Abstract: A skip-field guard-bandless video tape recorder records and plays back adjacent tracks on a video tape with two closely adjacent heads of opposing head gap azimuth angles (to suppress cross-talk), only during alternate (odd) half-rotations of the head drum. Unavoidable cross-talk of synchronization pulses from adjacent tracks does not create visible interference or timing errors during playback by virtue of a special offset angle .theta..sub.1, between the adjacent recording heads, proportional to the linear offset distance between adjacent tracks. During playback, skipped fields are "filled-in" by a repetition of each recorded field through a second (duplicate) pair of closely adjacent heads of opposing azimuth positioned to retrace the recorded tracks during the other alternate (even) half-rotations of the head drum. An offset angle .theta..sub.2 between the two head pairs (i.e.

Abstract: In a video recorder having a drum with opposing dual record heads, successive fields of only the luminance signal (without the chrominance signal) are recorded by the heads during successive head rotations through 180.degree.. The tape is overwrapped around the drum by a certain angle (over 216.degree., for example) so that the chrominance signal of each preceeding field may be compressed and recorded during each head rotation through the overwrap angle (i.e., from 180.degree. to 216.degree. in the example). Because the luminance signal is not mixed with the chrominance for recording (as has been usual), the luminance bandwidth may be increased by about 1 megaHertz to occupy the frequency band otherwise occupied by the color-under chrominance signal in the prior art. This provides a significant improvement in overall video image resolution.

Abstract: A removable container holds a plurality of video disks each storing prerecorded video pictures that are played back in a multi-disk video player. The container includes a magazine for storing the disks and a non-volatile, erasable memory supported adjacent the magazine between guide rails formed on one side of the magazine. The memory is locked in place on the rails when the container is outside the player by a movable locking key that is biased into a locking slot in the magazine. When the container is inserted into the player, the locking key is displaced out of the slot; the memory is detached from the magazine and connected into the player circuit, thus permitting movement of the magazine without disturbing transfer of data to and from the immobilized memory.

Abstract: By employing field store memories, a skip-field video recorder records odd and even fields of different frames and then plays back full frames reconstructed from the recorded odd and even fields, thus achieving maximum vertical resolution in the playback video image.

Abstract: A video cassette recorder (VCR) erase protection system which is responsive to the standard anti-erase switch on a video cassette, is capable of "filling-in" unused portions of an erase-protected video cassette without disturbing previously recorded material on the cassette and without requiring the user to turn off the anti-erase switch on the cassette. By eliminating the need to turn off the anti-erase switch before recording additional material, the possibility of forgetting to later rearm the switch is eliminated. A microprocessor, responding to the anti-erase switch position and to the video signal sensed during an initial fast winding of the tape, intelligently positions the tape prior to recording so that recording takes place in unused tape portions only, without requiring any further action by the user.

Abstract: A video circuit for use with an electronic still camera retrieves a fully-interlaced frame signal during a single field interval from a full-frame imager and provides . . . during the same interval . . . a pair of de-interlaced field signals for recording upon paired tracks on a magnetic disk. By switching the inputs and outputs of a set of clock-driven line delay elements according to variations of the line rate, the frame signal is converted into simultaneously accessible field signals, at the same time accounting for a time base discrepancy that arises due to readout from the imager at double the line rate.

Abstract: In an electronic still camera adapted for professional or amateur photography, a solid state thermo-electric cooler rapidly cools a solid state image sensor (imager) in accordance with the ambient illumination or subject brightness, so as to rapidly increase the sensitivity of the imager to the required level. Thus, the device may be used in place of a flash attachment for still photography under low-light conditions. A microprocessor controls the cooler and determines optimum imager temperature for a given set of subject brightness, shutter speed and aperture size values. These values are correlated to corresponding optimum imager temperatures by a set of polynomials--or by a set of look-up tables--stored in a read only memory accessed by the microprocessor.

Abstract: Geometric distortion in a scanning beam video laser porjector, or the like, is corrected by comparing the time of arrival of the projection beam at a selected pixel on the projection screen with a predetermined time of arrival, and computing therefrom the changes in beam control required to remove the distortion. A peripheral portion of the projected video field is blank, being reserved for projection of bright beam alignment fiducials comprising selected pixels of the peripheral field portion. An optical fiber is placed on the screen periphery so as to receive one pixel of each projected fiducial, its output being applied (through a light sensitive diode) to a beam control processor or the like. Geometric distortion or a change in projector alignment shifts the beam time of arrival at the sensor. The processor compares the time of arrival of the projector beam at each sensor with a lock-up table and, from this comparison, determines the beam control corrections required to remove geometric distortion.

Abstract: A video disk player is provided for playing back a series of still pictures prerecorded on a plurality of video disks. The disks are contained in a magazine that is inserted into the player. The magazine includes an erasable, non-volatile memory for containing data related to the pictures. The player includes an editing feature for generating picture file data prescribing an organized arrangement for viewing the pictures, including data pertaining to the assignment of pictures into one or more albums, the arrangement of the viewing order, the establishment of automated viewing times, the addition of text, and the like. The picture file data is put into the non-volatile magazine memory and remains there though the magazine is removed from the player. To view an album, the magazine is inserted into the player and the magazine memory is connected into the player circuit. An album is chosen by reference to the picture file data.

Abstract: A removable container holds a plurality of video disks each storing prerecorded video pictures that are played back in a multi-disk video player. The container includes a magazine for storing the disks and a non-volatile, erasable memory supported adjacent the magazine between guide rails formed on one side of the magazine. The memory is locked in place on the rails when the container is outside the player by a movable locking key that is biased into a locking slot in the magazine. When the container is inserted into the player, the locking key is displaced out of the slot; the memory is detached from the magazine and connected into the player circuit, thus permitting movement of the magazine without disturbing transfer of data to and from the immobilized memory.

Abstract: In an effort to provide exceptionally high resolution playback of video information recorded in the environment of an electronic still camera, the invention calls for:(a) Use of double side band FM recording, which in the prior art would have been productive of playback interference between the side bands of harmonics and the side bands of corresponding fundamentals unless the relative head-to-media speed was high enough to accommodate high carrier frequencies.(b) Bias recording such FM video information, thereby to prevent the inherent production of harmonic information within the media.(c) Up-converting the harmonic-free playback signal, before the harmonic-causing procedure of amplitude-limiting such playback signal, thereby to cause such signal to have a spectrum-wise wide disparity between the modulated fundamental in question and its harmonics, as caused by such amplitude limiting.(d) Removing the generated harmonics (and their side bands) prior to or during demodulation of the modulated fundamental.

Abstract: Apparatus for playing back from recording media (such as magnetic tape) recorded information which includes both preselected segments and unpreselected segments, such as edited video scenes (burst and still) and unedited video scenes. The apparatus includes a memory for storing start and end addresses (which may be the same) of preselected segments recorded on the media, and a device for designating an unpreselected segment for playback such as on a display monitor. The apparatus includes control logic (1) for determining from the stored start and end addresses of preselected segments the start and end addresses of a designated unpreselected segment, and (2) for causing playback of the designated segment.

Abstract: Because the lineal speed of a pre-recorded disc relative to a playback head depends on the radial position of the head with respect to the disc, the present invention calls for equalization that correspondingly varies as a function of the radial position of the playback head. Since the recorded tracks of the disc reside in a relatively narrow band about the disc--and because of the relatively large number of tracks within such band--an additional concept of the invention is to divide the band into head-position zones--each such zone corresponding to a different grouping of recorded tracks--and to employ equalization that is respective of the specified zones.

Abstract: Apparatus and method are disclosed for playing back a video signal representative of a still image. The video signal is recorded on a magnetic recording disk in the form of three separate signals on three respective tracks; a color component signal on a color track and two luminance component signals on two luminance tracks. The still image is reproduced by initially reading the color track with a playback head and storing the color component signal. Then the playback head is cycled back and forth between the two luminance tracks to read a continuous sequence of alternating first and second luminance component signals. The video signal is generated by repetitively combining each luminance component signal in the continuing sequence with the stored color component signal.

Abstract: In connecting a microprocessor to several condition-sensitive switches and several slow-reacting loads such as motors and solenoids, the input/output ports of the microprocessor may be simplified and reduced in number by incorporating a switch and a load on the same output port. Each load is connected to a separate output port. Each switch is also connected between an output port (which is also connected to a load) and a common input port. The switches are interrogated by a time-divided stream of pulses, each pulse being too short to noticeably affect the operation of any load. The closure of a switch is noted by detecting, at the input port, the presence of any pulses that passed through the closed switch.

Abstract: A battery check apparatus for an electronic strobe flash unit automatically indicates the charge condition of a battery under load. The electronic strobe flash unit includes means for charging a storage capacitor. During the charging process, the time needed to charge the capacitor to a relatively small predetermined fraction of its maximum voltage is compared with a predetermined reference time, which is short in comparison with the usual total charging time of the capacitor. An electronic indicator is then controlled in response to the result of this comparison to provide a visual indication of the charge condition of the battery, well in advance of the time required to charge the capacitor fully.