Lap and dissolve in video cameras with VTR
First Claim
1. A video camera comprising:
- (a) reversible drive means for advancing a magnetic record member in either first or second directions along a predetermined path;
(b) record means for magnetically recording successive multi-picture scenes on a moving record member as such member advances past a recording position in a first direction, said record means comprising magnetic head means, means for producing video signals representing scene information, a source of AC bias, means for combining said video signals and said AC bias and for applying the combined signal to said magnetic head means; and
(c) means for producing a lap and dissolve effect between successive scenes as recorded, said lap and dissolve producing means comprising;
(1) means operatively coupled to said source of AC bias for gradually reducing the level of AC bias applied to said magnetic head means while recording the end portion of a first scene, thereby gradually reducing the sensible level of the recorded pictures comprising said end portion while the recording member advances a predetermined distance in said first direction past said recording position;
(2) control circuit means operatively coupled to said drive means for advancing the recording member said predetermined distance in said second direction to position the magnetic record member so that said end portion is located at a position upstream of said recording position; and
(3) means operatively coupled to said source of AC bias for gradually increasing the level of AC bias applied to said magnetic head means while said record member is again advanced in said first direction from its upstream position to record the beginning portion of a second scene, thereby gradually increasing the sensible level of the recorded pictures of the second scene while the sensible level of the recorded pictures of the first scene is gradually reduced.
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Accused Products
Abstract
A video camera is provided with means for producing lap and/or dissolve effects between successively recorded scenes. Means are provided for controlling the level of AC bias accompanying the video signals applied to a magnetic recording head. A dissolve effect is achieved by gradually decreasing the level of such bias at the end of a recorded scene. A lap effect is achieved by gradually increasing the bias level at the beginning of a new scene. A simultaneous lap and dissolve effect is achieved by performing the individual lap and dissolve effects on the same segment of tape. To do this, the tape drive is reversed at the end of each scene to position the dissolved portion of the scene upstream of the magnetic recording head. Upon recording a new scene while gradually increasing the level of AC bias at the beginning thereof, a simultaneous lap and dissolve effect is achieved automatically.
28 Citations
14 Claims
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1. A video camera comprising:
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(a) reversible drive means for advancing a magnetic record member in either first or second directions along a predetermined path; (b) record means for magnetically recording successive multi-picture scenes on a moving record member as such member advances past a recording position in a first direction, said record means comprising magnetic head means, means for producing video signals representing scene information, a source of AC bias, means for combining said video signals and said AC bias and for applying the combined signal to said magnetic head means; and (c) means for producing a lap and dissolve effect between successive scenes as recorded, said lap and dissolve producing means comprising; (1) means operatively coupled to said source of AC bias for gradually reducing the level of AC bias applied to said magnetic head means while recording the end portion of a first scene, thereby gradually reducing the sensible level of the recorded pictures comprising said end portion while the recording member advances a predetermined distance in said first direction past said recording position; (2) control circuit means operatively coupled to said drive means for advancing the recording member said predetermined distance in said second direction to position the magnetic record member so that said end portion is located at a position upstream of said recording position; and (3) means operatively coupled to said source of AC bias for gradually increasing the level of AC bias applied to said magnetic head means while said record member is again advanced in said first direction from its upstream position to record the beginning portion of a second scene, thereby gradually increasing the sensible level of the recorded pictures of the second scene while the sensible level of the recorded pictures of the first scene is gradually reduced. - View Dependent Claims (2, 3)
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- 4. Apparatus for recording a scene with the sensible level of the pictures thereof gradually changing to obtain lap or dissolve effects at least at one end of said scene, said apparatus for use in a video camera which produces video signals and bias oscillations and records said signals with said bias oscillations on a moving magnetic record member, said apparatus comprising (1) means responsive to the movement of said record member for producing a control signal while said record member moves a predetermined distance at said end of each said scene, and (2) means responsive to said control signal for gradually varying the level of said bias oscillations so as to increase the level thereof when said one end is the start of the scene and to decrease the level thereof when said one end is the finish of the scene.
Specification