CN101587698A - Display apparatus, display control method, and display control program - Google Patents

Fig. 1 is the block diagram that is used to illustrate according to the configuration of the display device of present embodiment.As shown in Figure 1, the

100 of present embodiment is provided with picture

101, image

102 and lcd controller 103 (being labeled as LCDCTL in Fig. 1).

The

100 of present embodiment also is provided with

104, mean flow rate, minimum brightness (Min) and high-high brightness (Max) counting circuit 105 (below be referred to as the brightness calculation circuit), and parameter

106.

In addition, the

100 of present embodiment also is provided with PWMGAIN (that is regulated value) counting

107, PWM

108,

109, CPU (central processing unit) (CPU) 120 and

121.

Picture signal (that is Digital Image Data) via 101 inputs of picture signal input port at first is imported in image

102 and the brightness calculation circuit 105.For example, 102 pairs of processed picture signals of image quality improvement circuit are carried out various Flame Image Process, make to realize high-quality image replaying in the characteristic of the characteristic of considering picture signal and LCD panel 109.After 102 processing of image quality improvement circuit, picture signal is provided for

103 subsequently.

103 is made of the assembly such as video memory and LCD control circuit.The given picture signal that provides,

103 forms the picture signal that is used for display image that is provided for LCD panel 109.The picture signal that is used to show that forms like this in

103 is provided for

104 subsequently.

Image calibrating

104 is regulated at the performed backlight illumination of the function of also considering the

107 that hereinafter will describe when handling (that is, backlight intensity control), and (or adjusting) proofreaied and correct in the brightness of the picture signal that provided.The picture signal of handling like this in

104 is provided for

109 subsequently.

Simultaneously, a screen the average image brightness (that is average picture intensity (APL)) that provides the picture signal of coming to calculate single screen (that is frame) from picture

101 is provided brightness calculation circuit 105.In addition,

105 also detects screen minimum image brightness (that is minimum picture intensity (Min)) and a screen maximum image brightness (that is maximum picture intensity (Max)).

A screen average picture intensity (APL), a screen minimum picture intensity (Min) and the maximum picture intensity of screen (Max) that

105 is obtained are provided for PWMGAIN (that is backlight illumination regulated value) counting

107 subsequently.

In addition, be used for seven parameters that the brightness backlight of

109 is controlled are preconfigured in the register of parameter

106, these parameters be via

121 input and set via

120.

After in the register that is set at parameter

106, above-mentioned seven parameters are provided for PWMGAIN

107 subsequently.

In PWMGAIN

107, based on a screen the average image brightness from

105, and, calculate backlight intensity regulated value (PWMGAIN) from the linear luminance adjustment curve that seven parameters are determined that passes through of parameter

106.

Then, PWMGAIN

107 offers PWM

108 with the backlight intensity regulated value (PWMGAIN) that is calculated.In addition, PWMGAIN

107 offers

104 with the backlight intensity regulated value (PWMGAIN) that calculated with from three brightness correlations that

105 receives.

Here, PWM

108 from three brightness correlations that

105 received and offered subsequently

104 is: a screen average picture intensity (APL), a screen minimum picture intensity (Min) and a screen maximum picture intensity (Max).

Based on the backlight intensity regulated value (PWMGAIN) that comes is provided from PWMGAIN

107, PWM

108 is formed for making the pwm signal of white LEDs backlight luminescence of LCD panel 109.PWM

108 offers

109 with this pwm signal subsequently.

109 is provided with LCD, is used as white LEDs backlight and the led drive circuit that is used for white LEDs.Led drive circuit is backlight according to providing the pwm signal that comes to drive white LEDs from PWM

108.

Characteristic according to previously described processing (1), PWMGAIN

107 calculates backlight intensity regulated value (PWMGAIN), when making mean flow rate when the expressed image of the picture signal of handling low, not backlight excessively not dimmed and the image nature that can not become.In this process, the brightness of serving as the white LEDs backlight of

109 can be according to the image of handling and Be Controlled, and can excessively not dimmed.

Simultaneously, in

104, based on the enhancing amount that provides the parameter of coming to calculate the picture signal that is used for handling from

107, and to provide the picture signal of coming to carry out enhancement process from lcd controller 103.Then, the picture signal of enhancing is provided to the LCD of

109.

According to the characteristic of previously described processing (2), the enhancing ratio of the highlights of 104 pairs of formed images of picture signal of image calibrating circuit and dark portion is made amendment, so that image is saturated and distortion is not obvious.In this process, the hi-lite of picture signal can excessively not strengthened, thereby makes high-quality image can be displayed on the lcd screen of

109.

Like this, 100 pairs of the display device of present embodiment are served as the white LEDs backlight of

109 and are carried out brilliance control, also picture signal are carried out simultaneously to strengthen control.

Below, will describe the processing of performed enhancing (that is, the proofreading and correct) picture signal of the processing of the performed calculating backlight intensity regulated value (PWMGAIN) of

107 in the

100 of present embodiment and

104 respectively in detail.

(

107 performed processing)

At first, the processing that the PWMGAIN counting circuit in the

100 of description

107 is carried out.As previously mentioned,

107 provides the mean flow rate (APL) of coming to find the solution backlight intensity regulated value (PWMGAIN) by using from

105.

In addition, if the PWMGAIN counting circuit in the display device of

100 107 calculates backlight intensity regulated value (PWMGAIN) according to average picture intensity (APL), then

107 calculates PWMGAIN based on linear luminance adjustment curve (that is linear APL-PWMGAIN curve).In the case, use seven pre-configured parameters.

These seven parameters are preconfigured in the register in the parameter

106 in the display device 100.More specifically, these seven parameters comprise minimum value (MIN) and the maximal value (MAX) of backlight intensity regulated value (PWMGAIN), as previously mentioned.

Fig. 2 is used for illustrating the

107 employed linear luminance adjustment curves (that is linear APL-PWMGAIN curve) of

100 of present embodiment and the diagrammatic sketch of the relation between above-mentioned seven parameters.

As shown in Figure 2, linear luminance adjustment curve (A) utilizes above-mentioned seven parameters to come appointment, and these parameters are to come predetermined according to characteristic and the factor the picture quality state of a control such as

109.

Here, above-mentioned first threshold (TH1) and second threshold value (TH2) are separated the preset range of average picture intensity (APL).In the

107 of the

100 of present embodiment, first threshold (TH1) and second threshold value (TH2) are the APL points that is used for linear luminance adjustment curve (A) is divided into three scopes (that is zone).

In addition, in the

100 of present embodiment, not simply backlight intensity regulated value (PWMGAIN) to be compared with average picture intensity (APL).As shown in Figure 2, in the basic, normal, high zone of separating, carry out different adjustings respectively by first threshold (TH1) and second threshold value (TH2) (that is APL point).In other words, the

100 of present embodiment is configured to and can carries out three grades of adjustings according to average picture intensity (APL).

Like this, in the

100 of present embodiment, used the linear luminance adjustment curve (A) that as described in, forms, thereby made it possible to come the suitably regulated value (that is backlight brightness values) of definite backlight illumination based on average picture intensity (APL) with reference to figure 2.

Should be understood that it is that cost preferentially reduces power consumption slightly secretly that

100 can be configured to shown image by regulating aforesaid seven parameters.On the contrary,

100 can be configured to also reduce with power consumption that not to be evident as so that cost comes with picture quality serve as preferential.

In addition, actual seven parameters using also can be modified according to the characteristic and the picture quality state of a control of employed LCD panel.In the

100 of the present embodiment here, seven above-mentioned parameters are based on and are used for coming the repeated experiments of optimization setting and preassigned at LCD panel or employed other assemblies.

(

104 performed processing)

The performed processing of

104 in the

100 of present embodiment will be described now.In conjunction with the backlight intensity control that above-mentioned

107 is carried out,

104 carries out image signals strengthen control, so that prevent that LCD from going up the image that shows and seeming not nature.

Therefore, given picture signal to be processed,

104 in the

100 of present embodiment is set bigger enhancing ratio for the corresponding part of the image section with having relatively low brightness of picture signal, and sets less enhancing ratio for the corresponding part of the image section with having relative higher brightness of picture signal.

Fig. 3 is the diagrammatic sketch of the example of the

104 that is used for illustrating the

100 of the present embodiment linear image gamma correction curve that is used for the control of carries out image luminance signals.

Use description to the method for four parameters (that is, low-light level slope (LOWER), high brightness slope (UPPER), basic brightness BY (BASE_Y) and flex point IX (INFLEXTION_X)) of use in the specify

104 now.

For four parameters using in the

104, can find out and set suitable value in advance by experiment.Can also investigate the attribute of image input by software processes or similar means in advance, set above four parameters according to result then.

But, the picture carrier treatment for correcting of carrying out in the

104 preferably with

107 in the LCD backlight intensity control carried out carry out explicitly.

Therefore, in the

104 of the

100 of present embodiment, low-light level slope (LOWER) is based on that the backlight intensity regulated value (PWMGAIN) that calculates in the

107 determines.

At first, use description to specify the method for low-light level slope (LOWER).Low-light level slope (LOWER) is so set in

107, so that the degree that degree that input signal strength is exaggerated and backlight intensity are lowered is suitable.More specifically, if backlight intensity be lowered to intensity p (=PWMGAIN), input signal strength then is multiplied by 1/p=p ^-1

But in the practice, the image that shows on the

109 also is carried out gamma correction.Here, with the typical gamma value 2.2 in the consideration LCD panel and the situation of basic backlight intensity 1.0 (100%).In addition, the unit of backlight intensity and picture intensity (that is brill) is cd/m here ², " nit " in other words.

Therefore, in the

100 of present embodiment, by to Y '=Yp ^1/2.2Carry out inversion and bring setting low-light level slope (LOWER).In other words, low-light level slope (LOWER) is set to p ^-1/2.2(-1/2.2 power of p).Clearly, low-light level slope (LOWER) is not limited to this value, but can be set to other appropriate value according to employed concrete gamma value.

Simultaneously, set high brightness slope (UPPER), to get the value in the scope between 0.65 to 1.0 according to the value of screen average picture intensity (APL) and the maximum picture intensity of screen (Max) by using

100 to experimentize.

Therefore, based on screen average picture intensity (APL) and a screen maximum picture intensity (Max), set up the single value that a table determines to belong to the high brightness slope (UPPER) of the scope between 0.65 to 1.0.The table here is in the predetermined memory zone that is based upon in advance in the

104.

Set basic brightness BY (BASE_Y) by using

100 to experimentize, to get the value in the scope between 0 to-22 according to the minimum picture intensity of screen (Min).

Therefore, based on a screen minimum picture intensity (Min), set up the single value that a table determines to belong to the basic brightness BY (BASE_Y) of the scope between 0 to-22.Above-mentioned table is based upon in the predetermined memory zone in the

104 similarly in advance.

More specifically, the linear image gamma correction curve (B) that is lower than in the zone of flex point IX of input signal brightness value Yin is represented by following

1.

Under the situation that above-mentioned

1 and formula 2 equates (that is, the position that the line in

1 and formula 2 intersects), the flex point IX that find the solution (INFLEXTION_X) thus equal the value of input signal brightness value Yin.

From description, can know and find out that

107 and

104 can suitably be regulated the backlight illumination of

109, thereby reduce backlight power consumption the

100 of previous embodiment.In addition, owing in backlight intensity control, also suitably controlled the brightness of the picture signal of handling, therefore can the shown image of deterioration.

Utilize the

100 of present embodiment, confirm by experiment, when showing the rest image of common landscape or portrait, compare, power consumption can be reduced by 20% to 50% with the display device of prior art.In addition, confirm,, when display video, power consumption can be reduced about 30% to 80% because video has a large amount of relatively this characteristics of dark image section.

In the

100 of present embodiment, can suitably carry out backlight intensity control and picture signal enhancing control based on the simple parameter such as average picture intensity (APL), minimum picture intensity (Min) and maximum picture intensity (Max).

In addition, can utilize the relative small-scale circuit such as

104,

105, parameter

106 and

107 to carry out backlight intensity control and picture signal enhancing control.

In other words, the

100 of present embodiment has realized that by following a kind of novelty and relative simple algorithm backlight emission control and picture signal strengthen control, and also can not increase the scale of circuit.

In display device shown in Figure 1 100,

104,

105, parameter

106 and

107 are deployed in after the

103.

Therefore, in display device shown in Figure 1 100, be used in subsequently among the

103 by image

102 handled picture signals, be provided for the picture signal that is used to show of

109 with formation, this picture signal that is used for showing was accumulated in storer subsequently before being provided for

104.

Therefore, the processing in

105, parameter

106 and the

107 is to carry out when picture signal is processed in image

102 and LCDCTL103.

As a result, processing in the

104 and the processing in the PWM

108 are carried out simultaneously.Therefore, more than configuration make according to pwm signal carry out to the backlight drive control that causes by brilliance control of

109 can with above-mentioned

100 in synchronous by strengthening the picture signal display process that control causes.

In the

104 in the

100 of the present embodiment of describing referring to figs. 1 to Fig. 3, basic brightness BY (BASE_Y) is based on that the minimum picture intensity of screen (Min) disposes.But, should be understood that at basic brightness BY (BASE_Y) to be set under the situation of fixed value, can omit finding the solution to a screen minimum picture intensity (Min).

In addition, for example, can high brightness slope (UPPER) be set under the situation of fixed value, can omit finding the solution a screen maximum picture intensity (Max) by the test in advance of

100.

Therefore, the

200 of the variant according to the embodiment of the invention described below is configured to carry out backlight intensity control and picture signal and strengthens and control before lcd controller.

Fig. 4 is the block diagram that is used to illustrate according to the

200 of this variant.As shown in Figure 4, the

200 of this example is provided with picture

201, image

202 and lcd controller 203 (being labeled as LCDCTL in Fig. 4).

The

200 of this example also is provided with

204, mean flow rate, minimum brightness (Min) and high-high brightness (Max) counting circuit 205 (below be referred to as the brightness calculation circuit), and parameter

206.

In addition, the

200 of this example also is provided with PWMGAIN (that is regulated value) counting

207, PWM

208,

209, luminance parameter interframe and is averaged

210, CPU (central processing unit) (CPU) 220 and

221.

Here, among the circuit that is provided with in the

200 shown in Figure 4 with

100 shown in Figure 1 in each circuit of circuit corresponding (that is, same names being arranged) have and the similar function of describing with reference to display device shown in Figure 1 100 of related circuit.

But, when display device more shown in Figure 4 200 and

100 shown in Figure 1, can recognize, there are following two significant differences.

At first,

200 shown in Figure 4 is that with the significant difference of

100 shown in Figure 1

204,

205, parameter

206 and

207 are set at before the

203.

Next,

200 shown in Figure 4 is that with the difference of

100 shown in Figure 1

200 comprises that also the luminance parameter interframe between

205 and

207 is averaged

210.

In display device shown in Figure 4 200, luminance parameter interframe is averaged

210 makes the assembly such as

204 and

207 can be set at before the

203.

More specifically, under the situation of display device shown in Figure 1 100,

104,

105, parameter

106 and

107 are set at after the

103.

Therefore, the circuit such as

107 can play a role during picture signal remains in period among the

103 and this picture signal is carried out backlight intensity control and picture signal and strengthen and control, as previously mentioned.

Different with it, under the situation of

200 shown in Figure 4, the circuit such as

204 and

207 is set at before the LCDCTL 203.Therefore, before the picture signal from 202 outputs of image quality improvement circuit was provided for

204, the mean flow rate of given picture signal, minimum brightness and high-high brightness and regulated value backlight (PWMGAIN) were not calculated.

Therefore, in display device shown in Figure 4 200, luminance parameter interframe is averaged

210 and finds the solution

205 has for example calculated two most recent of average picture intensity (APL) for it the mean value of average picture intensity (APL) of frame.

More specifically, luminance parameter interframe is averaged mean value, the mean value of minimum picture intensity (Min) and the mean value of maximum picture intensity (Max) of average picture intensity (APL) that

210 calculates the frame of two most recent, then the result is offered

207.

207 uses the mean value that is averaged the average picture intensity (APL) of

210 from luminance parameter interframe to calculate backlight intensity regulated value (PWMGAIN) then.In other words, the function of

207 is identical with

107 shown in Figure 1, only wherein is not to use average picture intensity (APL), rather than uses the mean value of average picture intensity (APL).

Therefore, in

207 shown in Figure 4, the linear luminance adjustment curve of describing with reference to figure 2 (A) seven parameters providing from parameter

206 is provided comes appointment.

In addition, in

207, backlight intensity regulated value (PWMGAIN) is to provide the mean value of the average picture intensity (APL) of coming to calculate according to be averaged

210 from luminance parameter interframe, is provided for PWM

208 then.

Similar with PWM

108 shown in Figure 1, PWM

208 is according to providing the regulated value (PWMGAIN) that comes to form pwm signal from

207, and the LED that then this pwm signal is offered

209 drives.In this process, can carry out brilliance control to serving as LED backlight.

Simultaneously,

207 offers

204 with the backlight intensity regulated value (PWMGAIN) that calculates, and also will offer

204 from the luminance correlation information that luminance parameter interframe is averaged

210 simultaneously.

Similar with

104 shown in Figure 1,

204 is specified based on four parameters describing with reference to figure 3 will be to providing the linear image gamma correction curve (B) of the picture signal use that comes from image

202.

Then,

204 uses the linear image gamma correction curve (B) of appointment to come provide the picture signal of coming to carry out enhancing control from image

202 based on next information is provided from PWMGAIN counting circuit 207.The picture signal that strengthens after controlling is provided for

203 subsequently.

203 is subsequently according to provide the picture signal through strengthening control of coming to form the picture signal that will be provided for

209 from image calibrating circuit 204.The picture signal that obtains thus is provided for

209 subsequently.

In this process, be displayed on the lcd screen of

209 with the corresponding image of controlling through enhancing of picture signal.In addition, the LED backlight of

209 is created the pwm signal of controlling backlight illumination and drives.

Therefore, the

200 of this variant shown in Figure 4 also can suitably be carried out backlight intensity control according to the linear luminance adjustment curve of describing with reference to figure 2 (that is linear APL-PWMGAIN curve) similarly.

Simultaneously,

200 can also come the picture signal that will show is carried out enhancing control according to the linear image gamma correction curve of describing with reference to figure 3.

Like this, even when the circuit according to the embodiment of the invention is set at before the

203, also can suitably carry out backlight intensity control, and can realize the reduction of backlight power consumption.

In addition, under the situation of display device shown in Figure 4 200, the circuit such as

204 and

207 can be set at before the LCDCTL 203.As a result, can carry out backlight intensity control and picture signal enhancing control to the picture signal before being handled with relatively low frame rate by LCDCTL 203.Therefore, can prevent that backlight intensity control and picture signal from strengthening the power consumption that relates in the control and becoming excessive.

Here, in the scope of processing time permission, the luminance parameter interframe in the variant shown in Figure 4 is averaged

210 and also can be configured to more a plurality of frames are found the solution mean value.In addition, luminance parameter interframe is averaged the weighted mean that

210 also can be configured to use a plurality of frames certainly.

In addition, in variant shown in Figure 4,

204 is configured to dispose basic brightness BY (BASE_Y) based on the mean value of the minimum picture intensity of screen (Min).But, be set at basic brightness BY (BASE_Y) and can omit finding the solution under the situation of fixed value the mean value of the minimum picture intensity of screen (Min).

In the previous embodiment of describing referring to figs. 1 to Fig. 3, the LCD that installs in the

109 is corresponding to liquid crystal display cells, and the function of back lighting device is to realize by the white LEDs and the led driver that are installed in the

109.

In addition,

105 has been realized the function of mean flow rate calculation element, and

107 has been realized the regulated value calculation element.PWM

108 has realized that drive signal forms the function of device.

In addition,

105 has also been realized the function of monochrome information pick-up unit, and

104 has been realized the function of image correction apparatus.

Simultaneously, in the aforementioned variant of describing with reference to figure 4, the LCD that installs in the

209 is corresponding to liquid crystal display cells, and the function of back lighting device is to realize by the white LEDs and the led driver that are installed in the

209.

In addition,

205 has been realized the function of mean flow rate calculation element, realized that mean flow rate is averaged the function of device and luminance parameter interframe is averaged

210, and

207 has been realized the regulated value calculation element.PWM

208 has realized that drive signal forms the function of device.

In addition,

205 has also been realized the function of monochrome information pick-up unit, realized that monochrome information is averaged the function of device and luminance parameter interframe is averaged

210, and

204 has been realized the function of image correction apparatus.

100 and 200 according to previous embodiment has been employed display control method according to another embodiment of the present invention.In other words, the circuit in the

100 shown in Figure 1 is carried out following treatment step respectively:

(1)

105 is carried out the mean flow rate calculation procedure, wherein, the picture signal that show is calculated a screen average picture intensity (that is mean flow rate).

(2)

107 is carried out the regulated value calculation procedure, wherein, based on an average picture intensity of screen and a predetermined linear luminance adjustment curve that in the mean flow rate calculation procedure, calculates, calculate the regulated value of the intensity (that is brightness) of the back lighting device that is used for the regulator solution crystal display element.

(3) PWM

108 is carried out drive signals and is formed steps, wherein, calculates based on the regulated value that calculates in the regulated value calculation procedure and to be used to make the pwm signal (that is drive signal) of backlight luminescence of LCD panel 109.The LED that the pwm signal that calculates is provided for

109 subsequently drives.

(4)

105 is carried out monochrome information and is detected step, wherein, and for the picture signal that will show detects a minimum picture intensity of screen and a maximum picture intensity (that is, minimum and high-high brightness).

(5)

104 carries out image aligning steps, wherein, based on the regulated value that in the regulated value calculation procedure, calculates, the mean flow rate that in the mean flow rate calculation procedure, calculates, detect detected minimum brightness and high-high brightness and predetermined linear image gamma correction curve in the step, come picture signal to be processed carried out and strengthen control in monochrome information.Picture signal through overcorrect is provided for liquid crystal display cells subsequently.

Simultaneously, the circuit in the

200 shown in Figure 4 is carried out following treatment step respectively.

(A)

205 is carried out the mean flow rate calculation procedure, wherein, the picture signal that show is calculated a screen average picture intensity (that is mean flow rate).

(B) luminance parameter interframe is averaged

210 execution mean flow rates and is averaged step, wherein, on a plurality of frames the average picture intensity of a screen that calculates in the mean flow rate calculation procedure is being averaged.

(C)

207 is carried out the regulated value calculation procedure, wherein, based on mean value that is averaged the average picture intensity of calculating in the step in mean flow rate and predetermined linear luminance adjustment curve, calculate the regulated value of the intensity (that is brightness) of the back lighting device that is used for the regulator solution crystal display element.

(D) PWM

208 is carried out drive signals and is formed steps, wherein, calculates based on the regulated value that calculates in the regulated value calculation procedure and to be used to make the pwm signal (that is drive signal) of backlight luminescence of LCD panel 209.The LED that the pwm signal that calculates is provided for

209 subsequently drives.

(E)

205 is carried out monochrome information and is detected step, wherein, and for the picture signal that will show detects a minimum picture intensity of screen and a maximum picture intensity (that is, minimum and high-high brightness).

(F) luminance parameter interframe is averaged

210 execution monochrome informations and is averaged step, wherein, respectively detected minimum brightness and high-high brightness in monochrome information detection step is being averaged on a plurality of frames.

(G)

204 carries out image aligning steps, wherein, based on the regulated value that in the regulated value calculation procedure, calculates, mean flow rate be averaged the mean flow rate that calculates in the step mean value, be averaged the value and the predetermined linear image gamma correction curve of the value of the minimum brightness that on a plurality of frames, is averaged respectively in the step and high-high brightness in monochrome information, come picture signal to be processed carried out and strengthen control.Be provided for the LCD of

209 subsequently through the picture signal of overcorrect.

Display control program according to the embodiment of the invention can also be applied to the

200 of previous embodiment.In other words, in display device shown in Figure 4 200,

204,

205, parameter

206,

207 and luminance parameter interframe are averaged

210 function separately and can utilize

220 performed programs to realize.

More specifically, the performed respective handling of the circuit of

200 can utilize the program of

220 execution to be achieved as follows.This program can be configured to make that the

220 of

200 carries out the computer-readable program of following steps:

By the mean flow rate calculation procedure (A) that

205 is carried out, wherein, the picture signal that show is calculated a screen average picture intensity (that is mean flow rate);

The mean flow rate that is averaged

210 execution by luminance parameter interframe is averaged step (B), wherein, on a plurality of frames the average picture intensity of a screen that calculates in the mean flow rate calculation procedure is being averaged;

Regulated value calculation procedure (C) by 207 execution of PWMGAIN counting circuit, wherein, based on mean value that is averaged the average picture intensity of calculating in the step in mean flow rate and predetermined linear luminance adjustment curve, calculate be used to regulate

209 intensity backlight (promptly, brightness) regulated value, the regulated value that calculates then is provided to drive signal and forms device, and this drive signal forms device and is used to form and makes the drive signal of backlight luminescence;

The monochrome information of being carried out by

205 detects step (E), wherein, and for the picture signal that will show detects a minimum picture intensity of screen and a maximum picture intensity (that is, minimum and high-high brightness);

The monochrome information that is averaged

210 execution by luminance parameter interframe is averaged step (F), wherein, respectively detected minimum brightness and high-high brightness in monochrome information detection step is being averaged on a plurality of frames; And

Image rectification step (G) by

204 execution, wherein, based on the regulated value that in the regulated value calculation procedure, calculates, mean flow rate be averaged the mean flow rate that calculates in the step mean value, be averaged the value and the predetermined linear image gamma correction curve of the value of the minimum brightness that on a plurality of frames, is averaged respectively in the step and high-high brightness in monochrome information, come picture signal to be processed is carried out enhancing control, be provided for the LCD of

209 then through the picture signal of overcorrect subsequently.

The program here can be stored in the storer such as ROM (ROM (read-only memory)) in the display device 200 (not illustrating among the figure), and wherein program is to store in the mode that

220 can carry out.Program also can provide via various recording mediums, perhaps via the distribution of of the network phone calls such as the Internet.

In addition, under the situation of display device shown in Figure 1 100,

104,

105, parameter

106 and

107 are set at after the LCDCTL 103.Therefore, if attempt utilizing program to realize foregoing circuit, then be used for then becoming difficult with the control of

103 coordinated manipulations.

But,, also can utilize program to realize

104,

105, parameter

106 and

107 function separately by suitably controlling

103 and

120.

In above program, do not comprise the function of PWM

108 and 208.But the present invention is not limited to this program.If the processing power of CPU is higher, then PWM

108 and 208 function also can utilize program to realize.Can certainly use a plurality of CPU this processing that distributes.