JPH1144884A - Display device and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize light transmitted through a reflection type polarized light separating device by converting light passing through the 2nd polarized light separating device into electric power by a photoelectric conversion element and using it as electric energy related to the display device. SOLUTION: The light passing through the 2nd polarized light separating device 103 is converted into the electric power by the photoelectric conversion element 104a so as to be used as the electric energy related to the display device. In a semi-transmission and reflection type display device, the optical element 104 is constituted of the photoelectric conversion element 104a, and a light source 104b is provided between the elements 104a. By such constitution; in the case of performing display as a reflection type display device, power generation is realized from external light by the element 104a, and if the light source is turned on, it is possible to perform the display as a transmission type display device. The light from the light source 104b includes not only the light going upward but also light going downward to no small extent, shown in figure, but the light going downward is absorbed by the element 104a so as to be reduced to electricity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal device, and more particularly to a transflective liquid crystal display device. Further, the present invention relates to a liquid crystal display device and an electronic device using the same.

[0002]

BACKGROUND ART Conventional TN (Twisted Nematic) liquid crystal and ST
In a display device using a variable transmission polarization axis optical element such as an N (Super-Twisted Nematic) liquid crystal, the polarization axis of which is variable,
Since the structure in which the variable transmission polarization axis optical element is sandwiched between two polarizing plates is employed, light use efficiency is low. In particular, a reflective plate such as aluminum is placed outside one of the polarizing plates to reflect light. When using a type display device, the display becomes dark, which is problematic.

[0003] Among the light transmitted through a polarizing plate having a reflector (hereinafter referred to as a back surface and the opposite side is referred to as a front surface), light having a transmission axis direction component of the polarizing plate is included. Light is absorbed at the time of transmission, and the reflectance is 10
The light is reflected by a reflection plate made of aluminum or the like which is not 0%, and becomes dark because light is absorbed by the polarizing plate again.

Further, instead of a reflector made of aluminum or the like, a semi-transmissive reflector that transmits light to some extent and reflects light to some extent is used. The reflectance of the reflector becomes worse,
When viewed as a reflection type liquid crystal display device using external light from the front with the light source turned off, the display becomes darker. Also, when viewed as a transmissive display device with the light source attached, the light of the light source is absorbed by the semi-transmissive reflection plate, so that the display is also dark.

In order to solve this problem, of the incident light, only light having a polarization component in a predetermined direction is transmitted as linearly polarized light instead of the rear polarizing plate and the reflecting plate or the semi-transmissive reflecting plate. There is a method using a polarization separator that reflects light of a polarization component in a direction orthogonal to the direction. Examples of such a polarization separator include a polarization separator combining a (1/4) wavelength plate and a cholesteric liquid crystal layer, and an internationally published international application (international application numbers: WO95 / 27819 and WO95 / 17).
692).

The use of such a light separator eliminates unnecessary light absorbing members, and provides a bright display. Further, since a transflective plate is not required, the brightness of the light source is not attenuated, and the display becomes brighter when displayed as a transmissive display device.

[0007]

However, in such a configuration, the light transmitted through the polarization splitter is not utilized at all, and the energy of the light cannot be used effectively.

[0008] The present invention has been made in view of such a problem.

That is, an object of the present invention is to provide a transflective display device which displays as a reflective display device under bright external light and displays as a transmissive display device using a light source provided on the back in a dark place. It is intended to make effective use of light transmitted through a reflection type polarization splitter.

[0010]

According to a first aspect of the present invention, there is provided a display apparatus according to the present invention, wherein a transmission polarization axis variable means having a variable transmission axis and a first polarization separation means arranged on one side of the transmission polarization axis variable means. Means and a second polarized light separating means disposed on the other side of the variable transmission polarization axis means, and a first optical element disposed on the side opposite to the variable transmission polarization axis means with respect to the second polarization separating means. A display device comprising an element, wherein the first polarized light separating means has a first predetermined direction among light incident on the transmitted polarized light axis changing means from a side opposite to the second polarized light separating means. The linearly polarized light component is transmitted as linearly polarized light to the transmission polarization axis variable means side, and the first predetermined direction of the light incident on the transmission polarization axis variable means from the side opposite to the second polarization separation means. A linearly polarized light component in a second predetermined direction orthogonal to Does not transmit the over-polarization axis changing means side,
The linearly polarized light component in the first predetermined direction of the light incident from the second polarized light separating means side to the transmitted polarized light axis changing means is transmitted as linearly polarized light to the opposite side to the second polarized light separating means. A polarization separation unit that does not transmit the second predetermined linearly polarized light component of the light incident on the transmission polarization axis changing unit from the second polarization separation unit side to the side opposite to the second polarization separation unit. Means, wherein the second polarized light separating means transmits a linearly polarized light component in a third predetermined direction to the first optical element side, of the light incident from the transmitted polarization axis variable means side, The linearly polarized light component in a fourth predetermined direction orthogonal to the third predetermined direction is reflected toward the transmission polarization axis varying unit, and the fourth predetermined light component of the light incident from the first optical element side is reflected. Does not transmit the polarized light component in the direction of
Polarization splitting means capable of emitting linearly polarized light in the third predetermined direction to the transmitted polarization axis changing means side with respect to light incident from the first optical element side, wherein the first optical element comprises: At least a part of the first optical element is a photoelectric conversion element, and at least a part of the remaining first optical element is a first light source.

With this configuration, the light that has passed through the second polarization separator is converted into electric power by the photoelectric conversion element, and can be used as electric energy related to the display device, and the light is effectively used. .

According to a second aspect of the present invention, in the display device, the transmission polarization axis is variable with respect to the transmission polarization axis changing means, the first polarization separation means, the second polarization separation means, and the second polarization separation means. A second optical element located on the opposite side of the means;
A display device comprising a second light source disposed between the second polarization splitting means and the second optical element, wherein the second optical element has at least a part of the optical element. It is a photoelectric conversion element.

With this configuration, the area of the photoelectric conversion element can be made larger, and the light passing through the second polarization separator is converted into more electric power by the photoelectric conversion element, so that the light is used more effectively. You.

According to a third aspect of the present invention, in the display device of the first or second aspect, the transmission polarization axis changing means is a liquid crystal element.

In this way, it is possible to obtain an inexpensive transmission polarization axis changing means which is easy to control.

According to a fourth aspect of the present invention, in the display device of the third aspect, the transmission polarization axis changing means is a TN liquid crystal element, an STN liquid crystal element, an F-STN liquid crystal element, or an ECB.
It is a liquid crystal element.

In this way, more favorable response speed and contrast can be obtained.

The display device according to the fifth aspect is the display device according to the first or second aspect.
The display device according to any one of the preceding claims, wherein the first polarized light separating means is a polarizing plate.

In this way, it is possible to obtain polarized light separating means which is easy to manufacture.

According to a sixth aspect of the present invention, in the display device according to any one of the first to fifth aspects, the state of the transmission polarization axis changing means when not driven is the first polarization state changing means relative to the transmission polarization axis changing means. In which the linearly polarized light component in the first predetermined direction is substantially changed into the linearly polarized light component in the third predetermined direction, of the light incident from the side of the polarized light separating means, and emitted to the first optical element side. It is characterized by being.

According to this configuration, the light reaches the photoelectric conversion element even when it is not driven, and it is possible to generate electricity.

According to a seventh aspect of the present invention, there is provided a display device including the display device according to the first to sixth aspects, wherein the power generated by the photoelectric conversion element is reduced by the power of the display device. It is characterized in that it is used at least as a part.

With this configuration, at least a part of the electric energy required by the display device can be covered by the power generated by the photoelectric conversion element, and the power supplied from outside the display device can be reduced.

According to an eighth aspect of the present invention, there is provided an electronic apparatus including the display device according to the seventh aspect, wherein the power generated by the photoelectric conversion element is used as at least a part of the power of the electronic apparatus. It is characterized by the following.

With this configuration, at least a part of the electric energy required by the electronic device can be covered by the electric power generated by the photoelectric conversion element, and the electric power supplied from another battery or the outside of the electronic device can be reduced. As a result, the display portion of the electronic device is bright, high in contrast, high-quality image quality is obtained, and the quality of the electronic device is improved. With this,
Since power consumption can be reduced, battery life is prolonged, particularly in battery-powered electronic devices.

[0026]

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

[Embodiment 1] FIG. 1 is a schematic sectional view of a display device according to this embodiment, and particularly relates to a reflection type display device.

In the figure, reference numeral 100 denotes a display device according to the present embodiment.

Reference numeral 101 denotes a polarization separator, which only needs to have optical characteristics of transmitting linearly polarized light in a certain direction and absorbing linearly polarized light in a direction orthogonal to this direction. For example, a structure in which fine conductors are finely arranged in parallel (patterning) on a transparent member may be used. However, in the present embodiment, a polarizing plate is used as a preferable example because of ease of manufacturing.

The polarization splitter 101 does not transmit linearly polarized light in a direction perpendicular to the plane of the paper, but transmits linearly polarized light in a direction parallel to the paper, and is arranged as such.

Reference numeral 102 denotes a variable transmission polarization axis optical element, and in this embodiment, a TN liquid crystal element is used. Here, the variable transmission polarization axis optical element 102 includes a pair of substrates 102a and 10a.
2b has a structure that sandwiches the liquid crystal layers 102c and 102d. The left liquid crystal layer 102c shows a state in which no voltage is applied to the liquid crystal layer 102c, and emits light by twisting the direction of the incident linearly polarized light by about 90 °, and the right liquid crystal layer 102d applies a voltage thereto. In this state, the linearly polarized light is emitted with almost no twist.

Reference numeral 103 denotes a polarization separator, which in this embodiment is an international application published internationally (international application number: WO95 / 2).
7819 and WO95 / 17692). This polarized light separator 102 has a function of (1 /
4) A film in which a wave plate and a cholesteric liquid crystal layer are combined, and a multilayer film is laminated (USP 4,974,21).
9) Separation into reflected polarized light and transmitted polarized light by using the angle of Brewster (SID92 DIGEST No. 4
27 to 429), and a hologram may be used. In this case, the polarization separator 103 reflects linearly polarized light in a direction perpendicular to the paper surface and transmits linearly polarized light in a parallel direction, and is arranged as such.

Reference numeral 104 denotes an optical element, and reference numeral 104a denotes a photoelectric conversion element which generates electricity when irradiated with light, such as a so-called solar cell. A light source 104b is indicated by a plurality of semicircular symbols. In the figure, the photoelectric conversion element 104a
Are provided at some places between the two, but if the size of the display device is small, the light source 104b may be one. Further, in this embodiment, as the light source, an LED (light emitting diode) having a small size (area) of each light source itself is used as a preferable example, but other incandescent lamps, cold cathode tubes,
A hot cathode tube, EL, or the like may be used.

Reference numeral 104c denotes a diffusion plate for making the light from the light source 104b uniform. Therefore, the type of the light source 104b,
It may be omitted depending on the arrangement and the like.

The display device 100 has the above configuration.

In the case where the light source 104b of the display device 100 is displayed as a reflective display device without being turned on, 105a is a liquid crystal layer 102 on the left side of the display device 100.
The optical path of external light (light from above in the figure) at c (portion where voltage is not applied) is shown, and 106a is the right liquid crystal layer 102d of the display device 100 (portion where voltage is applied). 4 illustrates an optical path of extra-picture light. Symbols with arrows on the left and right on the optical path indicate linearly polarized light parallel to the paper surface, and symbols with x superimposed thereon indicate linearly polarized light perpendicular to the paper surface.

Here, the optical path 105a will be described first.

The external light is converted by the polarization separator 101 into linearly polarized light parallel to the paper surface.

Then, the polarization direction is twisted by about 90 ° by the liquid crystal layer 102c, and becomes a linearly polarized light perpendicular to the paper surface.

Then, since the light is linearly polarized light perpendicular to the plane of the paper, it is reflected by the polarization splitter 103.

The reflected light is again twisted by about 90 ° by the liquid crystal layer 102c to become linearly polarized light parallel to the plane of the drawing.

Then, since the light is linearly polarized light parallel to the plane of the paper, it passes through the polarization separator 101.

As described above, since the external light is reflected and returned, it becomes bright. That is, white display is performed.

Next, the optical path 106a will be described.

The external light is converted by the polarization separator 101 into linearly polarized light parallel to the paper surface.

Then, the polarization direction is hardly twisted by the liquid crystal layer 102d, and remains linearly polarized light parallel to the plane of the drawing.

Then, since the light is linearly polarized light parallel to the paper, the light passes through the polarization separator 103.

Then, the photoelectric conversion element 1 of the optical element 104
04a absorbs this light.

As described above, the external light does not return and darkens. That is, black display is performed.

At this time, light is absorbed by the photoelectric conversion element 104a corresponding to the black display portion, and is converted into electric power.

Thus, under external light, power is generated while displaying as a reflective display device.

Next, a case where the light source 104b of the display device 100 is turned on to display the image as a transmission type display device will be described.

FIG. 2 is a diagram showing a schematic cross section and an optical path of the display device 100 of this embodiment.

The structure of the display device 100 is the same as that of FIG.

Reference numeral 105b denotes an optical path of the light emitted from the light source 104b in the left liquid crystal layer 102c of the display device 100;
Reference numeral 106b denotes an optical path in the liquid crystal layer 102d on the right side of the display device 100.

Here, the optical path 105b will be described first.

The light emitted from the light source 104b is
03 makes the light linearly polarized parallel to the paper.

Then, the polarization direction is twisted by about 90 ° by the liquid crystal layer 102c, and becomes a linearly polarized light perpendicular to the paper surface.

Then, since the light is linearly polarized light perpendicular to the plane of the drawing, the light cannot pass through the polarization separator 101.

Accordingly, the light emitted from the light source 104b does not come out upward in the figure, and therefore, a black display is made.

Next, the optical path 106b will be described first.

The light emitted from the light source 104b is
03 makes the light linearly polarized parallel to the paper.

Then, the polarization direction is hardly twisted by the liquid crystal layer 102d, and remains linearly polarized light parallel to the paper surface.

Then, since the light is linearly polarized light parallel to the paper, the light passes through the polarization separator 101.

As described above, the light emitted from the light source 104b comes out upward in the figure and becomes white display.

Therefore, it is possible to perform display as a transmissive display device.

As described above, when the optical element 104 constituting the transflective display device is constituted by the photoelectric exchange device 104a and the light source 104b is provided between the optical device 104a and the display device as a reflective display device, display is performed. Electric exchange element 104
By generating electric power from external light by using a, and by turning on the light source 104b, it is possible to perform display as a transmissive display device.

Here, the light from the light source 104b includes not only upward light in the figure but also downward light, but this light is absorbed by the photoelectric exchange element 104a and reduced to electricity.

Further, when a display is performed as a reflection type display device, the light transmitted through the polarization separator 103 is reflected by the photoelectric exchange element 10.
Since the light is absorbed by the light 4a, the light returns to the polarization separator 103, thereby preventing a reduction in display contrast. Therefore, high-contrast display becomes possible.

In this embodiment, the polarization separator 101 is arranged to transmit linearly polarized light in a direction parallel to the plane of the paper. However, it is arranged to transmit linearly polarized light in a direction perpendicular to the plane of the paper. Is also good. In this case, black is displayed in a portion where no voltage is applied to the liquid crystal layer, and white display is performed in a portion where the voltage is applied. Here, when the case where the display device is not driven is considered, since no voltage is applied to the entire liquid crystal layer, all portions become black. In other words, light is absorbed by the photoelectric exchange element 104a over the entire surface.

As described above, by setting the state of the transmission polarization axis changing means in the non-driving state to the state in which external light reaches the photoelectric conversion element 104a, the state of the photoelectric conversion element 104a in the non-driving state is set. Power generation can be performed most efficiently.

[Embodiment 2] In Embodiment 1, the light source 104b is provided between the photoelectric conversion elements 104a.
The area of the photoelectric conversion element 104a is reduced by the installation area of 4b.

Therefore, the amount of power generation is reduced by the reduced area.

FIG. 3 is a schematic sectional view of this embodiment.

In FIG. 3, 300, 301, 301a, 30
The components other than 2b are the same as those in FIG.
Are not provided, and the area of the photoelectric exchange element 104a is accordingly increased.

In the figure, reference numeral 300 denotes a display device of this embodiment surrounded by a broken line. Reference numeral 301 denotes a light source, which includes 301a and 301b. Here, reference numeral 301a denotes a cold cathode tube or a hot cathode tube, in which the longitudinal direction of the cold cathode tube or the hot cathode tube is perpendicular to the plane of the drawing. A light guide 301b is made of a transparent member such as an acrylic plate, for example, and contains a material or a shape that diffuses light inside or on the surface of the transparent member.

The configuration of the present embodiment is as described above.

Here, when the cold cathode tube or the hot cathode tube is turned on, this light is guided to the light guide 301b, is scattered on the way, and irradiates the front side (upper side in the figure). Here, since only the form of the light source is different from that of the first embodiment, it is possible to perform display as a reflective display and a transmissive display as in the first embodiment. Therefore, a similar effect can be obtained.

The light guide 301b of the light source 301 is a transparent member, which partially scatters light but does not block light. Therefore, a large amount of light irradiates the enlarged photoelectric exchange element 104a. Therefore, more power can be generated than in the first embodiment.

In this embodiment, a cold cathode tube or a hot cathode tube having high luminous efficiency was used as a light source. This is because, in the configuration as in the present embodiment, the size of the cold cathode tube, the hot cathode tube, and the like does not affect the light emitted to the photoelectric exchange element 104a. That is, it is possible to give priority to the luminous efficiency over the outer shape. Therefore, the power of the light source can be reduced.

Of course, depending on other factors, it is also possible to use an LED, an incandescent lamp, an EL or the like.

The display device of the present invention has been described in Examples 1 and 2.

In the first and second embodiments, only the black display and the white display have been described. However, the display devices of these embodiments can perform a halftone display, and the display devices of these embodiments can be replaced with a color display device. Of course it can be applied.

Further, as a transmission polarization axis variable optical element, T
Although the description has been made using the N liquid crystal element, the present invention is not limited to this, and an STN liquid crystal element, an ECB liquid crystal element, or the like can be used. In particular, an STN liquid crystal element can easily obtain a high contrast, and an STN liquid crystal element using an optically anisotropic body for color compensation such as an F-STN liquid crystal element is preferably used. As the variable transmission polarization axis optical element, an inexpensive liquid crystal element that is easy to control is suitable, but is not limited thereto.
If necessary, for example, a ferroelectric porcelain PLZT or the like may be used.

The display device of the present invention has been described with reference to the first and second embodiments.

As in these embodiments, bright display can be achieved by using a polarization separator that reflects linearly polarized light in a predetermined direction and transmits linearly polarized light in a direction orthogonal to the predetermined direction. By appropriately arranging a photoelectric conversion element that absorbs light transmitted by the polarization separator and a light source, power can be generated during display as a reflective display device, and the light source is turned on. Thus, display can be performed as a transmission type display device.

[Embodiment 3] This embodiment relates to a display device of the present invention.

By using the display device described in Embodiments 1 and 2 as a display member as a display member, a bright display device can be provided, and electric power for driving the display device is generated by the display device (photoelectric exchange element). The liquid crystal device can supply a part of the power and can reduce power consumption.

FIG. 4 is a block diagram of the display device of this embodiment.

In FIG. 4, reference numeral 400 denotes a display device according to the present embodiment. Reference numerals 102, 104a, and 301 denote the transmission polarization axis variable element 102 and the photoelectric exchange element 10 in FIG.
4a, a light source 301. In FIG. 4, reference numeral 401 denotes a circuit (hereinafter, referred to as a circuit) that applies a drive waveform to some of a plurality of electrode groups (not shown) formed on the transmission polarization axis variable element 102
X driver. ), And a circuit 402 (hereinafter, referred to as a Y driver) for applying a drive waveform to some of the remaining electrode groups. A control circuit 403 controls the operation of the X driver 401 and the Y driver 402, and controls either lighting or non-lighting of the light source 301 or dimming.

Reference numeral 404 denotes a power supply circuit that includes a power storage member such as a capacitor for storing electricity, a storage battery, and has a structure in which a battery is provided as necessary or power can be supplied from the outside.

The configuration of the display device 400 according to the present embodiment is as described above.

The X driver 401 and the Y driver 40
2, the drive waveform output to the transmission polarization axis variable element 102 varies depending on the specific configuration of the transmission polarization axis variable element 102, and the specific waveform and voltage are not essential contents of the present embodiment. Therefore, this is not shown, and the flow of power is indicated by a line with an arrow.

Here, regardless of whether the display device is driven or not, the photoelectric exchange element 104a stores electricity generated by external light in a power storage member such as a capacitor or a storage battery of the power supply circuit 404.

When there is no external power supply, the X driver 401, the Y driver 402, and the control circuit 4 use the power of the power storage member or a battery provided as necessary.
03 is operated to display the display device.

Further, the light source 301 is turned on as required. That is, the display is made visible in a dark place. Here, the brightness at the time of lighting may be darker than when there is an external power supply.

As described above, the display device can be driven using the electric energy stored in the power storage member such as the capacitor and the storage battery of the power supply circuit 404.

Here, the photoelectric exchange element 104a is an average of the power generated by the external light, in other words, the power supply circuit 404.
If the electric energy stored in the power storage member such as a capacitor or a storage battery is equal to or higher than the power consumed by the display device,
There is no need to provide an additional battery.

As described above, according to the display device of this embodiment, at least a part of the power consumed by the display device is
Energy can be supplied from external light, and power consumption can be reduced.

Further, when the power consumed by the display device is small, there is no need to provide an additional battery or the like, and accordingly, the size and weight can be reduced and the cost can be reduced.

Of course, if the light source is turned on, the display can be viewed even in a dark place.

[Embodiment 4] This embodiment is an embodiment relating to the electronic apparatus of the present invention.

The liquid crystal device described in Embodiment 3 is bright and consumes low power.

Therefore, it is most suitable as a display means for portable information devices such as portable telephones, which are often used under external light such as natural light.

For example, when used as a display unit of a mobile phone, a clear display can be seen under bright external light.

Then, electric power is generated by the photoelectric exchange element provided in the display device to cover the electric power in the display device.

Here, if the amount of power generation exceeds the power consumption of the display unit, the amount of power generation may be stored in the power storage member. In such a case, it is possible to use power for operating other parts of the mobile phone. For example, it can be used as a power supply for an amplifier for audio output of a mobile phone.

Even when displayed as a reflective display device under slightly dim external light, the telephone number message display of the contact can be easily read, and a mistake in making a call can be prevented.

In a completely dark place, it is possible to turn on the light source and display as a transmissive display device.

[0110]

According to the display device of the present invention, the light passing through the second polarization separator is converted into electric power by the photoelectric conversion element and used as electric energy related to the display device. And light is used effectively.

According to the display device of the second aspect, the area of the photoelectric conversion element can be made larger, and the light passing through the second polarization splitter is converted into more electric power by this photoelectric conversion element, and the light is It is used more effectively.

According to the display device of the third aspect, it is possible to obtain an inexpensive transmission polarization axis changing means that is easy to control.

According to the display device of the fourth aspect, more favorable response speed and contrast can be obtained.

According to the display device of the fifth aspect, it is possible to obtain polarization separation means which is easy to manufacture.

According to the display device of the sixth aspect, the light reaches the photoelectric conversion element even when it is not driven, and the light can be generated.

According to the display device of the present invention, at least a part of the electric energy required by the display device can be covered by the electric power generated by the photoelectric conversion element, and supplied from outside the display device. Power consumption can be reduced.

According to the electronic device of the eighth aspect, at least a part of the electric energy required by the electronic device can be covered by the power generated by the photoelectric conversion element, and the power supplied from outside the electronic device can be reduced. As a result, the display portion of the electronic device is bright, high in contrast, high-quality image quality is obtained, and the quality of the electronic device is improved. With this,
Since power consumption can be reduced, battery life is prolonged, particularly in battery-powered electronic devices.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic cross-sectional view and an optical path of a display device 100 according to a first embodiment.

FIG. 2 is a schematic cross-sectional view of the display device 100 according to the first embodiment and a diagram illustrating another optical path.

FIG. 3 is a schematic cross-sectional view of a display device 300 according to a second embodiment.

FIG. 4 is a block diagram of a display device 400 according to a third embodiment.

[Explanation of symbols]

100 The display device of the first embodiment. 101 ··· Polarized light separator, polarizing plate. 102 ... Transmission polarization axis variable optical element (TN liquid crystal element). 102a ... board. 102b ... board. 102c ··· liquid crystal layer (state where voltage is not applied) 102d ··· liquid crystal layer (state where voltage is applied) 103 ··· polarization separator. 104 ··· Optical element. 104a ... photoelectric conversion element. 104b ... light source (LED). 104c ··· Diffusion plate 105a ··· The optical path in the liquid crystal layer 102c (portion where no voltage is applied). 106a: liquid crystal layer 101d (portion to which voltage is applied)
Light path in the sea.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroshi Ozawa 3-3-5 Yamato, Suwa-shi, Nagano Prefecture Seiko Epson Corporation

Claims (8)

[Claims] 1. A transmission polarization axis variable means having a variable transmission axis, a first polarization separation means disposed on one side of the transmission polarization axis variable means, and a second polarization separation means disposed on the other side of the transmission polarization axis variable means. A second polarized light separating means and a first polarized light separating means disposed on the opposite side of the transmission polarized light axis varying means with respect to the second polarized light separating means.
A display device comprising the optical element of (1), wherein the first polarization splitting means is configured to control the transmission polarization axis changing means by the second polarization splitting means.
The linearly polarized light component in the first predetermined direction of the light incident from the side opposite to the polarized light separating means is transmitted as linearly polarized light to the transmitted polarized light axis changing means side, and the second polarized light is transmitted to the transmitted polarized light axis changing means. Out of the light incident from the opposite side to the polarized light separating means, a linearly polarized light component in a second predetermined direction orthogonal to the first predetermined direction is not transmitted to the transmission polarized light axis changing means side; The linearly polarized light component in the first predetermined direction out of the light incident on the variable means from the second polarization separation means side is transmitted as linearly polarized light to the opposite side to the second polarization separation means, and the transmission is performed. A polarization separating unit that does not transmit the second predetermined linearly polarized light component of the light incident on the polarization axis changing unit from the second polarization separating unit side to the side opposite to the second polarization separating unit. , The second polarization separation means, A linearly polarized light component in a third predetermined direction of the light incident from the transmission polarization axis changing unit is transmitted to the first optical element, and a fourth predetermined direction orthogonal to the third predetermined direction is transmitted. Is reflected toward the transmission polarization axis changing unit, and does not transmit the polarization component in the third predetermined direction out of the light incident from the first optical element, and A polarization splitting unit that emits linearly polarized light in the fourth predetermined direction to the transmission polarization axis changing unit with respect to light incident from the optical element side, wherein the first optical element includes the first optical element; A display device, wherein at least a part of the optical element is a photoelectric conversion element, and at least a part of the remaining first optical element is a first light source. 2. The transmission polarization axis varying means, the first polarization separation means, the second polarization separation means, and the second polarization separation means are disposed on the side opposite to the transmission polarization axis variation means. A second optical element, and a second light source disposed between the second polarization splitting means and the second optical element, wherein the second optical element comprises: A display device, wherein at least a part of an optical element is the photoelectric conversion element. 3. The display device according to claim 1, wherein said transmission polarization axis changing means is a liquid crystal element. 4. The display device according to claim 3, wherein said transmission polarization axis changing means comprises a TN liquid crystal element, an STN liquid crystal element,
-A display device characterized by being an STN liquid crystal element or an ECB liquid crystal element. 5. The display device according to claim 1, wherein said first polarization splitting means is a polarizing plate. 6. The display device according to claim 1, wherein the state of said variable transmission polarization axis means when not driven is incident on said variable transmission polarization axis means from said first polarization separation means side. The linearly polarized light component in the first predetermined direction is substantially changed to the linearly polarized light component in the third predetermined direction, and the light is emitted toward the first optical element. Display device. 7. A display device comprising the display device according to claim 1, wherein the power generated by the photoelectric conversion element is used as at least a part of the power of the display device. Display device. 8. An electronic device comprising the display device according to claim 7, wherein the power generated by the photoelectric conversion element is used as at least a part of the power of the electronic device. .