U.S. Philips Corporation

Koninklijke Philips Corporation N.V.

Daniele Santilli

Pierre Chanteau

Herman J Schmitz

Bram P Van Sambeek

Steven T Slot

An interactive television system for selectively retrieving video images or teletext pages from a remote transmitter ( ). User requests are communicated to the transmitter through the telephone network ( ). The selected images (e.g. teletext pages) are provided with an image address (a personal teletext page number) and transmitted through a broadcast medium ( ). A broadcast receiver ( ) captures, stores and displays images having a particular address in a further autonomous manner. In order to prevent co-viewers from tracing the image address and thus watching personal information intended for an individual user on their broadcast receivers ( ), the service provider sends a control command (the teletext &ldquo;stop&rdquo; command) to the receiver through the network whenever a new image has been transmitted. Then, the provider broadcasts a different image having the same image address. In view of the stop command, the individual receiver will ignore this &ldquo;pseudo-image&rdquo; while this image will.

Interactive television

An interactive television system for selectively retrieving video images or teletext pages from a remote transmitter ( ). User requests are communicated to the transmitter through the telephone network ( ). The selected images (e.g., teletext pages) are provided with an image address (a personal teletext page number) and transmitted through a broadcast medium ( ). A broadcast receiver ( ) captures, stores and displays images having a particular address in a further autonomous manner. In order to prevent co-viewers from tracing the image address and thus watching personal information intended for an individual user on their broadcast receivers ( ), the image address is modified whenever a new image is transmitted. Prior to transmitting the image, the address is communicated to the individual user through the telephone network and applied ( ) to the broadcast receiver.

In interactive teletext, an individual user establishes a connection (6) with a central computer (14). Requested information is applied to a television transmitter (12) via a teltext inserter (11) and transmitted to the user as personal teletext pages for display on the user's receiver (3). However, other users (4) may be 'co-viewers'. In accordance with the invention, each personal page is transmitted with a teletext page number P and a sub-code S. Subsequently, a pseudo-page having the same page number P but a different sub-code S' is transmitted. Consequently, the personal page appears on the display screen of the co-viewer's receiver (4) only for a short time.

Method and device for securely transmitting teletext pages to specific

The receiver which comprises a flat picture screen (20) has an antenna which comprises two articulated main plates (4, 5) symmetrically disposed on either one of the two sides of the screen, and forming an angle with each other, as well as two plates (2, 3) parallel with the screen and symmetrical to each other relative to the median vertical plane (19) of the screen.

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Eindhoven, Netherlands

Daniele Santilli