1. Field of the Invention
The present invention relates to an imaging device, and more particularly relates to a technology to obtain an image from which effect of a camera shake is reduced.
2. Description of the Related Art
Conventionally, a digital still camera takes an image by making an image sensor receive light from a subject for a given time period. When a user moves the digital still camera during taking the image, a position of a subject image on the image sensor is moved from its original position. For this reason, the taken image is sometimes blurred. This phenomenon is called a camera shake phenomenon.
In view of the above problem, Japanese laid-open patent publication No. Hei 3-273221 discloses an imaging device (a digital still camera) that comprises an angular velocity sensor and a circuit for controlling the angular velocity sensor in order to detect the camera shake. However, this imaging device has a problem that it is difficult to reduce its production cost because it requires the above described angular velocity sensor and the circuit for controlling the angular velocity sensor.
Japanese laid-open patent publication No. Hei 7-43803 discloses an imaging device comprising an optical sensor for detecting displacement of the subject image on the image sensor caused by the camera shake. However, this imaging device has a problem that it is difficult to reduce its production cost because it requires the above described optical sensor.
An object of the present invention is to provide an imaging device that can reduce not only the effect on the image caused by the camera shake with a simple circuit structure but also its production cost, as compared to the above-described conventional imaging device.
According to an aspect of the present invention, this object is achieved by an imaging device comprising: an image sensor for receiving and converting light from a subject into electronic signals; image conversion means for converting the electronic signals converted by the image sensor into images; operating means having a shutter release button; control means for controlling each component in the imaging device; camera shake cycle calculating means for calculating camera shake cycle based on both displacement per unit time of an attention area between each image converted by the image conversion means and the time when the each image was taken; and imaging timing control means for controlling timing of imaging so as to take an image at the time when effect of the camera shake is at a minimum, based on the camera shake cycle calculated by the camera shake cycle calculating means.
With the above configuration, imaging timing control means controls timing of imaging so as to take an image at the time when effect of the camera shake is at a minimum based on the calculated camera shake cycle. Thus, the imaging device can reduce the effect on the image caused by the camera shake without a sensor only for detecting the camera shake, as compared to the conventional imaging device. Therefore, the imaging device can reduce not only the effect on the image caused by the camera shake with a simple circuit structure but also its production cost, as compared to the conventional imaging device.
Preferably, the imaging device further comprises shutter release button detection means for detecting whether the shutter release button is pressed, and the camera shake cycle calculating means calculates the camera shake cycle when the shutter release button detection means detects that the shutter release button is pressed.
More preferably, the operating means further has a mode switching button for switching on/off of the image stabilization mode, and the camera shake cycle calculating means calculates the camera shake cycle when the shutter release button detection means detects that the shutter release button is pressed, in a state where the mode switching button is previously set on so as to switch on the image stabilization mode.
While the novel features of the present invention are set forth in the appended claims, the present invention will be better understood from the following detailed description taken in conjunction with the drawings.
The present invention will be described hereinafter with reference to the annexed drawings. It is to be noted that all the drawings are shown for the purpose of illustrating the technical concept of the present invention or embodiments thereof, wherein:
Referring now to the accompanying drawings, an imaging device embodying the present invention is described. It is to be noted that the following description of preferred embodiment of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or to limit the present invention to the precise form disclosed.
The imaging unit 12 comprises an image sensor 21 for receiving and converting light from a subject into electronic signals; a shutter 22 which is opened and shut in order to limit the amount of light which enters the image sensor 21; and an imaging unit drive 23 for getting each component in the imaging unit 12 to work. The operation portion 10 has operation buttons 15 for operating each component in the imaging device 1, a mode switching button 16 for switching on/off of the image stabilization mode, and a shutter release button 13 which acts as a trigger for opening and shutting the shutter 22. The user can press the shutter release button 13 halfway or all the way down for his purpose.
The microcontroller 19 functions as control means, shutter release button detection means, camera shake cycle calculating means, and imaging timing control means recited in the claims. As shown in
As shown in
Referring now to
When the microcontroller 19 has completed the camera shake cycle analysis process (YES at S4), the microcontroller 19 lights the image stabilization mode indicator 17 (S5). Subsequently, the microcontroller 19 detects whether the shutter release button 13 is pressed all the way down (S6). On detecting that the shutter release button 13 is pressed all the way down by the user (YES at S7), the microcontroller 19 determines the timing when the effect of the camera shake is the least (S8), based on the result of the camera shake cycle analysis at the step S3. At this timing when the effect of the camera shake is the least (YES at S9), the microcontroller 19 executes imaging (S10). When the shutter release button 13 is not pressed all the way down by the user (NO at S7), the microcontroller 19 repeats the step S1 to S6.
While analyzing the camera shake cycle (NO at S4), the microcontroller 19 detects whether the shutter release button 13 is pressed all the way down (S12) after lighting the camera shake cycle analysis indicator 18 (S11). When detecting that the shutter release button 13 is pressed all the way down by the user (YES at S13), the microcontroller 19 turns off the camera shake cycle analysis indicator 18 after completing the camera shake cycle analysis process (S14). Subsequently, the microcontroller 19 performs the above step S8 to S10 after lighting the image stabilization mode indicator 17 (S15).
Referring now to
Referring now to
Note that this embodiment shows the case where the four attention areas 51a to 51d are disposed on image areas 41a to 41d in the four corners of each image. However, the number of the attention areas is not limited to four. Furthermore, the positions of the attention areas are not limited to the corners of the image. The positions of the attention areas may be arbitrary positions on the each image.
Referring now to
As described above, according to the imaging device 1 embodying the present invention, the microcontroller 19 controls the timing of imaging so as to take an image at the time when the effect of the camera shake is at a minimum based on the calculated camera shake cycle. Thus, the imaging device 1 can reduce the effect on the image caused by the camera shake without a sensor only for detecting the camera shake as compared to the conventional imaging device. Therefore, the imaging device 1 can reduce not only the effect on the image caused by the camera shake with a simple circuit structure but also its production cost, as compared to the conventional imaging device.
The present invention has been described above using a presently preferred embodiment, but those skilled in the art will appreciate that various modifications are possible. For example, in the above described embodiment, the microcontroller analyzes the camera shake cycle, when the shutter release button is pressed halfway. However, the microcontroller may analyze the camera shake cycle when the shutter release button is pressed all the way down. Alternatively, he microcontroller may start analyzing the camera shake cycle when the shutter release button is pressed halfway, and then continue analyzing the camera shake cycle even after the shutter release button is pressed all the way down.
This application is based on Japanese patent application 2006-324199 filed Nov. 30, 2006, the contents of which are hereby incorporated by reference.
Number | Date | Country | Kind |
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2006-324199 | Nov 2006 | JP | national |