A position-detecting device comprising a scale, a first photo-interrupter, and a second photo-interrupter. The scale is attached to a movable member, and has a plurality of slits arranged at regular intervals. Each photo-interrupter includes a light source and a light detector, which are located at opposing sides of said scale, respectively. The first and second photo-interrupters are spaced apart such that when the scale moves, they generate, respectively, a first signal and a second signal which have a phase difference of .pi./2. These signals are processed, thereby to determine the position of the movable member with high accuracy.
An improved CD transport apparatus wherein said apparatus incorporates a digital signal processor for processing digital audio signals read from a compact disc. The digital signal processor additionally serves to alter the gain of the digital audio signal when various control operations are commanded by the user so as to minimize audibility of extraneous noises which accompany such control operations and the potential damage which may be caused to audio components. The improved CD transport apparatus further includes a cueing switch for causing movement of the CD pickup only during movement of the cueing switch and a shuttle switch for causing movement of the CD pickup only when the shuttle switch is in an active position.
An information processing apparatus includes a main base and a drive base on which support frames are erected to face each other. A pair of parallel guide shafts are supported on the frames and extend in the radial direction of an optical disk. An optical head is supported by the guide shafts to be movable along the shafts. Insulating tape is wound around each end of the guide shaft to electrically insulate the head from the base, thereby preventing external noise from being transmitted to the head via the base. The drive base is further insulated from the main base by insulating seals interposed between the main base and the drive base and by insulating collars through which screws attach the drive base to the main base.
An objective lens drive apparatus applicable to an optical disk apparatus includes a base member disposed so as to oppose a recording surface of an optical disk and so as to be movable in a direction of a radius of the optical disk, a support mechanism supporting an objective lens on the base member and so as to be movable in the direction of the direction of the radius of the optical disk. The objective lens drive apparatus also includes a drive mechanism acting upon the support mechanism to move the objective lens on the base member, a displacement detector detecting a displacement of the objective lens on the base member, a controller controlling the drive mechanism so that the objective lens is maintained at a required position on the base member.
An optical head driving apparatus is constructed to move an optical head along the radius of an information storage medium which is rotating, to face the optical head to a predetermined position of the information storage medium where the optical head carries out a predetermined information process with respect to the information storage medium. The optical head driving apparatus comprises at least one circular bearing and at least one elliptic bearing. The bearings are disposed on opposite sides of a center of gravity of the optical head, respectively. A first guide shaft extends to pass through the circular bearing while a second guide shaft extends to pass through the elliptic bearing. The bearings and the first and second guide shafts constitute a guide means to movably support the optical head. The optical head driving apparatus further comprises an optical head moving means for controlling the movement of the optical head. A moving portion of the optical head moving means is connected to the optical head such that a center of gravity of the moving portion of the optical head moving means is positioned substantially under the first guide shaft.
An image-forming apparatus is disclosed. The apparatus includes a paper-carrying belt for carrying paper, drive unit for driving the paper-carrying belt, a scale provided on the paper-carrying belt that indicates position information and that partially has a scale seam portion, position-detection unit for reading the position information from the scale, and control unit for generating position information from an output of the position-detection means and controlling the drive means based on the position information in order to drive and control the paper-carrying belt.A first sensor and a second sensor for reading the position information from the scale are provided as the position-detection means, and the first sensor and the second sensor are provided in order to be separated by a distance which is more than or equal to a gap width of the scale seam.The control is configured to use as position information what is combined after putting weightings on a first sensor output which is output from the first sensor and a second sensor output which is output from the second sensor.
