Photographing apparatus

An image shooting apparatus comprising:

• an imaging unit operable to read out signals from an image sensor and output image frames in sequence at a predetermined frame rate, the image sensor collecting charges through a photoelectric conversion of incident light;
• a frame rate changing unit operable to change a frame rate while the imaging unit outputs the image frames in sequence;
• an aperture adjusting unit operable to adjust a level of aperture that determines an amount of the incident light;
• an exposure time adjusting unit operable to adjust an exposure time that is a time taken for collecting the charges through the photoelectric conversion of the incident light;
• a determining unit operable to determine a post-change aperture level so that a post-change amount is substantially equal to a pre-change amount, the post-change amount being an amount of collected charges per frame of image shot at a post-change frame rate, the pre-change amount being an amount of collected charges corresponding to each frame of image shot at a pre-change frame rate, where the frame rate changing unit changes the frame rate from the pre-change frame rate to the post-change frame rate;
• and
• a control unit operable, after the change of the frame rate, to control the aperture adjusting unit to adjust the level of aperture to transit to the post-change aperture level determined by the determining unit.

An integrated circuit for use in an image shooting apparatus, the integrated circuit comprising:

• an imaging unit operable to read out signals from an image sensor and output image frames in sequence at a predetermined frame rate, the image sensor collecting charges through a photoelectric conversion of incident light;
• a frame rate changing unit operable to change a frame rate while the imaging unit outputs the image frames in sequence;
• an aperture adjusting unit operable to adjust a level of aperture that determines an amount of the incident light;
• an exposure time adjusting unit operable to adjust an exposure time that is a time taken for collecting the charges through the photoelectric conversion of the incident light;
• a determining unit operable to determine a post-change aperture level so that a post-change amount is substantially equal to a pre-change amount, the post-change amount being an amount of collected charges corresponding to each frame of image shot at a post-change frame rate, the pre-change amount being an amount of collected charges corresponding to each frame of image shot at a pre-change frame rate, where the frame rate changing unit changes the frame rate from the pre-change frame rate to the post-change frame rate;
• and
• a control unit operable, before the change of the frame rate, to control the aperture adjusting unit to adjust the level of aperture to transit to the post-change aperture level determined by the determining unit, and to control the exposure time adjusting unit to adjust the exposure time in accordance with the level of aperture in transition so that the post-change amount of collected charges is substantially equal to the pre-change amount of collected charges.

An image shooting method f or use in an image shooting apparatus, the image shooting method comprising the steps of:

• reading out signals from an image sensor and outputting image frames in sequence at a predetermined frame rate, the image sensor collecting charges through a photoelectric conversion of incident light;
• changing a frame rate while the image frame outputting step outputs the image frames in sequence;
• adjusting a level of aperture that determines an amount of the incident light;
• adjusting an exposure time that is a time taken for collecting the charges through the photoelectric conversion of the incident light;
• determining a post-change aperture level so that a post-change amount is substantially equal to a pre-change amount, the post-change amount being an amount of collected charges corresponding to each frame of image shot at a post-change frame rate, the pre-change amount being an amount of collected charges corresponding to each frame of image shot at a pre-change frame rate, where the frame rate changing step changes the frame rate from the pre-change frame rate to the post-change frame rate;
• and
• before the change of the frame rate, controlling the aperture adjusting step to adjust the level of aperture to transit to the post-change aperture level determined by the determining step, and controlling the exposure time adjusting step to adjust the exposure time in accordance with the level of aperture in transition so that the post-change amount of collected charges is substantially equal to the pre-change amount of collected charges.