Rewind radio and television

Abstract

A radio or television apparatus has tuning circuitry for selecting a channel from an input spectrum, an output for presenting a presentation from a selected channel, a recording apparatus having a memory with capacity for recording a fixed time duration T of the selected presentation, and adapted to make an audio record sequentially in a circular fashion, such that when the memory capacity is filled, the device continues to record, overwriting the oldest recorded information, providing thereby, at any point in time, a stored copy of time duration T immediately preceding the point in time. This innovation provides limited rewind capability for real-time data streams. In alternative embodiments add-on devices are provided for existing radios and TVs.

1 . A radio apparatus comprising: 
 tuning circuitry for selecting a channel from an input rf spectrum;    an output for driving a speaker system with an audio presentation derived from the selected channel; and    a recording apparatus having a memory with capacity for recording a fixed time duration T of the audio presentation, and adapted to make an audio record sequentially in a circular fashion, such that when the memory capacity is filled, the device continues to record, overwriting the oldest recorded information, providing thereby, at any point in time, a stored copy of time duration T immediately preceding the point in time.    
   
   
       2 . The radio apparatus of  claim 1  wherein the recording apparatus comprises a tape recorder adapted to record in a circular fashion.  
   
   
       3 . The radio apparatus of  claim 1  further comprising an A/D converter, wherein the memory is a digital memory managed to record sequentially in a circular fashion, and the audio presentation is presented at the speakers and simultaneously digitized and recorded in the digital memory.  
   
   
       4 . The radio apparatus of  claim 1  further comprising user-operable inputs for interrupting circular recording, selecting beginning positions for playback, and playing back the recorded data.  
   
   
       5 . An add-on recorder for a radio apparatus, comprising: 
 an input for receiving an analog audio signal stream from a radio;    an output for driving a speaker system; and    a memory system with capacity for recording a fixed time duration T of received analog audio signals, and adapted to make an audio record in the memory sequentially in a circular fashion, such that when the memory capacity is filled, the system continues to record, overwriting the oldest recorded information, providing thereby, at any point in time, a stored copy of time duration T immediately preceding the point in time.    
   
   
       6 . The add-on recorder of  claim 5  wherein the memory system comprises a tape recorder adapted to record in a circular fashion.  
   
   
       7 . The add-on recorder of  claim 5  further comprising an A/D converter, wherein the memory system comprises a digital memory managed to record sequentially in a circular fashion, and the received analog audio signal stream is sent to the speaker system via the output and simultaneously digitized and recorded in the digital memory.  
   
   
       8 . The add-on recorder of  claim 5  further comprising user-operable inputs for interrupting circular recording, selecting beginning positions for playback, and playing back the recorded data.  
   
   
       9 . A television apparatus comprising: 
 tuning circuitry for selecting a channel from an input video spectrum;    an output for driving a television display with a video presentation derived from the selected channel; and    a recording apparatus having a memory with capacity for recording a fixed time duration T of the video presentation, and adapted to make a video record sequentially in a circular fashion, such that when the memory capacity is filled, the apparatus continues to record, overwriting the oldest recorded information, providing thereby, at any point in time, a stored copy of time duration T immediately preceding the point in time.    
   
   
       10 . The television apparatus of  claim 9  wherein the recording apparatus comprises a video tape recorder adapted to record in a circular fashion.  
   
   
       11 . The television apparatus of  claim 9  further comprising an A/D converter, wherein the memory is a digital memory managed to record sequentially in a circular fashion, and the video presentation is presented at the television display and simultaneously digitized and recorded in the digital memory.  
   
   
       12 . The television apparatus of  claim 9  further comprising user-operable inputs for interrupting circular recording, selecting beginning positions for playback, and playing back the recorded data.  
   
   
       13 . An add-on recorder for a television apparatus, comprising: 
 an input for receiving a video data stream;    an output for driving a television display system; and    a memory system with capacity for recording a fixed time duration T of the received video data stream, and adapted to make record in the memory sequentially in a circular fashion, such that when the memory capacity is filled, the system continues to record, overwriting the oldest recorded information, providing thereby, at any point in time, a stored copy of time duration T immediately preceding the point in time.    
   
   
       14 . The add-on recorder of  claim 13  wherein the memory system comprises a video tape recorder adapted to record in a circular fashion.  
   
   
       15 . The add-on recorder of  claim 13  further comprising an A/D converter, wherein the memory system comprises a digital memory managed to record sequentially in a circular fashion, and the received video data stream is sent to the television display via the output and simultaneously digitized and recorded in the digital memory.  
   
   
       16 . The add-on recorder of  claim 13  further comprising user-operable inputs for interrupting circular recording, selecting beginning positions for playback, and playing back the recorded data.