JP2013145254A - Glass lenticular lens structure and stereoscopic display device, and method of manufacturing glass lenticular lens structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lenticular lens structure and a manufacturing method of the same which can achieve a stereoscopic display device capable of coping with enlargement and miniaturization of a screen, and a stereoscopic display device using the lenticular lens structure.SOLUTION: A lenticular lens is formed on a substrate glass by a manufacturing method including steps of: forming a paste coating film containing a glass frit and a binder, of which the softening points are lower than that of the substrate glass, on the substrate glass; pressing a shaping mold to the coating film at a first temperature softening the binder; removing the binder at a second temperature higher than the first temperature; and melting the glass frit at a third temperature higher than the second temperature.

Description

  The present invention relates to a glass lenticular lens structure used in a stereoscopic display device, a manufacturing method thereof, and a stereoscopic image display device using the glass lenticular lens structure.

  As a stereoscopic display device that does not require special glasses or the like, a lenticular lens type stereoscopic display device is known. In this method, the direction of the light beam from the display unit is controlled by a lenticular lens (sheet), and different images are recognized by the left and right eyes, so that the viewer can see the image three-dimensionally.

  The lenticular lens used in such a stereoscopic display device is generally made of resin, but Patent Document 1 discloses a stereoscopic image display device using a glass lenticular lens (lens array unit).

JP 2008-191325 A

  The glass lenticular lens disclosed in Patent Document 1 is formed by integrally forming a glass substrate and a glass lens array layer. Patent Document 1 applies processing to the surface of a glass substrate, The shape of the lenticular lens is disclosed directly on the surface. That is, in the lenticular lens made of glass described in Patent Document 1, the lens array layer and the substrate are made of a single glass.

  However, molding in which a fine lens shape such as a lenticular lens is directly formed on the surface of the glass is generally difficult to create a shape and inferior in productivity as compared with resin lens molding. . Therefore, the glass lenticular lens described in Patent Document 1 causes a decrease in shape accuracy and a high cost of the display device.

Further, as the screen becomes larger, it is necessary to bend the light more greatly in order to deliver the image light around the screen to the viewer. Alternatively, in applications where the distance between the display device and the viewer is close, such as a mobile phone or a portable game machine, it is required to shorten the focal length of the lenticular lens.
For these reasons, it is necessary to increase the curvature of the lenticular lens. However, in the method of forming the lens directly on the surface of the glass, as the curvature increases, the shape creation tends to become difficult. On the other hand, if the lens curvature shape is the same, the focal length can be shortened by using glass having a high refractive index, but generally high refractive index glass is expensive and causes an increase in cost.

  The present invention has been proposed in view of the above-described conventional situation, and provides a lenticular lens structure that is all made of glass and capable of shortening a focal length, and a stereoscopic display device using the lenticular lens structure. To do.

  In order to achieve the above object, the glass lenticular lens structure of the present invention is characterized in that a lenticular lens made of glass having a composition different from that of the substrate glass is formed on the substrate glass. A lens structure is provided.

  In such a glass lenticular lens structure of the present invention, the refractive index of the glass constituting the lenticular lens is preferably equal to or higher than the refractive index of the substrate glass, and the thickness of the glass constituting the lenticular lens Is preferably 300 μm or less.

  Further, the stereoscopic display device of the present invention includes the glass lenticular lens structure of the present invention and a display unit that is arranged facing the glass lenticular lens structure and has a fixed pixel position. A stereoscopic display device is provided.

  Furthermore, in the method for producing a glass lenticular lens structure of the present invention, a coating film is formed by applying a paste containing a glass frit and a binder having a softening point lower than the softening point of the substrate glass on the surface of the substrate glass. Pressing the mold with the irregularities formed on the surface of the coating film at a first temperature at which the binder is softened and releasing the mold, and forming the irregularities on the surface of the coating film; A step of removing the binder in the coating film at a second temperature higher than the temperature of 1, and a step of fusing the glass frit at a third temperature higher than the second temperature. A method for producing a glass lenticular lens structure is provided.

  According to the present invention, a glass lenticular lens structure that realizes a stable image against heat, can cope with an increase in screen size, and is suitable for a mobile phone or a portable game machine, and the same are used. A stereoscopic display device can be easily realized at low cost.

It is a figure which shows notionally an example of the three-dimensional display apparatus of this invention. It is a figure which shows notionally an example of the glass lenticular lens structure used for the three-dimensional display apparatus shown by FIG. 1, Comprising: (A) is a top view, (B) is the cross section of the AA in (A). (C) is a partially enlarged view of (B). It is a figure which shows notionally another example of the glass lenticular lens structure of this invention, Comprising: (A) is a top view, (B) is sectional drawing of the AA line in (A). (A)-(E) are the conceptual diagrams for demonstrating an example of the manufacturing method of the lenticular lens structure body made from this invention glass. It is a flowchart for demonstrating the manufacturing method of the glass lenticular lens structure shown in FIG.

  Hereinafter, a glass lenticular lens structure and a stereoscopic display device according to the present invention, and a method for producing a glass lenticular lens structure will be described in detail with reference to the accompanying drawings.

FIG. 1 conceptually shows an example of the configuration of the stereoscopic display device of the present invention.
A stereoscopic display device 10 (hereinafter referred to as a display device 10) shown in FIG. 1 is a device that displays a stereoscopic image (so-called 3D image) using a lenticular lens, and is a display unit 12 and a light beam control element. The glass lenticular lens structure 14 of the present invention is provided.

  In the present invention, the display unit 12 is not particularly limited. For example, a pixel position such as a liquid crystal display panel, a plasma display panel, an organic EL (electroluminescence) display panel, a field emission display panel, a CRT (Cathode Ray Tube), etc. As long as is fixed, various known display units can be used.

A glass lenticular lens structure 14 (hereinafter referred to as a lens structure 14) is fixed to the front surface of the display unit 12 (in front of the image display surface) as shown in FIG.
In the example shown in FIG. 1, the lens structure 14 is fixed in close contact with the display unit 12, but the present invention is not limited to this, and the lens structure 14 and the display unit 12 are Alternatively, a gap may be provided, or some member such as a member that exhibits an optical action may be provided between the lens structure 14 and the display unit 12.

The lens structure 14 refracts a light beam (display image) emitted from the display unit 12 and controls the direction of the light beam. As shown conceptually in FIG. 2, the lens structure 14 and a linear lenticular lens are used. 24, and is fixed to the front surface of the display unit 12 with the substrate glass 20 facing the display unit 12.
2A is a top view (viewed from the light incident surface side of the lens structure 14 in the optical axis direction). 2B is a cross-sectional view taken along the line AA of FIG. 2A as viewed from the same direction as FIG. Further, FIG. 2C is a partially enlarged view of FIG.

In the lens structure 14, the substrate glass 20 and the lenticular lens 24 are both made of glass having different compositions, and both of them directly without using an adhesive layer or the like (without using an adhesive or the like), It is formed in contact. Here, the fact that the substrate glass 20 and the lenticular lens 24 are joined without using a resin adhesive or the like is referred to as “integrated”.
That is, the lens structure 14 is a glass lenticular lens structure of the present invention, and the substrate glass 20 and the lenticular lens 24 are formed of glasses having different compositions.

In the illustrated example, the substrate glass 20 is a flat plate glass.
In the present invention, the material for forming the substrate glass 20 is not particularly limited, and various glass materials can be used. As an example, soda lime silicate glass, aluminosilicate glass, borate glass, lithium aluminosilicate glass, quartz glass, borosilicate glass, alkali-free glass and the like are exemplified.
The substrate glass 20 constitutes the lens structure 14 that is an optical component (optical element). Therefore, it is preferable that the substrate glass 20 is formed of glass having high transparency and excellent optical characteristics. In particular, considering high light transmittance, soda lime silicate glass, so-called highly transmissive glass or the like with reduced iron content in soda lime silicate glass is preferably used.

In the present invention, the thickness of the substrate glass 20 is not particularly limited, and may be appropriately selected according to the design of the lens structure 14, required optical characteristics, strength, etc., but is 0.5 to 3 mm. Is preferred.
By setting the thickness of the substrate glass 20 within the above range, it is preferable in that the substrate glass 20 can be prevented from being damaged in the process.

The lenticular lens 24 is a lens composed of a plurality of linear cylindrical lenses (cylindrical lenses having a flat surface on one side) arranged in parallel. The lenticular lens 24 has an irregular shape as shown in FIG. Has a cross section.
At this time, as shown in FIG. 2C, the height of the circular arc in the vertical section of the cylindrical lens constituting the lenticular lens 24 is the lens height h, and the radius of the circular arc is the lens radius r.

In the example shown in FIG. 2, the lenticular lens 24 constituting the lens structure 14 is a cylindrical lens that extends linearly in one direction (Y direction), as shown in FIG. Are arranged in parallel in the X direction orthogonal to.
However, the present invention is not limited to this, and various configurations of known lenticular lenses can be used. As an example, like the lenticular lens 28 of the (glass lenticular) lens structure 26 shown in FIGS. 3A and 3B, the cylindrical direction is in the Y direction orthogonal to the X direction, which is the arrangement direction of the cylindrical lenses. It may have a shape in which the lens arrangement axis is inclined.

In the lens structure 14 of the present invention, the material for forming the lenticular lens 24 is not particularly limited, and various types of glass can be used as long as the glass has a composition different from that of the substrate glass 20.
For example, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ system, SiO ₂ —B ₂ O ₃ —Bi ₂ O ₃ system, B ₂ O ₃ —ZnO—Bi ₂ O ₃ system, SiO ₂ —B ₂ O _3— ZnO system, SiO ₂ —BaO—B ₂ O ₃ system, B ₂ O ₃ —BaO—ZnO system, SnO—ZnO—P ₂ O ₅ system, B ₂ O ₃ —ZnO—La ₂ O ₃ system, P ₂ O ₅ —B ₂ O ₃ —R ′ ₂ O—R ″ O—TiO ₂ —Nb ₂ O ₅ —WO ₃ —Bi ₂ O ₃ , TeO ₂ —ZnO, B ₂ O ₃ —Bi ₂ O ₃ Type, SiO ₂ —Bi ₂ O ₃ type, SiO ₂ —ZnO type, B ₂ O ₃ —ZnO type, P ₂ O ₅ —ZnO type, ZnO—B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ type, Bi ₂ O ₃ —B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ , Bi ₂ O ₃ —ZnO—B ₂ O ₃ —SiO ₂ , Bi ₂ O ₃ —ZnO—B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ type, P ₂ O ₅ —Nb ₂ O ₅ —T iO ₂ —R ′ ₂ O, SiO ₂ —TiO ₂ —R ′ ₂ O—R ″ O, SiO ₂ —B ₂ O ₃ —Nb ₂ O ₅ —R ′ ₂ O, P ₂ O ₅ —R _'2 O-R _{"O-based, SiO 2 -Bi 2 O 3 -R} ' 2 O -based, SiO ₂ -Bi ₂ O _{3 -BaO-based, SiO 2 -Bi 2 O 3 -La} 2 O 3 -R" O Various types of glass such as a system are preferably exemplified. In the above formula, R ′ represents an alkali metal element, and R ″ represents an alkaline earth metal element.

In the present invention, the refractive index of the glass forming the lenticular lens 24 is not particularly limited, but is preferably equal to or higher than the refractive index of the substrate glass 20.
If the refractive index of the glass forming the lenticular lens 24 is lower than the refractive index of the substrate glass 20, total reflection occurs at the interface between the substrate glass 20 and the lenticular lens 24, resulting in a decrease in transmittance or generation of a double image. There is a possibility of doing.

Further, the thickness t of the lenticular lens 24 is not particularly limited, but is preferably 300 μm or less. If the thickness of the lenticular lens 24 exceeds 300 μm, in the lenticular lens manufacturing process described later, shrinkage at the time of fusing the glass frit increases, and cracks may occur or the glass may break.
On the other hand, there is no particular lower limit on the thickness of the lenticular lens 24, but when the thickness is about the same as the particle diameter of the glass frit described later, the glass frit is fused to smooth the lens surface and the lens shape is maintained. It can be difficult to do both.
Considering the above points, the more preferable thickness t of the lenticular lens 24 is 10 to 200 μm.

  Furthermore, the lens height h and the lens radius r of the lenticular lens 24 are determined according to the resolution (pixel pitch) of the display device 12 to be combined, the required focal length, viewing distance, viewing angle, and the like. Similar to the lenticular lens used in the above, it may be set appropriately.

The lens structure 14 (glass lenticular lens structure of the present invention) composed of such a substrate glass 20 and a glass lenticular lens 24 can be suitably manufactured by the manufacturing method of the present invention to be described later. The glass lenticular lens structure can be easily manufactured.
That is, the present invention can easily cope with an increase in the screen size of a stereoscopic display device or the like. Further, according to the present invention, since the thermal expansion of the lens structure 14 is small, it is possible to easily cope with an increase in screen size in this respect.

In the manufacturing method of the lens structure 14 of the present invention, first, a glass frit paste containing a glass frit having a softening point lower than that of the substrate glass 20 and a binder is applied to the substrate glass 20. In addition, you may dry the coating film obtained by application | coating as needed.
Next, the mold is pressed onto the coating film at a first temperature to transfer the shape of the mold. Next, the transferred coating film is debindered at a second temperature higher than the first temperature. Further, the glass frit is fused by firing at a third temperature higher than the second temperature and lower than the softening point of the substrate glass 20.

  Hereinafter, an example of the manufacturing method of the lens structure 14 according to the present invention will be described in detail with reference to FIGS. 4A to 4E and the flowchart of FIG.

First, as shown in FIG. 4A, a substrate glass 20 is prepared.
On the other hand, a glass frit paste (hereinafter referred to as a paste) to be the lenticular lens 24 is prepared. This paste is a paste obtained by mixing (kneading) at least glass frit (glass fine particles) and a binder, in which the glass frit is dispersed in the binder.

The glass frit (that is, the glass that becomes the lenticular lens 24) is preferably a glass having a softening point lower than that of the substrate glass 20, and in particular, a glass frit made of glass that is 50 ° C. lower than the softening point of the substrate glass 20. Preferably there is. That is, in the present invention, the lenticular lens 24 is preferably formed of a material having a softening point lower than the softening point of the substrate glass 20.
If the softening point of the glass frit is lower than the softening point of the substrate glass 20, particularly 50 ° C. or more, it is preferable to prevent the substrate glass 20 from being thermally deformed in the baking step described later and to form the lenticular lens 24. The frit can be fused. For example, when the substrate glass 20 is soda lime glass, since the softening point is around 730 ° C., the softening point of the glass frit is preferably 680 ° C. or less.

On the other hand, the softening point of the glass frit is preferably higher than the decomposition temperature of the binder contained in the paste. Although it varies depending on the type of binder, the softening point of the glass frit is particularly preferably 350 ° C. or higher.
By using a glass frit having such a softening point, it is possible to suitably prevent the binder and glass from fusing at the same time in the binder removal step at the second temperature described later.

The glass frit preferably has a smaller viscosity change with respect to a temperature change in a temperature region near the softening point.
When this change in viscosity is small, it is possible to reduce the collapse of the shape in the glass frit sintering step due to the third temperature described later, and it is possible to produce a glass structure having a fine shape with higher accuracy. .

The average particle size of the glass frit is preferably 10 μm or less.
By setting the average particle size of the glass frit to 10 μm or less, it is possible to prevent the surface roughness of the coating film formed by applying / drying the paste from increasing, and to transfer the shape of the mold in the press process described later. Can be performed more reliably, and further, damage to the mold can be prevented more reliably.
The lower limit of the particle diameter is not particularly limited, but is preferably about 0.5 μm or more in consideration of the cost of pulverizing the glass when producing the glass frit.

As described above, the (glass frit) paste is a paste formed by mixing at least glass frit and a binder.
In the present invention, the binder holds the paste on the substrate glass 20, and plays a role of developing adhesiveness with the glass so that the glass frit is not peeled off from the substrate glass 20 in the pressing step described later, and in the pressing step. It plays the role of adjusting the hardness of the coating film formed by coating and improving the shape transferability of the mold.

The binder (binder resin) is not particularly limited, and various resins can be used.
Examples include cellulose polymers such as nitrocellulose, acetylcellulose, ethylcellulose, carboxymethylcellulose, and methylcellulose, natural polymers such as natural rubber, polybutadiene rubber, chloroprene rubber, acrylic rubber, isoprene synthetic rubber, and cyclized rubber, and polyethylene. And synthetic polymers such as polypropylene, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetate, polyester, polycarbonate, polyacrylonitrile, polyvinyl chloride, polyamide, polyurethane, etc. .
These resins may be used alone, or may be used as a mixture or a copolymer.

In this production method, the glass frit content in the paste is not particularly limited, but is preferably 20 to 90 wt%.
By setting the glass frit content in the paste to 20 wt% or more, a sufficient film thickness can be ensured by a single application of the paste, and a plurality of applications are performed to obtain a desired film thickness. The cost increase by this can be suppressed. On the other hand, by setting the content of glass frit in the paste to 90 wt% or less, the viscosity of the paste is prevented from becoming too high, and the paste can be applied uniformly and suitably. In addition, by setting the glass frit content to 90 wt% or less, the amount of the binder in the paste can be sufficiently secured, and thereby sufficient adhesion between the substrate glass 20 and the coating film can be obtained.
Considering the above points, the glass frit content in the paste is more preferably 50 to 80 wt%.

On the other hand, in the paste used in this production method, the binder content is not particularly limited, but the binder is preferably 1 to 50 parts by weight with respect to 100 parts by weight of the glass frit.
By setting the binder to 1 part by weight or more with respect to 100 parts by weight of the glass frit, sufficient adhesion between the substrate glass 20 and the coating film can be ensured. Further, by setting the binder to 50 parts by weight or less with respect to 100 parts by weight of the glass frit, it is possible to sufficiently obtain the rigidity of the coating film in the pressing process described later, and to prevent the coating film from adhering to the mold. . Further, by setting the binder to 50 parts by weight or less, voids generated by the binder removal process can be reduced, and the shape change in the subsequent glass frit baking process can be reduced, thereby controlling the shape of the lenticular lens 24 with higher accuracy. Can be done.
Considering the above points, the amount of the binder in the paste is more preferably 5 to 30 parts by weight with respect to 100 parts by weight of the glass frit.

In addition to such components, the paste may contain a solvent as necessary in order to adjust the viscosity of the paste and improve the coating property to glass.
Solvents include hydrocarbons such as toluene and xylenetetralin, alcohols such as methanol and ethanol, ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, ethylene glycol and diethylene glycol solvents. Can be used.
Furthermore, you may add surfactant for improving applicability | paintability, the plasticizer for adjusting the hardness of a coating film, etc. to a paste as needed.

The paste preparation method is not particularly limited. For example, a predetermined amount of glass frit and a binder or other necessary components such as a solvent is added to a mixing device or a kneading device so that the glass frit is uniformly dispersed. Can be sufficiently mixed (kneaded).
As an example, a paste may be prepared by preparing a mixture of a binder and a solvent (so-called vehicle), adding glass frit and other components to the vehicle, and mixing them.

After the paste is prepared in this way, the paste is applied to the surface of the substrate glass 20 as shown in FIG.
In the production method of the present invention, the paste coating method is not particularly limited, and various known coating methods can be used.
For example, roller coating, hand coating, brush coating, spin coating, dip coating, screen printing, curtain flow, bar coating, die coating, gravure coating, micro gravure coating, reverse coating, roll coating, flow coating, spray coating, etc. A method is illustrated.
Of these, die coating and screen printing are preferably used because large-area coating is easy and a sufficiently thick film can be obtained by one coating.

  The paste coating thickness may be set as appropriate according to the thickness t (shape height) of the lenticular lens 24 to be formed, the shape of the irregularities of the lenticular lens 24 to be formed with a mold described later, and the like.

Furthermore, as shown in FIG. 4B, when the paste is applied to the surface of the substrate glass 20, the coating film (that is, the paste) is dried to form the coating film 30 as necessary.
The method for drying the paste is not particularly limited, and for example, a method of heating the substrate glass 20 coated with the paste in an oven, a method of irradiating UV, or the like can be used.
In addition, when drying the coating film of a paste by heating, it is preferable to heat at the temperature which does not change a binder. Specifically, the heating is preferably performed at a temperature of 80 to 200 ° C. in the atmosphere for 5 to 60 minutes.

  Further, when the coating film is dried, the layer thickness of the coating film 30 becomes thinner than the coating thickness of the paste. In this case, in consideration of the layer thickness of the coating film 30 obtained after drying, the paste described above is used. It is preferable to set the coating thickness.

When the coating film 30 is thus formed on the surface of the substrate glass 20, the coating film 30 is then heated to a first temperature.
In addition, there is no limitation in particular in the heating method of the coating film 30, Various well-known heating methods, such as the method of heating with an oven, can be utilized. In this regard, the following heating to the second temperature and the third temperature is the same.

The first temperature is not particularly limited, and the temperature at which the binder of the coating film 30 is softened and can be press-molded by the mold 32 may be appropriately set according to the type of the binder. 100 to 200 ° C. is preferable.
As will be described later, in the present invention, the coating film 30 is formed into the shape of the lenticular lens 24 by pressing the coating film 30 with the molding die 32 at the first temperature. Here, by setting the first temperature to 100 ° C. or higher, the paste layer can be sufficiently softened for many pastes, and accurate molding can be performed. In addition, by setting the first temperature to 200 ° C. or lower, it is possible to suppress excessive softening of the binder due to the temperature being too high, and the adhesion of the binder to the mold caused by this or excessive heating of the binder. Decomposition and alteration can be suitably prevented.

When the coating film 30 is set to the first temperature, as shown in FIGS. 4C to 4D, a mold having a pressing surface on which irregularities corresponding to the irregularities of the lenticular lens 24 to be formed are formed. The coating film 30 is pressed (pressed) by 32.
In addition, when pressing, the shaping | molding die 32 may be heated. The heating temperature of the mold 32 is not particularly limited, and may be set as appropriate according to the type of the binder and the like, as with the coating film 30, but is preferably 100 to 200 ° C.

In the illustrated example, the forming die 32 is a roll-type forming die, and is formed by arranging concave portions (grooves) 32a extending in the circumferential direction on the circumferential surface of the cylinder in the direction of the center line of the cylinder. In other words, the concave portion 32 a is an arc-shaped concave portion corresponding to the cylindrical lens constituting the lenticular lens 24.
The mold 32 is rotatably supported on the support member 34 by a support shaft 32b coinciding with the center line of the cylinder. As shown in FIG. 4D, such a mold 32 is pressed against the coating film 30 and moved in the direction of the arrow, so that the substantially cylindrical molding mold 32 is pressed against the coating film 30. It rotates around the support shaft 32b and rolls in the direction of the arrow.

Next, as shown in FIGS. 4D to 4E, the mold 32 is removed from the coating film 30.
As a result, the shape of the mold 32 can be transferred to the coating film 30 and molded into a predetermined shape corresponding to the irregularities of the lenticular lens 24.

In the manufacturing method of the present invention, the bulk glass is not directly molded, but the softer coating film 30 is press-molded to keep the press temperature and pressure low and to make the press conditions mild. Therefore, the wear of the expensive press mold can be almost eliminated and the life can be extended, and the glass structure can be manufactured at low cost. In addition, since the manufacturing method of the present invention press-molds the soft coating film 30 at a relatively low temperature and low pressure, it is possible to perform very fine molding, and a lenticular lens structure made of total glass having fine irregularities. The body can be manufactured with high accuracy.
Moreover, the moldability of the coating film 30 and the releasability (peelability) between the coating film 30 and the mold 32 can be controlled by a binder contained in the paste. That is, since the moldability and releasability do not depend on the material characteristics of the glass frit, the glass frit material selection range is wide.

The forming material of the mold 32 is not particularly limited, and can provide desired dimensional accuracy, can maintain the required accuracy with little deformation of the coating film 30 by pressing, and the temperature during pressing. Various materials can be used as long as they do not soften or change quality.
For example, metal, ceramics, etc. can be used. Specifically, examples of the material of the metal mold include nickel, hardened steel, and various other materials used for press-molding ceramic fired products. Further, as the ceramic type material, there are silicon nitride, alumina, zirconia and the like.

Here, in the example shown in FIG. 4, a roll die that can be continuously formed is illustrated as the forming die 32.
In the case of a flat type mold, two-dimensional mold processing is easy, but on the other hand, it is necessary to apply a load to the entire surface, and more load is required depending on the press area, and compared to a roll mold. It is difficult to release.
On the other hand, in the case of the roll type, for example, complicated two-dimensional processing in which cylindrical lenses constituting the lenticular lens 28 are inclined and arranged as shown in FIG. 3 is difficult. On the other hand, since the load of the mold is concentrated in a line shape, the shape can be transferred satisfactorily with a small load, and the mold release is easy.
Therefore, as the mold 32, a roll mold can be suitably used for the shape of a lenticular lens formed by arranging linear cylindrical lenses.

In the production method of the present invention, the binder is removed from the coating film 30 formed in the binder removal step at the second temperature described later, and further, the coating film 30 exists in the baking step at the third temperature. The glass frit is fused so as to fill the voids generated and the voids generated by the binder removal.
Therefore, volume shrinkage is unavoidable in the entire coating film 30 formed by the mold 32. Therefore, the mold 32 for press-molding the coating film 30 needs to design the shape of the mold by incorporating the shrinkage.

Although the press pressure by the shaping | molding die 32 changes with paste materials, it is preferable that it is 10-80 Mpa.
By setting the pressing pressure to 10 MPa or more, the shape of the mold 32 can be reliably transferred to the paste layer, that is, sufficient transferability of the mold shape can be obtained. Further, by setting the press pressure to 80 MPa or less, it is possible to suitably prevent the substrate glass 20 and the mold 32 from being damaged due to the pressure being too high. Considering the above points, the press pressure by the mold 32 is more preferably 30 to 50 MPa.
In addition, although there is no limitation in particular also in the press speed of the coating film 30 by the shaping | molding die 32, since sufficient shaping | molding will become difficult if too early, and it will lead to the fall of productivity when too late, 2-50 cm / min is preferable.

  After the coating film 30 is pressed by the mold 32 and molded in this manner, the coating film 30 (paste) is then brought to a second temperature higher than the first temperature, and the binder is removed from the coating film 30. A binder removal step is performed.

The second temperature, that is, the binder removal temperature may be appropriately set according to the type of the binder, but is preferably 300 to 500 ° C. The binder removal time (time for keeping the coating film 30 at the second temperature) varies depending on the type of binder and the amount of binder in the paste, but is preferably 5 to 60 minutes.
Note that the binder removal at the second temperature is preferably performed in an air atmosphere in order to promote oxidative decomposition of the binder.

  After the binder removal is performed in this manner, firing is then performed at a third temperature higher than the second temperature and lower than the softening point of the substrate glass 20, and the glass frit is fused. Then, the lenticular lens 24 is completed, and the substrate glass 20 and the lenticular lens 24 are fused to complete the lens structure 14 in which the substrate glass 20 and the lenticular lens 24 are integrated.

The third temperature, that is, the firing temperature, may be appropriately set according to the glass frit used, but it is preferably performed at 350 to 650 ° C.
The firing atmosphere may be in the air, but it is more preferred to fire under reduced pressure in order to positively discharge bubbles present in the frit film out of the film.
Thereby, bubbles do not exist in the lenticular lens 24, and a film with higher transparency can be obtained.

In the manufacturing method of the present invention, the coating film 30 is heated to a second temperature at which the binder is decomposed, and the binder removal treatment is performed by holding the coating film for a certain period of time. Thereafter, the glass frit is further fused. It is preferable that the glass frit is fused by heating to a temperature and holding for a certain period of time for firing.
However, the present invention is not limited to this. For example, in the case where the binder is easily decomposed, after the formation of the coating film 30 at the first temperature, from the first temperature to the third temperature, A method of terminating the binder removal while heating up to the third temperature at which the frit of the glass frit occurs gradually (or stepwise) can be suitably used. . That is, in this case, the second temperature is not a constant temperature, and the temperature that is higher than the first temperature and that is lower than the third temperature is the second temperature.

  Such a manufacturing method of the present invention does not directly press-mold bulk glass but presses a softer (glass frit) coating film 30 to perform molding, so that the selection of materials and shapes can be performed at low cost. The degree of freedom is high, the area can be easily increased, and fine irregularities can be formed.

  As described above, the glass lenticular lens structure, the stereoscopic display device, and the method for producing the glass lenticular lens structure of the present invention have been described in detail. However, the present invention is not limited to the above-described examples, and the gist of the present invention. Of course, various improvements and changes may be made without departing from the scope of the present invention.

  Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention. The present invention is not limited to these.

[Example 1]
<1. Formation of coating film>
First, 20 parts by weight of a binder (butyral resin: Mowital B30HH manufactured by Kuraray Co., Ltd.) was dissolved in 80 parts by weight of a solvent (butyl carbitol acetate) to prepare a binder solution (vehicle).
Subsequently, 100 parts by weight of this binder solution, glass frit (Bi ₂ O ₃ —ZnO—B ₂ O ₃ —SiO ₂ —Al ₂ O ₃ glass, thermal expansion coefficient 79 ± 5 × 10 ⁻⁷ / ° C., softening A point of 578 ° C. and a refractive index of 1.72) and 100 parts by weight were mixed and stirred to prepare a (glass frit) paste.

As the substrate glass 20, soda lime glass having a plate thickness of 300 m square was prepared.
The prepared paste was applied to the substrate glass 20 by a screen printing method using a metal mask having a mask thickness of 200 μm. Thereafter, the substrate glass 20 to which the paste was applied was placed in a dryer and dried at 180 ° C. for 40 minutes to obtain a substrate glass 20 on which a coating film 30 having a thickness of 150 μm was formed.

<2. Press>
The substrate glass 20 on which the coating film 30 was formed was set in a press machine whose surface plate was heated to 120 ° C. On the coating film 30, a roll-shaped molding die 32 heated to 200 ° C. and having irregularities corresponding to the lenticular lens is placed, and the pressure applied to the substrate glass is 3.3 cm / min. Pressed at speed.
The forming die 32 is made of nickel and extends in the circumferential direction of the forming die 32 (cylinder). The arc-shaped concave portion (groove) 32a having a radius of 90 μm and a depth of 90 μm is formed into a press width of 500 mm. Thus, what was continuously arranged in the center line direction of the mold 32 was used.

Thereafter, the mold 32 was separated from the coating film 30 to obtain the coating film 30 onto which the shape of the mold 32 (that is, the lenticular lens 24) was transferred. The lens radius r and the lens height h were measured at arbitrary 10 points, and the average values were taken as the lens radius r and the lens height h of the coating film 30.
As a result, the lens radius r was about 90 μm, the lens height h was about 90 μm, and the shape of the mold 32 was accurately transferred. The lens radius r and the lens height h were obtained by observing the cross section of the coating film with an optical microscope.

<3. Firing>
The substrate glass 20 on which the coating film 30 to which the shape of the mold 32 has been transferred is formed is placed in a firing furnace, heated to 450 ° C. at a temperature increase rate of 10 ° C./min in the air atmosphere, and 90 ° C. at 90 ° C. The binder was removed by holding for a minute.
Thereafter, the inside of the firing furnace is depressurized to 30 Pa, heated to 540 ° C. at a heating rate of 10 ° C./min, and held at 540 ° C. for 30 minutes to perform firing, thereby fusing the glass frit. As shown in FIG. 2, the lens structure 14 in which the substrate glass 20 and the lenticular lens 24 were directly joined (glass lenticular) was obtained.

<4. Evaluation>
The lens shape of the obtained lens structure 14 was measured by the following method. That is, the surface contour shape of the lens surface was measured along the vertical direction (X direction) with respect to the extending direction of the cylindrical lens constituting the lenticular lens 24 (Y direction in FIG. 2A).
The shape of the measured lens structure 14 seems to have shrunk mainly in the vertical direction from that of the coating film 30 to which the shape of the molding die 32 was transferred due to shrinkage due to baking or sagging of the softened frit glass. It was a shape. Therefore, a lens radius r was obtained by fitting a circle to a lens effective portion excluding a lens trough having a large shape sag, and a lens height h was obtained from the difference between the lens apex and the lens trough lowest point.
As a result, the lens radius r was 86.9 μm, and the lens height h was 60.4 μm. When calculated from the refractive index of the material, the focal length is 121 μm.
When the focal length is calculated in the case of a lenticular lens structure in which a lenticular lens made of PMMA (polymethyl methacrylate refractive index 1.5) is bonded to the same substrate glass 20 in exactly the same shape, the focal length is calculated. The distance was 174 μm. That is, the lens structure 14 of the present invention can reduce the focal length from 174 μm to 121 μm by about 70% compared to the lens structure having the same configuration using a PMMA lenticular lens.
On the other hand, when trying to obtain the same focal length of 121 μm with the structure having the same configuration using this PMMA lenticular lens, the lens radius is 60.3 μm, which is also 70% of the value. Thus, the shape becomes more difficult to manufacture.
In addition, since general soda lime glass (refractive index 1.51) has almost the same refractive index as PMMA, it is necessary to realize the same shape as PMMA even in the method of directly molding soda lime glass. Becomes a difficult shape.
From the above results, the effect of the present invention is clear.

  The present invention is particularly applicable to a lenticular lens type stereoscopic display device.

DESCRIPTION OF SYMBOLS 10 (3D) display apparatus 12 Display unit 14,26 (Glass lenticular) Lens structure 20 Substrate glass 24,28 Lenticular lens 30 Coating film 32 Mold 34 Support member

Claims (5)

  A glass lenticular lens structure, wherein a lenticular lens made of glass having a composition different from that of the substrate glass is formed on the substrate glass.   The glass lenticular lens structure according to claim 1, wherein a refractive index of the glass constituting the lenticular lens is equal to or higher than a refractive index of the substrate glass.   The glass lenticular lens structure according to claim 1 or 2, wherein the glass constituting the lenticular lens has a thickness of 300 µm or less.   A glass lenticular lens structure according to any one of claims 1 to 3, and a display unit arranged to face the glass lenticular lens structure and having a fixed pixel position. 3D display device. Applying a paste containing a glass frit and a binder having a softening point lower than the softening point of the substrate glass on the surface of the substrate glass to form a coating film;
At a first temperature at which the binder is softened, pressing the mold on which the unevenness is formed against the surface of the coating film and releasing it, and forming the unevenness on the surface of the coating film;
Removing the binder in the coating film at a second temperature higher than the first temperature;
And a step of fusing the glass frit at a third temperature higher than the second temperature. A method for producing a glass lenticular lens structure.

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