Braked media transport for laser scanners
AssigneeMatrix Instruments Inc.
InventorsN. Balasubramanian, Alan L. Helgesson
Life of this patent
Estimating the term…
Abstract
A servo system for a braked accelerative transport in which a signal representing velocity of a carriage within the transport is compared to a first reference signal representing desired carriage velocity. The comparison yields an error signal which is used to adjust the brake of the transport. A hydraulic valve having an adjustable needle is used as the brake. A second selectable reference signal is provided so that the first reference signal can be bypassed when the carriage is reset at high velocity or is at reset. The valve is also bypassed on reset so that the adjusted brake mechanism is left intact on reset.
Claims20
Apparatus comprising;
- carriage for moving a data recording or storage member relative to a laser beam, the carriage mounted for motion propelled by accelerative force, with its motion braked by a brake having a variable braking element,
- means for measuring carriage velocity and having an output signal representing said carriage velocity,
- servo control means for comparing said output signal representing velocity to a reference signal in order to generate a velocity error signal, and
- a carriage brake actuator connected to receive said velocity error signal and connected to the variable braking element of the transport brake, the actuator being responsive to the velocity error signal in changing the variable braking element to reduce the velocity error signal.
A servo controlled transport for moving a recording medium relative to a light source comprising,
- a carriage propelled by an accelerative force, said carriage moving along a predefined path,
- braking means connected to the carriage for braking the accelerative force to a uniform velocity, said braking means having a variable braking element,
- a laser having optical means for scanning in a line, transverse to the direction of motion of the carriage,
- a photosensitive medium disposed to receive said scanning line from the laser, with the laser or said photosensitive medium mounted on said carriage, the other mounted in a fixed position in optical communication with the first,
- means for measuring carriage velocity and having an output signal representing said carriage velocity,
- servo control means for comparing said output signal representing velocity to a reference signal in order to generate a velocity error signal, and
- a carriage brake actuator connected to receive said velocity error signal and connected to the variable braking element of the transport brake, the actuator being responsive to the velocity error signal in changing the variable braking element to reduce the velocity error signal.
Apparatus comprising;
- transport for moving a data recording or storage member relative to a laser beam, the transport having a carriage propelled by an accelerative force,
- means for measuring carriage velocity and having an output signal representing said carriage velocity,
- servo control means for comparing the said output signal representing velocity to a reference signal in order to generate a velocity error signal,
- a hydraulic piston and cylinder connected to the carriage for braking the acceleration of the carriage, the hydraulic piston and cylinder having a variable valve metering the flow of hydraulic fluid therethrough, and
- a carriage brake actuator connected to receive said velocity error signal and connected to the variable valve, the actuator being responsive to the velocity error signal in changing the variable valve to reduce the velocity error signal.
Dependencies are inferred from the claim text.