System connecting power supply line to image sensing device upon data transport

• US 6,580,460 B1
• Filed: 02/26/1998
• Issued: 06/17/2003
• Est. Priority Date: 02/28/1997
• Status: Expired due to Fees

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Tajika, Hiroshi, Takahashi, Kenji, Ishikawa, Hisashi, Konno, Yuji, Kawatoko, Norihiro, Inoue, Hirowo, Fujita, Miyuki
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): Tillery, Rashawn N.
• Application Number:
  US09/030,767
• Time in Patent Office: 1,937 Days
• Field of Search: 348/372, 348/373, 348/374, 348/375, 348/376, 396/301, 396/302, 396/303
• US Class Current: 348/372
• CPC Class Codes: H04N 1/00885 Power supply means, e.g. arrangements for the control of power supply to the apparatus or components thereof
• CPC Class Codes: H04N 1/00891 Switching on or off, e.g. for saving power when not in use H04N1/00896 takes precedence
• CPC Class Codes: H04N 1/00899 Detection of supply level or supply failure
• CPC Class Codes: H04N 1/00901 Using different supplies or connection to an external supply H04N1/00893, H04N1/00896 take precedence
• CPC Class Codes: H04N 1/00904 Arrangements for supplying power to different circuits or for supplying power at different levels H04N1/00896 takes precedence

Abstract

According to the invention, a power supply for an image sensing device is obtained from a printer to prevent consumption of the battery. When the image sensing device is connected to the printer, a power management unit checks if electric power can be supplied from the printer. When electric power can be supplied from the printer, the power management unit switches the power supply from the battery to a power supply receiving/supplying unit that receives electric power from the printer. In this case, if the remaining capacity on the battery is small, the battery is charged by electric power from the printer. Also, the luminance of a display unit is increased, or the operation frequency of a control unit is raised. On the other hand, when electric power cannot be supplied from the printer, the power management unit switches the power supply to the battery. In this case, the power management unit reduces consumption power by decreasing the luminance of the display unit or reducing the operation frequency of the control unit.

Claims

1. An image input/output system built by connecting an image output device and an image input device, said image output device outputting an image signal received from said image input device, and supplying electric power to said image input device,

said image input device being connected to said image output device via a connection cable to transmit image data to said image output device and to receive the electric power supplied from said image output device, said image input device comprising:

a power supply unit; and

a power supply control unit (i) for determining whether to receive the electric power from said image output device, (ii) for, when it is determined that said image input device can receive the electric power from said image output device, using the electric power from said image output device, and (iii) for, when it is determined that said image input device cannot receive the electric power from said image output device, using electric power from said power supply unit,

wherein said image input device further comprises means for, when said image input device can receive the electric power from said image output device, measuring a supplied electric power amount, and optimizing an arithmetic operation speed of an image processing operation of said image input device in accordance with the obtained electric power value.

4. The system according to claim 1, wherein said power supply control unit comprises determination means for determining whether or not electric power capacity required for driving said image input device can be supplied from said image output device, and

wherein said power supply control unit cuts off electric power from said power supply unit and supplies electric power from said image output device when it is determined that electric power capacity required for driving said image input device can be supplied from said image output device.

5. The system according to claim 1, wherein said power supply unit comprises a rechargeable battery and said image input device further comprises means for determining if no operation input has been made for at least a predetermined period of time, and when it is determined that no operation input has been made for at least the predetermined period of time, said power supply control unit recharges said battery.

6. The system according to claim 1, wherein said power supply unit comprises a rechargeable battery and, when it is determined that said image input device cannot receive the electric power from said image output device, said power supply control unit detects a remaining charge on said battery, and when the remaining charge on said battery is not more than a predetermined value, said power supply control unit outputs a message indicating an insufficient remaining charge.

7. The system according to claim 1, wherein said image input device and said image output device are connected by an interface complying with IEEE 1394 standard.

8. The system according to claim 1, wherein a digital camera is used as said image input device and a printer is used as said image output device.

2. An image input device comprising:

connection means connected to an external device which exchanges data with a connected device, and can supply electric power to said image input device;

a power supply unit;

a power supply control unit (i) for checking if electric power can be received from said external device, (ii) for, when it is determined that the electric power can be received from said external device, using the electric power from said external device, and (iii) for, when it is determined that the electric power cannot be received from said external device, using electric power from said power supply unit; and

means for, when the electric power can be received from said external device, measuring a supplied electric power amount, and optimizing an arithmetic operation speed of an image processing operation of said image input device in accordance with the obtained electric power value.

9. The device according to claim 2, wherein said power supply control unit comprises determination means for determining whether or not electric power capacity required for driving said image input device can be supplied from said external device, and

wherein said power supply control unit cuts off electric power from said power supply unit and supplies electric power from said external device when it is determined that electric power capacity required for driving said image input device can be supplied from said external device.

10. The device according to claim 2, further comprising a rechargeable battery in said power supply unit and means for determining if no operation input has been made for at least a predetermined period of time, wherein when it is determined that no operation input has been made for at least the predetermined period of time, said power supply control unit recharges said battery.

11. The device according to claim 2, wherein said power supply unit comprises a rechargeable battery, and when it is determined that said image input apparatus cannot receive the electric power from said external device, said power supply control unit detects a remaining charge on said battery, and when the remaining charge on said battery is not more than a predetermined value, said power supply control unit outputs a message indicating an insufficient remaining charge.

12. The device according to claim 2, wherein said image input device and said external device are connected by an interface complying with IEEE 1394 standard.

13. The device according to claim 2, wherein a digital camera is used as said image input device and a printer is used as said external device.

3. A method of controlling an image input device, which has a power supply unit and a display unit, is connected to an external device, and is driven by electric power supplied from one of the external device and the power supply unit, comprising:

a determination step of checking if electric power can be received from the external device;

a power supply control step of using the electric power from the external device when it is determined that the electric power can be received from the external device, and using electric power from the power supply unit when it is determined that the electric power cannot be received from the external device; and

a measuring step of measuring a supplied electric power amount when it is determined in said determination step that the electric power can be received from the external device, and optimizing an arithmetic operation speed of an image processing operation of the image input device in accordance with the obtained electric power value.

14. The method according to claim 3, further comprising a determination step of determining whether or not electric power capacity required for driving the image input device can be supplied from the external device, and

wherein electric power from the power supply unit is cut off and electric power from the external device is supplied in said power supply control step, when it is determined that electric power capacity required for driving the image input device can be supplied from said external device.

15. The method according to claim 3, further comprising a step of determining if no operation input has been made for at least a predetermined period of time, and a step of recharging a battery used in the power supply unit,

wherein when it is determined in said determining step that no operation input has been made for at least the predetermined period of time, the battery is recharged in said recharging step.

16. The method according to claim 3, wherein the power supply unit comprises a battery, and when it is determined that the image input device cannot receive electric power from the external device, a remaining charge on the battery is detected in said power supply control step, and when the remaining charge on the battery is not more than a predetermined value, said method further comprises a step of outputting a message indicating an insufficient remaining charge.

17. The method according to claim 3, wherein the image input device and the external device are connected by an interface complying with IEEE 1394 standard.

18. The method according to claim 3, wherein a digital camera is used as the image input device and a printer is used as the external device.