CN100498897C - Method for implementing image gray scale display of field-emitting flat panel display - Google Patents

Abstract

The invention relates to a method for realizing image grayscale display of a field emission flat panel display device. The content and characteristics of the invention are: divide the display period per unit time into several sub-display periods, and set the size of the driving signal to several values of different sizes; in the same sub-display period, apply the same driving signal to the display unit; In the sub-display period, drive signals of different sizes are applied to the display unit; through the combination of different brightness in each sub-display period, the gray scale display of the field emission flat panel display device unit is realized. The realization of the gray scale display in the present invention adopts a digital gray scale modulation method combining time modulation and amplitude modulation. Using several quantization level signals to drive the display unit does not require an accurate amplitude control circuit; using the sub-display period as the display unit, different brightness displays can be obtained through different driving signal sizes, which can solve the problem of the time grayscale modulation method on the driving pulse width. request question.

Description

A method for realizing image gray scale display of field emission flat panel display device

technical field

The invention belongs to the technical field of image display, and in particular relates to the technical direction of image grayscale display of a field emission flat panel display device.

Background technique

Grayscale display technology is one of the key technologies to realize image display. There are three types of grayscale modulation methods commonly used in flat panel displays: amplitude grayscale modulation, spatial grayscale modulation and time grayscale modulation. The amplitude grayscale modulation method is to obtain the grayscale display effect by changing the driving signal amplitude of the display. This grayscale modulation method requires the linearity of the driving circuit to be good, and the nonlinear requirements of the circuit will bring difficulties to realize accurate grayscale display. . The spatial grayscale modulation method is to obtain grayscale display by controlling the number of luminous points in the display area of the pixel unit. This grayscale modulation method requires the pixel unit of the display device to be composed of luminous points with a spatial distribution structure, which generally involves micromachining technology, Complicated leads, complex drive and control circuit technology will bring high cost and limitations in application range. The time grayscale modulation method is to obtain grayscale display by controlling the light-emitting time of the pixel unit of the display device. In this grayscale modulation method, the high grayscale display effect will be limited because the display device cannot respond to too narrow pulses.

Field Emission Display (Field Emission Display, FED for short) is one of several flat panel displays currently under development. The research on grayscale display technology is an important content of the technology research on flat panel display devices under development. In order to obtain high grayscale display under the condition that the amplitude and frequency response characteristics of the device are not high, the present invention proposes a grayscale modulation method mixed with time and amplitude to realize the image grayscale display of the field emission flat panel display device.

Contents of the invention

A kind of image grayscale display method for realizing field emission flat panel display device according to the present invention, its content is: the display period of unit time is divided into several sub-display periods, the drive signal size is set to several numerical values with different sizes; In the same sub-display period, drive signals of the same size are applied to the display unit; in different sub-display periods, drive signals of different sizes are applied to the display unit; through different brightness combinations of each sub-display period, the field emission flat panel display device unit is realized displayed in grayscale. The realization steps of above-mentioned invention and feature are as follows:

a) Using digital signals as image display driving signals;

b) Dividing the display period T of the display unit into n sub-display periods Ti, wherein i=1, 2, 3,...n;

c) Set the size of the drive signal to n values U _i or I _i , each value of U _i or I _i corresponds to the value of the drive signal when the display unit displays 2 ^i-1 levels of grayscale, where i=0, 1, 2,...n-1;

d) In the sub-display period T _i , the display unit is driven by the display driving signal U _i or I _i to realize 2 ^i-1 level grayscale display.

e) During the display time T, the gray levels of the sub-periods are displayed one by one; through the combination of different gray levels of n sub-display periods, 2n levels of gray-scale display are realized.

The display period T described in step b) is evenly divided into n sub-display periods T _i .

The display unit driving signal described in step d) has the same magnitude in the same sub-display period, and has different magnitudes in different sub-display regions.

The one-by-one display described in step e) is displayed from the lowest gray level to the highest bit gray level.

The present invention combines the time modulation method with the amplitude modulation method, divides the unit display time into several sub-display periods and introduces several numerical display driving signal sizes into the display periods, so that different sub-display periods can have different brightness displays effect, and then realize the grayscale display through the display brightness combination of the sub-display periods. This grayscale display method is a digital grayscale modulation method. Using several quantization level signals to drive the display unit does not require an accurate amplitude control circuit; using the sub-display period as the display unit, different brightness displays can be obtained through different driving signal sizes, which can solve the problem of the time grayscale modulation method on the driving pulse width. request question. The present invention has unique advantages in realizing grayscale display.

Description of drawings

Fig. 1 is a principle schematic diagram of an example of realizing 256-level gray-scale display by a gray-scale modulation method of mixing time and amplitude.

Fig. 2 is a schematic diagram of a gray-scale modulation method for realizing time and amplitude mixing for a 16×16 array flat panel display unit, in which Fig. 2a is a schematic block diagram of the circuit system, and Fig. 2b is a schematic block diagram of the display module circuit.

Specific implementation example

An example of 256-level grayscale display realized by 16×16 array flat panel display units and 8-bit display driving data signals is used to illustrate the method for realizing grayscale display of a field emission flat panel display device by the time and amplitude mixed modulation method of the present invention.

In the first step, the unit display period T is equally divided into 8 sub-display periods T ₁ -T ₈ , and each sub-display period is T/8, as shown in FIG. 1 .

In the second step, the size of the display driving signal is set to 8 levels V ₁ ~ V ₈ , which correspond to the display unit driving signal voltages of 2 ^i-1 gray levels, where i=1, 2, ... 8, as shown in Figure 1 shown.

In the third step, in the sub-display period T _i , the display unit is driven by the display driving signal V _i to realize 2 ^i-1 level grayscale display, where i=1, 2, ... 8, as shown in FIG. 1 .

In the fourth step, in each display period T, the gray levels of the 8 sub-display periods are displayed one by one from _T1 to _T8 , that is, the grayscale display data is displayed bit by bit from the lowest bit to the highest bit; through the eight sub-display periods The combination of different gray levels can realize 256 levels of gray level display.

Figure 2 is a schematic block diagram of the circuit system for realizing time and amplitude mixed grayscale modulation, which consists of two parts: a control signal generator and a display module.

Figure 2 (a) is a block diagram of the control signal generator circuit. The control signal generator includes a clock manager (DCM), a 1/20 frequency divider, a drive voltage selection signal generator, a column gray scale signal generator, a row addressing signal generator, a display data receiving circuit and a row memory. The clock manager DCM divides the frequency of the input clock signal CLK ₀ , and the frequency division factor can be set by programming; after the signal output by the DCM is divided by a 1/20 frequency divider, it is used as a driving voltage selection signal generator, and the column grayscale signal is generated. Synchronous clock for generator, row addressing signal generator. The function of the display data receiving circuit is to receive the display data and lock the display data in the row memory. The line memory includes two register groups, each group is composed of 16 8-bit registers, the two register groups work alternately, one group is used to receive display data, and the other group is used to provide display data to the column grayscale signal generator. The column grayscale signal generator performs grayscale modulation on the display data to generate column switch control signals, the driving voltage selection signal generator generates voltage selection control signals, and the row address signal generator generates row address signals, and these signals are output to the display module circuit , so that the display unit can realize 16, 32, 64, 128, 256 grayscale display functions.

Figure 2(b) is a schematic block diagram of the display module circuit, which consists of a dot-matrix pixel display array, a row decoding circuit, a voltage selection switch circuit, and a column drive switch circuit. SELINE (0~3), SELV (0~2), COL (1~16) are the control signals input from the control signal generator. SELINE (0 ~ 3) is used for row addressing control, and is input to the row decoder to make a certain row Xi be addressed and strobed. COL(1~16) is used to control the gate switch of the column electrode, for example, when COL(i) is "1", the i-th column is gated, and the pixel corresponding to the addressed row in this column is in the display state ; Conversely, when COL(i) is "0", the column is not selected. V ₁ , V ₂ , V ₃ , V ₄ , V ₅ , V ₆ , V ₇ , V ₈ respectively correspond to gray levels of 2 ⁰ :2 ¹ :2 ² :2 3:2 ^{4 :} 2 ⁵ :2 ⁶ :2 ⁷ drive voltage. During the sub-display periods T ₁ -T ₈ , SELV (0-2) controls the switch selection circuit, and selects one of V ₁ to V ₈ as the driving voltage in turn. After the brightness combination of eight sub-display periods, a 256-level grayscale display is produced.

Claims (2)

1. method that realizes that image gray scale display of field-emitting flat panel shows, its content is: demonstration phase of unit interval is divided into experimental process shows the phase, the drive signal size is set to some numerical value that vary in size; Interim in same height demonstration, apply the identical drive signal of size to display unit; Interim in different son demonstrations, apply size drive signal inequality to display unit; Different brightness combinations by each sub-demonstration phase realize that the gray scale of display of field-emitting flat panel unit shows; Its feature may further comprise the steps:

A) adopt digitized signal as the image display drive signals;

B) the display cycle T of display unit is divided into n sub-demonstration phase Ti, i=1 wherein, 2,3 ... n;

C) the drive signal size is set to n numerical value U ₁Or I _i, each U _iOr I _iThe corresponding display unit of numerical values recited shows 2 ^1-1The drive signal value of level during gray scale, i=1 wherein, 2 ... n;

D) show that at son display unit is subjected to display drive signals U among the phase Ti ₁Or Ii drives realization 2 ^1-1The level gray scale shows;

E) in showing time T, show the gray scale of sub-demonstration phase one by one; The combination of the different grey-scale by n sub-demonstration phase realizes 2 ⁿThe gray scale of level shows; Described being shown as one by one from the lowest order gray level to the most significant digit gray level display.

2. a kind of method that realizes that image gray scale display of field-emitting flat panel shows according to claim 1 is characterized in that: the described display cycle T of step b) is divided into n sub-demonstration phase Ti.

Images