Abstract: A spectrometer is incorporated to a conventional lensometer. The spectrometer includes a uniform extended light source including a light source having visible and ultraviolet emission and an extending integrating sphere including ultraviolet transmission. In the preferred embodiment, an Ebert spectrometer is utilized, although other spectrometers may be used as well. Light is emitted from the light source through the spectacle lens to be tested to a spherical reflecting surface. Upon reflection, the light is incident to a grating, retro reflected to the spherical surface and thereafter reflected for incidence to a charge coupled device for analysis of the generated spectrum. The system is provided with a slit and a field stop dimensioned so that through all ranges of lenses expected to be tested within designated tolerances of sphere, cylinder and prism, the spectrometer sees only and always a portion of the uniform extended light source.

Abstract: In an instrument having an interrogating optical beam for the measurement of various optical properties of the eye, a detector is disclosed for triangulating the towards and away distance of the eye from the objective of the measurement equipment thus utilizing the beam for serendipitous purpose of ranging. A photosensitive detector having two photosensitive elements is placed in a plane which includes the optical axis of the interrogating instrument and the detector. The detector is mounted towards the eye with the division between the two photosensitive surfaces normal to the plane including the interrogating optical beam and the detector. Typically, the detector has line of sight off axis with respect to the interrogating beam and intersects the axis at the preferred position for eye placement. An imaging lens relays a conjugate image of the detector to that point in space on the optic axis in front of the eye where ultimate placement of the eye for measurement is desired.

Abstract: A light pen of the type having a photoreceptor for sensing the signal from a CRT computer display and outputting to computer logic the location of the photosensing light pen is disclosed. The improvement herein is the incorporation of an accelerometer on the light pen actuated by tapping the pen gently on the screen. The accelerometer has the preferred form of a microphone acoustically deadened as by the placement of silicone rubber over the acoustical channel. The rubber acts as an accelerometer mass outputting a high frequency signal upon tapping of the light pen on the glass covering a CRT screen. A monostable amplifier opens a signal gate to conventional computer measuring logic for that duration necessary to assure one complete raster sweep of the screen. A light receptor at the screen end of the light pen outputs through a video amplifier and fast comparator to measure the precise moment of video raster passage.