JP2011253026A - Subfield generating device and subfield generating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a subfield generating device capable of power-saving while maintaining image quality in PDP and a subfield generating method.SOLUTION: The subfield generating device of the present invention comprises: a subfield conversion unit 120 for dividing a frame image into the N (N: a positive integer) number of subfields; a frequency determination unit 162 for determining a frequency component of the frame image; an APL determination unit 163 for determining an average video signal level of the frame image; a format determination unit 1622 for determining a subfield for thinning out on the basis of the frequency component determined in the frequency determination unit 162 and the average video signal level determined in the APL determination unit 16; and a format conversion unit 133 for line-thinning out the subfield determined to be line-thinned out in the format determination unit 1622.

Description

  The present invention relates to a technique for displaying an image using a subfield, and more particularly, to a technique related to power saving during subfield display.

  In recent years, display devices using display devices such as liquid crystal displays and plasma displays have become widespread.

  Among them, in the case of a plasma display (hereinafter abbreviated as “PDP”), a certain amount of electric energy is required to perform display by exciting a phosphor using a discharge phenomenon between electrodes. On the other hand, energy saving is demanded as a social demand in recent years, and power saving is one of the important technical problems in PDP.

  On the other hand, a method for realizing a power saving mode by selectively causing a light emitting element made of a phosphor to emit light has been proposed (for example, see Patent Document 1). Specifically, when the power saving mode is selected, light emission of only even-numbered light-emitting elements and light emission of only odd-numbered light-emitting elements are alternately performed.

  However, in a PDP that requires high image quality, it is required to maintain the display image quality even when power saving measures are taken.

  In relation to the brightness and gradation of the PDP, several image quality improvement methods have been conventionally proposed (see, for example, Patent Documents 2 and 3).

JP 2007-41221 A Japanese Patent Laid-Open No. 11-24628 Japanese Patent No. 3850625

  However, the above conventional technique cannot realize effective power saving while maintaining the image quality in the PDP.

  An object of the present invention is to provide a subfield generation device and a subfield generation method capable of saving power while maintaining image quality in a PDP.

  In order to achieve the above object, the subfield generating apparatus of the present invention includes a frame dividing unit that divides a frame image into N (N: positive integer) subfields (hereinafter abbreviated as “SF”), A frequency component calculating means for determining a frequency component of a frame image; a line thinning determining means for determining that thinning is performed for all SFs when the frequency component obtained by the frequency component calculating means does not exceed a predetermined frequency; And a line thinning unit that performs line thinning on the SF that has been determined to be thinned by the determining unit.

  With such a configuration, it is possible to perform line thinning of the SF of a low-frequency frame image that is not susceptible to quality degradation due to thinning. Therefore, the driving power of the SF can be reduced while maintaining the display quality of the frame image. As a result, it is possible to realize image display with low power consumption and maintaining image quality.

  Further, the subfield generation device of the present invention counts the number of switching of lighting / non-lighting in the data writing direction in the SF, and frame dividing means for dividing the frame image into N (N: positive integer) SFs. Switching number counting means, line thinning determining means for determining that the thinning is performed for the SF whose switching number counted by the switching number counting means is equal to or greater than a predetermined number, and line thinning by the line thinning determination means. Line thinning means for performing line thinning on the determined SF.

  With such a configuration, it is possible to perform line thinning of the SF in which the number of switching between lighting and non-lighting in the SF exceeds a predetermined value and the driving power becomes a predetermined value or more. Therefore, the driving power of SF can be effectively reduced. As a result, it is possible to realize image display with low power consumption and maintaining image quality.

  Further, the subfield generation device according to the present invention is obtained by a frame dividing unit that divides a frame image into N (N: positive integer) SFs, a luminance calculating unit that calculates the luminance of the frame image, and a luminance calculating unit. Line thinning determining means for determining that thinning is performed for all SFs when the luminance is equal to or higher than a predetermined luminance, and line thinning means for performing line thinning for SFs determined to be thinned by the line thinning determining means And have.

  With such a configuration, it is possible to perform line thinning of a high-luminance frame image that is unlikely to suffer quality degradation due to thinning. Therefore, the driving power of the SF can be reduced while maintaining the display quality of the frame image. As a result, it is possible to realize image display with low power consumption and maintaining image quality.

  The subfield generation device of the present invention also includes a frame dividing unit that divides a frame image into N (N: positive integer) SFs, and a predicted power value that is predicted to be used when displaying the SFs. A predicted power value calculation unit to calculate, a line thinning determination unit to determine that thinning is performed on an SF whose power predicted value calculated by the power predicted value calculation unit is equal to or greater than a predetermined power value, and a line thinning determination unit. Line thinning means for performing line thinning on the SF that has been decided to be thinned.

  With such a configuration, it is possible to perform line thinning of the SF whose predicted power value predicted to be used when displaying the SF exceeds a predetermined value. Therefore, the driving power of SF can be effectively reduced. As a result, it is possible to realize image display with low power consumption and maintaining image quality.

  Further, the subfield generation device of the present invention includes a frame dividing unit that divides a frame image into N (N: positive integer) SFs, an SF that performs thinning on a plurality of SFs, and an SF that does not perform thinning. A combination generation unit that generates all combinations, and a power prediction value that calculates a sum of power prediction values that are predicted to be used when displaying a plurality of SFs for all combinations generated by the combination generation unit Sum total calculating means, line thinning determining means for determining the SF to be thinned out based on the combination that minimizes the sum of the predicted power values calculated by the predicted power sum calculating means, and line thinning by the line thinning determining means Line thinning means for performing line thinning on the SF that has been determined.

  With such a configuration, it is possible to perform line thinning of SFs based on the combination that minimizes the sum of the predicted power values from all combinations of SFs that are thinned and SFs that are not thinned. Therefore, the driving power of SF can be minimized. As a result, it is possible to realize image display with low power consumption and maintaining image quality.

  Also, the subfield generation apparatus of the present invention is a combination of a frame dividing unit that divides a frame image into N (N: positive integer) SFs, an SF that performs thinning between subsequent frame images, and an SF that does not perform thinning. Line thinning determining means for determining the SF to be thinned out so as to be different from each other, and line thinning means for performing line thinning on the SF determined to be thinned by the line thinning determining means.

  With such a configuration, line thinning is performed so that the combination of the SF that performs thinning and the SF that does not perform thinning differ between successive frame images, and the line positions of the SFs that are thinned are evenly distributed in the time direction. It becomes possible. Therefore, the SF driving power can be reduced while maintaining the display quality of the frame image in the time direction. As a result, it is possible to realize image display with low power consumption and maintaining image quality.

  Further, in the subfield generation device of the present invention, the line thinning means performs line thinning every other line. With such a configuration, every other line to be thinned out, the line thinning process becomes easy.

  Further, the subfield generation device of the present invention calculates for each line the frame dividing means for dividing the frame image into N (N: positive integer) SFs and the SF divided by the frame dividing means. Line decimation determining means for determining to perform line decimation of SF when lines whose frequency components are equal to or lower than a predetermined frequency continue for a predetermined number of lines, and SF for which line decimation is determined by the line decimation determining means. And a line thinning unit that identifies a low frequency region in which lines having a frequency component calculated for each line equal to or lower than a predetermined frequency continue for a predetermined number of lines and thins lines other than the first line in the low frequency region.

  With such a configuration, it is possible to perform SF line thinning for a low frequency region in which lines whose frequency components calculated for each line are equal to or lower than a predetermined frequency continue for a predetermined number of lines or more. Therefore, the driving power of the SF can be reduced while maintaining the display quality of the frame image. As a result, it is possible to realize image display with low power consumption and maintaining image quality.

  The subfield generation device of the present invention includes a frame dividing unit that divides a left-eye frame image into N (N: positive integer) left-eye SFs and a right-eye frame image into N right-eye SFs; When it is determined that the Kth (K: integer from 1 to N) left-eye SFs are to be thinned out for the N left-eye SFs and N right-eye SFs divided by the frame dividing unit. Determines that the Kth right-eye SF is not thinned, and if it is determined that the Lth (L: integer between 1 and N) right-eye SF is thinned, the Lth Line thinning determination means for determining that the left-eye SF is not thinned, and line thinning means for performing line thinning on the left-eye SF and the right-eye SF that are determined to be thinned by the line thinning-out determination means. .

  With such a configuration, it is possible to perform line thinning only for one of the SF for the left eye and the SF for the right eye. Therefore, when line thinning is performed on a stereoscopic image, the display quality of the stereoscopic image can be displayed by complementing the display quality of the other SF where thinning is performed by either SF that does not perform line thinning for a pair of left and right SFs. The driving power of the SF can be reduced while maintaining the quality. Thereby, it is possible to realize a stereoscopic image display with low power consumption and maintaining image quality.

  According to the subfield generation device and the subfield generation method of the present invention, it is possible to realize an image display in which the driving power of the subfield is reduced while maintaining the image quality.

Explanatory drawing regarding the driving power of the PDP in Embodiment 1 of the present invention 1 is a block diagram showing a configuration of a PDP in Embodiment 1 of the present invention. Explanatory drawing of the subfield generation method in Embodiment 1 of this invention The figure which shows the subfield conversion table in Embodiment 1 of this invention. Explanatory drawing of the format conversion method of the subfield in Embodiment 1 of this invention The block diagram which shows the structure of PDP in Embodiment 2 of this invention. The block diagram which shows the structure of the format converter in Embodiment 2 of this invention. The block diagram which shows the structure of PDP in Embodiment 3 of this invention. Explanatory drawing of SF information which the frequency discriminator in Embodiment 3 of this invention outputs Explanatory drawing of SF information which the APL determination device in Embodiment 3 of this invention outputs Explanatory drawing of SF information which the subfield switching frequency determination device in Embodiment 3 of this invention outputs Explanatory drawing of SF information which the writing power determination device in Embodiment 3 of this invention outputs Explanatory drawing of the format conversion method of the subfield in Embodiment 3 of this invention The block diagram which shows the structure of PDP in Embodiment 3 of this invention. Explanatory drawing of the subfield generation method in Embodiment 4 of this invention Explanatory drawing of the thinning line information which the thinning line detector in Embodiment 4 of this invention outputs Explanatory drawing of the format conversion method in Embodiment 4 of this invention Block diagram showing a configuration of a stereoscopic display PDP in a fifth embodiment of the present invention The figure which shows an example of the subfield production | generation method in Embodiment 5 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

(Embodiment 1)
The PDP according to Embodiment 1 of the present invention divides one frame constituting a screen into several SFs, and displays intermediate gradations by changing the light emission time of the SFs.

  FIG. 1 is an explanatory diagram regarding the driving power of the PDP in Embodiment 1 of the present invention, and shows a case where one displayed frame is divided into four subfields SF1 to SF4 having different brightness weighting factors. .

  The driving power when writing data in one SF is determined by the power consumed when controlling the light emission and non-light emission of each pixel in the SF. Light emission and non-light emission of each pixel due to data writing are controlled by charge / discharge of capacitance. Therefore, in the case of an image in which switching between light emission and non-light emission is reduced, power consumption due to charge / discharge at the time of data writing in the vertical direction is reduced.

  For example, in the case of SF4 shown in FIG. 1, the light emission and non-light emission are switched once in the vertical direction of the display screen, and in the case of SF3 shown in FIG. 1, light emission and non-light emission are made in the vertical direction of the display screen. Since switching is performed three times, SF3 consumes more power when writing data than SF4.

  FIG. 2 is a block diagram showing the configuration of the PDP in Embodiment 1 of the present invention, and shows that the PDP is composed of a subfield generation device 101 and a PDP unit 200 that divide one frame into a plurality of SFs. Yes.

  As shown in FIG. 2, the subfield generation apparatus 101 includes an inverse gamma corrector 110, a subfield converter 120, a format converter 131, and a subfield processor 140, and is input to the subfield generation apparatus 101. The SF is generated based on the video signal and output to the PDP unit 200 to display the video.

  The inverse gamma corrector 110 performs inverse gamma correction on the A / D converted R, G, and B video input signals and outputs the corrected video signal to the subfield converter 120.

  The subfield converter 120 divides the frame image of the corrected video signal output from the inverse gamma corrector 110 into N (N: positive integer) SFs and outputs them to the format converter 131.

  The format converter 131 performs predetermined format conversion on the SF output from the subfield converter 120, outputs the converted SF to the subfield processor 140, and scans / maintains / maintains the PDP unit 200. The subfield drive information is output to the erase drive circuit 220. The predetermined format conversion will be described later.

  The subfield processor 140 generates a drive data signal from the converted SF output from the format converter 131 and outputs the drive data signal to the data drive circuit 230 of the PDP unit 200.

  Note that the subfield processor 140 is a line that has not been thinned out of the thinned-out line data with respect to the line-thinned SF obtained by the predetermined format conversion, and is located on the upper side closest to the thinned-out line. A drive data signal is generated from the data supplemented with the line data.

  The PDP unit 200 drives the PDP 210 based on driving information input from the format converter 131 to the scanning / maintenance / erasing driving circuit 220 and driving data signals input from the subfield processor 140 to the data driving circuit 230. Display video.

  FIG. 3 is an explanatory diagram of a subfield generation method in the subfield generation apparatus 101.

  As shown in FIG. 3, the subfield converter 120 divides one frame of the input image into five subfields SF1 to SF5. Further, the format converter 131 displays all lines for SF2, SF4 and SF5 for the divided SF1 to SF5, while thinning lines for SF1 and SF3 (for example, thinning odd or even lines). ) To convert the format. In this way, it is possible to select either all line display or line thinning display for each SF, and mix all line display SF and thinning display SF.

  As an example of the mixing method, the number of all line displays SF and the number of thinning displays SF are fixed to a predetermined number (in the case of FIG. 3, three all line displays and two thinning displays) The predicted power values for all combinations of all line display SF and thinning line display SF are calculated, and the combination that minimizes the value is selected. Thereby, the power saving effect can be enhanced while maintaining the image quality to some extent. Note that the number of times of switching between light emission and non-light emission in each SF can be used as the predicted power value.

  FIG. 4 is a subfield conversion table used by the subfield converter 120 to convert a video signal into SF data. Here, the subfield conversion table is shown when the number of SFs is 5 and the weighting factor is a power of 2. A conversion formula may be used instead of the conversion table.

  FIG. 5 is an explanatory diagram of the SF format conversion method performed by the format converter 131.

As shown in FIG. 5, all combinations of all line display SF and thinning display SF are generated for SF1 to SF5 converted by the subfield converter 120 (I), and all SFs are displayed for all combinations. A predicted power value predicted to be used is calculated, and a combination of SFs having the minimum value is selected (II). Thereafter, format conversion is performed on the selected combination of SFs (III).

(Embodiment 2)
FIG. 6 is a block diagram showing the configuration of the PDP in Embodiment 2 of the present invention.

  In FIG. 6, the vertical synchronization frequency detector 161 detects the vertical synchronization frequency from the input vertical synchronization signal (VD) and horizontal synchronization signal (HD), calculates the frequency component of the frame image, and sends it to the format converter 132. Output.

  The subfield generation device 102 according to the second embodiment of the present invention switches the combination of the all-line display SF and the thinning display SF on the time axis. As a switching method, after fixing the total line display SF number and the thinning display SF number in advance, using fixed switching so that the combination of the full line display SF and the thinning display SF appears evenly on the time axis, Alternatively, random switching that randomly changes the combination of all line display SF and thinned line display SF for each frame is used. Note that the random switching has an advantage that it is difficult for the user to feel the periodicity of the thinning display compared to the fixed switching.

  FIG. 7 is a block diagram showing the configuration of the format converter 132.

  As shown in FIG. 7, the selection controller 1321 controls the selector 1322 corresponding to each of the SF1 to SF5 based on the vertical synchronization frequency output from the vertical synchronization frequency detector 161, and all the lines for each SF1 to SF5. Switching between display and thinning display is performed on the time axis, drive information corresponding to the switching and SF1 ′ to SF5 ′ whose format has been converted are output to the PDP unit 200, and a frame image is displayed.

(Embodiment 3)
FIG. 8 is a block diagram showing the configuration of the PDP according to Embodiment 3 of the present invention.

  As shown in FIG. 8, in addition to the inverse gamma corrector 110, the subfield converter 120, the format converter 133, and the subfield processor 140, the subfield generation device 103 includes a frequency determiner 162, an APL determiner 163, A subfield switching number determination unit 164 and a write power determination unit 165 are provided.

  The frequency determiner 162 and the APL determiner 163 are a high-frequency component (hereinafter abbreviated as “HPF”) and an average video signal for the corrected video signal output from the inverse gamma corrector 110, respectively. A level (Average Picture Level) (hereinafter abbreviated as “APL”) is calculated, and information (hereinafter abbreviated as “SF information”) for identifying the line thinning SF based on the calculated HPF and APL is generated. The data is output to the format converter 133.

  In addition, the subfield switching number determination unit 164 and the writing power determination unit 165 are each based on the number of switching of light emission / non-light emission of each SF and the number of switching times for each SF output from the subfield converter 120. The SF write power is calculated, and SF information based on the calculated write power is output to the format converter 133.

  The format converter 133 displays a thinning line based on the SF information output from the frequency determiner 162 and the APL determiner 163 and the SF information output from the subfield switching frequency determiner 164 and the write power determiner 165. The target SF is determined and line thinning processing is performed. SFs that can be thinned line display targets include SFs for frame images that have little effect on image quality due to thinned display due to low or bright frequencies, high frequency of switching between light emission and non-light emission, or high drive power when writing image frames Therefore, SF with a high power saving effect by thinning display can be used.

  FIG. 9 is an explanatory diagram of SF information output from the frequency determiner 162.

  As shown in FIG. 9, the frequency determiner 162 includes a frequency calculator 1621 and a format determiner 1622.

  The frequency calculator 1621 has 3 × 3 pixels centered on the target pixel C with respect to the frame A that is the corrected video signal output from the inverse gamma corrector 110 (the size of the frequency calculation filter of the frequency calculator 1621). The block B is extracted, and the HPF at the target pixel C is calculated. The frequency calculator 1621 calculates the sum of HPFs for each pixel in frame A, and outputs the sum to the format determiner 1622 as HPF of frame A.

  The format determiner 1622 generates SF information based on the HPF of frame A output from the frequency calculator 1621 and outputs the SF information to the format converter 133.

  As shown in FIG. 9, the format determiner 1622 generates SF information having a larger value as the HPF value of the frame A is smaller. Here, the value of the SF information indicates the SF to be thinned out. For example, when the value of the SF information is 7, it indicates that SF1 to SF3 become the line thinning SF.

  FIG. 10 is an explanatory diagram of the SF information output from the APL determination unit 163.

  As shown in FIG. 10, the APL determiner 163 includes an APL calculator 1631 and a format determiner 1632.

  The APL calculator 1631 calculates the APL for the frame A, which is the corrected video signal output from the inverse gamma corrector 110, and outputs the APL to the format determiner 1632.

  The format determiner 1632 generates SF information related to line thinning based on the APL of frame A output from the APL calculator 1631 and outputs the SF information to the format converter 133.

  As shown in FIG. 10, the format determiner 1632 generates SF information having a larger value as the APL value of the frame A is larger. Here, the value of the SF information indicates the SF to be thinned. For example, when the value of the SF information is 3, it indicates that SF1 to SF2 are the line thinning SF.

  FIG. 11 is an explanatory diagram of the SF information output from the subfield switching number determination unit 164.

  As shown in FIG. 11, the subfield switching number determination unit 164 includes a switching number calculation unit A1641, a switching number calculation unit B1642, a subtraction unit 1643, and a format determination unit 1644.

  SF1 to SF5 are input to the switching number calculator A1641 and the switching number calculator B1642, and the switching number calculator A1641 counts the number of switching of lighting / non-lighting in the data writing direction for all lines of SF, and the switching number The calculator B 1642 counts the number of times of switching for the thinned line obtained by thinning the SF every other line.

  The subtraction unit 1643 calculates a difference value between the switching times counted by the switching number calculator A1641 and the switching number calculator B1642. Furthermore, a weighted difference value obtained by multiplying the difference value calculated by the subtractor 1643 by a weighting factor corresponding to SF1 to SF5 is output to the format determiner 1644.

  The format determiner 1644 outputs SF information (for example, SF information = 1 + 4 + 16 = 21 when SF1, SF3, and SF5 are used as line thinning SF) based on the input weighted difference value. Since the SF with a larger weighted difference value has a larger power consumption difference between the case where the SF is displayed in all lines and the line thinned-out display, the format determiner 1644 corresponds to a predetermined number from the largest weighted difference value. SF is selected as line thinning SF.

  FIG. 12 is an explanatory diagram of the SF information output from the write power determiner 165.

  As shown in FIG. 12, the write power determination unit 165 includes a switching number calculation unit C1651, a total calculation unit 1652, and a format determination unit 1653.

  The switching number calculator C1651 counts the number of switching of lighting / non-lighting in the data writing direction for each column for all lines of SF.

  The total calculator 1652 calculates the total power, which is the sum of the driving powers of all SFs, based on the number of switching times of each SF counted by the switching number calculator C1651.

  The format determiner 1653 outputs SF information that identifies the line decimation SF based on the total power calculated by the sum calculator 1652. As shown in FIG. 12, line thinning is not performed for all SFs until the total power exceeds a predetermined value (the SF information to be output is 0), but if the total power exceeds the predetermined value, the total power value is large. A larger value of SF information is generated.

  FIG. 13 is an explanatory diagram of the SF format conversion method performed by the format converter 133.

  As shown in FIG. 13, the format converter 133 includes a selection signal synthesizer 1331 and a selector 1332.

  The selection signal synthesizer 1331 includes SF information (SF information 1) output from the frequency determiner 162, SF information (SF information 2) output from the APL determiner 163, and SF information (SF information 2) output from the subfield switching frequency determiner 164. The logical sum of the SF information 3) and the SF information (SF information 4) output from the write power determiner 165 is calculated for each SF and is output to the selector 1322 as synthesized SF information.

  Based on the synthesized SF information output from the frequency determiner 162, the selector 1322 converts the SF1 ′ to SF5 ′, which is either the full line display SF or the line thinning SF of each of the SF1 to SF5, into the subfield processor 140. Output to.

  With such a configuration, a plurality of factors (SF information 1 to SF information 4) can be considered in order to determine whether line thinning is required for each SF.

  In the third embodiment of the present invention, a case has been described in which a plurality of factors are considered in order to determine whether line thinning is necessary, but the factors to be considered and the number thereof can be arbitrarily determined. (For example, the determination may be made only with the SF information 2 output from the APL determination unit 163).

(Embodiment 4)
FIG. 14 is a block diagram showing the configuration of the PDP in Embodiment 4 of the present invention.

  As shown in FIG. 14, the subfield generation device 104 includes a thinning line detector 166 in addition to the inverse gamma corrector 110, the subfield converter 120, the format converter 134, and the subfield processor 140.

  As shown in FIG. 15, the subfield generation device 104 according to the fourth embodiment of the present invention compresses by thinning out a line group in a low frequency region in the vertical direction within one frame, thereby maintaining power quality and maintaining power consumption. Is reduced.

  FIG. 16 is an explanatory diagram of thinning line information output by the thinning line detector 166.

  As shown in FIG. 16, the thinning line detector 166 includes a line frequency calculator 1661 and a thinning line determination unit 1662.

  The line frequency calculator 1661 is a 3 × 3 pixel centered on the target pixel C with respect to the frame A that is the corrected video signal output from the inverse gamma corrector 110 (the frequency calculation filter of the line frequency calculator 1661). The block B corresponding to the size is extracted, and the HPF at the target pixel C is calculated. Further, the line frequency calculator 1661 calculates the HPF calculated for the target pixel C for each line of the frame A and outputs the sum to the thinned line determiner 1662 as a line HPF.

  Based on the line HPF output from the line frequency calculator 1661, the thinning line determination unit 1662 generates thinning line information regarding whether to thin out the line for each line, and outputs the thinning line information to the format converter 134.

  As shown in FIG. 16, the thinning line information is 1 when the line HPF is equal to or smaller than a predetermined value T (low frequency line) (indicating that the line is a thinning target line), and the line HPF is equal to or larger than the predetermined value T. In this case, it is 0 (indicating that the line is not a thinning target line).

  FIG. 17 is an explanatory diagram of a format conversion method performed by the format converter 134.

  The format converter 134 includes a display line number extractor 1341 and a line thinning processor 1342.

  The display line number extractor 1341 extracts the number of the line to be displayed (the line not to be thinned out) as the display line number based on the thinned line information output from the thinned line detector 166 and outputs it to the line thinning processor 1342. The display line number is extracted from the thinned-out line information that is a binary sequence of 0 and 1, with the line number corresponding to 0 as the thinned-out line information and the first 1 in the partial sequence that is followed by 1 as the thinned-out line information. Extract the corresponding line number. For example, when the thinning line information is 11110000, line numbers 1, 5, 6, 7, and 8 are extracted as display line numbers.

  The line thinning-out processor 1342 drives SF1 ′ to SF5 ′ obtained by thinning out other lines while leaving only the lines of the display line numbers output from the display line number extractor 1341 for all SF1 to SF5. At the same time, it is output to the subfield processor 140.

(Embodiment 5)
FIG. 18 is a block diagram showing a configuration of a stereoscopic display PDP according to Embodiment 5 of the present invention.

  The stereoscopic display PDP according to the fifth embodiment of the present invention is based on the configuration of the PDP according to the fourth embodiment of the present invention. Further, the subfield generation device 105 is for L indicating the line thinning display SF for the L image frame. A line thinning SF table 167 and an R line thinning SF table 168 indicating line thinning display SF for the R image frame are provided.

  The L line thinning-out SF table 167 and the R line thinning-out SF table 168 are used in the case where one of the corresponding L image SF and R image SF is a line thinning SF, and the other is an all-line display SF, and the image quality of the stereoscopic image frame. It has been created to compensate.

  Further, the subfield generation device 105 converts the line thinning display SF into the L line thinning SF table 167 or the R use based on the L / R image ID indicating whether the input video signal is an L image or an R image. An SF selector 169 that acquires from the line thinning SF table 168 and outputs it to the format converter 135 is provided.

  With such a configuration, when one of the corresponding L image and R image SF of the stereoscopic image is a line thinning SF, the other is always a full line display SF, and the stereoscopic driving power is reduced while maintaining the image quality. Display can be made.

  In FIG. 19, when SFL2, SFL3, and SFL4 of the L image are line thinning SF and SFL1 and SFL5 are all line display SF, SFR2, SFR3, and SFR4 of R image are all line display SF, and SFR1 and SFR5 are As the line thinning SF, the corresponding L image and R image SF are subjected to format conversion so as to complement each other.

  In the first to fifth embodiments of the present invention, the method of line thinning when data is written in the vertical direction has been described. However, column thinning when data is written in the horizontal direction or diagonal when data is written in the diagonal direction. The same method can be applied to the line thinning.

  INDUSTRIAL APPLICABILITY The subfield generation device and the subfield generation method of the present invention can be applied to an image display device for the purpose of reducing the subfield drive power while maintaining the image quality.

101, 102, 103, 104, 105 Subfield generator 110 Inverse gamma corrector 120 Subfield converter 131, 132, 133, 134, 135 Format converter 140 Subfield processor 161 Vertical synchronization frequency detector 162 Frequency determiner 163 APL determiner 164 Subfield switching frequency determiner 165 Write power determiner 166 Thinning line detector 167 L line thinning SF table 168 R line thinning SF table 169 SF selector 200 PDP unit 210 PDP
220 Scan / Maintenance / Erase Drive Circuit 230 Data Drive Circuit 1321 Selection Controller 1322, 1332 Selector 1331 Selection Signal Synthesizer 1341 Display Line Number Extractor 1342 Line Decimator 1621 Frequency Calculator 1622, 1632, 1644, 1653 Format Determination 1631 APL calculator 1641 Switching frequency calculator A
1642 Switching frequency calculator B
1643 Subtractor 1651 Switching frequency calculator C
1652 Sum total calculator 1661 Line frequency calculator 1662 Thinned line determiner

Claims (18)

Frame dividing means for dividing the frame image into N (N: positive integer) subfields;
A frequency component calculating means for determining a frequency component of the frame image;
Line thinning determination means for determining that thinning is performed for all subfields when the frequency component obtained by the frequency component calculation means does not exceed a predetermined frequency;
A subfield generation apparatus comprising: a line thinning unit that performs line thinning on a subfield that has been determined to be thinned by the line thinning determination unit. Frame dividing means for dividing the frame image into N (N: positive integer) subfields;
Switching number counting means for counting the number of switching of lighting / non-lighting in the data writing direction in the subfield,
Line thinning determination means for determining that thinning is performed for a subfield whose switching number counted by the switching number counting means is equal to or greater than a predetermined number;
A subfield generation apparatus comprising: a line thinning unit that performs line thinning on a subfield that has been determined to be thinned by the line thinning determination unit. Frame dividing means for dividing the frame image into N (N: positive integer) subfields;
Luminance calculation means for calculating the luminance of the frame image;
Line thinning determination means for determining that thinning is performed for all subfields when the luminance calculated by the luminance calculation means is equal to or higher than a predetermined luminance;
A subfield generation apparatus comprising: a line thinning unit that performs line thinning on a subfield that has been determined to be thinned by the line thinning determination unit. Frame dividing means for dividing the frame image into N (N: positive integer) subfields;
A predicted power value calculating means for calculating a predicted power value predicted to be used when displaying the subfield;
Line thinning determination means for determining that thinning is performed for subfields in which the power predicted value calculated by the power predicted value calculation means is equal to or greater than a predetermined power value;
A subfield generation apparatus comprising: a line thinning unit that performs line thinning on a subfield that has been determined to be thinned by the line thinning determination unit. Frame dividing means for dividing the frame image into N (N: positive integer) subfields;
Combination generating means for generating all combinations of subfields that perform thinning and subfields that do not perform thinning for the plurality of subfields;
A power predicted value sum calculating means for calculating a sum of power predicted values predicted to be used when displaying the plurality of subfields for all the combinations generated by the combination generating means;
Line thinning determination means for determining a subfield to be thinned based on the combination that minimizes the total power predicted value calculated by the power predicted value total calculation means;
A subfield generation apparatus comprising: a line thinning unit that performs line thinning on a subfield that has been determined to be thinned by the line thinning determination unit. Frame dividing means for dividing the frame image into N (N: positive integer) subfields;
Line thinning determination means for determining a subfield to be thinned out so that a combination of subfields to be thinned and subfields to be thinned is different between successive frame images;
A subfield generation apparatus comprising: a line thinning unit that performs line thinning on a subfield that has been determined to be thinned by the line thinning determination unit. The line thinning means is
The subfield generation device according to any one of claims 1 to 6, wherein line thinning is performed every other line. Frame dividing means for dividing the frame image into N (N: positive integer) subfields;
A line that is determined to be subjected to line decimation in the subfield when the frequency component calculated for each line is equal to or lower than a predetermined frequency for the subfield divided by the frame dividing means continues for a predetermined number of lines or more. Thinning determination means;
For the subfield that has been determined to perform line thinning by the line thinning determination means, a low frequency region in which lines whose frequency components calculated for each line are equal to or lower than the predetermined frequency continues for the predetermined number of lines or more is specified. A subfield generation device comprising: line thinning means for thinning lines other than the head line in the low frequency region. Frame dividing means for dividing the left-eye frame image into N (N: positive integer) left-eye subfields and the right-eye frame image into N right-eye subfields;
When the Nth left-eye subfield and the N right-eye subfields divided by the frame dividing means are thinned, the Kth (K: integer between 1 and N) left-eye subfields is thinned out. If it is determined that the Kth right-eye subfield is not thinned and it is determined that the Lth (L: integer between 1 and N) right-eye subfields is thinned Includes a line thinning determination means for determining that the Lth left-eye subfield is not thinned,
A subfield generation apparatus comprising: a line thinning unit that performs line thinning on a left-eye subfield and a right-eye subfield that have been determined to be thinned by the line thinning determination unit. A frame dividing step of dividing the frame image into N (N: positive integer) subfields;
A frequency component calculating step for obtaining a frequency component of the frame image;
A line thinning determination step for determining that thinning is performed for all subfields when the frequency component obtained in the frequency component calculation step does not exceed a predetermined frequency;
A subfield generation method comprising: a line thinning step that performs line thinning on the subfield that has been determined to perform line thinning in the line thinning determination step. A frame dividing step of dividing the frame image into N (N: positive integer) subfields;
A switching number counting step for counting the number of switching of lighting / non-lighting in the data writing direction in the subfield,
A line thinning determination step for determining that thinning is performed for a subfield in which the switching number counted in the switching number counting step is equal to or greater than a predetermined number;
A subfield generation method comprising: a line thinning step that performs line thinning on the subfield that has been determined to perform line thinning in the line thinning determination step. A frame dividing step of dividing the frame image into N (N: positive integer) subfields;
A luminance calculation step for determining the luminance of the frame image;
A line thinning determination step for determining that thinning is performed for all subfields when the luminance obtained in the luminance calculation step is equal to or higher than a predetermined luminance;
A subfield generation method comprising: a line thinning step that performs line thinning on the subfield that has been determined to perform line thinning in the line thinning determination step. A frame dividing step of dividing the frame image into N (N: positive integer) subfields;
A predicted power value calculating step for calculating a predicted power value predicted to be used when displaying the subfield;
A line thinning determination step for determining that thinning is performed for a subfield in which the power predicted value calculated in the power predicted value calculation step is equal to or greater than a predetermined power value;
A subfield generation method comprising: a line thinning step that performs line thinning on the subfield that has been determined to perform line thinning in the line thinning determination step. A frame dividing step of dividing the frame image into N (N: positive integer) subfields;
A combination generation step of generating all combinations of subfields that are thinned out and subfields that are not thinned out for the plurality of subfields;
A power predicted value sum calculating step for calculating a sum of power predicted values predicted to be used when displaying the plurality of subfields for all the combinations generated in the combination generating step;
A line decimation determining step for determining a subfield for decimation based on the combination that minimizes the sum of the power predicted values calculated in the power predicted value total calculating step;
A subfield generation method comprising: a line thinning step that performs line thinning on the subfield that has been determined to perform line thinning in the line thinning determination step. A frame dividing step of dividing the frame image into N (N: positive integer) subfields;
A line decimation determining step for determining a subfield for decimation so that a combination of subfields for decimation and subfields for which decimation is not performed differs between successive frame images;
A subfield generation method comprising: a line thinning step that performs line thinning on the subfield that has been determined to perform line thinning in the line thinning determination step. The line thinning step comprises:
16. The subfield generation method according to claim 10, wherein line thinning is performed every other line. A frame dividing step of dividing the frame image into N (N: positive integer) subfields;
A line that is determined to perform line thinning of the subfield when the frequency component calculated for each line is equal to or lower than a predetermined frequency for the subfield divided in the frame dividing step continues for a predetermined number of lines or more. A decimation determination step;
For the subfield that has been determined to perform line thinning in the line thinning determination step, a low frequency region in which lines whose frequency components calculated for each line are equal to or lower than the predetermined frequency continues for the predetermined number of lines or more is specified. A sub-field generation method comprising: a line thinning-out step for thinning out lines other than the head line in the low frequency region. A frame dividing step of dividing the left-eye frame image into N (N: positive integer) left-eye subfields and the right-eye frame image into N right-eye subfields;
When the Nth left-eye subfield and the N right-eye subfields divided in the frame division step are thinned, the Kth (K: integer between 1 and N) left-eye subfields is thinned out. If it is determined that the Kth right-eye subfield is not thinned and it is determined that the Lth (L: integer between 1 and N) right-eye subfields is thinned Includes a line thinning determination step for determining that the Lth left-eye subfield is not thinned, and
A subfield generation method comprising: a line thinning step for performing line thinning on the left-eye subfield and the right-eye subfield that are determined to be thinned in the line thinning determination step.

Images