Abstract: A readhead control mechanism serves to control a readhead included in an optical encoder that measures a mechanical displacement between a fixed portion and a movable portion by reading out a gradation mark on a scale provided on the fixed portion, by using the readhead that is provided on the movable portion. The readhead mechanism includes a securing member that secures the readhead onto the movable portion, an actuator that is directly or indirectly secured onto the readhead to shift the readhead in an approaching direction or in a distancing direction, and an actuator controller that controls the actuator to maintain a constant distance between the readhead and the scale.

Abstract: A readhead control mechanism serves to control a readhead included in an optical encoder that measures a mechanical displacement between a fixed portion and a movable portion by reading out a gradation mark on a scale provided on the fixed portion, by using the readhead that is provided on the movable portion. The readhead mechanism includes a securing member that secures the readhead onto the movable portion, an actuator that is directly or indirectly secured onto the readhead to shift the readhead in an approaching direction or in a distancing direction, and an actuator controller that controls the actuator to maintain a constant distance between the readhead and the scale.

Abstract: In one embodiment, an optical read/write apparatus includes first and second optical pickups 2a, 2b and a control section. The first optical pickup 2a includes a first lens 3a that condenses a light beam emitted from a first light source onto an optical storage medium, and a first lens actuator that can shift the first lens 3a in a track crossing section with respect to a middle position. The second optical pickup 2b includes a second lens 3b that condenses a light beam emitted from a second light source onto the optical storage medium, and a second lens actuator that can shift the second lens 3b in the track crossing section with respect to the middle position. The control section makes the lens actuators operate so that as the magnitude of shift of the first lens 3a increases, that of the second lens 3b decreases.

Abstract: In one embodiment, an optical read/write apparatus includes first and second optical pickups 2a, 2b and a control section. The first optical pickup 2a includes a first lens 3a that condenses a light beam emitted from a first light source onto an optical storage medium, and a first lens actuator that can shift the first lens 3a in a track crossing section with respect to a middle position. The second optical pickup 2b includes a second lens 3b that condenses a light beam emitted from a second light source onto the optical storage medium, and a second lens actuator that can shift the second lens 3b in the track crossing section with respect to the middle position. The control section makes the lens actuators operate so that as the magnitude of shift of the first lens 3a increases, that of the second lens 3b decreases.

Abstract: In a magnetic head, a multilayer film is disposed, the multilayer film including metal magnetic films and non-magnetic films that are alternately laminated, and a boundary between the multilayer film and a magnetic oxide substrate or a non-magnetic substrate on which the multilayer film is to be formed is parallel with a gap section at a surface of the magnetic head for sliding with respect to a magnetic recording medium. The metal magnetic films constituting the multilayer film have two or more types of thickness, or the metal magnetic films constituting the multilayer film have a uniform thickness, and the uniform thickness t satisfies t<v×cos?/fmax, where v denotes a relative speed of the head to the recording medium, fmax denotes an upper limit of frequencies to be used and ? denotes an azimuth angle. With this configuration, a magnetic head having a suppressed pseudo signal and reduced noise can be provided, and a magnetic recording/reproducing device incorporating this magnetic head can be provided.

Abstract: In a magnetic head, a multilayer film is disposed, the multilayer film including metal magnetic films and non-magnetic films that are alternately laminated, and a boundary between the multilayer film and a magnetic oxide substrate or a non-magnetic substrate on which the multilayer film is to be formed is parallel with a gap section at a surface of the magnetic head for sliding with respect to a magnetic recording medium. The metal magnetic films constituting the multilayer film have two or more types of thickness, or the metal magnetic films constituting the multilayer film have a uniform thickness, and the uniform thickness t satisfies t<v×cos ?/fmax, where v denotes a relative speed of the head to the recording medium, fmax denotes an upper limit of frequencies to be used and ? denotes an azimuth angle. With this configuration, a magnetic head having a suppressed pseudo signal and reduced noise can be provided, and a magnetic recording/reproducing device incorporating this magnetic head can be provided.

Abstract: The present invention is intended to obtain a reflector supporting mechanism capable of preventing axial deviation of a sleeve of a reflector side and a socket of a supporting mechanism side and facilitating remounting of the reflector supporting mechanism from/onto the reflector. The reflector supporting mechanism according to the present invention comprises a cylindrical sleeve, a socket which is provided with a flange and crowned at its tapered side part and adapted to come in contact with the sleeve by a side contact point and a flange part, and a universal joint provided on the socket.

Abstract: In an optical disc recording-reproducing apparatus using a standard optical disc enclosed in a cartridge, and optical plate for correcting various aberrations generated by a focusing lens is comprised therein in order to allow use of a double recording optical disc enclosed in the standard cartridge of the same size, the optical plate is placed in front of a focusing lens when the double recording optical disc is used, and is removed from the front of the focusing lens when the standard optical disc is used.

Abstract: A mirror support apparatus for a reflecting telescope employs an astatic lever with a counterweight to provide radial support and drives the lever parallel to the telescope axis to provide axial support. The axial supporting force is delivered to the mirror through a load cell which is located between the end of the lever and the mirror directly or indirectly (through a linking rod or diaphragms). The load cell therefore detects the entire axial force applied, and does not detect radial components even if the mirror shifts in relation to its cell. The lever is driven in the axial directing through a spring which helps achieve fine adjustment. A damping device can be added to damp vibrations. The counterweight can be attached to the lever by another spring to compensate for lever bending effects. This apparatus is capable of providing both axial and radial supporting forces with the high precision required by very large, thin telescope mirrors.

Abstract: In a mirror supporting apparatus, a lever pivots the center of gravity of the mirror, whereby performing exactly the same motion with respect to a mirror provided with a universal joint at the center of gravity of the mirror. Therefore, the same effect as that of conventional mechanism is obtained without provision of a hole in the mirror. Furthermore, a counter weight is secured to the mirror so as to position a substantial center of gravity of the mirror outside of the mirror, whereby obtaining a similar effect.

Abstract: A proportional flow control valve is disclosed in which an opening of a variable orifice formed by a proportion solenoid and a pilot spool is varied to vary a flow rate of fluid in a restriction passage by-passing a plunger of a main control portion connected to the variable orifice and hence a pressure difference across the plunger to thereby vary a position of the plunger. The pilot spool is inserted into a sleeve and has one end formed with a poppet portion which is able, with an aid of a spring, to contact with a valve seat formed in one end of the sleeve. The pilot spool is by-passed by a restriction passage and the poppet portion becomes in intimate contact with the valve seat when a force of the proportion solenoid in zero and the variable orifice is opened and connected through the poppet portion and the restriction passage to a drain when the pilot spool is moved by the force of the proportion solenoid.

Abstract: Disclosed is a method for preparing a light-sensitive cuprous halide emulsion which comprises reducing cupric ions by an ascorbic acid derivative represented by the general formula: ##STR1## wherein R is a hydrogen atom or a hydroxyl group, and n is an integer of 1 to 4, provided that R is a hydroxyl group when n is 1, or its alkali metal salt, in the presence of halogen ions.

Abstract: An image-forming method wherein a photosensitive material comprising a support having a photosensitive copper (I) halide emulsion that contains silver halide and which has grains of copper (I) halide crystal dispersed in a binder is subjected to imagewise exposure and development with an alkaline solution is disclosed. The imagewise exposure is effected either in a dry or wet state. The alkaline solution contains compounds selected from at least two of the following three groups: (A) a group consisting of .alpha.-amino acids, .alpha.

Abstract: A multilayer silver halide color photographic material submissive to rapid silver removal containing, in at least one layer, a salt of at least one compound selected from the group consisting of organic compounds containing sulfur such as, for example, mercaptotriazoles and the like and heterocyclic compounds containing no sulfur such as, for example, imidazole compounds and the like with at least one heavy metal ion such as, for example, ions of silver, zinc, cobalt and the like.

Abstract: In an optical disc recording-reproducing apparatus using a standard optical disc enclosed in a cartridge, and optical plate for correcting various aberrations generated by a focusing lens is comprised therein in order to allow use of a double recording optical disc enclosed in the standard cartridge of the same size, the optical plate is placed in front of a focusing lens when the double recording optical disc is used, and is removed from the front of the focusing lens when the standard optical disc is used.