JP3928677B2 - Information search method and information search apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to, for example, a method and apparatus for compressing and recording information on a recording medium such as a CD-ROM (compact disk ROM), a recording medium on which information compressed by these methods and apparatuses is recorded, and compression. The present invention relates to a search method and a search device for information recorded on a recording medium.
[0002]
[Prior art]
There is provided a so-called electronic book system in which contents information of various documents such as Japanese language dictionaries and English-Japanese dictionaries recorded on a CD-ROM can be searched using, for example, a dedicated information search device.
[0003]
In this electronic book system, for example, search key information (index information) such as a word or a word whose meaning and contents are to be known is input to an information search device, and is recorded on a CD-ROM loaded in the device. Search for information. Then, information corresponding to the input search key information is read from the CD-ROM and displayed on the display screen of the information search device, etc., and provided to the user.
[0004]
Therefore, users of e-book systems can quickly turn to the target without taking time and effort, such as turning over pages of documents such as Japanese dictionaries and English-Japanese dictionaries and finding descriptions of words and words that they want to look up. You can search and obtain words and meanings of words.
[0005]
By the way, in the electronic book system, in order to realize a quick search of information, index information having a hierarchical structure for information search is created, and this index information together with document content information (hereinafter referred to as body data) is a CD- It is recorded in ROM.
[0006]
Among the index information of the hierarchical structure for search, the index information of each layer other than the lowest layer includes comparison key information to be compared with the input search key information and index information of the next layer corresponding to the comparison key information. The address information indicating the head recording position is included. The index information in the lowest layer is key information to be compared with the input search key information, and is comparison key information that matches the input search key information and information corresponding to the input search key information. It has address information (text address information) indicating the head recording position on the CD-ROM.
[0007]
Then, by sequentially performing a comparison process between the input search key information and the comparison key information of the index information, the start recording start position on the CD-ROM of information corresponding to the input search key information is searched. Has been. In this case, the search range of the input search key information can be gradually narrowed down without performing a search on all comparison key information of the index information, so that the search input can be quickly performed. Information corresponding to the key information can be searched from the text data recorded on the CD-ROM and used.
[0008]
[Problems to be solved by the invention]
By the way, in recent years, there is an increasing demand for enhancing the contents of a CD-ROM of an electronic book system by storing more information. Thus, by increasing the amount of information stored in the CD-ROM, the convenience of the electronic book system can be expected to be improved, for example, the number of CD-ROM replacements can be reduced in the electronic book system. .
[0009]
However, the text data of various documents recorded on the CD-ROM of the electronic book system has been conventionally stored in an uncompressed state, and there is a problem of insufficient capacity of the CD-ROM.
[0010]
Therefore, it is conceivable to compress the text data and store it in a CD-ROM. However, there are the following problems, and it is not possible to simply compress the body data and record it on a CD-ROM.
[0011]
First, the processing unit of the text data to be compressed becomes a problem. For example, when the whole body data of one document is compressed as a set of data (processing unit), the compressed whole body data is taken into the information search device and compressed. Since the decompression process (decompression process) must be performed, a large memory must be installed in the information retrieval apparatus. Also, in this case, since the amount of text data per processing unit is large, it takes time to import compressed text data from the CD-ROM and decompression processing of the compressed text data, so that a quick search process can be performed. It cannot be realized.
[0012]
For this reason, it is conceivable to divide the text data for each piece of information (search target item) to be searched, for example, and compress the text data for each divided information. When the text data is, for example, data of a Japanese dictionary, the text data is compressed for each search target item, using a word and information indicating the meaning content of the word as a set of search target items to be searched. Like that.
[0013]
However, in this case, there is a possibility that efficient data compression cannot be performed because the search target data is too small or the data size of the search target item varies.
[0014]
In the case of an electronic book system, as described above, in order to enable a quick search, index information having an address indicating the head recording position on the CD-ROM of each search target item is stored together with the text data in the CD-ROM. Has been written to. For this reason, when the text data is compressed and recorded on the CD-ROM for each search target data, the index information of the software of the conventional electronic book system is also converted into the compressed text data. It must be recreated accordingly.
[0015]
As described above, the electronic book standard index information has a complicated hierarchical structure. To recreate the index information as the main text data is compressed, it takes about the same amount of time as when index information is newly created. costly. This is a cause of obstructing provision of the CD-ROM of the electronic book system in which more text data is recorded on the CD-ROM by compressing the text data.
[0016]
In view of the above, the present invention eliminates the above-mentioned problems and makes it possible to effectively use the storage capacity of the recording medium, the information recording method, the information recording apparatus, and the information recorded on the recording medium. An object of the present invention is to provide an information search method, an information search device, and an information recording medium on which information is recorded so that the target information can be searched reasonably and quickly. And
[0017]
[Means for Solving the Problems]
  In order to solve the above problem, the invention according to claim 1 is provided.Information search method is
  Used in an information retrieval apparatus comprising a reading means for reading data from a recording medium, a compression / decompression means for compressing and decompressing the read data, and a data output means for outputting the compressed and decompressed data,Search for index information for detecting a head recording position for each search target item when body data including a plurality of search target items is sequentially recorded on a recording medium without a break for each search target item An information search method for detecting a target search target item from text data including the plurality of search target items that are compressed and recorded as key information for
  In the recording medium, the body data is stored in a predetermined manner.equalThe data divided by the amount of data and compressed in the divided data units are sequentially recorded so that the recording positions are continuous, and the compressed data size for each divided data unit is accumulated. In addition to the index information, a compressed size table in which an arithmetic value is described in association with each divided data is recorded,
  By the reading means,Based on the index information, the head of the specified search target itemBy specifying the data amount up to the address indicating the position and dividing the data amount up to the address indicating the head position by the data amount of the predetermined size,,Including the head positionWhile specifying the divided data unit, based on the accumulated value of the compressed data size of the divided data, the recording start position of the compressed body data corresponding to the specified divided data unit, the data amount, And reading the body data corresponding to the specified divided data unit from the recording medium,
  By the compression / decompression means,The reading stepIn said reading meansA decompression step of decompressing the compressed body data compressed in units of the divided data read by
  By the data output means,The compression / decompression processIn the compression and decompression meansA target data output step for outputting data of the search target item from the head position of the specified search target item detected based on the index information in the compressed and decompressed data;
  It is characterized by providing.
[0027]
  thisClaim 1According to the information search method of the invention described in the above, text data including a plurality of search target items is predetermined on the recording medium.equalThe data is divided for each size data amount, compressed and recorded in this divided data unit, information on the data size after compression for each divided data unit, and the head of each search target item of the body data before compression Index information for detecting the position is recorded.
[0028]
  For reading processIn the reading meansThus, based on the index information and the information on the data size, a divided data unit including the head position of the specified search target item is specified, and the compressed body data corresponding to the specified divided data unit is , Read from the recording medium.
[0029]
  The compressed body data that has been read out is subjected to the compression / decompression process.In the compression and decompression meansThus, it is decompressed, ie decompressed, and restored to the original body data. In the target data output process, the data of the specified search target item is detected from the restored body data,In the data output process, by the data output meansFor example, it is displayed and output.
[0030]
As described above, the reading of the body data compressed and recorded on the recording medium and the compression / decompression processing of the read body data are performed in units of divided data. Therefore, for example, the amount of data per processing unit is not too large as in the case where the entire body data of one document is used as one processing unit, and the data of the target search target item can be quickly retrieved from the recording medium. It can be read out and quickly compressed and decompressed for use.
[0032]
  Also,Accumulated value obtained by accumulating the compressed data size of each divided data is described corresponding to each divided data(Compressed size table)Are recorded on the recording medium as information on the data size.
[0033]
In this case, the accumulated value of the compressed data size for each divided data indicates the first recording position after the compression of the next divided data, and the accumulated value of the compressed data size up to the target divided data From this, by subtracting the accumulated value of the data size after compression up to the previous divided data, the data amount after compression of the target divided data can be obtained.
[0034]
Thereby, in the reading step, the divided data including the head of the search target item designated with reference to the index information is specified, and the head recording position of the compressed body data corresponding to the specified divided data, The amount of data can be reasonably detected by simple arithmetic processing. That is, it is possible to quickly search and use the data of the designated search target item from the body data compressed and recorded on the recording medium.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
  The present invention will be described below with reference to the drawings.One of the method and apparatusEmbodiments will be described.
[0036]
In this embodiment, the present invention is applied to a so-called electronic book system. As described above, the electronic book system records the text data of various documents on, for example, a CD-ROM, and uses the information retrieval device to search from the text data recorded on the CD-ROM. The target search target item is searched.
[0037]
For example, a national language dictionary forms a body data of a single Japanese language dictionary by collecting a large number of search target data consisting of a word and information indicating the meaning content of the word. A CD-ROM of the electronic book system is created by recording on the CD-ROM.
[0038]
Then, for example, when the CD-ROM is loaded into an information search device for an electronic book system and a word to be checked is input as search key information, search target item data corresponding to the search key information (in this case, a word And information indicating its meaning) are retrieved from the text data recorded on the CD-ROM, and displayed on the display screen of the information retrieval device, and provided to the user.
[0039]
As described above, the electronic book system can quickly search and use the literature information recorded on the recording medium such as the CD-ROM with a simple operation.
[0040]
[Creation of CD-ROM for electronic book system]
First, creation of a so-called electronic book standard CD-ROM used in the electronic book system will be described. FIG. 1 is a block diagram for explaining an information recording apparatus according to this embodiment that creates an electronic book standard CD-ROM by writing information on a CD-ROM. The information recording apparatus of this embodiment is an application of the information recording method according to the present invention, and compresses and records on the CD-ROM the text data of various documents that have been recorded uncompressed conventionally. It was made to be able to.
[0041]
As shown in FIG. 1, the information recording apparatus of this embodiment includes an index information generation unit 1, a body data generation unit 2, a data division unit 3, a data compression unit 4, a compression size table generation unit 5, and a write control unit 6. It has. Further, the CD-ROM 200 is loaded into the information recording apparatus of this embodiment, and the body data, index information, and compression size table are written therein.
[0042]
Before the detailed description of the information recording apparatus of this embodiment shown in FIG. 1, the index information generated in the index information generator 1 of this embodiment and recorded on the CD-ROM 200 is described. explain. This index information is created and used in an electronic book system in order to realize quick search processing.
[0043]
FIG. 2 is a diagram for explaining an example of the electronic book standard index information output from the index information generation unit 1. The index information of the electronic book standard is created in an nth-order hierarchical structure according to the text data of documents recorded on the CD-ROM. The index information of the electronic book standard shown in FIG. 2 is an example of a tertiary hierarchical structure, for example, index information for a Japanese dictionary.
[0044]
As shown in FIG. 2, the index information in this example includes a primary index block 1B, a secondary index block 2B, and a tertiary index block 3B. The contents of the second index block 2B and the third index block which is the lowest index block in this example are further subdivided into a plurality of subdivided blocks 2B1, 2B2,..., A plurality of subdivided blocks 3B1. 3B2,...
[0045]
The primary index block 1B and the subdivision blocks 2B1, 2B2,... Of the secondary index block 2B are compared key information such as “Ama” and “Kaki” that is compared with the input search key information. And address information indicating the head recording position of the sub-block of the next layer corresponding to the comparison key information.
[0046]
Further, each of the subdivided blocks 3B1, 3B2,... Of the third index block 3B is the lowest-level index block in this example, and is key information to be compared with the input search key information. Comparison key information matching the search key information and address information (text address information) indicating the first recording position of the search target item corresponding to the comparison key information among the text data recorded on a recording medium such as a CD-ROM )have.
[0047]
Using the thus configured index information, information retrieval based on the inputted retrieval key information is performed as follows.
[0048]
In this example, first, the primary index block 1B is referred to, and the two-character information from the beginning of the input search key information is compared with the comparison key information of the primary index block 1B. As a result of this comparison processing, whether the two-character information from the beginning of the input search key information is information located in front of the comparison key information to be compared in the primary index block 1B in alphabetical order. Whether the information is located behind or the same information as the comparison key information of the primary index block 1B.
[0049]
When it is determined that the information of the two characters from the beginning of the input search key information is information that is located after the comparison key information that is the comparison target of the primary index block 1B in the order of the Japanese alphabet. The comparison process is performed in the same manner for the next comparison key information of the primary index block 1B.
[0050]
Also, the information of the two characters from the beginning of the input search key information is information located in alphabetical order before the comparison key information to be compared in the primary index block 1B, or When it is determined that the information is the same as the comparison key information of the primary index block 1B, the second index block 2B of the secondary index block 2B is based on the address information of the next layer corresponding to the comparison key information of the primary index block. Refer to the relevant subdivision block.
[0051]
Then, between the two-character information from the beginning of the input search key information and the comparison key information of the specified segmented block of the secondary index block 2B, the same as in the case of the above-mentioned primary index block. The comparison process is performed.
[0052]
In the comparison process performed with the comparison key information of the designated subdivision block of the secondary index block 2B, the information of the two characters from the beginning of the input search key information is in the order of the Japanese syllabary order. When it is determined that the information is located before the comparison key information that is the comparison target of the subdivision block of the secondary index block 2B, or the same information as the comparison key information that is the comparison target, The corresponding segmented block of the third index block 3B designated by the address information of the next layer corresponding to the comparison key information is referred to.
[0053]
Then, a comparison process is performed between the input search key information and the comparison key information of the designated subdivision block of the tertiary index block 3B, and comparison key information that matches the input search key information is detected. To do. The body address stored in correspondence with the detected comparison key information of the segmented block of the third index block 3B indicates the recording start position on the CD-ROM of search target data for the input search key information. Show. Therefore, the retrieval target data corresponding to the inputted retrieval key information can be acquired by reading the body data from the recording position of the CD-ROM indicated by the body address.
[0054]
For example, when “greeting” is input as the search key information, the two characters “ai” from the head of the search key information are compared with the comparison key information of the primary index block. First, the two characters “Ai” from the beginning of the search key information are compared with the comparison key information “Ama” of the primary index block. Since the two characters “Ai” from the beginning of the search key information are information located in front of the comparison key information “Ama” in Japanese alphabetical order, the address recorded corresponding to the comparison key information “Ama” Based on the information, the subdivision block 2B1 of the secondary index block is referred to.
[0055]
Then, the two characters “Ai” from the beginning of the search key information are compared with the comparison key information of the subdivision block 2B1 of the secondary index block 2B. First, the two characters “Ai” from the beginning of the search key information are compared with the comparison key information “Au” of the subdivision block 2B1 of the secondary index block 2B. Since the two characters “Ai” from the beginning of the search key information are information located in front of the comparison key information “AOU” in the order of the Japanese syllabary order, the address recorded corresponding to the comparison key information “AOU” Based on the information, the segmented block 3B1 of the third index block is referred to.
[0056]
Then, the comparison key information matching the search key information “greeting” is detected from the comparison key information of the subdivided block 3B1, and the body address recorded in correspondence with the detected comparison key information “greeting”. The data of the search target item corresponding to the input search key information is read out and provided. That is, in this case, the text data indicating the meaning content of the search key information “greeting” is read from the body data as the data of the search target item and provided to the user.
[0057]
In this embodiment, as described with reference to FIG. 2, the index information of the electronic book standard created in a hierarchical structure is provided in a CD-ROM in which text data is recorded, as shown in FIG. Recorded in the index area IDX.
[0058]
In this case, the index area IDX includes the first index block 1B, the second index block group 2B,..., The nth index block group in order from the lowest physical address of the index area IDX. To be recorded. Thereby, the hierarchy of the index information can be traced in order from the lowest physical address to the higher physical address.
[0059]
In this embodiment, a character management block MK is provided so that it can be determined from where in the primary index block the search is started according to the input search key information. For example, if the first character of the search key information is from “a line” to “na line” of the Japanese syllabary, the search starts from the top of the primary block 1B, and the first character of the search key information is “ha line”. After “”, the search can be started from a predetermined position near the intermediate position of the primary block, that is, from the start position of “ha” in the primary index block. .
[0060]
In this way, the index information of the electronic book standard can narrow down the search range efficiently by making the index information into a hierarchical structure without performing a search process on all comparison key information of the index information. The search target item corresponding to the searched search key information can be quickly searched from the body data and used.
[0061]
By the way, as described above, since the text data of the electronic book standard is stored in the CD-ROM in an uncompressed state, the text data of more documents cannot be recorded. In many cases, the limited storage capacity is not effectively utilized. Therefore, although compression of text data is conceivable, it cannot be compressed in a single order as described above.
[0062]
Further, when the main text data is compressed and recorded on the CD-ROM, it is necessary to recreate the index information. However, as described above with reference to FIG. 2, the electronic book standard index information has a complicated hierarchical structure. Therefore, it takes time and cost to recreate the index information. This is a cause of obstructing provision of a CD-ROM of an electronic book system having a more substantial content by recording more text data on the CD-ROM.
[0063]
Therefore, the information recording apparatus of this embodiment shown in FIG. 1 divides the text data into predetermined data amounts. Hereinafter, in this specification, a collection of data (part of the text data) formed by dividing the text data into predetermined data amounts is referred to as a unit block. Then, the body data is compressed for each unit block, and the compressed body data is sequentially packed into consecutive addresses and recorded on the CD-ROM.
[0064]
Also, the information recording apparatus of this embodiment records the index information already created corresponding to the text data before compression on the CD-ROM as it is. In order to be able to acquire the data of the search target item corresponding to the input search key information from the compressed body data using the index information created for the body data before compression. , Forming a compressed size table that stores the accumulated value of the compressed data amount for each unit block formed by dividing the body data corresponding to each unit block, and compresses this for each unit block The CD-ROM of the electronic book standard is created by storing it in the CD-ROM together with the text data and the index information.
[0065]
In this case, the recording area of the CD-ROM is separated into a body data area which is a body data recording area, an index area which is an index information recording area, and a compression size table area which is a compression area table recording area. The compressed body data, index information, and compressed size table are recorded in the corresponding recording areas. Hereinafter, the information recording apparatus of this embodiment shown in FIG. 1 will be described in detail.
[0066]
The index information generating unit 1 generates index information to be recorded on the CD-ROM 200 based on the index information created in advance corresponding to the uncompressed body data to be compressed and recorded on the CD-ROM 200. This is supplied to the write control unit 6.
[0067]
The body data generating unit 2 generates body data to be compressed and recorded on the CD-ROM 200 and supplies this to the data dividing unit 3. The data dividing unit 3 divides the supplied text data into unit blocks having a predetermined data amount, and supplies the text data to the data compression unit 4 for each unit block.
[0068]
FIG. 4 is a diagram for explaining text data division processing and compression processing performed in the data division unit 3 and the data compression unit 4. For the sake of simplicity, FIG. 4 shows text data before compression (hereinafter, before compression). (Excerpt from the text data).
[0069]
In this embodiment, the data dividing unit 3 divides the uncompressed text data DT into unit blocks DT1, DT2, DT3, DT4,... Having a predetermined size as shown in FIG.
[0070]
In FIG. 4A, 0000H, 1000H, 2000H, and 3000H attached to the left side of the uncompressed body data DT indicate the start addresses of the unit blocks DT1, DT2, DT3, and DT4 from the beginning of the uncompressed body data. Indicates the end address of the unit block DT4. The alphabet “H” appended to the end of each address indicates that the address is expressed in hexadecimal. Hereinafter, in this specification, “H” of the alphabet attached to the end of the address information, the compressed size, the number of bytes, and the like indicates that the information is expressed in hexadecimal.
[0071]
Therefore, in this embodiment, as shown in FIG. 4A, the uncompressed text data DT is divided into unit blocks DT1, DT2, DT3, DT4,... Which are units of compression every 4096 bytes. The uncompressed text data for each block is supplied to the data compression unit 4.
[0072]
  The data compressing unit 4 performs body data for each unit block.TheCompress. The text data compressed for each unit block in the data compression unit 4 is sequentially recorded on the CD-ROM 200 to form compressed text data DTA as shown in FIG. 4A. Here, the post-compression unit blocks DTA1, DTA2, DTA3, and DTA4 constituting the post-compression body data DTA are formed by compressing the data of the unit blocks DT1, DT2, DT3, and DT4 of the body data before compression. Is.
[0073]
As shown in FIG. 4B, for example, a unit block DT1 of about 4 kilobytes (4096 bytes) from address 0000H to address 0FFFH has 2066 bytes (hexadecimal number) as shown in the corresponding compressed unit block DTA1. Is compressed to 0812H bytes).
[0074]
Similarly, as shown in FIG. 4A, the unit block DT2 of about 4 kilobytes from the address 1000H to 1FFFH is compressed to 2294 bytes (08F6H bytes in hexadecimal) as shown in the post-compression unit block DTA2, The unit block DT3 from the address 2000H to 2FFFH is compressed to 1767 bytes (06E7H bytes in hexadecimal) as indicated by the post-compression unit block DTA3. The unit block DT3 from addresses 3000H to 3FFFH is compressed to 2578 bytes (0A12H bytes in hexadecimal) as indicated by the compressed unit block DTA4.
[0075]
Then, the data compression unit 4 supplies the body data compressed for each unit block to the write control unit 6. Further, the data compression unit 4 detects the data amount of the compressed body data for each unit block, and supplies this to the compression size table generation unit 5.
[0076]
In this embodiment, the compression size table generation unit 5 obtains an accumulated value of the data amount after compression for each unit block from the data compression unit 4, and uses this accumulated value as a compressed size for each unit block. The associated compressed size table is created and supplied to the write control unit 6.
[0077]
That is, the data compressing unit 4 sequentially supplies the compressed data size of the unit blocks DTA1 to DTA4 after compression formed by compressing the unit blocks DT1 to DT4 to the compressed size table generating unit 5. In this embodiment, the compressed size table generating unit 5 accumulates the compressed data amount for each unit block in order from the head unit block to obtain an accumulated value. A compressed size table TB in which unit blocks are associated is formed.
[0078]
In FIG. 4A, 0812H, 1108H, 17EFH, and 2201H attached to the right side of the compressed text data DTA indicate the accumulated values of the data amounts of the compressed unit blocks DTA1 to DTA4.
[0079]
That is, as described above, the data amounts of the compressed unit blocks DTA1, DTA2, DTA3, and DTA4 formed by compressing the unit blocks DT1, DT2, DT3, and DT4 are 0812H, 08F6H, 06E7H, and 0A12H. The compression size table generation unit 5 sequentially accumulates these to obtain an accumulated value of the amount of data after compression up to the unit block to be compressed corresponding to each unit block.
[0080]
Therefore, if the unit block after compression DTA1 is the first unit block after compression, the accumulated value up to the unit block after compression DTA1 is 0812H. The accumulated value up to the compressed unit block DTA2 is 0108H and 08F6H added to become 1108H. Similarly, 1108H and 06E7H are added to the accumulated value up to the compressed unit block DTA3 to become 17EFH, and the accumulated value up to the compressed unit block DTA4 is added to 17EFH and 0A12H to become 2201H. .
[0081]
  In this way, the compression size table generating unit 5 obtains an accumulated value by accumulating the data amount for each unit block, and uses the accumulated value of the data amount after compression as the compressed size.WhenThe associated compressed size table TB is formed.
[0082]
FIG. 5 is a diagram for explaining the compression size table TB of this embodiment. As shown in FIG. 5A, the accumulated value of the size of the compressed unit block obtained for each unit block is recorded in the compressed size table TB as a compressed size. In this case, each compression size (accumulated value of the data amount of the unit block after compression) is expressed in hexadecimal and 4 bytes. The address of the compressed size table TB is the head address of each compressed size from the head of the compressed size table TB. The compressed size table TB created in the compressed size table generation unit 5 is supplied to the write control unit 6.
[0083]
The writing control unit 6 writes information supplied from each unit to the CD-ROM 200. That is, the write control unit 6 writes the index information from the index information generation unit 1 in an index area formed on the CD-ROM 200. Further, the compressed body data for each unit block from the data compression unit 4 is sequentially packed and written in the body data area of the CD-ROM 200. Similarly, the compressed size table information from the compressed size table generating unit 5 is written into the compressed size table area.
[0084]
As described above, the information recording apparatus according to this embodiment stores the index information created corresponding to the uncompressed body data, the body data compressed for each unit block, and the compression size table on the CD-ROM. The data is written, and an electronic book standard CD-ROM is created.
[0085]
Then, as will be described in detail later, based on the index information recorded on the CD-ROM and the compressed size table, the compressed body data including the designated search target item is read and decompressed. By doing so, the designated search target data can be used.
[0086]
Next, the above-described creation process of the electronic book standard CD-ROM will be described with reference to the flowchart of FIG.
[0087]
The uncompressed body data to be recorded from the body data generating unit 2 is divided by the data compression unit 4 into unit blocks having a predetermined amount of data (step S1). That is, as described above with reference to FIG. 4, the processing of step S1 is to divide the uncompressed text data into unit blocks having a data amount of 4096 bytes, for example.
[0088]
Next, the data compression unit 4 performs a compression process of the body data for each unit block using a unit block of a certain size as a processing unit (step S2), and acquires the data amount of the unit block after compression. (Step S3).
[0089]
The text data compressed for each unit block is sequentially packed under the control of the writing controller 6 and recorded in the text area of the CD-ROM 200 (step S4). Further, the data amount of the unit block after compression acquired by the data compression unit 4 is supplied to the compression size table creation unit 5, and an accumulated value of the data amount of the unit block after compression is calculated (step S5). . In the process of step S5, for example, the accumulated value of the data amount of the unit block after compression up to the previous time is held, and the accumulated value up to the previous time and the compression of the unit block to be compressed this time are stored. The accumulated value of this time can be obtained by adding the subsequent data amount.
[0090]
Then, the compression size table creation unit 5 creates a compression size table in the memory provided therein, for example, by using the current accumulated value as the compression size so that it can be associated with the unit block targeted for the current compression. (Step S6).
[0091]
That is, in this step S6, the accumulated value of the size after compression up to the first unit block is recorded in the first in the compression size table, and the accumulated size after compression up to the second unit block. As the calculated value is recorded second in the compressed size table, a compressed size table for the body data to be compressed and recorded is created so that the accumulated value up to which unit block can be known.
[0092]
Then, it is determined whether or not the compression process has been completed for all the unit blocks of the body data to be compressed (step S7). If it is determined that the compression has not been completed, the next unit block is set as the processing target. (Step S8) and repeat the process from Step S2.
[0093]
If it is determined in step S7 that the compression processing has been completed for all unit blocks of the body data to be compressed, the compression size table created in the compression size table creation unit 5 and the index information generation unit 1 is supplied to the writing control unit 6 and the information is recorded in the index area and the compressed size table area of the CD-ROM (step S9). The body data compression processing and compression size table creation processing shown in FIG.
[0094]
In this way, the body data is divided into unit blocks, compressed for each unit block, recorded on the CD-ROM of the electronic book system, and the accumulated value of the data amount of the unit block after compression is compressed size. The compressed size table as shown in FIG. 5B and the index information created according to the body data before compression are recorded on the CD-ROM 200.
[0095]
As described above, since the body data is compressed and recorded on the CD-ROM, the body data of more documents can be recorded on the same CD-ROM than before. When the text data of a plurality of documents is compressed and recorded on one CD-ROM, a compressed size table corresponding to the text data compressed for each unit block of each document, By recording the index information created corresponding to the text data before compression on the same CD-ROM, various text data recorded on one CD-ROM can be used in the same way. .
[0096]
In addition, since the body data is compressed for each unit block of a predetermined size, it is only necessary to perform decompression processing in a compressed unit, so that it is not necessary to install a large memory in the information retrieval apparatus. it can. In addition, if the compression process is performed for each predetermined unit block, it is only necessary to process the data for each unit block, so that it does not take a long time to read and decompress the compressed body data.
[0097]
Further, when the index information has already been created, the existing index information can be used as it is, so that it is not necessary to create new index information corresponding to the compressed body data.
[0098]
In the above description, the text data of all unit blocks is compressed and recorded on the CD-ROM 200, and then the index information and the compressed size table for the text data are recorded on the CD-ROM 200. However, since the index information is created in advance corresponding to the text data before compression, a CD-ROM in which the index information is recorded is created in advance and compressed into this CD-ROM for each unit block. The body data and the compressed size table may be recorded.
[0099]
Further, after the compressed size table generation unit 5 completes a compressed size table composed of compressed sizes corresponding to all unit blocks, the completed compressed size table may be recorded on the CD-ROM 200. The accumulated value of the compressed data amount for each unit block can be sequentially recorded on the CD-ROM 200.
[0100]
[Information retrieval device]
Next, for the electronic book system created by recording the index information created according to the text data before compression, the text data compressed for each unit block, and the compressed size table as described above Information retrieval using the CD-ROM will be described. In this case, it is assumed that the body data before compression and the head of the body data after compression are made to coincide with the head (0000H) of the body data area of the CD-ROM 200 as shown in FIG. .
[0101]
FIG. 7 shows an electronic device according to this embodiment in which a CD-ROM 200 for an electronic book system created by the information recording apparatus described above with reference to FIG. 1 is loaded and information recorded on the CD-ROM 200 can be searched. It is a block diagram for demonstrating the information search device of a book system. This information retrieval apparatus is one to which the information retrieval method according to the present invention is applied.
[0102]
As shown in FIG. 7, the information retrieval apparatus of the electronic book system of this embodiment includes an optical pickup 11, a biaxial device 12, a spindle motor 13, a driver 14, an RF amplifier 15, a signal processing unit 16, and a display control unit 17. And a display panel 18 and a CPU 100 to which a ROM 101, a RAM 102, and a key operation unit 103 are connected.
[0103]
The CPU 100 has a function as a system controller that controls the operation of each unit of the search / playback apparatus. The ROM 101 stores programs and data used in the information retrieval apparatus such as operation programs and display character font data.
[0104]
The RAM 102 is used as a work area for processing performed in the information retrieval apparatus, such as temporarily storing reproduction data read from the CD-ROM 200. The key operation unit 103 includes a plurality of operation keys such as numeric keys and alphabet keys, and receives information input from the user such as search key information.
[0105]
When the operation key of the key operation unit 103 is operated by the user and the search key information is input, the CPU 100 accepts this and starts the search process of the body data recorded on the CD-ROM 200.
[0106]
First, the CPU 100 supplies a control signal for instructing the driver 14 to start search processing. In response to this control signal, the driver 14 drives the optical pickup 11, the biaxial device 12, and the spindle motor 13, and reads data recorded on the CD-ROM 200 by the optical pickup 11.
[0107]
Although not shown, the optical pickup 11 includes, for example, a laser diode, an objective lens, a half mirror, a photodetector, etc., irradiates a track of the CD-ROM 200 with a laser beam, receives the reflected light with the photodetector, and reflects the reflected light. Data recorded on the CD-ROM 200 is read based on the change in the amount of light.
[0108]
In this embodiment, the photodetector of the optical pickup 11 is divided into a plurality of light receiving areas in order to detect a focus error and a tracking error.
[0109]
The reflected light from the CD-ROM 200 received by each light receiving area of the photodetector of the optical pickup 11 is converted into an electric signal and supplied to the RF amplifier 15. The RF amplifier 15 forms a reproduction high-frequency signal, a focus error signal FE, and a tracking error signal TE from electric signals from the respective light receiving regions of the photodetector of the optical pickup 11.
[0110]
The focus error signal FE and tracking error signal TE formed in the RF amplifier 15 are supplied to the CPU 100. The CPU 100 controls the biaxial device 12 through the driver 14 based on these signals FE and TE so as to perform focus error control and tracking error control.
[0111]
The reproduced high-frequency signal formed by the RF amplifier 15 is supplied to the signal processing unit 16 where analog / digital conversion processing and demodulation processing according to the modulation method at the time of recording on the CD-ROM 200 are performed. Demodulated data is retrieved.
[0112]
In this case, as will be described later, the CPU 100 first refers to the index information recorded on the CD-ROM 200 based on the input search key information and inputs the input based on the index information. A unit block including the head of the search target item corresponding to the search key information is specified.
[0113]
That is, the CPU 100 refers to the index information created corresponding to the uncompressed text data recorded on the CD-ROM 200, and the text address indicating the head position of the search target item corresponding to the input search key information. To get. Then, the data amount of the body data before compression from the head before compression of the body data to the head position of the search target item is obtained. By dividing the obtained data amount by the data amount per unit block, which is the processing unit at the time of compression processing, the unit block that includes the start position of the search target item is the unit block number from the start unit block. Is identified.
[0114]
Next, the CPU 100 refers to the compressed size table, and reads out compressed body data corresponding to the specified unit block from the CD-ROM 200 based on the information of the compressed size table.
[0115]
That is, as described above with reference to FIG. 5, each compression size in the compression size table is an accumulated value of the data amount of the unit block after compression, and corresponds to the start position of the next unit block after compression. Also, subtracting the accumulated value (compressed size) of the data amount up to the previous compressed unit block from the accumulated value (compressed size) of the data amount up to the target compressed unit block, The target data amount of the unit block after compression can be obtained.
[0116]
Accordingly, for example, in the example shown in FIG. 4A, when the compressed data of the post-compression unit block DTA3 corresponding to the pre-compression unit block DT3 is read and used, the compression size shown in FIG. 5B is used. The compressed size 17EFH up to the compressed unit block DT3 and the compressed size 1108H up to the previous compressed unit block DT2 are read from the table TB, and the compressed unit block from the compressed size 17EFH up to the compressed unit block DT3 is read. By subtracting the compression size 1108H up to DT2, the data amount of the post-compression unit block DTA3 is obtained. In this case, the size of the compressed unit block DT3 is 1767H bytes as shown in FIG.
[0117]
Then, from the 1108Hth byte, which is the compression size from the beginning of the compressed body data to the post-compression unit table DTA2 immediately before the pre-compression unit block DT3, the data amount of the post-compression unit block DT3, that is, 1767H bytes If the compressed body data is read, the compressed body data corresponding to the unit block DT3, in this case, the entire compressed unit block DTA3 can be read out. The compressed body data corresponding to the specified unit block read out in this way is temporarily stored in the RAM 102.
[0118]
Then, the CPU 100 compresses and decompresses the compressed body data temporarily stored in the RAM 102 to obtain original body data before compression of the specified unit block. Then, as described above, the compressed and decompressed unit block body data is input based on the body address indicating the start position of the search target item corresponding to the input search key information acquired from the index information. The data of the search target item corresponding to the searched key information is acquired.
[0119]
That is, it is already known which unit block of the whole body data recorded in the CD-ROM 200 is identified as described above, and each unit block has a predetermined size. Therefore, the head position of the specified unit block from the head of the entire body data can be easily understood. That is, the head position of the specified unit block can be found by multiplying the number of unit blocks from the head unit block of the body data to the specified unit block by a predetermined amount of data per unit block.
[0120]
Therefore, if the address indicating the start position of the specified unit block is subtracted from the body address indicating the start position of the search target item corresponding to the search key information acquired from the index information, The head position of the target search target item from the head can be specified. Then, if the body data is read from the position corresponding to the head position of the specified search target item in the compressed and decompressed unit block, the data of the target search target item corresponding to the input search key information is acquired. be able to.
[0121]
In this way, the data of the search target item corresponding to the search key information is acquired, and based on the data of the search target item, the font data stored in the ROM 101 is used to display characters and the like to be displayed. Shape data of display information is formed and supplied to the display control unit 17.
[0122]
The display control unit 17 includes a display memory 71 and forms display image data in the display memory 71 in accordance with the shape data of the display information from the CPU 100. Then, the display control unit 17 controls the display panel 18 configured by a liquid crystal display panel or the like, and causes the display panel 18 to display an image corresponding to the image data formed in the display memory 71.
[0123]
Thereby, the display panel 18 displays the data of the search target item read from the CD-ROM 200 based on the search key information from the user.
[0124]
[Operations during information retrieval in the information retrieval device]
Next, the operation at the time of search of the information search apparatus of the electronic book system of this embodiment will be described with reference to the flowchart of FIG.
[0125]
When the CD-ROM 200 of the electronic book system of the information search apparatus of this embodiment is loaded and the search key information is input by the user through the key operation unit 103 (step S11), the CPU 100 of the information search apparatus displays the driver 14 Through the optical pickup 11, the 2-axis device 12, and the spindle motor 13, the index information created according to the text data before compression is referred to, and as described above, corresponding to the input search key information A unit block (before compression) including the head of the search target data is specified (step S12).
[0126]
Then, an accumulated value (compression size) RA of the size of the unit block after compression up to the specified unit block from the compression size table described above, and the size of the unit block after compression up to the previous unit block The accumulated value (compressed size) RB is read (step S13), and the size SA of the specified unit block is calculated by subtracting the compressed size RB from the compressed size RA (step S14).
[0127]
The subtraction process in step S14 will be specifically described. For example, when the compression size RA up to the specified unit block is 014C10CFH and the compression size RB up to the previous unit block is 014C09F6H, It can be seen that 014C09F6H is subtracted from 014C10CFH, and the size SA of the specified unit block is 1753 bytes.
[0128]
As described above, since the compression size is an accumulated value of the size of the unit block after compression, the compression size itself indicates the head position of the next unit block. Therefore, the CPU 100 positions the reading position at the head position of the specified unit block on the CD-ROM 200 indicated by the compressed size RB (step S15), and from this, the compressed body data is compressed by the size SA of the specified unit block. Is read (step S16).
[0129]
That is, according to the above-described example, since the compression size RB = 014C09F6H = 221762550 bytes up to the unit block immediately before the specified unit area, from the 2762550th byte based on the head of the compressed body data The compressed text data corresponding to 1753 bytes is read out.
[0130]
The compressed compressed body data is temporarily stored in the RAM 102. Since the text data temporarily stored in the RAM 102 is obtained by compressing the text data of the specified unit block, the original text data before compression of the specified unit block is obtained by compressing and decompressing the text data. (Step S17).
[0131]
Then, as described above, the head position of the data of the search target item corresponding to the input search key information is specified from the compressed and decompressed body data, and the target search target item data is compressed and decompressed. It reads out from the body data of the block and reproduces it (step S18).
[0132]
In this step S18, the search target item corresponding to the search key information is read from the body data temporarily stored in the RAM 102 and decompressed, and the search key information is supported using the font data stored in the RAM 101. A display image of the search target item is formed in the RAM 71 of the display control unit 17. The display image of the RAM 71 is displayed on the display panel 18, and text data corresponding to the input search key information is provided to the user.
[0133]
In consideration of the fact that the search target data corresponding to the input search key information extends over a plurality of blocks, the end of each search target data constituting the text data of each document is the end of the search target data. A so-called end mark is added. If this end mark is not detected, the processing from step S13 is performed with the unit block next to the specified unit block as the newly specified unit block. Thereby, it is possible to cope with the case where the search target data corresponding to the input search key information extends over a plurality of blocks.
[0134]
As described above, by using the information search device of this embodiment, index information created according to the text data before compression, text data compressed for each unit block, and a compression size table are recorded. The data of the search target item corresponding to the search key information input by the user can be quickly and accurately read out from the CD-ROM 200 of the electronic book system created in this way, and can be compressed and decompressed for use.
[0135]
Further, since the body data is compressed for each unit block of a predetermined size and recorded on the CD-ROM, the processing unit for reading the body data and the compression / decompression process can be reduced. For this reason, without reading the text data from the CD-ROM and the compression / decompression process, it is possible to retrieve the data of the search target item corresponding to the search key information from the text data recorded on the CD-ROM. Can be obtained quickly.
[0136]
In addition, since the index information that has already been created can be used as it is, there is a problem in an electronic book system with a large amount of content in which more text data is recorded by compressing the text data and recording it on a CD-ROM. It is possible to migrate without any problems.
[0137]
In the above-described embodiment, it has been described that the body data before compression and the head of the body data after compression coincide with the head of the body data area of the CD-ROM 200. However, when the text data of a plurality of documents is recorded on the CD-ROM, the positions of the text data of each document on the CD-ROM are different.
[0138]
Therefore, when the body data before compression of each document is recorded, information such as the head position information of the body data, the head position information of the body data after compression, or the data amount of the divided block is stored in the CD-ROM. It is stored in the TOC (table of contents) or other area of the CD-ROM, and the unit block before compression is the unit block of the body data, or the unit block before compression In this case, it can be used when calculating the amount of data from the head of the search target item data corresponding to the search key information to the head position of the search target information. Even when body data is recorded, it can be handled without any problem.
[0139]
Further, even if the index information or the compression size table creates the head of the text data of these information as, for example, 0000H, the text when the text data before compression of each document is recorded as described above. As described above, it corresponds to the search key information by recording information such as the head position information of the data, the head position information of the compressed body data, or the data amount of the divided blocks on the CD-ROM. The data of the search target item to be acquired can be acquired.
[0140]
In the above-described embodiment, the unit block has been described as having a size of 4096 bytes (about 4 kilobytes), but is not limited thereto. It can be increased or decreased in consideration of the storage capacity of the memory of the information retrieval apparatus, the data reading speed from the CD-ROM, the time required for compression / decompression processing, and the like.
[0141]
In the above-described embodiment, the accumulated value of the data amount for each unit block after compression is recorded in the compressed size table in association with each unit block as the compressed size. It is not limited to.
[0142]
For example, a compressed size table in which the data amount itself for each unit block after compression is associated with each unit block may be created. In other words, create a compression size table so that the amount of data after compression of each unit block can be known, such as how many bytes of data after compression of the first unit block and how many bytes of data of the second unit block. To do.
[0143]
Thus, the head position of the text data after compression of the target unit block can be obtained by adding the amount of data after compression from the head unit block to the target unit block. In addition, the data amount after compression of the target unit block is calculated from the total value of the data amount after compression from the head unit block to the target unit block, from the head unit block to the target unit block. It is obtained by subtracting the total value of the data amount after compression up to the previous unit block. Thus, even when the compression size table is created so that the data amount after compression of each unit block can be known, the data amount after compression of the target unit block and its head recording position are obtained, and the CD-ROM is obtained. It can be read from and used.
[0144]
In the above-described embodiment, the CD-ROM is used as a recording medium for the electronic book system, but the present invention is not limited to this. Various recording media such as a so-called floppy disk and a miniature magneto-optical disk called a mini disk (MD) and a DVD (digital video disk) can be used.
[0145]
Further, as text data of documents, not only text data but also graphics data can be processed in the same manner.
[0146]
Moreover, although the above-described information retrieval apparatus has been described as dedicated to an electronic book system, the present invention is not limited to this. For example, the present invention can be applied to an information processing apparatus such as a personal computer.
[0147]
【The invention's effect】
As described above, according to the present invention, since data can be compressed and recorded on a recording medium, more data can be recorded on the recording medium. In addition, for data to be compressed and recorded, if there is index information for the data before compression, even if the data is compressed and recorded on a recording medium, the existing index information is used, Search processing can be performed.
[0148]
In addition, compression of data to be recorded on a recording medium is necessary to specify a processing unit because the data is divided into unit blocks of a predetermined size and compressed for each unit block. Since the additional information is small and the calculation for the identification is simple, a reasonable and high-speed search process can be performed.
[Brief description of the drawings]
FIG. 1 is a block diagram for explaining an embodiment of an information recording apparatus according to the present invention.
FIG. 2 is a diagram for explaining an example of electronic book standard index information;
FIG. 3 is a diagram for explaining an example of electronic book standard index information;
FIG. 4 is a diagram for explaining information compression processing performed in an embodiment of an information recording apparatus according to the present invention;
FIG. 5 is a diagram for explaining a compressed size table created in an embodiment of an information recording apparatus according to the present invention;
FIG. 6 is a flowchart for explaining information compression processing and compression size table creation processing performed in an embodiment of the information recording apparatus according to the present invention;
FIG. 7 is a block diagram for explaining an embodiment of an information retrieval apparatus according to the present invention;
FIG. 8 is a flow chart for explaining an operation at the time of information search processing of the embodiment of the information search device according to the present invention;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Index information generation part, 2 ... Text data generation part, 3 ... Data division part, 4 ... Data compression part, 5 ... Compression data generation part, 6 ... Write control part, 11 ... Optical pick-up, 12 ... Two-axis device, DESCRIPTION OF SYMBOLS 13 ... Spindle motor, 14 ... Driver, 15 ... RF amplifier, 16 ... Signal processing part, 17 ... Display control part, 71 ... Display RAM, 18 ... Display panel, 100 ... CPU, 101 ... ROM, 102 ... RAM, 103 ... Key operation unit, DT ... Text data before compression, DTA ... Text data after compression, TB ... Compression size table

Claims (2)

A plurality of search objects used in an information search apparatus comprising a reading means for reading data from a recording medium, a compression / decompression means for compressing / decompressing the read data, and a data output means for outputting the compressed / decompressed data Index information for detecting the first recording position for each of the search target items when the body data including the items are sequentially recorded on a recording medium without a break for each of the search target items, key information for search As an information search method for detecting the target search target item from body data including the plurality of search target items that are compressed and recorded,
On the recording medium, the body data is divided into predetermined equal amounts of data, and compressed in units of the divided data are sequentially recorded so that the recording positions are continuous. In addition to the index information, a compressed size table in which an accumulated value of the compressed data size for each divided data unit is described in association with each divided data is recorded,
Based on the index information , the reading means specifies the data amount up to the address indicating the start position of the specified search target item, and the data amount up to the address indicating the start position is set to the predetermined size. By dividing by the data amount, the divided data unit including the head position is specified, and after the compression corresponding to the specified divided data unit based on the accumulated value of the compressed data size of the divided data A step of reading out the body data corresponding to the specified divided data unit from the recording medium, specifying the recording start position of the body data and the data amount thereof,
A compression / decompression step of decompressing the compressed body data of the divided data unit read by the readout unit in the readout step by the compression / decompression unit ;
The search target item from the head position of the designated search target item detected based on the index information in the data compressed and decompressed by the compression and decompression unit in the compression and decompression step by the data output unit. An information retrieval method comprising: a target data output step for outputting the data of Search for index information for detecting a head recording position for each search target item when body data including a plurality of search target items is sequentially recorded on a recording medium without a break for each search target item An information search device for detecting the target search target item from text data including the plurality of search target items that are compressed and recorded as key information for
Wherein the recording medium, the text data is divided into each data of a predetermined equal size, which has been compressed by the divided data units, with are sequentially recorded as recording position successively , the accumulated value of the data size after compression divided per data unit is compressed size table that is described in association with each divided data are recorded in addition to the index information,
A loading unit for the recording medium;
Search key information input means for receiving input of search key information for searching for a target search target item;
Based on the index information corresponding to the search target item corresponding to the search key information input through the search key information input means, specify the data amount up to the address indicating the start position of the specified search target item , By dividing the data amount up to the address indicating the head position by the data amount of the predetermined size, the divided data unit including the head position is specified, and the accumulated data size of the divided data is compressed. Based on the arithmetic value, the recording start position of the compressed body data corresponding to the specified divided data unit and the data amount thereof are specified, and the body data corresponding to the specified divided data unit is recorded in the recording Reading means for reading from the medium;
Compression and decompression means for decompressing the compressed body data compressed in units of the divided data read by the readout means;
Target data output means for outputting data of the search target item from the head position of the specified search target item detected based on the index information in the data compressed and decompressed by the compression / decompression means; An information retrieval device provided.

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