Patent ID: 8214909
Filing Date: 2012-07-03
Classification: H04N

Abstract:
1. An ebook reader comprising: a key input device; a main controller with a Central Processing Unit (CPU); a storage unit; a power source; a timer; a memorable display body configured to maintain display of contents displayed after a power supply from the power source has been interrupted; an authentication circuitry configured to prompt a user to perform an authentication operation upon the power supply from the power source being started and to determine whether the user is authorized to view the contents displayed on the memorable display body; a power supply controller configured to output a first instruction to the power supply controller when a predetermined amount of time lapses from when an input is last received by the key input device, to output a second instruction to the power supply controller when a power saving mode transition time period lapses from when the first instruction is output, and to output a reset instruction to the timer when a new input received from the key input device is received before the power saving mode transition time period has lapsed; an operation permission unit accepting an input to the ebook reader when the user who makes an authentication operation to the ebook reader is authorized; wherein the CPU calculates the power saving mode transition time period based on the contents displayed by the memorable display body, wherein the timer starts a counter indicating an amount of time that has lapsed since the state controller outputted the first instruction in response to a count start instruction outputted by the state controller, resets the counter when the reset instruction is outputted by the state controller, and counts the amount of time until the counter equals the power saving mode transition time period when the reset instruction is not outputted from the state controller; when the counter counts up to the power saving mode transition time period, the state controller outputs the second instruction to the power supply controller and the power supply controller interrupts the power supply to the authentication circuitry, and when the timer is reset, the CPU calculates a new power saving mode transition time based on a difference between the power saving mode transition time and an amount of time indicated by the counter; and wherein when the authentication circuitry initially recognizes the user, a sample document is displayed and the user is prompted to provide an input to the key input after viewing the sample document, wherein the new power saving mode transition time period is calculated based on the amount of time from when the sample document was displayed until the user provides the input to the key input and further based on an amount of contents in the sample document.