Television receiver with dynamically adjustable filtering

• US 7,136,114 B2
• Filed: 02/11/2002
• Issued: 11/14/2006
• Est. Priority Date: 02/09/2001
• Status: Expired due to Term

• Current Assignee: Harman Becker Automotive Systems GmbH (Samsung Electronics Co. Ltd.)
• Original Assignee: Harman Becker Automotive Systems GmbH (Samsung Electronics Co. Ltd.)
• Inventors: Zahm, Michael, Geiger, Erich
• Primary Examiner(s): Kostak, Victor R.
• Application Number:
  US10/073,817
• Publication Number:
  US 20020118313A1
• Time in Patent Office: 1,737 Days
• Field of Search: 348/725, 348/731, 348/732, 348/625, 348/607, 348/838, 348/678, 348/470, 334/5, 334/40, 455/226.2, 455/226.3, 455/245.1, 455/245.2, 455/297, 455/556.1, 455/161.3
• US Class Current: 348/731
• CPC Class Codes: H03J 3/24 of more than one resonant circuit simultaneously, the circuits being tuned to substantially the same frequency, e.g. for single-knob tuning

Abstract

A television receiver includes a tuner stage, a selective filter stage connected to the tuner stage, and a intermediate-frequency stage connected to the selective filter stage. A field-strength-detection stage is also provided, which generates a field strength signal proportional to the field strength of the received signal. The selective filter stage includes a transfer function that is modifiable by a control signal derived from the field strength signal.

Claims

1. A television receiver comprising:

a tuner that receives a transmitted signal from an antenna and bandshifis the transmitted signal to an intermediate frequency and provides a received signal indicative thereof;

a selective filter stage that receives the received signal containing chrominance and luminance components and provides a filtered signal;

an intermediate-frequency stage that receives the filtered signal and processes the filtered signal to provide a processed signal; and

at least one field-strength-detection stage that receives the transmitted signal, and generates a field strength signal proportional to the field strength of the transmitted signal, and which generates a control signal derived from the field strength signal,

where the selective filter stage implements a transfer function that is modifiable by the control signal.

2. The television receiver of claim 1, where the bandwidth of the selective filter stage is modified as a function of the control signal.

3. The television receiver of claim 1, where the selective filter stage comprises a frequency trap, the slope of which is modifiable by the control signal.

4. The television receiver of claim 3, where one chrominance signal and one luminance signal are contained in the received signal,

and where the frequency trap is dimensioned such that, in response to a higher field strength signal, spectral components of the chrominance signal are more strongly suppressed, while in response to a lower field strength signal noise signals in the spectral range of luminance and chrominance signal are reduced.

5. The television receiver of claim 1, where a black-and-white signal is contained in the received signal and, in response to a low field strength signal, only black-and-white signals are transmitted by the selective filter stage.

6. The television receiver of claim 5, where the received signal includes a video signal, and where

in response to a low field strength signal, higher-frequency video signals are suppressed by the selective filter stage.

7. The television receiver of claim 1, where the selective filter stage is controlled such that given a field strength signal above a certain threshold value there is no effect on the signal by the selective filter stage.

8. The television receiver of claim 1, where in response to a degrading signal, the selective filter stage adapts the filter response continually or in steps.

9. The television receiver of claim 1, where the at least one field-strength-detection stage evaluates the received signal and generates the field strength signal.

10. The television receiver of claim 1, where the at least one field-strength-detection stage comprises the intermediate-frequency stage, where the intermediate-frequency stage generates the field strength signal.

11. The television receiver of claim 1, where the field strength detector is also responsive to the processed signal.

12. A television receiver comprising:

a tuner that receives a transmitted signal from an antenna and bandshifts the transmitted signal to an intermediate frequency and provides a received signal indicative thereof;

a first selective filter stage that receives and filters the received signal to provide a filtered signal, wherein the selective filter stage implements a transfer function that is modifiable by one or more control signals derived from a field strength signal; and

an intermediate-frequency stage that receives and processes a signal indicative of the filtered signal to provide a processed signal and generates a first control signal of the one or more control signals.

13. The television receiver of claim 12, where the first selective filter stage modifies the bandwidth of the implemented transfer function based on the one or more control signals.

14. The television receiver of claim 12, where the television receiver further comprises:

a second selective filter stage connected to the intermediate-frequency stage, the second selective filter stage being controlled by at least one of the one or more control signals.

15. The television receiver of claim 14, where at least one of the first and second selective filter stages implements a frequency trap having a slope that is modifiable in response to the one or more control signals.

16. The television receiver of claim 15, where one chrominance signal and one luminance signal are contained in the received signal, and where the frequency trap is dimensioned such that, in response to a higher field strength signal, spectral components of the chrominance signal are more strongly suppressed, while in response to a lower field strength signal noise signals in the spectral range of luminance and chrominance signal are reduced.

17. The television receiver of claim 14, where a black-and-white signal is contained in the received signal and, in response to a low field strength signal, only black-and-white signals are transmitted by the first and second selective filter stages.

18. The television receiver according to claim 14, where the received signal comprises a video signal, and where, in response to a low field strength signal, higher-frequency video signals are suppressed by one or more of the first and second selective filter stages.

19. The television receiver according to claim 14, where in response to a degrading signal the first and second selective filter stages implement respective filter responses either continually and in increments.

20. The television receiver of claim 14, where the television receiver further comprises:

at least one additional signal-processing stage connected to and following the intermediate-frequency stage, where at least one of the one or more control signals is derived from at least one signal from the at least one additional signal-processing stage.

21. The television receiver of claim 14, further comprising a video signal processing device that receives the output signal from the second selective filter stage and provides a second control signal of the one or more control signals.

22. A mobile television receiver comprising:

a tuner that receives a transmitted signal from an antenna and bandshifts the transmitted signal to an intermediate frequency and provides a received signal indicative thereof;

a selective filter stage that receives the received signal containing chrominance and luminance components and provides a filtered signal;

an intermediate-frequency stage that receives the filtered signal and processes the filtered signal to provide a processed signal; and

at least one field-strength-detection stage that receives the received signal, and generates a field strength signal proportional to the field strength of the received signal, and which generates a control signal derived from the field strength signal,

where the selective filter stage implements a transfer function that is modifiable by the control signal.