JPH1062604A - Manufacture of optical board and liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide alignment marks with a simple process. SOLUTION: This method includes processes for preparing areas covered by photoresists 2 and areas exposed without being covered by the photoresists 2 are formed on a glass board, and lens areas (R) are formed by shaving the exposed areas using photoresist 2 as the masks. In the process of forming the lens areas also includes a process for preparing photoresist 2 playing as masks are completely removed and photoresists 2' which do not play as masks are not removed and become alignment mark areas AM.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical substrate and a method for manufacturing a liquid crystal display device in which an optical portion including a microlens and a microprism is formed on a light-transmitting substrate.

[0002]

2. Description of the Related Art In a liquid crystal display device such as a liquid crystal projector, a microlens array or a microprism array is formed on a counter substrate opposite to a driving substrate on which driving elements such as TFTs are formed, and illumination light is focused on a pixel area. There has been proposed a technique for improving the brightness of a display image.

A method for forming the microlens array is described in a projection type image display device disclosed in Japanese Patent Publication No. 6-42126. Also, as another forming method,
A technique of forming a microlens array by forming a concave portion in a glass substrate and embedding a high-refractive-index transparent resin therein is also considered.

[0004]

As described above, the optical substrate on which the microlens array and the microprism array are formed needs to collect illumination light on the pixel area to improve the brightness of the displayed image. Therefore, alignment with the driving substrate on which TFTs and the like are formed becomes very important. Also, alignment is required when dicing the optical substrate on which the microlens array and the like are formed into a predetermined size.

However, a light-transmitting substrate that transmits light is used as a substrate on which a microlens array or the like is formed. An alignment mark for positioning is separately formed on the surface of a light-transmitting substrate mainly composed of a glass substrate. This requires a very laborious process.

When a microlens array or the like is formed by using a high-refractive-index transparent resin, an alignment mark may be formed by embedding the high-refractive-index transparent resin. It is difficult to determine the pattern by the alignment illumination, and accurate alignment cannot be performed automatically.

In addition, since the substrate on which the microlens array and the like are formed is a light-transmitting substrate, there is a problem that unnecessary light is incident on the driving circuit of the opposing liquid crystal driving substrate to change the driving characteristics. In order to solve this problem, it is conceivable to provide a light-shielding film. However, forming such a light-shielding film separately complicates the manufacturing process.

[0008]

SUMMARY OF THE INVENTION The present invention is a method for manufacturing an optical substrate which has been made to solve such a problem.
That is, the present invention provides a process of forming a portion of a surface of a light-transmitting substrate covered with a protective film and a portion of the surface of the light-transmitting substrate which is not covered with the protective film and is exposed, and using the protective film as a mask. The process of forming the optical part by processing the part where the surface of the optical substrate is exposed, and completely protecting the protective film that serves as a mask for forming the optical part before the optical part is completed by processing Removing and leaving a protective film that does not become a mask for forming an optical portion.

Further, in bonding the optical substrate manufactured by the above-described manufacturing method to an opposing substrate and superimposing the optical substrate on a liquid crystal driving substrate, a liquid crystal display device in which a remaining protective film is used as a light shielding film of a driving circuit of the liquid crystal driving substrate. It is also a manufacturing method.

In the present invention, a mask for forming an optical portion and a mask for not forming an optical portion are provided at the same time when a protective film for forming an optical portion is applied to a light transmitting substrate. The former protective film is completely removed by the processing for forming the optical part, and the latter protective film is left. Since the pattern formed by the remaining protective film becomes the alignment mark of the translucent substrate, there is no need to separately form an alignment mark.

Further, by using the remaining protective film as a light-shielding film, the light-shielding protective film is opposed to the driving circuit of the liquid crystal driving substrate when the liquid crystal driving substrate is superimposed. The light-shielding of the drive circuit can be performed without forming a film.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the method for manufacturing an optical substrate according to the present invention will be described below with reference to the drawings. In the present embodiment, a method for manufacturing an optical substrate including a microlens and a microprism will be mainly described as an example.

FIGS. 1 and 2 are schematic sectional views for explaining the first embodiment. First, as shown in FIG. 1A, a photoresist 2 is applied to the surface of a glass substrate 1 having a light-transmitting property, and a lens portion R, which is a portion where a microlens to be described later is formed using photolithography, is formed. Open an alignment mark part AM for forming an alignment mark.

As the glass substrate 1, for example, a quartz glass substrate having a diameter of 6 inches and a thickness of 0.8 mm (refractive index: 1.47)
Using 2), as the photoresist 2, for example, using a negative photoresist, patterning is performed by mask exposure and development, and then post-baking is performed at a predetermined temperature to improve adhesion to the glass substrate 1. deep.

Next, as shown in FIG. 1B, an etching process is performed using the photoresist 2 on the glass substrate 1 as a mask to form a concave depression in the lens portion R. When wet etching is used as the etching process,
When an HF-based etchant is used, and when dry etching is used, CCl ₄ gas is used.

The lens portion R formed by this etching
Is formed using a photoresist 2 (FIG. 1) between the lens portions R.
(In the example of (b), the left two photoresists) are peeled off. Thereby, a depression of the lens portion R is formed, and in the example of FIG. 1B, two photoresists 2 on the right side remain. As shown in FIG.
Utilizing this photoresist 2 ', the space is used as the alignment mark part AM.

That is, in the present embodiment, the photoresist 2 for forming the lens portion R is removed by etching, and the photoresist 2 'forming the alignment mark portion AM has such a size that it remains even after etching. It is patterned. Thus, the alignment mark part AM can be formed by using the photoresist 2 ′ remaining at the stage when the lens part R is formed, simultaneously with the etching for forming the lens part R. In addition,
A scribe line can be formed in the same way as the alignment mark AM.

Next, as shown in FIG. 2A, the lens portion R, the alignment mark portion AM and the scribe line (not shown) of the glass substrate 1 are coated with a high-refractive-index transparent resin 3 to form a base glass. 4 is performed. As the high-refractive-index transparent resin 3, an ultraviolet irradiation curing type,
Alternatively, use an ultraviolet irradiation + heat-curing type or a thermosetting type (refractive index: 1.60 to 1.70).
For example, quartz glass having a diameter of 6 inches and a thickness of 0.5 to 0.8 mm (refractive index: 1.472) is used. Due to the refractive index difference between the high refractive index transparent resin 3 and the base glass 4 and the glass substrate 1, the lens effect of the lens portion R is exhibited.

After the high refractive index transparent resin 3 is coated and the base glass 4 is bonded thereto, the high refractive index transparent resin 3 is irradiated with ultraviolet rays (for example, 2000 to 300).
0 mJ / cm ² ), heating (for example, 150 to 180 ° C.)
To fix the base glass 4.

By bonding the base glass 4,
An alignment mark portion AM formed of a photoresist 2 ′ is sandwiched between the glass substrate 1 on which the lens portion R is formed and the base glass 4. It can be used as a target for alignment in a later process such as a scribe break.

Next, as shown in FIG. 2B, the base glass 4 is polished on one side to form a predetermined thickness. In one-side polishing, optical polishing is performed based on the glass substrate 1. That is, the thickness of the base glass 4 is important for the focal length determined by the refractive index difference and the radius of curvature of the lens portion R.

At this time, the glass substrate 1, the base glass 4,
Since both the high refractive index transparent resin 3 is transparent, the thickness measurement of the base glass 4 during optical polishing becomes inaccurate, the focal length becomes inaccurate, and a sufficient lens effect cannot be exhibited. However, since the photoresist 2 ′ of the present embodiment is opaque, the thickness of the base glass 4 during single-side polishing can be accurately measured based on the opacity, the accuracy of the focal length is improved, and a sufficient lens effect is obtained. Can be demonstrated.

Here, the focal length of the lens f = (r / Δ)
n) n, r: radius of curvature of lens portion R, Δn: difference in refractive index,
n: High refractive index. Therefore, for example, r = 25 μ
m, Δn = 1.7 (high refractive index)-1.472 (low refractive index), the focal length f of the lens = (2.5 /
(1.7-1.472)) × 1.7 = 186 μm.

After the base glass 4 is formed to a predetermined thickness, ITO 5 is formed on the surface thereof by sputtering. The thickness of ITO5 is about 130 to 150 nm. Thus, an optical substrate including the microlens array is completed.

After the optical substrate provided with the microlens array is completed, a predetermined polyimide alignment film is formed on the TFT substrate, rubbing is performed, a sealing agent is applied on the optical substrate side, and a common agent is applied on the TFT substrate side. Then, superposition is performed using both alignment marks. Thereafter, a scribe break is performed between the alignment mark and the scribe line, and liquid crystal injection and heat treatment are performed to complete the liquid crystal display device.

A predetermined polyimide alignment film is formed on the optical substrate provided with the microlens array and the TFT substrate, and after the rubbing treatment, the substrate is diced and divided by an alignment mark to make the optical substrate an optical chip and the TFT substrate a TFT chip. A sealant is applied to the optical chip, a common agent is applied to the TFT chip, and superposition is performed using both alignment marks. Thereafter, liquid crystal injection and heat treatment may be performed to complete the liquid crystal display device.

FIG. 3 is a schematic sectional view showing a state where the liquid crystal display device is completed, and FIG. 4 is a schematic plan view of the liquid crystal display device.
A photoresist 2 'for forming the alignment mark part AM is formed around the microlens array part MR by the manufacturing method described above. This photoresist 2 'is formed of a light-shielding film, and is left so as to surround the microlens array portion MR as shown in FIG.

Thus, it is possible to shield the drive circuit section 71 provided around the effective pixel area G from incident light in a state where the TFT substrates 7 are superimposed, thereby stabilizing the operation. .

FIG. 5 is a schematic sectional view showing a manufacturing method when the opposing substrate is provided with the prism P. Prism P
In the case of having, the following procedure is performed. (1) The substrate for microprisms 8 is bonded to the substrate (microlens substrate) on which the microlens array section MA is formed via the high-refractive-index transparent resin 3. (2) Alignment mark part AM of microlens substrate
Is optically polished so that the microprism substrate 8 has a predetermined thickness (for example, 0.2 mm thickness). (3) Alignment mark part AM of microlens substrate
Is performed and dry etching is performed with CCl ₄ or the like to form a microprism portion MP (see FIG. 5A). (4) The microprism section MP is filled with the high-refractive-index transparent resin 3 and a cover glass 9 (for example, 0.5 mm thick) is attached (see FIG. 5B). (5) The cover glass 9 has a predetermined thickness (for example, 0.1 m).
(m thickness). (6) ITO5 (transparent electrode) is formed (130 to 15)
0 nm thick) (see FIG. 5C). The thicknesses of the microprism substrate 8 and the cover glass 9 are determined by parameters such as the radius of curvature of the lens portion R and a transparent resin having a high refractive index.

FIG. 6 is a plan view showing the shape of the alignment mark. In the step shown in FIG. 1C described above, the photoresist 2 ′ remaining after the completion of the lens portion R is used as the alignment mark portion AM. 6 (a) to 6 (c).

That is, FIG. 6A shows an alignment mark portion AM with the photoresist 2 'remaining on the cross, and the direction of each cross indicates the xy direction of the glass substrate. In FIG. 6B, the alignment mark part AM is configured with a cross in the shape of a cross, and the directions of the cross in the cross indicate the xy directions of the glass substrate. Further, FIG. 6C shows an alignment mark part AM in which the xy directions are indicated by four L-type photoresists. Note that the alignment mark portion A
M preferably has a size of about 200 (μm) × 200 (μm).

As described above, it is sufficient to form the alignment mark portion AM so that the direction of the glass substrate can be specified by the shape of the remaining photoresist 2 '. If the direction of the glass substrate can be specified, FIGS. The shape shown in c) is not limited. In addition, alignment mark portion A
When scribe lines are formed in the same manner as M, the width is preferably about 250 to 300 μm.

Next, a second embodiment will be described with reference to the schematic sectional view of FIG. The second embodiment is characterized in that the photoresist 2 and the metal film 6 are used as protective films.

First, as shown in FIG. 7A, a metal film 6 having a light-shielding property is applied to the surface of a glass substrate 1 having a light-transmitting property, and a photoresist 2 is applied thereon. Using photolithography, openings are formed in the photoresist 2 corresponding to the lens portion R, the alignment mark portion AM, and the scribe line, which are portions for forming microlenses described later.

Thereafter, the metal film 6 is etched using the photoresist 2 as a mask to open the metal film 6 corresponding to the lens portion R.

As the glass substrate 1, for example, a quartz glass substrate having a diameter of 6 inches and a thickness of 0.8 mm (refractive index: 1.47)
2) is used, and as the metal film 6, for example, chromium, aluminum, tantalum, molybdenum, tungsten,
Chromium oxide or the like is deposited to a thickness of about 200 nm by sputtering. It is desirable that the metal film 6 be made of chromium, chromium oxide, or the like having a light-shielding property and a low reflection property.

As the photoresist 2, for example, a negative type photoresist is used, and after patterning by mask exposure and development, post-baking is performed at a predetermined temperature to improve adhesion to the metal film 6. Then, using the photoresist 2 as a mask, the metal film 6
Dry etching with F ₄ gas.

Next, as shown in FIG. 7B, an etching process is performed using the photoresist 2 and the metal film 6 on the glass substrate 1 as a mask to form a concave depression in the lens portion R. When wet etching is used as the etching treatment, an HF-based etchant is used, and when dry etching is used, CCl ₄ gas is used.

The lens portion R formed by this etching
Is continued until the photoresist 2 and the metal film 6 (the two left photoresists and the metal film in the example of FIG. 7B) between the lens portions R are peeled off. As a result, a depression of the lens portion R is formed, and at the same time, FIG.
In the example of (b), two photoresists 2 and a metal film 6 on the right side remain. As shown in FIG. 7C, the alignment mark portion AM is formed using the photoresist 2 'and the metal film.

The shape of the alignment mark AM formed by leaving the photoresist and the metal film is such that the orientation of the glass substrate can be specified, as shown in FIG. 6, for example.

Next, as shown in FIG. 7D, a process of coating the lens portion R, the alignment mark portion AM and the scribe line of the glass substrate 1 with the high refractive index transparent resin 3 and bonding the base glass 4 thereto. I do. The high-refractive-index transparent resin 3 is a UV-curable resin, a UV-irradiation + heat-curable resin, or a thermosetting resin (refractive index 1.
60 to 1.70), and the base glass 4 is, for example, quartz glass (refractive index: 1.472). Due to the difference in the refractive index between the high-refractive-index transparent resin 3 and the base glass 4, the lens effect of the lens portion R is exhibited.

After coating the high-refractive-index transparent resin 3 and bonding the base glass 4 thereto, the high-refractive-index transparent resin 3 is irradiated with ultraviolet rays (for example, 2000 to 300).
0 mJ / cm ² ), heating (for example, 150 to 180 ° C.)
To fix the base glass 4.

As in the first embodiment, by bonding the base glass 4, an alignment mark portion AM is formed between the glass substrate 1 on which the lens portion R is formed and the base glass 4.
Are sandwiched, and can be used as a target for alignment in a later process, for example, at the time of superposition with a TFT substrate, dicing or scribe break.

Next, similar to the step shown in FIG.
The base glass 4 is polished on one side to form a predetermined thickness. In one-side polishing, optical polishing is performed based on the glass substrate 1. That is, the thickness of the base glass 4 is important for the focal length determined by the refractive index difference and the radius of curvature of the lens portion R.

At this time, the glass substrate 1, the base glass 4,
Since both the high refractive index transparent resin 3 is transparent, the thickness measurement of the base glass 4 during optical polishing becomes inaccurate, the focal length becomes inaccurate, and a sufficient lens effect cannot be exhibited. However, since the photoresist 2 ′ of the present embodiment is opaque, the thickness of the base glass 4 during single-side polishing can be accurately measured based on the opacity, the accuracy of the focal length is improved, and a sufficient lens effect is obtained. Can be demonstrated.

Here, the focal length of the lens f = (r / Δ
n) n, r: radius of curvature of lens portion R, Δn: difference in refractive index,
n: High refractive index. Therefore, for example, r = 25 μ
m, Δn = 1.7 (high refractive index)-1.472 (low refractive index), the focal length f of the lens = (2.5 /
(1.7-1.472)) × 1.7 = 186 μm.

The subsequent steps are the same as in the first embodiment. That is, as shown in FIG. 2B, the base glass 4 is polished on one side to form a predetermined thickness. The thickness varies depending on the refractive index of the high-refractive-index transparent resin 3, but is set to about 150 to 200 μm.

After the base glass 4 is formed to a predetermined thickness, ITO 5 is formed on the surface thereof by sputtering. The thickness of ITO5 is about 130 to 150 nm. Thus, an optical substrate including the microlens array is completed.

When the opposing substrate is provided with the prism P, the prism P is formed in the same procedure as that shown in FIG.
To form Then, an optical substrate is completed by forming ITO5 on the prism P by sputtering.

After the optical substrate having the microlens array section MA is completed, a predetermined polyimide alignment film is formed on the TFT substrate, rubbing is performed, a sealant is applied to the optical substrate, and a common agent is applied to the TFT substrate. Is applied, and superposition is performed using both alignment mark portions AM. Thereafter, a scribe break is performed between the alignment mark portion AM and the scribe line, and liquid crystal injection and heat treatment are performed to complete the liquid crystal display device.

A predetermined polyimide alignment film is formed on the optical substrate having the microlens array section MA and the TFT substrate, and after the rubbing treatment, the optical substrate is optically chipped by dicing with an alignment mark, and the TFT substrate is converted into a TF.
As a T chip, a sealant is applied to the optical chip, a common agent is applied to the TFT chip, and superposition is performed using both alignment mark portions AM. Thereafter, liquid crystal injection and heat treatment may be performed to complete the liquid crystal display device.

In each of the first and second embodiments described above, the example in which wet etching or dry etching of the glass substrate 1 is used to form the lens portion R has been described, but other methods may be used. .

For example, a photosensitive dry film photoresist having good sandblast resistance is used as the photoresist 2, and the lens portion R is formed by photolithography.
After opening the portion corresponding to the above, a depression is physically formed by sandblasting. After that, the fine irregularities on the surface of the depression generated by the sandblasting process are slightly wet-etched with an HF-based etchant or dry-etched using CCl ₄ or the like so as to be adjusted to a predetermined lens shape.

Also, using the same photosensitive dry film photoresist as above, instead of the sandblast method,
Powder beam processing for spraying and cutting ceramic fine particles may be used. Also in this case, fine irregularities formed on the surface of the depression after the powder beam processing are slightly adjusted to a predetermined lens shape by wet etching with an HF-based etchant or dry etching using CCl ₄ or the like.

When such a method of forming the lens portion R by sandblasting or powder beam processing is applied, it is not necessary to use a quartz glass substrate as the glass substrate 1 on which the lens portion R is formed. And the like can be used. That is, since the glass substrate 1 can be physically shaved by the sand blast method or the powder beam processing, high etching uniformity such as when the lens portion R having a predetermined shape is formed by chemical wet etching or dry etching is not obtained. Not required. Therefore, a large-sized borosilicate glass substrate can be used at a lower cost than a quartz glass substrate, and mass production using a large-sized substrate can be performed by using the borosilicate glass substrate. In addition, the lens shape can be made more uniform and reproducibility can be improved as compared with the case of only wet etching or dry etching, and the cost can be reduced by using a large glass substrate.

In any of the embodiments described above, a photoresist 2 having a light-shielding property may be used. That is, the general-purpose photoresist 2 is made to have a light shielding property using a mixture of a black organic pigment and carbon. Also, general-purpose photoresist 2
On top of this, a photoresist for a resin black mask in which a black organic pigment or carbon is mixed may be formed.

In this case, as shown in FIG. 1C, in a state where the alignment mark portion AM is formed by the lens portion R and the remaining photoresist 2 ', a photoresist for a resin black mask having a thickness of 3 to 5 μm is formed on the surface. After application, the back surface exposure, development, and post-baking are performed from the back surface of the glass substrate 1 by self-alignment using the photoresist 2 'as a mask. As a result, a photoresist for a resin black mask is formed on the surface of the photoresist 2 ′.

This makes it possible to improve the light-shielding property when the manufactured optical substrate is used as a counter substrate for a driving substrate of a liquid crystal display device. That is, disturbance light can be blocked by the photoresist 2, and the TFT 2
It becomes possible to reduce an unstable operation element such as a threshold voltage fluctuation of the element. To this end, it is important to form a light-shielding film so that the optical density (Optical Density) is 3.0 or more.

[0059]

As described above, according to the method of manufacturing an optical substrate of the present invention, the following effects can be obtained. That is,
Since part of the protective film used when manufacturing optical parts such as microlenses is left as an alignment mark,
There is no need to form an alignment mark in a separate step, and the process can be simplified.
It is possible to easily and accurately perform the alignment of the translucent substrate with the easily read alignment marks.

Further, the alignment mark composed of the protective film facilitates the discrimination of the alignment mark.
Automatic alignment with a liquid crystal driving substrate such as FT can be accurately performed, and a liquid crystal display device having high accuracy, high productivity, and a high lens effect can be manufactured.

Further, by using a scribe or dicing alignment mark manufactured in the same manner as this alignment mark, highly accurate automated scribe or dicing can be performed, and the productivity can be improved.

Further, since the scribe or dicing line becomes clear, scribe or dicing with high accuracy can be performed.

Further, the drive circuit of the liquid crystal drive substrate can be shielded from external light by the protective film left when forming the optical portion and the like, and the threshold voltage fluctuation of the transistor of the drive circuit can be prevented, and stable high image quality can be obtained. Liquid crystal display becomes possible.

Further, since it is not necessary to peel off the protective film after forming the optical portion and the like, the number of steps can be reduced, and the cost can be reduced because an indirect material such as a peeling liquid is not required.

Further, since the thickness of the base glass bonded to the translucent substrate can be accurately measured with reference to the protective film remaining after forming the optical portion and the like, the focal length of the lens becomes accurate, and the lens effect is improved. Can be increased. Thus, the illuminance of the liquid crystal display device can be increased.

[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 sectional view showing a completed state of the liquid crystal display device.

FIG. 4 is a schematic plan view illustrating a liquid crystal display device.

FIG. 5 is a manufacturing process diagram when a prism is provided.

FIG. 6 is a plan view showing the shape of an alignment mark.

FIG. 7 is a schematic sectional view illustrating a second embodiment.

[Explanation of symbols]

Reference Signs List 1 glass substrate 2 photoresist 3 transparent resin with high refractive index 4 base glass 5 ITO 6 metal film AM alignment mark part P prism R
Lens section

Claims (16)

[Claims] Forming a portion of the surface of the light-transmitting substrate that is covered with a protective film and a portion of the surface of the light-transmitting substrate that is not covered with the protective film and that is exposed; Processing the part where the surface of the light-transmitting substrate is exposed to form an optical part, and until the optical part is completed by the processing.
Completely removing the protective film serving as a mask for forming the optical portion and leaving a protective film not serving as a mask for forming the optical portion. Method. 2. The manufacturing method of an optical substrate according to claim 1, wherein the optical part is filled with a light-transmitting resin having a refractive index different from that of the light-transmitting substrate to form a microlens. Method. 3. The optical substrate according to claim 1, wherein the optical portion is filled with a light-transmitting resin having a refractive index different from that of the light-transmitting substrate to form a microprism. Method. 4. The method according to claim 1, wherein the protective film is made of a photoresist film. 5. The method according to claim 1, wherein the protective film is made of a metal film. 6. The method according to claim 1, wherein the protective film comprises a photoresist film and a metal film. 7. The method according to claim 1, wherein the protective film is made of a light-shielding film. 8. The optical part according to claim 1, wherein the optical part is formed by shaving the exposed part of the surface of the light-transmitting substrate by sandblasting using the protective film as a mask. A method for manufacturing an optical substrate. 9. The optical part according to claim 1, wherein the optical part is formed by spraying ceramic fine particles onto an exposed part of the surface of the light-transmitting substrate by using the protective film as a mask. A method for manufacturing an optical substrate. 10. The alignment mark of the light-transmitting substrate is formed by using a protective film remaining on the surface of the light-transmitting substrate when the optical part is completed. 2. The method for manufacturing an optical substrate according to 1. 11. The method of manufacturing an optical substrate according to claim 8, wherein a step of shaving an exposed portion of the surface of the light-transmitting substrate is performed by using the sandblasting method, and then the surface of the shaved portion is etched. A method for manufacturing an optical substrate, comprising performing the treatment to form the optical portion. 12. The method for manufacturing an optical substrate according to claim 9, wherein the step of spraying the ceramic fine particles onto an exposed portion of the surface of the light-transmitting substrate and shaving is performed, and then etching the surface of the shaved portion. A method for manufacturing an optical substrate, comprising performing the treatment to form the optical portion. 13. The method of manufacturing an optical substrate according to claim 10, wherein a portion forming the alignment mark is filled with a light-transmitting resin having a refractive index different from that of the light-transmitting substrate. 14. A step of forming a portion of the surface of the light-transmitting substrate covered with a light-shielding protective film and a portion of the surface of the light-transmitting substrate that is not covered with the light-shielding protective film and is exposed. Processing a portion where the surface of the light-transmitting substrate is exposed by using a film as a mask to form an optical array region in which a plurality of microlenses or a plurality of microprisms are arranged; and until the processing completes the optical array region. In the meantime, the light-shielding protective film serving as a mask for forming the optical array region is completely removed, and the light-shielding protective film not serving as a mask for forming the optical array region surrounds the periphery of the optical array region. Leaving the optical array area formed on the opposing substrate, and leaving the optical array area formed around the optical array area on the opposing substrate. Overlapping the liquid crystal driving substrate and the opposing substrate so that the light-shielding protective film and the driving circuit provided around the effective pixel area of the liquid crystal driving substrate are opposed to each other; And a step of injecting a liquid crystal therebetween. 15. The method according to claim 14, wherein an alignment mark having a predetermined shape is formed on the light-shielding protective film surrounding the periphery of the optical array region. 16. The optical array region and the alignment mark are filled with a light-transmitting resin having a refractive index different from that of the light-transmitting substrate.
The manufacturing method of the liquid crystal display device according to the above.