4,556,904
`(11] Patent Number:
`United States Patent 15
`
` Monat [45] Date of Patent: Dec. 3, 1985 _
`
`
`[54] TELETEXT SYSTEM HAVING USER
`PROMPT COMMANDS
`
`Inventor: Robert A. Monat, Indianapolis, Ind.
`[75]
`[73] Assignee: RCA Corporation, Princeton, N.J.
`
`(21] Appl. No.: 472,417
`
`FOREIGN PATENT DOCUMENTS
`$7-59223 4/1982 Jagat wessesccsccseresseereessescerseeeee 340/365
`Primary Bxxarntner—Jobn'C. Martin
`Assistant Examiner—David E. Harvey
`Attorney, Agent, or Firm—Eugene M. Whitacre; Joseph
`J. Laks; Sammy S. Henig
`
`ABSTRACT
`[57]
`Special prompt characteridentifying control codes are
`Mar.4, 1983
`[22] Filed:
`inserted in teletext data for transmission to a teletext
`[51] a“ = scsneneeroneenteensenespnensethaanasiesidancas ae equipped receiver. The prompt character identifying
`
`[52]
`.S.
`: SearchSteteRSASHSNSREN358/147,142. 340/712
`codes are detected in the receiver and applied to a sym-
`[58] Field of Search «0... 3o736: VL: 364 522
`bol converter which alters the prompt characters dis-
`5
`5
`364/
`played on the receiver CRT to assure that all prompt
`;
`characters displayed conform to character symbols
`actually available on the users
`teletext keyboard
`References Cited
`U.S. PATENT DOCUMENTS
`thereby avoiding user confusion as to the particular
`3,157,037
`9/1973. Bialek wecesenwurennenenne 340/712
`Key-Strokes required to access materialidentified in the
`3,879,722
`4/1975 Knowlton....
`_. 340/705
`‘teletext menu.
`
`4,288,809 9/1981 Yabe servsecsesesnen
`we 358/147
`4,439,761
`3/1984 Fleming etal. .......ssce 358/147
`
`[56]
`
`5 Claims, 3 Drawing Figures
`
` 320
`
`DETECTOR
`
`PROWPT
`cone
`
`PMC Exhibit 2098
`Apple v. PMC
`IPR2016-00753
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`PMC Exhibit 2098
`Apple v. PMC
`IPR2016-00753
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`U.S. Patent Dec. 3, 1985
`
`Sheet 1 of 3
`
`4,556,904
`
`
` =
`18
`NEWS 74
`
`
`# WORLD NEWS _~ ||
`| “
`se
`
`
`2 # BUSINESS NEWS
`3 #LOCAL ews e
`
`4 #SPORTS NEWS
`NEXT WORLD NEWS
`
`
`
`PMC Exhibit 2098
`Apple v. PMC
`IPR2016-00753
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`U.S. Patent Dec. 3, 1985
`
`Sheet 2 of 3
`
`4,556,904
`
`MENU
`FORMAT
`
`200 DATA
`
`
`TELETEXT
`PAGE DATA
`
`SOURCE
`
`USER
`PROMPT
`DETECTOR
`
` PROMPT
`
`IDENTIFICATION
`
`CODE
`GENERATION
`
`
`
`
`
`TELETEXT
`PAGE
`STORAGE
`MEMORY
`
`
`
`TELETEXT
`
`ENCODER
`
`216
`218
`
`
`
`
`VIDEO
`
`AND AUDIO
`
`
`SOURCE
`
`
`TELEVISION
`TRANSMITTER
`
`Fig. 2
`
`PMC Exhibit 2098
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`IPR2016-00753
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`IPR2016-00753
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`U.S. Patent Dec. 3, 1985
`
`Sheet 3 of 3
`
`4,556,904
`
`j
`
`314
`
`310
`
`PCM
`DETECTOR
`
`52 |
`
`32
`
`TELETEXT
`
`304
`
`\A302
`
`TV RECEIVER
`PROCESSING
`
`{si
`
`308
`
`DISPLAY
`UNIT
`
`TELETEXT
`
`()
`
`TV
`CO)
`306
`C
`
`6
`PIXEL
`CONTROLLERJ.3 |6
`GENERATOR
`
`8~+
`
`DISPLAY
`MEMORY
`
`
`
`Lee]
`
`320
`
`PROMPT
`CODE
`DETECTOR
`
`Fig. 3
`
`-
`
`PMC Exhibit 2098
`Apple v. PMC
`IPR2016-00753
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`IPR2016-00753
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`1
`
`4,556,904
`
`TELETEXT SYSTEM HAVING USER PROMPT
`COMMANDS
`
`FIELD OF THE INVENTION
`
`This invention relates to teletext systems generally
`and particularly to teletext systems in which the trans-
`mitted teletext code may include special symbols or
`control characters indentifying user prompts.
`BACKGROUND OF THE INVENTION
`
`Teletext systems are under consideration for trans-
`mitting textual materials to users having television re-
`ceivers equipped with memories and decoders which
`capture the teletext information and display the data in
`character or graphical form on the screen ofthe associ-
`ated television receiver. In selecting the data to be dis-
`played it has been proposed to transmit so called
`“menus”of information available in the teletext system
`to the user. A menu mayincludea listing of available
`pages or topics within the teletext system which the
`user may access by entering numbers or symbols onhis
`keyboard identified in the text of the menuas being the
`location of the material. It will be highly desirable ifall
`keyboards contain keys identified by symbols which
`match the symbols which maybe used in identifying the
`location of information in the teletext menu. The choice
`ofthe users’ keyboard symbols,is a matter upon which
`different manufacturers may not agree. Some manufac-
`turers may include keyboards with symbols which ex-
`actly match the symbols used to identify material in the
`teletext menus, whereas other manufacturers may elect
`to manufacture keyboards having a fewer number of
`keys, for example, or having different symbols than
`those actually used in the transmission of teletext to
`identify the menu items. This in turn can lead to user
`confusion about which symbols he might key or use to
`select desired information if the symbols do not exactly
`match whatis transmitted.
`
`SUMMARYOF THE INVENTION
`
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`It is an object of the present invention to minimize the
`possibility of user confusion with regard to selection of
`particular menu itemsin a teletext transmission in cases
`where, for example, the symbols used to represent the
`menuitem do not match the symbols onthe users’ key-
`board.
`Thepresent invention resides in part in recognition of
`the need for transmission of a special control character
`along with the symbols of the teletext
`transmission
`which represent user prompts which direct the user of
`the teletext receiver to make particular keyboard entries
`on his system.
`Theinvention resides in a further part in utilizing the
`special prompt character identifying control codes of
`the teletext transmission to facilitate a prompt character
`symbol conversion within the users’ receiver to assure
`thatall transmission of the prompt characters displayed
`on the users’ receiver correspond to characters that are
`actually available on the users’ keyboard.
`A method of encodinga teletext signal in accordance
`with the invention comprises identifying those charac-
`ters of a teletext signal which correspond to user
`prompts of the displayed teletext material and inserting
`adjacent to each symbol or set of symbols representa-
`tive of user prompts a control character prefix or suffix
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`identifying that symbol as being a user prompting sym-
`bol.
`A teletext receiver for receiving teletext signals en-
`coded as described and embodying the invention in-
`cludes a teletext receiving means for receiving the
`codedteletext signals and a first memory means coupled
`to the teletext signal receiving means for storing in
`encoded form signals representative of prompting and
`nonprompting signals to be displayed and signals repre-
`sentative of associated control functions not intended
`for display. A signal separating means coupled to the
`first memory means separates the signals representative
`of symbols to be displayed from the signals representa-
`tive of control functions. A detector means coupled to
`the signal separating means generates a control signal
`representative of a prompting signal to be displayed. A
`controllable code conversion means coupled to the
`signal separating means and to the detector means con-
`verts the coded signals representative of prompting
`signals to be displayed into coded signals representative
`of other symbols underthe control of the control signal
`and passes unchanged those coded signals representa-
`tive of nonprompting signals. The other symbols to
`which conversion is made are symbols identifying the
`function keys of the remote control with which the
`receiver is associated. A coded symbol-to-pixel conver-
`sion means coupledto the controllable code conversion
`means receives the codedsignals to be displayed and
`generates pixel intensity information therefrom. A sec-
`ond memory means coupled to the coded symbol to
`pixel conversion meansstores the pixel intensity infor-
`mation and a display means coupled to the second mem-
`ory means displays the nonprompting symbols and the
`converted prompting symbols corresponding with sym-
`bols identifying the function keys of the remote control.
`DETAILED DESCRIPTION
`
`The foregoing and further features of the invention
`are described hereinafter and shown in the accompany-
`ing drawing wherein
`FIG.1 is a block diagram ofa teletext equipped illus-
`trating a teletext equipped receiver;
`FIG.2 is a block diagram of a teletext encoding sys-
`tem embodying the method of the invention; and
`FIG.3 is a block diagram ofa teletext receiver appa-
`ratus embodying the invention.
`.
`FIG.1 illustrates the nature of the problem solved by
`the present invention. Theteletext system comprises a
`television receiver 10 having a teletext decoder therein
`(not shown) and a remote key pad 12 coupled to an
`input 14 of the teletext decoder in receiver 10 by means
`of a cable 16. The key pad has provision for 10 keys
`labeled 0 through 9 as shown. The receiver is assumed
`to be in its teletext receiving modeandis displaying an
`image on the video screen 18 of a news “menu”. The
`menu comprises four items labeled | through 4. Behind
`each item on the menuis the prompting symbolsigni-
`fied by a lb. sign (#). For a user to access menu item |
`“world news” the user would be prompted by the 1#.
`symbolto enter the number | followed by the # on his
`keyboard unit 12. Unit 12, however, does not havea Ib.
`symbol as a key identifier, only the number1. It does
`however have two keys labeled a and b.
`In making his selection the user might be inclined to
`press the symbols la or 1b on his remote control 12 in
`response to the prompt character 1# symbol. Onepossi-
`ble solution to avoid the confusion as to what symbols
`to enter on the user keyboard would be for the manufac-
`
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`IPR2016-00753
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`4,556,904
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`3
`turer to provide a lookup table of symbol conversion
`characters which would identify which of the letters a
`and b correspond to the Ib. symbol. This, however
`requires that the user have sucha table in his possession
`at the time he wishes to makehis selection, or to simply
`guess as to the proper correspondenceof the displayed
`prompt characters and the characters on his keyboard.
`This problem is solved in accordance with the inven-
`tion by transmitting with the prompt characters a non-
`visible control character which identifies each prompt
`character or group of characters, in this case the sym-
`bols “1”. In the receiver the teletext decoderis ar-
`ranged in such a manneras to detect the occurrence of
`the prompt symbol identifying character and then per-
`form a symbol conversion prior to displaying the char-
`acter so as to display characters which agree with the
`legends on the remote keyboard control unit 12. In this
`case upon occurrenceofthe nonvisible controlled char-
`acter the symbols 1#, 2#, 3# and 4# would be con-
`verted for example to the symbols la, 2a, 3a and 4a.
`FIG.2 is a block diagram of a teletext encoding sys-
`tem for inserting the nonvisible prompt control charac-
`ter which identifies the user prompting symbols of the
`teletext data stream. The system comprises a teletext
`page data source 200 which may be a mass storage
`device or it may comprise a source of continuousinfor-
`mation such as wire service stories, news flashes, etc.
`The output of data source 200 is applied to a user
`prompt detector unit 202 which receives a source of
`menu format data. Detector 202 compares the teletext
`data stream with the menu formatdata and identifies all
`teletext characters corresponding to user prompts. The
`output of detector 202 is applied to a prompt character
`code generator 204 which may include a read only
`memory (ROM)for generating a user promptidentifi-
`cation code word. Theteletext data produced by source
`200 is coupled by a data inserter 206 to a teletext page
`storage memory 208. Data inserter 206 receives the
`promptidentification code character produced in unit
`202 whenever a prompt symbol occurs in the teletext
`data stream and inserts the control character either
`before or after the teletext prompt character.
`The output of memory 208 is applied to a teletext
`encoder 210 which converts the binary data of the
`memory into serial pulse code modulated luminance
`signal variations which are coupled by conductor212 to
`a first input of a signal summing circuit 214. A second
`inputofthe signal summingcircuit 214 is coupled to the
`output of a video source 216 for receiving the television
`program source. The summingunit 214 includes timing
`circuit synchronized with the video source so as to
`insert the pulse code modulated teletext data in a se-
`lected line or lines of the vertical interval of the video
`source signal. The resultant signal appearing at
`the
`output of unit 214 is applied to a television transmitter
`216 whereit is amplified and broadcast.
`Referring now to FIG.3 the specially encodedtele-
`text signal is received by antenna 302 coupled to the
`television receiver processing unit 304 ofthe users tele-
`text receiver 300. Unit 304 includes conventionaltelevi-
`sion receiving circuits for producing a television video
`output signal S1 which is normally coupled by a switch
`306 to a display unit 308 during the normal “‘t.v.” oper-
`ating modeofthe receiver. Whenin the teletext operat-
`ing mode switch 306 is placed in the position to couple
`a teletext signal processed as will be described to dis-
`play unit 308. The video signal S1 is applied to the input
`of a pulse code modulation (PCM) detector 310 which
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`senses the luminancesignal variations during the verti-
`cal
`interval representative of the teletext signal and
`produces a binary output signal S2 conveying thetele-
`text information. Signal S2 is applied to a teletext identi-
`fier unit 312 and to a memory unit 314. Unit 312 re-
`ceives timing signals from t.v. processing unit 304 for
`identifying the particular lines of the vertical interval
`where the teletext signal is encoded and identifies the
`teletext synchronizing code preamble. Whena line of
`teletext code is identified unit 312 supplies a control
`signal to controller 316 which in turn supplies a write
`enable signal to memory 314 whichstores the line (or
`lines) of teletext data. Control unit 316 also receives
`control signals from keyboard unit 12 for inputting user
`prompts into the teletext system as will be described.
`The data stored in unit 312 is built up line by line during
`the normal video transmissions such that memory 314
`can store one or several pages of information. After a
`page of data to be displayed is built up in memory 314
`controller 316 activates a memory read operation which
`sends the stored page of data via conductor 318 to a
`prompt code detector 320, to a first input of a switch
`322 and to an address input of a read only memory
`(ROM)324. The output of ROM 324 is applied to the
`second input of switch 322 which is controlled by an
`output of prompt code detector 320. In operation ofthis
`portion of the receiver detector 320 identifies each of
`the prompt codeidentifying symbols in the data stream
`on conductor318.
`,
`When taken together prompt code detector 320,
`ROM 324 and switch 322 cooperate to provide prompt
`character symbol conversion as follows. When the data
`from memory 314 contains no prompt characters the
`output of detector 320 is low,
`thereby maintaining
`switch 322 in a position to couple the data on conductor
`318 directly to the input of a pixel generator 326. Gener-
`ator 326 takes the coded teletext information (charac-
`ters or graphic symbols) and converts them and gener-
`ates pixel intensity information therefrom. The output
`of generator 326 is stored in a display memory 328.
`Memory 328 may have a capacity for storing 210 lines
`each comprised of 256 pixels. In teletext operation the
`output of memory 328 is coupled via switch 326 to a
`display unit 308 and memory 328 is continuously read
`out at conventionalt.v. line and field rates thereby dis-
`playing the page data stored in memory 314.
`Whenthe data on conductor 318 contains a prompt
`code identifying character, detector 320 produces an
`output pulse which changes switch 322 to its uppermost
`position for coupling the output of ROM 324to the
`input of pixel generator 326. ROM 324 is addressed by
`the data on conductor 318 and contains a character
`translation table the output of whichis signals represen-
`tative of symbols available on keyboard unit 12. With
`reference to the example of FIG. 1, when the symbol
`1# appears on conductor 318, the special prompt char-
`acter identifying code preceding a number 1 will be
`detected by detector 320. Switch 322 will be changed
`over and the signals representative of symbols 1L#
`which are applied sequentially to the address lines of
`ROM 324 will cause signals representative of the sym-
`bols la to appear at the output of the ROM sothat the
`image displayed on display unit 308 will agree with the
`keyboard symbols available on unit 12 even though the
`actual received character indicative of a promptsitua-
`tion is not available on unit 12. The switch control
`signal produced by prompt code detector 320 should be
`reasonably matched to the length to the number of
`
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`IPR2016-00753
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`4,556,904
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`5
`characters which are to be converted by ROM 324.
`Thatis, if the prompt symbols are two characters long
`then the prompt code detector 320 should change over
`switch 322 for a length of time substantially equal to
`two characters, and so forth. This may be accomplished
`by incorporating into prompt code detector 32 a delay
`element such as a monostable flip-flop or a counter
`arranged for counting clock pulses for holding switch
`322 in the “conversion” position for the appropriate
`length oftime.
`Pixel generator 326 therefore receives a stream of
`signals representative of non-prompting signals to be
`displayed interspersed with signals representing the
`prompting symbols to which conversion has been made.
`The prompting of the user therefore may be by means
`of symbols which correspond exactly to the designa-
`tions of the keys available to the user for accomplishing
`the prompted function.
`,
`It will be appreciated that various changes and modi-
`fications may be made to the embodiments of the inven-
`tion herein shown and described. For example,
`the
`remote control unit 12 may have more or fewer keys
`than those shown and may be coupled sonically or by
`infra red or by other means to controller 316. It will also
`be appreciated that the translation provided by ROM
`324 of the numberof characters in the prompt sequence
`need not be on a one-for-one basis. Thatis to say a three
`character prompt sequence may be foreshortened to
`one or two characters or in the alternative a shorter
`prompt sequence maybe lengthened to more characters
`or to special graphic symbolsif desired. It will also be
`appreciated thatthe storage and character generation of
`the signals produced at the output of switch 322 may be
`of different form. For example the position of pixel
`generator 326 and display memory 328 may be reversed
`that is the converted teletext data maybe first stored in
`the display memory and then converted to pixel form
`by generator 326. The teletext information may occupy
`a complete television channel to the exclusion of a host
`television signal, which in FIG. 2 would be represented
`by deletion of summing circuit 214 and video source
`216.
`Whatis claimedis:
`1. A teletext receiver for receiving teletext signals
`and for allowing ready use of a remote control having
`arbitrarily designated symbol keys, comprising:
`teletext signal receiving means for receiving coded
`teletext signals;
`first memory means coupled to said teletext signal
`receiving means for storing in coded form signals
`representative of prompting and non-prompting
`symbols to be displayed;
`detector means coupled to said first memory means
`for generating a control signalthat is indicative of
`the presence of a prompting signal to be displayed;
`controllable code conversion means coupled to said
`detector means for converting said coded signals
`representative of prompting symbols to be dis-
`played into coded signals representative of other
`symbols under the control of said control signal
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`and for passing unchanged those coded signals
`representative of non-prompting symbols,
`said
`other symbols being symbols identifying the sym-
`bol keys of the remote control with which the
`receiver is associated;
`coded-symbol-to-pixel conversion means coupled to
`said controllable code conversion means for re-
`ceiving said coded signals to be displayed and for
`generating pixel intensity information therefrom;
`second memory means coupled to said coded-sym-
`bol-to-pixel conversion meansfor storing said pixel
`intensity information; and
`display means coupled to said second memory means
`for displaying said non-prompting symbols and said
`converted prompting symbols corresponding with
`said other symbols identifying said symbol keys of
`said remote control.
`2. A receiver according to claim 1 wherein said de-
`tector means detects a promptsignal identifying prefix.
`3. A receiver according to claim 1 wherein said con-
`trollable code conversion means comprises a prepro-
`grammed ROM.
`4. A receiver according to claim 3 wherein said con-
`trollable code conversion means further comprises con-
`trollable switch means for selecting between ROM
`input data and ROM output data.
`5. A teletext receiver for receiving teletext signals
`and for allowing ready use of a remote control having
`arbitrarily designated symbol keys, comprising:
`teletext receiving means responsive to a video signal
`supplied thereto having a teletext signal compo-
`nent for providing a teletext data outputsignal;
`first memory meansfor storing said teletext data, the
`stored data being representative of prompting sym-
`bols and non-prompting symbols to be displayed,
`said stored prompting symbol data including a
`prompting symbolidentification code;
`detector means responsive to the stored data recov-
`ered upon a read operation of said first memory
`means for producing a control signal upon the
`occurrence of each prompting symbolidentifica-
`tion code;
`controllable code conversion means responsive to the
`recovered data and to said control signal for con-
`verting the recovered data representative of
`prompting symbolsto be displayed into coded data
`representative of symbols present on selected ones
`of said symbol keys and for passing unchanged
`those
`recovered data representative of non-
`prompting symbols;
`pixel converter means responsive to the converted
`and unchanged data produced bysaid code conver-
`sion means for generating pixel information; and
`means associated with said pixel converter means for
`providing storage anddisplayofsaid pixel informa-
`tion whereby non-prompting symbols are dis-
`played without alteration and prompting symbols
`are displayed so as to conform to symbols on said
`symbol keys.
`
`PMC Exhibit 2098
`Apple v. PMC
`IPR2016-00753
`Page 7
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`PMC Exhibit 2098
`Apple v. PMC
`IPR2016-00753
`Page 7
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