JPH10104405A - Optical substrate and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make accurate mass production of optical substrates formed with optical lens arrays. SOLUTION: The prescribed positions of a glass substrate 1 are etched to form a master disk G having the shape of the optical lens array. A resin 2 is applied at the shape parts of the optical lens array of this master disk G and is peeled after curing, by which a resin mold J having the inverted parts of the shapes of the optical lens array is formed. Next, this resin mold J is mounted at a metal mold and the cavity shapes of the metal mold are partly formed by the inverted parts of the shapes of the optical lens array. A translucent resin is injected into the cavities of such metal mold, by which the optical lens array having the inverted shapes of the inverted parts of the resin mold is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical substrate having an optical lens array including a microlens array and a microprism array, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a liquid crystal display device, a liquid crystal is sealed between a liquid crystal driving substrate (for example, a TFT substrate) and an opposing substrate disposed opposite thereto, and light is transmitted depending on the presence or absence of an electric field applied to the liquid crystal. And a device that controls opacity to form a display image.

[0003] Of these liquid crystal display devices, a transmissive display device that magnifies an image via a lens and projects the image on a screen uses three dichroic mirrors to emit white light from a white lamp in order to obtain the brightness of the image. R (red), G
(Green) and B (Blue) are separated into three primary colors, which are incident on a monochrome liquid crystal display device without a color filter via a microlens, and RGB components having an angle difference are collected into corresponding pixels. A technique for obtaining a desired color image by illuminating the light has been disclosed (see Japanese Patent Application Laid-Open No. 4-60538).

In the case of using a high-definition liquid crystal display device having a small pixel pitch in a so-called color filterless system without such a color filter, it is necessary to make the focal length of the microlens very short. For this reason, it is necessary to use a projection lens having a large aperture in order to project all the light beams that have passed through the liquid crystal display device.

Therefore, in order to cope with the miniaturization and high definition of the main body of a so-called color filter-less type transmissive display device, an opposing substrate provided with a combination of a microlens array and a microprism array is used. It is considered.

[0006]

However, the micro-lens array and the micro-prism array have an arrangement of minute lenses and prisms, and it is extremely troublesome to manufacture them by processing a glass substrate. . Therefore, it is extremely difficult to accurately mass-produce an optical substrate having such a microlens array or microprism array by a simple method.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to an optical substrate and a method of manufacturing the same to solve such problems. That is, the optical substrate of the present invention is formed by forming an optical lens array by forming an optical lens array in a liquid crystal display device in which an optical lens array is formed facing the liquid crystal driving substrate in the liquid crystal display device. It is.

In the method of manufacturing an optical substrate according to the present invention, first, a predetermined position of a glass substrate is subjected to photolithography and etching to form a master having the shape of an optical lens array, and a release film is formed on the entire surface. A resin is applied to the entire surface of the master including the optical lens array-shaped portion, cured, and then peeled off to form a resin mold having an inverted portion of the optical lens array. Next, this resin mold is attached to a mold, and a part of the cavity shape of the mold is constituted by the inverted portion of the resin mold, and a thermosetting translucent resin is injected into the cavity of the mold. To form an optical lens array in which the shape of the resin mold reversal portion is reversed.

Further, a predetermined position of the first glass substrate is subjected to photolithography and etching processing to form a first master having a microlens array shape, a release film is formed on the entire surface, and a microlens of the first master is formed. A first resin mold having an inverted portion of the shape of the microlens array is formed by applying a resin to the entire surface including the shape portion of the array, curing and peeling the resin, and then a predetermined position of the second glass substrate is set. Photolithography and etching are performed to form a second master having the shape of a microprism array, a release film is formed on the entire surface, and a resin is applied to the entire surface of the second master including the microprism array shape and cured. The second resin mold having a reversal portion of the shape of the microprism array is formed by being peeled off. Next, the first resin mold and the second resin mold are arranged such that the inverted portion of the shape of the microlens array and the inverted portion of the shape of the microprism array face each other.
The resin mold is attached to the mold, and each inverted portion forms a part of the cavity shape of the mold, and a heat-curable translucent resin is injected into the cavity of the mold to form a microlens array. This is also a method of forming an integrated optical lens array in which the inverted portion of the shape of the micro prism array and the inverted portion of the shape of the micro prism array are inverted.

In the present invention, the optical lens array provided on the optical substrate which is superimposed on the liquid crystal driving substrate in the liquid crystal display device is formed of a transparent resin by molding (injection molding, pressure molding, extrusion molding, transfer molding). ) Can be mass-produced by a simple manufacturing method.

Further, a master having an optical lens array shape using a glass substrate is formed, and a resin mold having an inverted portion of the optical lens array shape is formed using the master,
By mounting the resin mold in the cavity of the mold and injecting the translucent resin, the optical lens array in which the shape of the inversion portion of the resin mold is inverted can be formed of the translucent resin. In other words, a resin optical lens array can be mass-produced using the resin mold, and even if the resin mold is worn out, the resin mold can be easily formed from a master using a glass substrate. Can be mass-produced repeatedly.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an optical substrate and a method for manufacturing the same according to the present invention will be described below with reference to the drawings. The optical substrate of the present embodiment is mainly applied to a counter substrate facing a liquid crystal driving substrate of a liquid crystal display device, and an optical lens array for obtaining a light condensing effect provided on the counter substrate is formed of a transparent resin. And is characterized in that mass productivity is enhanced as compared with the case where an optical lens array is formed using glass.

The method of manufacturing an optical substrate described below is a method of manufacturing an optical substrate by forming an optical lens array by molding a light-transmitting resin. This is a specific method to increase

FIGS. 1 to 6 are schematic sectional views illustrating a method of manufacturing an optical substrate according to a first embodiment of the present invention. The first embodiment is characterized in that a microlens array substrate made of resin and a microprism array substrate made of resin, which are mainly optical lens arrays, are formed separately, and these are overlapped to manufacture an optical substrate.

First, a manufacturing method for forming a microlens array as an optical lens array will be described with reference to FIGS.

First, as shown in FIG. 1A, a process of applying a resist R on the surface of the glass substrate 1 and removing a part of the resist R by mask exposure, development and post-baking is performed. The removed portion of the resist R corresponds to a portion between the lenses of the microlens array later. As the glass substrate 1, for example, quartz glass having a diameter of 8 inches is used.

Next, the exposed portion of the glass substrate 1 is etched at a high selectivity by parallel plate plasma etching (using a reaction gas: CCl ₄ ) using the resist R as a mask to form a groove as shown in FIG. To form Thereafter, photolithography is performed so that the resist R ′ remains on the surface of the glass substrate 1 between the grooves. This resist R '
The remaining portion becomes the convex portion of each lens of the micro lens array.

Next, parallel plate plasma etching (reaction gas: CCl ₄ , C
F _4, CHF _3, etc.) is performed. At this time, the glass substrate 1 is taper-etched while etching the resist R ′ with oxygen. Thereby, a master G having a microlens array shape as shown in FIG. 1C is completed with the corners of the grooves formed in the glass substrate 1 as boundaries. Note that, around the microlens array shape, the shape of the alignment mark portion (not shown) and the shape of the scribe line portion (not shown)
Is also formed.

The glass master G is used in a later step to form a resin mold having an inverted microlens array shape. Accordingly, a resin mold is formed on the surface of the microlens array of the master G so that the resin can be easily peeled off from the master G by, for example, electroless Ni.
A plating film forming process or a fluororesin coating process (not shown) is performed.

Next, as shown in FIG. 2A, the resin 2 is placed on the microlens array of the master G by, for example, 50 μm.
Apply m thickness. As the resin 2, a UV-curable resin made of an acrylic or epoxy resin is used. Then, after the resin 2 is applied, ultraviolet rays are irradiated (for example, 50
00 mJ / cm ² ) to cure the resin 2.

Next, as shown in FIG. 2B, a base film B made of polyimide is placed on the cured resin 2.
(0.5 mm thick). The base film B has a silicone-based adhesive B ′ (10 μm thick) applied on both sides, and a protective film H is applied to the adhesive B ′ on the front side. Then, the cured resin 2 is peeled off from the master G while the base film B is stuck. As a result, a resin mold J having an inverted portion of the shape of the microlens array, the shape of the alignment mark portion (not shown), and the shape of the scribe line portion (not shown) is completed.

In order to improve the releasability between the resin mold J and the molded microlens array substrate during the injection molding of the microlens array substrate described later using the resin mold J, the surface of the resin mold J is improved. May be coated with a fluororesin.

Next, a manufacturing method for forming a microprism array will be described with reference to the schematic sectional views of FIGS.

First, as shown in FIG. 3A, a resist R is applied to the surface of the glass substrate 1 ', and a process of removing a part of the resist R by mask exposure, development, and post-baking is performed. The removed portion of the resist R corresponds to a portion between the respective prisms of the microprism array later. As the glass substrate 1 ', for example, quartz glass having a diameter of 8 inches is used.

Then, the exposed portion of the glass substrate 1 'is etched with a high selectivity by parallel plate plasma etching (using a reaction gas: CCl ₄ ) using the resist R as a mask, thereby forming a groove. Then, as shown in FIG.
Photolithography is performed such that the resist R ′ remains on the surface of the glass substrate 1 ′ between the grooves, and photolithography is performed such that the resist R ″ having a predetermined thickness remains on the inner surface of the groove. The portion where the resist R 'remains becomes a convex portion of each prism of the microprism array later.

Next, parallel plate plasma etching using the resists R ′ and R ″ as a mask (reaction gas:
CCl ₄ , CF ₄ , CHF _3, etc.). At this time, the glass substrate 1 'is taper-etched while etching the resists R' and R '' with oxygen. Thus, a master G ′ having a microprism array shape as shown in FIG. 3C is completed with the corners of the grooves formed in the glass substrate 1 ′ as boundaries. A shape of an alignment mark portion (not shown) and a shape of a scribe line portion (not shown) are also formed around the microlens array shape.

The glass master G 'is used for forming a resin mold in which the shape of the microprism array is inverted in a later step. Therefore, on the surface of the micro prism array of the master G ′, for example, an electroless Ni plating film forming process or a fluororesin coating may be performed so that a resin mold is formed and the master G ′ can be easily peeled when peeled from the master G ′. Processing (not shown) is performed.

Next, as shown in FIG.
The resin 2 ′ is applied, for example, to a thickness of 50 μm on the micro prism array. As the resin 2 ′, an ultraviolet-curable resin made of an acrylic or epoxy resin is used. Then, after applying the resin 2 ′, the resin 2 ′ is cured by irradiating ultraviolet rays (for example, 5000 mJ / cm ² ).

Next, as shown in FIG. 4B, a base film B made of polyimide is placed on the cured resin 2 '.
(0.5 mm thick). The base film B has a silicone-based adhesive B ′ (10 μm thick) applied on both sides, and a protective film H is applied to the adhesive B ′ on the front side. Then, the cured resin 2 'is peeled off from the master G' while the base film B is stuck. As a result, a resin mold J ′ having a reverse portion of the microprism array shape, the shape of the alignment mark portion (not shown), and the shape of the scribe line portion (not shown) is completed.

In order to improve the releasability between the resin mold J 'and the molded micro prism array substrate during the injection molding of the micro prism array substrate described later using the resin mold J', the resin mold J 'is used. The surface of 'may be coated with a fluororesin.

After completion of the resin mold J having the microlens array-shaped inverted portion and the resin mold J 'having the microprism array-shaped inverted portion by the steps shown in FIGS. 1 and 2 and FIGS. Molds a microlens array substrate and a microprism array substrate with a predetermined resin using these resin molds J and J ′.

FIG. 5A is a schematic sectional view showing a process of forming a microlens array substrate by injection molding of a transparent resin, and FIG. 5B is a process of forming a microprism array substrate by injection molding of a transparent resin. FIG. That is, when a microlens array substrate is manufactured, as shown in FIG. 5A, a base film B in which a resin mold J manufactured earlier is bonded to both sides of a mold, for example, an upper mold M1 is used. And attach it. As a result, the inverted portion of the microlens array shape of the resin mold J becomes the upper mold M
1 and a part of the cavity C formed between the lower mold M2.

Similarly, when manufacturing a microprism array substrate, as shown in FIG. 5 (b), the resin mold J 'previously manufactured is bonded to both sides of the upper mold M1' of the mold, for example. Using the base film B. As a result, the inverted portion of the micro prism array shape of the resin mold J ′ becomes a part of the cavity C ′ formed between the upper mold M1 ′ and the lower mold M2 ′.

With the resin molds J, J 'set in the respective dies, the transparent resins 3, 3' are injected into the cavities C, C ', respectively. As the transparent resin 3, 3 ', an acrylic, epoxy or polyolefin heat-curable transparent resin (both having a heat resistance temperature of 180 ° C. or higher) is used, and the refractive index is n = 1.57 to 1.60. Use something of the order. The temperature of the mold is 80 to 10
0 ° C.

After the microlens array substrate and the microprism array substrate are completed by injection molding, as shown in FIG.
A and the microprism array substrate MPA are overlapped and adhered via the translucent adhesive 4. At this time, the point is that the positions are aligned with the alignment marks formed on both sides, and then they are overlapped and bonded.

The light-transmitting adhesive 4 includes a microlens array substrate MLA and a microprism array substrate M
The refractive index (n = 1.57-1.n) of the transparent resin 3, 3 '(see FIGS. 5 (a) and 5 (b)) used when PA was injection-molded.
60) Use a smaller n = 1.34 to 1.40. Further, in order to improve the overlay accuracy, the transparent adhesive 4 is desirably an ultraviolet irradiation-curable type or an ultraviolet irradiation + heat-curable type.

Next, as shown in FIG. 6B, a low-refractive-index resin adhesive 4 'is applied on the microprism array substrate MPA, and after the bonding, optical polishing is performed to reduce the flatness and the predetermined thickness. Secure. The low refractive index resin adhesive 4 'has a refractive index of about n = 1.34 to 1.40.

Next, as shown in FIG. 6C, SiO ₂ is formed as a buffer film 5 on the micro-prism array substrate MPA by sputtering with a thickness of about 500 nm, and then ITO as a transparent electrode 6 is formed thereon. It is formed by sputtering with a thickness of 130 nm. Then, the substrate is cut into a predetermined size (such as dicing) to complete the optical substrate. In addition,
Since the optical substrate thus formed is made of resin, the support glass 7 may be bonded with a transparent adhesive, a transparent adhesive tape, or the like to reinforce the strength.

In order to improve the controllability of the focal length, a predetermined thickness may be polished using a cover glass instead of the buffer film 5, and then ITO may be formed by sputtering with a thickness of about 130 nm. By such a process, FIG.
An optical substrate as shown in the completed drawing shown in (a) and (b) can be manufactured.

Next, a method for manufacturing an optical substrate according to the second embodiment of the present invention will be described. 7 and 8 are schematic sectional views illustrating the second embodiment. The second embodiment is characterized in that a microlens array and a microprism array, which are optical lens arrays, are manufactured as an integrated substrate made of a transparent resin.

In the second embodiment, as in the first embodiment, a method of manufacturing a resin mold J having a microlens array-shaped inverted portion and a resin mold J 'having a microprism array-shaped inverted portion are provided. 1 and 2 and 3
This is the same as the examples shown in FIGS. Therefore, the description of the method of manufacturing the resin molds J and J 'will be omitted below, and the subsequent steps will be described.

After completion of the resin molds J and J ', FIG.
As shown in (a), for example, a resin mold J having a microlens array-shaped inversion portion is attached to an upper mold M1 ″ of a mold, and a microprism array-shaped inversion portion is provided to a lower mold M2 ″. Attach resin mold J '. by this,
The inverted portion having the microlens array shape and the inverted portion having the microprism array shape are part of the cavity C ″. At this time, a resin mold J having a microlens array shape inversion portion and a microprism array shape inversion portion are provided so that the optical central axes of the microlens array portion and the microprism array portion coincide with each other. The point is that the resin mold J 'is finely adjusted using both alignment marks.

Then, a transparent resin is injected into the cavity C ″. As the transparent resin, an acrylic, epoxy, or polyolefin-based heat-curable transparent resin (both having a heat resistance temperature of 180 ° C. or higher) is used, and has a refractive index of about n = 1.57 to 1.60. use. The temperature of the mold is set to 80 to 100 ° C.

By this injection molding, the microlens prism array substrate M in which the microlens array and the microprism array are integrated as shown in FIG.
LPA is molded.

Next, a light-transmitting base 8 is bonded to the microlens prism array substrate MLPA via a light-transmitting adhesive 4 ″. As the translucent adhesive 4 ″, the refractive index of the resin used when the microlens prism array substrate MLPA was injection-molded (n = 1.57 to
1.60) n = 1.34 to 1.40 are used. Further, in order to improve the overlay accuracy, the transparent adhesive 4 is desirably an ultraviolet irradiation-curable type or an ultraviolet irradiation + heat-curable type.

Further, as the base 8, for example, borosilicate glass (n = 1.55) or an acrylic transparent resin plate (n
= 1.55 to 1.57).

Next, as shown in FIG. 8A, a low-refractive-index resin adhesive 4 ′ ″ is applied on the microlens prism array substrate MLPA, and is optically polished after the bonding, so that the flatness and the predetermined Secure the thickness. The low refractive index resin adhesive 4 'has a refractive index of about n = 1.34 to 1.40.

Next, as shown in FIG. 8B, SiO ₂ is formed as a buffer film 5 on the microlens prism array substrate MLPA by sputtering to a thickness of about 500 nm, and then a transparent electrode 6 is formed thereon as ITO. About 1
It is formed by sputtering with a thickness of 30 nm. Then, the substrate is cut into a predetermined size (such as dicing) to complete the optical substrate. In order to improve the controllability of the focal length, a cover glass may be used instead of the buffer film 5 and polished to a predetermined thickness, and then ITO may be formed by sputtering with a thickness of about 130 nm. By such a process, FIG.
An optical substrate as shown in the completed drawing shown in (a) and (b) can be manufactured.

As described above, the microlens array substrate M
Even in the first embodiment in which the LA and the microprism array substrate MPA are manufactured separately, and in the second embodiment in which the microlens array substrate MLPA in which the microlens array and the microprism array are integrated, Injection molding of a transparent resin using the resin molds J and J ′ makes it possible to mass-produce an optical substrate having an optical lens array with high accuracy.

The optical substrates manufactured in the first and second embodiments use the alignment marks provided around the microlens array and the microprism array and the alignment marks of the liquid crystal driving substrate. Then, liquid crystal is injected and sealed into the gap, and the liquid crystal is aligned by heat treatment to manufacture a liquid crystal display device.

Even if the resin molds J and J 'are worn or broken, the masters G and G' of the resin molds J and J 'are made of glass. , J ′ can be easily formed.

[0052]

As described above, according to the optical substrate and the method of manufacturing the same of the present invention, the following effects can be obtained. That is, since the optical lens array portion of the optical substrate used as the counter substrate of the liquid crystal display device is made of a light-transmitting resin formed by injection molding or the like, the liquid crystal display device requiring the optical lens array can be mass-produced at low cost. It is possible to do.
In addition, by manufacturing the optical substrate by molding a translucent resin using a resin mold, the optical lens array can be mass-produced with high accuracy at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating a first embodiment (part 1).
It is.

FIG. 2 is a schematic cross-sectional view illustrating a first embodiment (part 2).
It is.

FIG. 3 is a schematic cross-sectional view illustrating a first embodiment (part 3).
It is.

FIG. 4 is a schematic sectional view for explaining the first embodiment (part 4);
It is.

FIG. 5 is a schematic sectional view for explaining the first embodiment (part 5);
It is.

FIG. 6 is a schematic sectional view for explaining the first embodiment (part 6);
It is.

FIG. 7 is a schematic cross-sectional view illustrating a second embodiment (part 1).
It is.

FIG. 8 is a schematic sectional view illustrating a second embodiment (part 2).
It is.

FIG. 9 is a schematic sectional view (part 1) showing a completed state of the optical substrate.

FIG. 10 is a schematic sectional view (part 2) showing a completed state of the optical substrate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Glass substrate 2, 3 Transparent resin 4 Translucent adhesive 5 Buffer film 6 Transparent electrode B Base film G, G 'Master J, J' Resin type M1 Upper mold
M2 Lower type MLA Micro lens array substrate MPA Micro prism array substrate MLPA Micro lens prism array substrate R
Resist

Claims (16)

[Claims] 1. An optical substrate on which an optical lens array is formed so as to be opposed to a liquid crystal driving substrate in a liquid crystal display device, wherein the optical lens array is formed by molding a translucent resin. Optical substrate. 2. A step of forming a master having an optical lens array by photolithography and etching a predetermined position of a glass substrate; applying a resin to the optical lens array in the master; A step of forming a resin mold having a reversal portion of the shape of the optical lens array by peeling after curing, attaching the resin mold to a mold, and forming the resin mold in a reversal portion of the shape of the optical lens array of the resin mold. Forming a part of the cavity shape of the mold; and injecting a translucent resin into the cavity of the mold to form an optical lens array in which the shape of the inversion portion of the resin mold is inverted. And a method of manufacturing an optical substrate. 3. The method according to claim 2, wherein the optical lens array is a micro lens array. 4. The method according to claim 2, wherein the optical lens array is a micro prism array. 5. The method for manufacturing an optical substrate according to claim 2, wherein the resin is applied after forming a release film on the optical lens array in the shape of the master. 6. The method of manufacturing an optical substrate according to claim 2, wherein a release film is formed on an inverted portion of the shape of the resin-type optical lens array, and then the resin mold is attached to the mold. 7. The method according to claim 2, wherein an alignment mark is formed around the optical lens array. 8. The method according to claim 2, wherein a scribe line is formed around the optical lens array. 9. A microlens array and a microprism array are formed as an optical lens array by the method of manufacturing an optical substrate according to claim 2, and the microlens array is interposed on the microlens array via a transparent adhesive. Laminating a surface opposite to the surface on which is formed, coating the micro-prism array with a light-transmitting adhesive, and polishing the surface thereof; forming a buffer film on the polished light-transmitting adhesive, Forming a translucent electrode thereon. A method of manufacturing an optical substrate, comprising: 10. A microlens array and a microprism array are formed as an optical lens array by the method of manufacturing an optical substrate according to claim 2, and the microlens array is interposed on the microlens array via a transparent adhesive. Laminating a surface opposite to the surface on which is formed, laminating a cover glass to the microprism array via a translucent adhesive, and polishing the cover glass to a predetermined thickness; Forming a light-transmissive electrode. 11. After forming a microlens array as an optical lens array by the method for manufacturing an optical substrate according to claim 2, a cover glass is attached to the microlens array via a light-transmitting adhesive, and the cover glass is formed. And a step of forming a light-transmissive electrode on the polished cover glass. 12. A first master having a microlens array shape is formed by subjecting a predetermined position of a first glass substrate to photolithography and etching processing, and a resin portion is formed on the microlens array shape portion of the first master disk. Forming a first resin mold having an inverted part of the shape of the microlens array by applying and curing the resin, and photolithography and etching processing on a predetermined position of the second glass substrate. Forming a second master having the shape of the microprism array, applying a resin to the shape of the microprism array of the second master and curing the resin;
A step of forming a second resin mold having a reversal portion of the shape of the microprism array by peeling the resin; and a reversal portion of the shape of the microlens array and a reversal portion of the shape of the microprism array. Attaching the first resin mold and the second resin mold to a mold so as to face each other;
A step of forming a part of the cavity shape of the mold by each inversion section; and injecting a translucent resin into the cavity of the mold to invert the shape of the microlens array and the microprism. Forming an integrated optical lens array in which an inverted portion of the array shape is inverted. 13. After forming an integrated optical lens array by the method for manufacturing an optical substrate according to claim 12, bonding a microlens array to a translucent base via a translucent adhesive; A step of coating the prism array with a light-transmitting adhesive and polishing the surface thereof; and a step of forming a buffer film on the polished light-transmitting adhesive and forming a light-transmitting electrode thereon. A method for manufacturing an optical substrate, comprising: 14. A method of manufacturing an optical substrate according to claim 12, wherein an integrated optical lens array is formed, and a micro lens array is bonded to a light-transmitting base via a light-transmitting adhesive; Bonding a cover glass to the microprism array via an optical adhesive, polishing the cover glass to a predetermined thickness, and forming a light-transmitting electrode on the cover glass. A method for manufacturing an optical substrate. 15. The method of manufacturing an optical substrate according to claim 12, wherein an alignment mark is formed around the micro lens array and around the micro prism array in the integrated optical lens array. 16. The method of manufacturing an optical substrate according to claim 12, wherein scribe lines are formed around the micro lens array and around the micro prism array in the integrated optical lens array.