JP3835319B2 - Manufacturing method of substrate with recess for microlens, substrate with recess for microlens, microlens substrate, counter substrate for liquid crystal panel, liquid crystal panel, and projection display device - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a method for manufacturing a substrate with concave portions for microlenses in which a large number of concave portions for microlenses are formed on the substrate, a substrate with concave portions for microlenses, a microlens substrate, a counter substrate for liquid crystal panels, a liquid crystal panel, and a projection display It relates to the device.
[0002]
[Prior art]
A projection display device that projects an image on a screen is known.
[0003]
In such a projection display device, a liquid crystal panel (liquid crystal light shutter) is mainly used for image formation.
[0004]
In this liquid crystal panel, for example, a liquid crystal driving substrate (TFT substrate) having a thin film transistor (TFT) for controlling each pixel and a pixel electrode, and a counter substrate for a liquid crystal panel having a black matrix, a common electrode, etc. It is the structure joined via.
[0005]
In the liquid crystal panel having such a configuration (TFT liquid crystal panel), since the black matrix is formed in a portion other than the portion of the counter substrate for the liquid crystal panel, the region of light transmitted through the liquid crystal panel is limited. For this reason, the light transmittance decreases.
[0006]
In order to increase the light transmittance, a counter substrate for a liquid crystal panel is known in which a large number of microlenses are provided at positions corresponding to each pixel. Thereby, the light which permeate | transmits the opposing board | substrate for liquid crystal panels is condensed by the opening formed in the black matrix, and the transmittance | permeability of light increases.
[0007]
In order to form such a microlens, for example, a technique disclosed in JP-A-9-101401 is known as a method for forming a recess in a substrate.
[0008]
However, with such a technique, it is difficult to appropriately manufacture a counter substrate for a liquid crystal panel having excellent characteristics, particularly high light transmission, and thus a liquid crystal panel, from a substrate having a recess for forming a microlens. It is.
[0009]
Further, only the hemispherical lens can be formed by the method using isotropic etching (wet etching). A lens having a small radius of curvature such as a microlens has a large spherical aberration, and a projection transmittance and a projection contrast ratio cannot be sufficiently obtained.
[0010]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a substrate with concave portions for microlenses capable of easily, quickly and reliably providing a substrate with concave portions for microlenses capable of forming an aspherical microlens with reduced spherical aberration. In addition, it is easy to provide a substrate with a concave portion for microlens, a microlens substrate, a counter substrate for liquid crystal panel, a liquid crystal panel, and a projection display device that can form an aspherical microlens with reduced spherical aberration It is to provide quickly and reliably.
[0011]
[Means for Solving the Problems]
Such an object is achieved by the present inventions (1) to (22) below.
[0012]
(1) forming a mask having openings in a predetermined pattern on the substrate;
Next, wet etching is performed using the mask, and after forming a large number of microlens recesses on the substrate,
A method of manufacturing a substrate with concave portions for microlenses that removes the mask,
A concave portion for an aspherical microlens is formed by performing wet etching in multiple stages while increasing the size of the opening of the mask without forming the mask during the wet etching. A method for manufacturing a substrate with concave portions for microlenses.
[0013]
(2) The method for manufacturing a substrate with concave portions for microlenses according to the above (1), wherein the mask is formed by laminating a plurality of mask layers having different opening sizes so that the openings are gradually enlarged. .
[0014]
(3) The method for manufacturing a substrate with concave portions for microlenses according to (2), wherein one of the openings of the adjacent mask layers of the plurality of mask layers is included in the other.
[0015]
(4) The method for manufacturing a substrate with concave portions for microlenses according to (2) or (3), wherein the openings of the plurality of mask layers are concentrically arranged.
[0016]
(5) The microlens according to any one of (2) to (4), wherein the plurality of mask layers have the same thickness and are made of the same material. Of manufacturing a substrate with concave portions for use.
[0017]
(6) forming a mask having openings in a predetermined pattern on the substrate;
Next, wet etching is performed using the mask, and after forming a large number of microlens recesses on the substrate,
A method of manufacturing a substrate with concave portions for microlenses that removes the mask,
The mask is formed on the substrate, has an annular first mask layer having a higher etching rate with respect to an etchant than the substrate, and an opening on the inner peripheral side of the first mask layer, and the substrate And a second mask layer formed over the first mask layer. A method for manufacturing a substrate with concave portions for microlenses.
[0018]
(7) When the etching rate of the first mask layer with respect to the etching solution is a and the etching rate of the substrate with respect to the etching solution is b, the etching rate ratio a / b is 1.1 or more ( The manufacturing method of the board | substrate with a recessed part for microlenses as described in 6).
[0019]
(8) The method for manufacturing a substrate with concave portions for microlenses according to the above (6) or (7), wherein the opening of the second mask layer is disposed at the center of the first mask layer.
[0020]
(9) The method for manufacturing a substrate with concave portions for microlenses according to any one of (6) to (8), wherein a plurality of the first mask layers are provided.
[0021]
(10) One of the adjacent first mask layers of the plurality of first mask layers is included in the other and separated from the other of the substrate with concave portions for microlenses according to (9). Production method.
[0022]
(11) The method for manufacturing a substrate with concave portions for microlenses according to (9) or (10), wherein the plurality of first mask layers are arranged concentrically.
[0023]
(12) The method for manufacturing a substrate with concave portions for microlenses according to any one of (1) to (11), wherein the entire surface is further subjected to wet etching after the mask is removed.
[0024]
(13) The method for manufacturing a substrate with concave portions for microlenses according to any one of (1) to (12), wherein the substrate is a quartz glass substrate.
[0025]
(14) A substrate with concave portions for microlenses, which is manufactured by the method for manufacturing a substrate with concave portions for microlenses according to any one of (1) to (13).
[0026]
(15) A microlens substrate manufactured using the substrate with concave portions for microlenses according to (14) and having a plurality of microlenses.
[0027]
(16) The microlens substrate according to (15), wherein the microlens is a biconvex microlens.
[0028]
(17) The substrate having the first microlens recesses having a plurality of aspherical first microlens recesses and the second having a plurality of aspherical second microlens recesses as described in (14) above. The first microlens concave substrate is joined to the first microlens concave portion via a resin so that the first microlens concave portion and the second microlens concave portion face each other. A microlens substrate comprising a biconvex microlens formed between a substrate with a recess and the second substrate with a recess for a microlens.
[0029]
(18) A counter substrate for a liquid crystal panel, comprising the microlens substrate according to any one of (15) to (17).
[0030]
(19) A liquid crystal panel comprising the counter substrate for a liquid crystal panel according to (18).
[0031]
(20) A liquid crystal driving substrate having a pixel electrode; a liquid crystal panel counter substrate according to (18) bonded to the liquid crystal driving substrate; and a gap between the liquid crystal driving substrate and the liquid crystal panel counter substrate. A liquid crystal panel comprising: a sealed liquid crystal.
[0032]
(21) The liquid crystal panel according to (20), wherein the liquid crystal driving substrate is a TFT substrate.
[0033]
(22) A projection display device comprising the liquid crystal panel according to any one of (19) to (21).
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
[0035]
The substrate with concave portions for microlenses and the microlens substrate of the present invention each include both an individual substrate and a wafer.
[0036]
1 to 7 are schematic longitudinal sectional views showing a manufacturing method of a substrate with concave portions for microlenses, and FIG. 8 is a schematic longitudinal sectional view showing a manufacturing method of a counter substrate for a liquid crystal panel of the present invention. 9 is a schematic longitudinal sectional view showing the counter substrate for a liquid crystal panel of the present invention, and FIG. 10 is a schematic plan view showing the substrate with concave portions for a microlens of the present invention.
[0037]
As shown in FIG. 9, the counter substrate 1 for a liquid crystal panel is bonded to a substrate 2 with concave portions for microlenses and a substrate 2 with concave portions for microlenses via a transparent resin layer 14 having a predetermined refractive index. A cover glass 13, a black matrix 11 formed on the cover glass 13 and having a plurality of (many) openings 111, and a transparent conductive film 12 formed on the cover glass 13 so as to cover the black matrix 11. have. The substrate 2 with concave portions for microlenses is composed of a glass substrate 5 having a plurality of (many) aspherical concave portions (microlens concave portions) 3 formed on the surface. In the resin layer 14, the aspherical microlenses 8 are formed of the resin filled in the concave portions 3 of the substrate 2 with concave portions for microlenses.
[0038]
In the counter substrate 1 for the liquid crystal panel, the black matrix 11 having a light shielding function is provided so as to correspond to the position of the microlens 8. Specifically, the black matrix 11 is provided so that the optical axis Q of the microlens 8 passes through the opening 111 formed in the black matrix 11. Therefore, in the counter substrate 1 for the liquid crystal panel, the incident light L incident from the surface facing the black matrix 11 is collected by the microlens 8 and passes through the opening 111 of the black matrix 11. The transparent conductive film 12 is a transparent electrode and transmits light. For this reason, when the incident light L passes through the counter substrate 1 for a liquid crystal panel, significant attenuation of the amount of light is prevented. That is, the liquid crystal panel counter substrate 1 has a high light transmittance.
[0039]
In the counter substrate 1 for the liquid crystal panel, one microlens 8 and one opening 111 of the black matrix 11 correspond to one pixel.
[0040]
In addition, the board | substrate 2 with a recessed part for microlenses may have other components, such as an antireflection layer, for example.
[0041]
Prior to describing the method for producing a microlens substrate or a counter substrate for a liquid crystal panel according to the present invention, first, a method for producing a substrate with concave portions for microlenses will be described with reference to FIGS.
[0042]
In the present invention, a concave portion for an aspherical lens (aspherical concave portion for a microlens) is formed by performing wet etching using a mask as described in detail later. In practice, a large number of microlens recesses are formed on the substrate. Here, in order to make the description easy to understand, a case where one microlens recess is formed will be described as an example.
[0043]
First, when manufacturing the board | substrate 2 with a recessed part for microlenses, the glass substrate 5 is prepared.
[0044]
The glass substrate 5 is preferably used with a uniform thickness and no deflection or scratches. The glass substrate 5 is preferably one whose surface is cleaned by washing or the like.
[0045]
Further, when the manufactured substrate 2 with concave portions for microlenses is used for manufacturing a liquid crystal panel, and the liquid crystal panel has a glass substrate other than the glass substrate 5, the thermal expansion coefficient of the glass substrate 5 is such a liquid crystal panel. It is preferable that the coefficient of thermal expansion of the other glass substrate is substantially the same. Thus, if the thermal expansion coefficients of the glass substrate 5 and the other glass substrates of the liquid crystal panel are substantially equal, the resulting liquid crystal panel is caused by the difference in thermal expansion coefficient between the two when the temperature changes. Warpage, deflection, etc. are prevented.
[0046]
From this viewpoint, it is preferable that the glass substrate 5 and the other glass substrate included in the liquid crystal panel are made of the same material. This effectively prevents warping, deflection, and the like due to differences in thermal expansion coefficients during temperature changes.
[0047]
In particular, when the manufactured substrate 2 with concave portions for microlenses is used for manufacturing a high-temperature polysilicon TFT liquid crystal panel, the glass substrate 5 is preferably made of quartz glass. The TFT liquid crystal panel has a TFT substrate as a liquid crystal driving substrate. For such a TFT substrate, quartz glass whose characteristics are unlikely to change depending on the manufacturing environment is preferably used. For this reason, by making the glass substrate 5 of quartz glass corresponding to this, it is possible to obtain a TFT liquid crystal panel excellent in stability, which is less likely to be warped or bent.
[0048]
Although the thickness of the glass substrate 5 changes with various conditions, such as the material which comprises the glass substrate 5, and a refractive index, about 0.3-3 mm is preferable normally and about 0.5-2 mm is more preferable. If the thickness is within this range, a compact substrate 2 with concave portions for microlenses having necessary optical characteristics can be obtained.
[0049]
<1> First, as shown in FIG. 1A, a first mask layer 6 is formed on a glass substrate 5. At the same time, a back surface protective layer 69 is formed on the back surface of the glass substrate 5 (the surface opposite to the surface on which the first mask layer 6 is formed). Of course, the first mask layer 6 and the back surface protective layer 69 can be simultaneously formed by using, for example, a CVD method.
[0050]
The first mask layer 6 preferably has resistance to wet etching in step <4> described later.
[0051]
From such a viewpoint, examples of the material constituting the first mask layer 6 include polycrystalline silicon (polysilicon), amorphous silicon, Au / Cr, Au / Ti, Pt / Cr, Pt / Ti, SiC, and the like. These metals, silicon nitride and the like.
[0052]
Among these, polycrystalline silicon is particularly preferable as a material constituting the first mask layer 6. When the first mask layer 6 is made of polycrystalline silicon, a dense layer can be formed on the surface of the glass substrate 5. For this reason, defects such as pinholes are unlikely to occur in the first mask layer 6. Polycrystalline silicon has high adhesion to glass. For this reason, in the step <4> described later, when the microlens is formed by performing wet etching on the glass substrate 5, it becomes difficult for the etching solution to enter the unnecessary portion, and an ideal lens shape is formed. It becomes possible to do. Therefore, by forming the first mask layer 6 from polycrystalline silicon, it is possible to obtain a high-performance microlens recessed substrate 2 with high yield.
[0053]
The thickness of the first mask layer 6 varies depending on the material constituting the mask layer 6, but is preferably about 0.01 to 10 μm when the first mask layer 6 is made of polycrystalline silicon. About 0.2 to 1 μm is more preferable. When the thickness is less than the lower limit of this range, the masked portion of the glass substrate 5 may not be sufficiently protected when performing wet etching in the step <4> described later. The mask layer 6 may be easily peeled off due to the internal stress of one mask layer 6.
[0054]
When the first mask layer 6 is made of polycrystalline silicon, for example, the first mask layer 6 can be suitably formed by a chemical vapor deposition method (CVD method). This is due to monosilane gas (SiH) according to the chemical vapor deposition method. ₄ ) Can react on the surface of the glass substrate 5 to form a polycrystalline silicon film, so that it is effective to generate defects such as pinholes that are likely to occur when the film is formed by sputtering or the like. In addition, it is possible to form a dense and adhesive film.
[0055]
When the first mask layer 6 composed of polycrystalline silicon is formed by the CVD method, the temperature at the time of forming the first mask layer 6 is not particularly limited, but is preferably about 300 to 800 ° C., and preferably 400 to 700 ° C. The degree is more preferable. Moreover, the pressure at the time of the 1st mask layer 6 formation is although it does not specifically limit, About 30-160 Pa is preferable and about 50-100 Pa is more preferable. SiH ₄ Although the supply rate of the gas used as a raw material for forming polycrystalline silicon is not particularly limited, it is preferably about 10 to 500 mL / min, more preferably about 40 to 400 mL / min. If the conditions for forming the polycrystalline silicon layer are within such a range, the first mask layer 6 can be suitably formed.
[0056]
In addition, the back surface protective layer 69 is for protecting the back surface of the glass substrate 5 after the next process. By this back surface protective layer 69, erosion, deterioration, etc. of the back surface of the glass substrate 5 are suitably prevented. The back surface protective layer 69 is made of, for example, the same material as the mask layer 6. For this reason, the back surface protective layer 69 can be provided in the same manner as the mask layer 6 simultaneously with the formation of the mask layer 6.
[0057]
<2> Next, as shown in FIG. 1B, a first opening 61 and a second opening 62 are formed in the first mask layer 6. For example, the first opening 61 and the second opening 62 are formed by applying a resist (for example, a photoresist) corresponding to the first opening 61 and the second opening 62 on the first mask layer 6. Then, a second mask is further applied on the first mask layer 6, and then the first mask layer 6 which is not masked by the second mask is removed, and then the second mask is removed. This can be done.
[0058]
The first mask layer 6 is removed when the first mask layer 6 is made of polycrystalline silicon, for example, dry etching using CF gas, chlorine-based gas, etc., hydrofluoric acid + nitric acid aqueous solution, alkaline aqueous solution, or the like. It can be carried out by immersion in a stripping solution such as (wet etching).
[0059]
Here, the first opening 61 of the first mask layer 6 and the third opening 631 of the second mask layer 63 described later are circular in the illustrated example, but are not limited thereto. Needless to say.
[0060]
<3> Next, as shown in FIG. 1C, a protective layer 7 is formed on the first mask layer 6 where the alignment mark 4 is to be formed.
[0061]
This protective layer 7 corresponds to the shape of the alignment mark 4. The protective layer 7 can be formed not only on the mask layer 6 but also directly on the glass substrate 5. For example, the second opening 62 may be covered with a protective layer 7 as shown in FIG.
[0062]
The protective layer 7 preferably has resistance to the etching solution in step <4> to be described later and the removal of the first mask layer 6 in step <5> to be described later. Thereby, the etching of the part of the first mask layer 6 protected by the protective layer 7 is prevented, and the shape of the alignment mark 4 can be accurately formed. Moreover, it is preferable that the protective layer 7 is comprised with the thin film. When the protective layer 7 is formed of a thin film, the glass substrate 5 can be easily handled in the step <4> and the step <8> described later, and the protective layer 7 can be easily removed in the step <9> described later. It becomes.
[0063]
From this point of view, the protective layer 7 is made of, for example, a metal such as Au / Cr, Au / Ti, Pt / Cr, Pt / Ti, or SiC, a silicon compound such as silicon nitride, a resist such as a negative resist, or a tape. It is preferable to be configured.
[0064]
The protective layer 7 is formed by forming a thin film corresponding to the shape of the alignment mark 4 on the portion where the alignment mark 4 is to be formed, for example, by vapor phase film forming methods such as vapor deposition (mask vapor deposition) and sputtering (mask sputtering). Can be formed.
[0065]
The protective layer 7 is formed on the entire glass substrate 5 so as to cover the mask layer 6, and then a resist corresponding to the shape of the alignment mark 4 is patterned on a portion where the alignment mark 4 is formed, It may be formed by etching or the like.
[0066]
Moreover, you may form the protective layer 7 by sticking the tape etc. which respond | correspond to the shape of the alignment mark 4 to the part which forms the alignment mark 4, for example.
[0067]
<4> Then, wet etching is performed on the glass substrate 5 using the first mask layer 6 to form the first recess 31 as shown in FIG. At this time, the glass substrate 5 is etched from a portion where the first mask layer 6 and the protective layer 7 are not present, that is, from the first opening 61. For this reason, the 1st recessed part 31 is formed in the part in which the 1st opening 61 was provided.
[0068]
When the wet etching method is used, the first recess 31 can be suitably formed. When etching is performed by a wet etching method, the glass substrate 5 can be selectively etched by using an etchant containing hydrofluoric acid (hydrofluoric acid-based etchant), and the recess 3 is preferably formed. Can do.
[0069]
In addition, wet etching can be performed with a simpler apparatus than dry etching, and more substrates can be processed at one time. Thereby, productivity improves and the board | substrate 2 with a recessed part for microlenses can be provided cheaply.
[0070]
<5> Next, as shown in FIG. 2E, the first mask layer 6 is removed. When the first mask layer 6 and the like are made of polycrystalline silicon, for example, dry etching with CF gas, chlorine gas, etc., immersion in a stripping solution such as hydrofluoric acid + nitric acid aqueous solution, alkaline aqueous solution (wet etching) Etc. At this time, the portion where the protective layer 7 is formed is protected by the protective layer 7, so the first mask layer 6 is not removed and remains on the glass substrate 5.
[0071]
<6> Next, after removing the first mask layer 6, a third opening 631 larger than the first opening 61 is formed on the first recess 31 as shown in FIG. A second mask layer 63 having the same is formed concentrically with the first opening 61.
[0072]
As the material of the second mask layer 63, the same material as that of the first mask layer 6 described above can be used. Further, the formation of the second mask layer 63 and the formation of the third opening 631 in the second mask layer 63 are the same as the formation of the first mask layer 6 and the first mask layer 6 described above. This can be performed in the same manner as the formation of the first opening 61.
[0073]
<7> Then, the glass substrate 5 is wet-etched using the second mask layer 63 to form the recesses 3 as shown in FIGS. Here, of the concave portion 3 formed by the second etching, the radius of curvature r of the portion near the center, that is, the portion where the first concave portion 31 was formed in advance. ₁ Becomes larger and the radius of curvature r near the periphery ₂ Becomes smaller. However, since the initial hole gradually increases and the center of etching moves to the peripheral edge, the radius of curvature gradually increases toward the peripheral edge. The outermost peripheral portion having a small radius of curvature overlaps with the adjacent lens and almost disappears. Thus, the recess 3 is a recess suitable for an aspheric lens.
[0074]
In addition, although the convex part generate | occur | produces in the boundary part of the curved surface from which a curvature differs from the difference in curvature, there exists a tendency which becomes smooth from the characteristic of wet etching. However, it is preferable to smooth the entire curved surface by further performing wet etching after the second mask layer 63 is peeled off in step <8> described later.
[0075]
<8> Next, as shown in FIG. 3H, the second mask layer 63 is removed. At this time, the back surface protective layer 69 is also removed together with the removal of the second mask layer 63.
[0076]
<9> Next, the protective layer 7 is removed.
Although this depends on the constituent material of the protective layer 7, for example, when the protective layer 7 is made of Au / Cr or the like, it may be performed by wet etching or the like using a mixed solution of hydrochloric acid and nitric acid as a stripping solution. it can. When the protective layer 7 is made of silicon nitride or the like, the protective layer 7 can be removed by wet etching or the like using phosphoric acid or the like as a stripping solution. Moreover, when the protective layer 7 is comprised with the tape etc., the protective layer 7 can be removed by peeling this tape. Thereby, as shown in FIG. 3 (i), the portion of the first mask layer 6 protected by the protective layer 7 remains as the alignment mark 4.
[0077]
As a result, as shown in FIG. 3 (i), the aspherical recess 3 is formed on the glass substrate 5. Actually, as shown in FIG. 10, a large number of recesses 3 are formed on the glass substrate 5.
[0078]
In this way, by performing wet etching in multiple stages using a plurality of masks having different opening sizes, it is possible to make a difference in the curvature radius between the central portion and the peripheral portion of the concave portion 3, and for aspherical lenses. The substrate 2 with concave portions for microlenses provided with concave portions can be formed.
[0079]
Since the substrate 2 with concave portions for microlenses is provided with a concave portion for aspherical lenses, the aspherical lens formed using the substrate 2 with concave portions for microlenses has reduced spherical aberration. . A microlens substrate or a counter substrate for a liquid crystal panel using the substrate with concave portions for microlenses of the present invention described later has high light utilization efficiency and excellent optical characteristics.
[0080]
In the above description, the case where etching is performed in two stages using two masks having different opening sizes has been described as an example. However, the number of times is not limited to this, and the number of times is not less than three (three stages). There may be. If the number of masks to be used, that is, the number of wet etching performed while increasing the opening of the mask is increased, a smoother lens concave portion can be formed.
[0081]
In the above description, the glass substrate 5 is used as the substrate of the microlens-concave substrate 2. However, in the present invention, the constituent material of the substrate is not limited to glass. It may be.
[0082]
The alignment mark 4 (see FIG. 10) formed on the microlens recessed substrate 2 is used as a positioning index when the liquid crystal panel counter substrate 1 is manufactured.
[0083]
The formation position of the alignment mark 4 is not particularly limited. For example, the alignment mark 4 can be formed outside the formation region of the recess 3 as shown in FIG.
[0084]
It is preferable to provide a plurality of alignment marks 4 on the substrate 2 with concave portions for microlenses. In particular, it is preferable to provide a plurality of alignment marks 4 at corners of the substrate 2 with concave portions for microlenses. Thereby, positioning can be performed more easily.
[0085]
FIG. 10 shows an example in which the alignment mark 4 has a cross shape. The shape of the alignment mark 4 is not particularly limited, but it is preferable that the alignment mark 4 has corner portions 41 that form corners as shown in FIG. Thus, when the alignment mark 4 has the corner | angular part 41, positioning can be performed more correctly.
[0086]
Furthermore, as shown in FIG. 10, it is preferable that the alignment mark 4 has a mark (circular second opening 62 in FIG. 10) indicating its central portion. Thereby, the positioning accuracy can be further improved.
[0087]
In the above-described method, the protective layer 7 is formed on the glass substrate 5 (see step <3> above) and then the recess 3 is formed (see step <4> above). For example, the protective layer 7 is formed. The recess 3 may be formed before the protective layer 7 is formed. That is, the protective layer 7 may be formed after the recess 3 is formed.
[0088]
In the method described above, the alignment mark is provided by forming a layer on the glass substrate 5. However, the alignment mark may not be formed as a layer on the glass substrate 5. For example, a recess having a shape different from that of the recess 3 may be provided on the glass substrate 5 as an alignment mark. For example, the second opening 62 is formed so as to correspond to the shape of the depression (alignment mark) in the step <2>, and then the protective layer 7 is not formed (the step <3 It can be provided by etching the glass substrate 5 (without performing the above step <4>).
[0089]
However, when the alignment mark 4 is formed as described above, the mask layer 6 constituting the alignment mark 4 and the glass substrate 5 in the vicinity of the alignment mark 4 are prevented from being eroded. It becomes easy to form accurately, and the accuracy in positioning can be improved.
[0090]
Thus, the alignment mark 4 can be formed without significantly increasing the number of processes by forming the alignment mark 4 in the middle of the process of forming the recess 3 by etching.
[0091]
This alignment mark 4 can be used for various positioning when assembling various types using the substrate 2 with concave portions for microlenses. For example, when manufacturing the counter substrate 1 for a liquid crystal panel having the black matrix 11 using the substrate 2 with concave portions for microlenses, the black matrix 11 is used as an index of the concave portions 3, that is, the microlenses 8. It can be positioned at the corresponding position.
[0092]
As a mask configuration and formation method in the present invention, for example, a method of laminating a plurality of masks having different opening sizes, or two types of masks having different etching rates are alternately formed concentrically. Methods and the like.
[0093]
Hereafter, these methods are demonstrated regarding the manufacturing method of the board | substrate with a recessed part for microlenses of this invention. In the following description, descriptions of the protective layer 7 for forming the alignment mark 4 and the back surface protective layer 69 are omitted, but both can be formed by the same method as described above.
[0094]
First, a method of performing multistage wet etching by laminating a plurality of masks will be described with reference to FIGS. Here, an example will be described in which three masks having different opening sizes are stacked and wet etching is performed in three stages.
[0095]
<A1> First, as shown in FIG. 4J, a first mask layer 641 and a second mask layer 642 each having substantially circular openings 611, 612, and 613 having different sizes on the glass substrate 5, respectively. The third mask layer 643 is concentrically stacked in this order to form a stacked mask 64.
[0096]
At this time, the first mask layer 641, the second mask layer 642, and the third mask layer 643 are formed to have the same thickness.
[0097]
In addition, the size of the opening of each mask layer increases in the order of the opening 611, the opening 612, and the opening 613, and one of the adjacent openings is included in the other. That is, the opening 611 is included in the opening 612, and the opening 612 is included in the opening 613.
[0098]
As materials and forming methods of the first to third mask layers 641 to 643 having the openings 611 to 613, conventionally known materials and forming methods can be adopted including the materials and forming methods described above. Specifically, for example, each mask layer may be formed by a photolithography technique.
[0099]
Needless to say, the shapes of the openings 611 to 613 are not limited to circular shapes.
[0100]
<A2> Then, as shown in FIG. 4K, the first recess 32 is formed by performing wet etching on the glass substrate 5 using the laminated mask 64. At this time, the glass substrate 5 is etched from a portion not covered with the laminated mask 64, that is, a portion of the opening 611.
[0101]
<A3> Next, as shown in FIG. 4L, the first mask layer 641 exposed from the opening 612 of the second mask layer 642 is removed, and the opening is replaced by the second mask layer 642. The size of the opening 612 is increased.
[0102]
Specifically, the entire stacked mask 64 is etched by the thickness of the first mask layer 641. As a result, the first mask layer 641 exposed from the opening 612 of the second mask layer 642 is removed, whereby the opening of the stacked mask 64 becomes the opening 612 of the second mask layer 642. It will spread to the size.
[0103]
Since the first to third mask layers have the same thickness, the third mask layer 643 is simultaneously removed at this time. In addition, the second mask layer 642 exposed from the opening 613 of the third mask layer 643 is also removed. As a result, the opening 612 of the second mask layer 642 expands to the size of the opening 613 that the third mask layer 643 had.
[0104]
<A4> Then, wet etching is performed on the glass substrate 5 using the laminated mask 64, thereby forming the second recess 33 as shown in FIG. At this time, in the second recess 33, the radius of curvature near the center is large and the radius of curvature near the periphery is small.
[0105]
<A5> Next, as shown in FIG. 5 (n), the first mask layer 641 exposed from the opening 612 of the second mask layer 642 is removed, and the opening has a third mask layer. The size of the opening 613 is expanded.
[0106]
Specifically, the entire stacked mask 64 is etched by the thickness of the first mask layer 641. As a result, the first mask layer 641 exposed from the opening 612 of the second mask layer 642 is removed, whereby the opening of the stacked mask 64 becomes the size of the opening 612 of the second mask layer 642, that is, First, the third mask layer 643 expands to the size of the opening 613. At this time, the second mask layer 642 is also removed at the same time.
[0107]
<A6> Then, the glass substrate 5 is wet-etched using the laminated mask 64, thereby forming the recesses 3 as shown in FIG. Of the recesses 3 formed in this way, the radius of curvature near the center increases, and the radius of curvature decreases toward the periphery.
[0108]
As described above, the concave portion for the aspheric lens is formed. Finally, after removing the first mask layer 641, it is preferable that the entire curved surface is smoothed by further wet etching.
[0109]
According to the method using the laminated mask 64, there is no step of forming a mask layer in the middle, so that the recess 3 can be formed on the glass substrate 5 more easily and quickly.
[0110]
In the present invention, two masks having different opening sizes may be formed in layers, and wet etching may be performed in two stages, or four or more masks having different opening sizes may be formed in layers. Wet etching may be performed in four or more stages.
[0111]
Next, a method of performing multistage wet etching by alternately forming two types of masks having different etching rates with respect to the etching solution in a concentric manner will be described with reference to FIGS. Here, a case where wet etching is performed in three stages will be described as an example.
[0112]
<B1> First, two annular first mask layers 651 and 652 having different sizes are formed concentrically at a predetermined interval on the glass substrate 5.
[0113]
That is, the inner diameter of the first mask layer 652 is made larger than the outer diameter of the first mask layer 651, and the two first mask layers 651 and 652 are arranged concentrically. Accordingly, one mask layer 651 of the two adjacent first mask layers 651 and 652 is included in the other mask layer 652 and is separated from the inner periphery of the other mask layer 652.
[0114]
As a method for forming the first mask layers 651 and 652, a conventionally known forming method can be adopted, including the above-described forming method. Note that, as will be described in detail later, the sizes of the outer circumferences of the first mask layer 651 and the first mask layer 652 are the sizes of the openings of the mask at the time of etching in the second stage and the third stage, respectively. Equivalent to.
[0115]
Next, as shown in FIG. 6P, a second mask layer 653 is formed over the glass substrate 5 and the first mask layers 651 and 652. Next, a substantially circular opening 614 is formed in the second mask layer 653. The opening 614 is formed on the inner peripheral side of the first mask layer 651, that is, in a portion corresponding to the center portion of the first mask layers 651 and 652.
[0116]
As the formation method of the second mask layer 653, a conventionally known formation method can be adopted including the above-described formation method.
[0117]
In this manner, the inner periphery side of the first mask layer 651, the first mask layer 651, between the first mask layer 651 and the first mask layer 652, and the first mask layer 652. A second mask layer 653 is formed on the upper side and on the outer peripheral side of the first mask layer 652, respectively. In the thickness portions of the first mask layers 651 and 652, the first mask layers 651 and 652 The second mask layers 653 are alternately arranged concentrically.
[0118]
Here, the first mask layers 651 and 652 and the second mask layer 653 have significantly different etching rates with respect to the etchant, and the etching rates of the first mask layers 651 and 652 are the same as those of the second mask layer 653. It is much larger than the etching rate.
[0119]
That is, the second mask layer 653 is a portion that functions as a mask, and is configured so that the etching rate with respect to the etching solution is smaller (preferably far smaller) than that of the glass substrate 5.
[0120]
As the material of the second mask layer 653, conventionally known materials can be used including the above-described materials.
[0121]
On the other hand, the first mask layers 651 and 652 are configured so that the etching rate with respect to the etchant is larger (preferably much larger) than that of the glass substrate 5.
[0122]
When the etching rate of the first mask layers 651 and 652 with respect to the etching solution is a and the etching rate of the glass substrate 5 with respect to the etching solution is b, the ratio a / b of the etching rate is preferably as large as possible.
[0123]
That is, the etching rate ratio a / b is preferably 1.1 or more, more preferably 1.5 or more, and even more preferably about 2 to 10.
[0124]
Thereby, in the wet etching described later, when the etching of the glass substrate 5 proceeds and the etching solution comes into contact with the first mask layers 651 and 652, the first mask layers 651 and 652 are respectively attached to the glass substrate 5 Since the size of the mask opening quickly reaches the size of the next stage, the recesses 3 can be formed in the glass substrate 5 with higher accuracy.
[0125]
Examples of the material constituting the first mask layers 651 and 652 include metals such as Au, Pt, Cr, and Ti, and metal film stacks such as Au / Cr, Au / Ti, Pt / Cr, and Pt / Ti. Body, SiO ₂ Oxides, various resist materials, polyimides, acrylic resins, epoxy resins, etc. ₂ Sputtered film, SiO ₂ CVD film, SiO ₂ A TEOS film or the like is preferable.
[0126]
Needless to say, the shapes of the first mask layers 651 and 652 are not limited to an annular shape.
[0127]
<B2> Next, wet etching is performed on the glass substrate 5 using the concentric mask 65 formed as described above, thereby forming the first recess 34 as shown in FIG. 6 (q). At this time, the glass substrate 5 is etched from a portion not covered with the concentric mask 65, that is, a portion of the opening 614. In addition, the second mask layer 653 having a low etching rate is hardly etched and functions as a mask.
[0128]
<B3> Then, when the etching of the glass substrate 5 proceeds and the first concave portion 34 becomes larger than the inner periphery of the first mask layer 651 as shown in FIG. The etching solution comes into contact with 651. Then, the first mask layer 651 having a high etching rate is etched at a relatively high speed. On the other hand, as described above, the second mask layer 653 having a small etching rate is hardly etched. Thus, only the first mask layer 651 is etched and removed due to the difference in etching rate between the first mask layer 651 and the second mask layer 653. Then, as shown in FIG. 6 (r), a gap 651 ′ is formed between the portion where the first mask layer 651 is disposed, that is, between the glass substrate 5 and the second mask 653.
[0129]
Then, the etchant enters the gap 651 ′, and the glass substrate 5 in the portion masked by the first mask layer 651 starts to be etched. That is, since the first mask layer 651 is etched and removed, the opening of the concentric mask 65 is the same as that of the outer periphery of the first mask layer 651.
[0130]
<B4> Further, wet etching is performed on the glass substrate 5 to form the second recess 35 as shown in FIG. At this time, in this second recess 35, the radius of curvature near the center is increased and the radius of curvature near the periphery is decreased.
[0131]
<B5> Similarly, the etching of the glass substrate 5 proceeds and the second concave portion 35 becomes large. As shown in FIG. 7 (t), the second concave portion 35 is formed in the first mask layer 652. When larger than the circumference, the etchant comes into contact with the second mask layer 652. Then, the first mask layer 652 having a high etching rate is etched at a relatively high speed. On the other hand, as described above, the second mask layer 653 having a small etching rate is hardly etched. Thus, only the first mask layer 652 is etched and removed, and as shown in FIG. 7 (t), the portion where the first mask layer 652 is disposed, that is, the glass substrate 5 and the second mask layer A gap 652 ′ is formed between the mask 653 and the mask 653.
[0132]
Then, the etchant enters the gap 652 ′, and the glass substrate 5 in the portion masked by the first mask layer 652 starts to be etched. That is, since the first mask layer 652 is etched and removed, the opening of the concentric mask 65 is expanded to the outer peripheral portion of the first mask layer 652.
[0133]
<B6> Further, wet etching is performed on the glass substrate 5 to form the recess 3 as shown in FIG. Of the recesses 3 formed in this way, the radius of curvature near the center increases, and the radius of curvature decreases toward the periphery.
[0134]
As described above, the concave portion for the aspheric lens is formed. Finally, after removing the second mask layer 653, it is preferable to further wet-etch the entire curved surface.
[0135]
According to the method using the concentric mask 65, there is no process of forming a mask layer and a process of removing the mask layer in the middle, so that the recess 3 can be formed on the glass substrate 5 more easily and quickly.
[0136]
In the present invention, one first mask layer may be provided and wet etching may be performed in two stages, or three or more first mask layers may be provided and wet etching may be performed in four stages or more. Good.
[0137]
Hereinafter, a method of manufacturing the microlens substrate and the liquid crystal panel counter substrate 1 using the microlens recessed substrate 2 will be described with reference to FIG.
[0138]
In addition to the counter substrate for liquid crystal panels and the liquid crystal panel described below, the substrate with concave portions for microlenses and the microlens substrate of the present invention include, for example, various electro-optical devices such as CCDs and optical communication elements, and other devices. It goes without saying that it can be used for the above.
[0139]
<10> First, as shown in FIG. 8 (v), the cover glass 13 is bonded to the surface on which the concave portion 3 of the substrate with concave portions 2 for microlenses is formed via an adhesive.
[0140]
When this adhesive is cured (solidified), a resin layer (adhesive layer) 14 is formed. As a result, the microlens 8 made of the resin filled in the recess 3 and functioning as a convex lens is formed in the resin layer 14.
[0141]
For this adhesive, an optical adhesive having a refractive index higher than the refractive index of the glass substrate 5 (for example, about n = 1.60) is preferably used.
[0142]
<11> Next, as shown in FIG. 8 (w), the cover glass 13 is made thinner.
[0143]
This can be performed by, for example, grinding, polishing, etching, or the like on the cover glass 13.
[0144]
The thickness of the cover glass 13 is preferably about 10 to 1000 μm and more preferably about 20 to 150 μm from the viewpoint of obtaining the counter substrate 1 for liquid crystal panel having necessary optical characteristics.
[0145]
In addition, this process does not need to be performed when the laminated cover glass 13 is the optimal thickness for performing the subsequent processes.
[0146]
<12> Next, as shown in FIG. 8 (x), the black matrix 11 having the openings 111 is formed on the cover glass 13.
[0147]
At this time, the black matrix 11 is formed so that the optical axis Q of the microlens 8 passes through the opening 111 of the black matrix 11 so as to correspond to the position of the microlens 8 (see FIG. 9).
[0148]
The black matrix 11 is composed of, for example, a metal film such as Cr, Al, Al alloy, Ni, Zn, or Ti, a resin layer in which carbon, titanium, or the like is dispersed. Among these, the black matrix 11 is preferably composed of a Cr film or an Al alloy film. When the black matrix 11 is composed of a Cr film, it is possible to obtain the black matrix 11 having excellent light shielding properties. Moreover, when the black matrix 11 is comprised with Al alloy film, the opposing board | substrate 1 for liquid crystal panels which has the outstanding heat dissipation is obtained.
[0149]
The thickness of the black matrix 11 is preferably about 0.03 to 1.0 μm, more preferably about 0.05 to 0.3 μm, from the viewpoint of suppressing the influence on the flatness of the counter substrate 1 for liquid crystal panel.
[0150]
The black matrix 11 in which the openings 111 are formed can be formed as follows, for example. First, a thin film to be the black matrix 11 is formed on the cover glass 13 by a vapor deposition method such as sputtering. Next, a resist film is formed on the thin film to be the black matrix 11. Next, using the alignment mark 4 as an index, the resist film is exposed to form a pattern of the opening 111 on the resist film so that the opening 111 of the black matrix 11 comes to a position corresponding to the microlens 8 (recess 3). To do. Next, wet etching is performed to remove only the portion of the thin film that becomes the opening 111. Next, the resist film is removed. In addition, as a peeling liquid at the time of performing wet etching, for example, when the thin film to be the black matrix 11 is made of an Al alloy or the like, a phosphoric acid-based etching liquid can be used.
[0151]
Note that the black matrix 11 in which the opening 111 is formed can also be suitably formed by dry etching using a chlorine-based gas or the like.
[0152]
<13> Next, a transparent conductive film (common electrode) 12 is formed on the cover glass 13 so as to cover the black matrix 11.
[0153]
As a result, it is possible to obtain a liquid crystal panel counter substrate 1 or a wafer on which a plurality of liquid crystal panel counter substrates 1 can be obtained.
[0154]
The transparent conductive film 12 is made of, for example, indium tin oxide (ITO), indium oxide (IO), tin oxide (SnO). ₂ ) Etc.
[0155]
The thickness of the transparent conductive film 12 is preferably about 0.03 to 1 μm, and more preferably about 0.05 to 0.30 μm.
[0156]
This transparent conductive film 12 can be formed by sputtering, for example.
[0157]
<14> Finally, the wafer of the counter substrate 1 for the liquid crystal panel is cut into a predetermined shape and size (for example, as indicated by a one-dot chain line in FIG. 10) using a dicing apparatus or the like.
[0158]
Thereby, the counter substrate 1 for a liquid crystal panel as shown in FIG. 9 can be obtained. Since the microlens 8 included in the counter substrate 1 for the liquid crystal panel is an aspheric lens, spherical aberration is suppressed and excellent optical characteristics are obtained.
[0159]
In addition, this process does not need to be performed, when it is not necessary to cut, such as when the counter substrate 1 for liquid crystal panels is obtained by the said process <13>.
[0160]
In the embodiment described above, the alignment mark 4 is formed outside the region where the concave portion 3 of the substrate with concave portions 2 for microlenses is formed. However, the alignment mark 4 may be formed within the region where the concave portion 3 is formed. Needless to say.
[0161]
When manufacturing the counter substrate for a liquid crystal panel, for example, the transparent conductive film 12 may be formed directly on the cover glass 13 without forming the black matrix 11.
[0162]
In the above-described embodiment, the alignment mark 4 is used for positioning the black matrix 11. However, when the counter substrate 1 for liquid crystal panel or its wafer has other components, the alignment mark 4 is positioned. You may use for.
[0163]
Further, the alignment mark 4 may be used for positioning other substrates than the components of the counter substrate 1 for the liquid crystal panel, for example, other substrates such as a TFT substrate (liquid crystal driving substrate).
[0164]
In the description of the manufacturing method of the counter substrate 1 for the liquid crystal panel, the resin 14 is filled in the recess 3 of the substrate 2 with the microlens recess and sandwiched between the cover glasses 13, and the microlens 8 is configured by the resin 14. Although the case has been described as an example, a microlens substrate can be manufactured by a 2P method (photopolymerization) using the substrate 2 with concave portions for microlenses as a mold.
[0165]
Hereinafter, a method for manufacturing a microlens substrate by the 2P method will be described with reference to FIGS.
[0166]
First, as shown to Fig.11 (a), the board | substrate 2 with the concave part for microlenses in which the recessed part 3 for microlenses manufactured by this invention was formed is prepared. In this method, the substrate 2 with concave portions for microlenses formed with the concave portions 3 is used as a mold. The microlenses 8 are formed by filling the recesses 3 with resin. For example, a release agent may be applied to the inner surface of the recess 3. The substrate 2 with concave portions for microlenses is placed so that, for example, the concave portions 3 are opened vertically upward.
[0167]
<C1> Next, an uncured resin that constitutes the microlens 8 is supplied onto the substrate 2 with a concave portion for a microlens in which the concave portion 3 is formed.
<C2> Next, the transparent substrate 51 is bonded to the resin and pressed and adhered.
[0168]
<C3> Next, the resin is cured. This curing method is appropriately selected depending on the type of resin, and examples include ultraviolet irradiation, heating, and electron beam irradiation.
[0169]
Thereby, as shown in FIG. 11B, the microlens 8 is formed by the resin 141 filled in the recess 3.
[0170]
<C4> Next, as shown in FIG. 11 (c), the substrate 2 with concave portions for microlenses, which is a mold, is removed from the microlenses 8.
[0171]
<C5> Next, as shown in FIG. 12, for example, after setting the transparent substrate 51 so that the microlens 8 faces vertically upward, the uncured resin that will form the resin layer 142 is replaced with the microlens 8. Feed on. Examples of the supply method include a coating method such as spin coating, and a 2P method using a flat plate mold.
[0172]
<C6> Next, as shown in FIG. 13, a glass substrate (glass layer) 52 is bonded to the resin and pressed and adhered, and then the resin is cured to form a resin layer 142.
[0173]
<C7> Thereafter, the thickness of the glass substrate 52 may be adjusted by grinding, polishing, or the like, if necessary.
Thereby, a microlens substrate as shown in FIG. 13 is obtained.
[0174]
Thereafter, in the same manner as described above, a counter substrate for liquid crystal panel can be obtained by forming a black matrix, a transparent conductive film, or the like on the glass substrate 52.
[0175]
In the above description, a microlens substrate including a planoconvex lens (planoconvex microlens) configured using a single microlens concave substrate is used. However, the present invention is not limited to this.
[0176]
Hereinafter, a microlens substrate including a biconvex lens (biconvex microlens) configured using two microlens recessed substrates will be described.
[0177]
FIG. 14 is a schematic longitudinal sectional view showing an embodiment of the microlens substrate.
[0178]
As shown in the figure, the microlens substrate includes a first substrate 21 with concave portions for microlenses (first substrate) 21 and a second substrate with concave portions for microlenses (second substrate) manufactured according to the present invention. Substrate) 22, resin layer 14, microlens 8, and spacer 9.
[0179]
The first substrate 21 with concave portions for microlenses has a plurality of (many) first concave portions (microlenses) having an aspheric concave curved surface (lens curved surface) on a first glass substrate (first transparent substrate) 53. For this reason, a concave portion 36 and a first alignment mark 42 are formed.
[0180]
The second substrate 22 with concave portions for microlenses has a plurality of (many) second concave portions (microlenses) each having an aspheric concave curved surface (lens curved surface) on a second glass substrate (second transparent substrate) 54. For this purpose, a concave portion 37) and a second alignment mark 43 are formed.
[0181]
The microlens substrate has a first microlens recessed substrate 21 and a second microlens recessed substrate 22 so that the first recessed portion 36 and the second recessed portion 37 face each other. It is the structure joined through the resin layer (adhesive layer) 14. Further, in this microlens substrate, filling is performed between the first concave portion 36 and the second concave portion 37 between the first microlens concave portion substrate 21 and the second microlens concave portion substrate 22. The formed resin constitutes a microlens 8 made of an aspherical biconvex lens.
[0182]
This microlens substrate has two areas, an effective lens area 99 and an ineffective lens area 100. The effective lens region 99 refers to a region in which the microlens 8 formed of the resin filled in the first recess 36 and the second recess 37 is effectively used as a microlens during use. On the other hand, the ineffective lens region 100 is a region other than the effective lens region 99.
[0183]
Such a microlens substrate is used, for example, by allowing light L to enter from the first microlens concave substrate 21 side and emitting light L from the second microlens concave substrate 22 side. .
[0184]
If the microlens 8 is formed of a convex lens like this microlens substrate, the aberration (particularly spherical aberration) of the microlens 8 is further reduced. For this reason, not only the vicinity of the center of the microlens 8 but also the incident light L incident on the vicinity of the edge of the microlens 8 is suitably condensed by the microlens 8. That is, the light utilization efficiency of the microlens 8 is high. Therefore, this microlens substrate can emit outgoing light L having high luminance.
[0185]
In addition, when the aberration of the microlens 8 is reduced, it is possible to suitably prevent the outgoing light from being emitted in a direction significantly deviated from the optical axis of the microlens 8. For this reason, when the microlens substrate is used for the liquid crystal panel, it is possible to suitably prevent the outgoing light that has passed through the microlens 8 from entering the adjacent pixels. That is, crosstalk is prevented between pixels. Therefore, when an image is formed using a liquid crystal panel provided with this microlens substrate, the luminance of black is extremely low.
[0186]
Since the microlens substrate having the above-described configuration has such advantages, when an image is formed using a liquid crystal panel including the microlens substrate, black is darker and white is brighter. Therefore, in a liquid crystal panel provided with a microlens substrate, a high contrast ratio can be obtained and a more beautiful image can be formed.
[0187]
And such a microlens board | substrate can be manufactured as follows, for example. Hereinafter, a method for manufacturing a microlens substrate will be described with reference to FIGS.
[0188]
When the microlens substrate is manufactured, first, the first substrate 21 with concave portions for microlenses and the second substrate 22 with concave portions for microlenses manufactured according to the present invention are prepared.
[0189]
When manufacturing the second substrate 22 with concave portions for microlenses, at least one of the area of the opening formed in the mask or the etching conditions (for example, etching time, etching temperature, etching solution composition, etc.) By making it different from the conditions for manufacturing the substrate 21 with concave portions for one microlens, the aspherical shape (for example, the radius of curvature) of the first concave portion 36 and the aspherical shape of the second concave portion 37 are changed. It may be different. By making the aspherical shape of the first concave portion 36 different from the aspherical shape of the second concave portion 37, aberration can be effectively reduced.
[0190]
<D1> First, as shown in FIG. 15, a predetermined refractive index (1) is formed so as to cover at least the effective lens region 99 on the surface of the first substrate 21 with concave portions for microlenses formed on the first concave portion 36. In particular, an uncured resin 143 having a refractive index higher than that of the first glass substrate 53 and the second glass substrate 54 is supplied, and the first recess 36 is filled with the resin 143. At this time, the uncured resin 144 including the spacers 9 is supplied onto the first substrate 21 with concave portions for microlenses. The resin 144 is supplied to a portion where the spacer 9 is installed, for example.
[0191]
The resin 143 and the resin 144 are preferably made of the same type of material. Thereby, in the microlens substrate to be manufactured, it is suitably prevented that the resin 143 and the resin 144 have different thermal expansion coefficients, thereby causing warpage, deflection, and the like.
[0192]
When the resin 143 is supplied onto the first substrate 21 with concave portions for microlenses, if the spacers 9 are dispersed in the resin 144, the spacers 9 can be easily disposed uniformly. Thereby, the thickness nonuniformity of the resin layer 14 formed is suppressed suitably.
[0193]
<D2> Next, as shown in FIG. 15, the second substrate 22 with a concave portion for microlens (a counterpart) 22 is placed on the resin 143 and the resin 144 (the second substrate 22 with a concave portion for microlens is made of resin). In close contact).
[0194]
At this time, the second substrate 22 with concave portions for microlenses is placed on the resin so that the first concave portion 36 and the second concave portion 37 face each other. At this time, the second substrate 22 with concave portions for microlenses is placed on the resin so that the second substrate 22 with concave portions for microlenses contacts the spacer 9. Thus, the distance between the opposing end surfaces of the first microlens concave substrate 21 and the second microlens concave substrate 22 is defined by the spacer 9. Therefore, the edge thickness and the maximum thickness of the microlens 8 are defined with high accuracy.
[0195]
<D3> Next, the first recess 36 and the second recess 37 are aligned using the first alignment mark 42 and the second alignment mark 43. As a result, the second recess 37 can be accurately positioned at a position corresponding to the first recess 36. For this reason, the shape and optical characteristics of the formed microlens 8 become closer to the design values.
[0196]
<D4> Next, the resin layer 143 is formed by curing the resin 143 and the resin 144.
[0197]
As a result, the second substrate 22 with concave portions for microlenses is bonded to the first substrate 21 with concave portions for microlenses via the resin layer 14. Further, among the resins constituting the resin layer 14, the microlens 8 is formed by a resin filled between the first recess 36 and the second recess 37. The resin can be cured by, for example, irradiating the resin with ultraviolet rays or an electron beam, or heating the resin.
[0198]
<D5> Thereafter, as shown in FIG. 16, the thickness of the second substrate 22 with concave portions for microlenses may be adjusted by grinding, polishing, or the like, as necessary.
[0199]
Thereby, a microlens substrate having a biconvex lens as shown in FIG. 14 can be obtained.
[0200]
Thereafter, the liquid crystal panel counter substrate 1 can be obtained by forming a black matrix, a transparent conductive film, or the like on the second glass substrate 54 in the same manner as described above.
[0201]
Next, a liquid crystal panel (liquid crystal optical shutter) using the counter substrate 1 for liquid crystal panel shown in FIG. 9 will be described with reference to FIG.
[0202]
As shown in FIG. 17, the liquid crystal panel (TFT liquid crystal panel) 16 of the present invention includes a TFT substrate (liquid crystal drive substrate) 17, a counter substrate 1 for liquid crystal panel bonded to the TFT substrate 17, a TFT substrate 17 and a liquid crystal. And a liquid crystal layer 18 made of liquid crystal sealed in a gap with the counter substrate 1 for a panel.
[0203]
The TFT substrate 17 is a substrate for driving the liquid crystal of the liquid crystal layer 18. The TFT substrate 17 is provided in the vicinity of the glass substrate 171, a large number of pixel electrodes 172 provided on the glass substrate 171, and the pixel electrodes 172. A number of thin film transistors (TFTs) 173 corresponding to the pixel electrodes 172 are provided.
[0204]
In this liquid crystal panel 16, the TFT substrate 17 and the liquid crystal panel counter substrate 1 are arranged so that the transparent conductive film (common electrode) 12 of the liquid crystal panel counter substrate 1 and the pixel electrode 172 of the TFT substrate 17 face each other. They are joined at a certain distance.
[0205]
The glass substrate 171 is preferably made of quartz glass for the reasons described above.
[0206]
The pixel electrode 172 drives the liquid crystal of the liquid crystal layer 18 by charging and discharging with the transparent conductive film (common electrode) 12. The pixel electrode 172 is made of, for example, the same material as that of the transparent conductive film 12 described above.
[0207]
The thin film transistor 173 is connected to the corresponding pixel electrode 172 in the vicinity. The thin film transistor 173 is connected to a control circuit (not shown) and controls a current supplied to the pixel electrode 172. Thereby, charging / discharging of the pixel electrode 172 is controlled.
[0208]
The liquid crystal layer 18 contains liquid crystal molecules (not shown), and the alignment of the liquid crystal molecules, that is, the liquid crystal changes corresponding to the charge / discharge of the pixel electrode 172.
[0209]
In the liquid crystal panel 16, usually, one microlens 8, one opening 111 of the black matrix 11 corresponding to the optical axis Q of the microlens 8, one pixel electrode 172, and such pixel electrode 172. One thin film transistor 173 connected to one corresponds to one pixel.
[0210]
Incident light L incident from the microlens concave substrate 2 side passes through the glass substrate 5 and is condensed when passing through the microlens 8, while being collected by the resin layer 14, the cover glass 13, the openings 111 of the black matrix 11, The transparent conductive film 12, the liquid crystal layer 18, the pixel electrode 172, and the glass substrate 171 are transmitted. At this time, since a polarizing plate (not shown) is usually disposed on the incident side of the substrate 2 with concave portions for microlenses, the incident light L is linear when the incident light L passes through the liquid crystal layer 18. It is polarized. At this time, the polarization direction of the incident light L is controlled in accordance with the alignment state of the liquid crystal molecules in the liquid crystal layer 18. Therefore, the luminance of the emitted light can be controlled by transmitting the incident light L transmitted through the liquid crystal panel 16 through a polarizing plate (not shown).
[0211]
The polarizing plate is composed of, for example, a base substrate and a polarizing substrate laminated on the base substrate, and the polarizing substrate is added with a polarizing element (iodine complex, dichroic dye, etc.), for example. Made of resin.
[0212]
As described above, the liquid crystal panel 16 includes the microlenses 8, and the incident light L that has passed through the microlenses 8 is collected and passes through the openings 111 of the respective black matrices 11. Moreover, the liquid crystal panel counter substrate 1 included in the liquid crystal panel 16 is suitably positioned between the substrate 2 with the microlens recesses (that is, the microlenses 8 formed in the recesses 3) and the black matrix 11 as described above. Matching is done. Therefore, the attenuation of the incident light L when passing through the liquid crystal panel 16, particularly the black matrix 11, is suppressed. That is, the liquid crystal panel 16 has a high light transmittance and can form a bright image with a relatively small amount of light.
[0213]
The liquid crystal panel 16 is obtained by, for example, aligning the TFT substrate 17 manufactured by a known method and the counter substrate 1 for liquid crystal panel, and then joining the two through a sealing material (not shown). The liquid crystal can be injected into the gap from a sealing hole (not shown) in the gap formed by the above, and then the sealing hole is closed. Thereafter, a polarizing plate may be attached to the incident side or the emission side of the liquid crystal panel 16 as necessary.
[0214]
In the liquid crystal panel 16, a TFT substrate is used as the liquid crystal drive substrate. However, a liquid crystal drive substrate other than the TFT substrate, for example, a TFD substrate, an STN substrate, or the like may be used as the liquid crystal drive substrate.
[0215]
In the above-described embodiment, the alignment mark 4 is not left on the finally obtained liquid crystal panel counter substrate 1. However, the alignment mark 4 is left on the liquid crystal panel counter substrate 1, and this is used for the liquid crystal panel. You may use for positioning at the time of manufacturing 16.
[0216]
Hereinafter, a projection display apparatus using the liquid crystal panel 16 will be described.
FIG. 18 is a diagram schematically showing an optical system of the projection display device of the present invention.
[0217]
As shown in the figure, the projection display apparatus 300 includes a light source 301, an illumination optical system including a plurality of integrator lenses, a color separation optical system (light guide optical system) including a plurality of dichroic mirrors, and the like. A liquid crystal light valve (liquid crystal optical shutter array) 74 corresponding to red (liquid crystal optical shutter array) 74 corresponding to red, a liquid crystal light valve (liquid crystal optical shutter array) 75 corresponding to green (liquid crystal optical shutter array) 75, and a liquid crystal light valve corresponding to blue (for blue) ) A liquid crystal light valve (liquid crystal light shutter array) 76, a dichroic prism (color combining optical system) 71 formed with a dichroic mirror surface 711 reflecting only red light and a dichroic mirror surface 712 reflecting only blue light, and projection And a lens (projection optical system) 72.
[0218]
The illumination optical system includes integrator lenses 302 and 303. The color separation optical system includes mirrors 304, 306, and 309, a dichroic mirror 305 that reflects blue light and green light (transmits only red light), a dichroic mirror 307 that reflects only green light, and a dichroic that reflects only blue light. A mirror (or a mirror that reflects blue light) 308 and condenser lenses 310, 311, 312, 313, and 314 are included.
[0219]
The liquid crystal light valve 75 is connected to the liquid crystal panel 16 described above and the first polarized light bonded to the incident surface side of the liquid crystal panel 16 (the surface side on which the microlens concave substrate 2 is located, that is, the side opposite to the dichroic prism 71). A plate (not shown), and a second polarizing plate (not shown) bonded to the emission surface side of the liquid crystal panel 16 (the surface side facing the substrate 2 with concave portions for microlenses, that is, the dichroic prism 71 side) It has. The liquid crystal light valves 74 and 76 have the same configuration as the liquid crystal light valve 75. The liquid crystal panels 16 included in these liquid crystal light valves 74, 75 and 76 are connected to drive circuits (not shown).
[0220]
In the projection display device 300, the dichroic prism 71 and the projection lens 72 constitute an optical block 70. The optical block 70 and liquid crystal light valves 74, 75 and 76 fixedly installed on the dichroic prism 71 constitute a display unit 73.
[0221]
Hereinafter, the operation of the projection display apparatus 300 will be described.
White light (white light beam) emitted from the light source 301 passes through the integrator lenses 302 and 303. The light intensity (luminance distribution) of the white light is made uniform by the integrator lenses 302 and 303.
[0222]
The white light transmitted through the integrator lenses 302 and 303 is reflected to the left side in FIG. 18 by the mirror 304, and blue light (B) and green light (G) of the reflected light are respectively reflected by the dichroic mirror 305 in FIG. The red light (R) is reflected downward and passes through the dichroic mirror 305.
[0223]
The red light transmitted through the dichroic mirror 305 is reflected downward in FIG. 18 by the mirror 306, and the reflected light is shaped by the condenser lens 310 and enters the liquid crystal light valve 74 for red.
[0224]
Green light of blue light and green light reflected by the dichroic mirror 305 is reflected to the left side in FIG. 18 by the dichroic mirror 307, and the blue light passes through the dichroic mirror 307.
[0225]
The green light reflected by the dichroic mirror 307 is shaped by the condenser lens 311 and enters the green liquid crystal light valve 75.
[0226]
Further, the blue light transmitted through the dichroic mirror 307 is reflected on the left side in FIG. 18 by the dichroic mirror (or mirror) 308, and the reflected light is reflected on the upper side in FIG. 18 by the mirror 309. The blue light is shaped by the condenser lenses 312, 313, and 314, and enters the liquid crystal light valve 76 for blue.
[0227]
As described above, the white light emitted from the light source 301 is separated into the three primary colors of red, green, and blue by the color separation optical system, and is guided to the corresponding liquid crystal light valve and enters.
[0228]
At this time, each pixel (the thin film transistor 173 and the pixel electrode 172 connected thereto) of the liquid crystal panel 16 included in the liquid crystal light valve 74 is subjected to switching control by a drive circuit (drive means) that operates based on the image signal for red. (On / off), ie modulated.
[0229]
Similarly, green light and blue light are incident on the liquid crystal light valves 75 and 76, respectively, and modulated by the respective liquid crystal panels 16, thereby forming a green image and a blue image. At this time, each pixel of the liquid crystal panel 16 included in the liquid crystal light valve 75 is switching-controlled by a drive circuit that operates based on a green image signal, and each pixel of the liquid crystal panel 16 included in the liquid crystal light valve 76 is used for blue color. Switching control is performed by a drive circuit that operates based on the image signal.
[0230]
Thereby, the red light, the green light, and the blue light are respectively modulated by the liquid crystal light valves 74, 75, and 76, and an image for red, an image for green, and an image for blue are formed.
[0231]
The red image formed by the liquid crystal light valve 74, that is, the red light from the liquid crystal light valve 74, is incident on the dichroic prism 71 from the surface 713, and is reflected by the dichroic mirror surface 711 to the left in FIG. The light passes through the surface 712 and exits from the exit surface 716.
[0232]
Further, the green image formed by the liquid crystal light valve 75, that is, the green light from the liquid crystal light valve 75, enters the dichroic prism 71 from the surface 714, passes through the dichroic mirror surfaces 711 and 712, and exits. The light exits from the surface 716.
[0233]
Further, the blue image formed by the liquid crystal light valve 76, that is, the blue light from the liquid crystal light valve 76, is incident on the dichroic prism 71 from the surface 715, and is reflected by the dichroic mirror surface 712 to the left in FIG. The light passes through the dichroic mirror surface 711 and exits from the exit surface 716.
[0234]
Thus, the light of each color from the liquid crystal light valves 74, 75 and 76, that is, the images formed by the liquid crystal light valves 74, 75 and 76 are synthesized by the dichroic prism 71, thereby forming a color image. Is done. This image is projected (enlarged projection) onto the screen 320 installed at a predetermined position by the projection lens 72.
[0235]
At this time, since the liquid crystal light valves 74, 75, and 76 include the liquid crystal panel 16 as described above, attenuation when the light from the light source 301 passes through the liquid crystal light valves 74, 75, and 76 is suppressed. A bright image can be projected on the screen 320.
[0236]
In the above description, the case where the microlens substrate of the present invention is used in a projection display device including a counter substrate for a liquid crystal panel, a liquid crystal panel, and the liquid crystal light valve has been described as an example. However, the microlens substrate of the present invention is used for various electro-optical devices such as a CCD and an optical communication element, an organic or inorganic EL (electroluminescence) display device, and other devices. Needless to say, you can.
[0237]
Further, the display device is not limited to the rear projection type display device. For example, the microlens substrate of the present invention can be used for a front projection type display device.
[0238]
【Example】
(Reference Example 1)
A substrate with concave portions for microlenses having concave portions for aspherical lenses was manufactured as follows, and a counter substrate for liquid crystal panel was manufactured using the substrate with concave portions for microlenses.
[0239]
First, a quartz glass substrate having a thickness of 1 mm was prepared as a glass substrate.
This quartz glass substrate was cleaned by immersing it in a cleaning solution (80% sulfuric acid + 20% hydrogen peroxide solution) heated to 85 ° C. to clean the surface.
[0240]
Next, this quartz glass substrate is placed in a CVD furnace set at 600 ° C. and 80 Pa, and SiH ₄ Was supplied at a rate of 300 mL / min, and a 0.6 μm thick polycrystalline silicon film (first mask layer and back surface protective layer) was formed by a CVD method.
[0241]
-2A- Next, a resist having a pattern of microlenses and alignment marks is formed on the formed polycrystalline silicon film (mask layer) with a photoresist, and then the polycrystalline silicon film (first mask layer) is formed. Then, dry etching with CF gas was performed, and then the resist was removed to form openings (first opening and second opening) in the polycrystalline silicon film (mask layer) (see FIG. 1B). ).
[0242]
-3A- Next, an Au / Cr thin film corresponding to the shape of the alignment mark is formed on the polycrystalline silicon film (first mask layer) and the portion where the alignment mark is to be formed on the quartz glass substrate by sputtering and photolithography. (Protective layer) was formed.
[0243]
-4A- Next, first wet etching was performed on the quartz glass substrate to form a large number of first recesses on the quartz glass substrate (see FIG. 2D).
Note that a hydrofluoric acid-based etching solution was used as the etching solution.
[0244]
-5A- Next, dry etching with CF gas was performed to remove the polycrystalline silicon film (first mask layer).
[0245]
−6A− Next, a 0.6 μm-thick polycrystalline silicon film (second mask layer) was formed on the quartz glass substrate by the CVD method similar to the above.
[0246]
-7A- Next, an opening (third opening) was formed in the formed polycrystalline silicon film (second mask layer) by the same photolithography technique as described above (see FIG. 2F).
[0247]
-8A- Next, the quartz glass substrate was subjected to second wet etching to form a large number of recesses on the quartz glass substrate (see FIG. 3G).
Note that a hydrofluoric acid-based etching solution was used as the etching solution.
[0248]
-9A- Next, dry etching with CF gas was performed to remove the polycrystalline silicon film (second mask layer and back surface protective layer).
[0249]
-10A- Next, the quartz glass substrate was immersed in a mixed solution (stripping solution) of nitric acid and hydrochloric acid to remove the Au / Cr thin film.
[0250]
As a result, a wafer-like substrate with concave portions for microlenses in which a large number of concave portions for aspherical lenses were formed on a quartz glass substrate was obtained. At this time, a cross-shaped alignment mark having a circular opening at the center is also formed at the same time.
[0251]
-11A- Next, an ultraviolet (UV) curable epoxy optical adhesive (refractive index: 1.59) was used to bond the cover glass to the surface of the substrate with concave portions for microlenses.
[0252]
Thereby, the microlens made of the optical adhesive filled in the concave portion of the substrate with the concave portion for microlens was formed on the resin layer composed of the cured optical adhesive.
[0253]
-12A- Next, the bonded cover glass was ground and polished, so that the thickness of the cover glass was 50 μm.
[0254]
-13A- Next, a black matrix having openings was formed on the cover glass. This was done as follows. First, a Cr film having a thickness of 0.16 μm was formed on the cover glass by sputtering. Next, a resist film was formed on the Cr film. Next, using the alignment mark as an index, an exposure machine was used to expose each aperture of the black matrix pattern so as to coincide with the optical axis of each microlens, thereby forming a black matrix pattern on the resist film. Next, wet etching was performed using a cerium / ammonium nitrate aqueous solution as a peeling solution to form black matrix openings in the Cr film. Next, the resist film was removed.
At this time, the alignment mark was used as a positioning index.
[0255]
-14A- Next, an ITO film (transparent conductive film) having a thickness of 0.15 μm was formed on the cover glass by sputtering so as to cover the black matrix.
As a result, a wafer including a plurality of counter substrates for a liquid crystal panel was obtained.
[0256]
-15A- Finally, the wafer was cut using a dicing apparatus to obtain a counter substrate for a liquid crystal panel. When the substrate with concave portions for microlenses is obtained as an individual substrate, the counter substrate for liquid crystal panel is also obtained as an individual substrate, so there is no need to cut and separate the wafer.
[0257]
(Reference Example 2)
In the same manner as in Reference Example 1, a first substrate with a concave portion for a microlens having a first concave portion and a second substrate with a concave portion for a microlens having a second concave portion were obtained.
[0258]
And the counter substrate for liquid crystal panels provided with the biconvex lens was manufactured as follows using these two board | substrates with a concave part for microlenses.
[0259]
-1B- First, an uncured resin having a predetermined refractive index is supplied to the surface of the first microlens-provided substrate with the first recess so as to cover at least the effective lens region, The resin was filled into the recesses of 1. At this time, an uncured resin containing a spacer was supplied onto the first substrate with concave portions for microlenses. Here, an ultraviolet (UV) curable epoxy-based optical adhesive (refractive index: 1.59) was used as the resin.
[0260]
-2B- Next, the 2nd board | substrate with a recessed part for microlenses was installed on resin.
At this time, the second substrate with concave portions for microlenses is placed on the resin so that the first concave portion and the second concave portion are opposed to each other, and the second substrate with concave portions for microlenses is in contact with the spacer. Install in.
[0261]
In addition, the alignment between the first recess and the second recess was performed using the alignment mark.
[0262]
-3B- Next, the resin was cured. Thereby, the 2nd board | substrate with a recessed part for microlenses is joined to the 1st board | substrate with a recessed part for microlenses through a resin layer. Further, among the resins constituting the resin layer, a biconvex microlens is formed by a resin filled between the first recess and the second recess.
[0263]
Thereafter, steps -13A- to -15A- were performed, and a counter substrate for a liquid crystal panel was obtained in the same manner as in Example 1.
[0264]
Example 1
In the manufacture of the substrate with concave portions for microlenses of Reference Example 1, as the mask, the size of the opening is sequentially increased, and three polycrystalline silicon films each having a thickness of 0.6 μm are laminated to form FIG. Except that the formation of the recesses by wet etching with a hydrofluoric acid-based etching solution and the removal of the polycrystalline silicon film by dry etching with CF gas were alternately performed three times each. In the same manner as in Reference Example 1, a substrate with concave portions for microlenses was obtained.
[0265]
And the counter substrate for liquid crystal panels was obtained like Example 1 using the obtained board | substrate with a recessed part for microlenses.
[0266]
(Example 2)
In the same manner as in Example 1, a first substrate with a concave portion for a microlens having a first concave portion and a second substrate with a concave portion for a microlens having a second concave portion were obtained.
[0267]
And the counter substrate for liquid crystal panels provided with the biconvex lens was manufactured like Example 2 using these 2 board | substrates with a concave part for microlenses.
[0268]
Example 3
In the manufacture of the substrate with concave portions for microlenses in Reference Example 1, two annular first mask layers having different sizes are formed concentrically as a mask, and the quartz glass substrate and the two first masks are formed. By forming the second mask layer over the layer, the concentric mask shown in FIG. 6 (p) is provided, forming a recess by wet etching with a hydrofluoric acid based etchant, and dry etching with CF gas. A substrate with concave portions for microlenses was obtained in the same manner as in Reference Example 1 except that the removal of the second mask layer was performed.
[0269]
As the first mask layer, SiO ₂ A sputtered film was formed to a thickness of 0.6 μm, and a polycrystalline silicon film was formed to a thickness of 0.6 μm as the second mask layer.
[0270]
The etching rate a for the etchant of the first mask layer is 0.5 μm / min, the etch rate b for the etchant of the quartz glass substrate is 0.1 μm / min, and the etching rate ratio a / b Was 5.
[0271]
And the counter substrate for liquid crystal panels was obtained like Example 1 using the obtained board | substrate with a recessed part for microlenses.
[0272]
Example 4
In the same manner as in Example 3, a first substrate with concave portions for microlenses having a first concave portion and a second substrate with concave portions for microlenses having a second concave portion were obtained.
[0273]
And the counter substrate for liquid crystal panels provided with the biconvex lens was manufactured like Example 2 using these 2 board | substrates with a concave part for microlenses.
[0274]
(Comparative example)
In the production of the substrate with concave portions for microlenses, the wet etching was not performed in two stages, but was performed in one stage (the above-mentioned steps -5A- to -8A- were not performed). Then, a substrate with concave portions for microlenses having a large number of concave portions for spherical lenses was obtained, and a counter substrate for liquid crystal panel was obtained in the same manner as in Reference Example 1 using this substrate with concave portions for microlenses.
[0275]
(Evaluation)
When the light was incident on the counter substrate for liquid crystal panel obtained in Examples 1 to 4 from the substrate side with the concave portion for microlens to transmit the light, the light was effectively applied to the openings of the black matrix. As a result, bright outgoing light was obtained.
[0276]
The light transmittance was 1.72 times in the counter substrate for the liquid crystal panel of the comparative example (spherical plano-convex lens) as compared with the counter substrate for the liquid crystal panel having no microlens. 1 (aspherical plano-convex lens) for the liquid crystal panel counter substrate 1.85 times, the liquid crystal panel counter substrate of Example 2 (aspherical biconvex lens) 1.90 times, Example 3 (aspherical plano-convex lens) It was confirmed that excellent transmittance was obtained for both the counter substrate for liquid crystal panel 1.95 times and the counter substrate for liquid crystal panel of Example 4 (aspherical biconvex lens) 2.0 times. The counter substrate for the liquid crystal panel of Reference Example 1 (aspherical plano-convex lens) was 1.82 times, and the counter substrate for the liquid crystal panel of Reference Example 2 (aspherical biconvex lens) was 1.87 times.
[0277]
(Example 5)
Furthermore, the TFT liquid crystal panel having the structure shown in FIG. 17 was assembled using the counter substrate for liquid crystal panels obtained in Examples 1 to 4.
[0278]
All of the assembled TFT liquid crystal panels had high light transmittance, similar to the counter substrate for liquid crystal panels.
[0279]
Therefore, it is easily guessed that a projection display device using such a liquid crystal panel can project a bright image on the screen.
[0280]
【The invention's effect】
As described above, according to the present invention, a substrate with concave portions for microlenses corresponding to an aspherical lens in which spherical aberration can be suppressed can be easily and reliably manufactured.
[0281]
That is, a microlens recess corresponding to an aspheric lens (aspheric microlens recess) corresponding to an aspheric lens can be formed on the substrate by wet etching, thereby reducing (or substantially reducing) the spherical aberration of the microlens. Can be eliminated).
[0282]
In addition, according to the present invention, it is possible to provide a microlens substrate, a counter substrate for a liquid crystal panel, and a liquid crystal panel that have reduced spherical aberration, high light transmittance, and excellent optical characteristics.
[0283]
Furthermore, according to the present invention, a projection display device capable of projecting a bright image can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic longitudinal sectional view showing a method for manufacturing a substrate with concave portions for microlenses.
FIG. 2 is a schematic longitudinal sectional view showing a method for manufacturing a substrate with concave portions for microlenses.
FIG. 3 is a schematic longitudinal sectional view showing a method for manufacturing a substrate with concave portions for microlenses.
FIG. 4 is a schematic longitudinal sectional view showing a first manufacturing method of a substrate with concave portions for microlenses according to the present invention.
FIG. 5 is a schematic longitudinal sectional view showing a first manufacturing method of a substrate with concave portions for microlenses according to the present invention.
FIG. 6 is a schematic longitudinal sectional view showing a second manufacturing method of the substrate with concave portions for microlenses according to the present invention.
FIG. 7 is a schematic longitudinal sectional view showing a second manufacturing method of the substrate with concave portions for microlenses according to the present invention.
FIG. 8 is a schematic longitudinal sectional view showing a method for manufacturing a counter substrate for a liquid crystal panel according to the present invention.
FIG. 9 is a schematic longitudinal sectional view showing a counter substrate for a liquid crystal panel of the present invention.
FIG. 10 is a schematic plan view showing a substrate with concave portions for microlenses according to the present invention.
FIG. 11 is a schematic longitudinal sectional view showing a method for manufacturing a microlens substrate of the present invention.
FIG. 12 is a schematic longitudinal sectional view showing a method for manufacturing a microlens substrate of the present invention.
FIG. 13 is a schematic longitudinal sectional view showing a microlens substrate of the present invention.
FIG. 14 is a schematic longitudinal sectional view showing a microlens substrate of the present invention.
FIG. 15 is a schematic longitudinal sectional view showing a method for manufacturing a microlens substrate of the present invention.
FIG. 16 is a schematic longitudinal sectional view showing a method for manufacturing a microlens substrate of the present invention.
FIG. 17 is a schematic longitudinal sectional view showing a liquid crystal panel of the present invention.
FIG. 18 is a diagram schematically showing an optical system of a projection display device of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Counter substrate for liquid crystal panels, 2 ... Substrate with concave part for microlens, 21 ... Substrate with concave part for first microlens, 22 ... Substrate with concave part for second microlens, 3 ···, recess, 31 ··· first recess, 32 ··· first recess, 33 ··· second recess, 34 ··· first recess, 35 ··· second recess, 36 ... 1st recessed part, 37 ... 2nd recessed part, 4 ... Alignment mark, 41 ... Corner part, 42 ... 1st alignment mark, 43 ... 2nd alignment Mark 5 ... Glass substrate 51 ... Transparent substrate 52 ... Glass substrate 53 ... First glass substrate 54 ... Second glass substrate 6 ... First Mask layer, 61 ... first opening, 611 to 614 ... opening, 62 ... second opening, 63 ... 2 mask layer, 631... Third opening, 64... Laminated mask, 641... First mask layer, 642... Second mask layer, 643. 65, concentric masks, 651, 652 ... first mask layer, 651 ', 652' ... gap, 653 ... second mask layer, 69 ... back protective layer, 7 ... Protective layer, 8 ... Micro lens, 9 ... Spacer, 99 ... Effective lens area, 100 ... Ineffective lens area, 11 ... Black matrix, 111 ... Aperture, 12 ... Transparent conductive film, 13 ... Cover glass, 14 ... Resin layer, 141, 142 ... Resin layer, 143, 144 ... Resin, 16 ... Liquid crystal panel, 17 ... TFT Substrate, 171... Glass substrate, 172... Pixel electrode, 173. .. Thin film transistor, 18 ... Liquid crystal layer, 70 ... Optical block, 71 ... Dichroic prism, 711, 712 ... Dichroic mirror surface, 713-715 ... Surface, 716 ... Output surface, 72 ... Projection lens, 73 ... Display unit, 74-76 ... Liquid crystal light valve, 300 ... Projection type display device, 301 ... Light source, 302, 303 ... Integrator lens, 304, 306, 309 ... Mirror, 305, 307, 308 ... Dichroic mirror, 310-314 ... Condensing lens, 320 ... Screen

Claims (22)

Forming a mask having openings in a predetermined pattern on the substrate;
Next, wet etching is performed using the mask, and after forming a large number of microlens recesses on the substrate,
A method of manufacturing a substrate with concave portions for microlenses that removes the mask,
A concave portion for an aspherical microlens is formed by performing wet etching in multiple stages while increasing the size of the opening of the mask without forming the mask during the wet etching. A method for manufacturing a substrate with concave portions for microlenses.   2. The method for manufacturing a substrate with concave portions for microlenses according to claim 1, wherein the mask is formed by laminating a plurality of mask layers having different opening sizes so that the openings are gradually enlarged. 3.   The method for manufacturing a substrate with concave portions for microlenses according to claim 2, wherein one of the openings of adjacent mask layers of the plurality of mask layers is included in the other.   4. The method for manufacturing a substrate with concave portions for microlenses according to claim 2, wherein the openings of the plurality of mask layers are concentrically arranged.   The manufacturing of a substrate with concave portions for microlenses according to any one of claims 2 to 4, wherein the plurality of mask layers have the same thickness and are made of the same material. Method. Forming a mask having openings in a predetermined pattern on the substrate;
Next, wet etching is performed using the mask, and after forming a large number of microlens recesses on the substrate,
A method of manufacturing a substrate with concave portions for microlenses that removes the mask,
The mask is formed on the substrate, has an annular first mask layer having a higher etching rate with respect to an etchant than the substrate, and an opening on the inner peripheral side of the first mask layer, and the substrate And a second mask layer formed over the first mask layer. A method for manufacturing a substrate with concave portions for microlenses.   The etching rate ratio a / b is 1.1 or more, where a is an etching rate of the first mask layer with respect to the etching solution and b is an etching rate of the substrate with respect to the etching solution. Of manufacturing a substrate with concave portions for microlenses.   8. The method for manufacturing a substrate with concave portions for microlenses according to claim 6, wherein the opening of the second mask layer is disposed at a central portion of the first mask layer. 9.   The method for manufacturing a substrate with concave portions for microlenses according to claim 6, wherein a plurality of the first mask layers are provided.   The method for manufacturing a substrate with concave portions for microlenses according to claim 9, wherein one of the first mask layers adjacent to the plurality of first mask layers is included in the other and is separated from the other.   The method of manufacturing a substrate with concave portions for microlenses according to claim 9 or 10, wherein the plurality of first mask layers are arranged concentrically.   The method for manufacturing a substrate with concave portions for microlenses according to claim 1, wherein the entire surface is further subjected to wet etching after the mask is removed.   The method for manufacturing a substrate with concave portions for microlenses according to claim 1, wherein the substrate is a quartz glass substrate.   A substrate with concave portions for microlenses, which is manufactured by the method for manufacturing a substrate with concave portions for microlenses according to claim 1.   A microlens substrate manufactured using the substrate with concave portions for microlenses according to claim 14 and having a plurality of microlenses.   The microlens substrate according to claim 15, wherein the microlens is a biconvex microlens.   15. A substrate with a first microlens recess having a plurality of aspherical first microlens recesses and a second microlens having a plurality of aspherical second microlens recesses according to claim 14. A substrate with a recess is bonded via a resin so that the first microlens recess and the second microlens recess are opposed to each other, and the first microlens recess substrate A microlens substrate comprising a biconvex microlens formed between the second microlens recessed substrate.   A counter substrate for a liquid crystal panel, comprising the microlens substrate according to claim 15.   A liquid crystal panel comprising the counter substrate for a liquid crystal panel according to claim 18.   19. A liquid crystal drive substrate having pixel electrodes, a liquid crystal panel counter substrate according to claim 18 bonded to the liquid crystal drive substrate, and liquid crystal sealed in a gap between the liquid crystal drive substrate and the liquid crystal panel counter substrate. A liquid crystal panel characterized by comprising:   The liquid crystal panel according to claim 20, wherein the liquid crystal driving substrate is a TFT substrate.   A projection display device comprising the liquid crystal panel according to any one of claims 19 to 21.

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