JP2006256906A - Forming die and method of manufacturing optical glass lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forming die for an optical glass lens capable of forming a lens sheet having large difference of thickness between a leans part and a edge part in a short forming time while preventing the occurrence of breaking without applying large pressing force, and a method of manufacturing the optical glass lens. <P>SOLUTION: The optical glass sheet in which a plurality of number of glass lenses are formed in a grid pattern is manufactured by using the forming die 1 and heat-press-forming raw material glass 10 placed on a cavity. The forming die 1 is constituted so that the cavity is formed by combining cavity surfaces 2b, 3b of an upper die 2 and a lower die 3, a plurality of surfaces 2a, 3a forming the lens surfaces of the glass lenses are formed on the cavity surfaces 2b, 3b of the upper die 2 and the lower die 3 and glass material retaining parts comprising recessed parts 2c, 3c recessed from the cavity surfaces are formed at least on one of the cavity surfaces of the upper die 2 and the lower die 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a molding die for an optical glass lens used for a solid-state imaging device such as a CCD or CMOS, and a method for manufacturing the optical glass lens, and more particularly to a glass lens sheet in which a plurality of optical glass lenses are integrated by hot press molding. .

In recent years, the progress of multimedia has been remarkable, and imaging devices including solid-state imaging devices such as CCD (Charge Coupled Device) and CMOS (Complementary Metal-Oxide Semiconductor), such as mobile phones and digital still cameras, are rapidly spreading. Yes. As an imaging lens used in such an imaging apparatus or the like, higher image quality, higher resolution, miniaturization, and cost reduction are required.
In order to cope with such downsizing and cost reduction, the optical element-integrated glass sheet is formed by heat-pressing the raw material glass material, having a plurality of lens portions and connecting portions, etc., and having a cutting margin for separation into a plurality of portions. Has been proposed (see, for example, Patent Document 1).

  As a method of manufacturing a large number of optical glass lenses (hereinafter referred to as glass lenses) on such a glass lens sheet (hereinafter referred to as lens sheets), a raw material glass material (hereinafter referred to as glass material) is used. ) Is processed into a predetermined fixed volume (or constant weight) in the shape of a flat plate, plano-convex plate, plano-concave plate, etc. in advance, and a molding die provided with an upper die and an optical die formed with an optical surface shape Place in the mold cavity. A method of forming a glass lens by heating and pressing a softened glass material, so-called hot press molding, is used.

JP 2003-277084 A

An example of a lens sheet molded by hot press molding is shown in FIG. FIG. 7A is a plan view of a molded lens sheet, and FIGS. 7B to 7D are partial cross-sectional views of lens sheets having different lens part shapes.
In FIG. 7A, the molded lens sheet S10 has a plurality of lens portions 10a arranged in a lattice pattern at the same pitch on the lens sheet, and the lens portions 10a are connected by connecting portions 10b as edge portions. ing. Thereafter, the molded lens sheet S10 is cut and separated by a cut line 10d indicated by a two-dot chain line with reference to a cross-shaped alignment mark 10c formed on the surface of the connection portion 10b by transfer from a mold. A plurality of lenses 10e are obtained.

  The glass material used for hot press molding is generally a flat plate that has been cut or polished into a predetermined planar shape from the viewpoint of cost. However, the difficulty of molding differs greatly depending on the cross-sectional shape of the lens part to be molded. For example, as shown in FIG. 7B, in the case of the lens sheet S11 having a value close to the thickness TC of the lens portion 11a to be molded and the thickness TE of the edge portion (peripheral portion) 11b, the molding is relatively easy. is there. However, as shown in FIGS. 7C and 7D, the lens sheets S12 and S13 are molded when the difference between the thickness TC of the lens portions 12a and 13a and the thickness TE of the edge portions 12b and 13b is large. It is not easy and may not be molded.

  The volume of the glass material used for molding is set based on the volume of the lens sheet to be molded. For example, in the rectangular lens sheet S10 as shown in FIG. 7A, the vertical and horizontal dimensions of the glass material are molded on the basis of the plane size of the upper and lower molds of the square used for molding. The thickness is determined by setting the planar shape to be equal to or slightly larger than S10. Therefore, in the case of the lens sheet S11 (see FIG. 7B), the thickness of the glass material is a dimension close to the thickness TC of the lens portion 11a and the thickness TE of the edge portion 11b. On the other hand, in the case of the lens sheets S12 and S13 (see FIGS. 7C and 7D), an intermediate thickness between the thickness TC of the lens portions 12a and 13a and the thickness TE of the edge portions 12b and 13b. Is set.

  In the molding of the lens sheets S12 and S13, the portion thicker than the thickness of the glass material and the portion to be thinned are hot-pressed and molded. However, since the amount of deformation of the glass material by the press is large, a large pressing force is required. To do. At this time, if the pressing force necessary for molding cannot be obtained, the upper die 62 and the lower die 63 are formed on the molding die 61 as shown in the partial sectional view of the pressing state by the molding die in FIG. In addition, a gap α is generated between each optical surface 62a, 63a and the glass material 14 to be molded, and a predetermined optical surface shape is not transferred to the lens sheet S12 to be molded.

  Generally, the press capability of a hot press machine that heat-molds a glass material is about 1 to 4 tons, which is smaller than that of a sheet metal press machine or an injection molding machine. In the thermoforming, a force for enlarging the glass material 14b in the vicinity of the edge portion to the lens central portion 14a (fluid force of the glass material) is required, but the pressing force when the glass material is thickened is equal to the pressing force when the glass material is thinned. In comparison, since a larger force is required, there are many cases where molding cannot be performed. In addition, even if the pressing force is sufficient, there are problems such as a long molding time or a tendency to crack the molded lens portion 14a.

  Therefore, the present invention has been made in view of such circumstances, and enables the molding of a lens sheet having a large difference between the thickness of the lens portion and the thickness of the edge portion, which has conventionally been difficult to mold, and in a short molding time. An object of the present invention is to provide an optical glass lens molding die and a manufacturing method of an optical glass lens that do not use a large pressing force and prevent cracking.

  In order to solve the above-mentioned problems, a molding die of the present invention is a molding die for manufacturing an optical glass lens sheet in which a plurality of glass lenses are formed in a lattice shape by hot press molding a raw material glass material. The molding die has a cavity formed by combining two cavity surfaces of an upper die and a lower die, and a surface for molding a lens surface of the glass lens on each cavity surface of the upper die and the lower die. And at least one of the upper mold and the lower mold is formed with a glass material reservoir formed of a concave surface recessed from the cavity surface.

  According to this, since the glass material reservoir part consisting of the concave surface recessed from the cavity surface is formed on the cavity surfaces of the lower mold and the upper mold, the raw glass material to be hot-press molded all forms the lens surface of the glass lens. The optical surface is filled without gaps. Therefore, it is possible to mold a lens sheet having a large difference between the thickness of the lens part and the edge part of the glass lens, which has been difficult to mold, and the concave glass as the glass material reservoir is filled with the raw material glass material. Thus, a molding die for producing an optical glass lens in which a plurality of glass lenses, in which molding distortion is reduced and cracking is prevented, is formed in a lattice shape is obtained.

  The molding die of the present invention is a molding die for producing an optical glass lens sheet in which a plurality of glass lenses are formed in a lattice shape by hot press molding a raw material glass material. A cavity is formed by combining two cavity surfaces of the upper mold and the lower mold, and a surface for molding the lens surface of the glass lens on each of the cavity surfaces of the upper mold and the lower mold, and at least the upper mold Further, a glass material protruding portion made of a convex surface protruding from the cavity surface is formed on one of the cavity surfaces of the lower mold.

  According to this, on the cavity surface of the lower mold and the upper mold, by forming a glass material protruding portion consisting of a convex surface protruding from the cavity surface, at the time of hot press molding, the glass material protruding portion first comes into contact with the raw material glass material, The raw glass material is pressed and deformed in the thickness direction, and fluidity is generated in the direction of the optical surface that forms the lens surface of the glass lens. As a result, spreading is easily performed in the cavity, and the raw material glass material is filled without any gaps on all surfaces that form the lens surface of the glass lens. For this reason, it is possible to mold a lens sheet with a large difference between the thickness of the lens part and the edge part of the glass lens, which has been difficult to mold, and a plurality of glass lenses that prevent cracking are formed in a lattice shape. Thus, a molding die for producing the optical glass lens sheet can be obtained.

  In addition, when the planar shape of the glass material protruding portion that protrudes from the cavity surface is molded using a molding die formed into a square, a square groove is formed on the molded lens sheet, This square groove can be used as an alignment mark for positioning when it is cut into a plurality of glass lenses by cutting with a dicer or the like, and an optical surface for molding the lens surface is formed on the cavity surface of the molding die. More can be arranged.

  The method for producing an optical glass lens of the present invention is the method for producing an optical glass lens in which a raw glass material is heated and press-molded to produce an optical glass lens sheet in which a plurality of glass lenses are formed in a lattice shape. The raw glass material is formed of a flat plate, and at least one through hole or non-through hole is formed on the flat plate.

  According to this manufacturing method, at least one or more through holes or non-through holes are formed on a raw material glass material made of a flat plate. This through-hole or non-through-hole can have a directionality to deform the raw material glass material during pressing, and a glass lens sheet, that is, a glass lens can be produced in a short molding time without using a large pressing force. .

  The method for producing an optical glass lens of the present invention is the method for producing an optical glass lens in which a raw glass material is heated and press-molded to produce an optical glass lens sheet in which a plurality of glass lenses are formed in a lattice shape. The raw glass material is formed of a flat plate, and grooves are formed in a lattice shape over part or all of the positions between the plurality of glass lenses formed on the flat plate.

  According to this manufacturing method, grooves are formed on a raw material glass material made of a flat plate in a lattice shape over a part or all of the positions between a plurality of glass lenses to be molded. By forming the formed glass material to have a direction to be deformed, the formed groove can produce a glass lens sheet, that is, a glass lens in a short molding time without using a large pressing force.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
In this embodiment, the difference between the thickness of the lens portion and the thickness of the edge portion is large by forming the glass material reservoir portion on the cavity surface of the upper mold or / and the lower mold of the molding die for hot press molding the raw material glass material. It is one Embodiment which enables shaping | molding of a lens sheet (glass lens).
FIG. 1 is a schematic view of the cavity surface of the lower mold of the molding die, FIG. 2 is a sectional view of the cavity during molding, FIG. 2 (a) shows a state in which the cavity is opened, and FIG. Indicates a pressed state. FIG. 2 shows an AA cross section in FIG.

  1 and 2, the molding die 1 has a cavity formed by combining the lower cavity 3 and the two cavity surfaces 3b, 2b of the upper mold 2. As shown in FIG. The cavity surfaces 3b, 2b of the lower mold 3 and the upper mold 2 are formed with concave surfaces 3c, 2c, which are recessed in a hemispherical shape as glass material reservoirs, at the center, and around the concave surfaces 3c, 2c, the lens portion Sa. A plurality of concave surfaces 3a and 2a made of a predetermined spherical surface or aspherical surface for forming the substrate are arranged in a lattice shape at the same pitch to constitute a multi-cavity molding die.

  The concave surface 3a formed on the lower die 3 and the concave surface 2a formed on the upper die 2 facing the concave surface 3a form a plurality of lens portions Sa having a predetermined optical surface. In addition, the magnitude | size (volume) of the concave surfaces 3c and 2c is set larger than the magnitude | size (volume) of one concave surface 3a, 2a. The concave surfaces 3a and 2a and the concave surfaces 3c and 2c can be formed directly on the cavity surfaces 3b and 2b of the lower mold 3 and the upper mold 2 or can be formed by nesting.

  The molding die 1 in which the cavity surfaces 3b and 2b are thus formed is attached to a hot press machine (not shown) and molding is performed. The hot press machine is provided with heaters for heating the lower mold 3 and the upper mold 2 at the upper and lower positions of the molding die 1, and the upper and lower molds are pressurized with a predetermined pressure to move up and down, and the cavity is closed.

Next, a molding method (manufacturing method) of the lens sheet (glass lens) S will be described with reference to FIG.
First, as shown in FIG. 2A, the lower mold 3 and the upper mold 2 are opened, and the glass material 10 processed into a predetermined shape (volume) is placed in the cavity. Then, the molding die 1 is heated to a temperature higher than the glass transition temperature (Tg) of the raw glass material by a heater or the like, and the glass material 10 is softened.

  The material of the glass material 10 is not particularly limited, and low melting point optical glass having a predetermined refractive index and Abbe number (for example, Tg = 534 ° C. in the present embodiment) is used. Further, the shape of the glass material is the size of a substantially planar dimension of the molding die 1 (the lower mold 3 and the upper mold 2), and the thickness dimension is set from the volume of the molded product and the substantially planar dimension. In a press, it is easier to form a thin part from a thicker part than to form a thick part from a thin part.

  As shown in FIG. 2B, the glass material 10 placed in the cavity is sandwiched between the lower die 3 and the upper die 2 as the lower die 3 and the upper die 2 move to a predetermined distance. Is heated and pressed. The lower mold 3 and the upper mold 2 are heated to about 575 to 580 ° C. by a heater, and the glass material 10 softened by heating is spread into the cavity by a press to form the lens sheet S. At the time of this hot pressing, the glass material 10 is formed with the molding reservoir Sc so as to fill the concave surfaces 3c and 2c as glass material reservoir portions formed at the center of the cavity surfaces 3b and 2b of the lower die 3 and the upper die 2. The plurality of concave surfaces 3a and 2a which are spread while being molded and mold the lens portion Sa are filled without gaps. Further, the excess glass material 10 is formed so as to protrude in the outer peripheral direction of the lens sheet S to be molded.

In this state, after the glass material 10 is cooled to a predetermined temperature, the lower mold 3 and the upper mold 2 are opened, and a molded product is taken out from the cavity of the molding die 1 to form a plurality of lens portions Sa. The finished lens sheet S is completed.
The completed glass lens sheet S is cut by a dicer or the like and separated into a plurality of optical glass lenses (see FIG. 7).

  In the above description, the case where the concave surfaces 3c, 2c that are hemispherically recessed are formed on the cavity surfaces 3b, 2b of the lower die 3 and the upper die 2 as the glass material reservoir, but the shape of the concave surfaces 3c, 2c is as follows. Any shape such as a cross-sectional shape recessed in a V shape or a cross-sectional shape recessed in a trapezoid may be used. The concave surfaces 3c and 2c may be formed on either the lower mold 3 or the upper mold 2.

  According to the first embodiment described above, the glass material 10 is formed by forming the concave surfaces 3c and 2c as the glass material reservoir portions on the cavity surfaces 3b and 2b of the lower mold 3 and the upper mold 2 of the molding die 1. Are filled in all the concave surfaces 3a, 2a forming the lens portion Sa without gaps. Therefore, it is possible to mold the lens sheet S having a large difference between the thickness of the lens portion Sa and the thickness Sb of the edge portion, which has been difficult to mold, and the concave surfaces 3c and 2c are filled with the glass material 10, thereby forming the lens sheet S. Distortion is relieved, cracking is prevented, and a plurality of optical glass lenses are obtained by a single molding.

(Second Embodiment)
The present embodiment is a modification of the first embodiment, and the lens portion is formed by forming the glass material protruding portion on the cavity surface of the upper mold and / or the lower mold of the molding die for hot press molding the raw material glass material. It is one Embodiment which enables shaping | molding of a lens sheet (glass lens) with the large difference of the thickness of this, and the thickness of an edge part. The configuration other than the molding surface shape formed on the cavity surface of the molding die, the molding method, and the like are all the same as in the first embodiment.

FIG. 3 is a cross-sectional view showing a state where the cavity is opened.
In FIG. 3, the molding die 21 has a cavity formed by combining a lower mold 23 and two cavity surfaces 23 b and 22 b of an upper mold 22. The cavity surfaces 23b and 22b of the lower mold 23 and the upper mold 22 are formed with convex surfaces 23c and 22c projecting in a hemispherical shape as glass material protruding portions at the respective central portions, and a lens portion around each convex surface 23c and 22c. A predetermined spherical or aspherical concave surface 23a, 22a is formed into a multi-cavity molding die in which a plurality of lattices are arranged at the same pitch (see FIG. 1).
The concave surfaces 23a and 22a and the convex surfaces 23c and 22c can be formed directly on the cavity surfaces 23b and 22b of the lower mold 23 and the upper mold 22 or can be formed by nesting.

  In the hot press molding by the molding die 21, when the lower mold 23 and the upper mold 22 are moved to a predetermined interval and the cavity is closed, the convex surfaces 23 c and 22 c formed on the lower mold 23 and the upper mold 22 are first formed. In contact with the glass material 11. Then, the glass material 11 is hot-pressed in the thickness direction and deformed, and fluidity is generated in the direction of the arrow in the figure (that is, the direction of the concave surface for molding the lens portion), so that the glass material 11 can be easily spread in the cavity. All the concave surfaces 23a and 22a for molding the lens portion are filled without any gaps. Excess glass material 11 is formed in the outer peripheral direction of the lens sheet to be molded.

  In the above description, as the glass material protruding portion, the case where the convex surfaces 23c and 22c projecting hemispherically are formed on the cavity surfaces 23b and 22b of the lower mold 23 and the upper mold 22, but the shape of the convex surfaces 23c and 22c is described. May have any shape such as a cross-sectional shape projecting in an inverted V shape or a cross-sectional shape projecting in a trapezoidal shape. Further, the convex surface may be formed on one of the lower mold 23 and the upper mold 22. In addition, when the predetermined spherical surface or aspherical shape for forming the lens portion is formed as a convex surface, the height of the protruding convex surfaces 23c and 22c is set higher than the height of the convex surface for forming the lens portion. .

  According to the second embodiment described above, the convex surfaces 23c and 22c as the glass material protruding portions are formed on the cavity surfaces 23b and 22b of the lower mold 23 and the upper mold 22 of the molding die 21. First, the convex surfaces 23c, 22c come into contact with the glass material 11, the glass material 11 is hot-pressed in the thickness direction and deformed, and fluidity is generated in the direction of the plurality of concave surfaces 23a, 22a forming the lens portion. Spreading is easily performed in the cavity, and all the concave surfaces 23a and 22a for molding the lens portion are filled without gaps, and a plurality of optical glass lenses can be obtained by one molding.

(Third embodiment)
This embodiment is a modification of the first embodiment and the second embodiment. On the cavity surface of the upper mold or / and the lower mold of the molding die for hot press molding the raw glass material, a glass material reservoir, Alternatively, by forming the glass material protruding portion, the lens sheet (glass lens) having a large difference in thickness between the lens portion and the edge portion can be formed. The configuration other than the shape of the molding surface formed on the cavity surface of the molding die, the molding method, and the like are all the same as in the first embodiment.

4A is a schematic view of the cavity surface of the lower mold of the molding die, and FIG. 4B is a cross-sectional view of the lower mold of the molding die. FIG. 4B shows a BB cross section in FIG.
In the molding die 31, a cavity is formed by combining a lower die 33 and two cavity surfaces 33b and 32b of an upper die 32 (not shown). On the cavity surface 33b of the lower mold 33, a plurality of concave surface groups in which four predetermined spherical or aspherical concave surfaces 33a for molding the lens portion are formed in the same pitch in the same pitch are arranged at the same pitch. Has been. A substantially square groove 33c is formed at a position surrounding the concave surface group formed at the center of the plurality of concave surface groups. A similar molding surface shape is formed on the cavity surface 32 b of the upper mold 32 at a position corresponding to the cavity surface 33 b of the lower mold 33.

  The substantially square grooves 33c and 32c formed on the cavity surfaces 33b and 32b function as a glass material reservoir when the glass material is sandwiched between the lower mold 33 and the upper mold 32 and heated and pressed. The lens sheet that is spread so as to fill in 33c and 32c and is filled without gaps in all the concave surfaces 33a and 32a forming the lens portion is completed.

  In the above description, instead of the grooves 33c and 32c, convex surfaces protruding from the cavity surfaces 33b and 32b may be formed. In this case, when the glass material is sandwiched between the lower mold 33 and the upper mold 32 and heated and pressed, the protruding convex surface functions as a glass material protruding portion. When the protruding convex surface first comes into contact with the glass material, the glass material is deformed in the thickness direction, and the glass material is spread in the cavity while the fluidity is generated, so that all the concave surfaces 33a and 32a forming the lens portion are formed. Fills without gaps.

  Further, the cross-sectional shape of the grooves 33c and 32c and the protruding convex surface may be any shape such as a hemispherical shape, a V shape, a trapezoidal shape, and the grooves 33c and 32c are either the lower die 33 or the upper die 32. It may be formed on one side. In addition, the planar shape of the grooves 33c and 32c has been described as being substantially square, but any rectangular shape may be used.

According to the third embodiment described above, the cavity surfaces 33b and 32b of the molding die 31 are formed with grooves 33c and 32c as glass material reservoirs, or protruding convex surfaces as glass material protrusions. In addition to the same effects as those of the first and second embodiments, there are the following effects.
The substantially square protrusion formed by the grooves 33c and 32c on the lens sheet, or the groove formed by the protruding convex surface, is obtained when the completed lens sheet is cut by a dicing device or the like and separated into a plurality of glass lenses. It can be used as an alignment mark for positioning. Thereby, more lens parts can be formed on the cavity surfaces 33b and 32b of the molding die 31, and an efficient manufacturing method is obtained.

(Fourth embodiment)
In this embodiment, a lens sheet (glass lens) having a large difference between the thickness of the lens portion and the thickness of the edge portion is formed by forming a hole on the raw glass material placed in the cavity of the molding die. This is one embodiment that enables and minimizes the pressing force to be molded. The configuration other than the shape of the molding surface and the shape of the glass material formed on the cavity surface of the molding die, the molding method, and the like are all the same as in the first embodiment.

FIG. 5A is a schematic diagram of the cavity surface of the lower mold of the molding die, and FIG. 5B is a schematic diagram of the raw glass material.
In FIG. 5A, the molding die 41 has a cavity formed by combining two cavity surfaces 43b and 42b of a lower die 43 and an upper die 42 (not shown). In the lower mold 43, a plurality of predetermined spherical or aspherical concave surfaces 43a for molding a lens portion of a glass lens are arranged in a lattice pattern at the same pitch on a cavity surface 43b excluding the central area.

  The central area where the concave surface 43a is not formed on the cavity surface 43b is a position range of a circular hole 12a (shown by a two-dot chain line) formed on the glass material 12 placed in the cavity described later. The cavity surface 42b of the upper mold 42 is formed with a concave surface 42a having a predetermined shape that forms the other optical surface of the lens portion at a position corresponding to the cavity surface 43b of the lower mold 43.

On the other hand, as shown in FIG. 5B, the glass material 12 placed in the cavity of the molding die 41 is formed with a circular hole 12a penetrating the front and back of the glass material 12 at the center. The formation of the hole 12a is processed by a scriber or the like together with glass material processing that is previously cut into a predetermined planar shape.
The planar shape of the glass material 12 is the size of a substantially planar dimension of the molding die 41 (the lower mold 43 and the upper mold 42), and the thickness is set from the volume of the circular hole 12a and the volume of the molded product. .

  When the glass material 12 in which the circular hole 12a is formed is placed in the cavity of the molding die 41 and sandwiched between the lower mold 43 and the upper mold 42 and heated and pressed, the glass material 12 is first circular. The glass material 12 is spread so as to fill the concave surfaces 43a and 42a, and all the concave surfaces 43a and 42a forming the lens portion are filled without gaps. The formed lens sheet is completed. That is, the circular hole 12a has a directionality in which the glass material 12 is deformed (expanded) (creates a direction in which the glass material 12 is easy to expand), thereby minimizing the pressing force when the glass material 12 is pressed. Can do.

  In the above description, the hole 12a formed in the glass material 12 has been described in the case where only one circular hole 12a penetrating the front and back of the glass material is formed in the center, but the concave surface formed on the molding die 41 is described. A plurality of desired holes may be formed on the glass material 12 other than the area corresponding to 43a, and the shape of the holes 12a may be any shape other than a circle. Further, instead of the hole 12a penetrating the front and back surfaces of the glass material, a similar effect can be obtained by forming a hole that does not penetrate the front and back surfaces of the glass material 12, a so-called dent, on at least one of the front and back surfaces of the glass material 12. Is obtained.

  According to the fourth embodiment described above, the holes 12a penetrating the front and back surfaces are formed on the glass material 12 to be hot press-molded, so that the effects of the first embodiment can be obtained in the same manner. The glass lens sheet (glass lens) can be molded (manufactured) in a short molding time without using a large pressing force for the glass material 12 by having the direction in which the glass material 12 is deformed by 12a.

(Fifth embodiment)
In the present embodiment, a lens sheet (glass lens) having a large difference in thickness between the lens portion and the edge portion is formed by forming a plurality of grooves on the raw glass material placed in the cavity of the molding die. It is one embodiment that enables hot press molding and minimizes the pressing force to be molded. The configuration other than the shape of the molding surface and the shape of the glass material formed on the cavity surface of the molding die, the molding method, and the like are all the same as in the first embodiment.

FIG. 6A is a schematic diagram of the cavity surface of the lower mold of the molding die, and FIG. 6B is a schematic diagram of the raw glass material.
In FIG. 6A, a mold 51 is formed by combining two cavity surfaces 53b and 52b of a lower mold 53 and an upper mold 52 (not shown). In the lower mold 53, a plurality of predetermined spherical or aspherical concave surfaces 53a for forming a lens portion of a glass lens on the cavity surface 53b are arranged in a lattice pattern at the same pitch. The cavity surface 52b of the upper mold 52 is formed with a concave surface 52a having a predetermined shape that forms the other optical surface of the lens portion at a position corresponding to the cavity surface 53b of the lower mold 53.

On the other hand, the glass material 13 placed in the cavity of the molding die 51 is shown in FIG. 6B on the surface of the molding die 51 (the lower die 53 and the upper die 52) having a substantially planar size. As described above, the grooves 13c that are linearly recessed are formed in a lattice pattern at positions where all of the plurality of concave surfaces 53a (partial concave surfaces are indicated by two-dot chain lines) formed in the molding die 51 are divided at equal intervals. ing. The formation of the groove 13c is processed by a dicer or the like together with a glass material processing that is previously cut into a predetermined planar shape. Further, the cross-sectional shape of the groove 13c may be any shape such as a hemispherical shape, a V-shape, or a trapezoid.
The thickness of the glass material 13 is calculated from the volume of the groove 13c and the volume of the molded product.

  When the glass material 13 in which the plurality of grooves 13c are formed is placed in the cavity of the molding die 51 and sandwiched between the lower mold 53 and the upper mold 52 and heated and pressed, first, the glass material 13 All the concave surfaces 53a, which extend toward the plurality of grooves 13c surrounding the concave surface 53a formed in the lens portion, and the glass material 13 is extended so as to fill the concave surfaces 53a, 52a. A lens sheet in which a plurality of lens portions are formed by filling 52a without a gap is completed. That is, the groove 13c has a directionality in which the glass material 13 is deformed (expanded) (creates a direction in which the glass material 13 is easy to expand), thereby minimizing the pressing force.

In the above embodiment, the description has been given of the case where the linearly recessed groove 13c is formed in a lattice shape at a position that divides all of the plurality of concave surfaces 53a at equal intervals. For example, as shown in FIG. The grooves 13c formed in a lattice shape are formed in a lattice shape in which the vertical and horizontal directions of the lattice shape are thinned out one by one, or only the lattice-like vertical grooves 13c are thinned out one by one in a lattice shape. You may form in a part of position between glass lenses, such as forming.
According to the above fifth embodiment, the plurality of grooves 13c are formed on the glass material 13 to be hot press-molded so as to surround the concave surface 53a on which each lens part is molded, so that the fourth embodiment. The same effect can be obtained.

  In the first to fifth embodiments described above, concave surfaces made of a predetermined spherical surface or aspherical surface for forming the lens portion are formed on the cavity surfaces of the upper mold and the lower mold of the molding die. In the case of molding a positive lens composed of a convex surface and a convex surface as shown in FIG. 7C, but in the case of a molding die and a manufacturing method for molding a concave lens composed of a concave surface and a concave surface as shown in FIG. However, the same effect can be obtained. The same applies to a plano-convex lens composed of a plane and a convex surface. Furthermore, when applied to a meniscus lens having a convex surface and a concave surface as shown in FIG. 7 (b), it is possible to obtain a molding die and a manufacturing method in which the occurrence of cracking is further suppressed and the molding time is further shortened.

  The optical glass lens manufactured by the molding die and the manufacturing method in the first to fifth embodiments described above can be used alone or in combination with an imaging device such as a CCD or CMOS, or various small cameras such as a mobile phone. It can be used for a condenser lens.

The schematic diagram of the cavity surface of the lower mold | type of a shaping die. (A) is sectional drawing which shows the state which the molding die opened in 1st Embodiment, (b) is sectional drawing which shows the press state of a shaping die. Sectional drawing which shows the state which the molding die of 2nd Embodiment opened. In 3rd Embodiment, (a) is a schematic diagram of the cavity surface of the lower mold | type of a shaping die, (b) is sectional drawing of the lower mold | type of a shaping die. In 4th Embodiment, (a) is a schematic diagram of the cavity surface of the lower mold | type of a shaping die, (b) is a schematic diagram of raw material glass material. In 5th Embodiment, (a) is a schematic diagram of the cavity surface of the lower mold | type of a shaping die, (b) is a schematic diagram of raw material glass material. (A) is a top view which shows an example of a lens sheet, (b) is a fragmentary sectional view of a lens sheet, (c) is a fragmentary sectional view of a lens sheet of another lens part shape, (d) is another lens part. The fragmentary sectional view of a shape lens sheet. The fragmentary sectional view which shows the press state of the conventional shaping die.

Explanation of symbols

1, 21, 31, 41, 51 ... Mold, 2, 22, 32, 42, 52 ... Upper die, 3, 23, 33, 43, 53 ... Lower die, 2a, 3a, 22a, 23a, 32a, 33a, 42a, 43a, 52a, 53a ... concave surfaces of spherical or aspherical shapes, 2b, 3b, 22b, 23b, 32b, 33b, 42b, 43b, 52b, 53b ... cavity surfaces, 2c, 3c ... as glass material reservoirs Concave surfaces, 10, 11, 12, 13 ... raw glass material, 12a ... hole, 13c, 33c ... groove, 22c, 23c ... convex surface as glass material protruding portion, S, S10, S11, S12, S13 ... glass lens sheet, Sa , 10a, 11a, 12a, 13a ... lens part, Sb, 10b, 11b, 12b, 13b ... connection part.

Claims (4)

In a molding die for producing an optical glass lens sheet in which a plurality of glass lenses are formed in a lattice shape by hot press molding a raw glass material,
In the molding die, a cavity is formed by combining two cavity surfaces of an upper mold and a lower mold,
A surface for molding a lens surface of the glass lens on each cavity surface of the upper mold and the lower mold;
A molding die characterized in that at least one of the upper die and the lower die is formed with a glass material reservoir portion having a concave surface recessed from the cavity surface. In a molding die for manufacturing an optical glass lens sheet in which a plurality of glass lenses are formed in a lattice shape by hot press molding a raw glass material,
In the molding die, a cavity is formed by combining two cavity surfaces of an upper mold and a lower mold,
A surface for molding a lens surface of the glass lens on each cavity surface of the upper mold and the lower mold;
A molding die characterized in that at least one of the upper die and the lower die is formed with a glass material protruding portion made of a convex surface protruding from the cavity surface. In the method for producing an optical glass lens, which is produced by heating and pressing a raw material glass material to produce an optical glass lens sheet in which a plurality of glass lenses are formed in a lattice shape,
The glass material manufacturing method, wherein the raw glass material is a flat plate, and at least one through hole or non-through hole is formed on the flat plate. In the method for producing an optical glass lens, which is produced by heating and pressing a raw material glass material to produce an optical glass lens sheet in which a plurality of glass lenses are formed in a lattice shape,
The method for producing a glass lens, wherein the raw glass material is a flat plate, and grooves are formed in a lattice shape over a part or all of the positions between the plurality of glass lenses formed on the flat plate. .

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