ELECTRONIC DOCUMENT READING DEVICE

• US 20110018854A1
• Filed: 02/16/2009
• Published: 01/27/2011
• Est. Priority Date: 02/15/2008
• Status: Active Grant

• Current Assignee: FlexEnable Limited (Plastic Logic JSC)
• Original Assignee: Plastic Logic Limited (Plastic Logic JSC)
• Inventors: Barclay, Duncan, Farmer, Steven
• Granted Patent: US 8,994,710 B2
• Time in Patent Office: Days
• US Class Current: 345/211
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3218 of display devices
• CPC Class Codes: G06F 1/3262 Power saving in digitizer or tablet
• CPC Class Codes: G06F 1/3265 Power saving in display device
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: G06F 15/0291 for reading, e.g. e-books constructional details of portable computers G06F1/1613
• CPC Class Codes: G06F 15/177 Initialisation or configuration control processor initialisation G06F9/4405
• CPC Class Codes: G06F 2203/0339 Touch strips, e.g. orthogonal touch strips to control cursor movement or scrolling; single touch strip to adjust parameter or to implement a row of soft keys
• CPC Class Codes: G06F 3/048 Interaction techniques based on graphical user interfaces [GUI]
• CPC Class Codes: G09G 2330/026 Arrangements or methods related to booting a display
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167
• CPC Class Codes: H04N 1/00129 with a display device, e.g. CRT or LCD monitor with a television apparatus H04N1/00283; arrangements for control of display devices G09G
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

We describe power control techniques for an document reader with an electrophoretic display. In embodiments the document reader comprises a main processor to display information and at least one secondary processor to detect, say, a user input gesture; a battery to provide power to both processors; and a controllable switch coupled between said battery and said main processor and having a control line coupled to said secondary processor, to switch power from said battery to said main processor whilst said secondary processor is powered. In embodiments a power consumption measured in months is desired so that rather than put the main processor into a standby mode power to the main processor is switched off entirely but the system is arranged to be able to start-up quickly from this configuration.

Claims

1. An electronic document reading device with an electrophoretic display, the electronic document reading device comprising:

a main processor to control display of information on said display; and

a secondary processor to process data from one or more user input devices, said secondary processor being coupled to said main processor;

a battery to provide power to said main processor and to said secondary processor; and

a first controllable switch coupled between said battery and said main processor and having a control line coupled to said secondary processor, said first controllable switch being configured to switch power from said battery to said main processor whilst said secondary processor is powered; and

wherein, in an operational mode;

said secondary processor is configured to detect a user input and, responsive to said detection, to control said switch to turn on a power supply from said battery to said main processor;

said main processor is configured to perform a cold boot responsive to said turning on of said power and then to perform an action in accordance with said detected user input, and wherein said electronic document reading device is configured to control said controllable switch to turn off said power supply to said main processor after said action has been performed.

2. An electronic document reading device as claimed in claim 1 further comprising a display driver for said electrophoretic display, said display driver having associated memory to store data for displaying on said electrophoretic display, wherein said associated memory includes a portion of the memory to store data representing a current state of the electrophoretic display, and wherein said controllable switch is coupled to switch off power to said display driver and to a part of said associated memory not including said portion of said memory storing data representing a current state of the electrophoretic display.

3. An electronic document reading device as claimed in claim 1 comprising a further controllable switch coupled between said battery and said first controllable switch to switch power to said first controllable switch;

and wherein said secondary processor is configured to receive power from a junction between said first controllable switch and said further controllable switch.

4. An electronic document reading device as claimed in claim 3 wherein said further controllable switch has a control line coupled to said secondary processor to enable said main processor, via said secondary processor, to turn off said further controllable switch.

5. An electronic document reading device as claimed in claim 2 comprising a further controllable switch coupled between said battery and said first controllable switch to switch power to said first controllable switch;

and wherein said secondary processor and said part of said associated memory not including said portion of said memory storing data representing a current state of the electrophoretic display are configured to receive power from a junction between said first controllable switch and said further controllable switch.

6. An electronic document reading device as claimed in claim 5 wherein said further controllable switch has a control line coupled to said secondary processor to enable said main processor, via said secondary processor, to turn off said further controllable switch.

7. An electronic document reading device as claimed in claim 1 wherein, when said first controllable switch is turned on, said secondary processor is configured to inform said main processor whether said cold boot should comprise an ab initio start-up for said electronic document reading device.

8. An electronic document reading device as claimed in claim 1 wherein said one or more user input devices include at least one further processor, coupled to said secondary processor, to receive and process touch sensor user input.

9. An electronic document reading device as claimed in claim 8 wherein said touch sensor user input includes at least a page turn gesture, and wherein said action performed by said main processor in response to said page turn gesture includes loading an image of at least part of a document page from non-volatile memory coupled to said main processor and outputting said image for display on said electrophoretic display.

10. An electronic document reading device as claimed in claim 1 wherein different said actions, selected responsive to said detected user input, are performed by different separately loadable computer program code modules;

and wherein said device is configured to selectively load a said code module for performing a selected said action following said cold boot.

11. An electronic document reading device having a non-volatile display, the device comprising:

a battery to provide power for said electronic document reading device,

a main processor for controlling display of information on said device;

a display controller coupled to said main processor and to said non-volatile display;

volatile display memory coupled to one or both of said main processor and said display controller, said display memory being configured as a plurality of memory blocks, at least one of said memory blocks for storing data representing a state of said electrophoretic display;

a secondary processor to provide a user interface to said device;

a first controllable switch connected for control by said secondary processor, to switch power from said battery to said main processor, to said display controller and to said display memory;

a second controllable switch coupled in series between said battery and said first controllable switch; and

wherein

said secondary processor and said at least one memory block for storing said data representing a state of said electrophoretic display are configured to be powered from a connection between said first and second controllable switches.

12. A method of operating an electronic document reading device with a non-volatile display, the method comprising:

using a secondary processor to detect a touch sensor input from a user of said device, said touch sensor input identifying an action said user wishes the device to perform;

controlling, using said secondary processor, a power supply to a main processor of said device from an off state in which all power is removed from said main processor to a state in which power is applied to said main processor, in response to said touch sensor input detection;

allowing said main processor to perform said action; and

then

controlling said power supply to said main processor back to said off state to remove all power from said main processor.

13. A method as claimed in claim 12 wherein said power supply derives from a rechargeable battery, the method further comprising:

switching off a power supply to said entire device responsive to a detected state of said battery;

providing information to said main processor from said secondary processor to enable said main processor to determine, when said main processor is started from said off state, if said device is starting from a state in which said power supply to said entire device was switched off.