US 6,388,415 B1 · System and method for controlling a step motor in a scanner

Abstract

A method for controlling a step motor of a scanner by using three sets of parameters is provided. The three sets of parameters include a pulse count number PCN, a count base CB, and a motor constant speed interval MCSI. The method includes the follow steps. First, generate a synchronous trigger signal in correspondence with each exposure trigger signal CVTR generated by an image sensing module of the scanner and clear a base accumulator BA. Then, add the count base CB to the base accumulator in correspondence with each reference pulse. Finally, generate an asynchronous trigger signal and clear the base accumulator when the base accumulator is greater than or equal to the pulse count number PCN. Since the speed of the step motor only relates to the pulse count number PCN and the count base CB, the step motor can be controlled by only setting these parameters.

Claims12

Dependent claims

A method for controlling a step motor of a scanner, wherein the scanner includes a microcontroller, a memory buffer and an image-sensing module, the micro-controller having a CB (count base) register, a PCN (pulse count number) register, an MCSI (motor constant speed interval) register, a TCB (temporary count base) register, a BA (base accumulator) register and a clockwise rotation flag, said method comprising the steps of:

generating a reference pulse in response to an extended oscillatory signal;
generating a synchronous trigger signal in response to each exposure trigger signal generated by the image-sensing module and clearing the BA register;
accumulating the BA register by adding the value of the CB register in response to the reference pulse;
generating an asynchronous trigger signal and clearing the BA register when the BA register is greater than or equal to the PCN register;
and
enabling a back-tracking control when the memory buffer is full.

3 more elements

A method for controlling a step motor of a seer, wherein the scanner included a micro-controller receiving a reference pulse, the step motor, a memory buffer and an image-sensing module, said method comprising the steps of:

(a) generating a synchronous trigger signal in response to each of an exposure trigger signal generated by the image-sensing module;
(b) generating an asynchronous trigger signal in response to each of a plurality of the reference pulses;
wherein the number of the plurality of the reference pulses which are determined by a count base CB and a pulse count number PCN;
and
(c) enabling a back-tracking control when the memory buffer is fill.

2 more elements

Dependencies are inferred from the claim text.

System and method for controlling a step motor in a scanner

Life of this patent

System and method for controlling a step motor in a scanner

Life of this patent

Abstract

Claims12