摘要:
An arrangement for effecting holographic recording of information occurring in the form of electrical signals, wherein a coherent object wave which has been pulse modulated by an electrical signal is to be recorded, and a coherent reference wave is used to produce a unidimensional hologram upon a moving photosensitive storage medium, and a divergent reference wave and a convergent object wave, or a convergent reference wave and a divergent object wave, or two convergent reference and object waves or two divergent object and reference waves are used. The present invention defines the equation for the position of the reference and object points so as to provide accuracy in reproducing the holograms.
摘要:
A process of recording information which is in the form of electrical signals by pulse amplitude modulating an object wave and directing it with a reference wave onto a moving light-sensitive storage medium to record hybrid holograms thereon characterized in that the object beam is split into a plurality of parallel object beams each of which is individually and separately pulse modulated with a separate signal to be recorded, focusing the parallel modulated beams into an astigmatic object wave and focusing the reference wave into an astigmatic reference wave, with each wave having a focal line extending parallel to the direction of feed being coplanar and each wave having a focal line which is extending perpendicular to the direction of feed being mirror symmetrical to the storage medium. Preferably, the rate of advance or feed of the storage medium is controlled so that the individual holograms are overlapping.
摘要:
A sensor for measuring a physical parameter at a first location which is remote from a second location. The sensor has a plurality of light transmitting fibers each having an input end for receiving light from a source and an output end for emitting the received light to a light detector and a lens for focusing light from the source on one of the input ends of the light transmitting fibers. The lens is displaced to project light to a specific one of the input ends of the fibers in accordance with the value of the physical parameter to be measured.
摘要:
A microphone ranging system for providing improved reproduced speech by compensating for the position of a speaker relative to the microphone system. An omnidirectional microphone system with a range finder for determining the distance between the omnidirectional microphone and a speaker is provided. In further embodiments, there are also provided a multiplicity of spaced range finders for determining the exact position of a speaker or speakers relative to a microphone or several microphones. Highly directional microphones are used which are trained on the speaker or speakers and follow them as they move about a room. A tracking system is controlled through signals which originate in a control circuit which is controlled by the range finders.
摘要:
The fingerprint sensor derives an electric output signal in accordance with the topographic relief of the finger under investigation. The sensor incorporates a contact body which is formed at least in part by a light-transparent elastic material. The contact body, preferably a flat sensor plate made of said elastic material and attached to a flat supporting plate, has a light receiving surface and a contact surface for receiving a contact pressure by the finger. Before an investigation process is started, the contact surface is smooth. By pressing the finger against the contact surface, the contact surface will attain a shape conforming to the fingerprint pattern of the finger. The sensor also incorporates a light source, a photodetector and an optical system. The light source obliquely passes light to the contact surface which reflects a light beam modulated in accordance with the fingerprint. The optical system passes the reflected light beam to the light sensitive area of the photodetector. In the optical path between finger and photodetector is included a light stop for blocking reflected light which does not contain fingerprint information.
摘要:
The fingerprint sensor device derives an electric output signal in accordance with the topographic relief of a finger under investigation. The sensor incorporates a radiation source, a fingerbed, a first radiation transmitting device, a scanning device, a second radiation transmitting device, and a measuring device responsive to the radiation. The fingerbed has an opening for passing a beam of radiation (light or ultrasound, for instance) from the source therethrough. The scanning device scans this beam of radiation across the finger. Thus, the finger relief is directly scanned by a beam of small impingement spot. The back scattered radiation is directed to the measuring device. Here, the intensity distribution is determined.
摘要:
The fingerprint sensor transforms the fingerprint information of a finger under investigation into an electric output signal. The sensor incorporates a contact device or sensor plate of a piezoelectric material. This sensor plate has a contact surface. The finger exercises a contact pressure thereon and changes thereby the distribution of electric charges on the contact surface. The new charge distribution is in accordance with the fingerprint pattern of the finger. The sensor further incorporates an electric device which provides the electric output signal in accordance with the distribution of charges.
摘要:
The fingerprint transducer contains a sensing member having a sensing surface for receiving a fingerprint. The sensing member is made of a material which has a transition or softening temperature that is higher than ambient temperature and close to the temperature of the finger. Particularly, the softening temperature is chosen such that the material of the sensing member will start to melt on the surface when the finger is pressed against the sensing surface. The sensing surface has a surface relief of random roughness. In other words, the sensing surface has variations in elevation which do not show a specific pattern. The method for analyzing fingerprints comprises the steps of generating a surface relief of random space on a sensing surface of a sensing member, generating the fingerprint on the sensing surface by pressing a finger thereto, and optically reading the fingerprint from the sensing surface.
摘要:
The fiber optical measuring device contains a fiber optical transmission line into whose input end are directed a first and a second light beam. Both light beams have wavelengths differing from each other. Associated with the output end of the transmission line is a mirror. This mirror passes the transmitted second light beam therethrough and reflects the transmitted first light beam back into the transmission line. Associated with the output end is also a sensor for measuring a physical parameter. This sensor receives the second light beam and returns a portion thereof back into the output end. This portion depends on the parameter to be measured. Arranged at the input end of the transmission line is an optical device which separates the reflected portion of the first light beam from the returned portion of the second light beam. A first optical detector transforms the first light beam portion into a first electric signal, and a second optical detector transforms the second light beam portion into a second electric signal. A signal processor determines the ratio between the second and the first electric signals. This ratio indicates the value of the physical parameter to be measured.
摘要:
The liquid level indicator contains a number of first light fibers, a number of second light fibers, optical lens means interposed between each output end of the first fibers and an associated input end of the second fibers, and light detectors associated with the output ends of the second fibers. The optical lens means has substantially the same index of refraction as the liquid. When the lens means is not immersed into the liquid, it focusses light from the first fiber to the second fiber. This focussing effect is eliminated when the lens is submerged into the liquid.