Method of confining the signal level range of a television camera
    2.
    发明授权
    Method of confining the signal level range of a television camera 失效
    限制电视摄像机信号电平范围的方法

    公开(公告)号:US4542403A

    公开(公告)日:1985-09-17

    申请号:US481862

    申请日:1983-04-04

    IPC分类号: H04N5/232 H04N5/235 H04N5/19

    CPC分类号: H04N5/2352 H04N5/23293

    摘要: Before the camera is used to transmit a scene, a key or button (21) is actuated which causes a measurement field generator (23) to define a small portion of the picture field, where the video signal level of the greatest of the three color components will be compared with a reference level in an aperture control circuit (6) for setting the camera lens aperture. If this should result in a lens aperture above an upper limit or below a lower limit, an amplification step control (26) for an amplifier (8) is shifted one step so as to bring the lens aperture between the aforesaid limits. The comparison of the video signal level with the reference level is repeated until the amplification is sufficient to bring the lens aperture into the desired range. The measurement field is shown in the camera finder (14) and likewise any off-limits setting of the lens aperture and whether the manual control (28) is on a setting that permits the automatic amplification control to operate.

    摘要翻译: 在相机用于传送场景之前,启动键或按钮(21),其使得测量场发生器(23)定义图像场的一小部分,其中三种颜色中最大的视频信号电平 将组件与孔径控制电路(6)中的参考水平进行比较,以设置摄像机镜头孔径。 如果这应该导致镜头光圈高于上限或低于下限,则用于放大器(8)的放大步进控制(26)移动一步,以使透镜孔径在上述限制之间。 重复视频信号电平与参考电平的比较,直到放大足以使透镜孔径达到所需范围。 相机取景器(14)中显示测量区域,以及镜头孔径的任何非限制设置以及手动控制(28)是否处于允许自动放大控制操作的设置。

    Automatic aperture control of a television camera
    3.
    发明授权
    Automatic aperture control of a television camera 失效
    自动光圈控制电视摄像机

    公开(公告)号:US4829382A

    公开(公告)日:1989-05-09

    申请号:US131816

    申请日:1987-12-11

    CPC分类号: H04N5/2351

    摘要: R, G and B outputs from the corresponding preamplifiers of a television camera are supplied to a non-additive mixer (NAM) circuit for continuous selection of the greatest of the three outputs and the selected output is continuously supplied to a set of 9 electronic switches each selecting out a subdivision of the picture field (a, b . . . i). The switched outputs for each of the subfields are then provided to respective subfield measurement detectors which each produce an average value output and a peak value output. These are stored into subfield buffer units and then read out through a multiplexer and an analog to digital converter to a microprocessor. The various values are compared with corresponding past values for selecting between various measurement schemes for obtaining a camera diaphragm control signal, namely spot measurement, center-emphasized integral measurement and selective field measurement. Except when a decision for no setting change is made, the selected scheme of measurement is used to obtain a control signal from the average and dynamic range values of the several subfield video signals.

    摘要翻译: 来自电视摄像机的相应前置放大器的R,G和B输出被提供给非加性混频器(NAM)电路,用于连续选择三个输出中的最大输出,并且所选择的输出被连续提供给一组9个电子开关 每个选择图片字段(a,b,...)的细分。 然后将每个子场的切换输出提供给各自产生平均值输出和峰值输出的各个子场测量检测器。 这些存储在子场缓冲器单元中,然后通过多路复用器和模数转换器读出到微处理器。 将各种值与相应的过去值进行比较,以在用于获得照相机光阑控制信号的各种测量方案之间进行选择,即光点测量,中心强调积分测量和选择场测量。 除了进行无设定变更的判定之外,使用所选择的测量方式,从多个子视频信号的平均值和动态范围值中获得控制信号。

    Method and system to reduce low-frequency noise in semiconductor sensors
    4.
    发明授权
    Method and system to reduce low-frequency noise in semiconductor sensors 失效
    降低半导体传感器低频噪声的方法和系统

    公开(公告)号:US4488052A

    公开(公告)日:1984-12-11

    申请号:US328475

    申请日:1981-12-08

    CPC分类号: H04N5/2173

    摘要: To eliminate or suppress amplifier noise in amplifiers (6, 7) connected to a semiconductor light sensor, for example of a charge coupled type, in which the noise introduced by the amplifiers has a frequency spectrum which is low with respect to the clock frequency of operation of the sensor, the minimum value signal from the light sensor, as amplified, is determined; the maximum value of the signal, as amplified, is determined; and a reference is derived based on the minimum value, for example by clamping the minimum value, or utilizing the minimum value as a dynamic reference for subtraction from the maximum value, to thereby eliminate the effect of low-frequency shift of signals due to low-frequency noise of the amplifiers; various circuits may be used, such as clamping circuits (FIG. 3), threshold or non-additive mixing circuits (FIGS. 4, 5) coupled to a subtraction stage (24), band-pass filtering and envelope demodulation (FIG. 6: 28, 29, 30) or synchronous demodulation (FIG. 7: 34, 35) using the scanning clock frequency (36, 37) for synchronous demodulation, coupled with frequency limiting the output to, for example, one-half clock frequency in a low-pass filter (39).

    摘要翻译: 为了消除或抑制连接到半导体光传感器(例如电荷耦合型)的放大器(6,7)中的放大器噪声,其中由放大器引入的噪声具有相对于时钟频率低的频谱 传感器的操作,确定来自光传感器的最小值信号,如放大; 确定放大的信号的最大值; 并且基于最小值导出参考,例如通过钳位最小值,或者利用最小值作为用于从最大值减去的动态参考,从而消除由于低的信号引起的低频偏移的影响 放大器的频率噪声; 可以使用各种电路,例如钳位电路(图3),耦合到减法级(24)的阈值或非加性混合电路(图4,5),带通滤波和包络解调(图6 :28,29,30)或使用用于同步解调的扫描时钟频率(36,37)的同步解调(图7:34,35),并将输出频率限制为例如二分之一时钟频率 低通滤波器(39)。