JP2007279103A - Liquid crystal device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal device which can have reliability of display quality by improving response of liquid crystal without providing an additional member for heating, and electronic equipment using the liquid crystal device. <P>SOLUTION: The liquid crystal device has an air layer 52 between a first substrate 7 and a light guide plate 29 on the opposite side of at least one substrate from a display side, and a heat radiation plate 34 which is in contact with a light source 28 and made of a metal material partially exposed so as to be able to emit heat from the light source 28 to the air layer 52. Thus, the heat from the light source 28 can efficiently be transferred, through the heat radiation plate, to the air layer 52 in contact with the first substrate 7 of a liquid crystal panel 2 and is accumulated in the air layer 52 to be supplied to the first substrate 7 more uniformly. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a liquid crystal device used for a personal computer, a mobile phone, and the like, and an electronic apparatus using the liquid crystal device.

Conventionally, a liquid crystal device is used as a display device of an electronic device such as a personal computer or a mobile phone. The liquid crystal device sandwiches a liquid crystal between a pair of substrates and applies a voltage to the liquid crystal. The image is displayed by the change of the arrangement.

However, if the temperature of the switching element that applies a voltage to each pixel of the liquid crystal is non-uniform, the switching characteristics differ depending on the location of the substrate surface, resulting in a display failure.

In addition, the responsiveness of the liquid crystal varies depending on the temperature, and in particular, the responsiveness at a low temperature is poor and the display performance is deteriorated.

Therefore, an electro-optical panel in which an electro-optical material is supported on a substrate, an optical member disposed adjacent to the electro-optical panel, a light guide plate disposed to face the electro-optical panel via the optical member, and A light source unit that irradiates light to the light guide plate, and a frame-shaped member that is disposed at least partially between the electro-optical panel and the light guide plate and surrounds the periphery of the optical member. It is proposed to arrange so as to be in contact with the light source unit (see, for example, Patent Document 1). In addition, in a liquid crystal display device having a liquid crystal panel in which liquid crystal is sealed between a pair of substrates provided opposite to each other, a translucent heat generating panel is brought into contact with at least one surface of the liquid crystal panel. Has been proposed (see, for example, Patent Document 2).
JP 2004-69825 A (paragraph [0009], FIG. 2). Japanese Patent Application Laid-Open No. 8-171084 (paragraph [0004], FIG. 1).

However, according to the proposal of Patent Document 1, heat is dispersed throughout the electro-optical panel, and display unevenness due to switching elements can be prevented. However, this is not always sufficient to improve the response of the liquid crystal at low temperatures. The problem of not being considered.

On the other hand, although the temperature of the liquid crystal can surely be raised by the proposal of Patent Document 2 and the response of the liquid crystal is improved, a heat generating panel has to be provided, and the number of parts increases and the cost increases. Further, the thickness of the liquid crystal device is increased by the amount of the heat generating panel, and further, there is a problem that the light transmittance is lowered.

The present invention has been made in view of the above-described problems, and a liquid crystal device capable of improving the responsiveness of liquid crystal without providing a new member for heating and improving the reliability of display quality, and the liquid crystal device therefor An object of the present invention is to provide an electronic device using the.

In order to achieve the above object, a liquid crystal device according to a main aspect of the present invention includes a light source that emits light, a light guide that receives light emitted from the light source on a side end surface, and a pair of substrates that sandwich the liquid crystal. A liquid crystal panel that receives the light emitted from the light guide from one of the pair of substrates, and a surface of the one substrate on the light guide, and at least one of the substrates An air layer interposed between the substrate and the light guide, and a metal material that is in contact with the light source and exposed so that part of the heat can be released from the light source to the air layer And a case for housing the liquid crystal panel, the air layer, the light source, the light guide, and the heat radiating body.

Here, the “substrate” refers to a glass substrate, for example, and includes a polarizing plate, a retardation plate, and the like provided on the surface of the glass substrate or the like.

The present invention is in contact with an air layer between at least one of the pair of substrates and the light guide and the light source, and a part thereof can release heat from the light source to the air layer. And a heat radiating body made of a metal material exposed to the surface. Therefore, the heat from the light source can be efficiently transmitted to the air layer in contact with the substrate of the liquid crystal panel through the radiator, and the heat is retained in the air layer, so that the heat can be supplied to the substrate more uniformly. Furthermore, the air cooled by supplying heat to the substrate in the air layer descends to the vicinity where the radiator is exposed, is heated again by the radiator and rises to the vicinity of the substrate, so the heat from the radiator to the liquid crystal panel is increased. Supply can be performed more efficiently. In particular, it becomes possible to improve the response of the liquid crystal at a low temperature.

Further, it is not necessary to prepare a heating element for heating the liquid crystal panel, the number of parts can be prevented from increasing, the cost can be reduced, and a thinner liquid crystal device can be obtained. Furthermore, since a heating element is not provided in the optical path of the backlight, the problem that the light transmittance is reduced can be avoided.

According to an aspect of the present invention, the air layer is provided between the case and a side surface of the light guide. Thereby, an air layer exists in the part between a board | substrate and a light guide, and the side part of the light guide, and more heat of a heat radiator and the air layer between a board | substrate and a light guide is shown. The exchange is smooth and efficient using, for example, air convection.

According to one form of this invention, the said case has 2nd thermal conductivity smaller than 1st thermal conductivity which is the thermal conductivity of the said heat radiating body, It is characterized by the above-mentioned. Thereby, the outflow of the heat of the heat radiating body from the case is suppressed, and the heat of the light source can be used for heating the liquid crystal panel more efficiently.

According to one form of this invention, the said heat radiating body is provided in the opposite side to the said liquid crystal panel side of the said light guide. Accordingly, it is possible to prevent the light from the light guide from being obstructed by the heat radiating body made of a metal material, and it is possible to release heat from the heat radiating body to the entire liquid crystal panel and to provide uniform heat.

According to an aspect of the present invention, the heat radiator also serves as a reflector that reflects the light emitted from the light guide. Thereby, since it is not necessary to provide a separate reflector, the liquid crystal device can be made thinner by that amount, and the number of parts can be reduced, thereby reducing the cost.

According to one form of this invention, the said heat radiating body is provided so that at least one part of the side surface of the said light guide may be enclosed. Thereby, since it is not necessary to arrange | position a heat radiator on the back side of a light guide, the influence of the heat to the said light guide plate can be suppressed to the minimum, and it becomes possible to ensure a higher quality display.

According to an aspect of the present invention, the light source includes a light emitting diode, and the light emitting diode is in direct contact with the heat radiator. Thereby, the heat of the light emitting diode which is a light source can be more efficiently supplied to the radiator.

According to an aspect of the present invention, the light emitting diode includes a plurality of the light emitting diodes, and the heat radiator is exposed between the adjacent light emitting diodes. This enables heat exchange between the heat radiating body and the air layer even between the light emitting diodes, and the use of heat from the light source becomes efficient. Also,
The thermal influence from the light source on the light guide can be further suppressed, and the display quality of the liquid crystal device can be improved.

According to an aspect of the present invention, the light source includes a light emitting diode, and further includes a flexible substrate electrically connected to the light emitting diode, and the light emitting diode is interposed through the flexible substrate. It is in contact with the heat radiator. As a result, for example, heat can be supplied from the flexible substrate for supplying current to the light emitting diode to the heat radiating body, and the use of heat from the light source can be made more efficient.

According to an aspect of the present invention, the light source includes a cold cathode tube and a reflector that reflects light from the cold cathode tube to the light guide, and the reflector is in contact with the radiator. It is characterized by being. Thereby, since the heat generated from the cold cathode tube is also collected by the reflector, the heat generated from the cold cathode tube can be supplied to the radiator more efficiently by bringing the radiator into contact with the reflector.

According to one form of this invention, the said reflector is integrally formed with the said heat radiating body, It is characterized by the above-mentioned. Thereby, the supply of heat from the reflector to the radiator becomes more efficient. The assembly process can be simplified and the manufacturing cost can be reduced.

  An electronic apparatus according to another aspect of the present invention includes the above-described liquid crystal device.

The present invention includes a liquid crystal device capable of improving the responsiveness of liquid crystal without providing a new member for heating and improving the reliability of display quality, so that an electronic device with high display quality can be manufactured at low cost. Can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description of the embodiments, an example of a liquid crystal device is a TFT (Thin Film Transistor).
An active matrix liquid crystal device and an electronic device using the liquid crystal device will be described, but the present invention is not limited thereto. Moreover, in the following drawings, in order to make each structure easy to understand, the actual structure and the scale and number of each structure are different.

  (First embodiment)

1 is a schematic perspective view of a liquid crystal device according to a first embodiment of the present invention, FIG. 2 is a partial cross-sectional view taken along line AA of FIG. 1 (a driver IC (Integrated Circuit) is not cut), and FIG. These are top views of an illuminating device, a heat sink, and a case.

  (Configuration of liquid crystal device)

For example, as shown in FIG. 1, the liquid crystal device 1 emits light to a liquid crystal panel 2, a flexible substrate 3 as a flexible substrate electrically connected to the liquid crystal panel 2 and a light source described later, and the liquid crystal panel 2. It has the illuminating device 4 and the case 5 which accommodates these liquid crystal panels, an illuminating device, etc. Here, in addition to the case 5 and the like, other incidental mechanisms are attached to the liquid crystal device 1 as necessary (not shown).

As shown in FIGS. 1 and 2, the liquid crystal panel 2 includes a first substrate 7 (one of the pair of substrates) and a second substrate 8 as a pair of substrates bonded via a sealant 6. It includes a TN (Twisted Nematic) type liquid crystal 9 enclosed in a gap between both substrates.

Each of the first and second substrates 7 and 8 includes first and second base materials 7a and 8a made of translucent plate-like members such as glass, for example. As shown in FIG. Second substrate 7a,
Polarizing plates 10 and 11 for polarizing incident light are attached to the outside of 8a (the side opposite to the liquid crystal).

In addition, the first base material 7a has a gate electrode 12 formed in the Y-axis direction and a source electrode 13 as a signal line formed in the X-axis direction as shown in FIGS. Further, an alignment film 14 is formed on the liquid crystal side such as the gate electrode 12 and the source electrode 13. The gate electrode 12 and the source electrode 13 are made of nickel, for example,
It is electrically connected to a TFT (not shown). The TFT is electrically connected to the pixel electrode 15 made of ITO (indium tin oxide) or the like.

As a result, when a voltage is applied to the gate electrode 12, the gate electrode 12 and the source electrode 13 cause a current to flow from the source electrode 13 to the pixel electrode 15 or vice versa. Here, the source electrode 13 applies a data signal to the pixel electrode 15, and the pixel electrode 15 applies a voltage to the liquid crystal 9 sandwiched between the common electrode described later.

Further, the first base material 7a has a projecting portion 16 projecting from the outer peripheral edge of the second base material 8a as shown in FIGS. 1 and 2, for example, and the projecting portion 16 includes the gate electrode 12 and the source. Electrode 1
A gate electrode wiring 17 and a source electrode wiring 18 are formed extending from the region 3 surrounded by the sealing material 6 to the overhanging portion 16. Further, a driver IC 19 for driving a liquid crystal electrically connected to each electrode wiring is mounted on the overhang portion 16.

Further, the overhanging portion 16 is, for example, an electrode terminal (not shown) electrically connected to the gate electrode wiring 17 and the source electrode wiring 18 in a region corresponding to the mounting surface of the driver IC 19 as shown in FIGS. In addition, an input terminal (not shown) for inputting a current from the flexible substrate 3 or the like to the driver IC 19 is provided.

Further, as shown in FIG. 2, for example, the overhang portion 16 includes an external terminal 20 that receives current from the flexible substrate 3 and the like, and an input wiring 21 that supplies current from the outside to the input terminal.

For example, as shown in FIG. 2, a light shielding member 51 is stuck on the opposite side to the mounting surface of the driver IC 19 of the overhang portion 16 so as to cover the entire overhang portion 16.

For example, as shown in FIG. 2, the driver IC 19 has a plurality of bumps 22 that are electrically connected to the electrode terminals and the input terminals on the mounting surface to be mounted on the projecting portion 16. This electrical connection is achieved by, for example, an anisotropic conductive film (ACF (Anisotropic Conductive Fibre) which is also an adhesive between the electrode terminal and the input terminal and the bump 22.
lm)).

On the other hand, the second substrate 8a has a common electrode 2 on its inner surface (liquid crystal side) as shown in FIG.
3 is formed, and an alignment film 24 is formed on the liquid crystal side of the common electrode 23.

In addition, although not shown in figure in the liquid crystal side of the 1st and 2nd base materials 7a and 8a, if necessary, a base layer,
A reflective layer, a colored layer, a light shielding layer, and the like are formed.

Next, for example, as shown in FIGS. 1 and 2, the flexible substrate 3 is formed by mounting a wiring pattern 26 made of copper (Cu) or the like on a base substrate 25 as a substrate.

Here, the base substrate 25 is a film-like member having flexibility. Further, the wiring pattern 26 is a connection terminal (not shown) formed at the end of the base substrate 25 on the protruding portion side.
The connection terminal is electrically connected to the external terminal 20 of the liquid crystal panel 2 through an anisotropic conductive film 27, for example. Further, a part of the wiring pattern 26 is formed on a branched base substrate 25a and is electrically connected to a light source.

Next, the illuminating device 4 is a backlight unit that supplies light to the liquid crystal panel 2 as shown in FIGS. 1, 2, and 3, for example, and includes a light source 28, a light guide plate 29 as a light guide, and two lenses. Sheets 30 and 31, a diffusion sheet 32, a reflection sheet 33, a radiator plate 34 as a radiator, and the like.

Here, the light source 28 includes, for example, four light emitting diodes (hereinafter referred to as “LED” (Light Em).
It is called “itching Diode”. ) 28a, 28b, 28c, 28d are used and FIG.
2 and 3, a light emitting surface 35 is disposed at a distance from the light source side end surface of the light guide plate 29.

Further, for example, as shown in FIG. 2, the bottom surfaces of the LEDs 28a, 28b, 28c, 28d are in direct contact with the heat radiating plate 34, and the LEDs 28a, 28b, 28c, 28d (hereinafter referred to as “LED28”).
a etc. " ) Can be efficiently transmitted to the heat radiating plate 34.

When the LED 28a or the like has a heat radiating portion, the heat radiating plate 34 is disposed in contact with the heat radiating portion. Further, the flexible substrate 3 for supplying current to the light source 28 is connected to the bottom surface and the heat sink 3.
4, that is, the light source 28 may be brought into contact with the heat radiating plate 34 via the flexible substrate 3. Thereby, while being able to use the space in case 5 more efficiently,
It becomes possible to increase the heat radiation area.

The light guide plate 29 has a flat plate shape with substantially the same thickness as shown in FIGS. 1, 2, and 3, for example, and both surfaces of the flat plate plate have the light incident from the light source 28 applied to the diffusion sheet 31. An exit surface 36 that emits light, and a reflective surface 37 that reflects light by the reflective sheet 33 on the side opposite to the exit surface 36.
And have.

The light guide plate 29 emits light incident from the light source 28 to the entire diffusion sheet 32, and the side end surface 38 is a light receiving surface that receives light from the light source 28. The light guide plate 29 is molded by injection molding or extrusion molding using, for example, an acrylic resin.

Next, the two lens sheets 30, 31, the diffusion sheet 32, and the reflection sheet 33 are formed in substantially the same size as the light guide plate 29 as shown in FIGS. 1, 2, and 3. Is a silver foil sheet having the same size as that of the reflecting surface 37 on the reflecting surface 37 (downward in the figure) of the light guide plate 29.

Further, a diffusion sheet 32 having the same size as that of the emission surface 36 is attached on the emission surface 36 (liquid crystal panel side) of the light guide plate 29, and two lens sheets 30 and 31 are further disposed thereon. .
The diffusion sheet 32 emits uniform light by diffusion, and the lens sheet 30,
31 is for improving the luminance of the light emitted from the diffusion sheet 32 and irradiating the polarizing plate 10 of the liquid crystal panel 2.

Here, the lens sheet 30 on the polarizing plate 10 side of the liquid crystal panel 2 out of the two lens sheets 30 and 31 is formed with a space 39 as shown in FIG. Has been placed. An air layer is formed in the space 39 and the like as will be described later.

Further, for example, as shown in FIGS. 1, 2, and 3, the heat radiating plate 34 has a flat plate shape that is substantially equal in thickness, and is disposed on the side opposite to the light guide plate side of the reflection sheet 33. Further, the heat radiating plate 34 is formed to be slightly larger than the reflecting sheet 33, the light guide plate, etc., for example, around three sides of the reflecting sheet 33 or between the LEDs 28a, 28b, 28c, 28d as shown in FIG. The surface (shaded area B in FIG. 3) is exposed.

The heat radiating plate 34 is made of, for example, a metal material such as aluminum (Al), and the thermal conductivity is about 200 W / m · K in the case of aluminum.

Next, the case 5 includes an upper case 5a and a lower case 5b as shown in FIG. 1, for example, and accommodates the liquid crystal panel 2, an air layer, a light source 28, a light guide plate 29, a heat radiating plate 34, and the like described later.

For example, as shown in FIGS. 1 and 2, the upper case 5a has a substantially rectangular display opening 40 at the center thereof, and is formed in a frame shape so as to cover the lower case 5b. Furthermore, the upper case 5a
The peripheral edge of the liquid crystal panel 2 is held and fixed via the polarizing plate 11 on the second substrate, but the peripheral edge of the display opening 40 is, for example, an effective display area C of the liquid crystal panel 2 as shown in FIG. It is formed so as to be adjacent to a parting part (not shown) on the outer periphery of the plane. Thereby, the portion that does not contribute to the display is covered with the upper case 5a, so that the liquid crystal display becomes clearer.

In addition, the upper case 5a is provided with an upper case guide groove 43 at the substantially lower center of the side wall 42 on the projecting portion 16 side of the liquid crystal panel 2 as shown in FIG. 1, for example, as shown in FIG. Has been pulled out.

The lower case 5b includes LEDs 28a, 28b, 28c, 2 as shown in FIGS.
A concave portion 41 is formed on the inner side so that the light guide plate 29 and the heat radiating plate 34 to which 8d, the reflection sheet 33, the diffusion sheet 32, and the two lens sheets 30 and 31 are stuck are stored.

Further, the lower case 5b is formed on the side wall 4 of the liquid crystal panel 2 on the projecting portion 16 side as shown in FIG.
A lower case guide groove 45 is provided at substantially the center of the upper end of 4, and the flexible substrate 3 is drawn out or bent as shown in FIG.

For example, as shown in FIG. 2, the lower case 5b includes a liquid crystal panel 2 whose surface on the light guide plate 29 side of the polarizing plate 10 is on the liquid crystal panel side surface of the lens sheet 30 (the outermost lens sheet of the two). A distance E (E in FIG. 2) is formed so as to be held apart by about 0.1 mm to 0.5 mm. Thereby, the space 39 described above is formed in a layered manner. For example, since the air is contained in the lower case 5b, the space 39 becomes a part of the air layer.

Further, for example, as shown in FIGS. 2 and 3, the lower case 5 b includes a side wall 46 that faces the side wall 44 and side walls 47 and 48 sandwiched between the side walls 44, 46. And the light guide plate 29 and the like. For example, the distance F (F in FIG. 3) from the inner surface of the side wall 44 to the side surface 49 facing the light guide plate 29 is 0.1 mm to 0.5 m.
m, about a distance G to the side wall 46 (G in FIG. 3) and a distance H to the side walls 47 and 48 (FIG. 3).
Middle H) is a predetermined distance. Thereby, the space 5 is also provided between each side wall and the light guide plate 29 and the like.
0 is formed, and the air layer 52 is formed by these spaces 39 and 50.

That is, the air layer 52 is in direct contact with the exposed area B (shaded area B in FIG. 3) of the heat radiating plate 34 and surrounds the side surfaces 49 of the light guide plate 29 and the lens sheets 30 and 31, and further includes the light shielding member 51 and the polarizing plate 10. The first base material 7a is in contact therewith, and the heat of the heat sink 34 is transferred to the first base material 7a.
It serves as a medium to convey to the whole.

The upper case 5a and the lower case 5b are, for example, 0.1 to 0.2 W / m as the second thermal conductivity.
It is made of K ABS resin or the like and is smaller than the thermal conductivity of the heat sink 34.
Accordingly, the heat of the warmed air in the lower case 5b is difficult to escape to the outside, and the polarizing plate 10 and the like can be heated by being more efficiently stopped in the space 39.

In the above description, the distance between the polarizing plate 10 and the lens sheet 30 is equal to the entire surface. For example, the distance E is formed. However, the distance E is not limited to the above. However, the present invention is not necessarily limited to the case where the film is formed on the entire surface of the polarizing plate 10. For example, when a prism with an apex angle of 90 degrees is formed on the surface of the lens sheet 30 on the liquid crystal panel side, an air layer may be formed at the valley portion. Further, the distance E may vary depending on the location. However, it is more preferable to form the air layer 52 having an equal distance on the entire surface between the polarizing plate 10 and the lens sheet 30.

Further, the distance between the side wall 49 of the lower case 5b and the side surface 49 such as the light guide plate is not limited to a certain value. For example, the distance between the side wall 49 and the side surface 49 such as the light guide plate may be partially eliminated. May be.

  (Operation of liquid crystal device)

Next, the operation of the liquid crystal device 1 configured as described above will be briefly described focusing on how the heat from the light source proceeds.

  FIG. 4 is a view for explaining how the heat of the light guide plate proceeds from the side surface side.

First, when a predetermined current is supplied to, for example, the LED 28a or the like by a drive circuit (not shown), the LED 28a or the like emits light from the light emitting surface 35 and generates heat. And the LED
For example, as shown in FIG. 4, the heat generated from 28a and the like is a heat sink 34 in contact with the bottom surface.
(Arrow I in FIG. 4) and the heat spreader 34 is spread throughout (arrow J in FIG. 4).

Further, the heat spread to the heat radiating plate 34 is transmitted to the air layer 52 in contact with the exposed area B of the heat radiating plate 34 (arrow K in FIG. 4), and the air heated in the air layer 52 as shown in FIG. Rises and moves in the space 50 between the light guide plate and the side wall of the lower case 5 b and reaches the light shielding member 51 and the polarizing plate 10. Here, since the space 39 is formed between the polarizing plate 10 and the lens sheet 30, the warmed air is stopped in the space 39, and the warm air layer 52.
Will be formed.

And the 1st base material 7a and the liquid crystal 9 will be heated via the polarizing plate 10 by the warm air layer 52 which has stopped.

On the other hand, the air that has been deprived of heat and cooled by the polarizing plate 10 or the like descends from the space 39 and returns to the vicinity of the exposed region B of the heat radiating plate 34, and is again warmed and raised by the heat of the heat radiating plate 34.

In this way, the heated air between the heat radiating plate 34 and the polarizing plate 10 causes convection, and the heat of the light source 28 is efficiently supplied to the liquid crystal 9 and the like through the polarizing plate 10 through the heat radiating plate 34. And
The heated air layer 52 is stopped on the entire surface of the polarizing plate 10, and the entire surface of the polarizing plate 10 is uniformly heated.

  Above, description of operation | movement of the liquid crystal device 1 is complete | finished.

As described above, according to the present embodiment, at least one substrate is in contact with the light source 28 and the air layer 52 between the first substrate 7 opposite to the display side and the light guide plate 29, and one of them. And the heat radiating plate 34 made of a metal material exposed so that the heat from the light source 28 can be released to the air layer 52. Therefore, the heat from the light source 28 can be efficiently transmitted to the air layer 52 in contact with the first substrate 7 of the liquid crystal panel 2 through the heat radiating plate 34, and the heat is retained in the air layer 52, so that the first Heat can be supplied to the substrate 7. Further, in the air layer 52, the air cooled by supplying heat to the first substrate 7 is lowered to the vicinity where the heat radiating plate 34 is exposed, and is heated again by the heat radiating plate 34 to rise to the vicinity of the first substrate. . Thereby, the liquid crystal panel 2 from the heat sink 34 is displayed.
Heat can be supplied more efficiently. In particular, the responsiveness of the liquid crystal 9 at a low temperature can be improved.

In addition, it is not necessary to prepare a heating element for heating the liquid crystal panel 2, the increase in the number of parts can be prevented, the cost can be reduced, and the thinner liquid crystal device 1 can be obtained. Furthermore, since a heating element is not provided in the optical path of the backlight, the problem that the light transmittance is reduced can be avoided.

Furthermore, since the heat radiating plate 34 is provided on the opposite side of the light guide plate 29 from the liquid crystal panel side, the light from the light guide plate 29 can be prevented from being blocked by the metal heat radiating plate 34, and the heat radiating plate 34. It is possible to provide more uniform heat by releasing the heat from the entire liquid crystal panel.

Since the air layer 52 is also provided between the case 5 and the side surface of the light guide plate 29,
The air layer 52 exists in the space 39 between the first substrate 7 and the light guide plate 29 and the space 50 in the side surface portion of the light guide plate or the like. Light plate 29
The heat exchange with the air layer 52 between the air and the air becomes smooth and efficient using, for example, air convection.

Furthermore, since the case 5 has a second thermal conductivity smaller than the first thermal conductivity which is the thermal conductivity of the heat radiating plate 34, the outflow of heat from the heat radiating plate 34 from the case 5 is suppressed, The heat of the light source 28 can be used for heating the liquid crystal panel 2 more efficiently.

Moreover, since the light source 28 consists of LED and was directly contacting with the heat sink 34, the heat | fever of LED which is a light source can be supplied to the heat sink 34 more efficiently.

Further, since the light source 28 is composed of a plurality of LEDs 28a and the like, and the heat radiating plate 34 is exposed between adjacent LEDs, it is possible to exchange heat between the heat radiating plate 34 and the air layer 52 between the LEDs. The use of heat becomes efficient. Moreover, the thermal influence from the light source to the light guide plate 29 can be further suppressed, and the display quality of the liquid crystal device 1 can be improved.

  (Modification)

Next, a modification of the liquid crystal device according to the present invention will be described. In the present modification, the point that a cold cathode tube is used as the light source is different from that of the first embodiment, so that this point will be mainly described. In the following description, the same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof is omitted or simplified.

  (Configuration of liquid crystal device)

  FIG. 5 is a cross-sectional view of a liquid crystal device according to a modification of the present invention.

For example, as shown in FIG. 5, the liquid crystal device 101 includes a liquid crystal panel 2, a flexible substrate 3 as a flexible substrate electrically connected to the liquid crystal panel 2, and the like, and an illumination device 104 that emits light to the liquid crystal panel 2. And a case 5 for housing the liquid crystal panel, the lighting device, and the like. Here, in addition to the case 5 and the like, other incidental mechanisms are attached to the liquid crystal device 101 as needed (not shown).

The illumination device 104 is a backlight unit that supplies light to the liquid crystal panel 2 as shown in FIG. 5, and includes a light source 28, a light guide plate 29 as a light guide, two lens sheets 30 and 31, a diffusion sheet 32, and a reflection. It has the sheet | seat 33 and the heat sink 34 etc. as a heat radiator.

Here, the light source 28 includes, for example, a cold cathode tube 161 and a reflector 162 that reflects light emitted from the cold cathode tube 161 in the opposite direction to the light guide plate 29 to the light guide plate 29 as shown in FIG.

For example, as shown in FIG. 5, the cold cathode tube 161 is disposed along the side end surface 38 of the light guide plate 29, and the current is supplied by the wiring pattern 26 of the flexible substrate 3, for example.

For example, as shown in FIG. 5, the reflector 162 is formed like a substantially concave mirror in cross section, and is arranged on the opposite side of the cold cathode tube 161 from the light guide plate 29 so as to cover the cold cathode tube 161. Further, the bottom surface of the reflector 162 is in contact with the heat radiating plate 34.
The heat of the reflector 162 heated by receiving the heat of 61 is efficiently transmitted to the heat radiating plate 34.

  (Operation of liquid crystal device)

Next, with respect to the operation of the liquid crystal device 101 configured as described above, how the heat from the light source proceeds is substantially the same as that of the first embodiment, except that the light source 28 is changed from the LED to the cold cathode tube 161. Therefore, the description is omitted.

However, compared to the case where a plurality of LEDs 28a and the like are used as light sources, for example, in the case of one cold cathode tube 161 as in the present modification, naturally there is no exposed region B of the heat sink 34 between the light sources. Of course, this does not exclude the case where a plurality of cold-cathode tubes are used, and in that case, it is the same as in the first embodiment.

As described above, according to this modification, the light source 28 includes the cold cathode tube 161 and the reflector 162 that reflects the light from the cold cathode tube to the light guide plate 29, and the reflector 162 includes the heat radiating plate 3.
4 was touching. Therefore, the heat generated from the cold cathode tube 161 is also reflected by the reflector 1.
Therefore, the heat generated from the cold cathode tube 161 can be more efficiently supplied to the heat radiating plate 34 by bringing the heat radiating plate 34 into contact with the reflector 162. Thereby, since the heat generated from the cold cathode tube 161 can be supplied to the entire surface of the polarizing plate 10 by the air layer 52, a new member for heating is not required, and the responsiveness of the liquid crystal can be improved.

In the above description, the reflector 162 and the heat radiating plate 34 are configured separately. However, the present invention is not limited to this. For example, the reflector and the heat radiating plate may be integrally formed. Thereby, the supply of heat from the reflector to the radiator becomes more efficient. The assembly process can be simplified and the manufacturing cost can be reduced.

  (Second Embodiment)

Next, a second embodiment of the liquid crystal device according to the present invention will be described. In this embodiment, since the point which the heat sink serves also as a reflection sheet differs from 1st Embodiment, it demonstrates centering on the point. Since the operation of the liquid crystal device is substantially the same as that of the first embodiment, the description thereof is omitted.

  (Configuration of liquid crystal device)

6 is a cross-sectional view of a liquid crystal device according to a second embodiment of the present invention, and FIG. 7 is a plan view of a lighting device, a heat sink, and a case.

The liquid crystal device 201 includes, for example, a liquid crystal panel 2 and the liquid crystal panel 2 as shown in FIGS.
A flexible substrate 3 as a flexible substrate electrically connected to the liquid crystal panel 2, a lighting device 204 that emits light to the liquid crystal panel 2, and a case 5 that houses the liquid crystal panel, the lighting device, and the like. Here, in addition to the case 5 and the like, other incidental mechanisms are attached to the liquid crystal device 201 as needed (not shown).

The illumination device 204 is a backlight unit that supplies light to the liquid crystal panel 2 as shown in FIG. 6, and includes a light source 28, a light guide plate 29 as a light guide, two lens sheets 30 and 31, a diffusion sheet 32, and heat dissipation. It has a heat sink 234 as a body.

Here, for example, as shown in FIG. 6, the light guide plate 29 has a flat plate shape with substantially the same thickness, and both surfaces of the flat plate plate have an emission surface 36 for emitting the light incident from the light source 28 to the diffusion sheet 31. And a reflection surface 37 on the side opposite to the emission surface 36, on which light is reflected by the heat radiating plate 234 that also serves as a reflection sheet.

Further, for example, as shown in FIG. 6, the heat radiating plate 234 has a flat plate shape with substantially the same thickness, and is attached to the reflecting surface 37 side of the light guide plate 29. Further, the heat radiating plate 234 is formed to be slightly larger than the light guide plate or the like. For example, as shown in FIG.
The surface (shaded area B in FIG. 7) is exposed from between a, 28b, 28c, and 28d.

The heat radiating plate 234 is made of a metal material such as aluminum (Al) or silver (Ag), and the thermal conductivity is about 200 W / m · K if aluminum.

As described above, according to the present embodiment, the heat radiating plate 234 as the heat radiating member also serves as a reflecting sheet that reflects the light emitted from the light guide plate 29, so that there is no need to separately provide a reflecting sheet, and accordingly, the liquid crystal The apparatus 201 can be thinned, the number of parts can be reduced, and the cost can be reduced.

  (Third embodiment)

Next, a third embodiment of the liquid crystal device according to the present invention will be described. In the present embodiment, the point that the heat radiating plate has a frame shape is different from that of the first embodiment, and therefore, this point will be mainly described.

  (Configuration of liquid crystal device)

FIG. 8 is a cross-sectional view of a liquid crystal device according to a third embodiment of the present invention, and FIG. 9 is a plan view of a lighting device, a heat sink, and a case.

For example, as shown in FIG. 8, the liquid crystal device 301 includes a liquid crystal panel 2, a flexible substrate 3 as a flexible substrate electrically connected to the liquid crystal panel 2, and the like, and an illumination device 304 that emits light to the liquid crystal panel 2. And a case 5 for housing the liquid crystal panel, the lighting device, and the like. Here, in addition to the case 5 and the like, other incidental mechanisms are attached to the liquid crystal device 301 as necessary (not shown).

The illumination device 304 is a backlight unit that supplies light to the liquid crystal panel 2 as shown in FIG. 8, and includes a light source 28, a light guide plate 329 as a light guide, two lens sheets 330 and 331,
It has a diffusion sheet 332, a reflection sheet 333, a heat dissipation plate 334 as a heat dissipation body, and the like.

Here, for example, four LEDs 28a, 28b, 28c, and 28d are used as the light source 28, and a light emitting surface 35 is disposed apart from the light source side end surface of the light guide plate 329 as shown in FIG.

Further, for example, as shown in FIG. 8, the back surface (the side opposite to the light emitting surface) of the LED 28 a and the like is in direct contact with the heat radiating plate 334, and heat generated from the LED 28 a and the like can be efficiently transmitted to the heat radiating plate 334. Further, for example, as shown in FIG. 8, the LED 28a and the like are provided with a flexible substrate 3 for supplying current on the bottom side thereof. In addition, when the said LED28a etc. have a thermal radiation part, it arrange | positions so that the thermal radiation board 334 may contact | connect the thermal radiation part.

For example, as shown in FIG. 8, the light guide plate 329 has a flat plate shape having substantially the same thickness, and both surfaces of the flat plate plate have an emission surface 36 for emitting light incident from the light source 28 to the diffusion sheet 331.
And a reflection surface 37 on the side opposite to the emission surface 36 from which light is reflected by the reflection sheet 333.

The light guide plate 329 emits light incident from the light source 328 to the entire diffusion sheet 332, and the side end surface 38 is a light receiving surface that receives light from the light source 328. The light guide plate 329 is molded by injection molding or extrusion molding using, for example, an acrylic resin.

Next, the two lens sheets 330 and 331, the diffusion sheet 332, and the reflection sheet 333 are formed to have substantially the same size as the light guide plate 329 as shown in FIG.
3, a silver foil sheet or the like having the same size as that of the reflecting surface 37 is attached on the reflecting surface 37 (downward in the drawing) of the light guide plate 329.

In addition, a diffusion sheet 332 having substantially the same size as the exit surface 36 is attached on the exit surface 36 (liquid crystal panel side) of the light guide plate 329, and two lens sheets 330 and 331 are further disposed thereon. . Note that the diffusion sheet 332 emits uniform light by diffusion, and the lens sheets 330 and 331 improve the luminance of the light emitted from the diffusion sheet 332, and the liquid crystal panel 2.
The polarizing plate 10 is irradiated.

Here, of the two lens sheets 330 and 331, the lens sheet 330 on the polarizing plate 10 side of the liquid crystal panel 2 forms a space 39 between the polarizing plate 10 as shown in FIG. Has been placed. An air layer 52 is formed in the space 39 or the like.

Further, the heat radiating plate 334 has a substantially rectangular frame shape as shown in FIGS. 8 and 9, for example, and is arranged so as to surround the light guide plate and the like. Further, for example, as shown in FIG. 9, the heat sink 334 has an inner wall 371 that holds a predetermined distance L (L in FIG. 9) from the side surface 49 of the reflection sheet 333, the light guide plate, etc. It arrange | positions so that the side wall 44 etc. of the lower case 5b may contact substantially.

Of course, the predetermined distance L is not limited to a certain distance, and may be a different distance depending on the location, for example. Further, the inner wall 371 may be in contact with part of the side surface 49 such as the light guide plate, or may be in contact with all of the side surface 49 such as the light guide plate. In this case, the exposed area of the heat radiating plate 334 becomes a part of the heat radiating plate 334, for example, near the upper end thereof. However, heat can be radiated from the heat radiating plate 334 to the air layer 52 to some extent.

Further, for example, as shown in FIG. 8, the upper edge 373 of the heat radiating plate 334 is not in contact with the polarizing plate 11 or the light guide plate side surface of the light shielding member 51, but is provided close to the lower rim 374. It is being fixed to the recessed part 41 of 5b. Accordingly, since the heat radiating plate 334 surrounds the air layer 52 formed in the lower case 5b, the entire air layer can be heated so as to be confined by the heat radiating plate 334, and the light source 28 can be more efficiently used. This heat can be transmitted to the polarizing plate 10.

The heat radiating plate 334 is made of, for example, a metal such as aluminum (Al), and the thermal conductivity is about 200 W / m · K if it is aluminum.

  (Operation of liquid crystal device)

Next, the operation of the liquid crystal device 301 configured as described above will be briefly described focusing on how the heat from the light source proceeds.

  FIG. 10 is a view for explaining how the heat of the light guide plate proceeds from the side surface side.

First, when a predetermined current is supplied to, for example, the LED 28a or the like by a drive circuit (not shown), the LED 28a or the like emits light from the light emitting surface 35 and generates heat. And the LED
For example, as shown in FIG. 10, the heat generated from 28a etc.
34 (arrow M in FIG. 10), the heat dissipation plate 334 is spread throughout.

Further, the heat spread to the heat radiating plate 334 is transmitted to the air layer 52 in contact with the exposed region N of the heat radiating plate 334 as shown in FIGS. 9 and 10, and the air heated in the air layer 52 rises and the light guide plate Etc. and the heat sink 334 are moved to reach the light shielding member 51 and the polarizing plate 10. Here, for example, a space 39 is provided between the polarizing plate 10 and the lens sheet 330 as shown in FIG.
Therefore, the warmed air stops in the space 39, and the warm air layer 52 is formed.

And the 1st base material 7a and the liquid crystal 9 will be heated via the polarizing plate 10 by the warm air layer 52 which has stopped.

On the other hand, the air that has been deprived of heat by the polarizing plate 10 or the like is lowered from the space 39 until it returns to the vicinity of the exposed region N of the heat radiating plate 334, and is again heated and raised by the heat of the heat radiating plate 334.

In this way, the air heated between the heat radiating plate 334 and the polarizing plate 10 causes convection, and the heat of the light source 28 is efficiently supplied to the liquid crystal 9 or the like through the heat radiating plate 334. At the same time, the heated air layer 52 stays on the entire surface of the polarizing plate 10, and the entire surface of the polarizing plate 10 is uniformly heated.

  This is the end of the description of the operation of the liquid crystal device 301.

As described above, according to the present embodiment, the heat radiating plate 334 as the heat radiating member is provided so as to surround at least a part of the side surface 49 of the light guide plate 329 as the light guiding member. Is not required to be disposed behind the light guide plate 329. Therefore, the influence of heat on the light guide plate 329 can be minimized, and the responsiveness of the liquid crystal 9 can be improved by efficiently using the heat of the light source 28 while ensuring a higher quality display. It becomes possible.

  (Fourth Embodiment / Electronic Device)

Next, an electronic apparatus according to the fourth embodiment of the present invention including the above-described liquid crystal devices 1, 101, 201, 301 will be described.

FIG. 11 is a schematic external view of a mobile phone according to a fourth embodiment of the present invention, and FIG. 12 is a schematic external view of a personal computer.

For example, as shown in FIG. 11, the mobile phone 400 includes, for example, the liquid crystal device 1 in an outer frame that includes a plurality of operation buttons 471, an earpiece 472, and a mouthpiece 473.

The personal computer 500 includes a main body 582 having a keyboard 581 and a liquid crystal display unit 583 as shown in FIG.
For example, the outer frame 83 includes the liquid crystal device 1.

In addition to the liquid crystal device 1, these electronic devices include various circuits such as a display information output source and a display information processing circuit, and a display signal generation unit including a power supply circuit that supplies power to these circuits, although not shown. Consists of.

Further, for example, in the case of the personal computer 500, the liquid crystal device 1 is supplied with a display signal generated by the display signal generation unit based on information input from the keyboard 581, so that a display image is supplied to the liquid crystal device 1. Is displayed.

According to the present embodiment, since the liquid crystal device 1 that can improve the responsiveness of the liquid crystal 9 and improve the display quality without providing a new member for heating is provided, an electronic device with high display quality is provided. Equipment can be provided at low cost.

In particular, portable electronic devices such as those described above are required to have a clear screen display even when used outdoors. For example, the present invention that can improve liquid crystal response even at low temperatures is significant. It can be said.

In addition, examples of the electronic device include a touch panel equipped with a liquid crystal device, a projector, a liquid crystal television, a viewfinder type, a monitor direct view type video tape recorder, a car navigation, a pager, an electronic notebook, a calculator, and the like. Needless to say, for example, the liquid crystal devices 1, 101, 201, and 301 described above can be applied as display units of these various electronic devices.

The present invention is not limited to any of the above-described embodiments and modifications, and can be implemented with appropriate modifications within the scope of the technical idea of the present invention. Moreover, in the range which does not deviate from the summary of this invention,
Each embodiment and modification which were mentioned above can be combined.

For example, in the above-described embodiment, the thin film transistor element active matrix type liquid crystal device has been described as an example of the electro-optical device. However, the present invention is not limited thereto.
It may be a thin film diode element active matrix type or passive matrix type liquid crystal device. As a result, even in a wide variety of liquid crystal devices, the responsiveness of the liquid crystal 9 can be improved without providing a new heating member, and the display quality can be improved.

Further, in the above description, the driver IC 19 is described as COG (Chip On Glass). However, the present invention is not limited to this. For example, the driver IC 19 is mounted on the flexible substrate 3.
The case of F (Chip On Film) may also be used. As a result, even in a wide variety of liquid crystal devices, the responsiveness of the liquid crystal 9 can be improved without providing a new heating member, and the display quality can be improved.

1 is a schematic perspective view of a liquid crystal device according to a first embodiment. FIG. 2 is a partial cross-sectional view taken along line AA in FIG. 1 (a driver IC is not cut). It is a top view of the illuminating device, heat sink, and case which concern on 1st Embodiment. It is a figure explaining how to advance the heat of the light-guide plate which concerns on 1st Embodiment from the side surface side. It is sectional drawing of the liquid crystal device which concerns on a modification. It is sectional drawing of the liquid crystal device which concerns on 2nd Embodiment. It is a top view of the illuminating device, heat sink, and case which concern on 2nd Embodiment. It is sectional drawing of the liquid crystal device which concerns on 3rd Embodiment. It is a top view of the illuminating device, heat sink, and case which concern on 3rd Embodiment. It is a figure explaining how to advance the heat of the light-guide plate which concerns on 3rd Embodiment from the side surface side. It is the external appearance schematic of the mobile telephone which concerns on 4th Embodiment. It is the external appearance schematic of the personal computer which concerns on 4th Embodiment.

Explanation of symbols

1, 101, 201, 301 Liquid crystal device, 2 Liquid crystal panel, 3 Flexible substrate, 4, 104, 204, 304 Illumination device, 5 Case, 6 Sealing material, 7
First substrate, 8 Second substrate, 9 Liquid crystal, 10, 11 Polarizer, 12 Gate electrode, 13 Source electrode, 14, 24 Alignment film, 15 Pixel electrode, 16 Overhang, 17 Gate electrode wiring, 18 Source Electrode wiring, 19 Driver IC,
20 External terminal, 21 Input wiring, 22 Bump, 23 Common electrode, 25
Base substrate, 26 wiring pattern, 27 anisotropic conductive film, 28 light source, 29, 3
29 light guide plate, 30, 31, 330, 331 lens sheet, 32, 332 diffusion sheet, 33, 333 reflection sheet, 34, 234, 334 heat sink, 35 light emitting surface, 36 exit surface, 37 reflection surface, 38 side end surface, 39,50 space, 40
Display opening, 41 recess, 42, 46, 47, 48 side wall, 49 side surface, 5
1 light shielding member, 52 air layer, 161 cold cathode tube, 162 reflector, 37
DESCRIPTION OF SYMBOLS 1 Inner wall, 372 Outer wall, 373 Upper edge, 374 Lower edge, 400 Mobile phone, 471 Operation button, 472 Earpiece, 473 Mouthpiece, 500 Personal computer, 581 Keyboard, 582 Main unit, 583 Liquid crystal display unit, B, N Exposure area, C effective display area, E, F, G, H, L distance,
I, J, K, M arrows

Claims (12)

A light source that emits light;
A light guide that receives light emitted from the light source on a side end surface;
A liquid crystal panel having a pair of substrates sandwiching liquid crystal, and receiving the light emitted from the light guide from one of the pair of substrates;
An air layer that is in contact with the surface of the one substrate on the light guide side and is interposed between at least the one substrate and the light guide;
A radiator made of a metal material that is in contact with the light source, and a part of which is exposed so that heat from the light source can be released to the air layer;
A liquid crystal device comprising: a case for housing the liquid crystal panel, the air layer, the light source, the light guide and the heat radiating body. The liquid crystal device according to claim 1, wherein the air layer is interposed between the case and a side surface of the light guide. The liquid crystal device according to claim 1, wherein the case has a second thermal conductivity smaller than a first thermal conductivity that is a thermal conductivity of the heat radiating body. 4. The liquid crystal device according to claim 1, wherein the heat radiator is provided on a side opposite to the liquid crystal panel side of the light guide. 4. The liquid crystal device according to claim 1, wherein the heat radiator also serves as a reflector that reflects the light emitted from the light guide. 5. 4. The liquid crystal device according to claim 1, wherein the heat dissipating body is provided so as to surround at least a part of a side surface of the light guide body. 5. The light source comprises a light emitting diode,
The liquid crystal device according to claim 1, wherein the light emitting diode is in direct contact with the heat radiator. The light emitting diode has a plurality,
The liquid crystal device according to claim 7, wherein the heat radiator is exposed between the adjacent light emitting diodes. The light source comprises a light emitting diode,
Further comprising a flexible substrate electrically connected to the light emitting diode;
The liquid crystal device according to claim 1, wherein the light emitting diode is in contact with the heat radiating body through the flexible substrate. The light source includes a cold cathode tube and a reflector that reflects light from the cold cathode tube to the light guide,
The liquid crystal device according to claim 1, wherein the reflector is in contact with the heat radiator. The said reflector is integrally formed with the said heat radiator.
The liquid crystal device according to 0. An electronic apparatus comprising the liquid crystal device according to any one of claims 1 to 11.

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