Special services teletext communications system

• US 4,393,404 A
• Filed: 02/26/1981
• Issued: 07/12/1983
• Est. Priority Date: 02/26/1981
• Status: Expired due to Fees

• Current Assignee: Zenith Radio Corporation (LG Corporation)
• Original Assignee: Zenith Radio Corporation (LG Corporation)
• Inventors: Thomas, William L., Cox, Charles M.
• Primary Examiner(s): RICHARDSON, ROBERT
• Application Number:
  US06/238,510
• Time in Patent Office: 866 Days
• Field of Search: 358/141, 358/142, 358/147, 358/146, 358/114, 358/122, 455/26, 375/2
• US Class Current: 348/467
• CPC Class Codes: H04N 7/03 Subscription systems therefor

Abstract

A teletext communications system includes a transmitter cyclically transmitting a plurality of conventional teletext encoded data rows together with one or more teletext encoded special services data rows. A plurality of teletext decoder equipped receivers are operable for acquiring the conventional teletext rows but not the special services rows. Subscribers to the special services data are provided with data decoders responsive to the cyclical transmissions for acquiring only the special services data rows, the data decoders including apparatus for storing the data encoded in an acquired special services data row and for providing a display of the information represented thereby.

Claims

1. In a teletext communications system including a transmitter cyclically transmitting a plurality of teletext encoded data rows a selected number of which define a data page, the first data row of each data page comprising a page-header data row characterized by a page number address code for enabling acquisition of the remaining data rows of the respective data page by each of a plurality of standard teletext decoders, the improvement comprising:

means cooperating with said teletext transmitter for inserting at least one additional page-header formatted data row in said cyclical transmission, said additional page-header formatted data rows each including selected encoded data and a page number address code adapted for preventing acquisition thereof by said plurality of standard teletext decoders; and

at least one data decoder comprising means adapted for receiving said cyclical transmission, means responsive to the page number address code of a received additional page-header formatted data row for acquiring only said additional page-header formatted data row and means comprising a single data row memory for storing the data encoded in said acquired additional page-header formatted data row.

2. The improvement according to claim 1 wherein said data decoder further comprises an output device adapted for presenting an intelligible representation of said stored encoded data to a system subscriber.

3. The improvement according to claim 2 including buffer means interposed between said storage means and said output device for coupling said stored encoded data to said output device at a rate compatible with the operating characteristics thereof.

4. A data decoder for receiving a plurality of cyclically transmitted teletext encoded data rows a selected number of which define a data page, the first data row of each data page comprising a page-header data row characterized by a page number address code for enabling acquisition of the remaining data rows of the respective data page by each of a plurality of standard teletext decoders and at least one additionally transmitted page-header formatted data row comprising a special services row including encoded data and a page number address code adapted for preventing acquisition thereof by said plurality of standard teletext decoders, said data decoder comprising:

means adapted for receiving said cyclical transmission;

means responsive to the page number address code of a received additional page-header formatted data row for acquiring only said special services data row; and

means comprising a single data row memory for storing the data encoded in said acquired special services row.

5. A data decoder according to claim 4 wherein said data decoder further comprises an output device adapted for presenting an intelligible representation of said stored encoded data to a system subscriber.

6. A data decoder according to claim 5 including buffer means interposed between said storage means and said output device for coupling said stored encoded data to said output device at a rate compatible with the operating characteristics thereof.