in direct contact with the support plate 132.

A portion of the press bar 620 is inserted in the mold 100. In more detail, the press bar 620 passes through the first through hole 116 and directly applies force to the support plate 132 to thus push up the support plate 132. Accordingly, the pressure in the mold 100 can be increased.

The molding apparatus for a lens array substrate according to this embodiment may be used not only to manufacture the lens array substrate but also to manufacture various polymer molded articles.

Furthermore, referring to Fig. 9, an apparatus for manufacturing a lens array substrate according to an embodiment may manufacture a lens array substrate through the following processes. A method of manufacturing the lens array substrate, described herein, is not limited to manufacturing the lens array substrate, but may be widely used to manufacture a variety of polymer molded articles.

First, the mold 100 is assembled, and the mold 100 is mounted on the base 10 in operation S10. The mold 100 is firmly secured to the base 10 by the pressure strong in vertical direction.

Thereafter, the raw material is cooled, and the mold 100 is also cooled in operation S20. Subsequently, the cooled raw material is injected into the mold 100 in operation S30. In more detail, the raw material flows into the cylinder of the packing part 200, and passes through the passage where the cooling part 300 is disposed, due to the pressure of the piston 210 of the packing part 200. Thus, the cooled raw material is injected through the inlet 103 of the mold 100. In this case, the temperature of the raw material may range from approximately 5℃ to approximately 15℃.

Since the raw material in a cooled state is injected into the mold 100, the raw material is sufficiently compressed when injected into the mold 100. Thus, when the raw material is cured, the temperature is increased. Thus, shrinkage occurring when the raw material is cured can be compensated for.

After the injection of the raw material is completed, the packing part 200 increase the pressure of the raw material injected into the mold 100 by using the piston 210, the screw 211 and the like in operation S40. For example, the packing part 200 may increase the pressure in the mold 100 to approximately 200 kgf/㎠ to approximately 300 kgf/㎠ through the inlet 103. For example, the screw 211 may apply a force of approximately 3000 kgf to approximately 5000 kgf to the piston 210 of the packing part 200. Accordingly, the packing part 200 can increase the pressure in the mold 100.

As the pressure of the aforementioned level is applied to the raw material through the packing part 200, shrinkage occurring in the process of curing the raw material is compensated for. That is, since the raw material is liquid, it may need to be compressed at very high pressure in advance as described above for the compensation of the shrinkage.

Thereafter, in the state where the packing part 200에 has increased the pressure in the mold 100, the mask 500 is provided between the light source 400 and the mold 100, and ultraviolet rays are applied to the raw material within the mold 100 through the mask in operation S50.

Accordingly, the raw material within the mold 100 may be partially cured. For example, the raw material corresponding to the second cores 151 may be cured first. In this case, the shrinkage, occurring in the process of curing the raw material, may be compensated for by the packing effect of the packing part 200.

Thereafter, the mask 500 is removed in operation S60 while the light source 400 emits ultraviolet rays. Thus, the entirety of the raw material is irradiated with the ultraviolet rays. Thus, the raw material injected into the mold 100 may be entirely cured.

Subsequently, very high pressure is applied to the cured raw material by the press part 600 in operation S70. For example, pressure more than doubling the pressure exerted by the packing part 200 may be applied to the cured raw material.

For example, the press part 600 may exert a force of approximately 4000 kgf to approximately 5000 kgf upon the support plate 132, thus increasing the pressure in the mold 100. In this case, the pressure in the mold 100 may be increased to approximately 800 kgf/㎠ to approximately 1000 kgf/㎠.

Since the cured raw material is compressed by the high pressure as above, the curved surfaces of the lens parts 21 can be formed more smoothly. That is, fine shrinkage may occur even when the shrinkage of the raw material is compensated for by the cooling part 300 and the packing part 200. That is, by the high pressure as described above, fine unevenness in the curved surfaces of the lens parts 21 can be removed.

As described above, the press part 600 exerts pressure upon to the cured raw material, and the final lens array substrate 20 is formed. Thereafter, the mold 100 is opened, and thus formed lens array substrate 20 is taken out in operation S80.

The shrinkage control for the lens array substrate 20 controls shrinkages is made by cooling the raw material, packing by the packing part 200, and pressurization by the press part 00. Accordingly, the lens parts 21 of the lens array substrate 21 can have smooth curved surfaces.

In particular, according to an embodiment, the lens array substrate 20 is formed by increasing the pressure in the mold 100, having therein the injected raw material, in two stages, and dividing the curing process into two stages.

Accordingly, the method of manufacturing a lens array substrate according to the embodiment can provide a lens array substrate having a considerably smooth curved surface and a desired shape.

The embodiment is not limited to a method of forming the lens array substrate, and may be used to form various polymer molded articles with complicated and fine structures.

Inventive example

A resin composition was prepared. The resin composition included pentaerythritol triacrylate at 60wt% and dipentaerythritol hexaacrylate at 40wt% as photo-curable monomers, and included 1-hydroxy-cyclohexyl-phenyl-keto at 0.8wt% as a photo-initiator. The resin composition was injected into the mold and was subjected to packing by the packing part with a pressure of approximately 2000kgf/㎠ for approximately 30 seconds. Thereafter, the resin composition within the mold was irradiated with ultraviolet rays having a wavelength of approximately 365㎚ for approximately 90 seconds, while the press part applied a pressure of approximately 2500kfg/㎠ to the inside of the mold for approximate 70 seconds. In the above manner, lens array substrate#1 was formed.

Comparative example

The same resin composition as that of the inventive example was injected to a mold, the packing of the packing part and the pressure of the press part were not applied thereto, and the resin composition was irradiated with ultraviolet rays in the same manner as in the above inventive example. Thus, lens array substrate#2 was formed.

Results

With reference to the shape of the mold, the shape error of the lens array substate#1 was approximately 0.5㎛, and the shape error of the lens array substrate#2 was approximately 7㎛. The molding apparatus according to this embodiment may efficiently provide a lens array substrate with a desired shape.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.

The molding apparatus for a lens array substrate and the method of manufacturing a lens array substrate using the same according to embodiments may be used to manufacture a molded object or the like.

Claims

A molding apparatus, comprising:

a mold in which a raw material is injected;

a packing part injecting the raw material into the mold through an inlet of the mold, the packing part increasing pressure in the mold through the inlet;

a light source emitting light to the raw material within the mold; and

a press part increasing pressure in the mold by applying pressure to the mold.
The molding apparatus according to claim 1, comprising a cooling part cooling the raw material.
The molding apparatus according to claim 2, wherein the cooling part cools the raw material to a temperature ranging from 5℃ to 15℃.
The molding apparatus according to claim 1, wherein the mold comprises:

a plurality of cores directly contacting the raw material and each having a curved surface;

a core receiving part receiving the cores; and

a frame housing the core receiving part.
The molding apparatus according to claim 4, comprising a mask disposed between the light source and the mold.
The molding apparatus according to claim 5, wherein the mask comprises a plurality of transmission portions corresponding to the cores, respectively.
The molding apparatus according to claim 4, wherein the press part comprises:

a hydraulic cylinder generating force; and

a press bar transmitting the force, generated from the hydraulic cylinder, to the mold,

wherein the mold comprises a support plate directly contacting the press bar, received in the frame, and supporting the core receiving part, the framing comprising a hole in which the press bar is inserted.
The molding apparatus according to claim 7, wherein the core receiving part comprises:

a first core receiving part disposed on the support plate; and

a second receiving part disposed on the first core receiving part, spaced apart from the first core receiving part, and facing the first core receiving part,

wherein the cores comprise first cores received by the first core receiving part, and second cores received by the second core receiving part.
The molding apparatus according to claim 8, wherein the second core receiving part and the second cores are transparent.
The molding apparatus according to claim 1, wherein the packing part increases the pressure in the mold to 300 kgf/㎠, and the press part increases the pressure in the mold to 1000 kgf/㎠.
A method of manufacturing a polymer molded article, the method comprising:

injecting a raw material into a mold through an inlet of the mold;

primarily increasing pressure of the raw material within the mold through the inlet;

irradiating the raw material, having the primarily increased pressure, with light; and

secondarily increasing the pressure of the raw material, the pressure of which has been primarily increased.
The method according to claim 11, wherein, in the primarily increasing of the pressure of the raw material, the pressure of the raw material is increased to 200 kgf/㎠ to 300 kgf/㎠, and, in the secondarily increasing of the pressure of the raw material, the pressure of the raw material is increased to 800 kgf/㎠ to 1000 kgf/㎠.
The method according to claim 11, comprising cooling the raw material.
The method according to claim 11, wherein the irradiating of the raw material comprises:

selectively irradiating the raw material by using a mask; and

removing the mask and irradiating the raw material.
The method according to claim 11, wherein, in the secondarily increasing of the pressure of the raw material, pressure is directly applied to the mold to thus secondarily increase the pressure of the raw material.
The method according to claim 11, comprising cooling the mold.
The method according to claim 11, wherein the raw material comprises a photo-curable resin, and the polymer molded article is transparent.
The method according to claim 11, wherein the polymer molded article comprises:

a plurality of lens parts each having a curved shape; and

a support part extending from the lens parts and supporting the lens parts.