JPH11288253A - Liquid crystal display device and its using method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device of high practical use which functions as a moving picture screen of a personal computer PC on a desk or functions as a portable document and picture display device as a single substance. SOLUTION: A liquid crystal display device 100 of a note type PC is separated from a PC main body 101, and an incorporated picture memory (desirably, a non-volatile ferroelectric memory) 30 is added to the liquid crystal display part 100, and a selection circuit of incorporated and external picture memories and an incorporated picture memory R/W circuit 22 are added to an incorporated controller 20, and a connection interface 214 with an external device 101 by a digital data high-speed transmission cable is added. Thus, the liquid crystal display device of high practical use is obtained which can be used as a moving picture display device of a general-purpose PC system and as a portable picture display device as a single substance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device having a liquid crystal screen, and more particularly to a portable liquid crystal display device having high versatility.

[0002]

2. Description of the Related Art Personal computers (hereinafter referred to as PCs)
The performance of liquid crystal image display devices used as display screens has been remarkably improved. With the increase in screen size, resolution, and graphic display performance, not only notebook PCs but also desktop PCs have been developed. Is also being adopted.

In a liquid crystal image display device in which image data is transmitted by a digital signal, unlike a CRT display in which image data is transmitted by an analog signal, it is conventionally required to connect a PC to the main body with a cable due to a problem of noise generation at high speed transmission. It was difficult. However, Nikkei Byte 199
As described in February, 2006, pages 158 to 167, recent advances in interface technology have made it possible to connect a digital signal cable between a liquid crystal image display device and a PC main body. FIG. 11 shows a basic configuration of such a general-purpose PC system. Liquid crystal image display device 95
Reference numeral 0 is connected to the notebook PC main body 951 by a digital signal cable 952. For example, a liquid crystal image display device 950 can be connected to a large screen on a desk, and an A4 size can be connected to a portable device. . Further, the above-mentioned document states that not only one-way signal transmission from the notebook PC main body 951 to the liquid crystal image display device 950 but also two-way communication via a digital signal cable 952 will be possible in the future. ing.

[0004] On the other hand, a device specialized in the information retrieval function, which is different from the general-purpose PC system, is disclosed in Japanese Patent Application Laid-Open No. 07-17570.
No. 8 has been proposed. FIG. 12 shows the basic device configuration. The apparatus includes a screen 961, a nonvolatile memory 962 for storing a plurality of sets of still image data, and a controller 96 for selecting one of the plurality of sets of still image data and outputting to the display screen 961.
3 and a switch 964 provided to instruct the controller 963 to select the image. With this device configuration, a function like an “electronic book” can be obtained at low cost.

Further, a device utilizing a liquid crystal screen in various aspects has been proposed in Japanese Patent Application Laid-Open No. 5-213113. This device has a display screen, internal memory,
Means for displaying analog image data sent from the outside on the screen; and data to be displayed on the screen, arbitrarily selected from the data in the internal memory and the analog image data from the outside. Means for synthesizing.

Paying attention to the fact that the liquid crystal display device is space-saving compared to a conventional desk-mounted display, two persons positioned on a desk or the like or placed on a desk and facing each other can easily view the screen. Is proposed in Japanese Patent Application Laid-Open No. 9-274444.

[0007]

SUMMARY OF THE INVENTION The present invention focuses on the above-mentioned cable connection technology capable of transmitting moving image data at high speed by digital signals, and provides a portable liquid crystal image display device which can be utilized in various fields by utilizing the technology. Is what you do.

According to the present invention, a liquid crystal image display device having a relatively large screen of about A4 size, which is thin, suitable for portable use, and has a high resolution and a high-speed moving image display function is provided.
You can connect to a PC with high graphics
It is intended to provide a novel device configuration which can be connected to various other computer systems incorporating U, or can be operated by a liquid crystal image display device alone.

[0009]

According to the liquid crystal image display device of the present invention, a liquid crystal display is connected to a digital signal cable via a digital signal cable capable of high-speed transmission.
It can be electrically connected to the C body. The liquid crystal image display device,
The digital image data such as a document, a moving image, and a still image transmitted from the PC through the digital signal cable is displayed on the liquid crystal screen. The display device has, for example, a volume capacity of about the liquid crystal screen portion of a notebook PC, a size of about A4 size, and a thickness of at most 1c.
m. The liquid crystal image display device includes at least a liquid crystal screen, a built-in image memory for storing image data, a controller, and a power switch. The controller is configured to select one of digital image data transmitted through the digital signal cable and image data in the built-in image memory to be display data, and to transmit the digital image data via the digital signal cable. Means for directly writing incoming digital image data into the built-in image memory. (Claim 1)

In one embodiment of the present invention, the built-in image memory is a nonvolatile ferroelectric memory whose memory cell is constituted by a ferroelectric capacitor and a field-effect transistor, and the controller is connected to the digital signal cable. It has a function of displaying digital moving image data sent via the LCD on the liquid crystal screen and simultaneously writing the digital moving image data to the built-in image memory.
According to another embodiment of the present invention, the built-in image memory is a volatile memory such as a dynamic random access memory (DRAM) and / or a static random access memory (SRAM). Can be configured. (Claim 3)

In another modification of the first embodiment of the present invention in which the built-in image memory is a nonvolatile ferroelectric memory, a clock transmitted from the outside to the liquid crystal image display device via the digital signal cable is used. When the signal is stopped for more than a predetermined time, the controller selects data in the built-in nonvolatile ferroelectric memory as display image data. Alternatively, when the controller receives the clock signal, the controller selects data transmitted via the digital signal cable as display image data. Preferably, the liquid crystal image display device of the present invention is connected to a plurality of common PCs via the digital signal cable, and a user of the common PC can work while viewing a plurality of liquid crystal screens. You. (Claim 5
And 6)

In still another modification of the above embodiment of the present invention, in which the built-in image memory is a nonvolatile ferroelectric memory, a part of the nonvolatile ferroelectric memory is used as a configuration register and a liquid crystal screen. Information on the control, such as the number of dots, color tone, operating frequency, etc., is stored therein. In this case, the digital signal cable is capable of bidirectional communication. (Claim 7)

The liquid crystal display device of the present invention having a digital video signal interface and a built-in image memory functions as a display screen of a PC having advanced graphic functions. PC with the advanced graphic function
Has its own built-in image memory, and the advanced graphic function generates new image data while utilizing information in the PC built-in image memory. (Claim 8)

The liquid crystal display device of the present invention can display the data of the built-in image memory on the liquid crystal screen by itself. Further, the liquid crystal display device of the present invention can be electrically connected to a system with a built-in CPU other than a PC having an advanced graphic function, for example, a mobile phone or a personal digital assistant (PDA) via the digital signal cable. (Claims 9 and 1
0)

A PC having the above-mentioned advanced graphic function
Other than the CPU built-in system, the built-in CPU uses the compressed data stored in the image memory built in the liquid crystal display device as described above.
Is used to generate a plurality of still image data and display the data on the liquid crystal screen of the liquid crystal display device. Also in this case, the digital signal cable is capable of bidirectional communication.
(Claim 11)

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail with reference to the drawings.

Embodiment 1 FIG. 1 shows a basic configuration of a liquid crystal image display device according to an embodiment of the present invention. The image display device 100 includes a liquid crystal screen 1
0, X driver 11 and Y driver 1 for driving this
2, image memory 30, controller 2 for controlling display
0, a switch 40 including at least a power switch. Further, the image display device of the present invention can be connected to a general-purpose computer system (for example, PC body) 101 via a cable capable of transmitting digital signals of moving images at high speed.
The controller 20 includes an image memory selection circuit 21 for selecting one of the built-in image memory 30 and the external image memory 61 and designating data stored therein as display data on the liquid crystal screen 10. The digital image data sent through the internal image memory 30 is directly stored in the internal image memory 30 or the image data in the internal image memory 30 is stored in the liquid crystal screen 1.
0: Built-in image memory for display to 0 Read / Write (R /
W) A point including a circuit 22 is different from a controller provided in a conventional liquid crystal image display device.

From the general-purpose computer system 101,
The power supply voltage, control signal S0, and digital image data signal Dext are transmitted to the image display device 1 via the digital signal cable.
00 is supplied. General-purpose computer system 101
Are well-known CPU 70, memory 80,
It includes a graphic module 60, which is connected by an internal bus BUS-I. The graphic module 60 has an image memory 61. The general-purpose computer system 101 is connected via an external bus BUS-E.
It may be connected to a peripheral device 90 such as a printer or a hard disk drive (HDD).

An outline of the operation when the data in the external image memory 61 becomes display data is as follows. The image memory selection circuit 21 selects the external image memory 61 according to the signal S0 or S1. Data in the external image memory 61 is burst-read under the control of the general-purpose computer system 101, and digital image data Dext is transmitted to the liquid crystal image display device 100. Dext is directly used as the internal image data Dint and sent to the Y driver 12. The signal S0 includes at least the external clock CLKext, and the controller 20 uses this CLKext to generate Din.
Control signals XS and YS for displaying t on the liquid crystal screen 10 at appropriate timing are generated. The above signal flow is the same as in the conventional liquid crystal image display method.

An outline of the operation when the data in the built-in image memory 30 becomes display data is as follows. The image memory selection circuit 21 selects the internal image memory 30 according to the signal S0 or S1, and sends the read signal RS to the built-in image memory R / W circuit 22. Built-in image memory R /
The data in the internal image memory 30 is burst-read by the control of the W circuit 22 (memory control signal MS and address signals A0 to An), and becomes internal image data Dint. The controller 20 uses an internal clock generation circuit (not shown) to set Dint at an appropriate timing at the liquid crystal screen 10.
To generate control signals XS and YS to be displayed.

The outline of the operation when the digital image data Dext sent via the digital signal cable is stored in the built-in image memory 30 is as follows. The built-in image memory R / W circuit 22 starts writing to the built-in image memory 30 according to the signal S0 or S1. That is, the external image data Dext is replaced with the internal image data Dext.
In addition, burst writing to the internal image memory 30 is performed by the memory control signal MS and the address signals A0 to An.

According to the above-described embodiment of the present invention, a liquid crystal image display device which can be used as a liquid crystal screen for high-speed moving image display of a general-purpose computer system or as a stand-alone portable display device can be obtained. In particular, by providing the built-in image memory 30 in a liquid crystal image display device that receives image data as digital signals, there is an effect that the configuration of the device is simplified and the size of the device is easily reduced. That is, the interface with the external device can be shared between displaying external image memory data and receiving write data to the internal image memory 30. No AD converter is required. As a result, the liquid crystal image display device of the present embodiment can be made as thin as the liquid crystal image display device of an existing notebook PC, and is a multipurpose display excellent in portability comparable to an A4 size notebook. A device is obtained. By using the external image memory 61 in the graphic module 60 as an image memory when a general-purpose computer system is connected, the current system form can be utilized as it is, and advanced processing using a graphic accelerator or the like in the module 60 can also be performed. Low noise, low power consumption, and high speed.

Hereinafter, a modified configuration example of the liquid crystal image display device of the first embodiment will be described. FIG. 2 shows a modified configuration example of the controller 20 in the liquid crystal image display device of the first embodiment. In the controller 20 shown in FIG. 1, writing to the internal image memory 30 is configured to be instructed by an external signal S0 or S1. In displaying the data in the external image memory 61 on the liquid crystal screen 10 in the controller of FIG.
Is written at the same time. That is, when the image memory selection circuit 21 selects the external image memory 61 according to the signal S0 or S1 from the outside, the image memory selection circuit 21 outputs the signal from the internal image memory R /
The signal WEB0 to the W circuit 22 becomes "low level". As a result, the data from the external image memory 61 is displayed on the liquid crystal screen 10 at the same time as the internal image memory R / W.
The circuit 22 performs burst writing to the internal image memory 30. When the image memory selection circuit 21 selects the internal image memory 30 according to the signal S0 or S1 from the outside, the signal WEB0 from the image memory selection circuit 21 to the built-in image memory R / W circuit 22 is set to "high level". Become. As a result, built-in image memory R / W circuit 22 performs burst reading of image data from internal image memory 30.

According to the above-described first embodiment and its modifications, the structure of the apparatus is simplified and the effect of improving the usability is obtained. Further, as described later with reference to FIGS. 7 and 8, a multipurpose portable display device can be obtained with a simpler configuration.

When the controller 20 has the configuration shown in FIG. 2, the built-in image memory 30 can be a high-speed read / write following a moving image, for example, a dynamic random access memory (DRAM). A synchronous graphic random access memory (SGRAM) or the like, which is one of the above, is suitable. The storage capacity of the SGRAM is 1 MB to 2 MB in consideration of holding image data of a liquid crystal screen connected to a PC.
is necessary. A more suitable memory is a nonvolatile ferroelectric memory. The flash EEPROM, which is the same non-volatile memory, has a low writing speed and requires an erasing operation, so that writing to the built-in image memory while displaying external image data is impossible. On the other hand, a ferroelectric memory is a nonvolatile memory in which a memory cell is configured by a ferroelectric capacitor and a field-effect transistor, and has a feature that an erasing operation is unnecessary and a writing speed is high. In particular, the 1996 IEICE English language journal volume C separate volume E79-
Volume C, pages 234 to 242 (IEICE Transactions on E
Electronics, vol.E79-C, no.2, pp.234-242, 1996), "Vcc / 2 plate non-volatile DRAM having a ferroelectric capacitor" is a non-volatile DRAM, High-speed burst writing is possible. It is known that a ferroelectric memory has a limit of 10 9 to 12 rewrites. For example, even if one screen is swept for 30 msec, the number of rewrites per memory cell during one year of continuous use is known. Since the number of rewriting is about 10 9, it can be sufficiently used. According to the above embodiment of the present invention in which writing to the built-in ferroelectric image memory is performed while displaying image data from the outside, even if a trouble occurs in the computer system, at least the last working state is displayed as display data. Can be left.

Hereinafter, a more specific example of the circuit configuration of the controller 20 will be described with reference to FIGS. FIG. 3 shows an example of a more specific circuit configuration of the controller 20 in FIG. In FIG. 3, the external clock CL
When Kext (= S0) is stopped for a certain period of time, a reset signal Reset-A is generated and the image memory is automatically switched to the built-in image memory 30. When CLKext is received again from that state, Reset-A is generated at the first clock, and
Dext is displayed on the liquid crystal screen 10 in synchronization with the timing from the next clock. That is, the image memory is switched to the external image memory 61.

FIG. 3 will be described in more detail. FIG.
, The selection circuit 21 starts / stops the internal clock.
It includes an internal clock control circuit 201 for generating a signal to be stopped, an internal clock generation circuit 202 for performing burst reading from the built-in image memory 30, and the like. The control circuit 201 generates a pulse Start when the CLKext has stopped for a certain period of time, and generates a pulse Stop when the CLKext has been received again. An external signal S1 is also input to the control circuit 201, and an internal clock can be generated from the switch 40.
Specific circuit configuration example of control circuit 201 described later (FIG. 4)
Is omitted. Now, the SR register 204 stores
When a pulse is input, the Q output is changed to a high level and the QB output is changed to a low level (set). When a pulse is input to the R input, the Q output is set to a low level.
This is a circuit for causing the QB output to transition (reset) to a high level, and its circuit configuration is well known. The internal clock generation circuit 202 generates the clock CLKint while the high level signal is being input. Latch circuit 203
Latches the input data (in FIG. 3, the QB output data of the SR register 204) at the moment when a pulse is inputted to the Clock input terminal, and latches the latched data until the next pulse is inputted to the Clock input terminal. It is a circuit that keeps outputting, and its own circuit configuration is well known.

The operation of the selection circuit 21 of FIG. 3 is as follows. When CLKext stops for a certain period of time, pulse Start
Occurs, the Q output of the circuit 204 transitions to a high level,
As a result, the circuit 202 generates the internal clock CLKint. Since one input CLKext of the AND circuit 205 is at a low level, its output (that is, one input of the next-stage OR circuit 206) is also at a low level. Therefore,
CLKint becomes the output clock CLK as it is. The output clock CLK is a clock for determining the operation timing of the liquid crystal image display device 100. Q of circuit 204
The output is a signal WE for setting the built-in image memory 30 to either the burst read mode or the burst write mode.
B0, and in this case, WEB0 is set to the high level, that is, the burst read mode. On the other hand, OR
Circuit 207, delay circuit delay 1, inverter I208,
According to the logic configured by the AND circuit 209, the pulse Sta
A pulse Reset-A is generated with the occurrence of rt. Reset-A is a signal for resetting the entire liquid crystal image display device 100 to an initial state.

On the other hand, in the selection circuit 21, the pulse Sta
When CLKext is received again after the occurrence of rt, the pulse S
The occurrence of top causes the Q output of the circuit 204 to transition to a low level, thereby stopping the internal clock CLKint. Also, an OR circuit 207, a delay circuit delay 1, an inverter I
208, the pulse Reset-A is generated by the logic constituted by the AND circuit 209. CLKext is the AND circuit 2
05, and is output as CLK from the second clock through the OR circuit 206. That is, the Q output transitions to the low level and the QB output transitions from the low level to the high level, but the output of the latch circuit 203 is reset.
-A transitions from low level to high level when falling. The fall timing of Reset-A can be set to an appropriate value by adjusting the delay time by the delay circuit delay1. As a result, the second and subsequent clocks of CLKext pass through the AND circuit 205. At this time, CLKint is at the low level, and further passes through the OR circuit 206 to become the output clock CLK. Note that the pulse Stop
Occurs, the output signal WEB0 transitions to the low level, and the built-in image memory 30 is set to the burst write mode. That is, the image data corresponding to the liquid crystal screen 10 is always stored and updated in the built-in image memory 30.

The above three signals generated by the selection circuit 21
Based on Reset-A, CLK, and WEB0, the control signals XS and YS of the X driver 11 and the Y driver 12 are the driver control circuit 23, and the control signal MS of the image memory 30 and the address signals A0 to An are stored in the built-in image memory R. / W circuit 22
, Respectively. In the driver control circuit 23, the delay setting circuit 211 allows CLK to pass as CLK-D without delay when the external image memory 61 is selected, and causes CLK to pass through several clocks when the built-in image memory 30 is selected. After being delayed by a minute, the signal is passed as CLK-D. This delay corresponds to the latency in the burst reading of the image memory 30 (the delay from the first clock input to the output of the first data). In the built-in image memory R / W circuit 22, the address counter 212 resets at Reset-A,
The count is incremented by LK, and an address of the image memory 30 is generated. The memory control signal generation circuit 213
When 0 is at the high level, the image memory 30 is set to the burst read mode. When WEB0 is at the low level, the image memory 30 is set to the burst write mode. This setting signal is a control signal MS
include. Furthermore, a clock CLK that matches the clock CLK
Based on −M, a control signal MS of the image memory 30 is generated according to the memory specification. In the simplest case, WEB
When 0 is at the high level, the first data is output from the image memory 30 several clocks later than the first clock of CLK-M by the latency, and thereafter, CLK-M is output.
Data is burst output in synchronization with M. When WEB0 is at the low level, burst writing to the image memory 30 is performed in synchronization with CLK-M. Interface circuit 21
Reference numeral 4 denotes a circuit for receiving image data Dext sent from the outside via a cable at a high speed. The internal image data Dint matches the external image data Dext when WEB0 is at a low level, and becomes the output data from the built-in image memory 30 when WEB0 is at a high level. Note that, in the circuit of FIG.
It should be noted that since the first clock of ext is used for generation of Reset-A, data Dext synchronized with this is not displayed on the screen.

FIG. 4 shows a specific circuit configuration example of the internal clock control circuit 201. While the circuit 201 is receiving CLKext, even if the potential of the node N303 transitions to a high level beyond the inversion threshold level of the inverter I307 by the time constant determined by the resistor R304 and the capacitor C305, the field-effect transistor M306 remains Periodically turned on and node N
303 is reset to the ground potential. That is, the output of the inverter I308 periodically transitions between a high level and a low level. The frequency of CLKext may be high enough to always set the output of the inverter I308 to low level. After the input Set transitions to the high level, the timer 301 determines that the input Reset does not transition to the high level within a predetermined time range defined by the timer.
A pulse is output to the output Out. Therefore, while CLKext is being received, the timer 301 is periodically reset, so that the output Out is maintained at a low level. However, when CLKext stops for a predetermined time set by the timer, a pulse is generated in the output Out. . That is, a Start pulse is generated. On the other hand, the SR register circuit 302 outputs the signal Sto
is involved in p. This circuit 302 corresponds to the circuit 20 described above.
This circuit operates in the same manner as in FIG. 4, and its output Q is maintained at a high level while CLKext is being received. When CLKext is stopped and a Start pulse is generated for a predetermined time set by the timer, the output Q changes to low level. According to the operation of the circuit 302, the output Q transitions from the low level to the high level at the moment when the CLKext, which has been stopped until then, is received again, the delay circuit delay2, the inverter I310, the AND
The rising edge is detected by the logic constituted by the circuit 311 to generate a Stop pulse, and the switching from the internal image memory 30 to the external image memory 61 can be performed as shown in FIG. Note that I309 is an inverter.

FIG. 5 shows a memory control signal generation circuit 213.
Shows how the state of the built-in image memory 30 is set according to the state of WEB0. When WEB0 is at the high level, the control signal MS designates and controls burst read, and read data is output from the image memory 30. When WEB0 is at the low level, the control signal MS
Designates and controls burst writing, and sets the output of the image memory 30 to a high impedance state.

FIG. 6 shows how the image memory can be switched according to the circuits of FIGS. After the power is turned on, the predetermined time set by the timer elapses without receiving CLKext, or
If the predetermined time determined by the timer elapses after the reception of t is stopped, a Start pulse is generated. As a result, a pulse Reset-A is generated, the states of the X driver 11 and the Y driver 12 are reset (not shown), and the address counter 212 for specifying the address of the built-in image memory 30 is reset. Further, the Start pulse causes WEB0 to transition to the high level, and sets the built-in image memory 30 to the burst read state. When WEB0 transitions to the high level, the internal clock generation circuit 202 becomes active and generates CLKint. In FIG. 6, the active timing of the circuit 202 is set so that the first clock of CLKint (that is, the operation clock CLK) is generated after the reset operation. In synchronization with the first rising of clock CLK, reading of address “0... 00” (= 0) in built-in image memory 30 is instructed. Next, the address is counted up in synchronization with the falling edge of CLK, and the address "0... 01" (= 1) in synchronization with the second rising edge of CLK.
Is read. In this way, burst reading of the built-in image memory 30 is instructed. If the read latency of the built-in image memory 30 is, for example, 3, the address “0” is already set at the fourth rising edge of CLK.
.., 00 "(= 0) has been completely output to Dint. The delay at the time of WEB0 high level in the delay setting circuit 211 is set to 3 clocks, and 4
The first clock of the clock signal CLK-D of the X driver 11 and the Y driver 12 is generated in synchronization with the second rising. In this manner, the image data in the built-in image memory 30 is sequentially displayed on the liquid crystal screen 10.

In FIG. 6, when CLKext is received again, the Stop signal transitions to the high level at the first rise of CLKext. As a result, a pulse Reset-A is generated, the states of the X driver 11 and the Y driver 12 are reset (not shown), and the built-in image memory 30 is reset.
Is reset. Also, the rise of the Stop signal is WEB
By changing 0 to a low level, the built-in image memory 30 is set to a burst write state, and Dext is set to be taken in from outside as Dint. In synchronization with the fall of Reset-A, the latch circuit 203 and the AND circuit 2
05 and the operation of the OR circuit 206 allow CLKext to be taken in as the operation clock CLK. As a result, the operation clock CLK is generated in synchronization with the second and subsequent CLKext. In the delay setting circuit 211, WE
When B0 is at the low level, the delay time is set to 0 clock, and CLK-D is generated in synchronization with CLK. Since image data Dext is sent from the outside in synchronization with the second and subsequent CLKext, the D
int is displayed on the liquid crystal screen 10 in synchronization with CLK-D. In the internal image memory 30, WE
Burst writing is performed in response to B0 being at a low level. The generation of the address is performed by reset-A in the address counter 212 as in the case of the burst read.
And a count-up operation synchronized with the falling edge of CLK.

Hereinafter, a method of using the liquid crystal image display device 100 according to the present invention will be described with reference to FIGS.

<Embodiment 2> FIG. 7 shows a liquid crystal image display device 1.
00 is a general-purpose computer system (PC body, etc.) 101
Shows a case in which a cable is used for connection. The liquid crystal image display device 100 is a multi-connector 60 for an image display device.
3 can be connected to a plurality of computer systems 101. The liquid crystal image display device 100 has a size of, for example, about A4 size, and is installed in an arbitrary orientation such as vertical or horizontal using the partition 601. The image data in the image memory 61 in the system 101 is transferred to a plurality of liquid crystal image display devices 1.
00 is transmitted, for example, in system 1
01 from the keyboard 602 connected to
This can be performed by switching and using the multi-connector 603. Note that the liquid crystal image display device 100 that has stopped receiving external image data from the system 101 is
As described above, the circuit configuration shown in FIGS. 2 to 6 automatically switches to receiving the output data from the built-in image memory 30, so that the display image data immediately before the reception of the external image data is stopped is displayed on the display screen. to continue. Also,
When the transmission of the external image data from the system 101 is completely stopped for any of the liquid crystal image display devices 100, the liquid crystal image display device 100 converts the display image data immediately before the reception is interrupted for each display device to each of the display devices. Keep displaying on the display screen. In the system 101,
It is necessary to set in advance the environment (setting such as vertical or horizontal positioning, number of dots on the display screen, color tone, operating frequency, etc.) corresponding to each liquid crystal image display device 100 connected thereto.

According to the second embodiment of the present invention, a comfortable working environment such as the creation of the document B while referring to the document A can be obtained. Further, it is not necessary to drive the connection cable between the liquid crystal image display device 100 and the computer system 101 unnecessarily, so that power consumption can be reduced. This is because, when the work screen is switched from the first image display device to the second image display device, the first image display device in which the display data does not change uses the contents stored in the built-in image memory as the display data. is there. Alternatively, even when the work screen is not switched, when a still image is displayed, transmission of data from the system 101 can be stopped (that is, automatically switched to the built-in image memory). In particular, if the above-described modification of the first embodiment and the controller configuration described with reference to FIGS. 2 to 6 are applied, the above effects can be obtained with a simple control and configuration.

Embodiment 3 FIG. 8 shows a liquid crystal image display device 1
An example is shown in which the portable information device 701 rewrites image data in the internal image memory 30 of 00 and displays the rewritten image data on the screen 10 of the display device 100. Examples of the portable information device 701 include a mobile phone and a PDA. Since the portable information device 701 normally has an IC card slot, an IC card on which compressed image data is recorded is inserted into this slot, and the recording data is loaded into a memory in the portable information device 701. Portable information device 701
The compressed image data loaded is decompressed by using the CPU in the CPU and transmitted to the display device 100 as image data. It is convenient from the viewpoint of portability that the compressed image data is stored in the built-in image memory 30 of the liquid crystal image display device 100 instead of the IC card. Also in this case, since the display device 100 cannot directly display the compressed image data, the compressed image data is temporarily loaded into the memory of the portable information device 701, and then the compressed image data is loaded using the CPU of the portable information device 701. After decompressing the compressed image data,
It is transmitted to the display device 100 as image data again.
However, the liquid crystal image display device 100 and the portable information device 701
And a digital signal cable for bidirectional communication, and a built-in image memory 3 of the liquid crystal image display device 100.
It is necessary that the compressed image data of 0 can be read out to the outside.

In FIG. 8, a connector card 702 for an image display device which can be inserted into an IC card slot is used in order to match the output interface of the portable information device 701 with the input interface of the display device 100. . It should be noted that the portable information device 701 transmits the display device 100
The transmission of the image data to the display device 100 is intended for writing into the built-in image memory 30 of the display device 100, and therefore, the transmission frequency may be lower than the frequency corresponding to the screen display. In particular, according to the configuration described in the modification of the first embodiment,
After the writing of the image data to the built-in image memory 30 is completed, the transmission clock from the portable information device 701 is interrupted, so that the written image data is automatically displayed on the liquid crystal display screen.

The method of use in the third embodiment focuses on the fact that portable information equipment 701 having a built-in CPU is now widely used, and that it has sufficient functions as a computer system except for a display function. . The liquid crystal display device of the present invention greatly improves the use environment of these various portable information devices (from the viewpoint of enlargement of the display screen). Further, when the liquid crystal display device of the present invention is used alone, on the contrary, the CP of these widely used portable information devices is used.
There is also an effect that the use environment of the liquid crystal display device of the present invention can be significantly improved by utilizing the U function. That is, for a high-definition liquid crystal screen that is A4 size and has a large screen and is also assumed to be connected to a PC or the like, the image data capacity of 1 to 2 MB per screen is required. It is difficult to hold several pages of image data in the memory. By utilizing the CPU of the portable information device 701 to decompress the compressed image data, the built-in image memory 3
The image information compressed and recorded at 0 can be displayed, and much image data can be displayed on the liquid crystal screen 10 of the liquid crystal display device 100.

FIG. 9 shows an example in which the battery pack 801 is connected to the liquid crystal display device 100 and the liquid crystal display device 100 is used alone. As described in FIG. 8, the number of image data sets that can be stored in the built-in image memory 30 is not large. However, by dividing the liquid crystal display screen 10 into a plurality of screens, it is possible to display more image data sets while each screen is small.

<Embodiment 4> FIG.
1 is a configuration example of a liquid crystal image display device of the present invention using a nonvolatile ferroelectric memory as 0. Non-volatile image memory 90
0 indicates that a part of the memory cell is a configuration register 901 and the liquid crystal image display device 10
0 between the data D and the general-purpose computer system 101
The exchange of ext is bidirectional. The configuration register 901 stores vendor information and device information of the liquid crystal image display device 100. When the general-purpose computer system 101 is connected, the stored information is stored in the system 1
01, the driving method of the display device 100 is determined. The configuration according to the fourth embodiment further improves the usability as a liquid crystal image display device.

Further, in FIG. 10, the general-purpose computer system 101 is provided with a power supply stop circuit 9 at the time of resume.
02 is provided. When the system 101 enters the resume mode, power supply to the liquid crystal image display device 100 is stopped. If the control signal S0 is inactive when the power is supplied to the liquid crystal image display device 100 again, the image data in the built-in nonvolatile image memory 900 described above is read, and the image display is reproduced. With this configuration, the effect of reducing power consumption can be obtained.

As shown in FIG. 10, if the built-in image memory 30 is a nonvolatile ferroelectric memory, no power is supplied when the liquid crystal image display device 100 is carried (non-display). There is also the advantage that it can be used.

[0045]

According to the present invention, a highly utilizable liquid crystal display device which can be used as a moving image display device of a general-purpose computer system or as a portable image display device can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic configuration of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a modified configuration example of a controller 20 in FIG. 1;

FIG. 3 is a diagram showing a more specific circuit configuration example of a controller 20 in FIG. 2;

FIG. 4 is a diagram showing a specific circuit configuration example of an internal clock control circuit 201 in FIG. 3;

FIG. 5 is an operation explanatory diagram of the memory control signal generation circuit 213 in FIG. 3;

FIG. 6 is a diagram showing how the image memory is switched in FIGS. 3 and 4;

FIG. 7 is a diagram showing an example of a method for using the liquid crystal image display device according to the present invention.

FIG. 8 is a diagram showing another example of a method for using the liquid crystal image display device according to the present invention.

FIG. 9 is a diagram showing still another example of a method for using the liquid crystal image display device according to the present invention.

FIG. 10 is a diagram showing a configuration example of a liquid crystal image display device of the present invention using a nonvolatile ferroelectric memory as a built-in image memory.

FIG. 11 is a diagram showing a basic configuration example of a general-purpose PC system using a conventional liquid crystal image display device.

FIG. 12 is a diagram showing a basic configuration example of an information search device using a conventional liquid crystal image display device.

[Explanation of symbols]

10: LCD screen, 11: X driver, 12: Y driver, 20: Controller, 21: Image memory selection circuit, 22: Built-in image memory R / W circuit, 23: Driver control circuit, 30 ... Internal image memory, 40 ... Switch, 60 ... Graphic module, 61 ... External image memory, 70 ... CPU, 80 ... Memory, 90 ... Peripheral device, 100 ... Liquid crystal image display device, 101 ... … General-purpose computer system, 201… internal clock control circuit, 202… internal clock generation circuit, 203… latch circuit, 204… SR register, 205… AND circuit, 206… OR circuit, 207…… OR circuit , I208 ...... Inverter, 209 ...... AND circuit, 211 ...... Extension setting circuit, 212 ... Address counter, 213 ... Memory control signal generation circuit, 214 ... Interface circuit, 301 ... Timer, 302 ... SR register, N303 ... Node, R304 ... Resistance, C305 ... Capacity , M306 ... field-effect transistor, I307 ... inverter, I308 ... inverter, I309 ... inverter, I310 ... inverter, 311 ... AND circuit, 601 ... screen, 602 ... keyboard, 603 ... multi-connector, 701: portable information equipment, 702: connector card, 801: battery pack, 900: nonvolatile image memory, 901: configuration register, 902: power supply stop circuit, delay 1: delay circuit, delay 2 ...... Delay circuit, A0 to An Built-in image memory address signal, MS ... Built-in image memory control signal, XS ... X driver control signal, YS ... Y driver control signal, S0, S1 ... Control signal, Dint ... Internal image data, Dext ... External image data, BUS-I ... Internal bus signal, BUS-E ... External bus signal, CLKext ... External clock signal, CLKint ... Internal clock signal, CLK ... Operation clock signal, Start: Internal clock generation signal, Stop: Internal clock stop signal, Reset-A: Reset signal, WEB0: Burst read / write setting signal.

Claims (11)

[Claims] 1. A liquid crystal display device having at least a liquid crystal screen for displaying a document, a moving image, and a still image, a driver circuit for the liquid crystal screen, a first image memory, and a controller circuit. The display device can be connected to an external device that can generate digital image data via a digital signal cable capable of transmitting a moving image, and the controller circuit reads image data from the first image memory and reads the image data on the liquid crystal screen. A first means for displaying, a second means for displaying digital image data transmitted from the external device to the liquid crystal display device via the digital signal cable on the liquid crystal screen, and a second means for displaying the digital image data via the digital signal cable. The digital image data sent from the external device to the liquid crystal display device directly to the first image memo. The liquid crystal display device characterized by having a third means for writing the. 2. The nonvolatile memory according to claim 1, wherein said first image memory is a nonvolatile ferroelectric memory in which a plurality of memory cells each comprising a ferroelectric capacitor and a field effect transistor are arranged in a matrix. Liquid crystal display device. 3. The image processing apparatus according to claim 1, wherein the first image memory is a dynamic image memory.
Random access memory (DRAM) and / or static random access memory (SRA)
2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a volatile memory made of M). 4. The controller circuit displays the digital image data transmitted via the digital signal cable on the liquid crystal screen by the second means, and at the same time, displays the digital image data by the third means. 4. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is configured to write data into an image memory. 5. The controller circuit according to claim 1, wherein a display control clock signal is sent from said external device to said liquid crystal display device via said digital signal cable for display control on said liquid crystal screen by said controller circuit. 5. The method according to claim 4, wherein the second period is performed by the second unit, and the predetermined period after the supply of the clock signal is stopped is performed by the first unit. Liquid crystal display device. 6. The computer system according to claim 4, wherein said external device is a general-purpose computer system having a second image memory, and said liquid crystal display device is connected to said general-purpose computer system. How to use the liquid crystal display device. 7. The liquid crystal display device according to claim 2, wherein information related to the control method of the liquid crystal screen is stored in a part of the plurality of memory cells of the nonvolatile ferroelectric memory. 8. The external device is a general-purpose computer system having a second image memory. The general-purpose computer system reads out information in the second image memory and uses the information to generate new image data. 2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is configured to generate the data. 9. The external device is a first computer system having a graphic accelerator including a second image memory or a second computer system having no graphic accelerator, and the controller circuit is configured to control the liquid crystal by the controller circuit. The display control on the screen is performed using the second means when the external device is the first computer system, and the control is performed when the external device is the second computer system. 2. The liquid crystal display device according to claim 1, wherein the operation is performed by using the first means after using the three means. 10. The computer system according to claim 1, wherein the second computer system is a mobile phone or a personal digital assistant (P).
10. The liquid crystal display device according to claim 9, wherein DA). 11. The first image memory stores compressed image data which can be converted into a plurality of still image data according to a predetermined rule. The second computer system reads out the compressed image data and reads the compressed image data from a built-in CPU. 10. The method according to claim 9, wherein the still image data is converted into the still image data according to (1), and the still image data is displayed on the liquid crystal screen.