JP2002311939A - Display controller, display device and handset - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size and the power consumption of a display controller such as a source driver or the like in which a window display is made possible. SOLUTION: The display controller is provided with a display memory U which stores window display data D2 to indicate the contents to be displayed within a window, a data latch circuit 30 or the like which takes in all screen display data D1 to indicate the contents to be displayed on the entire screen of a liquid crystal panel 10, an output circuit 46 or the like which outputs output signals to the panel 10 based on the transmitted display data and a display switching circuit 38 which conducts a switching between the data D2 from the memory U side and the data D1 from the circuit 30 side and transmits the data to the circuit 46 side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display control device capable of displaying a window, a display device, and a portable telephone.

[0002]

2. Description of the Related Art Conventionally, in a display device having a window display function, a display memory (RAM) stores a first screen area for storing display data corresponding to all pixels of a display screen and a display required for window display. There has been a method of providing a second screen area for storing data, and reading display data necessary for window display from the second screen area. A display device having first and second screen areas is disclosed in, for example,
Japanese Patent Application Laid-Open No. 7-72841 and Japanese Patent Application Laid-Open No. 7-72844. These publications disclose that a window is displayed at an arbitrary display position and an arbitrary display size on a screen by setting a display position and a display size of the window.

FIG. 5 is a block diagram showing an example of the configuration of the conventional display device 100. As shown in FIG. The display device 100 is
PU (microprocessor unit) 111, CRT display 113, RAM (random access memory)
114, a CRT controller 115, an address selector 116, a window width signal generation circuit 117, a priority circuit 118, an offset memory 119, and an address adder 120.

In the display device 100, display data to be displayed on the CRT display 113 is stored in the RAM 114. Display data is sent from the RAM 114 to the CRT display 113 under the control of the CRT controller 115, and a display based on the display data is performed. Is performed.

Here, the RAM 114 has a capacity for two screens of the CRT display 113, and a first screen area is used for main display, and a second screen area is used for window display. The window width signal generation circuit 11
7, priority circuit 118, offset memory 11
Reference numeral 9 and the address adder 120 are functional blocks for displaying a window, and set a display state of the window such as a window width. The control of the display screen including the window is controlled by the MPU 111.

[0006]

The above-mentioned Japanese Patent Application Laid-Open No. 7-728.
No. 41 and JP-A-7-72844 disclose C
Although a display device using the RT display 113 is disclosed, a display device using a liquid crystal display panel is also conceivable. 2. Description of the Related Art Liquid crystal display panels are used for display units in mobile phones, taking advantage of their relatively low power consumption. With respect to the display quality of liquid crystal panels used as display units of mobile phones, the need for higher quality has been increasing year by year, and accordingly, multi-gradation display by color display and a higher number of pixels have been pursued. ing. In a mobile phone driven by a battery, further reduction in power consumption of the entire liquid crystal display device has been pursued in order to extend the talkable time and the standby time after charging.

[0007] Here, the effects of multi-tone display by color display and display memory by increasing the number of pixels will be considered. For example, in a TFT liquid crystal panel, m = 96 source electrodes and n = 64 gate electrodes, and 96
Consider a case where three source electrodes are classified into three types for R (red), G (green), and B (blue) data, and 32 source electrodes are assigned to each color data. Assuming that display of 8 gradations for R data, 8 gradations for G data, and 4 gradations for B data is performed, display data of 3 bits for 8 gradations display and 2 bits for 4 gradations display Is required, a total (3 + 3 + 2) × 32 × 64 =
About 16 kilobits of display data is required. Therefore, when configuring a display device having the first and second screen areas in the display memory as described above, a capacity of about 16 kilobits is required for the first screen area. further,
The second screen area depends on the size of the window to be displayed. For example, if the window is displayed using M = 48 (16 for each color) source electrodes and N = 16 gate electrodes, the second screen area (3 + 3 + 2) as area
× 16 × 16 = approximately 2 kilobits of capacity is required.

[0008] As the number of pixels and the number of pixels are further increased in order to further enhance the display quality, the capacity of the display memory must be further increased. At present, the ratio of the RAM as the display memory to the source driver chip is large, and accounts for more than half of the chip size. In the future, for example, the number of source electrodes is m = 168 (56 for each color), and the number of gate electrodes is n =
If the display of 80 and RGB colors is 256 gradations (8-bit display data), a capacity of (8 + 8 + 8) × 56 × 80 = approximately 107 kilobits is required as the first screen area in the display memory. About 16 kilobits)
Approximately 7 times.

On the other hand, a RAM as a display memory
It is conceivable to advance the miniaturization of the display memory unit to reduce the size occupied by the display memory. Here, the source driver includes a logic unit (such as an interface input / output circuit 22 and a data latch circuit 30 in FIG. 1 described later) driven by a low voltage (for example, 5 V) and a high voltage (for example, 10 V).
And an analog circuit (e.g., an output circuit 46 in FIG. 1 described later) driven in the same manner is mixed in one chip. For this reason, miniaturization of only the display memory unit is inferior in terms of manufacturing.

Further, as described above, when the capacity of the display memory is increased to about 107 kilobits, the power consumed by the display memory cannot be ignored.

Here, considering the state of use of the display unit of the mobile phone, in the standby mode in which the mobile phone is not used, the area outside the window is set to, for example, a white background image in order to reduce power consumption. In many cases, for example, the date, clock, reception status, presence / absence of mail, and the like are displayed as window displays. Therefore, it is desirable to adopt a display method in consideration of such a usage situation, and to configure the source driver and the like to be suitable for the display method.

The present invention has been made in view of this point, and an object of the present invention is to reduce the size and power consumption of a display control device such as a source driver, and to provide a display device provided with the display control device. Another object of the present invention is to reduce the size and power consumption of a mobile phone including the display device.

[0013]

A display control device according to the present invention is a display control device for controlling a display on an image display means, wherein a window display using a part of the screen of the image display means is displayed on the image display means. A display control device capable of being performed by the means, in order to solve the above-described problems,
Storage means for storing display data indicating the content to be displayed in the window; capturing means for capturing the display data indicating the content to be displayed on the entire screen; and an output signal based on the display data sent to the image It is characterized by comprising output means for outputting to the display means, and switching means for switching display data from the storage means and display data from the capture means and sending the data to the output means.

In the above arrangement, the display means is fetched, for example, periodically sent from the outside by the fetching means, and the display data fetched by the fetching means is sent to the output means by the switching means. Can display the entire screen. In addition, the switching means sends the display data stored in the storage means to the output means, so that the image display means can display a window.

In this configuration, since display data indicating the content to be displayed on the entire screen is fetched from the outside, a large-capacity memory or the like for storing the display data becomes unnecessary.
Therefore, even when the present display control device is formed on, for example, a chip, it is possible to suppress an increase in the size of the chip. Further, when a large-capacity memory or the like becomes unnecessary, the power consumed by the memory or the like can be reduced accordingly.

Further, since the display data indicating the contents to be displayed in the window is stored in the internal storage means, even when the display data is not periodically sent from the outside, the display data is stored in the storage means. Window display can be performed using the stored display data. Therefore, even when a peripheral device of the display control device is set to, for example, a standby mode or the like and a part of the function is stopped, for example, a minimum necessary content can be displayed in the window.

In the display control device according to the present invention, in the display control device described above, it is preferable that the storage means stores a plurality of types of display data indicating contents to be displayed in the window. In the above configuration, the display in the window can be changed by changing the type of the display data.

It is preferable that the display control device according to the present invention further comprises a rewriting means for rewriting the display data stored in the storage means in the display control device. In the above configuration, the content displayed in the window can be changed, for example, periodically.

The display control device according to the present invention, in the above display control device, further comprises: when displaying the window on the image display means, displaying a single color outside the window.
It is preferable to include a background setting unit for setting a mosaic display or a block display. The single color display, the mosaic display, or the block display can be realized by a relatively simple and small circuit configuration. Therefore, in the above configuration, the outside of the window can be set to a predetermined display state when the window is displayed without causing a significant increase in the circuit scale.

It is preferable that the display control device according to the present invention further comprises, in the above-described display control device, a capture stop means for stopping capture of display data by the capture means. In the above configuration, when window display is performed by the image display unit, the capture of display data by the capture unit is stopped by the capture stop unit.
It is possible to reduce power consumption due to unnecessary display data acquisition.

A display device according to the present invention includes the display control device and the image display means in order to solve the above-mentioned problems. With the above structure, the display device can be reduced in size and power consumption by the above-described effects.

Further, a portable telephone according to the present invention is provided with the display device described above. In the above-described configuration, the mobile phone can be reduced in size and power consumption, and can be displayed on a full screen at the time of operation or the like, so that more information can be displayed. The information can be displayed.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a liquid crystal display (TF) according to this embodiment.
FIG. 2 is a block diagram illustrating a configuration of a (T liquid crystal module) 1.
FIG. 1 illustrates only main components and signal paths, and omits, for example, a power supply circuit and signal paths of some signals such as a clock signal, a reset signal, a read signal, a write signal, and a select signal. ing.

The liquid crystal display device 1 includes a liquid crystal panel 10, a source driver (TFT liquid crystal driver) 12, a gate driver 14, and an MPU (microprocessor unit).
16 is included. The liquid crystal panel 10 is a liquid crystal panel having TFT (thin film transistor) type pixels of m horizontal pixels × n vertical pixels formed by m source electrodes and n gate electrodes, and is a part of the entire screen. Can be displayed on the window W. In the following, the arrangement of pixels in one line in the horizontal direction is referred to as “row”, and
An array of pixels in a line is called a “column”. Here, m =
168, n = 80, and each pixel performs a gray scale display of 256 gray scales (8 bits) from the 0 th gray scale to the 255 th gray scale. Each row contains R (red), G (green), B
(Blue) Assume that pixels for displaying the respective colors are repeatedly arranged. Therefore, each row includes 56 pixels of RGB. The liquid crystal panel 10 includes a source driver 12 and a gate driver 1.
4 are connected, and the source driver 12 and the gate driver 14 are connected to the MPU 16.

The source driver 12 incorporates a display memory (window display memory) U constituted by a RAM (random access memory). This display memory U can store display data for M pixels in the horizontal direction × N pixels in the vertical direction. Here, M = 42, N =
20, and 256 gradations (8 bits) can be expressed by the display data corresponding to each pixel as described above. Therefore, the display memory U is 42 × 20
X8 = has a capacity of about 8 kilobits.

The source driver 12 further includes a peripheral circuit section 18, a source driver section 20, and an input / output circuit 22 of the display memory U. The peripheral circuit unit 18 includes a command decoder 24, an X address decoder (column decoder) 26, and a Y address decoder (row decoder)
28. The source driver section 20 includes a data latch circuit 30, a reference voltage generation circuit 32, a shift register 34, a sampling memory 36, a display switching circuit 38, a hold memory 40, a level shifter 42, a D / A conversion circuit 44, and an output circuit 46. In.

In the source driver section 20, full-screen display data D necessary for full-screen display
1 or window display data D2 necessary for displaying the window W is switched by the display switching circuit 38 and input to the hold memory 40. This hold memory 40
The display data input to the LCD panel 10 correspond to the first to m-th pixels included in each row of the liquid crystal panel 10, that is, the first to m-th source electrodes. Hold memory 40
Are latched by the horizontal synchronizing signal H, and the display data output from the hold memory 40 is fixed until the next horizontal synchronizing signal H is input. The display data output from the hold memory 40 is
The level shifter 42 performs level conversion such as boosting to match the signal processing level of the D / A conversion circuit 44 in the next stage, and inputs the signal to the D / A conversion circuit 44.

For example, the maximum potential E1 and the minimum potential E2 of the potential to be applied to the pixel are input to the reference voltage generating circuit 32 from a power supply circuit (not shown). The reference voltage generation circuit 32 internally divides the potential difference between the maximum potential E1 and the minimum potential E2, so that in the case of 256 gray scale display,
256 kinds of gradation display potentials are generated and output to the D / A conversion circuit 44. The D / A conversion circuit 44 selects one gradation display potential corresponding to the display data from the level shifter 42 from the 256 types of gradation display potentials for each pixel, and outputs the potential to the output circuit 46. I do. The output circuit 46 is a low-impedance conversion unit composed of a differential amplifier or the like. A display potential is applied. This gradation display potential is maintained for one cycle of the horizontal synchronization signal H, that is, one horizontal synchronization period, and in the next horizontal synchronization period, a gradation display potential corresponding to new display data is output.

On the other hand, the gate driver 14 includes a shift register 48, a level shifter 50, and an output circuit 52. In the gate driver 14, the shift register 4
8, a horizontal synchronizing signal H and a vertical synchronizing signal V are inputted,
Using the horizontal synchronization signal H as a clock, the vertical synchronization signal V is sequentially transferred at each stage in the shift register 48. Outputs from each stage of the shift register 48 correspond to first to n-th pixels included in each column of the liquid crystal panel 10, that is, first to n-th gate electrodes. Shift register 4
The output from each stage 8 is level-converted by a level shifter 50 to boost the voltage to a level that can control the TFT gate of each pixel, and is converted to a low impedance by an output circuit 52. Is output to each of the first to n-th gate electrodes. The output from the gate driver 14 becomes a scanning signal, and controls on / off of the gate of the TFT of each pixel of the liquid crystal panel 10.

Thus, the TFT whose gate is connected to one gate electrode selected by the scanning signal is turned on. Then, as the gate electrode is sequentially selected every one horizontal synchronization period, the pixel having the TFT to be turned on moves sequentially in the vertical direction. TFT selected by scanning signal
Is turned on, the gradation display potential is applied from the source electrode to the pixel capacitance provided in the pixel,
The pixel capacitance is charged in accordance with the potential, and when the TFT is turned off, the potential is held in the pixel capacitance, whereby gradation display is performed in the pixel.

The MPU 16 is connected to the source driver 12 and sends a vertical synchronizing signal V, a horizontal synchronizing signal H, a start pulse signal S, display data (full screen display data D1 and window display data D2) to the source driver 12. ) And a control signal C.

Here, in the input / output circuit 22 of the source driver 12, the window display data D2 necessary for displaying the window W among the display data and the control signal C are transmitted to the MPU.
Sent by the control of No. 16. The input / output circuit 22 includes an MPU
16 and functions as an input / output buffer.

The window display data D2 is temporarily stored in the display memory U. The address where the window display data D2 is stored in the display memory U is specified by the X address decoder 26 and the Y address decoder 28 based on the command of the control signal C decoded by the command decoder 24.

The control signal C includes various commands sent from the MPU 16, and each command is decoded by the command decoder 24. Hereinafter, a command included in the control signal C decoded by the command decoder 24 is simply referred to as a “command”.

Next, the operation of the source driver 12 will be described. First, the normal mode (full screen display) will be described. In the normal mode, the full screen display data D1 sent from the MPU 16 has an 8-bit value corresponding to each pixel, and is temporarily latched by the data latch circuit 30. On the other hand, the shift register 34 receives the start pulse signal S from the MPU 16 and synchronizes the start pulse signal S with a clock (not shown).
Are sequentially transferred at each stage. Note that the shift register 34
From the liquid crystal panel 10 to the output circuit 46.
Corresponding to the first to m-th m source electrodes.
M stages. In synchronization with the output from each stage of the shift register 34, the full-screen display data D1 latched by the data latch circuit 30 is temporarily stored in the corresponding stage of the sampling memory 36, and the display switching circuit 38 Then, the data is output to the corresponding stage of the next hold memory 40. The display switching circuit 38 is set to select the output from the sampling memory 36 in all stages and output the selected output to the hold memory 40 in the normal mode based on the command sent from the command decoder 24. The hold memory 40 stores m of one horizontal synchronization period.
When the full-screen display data D1 is input from the sampling memory 36, the sampling memory 36 receives a horizontal synchronization signal H (also referred to as a latch signal) from the MPU 16.
, And captures the full screen display data D1 from the controller and outputs it to the next level shifter. And the hold memory 40
Each full screen display data D1 is maintained until the next horizontal synchronization signal H is input. The subsequent operation is as described above.

The MPU 16 stores the full screen display data D
1 is repeatedly sent to the data latch circuit 30. Thus, the potential corresponding to the full-screen display data D1 is periodically written to the liquid crystal panel 10, and the liquid crystal display on the liquid crystal panel 10 is maintained.

Next, the standby mode (low power consumption mode) will be described. In the standby mode, the MPU 16 stops the output of the start pulse signal S to the shift register 34 of the source driver 12 and the output of the clock for the shift register 34.
8 so that the display switching circuit 38 selects the window display data D2 from the display memory U and outputs it to the hold memory 40. In this manner, power consumption can be reduced by stopping the operations of the shift register 34 and the sampling memory 36.

Further, the MPU 16 receives the control signal C
An instruction is given to read the window display data D2 from the display memory U, and a start address for determining the display position of the window W on the display screen is specified. The start address is the address (x address (column address, horizontal address of the liquid crystal panel 10) and y address (row address, vertical address of the liquid crystal panel 10) of the pixel located at the upper left corner of the window W on the display screen. Direction address)). Here, the pixel P1 in the horizontal direction xi and the vertical direction yj (hereinafter, referred to as (xi, yj)).
Is the start address.

A start address is input to the source driver 12 as a control signal C. Then, in response to a command from the command decoder 24, the X address decoder 26 and the Y address decoder 28 are controlled such that the window display data D2 is read at a predetermined timing based on the start address. Specifically, an output corresponding to the window display data D2 corresponding to the pixel included in the first row in the window W is output in synchronization with the timing at which the yjth gate electrode including the pixel P1 is selected. 4
The window display data D2 in the display memory U is read out so as to be output from 6 to the source electrode. Note that the x address of the start address is also sent to the display switching circuit 38, and the window display data D2 corresponding to the pixels included in each row in the window W with respect to the source electrodes subsequent to the x address of the start address (sith and after). , The window display data D2 is sequentially written in a predetermined stage or later of the display switching circuit 38 so that an output corresponding to the window output data is output.

After instructing the output of the window display data D2 corresponding to the pixel P1, the peripheral circuit section 18 outputs the X address (column address, the liquid crystal panel 10) of the display memory U.
Are sequentially incremented and counted to M (here, 42), and the Y address (row address, corresponding to the vertical direction of the liquid crystal panel 10) is sequentially incremented and counted to N (here, 20). . X address counted by the command decoder 24,
The window display data D2 stored corresponding to the Y address is sequentially transferred to the hold memory 4 via the display switching circuit 38.
Output for 0. Then, the hold memory 40 captures the window display data D2 based on the horizontal synchronization signal H, outputs the window display data D2 to the next level shifter 42, and latches the data until the next horizontal synchronization signal H is input.
The subsequent operation is as described above.

The peripheral circuit section 18 repeatedly sends the window display data D2 to the display switching circuit 38.
Thus, the potential corresponding to the window display data D2 is periodically written to the liquid crystal panel 10, and the liquid crystal display on the liquid crystal panel 10 is maintained.

As described above, the control signal C from the MPU 16
Because the start address is set based on
6, the window W can be displayed at an arbitrary position on the display screen by changing the start address.

The following display is possible for the area (background screen) outside the window W on the display screen. A source electrode to which a gradation display potential according to the window display data D2 from the display memory U is not output includes:
A gradation display potential according to the background display data set as the display data of the background screen is applied. The background display data is output from the display memory U to the display switching circuit 38, for example. As the background display data, for example, the 255th gradation (“11111”) for each of the RGB pixels
111 ") for white display. Also, the 0th gradation (“00000000”) for each of the RGB pixels
0 ”) can be set for black display. further,
It is also possible to set the 255th gradation for the R pixel and set the 0th gradation for the other G and B pixels to perform red display (the same applies to green display and blue display).

In order to store such background display data, for example, a simple set /
What is necessary is just to add the background display data storage part (output stage in display memory) Ua which consists of a reset circuit. The background display data is 8-bit display data of “11111111” or “00000000” for white display or black display, and “11111111” and “0” for red display.
Since it is 16-bit display data of “00000000”, the data amount is small. Therefore, even if the background display data storage stage Ua is added, it is difficult to increase the size of the source driver 12.

Further, the background display data may be generated by the hold memory 40 by the configuration shown in FIG. FIG.
FIG. 3 is a block diagram illustrating a configuration of a liquid crystal display device 2 as a modification of the liquid crystal display device 1 of FIG. 1. Components having the same functions as those of the liquid crystal display device 1 of FIG. ing. In this case, the hold memory 40 has a D-type flip-flop provided for each stage. Further, the command decoder 24 and the hold memory 40
Is a background screen area control circuit 54 for setting a background screen area in accordance with a command from the command decoder 24.
Connected through. This background screen area control circuit 5
Reference numeral 4 controls the setting / resetting of the D-type flip-flop in each stage of the hold memory 40 based on the command, whereby the background display as described above can be realized. For example, when setting the background screen to white display, the D-type flip-flop of the hold memory 40 corresponding to the source electrode in charge of displaying the background screen should always be set to output “1”. Good. The timing at which the background screen is displayed at the source electrode that is in charge of displaying both the background screen and the window W is determined by the D of the hold memory 40 corresponding to the source electrode.
What is necessary is just to set the type flip-flop so as to output “1”.

In addition to setting the background to a fixed gradation as described above, simple display such as mosaic display or block display is also possible. These displays are simple set /
It can be realized by a reset circuit, a switching circuit, and a counter circuit, and the control of the circuit is not particularly complicated, so that it can be easily realized.

It is also easy to arbitrarily change the background display by a command included in the control signal C from the MPU 16. Further, the inversion of the display (black and white inversion) can be easily realized only by inverting the display data "1" and "0". By providing a timer (measurement means), the background display can be changed periodically.

In the above description, the full-screen display is performed in the normal mode, the window is displayed in the standby mode, and the area outside the window W is set as the background display. A window W may be displayed. When such display is performed, the display switching circuit 38 determines which display data from the sampling memory 36 or the display memory U is sent to the hold memory 40 in each horizontal synchronization period and each stage.
May be switched based on the command. Then, a gradation display potential corresponding to the full-screen display data D1 from the sampling memory 36 is applied to the pixels in the area outside the window W, and the display memory U is applied to the pixels in the area where the window W is to be displayed. The gray scale display potential according to the window display memory D2 from the memory may be applied.

Next, a case where the window display data D2 stored in the display memory U is enlarged and displayed on the entire display screen will be described with reference to FIG. As described above, the liquid crystal panel 10 has pixels of horizontal direction m = 168 pixels × vertical direction n = 80 pixels. The display memory U is capable of storing display data for M = 42 pixels in the horizontal direction × N = 20 pixels in the vertical direction. Therefore, the display data that can be stored in the display memory U is equivalent to 1/16 of all the pixels of the liquid crystal panel 10. Size.

In order to perform full-screen display using display data stored in the display memory U, it is sufficient to enlarge the horizontal direction and the vertical direction by four times each. As described above, the MPU 16 outputs a command for enlarging the display data stored in the display memory U and displaying it on the liquid crystal panel 10 as the control signal C. With this command, the start address is set to the address of the pixel P2 in the first horizontal direction and the first vertical direction (hereinafter, referred to as (1, 1)). Further, by this command, the frequency of a clock (not shown) sent to X address decoder 26 and Y address decoder 28 is set to １ ／ of the normal frequency. As a result, 4 pixels in the horizontal direction × 4 pixels in the vertical direction on the liquid crystal panel 10 are displayed by one window display data D2 stored in the display memory U, and the window display data stored in the display memory U is displayed. The entire screen of the liquid crystal panel 10 can be displayed by the data D2. In this display, although the image quality is coarse, the display of the date, clock, reception status, presence / absence of mail, and the like is a simple display, and thus, it is often easier to view the display in such an enlarged manner. Further, the enlargement magnification is not limited to four times, and the enlargement may be performed at another magnification such as two times by the same method. FIG. 3 is a conceptual diagram illustrating the concept of enlarged display using display data stored in the display memory U. The start address is (1, 1) except when the image is enlarged to the entire screen of the liquid crystal panel 10.
Not limited to

The contents displayed in the window W are:
The content is not limited to a single one, and a plurality of contents may be switched and displayed. For this purpose, the liquid crystal display device 3 shown in FIG.
The configuration may be as follows. FIG. 4 is a block diagram illustrating a configuration of a liquid crystal display device 3 as another modified example of the liquid crystal display device 1 of FIG. 1. Components having the same functions as those of the liquid crystal display device 1 of FIG. The symbol is added.

In the liquid crystal display device 3, the display memory U in the liquid crystal display device 1 has a first area U1, a second area U2,.
It has a k-th region Uk. Window W is 1st to kth
Which of the areas U1 to Uk performs display based on the display data stored in the area is switched by a command. Note that a plurality of windows W may be displayed according to the display data stored in the first to k-th areas U1 to Uk.

The change of the display position of the window W, the change of the size of the window W, and the switching of the display content of the window W are performed at regular intervals, for example, based on a command included in the control signal C from the MPU 16. Good. Further, a separate timer (time measuring means) may be provided in the source driver 12, and the switching may be performed based on the timer.

The display data in the display memory U is M
It can be rewritten by the PU 16 as needed. For example, when the content of the window display data D2 is a clock display, the earliest operation may be changed once a second, and the display memory U may be rewritten once a second. If the contents of the window display data D2 are clock display, the amount of data to be rewritten is generally small. For this reason,
As described above, when the window W is superimposed and displayed on the full-screen display, if the full-screen display data D1 is for normal TV display, for example, the window display data D2 is displayed during the blanking period of the vertical synchronization signal V. Even if it is rewritten, it will be enough in time. Although FIGS. 1, 2 and 4 show that the full-screen display data D1 and the window display data D2 are separately input into the source driver 12, the same terminal is used for the full-screen display data D1. The window display data D2 in the display memory U may be rewritten during the flyback period of the vertical synchronization signal V in D1. For this purpose, a switching means may be provided in the input / output circuit 22 so as to serve also as an input terminal for inputting a signal from the MPU 16 in a time-division manner.

The source driver 12 and the gate driver 14 may each be constituted by one chip.
A plurality of chips may be connected in cascade. In this case, the display memory U may be formed by being divided into a plurality of chips. Further, the source driver 12 and the gate driver 14 may be formed in one chip.
Since the capacity of the display memory U is small and the layout area is small, it is relatively easy to form the source driver 12 and the gate driver 14 in one chip.

As described above, the display control device including the source driver 12 in the present embodiment is a display control device for controlling the display on the image display means (the liquid crystal panel 10). A display control device capable of causing the image display means to perform window display using a unit. The display control device includes a storage unit (display memory U) for storing display data (window display data D2) indicating contents to be displayed in the window W, and display data (display data U) indicating contents to be displayed on the entire screen. Capture means (data latch circuit 30, shift register 34, sampling memory 36) for capturing full screen display data D1), and output means for outputting an output signal based on the transmitted display data to the image display means (Hold memory 40, level shifter 42, D / A conversion circuit 4
4, an output circuit 46), and switching means (display switching circuit 38) for switching the display data from the storage means and the display data from the capture means and sending the display data to the output means.

In this configuration, M as an external writing means
For example, full-screen display data D1 periodically transmitted from the PU 16 is captured by the capture unit, and the full-screen display data D1 captured by the capture unit is transmitted to the output unit by the switching unit. The entire display can be displayed. The switching means sends the window display data D2 stored in the storage means to the output means, so that the image display means can display a window.

In this configuration, full-screen display data D1 indicating the content to be displayed on the entire screen is taken in from the outside.
A large-capacity memory or the like for storing the full-screen display data D1 becomes unnecessary. Therefore, even when the present display control device is formed on, for example, a chip, it is possible to suppress an increase in the size of the chip. Further, when a large-capacity memory or the like becomes unnecessary, the power consumed by the memory or the like can be reduced accordingly.

Also, since the window display data D2 indicating the contents to be displayed in the window W is stored in the internal storage means, a standby mode or the like is set, and the full-screen display data D1 is periodically transmitted from the MPU 16. Even in the case where it is not received, a window can be displayed using the window display data D2 stored in the storage means.
For example, the minimum necessary contents can be displayed in the window W.

Further, in the present display control device, the peripheral circuit section 18 as the window control means, based on the command included in the control signal C from the MPU 16, controls the window display data D2 from the storage means and the window display data D2. The correspondence between the output signal based on the data D2 and the position on the display screen where the display is performed is controlled by, for example, the timing of reading the window display data D2 from the display memory U, the stage of starting writing to the display switching circuit 38, and the like. The position, size, and the like of W on the display screen can be changed.

The display control device may store a plurality of types of window display data D2 indicating the contents to be displayed in the window W by the storage means. Thus, the display in the window W can be changed by changing the type of the window display data D2 sent to the switching means.

The display control device may include the MPU 16 as rewriting means, and the MPU 16 may rewrite the window display data D2 stored in the storage means. Thus, the content displayed in the window W can be changed, for example, periodically.

The display control device also includes background setting means (background display data storage stage Ua or source-side electrode area control circuit 54). When the image display means performs window display, the outside of the window is simply displayed. One color display, mosaic display, or block display may be set. The single color display, the mosaic display, or the block display can be realized by a relatively simple and small circuit configuration. Therefore, by providing the background setting means, the outside of the window W can be set to a predetermined display state at the time of window display without causing a significant increase in circuit scale.

Further, the display control device includes the MPU 16 as a capture stop means, and stops the capture of the full screen display data D1 by the capture means under the control of the MPU 16 in, for example, a standby mode. You may. As a result, it is possible to reduce power consumption due to unnecessary fetching of full-screen display data D1.

By using the present display control device and the liquid crystal display devices 1 to 3 as display devices using the liquid crystal panel 10 as the image display means, the size of the display device can be reduced.
Power consumption can be reduced. Furthermore, by configuring a mobile phone using the present display device, it is possible to reduce the size and power consumption of the mobile phone, display a full screen at the time of operation or the like, and display more information, and perform standby. And the like, a window is displayed to display the minimum necessary information.

[0067]

As described above, the display control device according to the present invention fetches the display data indicating the contents to be displayed in the window and the storage means for storing the display data indicating the contents to be displayed in the window. Capture means, output means for outputting an output signal based on the display data sent to the display control device image display means, display data from the display control device storage means, and display control device capture means. And a switching means for switching the display data of (1) and sending it to the display control device output means.

In the above configuration, since display data indicating the content to be displayed on the entire screen is fetched from the outside, a large-capacity memory or the like for storing the display data becomes unnecessary. Therefore, even when the present display control device is formed on, for example, a chip, it is possible to suppress an increase in the size of the chip. Further, when a large-capacity memory or the like becomes unnecessary, the power consumed by the memory or the like can be reduced accordingly.

Since the display data indicating the contents to be displayed in the window is stored in the internal storage means, even when the display data is not sent periodically from the outside, the display data is stored in the storage means. Window display can be performed using the stored display data. Therefore, even when a peripheral device of the display control device is set to, for example, a standby mode or the like and a part of the function is stopped, for example, a minimum necessary content can be displayed in the window.

The display control device according to the present invention is the display control device described above, further comprising:
It is preferable that a plurality of types of display data indicating contents to be displayed in the window be stored. Thus, the display in the window can be changed by changing the type of the display control device display data.

It is preferable that the display control device according to the present invention further comprises a rewriting means for rewriting display data stored in the display control device storage means in the above-mentioned display control device. Thereby, the content displayed in the window can be changed, for example, periodically.

The display control device according to the present invention, in the above display control device, further comprises, when displaying the window on the display control device image display means, displaying the outside of the window in a single color display, a mosaic display, or a block display. It is preferable to provide background setting means for setting. As a result, the outside of the window can be set to a predetermined display state when the window is displayed without significantly increasing the circuit size.

It is preferable that the display control device according to the present invention further includes, in the above-described display control device, a capture stop means for stopping capture of display data by the display control device capture means. Thus, when window display is performed by the image display unit, the capture of display data by the capture unit is stopped by the capture stop unit, so that power consumption due to unnecessary capture of display data can be reduced.

A display device according to the present invention includes the display control device and the image display means. This allows
With the above-described effects, the size and power consumption of the display device can be reduced.

Further, a portable telephone according to the present invention includes the above display device. This makes it possible to reduce the size and power consumption of the mobile phone, display more information by performing full screen display at the time of operation, etc., and display the minimum necessary information by performing window display at the time of standby etc. It can be displayed.

[Brief description of the drawings]

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

FIG. 2 is a block diagram illustrating a configuration of a modification of the liquid crystal display device of FIG.

FIG. 3 is a conceptual diagram illustrating a concept of enlarged display using display data stored in a display memory.

FIG. 4 is a block diagram illustrating a configuration of another modification of the liquid crystal display device of FIG.

FIG. 5 is a block diagram illustrating an example of a configuration of a conventional display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal display device 2 Liquid crystal display device 3 Liquid crystal display device 10 Liquid crystal panel 12 Source driver 14 Gate driver 16 MPU 18 Peripheral circuit part 22 Input / output circuit 24 Command decoder 26 X address decoder 28 Y address decoder 30 Data latch circuit 34 Shift register 36 Sampling memory 38 Display switching circuit 40 Hold memory 42 Level shifter 44 D / A conversion circuit 46 Output circuit 48 Shift register 50 Level shifter 52 Output circuit 54 Source side electrode area control circuit U Display memory Ua Background display data storage stage

Continued on front page F-term (reference) 2H093 NA51 NC22 NC23 NC26 NC34 NC50 ND39 5C006 AC21 AC22 AC24 AF01 AF11 AF51 BC03 BC11 BC16 BF01 FA41 FA47 5C080 AA10 BB05 DD26 JJ02 KK07 5C082 AA00 BA02 BA12 BB15 BD02 CA62 EA53 DA63 DA63 DA63 DA63 DA63 DA63 DA63 DA63 DA63 DA63 DA63 DA63 DA63 DA02

Claims (7)

[Claims] 1. A display control device for controlling display on an image display means, wherein the image display means can perform window display using a part of a screen of the image display means. Storage means for storing display data indicating the content to be displayed in the window; capturing means for capturing display data indicating the content to be displayed on the entire screen; and an output signal based on the received display data. A display control device comprising: output means for outputting to an image display means; and switching means for switching display data from the storage means and display data from the capture means and sending the display data to the output means. . 2. The display control device according to claim 1, wherein said storage means stores a plurality of types of display data indicating contents to be displayed in the window. 3. The display control device according to claim 1, further comprising rewriting means for rewriting display data stored in said storage means. 4. The display control device according to claim 1, wherein when the image display means displays a window, the outside of the window is displayed in a single color, a mosaic display, or a block display. A display control device comprising background setting means for setting. 5. The display control device according to claim 1, further comprising a capture stop means for stopping capture of display data by said capture means. 6. A display device comprising: the display control device according to claim 1; and the image display means. 7. A portable telephone comprising the display device according to claim 6.