In a video tape recorder having rotary recording, auxiliary and erasing heads, a circuit for short circuiting the auxiliary head during erasing

• US 4,743,985 A
• Filed: 06/03/1986
• Issued: 05/10/1988
• Est. Priority Date: 06/19/1985
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sato, Hiroyuki, Machida, Yoshinori, Shibata, Masahiro, Tsujibayashi, Tatsuo
• Primary Examiner(s): Cardillo, Raymond F.
• Assistant Examiner(s): Sachar, Surinder
• Application Number:
  US06/870,184
• Time in Patent Office: 707 Days
• Field of Search: 360/19.1, 360/61, 360/64
• US Class Current: 360/61
• CPC Class Codes: G11B 15/14 Masking or switching periodically, e.g. of rotating heads
• CPC Class Codes: G11B 5/00865 for transducing on more than one segment simultaneously
• CPC Class Codes: G11B 5/024 Erasing
• CPC Class Codes: G11B 5/534 inclined relative to the direction of movement of the tape, e.g. for helicoidal scanning

Abstract

A video tape recorder for recording a plurality of skewed recording tracks on a video tape includes a recording head, an auxiliary head and an erasing head mounted on a rotary body of a tape guide drum about which the tape is helically wrapped, a rotary transformer for transmitting signals to the recording head, auxiliary head and erasing head rotating with the rotary body, an erase signal generator for generating an earsing signal to be supplied to the erasing head by way of the rotary transformer, and a short circuit arrangement coupled to a signal path connected with the auxiliary head for short circuiting the latter upon applying the erasing signal form the erase signal generator to the erasing head by way of the rotary transformer.

Claims

1. A helical scan tape recorder for recording signals in a plurality of skewed recording tracks on a record tape comprising:

recording head means;

auxiliary head means;

erasing head means;

tape guide means including a rotary body having the record tape wrapped on the periphery thereof, said rotary body carrying said recording head means, auxiliary head means and erasing head means;

rotary transformer means for transmitting signals to said recording head means, auxiliary head means and erasing head means rotating with said rotary body and including a first section associated with said erasing head means and a second section having a primary winding connected to said auxiliary head means and a stationary secondary winding having its ends connected to output terminals;

erase signal generating means including oscillating means, gate means connected between said oscillating means and said first rotary transformer section for applying an oscillating output of said oscillating means as said erase signal to said erasing head means when said gate means is enabled, and means for applying an erase timing control signal to said gate means for enabling the latter; and

short circuit means responsive to said erase timing control signal for short circuiting said auxiliary head means whenever said gate means is enabled for applying said erase signal from said erase signal generating means to said erasing head means by way of said rotary transformer means, said short circuit means including an NPN-type transistor having an emitter-collector path connected between said output terminals for short circuiting the auxiliary head means when said NPN-type transistor is turned on, and means for turning on said NPN-type transistor including a PNP-type transistor having an emitter-collector path connected between a power source and a base electrode of said NPN-type transistor, and inverting means for applying an inverted version of said erase timing control signal to a base electrode of said PNP-type transistor, whereby said NPN-type transistor is turned on when said erase timing control signal is at a level for enabling said gate means.