GB2192479A - Braille read-out - Google Patents

Abstract

A Braille read-out for transliterating computer derived information comprises a line of modules 12. Each module 12 contains sets of character defining pins 15 which are arranged into cells 14, a cell being actuated by a single, movable actuating assembly 18 which travels along the line of modules 12 powered by a stepper motor 21. The actuating assembly 18 consists of a group of pin solenoids 23, each one corresponding to a pin 15 in a cell. To erase a character from the set of pins a latching plate 26 associated with a set of pins is moved from an engaged position in which the pins are prevented from movement, to a disengaged position the pins fall back into the body of the module 12. By this, characters may be erased and set in each cell in turn. A cell does not require a dedicated actuating assembly, thus less space is consumed per cell. The latching plates 26, being operated individually, allow new characters to be set in the cells without having to wait until the reader finishes a complete line of text. <IMAGE>

Description

SPECIFICATION Braille read-out This invention relates to the transliteration of information into tactual forms and more particularly to the transliteration of data into a tactual dotform such as Braille so that it can be read by a blind computer user. Each line or portion of a linewhich would normally be displayed on a computer visual display unit is converted into Braille which informed in movable pins. Once read, a line is erased and supplied with the next line or line portion to be read.

Existing apparatus for such transliteration of computer derived information into a tactual dotform use a group of individually actuated character cells which are actuated by means of solenoids or piezo-crystal bars which extend and retract a set of pins relative to a reading face. The individual character cells are addressed in turn according to addresses defined by built-in electronic circuitry. In one example the pins are maintained in their extended position by means of oversize ball bearings which are allowed to cover the return holes through which the pin shafts would travel.

A disadvantage of these types of apparatus is that each cell requires a great deal of dedicated circuitry, this makes them complex, cramped and difficultto manufacture. The only practicable application for such constructions is to six pin Braille, as used in the United States of America and Great Britain; so far these techniques have not been successfully applied to eight pin Braille, as used on the Continent of Europe. Another disadvantage is that the prior art apparatus may be reset only by a common delatching arrangement in which all the latches holding the pins in position are removed from the paths of the pin shafts at once. It is therefore not possible to allow the user to read the information and have it updated once it is read without waiting until the entire line has been read.Each cell also requires its own actuating assembly which takes up even more space in the apparatus, further complicating manufacture.

Thus, according to the present invention there is provided an apparatus for transliterating data into Braille, including aframewhich supports a line of a plurality of sets of pins, each pin being individually movable between a first position in which the pin is retracted below a reading face of the frame and a second position in which one end of the pin is proud ofthe reading face, a latching mechanism,which cooperates with a corresponding set of pins, being movable between an engaged position, in which the latching mechanism prevents a corresponding set of pins from moving, and a disengaged position in which the pins are movable between first and second positions, and the apparatus further including an actuating assembly which is movable along the line of sets of pins to actuate each set of pins and corresponding latching mechanism to define a Braille character.

This has the advantage of allowing more cells, of the six or eight pin standard for a given space, and for each character cell to be reset individually which allows the bank of cells to be set in either direction.

The cells may also be built up in modularform making the apparatus more adaptable to specific requirements.

An embodimentofthe present invention will now be described byway of example with reference to the accompanying drawings in which Figure 1 shows a front view of the frame and drive assembly of an apparatus in accordance with the invention; Figure2 shows the carriage and actuating assembly of Figure 1 from one end; Figure3 shows a simplified plan view of a module incorporating sets of pins for use in the apparatus of Figure 1; Figure4showsa sectional viewofthe module along the line IV-IV of Figure 3; and Figure Sshows a latch plate included in the module of Figures 3 and 4.

Referring to Figures 1 and 3, the readout apparatus comprises a frame 11 which fixedly supports a line of modules 12 between end pieces 13 of the frame 11.

Each module 12 contains fourcharacter cells 14, each having a set of weight pins 15 which define the characters. The number of character cells 14 per module 12 is not determined by the size of each cell 14 and may be more or less than this. The frame 11 also supports a pair of rails 16, laterally spaced across the frame 11,which run beneath the modules 12forthe length oftheframe 1 1.The raiis 16 support a carriage 17 on which is mounted an actuating assembly 18. The carriage 17 is pulled along the rails 16 by a belt 19 which has its ends attached to the carriage 17 and is looped around a pulley 20 on the shaft of a stepper motor 21 on one end oftheframe 11 and a tension puiley 22 on the other end ofthe frame 11.

The actuating assembly 18, shown in Figure 2, comprises a set of pin solenoids 23, each acting on a lever 24 pivoted about a point on a corresponding pin solenoid 23, to push an appropriate pin 15 above a reading face 25 on the module 12. The pin solenoids 28 are arranged on the actuating assembly 18 in two rows offourextending parallel to the rails 16. Thus, a row of pins 15 is actuated by two halves of each row of pin solenoids 23.

Figures 3 and 4 illustrate a single module. Each cell 14 has its eight pins 15arranged in two equai rows extending across the frame. Each pin 15 is mounted in the module 12 such that it is slidable along its axis between a first position, in which the pin 15 is retracted into the module 12, and a second position, in which one end of the pin 15 stands proud ofthe reading face 25 ofthe module 12. Each cell 14 hasa latch plate 26, shown in Figure 5, which is horizontally slidable along its length and mounted between each of the two rows of pins 15. The latch plate 26 is formed with a series of recesses on either side along its length. These recesses are not aligned with the pins 15 when the latch plate 26 is in an engaged position.The plate 26 is biased to the engaged position by a spring 27 acting at one end of the rows of pins 15 on the latch plate 26. This urges a shoulder on a plunger 28 which is attached to the other end ofthe latch plate to abut a complementary shoulder on an opening 29 in the side ofthe module 12 through which the plunger 28 extends. With the latch plate 26 in the engaged position the corresponding pins 15 are held in position by either the lowerflatface of an upwardly tapering collar30 on the shaft of each pin 15, or a shoulderformed on each pin shaft above the collar30, abutting the upper surface of a corresponding unrecessed portion ofthe latch plate 26. The plate 26 thus maintains the pins in the first and second positions respectiveiy.To erase a characterfrom a set of pins 15the plunger28 of a cell 24 is pushed inwardly by an arm 31 extending from a reset solenoid 32 mounted on the actuating assembly 18. The recesses ofthe latching plate 26 are thus aligned with the pin shafts, allowing the tapered collars 30 to move pastthe latching plate 26.

The pins 15 standing proud ofthe reading face 25are returned to the body ofthe module 12 by means of springs 33, coaxial with their respective pins 15, which act between collars 34 on the pin shafts and corresponding shoulders 35 formed on the inside of the pin housing.

To set a cell 14 with a Braillecharacterthe actuating assembly 18 travels along the rail 16 to align itself with a particular set of pins 15 according to instructions sent to the stepper motor. An existing character is removed bythe reset solenoid 21 pushing the latch plate 15 as previously described.

The new character is formed in the blank cell 14 by applying a voltage to the appropriate pin solenoid coils corresponding to the pins 15 to be raised. The tapered collars 30 on the raised pins are now located above the latching plate 26. After returning the latching plate 26to the engaged position the voltage applied to the pin solenoids 23 is removed and the pins 15 urged to fall back underthe influence ofthe return springs 22, but are held with the pin heads standing proud ofthe reading face 25 by the latching plate 26. The actuating assembly 18 is then moved on the carriage 17 to the next cell 14 to repeatthe procedure updating the cells all along the line.

The motor used to drive the carriage 17 may be a stepper motor or a motor moving according to opto-electrically derived information received from a photo cell aligning with appropriately spaced holes in the drive beit 19, or a suitable partoftheframe 1.

The solenoids 23 may be replaced by piezo-crystal bars which are bent by applying a voltage to them thus pushing the pins 15 above the reading face 25 of a corresponding module 12. The number of cells 14 actuated by a single actuating assembly 18 may be one or more than one depending on speed requirements and space limitations. It is also possible to increase the speed of transliteration by employing a plurality of carriages 17 running in predetermined sectors on the rails 16. These are either driven independently or bythe same motor.

An alternative embodiment of the invention comprises a plurality of lines of sets of pins mounted in a frame to give the apparatus a page-like format.

The carriage is mounted on first rails which are in turn mounted on a second pairof railsatrightangles to the first rails, thus allowing the actuating assemblyto move between the lines. The extra dimension of movement requires a further set of position co-ordinates to instruct a second motor to move the first rails between the lines. Again, separate actuating assemblies could be employed to work specific sectors of the array of sets of pins in order to increase the speed oftransliteration.

Claims (11)

1. Apparatusfortransliterating data into Braille, including a frame which supports a line of a plurality of sets of pins, each pin being individually movable between a first position, in which the pin is retracted below a reading face of the frame, and a second position in which one end of the pin is proud ofthe reading face, a latching mechanism, which cooperates with a corresponding set of pins, being movable between an engaged position, in which the latching mechanism prevents a corresponding set of pins from moving, and a disengaged position in which the pins are movable between first and second positions, and the apparatus further including an actuating assembly which is movable along the line of sets of pins to actuate each set of pins and corresponding latching mechanism to define a Braille character.

2. Apparatus as claimed in claim 1, wherein the latching mechanism comprises a latching plate which prevents movement of the pins, when in the engaged position, by means of portions ofthe plate abutting collars on the shafts of each of the pins and allows the movement of the pins, when in the disengaged position, by aligning recesses on the latching plate with corresponding pin shafts.

3. Apparatus as claimed in claim 1 or2,wherein the pins are biased to the first or second position by biasing means.

4. Apparatus as claimed in claim 1,2or3, wherein the latching mechanism is biased to the engaged position by biasing means.

5. Apparatus as claimed in any ofthe preceding claims, wherein groups of the sets of pins are mounted in separate modules.

6. Apparatus as claimed in any of the preceding claims, wherein the pins and latching mechanism are actuated by solenoids.

7. Apparatus as claimed in any of claims 1 to 5 wherein, the pins are actuated by piezo-crystal bars.

8. Apparatus as claimed in any of the preceding claims, wherein the actuating assembly is moved by a stepper motor.

9. Apparatus as claimed in any of claims 1 to 7, wherein the location of each set of pins is identified by an opto-electric device governing the movement ofthe actuating mechanism along the line of sets of pins.

10. Apparatus as claimed in any ofthe preceding claims, wherein a plurality of lines of sets of pins are supported by the frame and the actuating assembly is movable in a direction perpendicularto its movement along the said lines to enable it to actuate the sets of pins and latching mechanisms of other lines.

11. Apparatus substantially as described herein with reference to the drawings.