Document processing apparatus.

BACKGROUND OF THE INVENTION

(l)

Field of the Invention

0001The present invention relates generally to a document processing apparatus, and more specifically to a document processing apparatus which can from a logical document architecture with respect to chapters, itemized statements, paragraphs, etc. of a document.

(2)

Description of the Prior Art

0002In general, a document is divided into a plurality of blocks, and headings are assigned to the respective blocks to facilitate reading of the document. Further, each block is divided into subblocks, and subheadings are assigned to the respective subblocks. The headings and subheadings are composed of short sentences, and additionally heading symbols are often added to these introductory portions, for instance, such as "Chapter l" or "Section 3", respectively. When documents having the hierarchical structure as described above is processed by a computer, the following problem arises: In the conventional document processing systems, since document data are processed in units of frames on the display or of pages of printing sheets, where a given chapter is required to be replaced with another, both the start and end positions of the document data to be moved elsewhere should be designated by the cursor. In this case, if the document data of the any given chapter is long, the display screen must be scrolled many times from the start position to the end position to be designated. The above screen scrolling is troublesome and tends to result in operational errors.

0003When an operator drafts a document, he often wishes to see the previous sentenses, for instance, to check the contents of the previous sentences and the kinds of the previous heading symbols. In this case, he must guess the page and the position of the line which include the required sentence and heading symbol to be checked, and thereafter must search the desired sentence and heading symbol. The above search operation is troublesome and therefore the document drafting efficiency is greatly degraded.

0004To solve the above-mentiioned problem, the same applicant and the same inventors have already filed a novel document processing apparatus which comprises document data inputting means; heading dictionary means; heading rule dictionary means; heading deciding means; document architecture rule dictionary means; and document architecture deciding means.

0005The above document processing apparatus can prepare a logical document hierarchical architecture list by handling documents in units of items in order that the operator can readily designate any given headings, itemized statements, paragraphs for easy document editing.

0006In the above document processing apparatus, however, since document architecture is decided in accordance with only the document architecture dictionary, there exists a problem such that heading is decided erroneously. For instance, a heading "2.2 Class Training" can be decided as an addition of "2.2" (Heading Symbol) and "Class Training" (Heading Word) or of "2" (Heading Symbol) and "2 class Training" (Heading Word). Furhter, where itemized statement of "l ... ", "2 ... ", "3 ... ", and "4 ... " exist under a chapter heading "4 ... " and further "5 ... " follows, the "5 ... " can be decided as a chapter heading or an itemized heading.

0007Therefore, when the document architecture univocally decided by the computer is different from that intended by the user, the user should modifly the document architecture to an intended one, thus resulting in maloperability.

SUMMARY OF THE INVENTION

0008With these problems in mind, therefore, it is the primary object of the present invention to provide the document processing apparatus with an additional function such that a plurality of document architecture candidates can be decided and the operator can readily select any one of desired candidate for providing a better operability.

0009To achieve the above-mentioned object, the document processing apparatus according to the present invention comprises:     means for inputting document data; heading dictionary means for storing words and phrases frequently used as a heading; heading candidate extraction means for extracting, as a heading candidate, the word and phrase corresponding to the heading stored in said heading dictionary means from the document data input through said input means; heading rule dictionary means for storing rules for deciding the headings; heading deciding means for checking the heading candidate extracted by said heading candidate extracting means in accordance with the heading rule stored in said heading rule dictionary means and for deciding whether the heading candidate is a heading; document architecture rule dictionary means for storing rules associated with document logical architectures; document architecture deciding means for deciding the document architecture of a heading decided by said heading deciding means and the sentence decided as a non-heading in accordance with document architecture rules stores in said document architecture rule dictionary means; and, in particular, document architecture selecting and indicating means for allowing an operator to select a desired document architecture when the document architecture deciding means decides a plurality of document architecture candidates in accordance with document architecture rules.

0010The document architecture selecting and indicating means comprises rule application deciding means and candidate selecting and indicating means. The rule application deciding means is accessible to the document architecture rule dictionary to check a rule name reguesting candidate selection and to retrieve flags corresponding to the rule name from a table. The candidate selecting and indicating means is accessible to a candidate selecting key provided in the document input means to update flags so that any desired document architecture can be selected.

0011Further, the document architecture rule dictionary stores rule application record information indicative of past rule application situations, and the document architecture deciding means decides an architecture rule to be applied with reference to the stored rule application record information. The above record information can be updated.

BRIEF DESCRIPTION OF THE DRAWINGS

0012<ul id="ul0001" list-style="none"><li>Fig. l is a block diagram of the document processing apparatus according to the present invention;</li><li>Fig. 2 is an example of documents;</li><li>Fig. 3 is an examplary heading word dictionary;</li><li>Figs. 4A to 4D are an examplary heading rule dictionary;</li><li>Fig. 5 is a flowchart showing the operation procedure of the apparatus shown in Fig. l;</li><li>Figs. 6A to 6F show an examplary sequence of logical document architecture lists stored in the logical architecture storage,</li><li>Figs. 7A to 7C show few examples of application of heading rules shown in Figs. 4A to 4P to the document shown in Fig. 2;</li><li>Fig. 8 shows an example of stored rule tables including flags corresponding to rule names; and</li><li>Fig. 9 is a flowchard showing a procedure of the operation of the rule application decision section.</li></ul>

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

0013With reference to the attached drawings, the document processing apparatus according to the present invention will be described in detail hereinbelow:

0014With reference to Fig. l, a document processor l is connected to an input device 2 including a keyboard for achieving centralized handling and processing input documents. The document processor l is also connected to an original document storage 3 for storing input original documents and to a display controller 4 for causing a display 5 to indicate the input original document read out from the storage 3. The document processor l is furhter connected to a heading extractor 6, a heading decision section 8, a document architecture decision section 9, and a logical architecture storage l0. The heading extractor 6 is connected to a heading word dictionary 7 for storing many types of words representative of headings. The heading decision section 8 includes a heading rule dictionary 8a. The document architecture decision section 9 includes a document architecture rule dictionary 9a.

0015The document processor l sequentially detects document data segmentation codes stored in the original document storage 3, for example, such as a line return code, and extracts sentences segmented by the segmentation code. In this case, the document processor l measures each sentence length. The extracted sentences are sequentially sent to the heading extractor 6. The heading extractor 6 decides the heading word by comparison of the input sentence with heading words stored in the heading word dictionary 7, and the sentence length.

0016The heading word dictionary 7 stores frequently used words, phrases and symbols, all of which are defined as heading words. The words, phrases and symbols are classified into categories, as shown in Fig. 3, and are registered in advance in the dictionary 7. Words such as "introduction" and "abstract" are registered in a category of "reserved heading word". In addition, frequently used numerals and symbols are also registered as heading words being classified into the respective categories.

0017The heading extractor 6 decides whether the number of characters of an extracted sentence is less than a predetermined number. In other words, the extractor 6 decides whether an extracted heading word (a word and/or phrase, and/or numeral and/or symbol represented as a code string) corresponds to one of words registered in the dictionary 7. If a correspondence is detected, the extracted word is recognized as the corresponding heading word.

0018The extracted words decided by the extractor 6 as being the heading word are input, one by one, to the heading decision section 8, under the control of the processor l. The heading decision section 8 decides, in accordance with the heading rules (Figs. 4A to 4D) stored in the dictionary 8a, whether the recognized heading word is a heading word or another word.

0019The word discriminated as the heading word or any other word by the heading decision section 8 is input to the document architecture decision section 9 under the control of the processor l. The architecture decision section 9 decides whether the sentence or word sent from the heading decision section 8 is a chapter heading, a section heading, or a paragraph, in accordance with the document architecture rules (shown below) stored in the document architecture rule dictionary 9a: <tables id="tabl0001" num="0001"><img file="EP0241646A2_D0001.tif" /></tables><tables id="tabl0002" num="0002"><img file="EP0241646A2_D0002.tif" /></tables><tables id="tabl0003" num="0003"><img file="EP0241646A2_D0003.tif" /></tables><tables id="tabl0004" num="0004"><img file="EP0241646A2_D0004.tif" /></tables><tables id="tabl0005" num="0005"><img file="EP0241646A2_D0005.tif" /></tables><tables id="tabl0006" num="0006"><img file="EP0241646A2_D0006.tif" /></tables>

0020The logical architecture of a sentence or word, as determined by the document architecture decision section 9 in accordance with the above rules, is stored in the logical architecture storage l0.

0021The display controller 4 controls the display 5 to display the document data according to the document logical architecture stored in the logical architecture storage l0.

0022The operation of the document processing apparatus will now be described with reference to the flow chart shown in Fig. 5. When document data is input to the input device 2 (step a), the input document data is sequentially stored in the original document storage 3. At the same time, the input document data is segmented into a plurality of blocks by the document processor l, as shown in Fig. 2. In this segmentation processing, a line return codes etc. are determined as segmentation codes. The input document data is segmented in units of blocks at the segmentation codes. In this case, the segmentation sentence length is measured by counting characters. If the measured value falls within a predetermined value (e.g., 40 characters), the sentence is determined as having the possibility of being a heading sentence.

0023If the segmented sentence is determined as having the possibility of being a heading sentence according to the measured number of characters, the heading extractor 6 decides whether a character string (words, phrases, or symbols) constituting the segmented sentence is registered in the heading word dictionary 7 (step b). For example, when sentence "l. Introduction" in the input document data is extracted, it is checked as to whether it is registered in the heading dictionary 7. In this case, "l", "." and "Introduction" are retrieved from the heading dictionary 7, and the sentence is determined as being a heading candidate A (step c).

0024When heading candidate decision is performed, the heading decision section 8 accesses the heading rule dictionary 8a to determine whether the candidate A is a heading word (step d). If the candidate A is defined by any one of the rules shown in Figs. 4A to 4D, the candidate A is determined as being heading word B (step e). In this case, the type of heading word is determined according to the applied heading rule.

0025If the sentence segmented by the document processor l does not correspond to any heading word registered in the dictionary 7, or if the segmented sentence does not coincide with any heading rule although it is determined as being a heading candidate word, the segmented sentence is determined as being a sentence not included in the heading word rules (step f).

0026The sentence determined as being a heading word, and the sentence determined as not being a heading word are input to the document architecture decision section 9 in order to determine their document architecture. When the document architectures is determined, the decision section 9 determines whether the sentence architectures correspond to document architecture rules (Tables l to 4) stored in the rule dictionary 9a (step g). If the architecture of the input document is defined by one of the document architecture rules, the document architecture data corresponding to the determined rule is stored in the storage l0 (step h and i).

0027With reference to the example of segmented sentences as shown in Fig. 2, the above method of determining the document architecture will be described in further detail. In the segmented sentences in Fig. 2, the sentence of the first line, i.e., "document understanding system", and the sentence of the second line, i.e., "Okawa Tara" are not stored in the dictionary 7. These sentences are decided by the extractor 6 not to be heading words. However, the sentence of the first line is defined by a rule representing a noun phrase appearing at the head of the document, and the decision section 9 decides that "document understanding system" is a title. The sentence of the second line, "Okawa Taro" is a proper noun representing a male name. Since the male name follows the title, the name is determined as being an author's name.

0028The results obtained by the document architecture decision as described above are stored in a form, as shown in Fig. 6A, in logical architecture storage l0.

0029In the sentence of the third line, i.e., "l. Introduction", three words, i.e., "l", ".", and "Introduction" are stored in the dictionary 7. Therefore, this sentence is determined as being a heading candidate sentence Al (See Fig. 7A). At the same time, the categories constituting this sentence are recognized as a numeric portion, a punctuation portion, and a heading candidate word, respectively.

0030The heading decision section 8 accesses the heading rule dictionary 8a to determine whether the sentence determined as being heading candidate Al is defined by the heading rules. In this case, the order of the categories constituting candidate word Al is analyzed. The decision section 8 determines whether the order satisfies any one of the conditions in Figs. 4A to 4D. The first numeral "l" is defined by the rule d shown in Fig. 4D. The numeral "l" and punctuation portion "." are defined by the rule b shown in Fig. 4B. Therefore, "l." is determined as being a heading symbol according to the rule b shown in Fig. 4B. "Introduction" is defined by the rule c shown in Fig. 4C, and is determined as being a heading word. The relationship between the heading symbol and the heading word is defined by the rule a shown in Fig. 4A. The heading candidate Al is thus decided as heading Bl. The above decision process is shown in Fig. 7A.

0031In the above decision process, if the categories are not defined by the rules a, b, c, d shown in Figs. 4A to 4D, heading candidate Al is determined as not being a heading word.

0032The document architecture decision section 9 determines the document architecture of heading Bl in accordance with the rules in table l to 4. In this case, the logical architecture of the analyzed sentence is stored in the storage l0, as shown in Fig. 6A. No chapter heading is indicated in the stored logical architectures. Heading Bl, i.e., "l. Introduction" is defined by conditions (l), (l-l), (l-l-l), and (l-l-l-l) in Table l so that "l. Introduction" is determined constituting chapter heading Cl as shown in Fig. 7A. According to this decision, the logical architecture containing the chapter heading is stored in the logical architecture storage l0, as shown in Fig. 6B.

0033Since the number of characters of the sentence of the fourth and fifth lines shown in Fig. 2 exceeds the number for determining the possibility of a sentence being a heading word, this sentence is therefore determined as being other than a heading. As defined by the rule in Table 3, the sentence of the fourth and fifth lines is determined as being a sentence constituting a paragraph.

0034The sentence of the sixth line "2. Features of System" is recognized as heading candidate A2 in the same procedures as for heading candidate Al. In this case, the sentence of the sixth line is analyzed by the steps in fig. 7B and is determined as being a heading B2. The heading B2 is compared with the rules in Table 2 to determine it coincides with a specific one of the rules. The heading B2 is defined by conditions (l-l), (2-l), (3-l), and (4-l), and is determined as having the possibility of being of the same level as that of chapter heading Cl "l. Introduction". In this way, it is determined whether the heading B2 is defined by the rules in Table l. In other words, "2. Features of System" satisfies conditions (l), (l-l), (l-l-2), and (l-l-2-2-l), and thus, the heading word B2 is determined as constituting chapter heading C2. The resultant logical architecture data is stored in the storage l0 as shown in Fig. 6C.

0035The same processing as described above is performed for the sentences of the seventh and subsequent lines, and the document architectures of these sentences are stored in the storage l0, as shown in Figs. 6D and 6E. More specifically, for the sentence of the seventh line, heading candidate A3 is analyzed, as shown in Fig. 7C, and then is determined as being heading B3 according to the rules shown in Figs. 4A to 4D.

0036In the document architecture decision section 9, the heading B3 is compared with the rules in Table 2. Since the pattern of heading B2 does not previously appear, matching is unsuccessful. As a result, heading B3 is determined as being a heading having a level different from those of the previous headings. Heading B3 is checked in accordance with document architecture rules in Table l and is found to coincide with conditions (l), (l-l), (l-l-2), (l-l-2-2), and (l-l-2-2-2-l). Therefore, heading B3 is determined as being itemizing heading C3.

0037Similarly, since the sentence of the eighth line satisfies conditions (l-l), (2-l), (3-l), and (4-l), the level of the heading corresponding to the sentence of the eighth line is determined as being possibly the same as that of the itemized heading of the seventh line. The sentence of the eighth line is determined as satisfying conditions (l), (l-l), (l-l-2), (l-l-2-2), (l-l-2-2-2), (l-l-2-2-2-2), and (l-l-2-2-2-2-l) in Table l and therefore determined as an itemized heading, being stored as shown in Fig. 6D.

0038With respect to the ninth line "This system is ...", it is possible to consider this paragraph as having two cases or two candidates. That is, the first case is that the ninth line is a part of the eighth line itemized heading or "<img file="EP0241646A2_D0007.tif" />. High recognition rate", while the second case is that ninth line is a paragraph having the same level as that of the sixth line chapter heading or "2. Feature of System".

0039Therefore, in the apparatus according to the present invention, the apparatus is so configured as to allow the operator to select any one of the candidates.

0040To achieve the above-mentioned object, the apparatus further comprises a rule application decision section l2 and a candidate selection indication section l4 as depicted in Fig. l.

0041The rule application decision section l2 is allowed to be accessible to the document architecture rule dictionary 9a to check a rule name requesting candidate selection and to retrieve flags corresponding to the rule name from a table (not shown) whenever two or more candidates are decided. The candidate selecting and indicating section l4 is accessible to a candidate selection key (not shown) arranged in the document input device 2 to update flags so that any desired document architecture can be selected.

0042In Fig. 5, when a decided candidate does not match with a single document architecture rule or when plural candidates are created (in step g), control allows the rule application decision section l2 to be accessible to the document architecture rule dictionary 9a.

0043The above-mentioned candidate selection function is the feature of the present invention.

0044As already explained, the document architecture decision section 9 determines whether the sentence architectures correspond to the document architecture rules (Tables l to 4) stored in the document architecture rule dictionary 9a. In this case, there exists the case where the determined heading candidate word matches a plurality of rules and therefore it is impossible to univocally determine the document architecture. In this case, a plurality of artitecture candidates are written in the logical architecture storage l0 under the control of the document processor l, and any one of the candidates is selected by the candidate selection indication section l4 and displayed on the display unit 5 under the control of the display controller 4.

0045The already-explained example of the ninth line shown in Fig. 2 will be described in further detail. The two architecture candidates are the case where "This system is ...." is determined as a part of the eighth line itemized heading " <img file="EP0241646A2_D0008.tif" />. High recognition rate" and the case where the same ninth line paragraph is determined as a paragraph having the same level as that of the sixth line chapter heading "2. Features of system". Since there exists no such a rule as described above in the heading rule dictionary shown in Fig. 4, the above two sentences are recognized as "paragraph" in accordance with the document architecture rules shown in Table 4. Either of two paragraphs is written in the logical architecture storage l0 as shown in Fig. 6E or 6F, in accordance with the flow chart as shown in Fig. 9.

0046More specifically, in this case, condition l-l in Table 4 matches, so that control requests the rule application decision section l2 to set an applied flag information as to which results d₁ or d₂ should be executed. In response to a request of the applied flag information setting, the section l2 checks from which rule the request is generated (step 9l). In this case, since the request is generated from the rule (d), control retrieves applied flags corresponding to the above rule name d from an application rule decision table as shown in Fig. 8 (step 92), and display the table on the display unit 5 so that the applied flags corresponding to the condition name can be checked (step 93). Here, if the rule 2-l is required to be decided (step 94), the operator sets the flag information X₁ to ON (step 95) and the flag information X₂ to OFF (step 96).

0047By this, the condition (2-l) of table 4 is selected to execute the result dl, so that the level of the current "paragraph" of the ninth line is determined as a part of the eighth line itemized heading, being written in the storage l0 as shown in Fig. 6E.

0048The above document architecture determined by the operator can be changed by the use of a candidate selection key arranged in the input device 2. That is, if the candidate selection key is depressed in the input device 2, the document processor l decodes the contents of the key and sends the information to the candidate selection indication section l4. This section l4 updates the applied flag in such a way that the flag is OFF in condition 2-l but ON in condition 2-2 in the rule application table stored in the rule application decision section l2. Therefore, in the rule application decision section l2, ON is set to the applied flag information X₂ (step 97) and OFF is set to the applied flag information X₁ (step 98) so as to apply the condition 2-2, so that the result d₂ is executed and the "paragrah" of the ninth line is determined as the "paragraph" having the same level as that of the sixth line chapter heading shown in Fig. 2. Accordingly, the document architecture is rewritten in the logical architecture storage l0 as shown in Fig. 6F.

0049As described above, the rule to be applied can be switched by changing the application flag as explained above. In the above embodiemnt, any one of two candidates is selected. However, in the case of the presence of several candidates, it is possible to control the apparatus in such a way that application flags are turned on in sequence by repeatedly depressing the candidate selection key.

0050Additionally, in the present invention, rule application record information y₁, y₂ .... indicative of past rule application situations is added into the application rule table as shown in Fig. 8. That is, whenever a rule is selected by the operator, the rule application record information (including the number of times when a rule is applied and the state where a rule is applied) is updated, and further the selected rules are arranged in the table in the order of higher frequency information so as to be applicable in that order. Therefore, in the case of plural architecture candidates, it is possible to output the rules in the order of higher frequency or priority by the use of the candidate selection key, the above function being referred to as learning function.

0051In the above description, only a single architecture rule having plural candidates is selected according to the operator request. However, it is possible to configure the system so as to create plural document architecture candidates to plural architecture rules. In this case, the applied rule table is formed with a condition name, applied frags, and the rule application record information' being classified into each of rules.

0052Further, as the method of operator's selecting of another logical architecture through the candidate selection key, it is possible to indicate a candidate sentence by a cursor or on the basis of various indications such as display reversal, high luminance under line, etc.

0053Further, the document architecture can be classified according to other forms different from the shown in Fig. 6.

0054Further, without being limited to the hierarchical classification of document headings, it is possible to apply the present invention to other data having a hierarchical architacture from the formal standpoint, such as an organization diagram, by modifying the heading decision rules and the document architecture decision rules, and data related thereto.

0055Furthermore, in the above embodiment, the above system handles Japanese document. However, without being limited thereto, it is possible to apply the present invention to the system which handles other foreign language documents by modifying the decision rules and the architecture decision rules so as to correspond to the language.

0056According to the present invention as described above, the input document data is segmented in units of sentences, and it is determined whether each sentence constitutes a heading. At the same time, the document rule of each sentence is decided. Therefore, the input document data can be effectively processed according to the logical document architectures.

0057The document processing described above is performed effectively. In other words, the heading, the level (hierarchical level) of the heading in the document, and the document architecture, such as the paragraphs preceded by the heading, are obtained effectively according to the input document data. It is thus possible to process the document in units of chapters or sections according to the logical architectures, thereby greatly improving and simplifying document processing.

0058In addition, in the system according to the present invention, since the system can display some architecture candidates and the operator can select any one of them, it is unnecessary for the operator to amend the document architecture by using the editing functions.

0059Further, since the frequency information is added to each of the selected architecture candidates for providing a learning function, it is possible to increase the possibility of deciding any desired document architecture.

0060Further, when a higher priority value is previously set to the rule application record information of the rule to be applied, it is possible to first decide the most desired architecture candidate, in particular, in the case where the document has a specific document architecture as in a treatise.

0061Therefore, the system according to the present invention can efficiently form a docunment architecture and therefore can enhance the document forming efficiency.