TWI466088B - Display apparatus - Google Patents

Description

Display device

The present invention relates to a display method, and more particularly to a display device using color sequential display.

In current display devices, red (R), green (G), and blue (B) field sequential color (FSC) are often used to display images. However, driven by the color sequential method, when the display device displays the moving image and the viewer follows the moving direction of the moving image, or when the display device displays the still image and the viewer scans the still image, the viewer moves the eyeball. The position of the light from the dynamic/static image is projected on the retina of the viewer's eyeball, which causes the viewer to visually see a plurality of monochromatic lines, that is, a color breakup (CBU) phenomenon.

Therefore, how to provide a display method and a display device, which can improve the color separation phenomenon and improve the visual quality of the viewer, is one of the current important topics.

In view of the above problems, it is an object of the present invention to provide a display method and a display device which can improve the color separation phenomenon and improve the visual quality of a viewer.

The invention provides a display device comprising a display panel and a processor. The processor captures one of the frame time image data, and according to the image The image data produces a complex luminance value and a complex transmittance value. This image data corresponds to a target image. The display panel sequentially displays a first image and a second image according to the brightness values and the transmittance values. Both the first and second images are color images. The picture energy of the first color image is at least five times greater than the picture energy of the second color image. In addition, the picture energy of the first image occupies at least 70% of the total picture energy of the target image.

The present invention further provides a display method for controlling a display device. The display device includes a plurality of pixels configured as a display array, and further includes a plurality of backlight sources. The display method includes capturing image data of one frame time, and the image data corresponds to a target image. The display method further includes sequentially displaying a first image and a second image according to the image data, and the first and second images are all color images. The picture energy of the first image is at least five times greater than the picture energy of the second image. In addition, the picture energy of the first image accounts for at least 70% of the total picture energy of the target image. The invention can be combined with a fast liquid crystal, such as an Optically Compensated Bend (OCB) liquid crystal, a Blue Phase liquid crystal or a Ferroelectric Liquid Crystal (FLC), which has a high reaction time and can be achieved. The need for fast response to liquid crystals.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a display device and a display method according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

1 shows a display device in accordance with a preferred embodiment of the present invention. As shown in FIG. 1, the display device 1 includes a processor 10 and a display panel 11. In this embodiment, the display panel 11 is implemented as a liquid crystal display panel. The processor 10 receives the plurality of image data, thereby displaying a target image based on an image data within a frame time. In this embodiment, the processor 10 receives an image data D _{IN of} one frame time as an example. The processor 10 generates a complex luminance value B and a complex transmittance value T based on the image data D _IN . The display panel 11 receives the complex luminance value B and the complex transmittance value T from the processor 10. According to the brightness value B and the transmittance value T, the display panel 11 sequentially displays at least one first image and one second image, that is, two consecutive color images, in the above frame time, thereby presenting the frame time. A target image.

In another embodiment, according to the complex brightness value B and the complex transmittance value T from the processor 10, the display panel 11 sequentially displays two consecutive color images in sequence during the frame time, and then displays at least one A color image or at least one single primary image to display one of the target images of the frame time. For example, after two consecutive color images in one frame time, the display panel 11 then displays two color images, or then displays three single primary color images.

According to the embodiment of the present invention, the picture energy of the first image is at least five times greater than the picture energy of the second image, regardless of whether the first image and the second image (two color images) are displayed first or not. The image energy of an image occupies at least 70% of the total picture energy of the target image. In this embodiment, the picture energy of each image is determined according to the chromaticity, brightness, and transmittance of the image.

2A is a schematic view showing the display panel 11. Referring to FIG. 2A, the display panel 11 includes a display array 20, a backlight unit 21, a driving unit 22, and a backlight driving unit 23. In FIG. 2A, the display array 20 and the backlight unit 21 are presented in a side-by-side configuration for clarity of illustration. Actually, however, the backlight source 21 is disposed on one side of the display array 20, for example, oppositely disposed. Display array 20 includes a plurality of pixels 200 that are arranged on a plurality of pixel rows and a plurality of pixel columns. The drive unit 22 controls the steering of the plurality of liquid crystal molecules within each pixel based on the complex transmittance value T from the processor 10. Referring to FIG. 2B, the backlight unit 21 includes a plurality of backlight sources LS, for example, a plurality of red backlight sources LSR, a plurality of green backlight sources LSG, and a plurality of blue backlight sources LSB. The backlight unit 21 further includes a light guide plate LG. In FIG. 2B, the backlight source LS is disposed in two rows, which are respectively located on the left and right sides of the light guide plate LG. In other embodiments, the backlight source LS can be disposed on the lower side of the light guide plate LG or in the surrounding area of the four corners, as long as the configuration of the partition light can be controlled. The backlight driving unit 23 drives the backlight source LS to emit light in accordance with the luminance value B from the processor 10. The light emitted by the backlight source LS passes through the light guide plate LG to change the direction of light advancement for mixing. The light obtained by mixing is supplied to the display array 20. The display panel 11 can display an image by the mixed light from the light guide plate LG and the steering of the liquid crystal molecules in each pixel. The size of this image is equal to the size of display array 20. The number and arrangement order of the red backlight source LSR, the green backlight source LSG, and the blue backlight source LSB may be determined according to the backlight optical design of the display device 1.

FIG. 3 shows a processor 10 in accordance with a preferred embodiment of the present invention. Reference Referring to FIG. 3, the processor 10 includes a capture unit 30, a division unit 31, calculation units 32, 34, 36, and subtraction units 33 and 35. 4A and 4B are flowcharts showing a display method for the display device 1 according to an embodiment of the present invention.

In the following description, the display panel 11 sequentially displays a first image and a second image (two color images) D1 and D2 in a frame time, and then displays three single primary color images, such as a red image RF. , green image GF, and blue image BF. The display order of the three single primary color images is not limited to display the red image RF, the green image GF, and the blue image BF in order. According to the embodiment, after the display panel 11 can sequentially display at least two color images D1 and D2 in a frame time, the number of subsequent images is not limited. The color images D1 and D2 are images containing all the single primary colors in the original data screen. However, if the color of the source of the image data is monotonous, a single primary color image may appear. In another embodiment, at least five color images D1 through D5 may be displayed during a frame time. Each of the color images displayed by the color images D3 to D5 may include all image images of a single primary color or only a single primary image in the original data frame. And the color images D3 to D5 can also be all black pictures, and the calculation results are required.

Referring to FIG. 3, FIG. 4A and FIG. 4B, the capturing unit 30 captures an image data D _IN as described above (step S40), and the image data D _IN is related to a target image displayed in a frame time. The capturing unit 30 further obtains the plural pixel data P _xy based on the image data D _IN (step S41). Where x is the ordinal number of the pixel row of the display array 20, and y is the ordinal number of the pixel column of the display array 20. Therefore, each pixel data P _xy corresponds to a pixel arranged in the xth pixel row and the yth pixel column in the display array 20. According to an embodiment of the invention, each pixel data P _xy includes a red (r) pixel value , a green (g) pixel value And a blue (b) pixel value ( ).

Next, the dividing unit 31 divides the plural pixel data P _xy into a predetermined number of data groups (step S42). For example, the complex pixel data P _{xy is} divided into m*n data groups. Since each pixel data corresponds to one pixel, as shown in FIG. 5, the plurality of pixels of the display array 20 relatively have m*n pixel blocks, and each data group corresponds to one pixel block. . In Fig. 5, m=2 and n=8 are taken as an example, that is, the number of pixel blocks on the same column is equal to 2, and the number of pixel blocks on the same line is equal to 8. For each pixel, the red pixel value Green pixel value And blue pixel values It can be represented by equations (1) to (3) respectively:

Where mn is a partition block of the backlight. , , , ,versus It is the red backlight brightness value of the pixel block where each pixel is displayed when the images D1, D2, GF, BF, and RF are displayed at different timings. , , , ,versus The green backlight brightness values of the pixel blocks in which each pixel is displayed when displaying images D1, D2, GF, BF, and RF, respectively. , , , ,versus The blue backlight brightness values of the pixel blocks in which each pixel is displayed when displaying images D1, D2, GF, BF, and RF, respectively. T 1 _xy , T 2 _xy , T 3 _xy , T 4 _xy , and T 5 _xy represent the coordinates of each pixel at the pixel number (x, y) when displaying images D1, D2, GF, BF, and RF, respectively. The value of the penetration rate. It can be known from equations (1) to (3) that the sum of the images displayed by the complex pixels at different timings is the target image. That is, the equation (1) indicates that the sum of the luminances of the red light displayed at different timings is the red luminance value of the target image.

According to the above, after the first and second images D1 and D2, the display panel 10 displays the green image GF, the blue image BF, and the red image RF. When the green image GF is displayed, the red and blue backlight sources do not emit light, so And . When the blue image BF is displayed, the green and red backlight sources do not emit light, so And . When the red image RF is displayed, the green and blue backlight sources do not emit light, so And .

Therefore, equations (1) to (3) are simplified to equations (4) to (6), respectively.

Next, the calculating unit 32 calculates the total amount of red pixel values in each pixel block when displaying the color image D1 according to the equations (7) to (9), respectively. , the total amount of green pixel values And the total amount of blue pixel values (Step S43):

Where k is the number of degrees of complex pixel values, for example a total of 256 degrees (0 to 255). , ,as well as It is the degree of each pixel value of the red pixel value, the green pixel value, and the blue pixel value, respectively. F represents the number of pixels, and Fi represents the number of pixels of the i-th pixel value. therefore, , ,as well as Respectively represent the target image ( The number of pixels corresponding to the red pixel value, the green pixel value, and the i-th pixel of the blue pixel value in the (m, n)th region of the ).

Equations (7)~(9) (as shown in Figure 6) use statistical moments to calculate the red pixel values in each pixel block. Total amount Green pixel value Total amount And blue pixel values Total amount In this way, the distribution characteristics of red, green, and blue pixel values in each pixel block can be known. In Figure 6, the number of pixels in the pixel value level , ,as well as It is only an example and is not limited to this. In fact, the number of pixels of the pixel value , ,as well as It is based on the pixel data of the image data D _IN .

Next, for each pixel, calculate the total amount of red pixel values. , the total amount of green pixel values And the total amount of blue pixel values Thereafter, the calculation unit 32 calculates the red luminance value when displaying the color image D1 according to the equations (10) to (12). Green brightness value And blue brightness values (Step S44):

among them, Express , ,versus The main reason for taking the maximum value is to make the backlight brightness of the backlight unit 21 reach the maximum brightness of the target image. , ,as well as Represents the largest red, green, and blue pixel values in the pixel block where each pixel is located.

Calculating the red brightness value Green brightness value And blue brightness values Then, according to the formulas (4) to (6), since the values of the second and third items on the right side of each equation are greater than zero, we obtain:

In order to avoid the brightness of a certain primary color being too large and exceeding the brightness of the target picture, the calculation unit 32 takes , ,versus The minimum value is calculated to calculate the transmittance value T 1 _{xy of} each pixel when the color image D1 is displayed (step S45) as in the equation (13):

For each pixel, calculate the red brightness value Green brightness value And blue brightness values After the transmittance value T 1 _xy , the subtraction unit 33 sets the red pixel value Subtract red brightness value The product of the transmittance value T 1 _xy , the green pixel value Subtract green brightness value The product of the permeability value T 1 _xy and the blue pixel value Subtract blue brightness value The product of the permeability value T 1 _xy (step S46) to calculate three differences, as in equations (14) to (16):

In the equations (14) to (16), the left side of the equal sign is a known term.

Next, the calculating unit 34 calculates the red luminance value when displaying the color image D2 according to the three differences calculated in step S46 and using the operations as in steps S43 and S44. Green brightness value And blue brightness values (Step S47). In this case, in equations (7)~(9) , ,as well as The system respectively indicates that the P _{xy is} subtracted from the complex pixel data. , ,as well as Then, the number of pixels corresponding to each pixel value of the red, green, and blue pixel values in the remaining pixel data.

Calculating the red brightness value Green brightness value And blue brightness values Then, according to the equations (14) to (16), since the value of the second term on the right side of each equation is greater than zero, it is obtained:

In order to avoid the brightness of a certain primary color being too large and exceeding the brightness of the target picture, the calculation unit 34 takes three division values. , ,versus The minimum value in the middle is calculated to calculate the transmittance value T 2 _{xy of} each pixel when the color image D2 is displayed (step S48) as in the equation (17):

For each pixel, calculate the red brightness value Green brightness value And blue brightness values After the transmittance value T 2 _xy , the subtraction unit 35 shifts the first term of the right side of the equations (14) to (16) to the left side of the equal sign, in other words, the subtraction unit 35 will calculate the difference ( ) subtract the red brightness value The product of the permeability value T 2 _xy , the difference ( ) subtract the green brightness value The product of the permeability value T 2 _xy and the difference ( ) subtract the blue brightness value The product of the permeability value T 2 _xy (step S49) to calculate three differences, as in equations (18) to (20):

Next, for each pixel, after calculating the three differences of step S49, the calculating unit 36 calculates the green luminance value when the green image GF is displayed according to the equations (21) to (23), respectively. , display the blue brightness value of the blue image BF And display the red brightness value of the red image RF (Step S50):

According to equation (21), the calculation unit 36 selects the difference between the complex pixels in the same pixel block ( The largest of them as the green brightness value . According to equation (22), the calculation unit 36 selects the difference between the complex pixels in the same pixel block ( The largest of them as the blue brightness value . According to equation (23), the calculation unit 36 selects the difference between the complex pixels in the same pixel block ( The largest of them is red and the value is red .

For each pixel, the calculated green brightness value Blue brightness value And red brightness values Thereafter, the calculation unit 36 calculates the transmittance values T 3 _xy , T 4 _xy , and T 5 _xy from the equations (24) to (26), respectively (step S51):

Calculating the brightness value through the above steps S40-S51 , , , , , , , ,versus And after the transmittance values T 1 _xy , T 2 _xy , T 3 _xy , T 4 _xy , and T 5 _xy , the display panel 10 can drive the backlight source to emit light according to the brightness values, and can be based on the values of the transmittances. To control the steering of the liquid crystal molecules of each pixel.

7A is a timing diagram showing the display of two color images and three single primary color images in accordance with an embodiment of the present invention. Referring to FIG. 2A, FIG. 2B and FIG. 7A, in one period TP1 (from time point TP0-1 to time point TP1-2) in one frame time FT, the backlight unit 21 is based on the brightness of each corresponding pixel block. value , ,versus To drive the backlight source LS to emit light. Through the light mixing of the light guide plate LG, the pixels in each pixel block receive light having a corresponding color level. In addition, the driving unit 22 controls the steering of the respective liquid crystal molecules according to the transmittance value T 1 _xy corresponding to each pixel. In the period TP1, the display panel 11 displays the color image D1 by the illumination of the backlight source LS and the steering of the liquid crystal molecules.

In the period TP2 (from the time point TP1-2 to the time point TP2-3) after the connection period TP1, the backlight unit 21 is based on the luminance value corresponding to each pixel block. , ,versus To drive the backlight source LS to emit light. Through the light mixing of the light guide plate LG, the pixels in each pixel block receive colored light having a corresponding color degree. In addition, the driving unit 22 controls the steering of the respective liquid crystal molecules according to the transmittance value T 2 _xy corresponding to each pixel. In the period TP2, the display panel 11 displays the color image D2 by the light emission of the backlight source LS and the steering of the liquid crystal molecules.

In the embodiment of FIG. 7A, since the sensitivity of the human eye to green is high, in the period TP3 of the connection period TP2 (from the time point TP2-3 to the time point TP3-4), the backlight unit 21 according to each of the corresponding Luminance value of the pixel block To drive the backlight source LS to emit light. Through the light mixing of the light guide plate LG, the pixels in each pixel block receive green light having a corresponding color level. In addition, the driving unit 22 controls the steering of the respective liquid crystal molecules according to the transmittance value T 3 _xy corresponding to each pixel. In the period TP3, the display panel 11 displays the green image GF by the light emission of the backlight source LS and the steering of the liquid crystal molecules.

In the period TP4 of the connection period TP3 (from the time point TP3-4 to the time point TP4-5), the backlight unit 21 is based on the luminance value corresponding to each pixel block. To drive the backlight source LS to emit light. Through the light mixing of the light guide plate LG, the pixels in each pixel block receive blue light having a corresponding color degree. In addition, the driving unit 22 controls the steering of the respective liquid crystal molecules according to the transmittance value T 4 _xy corresponding to each pixel. In the period TP4, the display panel 11 displays the blue image BF by the light emission of the backlight source LS and the steering of the liquid crystal molecules.

In the period TP5 of the connection period TP4 (from the time point TP4-5 to the time point TP0-1' of the next frame time), the backlight unit 21 is based on the luminance value corresponding to each pixel block. To drive the backlight source LS to emit light. Through the light mixing of the light guide plate LG, the pixels in each pixel block receive red light having a corresponding color degree. In addition, the driving unit 22 controls the steering of the respective liquid crystal molecules according to the transmittance value T 5 _xy corresponding to each pixel. In the period TP5, the display panel 11 displays the red image RF by the light emission of the backlight source LS and the turning of the liquid crystal molecules.

In the frame time FT, the viewer can view the target image corresponding to the image data D _IN by the images D1, D2, GF, BF, and the sequential display of the RF and the persistence of the human eye.

According to the equations (7) to (17) in the above steps S43 to S48, the main colors in the target image are concentrated on the color images D1 and D2 of the periods TP1 and TP2. In addition, compared with the color images D1 and D2, the subsequent images GF, BF, and RF are darker and have lower chroma. Therefore, the color images D1 and D2 account for a large percentage of the total picture energy of the target image, that is, the energy is concentrated on the color images D1 and D2. The images GF, BF, and RF approximate the black insertion image with respect to the color images D1 and D2. As a result, when the viewer's eye moves relative to the target image, the visual perception of the images GF, BF, and RF is weak, thereby slowing down the visual separation. In a preferred embodiment, the color image D1 has a picture energy that is at least five times greater than the picture energy of the color image D2, and the picture energy of the color image D1 occupies at least 70% of the total picture energy of the target image.

The picture energy is defined as the time integral of the product of the backlight source LS backlight luminance value B (cd/m ² ) and the liquid crystal transmittance T of the plurality of liquid crystal molecules in the pixel per unit time. The total picture energy is defined as the integral of the product of backlight brightness and transmittance in a frame. If a picture frame consists of five time series pictures, the total picture energy can be written as shown in equation (27), five timings. The sum of the picture energy. Next, we define the energy of the time series picture, the first time series picture energy, that is, the product of the backlight brightness value B 1 and the liquid crystal transmittance T at the time point TP0-1 to the time point TP1-2 (ie during the period) The time integral in TP1) can be written as shown in equation (28). Similarly, the energy of the timing picture in the second timing, the third timing, the fourth timing and the fifth timing can be written as equations (29)~(31).

E = e ₁ + e ₂ + e ₃ + e ₄ + e ₅ (27)

Where E is the total picture energy, and e1 to e5 are the energy of the time series picture in the first to fifth timings. Five periods TP1 corresponding to time points TP0-1~TP1-2, TP1-2~TP2-3, TP2-3~TP3-4, TP3-4~TP4-5, and TP4-5~TP0-1' respectively Until TP5 is the integration time of the timing pictures in the first to fifth timings, the picture energy of different timings can be quantized according to the color and luminance values of the backlight and the transmittance of the liquid crystal molecules at different timings.

In the embodiment of FIG. 7A, since the human eye is highly sensitive to green light, the three single primary color images after the two color images D1 and D2 are sequentially green image GF, blue image BF, and red image RF. . In other embodiments, the order of the three single primary color images after the two color images D1 and D2 may be determined according to the percentage of the total screen energy of the target image according to the image energy of each single primary color image. For example, the percentage of the picture energy of the three single primary color images displayed in the periods TP3 to TP5 after the two color images D1 and D2 is decremented.

In another embodiment, after the two color images D1 and D2, the percentage of the picture energy of the single primary color image displayed during the period TP3 is greater than the percentage of the picture energy of the single primary color image displayed during the period TP4, and is displayed during the period TP5. The percentage of picture energy for a single primary color image is greater than the percentage of picture energy for a single primary color image displayed during period TP4. That is to say, the percentage of the picture energy displayed in the image of the period TP1-TP5 is decreasing, but the trend is only decremented to the second to last image (that is, the image displayed during the period TP4), and the last image is displayed in the period TP5. The image energy of the image is higher than the picture energy of the penultimate image. This embodiment can avoid the phenomenon of color separation or flicker caused by the excessive energy gap between the color images. According to the above, during the frame period, the picture energy of the image displayed during the period TP1 to TP5 exhibits a V curve, and it can be understood that the V curve is not symmetrical. The energy distribution of the V-type can make a darker picture between each frame time FT, which is similar to the effect of inserting black, which can reduce the visual effect of color separation when the human eye sees the dynamic picture.

According to the above, in the frame time, the image energy of the image D1 displayed in the first period T1 is the largest. When the complex target image is displayed in the plural frame time, the curve of the image energy of the image displayed between the two adjacent frame time periods T1 will show a trend of approximating the V curve, and the lowest point of the V curve trend is also visible. The display quality of the screen can be displayed during any display period between the color image D2 and the color image D1 of the next frame time, and the screen energy of the color image D1 must be greater than the screen energy of other screens, and the V curve can be understood. The trend is not symmetrical.

In another embodiment, the display period of the lowest point of the picture energy curve The farthest from the display period of the two largest picture energies, as shown in Figure 9. This driving method is similar to the Impulse driving method, which greatly reduces the phenomenon of color separation. FIG. 9 is only a schematic diagram showing the picture energy of D1~D5 in a picture frame time FT. In other embodiments, it is also possible to display the picture energy of D1~D3 in a picture frame time FT, and the picture energy thereof The lowest point does not necessarily have the farthest distance from the display period of the two largest picture energies, but presents a trend of asymmetric V-curves.

In another embodiment, two color images D1 and D2 of any color are followed by a color image D3, as shown in FIG. 7B, and D3 is not a single primary image. The backlight brightness B 3 _{mn of} D3 is calculated in the same way as D1 and D2. Therefore, equations (18)~(26) can be modified as follows:

Wherein, the backlight brightness value B 3 _mn and the transmittance T 3 _xy are used to display the third displayed image D3, and the equal sign "=" of the equations (18-1) to (26-1) is approximated by the symbol " "Replace, the result displayed in this mode can only be close to the target image. The main reason is that after the color images D1 and D2 are displayed, the remaining brightness ( P _xy - B 1 _mn T 1 _xy - B 2 _mn T 2 _xy ) is not Using three monochromatic images RF, GF and BF are displayed, and a color image D3 that is close to or equal to the energy of the remaining picture is used to display the remaining brightness. Similarly, we can generalize to the fourth color image D4 (see Figure 7C). The fifth color image D5 (shown in FIG. 7D), etc. The brightness value and the transmittance of the color image D4/D5 can be obtained according to an operation similar to the above-described calculation unit 34 and the subtraction unit 35. The common feature of these methods is that after the two color images D1 and D2, the picture energy of the color image D3 displayed during the period TP3 is greater than the picture energy of the color image D4 displayed during the period T4, and is displayed in the color image D4 of the period TP4. The picture energy is greater than the picture energy of the color image D5 displayed during the period TP5. In a preferred embodiment, the picture energy of the color image D1 is at least five times greater than the picture energy of the color image D2, and the picture of the color image D1 can Possession of at least the target screen image of the total energy of Qi Cheng.

In the embodiment of FIG. 7A, the lengths of the periods TP1, TP2, TP3, TP4, and TP5 of the images D1, D2, GF, BF, and RF are respectively displayed as equal to each other. Suppose the length of a frame time is 1/60s. Since the lengths of the periods TP1 to TP5 are equal to each other, the length of each of the periods TP1 to TP5 is 1/300 s, that is, the overall frame rate is 300 Hz. Similarly, in FIG. 7B, the periods TP1 to TP3 of the color images D1 to D3 are respectively displayed to be equal in length; in FIG. 7C, the periods TP1 to TP4 of the color images D1 to D4 are respectively displayed to be equal in length; In FIG. 7D, the periods TP1 to TP5 of the color images D1 to D5 are respectively displayed to be equal in length to each other.

In another embodiment, as shown in FIG. 8, the color image D1 is displayed separately. The lengths of TP1 and TP2 are equal to each other during the period D2, and the lengths of the periods TP3, TP4, and TP5 of the images GF, BF, and RF are respectively displayed as equal to each other. In particular, since the length of each of the periods TP1 and TP2 is longer than the length of each of the periods TP3, TP4, and TP5. Suppose the length of a frame time is 1/60s. In the embodiment of FIG. 8, the length of each of the periods TP1, TP2 is 1/240s, and the length of each of the periods TP3~TP5 is 1/360s, that is, the overall frame rate is 240Hz. In another embodiment, the periods TP1 and TP2 of the displayed color images D1 and D2 may not be equal. Since the color image D1 may already display most of the picture energy of the target image, the length of the period TP1 may be longer than the remaining period. Long, and D2 is second, the remaining other pictures can be as long or unequal as TP2 time.

In addition, the first red luminance value, the first green luminance value, and the first blue luminance value of the present invention may be calculated by using other methods (refer to equations (7-12)). Calculation, the following examples.

When the capturing unit 30 obtains the plural pixel data P _xy according to the image data (each pixel data includes a red pixel value) a green pixel value And a blue pixel value The first calculating unit 32 may calculate the characteristics of the maximum eigenvalues of the correlation matrix (correlation matrix) of the red pixel values, the green pixel values, and the matrix of the blue pixel values. An eigenvector obtains a first red luminance value, a first green luminance value, and a first blue luminance value. The correlation matrix is, for example, P ^T P, P=[ 】, after the expansion can get the following formula:

Its value is for example but not limited to

Thus, the three characteristic values of the correlation matrix P ^T P can be calculated to be 5.8299, 0.0038, and 0.1180, respectively. Here we take 5.8299 as the maximum eigenvalue, and calculate its corresponding eigenvector as [0.9300, 0.9743, 1.0000], and convert it into grayscale value to get [237.1518, 248.4556, 255], and smooth it to [237, 248, 255] respectively. Corresponds to the backlight brightness of red at 237 grayscale, the backlight luminance value when green is at 248 grayscale, and the backlight luminance value of blue at 255 grayscale.

It should be noted that if the pixel is divided into the specified number of pixel blocks, , , According to the formulas (1)~(3), each pixel block can calculate its own correlation matrix and its first red luminance value, the first green luminance value and the first blue luminance value.

Next, for each pixel, the first calculating unit 30 may be based on the red pixel value, the green pixel value and the blue pixel value, and the first red brightness value of the pixel block corresponding to the pixel, The first green brightness value and the first blue brightness value are used to calculate a first transmittance value. The calculation of this part is carried out according to the principle of equation (13). As described below, for each pixel, the first calculating unit 30 is based on (no backlight partition), or (There is a backlight partition) to calculate the first transmittance value.

In this way, the transmittance values of the pixels of the first image and the luminance values of the respective primary colors of each pixel partition of the first image can be calculated, and the display array of the display panel is controlled according to the transmittance values and the brightness values. And a backlight source to display the first image. Since the above control method has been described in detail in the above embodiments, it will not be described herein. It should be noted, however, that in the present embodiment, the light emitted by the backlight source 21 may have at least two different levels of brightness that are not zero, such as first brightness, second brightness, third brightness, and the like. 10 is a schematic diagram of general conventional backlight brightness, liquid crystal waveform, backlight and liquid crystal multiplying waveform, and efficiency loss. FIG. 11 is a schematic diagram of backlight brightness, liquid crystal waveform, backlight and liquid crystal multiplying waveform, and efficiency loss of the present embodiment. As shown in FIG. 10, the conventional backlight source has only two kinds of brightness, on and off, and the backlight source of the embodiment has, for example, three different brightness levels. Thus, it can be seen that the efficiency loss of this embodiment is less than that of the conventional driving method. Therefore, the present embodiment can use less energy to achieve the same display effect, thereby reducing cost and saving energy. In addition, the backlight driving mode of the embodiment can also reduce the phenomenon that the human eye feels flickering and overshooting, and improves display performance.

In this embodiment, there are various ways to make the backlight source have a plurality of different brightnesses, as exemplified below.

12 is a timing diagram showing display of a first image, a second image, a third image, and a fourth image in the display device of the embodiment, including waveform diagrams of the backlight colors of the three primary colors (red, green, and blue), and the first column of pixels. The penetration rate waveform, the transmittance waveform of the last column of pixels, and the multiplied waveform of the transmittance of the backlight and the last column of pixels. Need to pay attention, Figure 12 can correspond To the entire backlight source or only a partition corresponding to the backlight source, when corresponding to a certain partition, the first column of pixels is the first column of pixels corresponding to the partition, and the last column of pixels corresponds to the partition. The last column of pixels.

The first image is a color image, and the second image to the fourth image are single primary color images, which are a red image, a green image, and a blue image. In the first image, since it is a color image, the backlights of the three primary colors can be selectively turned on according to the image data. And the brightness waveform of the three primary color backlight sources may be stepped, and has amplitudes of, for example, three different brightnesses, and the amplitudes correspond to the magnitude of the transmittance, that is, when the transmittance is large, the amplitude is also large, by the light source. The relationship between the amplitude and the transmittance can improve the performance of the display device. In addition, the waveform of the backlight source is stepped, and the smooth change can reduce the flicker and overshoot of the human eye, thereby improving display performance.

In addition, the first image to the fourth image can be combined with black frame insertion technology. For example, when the TN liquid crystal is blacked out, the maximum rated voltage is given, at which time the liquid crystal transmittance decreases from the highest point to the low transmittance, and the black insertion time is from the first column to the last column of the region. When the liquid crystal transmittance of the last pixel in the last column is the smallest, if the timing is the first image, the backlight source is turned off (as shown in the thick dotted frame in FIG. 12 and FIG. 13), the main purpose is to avoid interference (Cross Talk) to the next color field, the same reason, the same is true for other color fields. The second image is a red image, so only the red light source is turned on, the other light sources are turned off, and the waveform of the red light source also has different amplitudes to achieve different brightness. The third image is a green image, so only the green light source is turned on, the other light sources are turned off, and the waveform of the green light source is also different. The amplitude reaches different brightness. The fourth image is a blue image, so only the blue light source is turned on, the other light sources are turned off, and the waveform of the blue light source also has different amplitudes to achieve different brightness.

FIG. 13 is another timing diagram of displaying the first image, the second image, the third image, and the fourth image in the display device of the embodiment, including waveform diagrams of the backlights of the three primary colors (red, green, and blue), and the first column. The penetration rate waveform of the pixel, the transmittance waveform of the last column of pixels, and the multiplied waveform of the transmittance of the backlight and the last column of pixels.

The first image is a color image, and the second image to the fourth image are single primary color images, which are a red image, a green image, and a blue image. The main difference from the aspect of FIG. 12 is that the backlight source shown in FIG. 13 is matched with a pulse width modulation (PWM) technique to achieve a dimming effect. The overall brightness obtained by this can be as shown in FIG. 14, wherein the portion of the hatching is bright, and the portion without hatching is no brightness, wherein 100% means the amplitude of the original PWM signal, and 200% means the original PWM signal. The amplitude of the amplitude is twice the amplitude, and so on.

The present invention is not limited to three brightness levels, and Figure 15 shows that the more the brightness level that the backlight source can provide, the better the performance of the backlight source and the liquid crystal. Moreover, the brightness level of the backlight source can be positively correlated with the liquid crystal wave, thereby achieving high performance.

After calculating the transmittance values of the pixels of the first image and the luminance values of the respective primary colors of the pixel regions of the first image, the transmittance values of the pixels of the second image and the respective paintings may be calculated. The brightness value of each primary color of the prime partition. In practice, the penetration value of each pixel of the second image and each pixel The calculation method of the brightness values of the primary colors of the partition may be performed by using the transmittance values of the pixels of the first image and the brightness values of the respective primary colors of each pixel partition, except that the values of the correlation matrix P are different.

In the calculation, please refer to equations (14)-(16). For each pixel, the first subtraction unit 33 can subtract the red pixel value from the product of the first red luminance value and the first transmittance value. Calculating a first difference, and subtracting the green pixel value by the product of the first green brightness value and the first transmittance value to calculate a second difference, and subtracting the blue pixel value from the first A product of a blue luminance value and a first transmittance value to calculate a third difference. Then, the second calculating unit 34 may calculate the feature vectors of the first eigenvalues of the respective pixel blocks, the second eigenvalues of the matrix of the second difference value and the matrix of the third difference values, A second red luminance value, a second green luminance value, and a second blue luminance value are obtained for each of the pixel blocks. Thus, the P matrix becomes a matrix composed of the left term of the equations (14) to (16), and then the eigenvector of the largest eigenvalue of the correlation matrix of the P matrix is calculated to obtain the second red luminance value. Second green brightness value And the second blue brightness value .

Then, for each pixel, the second calculating unit 34 is configured to: according to the first difference, the second difference and the third difference, and the second red brightness value of the pixel block corresponding to the pixel, the second The green brightness value and the second blue brightness value are used to calculate a second transmittance value. The calculation of this part is carried out according to the principle of equation (17). As described below, for each pixel, the second calculation unit 34 is based on (no backlight partition), or (There is a backlight partition) to calculate the second transmittance value.

In this way, the transmittance values of the pixels of the second image and the luminance values of the respective primary colors of the pixel regions of the second image can be calculated. The display array of the display panel and the backlight source can then be controlled to display the second image based on the transmittance values and the brightness values.

It should be noted that, in addition to the calculation method of the above feature vector, the third image, the fourth image, and the like may be used in the embodiment. In addition, the second image may not use the calculation method of the feature vector, but use the principles of equations (18) to (26) to calculate the luminance value and the transmittance value.

In other embodiments, please refer to Equation (13), when the color of an image is concentrated in a specific color system, it means that the ratio of a certain color to the target image is quite low. in case or or If it is quite small, T 1 _xy will also be relatively small, and the result of multiplying the first image system T1 and B1. If T 1 _{xy is} relatively small, the pixel value of the first image will also become corresponding. Very small, this means that too many pixel values in the first image are too small to cause the picture energy of the first image to be too small.

Therefore, when the color of an image is concentrated in a specific color system, the first calculating unit may further determine at least a plurality of main effect matrix values (ie, Cor _rr , Cor _gg , Cor _bb ) of the correlation matrix according to at least one preset value. One of them determines whether the first red brightness value, the first green brightness value, or the first blue brightness value is too small, and accordingly corrects the values of T1 and B1 of the first image frame, for example, selecting not to open a certain ratio. Quite a low backlight for this color.

Taking the lower ratio of red color as an example, the main effect matrix value Cor _rr can be determined as follows: , 10% of which is the default value. When it is determined that the ratio of Cor _rr is less than 10%, the first image is selected to set the first red brightness value to zero (ie, the backlight source does not provide red light), then equation (13) is corrected as follows:

That is, in the first image, the backlight provides only a light source other than red. Red is displayed in the second or subsequent image after it. The representative image can display the color energy that is larger than the target image in the first image, that is, the image that is closer to the target image energy can be displayed on the first image, and the remaining image energy ratio is relatively low. The effect can also be approximated by inserting a black screen, thereby improving the quality of the display screen and reducing the problem of color separation.

For example, the ratio of the red color ratio is lower, and the judgments of the main effect matrix values Cor _gg and Cor _bb of green or blue can be deduced by analogy, and will not be described herein.

In this embodiment, not only the picture energy of the first image is at least 70% of the total picture energy of the target image; preferably, it can occupy at least 80% of the total picture energy of the target image.

In addition, in the case of a single color, when the ratio of the single color to the target image is more than 55%, and the color selected in the above manner is less than 10%, the color energy of the image energy of the first image may be At least eighty-five percent of the color energy of the target image. For example, when the red color accounts for less than 10% (ie ), and blue accounts for more than 55% of the target image (ie In the case of the above modified formula (13-1), it is indicated that the ratio of blue in the first image is relatively high, and the ratio of red is relatively low. The red backlight is turned off according to the above manner, and green light and blue light are turned on. Compared with red, green and blue are better in this way, and the blue energy in the first image can better account for more than 85% of the target image.

In summary, the display device of the embodiment can calculate the backlight color of the first image closest to the color of the target image by calculating the feature value and the feature vector, thereby maximizing the transmittance of the liquid crystal, and most of the energy is Focusing on the first screen, the rest of the picture becomes darker, and the phenomenon of color separation is minimized.

The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

1‧‧‧ display device

10‧‧‧ processor

11‧‧‧ display panel

20‧‧‧Display array

200‧‧ ‧ pixels

21‧‧‧Backlight unit

22‧‧‧Drive unit

23‧‧‧Backlight control unit

30‧‧‧Capture unit

31‧‧‧Dividing unit

32, 34, 36‧‧‧ calculation unit

33, 35‧‧‧ Subtraction unit

B‧‧‧Brightness value

BF‧‧‧Blue Image

D _IN ‧‧‧Image data

D1, D2‧‧‧ color image

, , ‧‧‧Red, green, blue pixel values

, , ‧‧‧Number of pixels corresponding to each red, green, and blue pixel value

FT‧‧‧ frame time

GF‧‧ Green Image

LG‧‧‧Light guide plate

LS‧‧‧Backlight source

LSB‧‧‧Blue Backlight Source

LSG‧‧‧Green Backlight Source

LSR‧‧‧Red Backlight Source

m‧‧‧Number of pixel blocks in the same column

n‧‧‧Number of pixel blocks on the same line

P _xy ‧‧‧ pixel data

RF‧‧‧Red Image

S40~S51‧‧‧ method steps

T‧‧‧ penetration value

TP1~TP5‧‧‧

TP 0-1, TP 0-1', TP 1-2, TP 2-3, TP 3-4, TP 4-5‧‧‧ time point

1 shows a display device according to an embodiment of the present invention; FIG. 2A is a schematic view of a display panel of the display device of FIG. 1; 3 is a view showing a processor of the display device of FIG. 1; FIGS. 4A-4B are flowcharts showing a display method for a display device according to an embodiment of the present invention; FIG. 5 is a view showing a m*n pixel block in a display array; 6 represents a statistical statistical moment diagram for calculating the total amount of red, green, and blue pixel values; and FIGS. 7A-7D illustrate displaying two color images and three single primary color images according to an embodiment of the invention. FIG. 8 is a timing chart showing two color images and three single primary color images according to another embodiment of the present invention; FIG. 9 is a V curve of the picture energy; FIG. 10 is a general conventional backlight brightness, liquid crystal waveform, and backlight. FIG. 11 is a schematic diagram of backlight luminance, liquid crystal waveform, backlight and liquid crystal multiplication waveform, and efficiency loss according to a preferred embodiment of the present invention; FIG. 12 is a schematic diagram of the present embodiment; The device displays a timing diagram of the first image, the second image, the third image, and the fourth image. FIG. 13 shows the first image, the second image, the third image, and the fourth image in the display device of the embodiment. Another timing diagram; FIG. 14 shows the overall brightness of the backlight 13 of the light source; and FIG. 15 shows that as the backlight light source can provide more brightness levels, and the liquid crystal backlight light source with the better the performance.

BF‧‧‧Blue Image

D1, D2‧‧‧ color image

FT‧‧‧ frame time

GF‧‧ Green Image

RF‧‧‧Red Image

TP1~TP5‧‧‧

TP0-1, TP0-1', TP1-2, TP2-3, TP3-4, TP4-5‧‧‧ time points

Claims (15)

A display device includes: a display panel; and a processor that captures image data of one frame time and generates a plurality of brightness values and a plurality of transmittance values according to the image data, wherein the image data corresponds to a target The first display image and the second image are sequentially displayed according to the brightness values and the transmittance values, and the first image and the second image are both color images; and The picture energy of the first image is at least five times greater than the picture energy of the second image, and the picture energy of the first image occupies at least 70% of the total picture energy of the target image. The display device of claim 1, wherein after the second image, the display panel further displays a third image according to the brightness values and the transmittance values. The display device of claim 2, wherein the third image is a color image. The display device of claim 3, wherein after the third image, the display panel further displays a fourth image according to the brightness values and the transmittance values, and the fourth image is presented. A fourth color picture. The display device of claim 2, wherein the third image is a single primary color image. The display device of claim 5, wherein After the third image, the display panel sequentially displays a fourth image and a fifth image according to the brightness values and the transmittance values, wherein the fourth and fifth images are single primary color images, and The display panel sequentially displays the first to fifth images to present the target image. The display device of claim 6, wherein the third image is a green image, the fourth image is a blue image, and the fifth image is a red image. The display device of the sixth aspect of the invention, wherein the image energy of the third image is greater than the picture energy of the fourth image and the picture energy of the fifth image, and the picture energy of the fifth image is greater than the fourth The picture energy of the image. The display device of claim 2, wherein during the frame time, the display period of the first image and the display period of the second image are equal to each other and longer than the display period of the three images. The display device of claim 1, wherein the processor comprises: a capturing unit, and obtaining a plurality of pixel data P _xy according to the image data, wherein the pixel data respectively correspond to a display array a pixel, wherein each of the pixel data includes a red pixel value, a green pixel value, and a blue pixel value; and a dividing unit that divides the pixel data into a predetermined number of plural data a group, wherein the pixels are divided into the predetermined number of plural pixel blocks, and each of the data groups corresponds to one of the pixel blocks; and a first computing unit; wherein, for each In the case of the pixel, the first calculating unit is based on the total amount of the red pixel values in the corresponding pixel block, the total amount of the green pixel values, and the blue pixel values. a total amount, to calculate a first red luminance value, a first green luminance value, and a first blue luminance value corresponding to the pixel block; and wherein, for each of the pixels, the The first computing unit is based on the red, green, and blue a pixel value and the first red color, the first green color, and the first blue brightness value to calculate a first transmittance value; and wherein the display panel is based on the first red brightness values, the first The first green brightness value, the first blue brightness value, and the first transmittance values are used to display the first image, and the display panel includes: a plurality of backlight sources, wherein each of the backlight sources is And one of the first red luminance values, one of the first green luminance values, or one of the first blue luminance values to drive illumination; and the display array includes a plurality of pixels, wherein each A plurality of liquid crystal molecules in the pixel are turned according to the corresponding first transmittance value. The display device of claim 1, wherein the processor comprises: a capturing unit, and obtaining a plurality of pixel data P _xy according to the image data, wherein the pixel data respectively correspond to the display panel a pixel, wherein each of the pixel data includes a red pixel value a green pixel value And a blue pixel value And a first calculating unit that calculates a feature vector of the maximum eigenvalues of the correlation matrix of the red pixel values, the green pixel values, and the matrix of the blue pixel values to obtain a first a red luminance value, a first green luminance value, and a first blue luminance value, wherein the correlation matrix is P ^T P, P=[ And for each pixel, the first calculating unit is based on the red pixel value, the green pixel value and the blue pixel value, and the first red brightness value, the first green brightness value, And the first blue brightness value to calculate a first transmittance value, and the display panel is configured according to the first red brightness value, the first green brightness value, the first blue brightness value, and each pixel Each of the first transmittance values displays the first image. The display device of claim 1, wherein the processor comprises: a capturing unit, and obtaining a plurality of pixel data P _xy according to the image data, wherein the pixel data respectively correspond to the display panel a pixel, wherein each of the pixel data includes a red pixel value a green pixel value And a blue pixel value And a dividing unit, the pixel data is divided into a predetermined number of complex data groups, wherein the pixels are divided into the predetermined number of plural pixel blocks, and each of the data groups corresponds to One of the pixel blocks; and a first computing unit that calculates, for each pixel block, the red pixel values, the green pixel values, and the blue of each pixel block a feature vector of a maximum eigenvalue of a correlation matrix of the matrix formed by the color pixel values to obtain a first red luminance value, a first green luminance value, and a first blue luminance value of each pixel block, wherein The correlation matrix is P ^T P, P=[ And for each pixel, the first calculating unit is configured according to the red pixel value, the green pixel value and the blue pixel value, and the pixel block corresponding to the pixel a red brightness value, the first green brightness value, and the first blue brightness value to calculate a first transmittance value, and the display panel is configured according to the first red brightness value, the first green brightness The value, the first blue luminance value, and each of the first transmittance values of each pixel display the first image. The display device of claim 1, wherein the display panel comprises: a plurality of backlight sources, driving the illumination according to the color brightness values; and a display array comprising a plurality of pixels, the plurality of pixels of the pixels The molecules are turned according to the values of the transmittances, wherein the light emitted by the backlight sources has at least two different brightness levels that are not zero. The display device of claim 1, wherein the image energy of the first image occupies at least 80% of the total picture energy of the target image. The display device of claim 1, wherein one of the picture energy of the first image occupies at least eighty-five percent of the color energy of the target image.