BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an image capturing apparatus and control method thereof, and an image capturing system and, more specifically, to control of shooting timings of images and display timings of shot images.

Description of the Related Art

Some digital cameras and electronic devices having a camera function (hereinafter collectively referred to as “image capturing apparatus”) have a live view (LV) function. The LV function is a function of shooting a moving image and displaying the obtained image (hereinafter, referred to as “LV image”) on a display in parallel. By using the displayed LV image as a finder, a user can find a desired composition for still image shooting or moving image shooting while checking the LV image. Hereinafter, the operation of adjusting a shooting composition is referred to as “framing”.

Operability for framing is important for a user to shoot an image as the user intends. For example, if the time lag (display time lag) from the shooting of an LV image to the displaying of the LV image on the display is long, a phenomenon in which a subject has already moved to somewhere at the timing when the image of the subject is displayed on the display may occur. Thus, the display time lag greatly affects the operability for framing.

In an image capturing apparatus that captures a still image by performing framing using the LV function, when performing continuous shooting of still images, the framing cannot be performed unless the LV image is continuously displayed on the display even during the continuous shooting of still images. However, in a case where shooting and displaying of the LV image are performed between frames of still images during continuous shooting of still images, it is difficult to adjust the timing of capturing each frame of the LV image if the interval of the continuous shooting of still images is short. As a result, during the continuous shooting of still images, a period from the timing of capturing each frame of the LV image to the timing of updating the LV image on the display becomes long, a display time lag increases, and the framing becomes difficult.

To solve this problem, Japanese Patent Laid-Open No. 2007-243615 discloses a method for reducing a display time lag by synchronously controlling the image shooting timing of the image sensor and the display start timing of the display with a predetermined time difference.

In the prior art disclosed in Japanese Patent Laid-Open No. 2007-243615 described above, a method of adjusting the image shooting timing based on the image reproduction timing is disclosed in order to reduce the display time lag. However, such a method is not always the optimum control method. For example, in still image shooting, the release time lag is important when controlling the shooting timing and the playback timing, and in moving image shooting, it is necessary to control the shooting timing and the playback timing in consideration of audio recording, time recording, and the like.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the above situation, and displays a live view image at a timing suitable for each of a plurality of driving methods of the image sensor.

According to the present invention, provided is an image capturing apparatus comprising: a first generation circuit that generates a first synchronization signal with a predetermined cycle; a second generation circuit that generates a second synchronization signal for controlling timings for driving an image sensor including timings for repeatedly reading out image signals from the image sensor; a control circuit that controls the second generation circuit in accordance with a driving method of the image sensor; a selector that selects the first synchronization signal or the second synchronization signal in accordance with the driving method of the image sensor and outputs the selected synchronization signal; and a display panel that updates and displays image signals which are repeatedly read out from the image sensor at timings based on the synchronization signal selected by the selector.

Further, according to the present invention, provided is an image capturing system comprising: an image capturing apparatus comprising: a first generation circuit that generates a first synchronization signal with a predetermined cycle; a second generation circuit that generates a second synchronization signal for controlling timings for driving an image sensor including timings for repeatedly reading out image signals from the image sensor; a control circuit that controls the second generation circuit in accordance with a driving method of the image sensor; a selector that selects the first synchronization signal or the second synchronization signal in accordance with the driving method of the image sensor and outputs the selected synchronization signal; and a display panel that updates and displays image signals which are repeatedly read out from the image sensor at timings based on the synchronization signal selected by the selector; and a processing apparatus, connected to the image capturing apparatus, that includes a processing circuit that processes an image signal output from the image sensor without taking synchronization with the image capturing apparatus.

Furthermore, according to the present invention, provided is a control method of an image capturing apparatus, the method comprising: generating a first synchronization signal with a predetermined cycle; generating a second synchronization signal for controlling timings for driving an image sensor including timings for repeatedly reading out image signals from the image sensor; controlling generation of the second synchronization signal in accordance with a driving method of the image sensor; selecting the first synchronization signal or the second synchronization signal in accordance with the driving method of the image sensor and outputting the selected synchronization signal; and updating and displaying image signals which are repeatedly read out from the image sensor on a display panel at timings based on the selected synchronization signal.

Further, according to the present invention, provided is a non-transitory computer-readable storage medium, the storage medium storing a program that is executable by a computer, wherein the program includes a program code for causing the computer to perform a control method of an image capturing apparatus, the method comprising: generating a first synchronization signal with a predetermined cycle; generating a second synchronization signal for controlling timings for driving an image sensor including timings for repeatedly reading out image signals from the image sensor; controlling generation of the second synchronization signal in accordance with a driving method of the image sensor; selecting the first synchronization signal or the second synchronization signal in accordance with the driving method of the image sensor and outputting the selected synchronization signal; and updating and displaying image signals which are repeatedly read out from the image sensor on a display panel at timings based on the selected synchronization signal.

Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).

