Automatic recording mode detecting apparatus for use in video tape
reproducer
    2.
    发明授权
    Automatic recording mode detecting apparatus for use in video tape reproducer 失效
    自动录像模式检测设备用于视频录像机

    公开(公告)号:US5164862A

    公开(公告)日:1992-11-17

    申请号:US537698

    申请日:1990-06-14

    申请人: Mitsuo Kawamata

    发明人: Mitsuo Kawamata

    摘要: A video signal recording mode detecting apparatus is provided to detect a plurality of recording modes in which frequencies of the carriers in FM video signals are different. By counting the number of pulses that result from wave-shaping the carrier of an FM video signal during a predetermined period, it is possible to detect the particular video signal recording mode being employed. By using a digital detecting mode circuit recording modes having different carriers can be positively detected by relative small-scale circuits suitable for fabrication as integrated circuits.

    摘要翻译: 提供了一种视频信号记录模式检测装置,用于检测FM视频信号中的载波频率不同的多个记录模式。 通过在预定时间段内对由FM视频信号的载波进行波形整形而产生的脉冲数进行计数,可以检测正在采用的特定视频信号记录模式。 通过使用具有不同载波的记录模式的数字检测模式电路可以通过适合于作为集成电路制造的相对小尺度电路来积极地检测。

    Video signal processing circuit
    3.
    发明授权
    Video signal processing circuit 失效
    视频信号处理电路

    公开(公告)号:US4369466A

    公开(公告)日:1983-01-18

    申请号:US209023

    申请日:1980-11-21

    IPC分类号: H04N5/16 H04N5/18

    CPC分类号: H04N5/185 H04N5/165

    摘要: A video signal processing circuit for an input video signal having a DC level, a pedestal level, and a blanking period, includes a first clamp circuit for clamping the pedestal level of the input video signal to a first predetermined DC level in response to a clamp voltage supplied from a clamp voltage source, a blanking circuit for setting the level of the input video signal to a second predetermined DC level which is higher than the pedestal level of the input video signal during the blanking period of the input video signal and for producing a wave-formed signal, a peak-hold circuit for detecting and holding the darkest level of the wave-formed signal and for producing a peak-held signal, a series circuit of a diode and resistor, which produces a threshold level signal, connected between the first clamp circuit and the output of the peak-held circuit, a comparator circuit supplied at one input with the lower of the threshold level signal and the peak-held signal and supplied at another input with the output from the first clamp circuit for comparing the signals supplied thereto and for producing an output signal corresponding to the higher one of the compared signals, and an average picture level detecting circuit including a variable impedance element connected to the resistor for increasing the threshold level signal in response to increases in the average picture level of the input video signal.

    摘要翻译: 用于具有DC电平,基座电平和消隐周期的输入视频信号的视频信号处理电路包括:第一钳位电路,用于响应于钳位钳位输入视频信号的基准电平到第一预定DC电平 由钳位电压源提供的电压,用于将输入视频信号的电平设置为比输入视频信号的消​​隐期间输入视频信号的基准电平高的第二预定DC电平的消隐电路, 波形信号,用于检测和保持波形信号的最暗电平并产生峰值保持信号的峰值保持电路,产生阈值电平信号的二极管和电阻器的串联电路,连接 在第一钳位电路和峰值保持电路的输出之间,在一个输入端提供阈值电平信号和峰值保持信号的较低值的比较器电路,并在anot提供 其输入与来自第一钳位电路的输出相比较,用于比较提供给它们的信号并产生与较高比较信号相对应的输出信号,平均图像电平检测电路包括连接到电阻器的可变阻抗元件以增加 该阈值电平信号响应于输入视频信号的平均图像电平的增加。