# US 7,609,243 B2 · Liquid crystal display device, liquid crystal display control method, program thereof, and recording medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,243 B2 - Document ID: US7609243B2 - Status: Granted - Kind: B2 - Application number: 10/541,093 - Filed: 2004-04-08 - Published: 2006-08-10 - Granted: 2009-10-27 - Earliest claimed: 2003-11-20 - Assignees: Sharp Kabushiki Kaisha - Inventors: Toshiyuki Fujine; Takashi Yoshii - Web page: https://patentgrep.com/patent/US7609243B2 ## CPC - G09G 3/3611: {Control of matrices with row and column drivers} - G09G 2310/0229: De-interlacing - G09G 2320/0247: Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes - G09G 2320/0252: Improving the response speed - G09G 2320/041: Temperature compensation - G09G 2340/16: Determination of a pixel data signal depending on the signal applied in the previous frame - G09G 2360/18: Use of a frame buffer in a display terminal, inclusive of the display panel - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) ## Abstract When a video signal type detecting section detects an interlace signal, an I/P conversion section subjects the interlace signal to I/P conversion, and the signal is supplied to an enhancing conversion section. In the enhancing conversion section, the image data is subjected to enhancing conversion, so that optical characteristics of a liquid crystal display panel is corrected. On this occasion, the degradation of the quality of a reproduced image due to the enhancement of unwanted changes (false signal), by causing the degree of the enhancing conversion of the image data having been subjected to the I/P conversion to be lower than the degree of the enhanced conversion of the image data inputted as the progressive signal. As a result, the enhancing conversion of the input image data is performed in such a manner as to correct the optical response characteristics of the liquid crystal panel, so that it is possible to restrain the enhancement of unwanted changes occurring at the outline of the image on the occasion of subjecting the interlace image signal to the I/P conversion, and hence high-quality image reproduction is realized. ## Claims ### Claim 1 A liquid crystal display apparatus that corrects optical response characteristics of a liquid crystal display panel, by subjecting image data supplied to the liquid crystal display panel to enhancing conversion at least in accordance with image data of a directly previous vertical period and image data of a current vertical period, the liquid crystal display apparatus comprising: signal type detection section for detecting whether a signal type of input image data is a progressive signal or an interlace signal; I/P conversion section for converting an interlace signal to image data that is a quasi-progressive signal, if the input image data is an interlace signal; and enhancing conversion section for subjecting the image data to overshoot enhancing conversion, in a direction of gray level transition, when the enhancing conversion section subjects the quasi-progressive signal to the overshoot enhancing conversion in accordance with a result of detection performed by the signal type detection section, the enhancing conversion section performs such enhancing conversion that when the input image data is an interlace signal, the degree of the enhancing conversion of the image data is lower than when the input image data is a progressive signal. ### Claim 2 (depends on 1) The liquid crystal display apparatus as defined in claim 1, further comprising a table memory that stores an enhancing conversion parameter specified by the image data of the current vertical period and the image data of the directly previous vertical period, the enhancing conversion means including: an operation section that performs an operation on the image data so as to enhance the image data, using the enhancing conversion parameter; and a multiplying section that multiplies output data of the operation section by a coefficient corresponding to the result of the detection by the signal type detection means. ### Claim 3 (depends on 2) The liquid crystal display apparatus as defined in claim 2, wherein, the coefficient in a case where the input image data is an interlace signal is smaller than the coefficient in a case where the input image data is a progressive signal. ### Claim 4 (depends on 1) The liquid crystal display apparatus as defined in claim 1, further comprising: a first table memory that stores an enhancing conversion parameter specified by the image data of the current vertical period and the image data of the directly previous vertical period, the first table memory being referred to when the input image data is a progressive signal; and a second table memory that stores an enhancing conversion parameter specified by the image data of the current vertical period and the image data of the directly previous vertical period, the second table memory being referred to when the input image data is an interlace signal, the enhancing conversion means including an operation section that performs, using the enhancing conversion parameter read out from the first or second table memory in accordance with the result of the detection by the signal type detection means, an operation on the image data so as to enhance the image data. ### Claim 5 (depends on 4) The liquid crystal display apparatus as defined in claim 4, wherein, the enhancing conversion parameter in a case where the input image data is a progressive signal is larger than the enhancing conversion parameter in a case where the input image data is an interlace signal. ### Claim 6 (depends on 1) The liquid crystal display apparatus as defined in claim 1, further comprising: temperature detection means for detecting a temperature in the liquid crystal display apparatus, the enhancing conversion means varying the degree of the enhancing conversion of the image data, in accordance with a result of detection by the temperature detection means. ### Claim 7 (depends on 6) The liquid crystal display apparatus as defined in claim 6, further comprising a table memory that stores an enhancing conversion parameter specified by the image data of the directly previous vertical period and the image data of the current vertical period, the enhancing conversion means including: an operation section that performs an operation on the image data so as to enhance the image data, using the enhancing conversion parameter; and a multiplying section that multiplies output data of the operation section by a coefficient corresponding to the result of the detection by the signal type detection means and the result of the detection by the temperature detection means. ### Claim 8 (depends on 6) The liquid crystal display apparatus as defined in claim 6, further comprising: a first table memory that stores an enhancing conversion parameter specified by the image data of the current vertical period and the image data of the directly previous vertical period, the first table memory being referred to when the input image data is a progressive signal; and a second table memory that stores an enhancing conversion parameter specified by the image data of the current vertical period and the image data of the directly previous vertical period, the second table memory being referred to when the input image data is an interlace signal, the enhancing conversion means including: an operation section that performs, using the enhancing conversion parameter read out from the first or second table memory in accordance with the result of the detection by the signal type detection means, an operation on the image data so as to enhance the image data; and a multiplying section that multiplies output data of the operation section by a coefficient corresponding to the result of the detection by the temperature detection means. ### Claim 9 (depends on 6) The liquid crystal display apparatus as defined in claim 6, further comprising: first table memories that store enhancing conversion parameters that correspond to respective temperatures in the liquid crystal display apparatus and are specified by the image data of the current vertical period and the image data of the directly previous vertical period, the first table memories being referred to when the input image data is a progressive signal; and second table memories that store enhancing conversion parameters that correspond to respective temperatures in the liquid crystal display apparatus and are specified by the image data of the current vertical period and the image data of the directly previous vertical period, the second table memories being referred to when the input image data is an interlace signal, the enhancing conversion means including an operation section that performs, using the enhancing conversion parameter read out from the first or second table memory in accordance with the result of the detection by the signal type detection means and the result of the detection by the temperature detection means, an operation on the image data so as to enhance the image data. ### Claim 10 (depends on 6) The liquid crystal display apparatus as defined in claim 6, further comprising a table memory that stores enhancing conversion parameters that correspond to respective temperatures in the liquid crystal display apparatus and are specified by the image data of the current vertical period and the image data of the directly previous vertical period, the enhancing conversion means including an operation section that performs, using the enhancing conversion parameter read out from the table memory, an operation on the image data so as to enhance the image data, in accordance with a result of comparison between (i) a switching temperature determined by the result of the detection by the signal type detection means and (ii) the result of the detection by the temperature detection means. ### Claim 11 (depends on 10) The liquid crystal display apparatus as defined in claim 10, further comprising: a control section that controls switching and selection of the enhancing conversion parameters, the control means including: an operation section that performs, on temperature data detected by the temperature detection means, a predetermined operation corresponding to each signal type of the input image data; a threshold discriminating section that compares the temperature data, which has been subjected to the operation by the operation section, with predetermined threshold temperature data; and a control signal output section that generates a switching control signal with which the enhancing conversion parameters are switched and controlled, in accordance with a result of detection by the threshold discriminating section. ### Claim 12 (depends on 10) The liquid crystal display apparatus as defined in claim 10, further comprising control means that controls switching and selection of the enhancing conversion parameters, the control means including: a threshold discriminating section that compares the temperature data detected by the temperature detection means with predetermined temperature data corresponding to each signal type of the input image data; and a control signal output section that generates a switching control signal with which the enhancing conversion parameters are switched and controlled in accordance with a result of detection by the threshold discriminating section. ### Claim 13 (depends on 1) The liquid crystal display apparatus as defined in claim 1, further comprising: temperature detection section for detecting a temperature in the liquid crystal display apparatus, and table memories each storing an enhancing conversion parameter specified by the image data of the current vertical period and the image data of the directly previous vertical period, at least one of the table memories being referable irrespective of the signal type, and the enhancing conversion section subjecting the image data to the enhancing conversion, referring to one of the table memories which is selected in accordance with a result of detection by the signal type detection section and a result of detection by the temperature detection section, and using the enhancing conversion parameter read out from said selected one of the table memories. ### Claim 14 A liquid crystal display control method for correcting optical response characteristics of a liquid crystal display panel, by subjecting image data supplied to the liquid crystal display panel to enhancing conversion at least in accordance with image data of a directly previous vertical period and image data of a current vertical period, the method comprising the steps of: (i) detecting whether a signal type of input image data is a progressive signal or an interlace signal; (ii) converting the interlace signal to image data that is a quasi-progressive signal, if the input image data is an interlace signal; and (iii) subjecting the image data to overshoot enhancing conversion, in a direction of gray level transition, when subjecting the quasi-progressive signal to the overshoot enhancing conversion in accordance with a result of the detecting, performing enhancing conversion such that when the input image data is an interlace signal, the degree of the enhancing conversion of the image data is lower than when the input image data is a progressive signal. ### Claim 15 (depends on 14) The liquid crystal display control method as defined in claim 14, further comprising the steps of: (iv) referring to a table memory that stores an enhancing conversion parameter specified by the image data of the directly previous vertical period and the image data of the current vertical period; (v) performing an operation on the image data so as to enhance the image data, using the enhancing conversion parameter; and (vi) multiplying output data as a result of the step (v) by a coefficient corresponding to the signal type detected in the step (i). ### Claim 16 (depends on 14) The liquid crystal display control method as defined in claim 14, further comprising the steps of: (iv) referring to a table memory that stores an enhancing conversion parameter specified by the image data of the directly previous vertical period and the image data of the current vertical period, the table memory being referred to in a case where the input image data is a progressive signal; (v) referring to a table memory that stores an enhancing conversion parameter specified by the image data of the directly previous vertical period and the image data of the current vertical period, the table memory being referred to in a case where the input image data is the interlace signal; and performing an operation on the image data so as to enhance the image data, using the enhancing conversion parameter read out from the table memory in accordance with the signal type detected in the step (i). ### Claim 17 (depends on 14) The liquid crystal display control method as defined in claim 14, further comprising the steps of: (iv) detecting a temperature in an apparatus; and (v) varying the degree of the enhancing conversion on the image data, in accordance with the temperature detected in the step (iv). ### Claim 18 (depends on 17) The liquid crystal display control method as defined in claim 17, further comprising the steps of: (vi) referring to a table memory that stores an enhancing conversion parameter specified by the image data of the directly previous vertical period and the image data of the current vertical period; (vii) performing an operation on the image data so as to enhance the image data, using the enhancing conversion parameter; and (viii) multiplying output data as a result of the step (vii) by a coefficient corresponding to the signal type detected in the step (i) and the temperature detected in the step (iv). ### Claim 19 (depends on 17) The liquid crystal display control method as defined in claim 17, further comprising the steps of: (vi) referring to a first table memory that stores an enhancing conversion parameter specified by the image data of the directly previous vertical period and the image data of the current vertical period, the first table memory being referred to in a case where the input image data is a progressive signal; (vii) referring to a second table memory that stores an enhancing conversion parameter specified by the image data of the directly previous vertical period and the image data of the current vertical period, the second table memory being referred to in a case where the input image data is an interlace signal; (viii) performing an operation on the image data so as to enhance the image data, using the enhancing conversion parameter read out from the first or second table memory in accordance with the signal type detected in the step (i); and (ix) multiplying output data as a result of the step (viii) by a coefficient corresponding to each temperature detected in the step (iv). ### Claim 20 (depends on 17) The liquid crystal display control method as defined in claim 17, further comprising the steps of: (vi) referring to first table memories that store enhancing conversion parameters that correspond to respective temperatures in the apparatus and are specified by the image data of the current vertical period and the image data of the directly previous vertical period, the first table memories being referred to in a case where the input image data is a progressive signal; (vii) referring to second table memories that stores enhancing conversion parameters that correspond to respective temperatures in the apparatus and are specified by the image data of the current vertical period and the image data of the directly previous vertical period, the second table memories being referred to in a case where the input image data is an interlace signal; and (viii) in accordance with the signal type detected in the step (i) and the temperature detected in the step (iv), performing an operation on the image data so as to enhance the image data, using the enhancing conversion parameter read out from the first or second table memory. ### Claim 21 (depends on 17) The liquid crystal display control method as defined in claim 17, further comprising the steps of: (vi) referring to table memories that store enhancing conversion parameters that correspond to respective temperatures in the apparatus and are specified by the image data of the directly previous vertical period and the image data of the current vertical period; and (vii) performing an operation on the image data so as to enhance the image data, using the enhancing conversion parameter read out from the table memory with reference to a result of comparison between a switching temperature determined by the signal type detected in the step (i) and the temperature detected in the step (iv). ### Claim 22 (depends on 21) The liquid crystal display control method as defined in claim 21, further comprising the steps of: (viii) performing, on temperature data corresponding to the temperature detected in the step (iv), a predetermined operation corresponding to each signal type of the input image data; (ix) comparing the temperature after being subjected to the predetermined operation with predetermined threshold temperature data; and (x) in accordance with a comparison in the step (ix), generating a switching control signal for switching and controlling the enhancing conversion parameters. ### Claim 23 (depends on 21) The liquid crystal display control method as defined in claim 21, further comprising the steps of: (viii) comparing temperature data corresponding to the temperature detected in the step (iv) with predetermined threshold temperature data corresponding to each signal type of the input image data; and (ix) in accordance with a comparison in the step (viii), generating a switching control signal for switching and controlling the enhancing conversion parameters. ### Claim 24 (depends on 14) The liquid crystal display control method as defined in claim 14, further comprising the step of: (iv) detecting a temperature in a liquid crystal display apparatus, the step (iii) being performed for each of temperatures in the liquid crystal display apparatus, and in the step (iii), one of table memories, each storing an enhancing conversion parameter specified by the image data of the current vertical period and the image data of the directly previous vertical period and at least one of which being referable irrespective of the signal type, being selected in accordance with a result of detection by the signal type detection section and a result of detection by the temperature detection section, and the enhancing conversion being carried out with respect to the image data, using the enhancing conversion parameter read out from said selected one of the table memories. ### Claim 25 A recording medium storing a program for a computer controlling a liquid crystal display apparatus including I/P conversion section that converts an interlace signal to image data of a quasi-progressive signal, in a case where input image data is an interlace signal, the liquid crystal display apparatus correcting optical response characteristics of a liquid crystal display panel by performing overshoot enhancing conversion of the image data in a direction of gray level transition, in accordance with image data of a directly previous vertical period and image data of a current vertical period, in such a manner as to causing the liquid crystal panel to have a transmittance specified by the image data, within a predetermined period of time, the program causing the computer to perform a step of when subjecting the quasi-progressive signal to the overshoot enhancing conversion, in accordance with a result of detection of whether a signal type of input image data is a progressive signal or an interlace signal, performing enhancing conversion such that when the input image data is an interlace signal, the degree of the enhancing conversion of the image data is lower than when the input image data is a progressive signal.