JP3021137B2 - Liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical coupling optical device comprising a light source and a light propagation medium on which light from the light source is incident.
And a liquid crystal display device having the same .

[0002]

2. Description of the Related Art Conventionally, an optical waveguide, a light emitting element such as an LED (light emitting diode) and an LD (laser diode), and a PD
When optically coupling with a light receiving element such as a (photodiode), as shown in a waveguide type photocoupler for optical communication, light is condensed by a condensing system such as a microlens to an optical fiber which is an optical waveguide. In this structure, the lens and the incident end of the optical fiber are connected to each other by an adhesive such as an ultraviolet curable resin (see Japanese Patent Application Laid-Open No. 61-93419).

On the other hand, as a method for coupling an optical waveguide and a light emitting element or a light receiving element without using an optical system such as a lens,
The following are known.

The first method is to directly couple a semiconductor laser and an optical fiber. First, the center of the optical fiber is aligned with the center of the light emitting point of the semiconductor laser chip. The tip is cut off, the outer shell phenol is cut out in an L-shape so that chip bonding can be performed, a semiconductor laser chip is aligned at that portion, and the optical fiber and the semiconductor laser are brought into close contact with each other. -253315).

A second method is to directly optically couple the semiconductor laser chip and the optical waveguide, and the active layer of the semiconductor laser is sandwiched between the active layer end faces of the semiconductor laser or the optical waveguide end faces. The light from the semiconductor laser chip is directly optically coupled to the optical waveguide while protecting the active layer end surface and the optical waveguide end surface by abutting the end surface with the optical waveguide end surface (Japanese Patent Laid-Open Publication No. 3-3991).
3).

On the other hand, a drive using an XY matrix electrode configuration
The conventional liquid crystal display device of the moving type has a scanning electrode X and a signal electrode.
Y, and an electric distribution is provided to the scanning electrode X and the signal electrode Y.
Display an image by sending a signal through a wire
It is configured as follows.

Generally, high-density signals are transmitted by electric wiring.
The signal wave by the wiring resistance and capacitance.
Delays in form, realizing large or high-density equipment
There is a problem that it is difficult.

[0008] This problem occurs in a liquid crystal display device.
An optical waveguide is used to transmit the
The solution is to use a photoconductor with varying impedance.
Such a liquid crystal display device is an optical scanning type
It is known as a liquid crystal display device.

[0009]

In any of the conventional optical coupling methods, an optical distance is generated between the light emitting surface of the light emitting element and the optical waveguide in any of the methods. Since various optical systems are provided between the optical waveguides, it is difficult to efficiently make light from the light emitting element incident on the optical waveguide, and it is also difficult to reduce the size and the array.

In the optical scanning type liquid crystal display device, a sufficient
The more the light is irradiated on the photoconductor with the quantity of light, the more
The change of the dance becomes large, and as a result, the optical scanning type liquid crystal display
Improve the basic performance of the device, ie, contrast and gradation
be able to. Liquid crystal display devices based on this idea
Some proposals have been made for
Report: Japanese Patent Application Laid-Open No. 2-134617).
Cannot be introduced into the optical waveguide efficiently, and
There is a problem that a large amount of light cannot be irradiated.

[0011] The present invention, it is possible to enter efficiently waveguide light from the light emitting element, having a light coupling optical system can be easily made compact and arraying
Liquid crystal display device .

[0012]

According to the present invention, there is provided a liquid crystal display device having an optical coupling optical device including a plurality of light emitting elements and a plurality of light propagation media on which light from the light emitting elements is incident. in the plurality of light emitting elements, and a formed on the same semiconductor light-emitting layer formed in an array on a substrate and said semiconductor substrate is formed under the electrodes and the light emitting layer on the electrode, the semiconductor Formed in an array on the substrate
Guide made of the same material as the light emitting layer formed
The light propagation medium is formed on a substrate, and is fixed such that a light incident surface of the light propagation medium and a light emission end of a light emitting layer of the light emitting element are in direct contact with each other according to the guide. It is characterized by having.

[0013]

A plurality of light emitting elements used as light sources are formed in an array on a semiconductor substrate, and a plurality of light propagation media are formed in an array on a substrate. The two substrates, the semiconductor substrate on which the light emitting element is formed and the substrate on which the light propagation medium is formed, are arranged such that the light emitting end of the light emitting layer of each light emitting element is in direct contact with the light incident surface of the corresponding light propagation medium. Fixed. Therefore, there is no optical distance between the light emitting layer of the light emitting element and the light propagation medium, and light from the light emitting element can be extremely efficiently incident on the light propagation medium. Further, since an optical system is not required, it is extremely easy to increase the degree of integration and reduce the size. Furthermore, the gas formed simultaneously with the light emitting element
Align the light emitting device and the light propagation medium according to the
The pitch of the light emitting element and the pitch of the light propagation medium.
Switches and guides are set accurately with the accuracy of the mask.
Light emitting element and light propagation medium
High-precision alignment of the light-emitting element and the light propagation medium
Adjustment of the liment in one direction can be completed
As a result, a large-scale array of light emitting elements and light propagation media can be realized at low cost and with high productivity.

As a result, the light from the light emitting element can be efficiently
Enough for the photoconductor because it can be introduced into the waveguide
It is possible to irradiate a large amount of light, and an optical scanning liquid crystal display
It is possible to improve the basic characteristics of the device.

[0015]

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

FIG. 1 is a sectional view showing the structure of an embodiment of an optical coupling optical device in a liquid crystal display device according to the present invention.
FIG. 2 is a plan view of one embodiment of the optical coupling optical device in the liquid crystal display device according to the present invention.

As shown in these figures, 11 is a glass substrate, and 12 is an optical waveguide formed on the glass substrate 11 in an array.

For example, Al _x Ga _{1 -x} As (composition ratio x is 0.1.
The light emitting elements 13 in an array composed of 27) are made of GaAs having a thickness of about 1 mm by MBE (Molecular Beam Epitaxy).
The (001) crystal is formed on the low-resistance substrate 15.

At this time, first, the GaAs (001) substrate 15
It is necessary to obtain a clean surface of the above, and there are two methods as follows.

The first method is to degrease with an organic solvent (acetone, trichloroethylene, methanol) and then add sulfuric acid (G
etching the GaAs (001) surface, sulfuric acid etchant _{(H 2 SO 4: H 2} O 2: H 2 O = n: 1: 1, preferably n = 3~5) GaAs (001) substrate 15 by)
Is a method of forming an oxide film on the surface of the substrate.

The second method is to use G with ammonium sulfide.
This is a method of forming a sulfur passivation film on the surface of the aAs (001) substrate 15.

A clean surface of the GaAs (001) substrate 15 can be obtained by either the first or second method.

Next, the film formed on the GaAs (001) substrate 15 is removed by thermal cleaning. When removing the above-mentioned oxide film, the substrate temperature should be 5 to 630 ° C.
When the sulfur passivation film is removed for about 20 minutes, heat treatment is performed at a substrate temperature of 300 to 450 ° C. for about 2 to 15 minutes to obtain a completely clean surface.
Whether or not a completely clean surface has been obtained can be determined by RHEED (reflection high-speed electron diffraction) during thermal cleaning.
The determination can be made by observing a sub-streak pattern that appears due to the surface reconstruction structure peculiar to the clean surface of the aAs (001) substrate.

Next, on the clean surface of the GaAs (001) substrate 15, n-type Al _x Ga _{1 -x} As (composition ratio x is 0.27)
Is grown by MBE.

The growth conditions at this time are as follows: the growth temperature is 650 ° C., and the molecular beam intensity ratio is As _{4 in a} normal K-cell.
/ (Al + Ga) = 10~20 , if thermal cracking K- cells and _{As 2 / (Al + Ga)} = 2~10, growth rate 0.1-2 .mu.m / time and the emission wavelength to 670 nm. Note that, depending on the growth conditions, the composition ratio is x = 0.01 to
It is also possible to form a film with a value in the range of 0.30.

Silicon (Si) is used as the n-type dopant, and beryllium (Be) is used as the p-type dopant. However, germanium (G
e), tin (Sn), sulfur (S), selenium (Se), tellurium (Te), etc., and silicon (Si), germanium (Ge), carbon (C), magnesium (Mg) as a p-type dopant, Zinc (Zn), manganese (Mn), or the like can also be used.

In this embodiment, the n + layer Al _x Ga _{1 -x} As
24 has an epitaxial film thickness of about 50 μm and an n-layer Al _x G
The film thickness of a _1-x As25 is about 2 μm, and the p-layer Al _x Ga _1-x As
26 has a thickness of about 2 μm and a p + layer Al _x Ga _{1 -x} As2
The film thickness of No. 7 was about 5 μm.

Light beam 35 emitted from light emitting element 13
In order to efficiently guide the light to the optical waveguide 12, the light emitting element 13
Need to be positioned at the center of the optical waveguide 12. Therefore, it is important that the thickness of the epitaxial layer of n + Al _x Ga ₁ -xAs 24 is thicker than that of the conventional light emitting element, and it is appropriate that the thickness is 3 to 50 μm.

For example, if the thickness of the optical waveguide 12 is 100 μm
In the case of the optical waveguide 1, ideally,
It is desirable that the active layer of the light emitting element 13 be located at the center of the light emitting element 2, that is, at a position 50 μm from the bottom or top. However, actually, it is not always necessary to limit to such a position.

After the film is grown, the light emitting element 13 and the guide 14 are left by a reactive ion etching (RIE) technique. In this embodiment, in order to leave the light emitting element 13 and the guide 14 with high accuracy, an anisotropic etching method is used, and chlorine gas (Cl ₂ ) is used as a reactive gas. In addition, as the reactive gas, CCl ₄ , CCl ₂ F ₂ , CCl ₄
/ H ₂ or the like can also be used.

Further, the electrode 28 on the light emitting element 13 and the GaAs
The electrode 16 on the s (001) substrate 15 and the GaAs (0
01) The cathode electrode 32 on the back side of the substrate 15 is mask-deposited by a vacuum deposition method. Then, the Au (gold) wire 31 is bonded between the electrode 28 and the electrode 16.

Optical waveguide 12 formed on glass substrate 11
The end face on the light emitting element 13 side is mirror-polished in advance, and then an antireflection film 20 is attached. In order to protect the alignment during alignment and prevent light scattering, it is desirable to coat the transparent resin thinner.

Next, the light emitting element 13 and the optical waveguide 12 are aligned in accordance with the guide 14 provided on the light emitting element side, and the glass substrate 11 and the GaAs
By fixing the (001) substrates 15 to each other, the light emitting element 13 and the optical waveguide 12 are brought into direct contact and coupled.

In order to prevent light from entering the other optical waveguides 12 from the light emitting element 13 and extend the life of the light emitting element 13, a carbon-based insulating protective film 29 is applied to the light emitting element 13, Further, the Au wire 31 is protected and the light emitting element 1
In order to fix the light incident surface of the optical waveguide 12 to the glass substrate 11, the connecting portion between the glass substrate 11 and the light emitting element 13 is made of an insulating resin 33.
Coat with

The optical waveguide 12 is an embodiment of the light propagation medium of the present invention. The light emitting element 13 is an embodiment of the light emitting element of the present invention.

According to the optical coupling optical device of this embodiment, since the light emitting layer of the light emitting element 13 and the light incident surface of the optical waveguide 12 are in direct contact, the light from the light emitting element 13 can be guided very efficiently. The light can be incident on the wave path 12, and the light introduction efficiency can be greatly improved. Further, since an optical system is not required, it is extremely easy to increase the degree of integration and reduce the size.

Further, since the optical waveguide and the optical fiber have conventionally been mechanically processed for optical coupling, it has been difficult to accurately align the optical waveguide with the light emitting element. For example, since the pitch of the optical waveguide 12, the pitch of the light emitting element 13 and the position of the guide 14 are accurately set with the accuracy of the mask, the alignment between the optical waveguide 12 and the light emitting element 13 can be completed by adjusting only one direction. can do. Therefore, the alignment property between the optical waveguide 12 and the light emitting element 13 is improved, and a large-scale array and high integration of the light emitting element and the optical waveguide as the light propagation medium can be realized at low cost and high productivity. Can be.

In this embodiment, the light emitting element is LE
Although the example using D has been described, it is also possible to use LD (laser diode), SQWLD (single quantum well laser diode) and MQWLD (multiple quantum well laser diode) instead of LED.

As a method of manufacturing the light emitting element 13, MB
Although the example using the E method has been described, the material to be used is different depending on the required wavelength of light, and the growth method to be used is different accordingly. Therefore, as a growth method, MOCV
Method D (metal organic chemical vapor deposition), OMVPE, MOVPE
Method (organic metal vapor phase epitaxy), OMCVD (organic metal chemical deposition), MOMBE (organic metal molecular beam epitaxy), CBE (chemical beam epitaxy), LPE (liquid phase epitaxy), etc. Will be used as needed. However, no matter which of these growth methods is used to manufacture the light emitting device, light can be directly introduced into the optical waveguide 12 within the range of the reactive ion etching technique.

As the light emitting element 13, an amorphous semiconductor such as amorphous silicon hydride (a-Si: H) and amorphous hydrogenated silicon carbide (a-SiC: H) can be used. .

The case where light from the light emitting element is guided to the optical waveguide has been described above as an example. By replacing the light emitting element 13 with a photodiode serving as a light receiving element, light from the optical waveguide 12 is made incident on the light receiving element. An optical coupling optical device can also be realized. Also in this case, light from the optical waveguide can be extremely efficiently incident on the light receiving element, and compactness and arraying can be easily performed as in the case of the light emitting element.

The light receiving element includes a-Si:
An amorphous semiconductor such as H or a-SiC: H can be used.

Next, a book using the above-described optical coupling optical device will be described.
The liquid crystal display device according to the invention will be described.

FIG . 3 shows an embodiment of the liquid crystal display device according to the present invention.
FIG. 2 is a cross-sectional view illustrating an example of a configuration of an optical scanning type liquid crystal display device having an optical coupling optical device . FIG. 3 shows an enlarged portion where light emitted from the light emitting element 90 is incident on the optical waveguide 51.

As shown in the figure, a glass substrate 52 has an optical waveguide 5 instead of a conventional wiring for transmitting a scanning signal.
The GaAs (001) crystal low resistance substrate 75 on which the light emitting element 90 is formed is attached to the glass substrate 52.

The manufacturing method and structure of the light emitting device 90 are shown in FIG.
This is the same as the light emitting element 13 of the embodiment shown in FIG.

The attachment of the GaAs (001) substrate 75 is performed as follows.

A guide (not shown) formed on the GaAs (001) substrate 75 (a guide corresponding to the guide 14 shown in FIG. 2) is brought into contact with the end face of the glass substrate 52, and after alignment, the seal 72 of the liquid crystal panel is contacted. GaAs (001)
An adhesive 74 is poured between the substrate 75 and the substrate 75 to fix them.

In order to prevent light from entering the light guide 51 from the light emitting element 90 and extend the life of the light emitting element 90, a carbon-based insulating protective film 79 is applied to the light emitting element 90. Further, in order to protect the Au wire 81 and fix the light emitting element 90 and the light incident surface of the optical waveguide 51, the connecting portion between the glass substrate 52 and the light emitting element 90 is made of insulating resin 8
Coat with 3.

At the opposite end of the optical waveguide 51, a reflecting mirror 71 for preventing light loss is attached. Reflector 7
Aluminum (Al), silver (Ag), or the like is used as the material of the first method, and the material is deposited on the end of the optical waveguide 51 by a vacuum deposition method. Note that a dielectric mirror in which dielectric films having different refractive indexes are alternately stacked may be used as the reflecting mirror.

The electrode 88 on the light emitting element 90 and the GaAs (0
01) Electrode 86 on substrate 75 and GaAs (001)
The cathode electrode 82 on the back side of the substrate 75 is formed by mask evaporation using a vacuum evaporation method. Electrode 88 and electrode 86
Is bonded by an Au wire 81.

An optical waveguide 51 formed on a glass substrate 52
The end face on the light emitting element 90 side is mirror-polished in advance, and then an antireflection film 80 is attached. In order to protect the alignment during alignment and prevent light scattering, it is desirable to coat the transparent resin thinner.

FIG. 4 is a sectional view taken along line AA of FIG. FIG. 1 shows a configuration of a liquid crystal light valve which is included in the optical scanning type liquid crystal display device of this embodiment and is used in, for example, a projection type image display device.

As shown in the figure, the liquid crystal light valve of this embodiment comprises an optical waveguide 51, glass substrates 52 and 59,
It includes a transparent electrode 53, a cladding layer 54, a metal film 55, a photoconductor layer 56, a dielectric mirror 57, an electrode 60, and a polyimide film 61.

The scanning optical signal is transmitted along the optical waveguide 51. The optical waveguide 51 is formed in a stripe shape on a glass substrate 52 by using an ion exchange method using heat and an electric field.

In this embodiment, a multi-mode thallium (Tl) ion exchange waveguide is used as the optical waveguide 51 so as to guide light having poor directivity such as a light emitting element. Ions and the like may be used.

When the transparent electrode 53 is provided on the optical waveguide 51 and the glass substrate 52, the refractive index of tin-doped indium oxide (ITO) forming the transparent electrode 53 is larger than that of the optical waveguide 51. , It is necessary to provide the cladding layer 54. As a material of the cladding layer 54, silicon dioxide (SiO ₂ ), which is a low refractive index dielectric, is suitable, and the cladding layer 54 is formed by vapor deposition on the glass substrate 52 by a sputtering method. At that time, S
It is necessary to set the film thickness of iO _{2 so that} the optical waveguide 51 generates an appropriate light leakage as a light emitting source, and a value in the range of 500 Å to 5000 Å is appropriate. In this embodiment, for example, the thickness of SiO ₂ is 30
00 angstroms.

The transparent electrode 53 is formed on the cladding layer 54 by a sputtering method. The transparent electrode 53 on the optical waveguide 51 may be patterned in a stripe shape so as to overlap the optical waveguide 51.

In order to block light from other than the optical waveguide 51,
A metal film 55 is provided on the back surface of the glass substrate 52, that is, on the surface opposite to the surface on which the optical waveguide 51 is formed. The metal film 55 can be formed from Ag, Al, molybdenum (Mo), or the like. It is also possible to use a pigment-dispersion type light-shielding film used for a color filter or the like of a liquid crystal panel.

Next, a-Si: H is formed on the transparent electrode 53 as a photoconductor layer 56 for receiving light from the optical waveguide 51 by a plasma CVD method (plasma chemical vapor deposition). A-Si on the photoconductive layer 56: the other H, as long as the impedance corresponding to the irradiation amount of light has a characteristic that varies, bismuth silicate (Bi ₁₂ SiO _20),
Cadmium sulfide (CdS), a-SiC: H, amorphous hydrogenated silicon oxide (a-SiO: H), amorphous hydrogenated silicon nitride (a-SiN: H), or the like may be used.

Next, on the photoconductor layer 56, a dielectric mirror 57 composed of a multilayer film in which titanium dioxide (TiO ₂ ) and SiO ₂ are alternately laminated is formed by an electron beam evaporation method.

Incidentally, a light-shielding layer may be provided between the dielectric mirror 57 and the photoconductor layer 56 in order to prevent the reading light from leaking to the photoconductor layer 56 through the dielectric mirror 57. As the light-shielding layer, a carbon-dispersed organic thin film or an aluminum oxide (Al ₂ O ₃ ) film obtained by electroless plating cadmium telluride (CdTe) or Ag can be used.

Glass substrate 59 facing glass substrate 52
Is provided with an electrode 60 for data transmission, and the electrode 60 is formed by vapor-depositing ITO by a sputtering method and patterning it in a stripe shape.

The electrode 60 and the dielectric mirror 57 are spin-coated with a polyimide film 61 as an alignment film, and then rubbed to perform an alignment process.

The glass substrate 52 and the glass substrate 59 are bonded together via a spacer (not shown) so that the electrode 60 for data transmission and the optical waveguide 51 for scanning have a vertical intersecting relationship. A liquid crystal layer 62 is formed by injecting liquid crystal therebetween.

The impedance of the liquid crystal forming the liquid crystal layer 62 is larger than the impedance of the photoconductor layer 56 selected as a scanning line by light irradiation.
In addition, a liquid crystal that is smaller than the impedance of the photoconductor layer 56 that is not selected is selected.

Therefore, the impedance of the liquid crystal layer 62 is
Photoconductor layer 5 selected as a scanning line by light irradiation
The data signal applied between the electrodes is mostly applied to the liquid crystal layer 62 because the impedance is much larger than the impedance of the liquid crystal layer 6. However, the data signal is not applied to the liquid crystal layer 62 because the impedance of the photoconductor layer 56 that is not irradiated with light is larger than the impedance of the liquid crystal layer 62.

For this reason, as compared with the conventional XY simple matrix drive system in which the scanning signal is transmitted by the electric wiring, the data signal is not always applied to the liquid crystal of the non-selection part, and the voltage averaging usually limited by the number of scanning lines The operating voltage margin in the method is increased, and high contrast can be obtained. Further, by modulating the waveform of the data signal, gray scale display is also possible .

The optical waveguide 51 is an embodiment of the light propagation medium of the present invention. The light emitting device 90 is an embodiment of the light emitting device of the present invention.

According to the above-described embodiment, an optical signal can be introduced into the scanning optical waveguide with high efficiency, and the impedance of the photoconductor can be largely changed. Gradation can be greatly improved.

Further, the structural feature that the light emitting element and the optical waveguide are coupled by direct contact makes it possible to increase the degree of integration and the scale of the device.

Further, since various light emitting diodes, various semiconductor lasers and quantum wells (multiple quantum well lasers) can be used as a light source, a photoconductive waveguide, which serves as a basis for driving an optical scanning type liquid crystal display device, can be used as a light source. The efficiency of extracting light to the body in the vertical direction can be increased, and the degree of freedom in selecting a light source can be increased, so that a high degree of freedom can be obtained in the selection of a photoconductor material. Therefore, from these points, it is possible to increase the amount of light irradiation on the photoconductor, thereby increasing the impedance change of the photoconductor .

[0073]

As described above, the present invention relates to a liquid crystal display device having an optical coupling optical device including a plurality of light emitting elements and a plurality of light propagation media on which light from the light emitting elements is incident. The plurality of light-emitting elements have a light-emitting layer formed in an array on the same semiconductor substrate, an electrode formed under the semiconductor substrate, and an electrode formed on the light-emitting layer,
On the semiconductor substrate, the light emission formed in the array shape
Guides made of the same material as the layers
The light propagation medium is formed on a substrate,
The light incident surface of the light propagation medium and the light emitting end of the light emitting layer of the light emitting element are fixed so as to be in direct contact with each other according to the guide . Therefore, the light emitting element and the light
Achieve high-accuracy alignment with the propagation medium with high productivity
And light from the light emitting element can be efficiently introduced into the optical waveguide, so that the photoconductor can be irradiated with a sufficient amount of light, and the basic characteristics of the optical scanning type liquid crystal display device. Can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of an embodiment of an optical coupling optical device according to the present invention.

FIG. 2 is a plan view of one embodiment of the optical coupling optical device according to the present invention.

FIG. 3 is an example of a liquid crystal display according to the present invention, which is an optical scanning device
FIG. 2 is a cross-sectional view showing a configuration of a liquid crystal display device .

FIG. 4 is a sectional view taken along line AA of FIG. 3;

[Explanation of symbols]

11, 52, 59 Glass substrate 12, 51 Optical waveguide 13, 90 Light emitting element 24 n + layer Al _x Ga _1-x As 25 n layer Al _x Ga _1-x As 26 p layer Al _x Ga _1-x As 27 p + layer Al _x Ga _1-x As 34, 74 Adhesive 53 Transparent electrode 56 Photoconductor layer 62 Liquid crystal layer

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-134617 (JP, A) JP-A-63-253315 (JP, A) JP-A-1-288802 (JP, A) JP-A-58-1983 175884 (JP, A)

Claims (1)

(57) [Claims] 1. A liquid crystal display device having an optical coupling optical device including a plurality of light emitting elements and a plurality of light propagation media into which light from the light emitting elements is incident, wherein the plurality of light emitting elements are the same semiconductor. A light-emitting layer formed in an array on the substrate, an electrode formed under the semiconductor substrate, and an electrode formed on the light-emitting layer; and the semiconductor substrate is formed in the array. Glow
Guides made of the same material as the layers
The light propagation medium is formed on a substrate, and is fixed such that a light incident surface of the light propagation medium and a light emission end of a light emitting layer of the light emitting element are in direct contact with each other according to the guide . A liquid crystal display device characterized by the above-mentioned.