US 3640368 A
Apparatus for converting a standard typewriter to record in Braille includes a plurality of character-key switches, a Braille recording device, an electrical switching network between the character-key switches and the recording pin actuators of the Braille recording device, and record sheet advancing means. The electrical switching network includes a diode matrix having an input line for each character key and an output line for each recording pin actuator, and a pulse generator connected to each recording pin actuator. The standard typewriter has a shift-key and one or more double-element keys and therefore the apparatus includes a switch for each of these keys, and a circuit having a pair of AND gates for each of the double-element keys controlling the switching network in accordance with whether or not the shift-key is depressed with a double-element key.
Description (OCR text may contain errors)
[151 BflMfiM 1 Feb. 9, i972 FOREIGN PATENTS 0R APPLICATIONS Primary Examiner-Edgar S. Burr Attorney-Benjamin J. Barish  ABSTRACT Apparatus for converting a standard typewriter to record in Braille includes a plurality of character-key switches, a Braille recording device, an electrical switching network between the Marshal Weinherger, Jerusalem, Israel Aug. 114, 1969 Foreign Application Priority Data Aug. 20, 1968 Israel ....30578 6 aeame m md ck. e whdmw w m m f O I e a r m m w w wo w n a u wfi e o m a Md w w am m mwmfifi V .1 ad f n m wm wm .mmw ywm mm m m w m-ul h msee d m r m r W d m .m.m m m dnw mm mmwnwmew m m wa,mo. aw a mmmm m m m 3 m vn l-m mS m e Pcmamm m m sf m m ewzl n 0 I. m h m d mt C t mon h m m 3 m m m e n. Pm 8m gm mm am m w n w 6 J A m yd vun SBO G fiwimmdwmy. n? wyn w A n fiv m mmm wa 4 .l h m m mm. Wh w m t1 J h au m m 5m in e m a; a cBnmew mmdmmd 0 4 5 0 2. mu" n 12... X r0 2 r1 6 B6 66W 66 r\ :0 7 7 77 77 6 9H9 99 U999 1 4 J ul Q u n m u l l l IIL m m w T m m m m m M m m u m m m c e m m m... m m m a m 33 w r u c T mtom e m m n A e m m m w mwaw um u n rm m m D KFCWPG m n m R m i "uh 66 m wflfim u "mm 999999 m s "HHHHH L Ur 665236 C 1 d m Mmn%mw Mum ll] mwfi fim 218 6 U55 5 22333 United Slams Patent Weinherger  lBlRAllLlLlE TYPEWRHTIER  Inventor:
 Assignee: State of llsrael  Filed:
 Appl.No.: 850,202
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to apparatus particularly useful for converting a standard typewriter to record in Braille. Features of the invention, however, may be used in other applications.
2. Description of the Prior Art A number of Braille recorders have heretofore been devised. However, some of the known machines are specially constructed, complicated mechanical mechanisms, and are therefore expensive. Others are cumbersome to use.
SUMMARY OF THE PRESENT INVENTION The present invention provides apparatus for converting a standard typewriter to record in Braille and includes: a plurality of character-key switches one for each character-key of the standard typewriter positionable so as to be actuated upon depression of the respective character-key; a Braille recording device including a plurality of recording pins for recording on a record sheet in accordance with the Braille code, there being an actuator for each recording pin; an electrical switching network connected between the character-key switches and the recording pin actuators for actuating those of the latter corresponding in the Braille code to the character-key depressed; and record sheet advancing means for advancing the record sheet following each depression of a character-key.
Such an apparatus has a number of important advantages. First, there is the financial advantage in permitting the user to use his own standard typewriter, adding only an attachment. There is also an important psychological advantage in permitting the blind person to use his own familiar typewriter, in that he does not have to learn how to use a new, unfamiliar machine. In addition, by producing both a Braille output and a standard typewriter output, the blind person is able to carry out correspondence in a convenient manner with a seeing person, and vice versa. Also, it enables him to check what he has typed, by means of the Braille copy, which can be important, tag, to a blind computer programmer.
In the described embodiment, the electrical switching network includes a diode matrix having an input line for each character key and an output line for each recording pin actuator.
According to still further feature, wherein the invention is used with a standard typewriter including a shift key and one or more double-element keys each effective to print one of two elements, e.g., symbols or characters, depending upon whether or not the shift key is depressed with the double-element key, the apparatus further includes a shift-key switch positionable to be actuated by the depression of the shift key, and a switch for each of said double-element keys positionable so as to be actuated by the depression of each of the latter keys; the apparatus further including a first and a second AND gate for each of said double-element keys; the first AND gate including two input conductors one connected to said shiftkey switch, and the other connected to the respective doubleelement switch, and an output conductor connected to the input conductor of the electrical switching network corresponding to one of its two elements; the second AND gate including an inverter and two input conductors one connected to said shift-key switch through said inverter and the other connected to the respective double-element key switch, and an output conductor connected to the input conductor of the electrical switching network corresponding to the other of its two elements.
Further features and advantages of the invention will be apparent from the description below.
BRIEF DESCRIPTION OF THE DRAWINGS The invention is herein described, somewhat diagrammatically and by way of example only, with reference to the accompanying drawings, wherein:
FIG. 1 schematically illustrates the main units of one form of apparatus constructed in accordance with the present inventron;
FIG. 2 is a circuit diagram illustrating the operation of the apparatus of FIG. l; and
FIG. 3 is a logic diagram illustrating a further feature of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, there is illustrated a standard typewriter T having the conventional character keys 2 and a spacebar 4.
According to the invention, an attachment I0 is provided for the typewriter which attachment includes a plurality of electrical switches 12 (FIG. 2) one for each character-key 2 of the typewriter. These switches, hereinafter referred to as the character-key switches, are disposed within the attachment so as to be actuated upon depression of its respective character key. Attachment I0 also includes a further switch 14 disposed so as to be actuated by the space bar 4 of the typewriter, the latter switch being hereinafter referred to as the spacebar switch. The foregoing switches could of course be attached individually to the typewriter so as to be actuated by the depression of the character-keys and space bar, or be disposed in a separate attachment unit.
Switches 12 and 14 are connected by conductors 16 to a switching network 18, the output of which is connected by conductors 20 to a Braille recording device 22. The output from switching network 18 includes a further electrical conductor 24 which controls the record sheet (e.g., paper) advancing means, schematically designated 26 in FIG. I, for advancing the record sheet following the depression of each character key or of the space bar.
With reference to FIG. 2, the Braille recording device 22 includes six recording pins Pl-P6 arranged in two vertical columns of three each, each pin including an actuator SI-S6 (e.g., a solenoid) for actuating same. In addition, the Braille unit includes the above-mentioned paper-drive advance 26 for advancing the paper one character increment upon each recording operation.
The switching network 18, as shown in FIG. 2, includes a diode matrix 19 having an input line 16 for each character-key and an output line 20 for each recording pin actuator. Each of the input lines 16 is connected to a vertical conductor (i.e., conductors l6a-l6z) of the matrix and each of the output lines 20 is connected to a horizontal conductor (i.e., conductors 20-1 to 20-6) of the matrix. Rectifier diodes R are applied between selected vertical and horizontal conductors to produce an output pulse on those lines 20 corresponding, according to the Braille code, to the character-key switch 12 actuated upon depression of a character-key. For example, as shown by the diode matrix arrangement in FIG. 2, depression of the A" character key will produce a pulse on conductor 20-1 alone; key 8", on conductors 20-1 and 20-2; key C, on conductors 20-l and 20-4; and key Z", on conductors 20- 1, 20-3, 20-5 and 20-6.
A pulse generator Gl-G6 is connected to each of the conductors 20-I to 20-6; at the output side of the diode matrix. The pulse generators are in turn connected to the recording pin actuators S16. The pulse generators produce a standard pulse for each closure of the switches 12, and therefore the actuation of the Braille recording pins PlP6 becomes independent of the quality of the typists touch.
The pulse generators GI-G6 also produce an output pulse applied through a single conductor 30 to line 24 for controlling the paper-tape advancing means 26 in order to advance the record sheet of the Braille recorder one character increment for each depression of a character key on the typewriter. The paper advance is of course effected after the operation of the recording pins Pl-P6 is completed. A delay circuit 31 may be included in line 24 for providing this delay.
Space-bar switch 14, actuated by depression of the space bar 4, is connected through conductor 32 to line 24 of the paper-tape advancing means, so that the paper tape is also advanced one character increment following the depression of the spacebar.
The operation of the apparatus will be apparent from the above description. When the user depresses a character key on the typewriter T, the character is printed by the typewriter in the normal manner, and in addition, the switch 12 corresponding to the character key depressed is closed. Diode matrix 19 produces a pulse on those of lines 20-1 to 20-6 corresponding in the Braille code to the character key depressed, and these pulses are transmitted to their respective pulse generators 01-66 which actuate the respective solenoids 51-86 of the Braille recording pins Pl-P6. Thus, the character will also be printed in Braille. In addition, actuation of one or more of the pulse generators Gl-G6 produces a pulse on conductor which pulse is transmitted through delay circuit 31 and conductor 24 to the paper-tape advance mechanism 26, whereby the paper tape is advanced one increment after the recording pins have completed their operation. Advancing of the paper tape is also effected by depression of the typewriter space bar 4, which closes spacebar switch 14 to transmit a pulse through conductor 32 to line 24 of the paper-tape advance mechanism 26.
Thus, as the user operates the typewriter in the conventional manner to produce the normal typewriter output, a corresponding Braille output is produced by the Braille recording device 22.
In a standard typewriter, there are many double-element keys each effective to print one of two elements (e.g., a symbol or a character) arranged one above the other, depending upon whether or not the typewriter shift key is also depressed. Many of these double-element keys selectively print the upper or lower case of the character. However, other double-element keys are effective to print different characters or symbols important to Braille. For example, one key may be effective to print a (the lower element) when the shift key is not depressed, and a (the upper element) when the shift key is depressed.
In the present invention, in order to identify the element to be printed a switch is included so as to be operated by depression of the shift key, and a preliminary selection circuit is pro vidcd which determines if the shift key has been depressed or not. Ifthe shift key has not been depressed with the characterkcy, an electrical signal is passed to the input of the switching network corresponding to one of the elements (e.g., the lower element), and if the shift key has been depressed, the signal from the character-key is passed to the input of the switching network corresponding to the other element (e.g., the upper one).
FIG. 3 illustrates a logic circuit for accomplishing the foregoing. The shift key of the standard typewriter is indicated at 40, and the double-element key, effective to print either a or a is indicated at 42. The switches actuated by each are indicated, respectively at 40 and 42.
The preliminary circuit for determining whether the shift key 40 has been depressed or not includes two AND-gates 44 and 46.
AND-gate 44 includes two input lines, namely, line 48 connected to switch 40 and line 50 connected to switch 42'. In addition it includes one output line 52 connected to the input of the switching matrix 19 corresponding to one of the elements to be printed, i.e., the higher element (in this case a of the double-clement key 42.
The second AND-gate 46 also includes two inputs, namely, line 54 connected to switch 40', and line 56 connected to switch 42'. Line 54 however is connected to gate 46 through an inverter 58. AND-gate 46 includes a single output line 60, this one being connected to the input line of the switching matrix for the other element, i.e., the lower element (in this case the double-element key 42.
The operation of the circuit of FIG. 3 is as follows: When only key 42 is depressed (i.e., not shift key 40) a positive pulse is applied to input line 50 of AND-gate 44, and a ground (or zero) pulse is applied to input line 48 of AND-gate 44. Thus, since both inputs are not positive, no output pulse is produced on line 52 connected to the higher element (the line of the diode matrix 1?. Upon depression of key 42 alone, a positive pulse is also produced on input line 56 of AND-gate 46, and a ground (or zero) pulse on input line 54 of that gate. However, the latter pulse is inverted by inverter 58 before ap plied to gate 46, and therefore the gate receives two positive pulses. A positive pulse is thus produced on line 60 connected to the lower element (the line of the diode matrix I9. Accordingly, the lower element (the will be printed by the Braille unit.
Now, if both the shift key 40 and the double-print key 42 are depressed, two positive pulses are received in gate 44, producing a positive output on line 52 to the upper element (the line of the switching network. Two positive pulses are also produced on lines 54 and 56 but the former one is inverted by inverter 58 and therefore gate 46 receives a positive and a ground pulse. Thus no output pulse is produced on line 60 to the lower element (the line of the switching network. Accordingly, the higher element (the will be printed by the Braille unit.
Many variations and other applications of the invention can be made. For example, the invention could be used, not in the form of an attachment to a standard typewriter, but actually built into the typewriter itself. Also, features of the invention could be used for recording (e.g., printing), punching, or embossing) in codes other than Braille. Further, the signals to the switching network and the paper tape punch could be derived from a character-recognition system or a card or tape reader used in conjunction with business machines.
Other variations, modifications and applications of the illustrated embodiment will be apparent.
What is claimed is: v
1, Apparatus for recording in Braille, comprising a typewriter including a plurality of character-keys, a shift key, and at least one double-element key effective to selectively print one of two elements; a character-key switch for each character-key and actuated upon depression of the respective character-key; a shift key switch actuated upon depression of the shift key; a further switch for each double-element key actuated upon depression of the respective double-element key; a Braille recording device including a plurality of recording pins for recording on a record sheet in accordance with the Braille code; an actuator for each recording pin; an electrical switching network connected between said character-key switches and the recording pin actuators for actuating those of the latter corresponding in the Braille code to the characterkey depressed; a selection circuit effective to select the recording pin actuators corresponding to one element of the double element key depressed, when the shift key is depressed concurrently with the double-element key, and to select the recording pin actuators corresponding to the other element of the double-element key depressed when the double-element key is depressed alone; and record sheet advancing means for advancing the record sheet upon each depression of a character-key or double-element key; said selection circuit including a first and a second AND gate for said double-clement key; said first AND gate including two input conductors one connected to said shift key switch and the other connected to the respective double-element key switch, and an output conductor connected to the input conductor of the electrical switching network corresponding to one of its two elements; said second AND gate including an inverter and two input conductors one connected to said shift-key switch through said inverter and the other connected to the respective double-element key switch, and an output conductor connected to the input conductor of the electrical switching network corresponding to the other of its two elements.
2. Apparatus according to claim 1, wherein said electrical switching network includes a pulse generator at the output side thereof connected to each recording pin actuator.
3. Apparatus according to claim 2, wherein said pulse generators are also connected to said record sheet advancing means for applying a pulse to the latter to advance the record sheet following each depression of a character-key.