JPH1173121A - Liquid crystal display device with light collecting function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small and thin type liquid crystal display device keeping good display quality and also decreasing the power consumption. SOLUTION: This device is a liquid crystal display device provided with a display light source unit 18 on the rear side of the screen of the liquid crystal panel, and when light collection is not required, the light collecting panel 30 is housed into a housing space of an air light-guiding part 42 of the display light source unit 18. Further, if a 2nd air light guiding part exists, the light collecting panel is housed into the housing space of the 2nd air light guiding part. Thus, it becomes easy to collect sufficient light quantity by the collecting panel 30 and it is also possible to improve display quality and also reduce power consumption, and on the other hand, since the light collecting panel is housed into the air light guiding part, the device is substantially decreased in size when the collecting panel is not used, for making it compact and excellent in portability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device,
In particular, the present invention relates to a liquid crystal display device provided with an external light condensing mechanism for taking in external light and using the auxiliary light as a supplementary light for a display light source or as driving power.

[0002]

2. Description of the Related Art A transmissive liquid crystal display device comprises a liquid crystal display panel composed of a set of substrates in which liquid crystal is sealed, and a display light source called a backlight or the like provided on the opposite side of the display surface. By controlling the light transmittance of the light source light in each display pixel of the liquid crystal display panel, a desired image is obtained on the display surface.

[0003] Such a liquid crystal display device is basically composed of a unit having a liquid crystal display panel and a display light source unit arranged behind it. It is widely used as a portable device or a display device mounted on a vehicle.

However, it is desired that the continuous operation time of a portable device or the like be as long as possible, and it is indispensable to suppress the power consumption of a display device as well. At present, many improvements have been made to the material of the liquid crystal panel and its driving circuit, the power consumption of the liquid crystal display panel itself is low, and its usefulness as a low power consumption type display device is highly evaluated. On the other hand, the power consumption of the display light source has not been reduced so much, and the advantage that the liquid crystal panel itself has low power consumption cannot be fully utilized. By lowering the brightness of the display light source,
Power consumption in the light source can be reduced. However, when the luminance of the display light source is reduced in the transmission type liquid crystal display device, the display quality such as luminance and contrast on the liquid crystal display screen is directly affected. Therefore, in the present situation where the display quality must be maintained or further improved, it is not possible to simply reduce the amount of light in order to suppress power consumption. In particular, in a portable display device (for example, a liquid crystal view cam or a liquid crystal television) which is often used in a bright place such as outdoors, in order to perform a liquid crystal display of sufficient quality even in a bright place, it is necessary to have a sufficient luminance. A display light source is required.

Therefore, conventionally, a configuration has been proposed in which a light condensing function is added to a liquid crystal display device to compensate for the light amount of a display light source, thereby enabling bright display while suppressing power consumption.

FIG. 5 shows a configuration of a liquid crystal display device having such a light collecting function. In FIG. 5, a liquid crystal display device main body 10 has a main body housing 12 having an opening, and a driving circuit is arranged around the panel so that the display surface of the liquid crystal panel is exposed at the opening of the main body housing 12. And a display light source unit 16 provided on the rear side of the panel unit 14. The light collector 20 is integrally attached to one side of the main body 10. The light collecting unit 20 is attached to the main body 10 and is configured by disposing a light guide material made of a transparent acrylic resin or the like in a light collecting unit housing 22 having an open upper surface. Further, the inner wall of the light collecting unit housing 22 is a light reflecting surface, and external light such as sunlight or indoor illumination light taken in from the daylighting unit 24 formed in the opening portion of the light collecting unit housing 22 is provided. The light travels through the light guide member while being repeatedly reflected on the reflection surface in the housing 22, and is guided to the display light source unit 16 as auxiliary light. The display light source unit 16 includes a light guide member, a reflection surface, and a light scattering member therein, and irradiates the liquid crystal panel 14 with auxiliary light supplied from the light condensing section 20 together with the display light source light as plane light.

As described above, by providing the light condensing section 20 to capture external light and using the external light as auxiliary light of the light source light from the display light source, if the light source light from the display light source is supplemented, the light source luminance can be increased. Even without this, a bright liquid crystal display becomes possible. In addition, since the light amount condensed by the light condensing unit 20 increases as the surrounding area becomes brighter, sufficient visibility can be obtained without using a high-brightness light source intended for use in a bright place as a display light source. High-quality liquid crystal display becomes possible. Therefore, it is possible to relatively reduce the power consumption of the display light source.

[0008]

However, the condensing unit 20 conventionally proposed is fixedly attached to the main body 10 of the liquid crystal display device, so that the area of the entire device becomes large, and the portability and the portability are limited. This poses a problem in terms of installation at a place.

Further, in order to further reduce the power consumption of the display light source unit 16 and make the display brighter, it is necessary to increase the area of the light-collecting portion in order to collect more external light. However, as described above, the light collecting section 20 is
Is fixed, so that if the condensing unit 20 is enlarged, the size of the apparatus is further increased, which is not preferable.

Therefore, there is a demand for a liquid crystal display device having low power consumption and high display quality without impairing the essential advantages of being small, thin, and excellent in portability and the like.

[0011] In order to solve the above problems, it is an object of the present invention to provide a small and thin liquid crystal display device which can reduce power consumption while maintaining display quality.

[0012]

To achieve the above object, the present invention has the following features.

First, the present invention relates to a liquid crystal display device comprising a liquid crystal panel, a display light source unit disposed on the opposite side of the display surface of the liquid crystal panel, and a light collecting section for collecting external light. The display light source unit has at least an air light guide unit having a space corresponding to a display surface of the liquid crystal panel, and the liquid crystal unit is configured such that the light condensing unit can be housed in the space of the air light guide unit. It is characterized by being attached to a display device.

Further, the present invention is a liquid crystal display device comprising a liquid crystal panel, a display light source unit disposed on a side opposite to a display surface of the liquid crystal panel, and a light collecting section for collecting external light. The display light source unit includes a first light guide unit that creates plane light to irradiate the liquid crystal panel, and a second air light guide unit that has a space corresponding to at least a plane of the display surface of the liquid crystal panel. , And the light condensing unit is attached to the liquid crystal display device so as to be housed in the space of the second air light guide unit.

Further, in the above configuration, according to the present invention,
The display light source unit may be the air light guide unit or the second light source unit.
And a display light source for irradiating the air light guide part with light.

As described above, if the light condensing portion condenses the external light and irradiates the light onto the liquid crystal panel, liquid crystal display can be performed without providing a display light source with large power consumption in the device. Also,
When the display light source is provided, if the external light collected by the light collecting unit is used as auxiliary light of the light source light from the display light source, brighter display can be performed by effectively using the external light. . Further, if the power is used as the driving power of the liquid crystal display device, the power consumption can be reliably reduced. If the driving voltage of the liquid crystal is increased by using this power, it is easy to obtain a bright display. In addition, for example, when not displayed or for other reasons,
If it is not necessary to collect the light, the light collecting section can be stored in the main body of the device to make it compact except when necessary.
Does not interfere with carrying. Further, for this reason, it is possible to make the condensing portion a size necessary for exhibiting a sufficient condensing function. Furthermore, since it can be stored, the possibility of damage to the light collecting unit itself when not in use is reduced.

Further, according to the present invention, there is provided a light-collecting portion detection sensor for detecting when the light-collecting portion is accommodated in the space in the air light guide portion or the space in the second air light guide portion, On / off control of the display light source is performed according to a detection result of the section detection sensor. For example, the light condensing unit is an air light guide unit (including the second air light guide unit).
If the display sensor is configured to guide the display light source light to the liquid crystal panel when stored in the storage space, the display light source is turned on when the detection sensor detects the light condensing part in the storage space, and when the light source is not present in the storage space. Turn off the display light source. At this time, since the light condensing part is drawn out of the storage space and condenses external light, liquid crystal display can be performed by the external light, and power consumption of the display light source is eliminated by controlling the display light source to off. it can. In addition, only when the light collector is stored in the storage space, the display light source is automatically turned on,
The power consumption of the display light source can be reduced, and the user can save the trouble of turning on the display light source.

Further, according to the present invention, in the above device,
When the light condensing part is housed in the space in the air light guiding part or the second air light guiding part, the light collecting part is used as a light source light guiding member for irradiating the display light source light to the liquid crystal panel. It is characterized by doing. If the light condensing part can be used also as a light source light guide member, liquid crystal display can be performed even when stored in the storage space. In other words, the liquid crystal display is performed, but at that time, when it is not necessary to use the external light, the light collecting unit may be stored in the storage space, and the light collecting unit does not become an obstacle.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention (hereinafter, referred to as embodiments) will be described below with reference to the drawings.

[Embodiment 1] FIG. 1 shows a schematic configuration of a liquid crystal display device having a condensing function according to an embodiment of the present invention, and FIG. 2 shows a schematic top configuration of the device.

The main body 10 of the liquid crystal display device includes a main body housing 12.
Inside, the liquid crystal panel unit 14 and the display light source unit 18
The light-collecting panel 30 serving as a light-collecting unit is mounted so as to be housed in a storage space that also serves as an air light guide unit 42 that is a space in the display light source unit 18.

The main housing 12 has an opening as in the prior art, and the display surface of the liquid crystal panel is exposed in the opening. Although not shown in detail, the liquid crystal panel unit 14 includes a liquid crystal panel in which a liquid crystal layer is sealed between a pair of substrates,
The liquid crystal panel is positioned so as to match the position of the opening of the main body housing 12. In addition, a drive circuit, a power supply circuit, and the like are attached to the periphery of the liquid crystal panel or are built in.

A display light source unit 18 is disposed behind the display surface of the liquid crystal panel unit 14. The display light source unit 18 includes a display light source 40 and an air light guide 42. The air light guide section 42 has a reflection section 42a with irregularities formed on the lower surface side thereof, and a diffusion plate 42b disposed on the upper surface side. The display light source light (including light reflected by the reflector) and The display light source light and the external light from the light collecting panel 30 radiated from the opposite side are radiated to the entire liquid crystal panel as plane light.

The light-collecting panel 30 is a member for collecting external light from an external light source such as the sun or an indoor fluorescent lamp. When housed in the liquid crystal panel, it also functions as a light source light guide member for introducing light from the display light source 40 from the incident surface also serving as the external light emission surface 30a and irradiating the liquid crystal panel as flat light. The light condensing panel 30 includes the light guide member 3.
4 and a condenser lens 36, the light guide member 34 is made of a transparent material such as acrylic resin or polycarbonate, and the condenser lens 36 formed on the upper surface side of the light guide member 34 It consists of a lens. A reflection layer called a lighting curtain 46 is formed on the upper surface of the light guide member 34 in order to function as the light source light guide member. In addition, the lighting curtain 46 is formed by printing a reflective material by printing or the like in order to reflect light traveling in the light guide member 34 into the member and to make light emitted outside the member uniform. Here, the reflective material is formed so that the display light source 40 side is coarse and the opposite side is dense. For this reason, when the light-collecting panel 30 is inserted into the air light guide section 42, which is a storage space, the display light source light is irradiated onto the liquid crystal panel as uniform plane light.

A draw-out handle 32 is provided at an end of the light-collecting panel 30. The left and right side surfaces of the light-collecting panel 30 are respectively engaged with the guide grooves 12a of the main body housing 12. When the light collecting panel 30 is housed in the air light guide section 42 because the panel slide protrusion 38 is formed, the panel slide protrusion 38 moves in the guide groove 12 a of the housing 12 to collect light in the storage space. The panel 30 is guided and stored.

As shown in FIG. 2, a fixing claw 48a and a release claw 48b are provided on both sides of the front end of the light-collecting panel 30, respectively. Further, when the light-collecting panel 30 is housed in the air light guide section 42, a lock mechanism 50 is provided in a portion of the main body housing 12 facing the claw. The lock mechanism 50 includes a panel stopper 54 rotatably attached to a shaft 58, a stopper control spring 52 for weakly holding the stopper, and a panel press for strongly pushing the light collecting panel 30 outward. And a spring 56.

When the light collecting panel 30 is pushed into the air light guide section 42 and the fixing claw 48a engages with the panel stopper 54, the light collecting panel 30 is fixed inside. When the light-collecting panel 30 is further pushed in from the fixed state, the release claw 48b pushes the panel stopper 54 sideways, so that the fixing claw 48 of the light-collecting panel 30 and the panel stopper 54 are engaged. Is canceled. In this state, the pushing back of the panel stopper 54 is stronger than the returning of the panel stopper 54, so that the fixing claws 48a pass before the panel stopper 54 returns to the original position, and the light collecting panel 30 automatically moves outward. Extruded. By such a mechanism, the light collecting panel 30 at the time of storage is securely fixed in the storage space. Conversely, when external light is collected by using the light collecting panel 30, The light-collecting panel 30 can be pulled out from

As shown in FIG. 1 and FIG.
In a state where 0 is drawn out, external light such as sunlight or indoor illumination light is collected on the light guide member 34 of the light collection panel 30 and reflected by the light collection lens 36 on the lower surface side of the light guide member 34, The condensed external light travels inside the light guide member 34 and is emitted from the common exit surface 30a as the incident surface. Light collection panel 30
External light emitted from the air guide section 42 to the air light guide section 42
The light is reflected by the second reflection part 42a and diffused by the diffusion plate 42b,
The liquid crystal panel is irradiated as flat light together with the display light source light.

When the light collecting panel 30 is housed in the housing space of the air light guide section 42, the light collecting panel 30 functions as a light source light guide member as described above, so that the light source Light is applied to the liquid crystal panel as plane light.

In the first embodiment, the light collecting panel 3
0 is provided with a function as a light source light-guiding member as an example. However, when such a light source member does not have such a function as a light source light-guiding member, that is, the light is collected from the exit surface 30a also serving as the incident surface. When the display light source light entering the optical panel 30 cannot be emitted as flat light toward the liquid crystal panel, when the liquid crystal display device is not used, the light collection panel 30 is stored in the air light guide section 42. Store in space.
If a liquid crystal display device is not used, the light collecting panel 30
Since the light collecting panel 30 can be housed in the device at that time, the size of the device can be reduced, and the device can be easily stored.

[Second Embodiment] In the second embodiment, a sensor for detecting whether or not the light collecting panel 30 is present in the storage space is provided, and the on / off of the display light source is controlled in accordance with the detection result of the sensor. Other configurations are the same as those of the first embodiment.

FIG. 3 shows a schematic configuration of the apparatus according to the second embodiment. Note that, in FIG. 3, the same portions as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.

The light collecting panel detection sensor 60 is provided, for example, near the shaft 58 of the lock mechanism 50 shown in FIG. 2 and detects whether or not the light collecting panel 30 is stored in the storage space of the air guide section 42. I do. The detection sensor 60 does not necessarily have to be provided near the lock mechanism 50. However, in order to determine whether the light collecting panel 30 is almost completely stored in the storage space, as shown in FIG. It is preferable to install in a suitable position. Also, to increase the detection accuracy, the left and right sides of the storage space
It is preferable to provide the light collecting panel detection sensors 60 respectively.

When the light-collecting panel 30 is inserted into the storage space and its exit surface 30a passes in front of the light-collecting panel detection sensor 60, the sensor 60 detects this and generates a detection signal. In the second embodiment, when the light collecting panel 30 is stored in the storage space and a detection signal is generated, the display light source 40
Is turned on. Conversely, when the light collecting panel 30 is pulled out, the display light source 40 is turned off. In the second embodiment, the light-collecting panel 30 has a function as a light source light guide member, so that the light from the display light source 40 is converted into plane light to be applied to the liquid crystal panel when housed in the air light guide section 42. Irradiation is possible. When the light-collecting panel 30 is pulled out, external light from an external light source can be collected. Therefore, the collected external light is used as the display light source of the liquid crystal panel, and the light-collecting panel 30 is stored. The display light source 40 is turned on only when external light is not collected. By doing so, the power consumption of the display light source 40 during the period of using external light can be cut, and the total power consumption can be reduced.

In the case where the light collecting panel 30 does not have a function as a light source light guiding member and the light from the display light source is blocked by the light collecting panel 30 when housed in the air light guiding section 42, The display light source 40 is turned on when the light-collecting panel 30 is pulled out, and turned off when the light-collecting panel 30 is stored in the storage space. For example, in the case where the display light source 40 is manually turned on and off separately, if the display light source is automatically and forcibly turned off when the light collecting panel 30 is stored using the detection signal, the display light source For example, forgetting to turn off the power 40 can be prevented, and unnecessary power consumption can be prevented.

Third Embodiment Next, a third embodiment will be described with reference to FIG. Note that the same reference numerals are given to the same portions as the members shown in the already described figures, and the description will be omitted.

In the third embodiment, the display light source unit 1
An air light guide 42 and a second air light guide 44 are provided as spaces in the space 8, and the light collecting panel 30 can be housed in a storage space that also serves as the second air light guide 44. A lock mechanism 50 similar to that shown in FIG. 2 is provided at the back of the second air light guide section 44 to fix the stored light collecting panel 30 so that the fixed state can be easily released at the time of removal. Further, a light-collecting panel detection sensor 60 is provided in the same manner as in the above-described second embodiment to detect whether the light-collecting panel 30 is housed in the second air light guide 44, and accordingly, the display light source 40 is turned on. On / off control. However, it is not always necessary to provide the sensor 60 and control on / off of the display light source 40.

A guide groove 12a is formed in the storage space for the second air light guide 44 as shown in FIGS. 1 and 2, and the guide groove 12a is formed in the guide groove 12a. The slide projection 38 is movably engaged so that the light collection panel 30 can be housed in the air light guide 44 or pulled out as shown in FIG.

When the external light condensed by the condensing panel 30 extracted as shown in FIG. 4 is emitted from the exit surface 30a into the light guide section, the second air light guide section 44 converts the external light into an auxiliary plane. The liquid crystal panel is irradiated as light. At the same time, this second
The air light guide section 44 transmits the plane light emitted from the air light guide section 42 as it is. Therefore, the air light guide 42
The outside light to be transmitted from the light condensing panel 30 to the second air light guide 44 is transmitted between the light guide 42 and the second air light guide 44 while diffusing the plane light from the air light guide 42 while transmitting the light. And a selective diffusion reflection plate 42c that reflects light. The diffusion intensity of the selective diffuse reflection plate 42c on the air light guide portion 42 side is set to increase as the distance from the display light source 40 increases.
The reflection intensity on the side of the second air light guide 44 is set to be weaker as the distance from the exit surface 30a of the light-collecting panel 30 in the pulled-out state is increased. Can be evenly applied to the liquid crystal panel.

In the third embodiment, when the light is not condensed, the light condensing panel 30 is housed in the housing space of the second air light guide 44 by pushing the light condensing panel 30 into the space, and the device is compact. State. Further, if the light collecting panel 30 has a function as a light source light guiding member, the light collecting panel 30 is housed when the liquid crystal display does not need to be sufficiently bright to collect light. Liquid crystal display can be performed using only the light source light.

In the third embodiment, it is not always necessary to use the air light guide section 42 in order to convert the light from the display light source 40 into plane light. Instead, a light guide made of acrylic resin or the like is used instead. A light plate can also be used.

[0042]

As described above, according to the present invention, since the light collecting section is stored in the storage space of the air guide section in the display light source unit, the size of the apparatus when the light collecting function is not used is reduced. The device can be reduced in size, and can be made compact and excellent in portability. In addition, since the light-collecting unit does not interfere when the light-collecting function is not used, it is easy to increase the light-collecting area of the light-collecting unit as needed, and a liquid crystal display device with low power consumption and high display quality can be provided. Obtainable. Furthermore, by using the air light guide, it is possible to reduce the weight of the device and increase the efficiency of use of light from the light source.

Further, in the present invention, the space of the air light guide portion for the display light source or the second air light guide portion is used as a storage space of the light collecting portion, so that the light collecting portion is stored in the device. The liquid crystal display does not become thick. Especially,
In the configuration in which the light condensing part is housed in the air light guide part for creating plane light to irradiate the liquid crystal panel from the display light source light, condensing is possible with almost the same thickness as a liquid crystal display device without a condensing function In addition, the light collector can be stored in the main body.

Further, in the present invention, the sensor detects whether or not the light-collecting portion is stored in the storage space, and automatically controls the on / off of the display light source. The light source can be turned off, and unnecessary power consumption of the display light source can be reduced.

In the present invention, when the light-collecting portion is stored in the storage space, the light-collecting portion functions as a light guide member for the display light source, so that the light-collecting portion is stored in the storage space. Liquid crystal display can be performed even in this state. Therefore, at the time of liquid crystal display, external light is condensed to make the display brighter, and when unnecessary, the liquid crystal display is performed only with the display light source light without using external light. It is easy to perform an optimal liquid crystal display using the material.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a liquid crystal display device with a light collecting function according to a first embodiment of the present invention.

FIG. 2 is a conceptual top view of the apparatus of FIG.

FIG. 3 is a schematic side view of a liquid crystal display device with a light collecting function according to a second embodiment of the present invention.

FIG. 4 is a conceptual side view showing a liquid crystal display device with a light collecting function according to Embodiment 3 of the present invention.

FIG. 5 is a diagram illustrating a configuration of a conventional liquid crystal display device with a light-condensing function.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Main body, 12 Main body housing, 12a Guide groove, 14
Liquid crystal panel unit 18 Display light source unit, 30 Light-collecting panel, 30a Exit surface, 32 Pull-out handle, 34
Light guide member, 36 Condensing lens, 38 Panel slide protrusion, 40 Display light source, 42 Air light guide, 42a Reflector, 42b Diffuser, 42c Selective diffuse reflector, 44
2nd air light guide, 46 lighting curtains, 4
8a fixing claw, 48b release claw, 50 locking mechanism, 52 stopper control spring, 54 panel stopper, 5
6 Panel press spring, 60 Condensing panel detection sensor.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makio Ohashi 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Makoto Shimizu 2-chome Keihanhondori, Moriguchi-shi, Osaka No. 5-5 in Sanyo Electric Co., Ltd.

Claims (5)

[Claims] 1. A liquid crystal display device comprising: a liquid crystal panel; a display light source unit disposed on a side opposite to a display surface of the liquid crystal panel; and a light collecting unit for collecting external light. The display light source unit has at least an air light guide unit having a space corresponding to the display surface of the liquid crystal panel, and the light condensing unit is attached to the liquid crystal display device so as to be housed in the space of the air light guide unit. A liquid crystal display device with a light-condensing function, comprising: 2. A liquid crystal display device comprising: a liquid crystal panel; a display light source unit disposed on a side opposite to a display surface of the liquid crystal panel; and a light collecting unit for collecting external light. The display light source unit includes: a first light guide unit that creates plane light to irradiate the liquid crystal panel; and a second air light guide unit that has a space corresponding to at least a plane of the display surface of the liquid crystal panel, The liquid crystal display device with a light condensing function, wherein the light condensing portion is attached to the liquid crystal display device so as to be housed in the space of the second air guide portion. 3. The liquid crystal display device with a light-condensing function according to claim 1, wherein the display light source unit is the air light guide unit or the second light source unit.
A light source for irradiating the air light guide part with light. 4. The liquid crystal display device with a light-condensing function according to claim 1, wherein the light-condensing portion is housed in a space in the air guide portion or in a space in the second air guide portion. A liquid crystal display device with a light-condensing function, comprising: a light-condensing portion detection sensor for detecting the display light source, and turning on and off the display light source according to a detection result of the light-condensing portion detection sensor. 5. The display light source according to claim 1, wherein the light-collecting unit is housed in a space in the air light guide unit or in the second air light guide unit. A liquid crystal display device having a condensing function, wherein the condensing portion is used as a light source light guiding member for irradiating the liquid crystal panel with light.