Abstract:
An automatic translating apparatus stores in a memory in machine readable format a plurality of translation combinations. Each translation combination includes (1) a predetermined part of speech such as an auxiliary verb of a source language like English, (2) a usage condition of that word, and (3) a translation word in a target language such as Japanese. A machine readable dictionary includes a plurality of entries. Each dictionary entry includes a source language word and a corresponding general translation word. A translation word is selectively retrieving from the translation combination memory or the general translation word stored in the dictionary based on the text of the source language and the usage condition of that word in the text. If a source text word corresponds to the predetermined part of speech, the source text word and its usage condition (e.g., the type of sentence in which the word is used) is matched to the translation combinations stored in memory. If there is a match, the corresponding translation word is retrieved from the memory. If there is no match, a general translation word is retrieved from the dictionary.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus for automatically translating a language and a method thereof. 
     2. Description of the Related Art 
     In general, an automatic translating apparatus reads a source text written in a source language (for example, English) and carries out morphological analysis. Then, a dictionary for translation is accessed to obtain grammatical information such as the part of speech for each word and a corresponding translation word for the target language, followed by analysis of the tense, person, number, and the like. An internal structure of the source language as a result of the morphological analysis and rules prepared in advance for that source language. The internal structure of the source language is transformed into an internal structure of the target language using a transformation rule. In accordance with the transformed internal structure, a translated sentence in the target language is generated using the translation words obtained by the dictionary look-up process during the morphological analysis. 
     In order to obtain an appropriate translation of the target language, an appropriate selection of a translation word for the target language is important. The selection of a translate on word conventionally includes the problems set forth in the following . 
     For example, the English language has the following problem regarding the auxiliary verb. Differing from other parts of speech such as the verb and noun, the auxiliary verb varies in its translation according to the &#34;circumstance&#34; in which it is used. This circumstance includes conditions such as whether the sentence including that word is an affirmative sentence or a negative sentence, or whether it is a declarative sentence or an interrogative sentence. Because the translation varies according to its circumstance as in the case of an auxiliary verb, just a simple translation setting will have a great side effect, making it harder to obtain an appropriate translation. For example, the word &#34;may&#34; alone will be translated into &#34;suru kamo shirehal&#34; in Japanese. In contrast, in the case of &#34;may not&#34;, the translation should be &#34;shite wa ikenai&#34; Therefore, an adequate result can not be obtained just by setting a translation for an auxiliary verb of the English language to translate into a target language, for example Japanese. 
     In order to solve such a problem, there is a device having the priority allocated in advance for a translation word. A plurality of translation words are displayed according to this priority at the time of translation, whereby the operator selects an appropriate one. An example of such a technique is disclosed in Japanese Patent Laying-Open No. 61-90272. 
     A known improvement to the above-described technique includes update of the priorities of the translation words based on a learning process of the result selected by the operator. Such a technique is disclosed in Japanese Patent Laying-Open No. 63-136265, for example. 
     However, if the priorities for translation words are allotted and the display for selection is carried out according to the priority, the order of the displayed translation word or the selected result may not be appropriate for some subjects to be translated. 
     For example, consider the English auxiliary verb &#34;shall&#34;. When the sentence including &#34;shall&#34; is an affirmative and declarative sentence in the first person, the translation output is &#34;SURU DARO&#34;, otherwise &#34;SURU KOTO NI NATTEIRU&#34;. However, in the case of translating a document related to the patent field, for example, the auxiliary verb &#34;shall&#34; should be output as &#34;subeki&#34; in most cases. In contrast, it is better to output the above former translation in a general literature. 
     In a conventional device where a priority is fixedly allocated to each translation word, the operator had to specify an appropriate translation for substitution every time this auxiliary verb appears in a sentence. In a conventional device where the display order of a translation word is changed according to a learning process of selected results, the learned result could be reflected only after the selection process was carried out several times in the case of translating documents of particular field such as patent related documents. Furthermore, the learned result obtained during translation of particular documents such as patent related documents would be lost if translation of a document of another field is carried out or when the power of the device is turned off. When the translation of a document of the same particular field such as patent related document is to be carried out subsequently, the specification of an appropriate translation had to be newly carried out. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, an object of the present invention is to provide a method and an automatic translating apparatus that can carry out more appropriately translation of a source text including a word of a particular part of speech that must have its translation varied according to the used environment. 
     Another object of the present invention is to provide a method and an automatic translating apparatus that can carry out more easily and appropriately translation of source texts of the same field or same area including a word of a particular part of speech that must have its translation varied according to the used environment. 
     A further object of the present invention is to provide a method and an automatic translating apparatus that can carry out more easily and appropriately translation of source texts of a plurality of fields or a plurality of various areas including a word of a particular part of speech that must have its translation varied according to the used environment. 
     An automatic translating apparatus according to the present invention includes: a memory device; a device for preparing in advance in the memory device in a machine readable format a plurality of translation combinations constituted by a predetermined part of speech word, for example an auxiliary verb of a predetermined source language (for example, English), an appearing condition of that word, and a translation word of a predetermined target language (for example, Japanese) selected in advance based on the word and the appearing condition; a machine readable dictionary including a plurality of entries, each entry including a word in the source language and a translation word selected in advance as a general translation of that word; a module for selectively retrieving a translation for a word from the translation combination or the dictionary based on each of the words included in the text of the source language and the appearing condition in the text of that word; and a module for translating the text of a source language into the text of a target language using the translation words extracted for each of the words in the text of the source language by the retrieve module. 
     In this automatic translating apparatus, a plurality of translation combinations are prepared in advance in the memory device in a machine readable format. At the time of translating the text of the source language, a translation word is selectively retrieved from the translation combinations or dictionary stored in the memory device according to each of the words of a particular part of speech included in the text of the source language and the appearing condition in which each word appears in that text, whereby translation of tile text is executed according to the extracted words. Because a translation word can be extracted from the translation combinations in the memory device when a certain word appears under a particular condition, a word required to have its translation varied according to the appearing condition can be output as an appropriate word. 
     A method of automatic translation according to the present invention is to translate a text of a source language into a text of a target language in an automatic translating apparatus including a memory device and a module for translating the text of the source language into the text of the target language by receiving the text having a translation word of the target language allocated to each word of the text of the source language. This method includes the steps of: preparing in advance in the memory device in a machine readable format a plurality of translation combinations including a predetermined part of speech word of the source language, the appearing condition of that word, and the translation word in the target language selected in advance according to that word and the appearing condition; and preparing a machine readable dictionary including a plurality of entries, each including a word of the source language, and a translation word thereof selected in advance as a general translation. This method further includes the steps of: selectively retrieving a translation word of a word from the translation combinations or the dictionary according to each word included in the text of the source language and the appearing condition in the text of that word; and translating the text of the source language into the text of the target language using the retrieved translation words. 
     In this automatic translating method, a plurality of translation combinations are prepared in advance in a memory device in a machine readable format. At the time of translating the text of the source language, a translation word is selectively retrieved from the translation combinations or dictionary stored in the memory device according to each of words of a certain part of speech included in the text of the source language and the appearing condition in the text, whereby translation of the text is executed according to the retrieved words. Because a translation word can be retrieved from the translation combinations in the memory device when a certain word appears under a particular condition, a word whose translation word should be selected according to the appearing condition can be translated appropriately. 
     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a machine translating apparatus according to an embodiment of the present invention. 
     FIG. 2 is a block diagram of a translation user interface module. 
     FIG. 3 is a block diagram of a translation module. 
     FIG. 4 is flow chart of a buffer creation process for auxiliary verb translation specification. 
     FIG. 5 schematically shows an auxiliary verb selection menu. 
     FIG. 6 schematically shows a condition specify menu. 
     FIG. 7 schematically shows a translation specify menu. 
     FIG. 8 is a flow chart showing the auxiliary verb translation allocation process in generating a translation sentence. 
     FIG. 9 schematically shows a condition select menu of after a translation word is selected. 
     FIG. 10 schematically shows three typical auxiliary verbs and translation candidates allocated by the appearing conditions. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of the present invention will be described in detail hereinafter with reference to the drawings. Although the following embodiment is described of machine translation from English to Japanese, the present invention is not limited to this and can similarly be applied to other languages such as from Japanese to English, between Japanese and a language other than English, or between languages other than Japanese. 
     FIG. 1 is a block diagram of a machine translating apparatus according to an embodiment of the present invention. Referring to FIG. 1, a machine translation apparatus includes a translation user interface module 1, a translation module 2, a dictionary/rule 3 storing dictionary for translation, grammatical rules, and a tree structure transformation table, a memory for translation 4, a CRT (Cathode Ray Tube) 5 and a keyboard 6 connected to translation user interface module 1, a document file 8 connected to translation user interface module 1, and a printer 7 connected to translation user interface module 1. 
     Referring to FIG. 2, translation user interface module 1 includes a control unit 9 for reading out an externally applied request such as via a key input by a user through keyboard 6 and for calling each of the modules which will be described in the following. Translation user interface module 1 further includes a translation unit 10, a source language editor 11, a target language editor 12, a document input/output module 13, an environment specifying module 14, an auxiliary verb specifying module 15, a learning module 16, an option dictionary selection module 17, a dictionary maintenance module 18, an original sentence checking module 19, and a printer module 20, all connected to control unit 9. 
     Referring to FIG. 3, translation module 2 shown in FIG. 1 includes a dictionary look-up/morphological analysis unit 22 for reading out an original sentence 21 stored in memory 4 of FIG. 1 to carry out dictionary look-up/morphological analysis, a syntax analysis unit 23 for carrying out a syntax analysis according to the processing results of dictionary look-up/morphological analysis unit 22 to obtain an internal structure (tree structure and the like) of original sentence 21 in the source language, a transforming unit 24 for transforming the obtained internal structure into an internal structure of a target language by referring to a tree structure transformation table included in dictionary/rule 2 (refer to FIG. 1), and a generating unit 25 for generating a translation sentence 26 in the target language according to the transformed internal structure of the target language. 
     Referring to FIG. 1 again, keyboard 6 serves to provide to translation user interface module 1 various commands and information for the maintenance of dictionary/rule 3 according to a manual operation of the user. Dictionary/rule 3 stores dictionaries and grammatical rules for translation, a tree structure transformation rule table and the like, as mentioned above. The dictionaries included in dictionary/rule 3 include a user dictionary, a specialized dictionary, a learning dictionary and the like. The process for selecting an option of these dictionaries is carried out by option dictionary selection module 17 shown in FIG. 2. The maintenance of the dictionaries such as registration and deletion of the headings of these dictionaries is carried out by dictionary maintenance module 18 shown in FIG. 2. Dictionary maintenance is well known and will not be described in detail here. 
     Referring to FIG. 2, translation unit 10 calls up translation module 2 shown in FIG. 1. Document file input/output module 13 carries out the input and output of an original sentence and a translation sentence with document file 8 shown in FIG. 1. Learning module 16 and dictionary maintenance module 18 serve to process the dictionaries included in dictionary/rule 3. An internal buffer is provided in memory 4 of FIG. 1 for storing information indicating which translation word in Japanese is to be assigned according to the environment of the appearing word for each English auxiliary verb. Auxiliary verb translation specifying module 15 of FIG. 2 serves to store in internal buffer in memory 4 a combination constituted by a word of the source language, the appearing condition thereof, and a translation thereof used by the user via keyboard 6 and CRT 5 shown in FIG. 1. 
     The operation of this machine translating apparatus is set forth in the following. First, the operation of auxiliary verb translation specifying module 15 will be described with reference to FIG. 4 to specify which translation word is to be assigned according to the appearing condition of an auxiliary verb for each English auxiliary verb. 
     The conditions required for specific translation of an auxiliary verb are as follows. In the present embodiment, affirmative/negative is set as condition 1 and declarative/interrogative is set as condition 2 by which the appearing conditions are classified to select a translation word. The appearing condition of one auxiliary verb is classified into four cases of (affirmative-declarative), (affirmative-interrogative), (negative-declarative), and (negative-interrogative). 
     In the present embodiment, one translation word is specified for each of the above-described four types of conditions for each auxiliary verb. A buffer for storing one translation word with respect to each set of an auxiliary word and condition is prepared in memory 4 of FIG. 1. 
     The data structure of the internal buffer prepared in memory 4 is shown in the following Table 1. 
     
                       TABLE 1______________________________________Auxiliary               TranslationVerb   Usage Type       Word______________________________________may    affirmative/declarative                   subeki de arumay    affirmative/interrogative                   SYSTEM.sub.-- DEPENDmay    negative/declarative                   SYSTEM.sub.-- DEPENDmay    negative/interrogative                   SYSTEM.sub.-- DEPENDcan    affirmative/declarative                   SYSTEM.sub.-- DEPENDcan    affirmative/interrogative                   SYSTEM.sub.-- DEPENDcan    negative/declarative                   SYSTEM.sub.-- DEPENDcan    negative/interrogative                   SYSTEM.sub.-- DEPENDshall  affirmative/declarative                   beki de arushall  affirmative/interrogative                   YAKUSHUTU SINAIshall  negative/declarative                   beki de naishall  negative/interrogative                   SYSTEM.sub.-- DEPEND.      .                ..      .                ..      .                .______________________________________ 
    
     The words represented by large alphabet letters in Table 1 mean that a particular translation is not stored in the internal buffer, and that a predetermined process is to be carried out according to the flag represented by these large alphabet letters. The flag &#34;SYSTEM --  DEPEND&#34; indicates &#34;follow system specific translation&#34;. This means that a process similar to the conventional case is carried out when this flag is indicated. The flag &#34;YAKUSHUTSU --  SINAI&#34; indicates &#34;do not provide a translation of this auxiliary verb&#34;. This means that the corresponding translation is to be generated as a NULL character string. 
     Referring to FIG. 4, a translation combination (auxiliary verb-condition-translation) is specified by the user as set forth in the following. 
     At step 27, a process of selecting an auxiliary verb of which a translation is to be determined is carried out. A display example is shown in FIG. 5. Referring to FIG. 5, a list of auxiliary verbs used in a source language (in the present embodiment, English) is displayed as headings 40 on the display screen. The user moves the cursor onto an auxiliary verb to be selected and then depresses the return key (not shown) on keyboard 6. 
     Referring to FIG. 4 again, specification of the two conditions (declarative/interrogative) and (negative/affirmative) is carried out at steps 28 and 29. An example of this specification is shown on the display screen of FIG. 6. Referring to FIG. 6, four combinations of the first condition 41 and the second condition 42 are displayed on the screen with a respective specified translation 43 for each set. In FIG. 6, those having the flag &#34;SYSTEM --  DEPEND&#34; specified as the &#34;Translation Word&#34; of Table 1 is represented by &#34;SYSTEM SPECIFIED TRANSLATION&#34; and those specified with the flag &#34;YAKUSHUTSU SINAI&#34; is represented by &#34;&lt;no translation&gt;&#34;. By moving the cursor to a corresponding section of a corresponding combination of conditions and depressing the return key, the selection process of conditions is completed. The example shown in the menu of FIG. 6 has &#34;negative-declarative&#34; sentence specified as the condition. 
     At step 30 in FIG. 4, translation candidates prepared in advance in the system are displayed. This display of candidates is shown in FIG. 7. Referring to FIG. 7, a heading 44 indicating the specified condition and the current specified translation (currently in the present embodiment &#34;system specified translation&#34;) and translation candidates 45 are displayed on the display screen. 
     At step 31, the user selects a desired translation from the translation candidates displayed at step 30. This selection is carried out by moving the cursor to a translation to be selected under the display state shown in FIG. 7 and depressing the return key. 
     At step 32, a selected auxiliary verb, an appearing condition specified for that auxiliary verb (&#34;negative/declarative&#34; in this case), and a selected translation (&#34;BEKIDENAI&#34;) as a translation combination is set in the auxiliary verb specifying buffer. The process of step 32 will complete the translation specifying process for one auxiliary verb. As a result of this specification, the display will be shown in FIG. 9, where a specified translation for &#34;negative/declarative&#34; sentence is displayed as &#34;bekidenai&#34;. 
     By carrying out the above-described steps of 27-32 for all the auxiliary verbs which a translation is to be specified and all the appearing conditions thereof, the auxiliary verb translation specification buffer is completed. The actual translation is carried as set forth in the following using this auxiliary verb translation specification buffer. 
     Referring to FIG. 3, an original sentence 21 (read out from document file 8 of FIG. 1 and stored in memory 4) is subjected to morphological analysis by dictionary look-up/morphological analysis unit 22. More specifically, each word in original sentence 21 is looked up in the translation dictionary in dictionary/rule 3 to obtain grammatical information such as the part of speech and a translation word for carrying out an analysis process regarding the tense, person and number. 
     Then, an internal structure of the source language is obtained based on the output of dictionary look-up/morphological analysis unit 22 and the grammatical rules included in dictionary/rule 3 (refer to FIG. 1) by syntax analysis unit 23. 
     Transformation unit 24 shown in FIG. 3 refers to the tree structure transformation rule table included in dictionary/rule 3 (refer to FIG. 1) for transforming the internal structure of the source language obtained by syntax analysis unit 23 into the internal structure of the target language. The converted internal structure is supplied to generating unit 25. 
     Generating unit 25 allocates a translation word for each word in the internal structure of the target language while referring to the basic dictionary for target language generation included in dictionary/rule 3 (refer to FIG. 1) and the auxiliary verb translation specification buffer, which is the characteristic of the present invention, prepared in memory 4 of FIG. 1 to generate a translated sentence 26. The selection of a translation word represents the feature of the present invention. Assignment of a translation will be described hereinafter with reference to FIG. 8. For the sake of simplicity, it is assumed that the word which is subject to translation is already identified as to be an auxiliary verb, and only the process of which translation word is to be allocated for that word will be described. 
     Referring to FIG. 8, a process to specify an auxiliary verb which is to be processed is carried out at step 33. 
     At step 34, the use of the sentence being analyzed is referred to. More specifically, determination is made whether the auxiliary verb to be processed appears in an affirmative sentence or a negative sentence (condition 1), and in a declarative sentence or an interrogative sentence (condition 2). 
     At step 35, a process to refer to the auxiliary verb translation specification buffer is carried out to identify whether there is a translation combination matching the auxiliary verb and appearing conditions specified at steps 33 and 34 in the auxiliary verb translation specification buffer. 
     At step 36, determination is made whether a translation is specified for the relevant auxiliary verb and condition as the result of the referring process of step 35. If specification has been made, a process of retrieving a translation word from the translation combination is carried out at step 37. Otherwise, a process of retrieving a translation word from a basic dictionary and assigning that word is carried out at step 38. 
     At step 39, a process of setting the translation word retrieved at step 37 or 38 is carried out in the buffer for generating a translation sentence. 
     With a translation word specified in advance by the user according to the appearing condition for an English auxiliary verb, a translation procedure set forth in the following is carried out. As an example, it is assumed that the system specified translation word in the basic dictionary for the auxiliary verb of &#34;shall&#34; is &#34;koto ni natteiru&#34;. The user has specified the translation word of &#34;bekidenai&#34; when the condition is &#34;negative/declarative&#34;, as described in the foregoing. Consider the translation of the following English sentence: 
     You shall not copy this software. 
     If this sentence is translated using the system specified translation, the result will be a Japanese sentence: 
     which literally means &#34;You will not copy this software.&#34; This result does not properly represent the meaning of the original English sentence. If the translation combination set in the auxiliary verb specification buffer is used, the above English sentence will be translated into the Japanese sentence of: 
     which means &#34;You must not copy this software.&#34; This result is closer to the actual meaning of the original sentence. Thus, a translation according to the specification of the user can be carried out for an auxiliary verb included in the original sentence by preparing, in the auxiliary verb translation specification buffer, translation combinations of each of the auxiliary verbs, the appearing condition thereof, and a corresponding translation word when that appearing condition is met which are specified by carrying out the procedures shown in FIG. 4. By preparing in advance a set of user&#39;s specifications so that appropriate translation is carried out according to the related field, translation of documents of a particular field or area can be carried out in a more appropriate manner. 
     In the above description, the specification of an auxiliary verb translation by the user is carried out in an auxiliary verb translation specification buffer prepared on memory 4. If memory 4 is a DRAM (Dynamic Random Access Memory), the contents of the auxiliary verb translation specification buffer will be lost when the power of the apparatus is turned off and the buffer is not backed-up. If the contents of this auxiliary verb translation specification buffer is saved in non-volatile memory device 3 in which dictionaries and rules are stored, and by reading out the data to memory 4 prior to calling up translation module 2, the above-described operation can be carried out width no problem. In this case, the auxiliary verb translation specification buffer can be provided in a continuous region on the memory. This is because, although the buffer has a particular data structure, the buffer does not include index such as a pointer to another area. Thus, this buffer may take an array format, for example. 
     Because the auxiliary verb translation specification buffer may be provided in a continuous area, data transfer between memory 4 and memory device 3 storing the dictionaries and rules can be carried out in a manner of block transfer. More specifically, the contents of the auxiliary verb translation specification buffer is saved by block transferring from memory 4 the same to a file on memory device 3 while maintaining the structure thereof. The read out operation from memory device 3 is carried out by transferring and directly writing in the units of blocks the contents read out from the file into the auxiliary verb translation specification buffer area provided on memory 4. This is possible because the structure on the memory is saved just as it is in the file. 
     Such a process can directly employ the general process of the conventional processing of files. 
     The structure of the auxiliary verb translation specification buffer can be made more sophisticated, and data for auxiliary verb translation specification may be held in the file under a structure other than that of the memory. In any case, the element of the translation combination of the information held in the buffer is the translation combination of an auxiliary verb, an appearing condition, and a translation word thereof. The save format of the file is arbitrary as long as it is of a structure that can restore the translation combination. Such a data transfer between a memory and a file can easily be implemented with the conventional techniques used in currently available editors, word processors and data bases. 
     A plurality of files of auxiliary verb translation specification information can be provided in advance in memory 3. Each file is registered with a name specified by the user according to the contents thereof via the keyboard at the time of file register. The contents thereof are prepared individually for each file. In reading out auxiliary verb translation specification information from a file, the most appropriate file is selected to be read out from the plurality of files to be developed in memory 4. By providing a plurality of files and saving a plurality of sets of appropriate translation combinations to translate documents of a particular field and area for each file, translation is possible based on more appropriate translation words for documents of various fields and areas in comparison with the case where translation is carried out using general translation words. 
     The specification of a file name may be carried out by the user via keyboard 6. Alternatively, when a user dictionary is selected, a selection system can be taken where a file name assigned in advance in the user dictionary is automatically indicated. This can be realized by various methods such as establishing an auxiliary verb translation specification file name by adding an extension to the name of the user dictionary. 
     FIG. 10 shows a list of translation candidates indicating which translation is to be assigned for the aforementioned four conditions regarding the three typical English auxiliary verbs of &#34;may&#34;, &#34;can&#34;, and &#34;shall&#34;. The list of candidates shown in FIG. 10 is only a way of example, and other appropriate translation words can be specified according to each user&#39;s experience. 
     Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.