Definitions

A tube containing mercury vapor and lined with a phosphor. When current is passed through the vapor the strong ultraviolet emission excites the phosphor, which emits visible light. The ultraviolet...

A fluorescent screen refers to a phosphorescent or fluorescent-coated surface that emits visible light when exposed to other forms of electromagnetic radiation, such as x-rays or ultraviolet light....

The time it takes a cathode-ray tube's electron beam to return to its starting point after completing one line, one field or one trace.

The moving spot of light emitted by a source, generally a cathode-ray tube, to illuminate specific points of an area carrying light and dark regions according to a specific pattern.

A microscope that uses a flying spot scanner, directed through the eyepiece, as a light source to determine the features of a transparent specimen. The flying spot is modulated by the varying density...

A collimator having, at one end of a tube, an objective lens, and at the other, a reticle with a pair of spaced lines located accurately in its focal plane. It is generally useful as an apparatus for...

1. The focal point. 2. To adjust the eyepiece or objective of a telescope so that the image is clearly seen by the observer. 3. To adjust the camera lens, plate, or film holder so that the image is...

1. A mechanism that permits the focusing of an optical system.2. A means of obtaining the sharpest image from a cathode-ray tube display by adjusting the size of the spot where it reaches the screen.

One of the electrodes used to focus the electron beam of a cathode-ray tube. As the electrode's voltage is changed, its electrical field is changed, resulting in a change of the electron beam's spot...

Molecules composed entirely of carbon, in the form of a hollow sphere, ellipsoid or tube. Also called buckyballs. Cylindrical fullerenes are called carbon nanotubes or buckytubes.

Fused quartz and silica are closely related materials, both composed primarily of silicon dioxide (SiO2), but they are produced through different manufacturing processes and have distinct properties...

Modification of a system to provide for a linear transfer characteristic from an input to an output device. A circuit for this purpose is built into a television camera to compensate for display tube...

The positive ion current created in an electron tube as a result of the collisions between electrons and residual gas molecules.

The increase in current of a phototube as a result of the gas in the tube becoming ionized.

Also called Geiger-Müller counter. An instrument designed to detect and measure radioactivity through the use of a gas-filled metallic tube containing a needle electrode. Radiation traveling...

An electron tube having two electron guns, one on each side of the storage medium, to encode the information onto the medium, and to read and simultaneously erase the electrostatic encoding.

Graphene is a two-dimensional allotrope of carbon consisting of a single layer of carbon atoms arranged in a hexagonal lattice pattern. It is the basic building block of other carbon-based materials...

1. In a cathode-ray tube, the glow surrounding a bright spot that appears on the fluorescent screen as the result of the screen's light being reflected by the front and rear surfaces of the tube's...

Text or images printed on paper or another tangible medium, as opposed to those viewed electronically on a cathode-ray-tube screen.

An optical system that superimposes a synthetic display providing navigational or weapon-aiming information on a pilot's or driver's field of view. The system includes a cathode-ray tube, collimating...

A helium-neon (HeNe) laser is a type of gas laser that emits visible red light at a wavelength of 632.8 nm. It operates based on the principle of stimulated emission of photons from excited helium...

A camera tube that employs a high-velocity electron beam to scan a photoemissive mosaic and to store electrical charge patterns.

A desklike apparatus with an opal glass surface illuminated from beneath by fluorescent tubes. It is equipped with roll holders for aerial films and a low-power microscope or some form of...

An electron tube that employs electromagnetic radiation to produce a visual replica of an image produced on its cathode. Electrons ejected from the cathode by the incident radiation are accelerated...

A camera that uses an image converter tube in such a way that voltage waveforms applied to internal electrodes cause the original image to be switched on and off very rapidly, thus offering time...

A camera tube similar in design to the iconoscope. However, the image formed in the image iconoscope is projected on a photocathode that emits photoelectrons to be focused on a material, forming the...

A television camera tube that preceded the development of the vidicon tube and incorporated a method to separate reflected and scattered portions of the return beam so that only the scattered...

A camera tube widely used in television broadcasting. It consists of three sections within a single vacuum envelope. 1. A photosensitive film sometimes called the photocathode. The scene to be...

In vitro is a Latin term that translates to "in glass." In scientific contexts, particularly in biology and medicine, it refers to experiments or procedures conducted outside of a living organism,...

A lamp that emits light when an electric current passes through a resistant metallic wire situated in a vacuum tube.

Any of the photoelectric and thermal detectors, spectrographs and monochromators, thermographs, scanners, amplifier tubes, snooperscopes and related equipment developed for use with infrared...

A method that produces low-loss optical fibers. A glass tube rotates while reactants pass through the tube and heat is externally applied by a burner that traverses the tube. The oxidizable vapors in...

An intensified charge-coupled device (ICCD) camera is an advanced imaging device that combines the capabilities of both an image intensifier and a charge-coupled device (CCD) sensor to achieve...

A standard direct-readout vidicon tube linked by fiber optics to an intensifier for increased sensitivity.

The process in which the electron beam of a cathode-ray tube varies in intensity in accordance with the magnitude of the signals it receives.

A laser in which the transition involved in stimulated emission of radiation takes place between two levels of an ionized gas. The gases are electrically excited in a container called a plasma tube,...

Also known as gas focusing. The introduction of an inert gas into a cathode-ray tube for the concentration of the electron beam. The gas molecules are ionized by the electrons, producing a core of...

An instrument designed to measure the index of refraction of a gas by the interference patterns formed by two beams, one of which passes through a vacuum tube in which the gas is slowly released.

1. In relation to cathode-ray tube displays, errors in the signal's amplitude, phase or both that result in small, rapid aberrations in size or position of the image. 2. Errors of synchronization...

A cathode-ray tube that serves as a picture tube in a television receiver. The signal representing the picture intensity is transmitted to the electron gun grid so that the beam intensity varies with...

A thermionic tube that has a velocity-modulated electron stream and that may be used as a microwave amplifier or oscillator.

A term applied to an electric charge image in a camera tube that remains for a period of a few frames after its initial formation.

Laser lithotripsy is a medical procedure that uses laser energy to break down or fragment stones in various parts of the body, particularly in the urinary and biliary systems. The term "lithotripsy"...

The variation of the electronically detected signal with respect to the scaled version of the classical optical signal incident on the photomultiplier tube.

A Laurent polarimeter is an instrument used in optics for measuring the rotation of plane-polarized light caused by optically active substances. Optical rotation, also known as optical activity, is a...

The metal tube that maintains the optical components of a lens in proper relationship. Some lenses are mounted in metal cells, which in turn are screwed to the front and rear of a shutter or lens...

The pattern, formed by a character generation cathode-ray tube system, in which the characters are made up of wave shapes synthesized by a series of sine and cosine terms.

A device using the Kerr effect to read back the signals from mechanically recorded tapes and discs. It consists of a light source, optical lenses to focus and direct the light beam, a pair of...