# US 5,345,276 A · Spectrum distribution luminance/color signal separating device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,345,276 A - Document ID: US5345276A - Status: Granted - Kind: A - Application number: 07/980,663 - Filed: 1992-11-24 - Granted: 1994-09-06 - Earliest claimed: 1991-11-26 - Assignees: Gold Star Co., Ltd. - Inventors: Sung H. Hong - Web page: https://patentgrep.com/patent/US5345276A ## CPC - H04N 9/78: for separating the brightness signal or the chrominance signal from the colour television signal, e.g. using comb filter - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A composite video signal is separated into a luminance signal and a color signal according to spectrum distributions thereof. A band-pass filter extracts a composite video signal existing in a predetermined frequency band; a band-rejection filter removes a composite video signal existing in a predetermined frequency band; first and second line comb filters each separate a luminance signal and a color signal from an output signal of the band-pass filter; a frame comb filter separates a luminance signal and a color signal from an output signal of the band-pass filter by a correlation between frames; a vertical variation detector detects a picture variation component in a vertical axis from an output signal of the band-pass filter; a temporal variation detector detects a picture variation component in a temporal axis from an output signal of the band-pass filter; a horizontal variation detector detects a picture variation in a horizontal axis from the composite video signal; a first mixer mixes the color signals separated by the first and second line comb filters and the frame comb filter and an output signal of the band-pass filter according to output signals of the horizontal, vertical and temporal variation detectors; and a second mixer mixes luminance signals separated by the first and second line comb filters and the frame comb filter and an output signal of the band-rejection filter, according to output signals of horizontal, vertical and temporal variation detectors. ## Claims ### Claim 1 A luminance/color signal separating device comprising: a means for receiving a composite video signal; a band-pass filter means for detecting a composite video signal existing in a predetermined frequency band having a centered chrominance subcarrier frequency from said composite video signal; a band-rejection filter means for removing a composite video signal existing in a predetermined frequency band having a centered chrominance subcarrier frequency from said composite video signal; a first line comb filter means for separating a luminance signal and a color signal from an output signal of said band-pass filter means by a correlation between three lines; a second line comb filter means for separating a luminance signal and a color signal from an output signal of said band-pass filter means by a correlation between five lines; a frame comb filter means for separating a luminance signal and a color signal from an output signal of said band-pass filter means by a correlation between frames; a vertical variation detecting means for detecting a variation component of picture in a vertical axis from an output signal of said band-pass filter means; a temporal variation detecting means for detecting a variation component of picture in a temporal axis from an output signal of said band-pass filter means; a horizontal variation detecting means for detecting a variation of picture in a horizontal axis from said composite video signal; a first mixing means for mixing color signals separated by said first and second line comb filter means, and said frame comb filter means, and an output signal of said band-pass filter means, according to detected results of said horizontal, vertical and temporal variation detecting means; and a second mixing means for mixing luminance signals separated by said first and second line comb filter means and said frame comb filter means, and an output signal of said band-rejection filter means, according to detected results of said vertical, temporal variation detecting means; wherein said first mixing means further, A) selects an output signal of said band-pass filter means, when a variation of picture does not exist in a horizontal direction; B) selects a color signal separated in said frame comb filter, when a variation of picture exists in a horizontal direction and does not exist in a temporal axis; C) selects a color signal separated by said first line comb filter, when a variation of picture exists in horizontal and temporal axes, and does not exist in a vertical axis; and D) selects a color signal separated by said second line comb filter, when a variation of picture exists in horizontal, temporal, and vertical axes. ### Claim 2 A luminance/color signal separating device comprising: a means for receiving a composite video signal; a band-pass filter means for detecting a composite video signal existing in a predetermined frequency band having a centered chrominance subcarrier frequency from said composite video signal; a band-rejection filter means for removing a composite video signal existing in a predetermined frequency band having a centered chrominance subcarrier frequency from said composite video signal; a first line comb filter means for separating a luminance signal and a color signal from an output signal of said band-pass filter means by a correlation between three lines; a second line comb filter means for separating a luminance signal and a color signal from an output signal of said band-pass filter means by a correlation between five lines; a frame comb filter means for separating a luminance signal and a color signal from an output signal of said band-pass filter means by a correlation between frames; a vertical variation detecting means for detecting a variation component of picture in a vertical axis from an output signal of said band-pass filter means; a temporal variation detecting means for detecting a variation component of picture in a temporal axis from an output signal of said band-pass filter means; a horizontal variation detecting means for detecting a variation of picture in a horizontal axis from said composite video signal; a first mixing means for mixing color signals separated by said first and second line comb filter means, and said frame comb filter means, and an output signal of said band-pass filter means, according to detected results of said horizontal, vertical and temporal variation detecting means; a second mixing means for mixing luminance signals separated by said first and second line comb filter means and said frame comb filter means, and an output signal of said band-rejection filter means, according to detected results of said vertical, temporal variation detecting means; wherein said vertical variation detecting means further comprises; a second band-pass filter means for extracting a composite video signal distributed in a band having principal frequencies of 1/4(n+1) Fn and 3/4(n+1)Fn from an output signal of said band-pass filter means; a first demultiplying means for dividing an output signal of said band-pass filter means by an output signal of said second band-pass filter means; and a first threshold comparator for comparing an output signal of said first demultiplying means with a threshold of predetermined level to generate a control signal of logic signal type and supplying a generated control signal to said first mixing means. ### Claim 3 A luminance/color signal separating device comprising: a means for receiving a composite video signal; a band-pass filter means for detecting a composite video signal existing in a predetermined frequency band having a centered chrominance subcarrier frequency from said composite video signal; a band-rejection filter means for removing a composite video signal existing in a predetermined frequency band having a centered chrominance subcarrier frequency from said composite video signal; a first line comb filter means for separating a luminance signal and a color signal from an output signal of said band-pass filter means by a correlation between three lines; a second line comb filter means for separating a luminance signal and a color signal from an output signal of said band-pass filter means by a correlation between five lines; a frame comb filter means for separating a luminance signal and a color signal from an output signal of said band-pass filter means by a correlation between frames; a vertical variation detecting means for detecting a variation component of picture in a vertical axis from an output signal of said band-pass filter means; a temporal variation detecting means for detecting a variation component of picture in a temporal axis from an output signal of said band-pass filter means; a horizontal variation detecting means for detecting a variation of picture in a horizontal axis from said composite video signal; a first mixing means for mixing color signals separated by said first and second line comb filter means, and said frame comb filter means, and an output signal of said band-pass filter means, according to detected results of said horizontal, vertical and temporal variation detecting means; a second mixing means for mixing luminance signals separated by said first and second line comb filter means and said frame comb filter means, and an output signal of said band-rejection filter means, according to detected results of said vertical, temporal variation detecting means; wherein said horizontal variation detecting means further comprises; a third band-pass filter means for extracting a composite video signal existing in a predetermined frequency band having a centered chrominance subcarrier frequency from said composite video signal supplied from said input means; a fourth band-pass filter means for extracting a composite video signal existing in a predetermined frequency band having a centered 1/2-chrominance subcarrier frequency from said composite video signal supplied from said input means; a second demultiplying means for dividing an output signal of said third band-pass filter means by an output signal of said fourth band-pass filter means; and a second threshold comparing means for comparing an output signal of said second demultiplying means with a threshold of predetermined level to generate a control signal of logic signal type, and supplying a generated control signal to said first and second mixing means.