Patent Document

CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority from Korean Patent Application No. 2003-45389 filed Jul. 4, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to address detection and/or correction, and more particularly, to a method of and apparatus for efficiently detecting and/or correcting address information in an optical recording and/or reproducing apparatus. 
   2. Description of the Related Art 
   In an optical recording and/or reproducing apparatus, an address is important information indicating a location on which information is recorded or is to be recorded. Addresses can be broken down into physical addresses that exist even before user data are recorded on a recording medium, and logical addresses that are recorded together with user data when user data are recorded. In addition to address information, additional information may be recorded together on an area where an address is recorded and at this time, an error correction parity for accurately detecting address information/additional information is recorded together. 
     FIG. 1  is a block diagram of a conventional optical recording and/or reproducing apparatus. 
   Referring to  FIG. 1 , reference number  10  indicates a disc, and the optical recording and/or reproducing apparatus comprises a pickup  11 , an automatic laser power control (ALPC) circuit  12 , a radio frequency amplifier (RF-AMP)  13 , a data processor  14 , a host interface (I/F)  15 , a host  16 , a servo processor  17 , a motor and driver  18 , a micom  19 , and an address detector  141  in the data processor  14 . 
   The ALPC  12  controls the quantity of light of the pickup  11  so as to write data on the disc  10  and the RF-AMP  13  amplifies a minute signal picked up by the pickup  11  from the disc  10 . The data processor  14  generates data from the amplified signal, detects a physical address from the generated data, performs writing control for the physical address and logical address, and other operations including synchronization signal detection, insertion, protection, modulation and demodulation, and generates a variety of control signals for the RF-AMP  13  and error correction. In addition, the data processor  14  includes the address detector  141  which detects address and/or additional information of an address area from the generated data, and if there is an error in the detected address and/or additional information, corrects the error, and returns the obtained result whenever address information is needed in the data processor  14 . 
   The host interface  15  interfaces the data processor  14  with the host  16 . The servo processor  17  performs servo control, including control of a variety motors related to the disc  10 , tracking, and focusing. The motor and driver  18  performs functions for driving motors related to rotation of the disc  10 , and the micom  19  controls the operation of the entire system of the optical recording and/or reproducing apparatus. 
     FIG. 2  is an example of the format of an address area on an optical recording medium. 
   Referring to  FIG. 2 , the address area comprises address information, additional information and parity information. Here, in some cases, additional information is recorded based on a specified characteristic with respect to an area of a medium, and in order to find this area, address information should be known. That is, only after address information is known, additional information can be known, and in order to find address information, error correction including additional information should be performed. This lowers the error correction efficiency to the extent that the additional information is needed. 
     FIG. 3  is a flowchart of operations performed in a conventional method for detecting and/or correcting address information, and will now be briefly explained referring to  FIG. 1 . 
   Referring to  FIG. 3 , when the data processor  14  wants to use address information of a disc or additional information in an address area, the data processor  14  detects a synchronization pattern and data corresponding to the address area in operation  31 . Through the detected synchronization pattern, data corresponding to the location of the address area are collected to form the address area data, and then by using the detected value of additional information of the address area without change, an error is detected and/or corrected in operation  32 . It is determined whether or not there is an error in the address area data of the operation  32 , in operation  33 , and if there is no error, the detected address and additional information are used without change in operation  34 . 
   If there is an error in the address area data in the operation  33 , it is determined whether or not the error is corrected in operation  35 , and if the error is corrected, the error-corrected address and additional information are used in operation  36 , and if the error is not corrected, the error is indicated in operation  37 . 
   In an additional information field in an address area, data having a different characteristic depending on an area of a disc is contained. In the related art, however, error correction is performed without considering this characteristic. In particular, even when an additional information field is filled with an already known value, error correction is performed without considering this value. This is because in order to know the value of additional information, a current area should be known. That is, information on the current area is address information, which can be known only after error correction for the address information is performed. In addition, since error correction for address information needs to include the additional information, even though a predetermined value is used as additional information, the value cannot be used unless error correction is performed. Accordingly, in the related art, even though additional information corresponding to a predetermined area of a disc is an already known value, the value cannot be used and this is inefficient in the aspect of error correction. 
   SUMMARY OF THE INVENTION 
   The present invention provides a method and apparatus for efficiently detecting and/or correcting address information by using additional information that can be known in advance among address information in an optical recording and/or reproducing apparatus. 
   The present invention also provides a method and apparatus for efficiently detecting and/or correcting address information by using the characteristic of a medium when there is additional data having a predetermined value with respect to an area of a medium among address area data in an optical recording and/or reproducing apparatus. 
   The present invention also provides a method and apparatus for efficiently detecting and/or correcting address information by using the characteristic of an address that the address increases by predetermined unit. 
   The present invention also provides a method and apparatus of efficiently detecting and/or correcting address information by utilizing part of data of an already known previous address area even though current address information is not known. 
   According to an aspect of the present invention, there is provided a method of detecting address information for an optical recording and/or reproducing apparatus, including: detecting and/or correcting by using the characteristic of a medium when additional data has a specific value with respect to an area of the medium among address area data on the medium, and/or the characteristic of an address that the address increases by specified unit, an error in detected address area data and outputting the result of error detection and/or correction; and providing optimal address information by using the result of the error detection and/or correction. 
   According to another aspect of the present invention, there is provided a method of detecting address information for an optical recording and/or reproducing apparatus, including: detecting address area data containing address and additional information; detecting and/or correcting an error and outputting a first result by using the detected address and additional information without change; replacing only additional information in the detected address data with an already known value for a specified area on an optical recording medium, detecting and/or correcting an error and outputting a second result; and selecting one of the first and second results, according to a specified rule. 
   According to still another aspect of the present invention, there is provided a method of detecting and/or correcting a current address by using previous address values detected continuously, including: detecting current address area data; detecting and/or correcting an error in the entire address information of the detected current address area data without change and outputting a first result; replacing part of the entire address information with a previous address value, detecting and/or correcting an error in the data and outputting a second result; and selecting one of the first and second results by a specified rule. 
   According to yet still another aspect of the present invention, there is provided a method of detecting and/or correcting a current address by using previous address values detected continuously, including: detecting current address area data containing address and additional information; detecting and/or correcting an error in the detected address area data without change and outputting a first result; replacing additional information of the detected address area data with an already known value, detecting and/or correcting an error and outputting a second result; replacing part of the address information with a previous address value, detecting and/or correcting an error by using the address information, and outputting a third result; replacing part of the detected address with a previous address value, replacing additional information with an already known value, and detecting and/or correcting an error by using the address information and additional information and outputting a fourth result; and comparing the first through fourth results, and selecting one of the first through fourth results according to a specified rule. 
   According to a further aspect of the present invention, there is provided an apparatus for detecting an address of an optical recording and/or reproducing apparatus, including: N storage units respectively storing detected address area data regarding a characteristic of a medium when additional data has a specific value with respect to an area of the medium among address area data on the medium, and/or the characteristic of address information that is increased by a specified unit; an error corrector which corrects an error in the outputs of the N storage units storing address area data regarding each characteristic; and a selector which compares error-corrected results according to a specified rule and selects one result from the error-corrected results. 
   According to an additional aspect of the present invention, there is provided an apparatus for detecting an address of an optical recording and/or reproducing apparatus having a data processor, including: N storage units respectively storing detected address area data regarding a the characteristic of a medium when additional data has a specific value with respect to an area of the medium among address area data on the medium, and/or the characteristic of address information that is increased by a specified unit; an error corrector which corrects an error in the outputs of the N storage units storing address area data regarding each characteristic; and a selector which compares error-corrected results according to a specified rule, selects one result from the error-corrected results and provides the result at the request of the data processor. 
   According to an additional aspect of the present invention, there is provided an address detection apparatus for detecting address area data containing address and additional information of an optical recording and/or reproducing apparatus, including: a first storage unit which stores the address and additional information as detected without change; a second storage unit which replaces additional information of the detected address area data with an already known value and stores the address area data; an error corrector which corrects an error in data stored in the first and second storage units and respectively outputs a first result and a second result; and a selector which compares the first and second results according a specified rule and selects one of the first and the second results. 
   According to an additional aspect of the present invention, there is provided an address detection apparatus for detecting a current address of an optical recording and/or reproducing apparatus by using previous address value detected continuously, including: a first storage unit which stores the entire address information of detected current address area data without change; a second storage unit which replaces part of the entire address information with a previous address value and stores the address information; an error corrector which corrects an error in data stored in the first and second storage unit and respectively outputs a first result and a second result; and a comparison and selector which compares the first and second results according to a specified rule and selects one of the first and second results. 
   According to an additional aspect of the present invention, there is provided an address detection apparatus for detecting and/or correcting a current address of an optical recording and/or reproducing apparatus by using previous address values detected continuously, including: a first storage unit which stores current address area data containing address and additional information without change; a second storage unit which replaces additional information in the detected address area data with an already known value and stores the address area data; a third storage unit which replaces part of the address information with a previous address value and stores the address area data; a fourth storage unit which replaces part of the detected address information with a previous address value, replaces additional information with an already known value and stores the address area data; an error corrector which corrects an error in the data stored in the first through fourth storage units and outputs first through fourth results; and a comparison and selector which compares the first through fourth results according to a specified rule and selects one result. 
   Additional and/or other aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following detailed description, taken in conjunction with the accompanying drawings of which: 
       FIG. 1  is a block diagram of a conventional optical recording and/or reproducing apparatus; 
       FIG. 2  is an example of the format of an address area on an optical recording medium; 
       FIG. 3  is a flowchart of a conventional method of detecting and/or correcting address information; 
       FIG. 4  is a detailed block diagram of an apparatus for detecting and/or correcting address information according to an embodiment of the present invention; 
       FIG. 5  is a flowchart of a method for detecting and/or correcting address information according to an embodiment of the present invention; 
       FIGS. 6A and 6B  are a flowchart of a method for detecting and/or correcting address information by replacing part of address area data with already known values; 
       FIG. 7  is an example of the characteristic of address information that is increased by a specified unit; 
       FIG. 8  is a flowchart of a method for detecting and/or correcting address information by using the characteristic of address information shown in  FIG. 7 ; and 
       FIG. 9  is a flowchart of a method for detecting and/or correcting address information by using the characteristic of address information shown in  FIG. 7 . 
   

   DETAILED DESCRIPTION OF EMBODIMENTS 
   Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. 
   Referring to  FIG. 4 , in order to detect or correct an error with considering the characteristic of an address area, N registers for storing the same amount of data as one address area are disposed and store data with considering each characteristic. For example, detected address area data is stored in a first register  41 . 1  without change, after replacing part of the address area with a first characteristic value, is stored in a second register  41 . 2 , and after replacing part of the address area with an (N−1)-th characteristic value, is stored in an N-th register  41 .N. The apparatus also comprises an error corrector  42  for correcting an error in the output of N registers  41 . 1  through  41 .N that store address area data with considering each characteristic, and a selector  43  for comparing error-corrected results by a predetermined rule and selecting one result value. Though not shown in the figure, the apparatus may be built to include a display controller which indicates an error when the selector  43  determines that errors occur in all results of error correction. 
     FIG. 5  is a flowchart of a method of detecting and/or correcting address information according to an embodiment of the present invention. According to the method, in each part area of address areas located in predetermined areas of a medium, a predetermined value is stored and if the value is already known, one address area data is detected in an arbitrary area and from this, address information is detected and/or corrected. The method will now be explained with concurrent reference to  FIGS. 4 and 5 . 
   Referring to  FIG. 5 , one address area data is detected in operation  51 , and data is written in N registers  41 . 1  through  41 .N. In writing data, detected data is written without change in one register (here, the first register  41 . 1 ) in operation  52 . 1  and is written in other registers after replacing a part with an already known data value of a predetermined area. In the second register  41 . 2 , after part of the detected address area is replaced by a first characteristic value, the data is written in operation  52 . 2 . In the N-th register  41 .N, after part of the detected address area is replaced by a first characteristic value, the data is written in operation  52 .N. 
   The error corrector  42  performs error detection or correction for data written in N registers  41 . 1  through  41 .N in operations  53 . 1  through  53 .N, and outputs a first result through an N-th result in operations  54 . 1  through  54 .N. The selector  43  determines one of the results as address and additional information by using the first through N-th results in operation  55 . 
     FIGS. 6A and 6B  illustrate a flowchart of a method of detecting and/or correcting address information by replacing part of address area data with already known values according to an embodiment of the present invention. According to the method, when the area of a disc is divided into a disc area and a user area in the disc structure, medium information is stored in an additional area in an address area in the disc area, and an additional area in an address area in the user area is not defined and therefore stores ‘00’, additional information among address area data is replaced by ‘00’ so that address information is detected and/or corrected. The method will now be explained with concurrent reference to  FIGS. 4 ,  6 A, and  6 B. 
   Referring to  FIG. 6A , one address area data is detected in operation  61 , and detected values of address and additional information are written in the first register  41 . 1  without change in operation  62 . 1 . At the same time, only additional information among detected address area data is replaced by ‘00’ and the address area data is written in the second register  41 . 2  in operation  62 . 2 . 
   The error corrector  42  detects or corrects an error in the data written in the first register  41 . 1  in operation  63 . 1  and outputs the first result in operation  64 . 1 . Also, the error corrector  42  detects or corrects an error in the data written in the second register  41 . 2  in operation  63 . 2  and outputs the second result in operation  64 . 2 . 
   Operation  65  of  FIG. 6B  showing shows an example of a rule for selecting one result by using the first and second results in the selector  43  and will now be explained. 
   If no error is detected in the first result in operation  65 . 1 , the first result is used. That is, address and additional information written in the first register  41 . 1  are used without change in operation  65 . 2 . 
   If an error is detected in the first result, and if the error is corrected and no error is detected in the second result in operation  65 . 3 , the second result is used. That is, address information written in the second register  41 . 2  and additional information replaced with ‘00’ are used in operation  65 . 4 . 
   If there are errors both in the first and second results and if the errors are all successfully corrected, or if only the first result is corrected in operation  65 . 5 , the first result is used. That is, error-corrected address information and additional information written in the first register  41 . 1  are used in operation  65 . 6 . 
   If there are errors both in the first and second results and if only the second result is corrected in operation  65 . 7 , error-corrected address information written in the second register  41 . 2  and additional information replaced with ‘00’ are used in operation  65 . 8 . 
   If there are errors both in the first and second results and correction of the errors is all failed, it is regarded as a failure to detect an address and the error is indicated in operation  65 . 9 . 
   The rule shown in  FIG. 6B  is a non-limiting example using a priority of correction results. However, it is to be understood that other rules may also be used. 
     FIG. 7  is an example of the characteristic of address information that it increases by a specified unit and shows a case where address information items each formed with 3 bytes are detected continuously and a following address is desired to be found. That is, when (N−3)-th address data is (a, b, c), (N−2)-th address data is (a, b, c+1), and (N−1)-th address data is (a, b, c+2), it is highly probable that the current address is ‘previous address+1’. 
     FIG. 8  is a flowchart of a method of detecting and/or correcting address information by using the characteristic of address information shown in  FIG. 7  according to an embodiment of the present invention.  FIG. 8  shows an example of obtaining a current address when address data contains 3 bytes for address information, 0 byte for additional information and 3 bytes for parity information (parity), and it is highly probable that the current address (a′, b′, c′) estimated by using continuously detected previous address values is ‘previous address+1’. This will now be explained with concurrent reference to  FIGS. 4 and 8 . 
   Referring to  FIG. 8 , current address area data (a′, b′, c′, parity 4 ) is detected in operation  81 . It is assumed that in the previous (N−3)-th address area data is (a, b, c, parity 1 ), (N−2)-th address area data is (a, b, c+1, parity 2 ), and (N−1)-th address area data is (a, b, c+2, parity 3 ). 
   In the first register  41 . 1 , detected address area data (a′, b′, c′, parity 4 ) is written without change in operation  82 . 1 . In the second register  41 . 2 , part of address information is replaced and is written. For example, for the first and second bytes, the continuously detected previous address (a, b) is used and for the lower byte, the detected address c′ is used without change such that the address is written in the form of (a, b, c′, parity 4 ) in operation  82 . 2 . Here, for the previous address (a, b), an error-corrected one is used. 
   The error corrector  42  detects and/or corrects an error in the data written in the first register  41 . 1  in operation  83 . 1  and outputs the first result in operation  84 . 1 . The error corrector  42  also detects and/or corrects an error in the data written in the second register  41 . 2  in operation  83 . 2  and outputs the second result in operation  84 . 2 . By using the first and second results, for example, one address and additional information are determined by a rule such as that in the operation  65  of  FIG. 6 , in operation  85 . 
     FIG. 9  is a flowchart of a method of detecting and/or correcting address information by using the characteristic of address information shown in  FIG. 7 .  FIG. 9  shows an example of obtaining a current address when address data contains 3 bytes for address information, 2 bytes for additional information (aux) and 3 bytes for parity information (parity), it is highly probable that the current address estimated by using continuously detected previous address values is ‘previous address+1’, and additional information is already known. This will now be explained referring to  FIG. 4 . 
   Referring to  FIG. 9 , current address area data (a′, b′, c′, aux 4 , parity 4 ) is detected in operation  91 . It is assumed that in the previous address (N−3)-th address area data is (a, b, c, aux 1 , parity 1 ), (N−2)-th address area data is (a, b, c+1, aux 2 , parity 2 ), and (N−1)-th address area data is (a, b, c+2, aux 3 , parity 3 ). 
   In the first register  41 . 1 , detected address area data (a′, b′, c′, aux 4 , parity 4 ) is written without change in operation  92 . 1 . Additional information in the detected address area data is replaced by value ‘00’ such that the data is written in the form of (a′, b′, c′,  00 , parity 4 ) in the second register  41 . 2 , in operation  92 . 2 . Part of address information is replaced and is written in the third register. For example, for the first and second bytes, the continuously detected previous address (a, b) is used and for the lower byte, the detected address c′ is used without change such that the address is written in the form of (a, b, c′, aux 4 , parity 4 ) in operation  82 . 3 . For the first and second bytes, part of the detected address information, that is, the continuously detected previous address (a, b), is used for replacement and additional information is replaced by value ‘00’ such that the address is written in the form of (a, b, c′,  00 , parity 4 ) in the fourth register in operation  92 . 4 . 
   The error corrector  42  detects and/or corrects an error in the data written in the first register  41 . 1  in operation  93 . 1  and outputs the first result in operation  94 . 1 . Also, the error corrector  42  detects and/or corrects an error in the data written in the second register  41 . 2  in operation  93 . 2  and outputs the second result in operation  94 . 2 . The error corrector  42  detects and/or corrects an error in the data written in the third register in operation  93 . 3  and outputs the third result in operation  94 . 3 . 
   The error corrector  42  detects and/or corrects an error in the data written in the fourth register in operation  93 . 4  and outputs the fourth result in operation  94 . 4 . By using the first through fourth results, the selector  43  determines one address and additional information by a predetermined rule in operation  95 . 
   Here, an example of the predetermined rule will now be explained. If no error in the first result is detected, detected address and additional information corresponding to the first result are used without change. If an error in the first result is detected and corrected and no error in the second result is detected, address and already known additional information corresponding to the second result are used. If errors in both the first and second results are detected and corrected and no error is detected in the third result, partly replaced address information corresponding to the third result and detected additional information are used. If errors are detected in all the first through third results and are corrected and no error is detected in the fourth result, partly replaced address information corresponding to the fourth result and already known additional information are used. If errors are detected in all the first through fourth results and correction is performed, and if all corrections are successful or only the first result is corrected, the error-corrected first result is used. If errors are detected in all the first through fourth results and if the errors are successfully corrected except the first result, or only the second result is corrected, the error-corrected second result is used. If errors are detected in all the first through fourth results and if the errors are successfully corrected except the first and second results, or only the third result is corrected, the error-corrected third result is used. If errors are detected in all the first through fourth results and if only the fourth result is corrected, the error-corrected fourth result is used. If errors are detected in all the first through fourth results and error corrections are all failed, it is regarded as a failure to detect an address and an error is indicated. 
   According to the above-described embodiments of the present invention, by considering the characteristic that additional area data has a specified value with respect to an area of a medium, the characteristic that couldn&#39;t be used in the related art, error detection or correction is performed such that more reliable address information and additional information can be obtained. In addition, by using the characteristic of an address that it increases by specified unit, the present invention can improve the performance for detecting or correcting an error by utilizing part of data of an already known address area even when current address information is not known. 
   Although a few embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Technology Category: g