JP2001255850A - Liquid crystal display device and information portable equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption by providing an area where information are always displayed and an area where information are displayed only at a necessary time on a sheet of a liquid crystal panel in an active matrix type liquid crystal display device. SOLUTION: The display area of a liquid crystal panel is divided into a first display area 12 and a second display area 13. The scanning line G1 of a scanning line driving circuit 16 is assigned to the first display area 12 and scanning lines G2 to Gn are assigned to the second display area 13 and respective scanning lines are successively selected. A signal line driving circuit 17 outputs a display signal via signal lines S1, S2... and a counter electrode driving circuit 19 applies an counter voltage to a counter electrode 18. In the case of displaying information only on the first display area 12, when the scanning lines G2 to Gn are selected, the signal line driving circuit 17 outputs a voltage equal to the voltage Vcom of the counter electrode 18 as the display signal to the signal lines S1, S2....

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 for displaying two types of information, such as portable telephones, which are required to be small, light, and power-saving, and are to be displayed constantly and to be displayed as needed. The present invention relates to a device and an information portable device using the liquid crystal display device.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have attracted attention in terms of thinness and power saving, and have been put to practical use as display devices for many information portable devices such as mobile phones. FIG. 6 is an external view showing an operation surface of a conventional mobile phone, and has an operation unit including a large number of push buttons and a display unit 1 for displaying an operation state, a telephone number, and the like. FIG. 7 is an enlarged view of the display unit 1, in which the remaining amount of the battery and the electric field strength are displayed as information on the operation state.
As the setting information, a date, a current time, a telephone number, and the like are displayed.

In FIG. 6 and FIG. 7, an STN liquid crystal is used for a display unit 1 of a conventional mobile phone, and information that is always required when the power is turned on, such as a battery remaining amount, an electric field strength, and incoming call information; Setting information whose display timing is limited, such as a telephone number, is displayed on the same panel.

In portable video equipment (not shown), information that is always displayed, such as the current time, is displayed on a panel using STN liquid crystal, and video information is displayed on a panel using active matrix liquid crystal with excellent image quality. Some displays each information in a separate panel, such as displaying.

[0005]

However, in cellular phones, after 2000 AD, infrastructures for transmitting not only voice and text information but also video are provided. As a result, when the power is turned on, it is required that information that should be constantly displayed, such as the remaining battery level, and information that should be displayed only when necessary, such as video information, be displayed on the same display panel. In order to display video information, it is desirable to use an active matrix liquid crystal panel suitable for video display in the display unit.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and uses a single active matrix liquid crystal panel to increase power consumption by displaying information that is always displayed and information that is displayed only when necessary. It is an object of the present invention to realize a liquid crystal display device capable of displaying without accompanying.

[0007]

According to a first aspect of the present invention, a plurality of scanning lines and a plurality of signal lines are provided on a transparent substrate,
A switching element is provided at an intersection of the scanning line and the signal line, and a liquid crystal panel in which a liquid crystal cell is disposed between a driving electrode and a counter electrode of the switching element, and each scanning line of the liquid crystal panel is sequentially arranged. A scanning line driving circuit for controlling the timing of applying a display signal for one row to the liquid crystal cell every one horizontal period, and one line selected by the scanning line driving circuit.
A liquid crystal display device comprising: a signal line driving circuit that outputs a display signal for applying a pixel voltage to liquid crystal cells of a row; and a counter electrode driving circuit that applies a counter voltage to a counter electrode of each liquid crystal cell. A first display area for constantly displaying information on the liquid crystal panel when the power is turned on, and a second display area for displaying information only when necessary.

According to a second aspect of the present invention, in the liquid crystal display device of the first aspect, the signal line driving circuit switches the first display area when it is not necessary to display information in the second display area. Except when driving, a voltage equivalent to the common voltage output from the common electrode driving circuit is output to each signal line instead of the display signal.

The invention of claim 3 of the present application is directed to claim 1 or 2
In the liquid crystal display device, at least one of the signal line drive circuit, the scan line drive circuit, and the counter electrode drive circuit is independent of a first display area and a second display area of the liquid crystal panel. Is provided.

According to a fourth aspect of the present invention, in the liquid crystal display device according to any one of the first to third aspects, at least one of the signal line driving circuit, the scanning line driving circuit, and the counter electrode driving circuit is provided. And a low-temperature polysilicon transistor formed on the transparent substrate.

According to a fifth aspect of the present invention, in the liquid crystal display device according to any one of the first to fourth aspects, each of the first display area and the second display area is individually connected to an external circuit. A signal connection portion is provided.

According to a sixth aspect of the present invention, a liquid crystal display device according to any one of the first to fifth aspects is provided in an information display section.

According to a seventh aspect of the present invention, in the portable information device of the sixth aspect, the first display area displays information relating to an operation state of the portable information apparatus, and the second display area includes an image. And information including characters.

[0014]

(Embodiment 1) A liquid crystal display device according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a circuit configuration diagram of the liquid crystal display device according to the present embodiment. A display area 11 indicated by a dotted line is formed on a liquid crystal panel of an active matrix using a transparent substrate, and has a first display area 12 for constantly displaying information when the power is turned on, and displaying information only when necessary. And a second display area 13. The first display area 12 is scanned by a scanning line G1, and the scanning line G1 is a scanning line driving circuit 1.
6 is connected to the first output terminal. The information in the second display area 13 is scanned by scanning lines G2 to Gn,
Gn are connected to the second output terminal to the n-th output terminal of the scanning line driving circuit 16, respectively.

In the display area 11, scanning lines G1, G2,... Gn and signal lines S1, S2 formed on the first transparent substrate are formed.
The switching element 14 is arranged at the intersection with 2.
A liquid crystal cell 15 is arranged on a drive electrode portion of the switching element 14. The switching element 14 is formed of, for example, a polysilicon thin film transistor (TFT). The scanning line driving circuit 16 sequentially scans each of the scanning lines G1, G2,... Gn and selects one row of pixel columns every one horizontal period. The signal line driving circuit 17 outputs a display signal via each of the signal lines S1, S2,..., And controls the switching element 14 for one row of liquid crystal cells selected by the scanning line driving circuit 16 within one horizontal period. The pixel voltage is applied via Further, a counter electrode 18 is provided on the second transparent substrate with each liquid crystal cell 15 inserted. The common electrode driving circuit 19 applies a common common voltage to all the liquid crystal cells via the common electrode 18. As described above, the drive voltage equal to the difference between the display signal and the counter voltage is applied to each liquid crystal cell 15, and the optical characteristics of the liquid crystal cell 15 are controlled.

FIG. 2 shows a portable telephone as an example of an information portable device equipped with the liquid crystal display device of the present embodiment. The mobile phone has an operation unit including a large number of push buttons, and a display unit 20 for displaying an operation state, a telephone number, and the like. FIG. 3 is an enlarged view of the display unit 20. The display unit 20 includes a first display area 21 that constantly displays information on the operating state when the power of the mobile phone is turned on, and a second display area that displays input information such as a telephone number and transmitted image information when necessary. 22.

The display section 20 of the liquid crystal display device uses an active matrix liquid crystal panel. First display area 2
1 displays information that is always needed, such as the remaining battery level and incoming call information, and is provided with the scanning line G1 in FIG. The structure of the pixel electrode in the first display area 21 is not a dot shape as in the second display area 22, but is a segment shape having a battery mark and an antenna mark as shown in FIG. FIG.
In the figure, the number of signal lines in the first display area 21 and the number of signal lines in the second display area 22 are shown as the same number. In this case, a plurality of signal lines are connected to the same segment. .
However, the number of signal lines in the first display area 21 may be smaller than the number of signal lines in the second display area 22. In the second display area 22, images and characters are displayed in a multiplex manner, and the scanning lines G are displayed.
2 to Gn.

FIGS. 4 and 5 are operation timing diagrams of the liquid crystal display device according to the present embodiment. FIG. 4 is a timing chart when displaying information in both the first display area 12 and the second display area 13. FIG. 5 is a timing chart when information is displayed only in the first display area 12 and the second display area 13 is not displayed.

The operation of the present embodiment will be described below with reference to FIGS. 1, 4 and 5. When the start signal VS shown in FIG. 4 is supplied, the scanning line driving circuit 16 outputs the horizontal clock HS.
, The scanning lines G1 to Gn are sequentially selected. The signal line drive circuit 17 transmits the data D to be displayed to the clock signal CLK.
, And each signal line Si (i = 1, 2,...
・ Display signal is output via). In FIG. 4, H
Data of the first display area 12 is fetched in synchronization with S-1, data of the second display area 13 is fetched in synchronization with HS-2 to HS-n, and information is stored in each display area. Are displayed at the same time.

FIG. 5 shows the operation in the case where the information of only the first display area 12 is displayed and the second display area 13 is not displayed. The data input to the signal line driving circuit 17 and the clock signal CLK are present only in the portion corresponding to the first display region 12 and not in the portion corresponding to the second display region 13. The signal line driving circuit 17 outputs the display signal Vsig to a portion corresponding to the first display area 12, but outputs the second display signal Vsig.
The portion corresponding to the display region 13 outputs a direct-current (DC) counter voltage Vcom. This common voltage Vcom is substantially equal to the output voltage of the common electrode drive circuit 19. As a result, operation information such as the remaining amount of the battery and the electric field strength of the base station is displayed in the first display area 12, and the driving voltage of the liquid crystal cell 15 becomes zero in the second display area 13 so that no operation information is displayed. Display.

In the liquid crystal display device configured as described above, a first display area that always needs to be displayed when the power is turned on, and a second display area that displays information only when necessary,
It can be formed by one active matrix liquid crystal panel. Compared to the case where two active matrix liquid crystal panels are used, the number of circuit components, the volume of the liquid crystal display device, and the display area occupied by the liquid crystal panel can be increased. Further, in the present embodiment, when the second display area is set to non-display, the clock signal CLK and data input are stopped, so that power consumption can be reduced.

Further, in this embodiment, the output voltage of the signal line in FIG. 5 is set to Vcom of DC, but Vcom is not limited to DC, and may be AC if it is the same as the drive voltage of the counter electrode. Absent. Furthermore, in the present embodiment, the first display area has one scanning line, and the display of the first display area is segment display. However, the display is driven by a plurality of scanning lines, and the remaining battery level and incoming information are displayed in a dot matrix display. It is also possible to use

Embodiment 2 Next, a liquid crystal display device according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 8 is a circuit configuration diagram of the liquid crystal display device according to the present embodiment, and the same parts as those in FIG. 1 will be described with the same reference numerals.

The display area 11 indicated by the dotted line is composed of a first display area 12 for always displaying information when the power is turned on, and a second display area 13 for displaying information only when necessary. First
Are scanned by scanning lines G11 to G1m, and the scanning lines G11 to G1m are
a is connected to the output terminal. The information in the second display area 13 is scanned by scanning lines G21 to G2n, and is scanned by a scanning line G21.
G2n are connected to the output terminal of the scanning line driving circuit 16b.

In the display area 11, scanning lines G11-G
1m and the signal lines S11, S12,... And the scanning lines G21 to G2n and the signal lines S1, S2,. A liquid crystal cell 15 is arranged on the drive electrode section. The scanning line driving circuit 16a includes scanning lines G11 to G1.
m is sequentially scanned to select one row of pixel columns every one horizontal period. The scanning line driving circuit 16b is connected to each of the scanning lines G21 to G2.
n is sequentially scanned to select one row of pixel columns every one horizontal period. Each of the signal lines S11, S12,... Is connected to the signal line driving circuit 17a, and writes a display signal to one row of liquid crystal cells selected by the scanning line driving circuit 16a within one horizontal period. Each of the signal lines S21, S22,... Is connected to the signal line driving circuit 17b, and writes a display signal to one row of liquid crystal cells selected by the scanning line driving circuit 16b within one horizontal period.

A counter electrode 18 is provided on the second transparent substrate with each liquid crystal cell inserted. Counter electrode drive circuit 19
Applies a common counter voltage to all the liquid crystal cells via the counter electrode 18. As described above, the drive voltage having the difference between the display signal and the counter voltage is applied to each liquid crystal cell 15, and the liquid crystal cell 15
Is controlled.

To display information in the first display area 12, when a start signal VS is supplied, the scanning line driving circuit 16a causes the scanning lines G11 to G11 to synchronize with the horizontal clock HS1.
G1m are sequentially selected. The signal line drive circuit 17a captures the data D1 to be displayed in synchronization with the clock signal CLK1, and outputs a display signal via each signal line S1i (i = 1, 2,...). When displaying information in the second display area 13, when the start signal VS is supplied, the scanning line driving circuit 16b sequentially selects the scanning lines G21 to G2n in synchronization with the horizontal clock HS2. Signal line drive circuit 17
b fetches the data D2 to be displayed in synchronization with the clock signal CLK2, and the signal lines S2i (i = 1, 2,...)
The display signal is output via the. As described above, in synchronization with HS1, the data in the first display area 12 is fetched,
In synchronization with 2, the data in the second display area 13 is fetched, and the information is displayed simultaneously or independently in each display area. In this case, the signal line drive circuits 17a and 17b output the counter voltage Vcom as a display signal when one of the display regions is not displaying.
Need not be output, and can be controlled only by selecting the scanning line.

According to the present embodiment, the same effect as that of the first embodiment can be obtained, and the scanning line driving circuit and the signal line driving circuit are individually provided in the first display region 12 and the second display region 13. , The signal line drive circuits 17a, 17a,
7b can reduce the frequency of the clock signal and the data signal. Therefore, the power consumption of the liquid crystal display device can be further reduced. In this embodiment mode, both the scanning line driving circuit and the signal line driving circuit are provided as separate circuits. However, the same effect can be obtained by dividing only the signal line driving circuit and using one scanning line driving circuit. can get.

Embodiment 3 Next, a liquid crystal display device according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 9 is a circuit configuration diagram of the liquid crystal display device according to the present embodiment. The same parts as those in FIG. 8 are denoted by the same reference numerals, and detailed description will be omitted.

As shown in FIG. 8, the display area 11 has a first display area 12 for constantly displaying information when the power is turned on, and a second display area 13 for displaying information only when necessary.
The first display area 12 includes the first scan drive circuit 16a and the first
And the scanning line G1
1 to G1m and signal lines S1, S2,... The second display area 13 is driven by a second scan drive circuit 16b and a second signal line drive circuit 17b, and is provided with scan lines G21 to G2n and signal lines S1, S2. A horizontal clock signal HS1 is input to the first scan drive circuit 16a and the first signal line drive circuit 17a, and a clock signal CLK1 and data D1 are input to the first signal line drive circuit 17a. The horizontal scan signal H is supplied to the second scan drive circuit 16b and the second signal line drive circuit 17b.
S2 is input, and the clock signal CLK2 and data D2 are input to the second signal line drive circuit 17b. A switching element 14 and a liquid crystal cell 15 are arranged at the intersection of each scanning line and signal line.

Unlike the second embodiment, in this embodiment, the counter electrode 18a in the first display area 12 and the counter electrode 18b in the second display area 12 are electrically separated. The first counter electrode 18a is configured to be provided with a counter voltage by a first counter electrode drive circuit 19a, and the second counter electrode 18b is configured to be provided with a counter voltage by a second counter electrode drive circuit 19b.

With such a configuration, the same effects as in the first and second embodiments can be obtained. Further, in addition to the scanning line driving circuit and the signal line driving circuit, the opposing electrodes are provided separately in the first display region 12 and the second display region 13, so that independent display control can be performed. The design flexibility is improved. In addition, since the display characteristics of each display area can be independently set, a liquid crystal display device most suitable for the information display format can be realized.

In the present embodiment, the counter electrode driving circuit, the scanning line driving circuit, and the signal line driving circuit are divided respectively, but the design of the counter electrode driving circuit may be changed to another configuration. The easiness and display characteristics can be improved. In the present embodiment, the first display area 12
If the interface between the liquid crystal display device and an external circuit (not shown) is performed through a separate signal connection portion in the second display area 13, the external circuit can be easily designed.

(Embodiment 4) Next, a liquid crystal display device according to Embodiment 4 of the present invention will be described. In the liquid crystal display device of this embodiment, all or a part of the scanning line driver circuit, the signal line driver circuit, the counter electrode driver circuit, and the switching element described in Embodiment Modes 1 to 3 are formed of low-temperature polysilicon. It is characterized by. The operation of each circuit is the same as described above. According to this embodiment, the scanning line driving circuit, the signal line driving circuit, and the counter electrode driving circuit can be formed on a glass transparent substrate by using the same process as the transistor of the switching element. The connection circuit part to the panel becomes unnecessary. For this reason, the frame (non-display area) area of the liquid crystal panel can be reduced, and the superiority of the display unit of the portable device can be further secured.

[0035]

As described above, according to the liquid crystal display device of the present invention, the first display area for always displaying information when the power is turned on and the second display area for displaying information only when necessary are one. Since it is realized by two active matrix liquid crystal panels, it is possible to reduce the number of circuit components, reduce the volume of the liquid crystal display device, and increase the display area occupied by the liquid crystal panel, as compared with the case of using two liquid crystal panels. . In particular, when the second display area is set to non-display, the input of the clock signal and the data is stopped, so that the power consumption can be reduced.

According to the third aspect of the present invention, since the scanning line driving circuit and the signal line driving circuit are separately provided in the first display area and the second display area, the clock signal of the signal line driving circuit is provided. In addition, the frequency of the data signal can be reduced, and the power consumption of the liquid crystal display device can be further reduced. In addition, since the counter electrode is also provided separately in the first display area and the second display area, independent display control can be performed, and simplicity in designing each drive circuit is realized. In addition, since the display characteristics of each display area can be set independently of each other, a configuration optimal for the application can be obtained.

According to the fourth aspect of the present invention, it is possible to incorporate all or a part of the scanning line driving circuit, the signal line driving circuit, and the counter electrode driving circuit in the liquid crystal panel. For this reason, the area of the non-display area of the liquid crystal panel can be reduced, and the superiority of the display unit of the portable information device can be secured.

According to the fifth aspect of the present invention, the interface between the liquid crystal display device and the external circuit can be performed in the first display area and the second display area through separate connection portions, so that the design of the external circuit can be improved. Becomes easier.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a liquid crystal display device according to Embodiment 1 of the present invention.

FIG. 2 is an external view of a mobile phone using the liquid crystal display device in Embodiment 1.

FIG. 3 is an enlarged view of a display unit of the mobile phone.

FIG. 4 is a timing chart in the case where both the first display area and the second display area are displayed in the liquid crystal display device of Embodiment 1.

FIG. 5 is a timing chart in a case where information is displayed only in a first display area and no display is performed in a second display area in the liquid crystal display device of Embodiment 1.

FIG. 6 is an external view of a mobile phone using a conventional liquid crystal display device.

FIG. 7 is an enlarged view of a display unit of a conventional mobile phone.

FIG. 8 is a circuit configuration diagram of a liquid crystal display device according to Embodiment 2 of the present invention.

FIG. 9 is a circuit configuration diagram of a liquid crystal display device according to Embodiment 3 of the present invention.

[Explanation of symbols]

 Reference Signs List 11 display area 12, 21 first display area 13, 22 second display area 14 switching element 15 liquid crystal cell 16, 16a, 16b scanning line driving circuit 17, 17a, 17b signal line driving circuit 18, 18a, 18b opposing electrode 19, 19a, 19b Counter electrode drive circuit 20 Display unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H092 GA26 GA33 GA41 GA59 JA24 JB14 KA04 NA26 PA06 2H093 NA16 NA43 NA80 NC09 NC11 NC12 NC16 NC18 NC34 NC49 NC59 ND39 ND42 ND60 NE03 NE07 NF05 NG20 5C006 AA01 AA16 AF24 BC03 BC06 BC13 BC20 BF34 BF50 EC05 EC13 FA03 FA47 5C080 AA10 BB05 CC03 CC07 DD21 DD26 EE01 EE19 FF09 GG05 GG08 JJ01 JJ02 JJ04 KK07

Claims (7)

[Claims] 1. A plurality of scanning lines and a plurality of signal lines are provided on a transparent substrate, a switching element is provided at an intersection of the scanning line and the signal line, and a switching element is provided between a driving electrode and a counter electrode of the switching element. A liquid crystal panel provided with liquid crystal cells, a scanning line driving circuit for sequentially scanning each scanning line of the liquid crystal panel, and controlling a timing of applying a display signal for one row to the liquid crystal cells every one horizontal period; A signal line driving circuit for outputting a display signal for applying a pixel voltage to one row of liquid crystal cells selected by the scanning line driving circuit; a counter electrode driving circuit for applying a counter voltage to a counter electrode of each liquid crystal cell; A liquid crystal display device comprising: a first display area for constantly displaying information on the liquid crystal panel when power is turned on; and a second display area for displaying information only when necessary. LCD display Location. 2. The signal line drive circuit according to claim 1, wherein the counter electrode is provided for each signal line when it is not necessary to display information in the second display area, except when driving the first display area. 2. The liquid crystal display device according to claim 1, wherein a voltage equivalent to a counter voltage output by the drive circuit is output instead of the display signal. 3. The liquid crystal panel according to claim 1, wherein at least one of said signal line driving circuit, said scanning line driving circuit, and said counter electrode driving circuit is independently provided for a first display area and a second display area of said liquid crystal panel. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is provided. 4. The semiconductor device according to claim 1, wherein at least one of said signal line driving circuit, said scanning line driving circuit and said counter electrode driving circuit is formed on said transparent substrate by a low-temperature polysilicon transistor. The liquid crystal display device according to any one of the above items. 5. The signal processing device according to claim 1, wherein a signal connection portion for individually connecting to an external circuit is provided in each of the first display area and the second display area. Liquid crystal display. 6. An information portable device provided with the liquid crystal display device according to claim 1 in an information display section. 7. The information processing apparatus according to claim 6, wherein the first display area displays information on an operation state of the information portable device, and the second display area displays information including an image and characters. Information portable equipment.