A disk drive power manager that compares energy usage with a predetermined profile to select one of several reduced-power operating modes. An energy usage register is updated at regular intervals according to the energy used during each time interval. An attenuated average energy usage value is obtained by attenuating the energy usage measures over time and integrating the results. The average energy level is compared with several predetermined energy threshold profiles to select a full- or reduced-power operating mode. Operating mode selection automatically adapts to the usage pattern to optimally balance power consumption with operational accessibility.

Adaptive system for optimizing disk drive power consumption

A method for managing power in a portable computer uses past access history of the various electrically-powered computer components and a prediction of future user demands to determine power-save mode entry and exit conditions. The component or the computer system keeps track of the access patterns. In the case of the display system component, such as the LCD display panel, because the access occurs when the user is watching the display panel and is thus not possible to measure directly, the accesses are measured indirectly from keyboard and/or pointing device activity. Each component access is detected and used to compute a current access frequency. The current access frequency is compared to a previously calculated and continuously updated threshold frequency. The threshold frequency is representative of the access pattern, e.g., uniform or sporadic, and is computed from equations that include adjustable gain factors. During operation of the component the appropriate power-save mode is entered when the current access frequency falls below the threshold frequency. The component can also adapt dynamically to varying workload situations, thereby saving more energy without degrading performance. This is accomplished by adjusting the gain factors parameters in response to tracking the actual performance of the system, thereby changing the threshold frequency. The component also determines when to exit a power-save mode without necessarily waiting for a user access.

Portable computer with adaptive demand-driven power management

A data recording disk drive for use in a portable, battery-powered computer has several power-save modes of operation. The power-save modes are entered after a computed time since the last data read or write command. The computed time to enter a power-save mode is based on the computer user's real-time workload and is thus continuously varying during operation of the disk drive. The disk drive detects the current user workload by calculating the frequency of disk drive accesses and based on this history determines which of a plurality of power-save modes is appropriate and when to enter a power-save mode. Each disk drive read or write access is detected and used to compute a current access frequency. The current access frequency is compared to a previously calculated and continuously updated threshold frequency. The threshold frequency is representative of the access pattern, e.g., uniform or sporadic, and is computed from equations that include adjustable gain factors. The appropriate power-save mode is entered when the current access frequency falls below the threshold frequency. Intermediate power-save modes can be skipped, based on the detected access pattern. The disk drive can also adapt dynamically to varying workload situations, thereby saving more energy without degrading performance. This is accomplished by adjusting the gain factors in response to tracking the actual performance of the system, thereby changing the threshold frequency. The disk drive also determines when to exit a power-save mode without necessarily waiting for a user access.

Disk drive for portable computer with adaptive demand-driven power management

A photosensor system includes a photosensor array constituted by two-dimensionally arraying a plurality of photosensors, an image reading section which reads a subject image at a predetermined image reading sensitivity by using the photosensor array, a sensitivity adjustment image reading section which reads a sensitivity adjustment subject image while the image reading sensitivity in the photosensor array is changed to a plurality of stages, an optimal image reading sensitivity deriving section which derives an image reading sensitivity optimal for reading operation of the subject image, on the basis of a pixel data group relating to an image pattern of the subject image read by the sensitivity adjustment image reading section, and an image reading sensitivity setting section which sets the optimal image reading sensitivity as the image reading sensitivity in the image reading section.

Photosensor system and drive control method thereof

An electronic device monitors accelerations using an inertial sensor. The electronic device identifies a current motion state based on the accelerations. The electronic device determines an application that subscribes to a motion state identification service and notifies the application of the current motion state.

Program setting adjustments based on activity identification

A power supply circuit is so designed that the power supply is interrupted to the load after a predetermined period from a switch closing signal generated when the power switch is closed. The power supply circuit is capable of preventing unnecessary consumption of the battery power resulting from defective insulation of the power switch.

Power supply circuit for camera

An automatic control type electronic flash unit includes flashlight generator, a metering device for measuring the quantity of light emitted from the flashlight generator and reflected by an object to be photographed, a first detector for detecting the output of the metering device and generating a proper output when the output corresponds to a quantity of light which provides a proper exposure, and apparatus for discontinuing the flashlight generation of the flashlight generator in response to the proper output, a second detector for generating an over-exposure output when the output of the metering device related to the quantity of the reflection, by the object, of the flashlight generated during the time from the generation of the proper output until the discontinuation of the flashlight generation of the flashlight generator reaches a predetermined value, and an indicator operable by an over-exposure output to indicate an over-exposure.

Device for indicating condition of exposure in an automatic control type electronic flash unit for flash photography

An alarm device in a camera comprises a shutter speed manual/auto change-over dial having a first Auto position and a second Auto position, and alarm sound generating circuit operatively associated with the change-over dial so as to become operative in the first Auto position and to become non-operative in the second Auto position, and means for visually displaying the sound alarm non-operation condition which is operatively associated with the change-over dial so as to become non-operative in the first Auto position and to become operative in the second Auto position.

Sound alarm device in a camera

A diaphragm control apparatus for camera comprises a correcting circuit for correcting error in aperture stopping-down caused by a time lag from the generation of a signal for blocking the aperture stopping-down motion to the actuation of a blocking device in response to the signal.

Diaphragm control apparatus for camera

A combination of a camera and a flash unit is provided with a control system for flash photographing. The control system comprises a plurality of signal generating circuits each for converting information to be transmitted between the flash unit and the camera into a signal of a predetermined level with a plurality of detecting circuits each associated with the corresponding signal generating circuits for detecting a signal of a detection level corresponding to a predetermined level, and the signal generating circuits and the associated detecting circuits forming pairs with one of each of the pairs being provided on the camera and the other being provided on the flash unit.

Sakuji Watanabe

Papers

Power supply circuit for camera

Device for indicating condition of exposure in an automatic control type electronic flash unit for flash photography

Sound alarm device in a camera

Diaphragm control apparatus for camera

Control system for flash photographing apparatus