Scanner apparatus, image forming apparatus employing the same, and skew correction method

1. A scanner apparatus, comprising:

a document feeding path in which a reading device to read an image from a document is provided;

a first registration roller to feed the document along the document feeding path, and located at an upstream side of the reading device based on a feeding direction of the document;

a second registration roller aligned with the first registration roller in a width direction of the document, and disposed spaced apart from the first registration roller in the width direction;

a registration motor to drive the first registration roller independently of the second registration roller; and

a main motor to drive the second registration roller independently of the first registration roller.

2. The scanner apparatus of claim 1 , wherein end portions of the first and second registration rollers, which are adjacent to each other, are connected to each other through a bearing.

3. The scanner apparatus of claim 2 , further comprising a bearing holder fixed to one of the end portions of the first and second registration rollers and by which the bearing is supported,

wherein the other end portion of the first and second registration rollers is supported by the bearing.

4. The scanner apparatus of claim 1 , further comprising:

a first support to support a first end portion of the first registration roller; and

a second support to support a second end portion of the second registration roller,

wherein the first end portion and the second end portion are disposed adjacent to each other.

5. The scanner apparatus of claim 1 , further comprising a document feeding roller to feed the document along the document feeding path,

wherein the main motor is to drive the document feeding roller.

6. A scanner apparatus, comprising:

a document feeding path in which a reading device to read an image from a document is provided;

a first registration roller to feed the document along the document feeding path, and located at an upstream side of the reading device based on a feeding direction of the document;

a second registration roller aligned with the first registration roller in a width direction of the document, and disposed spaced apart from the first registration roller in the width direction;

a registration motor to drive the first registration roller;

a main motor to drive the second registration roller;

a registration sensor to detect the document, the registration sensor comprising a first registration sensor disposed at a downstream side of the first registration roller and a second registration sensor disposed at a downstream side of the second registration roller; and

a controller to detect a front end skew amount of the document from a detection time deviation of a front end of the document, based on the detection of the document by the first and second registration sensors.

7. The scanner apparatus of claim 6 , wherein the controller is further to drive the main motor and the registration motor at a constant speed such that a rotation linear speed of the first and second registration rollers is equal to a process speed, and change a speed of the registration motor such that the front end skew amount is corrected, after the front end of the document is detected by the first and second registration sensors.

8. The scanner apparatus of claim 7 , wherein the controller is further to drive the registration motor at a reference speed such that the rotation linear speed of the first registration roller is equal to the process speed, after the front end skew amount of the document is corrected.

9. The scanner apparatus of claim 7 , wherein the controller is further to detect a rear end skew amount of the document from a detection time deviation of a rear end of the document, based on the detection of the document by the first and second registration sensors, calculate a new reference speed based on the rear end skew amount, and drive the registration motor based on the new reference speed.

10. The scanner apparatus of claim 1 , wherein the main motor comprises a brushless direct current (BLDC) motor.

11. The scanner apparatus of claim 1 , wherein the registration motor is any one of a stepping motor, a direct current (DC) motor, and an inner-rotor type BLDC motor.

12. An image forming apparatus, comprising:

a printer to form an image on a recording medium; and

a scanner apparatus, comprising:

a document feeding path in which a reading device to read an image from a document is provided,

a first registration roller to feed the document along the document feeding path, and located at an upstream side of the reading device based on a feeding direction of the document,

a second registration roller aligned with the first registration roller in a width direction of the document, and disposed spaced apart from the first registration roller in the width direction,

a registration motor to drive the first registration roller independently of the second registration roller, and

a main motor to drive the second registration roller independently of the first registration roller.

13. The image forming apparatus of claim 12 , wherein end portions of the first and second registration rollers of the scanner apparatus, which are adjacent to each other, are connected to each other through a bearing.

14. The image forming apparatus of claim 13 , wherein the scanner apparatus further comprises a bearing holder fixed to one of the end portions of the first and second registration rollers and by which the bearing is supported,

wherein the other end portion of the first and second registration rollers is supported by the bearing.

15. The image forming apparatus of claim 12 , wherein the scanner apparatus further comprises:

a first support to support a first end portion of the first registration roller; and

a second support to support a second end portion of the second registration roller,

wherein the first end portion and the second end portion are disposed adjacent to each other.

16. The image forming apparatus of claim 12 , wherein the scanner apparatus further comprises a document feeding roller to feed the document along the document feeding path,

wherein the main motor is to drive the document feeding roller.

17. An image forming apparatus, comprising:

a printer to form an image on a recording medium; and

a scanner apparatus, comprising:

a document feeding path in which a reading device to read an image from a document is provided,

a first registration roller to feed the document along the document feeding path, and located at an upstream side of the reading device based on a feeding direction of the document,

a second registration roller aligned with the first registration roller in a width direction of the document, and disposed spaced apart from the first registration roller in the width direction,

a registration motor to drive the first registration roller,

a main motor to drive the second registration roller,

a registration sensor to detect the document, the registration sensor comprising a first registration sensor at a downstream side of the first registration roller and a second registration sensor at a downstream side of the second registration roller, and

a controller to detect a front end skew amount of the document from a detection time deviation of a front end of the document, based on the detection of the document by the first and second registration sensors.

18. A skew correction method, comprising:

rotating, at a process speed, a first registration roller located at an upstream side of a reading device based on a feeding direction of a document, by using a registration motor;

rotating, at the process speed, a second registration roller aligned with the first registration roller in a width direction of the document and spaced apart from the first registration roller in the width direction, by using a main motor;

calculating a front end skew amount from a detection time deviation of a front end of the document based on a detection of the document by first and second registration sensors disposed at a downstream side of the first and second registration roller, respectively, and spaced apart from each other in the width direction; and

correcting the front end skew amount by changing a speed of the registration motor.

19. The skew correction method of claim 18 , further comprising, after the correcting of the front end skew amount, driving the registration motor at a reference speed such that the first registration roller is rotated at the process speed.

20. The skew correction method of claim 19 , further comprising:

calculating a rear end skew amount from a detection time deviation of a rear end of the document, based on the detection of the document by the first and second registration sensors;

calculating a new reference speed for correcting the rear end skew amount; and

driving the registration motor at the new reference speed.