Sony Corporation

Masayuki Kondo

Tadashi Ozue

Yoshio Kishi

Takuya Kaeriyama

Kenji Kawakami

Masanori Kimizuka

Disclosed herein is a rotary head drum unit including a cylindrical drum surface and a magnetic head for recording/reproducing a signal to/from a magnetic tape running along the drum surface. The magnetic head has a tape sliding surface adapted to come into sliding contact with the magnetic tape. The tape sliding surface of the magnetic head is positioned at a level lower than the height of the magnetic tape flying above the drum surface. The magnetic tape is brought into contact with the tape sliding surface by negative pressure. With this configuration, an increase in contact pressure of the magnetic tape sliding on the tape sliding surface of the magnetic head can be prevented and the contact pressure can be uniformed to thereby prevent a reduction and variations in magnetic recording or reproduction output.

Negative pressure type rotary head drum unit and magnetic tape drive using the same

A tape guide arrangement for a tape recording and reproducing apparatus comprises a cylinder device provided with a rotary head, a first slant guide member for feeding a tape to the cylinder device, a second slant guide member for guiding the tape from the cylinder device into a predetermined direction, a first rotary guide member for guiding the tape to the first slant guide member, and a second rotary guide member for causing the tape from the second slant guide member to pass through a predetermined position. Each of the first and second rotary guide members is provided with an axis of rotation substantially perpendicular to an imaginary plane defined in relation to positions which are set on the first and second slant guide members and the cylinder device, respectively, and through which an elongated edge of the tape passes. Further, the first rotary guide member is so positioned that the tape is led to the first rotary guide member with a first gradient in reference to the imaginary plane and then guided to the first slant guide member with a second gradient opposite in up and down to the first gradient, and the second rotary guide member is so placed that the tape is guided to the second rotary guide member from the first slant guide member with a third gradient in reference to the imaginary plane and then leaves for the predetermined position with a fourth gradient opposite in up and down to the third gradient.

Guide arrangements for maintaining magnetic tape in proper position

A brushless DC motor includes a permanent field magnet secured to a rotor and having a radially directed annular surface, and two phase coil elements in the form of a sectorial loop secured to a stationary stator and disposed in a plane parallel to the annular magnet surface, the loop having circumferentially extending portions which are in inner and outer relation in respect to the center of the annular magnet surface, with the magnet and each coil element being relatively rotatable about the axis of the rotor. The mean radial distance f between the inner and outer circumferentially extending portions of each coil element and the radial width b of the annular surface of the magnet are selected as that the ratio b/f is within the range of 0.8 to 1.2 for maximizing the viscosity factor .mu. of the motor. In addition to providing the above ratio within the stated range or as an alternative thereto, the mechanical viscosity factor .mu. can be maximized by providing a reduced air gap d'=.sqroot.2d/.sqroot.ab, in which a is the mean radius of the magnet, d is the size of the air gap between the annular magnet surface and the stator, and d' has a value within the range of 0.15 to 0.30.

Growing community of inventors

Kanagawa, Japan

Masayuki Kondo