摘要:
An optical apparatus reproduces an information signal recorded as pits along track turns of a rotating recording medium. At least one kind of reference signal is recorded along and overlapping the lateral edges of the adjacent track turns of the information signal. A light source projects a first light beam onto the surface of the recording medium to simultaneously reproduce the information and reference signals. A detector responds to reflections of the projected light which includes and reproduces the information signal and the reference signal. The optical system is controlled so that the center of the light beam coincides with the centerline of the track. A circuit separates the reference signal from the total reproduced signal and produces a tracking control signal in response thereto.The optical system also projects a second light beam onto the recording medium and its reflected component is used for focus control. The depth of focus of the objective lens is substantially equal to or less than two times the pit depth, so that the focussing point of the reproduction light beam coincides with the upper surface of the rotating recording medium or the bottom surface of the pits. Thereby resulting in fine reproduction without introducing second-order harmonic distortion.
摘要:
An information signal recording medium of rotary type has a flat surface with successions of pits formed therein as respective concavities in response to an information signal. The successions of pits constitute respective circular tracks of a specific pitch. Each it is formed with a width, equal to the width of a track, which is substantially equal to or greater than said pitch of the track.
摘要:
An information signal recording medium of rotary type has a flat surface with first succession of pits formed therein as respective concavities in response to a first signal and with second succession of pits formed therein as respective concavities in response to a second signal. The second succession of pits are formed at positions substantially intermediate between the centerlines of adjacent tracks formed by the first succession of pits. Each pit of the first succession of pits and each pit of the second succession of pits respectively have widths W1 and W2 and depths D1 and D2, wherein the relationships between the widths and said depths are so selected that the levels L1 and L2 of the first and second signals which are reproduced when the first and second succession of pits are traced and thereby reproduced by reproducing means will be such that the level L1 is greater than the level L2, and the difference between the levels L1 and L2 will be greater than a specific level difference.
摘要:
A recording system records a television video signal of 60 fields per second converted from a signal of the picture image content of a cinematographic film for projection at 24 film frames per second, in a manner such that the video signal has parts in each of which the picture image content of one and the same film frame continues during at least 4 fields thereof, along a spiral track on a rotating recording medium rotating at a rotational speed of 900 revolutions per second at a recording rate of 4 fields per revolution of the recording medium. The rotating recording medium thus recorded has a part on which the picture image content of one and the same film frame is recorded over a part of a length of the track corresponding to at least one revolution of the recording mediu
摘要:
A reproducing stylus traces a track of a recording medium, in which track an information signal is recorded as variations of geometrical shape, and reproduces as variations in capacitance the information signal thus recorded. The reproducing stylus comprises a reproducing stylus main structure having a tip part with a flat sliding contact face for slidingly contacting at least one track of the recording medium at a time, and an electrode secured to the reproducing stylus main structure at the tip part thereof and adapted to trace one track and reproduce the information signal as the variations in capacitance in accordance with the variations in geometrical shape. The electrode has over a specific distance over the tip part of the stylus main structure from the extreme tip thereof, a width in the width direction of the track which is less than the width of the track. The extreme tip of the electrode has a flat or linear tip end contacting the track.
摘要:
A reproducing stylus traces a track of a recording medium, in which track an information signal is recorded as variations of geometrical shape, and reproduces as variations in capacitance the information signal thus recorded. The reproducing stylus comprises a reproducing stylus main structure having a tip part with a flat sliding contact face for slidingly contacting at least one track of the recording medium at a time, and an electrode secured to the reproducing stylus main structure at the tip part thereof and adapted to trace one track and reproduce the information signal as the variations in capacitance in accordance with the variations in geometrical shape. The electrode has over a specific distance over the tip part of the stylus main structure from the extreme tip thereof, a width in the width direction of the track which is less than said width of the track. The extreme tip of the electrode having a flat or linear tip end contacting the track.
摘要:
A reproducing stylus traces a track of a recording medium, in which track an information signal is recorded as variations of geometrical shape, and reproduces as variations in capacitance the information signal thus recorded. The reproducing stylus comprises a reproducing stylus main structure having a tip part with a flat sliding contact face for slidingly contacting a plurality of track of the recording medium at a time, and an electrode secured to the reproducing stylus main structre at the tip part thereof and adapted to trace one track and reproduce the information signal as the variations in capacitance in accordance with the variations in geometrical shape. The electrode has over a specific distance over the tip part of the stylus main structure from the extreme tip thereof, a constant width in the width direction of the track which is less than the width of the track. The extreme tip of the electrode has a flat or linear tip end contacting the track.
摘要:
For detection of signals recorded in the form of minute pits along tracks as capacitance variations, a record stylus is disclosed as comprising a shank having a portion of cross-sectional area decreasing toward one end of the stylus. A diamond, partially embedded in the shank, has a decreasing cross-sectional area toward said end of the stylus as a continuation of the decreasing cross-section of the shank. The bottom and rear face of the diamond are inclined so that the adjacent angle therebetween is smaller than 90 degrees. An electrode attached to the rear face of the diamond extends from the bottom of the diamond toward the other end of the stylus. The electrode is thus inclined in a direction opposite to the direction of movement of the recording medium to provide less concentration of electric lines of force on the rear bottom edge thereof.
摘要:
A capacitance detection type record stylus comprises a conductive shank and a diamond partially embedded in the shank so that the diamond projects downwardly from one end of the shank. The shank is formed with a bottom face for making slidable contact with the disk record. The shank and diamond are formed with a pair of common rear faces inclined with respect to the axis of the stylus to define an electrode forming face therebetween which extends from the bottom face of the diamond partially into the shank. The electrode forming face is inclined at an acute angle with respect to the axis so that the lower end of the electrode forming face is located at a point forward with respect to the upper end thereof and subtends at the lower end thereof at such an angle that the diamond can be lapped without causing defects to occur on the lapped surfaces. The electrode forming face is entirely covered by a conductive layer so that the latter establishes electrical connection with the shank to allow signals detected by the electrode to pass through the shank to an external circuit.
摘要:
A cosmetic treatment apparatus comprises a discharge lamp, a capacitor, and a current controller. The capacitor supplies an electric current for the discharge lamp. The current controller controls the electric current flowing from the capacitor to the discharge lamp. In a first stage of the cosmetic treatment, the current controller performs a constant current control operation. In this operation, the current flowing to the lamp does not vary with variations of the capacitor voltage. In the end stage of the treatment, the current is lower, and it decreases with the capacitor voltage.