US 3880269 A
A Braille Telecommunications Terminal is described herein which is adapted to emboss complete lines of braille characters at high speed in response to code characters received by the terminal from a communications line or from a keyboard in the terminal. A plurality of pairs of pins are disposed in a row and are actuable to move forward to an extended position against an embossable sheet to form pairs of code elements of the characters in a line of braille characters. The sheet is advanced and successive pairs of code elements are embossed upon each advance until the code elements which constitute the braille characters are embossed. In this manner an entire line of braille characters can be embossed at very high speeds. The pins and the advancing of the sheet are automatically controlled in response to code signals received by the terminal, or from the keyboard.
Claims available in
Description (OCR text may contain errors)
United States Patent [191 Carbonneau 1 Apr. 29, 1975 BRAILLE COMMUNICATION TERMINAL  Inventor: Guy P. Carbonneau, West Henrietta, NY.
 Filed: Sept. 4, 1973  Appl. No.: 394,328
 US. Cl. 197/6.1; 101/18; 340/173 RC  Int. Cl B41j 3/32  Field of Search 197/1 R, 6, 6.1, 19;
178/92; 340/173 RC, 172.5; 101/3 R, 26, 28-32, 18; 61/93 C  References Cited UNITED STATES PATENTS 2,565,608 8/1951 Hoff 101/3 R 3.065.299 11/1962 Frey 178/92 3,174,427 3/1965 Taylor 101/93 C 3,453,648 7/1969 Stegenga 1 197/1 R X 3,534,846 10/1970 Watari 197/6.1 3,611,308 10/1971 Grinnell 197/19 X 3,640,368 2/1972 Weinberger 197/6.1
FOREIGN PATENTS OR APPLICATIONS 580,809 8/1958 ltaly 197/6.1
OTHER PUBLICATIONS Powered Braille Typing System," IBM Tech. Discl. Bulletin, Vol. 12, No.6, 11/69, p. 779
Automatic Braillewriter, IBM Tech. Discl. Bulletin, Vol. 10, No. 11, 4/68, pp. 177l-3 Embossing Braille Characters," IBM Tech. Disc]. Bulletin, Vol. 8, No. 10, 3/66, pp. 1424 High Speed Embossing of Braillemasters," IBM Tech. Discl. Bulletin, Vol. 11, No. 10, 3/69, pp. l2967.
Primary Examiner-E. H. Eickholt Attorney, Agent, or Firm-Martin LuKacher  ABSTRACT A Braille Telecommunications Terminal is described herein which is adapted to emboss complete lines of braille characters at high speed in response to code characters received by the terminal from a communications line or from a keyboard in the terminal. A plurality of pairs of pins are disposed in a row and are actuable to move forward to an extended position against an embossable sheet to form pairs of code elements of the characters in a line of braille characters. The sheet is advanced and successive pairs of code elements are embossed upon each advance until the code elements which constitute the braille characters are embossed. In this manner an entire line of braille characters can be embossed at very high speeds. The pins and the advancing of the sheet are automatically controlled in response to code signals received by the terminal, or from the keyboard.
20 Claims, 10 Drawing Figures PATENTEZ Z 3. 880,269
sum 2 0r 6 SECOND ROW OF IMPRESSIONS THIRD ROW OF IMPRESSIONS DOUBLE SPACED FOR FIRST ROW OF NEXT ROW OF IMPRESSIONS FIGAC.
' sum u 0F 6 SERIAL DATA FROM COMMUNlCATlON LINE AND 340 OR AND 33 SERIAL LOAD GND
FIGAA. FIGAA. FIGAB.
SHEET 5 BF 6 AND 408 EMBOSS CYCLE FLIP FLOP AND AND AND AND AND AND 414 I56 AND AND RESET A 5 FIGAB.
BUFFER I59 FULL BRAILLE COMMUNICATION TERMINAL TI-IE FIELD OF THE INVENTION This invention relates to braille communications ter minals and particularly to an improved system for embossing braille characters at very high speed.
BACKGROUND OF THE INVENTION There have heretofore been provided braille typewriters which are of a complex mechanical design thus making them relatively slow, noisy and expensive. Such braille typewriters are operative to emboss one braille character at a time. much in the same manner as a conventional typewriter which types alpha-numeric characters. Thus conventional braille typewriters are limited in speed of operation in that they are bound by the inherent limitations of the speed of their moving parts. Moreover, conventional braille typewriters are adapted to be manually operated and can not be operated by message data received from a telecommunications line or link as is the case for alpha-numeric teletypewriters and teleprinters. Thus there has not been available for persons who are not sighted the same high speed and flexible communications facilities (e.g. teletypewriters and teleprinters) which are available for sighted person. It is particularly important that braille information be presented at extremely high speed compatible with the speeds at which blind person who are adept in reading braille can read braille characters. There have not been made available for the benefit of blind persons. prior to the present invention, extremely high speed braille character embossing apparatus and particularly an apparatus which is automatically operated to receive the same type of message data which is provided for teletypewriters and teleprinters for embossing braille characters at high speeds a line at a time.
OBJECTS AND SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide improved apparatus for braille communications.
It is another object of the present invention to provide improved braille embossing apparatus which is capable of embossing braille characters a line at a time using message data of the type which is available and used conventionally for digital telecommunications applications.
It is a still further object of the present invention to provide an improved braille typewriter which is also operative as a braille teletypewriter when coded signals are applied thereto via a transmission line or other communications channel or link.
It is a still further object of the present invention to provide an improved braille communications terminal which is relatively low in cost.
It is a still further object of the present invention to provide an improved braille communications terminal capable of printing braille characters at extremely high speeds, say 120 characters per second or l80lines per minute.
It is a still further object of the present invention to provide an improved high speed braille communications terminal which is relatively quiet.
It is a still further object of the present invention to provide an improved high speed braille communications terminal which operates automatically in response to received message data, translates such data into braille characters, and enbosses a sheet with braille characters corresponding to the received message data and advances the sheet in to permit the embossing of successive lines of the braille characters.
Briefly described, a braille communications terminal involving the invention includes a row of embossing members for embossing the collinearly disposed elements of a line of braille code characters all at the same time. Each braille code character consists of three pairs of code elements disposed one below the other. or six code elements in all. In accordance with this invention a line of braille characters is embossed by successively embossing the pairs of code elements which constitute a line of braille characters all at the same time. The sheet-which is adapted to receive the embossing is advanced so that the second pair of code elements of the line of characters is embossed. Then the sheet is advanced a third time until the third pair of code elements is embossed. In this way entire lines of braille code characters is adapted to be embossed at extremely high speed. The communications terminal includes a system of electronic circuits such as registers, memories, gates. flip-flops, and sources of timing signals, all of which are responsive to the code signals of the data characters to be embossed in the from of braille characters for successively operating the embossing apparatus so that successive lines of the braille characters are embossed, and the sheet on which the characters are embossed is automatically advanced.
The foregoing and other objects and advantages of the present invention will be more readily understood from the following detailed description of an illustrative embodiment of the invention shown in the accompanying drawings. in which:
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a partially broken away top view of a braille FIGS. la. 1b, and 1c are fragmentary plan views of the portion of the structure shown in FIG. 1 which illustrates the operation of the appratus in embossing rows containing successive pairs of successive lines of braille characters so as to emboss such successive lines at very high speed.
FIG. 2 is fragmentary sectional view of the apparatus shown in FIG. 1, the section being taken along the line 22 in FIG. 1;
FIG. 3 is a fragmentary sectional view showing the embossing pins of the apparatus in greater detail, the section being taken along the line 33 in FIG. 2;
FIGS. 4A and 4B when joined together in the manner illustrated in FIG. 5, show a detailed block diagram of the electronic circuitry included in the braille communications terminal which is provided in accordance with the invention;
FIG. 5 is a diagram illustrating the relationship be tween FIGS. 4A and 4B; and
FIG. 6 shows timing diagram which is explanatory of the operation of the electronic circuitry shown in FIGS. 4A and 4B DETAILED DESCRIPTION Referring more particularly to the drawings. there is shown a braille communications terminal or teletypewriter for embossing lines consisting of 40 braille characters per line on an embossable medium. As shown in FIGS. 1 to 3 the embossable medium is a sheet 1 of paper of the type used in continuous computer forms. The paper has sprocket holes 2 along its longitudinal edges which are adapted to be engaged by the pins 3 of a tractor pin 4 mechanism (see FIG. 2) of the type used in computer printers. The tractor 4 has a sprocket wheel 5 which is adapted to be driven by a paper advance mechanism.
The apparatus has frame 6 on which its various parts are mounted. These parts are in general an embossing pin mechanism 7, an actuating mechanism 8, a die member 9.
The embossing mechanism 7 includes 40 pairs of embossing pins P-l to P-80. Only the pair 10 P-1 and six others are shown in detail in the drawing to simplify the illustration. The pins of these pairs P-l to P-14 are also shown in detail as is the case for the pin P-4 (see FIG. 2). Each pin is a cylindrical rod having an embossing tip 17 at the upper end thereof. The embossing pins are located in holes 18 in a support plate 19 which is mounted on the frame 6. Each pin has a hole 20, a spring wire 22 held on the plate 19 by a screw 23 extends through the hole in the pin and biases the pin downwardly in a direction away from the sheet 1 against the actuating mechanism 8. Also mounted in the plate 20, as by being screwed therein, are adjustable stop members 24. The tips 17 are adapted to enter recessed dies 25 in a die member 26 which is disposed above the plate 19 and held in the position shown with the recessed dies in alignment with the tips of the pins by a bracket member 27.
It will be observed from FIG. 1 that the embossing pins are collinearly disposed in a row transversely across the sheet 1. When actuated, the pins are extended upwardly into their cooperating dies 25 which are disposed in a line with the pins in a row across the sheet 1. The tips 17 of the pins thus emboss the sheet with protuberances which form the code elements of a line of code elements in a braille character. The pair of pins 10 form the upper pair of code elements of the first braille character. next pair of pins form the elements of the second braille character, and so forth, for the braille characters which are adapted to be embossed in a line across the sheet. The braille characters as in the case of the lines 28 to 33 partially shown in FIG. 1 consist of three pairs of code elements which may or may not be present depending upon the character represented by the braille code. The pins P-l to P-40 are selectively actuated by the actuating mechanism 8 so as to emboss entire lines consisting of the pairs of the braille code elements which constitute these characters.
The actuating mechanism itself contains 40 solenoids 5-1 to S-80 which are disposed in rows on opposite sides of the row of pins P-l to P-80. The solenoids are offset at different distances from the rows of pins and on opposite sides of the row of pins in the interest of simplicity and compactness and for limiting the mechanical movements .so as to reduce the noise produced from the operation of the apparatus thereby rendering it more silent. The solenoids are attached as by mounting bolts 41 to the frame 6. Each solenoid has an armature 42 which has a slot 43 in the upper end thereof. One end of a link or lever 44 is disposed in the slot 43 and is held there in position by a pin 45. The links or levers 44 are of three different lengths depending upon the distance between the solenoid and the row of pins P-l to P-80. Each line is privotally mounted intermediate the ends thereof at a fulcrum 46 provided by a set screw 47. The fulcrums 46 are disposed at different positions depending upon the length of their respective levers. The top edge of the forward end 49 of each link 44 is disposed below the bottom of a different one of the pins P-l to P-80. The armatures 42 of each of the solenoids are biased by coil springs 50 which are disposed about the armatures and bear upon the frame 6 and the bottom of their respective links 44.
The bias provided by the springs 50 maintains the links in unactuated position as shown in full line in FIG. 2 of the drawings. When a solenoid is actuated, for example the solenoid S-4, its armature is pulled in to the body of the solenoid so as to bring the line 44 which is disposed in the slot 43 of the solenoid armature 42 to the position shown in dash lines in FIG. 2. Such actuation causes the link 44 to pivot about its fulcrum 46 and drive or extend the pin P-4 upwardly so that the tip of the pin P-4 enters the recessed die 25 and embosses a protuberance representing the braille code character element in the sheet 1. By virtue of the location of the fulcrums 46 the travel of each of the links is the same no matter its length or the position of its actuating solenoid 8-1 to 5-80. The set screws 24 act as stops limiting the upward travel of the links 44 in response to the bias of the springs 50 about the solenoid armatures 42. It will be noted that the fulcrums 46 are projections which extend downward from the links into recesses 52 in the set screws 47.
The operation of the mechanisms to print lines of braille characters may be more apparent from FIGS. 1A to IC. The lines of characters 28 to 31 have already been embossed or printed on the sheet 1. Consider that the pins P-l to P-80 have been extended to emboss the first row of the next line 61 of braille characters as shown in FIG. 1A. The sheet 1 is then advanced by the tractor mechanism 4 (see FIG. 2) a distance awhich is measured for the sake of convenience from the right hand edge of the plate 19; amay be 0.088inch for example. Then the actuating mechanism 8 is operated to selectively emboss; the protuberances forming the second row 62 of code element of the line of characters 61.
As shown in FIG. 1B, in order to emboss the third row 63 of code elements, the sheet 1 is advanced another distance aor a total distance 2awith the embossing of the row 63 the entire line 61 of braille characters is embossed. Then. as shown in FIG. 1C, the sheet 1 is advanced or fed a double distance (viz., double space) so as to place the sheet in position for embossing the first row 64 of the next line of braille characters. has much as the plate 19 is cut away over the die section 27 the line of braille characters can be edited, conveniently, by scanning the finger of a person who can read braille across the line. The blind person can thus read the lines of braille characters for editing or other purposes as quickly as they are printed. The mechanism as illustrated in FIGS. 1 to 3, has a relatively small number 7 of mechanical parts which execute relatively small of braille characters on the sheet 1 is illustrated in FIGS. 4A and 4B. The timing of the circuit operations is illustrated by the waveforms shown in FIG. 6, to which reference should be made as the description of the circuitry proceeds.
The terminal may be provided with its own keyboard 162 or it may receive serial data in the form of baudot"or selectricbr ascil coded signals from a communication line or other link. The apparatus operates in accordance with any such digital data messages to provide the lines of braille characters on the sheet 1.
Consider the case when the keyboard 162 is used. The keyboard may be any conventional keyboard which inputs a 7-bit binary code for each character into a register 160. The keyboard automatically provides a load command to the register 160 whenever a key is depressed. The register 160 itself maybe a paralletin/serial-out register. such as an integrated circuit (IC) that is available from the General Instruments Company as their part AY51010. When data is contained in the register 160, abuffer full level enables an AND gate 321 which allows clock pulses from a clock oscillator CLK-l, which is also designated by reference numeral 163, to the shift input of the register 160 for reading our the register. The clock pulses are divided by 2 in a triggerable flip-flop 164 which operates as a divide-by- 2 counter. The IC 160 is internally provided with a divide-by-eight counter which affords the requisite timing. Thus, each character in the keyboard code is read out through an OR gate 172. The register 160 provides a serial code for each character consisting ofa start bit, and six data bits. The stop bits are always levels indicated as being positive voltage representing binary ls and the start of bit level is always indicated by a binary 0, (see Waveform (A), Fig. 6). The serial data from the communications line is also made up of multi-bit characters, the first bit of each character being a binary 0 level. In the case of ascii there are special control characters which are represented by the value of the 6th and 7th bits of the code. In selectric and baudot" codes (baudot being the usual teletypewriter code) there are upper case and lower case characters. These characters are not embossable and provisions are made in the electronic circuitry for inhibiting the embossing of such characters, as will be described more fully hereinafter. The six bits of each character, after the start bit, represent and distinguish the particular character. it is these bits which are translated or converted into braille code characters and used by the system to control the embossing mechanism.
The start bit, whether from the register 160 or from the characters which are received from the communication line, are operative to set a latch 200. The latch 200 when set enables an AND gate 340 to pass the CLK-] pulses to a divide-by-l6 counter 205. The output of this counter (viz., the five stages which make up the counter) are decoded in an AND gate decoder 204 to provide timing pulses TP-9, TP-10, and TP-11 for each received character.
TP-9 corresponds to the ninth received clock pulse; TP-lO to the tenth; and TP-ll to the eleventh received clock pulse. TP9 is applied as a shift pulse to an input buffer 171. The rate of the CLK-l pulse is sufficiently higher than the data rate so that a TP-9 pulse will occur during the interval of each bit of the coded characters form the line or from the register 160.
By the time the eighth advance, as provided by TP-9 shift pulses to the input buffer 171 occurs, the start bit will be in the first or start stage of the buffer 171 (see Waveform (C), FIG. 6). The start bit is applied to a delay one-shot 202 which produces a reset pulse RST-l (see Waveform (G), FIG. 6) which resets the latch 200 and the counter 205 thus ending a character timing cycle. Upon occurrence of the start bit and during the time of that bit, the input buffer 171 will be loaded and full of the data bits of a character.
The six stages of the buffer which contain the six data bits of the character are applied to code converters and 176 for upper and lower case character respectively. These code converters may be conventional Read Only Memories (ROMs) which are programmed to convert the binary codes in the buffer into braille codes having six bits. The lower case ROM 175 also decodes an upper case character by providing an output level on the LC-8 output of the ROM 175. The upper case converter 176 decodes a lower case character by providing a UC-8 output. Special characters are decoded by an AND gate 330 which is interconnected to the sixth and seventh stages of the input buffer 171. During the time of TP-10 and during the start bit time. an AND gate 326 will be enabled when UC8 is decoded by the upper case ROM 176. During the same time period and LC-S level from the lower case ROM 175 will enable another AND gate 328. Therefore for subsequent lower case characters a latch 324 will be set by the output of the AND gate 326 so as to enable the lower case ROM 175 to provide braille output codes and for subsequent upper case characters the AND gate 328 will reset the latch 324 thus enabling the upper case ROM 176 to provide the braille code characters. An OR gate 332 passes either the special character LC-8 or UC-8 levels. and when TP-10 occurs, an AND gate 334 will be enabled so'as to set a latch 336. The latch 336 when set inhibits an AND gate 211 which otherwise passes TlP-ll during the start bit period. TP-ll (see Waveform (F), FIG. 6) enables a group of AND gates 180, only two of which (for the first bit of the braille code character) are shown to simplify the illustration. These AND gates pass the braille characters through OR gates 183 to an output buffer 185. Thus when the AND gate 211 is inhibited, as when upper case/ lower case or other special characters are decoded, there is no readout from the ROMs 175 or 176 and embossing will not occur.
The reset pulse from the delay one-shot 202 also resets the latch 336 and the output buffer at the end of each character reception cycle.
The braille code characters from the output buffer 185 are loaded into a pair of parallel-input/serialoutput registers 150 and 151 upon occurrence of the load pulse (TP-ll) (see Waveform (F), FIG. (6)). The registers 150, 151 have their first stage connected to a positive source of voltage and their last, or seventh stage, connected to ground so as to be preset to have a binary 1 level start bit in their first stage and binary 0 level stop bit level in their last stage.
The same load pulse (see Waveform (F), FIG. 6) sets a latch 152. An AND gate 153 is enabled when the latch 152 is set and allows CLK-2 pulses from a clock oscillator 154 to be applied to the input of fill AND gates 155 and 156. The output of the fill AND gate 155 applies shift pulses to the register 150 for shifting or reading out data out of the register 150 into the input of the fortieth character or last register of a first group of buffer registers 158. The AND gate 156 applies shift pulses to the other register 151 for shifting the characters stored in that register into the last orrfortieth character register of a second group 159 of output buffer registers. Only one of the AND gates 155 or 156 is enabled depending upon the state of a buffer pointer flip-flop 400.
Tl-Ie output buffer registers 158 and 159 consist of forty serially connected eight-stage shift registers. each corresponding to a successive character of the forty characters in a line of characters that can be printed by the embossing apparatus illustrated in FIGS. 1 to 3. One of the group of registers is filled with forty successive characters which are received form the line or from the keyboard 160, converted into braille code characters and stored in one of the parallel-in/serialout registers 150 and 151. The other group of registers has the data stored therein read out for the purpose of operating the actuating mechanism and printing a line of braille characters.
Consider that the pointer flip-flop 400 is set so that its output is high. The fill AND gate 156 will then be enabled so as to apply shift pulses to read out the register 151. The shift pulses are also applied via an OR gate 401 to shift data in the forty registers which make up the output buffer group 159. The registers of the group 159 will be filled one at a time during each received character cycle. It will be appreciated that the CLK-2 oscillator 154 is a high speed clock having a rate, say 100 times greater than the CLK-1 oscillator 163. For each character that is received, converted into braille characters. and stored in the registers 150 and 151, eight CLK-Z pulses are produced because a divide by 16 counter 402 counts the CLK-2 pulses. The eighth pulses when counted resets both the counter 402 and the latch 152; thus only eight shift pulses will be produced upon the reception of each character. The forty registers in the output buffer group 159 will then be filled successively one at a time. When the register group 159 is filled. the start bit of the first character will be located in the first or start bit stage 161 of the first register in the group 159. A buffer 159 full pulse then appears which is applied via an OR gate 404 to trigger the pointer flip-flop 400 which then provides a level which enables the fill AND gate 155 to shift characters from the register 150 into the buffer group 158. The shift pulses for the register group 158 are applied via an OR gate 405.
Consider the case where the buffer group 158 has just filled with forty characters and a buffer 158 full level is obtained from the first or start stage of the first character register of the group 158. The buffer 158 full signal is applied via an OR gate 406 to set an emboss cycle flip-flop 407. When set, the flip-flop 407 enables an AND gate 408 to pass CLK-3 pulses from a clock oscillator 409. The repetition rate of the CLK-3 pulses may be approximately equal to or slightly less than the CLK-l pulse rate. When the flip-flop 407 is set it initiates an embossing'cycle. The timing of embossing operations during the cycle is controlled by a divide by 16 counter 413. The five stages of that counter are connected to an AND gate decoder 410 which provides outputs on the first, fifth, ninth and thirteenth of the CLK-3 clock pulses which are counted by the counter 413. The decoder 410 thus provides four timing pulses, TP-l, TP-S, TP-9, and TP-l3. The first three pulses, TP-l, -5, and -9 are applied via an OR gate 411 to trigger a one-shot 412 which provides three embossing pulses of sufficient time duration during the embossing cycle (viz., the period during which the emboss cycle 8 flip-flop 407 is set) (see Waveform (.1), FIG. 6). The
one-shot 412 may be adjusted so as to adjust the embossing pulse duration (see Waveform (K)) to accommodate for the travel of the solenoid armatures 42, link 44 and pins P-l to P- (see FIGS. 1 to 3). An approximately thirty millisecond embossing pulse from the flipflop 412 has been found suitable for an embossing rate of lines of braille characters per minute.
The embossing pulse passes through an AND gate 414 which is enabled when the pointer flip-flop is set. This AND gate 414 is referred to as the embossing AND gate. It will be noted that another embossing AND gate 416 is provided for passing embossing pulses when the pointer flip-flop 400 is reset (Q hight). Each embossing pulse passes through the OR gate 405 for shifting or advancing the bits in each of the forty character registers of the buffer group 158. There are three embossing pulses per cycle (viz., corresponding to TP-l, -5 and -9). During each pulse period a pair of braille code elements will be embossed. As explained above, the braille code is made up of six elements in three pairs. Aside from the start and stop bits there are six bits stored in each of the forty character registers of the buffer group 158. The first and fourth bits in the register, the second and fifth bits in the register and the third and sixth bits in the register, respectively, correspond to each of the three pairs of braille code elements per character. By reading out the first and fourth stages of each of the character registers in the forty registers which make up the buffer group 158, signals representing each pair of braille code elements can be provided.
A pair of AND gates R-l, R-2, forty pairs in all, are respectively interconnected to the first and fourth stages of each of the forty character records to the buffer group 158. These gates are enabled by the embossing pulses which are applied thereto via a second embossing AND gate 420. The leading edge of the embossing pulse which is applied to the shift inputs of the character registers of th buffer group 158 advances the data in the forty registers. The rest of the embossing pulse enables the AND gates R-1 and R-2. Thus on the first embossing pulse (tp-l) the first and fourth bits of each braille character will be advanced into the first and fourth stages of the character registers of the buffer group 158, and the AND gates R-1, R-2 will be enabled. Output pulses are then applied forty pairs of output OR gates R-3, R-4. Of course, pulses will not be passed through the AND gates R-l, R-2 if the bits in the register are binary 0 bits. THe outputs of the OR gates are applied via driver amplifiers R-5, R-6 to the operating windings of the solenoids 8-1 to 5-80. Alternatively, the output amplifier pairs R-5, R-6 may be inverters, which when the output of the OR gates R-3, R4 are high, provide a low level at their outputs so as to permit current to pass through the operating windings of the selenoids 8-1 to S-80 from sources of operating voltage indicated at +V.
In this manner a row consisting of forty pairs of braille code elements is simultaneously printed on the sheet 1 (FIGS. 1 to 3). The sheet is advanced one space (distance 0, FIGS. 1A to IC) upon the trailing edge of each embossing pulse. The trailing edge of each pulse triggers a one-shot 421 which provides an output pulse (see Waveform (L), FIG. 6) immediately after each embossing pulse. The one-shot 421 output pulse passes through an OR gate 422 and triggers another one-shot 423 which provides a paper advance motor drive pulse (Waveform (M)), which may for example be 20 milliseconds in duration to allow a paper movement of 0.088 inch. this pulse is applied to a paper advance motor 424 via a drive amplifier 425. The paper advance motor is mechanically coupled to the sprocket of the pin tractor 4 (FIG. 2) and advances the sheet 1 by the distance a (.088). The sheet is then in position to receive the second row of braille character elements.
The second embossing pulse TP- then advances bits two and five of the braille characters into the first and fourth stages of the character registers of the buffer group 158. Embossing and paper feed then occurs as was the case for the first pair of braille character elements in the first row. The sheet is then advanced into position to receive the third row of braille element pairs. The third embossing pulse TP-9 then advances the third and sixth braille character code elements into the first and fourth stages of the register. Embossing then occurs as was the case for the first and second row of braille character element pairs.
The next timing pulse from the decoder is the TP-13 pulse (see Waveform (N)). That pulse resets the counter 413 ending the embossing cycle. It also is applied via the OR gate 422 to trigger the one-shot 423 and produces a second paper advance (thus after printing the third row of characters there are two paper advances, one due to the TP-9 and the other due to the TP-13 pulses from the decoder 410. The sheet is now in position to receive the next line of braille characters (see FIG. 1C). The next or successive line of charcters are read out of the buffer group 159 which has been filling with characters while the characters stored in the buffer group 158 were being read out and used to operate the embossing mechanism. The TP-l3 pulse also passes through an AND gate 427 which is enabled by the Q output of the pointer flip-flop 400. IT Will be recalled that the Q output of the pointer flip-flop 400 is high during an embossing cycle when the buffer group 158 is read out. The TP-13 pulse then resets the registers in the buffer group 158. The buffer group 159 has an embossing AND gate 430 and a reset AND gate 431 which operates when the buffer group 159 is read out during its embossing cycle.
The buffer group 159 also has associated with the first and fourth stages of each of its character registers, a pair of AND gates R-7, R-8 which serves the same purpose as the AND gate pairs R-l, R-2 for providing embossing signals via and OR gates R-3, R-4 to the solenoid 8-1 to 8-80 operating windings. After each embossing cycle the TP-13 pulse resets the emboss cycle flip-flop 407 to terminate the cycle.
In the event that it is desired to emboss partial lines rather than full lines and alternate path for CLK-2 pulses to the AND gates 155 and 156 may be provided via another AND gate (not shown). When less than forty characters per line are desired a flip-flop (not shown) may be set, say by a button such as the character return key on th keyboard 162. The buffer full signal from the first character register stages may be applied to reset the flip-flop. When set, the flip-flop enables the AND gate in the alternate pair to apply.
From the foregoing description it will be apparent that there has been provided an improved braille communications terminal or typewriter which is capable of printing or embossing braille characters a line at a time and thus provides extremely high speed brail-ling operations. Variations and modifications in the herein described embodiment of the invention will undoubtedly suggest themselves to those skilled in the art. Accordingly the foregoing description should be taken merely as illustrative and not in any limiting sense.
Whatt is claimed is:
1. Braille communications apparatus which comprises:
a. means including a collinear row of embossing elements grouped in a plurality of pairs for embossing the collinearly disposed code elements in a line of braille code characters on a sheet, and
b. means coupled to each of said embossing elements and responsive to code signals representing said characters for successively operating said embossing means to emboss on each of said successive operations successive entire lines of said braille code elements until an entire line of braille code characters is formed.
2. The invention as set forth in claim 1 wherein said embossing means includes means for advancing said sheet to present lines on said sheet which have a first displacement from each other between the lines of collineraly disposed code elements in each line of braille characters, which lines of elements are embossed on each advance until the line of code characters is formed, and second displacement greater than said first displacement between successive lines of braille characters.
3. The invention as set forth in claim 1 wherein said embossing means comprises a row of pins each corresponding to a different braille character code element, and means for reciprocating said pins into and out of embossing relationship with said sheet.
4. The invention as set forth in claim 3 wherein different pairs of said pins are laterally offset from each other in said row for embossing successive pairs of code elements of different braille code characters in each said line of braille code characters.
5. The invention as set forth in claim 4 including a member havng a plurality of pairs of recessed dies corresponding to said pins and disposed in a row, said member being disposed opposite to said pins and spaced therefrom to permit said sheet to pass therebetween, and with said dies aligned with their corresponding pins.
6. The invention as set forth in claim 5 further comprising a plurality of electromechanical actuators each for a different one of said pins.
7. The invention as set forth in claim 6 wherein pairs of said plurality of actuators are provided for each of said pairs of pins, each of said actuators in each of said pairs being disposed on an opposite side of said row of pins.
8. The invention as set forth in claim 6 wherein each of said actuators includes a solenoid, and a link pivotally mounted intermediate the ends thereof and extending between said solenoid on the one of said pins actuated by said solenoid.
9. The invention as set forth in claim 8 including spring means for biasing each of said pins away from said sheet, said bias being overcome by said solenoid when actuated to advance said pin into embossing relationship with the sheet.
10. The invention as set forth in claim 9 wherein said solenoids are disposed in rows parallel to said row of pins and on opposite sides of said row of pins, and wherein said links extend perpendicularly to said row of pins.
11. The invention as set forth in claim 10 wherein said rows of solenoids are offset at different distances form said row of pins, said links being of different length corresponding to the distance between their respective solenoids and the pins actuated thereby, and a plurality of members each defining a fulcrum on which said links are separately pivotally mounted, said fulcrum members being disposed in rows parallel to said row of pins and offset from said pin rows by different distances in accordance with the lengths of the links pivoted thereon whereby said links have substantially equal travel paths when actuated by their respective solenoids.
12. The invention as set forth in claim 2 wherein said advancing means comprises a pin tractor mechanism adapted to engage holes disposed along the edge of said sheet, and an electromagnetic actuator for providing stepwise movement of said pin tractor mechanism for electively feedng said shee '1 distance corresponding to the separation of on plurality of braille character code element lines.
13. The invention as set forth in claim 1 wherein said operating means comprises means for receiving code signals representing successive characters,
means having storage for a plurality of said characters which are adapted to constitute a line of braille characters, and
means for reading out said storage means a plurality of times, each time to read out simultaneously all of the signals corresponding to the collinearly disposed elements in said line of braille characters.
14. The invention as set forth in claim 13 wherein said storage means comprises a plurality of registers each for a successive one of said braille characters, each of said registers having a plurality of stages which provide storage for code signals correponding to different ones of the code elements of said braille characters, and means for successively reading out of said registers the different pairs of said code signals, each of said pairs corresponding to a collinearly disposed pair of code elements of a braille character whereby the collinearly disposed code elements in each line of element constituting a line of braille elements are presented for operating said embossing means.
15. The invention as set forth in claim 14 wherein said embossing means comprises a separate pair of pins for embossing each of said pairs of code elements, said pins being disposed in a row extending across the sheet,
and electromagnetic means for actuating said pins into embossing relationship with said sheet, said operating means further comprising means responsive to each of said different pairs of code signals read out of said registers for operating said actuating means for each of said separate pairs of pins.
16. The invention as set forth in claim 15 including means for feeding said sheet upon each read-out of said pairs of code signals and the embossing of line of said braille code character elements in response thereto.
17. The invention as set foth in claim 16 including means for operating said feeding means for feeding said sheet a distance greater than the distance said sheet is fed after read-out of a line of said braille code character elements when a plurality of said pairs of said code signals constituting an entire braille character are read out of said registers.
18. The invention as set forth in claim 14 wherein said register read-out means comprises means for simultaneously reading the code signals stored in two of the stages of said registers, and means for shifting said code signals through said register stages a plurality of times, each such shifting providing a successive pair of said code signals for read-out, and means responsive to said shifting means for operating said embossing means in response to each of said successive pairs of code signals.
19. The invention as set forth in claim 18 further comprising means included in said receiving means for converting said code signals representing each of said characters into braille character code signals, and means for entering said braille character code signals serially into said registers.
20. The invention as set forth in claim 19 wherin said registers comprise a plurality of groups of registers each having storage for a plurality of said braille character code signals equal in number to the number of said braille characters adapted to be embossed in each of said lines of braille characters, and means operative when the one of said registers in one of said plurality of groups which has storage for the braille character to be embossed at the beginning of the line is full for operating said reading out means for reading out said full register in said one register group while enabling another of said plurality of register groups to receive additional braille character code signals whereby successive lines of said braille characters corresponding to braille character code signals stored in differnt ones of said register groups are embossed on said sheet.