Video signal processing device and television receiving device

• US 7,355,656 B2
• Filed: 09/17/2004
• Issued: 04/08/2008
• Est. Priority Date: 09/19/2003
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Yoshida, Yoshifumi
• Primary Examiner(s): Natnael; Paulos M.
• Application Number:
  US10/944,208
• Publication Number:
  US 20050062890A1
• Time in Patent Office: 1,299 Days
• Field of Search: 348/678, 348/679, 348/572, 348/573, 348/575
• US Class Current: 348/678
• CPC Class Codes: H03M 1/187 using an auxiliary analogue/digital converter
• CPC Class Codes: H04N 21/4318 by altering the content in the rendering process, e.g. blanking, blurring or masking an image region image enhancement or restoration in general G06T5/00
• CPC Class Codes: H04N 21/44008 involving operations for analysing video streams, e.g. detecting features or characteristics in the video stream arrangements characterised by components specially adapted for monitoring, identification or recognition of video in broadcast systems H04H60/59
• CPC Class Codes: H04N 5/20 Circuitry for controlling amplitude response
• CPC Class Codes: H04N 5/44 Receiver circuitry for the reception of television signals according to analogue transmission standards H04N5/14 takes precedence
• CPC Class Codes: H04N 5/57 Control of contrast or brightness

Abstract

A video signal processing device is provided comprising an input level detecting circuit for detecting an amplitude of a video signal to be processed and an analog/digital converter for performing analog/digital conversion of the video signal using as a reference voltage a voltage in accordance with the amplitude of the video signal detected by the input level detecting circuit.

Claims

1. A video signal processing device, comprising:

an input level detecting circuit for detecting an amplitude of a video signal to be processed, and providing a control signal in accordance with the amplitude;

a PWM circuit for receiving the control signal from said input level detecting circuit, modulating a pulse width in accordance with the amplitude of said video signal, and providing a PWM signal; and

an analog/digital converter for performing analog/digital conversion of said video signal using as a reference voltage a voltage obtained by smoothing said PWM signal in terms of time.

2. The video signal processing device according to claim 1, further comprising:

a resistor element forming a low pass filter for smoothing said PWM signal, and having an end connected to an external terminal for connecting to a capacitor outside the device.

3. The video signal processing device according to claim 1, further comprising:

a constant voltage generating circuit, and

a switching circuit for switching between a voltage output from said constant voltage generating circuit and a voltage obtained by smoothing said PWM signal in terms of time, and providing an output as the reference voltage of said analog/digital converter.

4. The video signal processing device according to claim 2, further comprising:

a constant voltage generating circuit, and a switching circuit for switching between a voltage output from said constant voltage generating circuit and a voltage obtained by smoothing said PWM signal in terms of time, and providing an output as the reference voltage of said analog/digital converter.

5. A television receiving device, comprising:

video signal receiving circuit for receiving a video signal;

an input level detecting circuit for detecting an amplitude of the video signal received by said video signal receiving circuit, and providing a control signal in accordance with the amplitude;

a PWM circuit for receiving the control signal from said input level detecting circuit, modulating a pulse width in accordance with the amplitude of the video signal received by said video signal receiving circuit, and providing a PWM signal; and

an analog/digital converter for performing analog/digital conversion of said video signal received by said video signal receiving circuit using as a reference voltage a voltage obtained by smoothing said PWM signal in terms of time, wherein a video image is displayed based on the video signal digitized by said analog/digital converter.