JP2003076337A - Liquid crystal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal device in which a refresh rate are set in accordance with a display mode and flicker is prevented and a saturation is held and the power consumption is reduced. SOLUTION: The liquid crystal device is provided with a setting register part 3 where the display mode, the refresh rate, etc., are set, a display memory 5 in which pictures are stored, a liquid crystal panel 6, a liquid crystal controller 3 which generates pixel data from display data in the display memory in accordance with set contents of the setting register part 4 and displays the pixel data on the liquid crystal panel, a central processor 1 which sets contents of the setting register part 4, and an input device 2, and the central processor 1 is provided with a refresh rate setting means which sets the refresh rate in accordance with a input display mode and an output means which outputs the display mode and the set refresh rate to the setting register part 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device used in a facsimile machine or the like and displaying image information stored in a display memory as an image on a liquid crystal panel.

[0002]

2. Description of the Related Art A pixel of a liquid crystal panel generates a density by applying an ON voltage. Since each pixel of the liquid crystal panel cannot store and hold the on-voltage, it shifts to a low density with time. Therefore, in order to hold a still image on the liquid crystal panel, it is necessary to repeatedly apply the same ON voltage or OFF voltage to the same pixel within a predetermined time. Rewriting (voltage application) per panel is called one frame, and the rewriting cycle is called a frame cycle.

On the other hand, in the density expression, some frames are treated as one cycle, and the density level is expressed by the appearance frequency of ON pixels in one cycle. For example, 5 levels of density expression can be obtained by repeating 4 frames as 1 cycle. That is, 5 levels that are turned on 0 to 4 times in 4 frames can be expressed. If one cycle is set to 16 frames, it is possible to express 17 levels of density which are turned on 0 to 16 times in 16 frames. In order to express a large number of concentrations in this way, it is necessary to increase the number of repetitions per cycle.

When the same frame period is used, a large number of density expressions have a lower occurrence frequency of ON at a lower density level than a small number of density expressions, so that a visual level difference is less likely to occur and flicker is noticeable. Come on. In order to prevent this, a shorter frame period (high refresh rate) is required in the case of a large number of density expressions.

The refresh rate will be described on the screen. FIG. 4 is a screen view showing the screen of the liquid crystal panel in horizontal display and vertical display. Normally, the pixel value (on, off) for each pixel is written in one line in the horizontal direction from the upper left of the liquid crystal panel (horizontal display period), after a non-writing period (horizontal non-display period), and then to the next line. This is repeated for the number of lines of the liquid crystal panel (vertical display period), and after a non-writing period (vertical non-display period), writing of a new frame is started. The reciprocal of one frame period = 1 / ((horizontal display period + horizontal non-display period) × (vertical display period + vertical non-display period)) is called the refresh rate or frame frequency. Here, (horizontal display period + horizontal non-display period) is represented by time (that is, represented by time required for writing one line), and (vertical display period + vertical non-display period) is represented by number of lines. The higher the frame frequency, the more frequently the display data is read from the display memory, and thus the more power consumed for reading the display memory is consumed. In a mode in which the number of display colors is large, the amount of data per pixel is large, so the access frequency of the display memory is correspondingly high,
It will consume more power.

FIG. 1 is a block diagram showing a general liquid crystal device. In FIG. 1, 1 is a CPU (central processing unit) for controlling the whole, 2 is an input device for inputting data and the like, 3 is a liquid crystal controller (LCD controller), 4 is a setting register section including various registers, and 5 is a display. A display memory that stores data (for example, image data), 6 is a liquid crystal panel (LCD panel) that displays an image, 31 is a control timing generation circuit that generates control timing (control timing) of the liquid crystal controller 3, and 32
Is a memory address generation circuit for generating address data from the address request signal output from the control timing generation circuit 31, 33 is a control signal for the display memory 5 and data latch timing for the data buffer 34 from the memory data request signal output from the control timing generation circuit 31 And a data selector circuit for selecting latch data (display data) output from the data buffer 34 from the data select signal from the control timing generation circuit 31, and a display for the output of the data selector circuit 35. A pixel data generation circuit that generates pixel data from the data, 37 is a liquid crystal control signal generation circuit (LCD) that generates a control signal from the pixel timing signal from the control timing generation circuit 31. Control signal generation circuit), 41 is a screen position shape setting register that sets the screen start address and memory line width, 42 is a display mode setting register that sets the screen mode (display mode), and 43 is a horizontal non-display period and a vertical non-display period. A refresh rate setting register that sets a refresh rate according to the marking period and the pixel clock frequency, and 44 is a palette storage register that stores a plurality of palettes for generating pixels by palette numbers.

With respect to the liquid crystal device configured as described above,
The conventional operation will be described with reference to FIG. FIG. 5 is a flowchart showing the operation of the CPU 1 of the conventional liquid crystal device.

In FIG. 5, first, at initialization, a predetermined refresh rate is set to the refresh rate setting register 4
3 is input (S11). Next, the display mode is input via the input device (S12), and the input display mode is input to the display mode setting unit 42 (S13). here,
As the display modes, there are a multicolor mode in which multicolors (for example, 16 colors) are displayed and a low color mode in which low colors (for example, 4 colors) are displayed.

In this way, the control timing generation circuit 31 operates according to the display mode and refresh rate set in the registers 42 and 43, and controls the circuits 32 to 37 to generate an image on the liquid crystal panel 6.
The CPU 1 controls the activation and deactivation of the control timing generation circuit 31.

FIG. 6 and FIG. 7 are explanatory views showing a density generating method.

As shown in FIG. 6, when the display data output from the display memory 5 is "5", the pallet number "5" is selected. The density is determined according to this pallet number. That is, the density is determined by the number of times the pallet number “5” is turned on in black and white (white indicates off, black indicates on), and as can be seen from FIG. 6, pallet number “15” indicates the pallet with the highest density. is there. The palette consists of 16 bits, and the frame also consists of 16 bits as shown in FIG. That is, the frame number and the bit number of the pallet have a one-to-one correspondence, and as shown in FIG. 6, in the case of the frame number 4, the data (off data) of the bit number 4 of the pallet number “5” is output. It

Since the density is generated in this way, the refresh rate is a fixed rate in which 16 frames are repeated. In this case, the refresh rate is set to a high rate corresponding to multiple colors as shown by the number of frames 16 in order to prevent flicker and maintain saturation.

[0013]

However, the conventional liquid crystal device has a problem that the refresh rate is set to a high rate in order to prevent flicker and maintain the saturation, and the power consumption is large.

In this liquid crystal device, it is required to prevent flicker, maintain saturation, and reduce power consumption by setting a refresh rate according to a display mode.

In order to meet this demand, the present invention provides a liquid crystal device capable of setting a refresh rate according to a display mode, preventing flicker and maintaining saturation, and reducing power consumption. The purpose is to do.

[0016]

In order to solve the above problems, a liquid crystal device of the present invention stores a setting register unit for setting a display mode, a refresh rate, etc., a camera output image, a menu image, etc. The display memory, the liquid crystal panel that performs pixel display, the liquid crystal controller that reads the display data from the display memory according to the setting contents of the setting register unit, generates the pixel data from the display data and displays the pixel data on the liquid crystal panel, and the contents of the setting register A central processing unit that sets and controls the liquid crystal controller,
A liquid crystal device having an input device for inputting data and the like, wherein the central processing unit sets a refresh rate setting means for setting a refresh rate according to a display mode input via the input device, and a display mode. And a refresh rate and an output means for outputting the refresh rate to the setting register section.

As a result, a liquid crystal device can be obtained in which the refresh rate can be set according to the display mode, flicker can be prevented, saturation can be maintained, and power consumption can be reduced.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION A liquid crystal device according to claim 1 of the present invention comprises a setting register unit for setting a display mode, a refresh rate and the like, and a display memory for storing a camera output image, a menu image and the like. , A liquid crystal panel that displays pixels, a display controller that reads display data from the display memory according to the setting contents of the setting register unit, generates pixel data from the display data and displays the pixel data on the liquid crystal panel, and sets the contents of the setting register. A liquid crystal device having a central processing unit for controlling a liquid crystal controller and an input device for inputting data or the like, wherein the central processing unit is a refresh for setting a refresh rate according to a display mode input via the input device. The rate setting means, the display mode and the set refresh rate are output to the setting register section. It is obtained by the fact that an output means for.

With this configuration, since the refresh rate is set according to the input display mode, flicker is prevented, the required saturation is maintained, and when the input display mode is the small color mode, it is consumed. It has the effect of being able to reduce power.

A liquid crystal device according to a second aspect is the liquid crystal device according to the first aspect, wherein the display mode is composed of a multicolor mode and a low color mode, and the refresh rate setting means is
When the input display mode is the multi-color mode, the refresh rate is increased, and when the input display mode is the low-color mode, the refresh rate is decreased.

With this configuration, the refresh rate becomes high in the multicolor mode, so that flicker can be prevented and the required saturation can be maintained, and in the low color mode, the refresh rate becomes low, but low. Since the mode is the color mode, flicker is suppressed, necessary saturation is maintained, and power consumption can be reduced.

According to a third aspect of the present invention, in the liquid crystal device according to the first or second aspect, the liquid crystal controller outputs the liquid crystal controller according to the display mode and the refresh rate set in the setting register section. The display data is read from the memory, pixel data is generated from the display data, and the pixel data is displayed on the liquid crystal panel.

With this structure, the liquid crystal controller has the same structure as that of the conventional one and can perform the same operation, and further, it has an effect of reducing the power consumption.

FIG. 1 shows an embodiment of the present invention.
~ It demonstrates with reference to FIG.

(Embodiment 1) The liquid crystal device according to Embodiment 1 of the present invention has the structure shown in FIG. The present embodiment differs from the conventional example in the operation of the CPU 1.

FIG. 2 is a functional block diagram showing the function realizing means in the CPU 1. In FIG. 2, 11 is a judging means for making various judgments, 12 is a refresh rate setting means for setting a refresh rate, and 13 is an output means for outputting data and the like to the outside.

The operation of the CPU 1 of the liquid crystal device having such a configuration will be described with reference to FIG. FIG. 3 is a flowchart showing the operation of the CPU 1 of the liquid crystal device of FIG.

In FIG. 3, first, the determination means 11 determines whether or not there is a display mode input via the input device 2 (S1). If it is determined that the display mode has been input, the refresh rate is determined. The setting means 12 sets the refresh rate according to the input display mode (S2), and the output means 13 sets the input display mode and the set refresh rate to the display mode setting register of the setting register section 4. 42 and the refresh rate setting register 43 (S3). In this manner, the refresh rate according to the display mode is set in the refresh rate setting register 43.

In this way, the control timing generation circuit 31 operates according to the display mode set in the registers 42 and 43 and the refresh rate according to the display mode, and controls the circuits 32 to 37 to control the liquid crystal panel 6.
To generate an image. The CPU 1 controls the activation and deactivation of the control timing generation circuit 31.

As described above, according to the present embodiment, the central processing unit 1 sets the refresh rate setting means 12 for setting the refresh rate in accordance with the display mode input via the input device 2, and the display mode. Output means 1 for outputting the set refresh rate to the setting register section 4
Since the refresh rate is set according to the input display mode by including 3 and 4, flicker is prevented, necessary saturation is held, and when the input display mode is the low color mode, the consumption is reduced. The power can be reduced.

The display mode is composed of a multi-color mode and a low-color mode. The refresh rate setting means 12 raises the refresh rate when the input display mode is the multi-color mode, and the input display mode is low. By lowering the refresh rate in color mode,
In the multi-color mode, the refresh rate is high, so flicker can be prevented and the required saturation can be maintained.In the low-color mode, the refresh rate is low, but the flicker is low in the low-color mode. Is suppressed, the required saturation is maintained, and power consumption can be reduced.

Further, the liquid crystal controller 3 is output by the output means 13, and the display memory 5 is output in accordance with the display mode and the refresh rate set in the setting register section 4.
By reading the display data from the pixel data and generating pixel data from the display data and displaying the pixel data on the liquid crystal panel 6,
The liquid crystal controller 3 may have the same configuration as the conventional one and perform the same operation, and further, the power consumption can be reduced.

[0033]

As described above, according to the liquid crystal device of the first aspect of the present invention, the setting register unit for setting the display mode, the refresh rate, etc., the camera output image, the menu image, etc. are stored. Display memory,
A liquid crystal panel that displays pixels, an LCD controller that reads display data from the display memory according to the setting contents of the setting register section, generates pixel data from the display data and displays it on the liquid crystal panel, and sets the contents of the setting register and the liquid crystal A liquid crystal device having a central processing unit for controlling a controller and an input device for inputting data and the like, wherein the central processing unit sets a refresh rate according to a display mode input via the input device. Since the refresh rate is set according to the input display mode by including the setting means and the output means for outputting the display mode and the set refresh rate to the setting register section, flicker can be prevented and necessary When the saturation is maintained and the input display mode is the low color mode, Beneficial effect is obtained that it is possible to reduce power consumption in.

According to the liquid crystal device of the second aspect, in the liquid crystal device of the first aspect, the display mode is composed of a multicolor mode and a low color mode, and the refresh rate setting means is the input display mode. Is high in the multi-color mode and low in the multi-color mode when the input display mode is the low-color mode, so that the refresh rate is high in the multi-color mode. The refresh rate is low in the low color mode, but flicker is suppressed due to the low color mode, the required saturation is retained, and the power consumption is reduced. The advantageous effect that it is possible is obtained.

According to a third aspect of the liquid crystal device, in the liquid crystal device according to the first or second aspect, the liquid crystal controller outputs the display mode and the refresh rate output from the output means and set in the setting register section. According to the above, the display data is read from the display memory and the pixel data is generated from the display data to be displayed on the liquid crystal panel, so that the liquid crystal controller can perform the same operation with the same configuration as the conventional one, and further reduce the power consumption. The advantageous effect of being able to do is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a general liquid crystal device.

FIG. 2 is a functional block diagram showing a function realizing means in a CPU.

FIG. 3 is a flowchart showing the operation of the CPU of the liquid crystal device of FIG.

FIG. 4 is a screen diagram showing a liquid crystal panel screen in a horizontal display and a vertical display.

FIG. 5 is a flowchart showing the operation of a CPU of a conventional liquid crystal device.

FIG. 6 is an explanatory diagram showing a density generation method.

FIG. 7 is an explanatory diagram showing a density generation method.

[Explanation of symbols]

1 CPU (central processing unit) 2 input devices 3 LCD controller 4 Setting register 5 Display memory 6 LCD panel 11 Judgment means 12 Refresh rate setting means 13 Output means 31 Control Timing Generation Circuit 32 memory address generation circuit 33 Memory controller circuit 34 data buffer 35 data selector circuit 36 pixel data generation circuit 37 LCD control signal generation circuit 41 Screen position shape setting register 42 Display mode setting register 43 Refresh rate setting register 44 Palette storage register

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Claims (3)

[Claims] 1. A setting register unit for setting a display mode, a refresh rate, etc., a display memory for storing a camera output image, a menu image, etc., a liquid crystal panel for displaying pixels, and a setting for the setting register unit. A liquid crystal controller for reading the display data from the display memory according to the contents and for generating pixel data from the display data to display on the liquid crystal panel; a central processing unit for setting the contents of the setting register and controlling the liquid crystal controller; A liquid crystal device having an input device for inputting data etc., wherein the central processing unit sets a refresh rate according to a display mode input via the input device, and the display mode. And the set refresh rate are output to the setting register section. A liquid crystal device, comprising: 2. The display mode comprises a multi-color mode and a low-color mode, and the refresh rate setting means increases the refresh rate when the input display mode is the multi-color mode, and the input display The liquid crystal device according to claim 1, wherein the refresh rate is lowered when the mode is the low color mode. 3. The liquid crystal controller reads display data from the display memory according to a display mode and a refresh rate output from the output means and set in the setting register section, and generates pixel data from the display data. 3. The liquid crystal device according to claim 1, wherein the liquid crystal panel is displayed on the liquid crystal panel.