Braille generator and converter

Abstract

Techniques described herein relate to generating braille output and/or visual display output based on received mathematical expression input. Data corresponding to one or more mathematical expressions may be received via expression input devices or visual display devices, and may be converted to braille output characters for display on refreshable braille devices. Additionally, mathematical expression input data may be received via refreshable braille display devices and converted to output characters for display on visual display devices. In some embodiments, mathematical expression input data may be converted first to content markup, and then converted from the content markup to presentation markup and/or braille output characters. Further mathematical expression input data, such as updates to previously displayed expressions, may be received from an initial input device, visual display device, or refreshable braille device, and the updated expression data may be converted to visual output characters and/or braille output characters.

What is claimed is: 
     
         1 . A braille generator and converter system comprising:
 one or more refreshable braille display devices, each refreshable braille display device comprising:
 a plurality of electromechanical braille cells, each electromechanical braille cell comprising a plurality of output dots configured to raise and lower in response to voltages applied at the electromechanical braille cell; 
 a processing unit comprising one or more processors; and 
 memory coupled with and readable by the processing unit and storing therein a set of instructions which, when executed by the processing unit, causes the refreshable braille display device to:
 receive data corresponding to one or more braille output math characters; 
 determine an electromechanical braille cell for displaying each of the braille output math characters; and 
 transmit control instructions to each of the determined electromechanical braille cells to display the one or more braille output math characters; 
 
   one or more visual presentation and expression input devices, comprising:
 an I/O subsystem configured to receive mathematical expression input data via one or more input devices integrated into or connected with the expression input device; 
 a processing unit comprising one or more processors; and 
 memory coupled with and readable by the processing unit and storing therein a set of instructions which, when executed by the processing unit, causes the visual presentation and expression input device to:
 receive math input data via the I/O subsystem corresponding to a mathematical expression; and 
 transmit data representing the mathematical expression to an expression converter; and 
 
   the expression converter, the expression converter comprising:
 a processing unit comprising one or more processors; and 
 memory coupled with and readable by the processing unit and storing therein a set of instructions which, when executed by the processing unit, causes the expression converter to:
 initiate a multi-user interactive math computing session including at least one of the refreshable braille display devices and at least one of the visual presentation and expression input devices; 
 receive initial math input data corresponding to a mathematical expression, during the multi-user interactive math computing session; 
 receive a plurality of single-character revisions to the mathematical expression during the multi-user interactive math computing session, including at least a first single-character revision received as braille math input from at least one of the refreshable braille display devices, and a second single-character revision received as presentation markup math input from at least one of the visual presentation and expression input devices; and 
 in response to each of the plurality of single-character revisions to the mathematical expression received during the multi-user interactive math computing session:
 (a) determining an input data type of the received single-character revision to the mathematical expression; 
 (b) selecting a set of conversion rules for converting the revised mathematical expression to MathML, from a plurality of sets of conversion rules stored by the expression converter, based on the determined input data type; 
 (c) converting the revised mathematical expression incorporating the single-character revision into a revised mathematical markup language (MathML) of the mathematical expression, using the selected set of conversion rules; 
 (d) converting the revised MathML of the mathematical expression into one or more output math formats comprising at least one of braille math output or presentation markup math output; and 
 (e) transmitting the revised mathematical expression, converted into the one or more output math formats, to one or more output devices including at least one of the refreshable braille display devices or at least one of the visual presentation and expression input devices. 
 
 
   
     
     
         2 . The braille generator and converter system of  claim 1 , wherein in response to at least one of the plurality of single-character revisions to the mathematical expression received during the multi-user interactive math computing session, (d) comprises converting the revised MathML of the mathematical expression into braille math output, using a set of data conversion rules for MathML to braille math output includes a plurality of braille encoding rules that do not correspond to character mapping rules. 
     
     
         3 . The braille generator and converter system of  claim 2 , wherein converting the revised MathML of the mathematical expression into braille math output comprises using at least one braille encoding rule calling for a multipurpose indicator braille symbol, and wherein the set of braille output characters includes a first braille symbol corresponding to a fraction indicator and a second braille symbol corresponding to a nested fraction indicator. 
     
     
         4 . The braille generator and converter system of  claim 2 , wherein converting the revised MathML of the mathematical expression into the braille math output characters, using the set of data conversion rules for MathML to braille math output comprises:
 applying character mapping rules to the MathML representation of the mathematical expression, to generate a corresponding string of braille characters;   analyzing the generated string of braille characters to detect one or more predetermined characters patterns; and   using the at least one braille encoding rule that does not correspond to a character mapping rule, to convert the one or more predetermined characters patterns in the generated string of braille characters   
     
     
         5 . The braille generator and converter system of  claim 4 , wherein detecting the one or more predetermined characters patterns, and using the at least one braille encoding rule that does not correspond to a character mapping rule to convert the predetermined characters patterns comprises:
 determining that two consecutive characters in the generated string of braille characters correspond to a single mathematical symbol; and   inserting a designated indicator braille character in between the two consecutive characters, in response to determining that the two consecutive characters correspond to a single mathematical symbol.   
     
     
         6 . The braille generator and converter system of  claim 2 , wherein converting the revised MathML of the mathematical expression into the braille math output characters, using the set of data conversion rules for MathML to braille math output comprises:
 identifying a first character corresponding to a subscript or superscript character in the MathML representation of the mathematical expression, and a second character in the MathML representation of the mathematical expression to which the first subscript or superscript character applies;   determining that the first subscript or superscript character is an integer; and   based on the determination that the first subscript or superscript character is an integer, applying an abbreviated braille encoding rule by which the first character, the second character, and the relationship between the first character and the second character is represented by only two braille characters.   
     
     
         7 . The braille generator and converter system of  claim 1 , wherein for each of the plurality of single-character revisions to the mathematical expression received during the multi-user interactive math computing session, steps (a)-(e) are performed in real-time in response to receiving the single-character revision to the mathematical expression. 
     
     
         8 . A method, comprising:
 initiating, by an expression converter, a multi-user interactive math computing session including at least one refreshable braille display device and at least one visual presentation device;   receiving, by the expression converter, initial math input data corresponding to a mathematical expression, during the multi-user interactive math computing session;   receiving, by the expression converter, a plurality of single-character revisions to the mathematical expression during the multi-user interactive math computing session, including at least a first single-character revision received as braille math input from the at least one refreshable braille display device, and a second single-character revision received as presentation markup math input from the at least one visual presentation device; and   in response to each of the plurality of single-character revisions to the mathematical expression received during the multi-user interactive math computing session:
 (a) determining an input data type of the received single-character revision to the mathematical expression; 
 (b) selecting a set of conversion rules for converting the revised mathematical expression to MathML, from a plurality of sets of conversion rules stored by the expression converter, based on the determined input data type; 
 (c) converting the revised mathematical expression incorporating the single-character revision into a revised mathematical markup language (MathML) of the mathematical expression, using the selected set of conversion rules; 
 (d) converting the revised MathML of the mathematical expression into one or more output math formats comprising at least one of braille math output or presentation markup math output; and 
 (e) transmitting the revised mathematical expression, converted into the one or more output math formats, to one or more output devices including at least one of the visual presentation devices or at least one refreshable braille display devices. 
   
     
     
         9 . The method of  claim 8 , wherein in response to at least one of the plurality of single-character revisions to the mathematical expression received during the multi-user interactive math computing session, (d) comprises converting the revised MathML of the mathematical expression into braille math output, using a set of data conversion rules for MathML to braille math output includes a plurality of braille encoding rules that do not correspond to character mapping rules. 
     
     
         10 . The method of  claim 9 , wherein converting the revised MathML of the mathematical expression into braille math output comprises using at least one braille encoding rule calling for a multipurpose indicator braille symbol, and wherein the set of braille output characters includes a first braille symbol corresponding to a fraction indicator and a second braille symbol corresponding to a nested fraction indicator. 
     
     
         11 . The method of  claim 9 , wherein converting the revised MathML of the mathematical expression into the braille math output characters, using the set of data conversion rules for MathML to braille math output comprises:
 applying character mapping rules to the MathML representation of the mathematical expression, to generate a corresponding string of braille characters;   analyzing the generated string of braille characters to detect one or more predetermined characters patterns; and   using the at least one braille encoding rule that does not correspond to a character mapping rule, to convert the one or more predetermined characters patterns in the generated string of braille characters   
     
     
         12 . The method of  claim 11 , wherein detecting the one or more predetermined characters patterns, and using the at least one braille encoding rule that does not correspond to a character mapping rule to convert the predetermined characters patterns comprises:
 determining that two consecutive characters in the generated string of braille characters correspond to a single mathematical symbol; and   inserting a designated indicator braille character in between the two consecutive characters, in response to determining that the two consecutive characters correspond to a single mathematical symbol.   
     
     
         13 . The method of  claim 9 , wherein converting the revised MathML of the mathematical expression into the braille math output characters, using the set of data conversion rules for MathML to braille math output comprises:
 identifying a first character corresponding to a subscript or superscript character in the MathML representation of the mathematical expression, and a second character in the MathML representation of the mathematical expression to which the first subscript or superscript character applies;   determining that the first subscript or superscript character is an integer; and   based on the determination that the first subscript or superscript character is an integer, applying an abbreviated braille encoding rule by which the first character, the second character, and the relationship between the first character and the second character is represented by only two braille characters.   
     
     
         14 . The method of  claim 8 , wherein for each of the plurality of single-character revisions to the mathematical expression received during the multi-user interactive math computing session, steps (a)-(e) are performed in real-time in response to receiving the single-character revision to the mathematical expression. 
     
     
         15 . A computer-program product tangibly embodied in a non-transitory machine-readable storage medium, including instructions configured to cause one or more data processors to perform actions including:
 initiating a multi-user interactive math computing session including at least one refreshable braille display device and at least one visual presentation device;   receiving initial math input data corresponding to a mathematical expression, during the multi-user interactive math computing session;   receiving a plurality of single-character revisions to the mathematical expression during the multi-user interactive math computing session, including at least a first single-character revision received as braille math input from the at least one refreshable braille display device, and a second single-character revision received as presentation markup math input from the at least one visual presentation device; and   in response to each of the plurality of single-character revisions to the mathematical expression received during the multi-user interactive math computing session:
 (a) determining an input data type of the received single-character revision to the mathematical expression; 
 (b) selecting a set of conversion rules for converting the revised mathematical expression to MathML, from a plurality of sets of conversion rules, based on the determined input data type; 
 (c) converting the revised mathematical expression incorporating the single-character revision into a revised mathematical markup language (MathML) of the mathematical expression, using the selected set of conversion rules; 
 (d) converting the revised MathML of the mathematical expression into one or more output math formats comprising at least one of braille math output or presentation markup math output; and 
 (e) transmitting the revised mathematical expression, converted into the one or more output math formats, to one or more output devices including at least one of the visual presentation devices or at least one refreshable braille display devices. 
   
     
     
         16 . The computer-program product of  claim 15 , wherein in response to at least one of the plurality of single-character revisions to the mathematical expression received during the multi-user interactive math computing session, (d) comprises converting the revised MathML of the mathematical expression into braille math output, using a set of data conversion rules for MathML to braille math output includes a plurality of braille encoding rules that do not correspond to character mapping rules. 
     
     
         17 . The computer-program product of  claim 16 , wherein converting the revised MathML of the mathematical expression into braille math output comprises using at least one braille encoding rule calling for a multipurpose indicator braille symbol, and wherein the set of braille output characters includes a first braille symbol corresponding to a fraction indicator and a second braille symbol corresponding to a nested fraction indicator. 
     
     
         18 . The computer-program product of  claim 16 , wherein converting the revised MathML of the mathematical expression into the braille math output characters, using the set of data conversion rules for MathML to braille math output comprises:
 applying character mapping rules to the MathML representation of the mathematical expression, to generate a corresponding string of braille characters;   analyzing the generated string of braille characters to detect one or more predetermined characters patterns; and   using the at least one braille encoding rule that does not correspond to a character mapping rule, to convert the one or more predetermined characters patterns in the generated string of braille characters   
     
     
         19 . The computer-program product of  claim 18 , wherein detecting the one or more predetermined characters patterns, and using the at least one braille encoding rule that does not correspond to a character mapping rule to convert the predetermined characters patterns comprises:
 determining that two consecutive characters in the generated string of braille characters correspond to a single mathematical symbol; and   inserting a designated indicator braille character in between the two consecutive characters, in response to determining that the two consecutive characters correspond to a single mathematical symbol.   
     
     
         20 . The computer-program product of  claim 15 , wherein for each of the plurality of single-character revisions to the mathematical expression received during the multi-user interactive math computing session, steps (a)-(e) are performed in real-time in response to receiving the single-character revision to the mathematical expression.