JP2003158684A - Digital camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital camera that can easily set the angle of field optimum respectively to a high resolution still picture mode and a low resolution high frame rate moving picture mode so as to obtain an optimum image output. SOLUTION: A control circuit 4 applies switching control to an area block reading pixel data from a solid-state imaging element 2 depending on a photographing mode so as to optimize the angle of field in each mode. That is, when the photographing mode is selected to be the high resolution still picture mode, the digital camera picks up an object by using the entire imaging effective area of the solid-state imaging element 2. When photographing mode is selected to be the low resolution high frame rate moving picture mode, the digital camera selects a small partial area in the middle of the imaging effective area of the solid-state imaging element 2 and picks up part of a high resolution still picture as a moving picture. Thus, the digital camera can easily set the angle of field respectively optimum to the high resolution still picture mode and the low resolution high frame rate moving picture mode and obtain an optimum image output in each mode with a simple optical system without the need for provision of a zoom mechanism or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera having a high resolution still image mode and a low resolution high frame rate moving image mode.

[0002]

2. Description of the Related Art Conventionally, digital cameras having a high resolution still image mode and a low resolution high frame rate moving image mode have been provided. In this digital camera, when the high resolution still image mode is realized, pixel data is read from all the image pickup pixels of the solid-state image pickup device having multiple pixels to output a still image. On the other hand, the low resolution high frame rate video mode basically drops the number of pixels of the output image,
Instead, the frame rate is increased to output a moving image, and as a method of realizing it, a method of converting the resolution of pixel data from the solid-state image sensor by signal processing,
A method of reading out pixel data by thinning out imaging pixels of a solid-state imaging device is used. In the monitor mode for monitoring a still image, the number of pixels is reduced to display a low-resolution still image at high speed as in the moving image mode.

[0003]

However, in all of the conventional methods for realizing the low resolution and high frame rate moving image mode as described above, since the entire image pickup area of the solid-state image pickup device is scanned and the image is output, The frame rate cannot be extremely increased, and in reality, it was not possible to realize a frame rate higher than the frame rate in the monitor mode described above. Also, when the low resolution and high frame rate moving image mode is used for a video conference or the like, the angle of view becomes too wide. Therefore, in order to deal with such a problem, it is conceivable to provide the lens with a zoom function for the moving image mode to narrow the angle of view, but the zoom function complicates the camera and raises the price. . On the other hand, if the angle of view of the camera itself is narrowed, the angle of view in the high resolution still image mode is narrowed, and it becomes impossible to obtain a high quality still image.

Therefore, an object of the present invention is to provide a digital camera capable of easily setting the optimum angle of view for each of the high resolution still image mode and the low resolution high frame rate moving image mode and obtaining the optimum image output. It is in.

[0005]

In order to achieve the above object, the present invention provides a block-readable solid-state imaging device,
It has a block control circuit for controlling an image pickup block of the solid-state image pickup device and a signal processing circuit for performing signal processing on an output signal of the solid-state image pickup device, and largely uses an image pickup area of the solid-state image pickup device in a high-resolution still image mode. In the low-resolution high-frame-rate moving image mode, a small image pickup area of the solid-state image pickup device is selected to capture a part of the high-resolution still image as a moving image.

In the digital camera of the present invention, an image pickup area of the solid-state image pickup device is largely used in the high-resolution still image mode, and a small image pickup area of the solid-state image pickup device is selected in the low-resolution high frame rate moving image mode. However, since a part of the high-resolution still image is captured as a moving image, it is possible to use individual angles of view in the high-resolution still image mode and the low-resolution high frame rate moving image mode.
Therefore, in the high-resolution still image mode, a high-quality still image can be obtained with a large angle of view using the entire imaging area. Further, in the low resolution high frame rate moving image mode, a high frame rate can be easily realized by using a narrow angle of view of a partial image pickup area, and it is possible to easily cope with a video conference or the like. That is,
High resolution still image mode and low resolution high frame rate You can easily set the optimum angle of view for each video mode, and without a zoom mechanism, you can use the simple optical system for high resolution still image mode and low resolution high frame rate. Optimal image output can be obtained in the moving image mode.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a digital camera according to the present invention will be described below. The embodiments described below are preferred specific examples of the present invention, and various technically preferable limitations are given. However, the scope of the present invention is not limited to the present invention in the following description. Unless otherwise stated, the present invention is not limited to these embodiments. FIG. 1 is a block diagram showing the configuration of a digital camera according to an embodiment of the present invention. 2 is an explanatory diagram showing an image formed on the solid-state image sensor in the high resolution still image mode of the digital camera shown in FIG.
FIG. 3 is an explanatory diagram showing an image formed on the solid-state image sensor in the low resolution high frame rate moving image mode in the digital camera shown in FIG. Further, FIG. 4 is an explanatory diagram showing an imaging area on the solid-state imaging device in the digital camera shown in FIG.

As shown in FIG. 1, the digital camera of this embodiment includes a lens 1, a solid-state image pickup element 2, an image pickup signal processing circuit 3,
And a control circuit 4. The lens 1 focuses the imaging light on the solid-state imaging device 2. In the digital camera of this example, one lens 1 is used, and the distance between the lens 1 and the solid-state image sensor 2 is fixed. The solid-state image sensor 2 is capable of block reading, for example, a CMO.
The image pickup signal processing circuit 3 is an S image sensor and performs predetermined signal processing such as noise removal on a signal read from the solid-state image pickup device 2 to obtain a video signal such as a high resolution still image or a low resolution high frame rate moving image. Is to create.

The control circuit 4 also controls the read operation of the solid-state image pickup device 2. In particular, the control circuit 4 of this example functions as an angle-of-view optimization unit that controls switching of the area block for reading pixel data to the solid-state image sensor 2 according to the shooting mode, and the shooting mode is the high-resolution still image mode. Occasionally, the entire solid-state image pickup element 2 has a large image pickup effective surface (image pickup area) for image pickup. When the shooting mode is the low-resolution high-frame-rate moving image mode, a small area in the central part of the image pickup effective surface of the solid-state image pickup device 2 is selected, and a part of the high-resolution still image is picked up as a moving image.

As a concrete example, for example, horizontal 1280 pixels,
A case will be described in which a vertical 960 pixel block readable CMOS image sensor is used and horizontal 320 pixel and vertical 240 pixel block reading is performed. Here, when the system operation clock is set to 13.5 MHz, a frame rate of 10 frames (per second) or more at maximum cannot be realized if all pixel signals are read, but by performing block reading, horizontal 320 pixels and vertical 240 pixels are obtained. A maximum frame rate of 176 frames (per second) can be realized with pixels. Actually, such a high frame rate is not used, but a blanking period is inserted horizontally and vertically to adjust the rate to about 30 frames for use.

As shown in FIG. 2, in the high resolution still image mode, the entire image pickup effective surface of the solid-state image pickup device 2 serves as a block read area 2A, and as shown in FIG.
A still image with 0 pixels and 960 vertical pixels is read. On the other hand, as shown in FIG. 3, in the low-resolution high-frame-rate moving image mode, a small partial area in the central portion of the imaging effective surface of the solid-state image sensor 2 becomes the block reading area 2B, and as shown in FIG. 320 pixels horizontally, 240 vertically
The moving image of the pixel is read. As described above, in the high resolution still image mode and the low resolution high frame rate moving image mode, the block read area of the solid-state image sensor 2 is switched, and different data amounts for one frame are read. In this example, the read block in the low resolution high frame rate moving image mode is provided in the central area of the read block in the high resolution still image mode (the entire imaging area in this example). The configuration is such that an image having a common center position is captured in the mode and the high-resolution still image mode.

In the digital camera of this example as described above,
The block reading function of the CMOS image sensor enables high-resolution still image digital cameras suitable for portrait photography and landscape photography with a wide angle of view, and low resolution and high resolution suitable for video conferences with a narrow angle of view without changing lenses. It is possible to realize the two modes of the frame rate moving image digital camera with a single lens. Figure 5
FIG. 5 is an explanatory view showing a state at the time of shooting, and the subject (person) 5
An example of the case of shooting is shown. Here, an example of an image when a portrait is taken as a high-resolution still image digital camera with a wide angle of view under the condition where the distance from the subject 5 to the solid-state image sensor 2 in FIG. 5 is fixed is shown in FIG. 6B shows an example of an image when used as a low resolution high frame rate moving image digital camera with a narrow angle of view in a video conference.

In the above example, the block reading is performed using the function of the CMOS image sensor, but the present invention is not limited to this, and the type of the image pickup device is a CCD image sensor or a CMOS image sensor. However, any solid-state image sensor capable of block reading can be used. Further, the number of pixels of the solid-state image sensor, the system operation clock, and the like described above do not limit the present invention, and various modifications are possible. Also, in the above example, 1
Although the case where a single lens is used is shown, this is for convenience, and needless to say, a combination of a plurality of lenses may be used.

Further, in the above-mentioned example, the case where the size of the read block is determined in advance in the low resolution high frame rate moving image mode and the high resolution still image mode has been described, but it is arbitrarily selected by the user. It is also possible to adopt a configuration that can be selected or a configuration that a read block is selected and used from among several options. In the above example, the read block in the low resolution high frame rate moving image mode is provided in the central area of the read block in the high resolution still image mode, but the read block deviated from the central area is selected. It is also possible to adopt a configuration that is used afterwards.

[0015]

As described above, in the digital camera of the present invention, the image pickup area of the solid-state image pickup device is largely used in the high-resolution still image mode, and the solid-state image pickup device is used in the low-resolution high frame rate moving image mode. By selecting a small imaging area and capturing a part of the high-resolution still image as a movie, you can easily set the optimal angle of view for both high-resolution still image mode and low-resolution high frame rate movie mode. Optimal image output can be obtained in the high resolution still image mode and the low resolution high frame rate moving image mode by a simple optical system without providing a mechanism or the like.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a digital camera according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an image formed on a solid-state image sensor in the high resolution still image mode of the digital camera shown in FIG.

3 is an explanatory diagram showing an image formed on a solid-state image sensor in the low resolution high frame rate moving image mode in the digital camera shown in FIG.

FIG. 4 is an explanatory diagram showing an image pickup area on a solid-state image pickup element in the digital camera shown in FIG.

5 is an explanatory diagram showing a state at the time of shooting with the digital camera shown in FIG. 1. FIG.

6 is an explanatory diagram showing a specific example of an image taken by the digital camera shown in FIG.

[Explanation of symbols]

1 ... Lens, 2 ... Solid-state image sensor, 3 ... Imaging signal processing circuit, 4 ... Control circuit, 5 ... Subject.

Claims (6)

[Claims] 1. A solid-state imaging device capable of block reading, a block control circuit for controlling an imaging block of the solid-state imaging device, and a signal processing circuit for performing signal processing on an output signal of the solid-state imaging device, In the high-resolution still image mode, the image area of the solid-state image sensor is used largely, and in the low-resolution high frame rate movie mode, a small image area of the solid-state image sensor is selected to capture a part of the high-resolution still image. A digital camera having a control means for capturing a moving image. 2. An angle of view optimizing means for automatically selecting a large angle of view in the high resolution still image mode and a small angle of view in the low resolution high frame rate moving image mode by the same lens. The digital camera according to claim 1, further comprising: 3. The digital camera according to claim 1, wherein in the high-resolution still image mode, image pickup is performed using the entire image pickup area of the solid-state image pickup device. 4. The digital camera according to claim 1, wherein in the low resolution high frame rate moving image mode, image pickup is performed using a partial image pickup area of a solid-state image pickup device selected by a user. 5. The digital camera according to claim 1, wherein the imaging area used in the low resolution high frame rate moving image mode is provided in a central area of the imaging area used in the high resolution still image mode. 6. The digital camera according to claim 1, wherein a lens that guides imaging light to the solid-state image sensor is arranged at a position fixed with respect to the solid-state image sensor.