CCD scanner powered by a serial bus
A scanner has a scanning module for generating image data by way of scanning a document, a motor for driving the scanning module, and a control circuit electrically connected to the scanning module and the motor for controlling operations of the scanner. The scanning module has a light source for illuminating the document and a charge coupled device (CCD) for detecting reflected light from the document so as to generate the image data. The scanner is powered only by a serial bus.
1. Field of the Invention
The present invention relates to a scanner, and more specifically, to a charge coupled device (CCD) scanner powered by a serial bus.
2. Description of the Prior Art
Please refer to FIG. 1 and FIG. 2.
The scanner 10 is electrically connected to a sufficient power source to ensure the operation of the scanner 10. Normally, a cathode ray tube, employed as the light source 16 of the scanner 10, consumes a power of at least 16 W. In addition, the CCD 18 of the scanner 10, the motor 22 and the control circuit 24 consume powers of 0.5 W, 1.5 W and 0.5 W, respectively. Thus the total consumption of power during the operation of the scanner 10 exceeds the power of 2.5 W provided by the power rail 32 of the USB 30. Consequently, the external power source 20, needing extra space, is needed for the operation of the scanner 10 in addition to the power provided by the power rail 32 of the USB 30.
SUMMARY OF INVENTIONIt is therefore a primary object of the claimed invention to provide a charge coupled device (CCD) scanner powered by a serial bus to eliminate a use of an external power source.
According to the claimed invention, the CCD scanner includes a scanning module for generating image data by way of scanning a document, a motor for driving the scanning module, and a control circuit electrically connected to the scanning module and the motor for controlling operations of the scanner. In contrast to the prior art scanner, the CCD scanner is powered only by a serial bus. The CCD scanner further includes a light source with a light emitting diode (LED) tube having at least a light emitting diode (LED), for focusing light radiated from the LID tube on the document.
In another embodiment of the claimed invention, the control circuit of the CCD scanner periodically switches the power provided by the USB to the light source and the motor. The control circuit shuts down the motor when the light source focuses light on the document, and shuts down the light source when the motor drives the scanning module, so as to ensure the power provided by the USB sufficient for the operation of the scanner.
It is an advantage of the claimed invention over the prior art that the power consumption of the scanner during the operation is significantly reduced. In addition, the scanner in the claimed invention is powered only by the power rail the USB. Eternal power sources, requiring extra space, are thus omitted.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment, which is illustrated in the multiple figures and drawings.
Please refer to FIG. 3 and FIG. 4.
Since the CCD 48, the motor 52, and the control circuit 54 respectively consume powers of 0.5 W, 1.5 W and 0.5 W, the total power consumption for the operation of the scanner 40 is approximately 2.8 W. In order to reduce the total power consumption of the scanner 40 down to less than 2.5 W, the rotational speed is decreased so that the power consumption of the motor 52 is less than 1.2 W. Although the scanning speed of the scanning module 44 is thus lowered, the scanner 40 is powered only by the power rail 62 of the USB 60 without any external power source.
Please refer to
Please refer to FIG. 6 and FIG. 7.
The light source 76 is a cathode ray tube that consumes a power of 1.5 W during operation. Additionally, the CCD 78, the motor 82, and the control circuit 84 respectively consume powers of 0.5 W, 1.5 W and 0.5 W. This brings the total power consumption for the operation of the scanner 70 to approximately 4 W, which exceeds the power of 2.5 W provided by the power rail 92 of the USB 90. In order to reduce the total power consumption of the scanner 40 down to 2.5 W, the control circuit 84 is designed to periodically turn on/off the light source 76 and the motor 82. The control circuit 84 shuts down the motor 82 when the light source 76 focuses light on the document 72, so that the total power consumption of the scanner 70 is 2.5 W. When the motor 82 drives the scanning module 74, the control circuit 84 shuts down the light source 76, so that the total power consumption of the scanner 70 is 2.5 W as well. Consequently, the scanner 70 is powered only by the power rail 92 of the USB 90 without any external power source.
Please refer to
Please refer to
Alternatively, the control circuit 84 can be designed to detect three beams reflected from the document sequentially so as to simplify the design and save manufacturing costs of the scanner 70. In other words, only one of the first photo sensor 78r second photo sensor 78g, and third photo sensor 78b detect one of the three beams reflected from the document 72 in a same period.
Please refer to
Please refer to FIG. 11 and FIG. 12.
Alternatively, the light source 76 can be replaced by the LED tube, and the spotlight device 45 shown in
In comparison with the scanner 10 in the prior art, the scanners 40 and 70 provided in the present invention are powered respectively by the power rail 62 of the USB 60 and the power rail 92 of the USB 90 only. External power sources, requiring extra space, are thus omitted. In addition, the power consumption of the scanners 40 and 70 during the operation is reduced as well.
Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bound of the appended claims.
Claims
1. A scanner comprising:
- a scanning module for generating image data by way of scanning a document, the scanning module comprising: a light source for illuminating the document; and a charge coupled device (CCD) for detecting light reflected from the document so as to generate the image data; a motor for driving the scanning module; and a control circuit electrically connected to the scanning module and the motor for controlling operations of the scanner; wherein the scanner is only powered by a serial bus, the control circuit turns off the motor when the light source illuminates the document, and the control circuit turns off the light source when the motor drives the scanning module.
2. The scanner of claim 1 further comprising a timer for generating a clock signal, wherein the control circuit switches power of the serial bus between the light source and the motor periodically according to the clock signal.
3. A The scanner of claim 1 wherein the light source is a cathode ray tube.
4. The scanner of claim 1 wherein the light source is a light emitting diode tube (LED tube) which has at least a light emitting diode (LED) for radiating light.
5. The scanner of claim 4 wherein the LED radiates white light for illuminating the document, and the charge coupled device detects the light reflected from the document to generate the image data when the white light illuminates the document.
6. The scanner of claim 4 further comprising a spotlight device for focusing light radiated from the LED tube on the document.
7. The scanner of claim 1 wherein when the LED tube illuminates the document, the charge coupled device detects three beams reflected from the document simultaneously.
8. The scanner of claim 7 wherein the three beams are a red beam, a green beam, and a blue beam, and the charge coupled device has a first photo sensor, a second photo sensor, and a third photo sensor for detecting the red beam, the green beam, and the blue beam, respectively, to generate corresponding image data.
9. The scanner of claim 1 wherein when the LED tube illuminates the document, the charge coupled device detects three beams reflected from the document sequentially.
10. The scanner of claim 9 wherein the three beams are a red beam, a green beam, and a blue beam, the charge coupled device has a first photo sensor, a second photo sensor, and a third photo sensor, and the control circuit controls the first photo sensor, the second photo sensor, and the third photo sensor by turns, so that the first photo sensor detects the red beam, the second photo sensor detects the green beam, and the third photo sensor detects the blue beam, so as to generate corresponding image data.
11. The scanner of claim 1 wherein the scanner is electrically connected to a computer via the serial bus.
12. The scanner of claim 1 wherein the serial bus uses a universal serial bus (USB) architecture or an IEEE 1394 architecture.
13. A scanner comprising:
- a scanning module having a light source and a sensor disposed thereon;
- a motor adapted to drive the scanning module; and
- a control circuit electrically coupled to the scanning module and the motor, wherein the light source, the sensor, the motor and the control circuit are powered by a serial bus, and the control circuit is adapted to toggle power between the motor and the light source during a scanning operation.
14. The scanner of claim 13, further comprising a timer for generating a clock signal, wherein the control circuit is adapted to toggle power between the motor and the light source according to the clock signal.
15. The scanner of claim 13, wherein the light source comprises a cathode ray tube.
16. The scanner of claim 13, wherein the light source comprises a plurality of light emitting diodes (LED).
17. The scanner of claim 13, wherein the sensor comprises a charge coupled device (CCD).
18. The scanner of claim 13, wherein the serial bus complies with one of a universal serial bus (USB) architecture or IEEE 1394 architecture.
19. A scanner comprising:
- a scanning module having a light source and a sensor disposed thereon;
- a motor adapted to drive the scanning module; and
- a control circuit electrically coupled to the scanning module and the motor, and the control circuit is adapted to toggle power between the motor and the light source during a scanning operation.
20. The scanner of claim 19, further comprising a timer for generating a clock signal, wherein the control circuit is adapted to toggle power between the motor and the light source according to the clock signal.
21. The scanner of claim 19, wherein the light source comprises a cathode ray tube.
22. The scanner of claim 19, wherein the light source comprises a plurality of light emitting diodes (LED).
23. The scanner of claim 19, wherein the sensor comprises a charge coupled device (CCD).
24. A method, comprising:
- synchronously altering the power provided to a motor and a light source of a scanning module, wherein the altering comprises reducing power to one of the motor and the light source while increasing power to the other one of the motor and the light source substantially in accordance with a clock signal.
25. The method of claim 24, wherein the altering comprises toggling the power between the motor and the light source.
26. The method of claim 24, wherein the altering comprises reducing power to the motor while the power to the light source is cycled on.
27. The method of claim 24, wherein the altering is substantially performed by a control circuit electrically coupled to the scanning module and the motor.
28. The method of claim 24, wherein the light source comprises a cathode ray tube.
29. The method of claim 24, wherein the light source comprises a plurality of light emitting diodes (LED).
30. The method of claim 24, wherein the power is provided to a motor and a light source by use of a serial bus.
31. The method of claim 30, wherein the serial bus complies with one of a universal serial bus (USB) architecture or IEEE 1394 architecture.
Type: Grant
Filed: Mar 23, 2006
Date of Patent: Feb 2, 2010
Inventors: Ching-Fu Chung (Hsinchu City 300), Yu-Wen Lee (Miaoli City, Miaoli County 360)
Primary Examiner: Cheukfan Lee
Attorney: Perkins Coie LLP
Application Number: 11/390,538
International Classification: H04N 1/04 (20060101);