JP4012471B2 - Digital camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital camera in which a camera shake image can be easily confirmed even with a built-in monitor having a small screen size.
[0002]
[Prior art]
Digital still cameras that record image signals obtained by imaging a subject as still image data are widely used. Unlike conventional film cameras, the digital still camera can check the shot image on the spot using the built-in LCD monitor, and even if shooting fails, the image can be erased and retaken easily.
[0003]
When confirming a photographed image, the digital still camera is set to a playback mode, and an operation for selecting an image to be displayed is appropriately performed to switch and display each image. In addition, there is known a technique in which a plurality of index images are displayed on a monitor screen and the trouble of switching display images is eliminated (see Patent Document 1).
[0004]
Many built-in monitors of digital still cameras have a small screen size, and the number of display pixels is several steps smaller than the number of recorded pixels of a captured image. For this reason, conventionally, even when a captured image is reproduced and displayed, it is only possible to check the general tone of the entire image and what kind of subject was photographed, and a personal computer monitor or the like having a large display screen must be used. The quality of the photographed image could not be judged.
[0005]
Therefore, in the digital cameras described in Patent Document 2 and Patent Document 3, the captured image is enlarged and displayed on a small monitor screen to the same magnification so that the actual sharpness of the image can be confirmed.
[0006]
[Patent Document 1]
JP 2001-211421 A [Patent Document 2]
JP 2001-159730 A [Patent Document 3]
Japanese Patent Laid-Open No. 11-275426
[Problems to be solved by the invention]
However, in recent years when the number of pixels of an image sensor increases and the number of recording pixels increases, it is only possible to display a part of the image even if the captured image is enlarged, and it takes time to check the entire image. Take it. For this reason, there is a problem that it is difficult to determine on the spot whether the camera has shaken and the shooting has failed. Also, if you take a picture of an important scene several times just in case, you have to save all the images, and the memory capacity will be used up quickly.
[0008]
The present invention has been made in consideration of the above-mentioned problems. A digital camera capable of easily identifying a deteriorated image due to camera shake even on a small built-in monitor and erasing an image that has failed to be photographed on the spot to save memory capacity. The purpose is to provide.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a digital camera according to the present invention includes an imaging unit that images a subject and outputs an image signal, a still image recording unit that records the image signal as still image data, and a direction parallel to the imaging surface. The measurement means for measuring the size of the camera shake, the camera shake recording means for recording the measured value of the camera shake at the time of imaging, and immediately after the imaging instruction is taken, the image is newly taken and recorded by the imaging instruction. Each still image data of the still image and the still image captured by the previous imaging instruction and each corresponding camera shake measurement data are read out, and each still image and each camera shake measurement value are output to the image display means, respectively. compare to characterized in that a display control means for displaying simultaneously, immediately and two images the size of the camera shaking In which it was to be able to bet. Further, an acceleration sensor that detects vertical and horizontal accelerations is used as the measuring means.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, a digital still camera 1 has a protective cover 5 slidably provided on the front surface of a camera body on which an imaging lens 2, a strobe light emitting unit 3, and an optical viewfinder 4 are provided. When the protective cover 5 is closed, the imaging lens 2 and the strobe light emitting unit 3 are covered and the power is turned off. When the protective cover 5 is open, the imaging lens 2 and the strobe light emitting unit 3 are exposed, and the power is turned on to enable photographing. Inside the digital still camera 1, a vertical direction acceleration sensor 6 and a horizontal direction acceleration sensor 7 are provided to measure the magnitude of blur in the vertical direction and the horizontal direction of the shooting range, respectively.
[0011]
In FIG. 2, a slide switch 10 that switches between a shooting mode and a playback mode, a zoom switch 11 that operates digital zoom, and an operation key 12 are provided on the back of the digital still camera 1. Further, a first liquid crystal monitor 13 and a second liquid crystal monitor 14 capable of displaying a subject image in full color are provided. The first liquid crystal monitor 13 is used as a finder at the time of photographing and also for reproduction display of the photographed image. The second liquid crystal monitor 14 is a monitor dedicated to reproduction display of the photographed image.
[0012]
A memory card 15 on which image data is recorded is detachable from the camera body and is inserted into a memory card slot 16 provided on the side of the camera. In addition to image data, the memory card 15 stores shooting information such as shooting date and time and camera shake measurement values. The shooting button 17 provided on the upper surface of the camera can be pressed in two stages, half-pressing and full-pressing. Under the shooting mode, the half-pressing operation performs photometry and focusing. When the push operation is performed, the subject image is recorded.
[0013]
In FIG. 3, a CCD image pickup device 20 is disposed behind the image pickup lens 2 and outputs an image signal generated by photoelectrically converting an optical image of a subject. The image signal processing circuit 21 performs noise reduction processing, amplification processing, white balance processing, gamma correction processing, and the like on the image signal output from the CCD image sensor 20. The image signal output from the image signal processing circuit 21 is digitally converted by the AD converter 22 and sent to the camera control unit 23.
[0014]
The camera control unit 23 includes a memory in which a sequence program is stored and a microcomputer that executes the sequence program. The camera control unit 23 outputs a control signal to each unit to manage image recording processing, reproduction display processing, and the like. The image compression / decompression circuit 24 performs JPEG compression processing on the digital image signal output from the AD converter 22 at the time of shooting to reduce the size of the image data and reproduces the shot image from the JPEG compressed image data at the time of image playback. Perform the decompression process.
[0015]
The memory card interface 25 accesses the memory card 15 to write and read data. The input interface 26 detects input operations such as the slide switch 10 and the zoom switch 11, generates an operation signal corresponding to each operation, and outputs the operation signal to the camera control unit 23. The camera control unit 23 appropriately performs control associated with mode switching, zoom switching, and the like according to the input operation signal.
[0016]
The vertical acceleration sensor 6 detects the vertical acceleration of the digital still camera 1. The camera control unit 23 calculates the camera shake magnitude as the vertical shake measurement value from the detected acceleration value. The horizontal acceleration sensor 7 detects the lateral acceleration of the digital still camera 1. The camera control unit 23 calculates the horizontal camera shake magnitude as a horizontal shake measurement value. The acceleration in the vertical and horizontal directions of the shooting range is measured by the two acceleration sensors, and camera shake during shooting is determined.
[0017]
The drawing signal output circuit 27 converts image data and character data into analog drawing signals for display on the first and second liquid crystal monitors 13 and 14 and outputs them to the liquid crystal driver 28. The liquid crystal driver 28 performs drive control of the first liquid crystal monitor 13 and the second liquid crystal monitor 14 based on the drawing signal.
[0018]
Next, the operation of the digital still camera 1 will be described with reference to FIGS. 4 and 5. When the protective cover 5 is opened, the power of the digital still camera 1 is turned on, the camera control unit 23 is activated, and either the photographing mode or the reproduction mode is executed according to the operation position of the slide switch 10. When the shooting mode is executed, the CCD image pickup device 20 is driven and the subject light transmitted through the imaging lens 2 is picked up, and an image signal is output. Further, the first liquid crystal monitor 13 is driven, and the subject image is displayed in live view based on the image signal output from the CCD image sensor 20. If the second liquid crystal monitor 14 is turned on at this time, the image recorded on the memory card 15 at the previous photographing can be reproduced and displayed.
[0019]
When the shooting button 17 is operated, a shooting signal is sent from the input interface 26 to the camera control unit 23. The camera control unit 23 takes in an image signal for one frame output from the CCD image sensor 20 and outputs it to the image compression / decompression circuit 24. The camera control unit 23 operates the vertical acceleration sensor 6 and the horizontal acceleration sensor 7. Each acceleration sensor measures the amount of blurring of the digital still camera 1 within the charge accumulation time of the CCD image sensor 20. From each acceleration sensor, camera shake measurement values in the vertical and horizontal directions are sent to the camera control unit 23, respectively.
[0020]
The image compression / decompression circuit 24 outputs the compressed image signal and the decompressed image signal to the camera control unit 23. The camera control unit 23 temporarily stores the compressed image signal and sends the expanded image signal and the camera shake measurement value to the drawing signal output circuit 27. In the drawing signal output circuit 27, the camera shake measurement value and the expanded image signal are converted into a drawing signal and sent to the liquid crystal driver 28. The camera control unit 23 sends an instruction signal to the liquid crystal driver 28 to display the photographed image on the first liquid crystal monitor 13.
[0021]
On the first liquid crystal monitor 13, the camera shake information is displayed so as to overlap the photographed image and the photographed image. The camera shake information displays the vertical and horizontal blur sizes. The photographer confirms that there is no failure in photographing due to blurring, and performs an input operation for saving the photographed image. The camera control unit 23 outputs the stored compressed image data and camera shake measurement data to the memory card interface 25, and the memory card interface 25 performs a process of writing data to the memory card 15. Once the shooting is completed, the first liquid crystal monitor 13 resumes the live view display of the subject.
[0022]
When the same subject is photographed continuously, a newly photographed image is displayed on the first liquid crystal monitor 13 together with camera shake information at that time. Here, when the second liquid crystal monitor 14 is turned on, a photographed image taken immediately before is displayed together with camera shake information. The photographer compares the images on the first liquid crystal monitor 13 and the second liquid crystal monitor 14 and camera shake information, and performs an input operation to save the image when the second shot image has a smaller blur value. When the blur value of the first shot image is small, an operation to cancel saving of the shot image is performed.
[0023]
If the blur of the image taken at the second time is small, to erase the image taken at the first time, the slide switch 10 is operated to set the playback mode. The camera control unit 23 reads image data and camera shake data corresponding to the image data from the memory card 15. The read image data is sent to the image compression / decompression circuit 24 and decompressed. A reproduced image and camera shake information are displayed on the first liquid crystal monitor 13 and the second liquid crystal monitor 14. The operation key 12 is operated to select an image to be displayed on each monitor, an image obtained by photographing the same subject is compared with camera shake information, and an image with a large blur is deleted.
[0024]
In this way, the digital still camera 1 displays images for comparing quality on the two liquid crystal monitors together with the camera shake information, so that it is not necessary to enlarge each image and check the details, and an image that has failed to be captured. Can be easily erased. In the above embodiment, the captured images are displayed on the two liquid crystal monitors. However, the present invention is not limited to this, and the two captured images and camera shake information may be displayed separately on one monitor screen.
[0025]
In addition, the present invention provides a telephoto lens having a large influence of camera shake, such as a camera having an optical zoom function using a variable power lens and a digital zoom (electronic zoom) function that cuts out a part of a captured image and records an enlarged image. It is suitable for a digital camera capable of photographing, and can also be applied to a digital video camera capable of photographing a still image or a small digital camera built in a mobile phone or the like.
[0026]
【The invention's effect】
As described above, according to the present invention, camera shake is measured and recorded together with a photographed image, and at least two photographed images and corresponding camera shake information are displayed on a monitor that displays the photographed image. Even in a compact digital camera considering the convenience of the time, it is possible to easily judge the quality of the image by using the built-in monitor with a small screen size, and it is possible to save the memory capacity by erasing the failed image on the spot it can.
[Brief description of the drawings]
FIG. 1 is a front perspective view of a digital still camera.
FIG. 2 is a rear perspective view of the digital still camera.
FIG. 3 is a block diagram showing an electrical configuration of the digital still camera.
FIG. 4 is a flowchart showing an operation flow in a shooting mode.
FIG. 5 is a flowchart showing an operation flow in a reproduction mode.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Digital still camera 6 Vertical direction acceleration sensor 7 Horizontal direction acceleration sensor 13 1st liquid crystal monitor 14 2nd liquid crystal monitor

Claims (2)

Imaging means for imaging a subject and outputting an image signal, still image recording means for recording the image signal as still image data, measuring means for measuring the amount of camera shake in a direction parallel to the imaging surface, Each of a camera shake recording means for recording a camera shake measurement value, and a still image newly captured and recorded with the imaging instruction immediately after the imaging instruction is performed and a still image captured with the previous imaging instruction It comprises still image data and display control means for reading each camera shake measurement data corresponding thereto and outputting each still image and each camera shake measurement value to the image display means for simultaneous display. A digital camera. The digital camera according to claim 1, wherein the measuring unit is an acceleration sensor that detects acceleration in the vertical direction and horizontal direction.

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