Abstract:
Radiation receiver with a photodetector and a sensor, wherein the sensor receives the radiation intensity, and a shutter arranged before the photodetector is driven in dependence on the detected incident radiation intensity. The incident radiation is supplied to the photodetector via a delay device arranged before the shutter, so that no radiation destroying the photodetector can reach the photodetector, due to the shutter having been driven, and can if necessary be kept away or absorbed by the shutter.
Abstract:
Disclosed is a radiation detector which includes at least one photoconductive detector and a modulator, which modulates in an on-off manner radiation passing to the photoconductive detector from a radiation source. A bias source is connected to one terminal of the photoconductive detector. A first amplifier is connected to the other terminal of the photoconductive detector, and a second amplifier receives an output of the first amplifier. A first phase detector detects the phase of modulation of the radiation source by the modulator and generates a reference signal relating thereto. A switch in the second amplifier changes, in response to the reference signal generated by the first phase detector, the second amplifier between an inverting state and a non-inverting state as the modulator changes the phase of modulation of the radiation.
Abstract:
A device for controlling an amount of light of a lighting unit for use in an endoscope, used to view an image of an object. The device includes a light shield for shielding light generated by a light source and transmitted to the endoscope. A stepping motor drives the light shield for a series of predetermined time intervals. Brightness of the image is detected during each of the time intervals and pulses are generated during each of the time intervals. The number of pulses generated is determined in accordance with a difference between the brightness of the image detected during each of the time intervals and a desired brightness of the image. The pulses generated are used to drive the stepping motor in each of the plurality of time intervals.
Abstract:
Apparatus and method for radiometrically calibrating an imaging sensor array using the sun as a calibration light source in an optical system of the type having an accessible real conjugate of the entrance pupil, includes a flux concentrator for concentrating the sunlight. A flux modulator modulates the intensity of the concentrated sunlight and a flux relay for relaying the intensity modulated sunlight to the real conjugate of the entrance pupil of the optical system. A flux diffuser located at the real conjugate of the entrance pupil of the optical system illuminates the imaging sensor array with diffuse intensity modulated sunlight for calibrating the imaging sensor. A radiometric calibration assembly is proposed to calibrate an imaging sensor array of an earth imaging system. The calibration assembly comprises a flux concentrator, a flux modulator, a flux relay lens and a flux diffuser located within a conjugate pupil of the earth imaging system. The flux concentrator transfers solar flux to the flux modulator, which modulates the flux to a number of controlled, deterministic levels. The flux relay lens transfers the modulated flux to the flux diffuser. The diffused flux illuminates the imaging sensor array, resulting in electrical signals that provide information to allow accurate calibration for use in imagery.
Abstract:
A power supply circuit for a liquid crystal welding lens or shutter develops a relatively low voltage AC signal for driving or powering the liquid crystal shutter to the clear state and two relatively higher or larger magnitude AC electrical signals for initially driving the shutter to the dark state and then for maintaining the shutter in the dark state; a variable frequency circuit for varying the frequency of the driving signal to the shutter to minimize power usage in the dark state and to avoid flicker in the clear state; and power saving and battery level indicator features are included.
Abstract:
An electromagnetic wave detection apparatus 10 includes a first propagation unit 16, a second propagation unit 17, a first detector 19, and a second detector 20. The first propagation unit 16 propagates electromagnetic waves incident on a reference surface ss in a particular direction using each pixel px. The second propagation unit 17 includes a first surface s1, a second surface s2, a third surface s3, a fourth surface s4, a fifth surface s5, and a sixth surface s6. The first surface s1 propagates electromagnetic waves incident from a first direction in a second direction and propagates electromagnetic propagated in a third direction in a fourth direction. The second surface s2 separates electromagnetic waves propagated in the second direction d2 and propagate electromagnetic waves in a third direction d3 and a fifth direction d5. The first detector 19 detects electromagnetic waves emitted from the third surface s3. The second detector 20 detects electromagnetic waves emitted from the sixth surface s6.
Abstract:
A turbine engine including a stationary component having a probe opening, a plurality of rotor blades rotatable relative to the stationary component, and a sensor assembly disposed within the probe opening. The sensor assembly includes a sensor and a shutter mechanism having a shutter frame with a sensing window and at least one leaf member coupled to the shutter frame. The sensor assembly includes an actuator including a rotatable member having a receiving slot and a stator having a stopper member within the receiving slot. The rotatable member rotates relative to the stator over a range of motion defined relative to the stopper member, and the rotatable member is coupled to the at least one leaf member such that rotating the rotatable member in a first direction uncovers the sensing window, and such that counter-rotating the rotatable member in a second direction covers the sensing window with the at least one leaf member. Selectively covering the sensor when not in use protects the sensor from exposure to harsh conditions, extending its operative life.
Abstract:
An optical head for receiving an incident light is provided. The optical head comprises a reflective diffuser and a reflector disposed to face the reflective diffuser. The reflective diffuser is disposed in an optical path of the incident light and shields the reflector from the incident light. The reflective diffuser converts the incident light to scattered light having a Lambertian pattern. The reflector has an optical output section that transmits the scattered light and a reflective section that reflects the scattered light to the reflective diffuser and/or the other portions of the reflective sections. An optical system using the optical head is also provided.
Abstract:
An optical head for receiving incident light is provided. The optical head comprises a transmissive cosine corrector and a reflector disposed to face the transmissive cosine corrector. The transmissive cosine corrector is disposed in an optical path of the incident light and shields the reflector from the incident light. The transmissive cosine corrector converts the incident light to scattered light having a Lambertian pattern. The reflector has an optical output section that transmits the scattered light and a reflective section that reflects the scattered light to the transmissive cosine corrector and/or the other portions of the reflective sections. An optical system using the optical head is also provided.