# US 8,274,869 B2 · Method for detecting blank area of power calibration area > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,274,869 B2 - Document ID: US8274869B2 - Status: Granted - Kind: B2 - Application number: 12/474,824 - Filed: 2009-05-29 - Published: 2010-06-03 - Granted: 2012-09-25 - Earliest claimed: 2008-11-28 - Assignees: Sunplus Technology Co., Ltd. - Inventors: Yao Wen Liu; Chung Yi Wang - Web page: https://patentgrep.com/patent/US8274869B2 ## CPC - G11B 7/1267: Power calibration - G11B 7/00736: {Auxiliary data, e.g. lead-in, lead-out, Power Calibration Area [PCA], Burst Cutting Area [BCA], control information (sector headers or adresses in prepits G11B7/00745; address data in track wobble G11B7/24082)} - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract The present invention relates to a method for detecting a blank area of a power calibration area. The method includes the steps of: selecting a recording test area in the power calibration area; writing the recording test area with multiple stages of normal power and detecting power; forming multiple normal blocks and detecting blocks, wherein each of the detecting blocks includes one unit of unrecorded block and one unit of recorded block; and reading information from the unrecorded blocks of the detecting blocks and thus determining whether the unrecorded blocks of the detecting blocks are blank or not. Once all the unrecorded blocks of the detecting blocks are determined to be blank, it represents that the selected recording test area is totally blank. ## Claims ### Claim 1 A method for detecting a blank area of a power calibration area, the method comprising the steps of: selecting a recording test area in the power calibration area of an optical disc; writing the recording test area and thus forming a plurality of normal blocks and a plurality of detecting blocks, wherein each of the detecting blocks comprises one unit of an unrecorded block and one unit of a recorded block; determining whether the unrecorded blocks of the detecting blocks are blank; repeating the above-mentioned steps or entering an error recovery procedure if the unrecorded blocks of the detecting blocks are not totally blank; and determining the recording test area to be blank if the unrecorded blocks of the detecting blocks are totally blank. ### Claim 2 (depends on 1) The method according to claim 1, wherein the step of writing the recording test area comprises: writing the recording test area with a power composed of multiple stages of normal power and multiple stages of detecting power, wherein each stage of the normal power is composed of two units of recording power, and the normal block is formed when writing the recording test area with the normal power. ### Claim 3 (depends on 2) The method according to claim 2, wherein the step of forming the detecting blocks comprises: setting each stage of detecting power to be composed of one unit of reading power and one unit of recording power; and performing writing using the detecting power to form the detecting block having one unit of a recorded block and one unit of an unrecorded block. ### Claim 4 (depends on 2) The method according to claim 2, wherein the step of forming the detecting blocks comprises: setting one unit of each stage of detecting power to be the recording power, and the other unit to be insufficient to form a pit or a mark by reducing an output power of each of analog channels when a total output power is applied to the recording test area so that the detecting block having one unit of a recorded block and one unit of an unrecorded block is formed. ### Claim 5 (depends on 2) The method according to claim 2, wherein the step of forming the detecting blocks comprises: deviating a focus position or an optical head tilt such that a pit or a mark cannot be sufficiently formed on the optical disc when one of the units of the detecting powers is applied while keeping the focus position and the optical head tilt normal when the other unit of the detecting power is applied in order to form the detecting block having one unit of recorded block and one unit of unrecorded block. ### Claim 6 (depends on 1) The method according to claim 1, wherein the step of determining whether the unrecorded blocks of the detecting blocks are blank comprises: reading information from the detecting blocks and comparing the information with a threshold value; and determining the unrecorded blocks of the detecting blocks to be not blank when at least one piece of the information is smaller than the threshold value, and determining the unrecorded blocks of the detecting blocks to be blank when the information is greater than the threshold value. ### Claim 7 (depends on 6) The method according to claim 6, wherein the information comprises: a radio frequency signal, a peak hold value, a bottom hold value, a jitter value, an error rate value, a recorded flag of a blank detection circuit or the combination of the above. ### Claim 8 (depends on 1) The method according to claim 1, further comprising the step of: using signals read from the normal blocks and the recorded blocks of the detecting blocks as a basis for calculating an optimum power. ### Claim 9 (depends on 8) The method according to claim 8, wherein the signals comprise a radio frequency signal. ### Claim 10 A method for detecting a blank area of a power calibration area, the method comprising: selecting a recording test area in the power calibration area of an optical disc; applying multiple stages of normal power and multiple stages of detecting power to the recording test area and thus forming a plurality of normal blocks and a plurality of detecting blocks, wherein each detecting block comprises one unit of an unrecorded block and one unit of a recorded block, and the plurality of normal blocks are formed by applying the multiple stages of normal power having the same recording power and by changing a focus position each time; determining whether the unrecorded blocks of the detecting blocks are blank; repeating the above steps or entering an error recovery procedure if the unrecorded blocks of the detecting blocks are not totally blank; and determining the selected recording test area to be blank if the unrecorded blocks of the detecting blocks are totally blank. ### Claim 11 (depends on 10) The method according to claim 10, wherein the step of forming the detecting blocks comprises: setting each stage of detecting powers to be composed of one unit of reading power and one unit of recording power; and performing recording using the detecting power to form the detecting blocks having the recorded block and the unrecorded block. ### Claim 12 (depends on 10) The method according to claim 10, wherein the step of forming the detecting blocks comprises: setting one unit of each stage of detecting power to be the recording power, and the other unit power to be insufficient to form a pit or a mark by reducing an output power of each of analog channels when a total output power is applied to the recording test area so that the detecting blocks having the recorded block and the unrecorded block are formed. ### Claim 13 (depends on 11) The method according to claim 11, wherein the step of forming the detecting blocks comprises: deviating a focus position or an optical head tilt such that a pit or a mark cannot be sufficiently formed on the optical disc when one of the units of the detecting power is applied while keeping the focus position and the optical head tilt normal when the other unit of the detecting power is applied in order to form the detecting block having the recorded block and the unrecorded block. ### Claim 14 (depends on 10) The method according to claim 10, wherein the step of determining whether the unrecorded blocks of the detecting blocks are blank comprises: reading back information from the detecting blocks and comparing the information with a threshold value; and determining the unrecorded blocks of the detecting blocks to be not blank when at least one piece of the information is smaller than the threshold value, and judging the unrecorded blocks of the detecting blocks to be blank when the information is greater than the threshold value. ### Claim 15 (depends on 14) The method according to claim 14, wherein the information comprises: a radio frequency signal, a peak hold value, a bottom hold value, a jitter value, an error rate value, a recorded flag of a blank detection circuit or the combination thereof. ### Claim 16 (depends on 10) The method according to claim 10, further comprising the step of: using signals read from the normal blocks and the recorded blocks of the detecting blocks as a basis for calculating an optimum focus position. ### Claim 17 (depends on 16) The method according to claim 16, wherein the signals comprise a radio frequency signal.