Digital signal transmission system with priority information forcing display of text on a receiver

• US 5,760,820 A
• Filed: 02/07/1996
• Issued: 06/02/1998
• Est. Priority Date: 02/10/1995
• Status: Expired due to Term

• Current Assignee: Hitachi Maxell Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Shinkawa, Keiro, Katsumata, Kenji, Iimuro, Satoshi, Noda, Tsutomu, Eda, Takanori, Nagashima, Toshio, Nakagawa, Isao
• Primary Examiner(s): Kostak, Victor R.
• Application Number:
  US08/598,006
• Time in Patent Office: 846 Days
• Field of Search: 348/9, 348/6, 348/13, 348/12, 348/10, 348/387, 348/553, 348/555, 348/558, 348/563, 348/564, 348/569, 348/468
• US Class Current: 725/33
• CPC Class Codes: H04N 21/23614 Multiplexing of additional data and video streams arrangements for simultaneous broadcast of plural pieces of information H04H20/28
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams
• CPC Class Codes: H04N 21/4347 Demultiplexing of several video streams
• CPC Class Codes: H04N 21/4348 Demultiplexing of additional data and video streams
• CPC Class Codes: H04N 21/4882 for displaying messages, e.g. warnings, reminders arrangements for providing short real-time information to substation in data switching networks H04L12/1895
• CPC Class Codes: H04N 21/814 comprising emergency warnings arrangements specially adapted for emergency or urgency in broadcast systems H04H20/59; arrangements for providing alarms, notifications, alerts to substation in data switching networks H04L12/1895
• CPC Class Codes: H04N 7/147 Communication arrangements, e.g. identifying the communication as a video-communication, intermediate storage of the signals selecting H04Q

Abstract

A digital signal transmission system including a transmitter and a receiver and capable of transmitting highly efficiently compressed/coded digital video signals and receiving the video signals so that the text of emergency information or the like can be displayed together with video images without once expanding/decoding the digital video signals on the transmitter side. In this system, the multiplexer of the transmitter multiplexes digital video signals and digital audio signals with a digital information signal of text which is produced and has N-level priority information added by the information stream generator, and transmits the multiplex signal to the receiver. The receiver determines whether the text of the digital information signal is to be displayed on the basis of the priority information added to the digital information signal, and when it is determined that the text are to be displayed, the receiver can display the text of the digital information signal together with the image of the digital video signal.

Claims

1. A digital signal transmitting system comprising a transmitter and a receiver,

said transmitter comprising:

priority information adding means for adding N-level (N is a positive number) priority information to a digital information signal of texts;

first multiplexing means for multiplexing a plurality of compressed digital video signals of images to form a plurality of single bit streams;

second multiplexing means for multiplexing said digital information signal having said priority information added by said priority information adding means and each of said plurality of single bit streams produced from said first multiplexing means; and

transmitting means for transmitting said plurality of single bit streams each of which has said digital information signal added by said second multiplexing means, and said receiver comprising;

demultiplexing means for separating any one of said digital video signals from said plurality of single bit streams sent from said transmitter, and separating said digital information signal therefrom which has been multiplexed with said single bit streams;

discriminating means for determining whether said digital information signal is to be reproduced on the basis of previously fixed selection conditions for said priority information added to said separated digital information signal;

first reproducing means for reproducing said digital video signal separated by said demultiplexing means into an image and displaying said image; and

second reproducing means for reproducing said text of said digital information signal separated by said demultiplexing means, and mixing said text with said image to be displayed by said first reproducing means when said discriminating means determines that said digital information signal is to be reproduced.

wherein said priority information includes forced display information for indicating forced display, and said receiver, when receiving said forced display information, is ordered by said discriminating means to preferentially reproduce said digital information signal.

2. A digital signal transmission system comprising a transmitter and a receiver,

said transmitter comprising:

priority information adding means for adding N-level (N is a positive number) priority information to a digital information signal of texts;

first multiplexing means for multiplexing a plurality of compressed digital video signals of images to form a plurality of single bit streams;

second multiplexing means for multiplexing said digital information signal having said priority information added by said priority information adding means and each of said plurality of single bit streams produced from said first multiplexing means; and

transmitting means for transmitting said plurality of single bit streams each of which has said digital information signal added by said second multiplexing means, and said receiver comprising;

demultiplexing means for separating any one of said digital video signals from said plurality of single bit streams sent from said transmitter, and separating said digital information signal therefrom which has been multiplexed with said single bit streams;

discriminating means for determining whether said digital information signal is to be reproduced on the basis of previously fixed selection conditions for said priority information added to said separated digital information signal;

first reproducing means for reproducing said digital video signal separated by said demultiplexing means into an image and displaying said image; and

second reproducing means for reproducing said text of said digital information signal separated by said demultiplexing means, and mixing said text with said image to be displayed by said first reproducing means when said discriminating means determines that said digital information signal is to be reproduced,

wherein said priority information is two-level information which indicates whether forced display should be made or not, said receiver further has a reproduce-or-not information storage means for previously storing information which indicates whether said signal digital information signal should be displayed or not, said discriminating means decides that if the priority information added to said digital information signal which said demultiplexing means has separated indicates that said digital information signal should be forcibly displayed, the digital information signal should be reproduced irrespective of the information stored in the reproduce-or-not information storage means, while if the priority information added to the digital information signal indicates that the digital information signal should not be forcibly displayed, and if the information stored in the reproduce-or-not information storage means indicates that it is necessary to reproduce, the digital information signal should be displayed, in which case if the information stored in the reproduce-or-not information storage means indicates that it is not necessary to reproduce, the digital information signal should be displayed.

3. A transmitter for use in a digital signal transmission system with a receiver, comprising:

a priority information adder to add N-level (N is a positive integer number) priority information to a digital information signal of text,

multiplexing means for multiplexing said digital information signal having said priority information added by said priority information adder to each of a plurality of video signals transmitted in said digital signal transmission system, and

a transmitting unit to transmit at least one of said plurality of video signals multiplexed with said digital information signal having said priority information added by said priority information adder to said receiver; and

wherein said priority information includes forced display information ordering forced display for information whereby the text of the information is forcibly displayed on the receiver independently of any settings applied in the receiver for discriminating the priority information.

4. A receiver for use in a digital signal transmission system with a transmitter transmitting at least one video signal having a multiplexed digital information signal with added priority information, comprising:

demultiplexing means for separating said one video signal from said digital information signal with added priority information;

discriminating means for determining whether said digital information signal is to be reproduced on the basis of previously fixed selection conditions for said priority information added to said separated digital information signal; and

first reproducing means for reproducing said digital video signal separated by said demultiplexing means into an image and displaying said image,

wherein, when said added priority information includes forced display information, the text of the information is forcibly displayed on the receiver independently of said previously fixed selection conditions.