Focus detection apparatus and focus detection method
AssigneeCanon Kabushiki Kaisha
InventorTakeshi Sakaguchi
Life of this patent
Estimating the term…
Abstract
An apparatus includes a monitor unit configured to monitor and output an accumulation state of a monitor area, which is apart of the detection area, a control unit configured to start an accumulation for focus adjustment in a detection area, and to determine whether the accumulation is ended based on the accumulation state, and to end the accumulation, when it is determined that the accumulation is to be ended, and an adjusting unit configured to use, for a focus adjustment, an output signal in a first area including the monitor area in priority to an output signal in a second area not including the monitor area.
Claims9
An apparatus comprising:
- a focus detection sensor that detects a focal state of a photographing lens based on an image signal of an object based on light flux obtained from an object light transmitted through the photographing lens, and that has a plurality of detection areas for detection of the focal state of the photographing lens;
- a monitor unit configured to monitor and output an accumulation state of a signal level of a monitor area, which is associated with the detection areas;
- a control unit configured to start an accumulation in the plurality of detection areas at once, and to end the accumulation in the plurality of detection areas at once, when it is determined that the signal level reaches a predetermined level;
- a selection unit configured to select a detection area to perform focus adjustment from the plurality of detection areas, which is associated with the monitor area;
- and
- an adjusting unit configured to use, for the focus adjustment, a focal state of a photographing lens in the area selected by the selection unit.
A focus detection method comprising:
- starting an accumulation for focus adjustment in a plurality of focus detection areas;
- monitoring and outputting an accumulation state of a signal level of a monitor area, which is associated with the focus detection areas;
- determining whether the accumulation is ended based on the accumulation state, and ending the accumulation, when it is determined that the signal level reaches a predetermined level;
- selecting a focus detection area to perform the focus adjustment from the plurality of focus detection areas, which is associated with the monitor area.
An apparatus comprising:
- a focus detection sensor that detects a focal state of a photographing lens based on an image signal of an object based on light flux obtained from an object light transmitted through the photographing lens, and that has a plurality of detection areas for detection of the focal state of the photographing lens;
- a monitor unit configured to monitor and output an accumulation state of a signal level of a monitor area, which is associated with the detection areas;
- an area selecting unit configured to select the monitor area;
- a control unit configured to start an accumulation in the plurality of detection areas at once, and to end the accumulation in the plurality of detection areas at once, when it is determined that the signal level reaches a predetermined level;
- a selection unit configured to select the detection area to perform focus adjustment from the plurality of detection areas based on the reliability of the focal state;
- and
- an adjusting unit configured to use, for the focus adjustment, a focal state of a photographing lens in the area selected by the selection unit,
- wherein the selection unit lowers the reliability of the focal state of the detection area which does not associate with the monitor area selected by the area selection unit.
Dependencies are inferred from the claim text.