JP2000148116A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device of low electric-power consumption, from which an image or the like can be seen at hand instantly and simply. SOLUTION: When a power source switch 8 is operated and an image writing starting switch 9 is operated, a picture signal given from the outside is stored in a frame memory 10 for a while. A driving voltage to a driving circuit 13 is supplied to an LCD power source supply circuit 12. Simultaneously, the picture signal is read out from the frame memory 10 and sent to the driving circuit 13 through an LCD signal generation circuit 11. The driving circuit 13 writes the picture signal from the LCD signal generation circuit 11 on a liquid crystal display part 14 and displays it on the liquid crystal display part 14. After writing is finished, a power supply to the driving circuit 13 is stopped at least to the LCD power source supply circuit 12. The liquid crystal display part 14 has a storing performance and maintains the display after cutting off the power source. At least the liquid crystal display part 14 can be put on and taken off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device using display means having a memory property and being electrically rewritable.

[0002]

2. Description of the Related Art In a work on a computer, it is common practice to output a displayed document, particularly a document such as an e-mail or a document under proofreading, on a recording paper using a printer. Have been done. This is because there is a demand for viewing the recording paper in hand rather than looking at the computer screen. However, with the recent trend toward paperless use, reduction in the consumption of recording paper has been called out from the viewpoint of resource saving. Therefore, for example, Japanese Patent Application Laid-Open No. 3-158
A reusable paper and a display such as a paper as described in Japanese Patent Application Laid-Open No. 298 or 188489/1991 are also proposed. However, even when printing a document on a computer, a printer device is required.

Further, as a device capable of making a hard copy of a monitor screen or a television screen of a computer, for example, a hard copy device as disclosed in Japanese Patent Application Laid-Open No. 1-156663 has been proposed. This is intended to leave an image on a monitor or television, or to view it at hand.

In recent years, portable computers such as notebook computers and laptop computers have been increasing, and it has become possible to carry e-mails and documents on a computer anywhere by carrying them. However, there is a greater demand for holding documents in hand because of physical enjoyment rather than looking at the screen of a portable computer. Also, in places where there is no printer, such as when moving, it is not possible to hold documents or e-mail documents. Even if there is a printer that can be carried around, the power consumption of the printer itself is large to some extent, so that charging and battery replacement are frequently required. In addition, e-mails and proofreading documents are instantly at hand, especially on portable printers, etc. You will see it on your computer screen.

[0005] Therefore, there is a demand for the development of a means that allows the user to instantly and easily view a computer screen or document at hand. In addition, low power consumption is desired from the viewpoint of recent energy saving and to reduce the frequency of charging and battery replacement by suppressing power consumption of a portable computer.

[0006] For example, Japanese Patent Laid-Open Publication No. 2-254420 discloses a structure in which a matrix liquid crystal panel and a part or all of a driving circuit for driving the matrix liquid crystal panel can be separated. Has been proposed for the display. However, no consideration has been given to reducing power consumption.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and enables a computer screen, a document, and other images to be instantaneously, with low power consumption, and easily at hand. It is an object of the present invention to provide a display device that can be viewed on a computer.

[0008]

SUMMARY OF THE INVENTION The present invention provides a display means having a memory property and electrically rewritable, a driving means for driving the display means in accordance with an image signal, and a display for supplying power to the driving means. It has power supply means and control means. The driving unit rewrites the display on the display unit based on the input image signal. When the writing to the display means is completed, the supply of power to at least the driving means is stopped. Thereby, low power consumption is realized. Because of low power consumption, it can be driven by, for example, a solar cell or the like.

In a display device represented by a conventional CRT,
The display screen could not be maintained unless the display means was constantly driven. However, in the present invention, since the display means has a memory property, the display screen is maintained even when the power supply to the driving means is stopped.

Further, since the display means can be electrically rewritten, unnecessary screens can be deleted and a new screen can be displayed any number of times. As a result, even when the recording paper becomes unnecessary, such as recording paper, it is not discarded, thereby contributing to resource saving.

Further, according to the present invention, the display means, or the display means and the drive means can be integrated to be detachable. As a result, the screen on which the computer screen or other images are displayed can be removed and viewed at hand. At this time, a device such as a printer is not required, and the user can easily see the image when displayed. In addition, it is possible to remove the display unit while displaying it on a certain display unit, attach another display unit and display the display unit, and place a plurality of same or different screens at hand. In a configuration having a plurality of display means, such a plurality of screens can be obtained as needed.

[0012]

FIG. 1 is a block diagram showing an embodiment of a display device according to the present invention. In the figure, 1 is a monitor signal input terminal, 2 is a protection circuit, 3 is an addition circuit, 4 is a threshold setting circuit, 5 is a binarization circuit, 6 is a control circuit, 7 is a power control circuit, 8 is a power switch, 9 Is an image writing start switch, 10 is a frame memory, 11 is an LCD signal generation circuit, 12 is an LCD power supply circuit, 13 is a drive circuit, 14
Denotes a liquid crystal display unit.

An image signal to be displayed is input to a monitor signal input terminal 1. Here, it is assumed that an RGB analog signal obtained from a monitor output of a computer or the like is input. However, since a signal of an external monitor output from a computer or the like is always output, a protection circuit 2 for protecting the computer and the display device is disposed immediately after the monitor signal input terminal 1. The input image signal is not limited to this, and may be various image signals such as an NTSC video output.

The addition circuit 3 adds the RGB signals and converts them into a monochrome halftone signal. The binarizing circuit 5 binarizes the output signal from the adding circuit 3 according to the threshold value set by the threshold value setting circuit 4. If the input signal is a black-and-white signal, the addition circuit 3 may not be provided, or if a binary signal is input or the liquid crystal display unit 14
If it is possible to display a color image in the above, the addition circuit 3, the threshold setting circuit 4, and the binarization circuit 5 need not be provided.

The control circuit 6 samples the binary signal output from the binarization circuit 5 while synchronizing according to the H / V synchronization signal input to the monitor signal input terminal 1 together with the RGB signal. Write to. Also, the image writing start switch 9 is monitored, and when this switch is operated, the image in the frame memory 10 is read and sent to the LCD signal generation circuit 11 to generate a signal for display, and the driving circuit 13 Output. At the same time, the driving circuit 13 causes the LCD power supply circuit 12 to supply power for driving the liquid crystal display unit 14. When the writing to the liquid crystal display unit 14 is completed, the supply of power to at least the drive circuit 13 is stopped. In this example, a signal to turn off the power is sent to the power supply control circuit 7 to turn off the power of the entire apparatus.

The power supply control circuit 7 turns on the power of the apparatus when the power switch 8 is operated, and performs control to turn off the power of the apparatus when a signal for turning off the power is input from the control circuit 6.

The power switch 8 is a switch operated by a user when the power of the apparatus is turned on. The image writing start switch 9 is a switch operated by the user when displaying an image on the liquid crystal display unit 14. The form of each switch is arbitrary. Further, these switches may be combined into one switch, and the power may be turned on when displaying an image. Further, these switches may be configured to be operated by a user or externally controlled, for example, by a computer. The operability is improved by arranging the switches so that they can be operated with a small number of switches.

The frame memory 10 is storage means for temporarily storing an image signal. The image signal is held in accordance with the image signal and the write signal sent from the control circuit 6, and the image signal is output to the LCD signal generation circuit 11 in accordance with the read signal also sent from the control circuit 6.

The LCD signal generation circuit 11 receives the image signal read from the frame memory 10 and
3 and generates an image signal for display while synchronizing with 3 to output to the drive circuit 13.

The LCD power supply circuit 12 includes the liquid crystal display 1
When an image is displayed on the LCD 4, power for driving the liquid crystal display unit 14 is supplied to the drive circuit 13 in accordance with an instruction from the control circuit 6. Since the drive circuit 13 operates only when writing an image signal to the liquid crystal display unit 14, the power supplied from the LCD power supply circuit 12 to the drive circuit 13 is very small. Therefore, for example, it is also possible to configure a battery, a solar battery, or a solar battery and a storage battery. Note that a configuration may be employed in which a power supply common to the power supply of this device is used, and the power is adjusted to the voltage for the drive circuit 13. The LCD power supply circuit 12 starts the supply of power to the drive circuit 13 according to the control of the control circuit 6, and when the supply of power is stopped, in addition to the control from the control circuit 6, the power supply control circuit 7
The power supply to the drive circuit 13 may be stopped by turning off the power supply of this device.

The driving circuit 13 includes an LCD power supply circuit 12
Drive the liquid crystal display unit 14 using the power supplied from the
The image signal passed from the LCD signal generation circuit 11 is written into the liquid crystal display unit 14.

The liquid crystal display section 14 displays an image written by the drive circuit 13. The liquid crystal display unit 14 has a memory property, and can maintain a display without power supply from the drive circuit 13. However, the display can be changed by electrically rewriting by the drive circuit 13. In this example, a monochrome two-tone ferroelectric liquid crystal is used as the liquid crystal display unit 14. However, the present invention is not limited to this, and for example, a liquid crystal such as a color ferroelectric liquid crystal or a cholesteric liquid crystal as described in the above-mentioned Japanese Patent Application Laid-Open No. 2-254420 may be used. Further, any display means having a memorable property such as electrophoresis or magnetic induction can be used as the liquid crystal display unit 14 instead of the liquid crystal.

It should be noted that the liquid crystal display unit 14 alone or the liquid crystal display unit 14 and the drive circuit 13 can be configured to be detachable integrally. Since the liquid crystal display unit 14 has a memory property, the display can be maintained even when the liquid crystal display unit 14 is removed. For example, a plurality of mountable liquid crystal display units 14 are prepared, and an image can be displayed on a large number of liquid crystal display units 14 while exchanging the liquid crystal display units 14.

FIGS. 2 and 3 are flowcharts showing an example of the operation of the display device according to the embodiment of the present invention. When the power switch 8 is operated, the power control circuit 7 turns on the power of the apparatus, and inputs a power-on signal to the control circuit 6 in S21. As a result, the control circuit 6 performs an initialization operation.

On the other hand, to the monitor signal input terminal 1, for example, an RGB analog display image signal is always input. Of these image signals, the RGB signals pass through the protection circuit 2 and
It is input to the addition circuit 3. In S22, the addition circuit 3
Adds the R, G, and B signals. In S23,
The binarization circuit 5 compares the signal value added by the addition circuit 3 with a threshold value set in the threshold value setting circuit 4 in advance, and binarizes the image signal. The binarized image signal and the H / V synchronization signal input to the monitor signal input terminal 1 and passed through the protection circuit 2 are input to the control circuit 6.

The control circuit 6 monitors the image writing start switch 9 in S24, and if the image writing start switch 9 is not operated, writes the image signal in the frame memory 10 in S27. This writing is performed in synchronization with the H / V synchronizing signal while the binarizing circuit 5
Is sampled and stored as digital data in association with the position of the display screen.
In order to synchronize, prior to writing the image signal to the frame memory 10 in S27, H /
Determining whether a V synchronization signal is detected from the V synchronization signal,
If the V synchronization signal is detected, the write address of the frame memory 10 is set to the first address in S26. Thus, the synchronization of the head of the display screen is synchronized. For example, an image signal of, for example, 640 × 480 bits is written in the frame memory 10 in accordance with the resolution of the liquid crystal display unit 14. The writing to the frame memory 10 in S27 is always performed after the power is turned on until the image writing start switch 9 is operated.

Here, when the image writing start switch 9 is operated, the control circuit 6 detects this in S24,
Proceed to S28. First, in S28, the V synchronization signal among the H / V synchronization signals is detected. If the V synchronization signal is not detected, the frame memory 1 is determined in S29 as in S27.
The image signal is written to 0. If a V synchronization signal is detected in S28, it is determined whether or not the V synchronization signal has been detected twice in S30. In the first case, the write address of the frame memory 10 is set to the first address as in S26. Set to address. Then, the image signal for one screen until the next V synchronization signal is detected is stored in the frame memory 10. When the second V synchronization signal is detected in S30, the writing to the frame memory 10 is stopped in S32.

In step S41, the LCD power supply circuit 12 generates and supplies a drive voltage to the drive circuit 13. At the same time, in S42, the frame memory 10
The image signal is read out from the LCD while synchronizing with the timing at which the drive circuit 13 drives the liquid crystal display unit. L
The CD signal generation circuit 11 generates an image signal to be supplied to the liquid crystal display unit 14 based on the image signal read from the frame memory 10, and passes it to the drive circuit 13. Drive circuit 13
Writes the image signal from the LCD signal generation circuit 11 to the liquid crystal display unit 14. As a result, an image corresponding to the image signal is displayed on the liquid crystal display unit 14.

When all the screen displays are completed in S43, the control circuit 6 causes the LCD power supply circuit 1 in S44.
With respect to 2, the supply of the voltage to the drive circuit 13 is stopped, and the transmission of the image signal from the LCD signal generation circuit 11 is also stopped in S45. Thereby, the liquid crystal display unit 1
4 and the drive circuit 13 do not receive any power supply.

Thereafter, in S46, the control circuit 6 sends a signal to cut off the power to the power supply control circuit 7, and in S47
The power supply control circuit 7 turns off the power supply of this device.
In this manner, the image signal input to the monitor signal input terminal 1 can be displayed on the liquid crystal display unit 14 at the timing when the image writing start switch 9 is operated. Further, power can be turned off after the display.

As described above, since the liquid crystal display unit 14 is, for example, a ferroelectric liquid crystal having bistability, an image in which an image signal is written and displayed remains even after the power is turned off. Therefore, the image can be continuously viewed even after the power is turned off.
Also, since the power is turned off, power is not consumed while the same image is displayed, so that the power saving effect is great. Further, since power is consumed only at the time of writing, a power source having a small electromotive force, such as a battery or a solar cell, can be used as a power source. Further, since the power is turned off after the image signal is written, at least the liquid crystal display unit 14 can be removed. It can be used in the same manner as paper, such as holding the liquid crystal display unit 14 on which an image is displayed and viewing it. In addition, if you no longer need the image you left, by writing a new image,
Images can be rewritten.

FIG. 4 is a main block diagram showing a modification of the embodiment of the display device of the present invention. In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals. Reference numeral 15 denotes a mode selection switch. Note that FIG. 4 shows only the main parts, and may include the configuration shown in FIG. 1 not shown. This modification shows an example in which a plurality of liquid crystal display units 14 are provided. Each liquid crystal display unit 14 has
A drive circuit 13 is provided. Mode selection switch 1
Reference numeral 5 denotes a switch for selecting to which of the plurality of liquid crystal display units 14 the image signal is to be written. The liquid crystal display unit 1 to be displayed by the mode selection switch 15
By selecting “4” and operating the image writing start switch, an image signal can be written to the selected liquid crystal display unit 14 and a desired image can be displayed.

The mode selection switch 15 explicitly designates a certain liquid crystal display unit 14, for example, designates that the liquid crystal display units 14 are to be switched in a predetermined order, or displays the same image on a plurality of liquid crystal display units 14. A configuration can be made such that selection corresponding to various display modes, such as designating display, can be performed. If only the liquid crystal display unit 14 to which an image signal is to be written is designated, the mode selection switch 15 may not be provided and a plurality of image writing start switches 9 corresponding to each liquid crystal display unit 14 may be provided.

FIG. 5 is a block diagram of the vicinity of a liquid crystal display unit showing another modification of the embodiment of the display device of the present invention. In the modification shown in FIG. 4, a driving circuit 13 is provided for each liquid crystal display unit 14. In the example shown in FIG. 5, a plurality of liquid crystal display units 1 are driven by a common drive circuit 13.
4 is shown. The common drive circuit 13
For example, according to a selection signal given from the control circuit 6, L
The image signal sent from the CD signal generation circuit 11 is driven to be written to the selected liquid crystal display unit 14. The selection of the liquid crystal display section 14 into which the image signal is to be written can be made by the mode selection switch as in the example shown in FIG. 4 or by the image writing start switch 9 corresponding to each liquid crystal display section 14.

When attaching and detaching the liquid crystal display unit 14, in the example shown in FIG. 4, the liquid crystal display unit 14 alone or the liquid crystal display unit 14 and the drive circuit 13 can be configured to be detachable. In the example shown in FIG. 5, only the liquid crystal display unit 14 can be configured to be detachable.

FIG. 6 is a block diagram showing a first specific example of a system using the display device of the present invention. In the figure, 51 is a computer, 52 is an image transfer unit, 53 is a display button, 5
4 is a display unit, and 55 is a display unit. The computer 51 may be a general personal computer, a work station or the like. In this example, usually, an analog RGB terminal for connecting a CRT or the like is used.

The image transfer section 52 includes, for example, a configuration excluding the drive circuit 13 and the liquid crystal display section 14 in FIG. The display unit 5 receives analog RGB signals from the computer 51 and displays image signals in accordance with user instructions.
Send to 4. The computer 51 and the image transfer unit 52 are connected by a normal monitor cable, and the image transfer unit 52 and the display unit 54 are connected by a dedicated cable. Here, the image transfer unit 52 has an independent power supply, such as a battery, supplies internal power, and is used as a drive power supply for the display unit 54. Of course, receiving power supply from the computer 51,
Alternatively, a commercial power supply may be used. The display button 53
This is the image writing start switch 9 in FIG. Note that the power switch 8 may also be used. In this example, since there are a plurality of display units 55, a mode selection switch 15 as shown in FIG. 4 may be provided.

The display section 54 includes the drive circuit 13 and the liquid crystal display section 14 in FIG. Here, an example in which two display units 55 are provided is shown. Display 55
Is composed of only the liquid crystal display unit 14 or the liquid crystal display unit 14 and the drive circuit 13. Drive power is supplied to the display unit 54 from the image transfer unit 52 only when an image signal is written. When the writing of the image signal is completed, the power supply from the image transfer unit 52 is stopped. The display of the image on the display unit 55 is maintained even after the power supply is stopped. The display unit 55 is configured to be detachable. Unless the image signal is being written, the power is turned off, so there is no problem even if it is attached or detached. After the writing of the image signal is completed, the display unit 55 is detached, and the image can be viewed by holding it in the same manner as paper.

FIG. 7 is a schematic perspective view showing an example of the display unit. In the figure, reference numeral 56 denotes a binder portion. The display unit 55 is mounted on the binder unit 56. The binder unit 56 holds each display unit 55 rotatably. For example, if the two display units are rotated so as to match, the display unit 54 becomes approximately half the size, and is excellent in portability.

The power and image signals from the image transfer unit 52 are received by the binder unit 56 and supplied to each display unit 55. In a configuration in which the drive circuit 13 is provided in common to the plurality of liquid crystal display units 14 as shown in FIG. 5, the drive circuit 13 can be provided in the binder unit 56. The connection between the display unit 55 and the binder unit 56 is connected by a connector in this example. By pulling out the display section 55, the connector section comes off. Further, by inserting the display section 55 into the binder section 56, the connector section is fitted, and electrical connection can be achieved. Of course, an electrical connection method between the binder unit 56 and the display unit 55 is arbitrary.

It is preferable to provide a lock mechanism for the display unit 55 in the binder unit 56 so that the display unit 55 cannot be removed while an image signal is being written on the display unit 55. As the lock mechanism, for example, when power is supplied from the image transfer unit 52, an electromagnetic configuration or the like that locks in response to the power can be used.

FIG. 8 is a perspective view showing an example of the display unit, and FIG.
FIG. 3 is a three-view drawing showing an example of the internal configuration of the display unit. In the figure, 61 is a case, 62 is an image display unit, 63 is an edge connector terminal, 64 is a common side PWB, 65 is a segment side PWB, 66 is a substrate, 67 is a polarizing reflector, 6
8 is a lower electrode film substrate, 69 is an upper electrode film substrate, 70 is a gel-like buffer material, 71 is an upper polarizing plate, 72 is a TAB for a segment driver IC, 73 is a heat seal connector, 74 is a TAB for a common driver IC, 75 is a tape electric wire.

In the example shown in FIG. 8, a display substrate as shown in FIG. The case 61 is provided with an image display section 62. Further, in order to electrically connect with the binder section 56 shown in FIG. 7, an edge connector is used here, and a portion of the edge connector terminal 63 is also provided in the case 61 as an opening. In FIG. 8, the edge connector terminal 63 is exposed for convenience of illustration, but it is preferable to protect the edge connector terminal 63 with the case 61 so that the terminal 63 does not touch the hand. In addition, a part of the lock mechanism can be formed in the case 61 so that the display unit 55 is not accidentally removed during the writing of the image signal. The case 61 can be formed of, for example, an ABS material. The total thickness can be, for example, about 10 mm or less.

The display substrate accommodated in the case 61 is shown in FIG.
Can be configured as shown in FIG. A common-side electrode is formed on the upper electrode film substrate 69, and a segment-side electrode is formed on the lower electrode film substrate 68 so as to be orthogonal to each other. The electrodes can be formed by, for example, ITO, electrodes each having a width of 0.27 mm and a pitch of 0.3 mm. Then, the upper electrode film substrate 69 and the lower electrode film substrate 68 are arranged such that the common-side electrode and the segment-side electrode formed therein are inside, and a polymer ferroelectric liquid crystal is interposed therebetween. On the lower surface of the lower electrode film substrate 68, for example, a polarizing reflection plate 67 such as 3M RDF is bonded, and further on the lower surface,
For example, a substrate 66 made of a 1 mm thick acrylic plate or the like
Is affixed. On the upper surface of the upper electrode film substrate 69, for example, a gel-like buffer material 70 having a thickness of 0.5 mm is adhered, and an upper polarizing plate 71 is adhered to the outside thereof. The number of pixels is determined by the number of segment side (information line side) electrodes and the number of common side (scan line side) electrodes. For example, the number of segment side electrodes × the number of common side electrodes is 640 × 480 pixels, and the display area shown by hatching is 1
It can be about 92 × 144 mm. The number of pixels, display area, and the like are arbitrary.

On the lower electrode film substrate 68, the connection terminals for the TAB of the segment driver IC are formed of ITO, and the TAB 72 for the segment driver IC is directly connected to the A terminal.
They are connected by thermocompression bonding using CF. As the segment driver IC, for example, a commercially available IC for STN liquid crystal can be used. Further outside,
A segment-side PWB 65 for supplying a drive signal to the segment driver IC is provided. The segment driver IC TAB 72 and the segment-side PWB 65 are provided.
65 is connected with, for example, solder.

In the upper electrode film substrate 69, the electrodes are drawn out by ITO while keeping the wiring pitch of the common side electrodes.
3 are connected. Further, the heat seal connector 7
3 and the common driver IC TAB 74 are connected. As the common driver IC, for example, a commercially available common driver IC for STN liquid crystal can be used. And TAB74 for common driver IC
Are connected to the common-side PWB 64 for supplying signals by, for example, solder.

In this example, the terminal 63 for the edge connector is formed on the common side PWB 64. Common side P
WB64 and segment-side PWB65 are tape wires 75
Is used for electrical connection. Of course, it is also possible to provide the edge connector terminal 63 on the segment side PWB 65. In this example, the common side PWB 64, the segment side PWB 65 and the substrate 66 are formed separately.
These may be composed of two or one substrate.

In this example, the drive circuit 13 is connected to the display unit 5
5, and a driving IC is arranged around the display area as shown in FIG. But as mentioned above,
The drive circuit 13 and the display unit 55 may be configured to be separable. In this case, the common driver IC and the segment driver IC may be accommodated in the binder section 56 shown in FIG. In this case, the display unit 55 can be further reduced in size and weight. In addition, these drive circuits 13
If there is not, for example, the entire display substrate can be made of a flexible material. In this case, since the display unit is flexible like paper, it is possible to view images at hand like paper, or to distribute materials like paper at a meeting or the like, for example.

FIG. 10 is a block diagram showing a second specific example of a system using the display device of the present invention. In the figure, 81 is a main body, 82 is a display unit, 83 is a solar cell, and 84 is a display button. In the example shown in FIG. 6, an example is shown in which the image transfer unit 52 and the display unit 54 are configured separately, but in this specific example, an example in which they are integrated is shown. The main body 81 includes a configuration excluding the liquid crystal display unit 14 shown in FIG. 1 or a configuration excluding the liquid crystal display unit 14 and the drive circuit 13. The display unit 82 includes the liquid crystal display unit 14 shown in FIG. 1 or the liquid crystal display unit 14 and the drive circuit 13 and is configured to be detachable from the main body 81. As in the specific example described above, a lock mechanism may be provided so that the display unit 82 is not removed during the writing of the image signal. Note that, in this example, the display unit 82 is set to 2
An example is shown in which one is provided and mounted in a vertically long direction.

A solar cell 83 is provided on the front surface of the main body 81, and serves as a power supply for the entire display device. With the solar battery 83, a display operation can be performed without being connected to a commercial power supply and without being supplied with power from another device. Further, as described above, in the present invention, power is only consumed when an image signal is transferred to the display unit 82, and therefore, driving with the solar cell 83 having a small electromotive force is possible. A storage battery such as a nickel-cadmium storage battery can be combined with the solar battery 83 and charged while the display device is not driven. As a result, it is possible to make display possible even at night or the like. The solar cell 83 may be placed anywhere as long as it is well exposed to light, and need not be provided on the front surface of the main body 81 as in this example.

A display button 84 is provided on the front of the main body 81. In this example, it is provided corresponding to each display unit 82. That is, the configuration is such that a plurality of image writing start switches 9 in FIG. 1 are provided. By operating the display button 84, the image of the image signal being input at that time is displayed on the display unit 82 corresponding to the operated display button 84. The power switch 8 and the mode selection switch 15 shown in FIG. 5 are provided at positions not shown.

A monitor signal input terminal (not shown) is provided on the back of the main body 81, and can be connected to a monitor output terminal of a computer by a monitor cable or the like, for example, as in the specific example shown in FIG. With such a configuration, the display device of the present invention can be used without adding any new software to the computer and without any modification. Further, any computer can be connected.

In each of the first and second embodiments, in addition to receiving the image signal from the computer, various other devices can receive and display the image signal from the device.
For example, if a video input such as NTSC used in television broadcasting is received, the television screen can be easily copied. In particular, text information such as news and text broadcasting, recipes for cooking programs, and prizes can be obtained. Still information that the user wants to temporarily save, such as a destination, can be displayed on the screen. Similarly, an image output from a video camera can be received, and an image in which one scene is stopped can be displayed. In addition, if an output from a digital camera or the like is received, the display unit can be removed and handled in the same manner as a printed photograph.

FIG. 11 is a block diagram showing a third specific example of a system using the display device of the present invention. The reference numerals in the figure are the same as those in FIG. This example shows an example in which a computer and the display device of the present invention are combined. Although FIG. 11 is configured to display two screens, FIG.
As shown in FIG. 5, both the display device of the present invention and the display device of the present invention may be used, for example, with one of them being a conventionally used liquid crystal display device. Since the display device of the present invention is removable, when an image is displayed, it can be removed and viewed at hand. FIG.
Image writing start switch 9 and power switch 8
Can be realized by an electronic switching operation under the control of a computer. For example, display of an image can be instructed by an operation from a keyboard.

As described above, since the display device of the present invention consumes very little power, when it is combined with, for example, a portable computer, the consumption of the battery can be reduced.
By extending the interval between replacement and charging, the convenience can be improved. For example, even in a situation where supplies are insufficient such as in a disaster or the like, even when driven by a battery or the like, it can be used for a long time with low power consumption. by this,
For example, it is possible to receive and display information that changes from moment to moment, and to display the information by removing the display unit.
If the power consumption of the computer itself is small, it is not impossible to operate the computer without supplying energy from other sources such as a solar cell.

Further, for example, an image can be created and displayed by a computer using the display device of the present invention, and can be removed and posted or distributed as it is. At this time, the display image and the print image do not differ from each other as in the case of using paper, and it is possible to post or distribute the image as it is viewed. For example, even in the case of changing a shop menu or a bulletin board depending on the day or between day and night, the image created by the computer can be used as it is. Since power is only consumed when the display is rewritten, the running cost can be greatly reduced.

[0057]

As is apparent from the above description, according to the present invention, the power supply is cut off when the image signal has been transferred for display, so that a display device with very low power consumption can be obtained. Can be. At this time, the displayed image is maintained as it is because the display means has a memory property. Also, since the power is turned off except when the image signal is being written, there is no problem even if the display means is connected or disconnected, and the display means itself is excellent in portability. It can be treated in the same way as paper, such as looking at it. Of course, the display according to the image signal is faster than, for example, a printer. In addition, since unnecessary screens can be erased and new screens can be displayed many times, resources are not wasted like paper. According to the present invention, in addition to such effects, various effects described in the above description are obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a display device of the present invention.

FIG. 2 is a flowchart illustrating an example of an operation in the embodiment of the display device of the present invention.

FIG. 3 is a flowchart (continued) showing an example of an operation in the embodiment of the display device of the present invention.

FIG. 4 is a main block diagram showing a modification of the embodiment of the display device of the present invention.

FIG. 5 is a block diagram showing the vicinity of a liquid crystal display unit showing another modified example of the embodiment of the display device of the present invention.

FIG. 6 is a configuration diagram showing a first specific example of a system using the display device of the present invention.

FIG. 7 is a schematic perspective view illustrating an example of a display unit.

FIG. 8 is a perspective view illustrating an example of a display unit.

FIG. 9 is a three-view drawing showing an example of the internal configuration of the display unit.

FIG. 10 shows a second example of the system using the display device of the present invention.
FIG. 4 is a configuration diagram showing a specific example of the above.

FIG. 11 shows a third example of the system using the display device of the present invention.
FIG. 4 is a configuration diagram showing a specific example of the above.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 monitor signal input terminal 2 protection circuit 3 addition circuit 4 threshold setting circuit 5 binarization circuit 6 control circuit 7 power control circuit 8 power switch 9 image output Start switch, 10 ... frame memory, 11 ... L
CD signal generation circuit, 12 LCD power supply circuit, 13 ...
Drive circuit, 14: liquid crystal display, 15: mode selection switch, 51: computer, 52: image transfer unit, 53: display button, 54: display unit, 55: display unit, 56
... Binder part, 61 ... Case, 62 ... Image display part, 6
3: Terminal for edge connector, 64: PWB on common side, 6
5: Segment side PWB, 66: Substrate, 67: Polarizing reflector, 68: Lower electrode film substrate, 69: Upper electrode film substrate, 70: Gel buffer material, 71: Upper polarizing plate, 72
... TAB for segment driver IC, 73 ... Heat seal connector, 74 ... TAB for common driver IC, 75
... tape electric wire, 81 ... main body, 82 ... display part, 83 ... solar cell, 84 ... display button.

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 5C082 AA01 BA20 BA34 BB15 BD02 CB01 DA81 MM05 MM09 5G435 AA00 BB12 CC12 DD01 EE13 EE18 EE30 EE33 EE37 EE40 EE41 EE42 FF03 FF05 GG21 LL07 LL08

Claims (12)

[Claims] 1. An electronically rewritable display means having a memory property, a drive means for driving the display means in accordance with an image signal, a display power supply means for supplying power to the drive means, Only when it becomes necessary to rewrite the display means with the displayed image signal, the image signal is passed to the drive means, and when the writing to the display means is completed, at least the display power supply means is supplied with power to the drive means. A display device comprising control means for stopping the supply of the liquid. 2. The display device according to claim 1, wherein said display means is configured to be detachable. 3. The display device according to claim 1, wherein a plurality of the display units are provided and are driven by a common driving unit. 4. The display device according to claim 1, wherein the display unit and the driving unit are integrally and detachably configured. 5. The display device according to claim 2, further comprising a lock unit that cannot be removed while at least writing to the display unit is being performed. 6. The display device according to claim 1, wherein said display means is a ferroelectric liquid crystal. 7. The display device according to claim 1, wherein the display power supply unit includes a solar cell. 8. The image processing apparatus according to claim 1, further comprising display instruction means for giving a display instruction by a user, wherein said control means transmits an image signal to said driving means when a display instruction is given from said display instruction means. The display device according to any one of claims 1 to 7, wherein 9. A storage unit for temporarily storing an image signal, and a display signal generating unit for reading the image signal from the storage unit and supplying the image signal to the driving unit, wherein the control unit temporarily stores the image signal. 9. The image processing apparatus according to claim 1, wherein the display signal generation unit supplies an image signal to the driving unit after storing the image signal in the storage unit.
The display device according to item. 10. The apparatus according to claim 1, further comprising power supply operation means for allowing a user to turn on the power of the apparatus, wherein the control means turns off the power supply of the apparatus when the writing to the display means is completed. The display device according to claim 1. 11. The image signal input side according to claim 1, further comprising protection means for protecting a circuit on the image signal supply side when power is turned off.
The display device according to item. 12. The image signal is supplied from an image signal source.
The display device according to any one of claims 1 to 11, wherein the display device is a signal obtained by digitizing a GB analog output.