JP3758345B2 - Display device and electronic device using display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device and an electronic apparatus, and more particularly to a reflective full-color liquid crystal display device.
[0002]
[Prior art]
A reflection type full-color display device using a conventional color filter colors each pixel using a red, green, and blue color filter. By driving each pixel, it is possible to switch between each color and black. If all the pixels are in color, that is white display. That is, the state in which all of red, green, and blue are colored is white and dark. On the other hand, if the coloring of the red, green and blue color filters is lightened to make it brighter, the color purity is lowered.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide a reflective color display device, particularly a full color display device, which is bright and has high color purity in a display device using a transmission polarization axis variable optical element. Furthermore, it is providing the electronic device using this.
[0004]
[Means for Solving the Problems]
The principle will be described with reference to FIGS. FIG. 1 is a schematic perspective view of a polarization separator used as a polarization separator, and FIG. 2 is a diagram for explaining a display device using the polarization separator.
[0005]
In FIG. 1, the polarization separator 160 has a structure in which two different layers 1 (A layer) and 2 (B layer) are alternately stacked. The refractive index (nAX) in the X direction and the refractive index (nAY) in the Y direction of the A layer 1 are different. The refractive index (nAY) in the Y direction of the A layer 1 and the refractive index (nBY) in the Y direction of the B layer 2 are substantially equal.
[0006]
Accordingly, among the light incident on the polarization separator 160 from the direction perpendicular to the upper surface 5 of the polarization separator 160, the Y-direction linearly polarized light is transmitted through the polarization separator 160 and is converted from the lower surface 6 into Y-direction linearly polarized light. Exit. On the other hand, among the light incident on the polarization separator 160 from the direction perpendicular to the lower surface 6 of the polarization separator 160, the linearly polarized light in the Y direction is transmitted through the polarization separator 160 and linearly polarized in the Y direction from the upper surface 5. Emitted as light. Here, the transmitting direction (Y direction) is referred to as a transmission axis.
[0007]
On the other hand, if the thickness of the A layer 1 in the Z direction is tA, the thickness of the B layer 2 in the Z direction is tB, and the wavelength of the incident light is λ,
[0008]
[Expression 1]
tA · nAX + tB · nBX = λ / 2 (1)
By doing so, light of wavelength λ and linearly polarized light in the X direction out of light incident on the polarization separator 160 from a direction perpendicular to the upper surface 5 of the polarization separator 160 is the polarization separator. 160 reflects the X direction as linearly polarized light. Further, light having a wavelength λ and linearly polarized light on the lower surface 6 of the polarization separator 160 is reflected by the polarization separator 160 as linearly polarized light in the X direction. Here, the reflecting direction (X direction) is called a reflection axis.
[0009]
Then, by varying the thickness tA in the Z direction of the A layer 1 and the thickness tB in the Z direction of the B layer 2 so that the above (1) is established over the entire wavelength range of visible light, only a single color is obtained. In addition, a polarization separator that reflects the linearly polarized light in the X direction as the linearly polarized light in the X direction and transmits the linearly polarized light in the Y direction as the linearly polarized light in the Y direction is obtained over the entire white light. .
[0010]
For example, polyethylene naphthalate (PEN) is used for the A layer of the polarization separator 160, and a copolyester (coPEN; copolyester of naphthalene dicarboxylic acid and terephthalic acid is used for the B layer. of naphtalen dicarboxylic acid and terephthallic or isothalic acid). Of course, the material of the polarization separator used in the present invention is not limited to this, and the material can be appropriately selected. The details of such a polarization separator are disclosed as a reflective polarizer in JP-T-9-506985.
[0011]
FIG. 2 is a view for explaining a display device of the present invention using this polarization separator 160. In this liquid crystal display device, the TN liquid crystal panel 140 is used as the first transmission polarization axis variable optical element. A polarizing plate 130 is provided on the upper side of the TN liquid crystal panel 140. On the lower side of the TN liquid crystal panel 140, a light diffusion layer 150 and a polarization separator 160 are provided in this order. Further, on the lower side of the polarization separator 160, a color filter 170, a TN liquid crystal panel 180 as a second transmission polarization axis variable optical element, a polarization separator 190, and a black plate 200 as a light absorbing means are provided in this order. Yes. The polarization separator 190 has the same structure as the polarization separator 160.
[0012]
The transmission axis of the polarizing plate 130, the transmission axis of the polarization separator 160, and the transmission axis of the polarization separator 190 are parallel to each other.
[0013]
110 on the left side indicates a portion where no voltage is applied to the TN liquid crystal panel 140. The natural light 111 is linearly polarized in the direction parallel to the paper surface by the polarizing plate 130, and then the polarization direction is twisted by 90 ° by the TN liquid crystal panel 140 to be linearly polarized light in the direction perpendicular to the paper surface and reflected by the polarization separator 160. Is done. The linearly polarized light reflected from the polarization separator 160 is transmitted by the TN liquid crystal panel 140 as linearly polarized light whose direction of polarization is twisted by 90 ° and parallel to the paper surface, and is output from the polarizing plate 130 as linearly polarized light in the direction parallel to the paper surface. To do. The light emitted from the polarizing plate 130 passes through the light diffusion layer 150 and thus becomes white light.
[0014]
The center 120 applies a voltage to the TN liquid crystal panel 140 and indicates a portion where no voltage is applied to the TN liquid crystal panel 180. The natural light 121 is converted into linearly polarized light in the direction parallel to the paper surface by the polarizing plate 130, and then transmitted through the TN liquid crystal panel 140 without changing the polarization direction, and also transmitted through the polarization separator 160, and linearly polarized light in the direction parallel to the paper surface. Then, it passes through the color filter 170, and then the polarization direction is twisted by 90 ° by the TN liquid crystal panel 180 to become linearly polarized light in a direction perpendicular to the paper surface and reflected by the polarization separator 190. The reflected light is again twisted by 90 ° by the TN liquid crystal panel 180 to become linearly polarized light in a direction parallel to the paper surface, passes through the color filter 170 and is also transmitted through the polarization separator 160, and polarizes the TN liquid crystal panel 140. The light is transmitted without changing the direction, and is emitted from the polarizing plate 130 as linearly polarized light in a direction parallel to the paper surface. In this way, in a portion where a voltage is applied to the TN liquid crystal panel 140 and no voltage is applied to the TN liquid crystal panel 180, the incident light passes through the color filter 170 and is colored.
[0015]
125 on the right side indicates a portion where a voltage is applied to the TN liquid crystal panel 140 and a voltage is also applied to the TN liquid crystal panel 180. The natural light 126 is converted into linearly polarized light in a direction parallel to the paper surface by the polarizing plate 130, and then transmitted through the TN liquid crystal panel 140 without changing the polarization direction, and is also transmitted through the polarization separator 160, and is linearly polarized light in a direction parallel to the paper surface. Then, it passes through the color filter 170, and then passes through the TN liquid crystal panel 180 without changing the polarization direction, and also passes through the polarization separator 160 and is absorbed by the black plate 200. As described above, in the portion where the voltage is applied to the TN liquid crystal panel 140 and the voltage is also applied to the TN liquid crystal panel 180, the incident light is absorbed by the black plate 200 and becomes black.
[0016]
As described above, the combination of voltage application / non-application of the TN liquid crystal panel 140 and the TN liquid crystal panel 180 was light-absorbed by the bright white display not colored by the color filter, the color display colored by the color filter, and the black plate. Black display is obtained.
[0017]
In the above description, the TN liquid crystal panel 140 has been described as an example. However, instead of the TN liquid crystal panel 140, other transmission polarization axes such as an STN liquid crystal panel and an ECB (Electrically Controlled Birefringence) liquid crystal panel can be changed by a voltage or the like. Even if is used, the basic operation principle is the same.
[0018]
The present invention is based on the above principle, and according to the present invention,
First transmission polarization axis varying means for varying the transmission polarization axis;
First and second polarization separation means disposed on both sides of the first transmission polarization axis variable means across the first transmission polarization axis variable means;
Second transmission polarization axis variable means disposed on the opposite side of the first transmission polarization axis variable means with respect to the second polarization separation means;
A third polarization separation means disposed on the opposite side of the second polarization separation means with respect to the second transmission polarization axis variable means;
A light absorbing means disposed on the opposite side of the second transmission polarization axis varying means with respect to the third polarized light separating means;
A light diffusing means between the first polarized light separating means and the second polarized light separating means;
A coloring means between the second polarized light separating means and the third polarized light separating means;
A display device comprising:
The first polarization separation means is a linearly polarized light in a first predetermined direction from the other side located opposite to the one side with respect to light incident from one side of the first polarization separation means. Polarization separating means capable of transmitting component light and transmitting light of the linearly polarized component in the first predetermined direction from the one side with respect to light incident from the other side;
The second polarization separation means transmits light of a linearly polarized light component in a second predetermined direction out of the light incident from the first transmission polarization axis variable means side to the second transmission polarization axis variable means side. Then, the light of the linearly polarized light component in the third predetermined direction orthogonal to the second predetermined direction is reflected to the first transmission polarization axis variable means side, and from the second transmission polarization axis variable means side. Polarization separation means capable of transmitting light of the linearly polarized light component in the second predetermined direction toward the first transmission polarization axis variable means side with respect to incident light;
The third polarization separation unit transmits light of a linearly polarized component in a fourth predetermined direction out of light incident from the second transmission polarization axis variable unit side to the light absorption unit side, and A display device comprising: polarization separation means capable of reflecting linearly polarized light in a fifth predetermined direction orthogonal to the predetermined direction toward the second transmission polarization axis variable means side. Provided.
[0019]
In the display device according to the aspect of the invention, the light reflected from the second polarization separation unit may be used according to the state of the transmission polarization axis of the first transmission polarization axis variable unit and the second transmission polarization axis variable unit. A bright display state (first display state), a color display state (second display state) colored by the coloring means with light reflected from the third polarization separation means, and the light absorption means A dark display state (third display state) due to light absorption is obtained.
[0020]
Preferably, the second polarized light separating unit has a second predetermined direction out of the light incident from the first transmission polarization axis varying unit side with respect to the light in almost the entire wavelength range of the visible light region. Light of linearly polarized light component is transmitted to the second transmission polarization axis variable means side, and light of the linearly polarized light component of the third predetermined direction orthogonal to the second predetermined direction is transmitted to the first transmitted polarized light. The light reflected on the axis variable means side and in the almost all wavelength range of the visible light region and incident from the second transmission polarization axis variable means side is reflected on the first transmission polarization axis variable means side. The polarization separation means is capable of transmitting the light of the linearly polarized light component in the second predetermined direction. Further, the third polarization separation means is a straight line in the fourth predetermined direction out of the light incident from the second transmission polarization axis variable means side with respect to light in almost the entire wavelength range of the visible light region. Light of polarization component is transmitted to the light absorbing means side, and light of linear polarization component in the fifth predetermined direction orthogonal to the fourth predetermined direction is reflected to the second transmission polarization axis variable means side. This is a polarization separation means that can be used.
[0021]
In this way, white reflection can be obtained in the first display state, and black absorption can be obtained in the third display state.
[0022]
At least one of the first transmission polarization axis varying unit or the second transmission polarization axis varying unit is preferably a liquid crystal panel, and a TN liquid crystal panel, an STN liquid crystal panel, or an ECB liquid crystal panel is used. This STN liquid crystal panel includes an STN liquid crystal panel using a color compensating optical anisotropic body.
[0023]
Preferably, the first polarized light separating means is a polarizing plate.
[0024]
The second polarization separation means is a laminated body in which a plurality of layers are laminated in close contact with each other, and the refractive index of the plurality of layers is a sixth predetermined value between adjacent layers. The laminated bodies are equal in direction and different in a seventh predetermined direction orthogonal to the sixth predetermined direction. Further, the third polarization separation means is a laminate in which a plurality of layers are laminated in close contact with each other, and the refractive index of the plurality of layers is an eighth predetermined value between adjacent layers. The laminated bodies are equal in direction and different in a ninth predetermined direction orthogonal to the eighth predetermined direction.
[0025]
Preferably,
And further comprising first and second transparent substrates disposed on both sides of the first transmission polarization axis variable means with the first transmission polarization axis variable means interposed therebetween,
The first polarized light separating means is disposed on the opposite side of the first transparent polarization axis varying means with respect to the first transparent substrate;
The second polarization separating means is disposed on the opposite side of the first transparent polarization axis varying means with respect to the second transparent substrate;
And further comprising third and fourth transparent substrates disposed on both sides of the second transmission polarization axis variable means across the second transmission polarization axis variable means,
The second polarization separation means is disposed on the opposite side of the third transparent polarization axis variable means with respect to the third transparent substrate;
The third polarization separation means is disposed on the opposite side of the fourth transparent substrate with respect to the second transmission polarization axis variable means.
[0026]
The first and second transparent substrates and the third and fourth transparent substrates each include dot matrix pixels, and the pixel positions thereof coincide with each other.
[0027]
The second transparent substrate, the third transparent substrate, and the fourth transparent substrate are plastic film substrates. By doing so, a display without parallax can be obtained.
[0028]
More preferably, the coloring means is composed of red, green and blue color filters corresponding to the dot matrix pixels of the third and fourth transparent substrates. In this way, bright reflection type full-color display can be obtained by driving the first transmission polarization axis variable means and the second transmission polarization axis variable means in gradation.
[0029]
Furthermore, the electronic device of the present invention is equipped with the display device according to claim 1. Depending on the application, any one of the display devices described above may be mounted.
[0030]
In the display device of the present invention, active elements such as TFTs and MIMs may be provided.
In the display device of the present invention, in the display device, the first transmission polarization axis variable unit that varies the transmission polarization axis, and the first transmission polarization axis variable unit across the first transmission polarization axis variable unit. First and second polarization separation means disposed on both sides of the first polarization separation means, and a second transmission polarization axis variable disposed on the opposite side of the first transmission polarization axis variable means with respect to the second polarization separation means. Means, a third polarization separation means arranged on the opposite side of the second polarization separation means with respect to the second transmission polarization axis varying means, and the second polarization separation means with respect to the second polarization separation means. A backlight disposed on the opposite side of the transmission polarization axis varying means, and a coloring means disposed between the second polarized light separating means and the third polarized light separating means. The polarization separation means is configured to detect light incident from one side of the first polarization separation means. The light of the linearly polarized light component in the first predetermined direction can be transmitted from the other side located opposite to the one side, and the light incident from the other side can be transmitted from the one side. Polarization separation means capable of transmitting light of a linearly polarized light component in a first predetermined direction, wherein the second polarization separation means is a second of light incident from the first transmission polarization axis variable means side. Light having a linearly polarized component in a predetermined direction can be transmitted to the second transmission polarization axis variable means side, and light having a linearly polarized component in a third predetermined direction perpendicular to the second predetermined direction can be transmitted. Reflectable to the first transmission polarization axis variable means side, and the second predetermined predetermined value on the first transmission polarization axis variable means side with respect to light incident from the second transmission polarization axis variable means side Polarization separation means capable of transmitting light of a linearly polarized component in the direction, and the third polarization The separating means can transmit the linearly polarized light component in the fourth predetermined direction out of the light incident from the second transmission polarization axis variable means side to the backlight side, and the fourth predetermined direction. It is a polarization separation means capable of reflecting the light of the linearly polarized light component in the fifth predetermined direction orthogonal to the second transmission polarization axis variable means side.
The display device according to the present invention includes a first liquid crystal panel that changes a transmission polarization axis, and first and second liquid crystal panels that are disposed on both sides of the first liquid crystal panel with the first liquid crystal panel interposed therebetween. A second polarization separation unit; a second liquid crystal panel disposed on the opposite side of the first liquid crystal panel with respect to the second polarization separation unit; and a substrate constituting the liquid crystal panel. A color filter; third polarization separation means disposed opposite to the second polarization separation means with respect to the second liquid crystal panel; and the second liquid crystal with respect to the third polarization separation means. A backlight disposed on the opposite side of the panel, the first polarization separation means is a polarizing plate having a transmission axis, and the second polarization separation means and the third polarization separation means are: A transmission axis that is a direction of transmitting light, Characterized in that it has a reflection axis which is the direction for reflecting and light.
The liquid crystal display device may further include a polarizing plate disposed between the second liquid crystal panel and the backlight.
Further, a retardation film is provided between the second liquid crystal panel and the third polarization separation means.
Further, a retardation film is provided between the first polarized light separating means and the first liquid crystal panel.
Further, a diffusing plate is provided between the first polarized light separating means and the first liquid crystal panel.
The display device according to the present invention includes a first liquid crystal panel that changes a transmission polarization axis, and first and second liquid crystal panels that are disposed on both sides of the first liquid crystal panel with the first liquid crystal panel interposed therebetween. Second polarization separation means, a second liquid crystal panel disposed on the opposite side of the first liquid crystal panel with respect to the second polarization separation means, and a color filter provided in the second liquid crystal panel And a third polarization separation means disposed on the opposite side of the second polarization separation means with respect to the second liquid crystal panel, and the second liquid crystal panel with respect to the third polarization separation means, A backlight disposed on the opposite side, wherein the first polarization separation means is a polarizing plate having a transmission axis, and the second polarization separation means is a transmission axis that is a direction of transmitting light, And having a reflection axis that is the direction of reflecting light And it features.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0032]
(First embodiment)
FIG. 3 is an exploded cross-sectional view for explaining the liquid crystal display device according to the first embodiment of the present invention.
[0033]
In the liquid crystal display device 10 of the present embodiment, the STN panel 20 and the STN panel 70 are used as the first and second transmission polarization axis variable optical elements. On the upper side of the STN panel 20, a retardation film 14 and a polarizing plate 12 are provided in this order. Between the STN panel 20 and the STN panel 70, a diffusion plate 30, a polarization separator 40 as a polarization separation means, and a color filter 50 as a colored layer are provided. Under the STN panel 70, a retardation film 15, a polarization separator 80 as a polarization separation means, and a black plate 90 as a light absorption plate are provided in this order. The polarization separator 40 and the polarization separator 80 use the polarization separator as the polarization separation means described with reference to FIG.
[0034]
In the STN panel 20, STN liquid crystal 26 is sealed in a panel constituted by two glass substrates 21 and 22 and a seal member 23. A transparent electrode 24 is provided on the lower surface of the glass substrate 21, and a transparent electrode 25 is provided on the upper surface of the glass substrate 22. The transparent electrodes 24 and 25 form a dot matrix. As the transparent electrodes 24 and 25, ITO (Indium Tin Oxide), tin oxide, or the like can be used. The phase difference film 14 is used as an optical anisotropic body for color compensation, and is used to correct coloring generated in the STN panel 20.
[0035]
Also in the STN panel 70, STN liquid crystal 76 is sealed in a panel constituted by two glass substrates 71 and 72 and a seal member 73. A transparent electrode 74 is provided on the lower surface of the glass substrate 71, and a transparent electrode 75 is provided on the upper surface of the glass substrate 72. The transparent electrodes 74 and 75 form a dot matrix, and have the same dot pitch as that of the dot matrix formed by the transparent electrodes 24 and 25 to correspond to each dot. As the transparent electrodes 74 and 75, ITO (Indium Tin Oxide), tin oxide, or the like can be used. The phase difference film 15 is used as an optical anisotropic body for color compensation, and is used for correcting coloring generated in the STN panel 70.
[0036]
The color filter 50 matches the dot matrix formed by the transparent electrodes 24 and 25 (dot matrix formed by the transparent electrodes 74 and 75), and the three primary colors of red, green, and blue are arranged.
[0037]
The operation of the liquid crystal display device 10 of the present embodiment will be described with reference to FIG.
[0038]
In a portion where no voltage is applied to the STN liquid crystal panel 20, natural light becomes linearly polarized light in a predetermined direction by the polarizing plate 12, and then linearly polarized light whose polarization direction is twisted by a predetermined angle by the retardation film 14 and the STN panel 20. Then, the light is reflected by the polarization separator 40, the polarization direction is twisted by a predetermined angle by the STN panel 20, and is emitted from the polarizing plate 12 as linearly polarized light. The emitted light is diffused by the diffusing plate 30 to display white.
[0039]
Next, in a portion where a voltage is applied to the STN liquid crystal panel 20 and no voltage is applied to the STN liquid crystal panel 70, natural light is linearly polarized in a predetermined direction by the polarizing plate 12, and then the retardation film 14 and the STN panel 20 is linearly polarized light whose polarization direction is twisted by a predetermined angle, and passes through the polarization separator 40 and the color filter 50. Thereafter, the light becomes linearly polarized light whose polarization direction is twisted by a predetermined angle by the STN panel 70 and the retardation film 15, is reflected by the polarization separator 80, and is emitted from the polarizing plate 12 through the reverse path again. As described above, since the voltage is applied to the STN liquid crystal panel 20 and the voltage is not applied to the STN liquid crystal panel 70, the portion passes through the color filter 50, so that a colored display is obtained.
[0040]
Further, in a portion where a voltage is applied to the STN liquid crystal panel 20 and a voltage is also applied to the STN liquid crystal panel 70, natural light is linearly polarized in a predetermined direction by the polarizing plate 12, and then the retardation film 14 and the STN panel 20 is linearly polarized light whose polarization direction is twisted by a predetermined angle, and passes through the polarization separator 40 and the color filter 50. Thereafter, the light becomes linearly polarized light whose polarization direction is twisted by a predetermined angle by the STN panel 70 and the retardation film 15, passes through the polarization separator 80, and is absorbed by the black plate 90, resulting in black display.
[0041]
By the combination of voltage application / non-application of the STN liquid crystal panel 20 and the STN liquid crystal panel 70, bright white display by reflection of the polarization separator 40, color display colored by the color filter 50, and black display light absorbed by the black plate 70 are obtained. can get.
[0042]
A full color display can be obtained by driving the STN liquid crystal panel 20 and the STN liquid crystal panel 70 in a time division manner.
[0043]
(Second Embodiment)
In the first embodiment, the glass substrate 22 of the STN panel 20 and the two glass substrates 71 and 72 of the STN panel 70 are changed to 0.2 mm plastic films.
[0044]
The same effect as in the first embodiment was obtained, and a display with less parallax (low color overlap even at a low viewing angle) was obtained.
[0045]
(Third embodiment)
FIG. 4 is an exploded cross-sectional view for explaining a liquid crystal display device according to a third embodiment of the present invention.
[0046]
In the second embodiment, the color filter 50 is formed on the inner surface of the STN liquid crystal panel 70 (the inner surface of the plastic substrate 71). Further, the diffusion plate 30 was installed between the retardation plate 14 and the substrate 21 of the STN liquid crystal panel 20.
[0047]
By doing in this way, the same effect as the said 2nd Embodiment was acquired, and the display with much less parallax was obtained.
[0048]
(Fourth embodiment)
In the third embodiment, register marks are provided outside the active area with electrode patterns on the inner surfaces of the STN liquid crystal panel 20 and the STN liquid crystal panel 70. An adhesive was provided on the surfaces of the polarization separator 40 and the substrate 71 of the STN liquid crystal panel 70, and the polarization separator 40 was affixed to the substrate 22 of the STN liquid crystal panel 20 so that the registration marks of the STN liquid crystal panel 70 were matched. Since the substrates 71 and 72 of the STN liquid crystal panel 70 are made of plastic, they can be attached.
[0049]
(Fifth embodiment)
FIG. 5 is an exploded cross-sectional view for explaining a liquid crystal display device according to a fifth embodiment of the present invention.
[0050]
In the second embodiment, the polarizing plate 91 and the backlight 100 are provided instead of the black plate 90 as the light absorbing means. The angle between the transmission axis of the polarization separator 80 and the transmission axis of the polarizing plate 91 was set to 45 ° to 75 °. Then, the same effect as the second embodiment was obtained at the time of reflection, and full color display was possible even when the backlight was lit.
[0051]
In the embodiment of the present invention, the polarization separator 40 may be used as a substitute for the substrate 71.
[0052]
(Sixth embodiment)
The display device according to the first embodiment of the present invention is mounted on a PDA (Personal Digital Assistant). A bright reflective full-color display was obtained with 640 (× 3 RGB) × 240 dots and 0.3 dot pitch pixels.
[0053]
Similar results were obtained with PDAs equipped with the display elements of the second and third embodiments of the present invention.
[0054]
Moreover, although PDA was illustrated in embodiment of this invention, the display apparatus of this invention can be used for various electronic devices, such as household appliances, a mobile telephone, an electronic notebook, a calculator.
[0055]
【The invention's effect】
In the display device of the present invention, a bright display state by the light reflected from the second polarization separation unit according to the state of the transmission polarization axis of the first transmission polarization axis variable unit and the second transmission polarization axis variable unit (First display state), color display state colored by the coloring means with the light reflected from the third polarization separation means (second display state), and light absorption by the light absorption means A dark display state (third display state) is obtained.
[0056]
Further, red, green, and blue colored layers are formed in accordance with the dot matrix pixels formed on the transparent substrates of the first transmission polarization axis varying unit and the second transmission polarization axis varying unit. In this way, bright reflection type full-color display can be obtained by driving the first transmission polarization axis variable means and the second transmission polarization axis variable means in gradation.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a polarization separator used as polarization separation means in a display device of the present invention.
FIG. 2 is a diagram for explaining the principle of a display device of the present invention.
FIG. 3 is an exploded cross-sectional view for explaining the liquid crystal display device according to the first embodiment of the present invention.
FIG. 4 is an exploded cross-sectional view for explaining a liquid crystal display device according to a third embodiment of the present invention.
FIG. 5 is an exploded cross-sectional view for explaining a liquid crystal display device according to a fifth embodiment of the present invention.
[Explanation of symbols]
10. Liquid crystal display device
12, 130 ... Polarizing plate
14, 15 ... retardation film
20, 70 ... STN liquid crystal panel
21, 22, 71, 72 ... glass substrate
26, 76 ... STN liquid crystal
30 ... Diffuser
40, 80, 160, 190 ... polarization separator
50, 170 ... Color filter
90, 200 ... Black plate
91 ... Polarizing plate
100 ... Backlight
111, 121, 126 ... Natural light
112, 122 ... outgoing light
140, 180 ... TN liquid crystal panel
150: Light diffusion layer

Claims (8)

In the display device,
First transmission polarization axis varying means for varying the transmission polarization axis;
First and second polarization separation means disposed on both sides of the first transmission polarization axis variable means across the first transmission polarization axis variable means;
Second transmission polarization axis variable means disposed on the opposite side of the first transmission polarization axis variable means with respect to the second polarization separation means;
A third polarization separation means disposed on the opposite side of the second polarization separation means with respect to the second transmission polarization axis variable means;
A backlight disposed on the side opposite to the second transmission polarization axis varying unit with respect to the third polarization separating unit;
A coloring means disposed between the second polarized light separating means and the third polarized light separating means;
With
The first polarization separation means is a linearly polarized light in a first predetermined direction from the other side located opposite to the one side with respect to light incident from one side of the first polarization separation means. A polarization separation means capable of transmitting component light and transmitting light of the linearly polarized component in the first predetermined direction from the one side with respect to light incident from the other side;
The second polarization separation means transmits light of a linearly polarized light component in a second predetermined direction out of the light incident from the first transmission polarization axis variable means side to the second transmission polarization axis variable means side. The linearly polarized light component in a third predetermined direction orthogonal to the second predetermined direction can be reflected to the first transmission polarization axis variable means side, and the second transmission polarization axis Polarization separating means capable of transmitting light of the linearly polarized light component in the second predetermined direction to the first transmission polarization axis variable means side with respect to light incident from the variable means side;
The third polarization separation means is capable of transmitting light of a linearly polarized component in a fourth predetermined direction out of light incident from the second transmission polarization axis variable means side to the backlight side, and 4. A display device comprising: a polarization separation unit capable of reflecting light of a linearly polarized light component in a fifth predetermined direction orthogonal to a predetermined direction of 4 toward the second transmission polarization axis variable unit side. In the display device,
A first liquid crystal panel having a variable transmission polarization axis;
First and second polarization separation means disposed on both sides of the first liquid crystal panel across the first liquid crystal panel;
A second liquid crystal panel disposed on the opposite side of the first liquid crystal panel with respect to the second polarization separation means;
A color filter disposed between the substrates constituting the liquid crystal panel;
A third polarization separation unit disposed on the opposite side of the second polarization separation unit with respect to the second liquid crystal panel;
A backlight disposed on the side opposite to the second liquid crystal panel with respect to the third polarization separation means;
With
The first polarized light separating means is a polarizing plate having a transmission axis,
Each of the second polarization separation means and the third polarization separation means has a transmission axis that is a direction of transmitting light and a reflection axis that is a direction of reflecting light.   The display device according to claim 2, further comprising a polarizing plate disposed between the second liquid crystal panel and the backlight.   The display device according to claim 2, further comprising a retardation film between the second liquid crystal panel and the third polarization separation unit.   The display device according to claim 2, further comprising a retardation film between the first polarized light separating unit and the first liquid crystal panel.   The display device according to claim 2, further comprising a diffusion plate between the first polarization separation unit and the first liquid crystal panel. In the display device,
A first liquid crystal panel having a variable transmission polarization axis;
First and second polarization separation means disposed on both sides of the first liquid crystal panel across the first liquid crystal panel;
A second liquid crystal panel disposed on the opposite side of the first liquid crystal panel with respect to the second polarization separation means;
A color filter provided in the second liquid crystal panel;
A third polarization separation unit disposed on the opposite side of the second polarization separation unit with respect to the second liquid crystal panel;
A backlight disposed on the side opposite to the second liquid crystal panel with respect to the third polarization separation means;
With
The first polarized light separating means is a polarizing plate having a transmission axis,
The display device, wherein the second polarization separation means has a transmission axis that is a direction of transmitting light and a reflection axis that is a direction of reflecting light.   An electronic apparatus comprising the display device according to claim 1.

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