Abstract: A liquid level sensor confirms actual physical contact between a probe and a liquid by verifying that any change in capacitance of the sensor is constant over a given time period and thereby is not caused by spurious electrical disturbances or other measuring irregularities.

Abstract: The major/minor dimensions of elliptical elements are measured by simultaneously scanning both dimensions of the elements and arranging the data in a matrix for each of the dimensions. A first preselected number of the largest elements are arranged or averaged for one dimension to obtain an average for one of the dimensions. A second predetermined number of largest elements are averaged for the other dimension to obtain an average for the other dimension. The measured dimensions are compared with upper and lower limits to verify the acceptability of the dimensions.

Abstract: A method of inspecting a pattern of elements on a working plate includes producing a negative copy of the working plate and aligning the negative copy with a positive inspection plate having elements slightly larger than the elements of the working plate whereby flaws are revealed as light transmissive spots. The working plate and a negative inspection plate, having the elements slightly smaller than the elements of the working plate, are aligned and flaws are revealed as light transmissive spots.

Abstract: A method for measuring spaces in a periodic matrix having a period including a plurality of spaces and areas therebetween includes placing the matrix between a light source and an array of pixels for receiving the light shadow image for the matrix. A plurality of image lines from the matrix are scanned across the array and signals are produced representative of the spaces and areas therebetween, which signals are converted into data values and transmitted to means for storing the data values for each of the scan lines as a row and for successive scan lines as columns. Selected data values in predetermined groups of columns, representing corresponding nonadjacent spaces of the periodic matrix, are added to obtain a total for each group. The total for each group is divided by the number of selected data values in that group. The average data value for each group is multiplied by a linear value representing the average length of each pixel to obtain the average space length for each group.

Abstract: In measuring the dots of a color picture tube panel the panel is scanned and energy passing through the dots is detected. A large number of lines are scanned and the scan data are stored in a matrix having a row for each scan line and, columns for the dots and the spaces between the dots. Data for a preselected number of dots and spaces are stored. When scanning occurs between rows of dots, the preselected number of dots is not scanned and zeros are put into the matrix. Data processing is simplified by searching the last column of the matrix for zeros and rejecting all rows of data having a zero in that column.

Abstract: A RAM (Random Access Memory) interface control circuit is used for measuring spaces in a periodic matrix by controlling a RAM memory circuit coupled between a photodetector array interface circuit and a computer. A plurality of light sources simultaneously illuminate the matrix with light at a plurality of discrete locations. A plurality of linear photodiode arrays simultaneously receive the respective light/shadow images from the matrix at the discrete locations, and associated control and quantizer circuits produce signals representative of the spaces and areas therebetween. RETICON interface circuits are coupled, respectively, to the control and quantizer circuits for simultaneously converting the signals for each location into data values and transmitting the data values in parallel to respective RAMs. RAM interface control circuits are coupled, respectively, to the RAMs for sequentially addressing the respective RAMs for seriatim transfer of the data values to the computer.

Abstract: A system for fine focusing a camera on one surface of a moving curved transparent object includes a digital storage device. The focusing range of the camera is stored in the storage device. A thickness transducer provides a signal representative of the thickness of the object and a displacement transducer provides a signal representative of the distance between the object and the camera. The thickness and the displacement signals are added and provided to the storage device. When the added value is outside the stored range the camera is focused to cause the added value to fall at the middle of the range.

Abstract: A system for measuring spaces in a periodic matrix includes a plurality of light sources for simultaneously illuminating the matrix with light at a plurality of discrete locations. A plurality of linear photodiode arrays simultaneously receive the respective light/shadow images from the matrix at the discrete locations, and associated control and quantizer circuits produce signals representative of the spaces and areas therebetween. RETICON interface circuits are coupled, respectively, to the control and quantizer circuits for simultaneously converting the signals for each location into data values and transmitting the data values in parallel to respective RAMs. RAM interface control circuits are coupled, respectively, to the RAMs for sequentially addressing the respective RAMs for seriatim transfer of the data values to a computer.

Abstract: A photodetector array interface circuit includes a pixel counter circuit having a plurality of sequentially numbered counters for counting pulses in a pixel oscillator signal, and a pixel counter gating circuit coupled to the pixel counter circuit for receiving both the pixel oscillator signal and a digital video signal and sequentially selecting the counters to receive the pixel oscillator signal such that the next sequential counter receives the pixel oscillator signal whenever the digital video signal changes. The interface circuit further comprises circuitry for sequentially reading the counters such that a particular counter is read only when the next sequential counter has received the pixel oscillator signal.

Abstract: An auxiliary focusing circuit for an automatic focusing solid state array camera includes a control circuit and a drive circuit. The camera includes a switch which is actuated when the lens travels a selected distance without being focused. The control circuit responds to the switch and actuates the drive circuit. The switch also reverses the direction of travel of the lens. The drive circuit rotates an optical scanning member and the camera can be focused while the lens travels in the opposite direction.

Abstract: An interface circuit in a television receiver selects two pulses from a pulse train for transfer to a digital computer. The interface circuit includes first and second logic elements, a counter and a comparator for enabling a gating circuit to transfer the selected two pulses to the digital computer.

Abstract: A system for measuring the average area of apertures in an opaque member scans a large number of lines across the apertures in orthogonal directions. The width of two apertures are measured to obtain an average width. The lengths of two apertures are measured to obtain an average length. The average width and length are multiplied to obtain an average area. The width and length measurements are not necessarily from the same two apertures within the member.

Abstract: A system for measuring the black matrix on the faceplate of a color television picture tube provides measurements of the matrix line widths, the transparent space widths and the periods of the color barwidths formed by the lines and spaces.

Abstract: The voltage supplied to the welding electrode of a welding system repeatedly and accurately charges an energy storage device by directly sensing the charging voltage across the storage device and comparing the sensed voltage to a reference voltage to produce a control signal and by using the control signal to control the welding system. The charge storage device is charged through the part to be welded to warm the part and improve the weld.