Abstract: SIGHT-MOD (tm) is a commercially available array of magneto-optic light modulators each of which can cause light to be transmitted or blocked in response to an electrical signal. By combining a SIGHT-MOD (tm) array with a passive array of optical fibers arranged at one end to match the positions of the SIGHT-MOD (tm) pixels and at the other end arranged in a straight line, together with optical illuminating and imaging elements, a completely solid state digital print head can be created capable of generating 300 or more dots of modulated light per inch.

Abstract: A double Gauss reduction lens is optimized for projecting line images from an object plane onto a photosensor array. The six elements, four-component lens has a numeral focal length of 550 mm, a field of view of 17.degree. at the numeral 550 mm overall object to image conjugate length and a magnification of 0.1102. The lens is characterized by a high modulation transfer fequency, large depth of focus and low distortion.

Abstract: An optical system utilizes a variable focus half-lens reflector system for projecting images onto an image plane without the use of folding mirrors. The half lens is arranged with its optical axis parallel to the object and image planes. Attached to the entrance face of the lens is a pair of reflectors arranged to form a right angle which is bisected by the lens optical axis. Principal rays from an object are then reflected from the first mirror, reflected again from the back of the half lens, thus passing twice through the lens and then, via a final reflection from the second attached mirror, onto the image plane.

Abstract: An ink jet printer having improved droplet sensing apparatus for calibrating the printer. The improved apparatus defines a number of sensing sites each having first and second light sources for directing light signals through a sensing zone and a single fiber optic light pipe leading away from the sensing zone to circuitry for detecting the presence of ink droplets in that sensing zone. The preferred apparatus includes two light emitting diodes, each of which generate visible light signals of different wavelengths. These two light signals are received by an output light pipe and travel together along the right pipe to means for detecting the intensity of the two signals and determining droplet positioning in the sensing zone as a function of the two intensities. One apparatus for differentiating between the two light intensities comprises first and second photo detectors which respond to the wavelength light generated by the two light sources.

Abstract: An optical system including a Koster's prism for splitting an optical path into twin paths so that an image propagating along the path from an object plane is incident upon one or the other of two parallel linear arrays of photosensor elements disposed in a common image plane. The arrangement provides a way to optically compact the photosensors in a continuous image line to improve the resolution of the image sensed by the photosensors.

Abstract: An electro-optical display system particularly for projecting an enlarged color television image on a screen in which the transmitted signals are converted into points of light modulated by a multiple Fabry-Perot interferometric or multiple electro-optical light modulator assembly.