JPH09236785A - Display device, monitor device, head mout display device and window glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of seeing the rear side (opposite side) through the display device. SOLUTION: In a display device 100 provided with a display 600 and back lights 601, 602, 603 irradiating the display, a light scattering controller 604, transmitting external light through at the time of decreasing the degree of light scattering and scattering the external light at the time or increasing the degree of light scattering, is provided being opposed to the display while interposing the light transmitting plate 602 of the back light between them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly, to a display device capable of seeing a background behind a display device through the display device.

[0002]

2. Description of the Related Art With the increasing performance and functionality of various electronic devices, the role of a display device has become more important as a man-machine interface for displaying scanning procedures and operating states. .

Among them, a CRT display device using a cathode ray tube (CRT) or a liquid crystal display device using a liquid crystal display panel is required in modern society as an information display device for displaying a TV signal or a signal from a computer as an image. It has become indispensable.

[0004]

[Problems to be Solved by the Invention] However, a CRT
A display device or a display device typified by a liquid crystal display device cannot see the background on the back side (opposing side) through the display device.

Therefore, the monitor device using these display devices has a drawback that the area on the opposite side across the display device becomes a blind spot for the user using the monitor device.

[0006] This gives the user a visually occluded feeling and hinders communication between users when the display device is not used.
There is a problem that it becomes a cause of giving stress to the user.

Also, with the spread of navigation systems, such display devices are being installed in vehicles. However, since the display devices installed in the vehicle obstruct the driver's view, a large-sized display is provided. There is a problem that the device cannot be mounted in the vehicle.

Furthermore, as a display of a game machine,
A head-mounted display using a liquid crystal display panel has been attracting attention, but this head-mounted display has a problem in that eyes cannot be seen because the outside scenery cannot be seen.

The present invention has been made to solve the above-mentioned problems of the prior art. An object of the present invention is to allow a back side (opposing side) of a display device to be seen through the display device. It is to provide the technology that will be possible.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0011]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

(1) In a display device including a display and a backlight for illuminating the display, external light is transmitted when the light scattering property is reduced and is scattered when the light scattering property is increased. The light scattering control device is provided so as to face the display with the light guide plate of the backlight interposed therebetween.

(2) The means of (1) above is characterized in that it has a switch for adjusting the light scattering property of the light scattering control device.

(3) In the means of (1) or (2), when the light scattering property of the light scattering control device is increased, power is supplied to the backlight so that the light scattering control device can scatter light. When the lightness is reduced, the backlight is not supplied with power.

(4) In the means (1) to (3), the backlight is a sidelight type backlight in which a light source is arranged on the side surface of a light guide plate.

(5) In the means (4), the light guide plate has a rectangular cross section in a direction perpendicular to the light source.

(6) In the above means (1) to (5), the light scattering control device is a polymer dispersion type liquid crystal device.

(7) In the means of (6), the light guide plate of the backlight also serves as one substrate of the polymer dispersion type liquid crystal device.

(8) In the above means (1) to (7), the light scattering control device is a film-shaped light scattering control device.

(9) In the means described in (1) to (8), the display is a liquid crystal display device.

(10) In the above means (9), the liquid crystal display device is a liquid crystal display device for applying an electric field substantially parallel to a substrate surface to a liquid crystal layer injected and sealed between a pair of substrates. Is characterized by.

(11) In the means of (9) or (10), the liquid crystal display device is a normally white type liquid crystal display device.

(12) In the above means (9), the liquid crystal display device is a polymer dispersion type liquid crystal display device.

(13) In the means of (12), the light guide plate of the backlight also serves as one substrate of the polymer dispersion type liquid crystal display device.

According to each of the above-mentioned means, in the display device having the display and the backlight, the light scattering control device is provided so as to face the display with the light guide plate of the backlight interposed therebetween, and the light scattering control device is provided. Since the external light is transmitted when the light scattering property is reduced and the external light is scattered when the light scattering property of the light scattering control device is increased, the light scattering control device is controlled. Thus, for example, when the display device is not used, it is possible to see through the display and see its background.

[0026]

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

In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

[First Embodiment of the Invention] FIG. 1 is a block diagram showing a schematic configuration of a display device according to an embodiment (first embodiment of the invention) of the present invention.

As shown in FIG. 1, the display device 100 according to the embodiment of the present invention comprises a display 600, a backlight 605 and a light scattering control device 604.

Here, the backlight 605 is the light guide plate 6.
01, cold cathode tube 6 provided on the side surface of the light guide plate 601
02 and a reflection sheet 603 that reflects the irradiation light from the cold cathode fluorescent lamp 602, and the display 600 and the light scattering control device 604 sandwich the light guide plate 601 of the backlight 605. It is provided facing each other.

In the present invention, the polymer dispersion type liquid crystal device 200 is used as the light scattering control device 604 shown in FIG.

FIG. 2 is a diagram for explaining the schematic structure of the polymer dispersion type liquid crystal device 200 and its operation mode.

As shown in FIG. 2, the polymer dispersion type liquid crystal device 200 includes a pair of transparent substrates (201, 202) and a transparent electrode (2) provided on each transparent substrate (201, 202).
11 and 212) and a polymer dispersed liquid crystal 220 that is injected and sealed between the transparent electrodes (211 and 212).

Here, the polymer dispersed liquid crystal 220 is a base material 22 such as polyvinyl alcohol or acrylic resin.
Liquid crystal particles 221 dispersed in each of the transparent substrates (201, 212).
02) It is provided over the entire upper surface.

In the state where no voltage is applied between the transparent electrodes (211 and 212) of the polymer dispersed liquid crystal device 200, the liquid crystal molecules 22 in the liquid crystal grains 221 of the polymer dispersed liquid crystal 220.
2 is irregularly oriented, and in this state, FIG.
As shown in, external light 2 incident from the transparent substrate 201 side
Since 23 is scattered by the liquid crystal molecules 222 in the liquid crystal particles 221, the polymer dispersed liquid crystal device 200 becomes opaque and white.

Further, when a sufficient voltage is applied between both transparent electrodes (211 and 212) of the polymer dispersed liquid crystal device 200, the liquid crystal molecules 222 in the liquid crystal grains 221 of the polymer dispersed liquid crystal 220 have an electric field of the applied voltage. 2A, in this state, as shown in FIG. 2A, external light 223 incident from the transparent substrate 201 side receives the liquid crystal particles 221.
Since the light is emitted from the transparent substrate 201 without being scattered by the liquid crystal molecules 222 inside, the polymer dispersed liquid crystal device 20
0 is transparent.

FIG. 3 is a diagram for explaining operation modes of the display device 100 according to the embodiment of the present invention.

As shown in FIG. 3B, when the voltage is not applied between both transparent electrodes (211 and 212) of the polymer dispersion type liquid crystal device 200 constituting the light scattering control device 604, the light scattering control is performed. External light 610 incident on the device 604
Are scattered by the liquid crystal molecules 222 in the liquid crystal particles 221 of the polymer dispersed liquid crystal device 200, the display 60
Irradiation light 61 for displaying an image on the liquid crystal display panel 0
1 is limited to the irradiation light from the cold cathode tube 603.

In this case, a part of the irradiation light entering the light scattering control device 604 from the cold cathode fluorescent lamp 603 is scattered and reflected by the light scattering control device 604, and again the light guide plate 601.
And becomes a part of the irradiation light 611.

Further, as shown in FIG. 3A, a polymer dispersion type liquid crystal device 200 constituting a light scattering control device 604.
When a sufficient voltage is applied between both transparent electrodes (211 and 212) of the external light, the external light 61 incident on the light scattering control device 604 is incident.
0 enters the light guide plate 601 without being scattered and further enters the display 600.

In this case, when the power supplies of the display 600 and the cold-cathode tube 603 are “ON”, the image displayed on the display 600 appears to float in the background behind the display 600.

Further, if the display 600 is a type of display in which the irradiation light from the cold cathode fluorescent lamp 603 can pass through the display 600 when the power of the display 600 is “OFF”, that is, a normally white type display, Display 600 and cold cathode tube 60
When the power of 3 is “OFF”, the display 60
It is possible to see the background behind 0.

Here, as the display 600 shown in FIG. 1, a simple matrix type liquid crystal display device or an active matrix type liquid crystal display device can be used.

Hereinafter, as an active matrix type liquid crystal display device used for the display 600, an example of a horizontal electric field type active matrix type liquid crystal display device will be described.

FIG. 4 is a plan view showing one pixel and its periphery of the liquid crystal display panel in the horizontal electric field type active matrix liquid crystal display device used in the display 600 shown in FIG.

In the figure, the solid line shows the structure formed on the lower transparent glass substrate (SUB1) side which is the lower substrate, and the broken line shows the upper transparent substrate glass (SUB 1) which is the upper substrate.
The structure formed on the 2) side is shown.

As shown in FIG. 1, each pixel has two adjacent scanning signal lines (gate signal lines or horizontal signal lines) (G
L) and an adjacent two video signal lines (drain signal lines or vertical signal lines) (DL) are arranged in an intersecting region (in a region surrounded by four signal lines).

Each pixel has a thin film transistor (TFT),
Storage capacitor (Cstg), pixel electrode (PX), counter electrode (CT) and counter voltage signal line (common signal line) (C
L).

Here, the scanning signal line (GL) and the counter voltage signal line (CL) extend in the left-right direction in FIG. 1, and a plurality of them are arranged in the vertical direction, and the video signal line (DL) is in the vertical direction. And extends in the left-right direction.

The pixel electrode (PX) is connected to the source electrode (SD1) of the thin film transistor (TFT), and the counter electrode (CT) is formed integrally with the counter voltage signal line (CL).

The pixel electrode (PX) and the counter electrode (CT) face each other, and each pixel electrode (PX) and the counter electrode (CT).
The optical state of the liquid crystal layer (LC) is controlled by the electric field between and to control the display.

The pixel electrode (PX) and the counter electrode (CT) are formed in a comb-teeth shape, and in FIG. 4, they are long and thin electrodes in the vertical direction.

In the liquid crystal display panel shown in FIG. 4, the pixel electrode (PX) has a U-shape that opens downward, and the counter electrode (CT) has a comb-tooth shape that projects downward from the counter voltage signal line (CL). Therefore, the area between the pixel electrode (PX) and the counter electrode (CT) is divided into four in one pixel.

FIG. 5 is a sectional view showing a section taken along a section line 3-3 shown in FIG. 4, FIG. 6 is a sectional view showing a section of a thin film transistor (TFT) taken along a section line 4-4 shown in FIG. 4, and FIG. FIG. 5 is a cross-sectional view showing a cross section of the storage capacitor (Cstg) along the 5-5 cutting line shown in FIG. 4.

As shown in FIGS. 5 to 7, a liquid crystal layer (LC)
On the lower transparent glass substrate (SUB1) side,
A thin film transistor (TFT), a storage capacitor (Cstg) and an electrode group are provided, and an upper transparent glass substrate (SUB) is provided.
On the 2) side, a color filter (FIL) and a light shielding film (black matrix pattern; BM) are provided.

Further, transparent glass substrates (SUB1, SUB)
On the surface of each inner side (liquid crystal layer (LC) side) of 2), an alignment film (ORI1, OR) for controlling the initial alignment of the liquid crystal is formed.
I2) is provided, and a transparent glass substrate (SUB1,
Polarizing plates (POL1, POL2) are provided on the outer surface of each SUB2).

As shown in FIG. 6, the thin film transistor (TFT) has a gate electrode (GT) and a gate insulating film (G).
I), i-type (intrinsic, intrinsic, i-type semiconductor layer (AS) made of amorphous silicon (Si) not doped with conductivity determining impurities), a pair of source electrodes (SD)
1), having a drain electrode (SD2).

As the thin film transistor (TFT), in addition to an amorphous silicon thin film transistor element, a polysilicon thin film transistor element, a MOS type transistor on a silicon wafer, an organic TFT, or an MIM (Metal-Insulator-Me) is used.
It is also possible to use a two-terminal element such as a tal) diode.

The gate electrode (GT) is connected to the scanning signal line (G
L), and a part of the scanning signal line (GL) serves as a gate electrode (GT).

Here, the scanning signal line (GL), the gate electrode (GT), the counter electrode (CT) and the counter voltage signal line (C).
L) is, for example, an aluminum (Al) -based conductive film (g
1), the scanning signal line (GL), the gate electrode (G)
T), counter electrode (CT) and counter voltage signal line (CL)
Are formed in the same layer in the same manufacturing process.

Scan signal line (GL), gate electrode (G
T), counter electrode (CT) and counter voltage signal line (CL)
An insulating film (GI) made of, for example, a silicon nitride film formed by plasma CVD is provided on the above.

The insulating film (GI) is a thin film transistor (T
In the FT, as a gate insulating film for applying an electric field to the semiconductor layer (AS) together with the gate electrode (GT), or the scanning signal line (GL) and the counter voltage signal line (C).
It is used for electrical insulation between L) and the video signal line (DL).

On the i-type semiconductor layer (AS) in the connection region with the source electrode (SD1) and the drain electrode (SD2), N (+) type amorphous silicon doped with phosphorus (P) for ohmic contact is formed. A semiconductor layer is provided.

Each of the source electrode (SD1) and the drain electrode (SD2) has a conductive film (d1) in contact with the N (+) type amorphous silicon semiconductor layer and a conductive film (d2) formed thereon. ) And is composed of.

The conductive film (d1) is, for example, a chromium (Cr) film formed by sputtering, and the conductive film (d2) is an aluminum (Al) -based conductive film.

Video signal line (DL) and pixel electrode (P
X) is a source electrode (SD1) and a drain electrode (S
D2) and the conductive film (d1) formed in the same layer as the source electrode (SD1) and the drain electrode (SD2),
It is composed of a conductive film (d2) formed thereon.

The pixel electrode (PX) has an end opposite to the end connected to the thin film transistor (TFT).
It is configured to overlap the counter voltage signal line (CL).

In this superposition, as is clear from FIG. 7, the pixel electrode (PX) is one electrode (PL2),
A storage capacitor (electrostatic capacitance element) (Cstg) having the opposite voltage signal (CL) as the other electrode (PL1) is configured.

The dielectric film of this storage capacitor (Cstg) is
It is composed of an insulating film (GI) used as a gate insulating film of a thin film transistor (TFT) and an anodized film.

The storage capacitor (Cstg) is provided to store the video information written in the pixel (after the thin film transistor (TFT) is turned off) for a long time.

A protective film (PSV) made of, for example, a silicon oxide film or a silicon nitride film formed by a plasma CVD apparatus is provided on the thin film transistor (TFT).

This protective film (PSV) is provided mainly for protecting the thin film transistor (TFT) from moisture and the like, and a film having high transparency and good moisture resistance is used.

On the upper transparent glass substrate (SUB2) side,
The light-shielding film (BM) prevents the transmitted light from an unnecessary gap (a gap other than between the pixel electrode (PX) and the counter electrode (CT)) from being emitted to the display surface side and lowering the contrast ratio and the like.
(A so-called black matrix pattern) is formed.

The light shielding film (BM) also plays a role of preventing external light or backlight light from entering the i-type semiconductor layer (AS).

The closed polygonal contour line of the light shielding film (BM) shown in FIG. 4 indicates an opening inside which the light shielding film (BM) is not formed.

The light shielding film (BM) is formed in a lattice shape around each pixel, and the effective display area of one pixel is partitioned by this lattice. Therefore, the outline of each pixel is the light shielding film (BM).
To clarify.

That is, the light shielding film (BM) has two functions of a black matrix and a light shielding for the i-type semiconductor layer (AS).

The light-shielding film (BM) has a light-shielding property and is formed of a film having a high insulating property so as not to affect the electric field between the pixel electrode (PX) and the counter electrode (CT). In the liquid crystal display panel 1 shown in FIG. 4, the light shielding film (BM) is composed of an insulating organic resin (resist material) in which a black pigment is dispersed.

A color filter (FIL) is provided in the opening of the light shielding film (BM), and the color filter (FI) is provided.
L) is formed in a stripe shape by repeating red, green, and blue at a position facing the pixel, and also has a color filter (FI).
L) is configured to overlap the edge portion of the light shielding film (BM).

The color filter (FIL) can be formed as follows.

First, a dyeing base material such as an acrylic resin is formed on the surface of the upper transparent glass substrate (SUB2), and the dyeing base material other than the red filter forming region is removed by the photolithography technique.

After that, the dyed substrate is dyed with a red dye, and a fixing process is performed to form a red filter (R).

Then, by performing the same steps,
A green filter (G) and a blue filter (B) are sequentially formed.

Light-shielding film (BM) and color filter (F
IL), an overcoat film (OC) made of a transparent resin material such as acrylic resin or epoxy resin.
The overcoat film (OC) prevents the dye from leaking from the color filter (FIL) to the liquid crystal layer (LC), and prevents a step due to the color filter (FIL) and the light shielding film (BM). It is provided for flattening.

Upper and lower transparent glass substrates (SUB1, SUB)
A liquid crystal filling port (not shown) is provided along the edge between 2).
Except for the above, a seal pattern (not shown) is provided so as to seal the liquid crystal layer (LC).

On the protective film (PSV) on the lower transparent glass substrate (SUB1) side and on the upper transparent glass substrate (SUB
On the 2) side overcoat film (OC), alignment films (ORI1, ORI2) made of polyimide are provided, and the alignment films (ORI1, ORI2) are formed inside the seal pattern.

The liquid crystal layer (LC) is composed of a lower alignment film (ORI1) and an upper alignment film (ORI2) for setting the orientation of liquid crystal molecules.
It is enclosed in a region partitioned by a seal pattern between and.

In the liquid crystal display panel shown in FIG. 4, the lower transparent glass substrate (SUB1) and the upper transparent glass substrate (SUB) are used.
After 2) is formed by stacking various layers separately, a seal pattern is formed on the upper transparent glass substrate (SUB2) side, the lower transparent glass substrate (SUB1) and the upper transparent glass substrate (SUB2) are superposed, Liquid crystal (LC) is injected from the opening of the seal pattern, the injection port is sealed with epoxy resin, and the upper and lower substrates are cut to assemble.

FIG. 8 is a diagram showing a connection diagram of an equivalent circuit of the display matrix portion (AR) and its peripheral circuits in the liquid crystal display panel shown in FIG.

Although FIG. 8 is a circuit diagram, it is drawn corresponding to the actual geometrical arrangement.

In FIG. 8, AR indicates a display matrix section (matrix array) in which a plurality of pixels are arranged two-dimensionally, and Pix indicates the liquid crystal capacitance of the liquid crystal layer (LC).

PX indicates a pixel electrode, and the subscripts R and G
And B are added corresponding to red, green and blue pixels respectively.

The drain electrodes of a plurality of thin film transistors (TFTs) in each column direction among the thin film transistors (TFTs) arranged in a matrix are connected to the same video signal line (drain signal line) (DL), and the plurality of the plurality of thin film transistors (TFTs) are connected. The video signal line (DL) is connected to a video signal drive circuit (drain driver) (H) at the upper part of the liquid crystal display panel.

Further, the gate electrodes of a plurality of thin film transistors (TFTs) in each row direction among the thin film transistors (TFTs) arranged in a matrix are connected to the same scanning signal line (gate signal line) (GL), The plurality of scanning signal lines (GL) are connected to the vertical scanning circuit (gate driver) (V) on one side surface of the liquid crystal display panel.

Further, a common electrode (counter electrode) for applying an electric field to the liquid crystal layer in the direction parallel to the substrate is provided for each of the plurality of pixel electrodes (PX) arranged in the matrix, and arranged in the matrix. A plurality of counter electrodes facing the plurality of pixel electrodes (PX) in each row direction in the formed pixels are connected to the same counter voltage signal line (common electrode signal line) (CL).

This counter voltage signal line (common electrode signal line)
(CL) are collected by a common bus line on the other side surface of the liquid crystal display panel and led out to the counter electrode terminal (CTM). The counter electrode terminal (CTM) has a circuit (SU).
The counter voltage (Vcom) from P) is applied.

The vertical scanning circuit (V) and the video signal driving circuit (H) are supplied with the scanning signal (scanning voltage) and the video signal (gradation voltage) from the liquid crystal driving power supply circuit of the circuit (SUP), and The counter voltage (Vcom) applied to the counter voltage signal line (CL) is also supplied from the liquid crystal drive power supply circuit of the circuit (SUP).

The circuit (SUP) converts the image information (display data, control signal) from the host into image information (display data, control signal) for the liquid crystal display device, and displays the liquid crystal display device. Data for video signal drive circuit (H)
Then, the control signal for the liquid crystal display device is output to the vertical scanning circuit (V) and the video signal driving circuit (H).

In the liquid crystal display panel shown in FIG. 7, based on a control signal input from the information processing device to the circuit (SUP), the vertical drive circuit (V) sequentially outputs the scan signal to the plurality of scan signal lines (GL). (Scanning voltage) is applied to turn on and off a plurality of thin film transistors (TFTs) connected to the scanning signal line (GL), and the video signal from the video signal drive circuit (H) is synchronized with the timing. Line (D
A video signal (grayscale voltage) is applied to L) and a grayscale voltage is applied to the pixel electrode (PX).

Here, y0 and y of the scanning signal line (GL)
1, ... Yend indicate the order of the scanning timing.

In the liquid crystal display panel shown in FIG. 4, the upper alignment film (ORI2) on the upper transparent glass substrate (SUB2) side.
And the lower alignment film (ORI1) on the lower transparent glass substrate (SUB1) side are subjected to a rubbing treatment to control the initial alignment direction (φLC) of the liquid crystal molecules.

FIG. 9 shows an applied electric field direction (EDR), a rubbing direction (RDR) in the liquid crystal display panel shown in FIG.
It is a figure which shows the relationship of a polarization transmission axis (MAX1, MAX2).

The angle between the rubbing direction (RDR) and the applied electric field direction (EDR) is determined by the dielectric anisotropy Δ of the liquid crystal material.
If ε is positive, 45 ° C or more and less than 90 ° C, or 90 °
Is more than 135 ° and the dielectric anisotropy Δε is negative,
Since the liquid crystal molecules rotate in the direction perpendicular to the electric field direction,
It must be more than 45 ° and less than 45 ° or 145 ° C and less than 180 ° C.

As shown in FIG. 9, as the polarizing plate (POL), the polarization transmission axis (MAX) of the lower polarizing plate (POL1) is used.
The angle (φP) between 1) and the direction of the applied electric field (EDR) is
The angle is equal to the angle (φLC), and the polarization transmission axis (MAX2) of the upper deflection plate (POL2) is set to be orthogonal to it.

Then, as shown in FIG. 4, by applying a voltage between the counter electrode (CT) and the pixel electrode (PX) formed on the lower transparent glass substrate (SUB1),
The upper and lower transparent glass substrates (SUB1, S) are formed on the liquid crystal layer (LC).
An electric field (E) parallel to UB2) is generated, which causes
The light transmitted through the liquid crystal layer (LC) is modulated to display an image on the liquid crystal display panel.

Further, the polymer dispersion type liquid crystal device 200 is
It is also possible to form a film.

[Embodiment 2] FIG. 10 is a block diagram showing a schematic configuration of a display device according to another embodiment of the present invention (Embodiment 2 of the invention).

As shown in FIG. 10, the display device 100 according to the second embodiment of the present invention is characterized in that the light guide plate 601 has a rectangular sectional shape in a direction perpendicular to the cold cathode tubes 602 of the light guide plate 601. This is different from the display device according to the first embodiment of the invention.

In the display device 100 according to the first embodiment of the invention, the light guide plate 601 is formed in a trapezoidal shape in which the surface of the light guide plate 601 facing the light scattering control device 604 is slanted. It has a drawback that the transmittance of the external light 610 passing through the scattering control device 604 is reduced.

On the other hand, in the display device 100 according to the second embodiment of the present invention, the light guide plate 601 is the light guide plate 6.
01 has a rectangular cross-sectional shape in the direction perpendicular to the cold cathode fluorescent lamp 602, so that the transmittance of the external light 610 transmitted through the light scattering control device 604 can be improved.

[Third Embodiment of the Invention] FIG. 11 is a block diagram showing a schematic configuration of a display device according to another embodiment of the present invention (third embodiment of the invention).

The display device 100 according to the third embodiment of the present invention is an embodiment of the invention in which the polymer dispersion type liquid crystal display device 300 is used as the display 600.

A polymer dispersed liquid crystal display device 300 used in the display device 100 according to the third embodiment of the present invention.
Is a pair of transparent substrates (301, 302) and transparent electrodes (311,
312) and a polymer-dispersed liquid crystal 320 injected and sealed between the transparent electrodes (311, 312). The polymer-dispersed liquid crystal 320 is contained in a base material 324 such as polyvinyl alcohol or acrylic resin. It is composed of dispersed liquid crystal particles 321.

This polymer dispersion type liquid crystal display device 300 is
By applying a voltage between both transparent electrodes (311, 312), the liquid crystal molecules 32 in the liquid crystal particles 321 of the polymer dispersion type liquid crystal 320.
The arrangement of 2 is changed by an electric field, and an image is displayed by the change of the refractive index due to the change.

Further, as shown in FIG. 11, in the display device 100 according to the third embodiment of the present invention, one substrate of the polymer dispersion type liquid crystal display device used for the display 600 and the light scattering control device 604. The light guide plate 601 also serves as one of the substrates.

As a result, in the display device 100 according to the third embodiment of the present invention, since the number of transparent substrates can be reduced, it is possible to prevent the transmittance of external light from being reduced and the number of parts is reduced. Since it can be reduced and the manufacturing process can be simplified, the cost can be reduced.

In a simple matrix type liquid crystal display device or an active matrix type liquid crystal display device such as the above-mentioned horizontal electric field type active matrix type liquid crystal display device, a pair of substrates (for example, the transparent glass substrate (SUB1 shown in FIG. 4)) is used. , SUB2)), polarizing plates (POL1, POL2) orthogonal to each other are formed.

Therefore, when the simple matrix type liquid crystal display device or the active matrix type liquid crystal display device is used as the display 600 of the first embodiment of the present invention, the external light passing through the light scattering control device 604 is used. 610 is attenuated by the polarizing plates (POL1, POL2).

On the other hand, the polymer dispersion type liquid crystal display device has a pair of substrates (for example, 201 and 202 shown in FIG. 2).
Since it is not necessary to provide polarizing plates (for example, POL1 and POL2 shown in FIG. 5) orthogonal to each other on the outside of the display device, a light scattering control device 604 can be provided by using a polymer dispersion type liquid crystal display device as the display 600. It is possible to reduce the attenuation of the transmitted external light 610.

However, since the polymer dispersion type liquid crystal display device becomes transparent when a voltage is applied between both electrodes (for example, 211 and 212 shown in FIG. 2), the third embodiment of the present invention will be described.
When the display device 100 is not used, that is, when the power source is “OFF”, a sufficient voltage is applied between both electrodes (for example, 211 and 212 shown in FIG. 2) of the polymer dispersion type liquid crystal display device. I have to keep it.

In the display device 100 according to the third embodiment of the present invention, one substrate of the polymer dispersion type liquid crystal display device used with the display 600 and one substrate of the light scattering control device 604 are guided. Although the light plate 601 is also used, it goes without saying that the light plate 601 may be separately provided as in the display device 100 according to the first embodiment of the present invention.

[Fourth Embodiment of the Invention] FIG. 12 is a block diagram showing a schematic structure of a monitor device according to another embodiment of the present invention (fourth embodiment of the invention).

The fourth embodiment of the present invention is an embodiment of the invention when the display device 100 of each of the embodiments of the invention is applied to a monitor device.

In FIG. 12, 500 is a monitor device, 5
Reference numeral 02 denotes a volume, and the volume 502 is for adjusting the transmission amount of the external light 610 transmitted through the display device 100.

For example, by using the monitor device 500 according to the fourth embodiment of the present invention in a company or the like, the monitor device 50 can be operated when the main body device (not shown) is "OFF".
Through the 0 display area 501, the background behind the monitor device 500 can be seen.

As a result, it is possible to achieve communication between users without giving the user a visual sense of blockage.

In this case, a horizontal electric field type active matrix type liquid crystal display device having a wide viewing angle is used as the display 600 of the display device 100, and the monitor device 50 according to the fourth embodiment of the present invention is used.
It is possible for many people to monitor 0 at the same time.

[Fifth Embodiment of the Invention] FIG. 13 is a block diagram showing a schematic configuration of a vehicle-mounted display device according to a fifth embodiment of the present invention (fifth embodiment of the invention).

The fifth embodiment of the present invention is an embodiment of the invention in which the display device 100 of each of the above-described embodiments of the present invention is applied to a vehicle-mounted display device such as a navigation system.

In FIG. 13, reference numeral 700 is a vehicle-mounted display device, 710 is a windshield, 720 is a rearview mirror, 721 is a dashboard, and 722 is a steering wheel.

By using the vehicle-mounted display device 700 according to the fifth embodiment of the present invention, the driver can operate when the main body device (not shown) is "OFF", that is,
Since the background behind the vehicle-mounted display device 700 can be seen when the vehicle-mounted display device 700 is not used, the vehicle-mounted display device 700 can be seen.
As a result, the driver's visual field is not obstructed.

Therefore, by using the vehicle-mounted display device 700 according to the fifth embodiment of the present invention,
It is possible to use a large vehicle-mounted display device, which makes it easier for the driver to see the display screen displayed on the vehicle-mounted display device.

It goes without saying that the display device 100 according to the above-described embodiments of the present invention can be used as a display device mounted on all transportation means such as an aircraft.

[Sixth Embodiment of the Invention] FIG. 14 is a block diagram showing a schematic configuration of a head mounted display device according to another embodiment of the present invention (sixth embodiment of the invention). 14 (a) is a front view of FIG.
14B is a sectional view taken along line AA of FIG.
FIG. 14C is a cross-sectional view taken along the line BB of FIG. 14A.

The sixth embodiment of the present invention is an embodiment of the invention in the case where the display device 100 of each of the embodiments of the invention is applied to a head mounted display device.

In FIG. 14, reference numeral 750 is a head mounted display device, 751 is a main body portion, and 752 is a belt portion.

It is known that the head-mounted display device 750 is effectively provided with a see-through function of seeing the real world through the image to be displayed in order to suppress eye fatigue.

According to the head mounted display device 750 of the sixth embodiment of the present invention, it is possible to easily realize the see-through function.

In the head mounted display device 750 of the sixth embodiment of the present invention, by using a liquid crystal display device using a polysilicon thin film transistor element as a thin film transistor (TFT) as the display 600 of the display device 100, it is possible to reduce the size. It is possible to reduce the weight and the weight.

[Seventh Embodiment of the Invention] FIG. 15 is a block diagram showing a schematic structure of a window glass according to another embodiment (Seventh embodiment of the invention) of the present invention.
14A is a sectional view, and FIG. 14B is a front view.

The seventh embodiment of the present invention is an embodiment of the invention when the display device 100 of each of the embodiments of the invention is applied to a window glass.

In FIG. 15, 740 is a window glass, and 74 is a window glass.
1 is a window frame.

In the window glass 740 of the seventh embodiment of the present invention, when the main body device (not shown) is "OFF", the scenery on the other side of the window glass 740 can be seen.

Although the present invention has been specifically described based on the embodiments of the present invention, the present invention is not limited to the above-mentioned embodiments of the present invention, and various modifications can be made without departing from the scope of the invention. Not to mention getting it.

[0145]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1) According to the present invention, in the display device, the light scattering control device is provided so as to face the display with the light guide plate of the backlight interposed therebetween.
When the display device is not used, the background can be seen through the display.

(2) By applying the display device of the present invention as a monitor device, a user who uses the monitor device does not feel a visual obstruction, and
Communication between users can be achieved.

Further, as a display of the display device, a horizontal electric field type active matrix liquid crystal display device having a wide viewing angle is used, so that a large number of people can monitor at the same time.

(3) A large-sized display device can be used by applying the display device of the present invention as a display device mounted on a transportation means, whereby a display displayed on the display device can be displayed to the operator. The screen becomes easier to see.

(4) By applying the display device of the present invention to a head mounted display device, it is possible to easily realize a see-through function, which results in eye fatigue when using the head mounted display device. Can be suppressed.

(5) By applying the display device of the present invention to a window glass, when the main body device is "OFF",
It is possible to see the scenery on the other side of the window glass.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a display device according to an embodiment (Embodiment 1 of the invention) of the present invention.

FIG. 2 is a diagram for explaining a schematic configuration of a polymer dispersion type liquid crystal device 200 and an operation mode thereof.

FIG. 3 is a display device 100 according to an embodiment of the present invention.
FIG. 7 is a diagram for explaining an operation mode of FIG.

4 is a plan view showing one pixel and its periphery of a liquid crystal display panel in a horizontal electric field type active matrix liquid crystal display device used in the display 600 shown in FIG.

5 is a cross-sectional view showing a cross section taken along a line 3-3 in FIG.

6 is a cross-sectional view showing a cross section of a thin film transistor (TFT) taken along section line 4-4 shown in FIG.

FIG. 7 is a storage capacitance (C
It is sectional drawing which shows the cross section of stg).

8 is a diagram showing a connection diagram of an equivalent circuit of a display matrix portion (AR) and its peripheral circuits in the liquid crystal display panel shown in FIG.

9 is a diagram showing a relationship among an applied electric field direction (EDR), a rubbing direction (RDR), and polarization transmission axes (MAX1, MAX2) in the liquid crystal display panel shown in FIG.

FIG. 10 is a block diagram showing a schematic configuration of a display device which is another embodiment of the present invention (Embodiment 2 of the invention).

FIG. 11 is a block diagram showing a schematic configuration of a display device according to another embodiment of the present invention (Embodiment 3 of the invention).

FIG. 12 is a block diagram showing a schematic configuration of a monitor device according to another embodiment of the present invention (Embodiment 4 of the invention).

FIG. 13 is a block diagram showing a schematic configuration of a vehicle-mounted display device that is another embodiment of the present invention (Embodiment 5 of the invention).

FIG. 14 is a block diagram showing a schematic configuration of a head mounted display device according to another embodiment of the present invention (Embodiment 6 of the invention).

FIG. 15 is a block diagram showing a schematic configuration of a window glass which is another embodiment of the present invention (Embodiment 7 of the invention).

[Explanation of symbols]

100 ... Display device, 200 ... Polymer dispersion type liquid crystal device, 201, 202, 301, 302 ... Transparent substrate, 2
11,212,311,312 ... Transparent electrodes, 220,3
20 ... Polymer dispersed liquid crystal, 221, 321 ... Liquid crystal particles, 2
22, 322 ... Liquid crystal molecule, 223, 611 ... External light, 22
4, 324 ... Base material, 300 ... Polymer dispersion type liquid crystal display device, 500 ... Monitor device, 502 ... Volume, 600
... Display, 601 ... Light guide plate, 602 ... Cold cathode tube,
603 ... Reflective sheet, 604 ... Light scattering control device, 60
5 ... Backlight, 611 ... Irradiation light, 700 ... Vehicle-mounted display device, 710 ... Windshield, 720
... rearview mirror, 721 ... dashboard, 722 ... steering wheel, 750 ... head mounted display device, 7
51 ... Main body part, 752 ... Belt part, 740 ... Window glass,
741 ... Window frame, SUB ... Transparent glass substrate, GL ... Scan signal line, DL ... Video signal line, CL ... Opposing voltage signal line, PX
... Pixel electrode, CT ... Counter electrode, GI ... Insulating film, GT ... Gate electrode, AS ... i-type semiconductor layer, SD ... Source electrode or drain electrode, POL ... Polarizing plate, ORI ... Alignment film, O
C ... Overcoat film, PSV ... Protective film, BM ... Light-shielding film, FIL ... Color filter, LC ... Liquid crystal layer, TFT ...
Thin film transistor, Cstg ... Storage capacitor.

Claims (17)

[Claims] 1. A display device comprising a display and a backlight for illuminating the display, wherein external light is transmitted when the light scattering property is reduced, and external light is scattered when the light scattering property is increased. A display device, wherein a light scattering control device is provided to face the display with a light guide plate of the backlight interposed therebetween. 2. The display device according to claim 1, further comprising a switch for adjusting a light scattering property of the light scattering control device. 3. The light is supplied to the backlight when the light scattering property of the light scattering control device is increased, and the power is supplied to the backlight when the light scattering property of the light scattering control device is reduced. No supply is provided.
Alternatively, the display device according to claim 2. 4. The backlight according to claim 1, wherein the backlight is a side light type backlight in which a light source is arranged on a side surface of a light guide plate.
The display device described in the paragraph. 5. The display device according to claim 4, wherein a cross-sectional shape of the light guide plate in a direction perpendicular to the light source is a rectangle. 6. The light scattering control device is a polymer dispersion type liquid crystal device.
The display device described in any one of 1. 7. The display device according to claim 6, wherein the light guide plate of the backlight doubles as one substrate of the polymer dispersion type liquid crystal device. 8. The display device according to claim 1, wherein the light scattering control device is a film-shaped light scattering control device. 9. The display device according to claim 1, wherein the display is a liquid crystal display device. 10. The liquid crystal display device according to claim 9, wherein the liquid crystal display device applies a field substantially parallel to a substrate surface to a liquid crystal layer injected and sealed between a pair of substrates. Display device. 11. The liquid crystal display device is a normally white liquid crystal display device.
Alternatively, the display device according to claim 10. 12. The display device according to claim 9, wherein the liquid crystal display device is a polymer dispersion type liquid crystal display device. 13. The display device according to claim 12, wherein the light guide plate of the backlight doubles as one substrate of the polymer dispersion type liquid crystal display device. 14. The display device according to claim 1, wherein the display device is a display device mounted in a transportation means. 15. A monitor device using the display device according to any one of claims 1 to 13. 16. A head mounted display device, which uses the display device according to claim 1. Description: 17. A window glass using the display device according to any one of claims 1 to 13.