US2987715A - Signal-character translator - Google Patents

Description

June 6, 1961 c. E. JONES, JR., EI'AL 2,987,715

SIGNAL-CHARACTER TRANSLATOR Filed April 16, 1958 6 Sheets-Sheet 1 coUNT BY r p coum' BY N I? coon-r BY 5 4/ Z 511 swan? esNmA June 6, 1961 c. E. JONES, JR., ETAL 2,987,715

SIGNAL-CHARACTER TRANSLATOR Filed April 16, 1958 6 Sheets-Sheet 2 //v VENTaRs SIGNAL-CHARACTER TRANSLATOR 6 SheetsSheet 3 Filed April 16, 1958 XXX [NYE/wales c0100 E. uozvss, JR. JOSPH LUO/VGO Mega.

June 6, 1961 Filed April 16, 1958 K XE C. E. JONES, JR., ET AL SIGNAL-CHARACTER TRANSLATOR qm \I N m m l 6 SheetsSheet 4 olan-in.

/NVENTOR5 CLAUD 5. James, JR.

JOSEPH zuolvqo Ass/yr June 6, 1961 c. E. JONES, JR, ETAL 2,987,715

SIGNAL-CHARACTER TRANSLATOR Filed April 16, 1958 6 Sheets-Sheet 6 IHUXJIZQLdMm lM/ENTORS C0400 JON$,-/1 l I l l l l l l I I i l Jose/3 u/aA/qa United States Patent 2,987,715 SIGNAL-CHARACTER TRANSLATOR Claude E. Jones, In, Atlanta, Ga., and Joseph Luongo,

Cedar Grove, N J assiguors to International Telephone and Telegraph Corporation, Nutley, NJ., :1 corporation of Maryland Filed Apr. 16, 1958, Ser. No. 728,927 2 Claims. (Cl. 340-324) This invention relates to information translating circuits and in particular to an arrangement to translate coded information into characters, preferably alphanumeric characters, for readout or recording operations.

There have been various techniques developed in the prior art to produce alpha-numeric characters on cathode ray tubes for display purposes. These schemes have included arrangements to extrude a beam or bundle of beams through a templet or character forming member which has the characters cut therefrom, such that the beam or beams impinging the cathode ray tube face assume the shape of the character which has been cut from the templet or character forming member. In such schemes there is an inherent disadvantage in that precise control over the diameter of the electron beams or bundles must be incorporated in the system in order to insure that the beam when passing through one character cutout will not overlap and pass through an adjacent character cutout. In order to provide for a plurality of characters to be seen at the same time, for instance, to form a word, it becomes necessary to provide further controls of the extruded beam or bundle of beams to locate sequential figures on the cathode ray tube face.

Another arrangement which has been used to translate electrical signals into characters is one wherein either a monoscope type of video signal generator or video camera is used for the initial conversion element. In these schemes the characters are either painted on the face of the monoscope or else they are put on a card and viewed with a video camera. The signal which is to have the translation performed thereon is passed to the horizontal and vertical deflection circuits of the monoscope or camera. This signal enables the monoscope or the camera to scan the particular character painted on the face or on the card which the input signal represents. These systems necessarily rely on secondary emission and have the inherent disadvantages that accompany secondary emission devices. For instance, because of the secondary emission principle there very often results some distortion related to non-linearity in the scanning operation. Other inherent disadvantages which accompany this type of system are that the system is limited in the number of symbols which can be readily used, and can only indicate the symbols which are painted on the scope face. There is a further economic disadvantage in trying to acquire any flexibility in such systems by replacing the scopes to enlarge the library of symbols available.

The above arrangements do not lend themselves for use readily in a system wherein there is is a severe limitation on space. These systems, by having monoscope or video camera input devices, use bulky equipment. The direct viewing system having the beam passing through a templet also requires bulky equipment in order to house the controls and templet of the viewer.

It is therefore an object of this invention to provide an improved information translating circuit.

Another object is to provide an information translation device which can be packaged in a relatively small amount of space.

Another object is to provide an information translation circuit which operates without a beam scanning de- Vice at the input.

A further object is to provide a translation system in which the limitation on the number of symbols or characters which can be displayed is relatively small.

In accordance with a main feature of the present invention there is provided a matrix whose input lines each represent a possible increment necessary for the forma tion of any of the characters representative of the system input signals and whose output lines each represent a character which might be indicated, with these output lines tied to the proper input lines to give the necessary increment outputs to be arranged together in order to form the character which the respective output lines represent.

Another feature is the provision of a character indicative device having conditionable increments and a counting circuit which serves to provide a comparison circuit to compare each of the outputs of the matrix device, mentioned in the last feature, in order to determine which conditionable increments of the character indicative device should be conditioned in order to provide conditioned increments to form the character representation of the output information.

Still another feature includes an input means to which there is passed a coded signal and from which there are a plurality of output lines only one of which is conditioned to correspond to the coded signal and which is coupled to the matrix of the first-mentioned feature to provide an input thereto.

The foregoing and other objects and features of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, in which:

FIG. 1 shows the organization of FIGS. 2 through 7;

FIG. 2 is a schematic showing a counter chain coupled to a pair of control matrices and coupled to the horizon tal and vertical sweep generators of the cathode ray tube display device;

, FIG. 3 is a diode matrix whose inputs are coupled to the matrices of FIG. 2;

FIGS. 4 and 6 together show a diode matrix coupled to a coded input;

FIGS. 5 and 7 together show a diode matrix representing a character forming matrix which is coupled between the matrix of FIGS. 4 and 6 and the matrix of FIG. 3.

FIG. 8 shows a dotted raster with the numeral 2 formed thereon.

In FIG. 2 there is shown an input signal generator 11, which has its output coupled to the count-by-five circuit 12 which in turn has its output coupled to the count-byseven circuit 13. The count-by-seven circuit 13 has its output coupled to the count-by-M circuit 14 which in turn has its output coupled to the count-by-N circuit 15. Coupled to the count-by-five circuit 12, and the count-by-M circuit 14 on the lower side, is a diode and resistor network which is coupled to the horizontal step sweep generator 16 to provide a signal input thereto. The generator 16 is in turn coupled to the horizontal control plates 17 of the cathode ray tube 18. Coupled to the bottom half of the count-by-seven, and count-by-N circuits is a diode resistance network which is in turn coupled to the vertical step sweep generator 19. The output of the vertical step sweep generator 19 is coupled to the vertical control plates 20 of the cathode ray tube 18. The count-by-five, count-by-seven, count-by-M and count-by- N circuits are shown in block flip flop form. These circuits are well-known limited binary counters made up of bistable devices, for instance, bistable multivibrators. When the circuit 12 counts to 5 there is an output to the count-by-seven circuit 13. On the top side of the count.-

3 by-five circuit there is a diode matrix 21. On top of the count-by-seven circuit there is a diode matrix 22. The diode matrices 21 and 22 are connected to the diode matrix arrangement 23 of FIG. 3. The outputs from the matrices 21 and 22 comprise the inputs to the matrix 23.

The outputs to the matrix 23 are the inputs to the diode matrix 24 of FIG. 5. It should be noted that the countby-five circuit 12 and the count-by-seven circuit 13 being coupled respectively to the horizontal and vertical control plates, provide for the particular embodiment of FIGS. 2 through 7, a system which has a raster of thirtyfive dots. The inputs to the matrix 24 of FIG. as represented on the top side of the matrix, for example, by the leads 25, 26, 27 and 28, are thirty-five in number. One of each of these inputs is associated with a spot or dot on the raster, described above. The output leads to the matrix 24 are coupled to the collector elements of each of the transistors 29.. The emitters of the respective transistors 29 are connected in common between ground and the grid of the cathode ray tube 18 through the amplifier 18a of FIG. 2. In FIG. 6 there is shown on the bottom side of the matrix 30 a group of six paired inputs 31 through 36 labeled 1-0. These paired inputs represent the outputs of bistable devices although the devices are not shown. The particular code of the embodiment of the invention shown in FIGS. 2 through 7 uses a six-bit code and therefore there are six bistable devices shown. The outputs of the bistable devices of FIG.'6 which represent the code, are passed to the diode matrix 30. The output leads of the diode matrix 30 are passed, respectively, through resistance elements to a base element of an associated transistor of the transistor group 29. It is to be noted that there are as many outputs from the matrix 30 as there are characters to be represented on the cathode ray tube 18 of FIG. 2.

For a better understanding of the invention consider with the FIGS. 2 through 7 arranged as in FIG. 1, an operation of the circuit to provide the numeral 2 on the cathode ray tube 18. FIG. 8 shows the dotted raster with the numeral 2 formed thereon. In the particular code used with the embodiment shown by FIGS. 2 through 7, the numeral 2 is represented in binary form by 111000. When the binary coded number 111000 is passed to the bistable devices represented by 31 through 36 of FIG. 6, the bistable devices 31 through 33 are rendered conductive on the left hand or one side while the bistable devices 34 through 36 are rendered conductive on the right hand or zero side. With the bistable devices 31 through 36 conducting, as mentioned above, it appears that only line 37 shown on FIG. 4 will have a positive potential applied thereto. The line '37 has a positive potential appearing thereon because it is the only line in the matrix through which there is no electron flow, by

way of the many diode paths, to B-I- at 38. A careful examination ofFIGS. 4 and 6 will reveal that for each code input combination therewill be only one output line of thermatrix 30 whichwill be conditioned positive. With line 37 being conditioned positive and with the tran-' sistor 39 of FIG. 4 being an NPN type transistor, this transistor, whose base is tied to line 37, is conditioned to conduct. However, the transistor 39 will'not conduct even though there is a positive voltage applied'to the base element unless the collector element is also experiencing a positive voltage with respect to ground. This is'true because the emitter element is tied to ground. In order to determine Whether the transistor 39 should 'be conducting or not, it must be determined where the transistor 39, are connected through the diode matrix 24 of FIG. 5 to the diode matrix 23. It becomes obvious that if there is conduction through any of the diodes of the diode matrix 23, then the lower points of the resistances 40 will be held substantially negative with respect to B+ and therefore any transistors associated therewith will be held non-conductive. In order to determine what diode circuits are conducting in the matrix 23, consider What is taking place in FIG. 2. In FIG. 2 before there are pulses passed from the generator 11 to the count-byfive circuit 12 and on to the complete counting chain, the counter circuits all have their binary devices sitting on the zero side. Therefore, when the code signals are passed to the bistable devices 31 through 36 of FIG. 6 the bistable'devices of the count-by-five circut, etc., of FIG. 2 are all sitting on the zero side. With the bistable circuits 41, 42 and 43 of the count-by-five circuit of FIG. 2 sitting on the zero side, it becomes apparent that there is conduction taking place along the lines 44 through 47. Simultaneously the bistable devices 54, 55 and 56 are sitting on the zero side, therefore there is conduction on the lines 57 through 62 as Will be apparent from an examination of the matrix 22. However, there is no conduction taking place through the line 48 or 63 and therefore the point 49, which is the power point of the resistance 49a of the matrix 23, is substantially at B+. This condition would normally cause the transistor 39 to conduct excepting that an examination of the matrix 24 of FIG. 5 reveals that there is no diode connection between the collector element of transistor 39 and the line 25, therefore transistor 39 does not conduct. At the time that the counter circuits have their bistable devices sitting in the zero position, the voltage developed at the diode resistor networks, in conjunction with the sweep generators 16 and 19, renders the cathode ray tube 18 in such condition that if there were a beam passed to the face of the tube it would appear in position 50 of FIG. 8. Since transistor 39 of FIG. 4 was not caused to con duct, as described above, the position 50 of FIG. 8 remains blank and the generator 111 of FIG. 2 passes a clock pulse to the counting train to advance the bistable device 41 to the left hand or one side. With the bistable device 41 sitting on the left hand side, an examination of the matrix 21 will reveal that lines 44 and 63 are now non-conducting and thereforethe point 51, the lower point of resistance 51a, of FIG. 3 is positive to render the transistor 39 of FIG. 4 conducting. With the transistor 39 of FIG. 4 conducting, the grid of the cathode ray tube 18 is conditioned through the amplifier 18a such that the tube passes an electron beam to the face of the tube. With the first pulse from 11 advancing the countby-five circuit, there has been a change in the voltage application through the diode resistor network to the horizontal step sweep generator and therefore to the horizontal control plates 17to cause the electron beam to appear on the cathode ray tube in the position 52 as shown on FIG. 8. This operation continues with the count-by-five circuit 12'counting up to five and thereby providing a voltage application to place the beam in each position along the top row of the raster of FIG.'8. When the count-by-five circuit has reached the count of five, there is an output to the'count-by-seven circuit. The count-by-seven circuit having been advanced to one causes a pedestal voltage to be applied through the vertical step sweep generator to the vertical plates 20 of the cathode ray tube 18. 'Ihe pedestal voltage on the vertical plates causes the sixth dot of the raster to appear below the first dot as shown by dot 53 of FIG. 8. Simultaneously when the count-by-seven circuit advances to one, the line 63 becomes conductive and effects a shift in the input to matrix 24. This operation continues through the entire dotted raster. To determine'which dots of the raster will be illuminated the diode arrangement along the line of numeral'2, as labeled on the right hand side of the matrix 24 can be considered. Itwill .be noted considering that particular line that there is no diode,.then three diodes and nodiodewhich corresponds to a blank space, three illuminated dots, then a blank space on the first row of the raster of FIG; 8. 1

When the count-oy-seven circuit has advanced to the number seven there is an output to the count-by-M circuit which applies a horizontal voltage pedestal to move the entire dotted raster to the right. By moving the entire raster to the right the device enables the next character which is formed to be adjacent on the right side of the first letter formed. This repeated operation will lead to the forming of a word. Depending on how many stages are put in the count-by-M circuit there can be any arbitrary amount or number of 'characters forming a word or line Within the limitations of the display unit. When the count-by-M circuit has arrived at its complete count there is an output to the count-by-N circuit which now moves the raster below the first line of rasters so that there can be a second row of characters or words formed. Accordingly, like the count-by-M circuit, the count-by-N circuit can have any arbitrary number of stages which will determine the number of lines possible within the limitations of the display device.

In the particular embodiment of FIGS. 2 through 7 the raster is a five-by-seven raster. Obviously, by choosing different counter circuits other than the count-by-five circuit and the count-by-seven circuit, a raster can be formed with some other number, for instance twentyfour, with four dots across the top and six rows down.

The embodiment of FIGS. 2 through 7 has been shown without depicting any programing arrangement which would obviously be necessary for the proper practical operation of this system. In other words, in the actual application of the invention to the data processing art there has been provided a programing device which permits the coded signal to be applied at the bistable devices 31 through 36 to remain for a long enough period of time to permit the counting chain to be advanced for 35 pulses or counts to complete the raster picture. Such programing arrangements are well known in the data processing art and is not shown here in order to provide for simplicity of the inventive structure.

This invention is completely flexible in that in order to add any additional characters or to replace or change a character, the user need only decide what increments or dots of the raster will from the character and arrange the diodes of the matrix 24, on any particular line, to produce the necessary increments of the particular raster. The circuit has been designed such that there can be a plug-in character forming matrix whereby characters of one code, wherein the code formerly represented English, can be translated through the character matrix 24 into some language, for instance, Greek. The code can be adapted to represent other symbols such as weather symbols. This can be readily accomplished merely by arranging the diodes of the matrix 24 to provide increments or dots to make up the Greek characters that correspond to the English code characters passed to the input circuits 31 through 36. Another obvious flexibility of the present invention is the means for changing the code to fit some particular use by again changing the arrangement of the matrix 30. The matrices lend to compactness and therefore the system can be packaged in a relatively small space which is often desirable, for instance, in airborne equipment.

While we have described above the principles of our invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope .6 of our invention as set forth in the objects thereof and in the accompanying claims.

We claim:

1. An alpha-numeric character display arrangement wherein the characters are formed by properly arranged sequential and discrete dots comprising a source of information which can be represented by characters, a cathode ray tube having a beam generating means and a horizontal and vertical beam control means to display said dotted characters thereon, a counter chain having a plurality of stages, each counter of the chain counting discrete dot positions a diode resistor network coupled to said counter chain to provide a step sweep voltage output, horizontal and vertical step sweep generators coupled to said diode resistor network and said control means to provide a dotted raster on said cathode ray tube face in accordance with said step sweep voltage, a first diode matrix having a plurality of inputs and a plurality of outputs, each of said inputs representing a particular character to be formed and coupled to said source, each of said outputs representing a possible discrete dot in any character formation, gating means coupling said diode matrix to said beam generating means, a second diode matrix coupled between the outputs of said first diode matrix and said counter chain to sequentially condition for conduction the diodes of said first matrix in accordance with the possible positions of said dotted raster causing said gating means to render said beam generating means conducting to provide illuminated discrete dots at character representative positions of said raster.

2. A device to display information characters whereby the characters are formed by a plurality of distinctive increments comprising a source of information which can be represented by characters formed by an array of discrete dots, a cathode ray tube having a beam generating means and a horizontal and vertical control means to display said characters thereon, a raster control circuit coupled to said horizontal and vertical control means to direct the beam of said cathode ray tube according to a pattern of positions on said tube face, a first diode matrix to convert an input signal from said source into a plurality of outputs characteristic of said input signal, said outputs corresponding to particular discrete dot positions to which said beam can be directed, second means coupled to said outputs and said raster control circuit to compare the outputs and said positions to condition said beam generating means to pass a beam to those positions corresponding to said outputs thereby indicating on the face of said cathode ray tube the character representation of said input signal, said raster control circuit including a plurality of counters which count dot positions, a horizontal step sweep generator and a vertical step sweep generator and circuitry means coupling said counters with said generators to said horizontal and vertical control means to pass said beam to said pattern positions in accordance with the step signals developed.

References Cited in the file of this patent UNITED STATES PATENTS

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