JPH01110572U - - Google Patents
Info
- Publication number
- JPH01110572U JPH01110572U JP1988005714U JP571488U JPH01110572U JP H01110572 U JPH01110572 U JP H01110572U JP 1988005714 U JP1988005714 U JP 1988005714U JP 571488 U JP571488 U JP 571488U JP H01110572 U JPH01110572 U JP H01110572U
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- video
- pass filter
- signal
- low
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000001514 detection method Methods 0.000 claims description 7
- 230000010355 oscillation Effects 0.000 claims description 3
- 230000003321 amplification Effects 0.000 claims 2
- 238000003199 nucleic acid amplification method Methods 0.000 claims 2
- 238000010586 diagram Methods 0.000 description 3
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
- H04N5/50—Tuning indicators; Automatic tuning control
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/14—Picture signal circuitry for video frequency region
- H04N5/20—Circuitry for controlling amplitude response
- H04N5/205—Circuitry for controlling amplitude response for correcting amplitude versus frequency characteristic
- H04N5/208—Circuitry for controlling amplitude response for correcting amplitude versus frequency characteristic for compensating for attenuation of high frequency components, e.g. crispening, aperture distortion correction
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Television Receiver Circuits (AREA)
- Channel Selection Circuits, Automatic Tuning Circuits (AREA)
- Noise Elimination (AREA)
- Circuits Of Receivers In General (AREA)
Description
第１図は、本考案の一実施例を示す回路図、第
２図は、従来のＡＦＴ回路を示す回路図、第３図
イ，ロはローパスフイルタの具体回路例を示す回
路図、及び第４図は第３図のローパスフイルタの
特性図である。
３……混合回路、５，６……ＩＦ増幅回路、７
……リミツタ回路、８……ＡＦＴ検波回路、１１
……局部発振回路、１６……ローパスフイルタ。
FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing a conventional AFT circuit, FIGS. FIG. 4 is a characteristic diagram of the low-pass filter shown in FIG. 3. 3... Mixing circuit, 5, 6... IF amplifier circuit, 7
... Limiter circuit, 8 ... AFT detection circuit, 11
...Local oscillation circuit, 16...Low pass filter.
Claims (1)
合回路と、該混合回路からの映像ＩＦ信号を増幅
する映像ＩＦ増幅回路と、該映像ＩＦ増幅回路か
らの映像ＩＦ信号の振幅制限を行なうリミツタ回
路と、該リミツタ回路の出力信号をＦＭ検波する
ＡＦＴ検波回路と、該ＡＦＴ検波回路の検波出力
に応じて発振周波数が変化する局部発振回路とを
備える映像受信回路において、前記リミツタ回路
と前記ＡＦＴ検波回路との間にローパスフイルタ
を設けたことを特徴とする映像受信回路。 (2) 請求項第１項記載のローパスフイルタを能
動型のローパスフイルタとしたことを特徴とする
映像受信回路。 (3) 請求項第１項記載のローパスフイルタの遮
断周波数を映像ＩＦ信号周波数と、該周波数の３
倍の周波数との間に設定するようにしたことを特
徴とする映像受信回路。 (4) 請求項第１項において映像ＩＦ増幅回路と
、リミツタ回路と、ＡＦＴ検波回路と、ローパス
フイルタとを単一の集積回路に内蔵させるように
したことを特徴とする映像受信回路。 (5) 請求項第２項記載の能動型のローパスフイ
ルタにピーキング特性を持たせる様にしたことを
特徴とする映像受信回路。[Claims for Utility Model Registration] (1) A mixing circuit that converts a video RF signal into a video IF signal, a video IF amplification circuit that amplifies the video IF signal from the mixing circuit, and a video output from the video IF amplification circuit. A video receiving circuit comprising a limiter circuit that limits the amplitude of an IF signal, an AFT detection circuit that performs FM detection on the output signal of the limiter circuit, and a local oscillation circuit that changes the oscillation frequency according to the detection output of the AFT detection circuit. A video receiving circuit characterized in that a low pass filter is provided between the limiter circuit and the AFT detection circuit. (2) A video receiving circuit characterized in that the low-pass filter according to claim 1 is an active low-pass filter. (3) The cutoff frequency of the low-pass filter according to claim 1 is equal to the video IF signal frequency and 3 of the frequency.
A video receiving circuit characterized in that the video receiving circuit is set between twice the frequency. (4) A video receiving circuit according to claim 1, characterized in that a video IF amplifier circuit, a limiter circuit, an AFT detection circuit, and a low-pass filter are built into a single integrated circuit. (5) A video receiving circuit characterized in that the active low-pass filter according to claim 2 is provided with a peaking characteristic.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1988005714U JPH051181Y2 (en) | 1988-01-20 | 1988-01-20 | |
| KR2019890000510U KR940003931Y1 (en) | 1988-01-20 | 1989-01-19 | Image receiving circuit for tv |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1988005714U JPH051181Y2 (en) | 1988-01-20 | 1988-01-20 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01110572U true JPH01110572U (en) | 1989-07-26 |
| JPH051181Y2 JPH051181Y2 (en) | 1993-01-13 |
Family
ID=11618789
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1988005714U Expired - Lifetime JPH051181Y2 (en) | 1988-01-20 | 1988-01-20 |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH051181Y2 (en) |
| KR (1) | KR940003931Y1 (en) |
-
1988
- 1988-01-20 JP JP1988005714U patent/JPH051181Y2/ja not_active Expired - Lifetime
-
1989
- 1989-01-19 KR KR2019890000510U patent/KR940003931Y1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| KR890016825U (en) | 1989-08-19 |
| JPH051181Y2 (en) | 1993-01-13 |
| KR940003931Y1 (en) | 1994-06-15 |