JP3405282B2 - Display device and electronic device using the same - Google Patents

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 using a liquid crystal as a transmissive optical axis changing means. In particular, the present invention relates to a so-called transflective liquid crystal display device that functions as a transmissive liquid crystal display device when the light source is on, and functions as a reflective liquid crystal display device when the light source is off. Further, a clock provided with this display device as a display unit,
The present invention relates to an electronic device such as an electronic notebook or a personal computer.

[0002]

2. Description of the Related Art Conventional TN (Twisted Nematic) liquid crystal and S
As shown in FIG. 26, a liquid crystal display device using a variable transmission polarization axis optical element 2605 such as a TN (Super-Twisted Nematic) liquid crystal having a variable polarization axis has a variable transmission polarization axis optical element 2605 as two polarizing plates. Since the structure sandwiched between 2601 and 2606 is adopted, the utilization efficiency of light is poor, and in particular, when the reflection type is used, a dark display is caused, which is a problem.

[0003]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a display device which uses a variable transmission polarization axis optical element and which can obtain a bright display.

Further, in the conventional transflective liquid crystal display device, the Al reflector is formed thin or the opening is provided, so that the reflectance at the time of reflective display is lowered. In other words, the transflective type sacrifices the brightness during reflective display.

Therefore, another object of the present invention is to provide a light source on the back side of a reflection type liquid crystal display device so that not only reflective display by external light but also display by transmitted light from the light source on the back side can be performed. It is to provide a transmissive and bright reflective liquid crystal element.

Further, in the transflective liquid crystal display device, due to so-called positive / negative inversion, the display may be difficult to see if external light enters the display device when the light source is turned on.

Therefore, an object of the present invention is to provide a display device in which the display is not difficult to see even if positive / negative inversion occurs.

[0008]

According to the present invention, in a display device, a transmission polarization axis varying means for varying a transmission polarization axis and a first arrangement arranged so as to sandwich the transmission polarization axis varying means.
And a second polarized light separating means, the light source arranged on the opposite side of the second polarized light separating means from the transmission polarization axis varying means to emit colored light, and the second polarized light separating means.
Provided between the light source and the first polarized light separating means,
The transmission polarization axis changing means and the second polarization separating means
The light that has passed through the
Comprising a light scattering body for morphism, and the first polarized light separating means, a linearly polarized light component in the first direction passes, the linear polarized light component of the second direction different from the first direction The second polarized light separating means transmits the light of the linearly polarized light component in the third direction and does not transmit the light, and reflects the light of the linearly polarized light component in the fourth direction different from the third direction. . Alternatively,
In a display device, a liquid crystal panel in which liquid crystal is sandwiched between a pair of substrates, a polarizing plate arranged on one side of the liquid crystal panel, and a polarization separator arranged on the opposite side of the liquid crystal panel from the polarizing plate. And the light source arranged on the side opposite to the liquid crystal panel with respect to the polarization separator, and provided between the polarization separator and the light source, the polarizing plate and the liquid.
To transmit the light transmitted through the crystal panel and the polarization separator.
A light scatterer that changes the polarization state of the light and emits the light, wherein the polarizing plate transmits light having a linearly polarized component in a first direction, and a linear line in a second direction different from the first direction. The polarization separator does not transmit the light of the polarization component, but transmits the light of the linear polarization component of the third direction and reflects the light of the linear polarization component of the fourth direction different from the third direction. And

In the display device of the present invention, with respect to the light incident from the outside of the first polarized light separating means, the second polarized light separating means according to the state of the transmitting polarization axis of the transmitting polarization axis varying means. The first display state caused by the light reflected from the first display state and the light transmitted through the first polarization splitting means, the transmission polarization axis varying means and the second polarization splitting means are canceled by the light scatterer to obtain the second display state. The two display states, that is, the second display state in which the polarized light separating means of FIG. Then, the second display state becomes a darker display due to the absorption of light by not only the light source but also the light scatterer.

With respect to the light from the light source, depending on the state of the transmission polarization axis of the liquid crystal panel, there are a third display state by the light transmitted through the polarizing plate and a state in which the light is not transmitted through the polarizing plate. Two display states, that is, the fourth display state, can be obtained, and a transmissive display can be obtained.

[0012] Preferably, the second polarized light separating means selects the third light from the light incident from the transmission polarization axis varying means side with respect to the light in the substantially entire wavelength range of the visible light region.
Of a linearly polarized light component in a predetermined direction of the light source side,
The linear polarization component of the fourth predetermined direction different from the third predetermined direction is reflected to the transmission polarization axis varying means side, and is light in substantially the entire wavelength range of the visible light region from the light source side. The polarization splitting means is capable of emitting linearly polarized light in the third predetermined direction to the transmission polarization axis varying means side with respect to incident light.

In this way, the first to fourth display states are obtained for light in the entire wavelength range of the visible light region, and in the first and third display states, transparent or white. You can get the display.

Further, the second polarized light separating means directs the linearly polarized light component in the third predetermined direction out of the light incident from the transmission polarization axis varying means side to the optical element side to the third predetermined direction. It is characterized in that it is a polarized light separating means for transmitting it as linearly polarized light in the direction. Preferably, the second polarized light separating means is a multilayer film in which a plurality of layers are laminated, the refractive index of the plurality of layers is between adjacent layers, in a third predetermined direction. The polarization splitting means may be equal and different in the fourth predetermined direction.

Also, preferably, the first polarized light separating means is a polarizing plate.

Further, preferably, the transmission polarization axis varying means is a liquid crystal panel, and more specifically, a TN liquid crystal panel, an STN liquid crystal panel, an F-STN liquid crystal panel, or an ECB liquid crystal panel. . In addition, this ST
Specifically, the N liquid crystal panel is an F-STN (Film compens
ATED Super-Twisted Nematic) STN liquid crystal panel that uses an optical anisotropic body for color compensation such as a liquid crystal panel, or positively utilizing the birefringence of liquid crystal without using an optical anisotropic body for color compensation
STN LCD panel.

Further, preferably, by making the surface color of the light source dark, reflection on the surface of the light source can be suppressed, and as a result, the light transmitted through the optical envelope element is reflected by the light source and returns again. The amount can be reduced, and the reduction in contrast can be suppressed.

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029] Preferably, it further comprises means for condensing the light from the light source toward the front of the display device.

Normally, when a reflection type display by external light is viewed, the display is performed at a position inclined by a certain angle from the normal line to the front of the display device. This is because, when viewed from the direction normal to the front surface of the display device, the observer himself interferes with the external light incident on the display device, and the reflective display due to the external light becomes dark. On the other hand, when viewing the display by the transmitted light from the light source, since it is usually viewed from the direction normal to the front of the display device, a means for condensing the light from the light source toward the front of the display device is used. By preparing,
You can brighten the display by the transmitted light from the light source,
As a result, the transmissive display by the light from the light source becomes easy to be seen in the direction normal to the front of the display device.

Further, preferably, a light diffusing means is further provided. With this configuration, the external light is the first display state due to the light reflected by the second polarization separating means or the third light due to the light from the light source transmitted through the first polarization separating means.
The display state of can be displayed in white.

The light source may include a cold cathode tube capable of emitting white light and a light guide plate capable of emitting white light incident from the cold cathode tube toward the second polarization separation means side. Using, as described above, for light from the light source,
Depending on the state of the transmission polarization axis of the transmission polarization axis varying means, a third display state by the light transmitted through the first polarization separation means and a fourth state in which light does not pass through the first polarization separation means It is possible to obtain two display states of a display state and a transmissive display, but depending on the structure of the display device, for example,
When the state of the transmission polarization axis of the transmission polarization axis changing means is on, the third display state is obtained and white display is performed, and when the state of the transmission polarization axis of the transmission polarization axis changing means is off, the fourth display state is obtained. The display state is obtained and the display becomes black. Then, at this time, when external light is incident from the side of the first polarization separation unit of the display device, the external light enters the second display when the state of the transmission polarization axis of the transmission polarization axis changing unit is on. The state is obtained and black display is performed, and when the state of the transmission polarization axis of the transmission polarization axis varying means is off, the first display state is obtained and white display is performed.

As a result, in both cases of on and off, for example, when the display by the transmitted light from the light source is a white display, the reflection type black display by the external light is also added and the display becomes a gray display. Even when the display by the transmitted light is black, the reflection-type white display by the external light is added and the display becomes gray, so that a so-called positive / negative reversal phenomenon occurs, and the display becomes difficult to see.

Therefore, it is preferable to use a LED capable of emitting light in a predetermined wavelength region to the second polarization separating means side or an EL element capable of emitting light in a predetermined wavelength region to emit light from a light source. When colored light is used, this colored display is displayed on the gray background, and the transmissive display due to the light from the light source is easily visible.

In the case where an LED is used as the light source, the light source has a first LED capable of emitting light in a first predetermined wavelength range and a wavelength different from the first predetermined wavelength range. It is preferable to have a second LED capable of emitting light in a second predetermined wavelength range, which is a light source.
In the case of using an EL element, the light source is a first EL element capable of emitting light in a third predetermined wavelength region, and the first EL element.
It is preferable to include a second EL element capable of emitting light in a fourth predetermined wavelength range, which is a wavelength range different from the third predetermined wavelength range. And, preferably, if the first and second LEDs, or the first and second EL elements correspond to each character display portion, different display colors can be obtained in each character display portion, so that the design The range of choices is wide and very useful.

When an LED is used as the light source, the LED is capable of emitting light in a predetermined wavelength range.
And a light guide plate capable of emitting the light in the predetermined wavelength region incident from the LED to the second polarization separation means side. With this configuration, the light emitted from the LED can be made to enter the light guide slope once, and then the light can be emitted from the light guide plate to the second polarization dividing means side.
Since the position of arranging is relatively freely determined, the width of the design is widened and the light emitted to the second polarization separation means side becomes uniform.

Further, the light guide plate is the first LED.
From the first predetermined wavelength range light is incident from, and the first light guide region for emitting light of the first predetermined wavelength range to the second polarization separation means side, the second The light of the second predetermined wavelength range is incident from the LED, and the second
A second light guide region that emits light in the second predetermined wavelength range on the side of the polarized light separating means, and between the first light guide region and the second light guide region. It is preferable to provide a light shielding means. By providing such a light shielding means, the first
Since the predetermined wavelength region of and the second predetermined wavelength region do not mix with each other, the color purity is high.

In addition, the color of the light source and the second polarized light separating means can transmit or reflect light in a predetermined wavelength range and absorb light in a wavelength other than the predetermined wavelength range. Layers may be provided. In this way, the light from the light source is colored and is incident on the second polarized light separating means, so that this colored color is displayed on the gray background, and the transmissive display by the light from the light source is easily visible. In this case, since the light from the light source is colored by the coloring layer, a white light source such as a cold cathode tube may be used as the light source. Of course, the above-mentioned LED or EL element may be used.

The colored layer includes a first colored region capable of reflecting or transmitting light in the first predetermined wavelength range and a second predetermined wavelength different from the light in the first predetermined wavelength region. A second colored region capable of transmitting or reflecting light in the range is provided, and it is preferable that light having a wavelength other than the first or second predetermined wavelength range can be absorbed. And preferably, if the first and second colored areas correspond to the respective character display portions,
Since different display colors can be obtained in each character display part,
Wider range of design choices.

Further, between the colored layer and the light source,
The light from the light source is transmitted to the colored layer side, and the second
It is more preferable to further include a semi-transmissive reflection plate capable of reflecting the light that has entered the colored layer from the side of the polarized light separating means and transmitted through the colored layer, and emits the light to the colored layer side. The semi-transmissive reflection plate may be a specular reflection plate having an opening. By doing so, the light incident from the outside of the first polarization splitting means is reflected from the second polarization splitting means according to the state of the transmission polarization axis of the transmission polarization axis varying means. First display state by light, light transmitted through the second polarized light separating means is reflected by the coloring layer, and second display state by light once transmitted through the coloring layer and then reflected by the reflecting plate And two display states are obtained, and the display device becomes a reflection type. In the second display state, the presence of the reflector increases the degree of coloring.

The electronic equipment of the present invention is characterized by including the above-mentioned display device as a display portion.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

[0043]

EXAMPLES (First Embodiment) <Basic Structure> FIG. 1 is a sectional view of a display device according to a first embodiment of the present invention, and FIG. 2 is a sectional view of the first embodiment of the present invention. It is a schematic sectional drawing for demonstrating the display principle of a display apparatus.

The display device 100 is capable of displaying a reflection type display utilizing the reflection of external light in a place where there is external light, and a transmission type display using light from a light source even in a place where there is no external light. It is a reflection type display device capable of displaying and having a so-called semi-transmissive function.

First, the structure of the display device of this embodiment will be described with reference to FIG. In this display device 100,
The TN liquid crystal panel 10 is used as the variable transmission polarization axis optical element. In the TN liquid crystal panel 10, a TN liquid crystal 13 is held between two glass plates 11 and 12,
A plurality of character display units (not shown) are provided so that characters can be displayed. A polarizing plate 14 is provided on the upper side of the TN liquid crystal panel 10. A light scatterer 15, a polarization separator 16, and a light source 17 are provided in this order below the TN element panel 10. In addition, a TN mounted with a driver averaging IC for driving the liquid crystal 10
An AB board (not shown) is connected to the TN liquid crystal panel 10 to form a display device.

<Polarization Separator> Next, the polarization separator used in the present embodiment will be described with reference to FIGS. 3 and 4. FIG. 4 is a schematic configuration diagram of the polarization separator 16 used in this embodiment,
FIG. 4 is a diagram for explaining the operation of the polarization separator 16 shown in FIG. The polarization separator 16 has two different layers 4
It has a structure in which 1 (A layer) and 42 (B layer) are alternately laminated. In this polarization separator 16, A
Although the refractive index of the layer 41 in the X-axis direction (n _AX ) is different from the refractive index of the B layer 42 in the X-axis direction (n _BX ), the refractive index of the A layer 41 in the Y axis direction (n _AY ) and the B layer 42 are different. The refractive index (n _BY ) of 42 in the Y-axis direction is substantially equal. The linearly polarized light in the Y-axis direction of the light incident on the polarization separator 16 is transmitted through the polarization separator 16 because the A layer 41 and the B layer 42 in the polarization separator 16 have substantially the same refractive index. . On the other hand, the thickness of the A layer 41 of this polarization separator 16 in the Z-axis direction is t _A , B
Assuming that the thickness of the layer 41 is t _B , t _A · n _AX + t _B · n _BX = λ / 2 (1) so that the light of the wavelength λ that is incident on the polarization separator 16 is The linearly polarized light in the X-axis direction is reflected by the polarization separator 16. And layer A 4
The thickness of the B layer 42 in the Z-axis direction and the thickness of the B layer 42 in the Z-axis direction in 1 are variously changed. Reflects linearly polarized light in the X-axis direction.

The layer A 41 of the polarization separator 16 is made of, for example, polyethylene naphthalate (PEN).
napthalate) is stretched, and the B layer 42 has a copolyester of naphthalene dicarponic acid and terephthalic acid (coPEN; copolyester of napthalene dica).
rboxylic acid and terephthallic or isothalic aci
d) can be used.

Of course, the polarization separator 16 used in the present invention
The material of is not limited to this, and the material can be appropriately selected. In addition, such a polarization separator is disclosed in an internationally published international application (International application number: WO / 95/2781).
9 and WO95 / 17692), reflective polrize
The details are disclosed as r.

Further, in the present embodiment, the above-mentioned polarization separator is used, but in addition to this polarization separator, the cholesteric liquid crystal layer sandwiched between λ / 4 plates and the Brewster angle are used. Things (SID 92DIGEST
(Pages 427 to 429), the one using a hologram and the like have the same function as the above-mentioned polarization separator, and they may be used for the display device of this embodiment.

<Principle of Display> Next, the principle of display by the display device 100 will be described with reference to FIG. 2 with the right half of the display device 100 as a voltage applying part and the left half of the display device 100 as a non-voltage applying part. First, a reflective display when external light enters the display device 100 will be described.

In the non-voltage-applied portion on the left side, when external light is incident on the display device 100, the external light is linearly polarized in the direction parallel to the paper surface by the polarizing plate 14, and then T
The polarization direction is twisted by 90 ° by the N liquid crystal 13 to become linearly polarized light in the direction perpendicular to the paper surface, and the linearly polarized light in the direction perpendicular to the paper surface is reflected by the polarization separator 16 as it is, and the polarization direction by the TN liquid crystal 13 is 90 °. It is twisted to become linearly polarized light in the direction parallel to the paper surface, and is emitted from the polarizing plate 14 as linearly polarized light in the direction parallel to the paper surface. As described above, when no voltage is applied, the incident external light is reflected by the polarization separator 16 rather than being absorbed, so that a bright reflection type display can be obtained. Since the light scatterer 15 is provided between the polarization separator 16 and the TN liquid crystal panel 10, the polarization separator 16
The reflected light from is changed from specular to white.

In the right side voltage application section, when external light enters the display device 100, the external light becomes a linearly polarized light in a direction parallel to the paper surface by the polarizing plate 14, and then TN
The liquid crystal 13 is transmitted without changing the polarization direction, and the polarization separator 16
Also transmits without changing the polarization direction and reaches the light source 17. Most of the light that reaches the light source 17 passes through the light source or is absorbed by the light source, so that a dark display is obtained.

As described above, in the reflection type display when the external light is incident on the display device 100, the light reflected by the polarization separator 16 is applied to the light scatterer 1 in the voltage non-applied portion.
5, a bright display is obtained, and in the voltage applying section, most of the light that has passed through the polarization separator 16 passes through the light source 17.
Alternatively, since it is absorbed by the light source 17, the display is dark.

When no voltage is applied, the external light incident on the display device 100 is reflected by the polarization separator 16 without being absorbed, so that a bright display can be obtained.

Next, a transmissive display using light from the light source 17 will be described.

In the non-voltage-applied section on the left side, the light from the light source 17 is incident on the polarization separator 16 and is converted into linearly polarized light in a direction parallel to the paper surface by the polarization separator 16, and then TN
The polarization direction is twisted by 90 ° by the liquid crystal 13 to become linearly polarized light in the direction perpendicular to the paper surface, and is absorbed by the polarizing plate 14 to provide a dark display.

In the voltage applying section on the right side, the light from the light source 17 is incident on the polarization separator 16, becomes linearly polarized light in the direction parallel to the paper surface by the polarization separator 16, becomes scattered light by the light scatterer 15, and then becomes. The TN liquid crystal 13 is transmitted without changing the polarization direction, and the polarizing plate 14 is also transmitted to provide a bright display.

As described above, in the transmissive display by the light from the light source 17, the light from the light source 17 is absorbed by the polarizing plate 14 in the non-voltage application portion and becomes a dark display, and the light in the voltage application portion is polarized. A bright display is obtained through the plate 14.

Therefore, the display device 100 can perform a bright reflection type display utilizing the reflection of the external light in the place where the external light is present, and the light from the light source 17 can be displayed even in the place without the external light. A reflective display device having a so-called semi-transmissive function capable of displaying a transmissive display is provided.

<Scattering Plate> As the scattering plate used in the display device of the present embodiment, a scattering plate capable of emitting incident light without canceling the polarization state of the light as much as possible is used. Since this scattering plate has a function of scattering light emitted from the scattering plate to make it cloudy, a display device having a cloudy display (white display) can be obtained. On the other hand, when the scattering plate 15 is removed from the configuration, the display device can display a glossy color. Therefore, the scattering plate may be discarded depending on the application of the display device.

<Light Source> FIGS. 5 to 9 show the display device of the present embodiment when various light sources are used. In this embodiment, any of the light sources shown in FIGS. 5 to 8 can be used.

The light source used in the display device shown in FIG. 5 includes a cold cathode tube 50 and a light guide plate 51 which are light sources. As the light guide plate 51, one having a light absorbing function when the cold cathode tube 50 is turned off is used.

When the light source shown in FIG. 5 is used for the display device of the present embodiment, the display when the external light including the visible wavelength components of a plurality of colors is incident, that is, the reflection type display, is black at the voltage applying section. The display is displayed, and white is displayed in the non-voltage applied portion.
On the other hand, regarding the transmissive display by the light from the light source, the voltage application section displays the color of light emitted from the cold cathode tube, that is, white display, and the non-voltage application section displays black.

The light source used in the display device shown in FIG. 6 employs an LED 60 for emitting light of a red wavelength as a light source, and further includes a light guide sheet 61. When the light source shown in FIG. 6 is used in the display device of this embodiment,
Regarding the reflection type display, the voltage application section displays black and the voltage non-application section displays white. On the other hand, in the transmissive display by the light from the light source, the color of the light emitted from the LED 60 is displayed in the voltage application unit, that is, the red display, and the black display is displayed in the voltage non-application unit.

By the way, in the case of using the light source shown in FIG. 5, as described above, with respect to the light from the light source 17, a dark display is displayed in the voltage non-applied section and a bright display is displayed in the voltage application section. Respectively, and a transmissive display can be obtained. At this time, when external light is incident from the front side of the display device, the external light causes a bright display in a non-voltage-applied group and a voltage application section. Is displayed brightly in black. As a result, in both the voltage non-applied section and the voltage applied section, for example, when the display by the transmitted light from the light source 17 is a bright display, the reflection-type dark display by the external light is also added, and the display becomes gray. Even when the display by the transmitted light from 17 is a dark display, the reflection-type bright display by the external light is added and the display is also gray, so that the so-called positive / negative reversal phenomenon occurs, and the display may be difficult to see. is there.

When the light source shown in FIG. 6 is turned on when external light is incident, the light emitted from LED is visible in the voltage application section, and a grayish red display is obtained, and polarization separation is performed in the voltage non-application section. Since the external light reflected by the device 16 is visible, it is grayed out, which is much easier to see than a simple black and white display.

Although the LED 60 for emitting light of red wavelength is used in FIG. 6, of course, an LED for emitting light of wavelength other than red may be used.

The light source used in the display device shown in FIG. 7 is an EL element 70 that emits light of a green wavelength as a light source.
Has been adopted. When the light source shown in FIG. 7 is used in the display device of this embodiment, the reflective type display is black display in the voltage applying section and white display in the non-voltage applying section. On the other hand, regarding the transmissive display by the light from the light source, the voltage application section displays the color of light emitted from the EL element 70, that is, green display, and the voltage non-application section displays black. This Figure 7
When the light source is turned on when the external light is incident using the light source shown in, the light emitted from the EL element 70 can be seen in the voltage applying section, resulting in a grayish green display, and in the no voltage applying section, the light is reflected by the polarization separator. Since the outside light is visible, it is grayed out. In FIG. 7, an EL that emits light of a linear color wavelength
Although the element 70 is used, of course, an EL element that emits light having a wavelength other than green may be used.

The light source used in the display device shown in FIG. 8 includes a light guide plate 83, which is an LED 81 for emitting light of a red wavelength and an LED 82 for emitting light of a blue wavelength.
Is located on the side of. The light guide plate is partitioned by a reflection plate 84 for each region corresponding to each LED so that lights of respective wavelengths emitted from the light guide plate are not mixed with each other. Further, each LED is arranged so that its emitted light corresponds to a plurality of character display portions 85 and 86 formed on the liquid crystal panel. When the light source shown in FIG. 8 is used in the display device of the present embodiment, the reflective display provides a black display in the voltage applying section and a white display in the non-voltage applying section. on the other hand,
For transmissive display by light from the light source, each character display unit in the voltage application unit has its own LED
The display of the color of light emitted from, that is, red or blue display,
Black is displayed in the no voltage application part. When the light source shown in FIG. 8 is used to turn on the light source when external light is incident, the voltage application section can see the emitted light from each LED, so that each character display section is displayed in grayish red or blue, and no voltage is applied. In the add section, the external light reflected by the polarization separator is visible, so it is displayed in gray. In FIG. 8, LEDs emitting red wavelength light and LEDs emitting blue wavelength light
However, it is of course possible to use LEDs that emit light of wavelengths other than these colors, and the combination thereof can be appropriately selected depending on the application.

The light source used in the display device shown in FIG. 9 is a plurality of LEDs that emit light of red wavelengths as a light source.
91 and a plurality of LEDs 92 that emit light of a blue wavelength
Are arranged as an aggregate for each color. Incidentally, FIG.
No light guide plate is provided for the light source in FIG. Furthermore, each LE
Group D is arranged so that its emitted light corresponds to a plurality of character display portions 93, 94 formed on the liquid crystal panel. When the light source shown in FIG. 9 is used in the display device of the present embodiment, the reflective display provides a black display in the voltage applying section and a white display in the non-voltage applying section. On the other hand, regarding the transmissive display by the light from the light source, in the voltage applying section, each character display section displays the color of light emitted from each corresponding LED group, that is, red or blue display, and in the voltage non-applying section, it is black. Will be displayed. When the light source is turned on when external light is incident using the light source shown in FIG.
Since the emitted light from the ED group can be seen, a grayish red or blue display is provided for each character display portion, and the external light reflected by the polarization separator can be seen in the voltage non-applied portion, so a gray display is provided. In FIG. 9, an LED 91 that emits light of a red wavelength and an LED 9 that emits light of a blue wavelength
Although 2 is used, of course, an LED that emits light having a wavelength other than these colors may be used, and the combination thereof can be appropriately selected.

(Second Embodiment) FIG. 10 is a sectional view of a display device according to a second embodiment of the present invention.
FIG. 1 is a schematic sectional view for explaining a display principle of a display device according to a second embodiment of the present invention.

This display device 1000 can perform a reflection type display utilizing reflection of outside light in a place where there is outside light, and a transmission type display using light from a light source even in a place where there is no outside light. It is a reflection type display device capable of displaying and having a so-called semi-transmissive function.

<Basic Structure> First, the structure of the display device of the present embodiment will be described with reference to FIG. This display device 10
In 00, the TN liquid crystal panel 10 is used as a transmission polarization axis variable optical element. In the TN liquid crystal panel 10, a TN liquid crystal 13 is sandwiched between two glass plates 11 and 12, and a plurality of character display portions (not shown) are provided so that characters can be displayed. TN
A polarizing plate 14 is provided on the upper side of the liquid crystal panel 10. A light scatterer 15, a polarization separator 101, a light absorber 102, and a light source 17 are provided in this order below the TN element panel 10. The light absorber 102 is black, and the plurality of openings 103 are provided with a predetermined area density. Further, a TAB substrate (not shown) on which a driver IC for driving the TN liquid crystal 13 is mounted is connected to the TN liquid crystal panel 10 to form a display device.

<Polarization Separator> The polarization separator 101 is (1 /
4) A λ plate 104 and a cholesteric liquid crystal layer 105 are provided. The cholesteric liquid crystal 105 has a property of reflecting circularly polarized light having the same wavelength as the pitch of the liquid crystal and having the same rotation direction as the liquid crystal, and transmitting other light. Therefore, for example, the cholesteric liquid crystal layer 105
When a cholesteric liquid crystal with a pitch of 5000 angstrom and counterclockwise rotation is used, a left circularly polarized light having a wavelength of 5000 angstrom is reflected, and a right circularly polarized light or a left circularly polarized light having another wavelength is transmitted. Furthermore, by using a left-handed cholesteric liquid crystal and changing its pitch in the cholesteric liquid crystal over the entire wavelength range of visible light, left circularly polarized light is reflected not only in a single color but also in all bright colored light, and right circularly polarized light is transmitted. The element which does is obtained. In this embodiment, as the cholesteric liquid crystal layer 105, a left-handed cholesteric liquid crystal is used, and its pitch is changed in the cholesteric liquid crystal over the entire wavelength range of visible light.

A polarization separator 10 in which such a cholesteric liquid crystal layer 105 and a (1/4) λ plate 104 are combined.
In the case of No. 1, from the side of the (1/4) λ plate 104,
When linearly polarized light in the direction of 1 is incident, (1/4) λ plate 104
Is left-handed circularly polarized light by the cholesteric liquid crystal layer 105.
Is reflected by the (1/4) λ plate 104, and again emitted as linearly polarized light in the predetermined first direction. When linearly polarized light in the second direction orthogonal to the first direction is incident, (1
/ 4) It becomes right circularly polarized light by the λ plate 104 and is transmitted through the cholesteric liquid crystal layer 105. Further, with respect to light incident from the lower side of the cholesteric liquid crystal layer 105, (1 /
4) The linearly polarized light in the second direction is emitted above the λ plate 104.

Thus, the cholesteric liquid crystal layer 105
And a (1/4) λ plate 104 in combination
01 transmits the linearly polarized light component in the predetermined second direction out of the light incident from the (1/4) λ plate 104 side, and
Reflects the linearly polarized light component in the first direction orthogonal to the direction of
It is a polarization separation means capable of emitting linearly polarized light in the second direction to the (¼) λ plate 104 side with respect to the light incident from the cholesteric liquid crystal layer 105 side. The cholesteric liquid crystal layer 105 is used as a polarization separator having this function.
And a (1/4) λ plate 104 in combination
Other than 01, one using a film in which multilayer films are laminated (USP 4,974,219), one that separates into reflected polarized light and transmitted polarized light using the angle of Brewster (SI
D 92DIGEST pages 427 to 429),
The one using a hologram, the polarization separator described in the first embodiment described above with reference to FIGS. 3 and 4,
In other words, the internationally published international application (International application number: WO
95/27819 and WO 95/17692).

<Display Principle> Next, the display device 1000 will be described.
The display by the display device 1000 will be described by assuming that the right half is a voltage applying section and the left half is a voltage non-applying section.

First, a reflective display when external light enters the display device 1000 will be described.

In the non-voltage-applied section on the left side, when external light is incident on the display device 1000, the external light becomes linearly polarized light in a direction parallel to the paper surface by the polarizing plate 14, and thereafter,
The polarization direction is twisted by 90 ° by the TN liquid crystal 13 to become linearly polarized light in a direction perpendicular to the paper surface, (1/4) becomes left circularly polarized light by the λ plate 104, is reflected by the cholesteric liquid crystal layer 105, and is again (1/4). It is incident on the λ plate 104 and (1 /
4) The λ plate 104 forms linearly polarized light in the direction perpendicular to the paper surface, and the TN liquid crystal 13 twists the polarization direction by 90 ° to form linearly polarized light in the direction parallel to the paper surface. Is emitted as. In this way, when no voltage is applied, the incident external light is reflected by the polarization separator 101 instead of being absorbed, so that a bright reflective display can be obtained. Since the light scatterer 15 is provided between the (1/4) λ plate 104 and the TN liquid crystal panel 10, the reflected light from the polarization separator 101 changes from a mirror surface to a bright color.

In the voltage application section on the right side, when external light is incident on the display device 1000, the external light becomes linearly polarized light in a direction parallel to the paper surface by the polarizing plate 14, and then T
N liquid crystal 13 is transmitted without changing the polarization direction, and (1/4) λ
The plate 104 makes right-handed circularly polarized light, which is transmitted through the cholesteric liquid crystal layer 105. The right-handed circularly polarized light transmitted through the cholesteric liquid crystal layer 105 is absorbed by the black light absorber 102, resulting in a dark display.

As described above, the external light is emitted from the liquid crystal display device 1000.
As for the reflection type display when the light is incident on, the light reflected by the polarization separator 101 is transmitted through the light scatterer 15 in the voltage non-applied section and becomes a bright display, and the polarization separator 101 is turned on in the voltage applied section. Light absorber 1 whose transmitted light is black
It is absorbed in 02 and becomes a dark display.

When no voltage is applied, the external light incident on the display device 1000 is reflected without being absorbed by the polarization separator 101, so that a bright display can be obtained.

Next, the transmissive display by the light from the light source 17 will be described.

In the left non-voltage application section, the light source 17
From the opening 1 provided in the black light absorber 102
The light enters the cholesteric liquid crystal layer 105 of the polarization separator 101 via 03, and only right-handed circularly polarized light is transmitted through the cholesteric liquid crystal layer 105, and becomes a linearly polarized light in a direction parallel to the paper surface by the (1/4) λ plate 104. After that, TN liquid crystal 13
Causes the polarization direction to be twisted by 90 ° to become linearly polarized light in a direction perpendicular to the paper surface, and is absorbed by the polarizing plate 14 to provide a dark display.

In the voltage applying section on the right side, the light from the light source 17 is provided with the opening 10 provided in the black light absorber 102.
The light is incident on the polarization separator 101 and the cholesteric liquid crystal layer 105 via 3, and only right-handed circularly polarized light is transmitted through the cholesteric liquid crystal layer 105, and becomes a linearly polarized light in a direction parallel to the paper surface by the (1/4) λ plate 104. After passing through the light scatterer 15, the TN liquid crystal 13 is passed through without changing the polarization direction, and the polarizing plate 14 is also passed through to provide a bright display.

As described above, regarding the transmissive display by the light from the light source 17, the light from the light source 17 is absorbed by the polarizing plate 14 in the non-voltage application section and becomes a dark display, and the light in the voltage application section is polarized. A bright display is obtained through the slope 14.

Therefore, this display device 1000 can perform a bright reflection type display utilizing the reflection of external light in a place where there is external light, and the light from the light source 17 can be used even in a place where there is no external light. A reflective display device having a so-called semi-transmissive function capable of displaying a transmissive display is provided.

<Scattering Plate> As the scattering plate 15 used in the display device of this embodiment, a scattering plate capable of emitting incident light without canceling the polarization state of the incident light as much as possible is used.
Since the scattering plate 15 has a function of scattering and clouding the light emitted from the scattering plate, a display device with a cloudy display (white display) can be obtained. On the other hand, when the scattering plate 15 is removed from the configuration, the display device can display a glossy color. Therefore, the scattering plate may be discarded depending on the application of the display device.

<Light Absorber> In the present embodiment, in the reflection type display when external light is incident on the display device 1000, as described above, a bright display by the light reflected from the polarization separator 101. And a dark display in which the light that has passed through the polarization separator 101 is absorbed by the light absorber 102. However, the light absorber 102 is a black light absorber and is the polarization separator 101.
The light absorber 103 has a plurality of openings 103 and can transmit light through the openings 103. Therefore, in the dark display state, the light absorber 103 is absorbed.
Not all the light is absorbed by the light absorber 102, but some light is transmitted through the light absorber 102 through the opening 103 and is reflected by the light source 17 or the like, and is also absorbed through the opening 103. Is transmitted back to the TN liquid crystal panel 10 side and the contrast is lowered.

Therefore, it is preferable to limit the ratio of the opening 103 to the light absorber 102 so that light passes through the light absorber 102 through the opening 103 and is reflected by the light source 17 or the like. In addition, the opening 103 of the light absorber 102
It is possible to reduce the amount of light that returns via the light source, and to suppress deterioration of contrast.

In this embodiment, the light absorber 102 is used.
As a black light absorber having a plurality of openings 103 was used, a gray light absorber in a semi-transmissive state can also be used and also absorbs light from the polarization separator 101 side. The light from the light source 17 can be transmitted to the polarization separator 101 side. Since the light absorber in this case is in a gray semi-transmissive state, it is not necessary to provide an opening. A light diffusion film D202 (Tsujimoto Electric Co., Ltd.) or the like can be used as the light absorber in the gray semi-transmissive state.

Alternatively, a black light absorber having a plurality of openings 103 was used as the light absorber 102, but instead of the light absorber 102, a polarization separator 101 and a polarizing plate whose absorption axis is shifted are used. It can also be used. With this configuration, the polarization separator 101 and the polarizing plate with its absorption axis shifted can absorb the light from the TN liquid crystal panel 10 side and transmit the light from the light source 17 to the TN liquid crystal panel 10 side. .

<Light Source> The display device in this embodiment can use the various light sources shown in FIGS. 5 to 9 and described in the first embodiment. Since the operation and effect are the same as those in the first embodiment, the description thereof will be omitted here.

(Third Embodiment) <Basic Structure> FIG. 12 is a schematic sectional view for explaining a display device according to a third embodiment of the present invention.

In the above-described second embodiment,
Although the polarization separator 101 including the (1/4) λ plate 104 and the cholesteric liquid crystal layer 105 is used, in the present embodiment, the polarization separator 101 is replaced with (1 /
4) The λ plate 104, the cholesteric liquid crystal layer 105, and (1 /
4) The point that the polarization separator 121 including the λ plate 120 is used is different from the second embodiment, but the other points are the same.

<Polarization Separator> In the polarization separator 121 in which the (104) λ plates 104 and 120 are provided on both sides of the cholesteric liquid crystal layer 105, the (1/4) λ slope 1
When the linearly polarized light in the predetermined first direction is incident from the 04 side, it becomes left-handed circularly polarized light by the (1/4) λ plate 104, is reflected by the cholesteric liquid crystal layer 105, and is (1/4) λ plate 10
By 4 again, linearly polarized light in a predetermined first direction is emitted again. When linearly polarized light in the second direction orthogonal to the first direction is incident, it becomes right-handed circularly polarized light by the (1/4) λ plate 104, passes through the cholesteric liquid crystal layer 105, and becomes (1
/ 4) The λ plate 120 again converts the light into linearly polarized light in the second direction and emits it. Further, with respect to light incident from the lower side of the (1/4) λ plate 146, linearly polarized light in the second direction is emitted above the (1/4) λ plate 104.

Thus, the cholesteric liquid crystal layer 105
The polarization separator 121, which is a combination of the (1/4) λ plate 104 and the (1/4) λ plate 104 and 120, converts the linearly polarized light component in the predetermined second direction out of the light incident from the (1/4) λ plate 104 side into the second Direction linearly polarized light is transmitted, the linearly polarized light component of the first direction orthogonal to the predetermined second direction is reflected, and (1/4) λ plate 1
The polarization splitting means is capable of emitting linearly polarized light in the second direction to the (¼) λ plate 104 side with respect to the light incident from the 20 side. As a polarized light separating means having this function,
The cholesteric liquid crystal layer 105 and the (1/4) λ plate 10
In addition to the polarization separator 121 that is a combination of 4 and 120,
Using multi-layered film (USP4
974, 219), which separates into reflected polarized light and transmitted polarized light by utilizing Brewster's angle (SID 92 D)
IGEST pages 427 to 429), those using holograms, the polarization separator described in the first embodiment with reference to FIGS. 3 and 4, that is, the internationally published international application (international application number). : WO95 / 27819 and WO / 17692), there are those disclosed as reflective polrizers.

<Display Principle> Next, the display device 1200 will be described.
The display by the display device 1200 will be described with the right half of the figure as a voltage application section and the left half as a voltage non-application section.

First, a reflection type display when external light enters the display device 1200 will be described.

The function of the non-voltage applied section on the left side is the same as the function of the non-voltage applied section of the first embodiment described above. That is, when external light is incident on the display device 1200, the external light is converted into linearly polarized light in a direction parallel to the paper surface by the polarizing plate 14, and then the polarization direction is twisted by 90 ° by the TN liquid crystal 13 and is perpendicular to the paper surface. Linearly polarized light of (1/4)
The λ sheet 104 makes a left-handed circularly polarized light, which is reflected by the cholesteric liquid crystal layer 105 and again enters the (¼) λ plate 104, and becomes a linearly polarized light in a direction perpendicular to the paper surface by the (¼) λ plate 104 The polarization direction is 90 by the TN liquid crystal 13.
The light is twisted to become linearly polarized light in the direction parallel to the paper surface, and is emitted from the polarization sheet 14 as linearly polarized light in the direction parallel to the paper surface.
As described above, when no voltage is applied, the incident external light is reflected by the polarization separator 121 instead of being absorbed, so that a bright reflective display can be obtained. In addition, (1 /
4) Since the light scatterer 15 is provided between the λ sheet 104 and the TN liquid crystal panel 10, the reflected light from the polarization separator 121 is changed from specular to white.

In the voltage application section on the right side, when external light is incident on the display device 1200, the external light is made into linearly polarized light in a direction parallel to the paper surface by the polarizing sheet 14, and then T
N liquid crystal 13 is transmitted without changing the polarization direction, and (1/4) λ
The plate 104 turns the right-handed circularly polarized light, transmits the cholesteric liquid crystal layer 105, and the right-handed circularly polarized light that passes through the cholesteric liquid crystal layer 105 becomes a linearly polarized light in a direction parallel to the paper surface by the (1/4) λ plate 120, and then black. Is absorbed by the light absorber 102 to produce a dark display.

As described above, regarding the reflection type display when the external light is incident on the display device 1200, in the voltage non-applied section, it is reflected by the polarization separator 121 to be a bright display, and in the voltage applied section, the polarization separation is performed. The light transmitted through the container 121 is absorbed by the black light absorber 102, resulting in a dark display.

When no voltage is applied, the external light incident on the display device 1200 is reflected by the polarization separator 121 without being absorbed, so that a bright display can be obtained.

Next, a transmissive display by light from the light source 17 will be described.

In the left non-voltage application section, the light source 17
From the opening 1 provided in the black light absorber 102
(1/4) λ plate 120 of the polarization separator 121
Incident on the cholesteric liquid crystal layer 105 after passing through the (1/4) λ plate 120.
The right circularly polarized light is transmitted and the left circularly polarized light is reflected by 5. The transmitted circularly polarized light becomes a linearly polarized light in a direction parallel to the paper surface by the (1/4) λ plate 104, and thereafter, the polarization direction is twisted by 90 ° by the TN liquid crystal 13 to become a linearly polarized light in a direction perpendicular to the paper surface. It is absorbed by 14 and becomes a dark display.

In the voltage application section on the right side, the light from the light source 17 is provided with the opening 103 provided in the black light absorber 102.
Of the light incident on the (1/4) λ plate 120 of the polarization separator 121 through the cholesteric liquid crystal layer 105 and then transmitted only to the right circularly polarized light. Becomes linearly polarized light in a direction parallel to
, Then the TN liquid crystal 13 is transmitted without changing the polarization direction, and the polarizing plate 14 is also transmitted to provide a bright display.

As described above, regarding the transmissive display by the light from the light source 17, the light from the light source 17 is absorbed by the polarizing plate 14 in the non-voltage application section and becomes a dark display, and the light in the voltage application section is polarized. A bright display is obtained through the plate 14.

Therefore, the display device 1200 can perform a bright reflection type display utilizing the reflection of the external light in the place where the external light is present, and the light from the light source 17 can be displayed in the place without the external light. A reflective display device having a so-called semi-transmissive function capable of displaying a transmissive display is provided.

<Scattering Plate> As the scattering plate used in the display device of this embodiment, a scattering plate capable of emitting incident light without canceling the polarization state of the light as much as possible is used. Since this scattering plate has a function of scattering light emitted from the scattering plate to make it cloudy, a display device having a cloudy display (white display) can be obtained. On the other hand, when the scattering plate 15 is removed from the configuration, the display device can display a glossy color. Therefore, the scattering plate may be discarded depending on the application of the display device.

<Light Absorber> As the light absorber used in this embodiment, the same light absorber as used in the second embodiment can be used. And, similarly to the second embodiment, the reduction in contrast can be suppressed by limiting the ratio of the opening 103 to the light absorber 102. Of course, as in the second embodiment, it is possible to use a semi-transmissive light absorber or a polarizing plate whose absorption axis is offset from that of the polarization separator 121.

<Light Source> Various light sources described in FIGS. 5 to 9 and the first embodiment can be used for the display device in this embodiment. The operation and effect are the same as those in the first embodiment, and therefore the description thereof is omitted here.

(Fourth Embodiment) <Basic Structure> FIG. 13 is a schematic sectional view for explaining a display device according to a fourth embodiment of the present invention.

In the above-described second embodiment,
The polarization separator 101 including the (1/4) λ plate 104 and the cholesteric liquid crystal layer 105 is used. In the third embodiment, the (1/4) λ plate 104 cholesteric liquid crystal layer 105 (1/4) is used. Polarization separator 12 including λ plate 120
However, in this embodiment, the polarization separators 101 and 121 are replaced by the polarization separators described in the first embodiment with reference to FIGS. Published international application (International application number: WO
95/27819 and WO 95/17692) is used as the polarization separator 16.
2 and 3 are different from the third embodiment, but other points are the same as the second embodiment and the third embodiment.

<Polarization Separator> In this embodiment, the same one as described in the first embodiment with reference to FIGS. 3 and 4 is used. The detailed description is omitted here. Of course, in addition to this polarization separator, for example, a cholesteric liquid crystal layer sandwiched between λ / 4 plates, a device using Brewster's angle (SID 92DIGEST pages 427 to 429), and a device using holograms are available. It has the same function as the above-mentioned polarization separator, and may be used for the display device of this embodiment.

<Display Principle> Next, the display device 1300 will be described.
The display by the display device 11300 will be described, where the right half is the voltage applying section and the left half is the voltage non-applying section.

First, a reflection type display when external light enters the display device 1300 will be described.

In the non-voltage-applied portion on the left side, when external light enters the display device 1300, the external light is linearly polarized in the direction parallel to the paper surface by the polarizing plate 14, and thereafter,
The polarization direction is twisted by 90 ° by the TN liquid crystal 13 to become linearly polarized light in the direction perpendicular to the paper surface, and the linearly polarized light in the direction perpendicular to the paper surface is reflected by the polarization separator 16 as it is.
Thus, the polarization direction is twisted by 90 ° to become linearly polarized light in the direction parallel to the paper surface, and is emitted from the polarizing plate 14 as linearly polarized light in the direction parallel to the paper surface. As described above, when no voltage is applied, the incident external light is reflected by the polarization separator 16 rather than being absorbed, so that a bright reflection type display can be obtained. Since the light scatterer 15 is provided between the polarization separator 16 and the TN liquid crystal panel 10, the polarization separator 1
The reflected light from 6 changes from a specular shape to a bright color.

In the voltage application section on the right side, when external light is incident on the display device 1300, the external light becomes linearly polarized light in a direction parallel to the paper surface by the polarizing plate 14, and then T
Polarization separator 1 that transmits N liquid crystal 13 without changing the polarization direction
6 also transmits without changing the polarization direction, and is then absorbed by the black light absorber 102 to provide a dark display.

As described above, in the reflection type display when the external light is incident on the display device 1300, the light reflected by the polarization separator 16 is not reflected by the light scatterer 1 in the voltage non-applied portion.
5, a bright display is obtained, and in the voltage application section, the light transmitted through the polarization separator 16 is absorbed by the black light absorber 102, resulting in a dark display.

When no voltage is applied, the external light incident on the display device 1300 is reflected by the polarization separator 16 without being absorbed, and a bright display is obtained.

Next, a transmissive display by light from the light source 17 will be described.

In the left non-voltage application section, the light source 17
From the opening 1 provided in the black light absorber 102
And enters the polarization separator 16 via 03.
Results in linearly polarized light in a direction parallel to the paper, and then
The polarization direction is twisted by 90 ° by the TN liquid crystal 13 to become linearly polarized light in a direction perpendicular to the paper surface, and is absorbed by the polarizing plate 14 to provide a dark display.

In the voltage applying section on the right side, the light from the light source 17 is provided with the opening 10 provided in the black light absorber 102.
The light enters the polarization separator 16 via 3 and is converted into linearly polarized light in a direction parallel to the paper surface by the polarization separator 16 to generate the light scatterer 1.
As a result, the TN liquid crystal 10 transmits without changing the polarization direction of the TN liquid crystal 10, and also passes through the polarizing plate 14 to provide a bright display.

As described above, regarding the transmissive display by the light from the light source 17, the light from the light source 17 is absorbed by the polarizing plate 14 in the non-voltage application portion to be a dark display, and the light in the voltage application portion is polarized. A bright display is obtained through the plate 14.

Therefore, the display device 1300 can perform a bright reflection type display utilizing the reflection of the external light in the place where the external light is present, and the light from the light source 17 can be displayed in the place without the external light. A reflective display device having a so-called semi-transmissive function capable of displaying a transmissive display is provided.

<Scattering Plate> As the scattering plate used in the display device of this embodiment, a scattering plate capable of emitting the incident light without canceling the polarization state of the incident light as much as possible is used. Since this scattering plate has a function of scattering light emitted from the scattering plate to make it cloudy, a display device having a cloudy display (white display) can be obtained. On the other hand, when the scattering plate 5 is removed from the configuration, the display device can display a glossy color. Therefore, the scattering plate may be discarded depending on the application of the display device.

<Light Absorber> As the light absorber used in this embodiment, the same light absorber as used in the second embodiment can be used. And, similarly to the second embodiment, the reduction in contrast can be suppressed by limiting the ratio of the opening 103 to the light absorber 102. Of course, as in the second embodiment, it is also possible to use a light-transmitting body in a semi-transmissive state or a polarizing plate whose absorption axes are shifted from those of the polarization separators 101 and 121.

<Light Source> Various light sources described in FIGS. 5 to 9 and the first embodiment can be used for the display device in the present embodiment.

Since the operation and effect are the same as those of the first embodiment, the description thereof will be omitted here.

(Fifth Embodiment) FIG. 14 is a sectional view of a display device according to a fifth embodiment of the present invention.
FIG. 5 is a schematic cross-sectional view for explaining the display principle of the display device according to the first embodiment of the present invention.

This display device 100 can display a reflection type display utilizing the reflection of the external light in the place where the external light is present, and also can display the transmission type by the light from the light source even in the place without the external light. It is a reflection type display device capable of displaying and having a so-called semi-transmissive function.

<Basic Structure> First, the structure of the display device of the present embodiment will be described with reference to FIG. This display device 14
In 00, the TN liquid crystal panel 10 is used as a transmission polarization axis variable optical element. In the TN liquid crystal panel 10, a TN liquid crystal 13 is sandwiched between two glass plates 11 and 12, and a plurality of character display portions (not shown) are provided so that characters can be displayed. TN
A lighting plate 14 is provided on the upper side of the liquid crystal panel 10. Below the TN element panel 10, a light scatterer 15, a polarization separator 16, a diffusion plate 140, and a light source 17 are provided in this order. The diffusion plate 140 is a scattering plate that can change the polarization state of incident light and emit the light. Further, a TAB substrate (not shown) on which a driver IC for driving the TN liquid crystal 13 is mounted is connected to the TN liquid crystal panel 10 to form a display device.

<Polarization Separator> In this embodiment, the same one as described in the first embodiment with reference to FIGS. 3 and 4 is used. The detailed description is omitted here. Of course, in addition to this polarization separator, for example, a cholesteric liquid crystal layer sandwiched by λ / 4 plates, a Brewster angle (SID 92DIGEST pages 427 to 429), and a hologram are used. It has the same function as the above-mentioned polarization separator, and may be used for the display device of this embodiment.

<Principle of Display> Next, with reference to FIG. 15, the display by the display device 1400 will be described with the right half of the display device 1400 as a voltage applying part and the left half as a voltage non-applying part.

First, a reflection type display when external light is incident on the display device 1400 will be described.

In the non-voltage-applied portion on the left side, when external light is incident on the display device 1400, the external light becomes linearly polarized light in a direction parallel to the paper surface by the polarizing plate 14, and thereafter,
The polarization direction is twisted by 90 ° by the TN liquid crystal 13 to become linearly polarized light in the direction perpendicular to the paper surface, and is reflected by the polarization separator 16 as it is as linearly polarized light in the direction perpendicular to the paper surface.
Thus, the polarization direction is twisted by 90 ° to become linearly polarized light in the direction parallel to the paper surface, and is emitted from the polarizing plate 14 as linearly polarized light in the direction parallel to the paper surface. As described above, when no voltage is applied, the incident external light is reflected by the polarization separator 16 rather than being absorbed, so that a bright reflection type display can be obtained. Since the light scatterer 15 is provided between the polarization separator 16 and the TN liquid crystal panel 10, the polarization separator 1
The reflected light from 6 changes from specular to white.

In the voltage applying section on the right side, when external light is incident on the display device 1400, the external light is converted into linearly polarized light in a direction parallel to the paper surface by the polarizing plate 14, and then T
Polarization separator 1 that transmits N liquid crystal 13 without changing the polarization direction
6 also transmits without changing the polarization direction, and then the scattering plate 140
The polarization state is changed by and is scattered. Scattered sheet 14
Most of the light scattered to the polarization separator side by 0 cannot be transmitted through the polarization separator because the polarization state thereof has been canceled, resulting in a dark display.

As described above, regarding the reflection type display when the external light is incident on the display device 1400, the light reflected by the polarization separator 16 is applied to the light scatterer 1 in the voltage non-applied portion.
5 and a bright display is obtained, and in the voltage application section, the light transmitted through the polarization separator 16 is changed in polarization state by the scattering plate 140 and scattered, so that a dark display is obtained.

When no voltage is applied, the external light incident on the display device 1400 is reflected by the polarization separator 16 without being absorbed, so that a bright display can be obtained.

Next, a transmissive display by light from the light source 17 will be described.

In the left non-voltage application section, the light source 17
The light from is incident on the polarization separator 16 via the scattering plate 140, becomes linearly polarized light in the direction parallel to the paper surface by the polarization separator 16, and then the TN liquid crystal 13 changes the polarization direction to 9
It is twisted by 0 ° to become linearly polarized light in a direction perpendicular to the paper surface, and is absorbed by the polarizing plate 14 to provide a dark display.

In the voltage application section on the right side, the light from the light source 17 enters the polarization separator 16 via the scattering plate 40,
The polarization separator 16 converts the light into linearly polarized light in a direction parallel to the paper surface, and the light scatterer 15 converts the light into scattered light.
The N liquid crystal 13 is transmitted without changing the polarization direction, and the polarizing plate 14 is also transmitted to provide a bright display.

As described above, in the transmissive display by the light from the light source 17, the light from the light source 17 is absorbed by the polarizing plate 14 in the voltage non-applied portion and becomes a dark display, and the polarized light is displayed in the voltage applied portion. A bright display is obtained through the plate 14.

Therefore, this display device 1400 can perform a bright reflection type display utilizing the reflection of external light in a place where there is external light, and the light from the light source 17 can be used even in a place where there is no external light. A reflective display device having a so-called semi-transmissive function capable of displaying a transmissive display is provided.

<Scattering Plate> As the scattering plate used in the display device of this embodiment, a scattering plate capable of emitting the incident light without canceling the polarization state of the incident light is used. still,
Since this scattering plate has a function of scattering and fogging light emitted from the scattering plate, a display device with a cloudy display (white display) can be obtained. On the other hand, when the scattering plate 15 is removed from the configuration, the display device can display a glossy color. Therefore, the scattering plate may be discarded depending on the application of the display device.

<Light Source> The display device according to the present embodiment can use the various light sources described in FIGS. 5 to 9 and the first first embodiment. Both action and effect
1 is the same as that of the embodiment, so its explanation is omitted here.

(Sixth Embodiment) FIG. 16 is a sectional view of a display device according to a sixth embodiment of the present invention.
FIG. 7 is a schematic sectional view for explaining the display principle of the display device according to the sixth embodiment of the present invention.

This display device 1600 is capable of displaying a reflection type display utilizing reflection of outside light in a place where there is outside light, and a transmission type display using light from a light source even in a place where there is no outside light. It is a reflection type display device capable of displaying and having a so-called semi-transmissive function.

<Basic Structure> First, the structure of the display device of the present embodiment will be described with reference to FIG. This display device 16
In 00, the TN liquid crystal panel 10 is used as a transmission polarization axis variable optical element. In the TN liquid crystal panel 10, a TN liquid crystal 13 is sandwiched between two glass plates 11 and 12, and a plurality of character display portions (not shown) are provided so that characters can be displayed. A polarizing plate 14 is provided on the upper side of the TN liquid crystal panel 10.
Below the TN device panel 10, a light scatterer 15, a polarization separator 16, a colored film 160 as a colored layer, and a light source 60 are provided in this order. The colored film can change the polarization state of incident light having a predetermined wavelength and emit the light, and use a semi-transmissive film capable of absorbing light having a wavelength other than the predetermined wavelength, and a white light source as a light source. Was used. Further, a TAB substrate (not shown) on which a driver IC for driving the TN liquid crystal 13 is mounted is connected to the TN liquid crystal panel 10 to form a display device.

<Polarization Separator> In this embodiment, the same one as described in the first embodiment with reference to FIGS. 3 and 4 is used. The detailed description is omitted here. Of course, in addition to this polarization separator, for example, a cholesteric liquid crystal layer sandwiched between λ / 4 plates, one that uses the Brewster's angle (SID 92DIGEST pages 427 to 429), one that uses a hologram, etc. Has a function similar to that of the above-described polarization separator, and may be used for the display device of this embodiment.

<Display Principle> Next, with reference to FIG. 17, the display by the display device 1600 will be described with the right half of the display device 1600 as a voltage application part and the left half as a voltage non-application part.

First, a reflection type display when external light enters the display device 1600 will be described.

In the non-voltage-applied portion on the left side, when external light enters the display device 1600, the external light is linearly polarized by the polarizing plate 14 in the direction parallel to the paper surface, and thereafter,
The polarization direction is twisted by 90 ° by the TN liquid crystal 13 to become linearly polarized light in the direction perpendicular to the paper surface, which is reflected by the polarization separator 16 as it is in the direction perpendicular to the paper surface, and the TN liquid crystal 13 causes the polarization direction to be 90 °. It is twisted to become linearly polarized light in the direction parallel to the paper surface, and is emitted from the polarizing plate 14 as linearly polarized light in the direction parallel to the paper surface. As described above, when no voltage is applied, the incident external light is reflected by the polarization separator 16 rather than being absorbed, so that a bright reflection type display can be obtained. In addition, since the light scatterer 15 is provided between the polarization separator 16 and the TN liquid crystal panel 10, the polarization separator 16
The reflected light from is changed from specular to white.

In the voltage application section on the right side, when external light is incident on the display device 1600, the external light becomes linearly polarized light in a direction parallel to the paper surface by the polarizing plate 14, and then T
Polarization separator 1 that transmits N liquid crystal 13 without changing the polarization direction
6 also transmits without changing the polarization direction, and then the colored film 160 absorbs light within a predetermined wavelength range. Light in a predetermined wavelength range is absorbed by the colored film, resulting in a dark display.

As described above, regarding the reflection type display when the external light is incident on the display device 1600, the light reflected by the polarization separator 16 is not reflected by the light scatterer 1 in the voltage non-applied portion.
5, the display becomes bright, and in the voltage applying section, the light transmitted through the polarization separator 16 is absorbed by the colored film 50, so that the display becomes dark.

When no voltage is applied, the external light incident on the display device 1600 is reflected by the polarization separator 16 without being absorbed, so that a bright display can be obtained.

Next, the transmissive display by the light from the light source 17 will be described.

In the left non-voltage application section, the light source 17
The light from the polarization separator 16 is transmitted through the colored film 160.
Is incident on the polarized light separator 16, and becomes linearly polarized light in a direction parallel to the paper surface by the polarization separator 16. Then, the polarization direction is twisted by 90 ° by the TN liquid crystal 13 to become linearly polarized light in a direction perpendicular to the paper surface, which is absorbed by the polarizing plate 14. The display becomes dark.

In the voltage application section on the right side, the light from the light source 17 enters the polarization separator 16 while being colored by passing through the coloring film 160, and becomes linearly polarized in the direction parallel to the paper surface by the polarization separator 16. , Light scatterer 1
As a result, scattered light is generated by 5, and thereafter, the TN liquid crystal 13 is transmitted without changing the polarization direction, and the polarizing plate 14 is also transmitted to provide a bright display.

As described above, regarding the transmissive display by the light from the light source 17, the light from the light source 17 is absorbed by the polarizing plate 14 in the voltage non-applied section and becomes a dark display, and the polarized light is displayed in the voltage application section. A bright display is obtained through the plate 14.

Therefore, this display device 1600 can perform a bright reflection type display utilizing the reflection of the external light in the place where the external light is present, and the light from the light source 17 can be displayed in the place without the external light. A reflective display device having a so-called semi-transmissive function capable of displaying a transmissive display is provided.

<Scattering Plate> As the scattering plate used in the display device of this embodiment, a scattering plate capable of emitting incident light without canceling the polarization state thereof is used. Since this scattering plate has a function of scattering light emitted from the scattering plate to make it cloudy, a display device having a cloudy display (white display) can be obtained. On the other hand, when the scattering plate 15 is removed from the configuration, the display device can display a glossy color. Therefore, the scattering plate may be discarded depending on the application of the display device.

<Colored Layer> FIGS. 18 and 19 show the display device of this embodiment when various colored films are used as the colored layer. In this embodiment mode, FIG.
And any of the colored films shown in FIG. 19 can be used. The display device shown in FIG. 18 employs a colored film that transmits and reflects light having a red wavelength. In the display device shown in FIG. 18, for the reflection type display, a blackish red display is provided in the voltage application section and a white display is provided in the voltage non-application section. On the other hand, with regard to the transmissive display by the light from the light source, the light color of the light source colored by the coloring film, that is, the red display is displayed in the voltage application section, and the black display is displayed in the voltage non-application section.

By the way, when a white light emitting light source is used without using a colored film, as described above, a dark display is generated in the voltage non-applied portion with respect to the light from the light source 17 by the voltage. A bright display can be obtained in each of the application sections, and a transmissive display can be obtained. However, when external light is incident from the front side of the display device at this time, the external display causes a bright display in the non-voltage application section. And the display is dark in the voltage application section. as a result,
In both of the voltage non-applied section and the voltage applied section, for example, when the display by the transmitted light from the light source 17 is a bright display, the reflection-type dark display by the external light is also added and the display becomes a gray display. Even when the display by the transmitted light is a dark display, the reflection-type bright display by the external light is added and the display is also gray, so that a so-called positive / negative inversion phenomenon occurs, and the display may be difficult to see.

When the color filter shown in FIG. 18 is used to turn on the light source when external light is incident, the output light from the light source 17 that has passed through the color filter 160 in the voltage application section is visible, resulting in a grayish red display. The external light reflected by the polarization separator can be seen in the voltage non-applied portion, so that the display becomes gray, which is much easier to see than a simple black and white display.

Although a colored filter that reflects or transmits light having a red wavelength is used in FIG. 18, of course, light having a wavelength other than red may be used.

In the display device shown in FIG. 19, a colored film having a region for reflecting and transmitting light of red wavelength and a region for reflecting and transmitting light of blue wavelength is arranged as a colored layer. Each area is arranged so that the emitted light corresponds to each character display portion formed on the liquid crystal panel. When the colored film shown in FIG. 19 is used in the display device of the present embodiment, the reflective display provides black display in the voltage application section and white display in the voltage non-application section. On the other hand, regarding the transmissive display by the light from the light source, in the voltage application section, each character display section displays the color of light emitted from each area of the corresponding colored film, that is, red or blue display, and in the voltage non-application section. It is displayed in black. When the light source shown in FIG. 19 is used to turn on the light source when external light is incident, the voltage application section can see the emitted light from each LED group, and thus each character display section becomes a grayish red or blue display. In the non-voltage-applied portion, the external light reflected by the polarization separator is visible, so that it is grayed out. In FIG. 19, a colored film that transmits or reflects light of a red wavelength and a colored film that reflects or transmits light of a blue wavelength are used. Of course, a colored film that reflects or transmits light of wavelengths other than these colors is used. However, the combination may be appropriately selected.

(Seventh Embodiment) FIG. 20 is a sectional view of a display device according to a seventh embodiment of the present invention.
1 is a schematic sectional view for explaining a display principle of a display device according to a seventh embodiment of the present invention.

This display device 2000 can perform a reflection type display utilizing the reflection of outside light in a place where there is outside light, and a transmission type display using the light from the light source even in a place where there is no outside light. It is a reflection type display device capable of displaying and having a so-called semi-transmissive function.

<Basic Structure> First, the structure of the display device of the present embodiment will be described with reference to FIG. This display device 20
In 00, the TN liquid crystal panel 10 is used as a transmission polarization axis variable optical element. In the TN liquid crystal panel 10, a TN liquid crystal is sandwiched between two glass plates, and a plurality of character display portions 201 and 202 are provided so that character display can be performed. A polarizing plate 14 is provided on the upper side of the TN liquid crystal panel 10. Below the TN liquid crystal panel 10, a light scatterer 15 and a polarization separator 1 are provided.
6, a light absorber 200 in a gray semi-transmissive state, a colored film 160 as a colored layer, and a light source 17 are provided in this order. Further, a TAB substrate (not shown) on which a driver IC for driving the TN liquid crystal is mounted is frozen in the TN liquid crystal panel 10 to form a display device.

<Polarization Separator> In this embodiment, the same one as described in the first embodiment with reference to FIGS. 3 and 4 is used. The detailed description is omitted here. Of course, in addition to this polarization separator, for example, a cholesteric liquid crystal layer sandwiched between λ / 4 plates, utilizing the Brewster's angle (SID 92DIGEST pages 427 to 429), using holograms, etc. Has a function similar to that of the above-described polarization separator, and may be used for the display device of this embodiment.

<Principle of Display> Next, with reference to FIG. 21, the display on the display device 2000 will be described with the right half of the display device 2000 as the voltage applying part and the left half of the display device 2000 as the non-voltage applying part.

First, a reflection type display when external light enters the display device 2000 will be described.

In the non-voltage-applied portion on the left side, when external light is incident on the display device 2000, the external light is linearly polarized in the direction parallel to the paper surface by the polarizing plate 14, and thereafter,
The polarization direction is twisted by 90 ° by the TN liquid crystal 13 to become linearly polarized light in the direction perpendicular to the paper surface, and the linearly polarized light in the direction perpendicular to the paper surface is reflected by the polarization separator 16 as it is.
Thus, the polarization direction is twisted by 90 ° to become linearly polarized light in the direction parallel to the paper surface, and is emitted from the polarizing plate 14 as linearly polarized light in the direction parallel to the paper surface. As described above, when no voltage is applied, the incident external light is reflected by the polarization separator 16 rather than being absorbed, so that a bright reflection type display can be obtained. Since the light scatterer 15 is provided between the polarization separator 16 and the TN liquid crystal panel 10, the polarization separator 1
The reflected light from 6 changes from specular to white.

In the voltage applying section on the right side, when external light is incident on the display device 2000, the external light becomes linearly polarized light in a direction parallel to the paper surface by the polarizing plate 14, and then T
Polarization separator 1 that transmits N liquid crystal 13 without changing the polarization direction
6 also transmits without changing the polarization direction, and then is absorbed by the light absorber 200 in the semi-transmissive state, resulting in a dark display.

As described above, regarding the reflection type display when the external light is incident on the display device 2000, the light reflected by the polarization separator 16 is applied to the light scatterer 1 in the voltage non-applied section.
5, a bright display is obtained, and in the voltage application section, the light transmitted through the polarization separator 16 is in the semi-transmissive state of the light absorber 160.
Is absorbed by and becomes a dark display.

When no voltage is applied, the external light incident on the display device 2000 is reflected by the polarization separator 16 without being absorbed, so that a bright display can be obtained.

Next, a transmissive display using light from the light source 17 will be described.

In the left non-voltage application section, the light source 17
The light from passes through the light absorber 160 in the semi-transmissive state, passes through the coloring film and is incident on the polarized light separator 16 while being colored, and becomes linearly polarized light in the direction parallel to the paper surface by the polarized light separator 16, and thereafter, The polarization direction is 9 by the TN liquid crystal 13.
It is twisted by 0 ° to become linearly polarized light in a direction perpendicular to the paper surface, and is absorbed by the polarizing plate 14 to provide a dark display.

In the voltage applying section on the right side, the light from the light source 17 is transmitted through the light absorber 160 in the semi-transmissive state and is incident on the polarization separator 16 while being colored by the coloring film. Becomes linearly polarized light in a direction parallel to, becomes scattered light by the light scatterer 15, then passes through the TN liquid crystal 13 without changing the polarization direction, and also passes through the polarizing plate 14 to provide a bright display.

As described above, in the transmissive display by the light from the light source 17, the light from the light source 17 is absorbed by the polarizing plate 14 in the voltage non-applied section and becomes a dark display, and the polarized light is displayed in the voltage application section. A bright display is obtained through the plate 14.

Therefore, the display device 2000 can perform a bright reflection type display utilizing the reflection of external light in a place where there is external light, and the light from the light source 17 can be used even in a place where there is no external light. A reflective display device having a so-called semi-transmissive function capable of displaying a transmissive display is provided.

<Light Absorber> The light absorber 200 according to the present embodiment is the same as the one used in the second embodiment, that is, a black absorber, in addition to the light absorber in the semi-transmissive state. A light absorber provided with an opening can also be used. And, similarly to the second embodiment, a reduction in contrast can be suppressed by limiting the ratio of the opening to the light absorber. Of course, similarly to the second embodiment, it is possible to use a polarization separator 16 and a polarizing plate whose absorption axis is shifted.

<Coloring Layer> In the display device of this embodiment, various coloring films described in FIGS. 18 and 19 and the sixth embodiment can be used as the coloring layer. Since the operation and effect are the same as those of the sixth embodiment, the description thereof will be omitted here.

(Eighth Embodiment) FIG. 22 is a sectional view of a display device according to an eighth embodiment of the present invention.
FIG. 3 is a schematic sectional view for explaining the display principle of the display device according to the eighth embodiment of the present invention.

This display device 2200 is capable of displaying a reflection type display utilizing the reflection of external light in a place where there is external light, and a transmission type display using the light from the light source even in a place where there is no external light. It is a reflection type display device capable of displaying and having a so-called semi-transmissive function.

<Basic Structure> First, the structure of the display device of the present embodiment will be described with reference to FIG. This display device 2
In the 200, TN is used as a variable transmission polarization axis optical element.
The liquid crystal panel 10 is used. In the TN liquid crystal panel 10, a TN liquid crystal is sandwiched between two glass plates, and a plurality of character display portions 201 and 202 are provided so that characters can be displayed. A polarizing plate 14 is provided on the upper side of the TN liquid crystal panel 10. Below the TN element panel 10, a polarization separator 16, a colored film 160 as a colored layer, a reflector 220 having an opening, and a light source 17 are provided in this order. The reflector 22
In 0, a plurality of openings 221 are provided with a predetermined area density. Further, a TAB substrate (not shown) on which a driver IC for driving the TN liquid crystal is mounted is connected to the TN liquid crystal panel 10 to form a display device.

<Polarization Separator> In this embodiment, the same one as described in the first embodiment with reference to FIGS. 3 and 4 is used. The detailed description is omitted here. Of course, in addition to this polarization separator, for example, a cholesteric liquid crystal layer sandwiched between λ / 4 plates, one that uses the Brewster's angle (SID 92DIGEST pages 427 to 429), one that uses a hologram, etc. Has a function similar to that of the above-described polarization separator, and may be used for the display device of this embodiment.

<Principle of Display> Next, with reference to FIG. 23, the display by the display device 2200 will be described with the right half of the display device 2200 as the voltage applying portion and the left half as the voltage non-applying portion.

First, a reflective display when external light enters the display device 2200 will be described.

In the non-voltage-applied section on the left side, when external light is incident on the display device 2200, the external light is converted into linearly polarized light in a direction parallel to the paper surface by the polarizing plate 14, and thereafter,
The TN liquid crystal 13 has a polarization direction of 90 ° and becomes a linearly polarized light in a direction perpendicular to the paper surface. The polarization separator 16 reflects the linearly polarized light in a direction perpendicular to the paper surface, and the TN liquid crystal 13
Thus, the polarization direction is twisted by 90 ° to become linearly polarized light in the direction parallel to the paper surface, and is emitted from the polarizing plate 14 as linearly polarized light in the direction parallel to the paper surface. As described above, when no voltage is applied, the incident external light is reflected by the polarization separator 16 rather than being absorbed, so that a bright reflection type display can be obtained.

In the voltage application section on the right side, when external light is incident on the display device 2200, the external light is converted into linearly polarized light in a direction parallel to the paper surface by the polarizing plate 14, and then T
Polarization separator 1 that transmits N liquid crystal 13 without changing the polarization direction
6 also transmits without changing the polarization direction, part of which is colored layer 1
The TN liquid crystal 140 is reflected by 60, passes through the polarization separator 160 again, and remains linearly polarized in a direction parallel to the paper surface.
Is transmitted without changing the polarization direction and is emitted from the polarizing plate 14 as linearly polarized light in a direction parallel to the paper surface. A part of the light emitted from the polarization separator 16 is absorbed by the colored layer 160, transmitted through the colored layer 160, reflected by the reflection plate 220, and then absorbed again by the colored layer 160 to pass through the colored layer 160. The TN liquid crystal 13 is transmitted and is transmitted through the polarization separator 16 again to be linearly polarized light in a direction parallel to the paper surface.
Is transmitted without changing the polarization direction, and is emitted from the polarizing plate 14 as linearly polarized light in a direction parallel to the plane of the drawing, and color display is performed.

Next, a transmissive display by light from the light source 17 will be described.

In the left non-voltage application section, the light source 17
From the light enters the polarization separator 16 while being colored by the coloring film through the opening 221 provided in the reflection plate 220, and becomes the linearly polarized light in the direction parallel to the paper surface by the polarization separator 16, and then the TN liquid crystal. 13 causes the polarization direction to be 9
It is twisted by 0 ° to become linearly polarized light in a direction perpendicular to the paper surface, and is absorbed by the polarizing plate 14 to provide a dark display.

In the voltage application section on the right side, the light from the light source 17 passes through the opening 221 provided in the reflection plate 200, is incident on the polarization separator 16 while being colored by the coloring layer 160, and is then polarized. Then, linearly polarized light in a direction parallel to the paper surface is obtained, and thereafter, the TN liquid crystal 13 is transmitted without changing the polarization direction, and the polarizing plate 14 is also transmitted to provide a colored bright display.

As described above, in the transmissive display by the light from the light source 17, the light from the light source 17 is absorbed by the polarizing plate 14 in the voltage non-applied portion and becomes a dark display, and in the voltage applied portion, it is polarized. A bright display is obtained through the plate 14.

Therefore, the display device 2200 can perform a bright reflection type display utilizing the reflection of external light in a place where there is external light, and the light from the light source 17 can be used even in a place where there is no external light. A reflective display device having a so-called semi-transmissive function capable of displaying a transmissive display is provided.

<Reflector> An Al reflector or the like can be used in the display device of the present embodiment. Further, a half mirror or the like may be used instead of the reflection plate provided with the opening.

<Coloring Layer> For the display device of this embodiment, the various coloring films described in FIGS. 18, 19 and the sixth embodiment can be used. Action
Since the effect is the same as that of the sixth embodiment, the description is omitted here.

(Ninth Embodiment) FIG. 25 is a perspective view of a mobile phone using the display device introduced in the first to eighth embodiments of the present invention as its display section.
In the figure, (a) shows a mobile phone and (b) shows a wristwatch.

In the present embodiment, a mobile phone and a wrist watch are shown, but the display device of the present invention can be used in various electronic devices such as a personal computer, car navigation, and electronic notebook.

In the first to ninth embodiments, only the dark display, the bright display and the color display have been described, but it is natural that the display device of each embodiment can perform the halftone display. That is.

Further, in the first to ninth embodiments, the TN liquid crystal panel 10 has been described as an example of the transmission polarization axis varying means, but an STN liquid crystal element, an ECB liquid crystal element or the like can also be used. Then, as the STN liquid crystal element, an STN liquid crystal element using an optical anisotropic body for color compensation such as an F-STN liquid crystal element is preferably used.

In the first to ninth embodiments, it is preferable to reduce the amount of light reflected by the light source and returning again by increasing the distance between the polarization separator and the light source. It is possible to suppress deterioration of contrast.

Further, in the above second to fifth and seventh to eighth embodiments, the light transmitted through the light absorber is also increased by increasing the distance between the light absorber or the scattering plate and the light source. The amount of light reflected by the light source and returning to the light source can be reduced, and a reduction in contrast can be suppressed.

In the first to eighth embodiments, the surface color of the light source is darkened to suppress the reflection on the surface of the light source, and as a result, the light transmitted through the light absorber is the light source. It is possible to reduce the amount of light reflected by and returned again, and it is possible to suppress deterioration of contrast.

In the second to fifth and seventh embodiments, the bright display by the light reflected by the polarization separator side is the display by the light reflected by the polarization separator side. It is not affected by the structure of the light absorber arranged behind this polarization separator.

The display devices shown in the first to fifth embodiments may further include means for condensing the light from the light source toward the front of the display device.

Normally, when a reflection type display by external light is viewed, the display is performed at a position inclined by a certain angle from the normal line to the front of the display device. This is because, when viewed from the direction normal to the front surface of the display device, the observer himself interferes with the external light incident on the display device, and the reflective display due to the external light becomes dark. On the other hand, when viewing the display by the transmitted light from the light source, since it is usually viewed from the direction normal to the front of the display device, a means for condensing the light from the light source toward the front of the display device is used. The provision makes it possible to brighten the display by the transmitted light from the light source, and as a result, the transmissive display by the light from the light source becomes easy to be seen in the direction normal to the front of the display device. A prism sheet, for example, is preferably used as a means for condensing the light from the light source toward the front of the display device. Regarding the position where this prism sheet is arranged, it is advisable to provide a light source and a polarization separator in the first to fifth embodiments, and as shown in FIG. 24 in the sixth to eighth embodiments. It is preferably provided between the light source and the colored film.

In the display device of the present invention, with respect to the light incident from the outside of the first polarized light separating means, the second polarized light separating means according to the state of the transmitting polarization axis of the transmitting polarization axis varying means. Two display states are obtained, a first display state due to light reflected from the second display state and a second display state in which light transmitted through the second polarization splitting means is absorbed by the optical element, It becomes a reflective display device. Then, the first display state is a display state due to the light reflected from the second polarization splitting means, and thus becomes a bright display.

With respect to the light from the light source, depending on the state of the transmission polarization axis of the transmission polarization axis changing means, the third display state and the first display state by the light transmitted through the first polarization separating means are set.
Two display states, that is, a fourth display state in which light does not pass through the polarized light separating means, can be obtained, and a transmissive display can be obtained.

As described above, in the display device of the present invention, bright reflection type display utilizing reflection of external light can be performed in a place where external light is present, and also in a place without external light, A transmissive display by the light from the light source can be performed.

Then, the second polarized light separating means is adapted to form a straight line in the third predetermined direction out of the light incident from the transmission polarization axis varying means side with respect to the light in substantially the entire wavelength range of the visible light region. The polarization component is transmitted to the optical element side, and the third
The linearly polarized light component of the fourth predetermined direction orthogonal to the predetermined direction of is reflected to the transmission polarization axis variable means side, and is light in substantially the entire wavelength range of the visible light region and is incident from the optical element side. The third portion on the side of the transmission polarization axis changing means for light
By using a polarization separation means capable of emitting linearly polarized light in a predetermined direction, the first to fourth display states are obtained for light in the entire wavelength range of the visible light region, and the first and the fourth A transparent or bright display can be obtained in the third display state.

Further, the optical element is an optical element that absorbs light in almost the entire wavelength range of the visible light region, and in particular, a black light absorber is used, so that a dark display is obtained in the second and fourth display states. Obtainable.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a display device according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view for explaining the display principle of the display device according to the first embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a polarization separator 16 used in this embodiment.

FIG. 4 is a diagram for explaining the operation of the polarization separator 16 shown in FIG.

FIG. 5 is a diagram showing an example of a light source used in the present invention.

FIG. 6 is a diagram showing another example of a light source used in the present invention.

FIG. 7 is a diagram showing another example of a light source used in the present invention.

FIG. 8 is a diagram showing another example of a light source used in the present invention.

FIG. 9 is a diagram showing another example of a light source used in the present invention.

FIG. 10 is a sectional view of a display device according to a second embodiment of the present invention.

FIG. 11 is a schematic cross-sectional view for explaining the display principle of the display device according to the second embodiment of the present invention.

FIG. 12 is a schematic sectional view for explaining a display device according to a third embodiment of the present invention.

FIG. 13 is a schematic cross-sectional view for explaining the display device according to the fourth embodiment of the present invention.

FIG. 14 is a sectional view of a display device according to a fifth embodiment of the present invention.

FIG. 15 is a schematic cross-sectional view for explaining the display principle of the display device according to the first embodiment of the present invention.

FIG. 16 is a sectional view of a display device according to a sixth embodiment of the present invention.

FIG. 17 is a schematic cross-sectional view for explaining the display principle of the display device according to the sixth embodiment of the present invention.

FIG. 18 is a diagram showing an example of a colored layer used in the present invention.

FIG. 19 is a diagram showing another example of a colored layer used in the present invention.

FIG. 20 is a sectional view of a display device according to a seventh embodiment of the present invention.

FIG. 21 is a schematic cross-sectional view for explaining the display principle of the display device according to the seventh embodiment of the present invention.

FIG. 22 is a sectional view of a display device according to an eighth embodiment of the present invention.

FIG. 23 is a schematic cross-sectional view for explaining the display principle of the display device according to the eighth embodiment of the present invention.

FIG. 24 is a diagram showing an example in which a prism sheet is combined with the display device of the present invention.

FIG. 25 is a diagram showing an example of an electronic device including the display device of the present invention as a display unit.

FIG. 26 is a diagram showing an example of a conventional display device.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/1335

Claims (5)

(57) [Claims] 1. A display device comprising: a transmission polarization axis varying means for varying a transmission polarization axis; first and second polarization separating means arranged so as to sandwich the transmission polarization axis varying means; and the second polarization. The light source, which is disposed on the side opposite to the transmission polarization axis varying means with respect to the separating means, emits colored light, and is provided between the second polarization separating means and the light source,
The first polarization splitting means, the transmission polarization axis varying means, and
And the light transmitted through the second polarized light separating means,
And a light scatterer that changes the polarization state of the light and emits the light, wherein the first polarization separation unit transmits the light of the linearly polarized component in the first direction, and the second direction different from the first direction. The second polarized light separating means transmits the light of the linearly polarized light component of the third direction and transmits the light of the linearly polarized light component of the fourth direction different from the third direction. A display device characterized by reflection. 2. In a display device, a liquid crystal panel in which liquid crystal is sandwiched between a pair of substrates, a polarizing plate arranged on one side of the liquid crystal panel, and a liquid crystal panel on the side opposite to the polarizing plate. a polarization separator disposed were, and said light source located on the opposite side of the liquid crystal panel with respect to said polarized light separator is provided between the light source and the polarized light separator, the polarization
Light transmitted through the plate, the liquid crystal panel and the polarization separator
And a light scatterer that changes the polarization state of the light and emits the light, wherein the polarizing plate transmits light of a linearly polarized component in the first direction,
The polarization separator does not transmit the light of the linearly polarized light component in the second direction different from the first direction, the polarization separator transmits the light of the linearly polarized light component in the third direction, and the fourth direction different from the third direction. A display device characterized in that it reflects the light of the linearly polarized light component. 3. The display device according to claim 2, wherein the liquid crystal panel is a TN liquid crystal element, an STN liquid crystal element, an FN liquid crystal element.
-A display device including either an STN liquid crystal element or an ECB liquid crystal element. 4. The display device according to claim 1 or 2.
And the first direction and the third direction are parallel to each other.
And display device. 5. An electronic device comprising the display device according to claim 1 as a display unit.