Abstract: A disc cartridge includes a shell for storage of a recording medium taken in the form of a disc having a center core formed at the center thereof. The disc has signal recording portions formed around the center core on the opposite surfaces thereof. The shell has opposite inner surfaces facing to each other to define a disc receipt space containing the disc supported for rotation therein between the inner surfaces. The shell has a chucking hole through which the center core of the disc is exposed and read-write windows through which the respective signal recording portions are exposed. A shutter is mounted for sliding movement on the shell to open and close the read-write windows. A pair of slippery films are formed on the respective inner surfaces.

Abstract: A disc cartridge designed to prevent mistaken loading on a recording and/or reproducing apparatus in which only a disc cartridge having different specifications can be loaded. The disc cartridge includes a main cartridge body portion 13 for housing a magnetic disc 11 having different specifications from those of a magnetic disc housed in a conventional disc cartridge 101, and recording/reproducing apertures 26, 27 formed in the main cartridge body portion 13 so as to be faced by a recording/reproducing unit provided on the recording/reproducing apparatus. The disc cartridge also includes a shutter member 28 for opening/closing the recording/reproducing apertures 26, 27 and loading regulating portions 51, 52 provided on the main cartridge body portion 13 for regulating loading of the main cartridge body portion on the recording/reproducing apparatus 110 in which only the conventional disc cartridge 101 can be loaded.

Abstract: A recording medium device adapted so that a recording medium on which information signals are recorded is accommodated. This recording medium device comprises a cartridge body within which the recording medium on which information signals are recorded is accommodated, and an erroneous recording prevention member including a portion of detection detected by a detection mechanism of the recording/reproduction unit side, and attached to the cartridge body so that it can be moved within the range between a first position where the portion of detection is detected by the detection mechanism and a second position where it is not detected by the detection mechanism.

Abstract: A belt-drive tape cartridge includes tape guides arranged on both sides of a recess of a base plate for receiving a magnetic head, each tape guide having flanges formed at upper and lower ends thereof, and a drive roller arranged to be offset with respect to the center position of the base plate. A reproducing apparatus adapted to belt-drive tape cartridges includes a drive capstan roller having a diameter increased in accordance with the offset amount of the drive roller of the tape cartridge, or arranged to be offset with respect to the center position of a cartridge compartment.

Abstract: A tape cassette includes a cassette housing having formed therethrough a hub drive shaft insertion aperture, a slider slidably mounted on the lower surface of the casette housing so as to open and/or close the hub drive shaft insertion aperture or the like and a slider locking piece for locking the slider at a predetermined position in which the slider locking piece is molded together with the main body of the cassette housing by dichromatic molding.

Abstract: A laser drive circuit for modulating a laser beam intensity emitted from a laser device to a maximum power and a minimum power in accordance with a first and second values of a binary signal comprises: a photo-detector for detecting the laser beam emitted from the laser device to produce a detection output signal; a first differential amplifier for producing a maximum error detection signal representing a difference between the detection output signal applied thereto and a maximum reference; a second differential amplifier for producing a minimum error detection signal representing a difference between the detection output signal applied thereto and a minimum reference, a first sample and hold circuit for sampling and holding the maximum error detection signal at a timing of the first value of the binary signal and outputting the same as a maximum error signal; a second sample and hold circuit for sampling and holding the minimum error detection signal at a timing of the second value of the binary signal and

Abstract: A magnetic tape cassette having an upper part and a lower part combined during assembly to form a unitary housing, a front lid that can be moved between an open position and a closed position, a pair of reel hubs rotatably mounted within the cassette housing for winding a tape thereon, and a hub lock member for locking the pair of reel hubs, includes a structure to temporarily secure the hub lock member to the upper part in a range outside a normal movable range of the hub lock member. This structure is formed as a cut-away portion having a predetermined width in its movable direction formed on the hub lock member and a stopper portion formed on the lower part in association with the cut-away portion, so that an edge of the cut-away portion comes in contact with the stopper portion to prevent the hub lock member from being once again secured to the upper part once the housing is assembled.

Abstract: In a camera system including an electronic flash apparatus, a main capacitor of the flash apparatus is charged for a predetermined time interval, in response to a preparatory operation such as a first stroke of a release button. During this time interval, operation of an automatic distance measuring device, an automatic exposure controlling device and an object luminance discriminating circuit is prevented. A warning device warns a photographer that the main capacitor is insufficiently charged. Several voltage detectors detect different voltage levels of the main capacitor and produce detection signals for inhibiting the operation of the warning device and/or preventing further charging of the main capacitor.

Abstract: A method for analyzing a lipid peroxide, which comprises reacting a lipid peroxide with an aromatic phosphine compound of the formula: ##STR1## wherein each of R.sub.1 to R.sub.3 is an aromatic group, in a solvent, to form an aromatic phosphine oxide and observe any fluorescence of the aromatic phosphine oxide.

Abstract: A lens shutter camera comprises a mode signal output device for outputting either a first flash mode signal or a second flash mode signal, a shutter driving device for effecting the opening movement of the lens shutter slowly and effecting the closing movement of the lens shutter quickly when the first flash mode signal is being outputted, and for effecting both of the opening and closing movements of the lens shutter slowly when the second flash mode signal is being outputted, and a flash start signal output device for outputting a flash start signal during the opening movement of the lens shutter when the first flash mode signal is being outputted, and for outputting the flash start signal during the closing movement of the lens shutter when the second flash mode signal is being outputted.

Abstract: A distance-measuring apparatus comprises a first detecting device for detecting a distance to a central portion of an object field corresponding to a photographing frame and generating data corresponding to a detected distance, a second detecting device for detecting distances to a plurality of peripheral portions of the object field except for the central portion and generating data corresponding to detected distances, and an operating device for operating the first and second detecting devices. The oeprating device has a first operation step of operating the first detecting device and a second operation step of operating the second detecting device. The first step is executed to determine the detected distance to the central portion. The execution of the second step depends on the determination result and may produce an average peripheral distance output or a shortest peripheral distance output for driving a phototaking lens.

Abstract: In a camera system including an electronic flash apparatus, a main capacitor of the flash apparatus is charged for a predetermined time interval, in response to a preparatory operation such as a first stroke of a release button. During this time interval, operation of an automatic distance measuring device, an automatic exposure controlling device and an object luminance discriminating circuit is prevented. A warning device warns a photographer that the main capacitor is insufficiently charged. Several voltage detectors detect different voltage levels of the main capacitor and produce detection signals for inhibiting the operation of the warning device and/or preventing further charging of the main capacitor.

Abstract: There is disclosed a zooming control device for a camera, enabling photographing with a constant magnification of an object, and still avoiding overflowing of an object from the photographed frame in zooming of the lens. The frame is divided into plural areas, and there is discriminated whether an object is present only in the central area, or also in the peripheral area or areas. In the former case the lens is zoomed to achieve a preset image magnification, but, in the latter case, the zooming is limited in order to avoid overflowing of an object from the frame.

Abstract: An aromatic phosphine compound of the formula: ##STR1## wherein each of R.sub.1 to R.sub.3 is an aromatic group, or an oxide thereof.

Abstract: A magnetic tape cassette is provided with a pivotal closure lid pivotably secured to both sides of a casing for movement between a closed position, in which the front opening of the casing, through which a magnetic tape is accessible for loading onto a rotary head, is covered, and an open position wherein the closure lid is pivoted away from said opening to expose the tape while the cassette is in use. The magnetic tape cassette is also provided with a sliding closure member slidably mounted on the bottom of the casing and cooperative with the aforementioned pivotal closure lid. The sliding closure member is in a closed position while the pivotal closure lid is in its closed position, in which it covers a bottom clearance through which a device constituting part of a tape holding system is inserted, and in an open position while the pivotal closure lid is in its open position to allow the aforementioned device of the tape handling system to reach into the casing through the bottom clearance.