Abstract: An analog-to-digital converter (ADC) arrangement mounts at least one ADC integrated circuit on a six-layer printed circuit board including an analog ground plane in a second layer occupying a region distinct from a digital ground plane in a fifth layer. Analog signals are carried over paths of a first layer overlying the second layer ground plane. The analog signal paths may be configured as microstrip transmission lines. Digital signals produced by the IC are coupled onto digital signal paths overlying the digital ground plane. Third and fourth layers of the six-layer printed circuit board carry power to signal conditioning circuits. Conditioned power is coupled to the ADC integrated circuit and any other IC's.

Abstract: The height of an object is determined by projecting a beam of light there across to form a light stripe. A camera views the object obliquely, and forms an image of the light stripe. As a result of the oblique view, the light stripe is imaged as a series of bright vertical lines on a horizontally-scanned image. Each horizontal line scan crosses the light stripe at a particular horizontal position, representative of the height of the object at that point on the image. The projection and imaging optics cause the light stripe to be several pixels wide, so that the height is not exactly known. A logic circuit finds the pixel with the greatest intensity and stores its position and value, and the values of its neighboring pixels. At the end of each line scan, the sum of the stored intensities is formed, together with a weighted sum, so that a ratio may be formed which represents the center position.

Abstract: An apparatus is disclosed for coupling digital signals across a rotary mechanical gap as, for example, in a helical scan optical or magnetic tape recording/playback system where it is required to couple digital signals having a wide range of pulse widths between the stationary portion of the system and the rotating headwheel. The apparatus includes a rotary transformer comprising inductively-coupled first and second coils located, respectively, in the stationary and rotating portions. A capacitor positioned between the signal source and the primary winding of the rotary transformer converts the pulsed digital signals from the source into signals of changing current so that pulses of variable widths are efficiently coupled through the transformer. In this way, digital pulses having width ratios of approximately five-to-one can be transmitted across the gap.

Abstract: In optical disc systems a record level control is provided for adjusting the power of the recording source. The waveform of the data detected during a read-after-write operation contains information concerning the power of the record source. These read-after-write signals are the same as those that are used during an actual playback operation. The record level control is implemented in two ways. In the first, the detected data is averaged to determine the record level. In the second technique the detected data is compared with an "ideal" signal derived from the detected data to provide an indication of a high or low record level. Further, the system includes means for adjusting the record level in response to an indication of a variation in the record level.