摘要:
The photocathode of the present invention is provided with a supporting substrate composed of a single-crystal compound semiconductor, a light absorbing layer which is formed on the supporting substrate and smaller in an energy band gap than the supporting substrate to absorb incident light transmitted through the supporting substrate, thereby generating photoelectrons, and a surface layer which is formed on the light absorbing layer to lower a work function of the light absorbing layer, in which the supporting substrate comprises Al(1−x)GaxN (0≦X
摘要:
An optical or photon image is converted by a photocathode to an electron image. A semiconductor plate receives the electron image on a first side thereof. For an electronically controlled time, the image is integrated and stored in thousands of reversed biased PN junctions connected to micro-sized conductors, in the plate. An intensified image is then transferred from a second side of the plate, at an electronically controlled time, to an output plate where the intensified image may be viewed.
摘要:
An image intensifier tube is described as including a photocathode element for converting an incident radiation image into a corresponding electron image, a micro-channel plate for multiplying the electron image, and a phosphorous screen for converting the multiplied electron image into a corresponding radiation image to be viewed. The electron image may be turned ''''on'''' and ''''off'''' by selectively applying a gating signal to the photocathode element. A potential applied between the first and second electrodes of the micro-channel plate is varied in accordance with the current absorbed at the second electrode to control the degree of electron multiplication and to prevent saturation of the phosphorous screen. In an illustrative embodiment, a variable potential source coupled to the electrodes of the micro-channel plate, includes a variable oscillator responsive to the current derived from the second electrode and an AC/DC converter for applying a DC potential whose magnitude corresponds to the variable frequency of this oscillator. Significantly, the supply source for the phosphorous screen includes first and second sections, the first section including an AC/DC converter connected to the aforementioned variable oscillator, for providing a variable potential between the second electrode of the micro-channel plate and the phosphorous screen, dependent upon the variable potential applied between the electrodes of the micro-channel plate. The second section includes illustratively a fixed oscillator and a third AC/DC converter whose output is connected to the phosphorous screen.
摘要:
A photocathode device for use in an image intensifier, fabricated with a photoemissive semiconductor wafer having an active cathode layer which includes a central region of a first predetermined height surrounded by a peripheral region of a second predetermined height. The first predetermined height of the central region is configured to be greater than the second predetermined height of the peripheral region in order to create a recessed contact structure which is less likely to have unwanted emission points. A layer of conductive material covers the peripheral region to provide an electrical contact to the photocathode device. A layer of insulating material covers the layer of conductive material in order to protect the contact layer from being damage during handling operations.
摘要:
A night vision device includes an improved image intensifier tube providing an image with reduced dark spots caused by microscopic particulate contamination in the tube. A method of processing image intensifier tubes to reduce dark spots caused by such microscopic particulate contamination within the tubes is disclosed.
摘要:
A band for securing a catheter or similar device to a limb of a human comprising a stretchable primary strap adapted to encircle a limb. A part of the strap is made of a soft looped fabric and the strap also carries a male Velcro-type fastening material which cooperates with the looped fabric to enable the strap to be secured in place about the limb. A secondary strap made of a flexible material is secured, hooks up, intermediate its ends to the central portion of the primary strap on the looped fabric. The secondary strap is made of a male Velcro-type fastening material, and each end of the secondary strap is designed to be looped over and encircle the catheter or similar device and attach to the looped fabric to hold the catheter or similar device securely in place on the limb.
摘要:
Imaging apparatus suitable for photon counting applications or low light imaging includes a CCD sensor 4 arranged to receive electrons emitted from a photocathode 1. The CCD sensor includes a separate multiplication register into which signal charge from its output register is transferred to give improved noise performance and resolution.
摘要:
This image tube converts irradiated electrons into fluorescence by irradiating electrons converted from a light beam by a photocathode onto a YAG crystal member. Since the YAG crystal member is a single unitary solid, the fluorescence generated on the input surface of the YAG crystal member contains no fixed pattern noise.