JP2001330733A - Illuminator and liquid crystal device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten light emission luminance of an illuminator by heightening efficiency of light incidence from a light source to a light guide body. SOLUTION: The illuminator is constructed so as to accept light outgoing from the light source 21 through a light accepting face 4a of the light guide body 4 and to emit the light from a light emitting face. A reflection preventing film 10 to suppress light reflection is film formed on the light accepting face 4a of the light guide body 4 by seal sticking, vapor deposition, dipping and so on. When refractive indexes of surroundings of the light guide body 4, the reflection preventing film 10 and the light guide body 4 are expressed by n0, n1 and n2 respectively, it is desirable that inequalities n0<n1<n2 hold. Also it is desirable that reflectance of the reflection preventing film 10 is 0.1-5%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device for taking in light emitted from a light source from a light receiving surface of a light guide, guiding the light to a light exit surface of the light guide, and emitting the light to the outside. Further, the present invention relates to a liquid crystal device including the lighting device.

[0002]

2. Description of the Related Art Liquid crystal devices are widely known as electro-optical display devices. In general, a liquid crystal device sandwiches liquid crystal between a pair of substrates provided with electrodes, controls the orientation of the liquid crystal by applying a voltage between the electrodes, and thereby modulates light passing through the liquid crystal to display an image. I do.

A liquid crystal device can be distinguished based on how light is supplied to the liquid crystal. A reflection type liquid crystal device having a structure in which external light is reflected by a reflector provided on an outer surface or an inner surface of one substrate,
A transmissive liquid crystal device with a structure that supplies light to the liquid crystal two-dimensionally by an illuminating device provided outside one of the substrates, or a reflective type when external light is present and when the external light is insufficient Various liquid crystal devices, such as a transflective liquid crystal device functioning as a transmission type, are known.

[0004] Illumination devices used in transmissive liquid crystal devices and transflective liquid crystal devices and the like conventionally use a light source 71 such as an LED or a cold cathode tube as shown in FIG. It is arranged so as to face the capturing surface 74a, and the light from the light emitting source 71 is guided from the light capturing surface 74a of the light guide 74 to the light emitting surface 74b while being reflected by the reflecting plate 78,
The light exits from the light exit surface 74b to the outside. Light emitting surface 74b
A device that uses light in a planar manner, for example, a liquid crystal panel (not shown) is arranged, and light emitted planarly from the light exit surface 74b is supplied to the device. It should be noted that the symbol R conceptually indicates the traveling path of light, but does not indicate the actual traveling path of light.

In recent years, color display is often performed by a liquid crystal device or the like. In order to provide a good-looking display in this color display, light for illuminating the liquid crystal panel has high luminance. Something is needed. Specifically, while about 2 nt is required for monochrome display, high brightness of 5 nt or more is required for color display. Despite the demand for such a high luminance, the above-described conventional lighting device has a problem that the light incidence efficiency from the light source to the light guide plate is low, and the luminance of light emitted from the lighting device is low. .

[0006]

In order to solve this problem, according to Japanese Patent Application Laid-Open No. Hei 9-212232, in order to enhance the light condensing function of the light guide, the light taking-in surface of the light guide is formed into a lens shape or the like. A technique of setting an inclined shape is disclosed. However, even when the shape of the light intake surface of the light guide is changed as described above, it has been difficult to increase the light intensity of the illumination device to a sufficiently satisfactory level.

The present invention has been made in view of the above problems, and a first object of the present invention is to increase the light emission luminance of a lighting device by increasing the efficiency of light incidence from a light source to a light guide. I do. It is a second object of the present invention to increase display brightness of a liquid crystal device without increasing the light emitting ability of a light source.

[0008]

(1) In order to achieve the first object, a first lighting device according to the present invention comprises a light source and a light guide for receiving light from the light source from a light receiving surface. In a lighting device having a body, a reflection suppressing film is provided on the light capturing surface.

According to the illumination device having the above structure, the light emitted from the light source is efficiently taken into the light guide by the function of the reflection suppressing film. As a result, the light source of the illumination device can be improved without increasing the light emitting ability of the light source. The light emission luminance of light emitted from the light emission surface can be increased.

[0010] In the first lighting device, the antireflection film has a refractive index of a medium between the light source and the antireflection film as n.
0, where n1 is the refractive index of the reflection suppressing film and n2 is the refractive index of the light guide, it is preferable that n0 <n1 <n2. Further, it is desirable that the reflectance of the reflection suppressing film having the above-described configuration is 0.1% to 5%.

(2) Next, in order to achieve the first object, a second lighting device according to the present invention comprises a light source and a light guide for receiving light from the light source from a light receiving surface. In the lighting device having, the light intake surface is a lens shape,
Further, a reflection suppressing film is provided on the light capturing surface.

According to a third aspect of the present invention, there is provided a lighting device having a light source and a light guide for receiving light from the light source from a light receiving surface, wherein a lens portion is provided on the light receiving surface. Further, a reflection suppressing film is provided on the lens unit. The difference between the third lighting device and the second lighting device is that the light guide surface of the light guide is formed in a lens shape instead of forming the light intake surface itself into a lens shape. That is to assemble to the light body.

According to the second and third illuminating devices having the above-described structures, the light emitted from the light source is efficiently taken into the light guide by the function of the reflection suppressing film. As a result, the light emitting ability of the light source is reduced. The emission luminance of light emitted from the light emission surface of the lighting device can be increased without increasing the brightness. Further, the light from the light source can be condensed and taken into the light guide by the function of the lens formed on the light intake surface of the light guide or the lens portion attached to the light intake surface. The efficiency of light incidence on the light guide can be further increased as compared with the case where only a film is used.

In the second and third illuminating devices, the reflection suppressing film has a refractive index of the medium between the light source and the reflection suppressing film as n0, a refractive index of the reflection suppressing film as n1, and the light guide. When it is assumed that the refractive index is n2, it is preferable that n0 <n1 <n2. Further, it is desirable that the reflectance of the reflection suppressing film having the above-described configuration is 0.1% to 5%.

(3) Next, in order to achieve the second object, the liquid crystal device according to the present invention comprises a liquid crystal panel having a pair of substrates sandwiching liquid crystal, and an illumination for supplying light to the liquid crystal panel. And a lighting device, wherein the lighting device is constituted by the first, second, or third lighting device.

According to this liquid crystal device, the light from the light source can be efficiently taken into the light guide by the reflection suppressing film, the lens shape, etc., so that the display brightness of the liquid crystal device can be improved without increasing the light emitting ability of the light source. Can be increased.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS When a liquid crystal device is distinguished by a driving method of a liquid crystal, an active matrix type liquid crystal device in which a pixel electrode is driven by a switching element (that is, a non-linear element) and a simple liquid crystal device using no switching element. A passive matrix type liquid crystal device constituted by a matrix arrangement is considered. Compared with the active matrix method, it is considered that the active matrix method is more advantageous in that the contrast, the response, and the like are good and high-definition display can be easily achieved.

Further, as an active matrix type liquid crystal device, a method using a three-terminal type element such as a thin film transistor (TFT) as a switching element and a method using a thin film diode (TFD) are used.
A method using a two-terminal element such as an ilm diode is known. Among them, a liquid crystal device using a TFD or the like has advantages that a short circuit between wirings does not occur in principle because there is no intersection of wirings, and a film forming process and a photolithography process can be shortened. I have.

Hereinafter, the embodiment of the present invention will be described by taking as an example a case where the above-described first and second inventions are applied to an active matrix type liquid crystal device having a structure using a TFD as a switching element for a pixel electrode. explain. Further, the liquid crystal device of the present embodiment is a transflective liquid crystal device that functions as a reflective type when external light is present and functions as a transmissive type when external light is insufficient. .

FIG. 1 shows a liquid crystal device 1 according to the embodiment. In this liquid crystal device 1, an FPC (FPC
lexible Printed Circuit: Flexible substrate 3a and FPC
3b, and the light guide 4 is attached to the non-display surface side of the liquid crystal panel 2 (the lower surface side in FIG. 1). The light capturing surface 4a of the light guide 4 is formed in a lens shape, that is, a shape capable of refracting the light that has reached the light capturing surface 4a into the light guide 4.

A reflection suppressing film 10 for suppressing light reflection is provided on the surface of the light intake surface 4a formed in a lens shape as described above. The reflection suppressing film 10 is, for example, affixing the reflection suppressing film 10 formed as a seal to the light capturing surface 4a, forming a film on the surface of the light capturing surface 4a by vapor deposition, or suppressing the reflection of the light capturing surface 4a. Immersion in a material, so-called dipping, to suppress the reflection
It can be formed on the surface of the light intake surface 4a by various methods such as forming a film of 0.

Assuming that the refractive index of the periphery of the light guide 4, usually air, is n 0 and the refractive index of the light guide 4 is n 2, the refractive index n 1 of the reflection suppressing film 10 is n 0 <n 1 <n 2. It is set to be related. Thereby, it is possible to reliably suppress the reflection of light traveling toward the light intake surface 4a.
The efficiency of light incidence on the light guide 4 can be increased by suppressing the reflection.

The relationship between the refractive indices as described above is such that, for example, the light guide 4 is formed of an acrylic resin, a polycarbonate resin, glass or the like, and the reflection suppressing film 10 is formed of an optical film (such as magnesium fluoride). It can be realized by forming a single layer or a multilayer.

On the opposite side of the light guide 4 from the liquid crystal panel 2, a control board 5 is provided. The control board 5 is used as a component of a liquid crystal device or an electronic device to which the liquid crystal device is mounted, for example, a mobile computer, a mobile phone, or the like, as appropriate. In the case of the present embodiment, the FPC 3a and the FPC 3b are used to electrically connect the liquid crystal panel 2 and the control board 5.

The liquid crystal panel 2 has a pair of substrates 7a and 7b bonded to each other by an annular sealing material 6. A liquid crystal driving IC 8a is mounted on the surface of a portion of the first substrate 7a that protrudes from the second substrate 7b by an AFC (Anisotropic Conductive Film) 9. A liquid crystal driving IC 8b is mounted by an ACF 9 on the surface of the portion of the second substrate 7b that protrudes from the first substrate 7a (the lower surface in FIG. 1).

The liquid crystal device of this embodiment is an active matrix type liquid crystal device using a TFD as a switching element. One of a first substrate 7a and a second substrate 7b is an element substrate, and the other is a counter substrate. is there. In the present embodiment, the first substrate 7a is considered as an element substrate, and the second substrate 7a
Let b be considered a counter substrate.

As shown in FIG. 2, the first
The pixel electrode 66 is formed on the inner surface of the substrate 7a, and the deflection plate 12a is adhered on the outer surface. The data lines 52 are formed on the inner surface of the second substrate 7b as the opposing substrate, and the deflection plate 12b is adhered on the outer surface. Then, the liquid crystal L is sealed in a gap surrounded by the first substrate 7a, the second substrate 7b, and the sealing material 6, that is, a so-called cell gap.

Although not shown in FIG. 2, the first substrate 7a
Various optical elements other than those described above are provided on the second substrate 7b as necessary. For example, an alignment film for aligning the alignment of the liquid crystal L is provided on the inner surface of each substrate. These alignment films are formed, for example, by baking after applying a polyimide solution. It is said that the polymer main chain of the polyimide is stretched in a predetermined direction by a rubbing process, and the liquid crystal molecules in the liquid crystal L sealed in the cell gap are directionally aligned along the stretching direction of the alignment film.

When color display is performed, a portion of the opposing substrate facing the pixel electrode formed on the element substrate is
Color filters of each primary color of R (red), G (green), and B (blue) are formed in a predetermined arrangement, and a black matrix of Bk (black) is formed in a region not facing the pixel electrode. Further, a smoothing layer is coated for smoothing and protecting the surface of the color filter and the black matrix. The counter electrode provided on the counter substrate side is formed on the smoothing layer.

FIG. 3 schematically shows the electrical configuration of the liquid crystal panel 2. As illustrated, a plurality of scanning lines 51 are formed in the liquid crystal panel 2 in a row direction (X direction), and a plurality of data lines 52 are formed in a column direction (Y direction). A pixel 53 is provided at each intersection with the data line 52.
Is formed. Each pixel 53 has a liquid crystal layer 54 and a TFD (Th
in Film Diode) 56 in series.

Each scanning line 51 is driven by a scanning line driving circuit 57, and each data line 52 is driven by a data line driving circuit 58. In the case of the present embodiment, the scanning line driving circuit 57 is included in the liquid crystal driving IC 8a of FIG. 1, and the data line driving circuit 58 is included in the liquid crystal driving IC 8b of FIG.

In FIG. 3, the scanning line 51 and the TFD 56
Are formed on the inner surface of the element substrate 7a of FIG. 2, and the pixel electrodes 66 formed on the inner surface of the element substrate 7a are connected to the scanning lines 51. On the other hand, in FIG. 3, the data line 52 is formed as a stripe-shaped electrode on the inner surface of the counter substrate 7b in FIG. The element substrate 7a and the opposing substrate 7b are bonded to each other so that the pixel electrodes 66 for one column and one data line 52 have a positional relationship facing each other. Therefore, the liquid crystal layer 54 is constituted by the data lines 52, the pixel electrodes 66, and the liquid crystal L sandwiched between them.

The data line 52 is, for example, an ITO (Indium)
It is formed of a transparent conductive material such as Tin Oxide.
The pixel electrode 66 is formed of a reflective material such as Al (aluminum). In FIG. 3, T
The FD 56 is connected to the scanning line 51 side, and the liquid crystal layer 54 is connected to the data line 52 side.
The FD 56 can be connected to the data line 52 side, and the liquid crystal layer 54 can be set to the scanning line 51 side.

FIG. 4 shows the structure of one pixel on the element substrate 7a. In particular, FIG. 4A shows a planar structure for one pixel, and FIG.
2 shows a cross-sectional structure according to line -A. In these drawings, the TFD 56 includes a first TFD 56a and a second TFD 56 formed on an insulating film 61 formed on the surface of the element substrate 7a.
It is composed of two TFD parts called TFD56b. The insulating film 61 is made of, for example, tantalum oxide (TA ₂
O ₅₎ by being formed to a thickness of about 50 to 200 mm.

The TFDs 56a and 56b are respectively separated from the first metal film 62, an oxide film 63 formed on the surface of the first metal film 62 and acting as an insulator, and separated from each other on the surface of the oxide film 63. Metal film 64 formed by
a and 64b. Oxide film 63
Is, for example, tantalum oxide (TA) formed by oxidizing the surface of the first metal film 62 by an anodic oxidation method.
₂ O ₅ ). When the first metal film 62 is anodically oxidized, the surface of the portion serving as the basis of the scanning line 51 is simultaneously oxidized, and an oxide film made of tantalum oxide is formed similarly.

A preferred value of the thickness of the oxide film 63 is selected according to its use, for example, about 10 to 35 nm. This film thickness is half the thickness in the case where one TFD is used for one pixel. The chemical conversion solution used for the anodic oxidation is not limited to a specific one, but for example, a citric acid aqueous solution of 0.01 to 0.1% by weight can be used.

The second metal films 64a and 64b are, for example,
After a reflective material such as Al (aluminum) is formed by a film forming technique such as a sputtering method, the film is patterned by photolithography and etching, and finally formed to a thickness of about 50 to 300 nm. . On the other hand, the second metal film 64a is used as it is for the scanning line 51.
And the other second metal film 64b is connected to the pixel electrode 66.

Here, the first TFD 56a is connected to the scanning line 51.
From the side of the second metal film 64a / oxide film 63 in order.
/ Laminated structure of first metal film 62, that is, metal / insulator /
Since a metal sandwich structure is employed, its current-voltage characteristics are non-linear in both positive and negative directions. On the other hand, the second T
When viewed from the scanning line 51 side, the FD 56b
A metal film 62 / oxide film 63 / second metal film 64b,
It has current-voltage characteristics opposite to those of the first TFD 56a. Accordingly, the TFD 56 has a form in which two elements are connected in series in opposite directions to each other, so that the non-linear characteristic of current-voltage is symmetrical in both positive and negative directions as compared with the case where one element is used. .

The first metal film 62 is formed of, for example, tantalum alone or a tantalum alloy. The thickness of the first metal film 62 is appropriately selected depending on the use of the TFD 56, but is usually about 100 to 500 nm. When a tantalum alloy is used as the first metal film 62, for example, tungsten, chromium, molybdenum, rhenium, yttrium,
Elements belonging to Groups 6 to 8 in the periodic table, such as lanthanum and displorium, are added. At this time, tungsten is preferable as the additive element, and the content ratio is desirably, for example, 0.1 to 6% by weight.

The base 1 constituting the element substrate 7a
7a is formed of, for example, quartz, glass, plastic, or the like, together with the base 17b (see FIG. 2) constituting the counter substrate 7b. Here, in the case of a simple reflection type, it is not essential that the element substrate base 17a is transparent. However, in a case where both the reflection type and the transmission type are used as in the present embodiment, the element substrate base 17a is not used. It is an essential requirement that the table 17a be transparent.

The reason why the insulating film 61 is provided on the surface of the element substrate 7a is as follows. That is, first, the heat treatment after the deposition of the second metal films 64a and 64b prevents the first metal film 62 from peeling off from the base. Second, it is for preventing impurities from diffusing into the first metal film 62. Therefore, if these points do not matter, the insulating film 61 can be omitted.

The TFD 56 is an example of a two-terminal nonlinear element.
or) and the like using a diode cable structure, or those in which these elements are connected in series or parallel in the reverse direction. Further, when it is not necessary to strictly make the current-voltage characteristics symmetrical in both the positive and negative directions, the TFD can be constituted by only one element.

In FIG. 4, the pixel electrode 66 formed so as to extend from the second metal film 64b is formed of a metal film having a high reflectance such as Al (aluminum). Further, the pixel electrode 66 is provided with a slit-shaped opening 67 that opens in an oblique direction as shown in FIG. When this liquid crystal device functions as a transmission type,
Light passing through these openings 67 enters the liquid crystal layer 54 (see FIG. 3). It is desirable that the pixel electrode 66 be provided with fine undulations so that reflected light is scattered.

The liquid crystal panel 2 (see FIG. 1) is attached with the element substrate 7a and the opposing substrate 7b kept at a fixed distance from each other, and the liquid crystal L (see FIG. 2) is placed in this gap.
Is enclosed. The rubbing direction for giving the liquid crystal L an orientation is determined in consideration of the visual characteristics of the liquid crystal panel.
If the element substrate 7a in the direction indicated by the arrow R _A in FIG. 4 (a), and if the counter substrate 7b are respectively set in the direction indicated by the arrow R _B. In other words, the rubbing direction that determines the orientation of the liquid crystal molecules when no voltage is applied is obliquely upward and to the left on the opposing substrate 7b located on the near side when viewed from the opposing substrate 7b when both substrates are bonded to each other. 4
5 ° is the direction R _B, the element substrate 7a which is located on the rear side
In this case, the direction _RA is 45 ° obliquely downward and to the left. Therefore,
The slit direction of the opening 67 in the element substrate 7a is formed to coincide with the rubbing direction _RA .

Since the rubbing treatment is generally performed by rubbing a buff cloth wound around a roller in a certain direction, unfavorable situations in the manufacturing process such as generation of static electricity and generation of various dusts are likely to occur. . In the present embodiment, since the traveling direction of the buff cloth coincides with the slit direction of the opening 67 in the rubbing process, the pixel electrode 66
The effect of the step difference is reduced, and as a result, generation of static electricity and generation of various dusts can be suppressed.

In the above description, the second metal films 64a, 64a
Although the composition of the pixel electrode 66 is the same as that of the pixel electrode 66, a non-reflective metal such as chromium, titanium, or molybdenum is formed as the second metal films 64a and 64b by patterning. The conductive metal may be formed by patterning.

The direction of the electric field generated by the pixel electrode 66 and the data line 52 facing the pixel electrode 66 is perpendicular to both substrates except for the opening 67 as shown in FIG. Become uniform. On the other hand, since there is no electrode in the opening 67, an electric field is only generated by leakage from the opening end of the pixel electrode 66. Therefore, the electric field strength near the opening 67 becomes weaker as the distance from the opening end increases, and is not uniform. Conversely, at a point equidistant from the side edge of the opening 67 formed in the pixel electrode 66, that is, at a point indicated by a broken line in FIG.

On the other hand, the rubbing direction of the element substrate 7a on which the pixel electrode 66 is formed coincides with the slit direction of the opening 67 formed therein, so that no voltage is applied on the element substrate 7a side when no voltage is applied. The liquid crystal molecules M are aligned and oriented in parallel along the edge of the opening 67. Therefore, when a potential difference is generated between the pixel electrode 66 and the data line 52, and particularly when this potential difference is small, the electric field intensity at one end and the other end of the liquid crystal molecule M becomes equal, and thus the liquid crystal molecule M is located at the opening 67. The liquid crystal molecules M are located in a region where the electrode exists,
That is, the liquid crystal molecules are tilted similarly to the liquid crystal molecules located in the region contributing to the display when functioning as the reflection type. Therefore, the light passing through the opening 67 and the pixel electrode 6
Since the directions of optical rotation of the reflected light reflected by 6 are substantially equal to each other, the difference in display quality between the transmission type and the reflection type can be reduced.

As described above, it is desirable that the slit direction and the rubbing direction of the opening 67 coincide with each other. However, if the two are within the angle range of ± 15 °, the difference in display quality described above will not hinder practical use. It is thought that it can be to the extent that there is no.

When the rubbing direction and the slit direction of the opening 67 do not coincide with each other, as shown in FIG. 6B, the liquid crystal molecules M located in the opening 67 are exposed when no voltage is applied. The orientation is oriented in a direction intersecting the side edge of 67. For this reason, even if a potential difference occurs between the pixel electrode 66 and the data line 52, particularly when the potential difference is small, the electric field intensity at one end and the other end of the liquid crystal molecule M is different, so that the liquid crystal molecule M is used as a reflection type. In this case, the liquid crystal molecules do not tilt as in the case of liquid crystal molecules located in a region contributing to display. As a result, the direction of the optical rotation differs between the light passing through the opening 67 and the reflected light reflected by the pixel electrode 66, so that a difference occurs in the display quality between the transmission type and the reflection type.

Next, the opening 6 formed in the pixel electrode 66
The width and area of No. 7 will be examined. In general, when the liquid crystal sealed between a pair of substrates is a TN (Twisted Nematic) type, the substrate spacing is several μm. In this case, for example, in the case of normally white, a region where the electrodes of both substrates intersect with each other is used. Even at a point about 1.5 μm away from the end, if a voltage is applied, black display is performed due to the effect of an electric field leaking from one end of the outer periphery of the electrode. Based on this, FIG. 4 (a)
If the width of the slit-shaped opening 67 is about 3 μm or less, which is twice as large as 1.5 μm, the liquid crystal molecules in the opening 67 are similar to the region where the electrode exists due to the electric field leaking from both side ends of the opening 67. To tilt. Conversely, if the width W of the slit-shaped opening 67 is set to 3 μm or more, the liquid crystal molecules M according to the electric field in both the reflection type and the transmission type.
Is formed in the pixel electrode 66 without tilting. Therefore, the width W of the opening 67 is 3
It is considered that it is desirable to be not more than μm.

When the width W of the opening 67 is 3 μm or less, a sufficient amount of light enough to function as a transmissive type is obtained unless a plurality of openings 67 are provided depending on the size of the pixel electrode 66. Not expected. On the other hand, if a large number of openings 67 are provided to increase the total area, the amount of transmitted light in the case of the transmission type increases, but the amount of reflected light decreases accordingly, so that the display screen in the case of using the reflection type becomes dark. According to the experiment, the area of the opening 67 was changed to the pixel electrode 6
It was found that when the area was set to 10 to 25% with respect to the area No. 6, the transmission type display and the reflection type display were displayed in a well-balanced manner. Note that the area of the pixel electrode 66 here is
Strictly speaking, it is the area of the effective display area that is the intersection area between the pixel electrode 66 and the data line 52 and is not shielded from light by a black matrix or the like.

Returning to FIG. 1, a plurality of terminals 13a are formed on the protruding portion of the first substrate 7a as an element substrate.
These terminals are formed at the same time when the pixel electrodes 66 are formed on the surface of the first substrate 7a in a region facing the second substrate 7b as the opposite substrate. Also, a plurality of terminals 13b are formed on the protruding portion of the second substrate 7b. These terminals are formed at the same time when the data lines 52 are formed on the surface of the second substrate 7b in a region facing the first substrate 7a.

The FPCs 3a and 3b are manufactured by forming a metal film pattern in a desired pattern on a flexible base layer made of polyimide or another material. A plurality of terminals 22 are provided at the edge of the FPC 3b, and these terminals are conductively connected to the terminals 13b of the second substrate 7b using a conductive adhesive element such as an ACF. F
The plurality of terminals 23 formed on the other side of the PC 3b are connected to terminals (not shown) provided at appropriate positions on the control board 5.

On the other hand, for the FPC 3a, a plurality of panel terminals 14 are formed on the back side (lower side surface in FIG. 1) of the side edge on the liquid crystal panel 2 side, and the surface of the side edge on the opposite side to the liquid crystal panel 2 ( A plurality of control board side terminals 16 are formed on the upper side surface of FIG. 1). Also, an appropriate wiring pattern 18 is formed over a wide area of the surface of the FPC 3a, and this wiring pattern 18 is directly connected to the control board side terminal 16 on the one hand, and is connected to the back panel side terminal 14 via the through hole 19 on the other hand. linked.

On the back surface of the FPC 3a, that is, on the surface opposite to the wiring pattern 18, a plurality of LEDs (Light Emitters) as light emitting elements constituting a lighting device in cooperation with the light guide 4 are provided.
Itting Diodes 21 are mounted or mounted in a row at an appropriate distance from each other. The wiring for these LEDs 21 is connected to the control board side terminal 16 via a through hole, for example. The LED 21 is, for example, as shown in FIG.
As shown in FIG. 1A, pins 26 as positioning means are provided on both sides of a planar light emitting surface 24 having light emitting points F, and these light emitting surfaces 24 and pins 26 are shown by arrows B in FIG.
, That is, the direction opposite to the FPC 3a.

A diffusion plate 27 is attached to the surface of the light guide plate 4 on the liquid crystal panel 2 side, that is, the light emission surface of the light guide plate 4 by sticking or the like, and the surface of the light guide plate 4 opposite to the liquid crystal panel 2 is reflected. The plate 28 is attached by sticking or the like. Reflector 28
Reflects light taken in from the light taking-in surface 4 a of the light guide 4 toward the liquid crystal panel 2. Further, the diffusion plate 27 diffuses light emitted from the light guide 4 toward the liquid crystal panel 2 so as to have a uniform intensity in a plane.

The light taking-in surface 4a of the light guide 4 has an FPC 3
The positioning recesses 31 are provided in a number corresponding to the number of pins 26 provided on the light emitting surface 24 of the LED 21 mounted on the LED 21a. These positioning recesses 31 are formed in such a size and positional relationship that the pins 26 of the LEDs 21 can be inserted without looseness.

As shown in FIG. 2, the light guide 4 is mounted on the non-display surface side of the liquid crystal panel 2 with a buffer 32 made of rubber, plastic or the like interposed therebetween. Further, the control board 5 is disposed to face the surface of the light guide 4 on which the reflection plate 28 is mounted. The control board 5 may be mounted on the non-display side surface of the light guide 4 as a component of the liquid crystal device 1 or may be a component of an electronic device using the liquid crystal device 1. In some cases. A terminal 33 for connecting to an external circuit is formed at a side end of the control board 5.

When assembling the components of the liquid crystal device 1 shown in an exploded state in FIG. 1, as shown in FIG.
a of the side of the liquid crystal panel 2 on the side of the liquid crystal panel 2
It is adhered to the overhang portion of the substrate 7a. By this bonding, the terminal 13a of the first substrate 7a and the terminal 14 of the FPC 3a
Conductive connection is made by conductive particles in the CF 34. Thereafter, the FPC 3a is bent along the light receiving surface 4a of the light guide 4, and in this bent state, the edge of the FPC 3a is overlapped with the edge of the control board 5. Then, the terminal 16 on the FPC 3a side is connected to the terminal 33 on the control board 5 side by soldering or another conductive connection method.

When the FPC 3a is bent as described above for conductive connection, a plurality of LEs mounted on the surface of the FPC 3a are used.
D21 is disposed at a position where the light-emitting surface 24 faces the light-receiving surface 4a of the light guide 4, and further includes the light-emitting surface 2 of the LED 21.
The pin 26 provided on the fourth 4 is fitted into the positioning recess 31.
With the above operation, as shown in FIG. 2, the LED 21 is placed at a predetermined position facing the light intake surface 4a of the light guide 4, and an illumination device for supplying light to the liquid crystal panel 2 is configured. Similarly, the other end of the FPC 3b shown in FIG. 1 where the terminal 23 is formed is conductively connected to a terminal on the control board formed in an appropriate position on the control board 5.

In the liquid crystal device 1 formed as described above, when the LED 21 emits light in FIG.
Light emitted from the light guide 4 is introduced into the light guide 4, and the introduced light is reflected by the reflection plate 28 and travels toward the liquid crystal panel 2, and has a uniform intensity in a plane by the diffusion plate 27. Is supplied to the liquid crystal panel 2 in a state of being diffused as described above. The supplied light is supplied to the liquid crystal layer as a component that has passed through the light guide-side deflection plate 12a, and the orientation of each pixel is controlled according to a change in the voltage applied between the pixel electrode 66 and the data line 52. The modulated liquid crystal is modulated for each pixel, and the modulated light is passed through the display-side deflection plate 12b to display an image outside.

As described above, in the present embodiment, in the lighting device including the LED 21 as the light emitting element and the light guide 4, the reflection suppressing film 10 is provided on the surface of the light intake surface 4 a of the light guide 4. The light emitted from the light source is efficiently taken into the light guide 4 by the function of the reflection suppressing film 10 as a result, and as a result, the LED 2 as the light source is provided.
The light emission luminance of the light emitted from the light emission surface of the lighting device can be increased without increasing the light emission performance of (1).

In the above-described embodiment, the light guide surface 4a of the light guide 4 is formed in a lens shape.
Thus, the efficiency of light incident on the illuminating device can be further increased, and thus the luminance of light emitted from the light exit surface of the lighting device can be further increased.

Further, in the liquid crystal device 1 of the present embodiment, the FP that controls the electrical connection between the liquid crystal panel 2 and the control board 5
The LED 21 is supported by C3a,
Since a dedicated substrate for supporting D21 has been eliminated, L
The support structure for ED21 has been greatly simplified. Therefore, the cost and size of the liquid crystal device can be reduced.

The LED 21 has a pin 26 and a recess 31.
With the liquid crystal device 1, the liquid guide device 4 is always positioned at a fixed position with respect to the light intake surface 4 a of the light guide 4, and is prevented from being displaced with respect to the light guide 4 when the liquid crystal device 1 is used. Therefore, the brightness of the display of the liquid crystal panel 2 does not vary for each product, and the liquid crystal device 1 having uniform display characteristics
Can be stably manufactured in large numbers. The light guide 4
If it is not necessary to accurately position the LED 21 with respect to the
6 may not be provided.

In this embodiment, the LED 21 is set to the FP
C3a is mounted on the same surface as the terminal 14 on the liquid crystal panel 2 side, and the wiring pattern 18 of the FPC 3a is
Connected to the terminal 14 via the
It is provided on the surface opposite to 21. Therefore, the wiring pattern 18 can be freely designed without being disturbed by the LED 21.

According to an experiment conducted by the present inventor, when the reflectance of the reflection suppressing film 10 was set within the range of 0.1% to 5%, the reflection from the light guide 4 constituting the lighting device was reduced. It was found to be effective in increasing the brightness of the emitted light.

(Second Embodiment) FIG. 8 shows another embodiment of a lighting device and a liquid crystal device according to the present invention. In this embodiment, the same members as those in the embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. The configuration of the parts not shown in FIG. 8 is the same as that of the embodiment shown in FIGS.

This embodiment is different from the embodiment shown in FIGS. 1 and 2 in that the LED 21 is made of an FPC which is a flexible substrate.
Instead of being supported by 3a, the LED 21 is arranged at a predetermined position with respect to the light receiving surface 4a of the light guide 4 by an inflexible LED substrate 38 formed of glass epoxy resin or the like. The LED substrate 38 can be supported by, for example, a frame (not shown) that supports the liquid crystal panel 2, by the light guide 4, or by other various support methods.

When the non-flexible LED board 38 is used, it is considered that the pins 26 for positioning the LEDs 21 and the recesses 31 into which the pins 26 are fitted need not necessarily be used.

(Third Embodiment) FIG. 9 shows a main part of still another embodiment of the liquid crystal device according to the present invention. In this embodiment, the same members as those in the embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. The configuration of the parts not shown in FIG. 9 is the same as that of the embodiment shown in FIGS.

This embodiment is different from the embodiment shown in FIGS. 1 and 2 in that the light intake surface 4a of the light guide 4 is not formed in a lens shape itself, but is formed in the light intake surface 4a.
The lens member 37 is fixed in a close contact state by bonding or another fixing method. The reflection suppressing film 10 is provided on the surface of the lens member 37. This embodiment is advantageous when it is necessary to change the shape of the lens provided on the light intake surface 4a.

(Fourth Embodiment) FIG. 10 shows a main part of still another embodiment of the liquid crystal device according to the present invention. In this embodiment, the same members as those in the embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. The configuration of the parts not shown in FIG. 10 is the same as that of the embodiment shown in FIGS.

The present embodiment is different from the embodiments shown in FIGS. 1 and 2 in that the shape of the light intake surface 4a of the light guide 4 is not a lens shape but a simple planar shape. is there. As described above, in the illumination device of the present invention, the light intake surface 4a of the light guide 4 formed into a shape other than the lens shape.
Also, by providing the reflection suppressing film 10, the light incidence efficiency can be improved.

(Fifth Embodiment) FIG. 7B shows a modification 21A of an LED as a light emitting element. This LED
21A is different from the LED 21 shown in FIG. 7A in that a triangular prism-shaped protrusion 36 is used instead of the pin 26 as the positioning means.

(Other Embodiments) The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and various modifications may be made within the scope of the invention described in the claims. Can be modified.

For example, in the embodiment shown in FIG. 1, the present invention is applied to a semi-transmissive and semi-reflective type active matrix type liquid crystal device using a TFD. , A transmission type liquid crystal device, an active matrix type liquid crystal device using a switching element other than the TFD, a passive matrix type liquid crystal device using no switching element, and the like.

[0079]

As described above, according to the lighting device of the present invention, the light emitted from the light source is efficiently taken into the light guide by the function of the reflection suppressing film. The luminance of light emitted from the light exit surface of the device can be increased without increasing the light emitting ability of the light source.
Further, according to the liquid crystal device of the present invention, the brightness of the liquid crystal display can be increased without increasing the light emitting ability of the light source.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a lighting device and a liquid crystal device according to the present invention in an exploded state.

FIG. 2 is a cross-sectional view illustrating a cross-sectional structure of the illumination device and the liquid crystal device illustrated in FIG.

FIG. 3 is a diagram schematically showing an electrical configuration of a liquid crystal panel included in the liquid crystal device shown in FIG.

4A and 4B are diagrams showing a structure for one pixel in the liquid crystal panel of FIG. 3, wherein FIG. 4A is a plan view and FIG.
It is sectional drawing according to the -A line.

FIG. 5 is a cross-sectional view showing an electric field direction on an element substrate.

FIG. 6 is a diagram schematically showing a relationship between an electric field strength and an arrangement of liquid crystal molecules on an element substrate.

FIG. 7 is a perspective view illustrating some embodiments of a light emitting device.

FIG. 8 is a cross-sectional view showing another embodiment of the lighting device and the liquid crystal device according to the present invention.

FIG. 9 is a cross-sectional view showing still another embodiment of the illumination device and the liquid crystal device according to the present invention.

FIG. 10 is a cross-sectional view showing still another embodiment of a lighting device and a liquid crystal device according to the present invention.

FIG. 11 is a cross-sectional view illustrating an example of a conventional lighting device.

[Explanation of symbols]

 Reference Signs List 1 liquid crystal device 2 liquid crystal panel 3a FPC 4 light guide 5 control substrate 7a first substrate (element substrate) 7b second substrate (counter substrate) 8a, 8b liquid crystal driving IC 9 ACF 13a, 13b terminal 14 terminal 16 terminal 17a, 17b Base 21 LED (Light Emitting Element) 26 Positioning Pin 31 Positioning Recess 33 Terminal 36 Triangular Prism F Emission Point L Liquid Crystal M Liquid Crystal Molecule W Slit Width

Claims (8)

[Claims] 1. An illumination device comprising: a light source; and a light guide for receiving light from the light source from a light intake surface, wherein a reflection suppressing film is provided on the light intake surface. 2. The method according to claim 1, wherein a refractive index of a medium between the light source and the reflection suppressing film is n0, a refractive index of the reflection suppressing film is n1, and a refractive index of the light guide is n2. A lighting device, wherein n0 <n1 <n2. 3. The lighting device according to claim 1, wherein the reflectance of the reflection suppressing film is 0.1% to 5%. 4. An illuminating device having a light source and a light guide for receiving light emitted from the light source from a light-receiving surface, wherein the light-receiving surface has a lens shape, and further includes a reflection suppressing film provided with the light-receiving surface. A lighting device characterized by being provided on a surface. 5. An illuminating device having a light source and a light guide for receiving light from the light source from a light capturing surface, comprising: a lens portion on the light capturing surface; and a reflection suppressing film provided on the lens portion. A lighting device, comprising: 6. The refractive index of the light guide according to claim 4, wherein a refractive index of a medium between the light source and the reflection suppressing film is n0, a refractive index of the reflection suppressing film is n1, and a refractive index of the light guide. When n2, n0 <n1 <n2. 7. The reflection suppressing film according to claim 4, wherein the reflectance of the reflection suppressing film is 0.1%.
The lighting device is characterized by being about 5%. 8. A liquid crystal device comprising: a liquid crystal panel having a pair of substrates sandwiching liquid crystal; and an illumination device for supplying light to the liquid crystal panel, wherein the illumination device is any one of claims 1 to 7. A liquid crystal device comprising the lighting device according to one of the above aspects.