JP2001184033A - Display device and display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information display device arranged so that it uses a liquid crystal display element with memory property not requiring electric power for maintaining a display while power is necessary for changing the display; generates the power for changing over the display of the liquid crystal display element by a photo-generator (a solar cell); also charges a storage battery with the electricity generated by the solar cell; and uses the power for changing over the display of the liquid crystal display element as necessary. SOLUTION: The information display device 1 comprises a liquid crystal display element 2 with memory property, a photo-generator 26 for converting light energy into electric energy, a storage battery 27 for storing the electricity generated by the photo-generator, a display information receiver 21, and a control part 24 for supplying electricity to the liquid crystal display element 2 from the storage battery 27 based on the display information received by the display information receiver 21 and for changing the display of the liquid crystal display element 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a display device provided with a display element having a memory function, an information display device including the display device, and a display system.

[0002]

2. Description of the Related Art
Various information display devices using a liquid crystal display element have been provided. However, generally used liquid crystal display elements require electric power to maintain display contents. In addition, a larger display screen consumes more power.
Therefore, in consideration of cost-effectiveness, using a liquid crystal display device as a display device for an advertisement or the like has a problem in terms of economic efficiency.

[0003]

SUMMARY OF THE INVENTION Accordingly, a display device according to the present invention comprises a memory-type display element that does not require power to maintain a display, a light generator for converting light energy into electric energy, and a light generator. And a control unit for supplying power from the power storage device to the liquid crystal display element and changing the display of the display element.

A display device according to another aspect of the present invention is characterized by further comprising an information receiver for receiving information from the outside.

A display device according to another aspect of the present invention is characterized in that the information receiver receives information wirelessly.

A display device according to another aspect of the present invention is characterized by further comprising a booster circuit for boosting the output of the power storage device to a predetermined voltage.

A display device according to another aspect of the present invention is characterized in that the memory display device is a reflective liquid crystal display device.

A display device according to another aspect of the present invention is characterized in that the memory-type liquid crystal display element is formed by stacking a plurality of liquid crystal display elements.

A display device according to another aspect of the present invention is characterized in that the liquid crystal display element and the photovoltaic device are mounted on a window of a vehicle.

A display device according to another aspect of the present invention includes a speaker.

A display device according to another aspect of the present invention includes a light source for illuminating the liquid crystal display device.

Further, an information display device according to the present invention includes the display device described above. Furthermore, a display system according to the present invention includes the display device described above and a host device that transmits information to the display device.

[0013]

DETAILED DESCRIPTION OF THE INVENTION 1. Liquid Crystal Display FIG. 1 is a circuit block diagram of a liquid crystal display according to the present invention. As shown, a liquid crystal display device (information display device) 1
Has a liquid crystal display element 2. The liquid crystal display element 2 is shown in FIG.
As shown in FIG. 3, a substrate 3, a light absorber 4 disposed on the substrate 3, and three color display layers 5 (red display layer _5R , green display layer 5) stacked on the light absorber 4. _G , blue display layer _5B ). Each color display layer 5 includes an upper substrate 6 and a lower substrate 7 made of a transparent material, a resin structure 8 for bonding and supporting the upper substrate 6 and the lower substrate 7, and a gap formed by the resin structure 8. It has a filled liquid crystal 9. Although not shown, spherical spacers are also included between the upper and lower substrates. On the lower surface of the upper substrate 6, a plurality (n) of transparent strip-shaped scanning electrodes (common electrodes) 10 are arranged in parallel at predetermined intervals.
On the other hand, on the upper surface of the lower substrate 7, a plurality (m) of transparent band signal electrodes (individual electrodes) 11 are arranged in parallel at a predetermined interval. As shown in FIG. 3, the arrangement direction of the scanning electrode 10 and the signal electrode 11 is orthogonal to each other.
A point (intersection) where 0 and the signal electrode 11 face each other forms a pixel of the liquid crystal display element 2.

As the liquid crystal 9, a cholesteric liquid crystal having a memory property is used. Cholesteric liquid crystals
The state can be changed from the planar state to the focal conic state and vice versa from the focal conic state to the planar state, and any state can be maintained without supplying external energy (that is, electric power). In the planar state, assuming that the helical pitch of the cholesteric liquid crystal is P and the average refractive index of the liquid crystal is n, the liquid crystal 9 selectively reflects light of wavelength λ = P · n. On the other hand, in the focal conic state, the visible light is scattered when the selective reflection wavelength of the cholesteric liquid crystal is in the infrared region, and the visible light is scattered when the selective reflection wavelength is in the shorter wavelength region than the infrared region. Through. In the present embodiment, the cholesteric liquid crystal 9 filled in the three color display layers 5 is adjusted so as to selectively reflect the wavelength of the corresponding color in the planar state and transmit visible light in the focal conic state. Have been. It is also possible to take an intermediate state in which the planar state and the focal conic state are mixed, and it is possible to display a halftone by this intermediate state. Therefore, full-color display can be performed by setting each color display layer to the planar state, the focal conic state, and the intermediate state. Thus, a full-color photographic image can be displayed. Note that, by stacking a plurality of liquid crystal layers, there is an effect that the reflectance of the liquid crystal display element can be increased.

A state change of the liquid crystal 9 (ie, a state change from the planar state to the focal conic state, or conversely, a state change from the focal conic state to the planar state) is caused by applying a predetermined voltage between the scanning electrode 10 and the signal electrode 11. This is done by applying. For example, when switching the liquid crystal 9 at a certain position from the focal conic state to the planar state,
The potential difference between the scanning electrode 10 and the signal electrode 11 corresponding to the portion is set to a first threshold voltage required to untwist the liquid crystal exhibiting a cholesteric phase, and after a predetermined time,
The voltage is lowered to a second threshold voltage lower than the first threshold voltage. Conversely, when switching the liquid crystal 9 in a certain part from the planar state to the focal conic state, the potential difference between the scanning electrode 10 and the signal electrode 11 corresponding to that part is higher than the second threshold voltage and the first potential difference. Is maintained at a voltage lower than the threshold voltage for a predetermined time.

Returning to FIG. 1, the liquid crystal display device 1 will be described again. The scanning electrode 10 and the signal electrode 11 of the liquid crystal display element 2 are connected to a scanning electrode driving circuit 12 and a signal electrode driving circuit 13, respectively. The scan electrode drive circuit 12
A decoder 14 and a plurality (m) of switching circuits 15 corresponding to the plurality (m) of the scanning electrodes 10;
Each switching circuit 15 is driven based on a signal output from the decoder 14, and a predetermined voltage is applied to the corresponding scan electrode 10. On the other hand, the signal electrode drive circuit 13 includes a line buffer 16, a plurality (n) of digital / analog converters 17, and a plurality (n) of drive buffers 18, and a signal output from the line buffer 16. Each digital / analog converter 1 based on
7. Even if the driving buffer 18 is driven, the corresponding signal electrode 1
1, a predetermined voltage corresponding to the image data to be displayed is applied.

The display information transmission system 20 of the liquid crystal display device 1 also includes a receiving circuit (receiver) 21 for receiving image information, a data conversion circuit 22 for converting the image information received by the receiving circuit 21 into data, An image memory 23 that stores data converted by the circuit 22 and a control circuit 24 that outputs signals to the line buffer 16 and the decoder 14 based on the converted data are provided.

The receiving circuit 21 uses a radio receiving device.
For example, known loop antennas, dipole antennas,
Antennas such as diversity antenna, sleeve antenna, ground plane antenna, umbrella antenna,
Alternatively, it comprises an infrared light receiver for IRDA and a demodulation circuit. The reception information received by the reception circuit 21 is:
Display information such as image data to be displayed may be used, or the received information may be used as a command for updating the display, and the image may be updated based on the display information previously stored in a storage medium built in the display device. You may make it do.

The power required to drive these circuits and the like is supplied from a power supply 25. The power supply 25 includes a solar battery (photoelectric generator) 26, a storage battery (power storage device) 27 that stores the power generated by the solar battery 26, a primary booster circuit 28 that boosts the output of the storage battery 27 to a required voltage, And a secondary booster circuit 29 for further boosting the boosted voltage to a required voltage.

As the solar cell 26, a commercially available polycrystalline silicon solar cell can be suitably used. However, solar cells are not limited to this, and single-crystal silicon-based solar cells,
Amorphous silicon solar cells, microcrystalline silicon solar cells, polysilicon solar cells, multi-element solar cells, and the like can also be used. The storage battery 27 includes a lead storage battery,
Alkaline batteries, nickel cadmium (Ni-Cd) batteries, nickel-metal hydride batteries, lithium-ion batteries,
A polymer electrolyte battery, a polyacene battery, or the like is used.
The power storage device is not limited to a storage battery, and various types of conventionally known power storage devices can be used.

As the primary and secondary boosting circuits 28 and 29, various boosting circuits (for example, transistors, operational amplifiers,
Transformer, DC-DC converter) can be used.

In the liquid crystal display device 1 configured as described above, the solar cell 26 receives light to generate electricity, and outputs the generated electricity to the storage battery 27. The electricity stored in the storage battery 27 is supplied to the primary booster circuit 28 as needed. The primary boosted voltage is supplied to the image memory 23,
Image information is held in the image memory 23. Also,
The primary boosted voltage is supplied to the secondary booster circuit 29, and the secondary booster circuit 29 boosts the voltage to a predetermined voltage.

On the other hand, image information is output from the transmitter 30 and received by the receiving circuit 21. The receiving circuit 21 outputs the received image information to the data conversion circuit 22. The data conversion circuit 22 converts the image information into data,
Supply 3 Further, the conversion data supplied from the image memory 23 is supplied to the control circuit 24.

As described above, in the present display device, the power generated from the external light by the optical power generator is stored in the power storage device, and it is not necessary to connect the power to a commercial power supply or the like. By using this, a cableless display device is obtained. Therefore, the degree of freedom in setting the display is increased, and it becomes easy to assign a large number of display devices to the host device.

The control circuit 24 creates display data for one line based on the converted data, and outputs a signal to the decoder 14 and the line buffer 16 based on the display data. The decoder 14 drives a necessary switching circuit 15 according to the received signal, and applies a predetermined voltage to the target scanning electrode 10. On the other hand, the line buffer 16 drives the necessary digital-to-analog converter 17 in accordance with the received signal, and outputs the target signal electrode 1 via the drive buffer 18.
1 is applied with a predetermined voltage. The switching circuit 1
5. A predetermined drive voltage is supplied from the secondary booster circuit 29 to the drive buffer 18 and the like based on a signal output from the control circuit 24.

In this manner, the liquid crystal portions of the three color display layers 5 corresponding to the respective pixels are switched from the planar state to the focal conic state, or from the focal conic state to the planar state, and a target color image is displayed. Is done.

The liquid crystal whose state has been switched does not require electric power to maintain that state thereafter. Therefore, even if the maintenance power is not supplied, the image displayed on the liquid crystal display element 2 is held for a long time (for example, several years). Further, since the display is a reflection type display, even if there is no backlight or external light such as sunlight or illumination light, display contents can be visually recognized, which is extremely advantageous for energy saving.

As described above, in order to change the state of the liquid crystal 9 from the planar state to the focal conic state or vice versa, it is necessary to apply a predetermined voltage for a certain period of time. From the necessity, in the liquid crystal display device 1 of the present invention, the storage battery 27 is provided in the power supply 25, and the power supplied from the solar battery 26 is stored in the storage battery 27. .

Further, since the voltage is boosted by the booster circuit, a sufficiently large voltage can be applied to the memory-type liquid crystal display element which requires a relatively high voltage for rewriting. Can be rewritten. Furthermore, by using a reflective display device, the illumination light always exists in an environment where the display can be visually recognized. Therefore, power can be generated by the photovoltaic generator while the display is being performed.

The charging energy of the solar cell and the power consumption of the liquid crystal display element were examined. The solar cell includes an indoor amorphous silicon solar cell AM1815 manufactured by Sanyo Solar Industries Co., Ltd. (external dimensions: 58.1 × 48.
6 mm). This solar cell has an operating capacity of 3.0.
V, an output of 42 μA is possible, and the charging energy per second is 0.126 mJ / s (= 3.0 V × 42 μA). Also, if the indoor lighting is illuminated at 200 lux for 8 hours and left in an indoor environment for one week (however, the indoor lighting is turned on for only 5 days) (that is, if the lighting is for 40 hours), The charging energy is 18144mJ
(= 0.126 × 3600 × 40). In the case of outdoor, if the average sunshine is 10000 lux and the lighting time is 10 hours, the charging energy per week is 158760
0 mJ (= 0.126 × (10000 ÷ 200) × 36
00 × 70).

On the other hand, the liquid crystal display element has 2100 × pixels.
1480 dots (A4 size, equivalent to 180 dpi). When switching the display of all pixels of the liquid crystal display element, the energy consumption of the liquid crystal display element is 36 mJ / A4, the energy consumption of other electric circuits is 2442 mJ, and the total energy consumption of both is 2478 mJ.

Therefore, the number of times that a display image can be rewritten per week is seven times indoors (18144 ÷ 2478).
= 7.3), 637 outdoors (1587600 ÷ 247)
8 = 637).

In the above embodiment, only one liquid crystal display element is shown. However, a plurality of liquid crystal display elements may be connected to one power supply 25.

Further, a plurality of pieces of image information are transmitted in one transmission of image information, and the plurality of pieces of transmitted image information are recorded in the image memory 23, and new image information is stored in the image memory at predetermined time intervals. May be called to switch the display image.

Further, as shown in FIG. 4, a light transmitting body (acryl, styrene-acryl, polycarbonate, etc.) 31 and a light diffusing layer 32 are provided on the surface side of the liquid crystal display element 2, and one side of the light transmitting body 31 is provided. Along the fluorescent light (light source) 3
2 and a reflector 33, the light emitted from the fluorescent lamp 32 is incident on the light transmitting body 31 directly or through the reflector 33 so that the display contents of the liquid crystal display element 2 can be clearly seen even in a slightly dark place. You may. In this case, the light amount in the environment where the liquid crystal display device 1 is installed is detected by a light receiving sensor (not shown), and the fluorescent lamp 32 is turned on when it is determined from the detection result that the environmental light amount is low. Is also good. The power to the fluorescent lamp 32 may be supplied from the storage battery 27,
When the fluorescent lamp 32 is turned on for a long time, power is supplied from another power source by connecting to another dedicated battery or a commercial power source, and the power supply from the storage battery 27 turns on the fluorescent lamp in a short time. It is preferable to use it as an auxiliary power source, for example, by supplying power only when a fluorescent lamp is unnecessary.

Furthermore, as described above, in the case of a liquid crystal having a memory property, a large amount of power is required to switch the display of the liquid crystal display element 2. Therefore, the display may be switched only for the pixels that need to be rewritten, and the previous display may be maintained for the pixels that do not need to be rewritten. FIG.
A circuit block diagram of such a liquid crystal display device 1 'is shown. As shown in this block diagram, the liquid crystal display 1 ′
Has a first image memory 35 storing image data currently displayed, and a second image memory 36 storing image data to be newly displayed. In addition, the image memories 35 and 36 correspond to the corresponding line memories 37,
38, and one line of image data from the respective image memories 35, 36 corresponds to the corresponding line memories 37, 38.
Is output to The comparator 39 has a line memory 37,
38, and these line memories 37, 3
The pixel information (line address number) that does not match is stored in the address storage unit 40. Then, the scan electrode drive circuit 12 and the signal electrode drive circuit 13 obtain the output of the address storage unit 40 and change the state of only the liquid crystal portion corresponding to the pixel data that does not match. In this way, the power required for rewriting the display can be further reduced. In particular, when the image portion that needs to be rewritten is only a part of the liquid crystal display element 2, the time and energy required for rewriting is considerably reduced. For example, when rewriting is performed only in an area corresponding to 1/10 scanning line of the liquid crystal display element, the time and energy required for rewriting is about 1 unit.
/ 10. Therefore, even at night or the like when generation of electricity by the solar cell is interrupted,
, The number of times display contents are switched by the power supplied from the power supply can be increased. Note that the display device can be used in various forms, from a card-shaped small and lightweight display device to a large-sized display device, and is not limited to a specific model.

B. Usage Mode (1) Usage Mode 1 FIG. 6 is a diagram illustrating a first usage mode of the liquid crystal display device. In this use mode, for example, a liquid crystal display element is used for a price tag of a product handled in a department store or the like. In such a usage form, the liquid crystal display device 1 is installed for each product, and a communication terminal such as a host computer (transmitter 30)
, The product data (for example, the price of the product, the description of the product) is wirelessly transmitted to the liquid crystal display device 1. The liquid crystal display device 1
The product data transmitted from the communication terminal (transmitter 30) is received by the receiver 21 and is displayed (or rewritten) on the liquid crystal display element 2 based on the received data. At this time, the electric power necessary for displaying or rewriting the product data is supplied from the storage battery that stores the electricity generated by the solar cell 26.

In the case of this use form, electrical wiring is not required between the transmitter and each display device and between the commercial power supply and each display device. Further, since the display or rewriting of the product data is performed electronically, it is possible to save much trouble as compared with a store clerk rewriting the product data for each product. In the following usage modes, members having the same functions as those of the usage mode are denoted by the same reference numerals,
Detailed description is omitted.

(2) Usage Mode 2 FIG. 7 is a diagram showing a second usage mode of the liquid crystal display device 1. In this use mode, for example, the liquid crystal display element 2 is used for displaying a departure / arrival guide of a transportation system such as a train, a bus, and an aircraft. According to this mode of use, the timetable for weekdays and the timetable 41 for holidays (holidays) can be displayed on one display panel (liquid crystal display element 2). In addition, in the case of timetable revision, or when it becomes necessary to change the timetable due to an accident or the like, the timetable 41 can be immediately changed to a new timetable 41 '.

(3) Usage Mode 3 FIG. 8 is a diagram showing a third usage mode of the liquid crystal display device 1. In this use mode, information 42 necessary for passengers is displayed on the liquid crystal display element 2 and notified together with the timetable 41. According to this usage mode, for example, when the departure of the train is delayed due to an accident, the cause, the delay time, and the like can be displayed to notify the passenger.

(4) Usage Mode 4 FIG. 9 is a diagram showing a fourth usage mode of the liquid crystal display device 1. This usage mode is based on the timetable 41 and the local public notice 43.
And the like are displayed on the liquid crystal display element 2.

(5) Usage Mode 5 FIG. 10 is a diagram showing a fifth usage mode of the liquid crystal display device 1. In this usage mode, the liquid crystal display element 2 is provided in the vehicle of a vehicle 44 such as a train, and necessary information (for example, a route map, an arrival time, a stop solution, a last arrival station, a publicity advertisement, emergency information) is displayed. It was done. In the case of this use mode, an appropriate input device 44 may be provided near the liquid crystal display element 2 and the display content of the liquid crystal display element 2 may be changed according to the information input by the input device 44. In this case, for example, when a passenger inputs a specific station name, the time of arrival at that station can be displayed.

(6) Usage Mode 6 FIG. 11 is a diagram showing a sixth usage mode of the liquid crystal display device 1. This use mode is a display device for displaying the location of an employee (going out, a meeting place, etc.), a message device and a liquid crystal display element 2.
It is a thing using. In the case of this use mode, the communication terminal 45 [personal computer, touch panel type input device (resistive touch panel, optical touch panel, capacitive touch panel, ultrasonic touch panel), PH]
S, a mobile terminal (for example, a pocket board made by NTT,
Display contents can be wirelessly transmitted to the liquid crystal display device 1 and displayed from the mobile gear MC-R510 manufactured by NEC Corporation). Further, the place of use is not limited to the inside of the company, and can be used as a message board in a parking area, a waiting room such as a station, a stadium, an amusement park, and the like.

(7) Usage Mode 7 FIG. 12 is a diagram showing a seventh usage mode of the liquid crystal display device 1. In this use mode, the liquid crystal display element 2 is used as a display device of a GPS (Global Positioning System) 46. In the drawing, 47 is a GPS
Reference numeral 46 denotes a main body, 48 denotes an opening / closing cover, 49 denotes a receiving unit, 50 denotes a screen moving direction key, 51 denotes a dedicated key (address display key or the like), 52 denotes a power switch, and 53 denotes a mode key.
However, in the case of the GPS 46, since the display contents of the liquid crystal display element 2 are expected to be frequently rewritten,
The storage battery connected to 6 is preferably used as an auxiliary power supply.

(8) Usage Mode 8 FIG. 13 is a diagram showing an eighth usage mode of the liquid crystal display device 1. This use mode is a window 55 of a train 54 (or a building).
To which a liquid crystal display device 1 is attached. In the case of this usage mode, as shown in FIG. 14, the liquid crystal display element 2 is provided inside the window 55, and the solar cell 26 is disposed between the liquid crystal display element 2 and the window 55, so that the solar cell 26 is effectively used as a solar cell. It is preferable to receive the light. When two glasses are fitted in the window of the train, the liquid crystal display device 1 may be arranged between the two glasses.

(9) Ninth Usage Mode FIG. 15 is a diagram showing a ninth usage mode of the liquid crystal display device 1. In this use mode, a film speaker 56 is provided in a part of the liquid crystal display device 1, and the contents of the screen display are displayed by voice along with the screen display. This usage mode has an advantage that the information transmission effect is higher than the case where only the screen is displayed, because the information can be displayed on both the screen and the voice.

(10) Usage Mode 10 FIG. 16 is a diagram showing a tenth usage mode of the liquid crystal display device 1. This usage mode uses the liquid crystal display device 1 as a baseball score display panel 57, and displays the contents of the score display panel 57 based on a signal wirelessly transmitted from a personal computer (transmitter) 58 provided in a baseball field. Is changed.

In the above description, a cholesteric liquid crystal has been described as a liquid crystal having a memory property. The cholesteric liquid crystal has various advantages such as a need for a backlight by a reflection type display, energy saving can be achieved, a natural display which is easy on the eyes can be performed, a large area can be easily obtained, and a full-color display can be easily performed. It is preferred. However, the present invention is not limited to cholesteric liquid crystals,
In the case where it is permissible without these features, any liquid crystal having a memory property such as a ferroelectric liquid crystal can be used. In addition to the liquid crystal display panel, a memory display panel such as an electrochromic display panel can be used. In particular, the electrochromic display panel has the advantages that the driving voltage can be reduced to 2-3 volts, the power consumption is small, and small solar cells and storage batteries can be used.

[0049]

As is apparent from the above description, according to the display device of the present invention, since a display element having a memory property is used, power is consumed only when a display screen is changed, and usually, power is consumed. The display screen can be maintained without supplying power. Therefore, the power consumption is extremely small, and it is economical. In addition, using a photovoltaic generator, the electricity generated by the photovoltaic generator is stored in a power storage device and can be used to switch the screen display of the display element as needed. It is economical because it can be performed without receiving power supply. In a mode further provided with an information receiver for receiving information from the outside, the display can be updated by an instruction from the outside, or the display information can be transmitted from the outside. In particular, when the information receiver receives information wirelessly, there is no need to connect an external device to the display device with a cable, so that the degree of freedom in installing the display device is increased. In a mode in which a booster circuit for boosting the output of the power storage device to a predetermined voltage is further provided, a sufficiently large voltage required for rewriting can be applied to the memory display element, and rewriting can be performed satisfactorily. In a mode in which the memory display element is a reflective liquid crystal display element, the display content can be visually recognized even if there is no external light such as sunlight or illumination light without a backlight, which is extremely advantageous for energy saving. The memory-type liquid crystal display element in which a plurality of liquid crystal display elements are stacked is advantageous in terms of colorization and improvement in reflectance, and more colorful and high-quality display is possible. Furthermore, in the mode in which the liquid crystal display element and the photovoltaic device are attached to the window, the photovoltaic device can receive sufficient sunlight to supply sufficient electricity. Therefore, the display of the display element can be changed repeatedly in a short time. In addition, in the embodiment including the audio display unit, the contents of the screen can be displayed by audio together with the screen, so that a high display effect can be obtained. Further, in a mode in which light is supplied from a light source that illuminates the front surface of the liquid crystal display element, the display screen of the display element can be kept bright even in a place with insufficient brightness, such as in a train. According to the display system of the present invention, by including the display device according to claim 1 and a host device that transmits information to the display device, a display system having a simple configuration and advantageous in energy saving is configured. be able to.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of an information display device according to the present invention.

FIG. 2 is an enlarged partial cross-sectional view of a liquid crystal display element.

FIG. 3 is a diagram schematically showing an arrangement of electrodes in a liquid crystal display element.

FIG. 4 is an enlarged partial cross-sectional view of a light transmitting body attached to a surface of a liquid crystal display element.

FIG. 5 is a circuit block diagram of another embodiment of the information display device.

FIG. 6 is a diagram showing a first use mode of the information display device.

FIG. 7 is a diagram showing a second usage mode of the information display device.

FIG. 8 is a diagram showing a third mode of use of the information display device.

FIG. 9 is a diagram showing a fourth mode of use of the information display device.

FIG. 10 is a diagram showing a fifth use mode of the information display device.

FIG. 11 is a diagram showing a sixth mode of use of the information display device.

FIG. 12 is a diagram showing a seventh usage mode of the information display device.

FIG. 13 is a diagram showing an eighth mode of use of the information display device.

FIG. 14 is a cross-sectional view of the liquid crystal display element and the like shown in FIG.

FIG. 15 is a diagram showing a ninth mode of use of the information display device.

FIG. 16 is a diagram showing a tenth use mode of the information display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device (information display device), 2 ... Liquid crystal display element, 21 ... Receiving circuit, 26 ... Solar cell, 27 ... Storage battery,
30 ... Transmitter.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Naoki Shozumi 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Koichi Koriyama Chuo-ku, Osaka-shi, Osaka 2-13-13 Azuchicho Osaka International Building Minolta Co., Ltd. (72) Inventor Hideo Hotomi 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka International Building Minolta Co., Ltd. 2H093 NC02 NC07 NC10 NC12 NC24 NC28 NC49 NC50 NC72 ND01 ND08 ND17 ND39 NF17 5C006 AA16 AA22 AA28 AF51 AF83 AF84 BA11 BB08 BB11 BB28 BF02 BF05 BF14 BF15 BF26 BF45 BF46 EA01 EC08 FA47 5C080 BB05 KK05 BB05 KK05 BB05 BB05

Claims (10)

[Claims] 1. A memory-type display element that does not require power to maintain display, a photo-electric generator that converts light energy into electric energy, a power storage device that stores power generated by the photo-electric generator, and the power storage device. And a controller for supplying power to the liquid crystal display element from above and changing the display of the display element. 2. The display device according to claim 1, further comprising an information receiver for receiving information from outside. 3. The display device according to claim 2, wherein said information receiver receives information wirelessly. 4. The display device according to claim 1, further comprising a booster circuit for boosting an output of the power storage device to a predetermined voltage. 5. The display device according to claim 1, wherein said memory display element is a reflective liquid crystal display element. 6. The display device according to claim 1, wherein the liquid crystal display element having memory properties is a laminate of a plurality of liquid crystal display elements. 7. The information display device according to claim 1, wherein the liquid crystal display element and the photovoltaic generator are mounted on a window of a vehicle. 8. The display device according to claim 1, further comprising a speaker. 9. The information display device according to claim 1, further comprising a light source for illuminating the liquid crystal display element. 10. A display system comprising: the display device according to claim 1; and a host device that transmits information to the display device.