Cable broadcast TV receiver with automatic channel search responsive to mode change

• US 4,737,993 A
• Filed: 01/21/1987
• Issued: 04/12/1988
• Est. Priority Date: 01/21/1987
• Status: Expired due to Term

• Current Assignee: RCA Corporation
• Original Assignee: RCA Corporation
• Inventors: DeVilbiss, Warren C.
• Primary Examiner(s): MASINICK, MICHAEL A
• Application Number:
  US07/005,791
• Time in Patent Office: 447 Days
• Field of Search: 455/161, 455/166, 455/168, 455/180, 455/185, 455/186, 455/179, 358/191.1, 358/193.1
• US Class Current: 455/180.1
• CPC Class Codes: H03J 1/0033 for voltage synthesis with a D/A converter
• CPC Class Codes: H03J 5/0263 the digital values being held in an auxiliary non erasable memory

Abstract

A "cable-ready" receiver includes a controller for selecting broadcast ("air") and cable channels tuned by a tuner. When switching between air and cable tuning modes the controller stores the number of the channel tuned in the previous mode and retunes the tuner to the stored channel if the number is within a range of valid channel numbers for the new tuning mode. If not, the controller increments the number until it is both in the range and present in a user selected channel tuning list and retunes the turner to the incremented number. In another embodiment the controller increments the number until it is within the valid channel range and a video detector signifies that the channel is occupied. Both examples increase the likelihood that an active channel will be tuned when changing the air/cable tuner operating modes.

Claims

1. Tuning apparatus for a television receiver, comprising:

tuner means having an "air" tuning mode for tuning standard broadcast channels and a "cable" tuning mode for tuning cable channels;

switch means for selecting said cable and air tuning modes;

control means responsive to said switch means for placing said tuner means in a selected one of said tuning modes;

user programmable memory means for storing a list of user selected channel numbers; and

wherein;

said control means being further responsive to a change in said tuning mode selected by said switch means for causing said tuner means to tune to a previously tuned channel in the changed tuning mode if the previous channel number is within a range of valid channel numbers for the currently selected tuning mode;

said control means being responsive otherwise for incrementing said previous channel number until the incremented number is within said range and is also in said list for causing said tuner means to tune to a channel corresponding to said incremented number.

2. Tuning apparatus for a television receiver, comprising:

tuner means having an "air" tuning mode for tuning standard broadcast channels and a cable tuning mode for tuning cable channels and providing an output signal;

switch means for selecting said tuning modes;

control means responsive to said switch means for placing said tuner in selected ones of said modes;

detector means responsive to said tuner output signal for identifying occupied channels; and

wherein;

said control means being responsive to a change in said tuning mode selected by said switch means for causing said tuner means to tune to a channel tuned in the previous mode conditioned upon the previous channel number being within a range of valid channel numbers for the tuning mode selected;

said control means being responsive otherwise for incrementing said previous channel number until the incremented number is both in said range and is identified as being occupied by said detector means for causing said tuner means to tune to a channel corresponding to the incremented number.