JP2001318026A - Method of inspecting lens array substrate, method of manufacturing electro-optical device, and method of manufacturing projection type display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inspect a lens array substrate without trouble. SOLUTION: A light beam is made to get incident into the lens array substrate 20 of a liquid crystal device used as a light bulb in the projection type display, using a light source unit 1201 or an optical unit 1301 similar to that of a projection type display. The beam transmitted through the array substrate 20 is magnifiedly projected on a projected screen by a projection lens 1401, and the substrate 20 is inspected based on light quantity of the beam projected onto the projected screen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for inspecting a lens array substrate on which a plurality of microlenses are formed, a method for manufacturing an electro-optical device, and a method for manufacturing a projection display device. More specifically, the present invention relates to an inspection technique for a lens array substrate.

[0002]

2. Description of the Related Art A liquid crystal device is the most typical of various types of electro-optical devices which utilize the fact that an electric field is applied to an electro-optical material to change its orientation state and change optical characteristics. Can be This liquid crystal device, for example,
A liquid crystal (T) in which the transmission polarization axis is twisted between a pair of substrates.
N liquid crystal / twisted nematic mode liquid crystal) is interposed as an electro-optical material. In a liquid crystal device, a device in which pixels each including a pixel electrode and a pixel switching element are arranged in a matrix is an active matrix liquid crystal device, a direct-view display device, or
It is used as a light valve of the projection display device shown in FIG.

[0003] In a projection display device 1 shown in FIG.
The non-polarized light emitted from 01 is converted into one type of linearly polarized light by the integrator optical system 300 and emitted, and then separated by the color light separation optical system 380 into three color lights of red, green, and blue. , A liquid crystal light valve 4 for each color light
10R, 410G, 410B (liquid crystal device / electro-optical device). Each liquid crystal light valve 410R, 410
G, 410B are respectively modulated by the liquid crystal light valves 410R, 410G, 410B, emitted, and then incident on the cross dichroic prism 420, synthesized by the cross dichroic prism 420, and then transmitted from the projection lens 401. The image is projected as a color image on a projection screen (not shown).

In such a projection display device 1, a liquid crystal device (liquid crystal light valves 410R, 410G, 410)
As shown in FIG. 8, as shown in FIG. 8, on the lens array substrate 20 (opposite substrate) side, black made of a metal material such as chrome or resin black is provided on the side of the lens array substrate 20 (opposite substrate) for the purpose of improving display quality. Generally, a light-shielding film 6 called a matrix or a black mask is formed.

When strong light incident from the lens array substrate 20 side enters a channel forming region (not shown) of the pixel switching TFT 10, a photocurrent is generated by a photoelectric conversion effect in this region, and a photocurrent is generated. Since the transistor characteristics of the TFT 1 are deteriorated,
It is formed up to the region facing 0.

Therefore, when the number of pixels is increased by reducing the size of the pixels for the purpose of improving the quality of the projected image of the projection display device 1, the area ratio occupied by portions other than the pixels such as the light shielding film 6 becomes relatively large. And the area ratio (aperture ratio) directly contributing to the display decreases. In the projection display device 1, since strong light enters the liquid crystal device,
In order to reliably prevent light from entering the channel forming region of the TFT 10 by the light-shielding film 6, it is necessary to form the light-shielding film 6 wide. The amount of light contributing to the light is reduced. Further, even if the wide light-shielding film 6 is formed, it is not possible to reliably block light obliquely incident.

Therefore, a structure has been devised in which micro lenses 22 (small condenser lenses) are arranged in the in-plane direction on the side of the lens array substrate 20. According to such a structure,
Light incident on the lens array substrate 20 side can be efficiently condensed toward each pixel electrode 8 by each microlens 22. In addition, even if the width of the light shielding film 6 formed on the lens array substrate 20 side is small or the light shielding film 6 is not provided on the lens array substrate 20 side, light is prevented from entering the channel forming region of the TFT 10. can do. Therefore, deterioration of the transistor characteristics of the TFT 10 and reduction of the amount of light contributing to display can be prevented, so that a liquid crystal device which has high reliability and can perform bright display can be configured.

The lens array substrate 20 having such microlenses is manufactured by etching a surface of a transparent substrate using a photolithography technique to produce a lens array 21 having a plurality of microlenses 22 formed thereon. A thin glass 49 is attached to the array 21 with an adhesive 48, and thereafter, the thin glass 4
9 is manufactured by polishing and adjusting the thickness.

[0009]

The quality of the lens array substrate 20 manufactured as described above depends on the quality of the microlenses 22.
, The thickness of the adhesive 48, the thickness of the thin glass plate 49, and the refractive index of each layer. Also, the lens array substrate 2
The light shielding film 6 and the micro lens 22 formed on the 0 side
Misalignment also degrades the quality of the lens array substrate 20. Therefore, when manufacturing the lens array substrate 20, the lens array substrate 20 is inspected for each of the above factors in order to reduce the defect rate of the liquid crystal device or the projection display device due to the defect of the lens array substrate 20. However, these inspections require a lot of man-hours, and are not methods that can be adopted in actual manufacturing sites.

[0010] Also, Japanese Patent No. 2710257 discloses that
A lens array substrate and a reference mask having a plurality of openings are arranged so as to face each other, and in this state, when the lens array substrate is irradiated with parallel light, the amount of light transmitted through each opening of the reference mask There is disclosed a technology for inspecting a lens array substrate by detecting the.

However, according to the inspection technique disclosed in this patent publication, even if there is a slight shift in the positional relationship between the lens array substrate and the reference mask, the amount of light transmitted through each opening of the reference mask is significantly reduced. In addition, there is a problem that the inspection accuracy is low, for example, even if the lens array substrate is non-defective, it is determined to be defective. Also, since the size and number of microlenses formed on the lens array substrate differ depending on the type of liquid crystal device used, it is necessary to replace the reference mask each time the type of the lens array substrate to be inspected changes. It takes time to set up. Moreover,
Even if the positional relationship between the lens array substrate and the reference mask is slightly deviated, the inspection accuracy is reduced, so that such an inspection technology cannot be incorporated into actual manufacturing.
Furthermore, although the light incident on the liquid crystal device in the projection display device is not perfectly parallel light, when the lens array substrate is inspected with parallel light, the inspection results and the characteristics when incorporated into the projection display device are obtained. There is also a problem that often does not match.

As will be described in detail later, in the liquid crystal device, the contrast is reduced depending on the incident angle of light due to the fact that the long axis direction of the liquid crystal is twisted between the substrates. In order to solve such a problem, the applicant of the present application has proposed a technique of displacing the center of a microlens from the center of a pixel in a projection display device, and a technique of clearly viewing a light incident direction on a liquid crystal device from a normal direction. He has devised techniques for tilting in the direction, and has applied for patents for inventions related to these techniques.

However, in the lens array substrate used in the projection type display device to which the invention is applied, since the inspection result for the lens array substrate greatly changes depending on the direction from which the light is incident, the parallel light is applied to the lens array substrate. However, there is a problem in that the inspection result does not match the characteristic when incorporated into the projection display device.

[0014] In view of the above problems, an object of the present invention is to provide:
An object of the present invention is to provide a method for inspecting a lens array substrate, a method for manufacturing an electro-optical device, and a method for manufacturing a projection display device, which can inspect a lens array substrate without trouble.

Another object of the present invention is to provide a method of inspecting a lens array substrate which can obtain an inspection result having a high correlation with characteristics when the lens array substrate is mounted on an electro-optical device such as a projection display device. An object of the present invention is to provide a method of manufacturing an electro-optical device and a method of manufacturing a projection display device.

[0016]

In order to solve the above problems, a method for inspecting a microlens according to the present invention irradiates a lens array substrate on which a plurality of microlenses are formed with light emitted from a light source. In addition, light transmitted through the microlens is projected onto a projection surface via a projection optical system, and the lens array substrate is inspected based on the amount of light projected on the projection surface.

In the present invention, when inspecting the quality of the lens array substrate, the quality of the lens array substrate is not determined by factors such as the curvature of the microlens, the thickness of the adhesive, the thickness of the thin glass, and the refractive index of each layer. While irradiating the lens array substrate with light in the finished state, the light transmitted through the microlens is projected on the projection surface via the projection optical system, and the intensity of the light transmitted through the lens array substrate at that time. Is inspected visually or using a light receiving element. The quality of the entire lens array substrate is inspected based on whether the amount of light transmitted through the plurality of microlenses is large or small, rather than individual microlenses. Therefore, since it is not necessary to use a reference mask matched to the microlens, a troublesome setup operation such as accurately aligning the reference mask with the lens array substrate can be omitted. Also, unlike the method of comparing with the reference mask, even if the specification of the lens array substrate to be inspected changes, it is not necessary to change the optical system of the inspection apparatus. Can be omitted.

In the present invention, for example, at a plurality of places separated from each other on the projection surface, for example, a three-step
The amount of light is measured at nine places in a line, and the lens array substrate is inspected based on the measurement result.

In the present invention, it is preferable to irradiate the lens array substrate with light emitted from the light source, for example, so as to be substantially parallel light beams, as in an actual projection display device.

In the present invention, it is preferable to irradiate the lens array substrate with light whose optical axis is inclined with respect to the normal to the substrate surface of the lens array substrate, as in an actual projection display device. .

In the present invention, in order to irradiate the lens array substrate with light whose optical axis is inclined with respect to the normal to the substrate surface of the lens array substrate, for example, as in an actual projection display device, The lens array substrate is tilted.

According to the present invention, in order to irradiate the lens array substrate with light whose optical axis is inclined with respect to the normal to the substrate surface of the lens array substrate, the light source is provided similarly to an actual projection display device. Alternatively, the posture of an optical component disposed on an optical path from the light source to the lens array substrate may be inclined.

In the present invention, it is preferable that the light emitted from the light source is aligned with predetermined linearly polarized light and irradiated onto the lens array substrate, as in an actual projection display device.

In the present invention, even if the light emitted from the light source has a white color with respect to the lens array substrate,
It is preferable to irradiate red light, blue light or green light which is actually incident on the projection display device by passing through a filter or a color separation optical system.

In the present invention, the lens array substrate may be sequentially irradiated with a plurality of color lights per sheet. In this case, it is preferable that the color of the light applied to the lens array substrate be automatically switched at a predetermined timing.

In the present invention, the quality of the lens array substrate may be determined based on the amount of light applied to the surface to be irradiated, but the lens array substrate may be classified according to the rank of the optical characteristics. Good.

Such an inspection method is performed when an electro-optical device is manufactured, and further when a projection display device is manufactured by using the manufactured electro-optical device as a light modulator. In this method of manufacturing a projection display device, among the lens array substrates which have been inspected, an electro-optical device manufactured using a lens array substrate having a low optical characteristic rank is used as a light modulating means for blue light. Is preferred. In a projection display device, when three electro-optical devices are used for red light, green light, and blue light, respectively, blue light has the least effect on contrast. Therefore, in the inspection of the lens array substrate, a lens array substrate determined to have a low rank is not discarded as a defective product but is used exclusively for blue light, thereby improving the yield of the lens array substrate.

[0028]

Embodiments of the present invention will be described with reference to the drawings.

[First Embodiment] (Configuration of Projection Display Device) FIG. 1 is a schematic plan view showing the configuration of an optical system of a projection display device to which the present invention is applied. In the following description, unless otherwise specified, the light traveling direction is 12 when viewed from the positive z-axis direction and from the positive z-axis direction.
The direction of the hour is defined as the positive direction of the y-axis, and the direction of 3 o'clock is defined as the positive direction of the x-axis.

As shown in FIG. 1, the projection type display device 1 comprises:
It has a light source unit 201, an optical unit 301, and a projection lens 401.

The optical unit 301 includes the first optical element 3
20, second optical element 330, and superimposing lens 370
Is provided. The optical unit 301 includes a dichroic mirror 38.
2, 386, and a color light separation optical system 380 including a reflection mirror 384. Further, the optical unit 301
Has a light guide optical system 390 including an incident side lens 392, a relay lens 396, and reflection mirrors 394 and 398. Further, the optical unit 301 has three field lenses 400, 402, 404, three liquid crystal light valves 410R, 410G, 410B, and a cross dichroic prism 420.

The light source unit 201 includes the optical unit 30
The first optical element 320 is arranged on the incident surface side. The projection lens 401 is arranged on the exit surface side of the cross dichroic prism 420 of the optical unit 301.

FIG. 2 is an explanatory diagram showing an integrator illumination optical system for illuminating three liquid crystal light valves which are illumination areas of the projection display apparatus 1 shown in FIG. FIG.
(A), (B) and (C) respectively show the first optical element 3
20 is a front view, a side view, and a perspective view showing an enlarged view of a part of the first optical element 320 on the side where the microlenses are formed. FIG. 4A and 4B are a perspective view showing the appearance of the polarization conversion element array and an explanatory view showing the function of the polarization conversion element array. Note that FIG. 2 shows only main components for explaining the function of the integrator illumination optical system for ease of explanation.

The integrator illumination optical system shown in FIG. 2 has a light source 200 provided in a light source unit 201 and an integrator optical system 300 provided in an optical unit 301. The integrator optical system 300 includes a first optical element 320, a second optical element 330, and a superimposing lens 370 that is a third optical element. The second optical element 330 includes a condenser lens 340, a light blocking plate 350, and a polarization conversion element array 360.

The light source 200 includes a light source lamp 210 and a concave mirror 212. The radial light source (radiated light) emitted from the light source lamp 210 is reflected by the concave mirror 212 and becomes a first optical element 320 as a substantially parallel light beam.
In the direction of. As the light source lamp 210, a halogen lamp, a metal halide lamp, or a high-pressure mercury lamp is often used. As the concave mirror 212, a parabolic mirror is preferably used.

In FIGS. 3A, 3B and 3C, the first optical element 320 is composed of a small lens 321 having a rectangular outline, which is composed of M rows in the vertical direction and 2N columns in the horizontal direction. Are lens arrays arranged in a matrix. From the center in the lateral direction of the lens, there are N rows to the left and N rows to the right.
In this example, M = 10 and N = 4. Each small lens 32
1 when viewed from the z direction is a liquid crystal light valve 41.
It is set so as to form a substantially similar system to the shape of 0. For example, if the aspect ratio (the ratio between the horizontal and vertical dimensions) of the image forming area of the liquid crystal light valve is 4: 3, the aspect ratio of each small lens 321 is also set to 4: 3. As shown in FIG. 2, a condenser lens 340 is also formed on the second optical element 330.
Reference numeral 0 denotes a lens array having the same configuration as the first optical element 320 described with reference to FIG. Note that the directions of the lenses of the first optical element 320 and the condenser lens 340 are +
It may be oriented in either the z direction or the −z direction.
Moreover, as shown in FIG. 2, they may face in opposite directions.

Referring again to FIG. 2, the polarization conversion element array 3
In 60, two polarization conversion element arrays 361 and 362 are arranged symmetrically with respect to the optical axis.

This polarization conversion element array 361 is the same as that shown in FIG.
As shown in (A), the polarization beam splitter array 36
3 and a λ / 2 retardation plate 364 (shown by oblique lines in the figure) selectively disposed on a part of the light exit surface of the polarizing beam splitter array 363. The polarizing beam splitter array 363 has a shape in which a plurality of columnar translucent members 365 each having a parallelogram cross section are sequentially bonded. The polarization separating film 3 is provided at the interface of the light transmitting member 365.
66 and reflection films 367 are formed alternately. λ / 2
The phase difference plate 364 is formed of the polarization separation film 366 or the reflection film 3.
It is selectively affixed to the mapping part in the x direction of the light emitting surface of 67. In this example, a λ / 2 retardation plate 364 is attached to a portion of the polarization separation film 366 that is mapped in the x direction on the light exit surface.

The polarization conversion element array 3 configured as described above
Reference numeral 61 has a function of converting an incident light beam into one type of linearly polarized light (for example, s-polarized light or p-polarized light) and emitting the same.

That is, as shown in FIG. 4B, unpolarized light (incident light having a random polarization direction) including an s-polarized component and a p-polarized component is incident on the incident surface of the polarization conversion element array 361. Then, this incident light is first separated by the polarization separation film 366 into s-polarized light and p-polarized light. The s-polarized light is reflected almost vertically by the polarization separation film 366,
The light is emitted after being further reflected by the reflection film 367. On the other hand, the p-polarized light passes through the polarization separation film 366 as it is. A λ / 2 retardation plate 364 is disposed in an emission region of the p-polarized light transmitted through the polarization separation film, and the p-polarized light is converted into s-polarized light and emitted. Therefore, most of the light transmitted through the polarization conversion element array 361 is s.
The light is emitted as polarized light. When light emitted from the polarization conversion element array 361 is to be p-polarized light,
The λ / 2 retardation plate 364 may be arranged on the exit surface from which the s-polarized light reflected by the reflection film 367 exits.

As described above, the polarization conversion element array 361
Includes one polarization separation film 366 and one reflection film 367 adjacent to each other, and further converts one block constituted by one λ / 2 retardation plate 364 into one polarization conversion element 36.
8 can be considered. Therefore, it can be said that the polarization conversion element array 361 is such that such polarization conversion elements 368 are arranged in a plurality of rows in the x direction. In the example shown here, 4
It is composed of a row of polarization conversion elements 368. Since the polarization conversion element array 362 is exactly the same as the polarization conversion element array 361, the description is omitted.

In the projection display apparatus 1 configured as described above, the unpolarized light emitted from the light source 200 shown in FIG. 2 is transmitted to the plurality of small lenses 321 of the first optical element 320 constituting the integrator optical system 300. The light is divided into a plurality of partial light beams 202 by a plurality of small lenses 341 of a condenser lens 340 included in the second optical element 330, and is collected near the polarization separation film 366 of the two polarization conversion element arrays 361 and 362. Be lighted. Here, the condenser lens 340 has a function of guiding a plurality of partial light beams emitted from the first optical element 320 to be condensed on the polarization separation films 366 of the two polarization conversion element arrays 361 and 362. are doing. Therefore, the two polarization conversion element arrays 361, 3
The plurality of partial light beams incident on 62 are converted into one type of linearly polarized light and emitted as described with reference to FIG. The plurality of partial light beams emitted from the two polarization conversion element arrays 361 and 362 are superimposed on a liquid crystal light valve described later by the superimposing lens 370. Therefore,
This integrator illumination optical system can uniformly illuminate the liquid crystal light valve.

Referring again to FIG. 1, in the projection type display device 1, the reflecting mirror 372 is not necessarily required depending on the configuration of the illumination optical system.
It is provided to guide the light beam emitted from 70 toward the color light separation optical system 380.

The color light separation optical system 380 includes two dichroic mirrors 382 and 386, and a superimposing lens 370.
Has a function of separating the light emitted from the light into three color lights of red, green, and blue. First dichroic mirror 38
2 transmits the red light component of the light emitted from the superimposing lens 370 and reflects the blue light component and the green light component. The red light transmitted through the first dichroic mirror 382 is reflected by the reflection mirror 384, passes through the field lens 400, and the liquid crystal light valve 41 for red light.
Reaches 0R. The field lens 400 converts each partial light beam emitted from the superimposing lens 370 into a light beam parallel to its central axis (principal ray). The same applies to the field lenses 402 and 404 provided in front of the other liquid crystal light valves 410G and 410B. Of the blue light and the green light reflected by the first dichroic mirror 382, the green light is reflected by the second dichroic mirror 386, passes through the field lens 402, and reaches the liquid crystal light valve 410G for green light. On the other hand, the blue light is transmitted through the second dichroic mirror 386, and the light guide optical system 390, that is, the incident side lens 392, the reflection mirror 394, the relay lens 396, and the reflection mirror 3
98, and further through a field lens 404 to a liquid crystal light valve 410B for blue light. Note that the light guide optical system 390 is used for blue light because the optical path length of blue light is longer than the optical path lengths of other color lights.
This is for preventing a decrease in light use efficiency due to light diffusion or the like. That is, this is for transmitting the partial light beam incident on the incident side lens 392 to the field lens 404 as it is.

Three liquid crystal light valves 410R, 410
The three colors of light that have entered the G and 410B are respectively modulated by the liquid crystal light valves 410R, 410G and 410B, and then enter the cross dichroic prism 420. This cross dichroic prism 420
It has a function as a color light combining optical system that forms a color image by combining color modulated light. The cross dichroic prism 420 has a dielectric multilayer film that reflects red light,
A dielectric multilayer film that reflects blue light is formed in an approximately X-shape at the interface between the four right-angle prisms. The modulated light of three colors is combined by these dielectric multilayer films to form combined light for projecting a color image. The combined light generated by the cross dichroic prism 420 is emitted toward the projection lens 401. The projection lens 401 has a function of projecting the synthesized light on a projection screen, and displays a color image on the projection screen.

(Structure of Liquid Crystal Device / Liquid Crystal Light Valve)
Each of the liquid crystal light valves 410R, 410G, 410B has the configuration shown in FIGS. 5, 6, and 7.

FIGS. 5 and 6 are plan views of the liquid crystal device 100 used as the liquid crystal light valves 410R, 410G and 410B, respectively, as viewed from the lens array substrate side.
And the liquid crystal device 10 when cut along the line HH 'in FIG.
0 is a sectional view. FIG. 7 is a block diagram schematically illustrating the configuration of the liquid crystal device 100.

Referring to FIG. 5 and FIG.
(Liquid crystal light valves 410R, 410G, 410B)
Is roughly composed of an active matrix substrate 30 on which pixel electrodes 8 are formed in a matrix, a lens array substrate 20 on which counter electrodes 25 are formed, and a liquid crystal 39 sealed and sandwiched between these substrates 20 and 30. It is configured. The active matrix substrate 30 and the lens array substrate 20 are bonded to each other via a predetermined gap by a sealing material 52 including a gap material formed along the outer peripheral edge of the lens array substrate 20. In addition, a sealing material 52 containing a gap material is provided between the active matrix substrate 30 and the lens array substrate 20 by using a liquid crystal sealing region 40.
Are formed, and a liquid crystal 39 is sealed inside. As the sealing material 52, an epoxy resin, various ultraviolet curable resins, or the like can be used. Further, as the gap material, an inorganic or organic fiber or sphere of about 2 μm to about 10 μm can be used.

The lens array substrate 20 is smaller than the active matrix substrate 30, and the peripheral portion of the active matrix substrate 30 is bonded so as to protrude from the outer peripheral edge of the lens array substrate 20. Therefore, the drive circuits (the scan line drive circuit 70 and the data line drive circuit 60) and the input / output terminals 45 of the active matrix substrate 30 are exposed from the lens array substrate 20. Here, the sealing material 5
2 is partially interrupted to form a liquid crystal injection port 241. After bonding the lens array substrate 20 and the active matrix substrate 30, the liquid crystal 3
9 is filled with a liquid crystal 39, and the liquid crystal injection port 241 is closed with a sealing agent 242. Note that the lens array substrate 20 has a horizontally long rectangular image display area 7 inside the sealing material 52.
A light-shielding film 55 for parting the display for parting is also formed. In each of the corners of the lens array substrate 20, a vertical conductive member 56 for establishing electrical conduction between the active matrix substrate 30 and the lens array substrate 20 is formed.

In the liquid crystal device 100 configured as described above, the plurality of pixels formed in a matrix forming the image display area 7 control the pixel electrode 8 and the pixel electrode 8 as shown in FIG. And a data line 90 to which an image signal is supplied is connected to the TFT 1.
0 is electrically connected to the source. This data line 90
, Are sequentially supplied with image signals S1, S2,..., Sn. The scanning signals G1, G2,..., Gm are applied in a pulsed manner to the gate electrode of the TFT 10 via the scanning line 91 in this order. The pixel electrode 8 is electrically connected to the drain of the TFT 10,
By closing the switch of the TFT 10 for a certain period, the image signals S1 and S
2, ..., Sn are written at a predetermined timing. The image signal S of a predetermined level written in the liquid crystal through the pixel electrode 8
, Sn are held for a certain period between the counter electrodes 25 formed on the lens array substrate 20. Here, in order to prevent the held image signal from leaking,
A storage capacitor 40 is added in parallel with a liquid crystal capacitor formed between the pixel electrode 8 and the counter electrode. As a method of forming the storage capacitor 40 in this manner, a capacitor line 92 which is a wiring for forming a capacitor may be provided, or the scanning line 9 in the preceding stage may be provided.
A capacitance may be formed between the capacitor and the capacitor.

In the liquid crystal device 100 configured as described above,
By controlling the electric field applied to the liquid crystal for each pixel, the alignment state of the liquid crystal can be controlled for each pixel. Therefore, in the liquid crystal device 100, whether or not the incident light is transmitted can be controlled for each pixel, so that the liquid crystal device 100 functions as a light modulation unit that modulates based on given image information (image signal). Therefore, each color light that has entered the three liquid crystal light valves 410R, 410G, 410B is modulated according to the given image information and emitted from the liquid crystal light valves 410R, 410G, 410B.

(Structure of Lens Array Substrate 20) As shown in FIG. 8, the lens array substrate 20 has a plurality of convex microlenses 22 (see FIG. 8) raised toward each of the pixel electrodes 8 of the active matrix substrate 30. Lens array 21 in which small condenser lenses are formed in a matrix
And a micro lens 22 with respect to the lens array 21.
And a transparent thin glass 49 bonded with an adhesive 48 so as to cover The counter electrode 25 is formed on the surface of the thin glass 49, and the light-shielding film 6 is formed in a region of the surface of the counter electrode 25 corresponding to the boundary region of the microlens 22. In addition, the thin glass 49
A layer of a polyimide resin 47 serving as an alignment film is formed on the surface of the counter electrode 25 and the light-shielding film 6.

In the liquid crystal device 100 using the lens array substrate 20 having such a configuration, of the light incident from the lens array substrate 20, the light irradiated to the channel forming region of the TFT 10 is shielded by the light shielding film 6. At the same time, obliquely incident light and the like are collected by the microlenses 22 toward the pixel electrodes 8.

After the lens array 21 is manufactured by using the photolithography technique, a thin glass 49 is attached to the lens array 21 with an adhesive 48. It is manufactured by polishing and adjusting the thickness. Then, optical characteristics of the manufactured lens array substrate 20 are inspected by an inspection apparatus described below.

(Lens Array Substrate Inspection Apparatus and Inspection Method) FIGS. 9 and 10 are perspective views showing a main part of an inspection apparatus for performing the lens array substrate inspection method according to the present invention, and FIG. FIG. 3 is an explanatory diagram of a projection surface on which light transmitted through a lens array substrate is enlarged and projected.

As shown in FIG. 9, the inspection apparatus 1000
It has the same configuration as the projection display device 1 described with reference to FIG. 1, and has a light source unit 1201, an optical unit 1301, and a projection lens 1401 (projection optical system) on the device optical axis extending linearly. ) Are arranged in this order.

In the inspection apparatus 1000, the light source 1200
Includes a light source lamp 1210 and a concave mirror 1212, similarly to the light source 200 of the projection display apparatus 1 described with reference to FIGS. The radial light source (radiated light) emitted from the light source lamp 1210 is reflected by the concave mirror 1212 and emitted as a substantially parallel light beam. As the light source lamp 1210, a halogen lamp, a metal halide lamp, or a high-pressure mercury lamp is often used.
As the concave mirror 1212, it is preferable to use a parabolic mirror. In other words, the inspection apparatus 1000 has the same configuration as the projection display apparatus 1, and the aperture angle and the F value of the optical system with respect to the light emitted therefrom are as follows:
It is configured to have the same value as the projection display device 1.

The optical unit 1301 is also shown in FIGS.
Optical unit 3 of projection display device 1 described with reference to
As in the case of 01, an integrator optical system 1300 including a first optical element 1320, a second optical element 1330, and a superimposing lens 1370 is provided. The optical unit 1301 includes an incident side lens 1392, a holder 139,
Polarizing plate 1394 and glass block 1 held in 3
395. In the optical unit 1301, the first optical element 1320 and the second optical element 1330
In some cases, a filter 1309 for protecting the polarizing plate 1394 and the like may be arranged between the two.

The light source unit 1201 includes the optical unit 3
01 is disposed on the incident surface side of the first optical element 320. The projection lens 1401 is arranged on the emission surface side of the glass block 1395 of the optical unit 1301.

Here, the integrator optical system 1300
2A, 2B, 2C, and 4
Since it has the same configuration as the integrator optical system 300 of the projection display device 1 described with reference to (A) and (B), the detailed configuration of this integrator optical system 1300,
2 and 3 (A), (B),
(C) and FIGS. 4 (A) and 4 (B).

The inspection apparatus 1000 also emits non-polarized light from the light source 1200. This non-polarized light is emitted from the light source 1200 as shown in FIGS. 2, 3A, 3B, 4C and 4C. A),
As described in (B), the integrator optical system 130
In addition to being divided into a plurality of partial light beams 202 by a plurality of small lenses 321 of the first optical element 1320 and a plurality of small lenses 341 of the condenser lens 340 included in the second optical element 1330, two light beams 202 Light is condensed near the polarization separation films 366 of the polarization conversion element arrays 361 and 362. Here, the condenser lens 340 has a function of guiding the plurality of partial light beams emitted from the first optical element 1320 to be condensed on the polarization separation films 366 of the two polarization conversion element arrays 361 and 362. are doing. Therefore, the plurality of partial light beams incident on the two polarization conversion element arrays 361 and 362 are converted into one type of linearly polarized light and emitted.

Referring to FIG. 9 again, in the inspection apparatus 1000, between the incident side lens 1392 and the polarizing plate 1394,
The lens array substrate 20 to be inspected is automatically supplied one by one by a slide transport mechanism (not shown). Therefore, a plurality of partial light beams emitted from the two polarization conversion element arrays 361 and 362 shown in FIG.
The light is superimposed on the lens array substrate 20 to uniformly illuminate the lens array substrate 20. The light transmitted through the lens array substrate 20 is reflected by the polarizing plate 1394 and the glass block 1.
After passing through 394, the light is radiated by the projection lens 1401 onto the irradiation surface 1450 shown in FIG.

Here, on the irradiated surface 1450, photodetectors 1451 are arranged at nine positions separated from each other.
The light transmitted through the lens array substrate 20 is transmitted to the projection lens 140.
1 detects the amount of light that is enlarged and projected. Therefore, according to the detection result of the photodetector 1451, the intensity of the light transmitted through the lens array substrate 20 can be measured at each of the nine locations, and the variation in the light amount at these nine locations can be measured.

Therefore, in this embodiment, the quality of the lens array substrate 20 is determined based on the measurement result. That is, the optical characteristics of the lens array substrate 20 are as shown in FIG.
The curvature of the micro lens 22 shown in FIG.
The thickness is determined by the thickness of the thin glass 49 and the refractive index of each layer. In the present embodiment, light is applied to the lens array substrate 20 in a finished state as the lens array substrate 20 instead of each factor. Lens 2
The light transmitted through the lens array substrate 20 is enlarged and projected on the projection surface 1450 by the projection lens 1401, and the intensity and variation of the light transmitted through the lens array substrate 20 are inspected. Therefore, the quality of the entire lens array substrate 20 is inspected based on whether the amount of light transmitted through the plurality of microlenses 22 is large or small, rather than the individual microlenses 22. Therefore, unlike the inspection method using the reference mask matched to the microlens 22, there is no need to perform a troublesome process such as accurately aligning the reference mask with the lens array substrate 20. Also, unlike the configuration in which comparison with the reference mask is performed, it is not necessary to change the optical system of the inspection apparatus 1000 even if the specification of the lens array substrate 20 to be inspected changes. The time and effort required can be saved. Therefore, it is effective as an inspection method in a mass production line.

In the inspection apparatus 1000 of the present embodiment, the basic configuration of the optical system is the same as that of the projection display apparatus 1. Similarly to the case where the light including the light component inclined at 10 ° to 12 ° is incident on the liquid crystal device 100 (light valve), the light component includes the light component inclined at ± 10 ° to 12 ° from the central optical axis, and the angular distribution thereof is also included. Inspection light similar to that of the projection display device 1 is incident on the lens array substrate 20. Therefore,
According to the present embodiment, the microphone lens substrate 20 obtained in the inspection process
Has a high correlation between the evaluation of the liquid crystal device 100 and the inspection result when the liquid crystal device 100 is incorporated in the projection display device 1.

(Correspondence to other microlens substrates)
FIG. 11 is a cross-sectional view showing an active matrix substrate, a lens array substrate, and a bonding structure of these substrates, which are different from the liquid crystal device shown in FIG.

In the liquid crystal device 10, the contrast is lowered depending on the incident angle of light due to the major axis direction of the liquid crystal being twisted between the substrates. In order to solve such a problem, the applicant of the present application devised a technique of shifting the center of the microlens 22 from the center of the pixel in the projection display apparatus 1 and applied for a patent, but applied such an invention. By using the inspection method and the inspection apparatus according to the present embodiment, the quality of the lens array substrate 20 can be accurately inspected for the lens array substrate 20 without trouble.

That is, as shown in FIG. 11, the inventor of the present invention clearly views the center position 23 of the micro lens 22 formed on the lens array substrate 20 with respect to the center position 33 of the opening region 31 of the active matrix substrate 30. A liquid crystal device 100 having a configuration shifted in the direction is proposed. In the liquid crystal device 100, of the light incident from the lens array substrate 20 side, the light incident from the direction inclined toward the clear viewing direction is refracted by the microlens 22, and And is involved in the display. On the other hand, the light incident on the lens array substrate 20 from the direction inclined in the reverse clear viewing direction is refracted by the microlenses 22 and then applied to a position shifted from the opening region 31 with respect to the active matrix substrate 30. In addition, since each pixel of the active matrix substrate 30 is shielded by the light shielding film 66 formed on the clear viewing direction side, it is possible to suppress emission from the active matrix substrate 30. Therefore, even if the light incident from the lens array substrate 20 includes light inclined in the clear viewing direction and the reverse clear viewing direction, the light inclined in the reverse clear viewing direction, which causes a decrease in contrast, Active matrix substrate 3
Since emission from 0 can be suppressed, it is not involved in display. Therefore, according to the liquid crystal device 100, a display with high contrast can be performed.

In the lens array substrate 20 used in such a liquid crystal device 100, the amount of light emitted from the lens array substrate 20 changes greatly depending on the direction of the incident light. Although the quality of the lens array substrate 20 cannot be accurately determined by irradiating the lens array substrate 20, according to the inspection apparatus 1000 described with reference to FIGS. 9 and 10 and the inspection method using this apparatus, an actual projection display apparatus is used. 1 uses a light source unit 1201 and an optical unit 1301 similar to those of FIG. Includes light incident from a direction oblique to the direction. Therefore, when the lens array substrate 20 is inspected by the inspection method according to the present embodiment, the inspection result matches the result of the inspection performed in a state where the lens array substrate 20 is incorporated in the projection display device 1.

[Embodiment 2] As described with reference to FIG. 1, in the projection display device 1, three liquid crystal devices 100 are used.
Are used as light valves for red light, green light, and blue light, respectively. Therefore, in view of the fact that the refractive index changes depending on which wavelength of light is incident, in the present embodiment,
As shown in FIG. 12, filters 1100R and 1100 for three colors are provided in front of the lens array substrate 20 to be inspected.
G, 1100B, and the lens array substrate 20 to be inspected.
The inspection is performed while automatically switching the inspection light incident on the red light, the green light, and the blue light. Other configurations are the same as those described in the first embodiment, and a description thereof will not be repeated.

According to the inspection apparatus 1000 configured as described above, the inspection is performed using the actually incident color light, and the inspection result is the result of the inspection performed in a state where the inspection apparatus 1000 is incorporated in the projection display apparatus 1. There is an advantage that it matches more.

[Modification of Second Embodiment] Although not shown, one of red, green, and blue light color filters, for example, a blue color filter 1100R (see FIG. 12) May be fixed and arranged in front of the lens array substrate 20 to be inspected, and the lens array substrate 20 may be inspected using blue light having the largest refractive index among the three colors.

[Embodiment 3] FIG. 13 is an explanatory view showing the attitude of a liquid crystal device (liquid crystal light valve) and an incident side lens arranged in a projection type display device different from the projection type display device shown in FIG. is there.

In the liquid crystal device 10, the contrast is reduced depending on the incident angle of light due to the long axis direction of the liquid crystal being twisted between the substrates. In order to solve such a problem, the applicant of the present application has disclosed that in the projection display device 1, light is incident on the liquid crystal device 10 from a direction inclined obliquely toward the clear viewing direction with respect to the normal direction of the liquid crystal device 10. However, the lens array substrate 20 used in the projection display device 1 to which the present invention is applied can be applied to the lens array substrate 20 by using the inspection method and the inspection apparatus according to the present embodiment. The quality of the substrate 20 can be accurately inspected without trouble.

That is, in the projection type display device 1 described with reference to FIG. 1, as shown in FIG.
For example, by arranging the liquid crystal light valve 410R in an oblique posture shifted back and forth in the direction of the optical axis L (device optical axis), the optical axis of the light incident on the liquid crystal light valve 410R is changed in the direction normal to the light incident surface. The liquid crystal light valve 41 is tilted toward the clear viewing direction by a predetermined angle θ1 with respect to M.
The optical axis L of the light incident on 0R is inclined toward the clear viewing direction. In addition, the field lens 400 is tilted slightly backward from the upright position shown by the dashed line, so that the optical axis of light incident on the liquid crystal light valve 410R is normal to the light incident surface. It is inclined toward the clear viewing direction by a predetermined angle with respect to the direction M. Other liquid crystal device 100
(Light valve).

When the liquid crystal device 100 of the projection display device 1 having the above structure is tilted, when the lens array substrate 20 used for the liquid crystal device 100 is inspected, as shown by an arrow A in FIG. By supplying the array substrate 20 to the inspection device 1000 in a posture inclined obliquely in the front-rear direction, the inspection device 1000
The inspection is performed in a state where the optical axis of the light incident on the light source is inclined at a predetermined angle from the normal direction of the light incident surface.

When the field lens 400 is tilted slightly backward, as shown by the arrow B in FIG. 14, the incident side lens 1392 is arranged in the inspection apparatus 1000 in a tilted oblique direction in the front-rear direction. Thus, the inspection is performed in the inspection apparatus 1000 in a state where the optical axis of the light incident on the lens array substrate 20 is inclined at a predetermined angle from the normal direction of the light incident surface.

When the inspection is performed as described above, the inspection result is obtained in a state where the liquid crystal device 100 using the lens array substrate 20 is actually incorporated in the projection display device 1 described with reference to FIG. Test results.

[Other Embodiments] The irradiated surface 1
As a specific method of inspecting the lens array substrate 20 based on the amount of light applied to the light 450, the quality of the lens array substrate 20 may be determined and defective products may be removed.
The lens array substrate 20 may be ranked for each optical characteristic. In this case, the liquid crystal device 100 manufactured using the lens array substrate 20 having a low optical characteristic rank may be used as the light valve 410B (light modulation unit) for blue light. That is, in the projection display device 1, when three light valves are used for red light, green light, and blue light, respectively, blue light has the least effect on contrast. Therefore, the lens array substrate 20
As a result of the inspection described above, the lens array substrate 20 having a low rank is not discarded as a defective product but is used exclusively for blue light, thereby improving the yield of the lens array substrate 20.

In the above embodiment, the case where the microlenses 22 are formed on the side corresponding to the counter substrate has been described.
When a microlens is provided for each pixel of the active matrix substrate 30, the active matrix substrate may be inspected as a microlens lens substrate.
Microlenses may be provided on both the opposing substrate and the active matrix substrate, and any of these substrates may be inspected as a lens array substrate.

[0081]

As described above, according to the present invention, when inspecting the quality of the lens array substrate, factors such as the curvature of the micro lens, the thickness of the adhesive, the thickness of the thin glass, and the refractive index of each layer, etc. Not every time, in a state where the lens array substrate is finished, light is irradiated to the lens array substrate, and an inspection is performed based on a result of projecting light transmitted through the microlens. Therefore, since it is not necessary to use a reference mask matched to the microlens, a troublesome setup operation such as accurately aligning the reference mask with the lens array substrate can be omitted. Also, unlike the configuration that performs comparison with the reference mask, it is not necessary to change the optical system for performing inspection even if the specifications of the lens array substrate to be inspected change. The time and effort required can be saved.

[Brief description of the drawings]

FIG. 1 is a schematic plan view illustrating a configuration of an optical system of a projection display device.

FIG. 2 shows an illumination area 3 of the projection display device shown in FIG.
FIG. 3 is an explanatory diagram illustrating an integrator illumination optical system that illuminates a sheet of liquid crystal light valves.

FIGS. 3A, 3B, and 3C are a front view, a side view, and a first optical view, respectively, showing the appearance of a first optical element used in an integrator illumination optical system of a projection display device. It is a perspective view which expands and shows a part on the side where the micro lens of the element is formed.

4A and 4B are a perspective view showing an appearance of a polarization conversion element array used in the integrator illumination optical system shown in FIG. 2 and an explanatory view showing functions of the polarization conversion element array. .

FIG. 5 is a plan view of the liquid crystal device (light valve) when viewed from a lens array substrate (counter substrate).

FIG. 6 is a cross-sectional view of the liquid crystal device taken along the line HH ′ in FIG.

FIG. 7 is a block diagram illustrating a configuration of a liquid crystal device.

FIG. 8 shows an active matrix substrate used for a liquid crystal device,
It is sectional drawing of the panel end part which shows a lens array board | substrate and the bonding structure of these boards.

FIG. 9 is a perspective view showing a configuration of a main part of the lens array substrate inspection device according to the first embodiment of the present invention.

10 is an explanatory diagram of a surface to be irradiated with inspection light from the lens array substrate inspection device shown in FIG. 9, and a light receiving unit disposed on the surface to be irradiated;

FIG. 11 is a cross-sectional view illustrating an active matrix substrate, a lens array substrate, and a bonding structure of these substrates, which are different from the liquid crystal device illustrated in FIG.

FIG. 12 is a perspective view showing a configuration of a main part of a lens array substrate inspection device according to a second embodiment of the present invention.

FIG. 13 is an explanatory view showing a state in which the liquid crystal device and the incident side lens are tilted in a projection type display device different from the projection type display device shown in FIG.

FIG. 14 is a perspective view showing a configuration of a main part of a lens array substrate inspection device according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Projection display apparatus 20 Lens array substrate 21 Lens array 22 Micro lens 23 Center position of micro lens 25 Counter electrode 30 Active matrix substrate 39 Liquid crystal (electro-optical material) 48 Adhesive 49 Thin glass 100 Liquid crystal device (electro-optical device) 200 Light source 201 Light source unit 210 Light source lamp 212 Concave mirror 300 Integrator optical system 301 Optical unit 320 First optical element (condensing lens, lens array) 321 Small lens 330 Second optical element 340 Condensing lens 341 Small lens 360 Polarization conversion element Arrays 361, 362 Polarization conversion element array 363 Polarization beam splitter array 364 λ / 2 phase difference plate 366 Polarization separation film 367 Reflection film 368 Polarization conversion element 370 Superposition lens 372 Reflection mirror 380 Color light Separating optical system 382 First dichroic mirror 384 Reflecting mirror 386 Second dichroic mirror 390 Light guiding optical system 392 Incident side lens 394, 398 Reflecting mirror 396 Relay lens 400, 402, 404 Field lens 401 Projection lens 410R, 410G, 410B Liquid crystal light valve 420 Cross dichroic prism 1000 Inspection device 1201 Light source unit of inspection device 1300 Integrator optical system of inspection device 1301 Optical unit of inspection device 1320 First optical element of inspection device 1330 Second optical element of inspection device 1370 Inspection device Superimposed lens 1394 Polarizing plate of inspection device 1394 Glass block of inspection device 1401 Projection lens of inspection device 1450 Projected surface of inspection device 1451 Photodetector

Claims (15)

[Claims] 1. A lens array substrate on which a plurality of microlenses are formed is irradiated with light emitted from a light source, and the light transmitted through the microlenses is projected onto a projection surface via a projection optical system. Inspecting the lens array substrate based on the amount of light projected on the projection surface. 2. The inspection of a lens array substrate according to claim 1, wherein the amount of light is measured at a plurality of locations on the projection surface that are separated from each other, and the lens array substrate is inspected based on a result of the measurement. Method. 3. The inspection method of a lens array substrate according to claim 1, wherein the light emitted from the light source is irradiated on the lens array substrate so as to be substantially parallel. 4. The method according to claim 1, wherein
A method for inspecting a lens array substrate, comprising irradiating the lens array substrate with light whose optical axis is inclined with respect to a normal to a substrate surface of the lens array substrate. 5. The lens array substrate according to claim 4, wherein the lens array substrate is tilted to irradiate the lens array substrate with light whose optical axis is tilted with respect to a normal to the substrate surface of the lens array substrate. A method for inspecting a lens array substrate, comprising: 6. The light source according to claim 4, wherein the light source is configured to irradiate the lens array substrate with light whose optical axis is inclined with respect to a normal to a substrate surface of the lens array substrate.
Alternatively, a method of inspecting a lens array substrate, comprising tilting an attitude of an optical component disposed on an optical path from the light source to the lens array substrate. 7. The method according to claim 1, wherein
A method for inspecting a microlens array, comprising irradiating the light emitted from the light source with predetermined linearly polarized light to the lens array substrate. 8. The method according to claim 1, wherein
A method for inspecting a lens array substrate, wherein the lens array substrate is irradiated with colored light. 9. The method according to claim 1, wherein
A method for inspecting a lens array substrate, comprising sequentially irradiating the lens array substrate with a plurality of color lights per sheet. 10. The method for inspecting a lens array substrate according to claim 9, wherein the color of light applied to the lens array substrate is automatically switched at a predetermined timing. 11. The method for inspecting a lens array substrate according to claim 1, wherein the quality of the lens array substrate is determined based on the amount of light applied to the surface to be irradiated. 12. The lens array substrate inspection method according to claim 1, wherein the lens array substrates are ranked based on the amount of light applied to the surface to be irradiated. 13. A method of manufacturing an electro-optical device, comprising manufacturing an electro-optical device using a lens array substrate that has been inspected by the method defined in any one of claims 1 to 12. 14. An electro-optical device is manufactured by using a lens array substrate that has been inspected by the method defined in claim 1, and then the electro-optical device is used as a light modulating means for projection. A method for manufacturing a projection type display device, characterized by manufacturing a type display device. 15. An electro-optical device manufactured by using a lens array substrate having a low optical characteristic rank among the lens array substrates by performing an inspection according to the method defined in claim 12, and a light modulating means for blue light. A method of manufacturing a projection display device, wherein the method is used to manufacture a projection display device.