Teletext system having user prompt commands

• US 4,556,904 A
• Filed: 03/04/1983
• Issued: 12/03/1985
• Est. Priority Date: 03/04/1983
• Status: Expired due to Term

• Current Assignee: RCA Corporation (General Electric Company)
• Original Assignee: RCA Corporation (General Electric Company)
• Inventors: Monat, Robert A.
• Primary Examiner(s): Martin, John C.
• Assistant Examiner(s): Harvey, David E.
• Application Number:
  US06/472,417
• Time in Patent Office: 1,005 Days
• Field of Search: 358/147, 358/142, 340/712, 340/365 VL, 364/522
• US Class Current: 348/468
• CPC Class Codes: H04N 21/47 End-user applications
• CPC Class Codes: H04N 21/4888 for displaying teletext characters
• CPC Class Codes: H04N 7/0884 for the transmission of additional display-information, e.g. menu for programme or channel selection

Abstract

Special prompt character identifying control codes are inserted in teletext data for transmission to a teletext equipped receiver. The prompt character identifying codes are detected in the receiver and applied to a symbol converter which alters the prompt characters displayed on the receiver CRT to assure that all prompt characters displayed conform to character symbols actually available on the users teletext keyboard thereby avoiding user confusion as to the particular key-strokes required to access material identified in the teletext menu.

Claims

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 signal that 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 displayed into coded signals representative of other symbols under the control of said control signal and for passing unchanged those coded signals representative of non-prompting symbols, said other symbols being symbols identifying the symbol 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 receiving said coded signals to be displayed and for generating pixel intensity information therefrom;

second memory means coupled to said coded-symbol-to-pixel conversion means for 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 detector means detects a prompt signal identifying prefix.

3. A receiver according to claim 1 wherein said controllable code conversion means comprises a preprogrammed ROM.

4. A receiver according to claim 3 wherein said controllable code conversion means further comprises controllable 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 component for providing a teletext data output signal;

first memory means for storing said teletext data, the stored data being representative of prompting symbols and non-prompting symbols to be displayed, said stored prompting symbol data including a prompting symbol identification code;

detector means responsive to the stored data recovered upon a read operation of said first memory means for producing a control signal upon the occurrence of each prompting symbol identification code;

controllable code conversion means responsive to the recovered data and to said control signal for converting the recovered data representative of prompting symbols to 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 by said code conversion means for generating pixel information; and

means associated with said pixel converter means for providing storage and display of said pixel information whereby non-prompting symbols are displayed without alteration and prompting symbols are displayed so as to conform to symbols on said symbol keys.