Device for determining amount of focus adjustment
AssigneeCanon Kabushiki Kaisha
InventorKazuyuki Nakagawa
Life of this patent
Estimating the term…
Abstract
A device for determining an amount of focus adjustment for an image-forming optical system which forms an image on a predetermined image plane includes a sensor, an image-re-forming optical system which re-forms the image on the sensor, and a reference member disposed at a position close to the predetermined image plane of the image-forming optical system. The projection image of the reference member is detected by the sensor, and a correction calculation is performed on the basis of the displacement of the projection image of the reference member from a preset position, so that errors in detection results caused by temperature variation, etc., are corrected.
Claims15
A device for determining an amount of focus adjustment for an image-forming optical system which forms an image on a predetermined image plane, the device for determining an amount of focus adjustment comprising:
- a sensor;
- an image-re-forming optical system which re-forms the image on the sensor;
- a reference member disposed at a position close to the predetermined image plane of the image-forming optical system;
- and
- a processing circuit which detects a projected image of the reference member by using the sensor and corrects the amount of focus adjustment on the basis of the detection result.
A device for determining an amount of focus adjustment for an image-forming optical system which forms an image on a predetermined image plane, the device for determining an amount of focus adjustment comprising:
- a sensor;
- an image-re-forming optical system which re-forms the image on the sensor;
- a reference member included in one of the image-forming optical system and the image-re-forming optical system;
- and
- a processing circuit which detects a projected image of the reference member by using the sensor and corrects the amount of focus adjustment on the basis of the detection result.
A device for determining an amount of focus adjustment for an image-forming optical system which forms an image on a predetermined image plane, the device for determining an amount of focus adjustment comprising:
- a first sensor;
- an image-re-forming optical system which re-forms the image on the first sensor;
- a reference member disposed at a position close to the predetermined image plane of the image-forming optical system;
- a second sensor onto which an image of the reference member is projected;
- and
- a processing circuit which corrects the amount of focus adjustment on the basis of the detection result obtained by the second sensor.
A device for determining an amount of focus adjustment for an image-forming optical system which forms an image on a predetermined image plane, the device for determining an amount of focus adjustment comprising:
- a first sensor;
- an image-re-forming optical system which re-forms the image on the first sensor;
- a reference member included in one of the image-forming optical system and the image-re-forming optical system;
- a second sensor onto which an image of the reference member is projected;
- and
- a processing circuit which corrects the amount of focus adjustment on the basis of the detection result obtained by the second sensor.
Dependencies are inferred from the claim text.