View Engineering, Inc.

Multilink Group

Singer & Singer

Jack Sacks

Ralph M Weisner

Gary L DeZotell

Richard A Hubach

Guy B Coleman

James W Henderson

Valerie A Liudzius

Gary DeZotell

Richard E DeKlotz

This invention concerns an optical system for use with a television camera for detecting the surface location of an object. A preferred optical image having a distinct, unique, recognizable pattern is projected on a surface along a defined path that ultimately falls on an imaging sensor associated with a television camera. The optical configuration causes a maximum light pattern energy to fall on the image sensor when the focal point coincides exactly with the surface of the object being detected. The system is not an automatic focussing system, since best focus is normally considered to be that condition which produces an image of maximum detail and sharpness, and the present invention does not rely on detail or sharpness of image for its operation. The invention can be used as an automatic focussing device if desired, since best focus can be derived as a useful by-product of accurate surface detection. In operation the camera moves in the Z direction through the point of maximum light pattern energy. The Z-axis position of the energy peak value is a function of the optical design. An output signal from the camera is filtered and processed and calculated to the Z-axis height of the camera as a measure of the distance to the object surface being detected.

Z-axis measurement system

A multiplexer for compressing two television programs into the bandwidth normally required for a single television signal is disclosed wherein vertically adjacent lines in the odd and even field of each frame are summed and differenced in pairs having the same color subcarrier phase. 'Line pair signals' respectively comprising the sum and difference of each line pair are then formed after the difference signal is time compressed without an overall increase in bandwdth. The line pair signals for each frame of one program are alternately transmitted with the line pair signals of a frame from the second program. The line pair signals of a video frame are fewer in number and longer in duration than NTSC field lines. Timing is such that one frame of both programs is transmitted during the time allotted to the transmission of one frame under the NTSC standard. The lines from odd fields of each program are reconstructed after transmission by adding the appropriate difference signals and sum signals. The lines from even fields are reconstructed by differencing the sum signals and the difference signals.

Method and apparatus for multiplexing television signals

A decoder for use in a multiplexing system wherein the adjacent frame lines of a first program are summed and differenced, and the sum signal and time-compressed difference signal of each line pair is transmitted during the period allotted for transmission of a single line, thereby transmitting data for two lines in the time allotted for a single line. The decoder avoids a need for complex digital wall filters at the input by sampling the timed-compressed difference signals at a non-unity multiple of the rate used for sampling the sum signals. The multiple is sufficiently fast to enable the standard 'front-end' low pass filter of the decoder to function as an interpolation filter, eliminating the artifacts which would otherwise require the use of the complex filter. The disclosed decoder additionally includes a first memory-sharing arrangement wherein memory addresses are accessed during each operating cycle in a manner which permits data to be written into memory prior to the complete reading out of data from the previous operating cycle. A second memory-sharing arrangement is included wherein memory addresses are accessed during each operating cycle in a manner which permits data to be read out of the memory prior to the complete writing of data for that operating cycle, enabling re-use of certain memory addresses during the operating cycle.

Z-axis height measurement system

An apparatus and method for storing a reference scene and a scene under search in separate addressable memories. The reference scene is addressed along a scan line at a selected angle giving the impression that the reference memory has been rotated. The search area information is convolved with a stored reference information to obtain a count representing the number of matches for each search position at a plurality of selected angles. The convolved count is accumulated and the search stopped when the accumulated count exceeds a given threshold value. The X Y coordinates of the best search is determined by evaluating the highest accumulation count. The angle orientation of the search area is determined by addressing each scan line readout of the stored reference area at small angles, convolving the readout against the memory readout, accumulating the count for a selected number of scan angles and determining the angle position having the highest count as a measure of the alignment angle of the search area.

High speed pattern recognizer

Video information obtained in real time is clocked and digitized according to light intensity. Changing light intensities are adaptively determined to vary the threshold level for determining black and white signals. The scene to be used as a reference is first recorded in a fine format and then in a coarse format. In the search mode the coarse stored information is compared in real time with coarse information from the field of view and convolved to generate a correlation number indicating the percentage of match. The location coordinates in the X and Y dimension for the best match is determined at the location of the highest correlation number. A fine search is then made around the coarse location previously determined by convolving in two dimensions previously stored information against information in real time from the scene under investigation to again determine the highest correlation as a measure of the location where the best possible match can be determined.

Pattern recognition apparatus and method

In a pattern recognition system the video output signal is a signal representative of either black or white. The shading effect of the video camera is minimized by using a high pass filter to accentuate the high frequency components of the signal by partially differentiating the substantially square wave input video signal and feeding forward a sample of the undifferentiated signal thereby retaining some low frequency components of the video signal and thereby minimizing the shading effect of the video camera without increasing detected noise components. Positive and negative-going zero crossings with respect to ground are detected through a capacitive coupled comparator circuit. In the absence of zero crossings the discharge circuit and charge circuit of the capacitor is interrupted thereby maintaining the value of the voltage on the capacitor with respect to ground. Changing the charge and discharge rate of the capacitor reduces the probability that noise on the signal will cause a false zero crossing.

Adaptive video processor

Video informatin obtained in real time is clocked and digitized according to light intensity. Changing light intensities are adaptively determined to vary the threshold level for determining black and white signals. The scene to be used as a reference is first recorded in a fine format and then in a coarse format. In the search mode the coarse stored information is compared in real time with coarse information from the field of view and convolved to generate a correlation number indicating the percentage of match. The location coordinates in the X and Y dimension for the best match is determined at the location of the highest correlation number. A fine search is then made around the coarse location previously determined by convolving in two dimensions previously stored information against information in real time from the scene under investigation to again determine the highest correlation as a measure of the location where the best possible match can be determined.

This invention describes a system and method for detecting unwanted pop and click sound signals caused by mechanical defects on a recording medium. A pair of wholly or partially correlated signals is generated from the recorded sound information by a conventional stereo pickup device. The output signals of the stereo pickup device are combined so that desired sound signals generated by horizontal movement on the record medium are subtracted and undesired signals generated by vertical movement on the record medium are added. The resulting undesired signal representing clicks and pops is detected as the noise signal. A gating signal starting before the leading edge of the detected undesired sound signal terminating innocuously on the sound signal, and having a width that is greater than the width of the detected undesired sound signal, is used in the system to eliminate the undesired signals.

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Thousand Oaks, CA, United States of America

Jack Sacks