JP2001281617A - Color liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color liquid crystal display device, in which necessary information can be obtained without performing key operation by a user and consumption of electric power can be reduced. SOLUTION: In the color liquid crystal display device, having at least red, green and blue color filters R, G, B and liquid crystal elements arranged corresponding to the color filters R, G, B to transmit or cut light, monochromatic display is performed by driving only the liquid crystal element arranged, corresponding to the color filter of any one color of the color filters R, G, B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a color liquid crystal display device, and more particularly to a color liquid crystal display device provided in a portable terminal such as a PHS (Personal Handyphone System) or a portable telephone which requires low power consumption.

[0002]

2. Description of the Related Art A liquid crystal display device has the characteristics that it can be driven at a low voltage and has low power consumption.
(Cathod Ray Tube) has been widely used in various applications as a display device. In recent years, the penetration rate of portable terminals such as cellular phones and PHSs has been increasing. However, in this portable terminal, the ability to be used over a long period of time is one guideline for measuring the performance of a model. It is extremely important to reduce power consumption.

Conventionally, the above-mentioned portable terminal generally includes a monochromatic liquid crystal display device as a display device. By the way, in recent years, the functions of mobile terminals have been advanced, and for example, it has become possible to transmit and receive not only voice information and character information but also image information and moving image information between mobile terminals. In order to enhance the expressive power of information transmitted and received due to such a change in the situation, portable terminals equipped with a color liquid crystal display device have been increasing.

As is well known, a single-color display device has a screen composed of a plurality of dots. To display one dot, a voltage is applied to one pixel electrode provided corresponding to the dot. May be applied. Further, the gradation is expressed by changing the voltage value of the voltage applied to the pixel electrode. However, a color liquid crystal display device uses R (red), G (green), and B (blue) for one dot.
These three pixel electrodes are provided, and eight colors are displayed by selecting a combination of whether or not to apply a voltage value to these three pixel electrodes. If necessary, multicoloring can be performed by changing the voltage value applied to these pixel electrodes.

Therefore, the power consumption of the color liquid crystal display device is higher than that of the single color liquid crystal display device. As described above, since low power consumption is important for mobile terminals, conventionally, when the mobile terminal is not used, that is, when no key operation is performed, the screen display is turned off, for example, a liquid crystal display is used. The clock display is performed by driving only a part of the device.

[0006]

In a conventional color liquid crystal display device, in order to reduce the power consumption by the above-described method, it is possible to display a character screen at all times, for example, in character distribution. In addition, there is a problem in that the display of information that the user wants to check, such as the presence or absence of an incoming call and the remaining amount of the battery, also causes a problem.

In order to solve these problems, it is possible to design a portable terminal so that the above information is displayed on a color liquid crystal display device when a key operation is performed by an operator. However, the user is required to perform key operations only to display information on the color liquid crystal display device, which is troublesome for the user. In addition, the backlight is turned on and unnecessary color display is performed. This causes a problem that extra power consumption occurs.

The present invention has been made in view of the above circumstances, and a color liquid crystal display device capable of obtaining necessary information without a user performing key operations and achieving low power consumption. The purpose is to provide.

[0009]

In order to solve the above problems, the present invention provides at least red, green, and blue color filters, and a liquid crystal provided corresponding to the color filters and transmitting or blocking light. In the color liquid crystal display device including the elements, in a predetermined case, only a liquid crystal element provided corresponding to any one of the red, green, and blue color filters is driven to perform a monochromatic display. It is characterized by having driving means. Also, the present invention
A key operation unit that outputs operation information according to a user operation, and a control unit that causes the driving unit to perform the monochrome display when a predetermined time has elapsed after the operation information is no longer input. It is characterized by. Furthermore,
The present invention is characterized in that the control means switches from the monochrome display to the color display when operation information is input from the key operation unit.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a color liquid crystal display according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram schematically showing a configuration of a display portion of a color liquid crystal display device according to an embodiment of the present invention. In this embodiment, a simple matrix type color liquid crystal display device will be described as an example for easy understanding, but the present invention is not limited to the simple matrix type color liquid crystal display device shown in FIG. . For example, TFT (Thin F
The present invention can be easily applied to a color liquid crystal display device of a type equipped with an ilm transistor.

In FIG. 1, BL indicates white backlight light illuminated from a backlight (not shown) provided on the back of the display unit. The color liquid crystal display device of the present embodiment includes a liquid crystal 3 between a glass substrate 10 and a glass substrate 20.
0 is sandwiched, and the backlight light enters from the glass substrate 20 side. Therefore, the user can use the glass substrate 20
The display contents of the color liquid crystal display device are visually recognized from the side, that is, the direction indicated by the reference symbol D in the figure.

A polarizing filter 12 is formed on the surface of the glass substrate 10 on which the backlight light BL is incident, and linear transparent electrodes 14a to 14e are formed on the other surface.
Reference numeral 16 denotes an alignment film provided to align the liquid crystal 30 in a desired direction. A polarizing filter 22 is formed on the surface of the glass substrate 20 facing the user, and color filters R, G, and B are sequentially formed on the other surface. The color filters R, G, and B are filters that transmit red light, green light, and blue light when white light enters. These color filters R, G, B
Are formed in a linear shape, and are arranged orthogonal to the transparent electrodes 14a to 14e.

In FIG. 1, the color filters R,
On G and B, linear transparent electrodes 24a, 24b and 24c are formed. These transparent electrodes 24a to 24c are
The color filters R, G, B are provided in parallel with the color filters R, G, B, respectively. Therefore, the transparent electrodes 24a to 24c are arranged orthogonally to the transparent electrodes 14a to 14c. Although the illustration is simplified in FIG. 1, the transparent electrodes 14a to 14e are provided by the number of dots arranged in the vertical direction of the color liquid crystal display device, and the transparent electrodes 24a to 24c are provided for each color in the color liquid crystal display device. Are provided by the number of dots arranged in the horizontal direction.
Reference numeral 26 denotes an alignment film provided for aligning the liquid crystal 30 in a desired direction. 32 is a spacer.

Therefore, at the intersection of the transparent electrode to which the voltage is applied among the transparent electrodes 14a to 14e and the transparent electrode to which the voltage is applied among the transparent electrodes 24a to 24c, the alignment state of the liquid crystal is changed. The backlight light BL is transmitted. That is, in the present embodiment, the transparent electrode 1
The liquid crystal disposed at the intersections between the transparent electrodes 4a to 14e and the transparent electrodes 24a to 24c serves as a liquid crystal element that transmits or blocks light.

Next, a circuit configuration of a driving circuit provided in the color liquid crystal display device according to one embodiment of the present invention will be described. FIG. 2 is a block diagram showing a schematic configuration of a driving circuit provided in the color liquid crystal display device according to one embodiment of the present invention. FIG. 2 shows only the main parts related to the present invention. Therefore, for example, a communication unit and the like included in the portable terminal are not illustrated. In FIG. 2, reference numeral 40 denotes a key operation unit having a push button or the like operated by the user, and outputs operation information according to the operation content of the user. Reference numeral 42 denotes a timer unit having a timing function, and outputs timing information.

Reference numeral 44 denotes an MPU (Micro Processor Unit)
And controls the operation of the entire color liquid crystal display device of the present embodiment. As will be described later in detail, the MPU 44 outputs an initialization signal to the timer unit 42 when the operation information is output from the key operation unit 40. Reference numeral 46 denotes an image signal generation circuit, which is an LCD (Liquid Crystal Displ.).
ay) Generate an image signal of an image to be displayed on the module 48. The LCD module 48 has the configuration shown in FIG. The image signal generated by the image signal generation circuit 46 is output to the source driver 50. The transparent electrodes 24 a to 24 c in FIG. 1 are electrically connected to the source driver 50. The source driver 50 is an LC
A voltage having a value corresponding to the gradation of the image signal output from the image signal generation circuit 50 is applied to the transparent electrodes 24a to 24c for each dot constituting the D module 48. Note that a polarity inversion signal is output from the controller 60 to be described later to the source driver 50.

Reference numeral 52 denotes a gate driver, to which the transparent electrodes 14a to 14e in FIG. 1 are electrically connected. The gate driver 52 receives the shift clock and the serial data from the controller 60 and
a to 14e are sequentially scanned. Therefore, the gate driver 5
A voltage is applied to the intersection of the transparent electrode 2 being scanned and the transparent electrode to which a voltage is applied from the source driver 50, and the orientation of the liquid crystal 30 changes to transmit the backlight BL. Note that the controller 60 controls the source driver 50 to perform single-color display in any of red, blue, and green according to a control signal output from the MPU 44. Note that a vertical synchronizing signal and a horizontal synchronizing signal are output from the image signal generating circuit 46 in FIG. 2 to the controller 60, and the controller 60 synchronizes the vertical synchronizing signal and the horizontal synchronizing signal with the source driver 50 and the gate driver 52. Control the operation of.

Next, the operation of the color liquid crystal display device according to one embodiment of the present invention having the above configuration will be described.
First, for example, an operation in a case where the key operation unit 40 is operated by a user and color display is performed on the LCD module 48 will be described. When the operator operates the key operation unit 40, operation information is output from the key operation unit 40 to the MPU 44. When the operation information is input, the MPU 44 outputs a control signal for causing the controller 60 to perform color display.

The controller 60 includes a gate driver 52
Output shift clock and serial data to
The transparent electrodes 14a to 14e in FIG. 1 are sequentially scanned. Further, the controller 60 outputs a polarity inversion signal to the source driver 50, takes in the image signal output from the image signal generation circuit 46, and alternates the polarity with a value corresponding to the gradation of the image signal. The inverted voltage is applied to the transparent electrode 24a.
To 24c. In this case, if the image signal performs color display, each color filter R,
A voltage is sequentially applied to all of the transparent electrodes 24a to 24c provided corresponding to G and B.

Next, if the user does not operate the key operation unit 40 for a predetermined time, for example, about 10 seconds, the MPU 44 sends a control signal for performing a single color display to the controller 60 based on the timing information output from the timer unit 42. Output to When this control signal is input, the controller 60 outputs the same shift clock and serial data to the gate driver 52 as in the case of performing color display, but performs the color display to the source driver 50. The operation is performed at a frequency of 1/3 of the case.

That is, in the case of color display, the transparent electrode 2
4a, 24b, 24c,... Are sequentially applied with a voltage corresponding to the gradation of the image signal.
The source driver 50 includes the transparent electrodes 24a, 24b, 24
Of the pixels c,..., for example, only the transparent electrodes provided corresponding to the red color filters R are sequentially scanned. Therefore, since voltage is not applied to the transparent electrodes provided corresponding to the blue color filter B and the green color filter G, the voltage of the transparent electrode to which the internal voltage of the transparent electrodes 24a, 24b, 24c,. Since the number is 1/3 of the whole, the operation is performed at the frequency of 1/3 of the color display. In addition, you may make it perform single-color display in any of red, blue, and green.

As described above, during color display, voltage is applied to the transparent electrode provided corresponding to the red color filter R, and voltage is applied to the transparent electrode provided corresponding to the green color filter G. Since it is necessary to apply a voltage and a voltage to the transparent electrode provided corresponding to the blue color filter B, power consumption is increased. In order to reduce the power consumption, in the present embodiment, a voltage is applied to the transparent electrode provided corresponding to the red color filter R, and a voltage is applied to the transparent electrode provided corresponding to the green color filter G. Since any one of voltage application and voltage application to the transparent electrode provided corresponding to the blue color filter B is performed, power consumption can be reduced. By performing such display control, information required by the user can be obtained without the user performing key operations while reducing power consumption. Here, the information required by the user is, for example, information such as presence / absence of incoming information, remaining battery level, and the like.

As described above, the color liquid crystal display device according to one embodiment of the present invention has been described. However, the present invention is not limited to the above embodiment, and can be freely changed within the scope of the present invention. For example, in the above embodiment, the key operation unit 40
The time for switching to the single-color display after the operation is not performed may be changed according to the user's will. The switching from the monochrome display to the color display may be performed when the user operates the key operation unit 40 or when a call is received. Further, the monochrome display may be used as a warning mode, or switching between the monochrome display and the color display may be performed as required by the user.

[0024]

As described above, according to the present invention, it is possible to obtain necessary information without the user performing key operations and to reduce power consumption. .

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a configuration of a display portion of a color liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of a drive circuit included in the color liquid crystal display device according to the embodiment of the present invention.

[Explanation of symbols]

 14a-14e Transparent electrode 24a-24c Transparent electrode 30 Liquid crystal 40 Key operation unit 42 Timer unit 44 MPU (Control unit) 48 LCD module 50 Source driver (Drive unit) 52 Gate driver (Drive unit) 60 Controller (Drive unit) R Red Color filter G green color filter B blue color filter

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 3/20 680 G09G 3/20 680S 3/36 3/36 F-term (Reference) 2H093 NA07 NA16 NA64 NA49 NC49 NC59 NC71 ND17 ND39 NE06 NG20 5C006 AA22 AC22 AF23 AF85 BB12 BC03 FA48 5C080 BB05 CC03 DD26 FF12 GG02 JJ02 JJ06 KK47 5C094 AA22 AA56 BA03 BA43 CA19 CA23 CA24 EA04 EA07 EB02 ED03 HA10

Claims (3)

[Claims] 1. A color liquid crystal display device comprising at least red, green, and blue color filters, and a liquid crystal element provided corresponding to the color filters and transmitting or blocking light. A color liquid crystal display device comprising: driving means for driving only a liquid crystal element provided corresponding to any one of red, green, and blue color filters to perform monochromatic display. 2. A key operation unit for outputting operation information according to a user's operation, and a control for causing the driving unit to perform the monochrome display when a predetermined time has elapsed after the operation information is no longer input. 2. A color liquid crystal display device according to claim 1, further comprising means. 3. The color liquid crystal display device according to claim 2, wherein said control means switches from said monochrome display to color display when operation information is input from said key operation section.