The present disclosure relates to a display unit displaying an image, and an image processing unit for use in such a display unit, and a display method.
Recently, a cathode ray tube (CRT) display unit has been actively replaced with a liquid crystal display unit or an organic electro-luminescence (EL) display unit. The liquid crystal display unit and the organic electro-luminescence display unit are each being a mainstream display unit due to low power consumption and a flat configuration thereof.
Display units are in general desired to have high image quality. Image quality is determined by various factors including contrast. Increase of peak luminance may be a technique for improving contrast. Specifically, reduction of a black level is limited by reflection of outside light, etc. Hence, in the above technique, peak luminance is increased (extended) to improve contrast. For example, Japanese Unexamined. Patent Application Publication No. 2008-158401 (JP-A-2008-158401) discloses a display unit, in which an increasing level (extending level) of peak luminance and gamma characteristics are each varied depending on an average of image signals to achieve improvement in image quality and reduction in power consumption.
In some display units, each pixel is configured of four sub-pixels. For example, Japanese Unexamined Patent Application Publication No. 2010-33009 discloses a display unit, in which each pixel is configured of sub-pixels of red, green, blue, and white to improve luminance or reduce power consumption, for example.
As described above, display units are desired to achieve high image quality. Hence, further improvement in image quality is expected for the display units.
It is desirable to provide a display unit, an image processing unit, and a display method capable of improving image quality.
A display unit according to an embodiment of the disclosure includes: a gain calculating section obtaining, based on first luminance information for each pixel, a first gain, in which the first gain is configured to increase with an increase in pixel luminance value in a range where the pixel luminance value is equal to or larger than a predetermined luminance value, and in which the pixel luminance value is derived from the first luminance information; a determination section determining, based on the first luminance information and the first gain, second luminance information for each of the pixels; and a display section performing display based on the second luminance information.
An image processing unit according to an embodiment of the disclosure includes: a gain calculating section obtaining, based on first luminance information for each pixel, a first gain, in which the first gain is configured to increase with an increase in pixel luminance value in a range where the pixel luminance value is equal to or larger than a predetermined luminance value, and in which the pixel luminance value is derived from the first luminance information; and a determination section determining, based on the first luminance information and the first gain, second luminance information for each of the pixels.
A display method according to an embodiment of the disclosure includes: obtaining, based on first luminance information for each pixel, a first gain, in which the first gain increases with an increase in pixel luminance value in a range where the pixel luminance value is equal to or larger than a predetermined luminance value, and in which the pixel luminance value is derived from the first luminance information; determining, based on the first luminance information and the first gain, second luminance information for each of the pixels; and performing display based on the second luminance information.
In the display unit, the image processing unit, and the display method according to the above-described respective embodiments, the first gain is obtained based on the first luminance information, the second luminance information is determined based on the first luminance information and the first gain, and the display is performed based on the second luminance information. In the range where the pixel luminance value derived from the first luminance information is equal to or larger than the predetermined luminance value, the first gain increases with the increase in the pixel luminance value.
According to the display unit, the image processing unit, and the display method of the above-described respective embodiments, the first gain is configured to increase with the increase in the pixel luminance value in the range where the pixel luminance value derived from the first luminance information is equal to or larger than the predetermined luminance value. Therefore, it is possible to improve image quality.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the technology as claimed.
The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the specification, serve to explain the principles of the technology.
Hereinafter, some embodiments of the present disclosure are described in detail with reference to the accompanying drawings. It is to be noted that description is made in the following order.
1. First Embodiment
2. Second Embodiment
3. Third Embodiment
4. Fourth Embodiment
5. Application Examples
The input section 11 is an input interface, and generates an image signal Sp0 based on an image signal supplied from an external unit. In this exemplary case, the image signal supplied to the display unit 1 is a so-called RGB signal including red (R) luminance information IR, green (G) luminance information IG, and blue (B) luminance information IB.
As described later, the image processing section 20 performs predetermined image processing such as extending processing of peak luminance to the image signal Sp0 to generate an image signal Sp1.
The display control section 12 controls a display operation of the EL display section 13 based on the image signal S0. The EL display section 13 is a display section using an organic EL display element as a display element, and performs the display operation based on the control by the display control section 12.
The pixel array section. 33 includes pixels Pix arranged in a matrix. In this exemplary case, each pixel Pix is configured of four sub-pixels SPix of red (R), green (G), blue (B), and white (W). In this exemplary case, the pixel Pix includes such four sub-pixels Pix arranged in a 2×2 matrix. Specifically, the pixel Pix includes the sub-pixel SPix of red (R) arranged at upper left, the sub-pixel SPix of green (G) at upper right, the sub-pixel SPix of white (W) at lower left, and the sub-pixel SPix of blue (B) at lower right.
It is to be noted that colors of the four sub-pixels SPix are not limited thereto. For example, the white sub-pixel SPix may be replaced with a sub-pixel SPix of another color the luminosity factor for which is high as for white. More specifically, a sub-pixel SPix of a color (for example, yellow) may be preferably used, the luminosity factor for the color being equal to or higher than the luminosity factor for green that is highest among luminosity factors for red, green, and blue.
The vertical drive section 31 generates a scan signal based on timing control by the display control section 12, and supplies the scan signal to the pixel array section 33 through a gate line GCI, to sequentially select the sub-pixel SPix in the pixel array section 33 at every line to perform line-sequential scan. The horizontal drive section 32 generates a pixel signal based on timing control by the display control section 12, and supplies the pixel signal to the pixel array section 33 through a data line SGL so that the pixel signal is supplied to each sub-pixel SPix in the pixel array section 33.
In this way, the display unit 1 displays an image with the four sub-pixels SPix. Consequently, a color gamut available for display is expanded as described below.
For example, when only the red sub-pixel SPix emits light, colors in a range of Saturation S of S1 or less and Value V of V1 or less in
On the other hand, as illustrated in
In this way, the white sub-pixel SPix is provided in addition to the sub-pixels SPix of red, green, blue, thereby the representable color gamut is expanded. Specifically, for example, when a luminance value of the case where all of the three sub-pixels Spix of red, green, and blue emit light at maximum luminance is equal to a luminance value of the case where the white sub-pixel Spix emits light at maximum luminance, the pixel Pix achieves luminance twice as high as luminance of the pixel including the three sub-pixels SPix of red, green, and blue.
(Image Processing Section 20)
The image processing section 20 includes a gamma conversion section 21, a peak luminance extending section 22, a color gamut conversion section 23, an RGBW conversion section 24, an overflow correction section 25, and a gamma conversion section 26.
The gamma conversion section 21 converts the received image signal Sp0 to an image signal Sp21 having linear gamma characteristics. Specifically, an image signal supplied from outside has a gamma value set to, for example, 2.2 in correspondence to characteristics of a common display unit, i.e., has nonlinear gamma characteristics. Hence, the gamma conversion section 21 converts such nonlinear gamma characteristics to linear gamma characteristics to facilitate processing in the image processing section 20. The gamma conversion section 21 may include, for example, a lookup table (LUT) that is used to perform such gamma conversion.
The peak luminance extending section 22 extends peak luminance of each of pieces of luminance information IR, IG, and IB contained in the image signal Sp21 to generate an image signal Sp22.
The Value acquiring section 41 acquires Values V in the HSV color space from the pieces of luminance information IR, IG, and IB contained in the image signal Sp21. Although Values V in the HSV color space are acquired in this exemplary case, the peak luminance extending section 22 is not limited thereto. Alternatively, for example, the peak luminance extending section 22 may be configured to acquire luminance L in the HSL color space, or may be configured to selectively acquire one of them.
The average-luminance-level acquiring section 42 obtains an average (average luminance level APL) of luminance information of a frame image, and outputs the average luminance level APL.
The gain calculating section 43 calculates the gain Gup based on the Value V for each of pieces of pixel information P supplied from the Value acquiring section 41 and the average luminance level APL of every frame image supplied from the average-luminance-level acquiring section 42.
The Gv calculating section 91 calculates a parameter Gv based on the Value V as described later. The parameter Gv is obtained through a function using the Value V.
The Garea calculating section 92 generates a map of a parameter Garea based on the Value V. The Garea calculating section 92 includes a map generating section 93, a filter section 94, a scaling section 95, and a computing section 96.
The map generating section 93 generates a map MAP1 based on the Value V obtained from each frame image. Specifically, the map generating section 93 divides an image region of a frame image into a plurality of (for example, 60×30) block regions B in horizontal and vertical directions, and calculates an average (region luminance information IA) of the Values V for individual block regions B to generate the map MAP1. The region luminance information IA indicates an average of the Values V in a particular block region B, and is therefore has a larger value with a larger number of pieces of pixel information P having the high Value V, i.e., with an increase in area of a bright region in that block region B.
Although the map generating section 93 calculates the average of the Values V for individual block regions B in the exemplary case, the map generating section 93 is not limited thereto. Alternatively, for example, the map generating section may calculate the number of pieces of pixel information P having the Value V equal to or more than a predetermined value in each block region B.
The filter section 94 smoothens the region luminance information IA contained in the map MAP1 between the block regions B, to thereby generate a map MAP2. Specifically, the filter section 94 may be configured of, for example, a five-tap finite impulse response (FIR) filter.
The scaling section 95 performs enlarging scaling of the map MAP2 from a map in block units to a map in pixel information P units to generate a map MAP3. In other words, the map MAP3 has information of the Values V of which the number is the same as that of the pixels Pix of the EL display section 13. In that operation, the scaling section 95 may perform the enlarging scaling through interpolation processing such as, for example, linear interpolation or bucubic interpolation.
The computing section 96 generates a map MAP4 of the parameter Garea based on the map MAP3. The computing section 96 may include, for example, a lookup table, and uses the lookup table to calculate the parameter Garea for each of pieces of pixel information P based on individual data of the map MAP3.
The Gbase calculating section 97 calculates a parameter Gbase based on the average luminance level APL. The Gbase calculating section 97 may include, for example, a lookup table, and uses the lookup table to calculate the parameter Gbase based on the average luminance level APL, as described later.
As described later, the Gup calculating section 98 performs predetermined computing described later based on the parameters Gv, Gbase, and Garea to calculate the gain Gup.
In
In
The RGBW conversion section 24 generates an RGBW signal based on the image signal Sp23 which is in a form of the RGB signal, and outputs the RGBW signal as an image signal Sp24. Specifically, the RGBW conversion section 24 converts the RGB signal containing the pieces of luminance information IR, IG, and IB of three colors of red (R), green (G), and blue (B) to the RGBW containing pieces of luminance information IR2, IG2, IB2, and IW2 of four colors of red (R), green (G), blue (B), and white (W).
The overflow correction section 25 performs correction (overflow correction) such that each of the pieces of luminance information IR2, IG2, and IB2 contained in the image signal Sp24 does not exceed a predetermined luminance level, and outputs such a corrected image signal as an image signal.
The gain calculating sections 51R, 51G, and 51B obtain the gains GRof, GGof, and GBof to prevent the pieces of luminance information IR2, IG2, and IB2 from exceeding predetermined luminance levels, respectively. The amplifying sections 52R, 52G, and 52B multiply the pieces of luminance information IR2, IG2, and IB2 by the gains GRof, GGof, and GBof, respectively.
The gamma conversion section 26 converts the image signal Sp25 having linear gamma characteristics to the image signal Sp1 having nonlinear gamma characteristics corresponding to the characteristics of the EL display section 13. The gamma conversion section 26 may include, for example, a lookup table as with the gamma conversion section 21, and uses the lookup table to perform such gamma conversion.
The multiplication section 44 corresponds to a specific example of “determination section” in one embodiment of the disclosure. The color gamut conversion section 23 and the RGBW conversion section 24 collectively corresponds to a specific example of “conversion section” in one embodiment of the disclosure. The overflow correction section 25 corresponds to a specific example of “correction section” in one embodiment of the disclosure. The gain Gup corresponds to a specific example of “first gain” in one embodiment of the disclosure. The Value V corresponds to a specific example of “pixel luminance value” in one embodiment of the disclosure. The image signal Sp21 corresponds to a specific example of “first luminance information” in one embodiment of the disclosure, the image signal Sp22 corresponds to a specific example of “second luminance information” in one embodiment of the disclosure, the image signal Sp24 corresponds to a specific example of “third luminance information” in one embodiment of the disclosure, and the image signal Sp25 corresponds to a specific example of “fourth luminance information” in one embodiment of the disclosure.
[Operations and Functions]
Operations and functions of the display unit 1 of this embodiment are now described.
(Summary of Overall Operation)
First, summary of an overall operation of the display unit 1 is described with reference to
(Peak Luminance Extending Section 22)
A detailed operation of the peak luminance extending section 22 is now described. In the peak luminance extending section 22, the Value acquiring section 41 acquires the Value V for each pixel Pix from the pieces of luminance information IR, IG, and IB contained in the image signal Sp21, and the average-luminance-level acquiring section 42 obtains the average of luminance information (the average luminance level APL) of a frame image. The gain calculating section 43 calculates the gain Gup based on the Value V and the average luminance level APL.
The Gbase calculating section 97 of the gain calculating section 43 calculates the parameter Gbase based on the average luminance level APL. The parameter Gbase decreases with an increase in average luminance level APL of the frame image (brightness while increases with a decrease in average luminance level APL of the frame image (brightness). The Gbase calculating section 97 obtains the parameter Gbase based on the average luminance level APL of every frame image supplied from the average-luminance-level acquiring section 42.
An operation of the Garea calculating section 92 is now described.
In the display unit 1, first, the Value acquiring section 41 acquires the Value V for each of pieces of pixel information P based on the frame image F illustrated in
Then, the scaling section 95 performs enlarging scaling of the map MAP2 into a map in pixel information P units through interpolation processing to generate the map MAP3 (
Then, the computing section 96 generates the map MAP4 (
In this way, the computing section 96 calculates the parameter Garea based on the individual Values V configuring the map MAP3, to thereby generate the map MAP4 (
The Gup calculating section 98 calculates the gain Gup for each of pieces of pixel information P with the following Formula (1) based on the three parameters Gv, Gbase, and Garea obtained in the above way.
Gup=(1+Gv×Garca)×Gbase (1)
In this way, the peak luminance extending section 22 increases the gain Gup with an increase in Value V, to thereby extend luminance. As a result, the dynamic range of the image signal is expanded. Consequently, the display unit 1 displays a high contrast image. For example, when an image of stars twinkling in the night sky is displayed, the stars are displayed more brightly, and when metal such as a coin is displayed, a high contrast image, including representation of luster of the metal, is displayed.
Moreover, as illustrated in
In addition, in the display unit 1, the gain Gup is varied based on the average luminance level APL, thereby making it possible to improve image quality. Specifically, for example, in the case where a display screen is dark, adaptation luminance of a viewer's eye is low; hence, the viewer is less likely to perceive a difference in grayscale between luminance levels at a high luminance-level portion in the display screen. On the other hand, in the case where a display screen is bright, adaptation luminance of a viewer's eye is high; hence, the viewer is likely to perceive a difference in grayscale between luminance levels at a high luminance-level portion in the display screen. In the display unit 1, the gain Gup is varied based on the average luminance level APL. Hence, for example, in the case where a display screen is dark (the average luminance level APL is low), the gain Gup is increased to facilitate perception of a difference in grayscale between luminance levels. In the case where a display screen is bright (the average luminance level APL is high), the gain Gup is decreased to prevent excessive perception of a difference in grayscale between luminance levels.
Moreover, in the display unit 1, the gain Gup is varied based on the parameter Garea, thereby making it possible to improve image quality as described below.
Furthermore, for example, in the case where a display unit disclosed in JP-A-2008-158401 displays the image as illustrated in
In contrast, in the display unit 1, the gain Gup is varied based on the parameter Garea. Specifically, as area of a bright region increases in a frame image, the parameter Garea decreases and thus the gain Gup decreases according to Formula (1). Similarly, as area of a bright region decreases, the parameter Garea increases and thus the gain Gup increases according to Formula (1). As a result, in the case of
The processing order of the image processing section 20 is now described.
In the display unit 1, the color gamut conversion section 23 is provided at a downstream of the peak luminance extending section 22, so that the color gamut and color temperature of the image signal Sp22 extended in peak luminance are converted to the color gamut and color temperature of the EL display section 13, thereby making it possible to improve image quality. Specifically, if the peak luminance extending section 22 is provided at a downstream of the color gamut conversion section 23, the peak luminance extending section 22 calculates the gain Gup based on the Value V of the luminance information subjected to the color gamut conversion. This may cause, for example, variation in object to be extended in peak luminance (chromaticity range), leading to a possibility of a reduction in image quality. In contrast, in the display unit 1, since the color gamut conversion section 23 is provided at a downstream of the peak luminance extending section 22, the object to be extended in peak luminance (chromaticity range) does not vary, thereby making it possible to suppress a reduction in image quality.
In addition, in the display unit 1, the RGBW conversion section 24 is provided at a downstream of the peak luminance extending section 22, and the RGB signal containing the pieces of luminance information IR, IG, and IB extended in peak luminance is subjected to RGBW conversion, thereby making it possible to suppress a reduction in image quality. Specifically, in general, each sub-pixel SPix of the EL display section 13 may vary in chromaticity depending on signal levels. Hence, if the peak luminance extending section 22 is provided at a downstream of the RGBW conversion section 24, chromaticity of a display image may be shifted. If image processing is performed to avoid this, complicated processing is necessary in consideration of nonlinearity. In contrast, in the display unit 1, the RGBW conversion section 24 is provided at a downstream of the peak luminance extending section 22, thereby making it possible to reduce a possibility of shift in chromaticity of a display image.
In addition, in the display unit 1, the Garea calculating section 92 (
In addition, in the display unit 1, the computing section 96 is provided at a downstream of the scaling section 95, and the computing section 96 obtains the parameter Garea based on the map MAP3 subjected to the enlarging scaling, thereby making it possible to suppress a reduction in image quality as described below.
One reason for this may be considered as follows. Specifically, when the computing section 96 obtains the parameter Garea based on the Value V as illustrated in
(Overflow Correction Section 25)
Overflow correction of the overflow correction section 25 is now described in detail. In the overflow correction section 25, the gain calculating sections 51R, 51G, and 51B respectively obtain the gains GRof, GGof, and GBof such that the respective pieces of luminance information IR2, IG2, and IB2 do not exceed the predetermined maximum luminance levels, and the amplifying sections 52R, 52G, and 52B respectively multiply the pieces of luminance information IR2, IG2, and IB2 by the gains GRof, GGof, and GBof.
As illustrated in
When the amplifying section 52R multiplies the luminance information IR2 by the gain GRof, as illustrated in
In this way, the overflow correction section 25 performs correction to prevent each of the pieces of luminance information IR2, IG2, and IB2 from exceeding the predetermined luminance level Imax. This reduces a possibility of disorder in images. In other words, in the display unit 1, the RGBW conversion section 24 generates the luminance signals IR2, IG2, IB2, and IW2 through the RGBW conversion, and the EL display section 13 performs display based on those luminance signals. During this operation, the RGBW conversion section 24 may generate the luminance signals IR2, IG2, and IB2 each having a level too high for the EL display section 13 to display the signal. If the EL display section 13 performs display based on such pieces of luminance signals IR2, IG2, and IB2 each having an excessively high level, a high-luminance portion is not appropriately displayed, leading to a possibility of disorder in images. In the display unit 1, however, the overflow correction section 25 is provided so that correction is performed to prevent each of the luminance signals IR2, IG2, and IB2 from exceeding the luminance level Imax, thereby making it possible to reduce such disorder in images.
[Effects]
As described above, in this embodiment, the peak luminance extending section is set such that the gain Gup increases with an increase in Value of the luminance information, and thus contrast is improved, thereby making it possible to improve image quality.
Moreover, in this embodiment, since the gain Gup is varied based on the average luminance level, extension of peak luminance is adjustable depending on adaptation luminance of a viewer's eye, thereby making it possible to improve image quality.
Moreover, in this embodiment, since the gain Gup is varied depending on area of a bright region, extension of the peak luminance is suppressed for a portion having large area of the bright region, and luminance is relatively increased for a portion having small area of the bright region, thereby making it possible to improve image quality.
Moreover, in this embodiment, the color gamut conversion section and the RGBW conversion section, etc., are each provided at a downstream the peak luminance extending section, thereby making it possible to suppress a reduction in image quality.
Moreover, in this embodiment, the overflow correction section is provided, and correction is performed such that luminance information does not exceed a predetermined luminance level, thereby making it possible to suppress a reduction in image quality.
Moreover, in this embodiment, the Garea calculating section has the scaling section provided at a downstream of the filter section, and enlarging scaling is performed based on the smoothened map MAP2, thereby making it possible to suppress a reduction in image quality.
Moreover, in this embodiment, the Garea calculating section has the computing section provided at a downstream of the scaling section, and the parameter Garea is obtained based on the map MAP3 subjected to enlarging scaling, thereby making it possible to suppress a reduction in image quality.
[Modification 1-1]
Although the overflow correction section 25 calculates the gains GRof, GGof, and GBof for the respective pieces of luminance information IR2, IG2, and IB2 in the above-described embodiment, the overflow correction section is not limited thereto. Alternatively, for example, as illustrated in
As illustrated in
The overflow correction section 25B according to this Modification multiplies the respective pieces of luminance information IR2, IG2, IB2, and IW2 by the common gain Gof. This reduces a possibility of occurrence of shift in chromaticity. In contrast, the overflow correction section 25 according to the above-described embodiment calculates the gains GRof, GGof, and GBof individually for the pieces of luminance information IR, IG, and IB, which makes it possible to brighten a display image.
[Modification 1-2]
Although the peak luminance extending section 22 obtains the parameter Gv by a function using the Value V in the above-described embodiment, the peak luminance extending section is not limited thereto. Alternatively, for example, the peak luminance extending section may determine the parameter Gv by a lookup table using the Value V. In such a case, a relationship between the parameter Gv and the Value V is more freely set, for example, as illustrated in
[Modification 1-3]
Although the peak luminance extending section 22 calculates the parameter Gv based on the Value with the threshold Vth1 as a fixed value in the above-described embodiment, the peak luminance extending section is not limited thereto. Alternatively, for example, as illustrated in
A display unit 2 according to a second embodiment is now described. In this embodiment, overflow correction is also performed during extension of the peak luminance. It is to be noted that substantially the same components as those of the display unit 1 according to the first embodiment are designated by the same numerals, and description of them is appropriately omitted.
The Gs calculating section 67 calculates the para Gs based on the Saturation S. The Gs calculating section 67 may include, for example, a lookup table, and uses the lookup table to calculate the parameter Gs based on the Saturation S.
The Gup calculating section 68 calculates the gain Gup using following Formula (2) based on the parameters Gv, Gbase, Garea, and Gs.
Gup=(1+Gv×Garea×Gs)×Gbase (2)
In this way, the parameter Gs decreases with an increase in Saturation S in the display unit 2. As a result, the gain Gup decreases, thereby achieving an effect equivalent to the effect of the above-described overflow correction.
As described above, in this embodiment, the parameter Gs is provided, and the gain Gup is varied depending on the Saturation S, thereby allowing the peak luminance extending section to perform overflow correction in addition to the extending processing of peak luminance. Other effects are similar to those in the first embodiment.
[Modification 2-1]
One or more of the Modifications 1-1 to 1-3 of the first embodiment may be applied to the display unit 2 according to the above-described embodiment.
A display unit 3 according to a third embodiment is now described. The display unit 3 according to this embodiment is configured as a liquid crystal display unit with a liquid crystal display element as a display element. It is to be noted that substantially the same components as those of the display unit 1 according to the first embodiment are designated by the same numerals, and description of them is appropriately omitted.
The image processing section 70 includes a backlight level calculating section 71, and a luminance information conversion section 72. The backlight level calculating section 71 and the luminance information conversion section 72 are provided to achieve a so-called dimming function as described below, which allows for reduction of power consumption of the display unit 3. As for the dimming function, reference is made to, for example, Japanese Unexamined Patent Application Publication No. 2012-27405.
The backlight level calculating section 71 calculates a backlight level BL indicating emission luminance of the backlight 17 based on the image signal Sp22. Specifically, for example, the backlight level calculating section 71 may obtain a peak value of each of pieces of luminance information IR, IG, and IB of each frame image, and calculates the backlight level BL such that emission luminance of the backlight 17 increases with an increase in that peak value.
The luminance information conversion section 72 performs conversion of the pieces of luminance information IR, IG, and IB contained in the image signal Sp22 through dividing the respective pieces of luminance information IR, IG, and IB by the backlight level BL, to thereby generate an image signal Sp72.
The display control section 14 controls a display operation of the liquid crystal display section 15 based on the image signal Sp1 The liquid crystal display section 15 is a display section using a liquid crystal display element as a display element, and performs a display operation based on the control by the display control section 14.
The backlight control section 16 controls light emission of the backlight 17 based on the backlight level BL The backlight 17 emits light based on the control by the backlight control section 16, and applies the light to the liquid crystal display section 15. The backlight 17 may be configured of, for example, a light emitting diode (LED).
According to such a configuration, in the display unit 3, the backlight level calculating section 71 and the luminance information conversion section 72 adjust the emission luminance of the backlight 17 depending on the respective pieces of luminance information IR, IG, and IB. Thus, the display unit 3 achieves a reduction in power consumption.
Also, in the display unit 3, the backlight level calculating section 71 and the luminance information conversion section 72 are provided at a downstream of the peak luminance extending section 22, and calculation of the backlight level BL and conversion of the respective pieces of luminance information IR, IG, and IB are performed based on the image signal Sp22 extended in peak luminance. Thus, the peak luminance is exclusively extended without darkening the entire screen.
As described above, effects similar to those, in the above-described embodiments and the Modifications are achieved also when embodiments of the present technology are applied to liquid crystal display units.
[Modification 3-1]
One or e of the Modifications 1-1 to 1-3 of the first embodiment, the second embodiment, and the Modification 2-1 of the second embodiment may be applied to the display unit 3 according to the third embodiment.
A display unit 4 according to a fourth embodiment is now described. In this embodiment, an EL display section is configured using a pixel Pix configured of sub-pixels SPix of three colors of red, green, and blue. It is to be noted that substantially the same components as those of the display unit 1 according to the first embodiment, etc., are designated by the same numerals, and description of them is appropriately omitted.
The display control section 12A controls a display operation of such an EL display section 13A.
As illustrated in
In this way, in the display unit 4, first, the respective pieces of luminance information IR, IG, and IB are reduced, and then the corresponding peak luminance is extended as in the first embodiment. During this operation, the peak luminance is extended by the extent corresponding to the reduction in the respective pieces of luminance information IR, IG, and IB, thereby making it possible to extend the peak luminance while a dynamic range is maintained.
In addition, in the display unit 1, as in the first embodiment, since the gain Gup is varied depending on area of a bright region, extension of the peak luminance is suppressed for a portion having large area of the bright region, and luminance is relatively increased for a portion having small area of the bright region, thereby making it possible to improve image quality.
As described above, effects similar to those in the above-described embodiments and the Modifications are achieved also when embodiments of the present technology are applied to EL display units having three colors of sub-pixels.
[Modification 4-1]
One or more of the Modifications 1-1 to 1-3 of the first embodiment, the second embodiment, and the Modification 2-1 of the second embodiment may be applied to the display unit 4 according to the fourth embodiment.
Application examples of each of the display units described in the above-described embodiments and the Modifications are now described.
The display unit according to any of the above-described embodiments and the Modifications is applicable to an electronic apparatus in any field. In addition to the television unit, examples of the electronic apparatus may include a digital camera, a notebook personal computer, a mobile terminal unit such as a mobile phone, a portable video game player, and a video camera. In other words, the display unit according to any of the above-described embodiments and the Modifications is applicable to an electronic apparatus that displays images in any field.
Although the present technology has been described with reference to the example embodiments, the Modifications, and the application examples hereinbefore, the technology is not limited thereto, and various modifications or alterations thereof may be made.
For example, although the four sub-pixels SPix are arranged in a 2×2 matrix to configure the pixel Pix in the pixel array section 33 of the EL display section 13 in any of the above-described first to third embodiments, etc., the pixel configuration is not limited thereto. As illustrated in
Furthermore, the technology encompasses any possible combination of some or all of the various embodiments described herein and incorporated herein.
It is possible to achieve at least the following configurations from the above-described example embodiments of the disclosure.
a gain calculating section obtaining, based on first luminance information for each pixel, a first gain, the first gain being configured to increase with an increase in pixel luminance value in a range where the pixel luminance value is equal to or larger than a predetermined luminance value, and the pixel luminance value being derived from the first luminance information;
a determination section determining, based on the first luminance information and the first gain, second luminance information for each of the pixels; and
a display section performing display based on the second luminance information.
the gain calculating section obtains the first gain based on a gain function that represents a, relationship between the pixel luminance value and the first gain, and
the first gain is configured to increase at a predetermined gradient with the increase in the pixel luminance value that is equal to or larger than the predetermined luminance value, in the gain function.
the display section includes a plurality of display pixels, and
each of the display pixels includes a first sub-pixel, a second sub-pixel, a third sub-pixel, and a fourth sub-pixel, the first sub-pixel, the second sub-pixel, and the third sub-pixel being associated with respective wavelengths that are different from one another, and the fourth sub-pixel emitting color light that is different from color light emitted by each of the first sub-pixel, the second sub-pixel, and the third sub-pixel.
wherein the second luminance information contains three pieces of second sub luminance information, the respective three pieces of second sub luminance information corresponding to the first sub-pixel, the second sub-pixel, and the third sub-pixel,
wherein the conversion section generates, based on the second luminance information, third luminance information that contains four pieces of third sub luminance information, the respective four pieces of third sub luminance information corresponding to the first sub-pixel, the second sub-pixel, the third sub-pixel, and the fourth sub-pixel, and
wherein the display section performs display based on the third lurinance information.
wherein the correction section obtains, based on the respective three pieces of third sub luminance information corresponding to the first sub-pixel, the second sub-pixel, and the third sub-pixel among the four pieces of third sub luminance information contained in the third luminance information, second gains for the respective three pieces of third sub luminance information,
wherein the correction section generates, based on the three pieces of third sub luminance information and the corresponding second gains, fourth luminance information that contains three pieces of fourth sub luminance information and the third sub luminance information, the respective three pieces of fourth sub luminance information corresponding to the first sub-pixel, the second sub-pixel, and the third sub-pixel, and the third sub luminance information corresponding to the fourth sub pixel, and
wherein the display section performs display based on the fourth luminance information,
wherein the correction section obtains, based on a largest luminance level among the respective three pieces of third sub luminance information corresponding to the first sub-pixel, the second sub-pixel, and the third sub-pixel among the four pieces of third sub luminance information contained in the third luminance information, a second gain for each pixel,
wherein the correction section generates, based on the four pieces of third sub luminance information and the second gain, fourth luminance information that contains four pieces of fourth sub luminance information, the respective four pieces of fourth sub luminance information corresponding to the first sub-pixel, the second sub-pixel, the third sub-pixel, and the fourth sub pixel, and
wherein the display section performs display based on the fourth luminance in formation.
the first sub-pixel, the second sub-pixel, and the third sub-pixel emit red color light, green color light, and blue color light, respectively, and
the color light emitted by the fourth sub-pixel has a luminosity factor that is substantially equal to or higher than a luminosity factor for the green color light emitted by the second sub-pixel.
a gain calculating section obtaining, based on first luminance information for each pixel, a first gain, the first gain being configured to increase with an increase in pixel luminance value in a range where the pixel luminance value is equal to or larger than a predetermined luminance value, and the pixel luminance value being derived from the first luminance information; and
a determination section determining, based on the first luminance information and the first gain, second luminance information for each of the pixels.
obtaining, based on first luminance information for each pixel, a first gain, the first gain increasing with an increase in pixel luminance value in a range where the pixel luminance value is equal to or larger than a predetermined luminance value, and the pixel luminance value being derived from the first luminance information;
determining, based on the first luminance information and the first gain, second luminance information for each of the pixels; and
performing display based on the second luminance information.
The present disclosure contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2012-134373 filed in the Japan Patent Office on Jun. 14, 2012, the entire content of which is hereby incorporated by reference.
It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.
Number | Date | Country | Kind |
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2012-134373 | Jun 2012 | JP | national |
The present application is a Continuation of application Ser. No. 13/899,030, filed May 21, 2013, which claims the benefit of Japanese Priority Patent Application JP 2012-134373 filed Jun. 14, 2012, the entire contents of which are incorporated herein by reference.
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Number | Date | Country | |
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Parent | 13899030 | May 2013 | US |
Child | 15914354 | US |