Digital convergence correcting apparatus
    1.
    发明授权
    Digital convergence correcting apparatus 失效
    数字会聚校正装置

    公开(公告)号:US4977446A

    公开(公告)日:1990-12-11

    申请号:US302353

    申请日:1989-01-27

    IPC分类号: H04N3/23 H04N9/28 H04N9/31

    CPC分类号: H04N9/28

    摘要: A convergence correcting apparatus is used in a projection television receiver including a CRT having an aspherical fluorescent screen and a projection lens apparatus which is attached to the display screen of the CRT and has aspherical plastic lenses. In the digital convergence correcting apparatus, a digital memory stores digital correction data corresponding to correction values of convergence adjustments points indicative of a plurality of points on the display screens divided in the horizontal and vertical directions. A multiplexer reads out predetermined digital correction data from the digital memory and time sharingly multiplexes. At least one digital/analog converter receives the time sharingly multiplexed data from the multiplexer and generates an analog signal. Sample and hold circuits extract a predetermined correction signal from the analog output of the digital/analog converter and sample and hold them. The convergence correcting apparatus is driven in accordance with the respective correction signals held by the sample and hold circuits.

    Dynamic noise reduction circuit for image luminance signal
    2.
    发明授权
    Dynamic noise reduction circuit for image luminance signal 失效
    用于图像亮度信号的动态降噪电路

    公开(公告)号:US4962426A

    公开(公告)日:1990-10-09

    申请号:US334330

    申请日:1989-04-07

    IPC分类号: H04N5/21

    CPC分类号: H04N5/21

    摘要: A noise reduction circuit comprising: a high-pass filter for extracting the high-frequency component of an image signal; a coring circuit for extracting a faint signal component included in the extracted high-frequency component as noise; a low-pass filter for extracting the low-frequency component of the image signal; an adder for adding the cored high-frequency component and the low-frequency component extracted by the low-pass filter; and a coring control circuit which detects the level of a luminance signal and controls the coring range of the coring circuit according to the level of the luminance signal. Since noise is visually more conspicuous in a dark portion of a picture than in a bright portion of a picture, the coring control circuit increases the coring range when the level of the luminance signal is low, namely, for a dark portion of a picture, and decreases the coring range when the level of the luminance signal is high, namely, for a bright portion of a picture to make noise indistinct over the entire area of a picture plane.

    摘要翻译: 一种降噪电路,包括:高通滤波器,用于提取图像信号的高频分量; 用于提取包含在所提取的高频分量中的微弱信号分量的取芯电路作为噪声; 用于提取图像信号的低频分量的低通滤波器; 加法器,用于将所述核心高频分量和由所述低通滤波器提取的低频分量相加; 以及取芯控制电路,其检测亮度信号的电平,并根据亮度信号的电平来控制取芯电路的取芯范围。 由于在图像的暗部比图像的亮部更加显着地显示噪声,所以当亮度信号的电平低时,即,对于图像的暗部分,取芯控制电路增大取芯范围, 并且当亮度信号的电平为高时,即对于图像的亮部使得在图像的整个区域上不清楚的噪声,降低取芯范围。

    Focusing voltage output circuit for cathode ray tube
    3.
    发明授权
    Focusing voltage output circuit for cathode ray tube 失效
    用于阴极射线管的聚焦电压输出电路

    公开(公告)号:US4549216A

    公开(公告)日:1985-10-22

    申请号:US561069

    申请日:1983-12-14

    申请人: Ikuo Yuki

    发明人: Ikuo Yuki

    IPC分类号: H04N3/18 H04N3/26 H04N5/68

    CPC分类号: H04N3/26

    摘要: In a focusing voltage output circuit for a cathode ray tube, a variable impedance circuit is connected in series with a variable resistor for adjustment of focusing voltage. The impedance of the variable impedance circuit is changed in response to a video luminance signal or a beam current to change the focusing voltage so as to optimize the focus tracking characteristic.

    摘要翻译: 在阴极射线管的聚焦电压输出电路中,可变阻抗电路与用于调整聚焦电压的可变电阻器串联连接。 可变阻抗电路的阻抗响应于视频亮度信号或束电流而改变,以改变聚焦电压,从而优化聚焦跟踪特性。

    Electronic channel selection apparatus with surface acoustic wave device
    4.
    发明授权
    Electronic channel selection apparatus with surface acoustic wave device 失效
    具声表面波装置的电子通道选择装置

    公开(公告)号:US4392249A

    公开(公告)日:1983-07-05

    申请号:US247268

    申请日:1981-03-25

    CPC分类号: H03J7/28

    摘要: There is disclosed an electronic selection apparatus comprising a surface acoustic wave comb filter, in which the local oscillator frequency of an electronic tuner is swept up to a frequency higher than a peak frequency of the surface acoustic comb filter corresponding to a desired channel number (an upward direction), and then swept toward the opposite direction (a downward direction) until a predetermined number of peaks of the comb filter is counted while checking the presence of an AFC signal, whereby an erroneous tuning operation may be prevented, provided that the signal of the desired channel is present within a predetermined range in the vicinity of the receiving frequency of the desired channel.

    摘要翻译: 公开了一种电子选择装置,其包括声表面波梳状滤波器,其中将电子调谐器的本地振荡器频率扫到高于对应于期望频道号的表面声梳状滤波器的峰值频率的频率(一 向上方向),然后向相反方向(向下方向)扫掠直到梳状滤波器的预定数量的峰值被计数,同时检查AFC信号的存在,从而可以防止错误的调谐操作,只要信号 的期望信道的存在位于期望信道的接收频率附近的预定范围内。