Abstract: An anti-static measure is taken against tape guide parts of a magnetic tape cassette by forming the tape guide parts of a conductive material and so on. An antistatic measure against a lid, an upper shell, a transparent window and a lower shell is taken by coating at least either of inside and outside of each of the lid, the upper shell, the transparent window and the lower shell with an anti-static film. A magnetic layer of a magnetic tape has a thickness of from 10 nm or more to 100 nm or less, and also contains oxygen in an amount of from 20 atm % or more to 30 atm % or less in a whole magnetic layer. An information recording surface of the magnetic tape has also a surface resistance of from 103&OHgr;/inch2 or more to 1012&OHgr;/inch2 or less.

Abstract: A magneto-optical recording medium 11 has, in order from the laser irradiation side, a second auxiliary magnetic film 4, first auxiliary magnetic film 5, and magneto-optical recording film 6. First and second auxiliary magnetic films 4 and 5 change from in-plane magnetization to perpendicular magnetization when their respective critical temperatures TCR1 and TCR2 are exceeded. The Curie temperatures TC0, TC1 and TC2 of the magneto-optical recording film and the first and the second auxiliary magnetic films 4, 5 and their critical temperatures TCR1 and TCR2 satisfy the relationship: room temperature<TCR2<TCR1<TC0, TC1,TC2. The first auxiliary magnetic layer has a film thickness greater than the thickness of the magnetic wall. In response to irradiation by the reproducing light beam, recording magnetic domain 22 of magneto-optical recording film 6 is transferred, with size reduction, to first auxiliary magnetic film 5 and is then transferred, with magnification, to second auxiliary magnetic film 4.

Abstract: A pair of reels of a magnetic cassette tape and a pair of reel supports of a magnetic tape drive comprise a conductive material as an antistatic treatment. Further, a head substrate and a projection substrate of a head drum comprise a conductive material having a resistance of 1×1010 &OHgr; or less and are connected to a metal base so as to be at the ground potential via the metal base and a rotating drum. These antistatic treatments allow static electricity charged on a magnetic tape to be discharged to the head substrate and the protection substrate without flowing to a magneto-resistive (MR) element, thereby preventing the electrostatic discharge breakdown of the MR element.

Abstract: When a magneto-resistance effect type magnetic head is used as a magnetic tape reproducing head, a contact noise which occurs when a magnetic tape contacts with a magneto-resistance effect element poses a problem. The invention provides a magneto-resistance effect type magnetic head which hardly causes such contact noise and a magnetic signal reproducing apparatus comprising such magneto-resistance effect type magnetic head. A part where a magneto-resistance effect element is formed in a magnetic tape sliding face of the magneto-resistance effect type magnetic head is formed to be a concave of 3 to 30 nm in depth. The contact noise hardly occurs even when the magnetic tape is slid by forming the part where the magneto-resistance effect element is formed into the concave. Still more, almost no output drops due to a spacing loss and a fully large reproduced output may be obtained by defining the depth t1 of the concave within a range of 3 to 30 nm.

Abstract: A magneto-optical recording medium 11 is irradiated with a reproducing light beam 13 so that only a minute magnetic domain 313b, which is subjected to recording in a recording layer 18 and which is smaller than ½ of a spot radius of the recording light beam 13, is selected by a gate layer 17 and transferred to a magnetic domain magnifying and reproducing layer 3. The magnetic domain transferred to the magnetic domain-magnifying and reproducing layer 3 is magnified by using a magnifying and reproducing magnetic field 411 of an alternating magnetic field. A large reproduction signal is obtained from the magnified magnetic domain 419, and the minute magnetic domain can be subjected to reproduction at a high resolving power and at a high SIN ratio. The magnified magnetic domain 419 is reduced by using a reducing reproducing magnetic field 415 of the alternating magnetic field. The gate layer 17 has a thickness which is not less than a thickness of a magnetic wall of the magnetic domain.

Abstract: A magnetic tape drive apparatus in which data are recorded/reproduced on/from a magnetic tape by recording/reproducing magnetic heads which are disposed on a head drum and moved on a circular locus comprising cleaning means for removing deposit such as stain adhering to a magnetic head to clean the magnetic head, error rate detection means for detecting the error rate of the magnetic tape when data are recorded/reproduced onto/from the magnetic tape, and error rate storage means for storing the error rate detected by the error rate detection means, wherein when the error rate detected by the error rate detection means is increased at a predetermined rate with respect to an error rate which is detected at any time point and stored, the magnetic head is cleaned by the cleaning means.

Abstract: A helical-scan system performs recording and reproduction on a magnetic tape by using a recording and reproducing head 5 comprising m magnetic head elements 7 (where m is 2 or larger integer). During this recording and reproduction, the following relationships are satisfied among a track width W for each of the head elements 7, a track pitch Tp between the head elements 7, and a feed amount S for a magnetic tape 6.

Abstract: A lens position adjusting method for a zoom lens includes at least two movable lens groups, one lens group being primarily utilized for focusing and the other lens group being primarily utilized for magnification, wherein an object at a predetermined distance is in-focus when each movable lens group is positioned at each of respective initialized positions thereof with the zoom lens being set at a first focal length, and wherein each movable lens group is moved to vary magnification in accordance with a moving amount from the initialized positions of the movable lens groups.

Abstract: An auto-focusing device of a camera includes a photographic lens having a focusing lens group guided along an optical axis, a stepping motor for moving the focusing lens group along the optical axis to bring an object into focus; and a controller for controlling the stepping motor to rotate stepwise when the depth of focus is smaller than a predetermined value and for controlling the stepping motor to rotate the rotor by even-numbered steps when the depth of focus of the photographic lens is greater than the predetermined value.

Abstract: A stepping motor driving apparatus for a camera includes 1-2 phase excitation type stepping motors and a drive controller for driving and stopping the stepping motors so that the driven stepping motors are stopped always at a detent position.

Abstract: A stepping motor driving apparatus for a camera having a 1-2 phase excitation type stepping motor which is driven by a 1-2 phase excitation in response to a drive signal includes a drive control device for stopping the stepping motor at a 1-phase excitation position by de-energizing the stepping motor at the 1-phase excitation position and for stopping the stepping motor at a 2-phase excitation position while maintaining the excitation in a high precision drive control in which the stepping motor is driven at high precision. The drive control device stops the stepping motor by de-energizing the stepping motor always at the 1-phase excitation position in a normal drive control in which no precise drive control of the stepping motor is needed.

Abstract: A time-sharing drive apparatus for a camera having a plurality of motors includes a motor drive control system which alternately drives the motors in a time-sharing control. When the camera includes a zoom lens provided with a first stationary lens group, a second movable lens group and a third movable lens group, the motors are composed of a first motor which opens and closes a diaphragm of the zoom lens, a second motor which moves the second lens group, and a third motor which drives the third lens group. The motor drive control system which drives the first, second and third motors is controlled via a time-sharing system.

Abstract: An automatic focusing apparatus of a camera includes a photographing lens having a focusing lens group and a focus control mechanism which moves the focusing lens group to a hyper-focal distance position when no effective object distance is obtained.

Abstract: A drive apparatus for a zoom lens barrel having at least two movable zooming lens groups which are moved upon zooming, comprising: two lens frames which support the movable zooming lens groups, two cam pins integral with the lens frames and extending in the same direction, two parallel rotatable drive plates which are provided with cam grooves in which the cam pins are fitted, and two drive units which drive the respective drive plates upon zooming. The cam profile of the cam grooves of the drive plates is such that the movable zooming lens groups are moved in predetermined directions by the rotation of the drive plates during zooming.

Abstract: A drive apparatus for a zoom lens barrel having a plurality of movable lens groups, comprising: a lens barrel body which supports lens frames of the movable lens groups to move linearly in the optical axis direction, a lens drive unit which is assembled independently of the lens barrel body, driven pins provided on the lens frames and projecting outward from the barrel body in the same direction, and a plurality of drive members having engaging portions engageable with the driven pins. The drive motor which independently drives the drive members and drive gears connects the drive members to the drive motor, is provided in said lens drive unit. The lens drive unit is secured to the lens barrel body in a state that the driven pins projecting from the lens barrel body are engaged by the engaging portions of the corresponding drive members of the lens drive unit.

Abstract: A motor-driven diaphragm apparatus for a lens barrel having a plurality of lens groups and a diaphragm mechanism, in which a diaphragm block provided with a plurality of diaphragm blades and a diaphragm-opening-and-closing ring which opens and closes an aperture defined by the diaphragm blades, is integrally provided with a diaphragm-opening-and-closing arm that projects from the diaphragm block and that is provided with a radial association groove for the diaphragm-opening-and-closing ring. Also provided are front and rear lens barrel blocks which support the lens groups, wherein said diaphragm block is held between the front and rear lens barrel blocks so that the diaphragm-opening-and-closing arm and the association groove project outwardly.

Abstract: A drive apparatus for a zoom lens barrel having at least two movable lens groups, one of which is used also as a focusing lens group comprising: a pair of lens frames which respectively hold the two movable lens groups, a pair of driven pins which are integrally provided on the lens a drive cam plate which is provided with a pair of cam surfaces which engage with the corresponding driven pins and which is rotatable about an axis, a rack plate which is supported to move in the optical axis direction of the movable lens groups and which is provided with an engaging portion which engages with the driven pin of the movable lens group that is used also as a focusing lens group, a first drive mechanism which includes a first motor for swinging the drive cam plate in the forward and reverse directions, and a second drive mechanism which includes a second motor for moving the rack plate without having an influence on the angular position of the drive cam plate.

Abstract: A drive apparatus for a zoom lens barrel having at least two movable lens groups, one of which is used also as a focusing lens group, comprising a pair of lens frames which respectively hold the two movable lens groups, a pair of driven pins which are integrally provided on the lens frames, a drive cam plate which is provided with a pair of cam surfaces which engage with the corresponding driven pins and which is rotatable about an axis, a drive mechanism which includes a motor for driving the drive cam plate, and a detection mechanism which detects the angular position of the drive cam plate. One of the cam surfaces that corresponds to the movable lens group, other than the focusing lens group, is defined by a stepped cam surface having discrete sections which are adapted to set the focal length discretely, so that no movement of the movable lens group takes place in the range of the angular position of the drive cam plate corresponding to the discrete sections.

Abstract: A drive apparatus for a zoom lens barrel, in which at least two movable zooming lens groups are moved upon zooming, includes lens frames which respectively hold the two movable zooming lens groups, two parallel drive plates which are provided with cam grooves and which are pivoted to a common shaft to move the two movable zooming lens groups, a pair of drive gears which are in mesh with corresponding sector gears of the drive plates, and two drive mechanisms which individually drive the drive gears upon zooming.

Abstract: A zoom electronic camera comprising a lens casing which contains therein a zoom lens having at least two movable zooming lens groups, a drive mechanism including a motor for driving the movable zooming lens groups, a solid state image pickup device which picks up an object image through the zoom lens, a lens CPU which controls the drive mechanism including the motor, and a body casing which contains therein a signal processing circuit which processes an image signal supplied from the solid state image pickup device and which is relatively rotatably connected to the lens casing through a cylindrical portion about which the relative rotation takes place. The zoom lens, the drive mechanism including the motor and the solid state image pickup device are located on the side of the cylindrical portion opposite to the lens CPU.