Television – Camera – system and detail – Optics
Reexamination Certificate
1997-10-10
2001-06-05
Garber, Wendy R. (Department: 2612)
Television
Camera, system and detail
Optics
C348S230100, C348S296000, C348S297000, C348S363000
Reexamination Certificate
active
06243136
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an image input device, and more particularly to an image input device such as a digital still camera and a digital video camera receiving image data obtained by imaging an object using a solid imaging element such as a CCD (Charge Coupled Device) imaging element as well as to an image input system with a computer connected to the image input device for executing the processing of operation for imaging.
BACKGROUND OF THE INVENTION
In the image input device and image input system as described above, for executing successive operations for imaging, it is necessary to read out image data and to store the read out data in a memory for each exposure, so that the time required to read out the data is different according to the number of pixels in a solid imaging element.
Especially, as a large number of pixels are set in a solid imaging element when a high-resolution image is to be obtained, a long time is required for reading out the data. And for this reason, in recent years, there has been proposed the pixel shift technique for achieving a higher resolution image with a smaller number of pixels.
Description is made herein of a conventional method of making a high resolution image.
FIG. 13
is a timing chart for explaining a timing for pixel shift in an example based on the conventional technology, and
FIG. 14
is a timing chart for explaining the pixel offset and a timing when an operation for imaging is executed in an enlarged dynamic range in an example based on the conventional technology.
At the timing for executing pixel shift shown in
FIG. 13
, a time for reading (TR) required for reading out image data from a CCD imaging element is set in a range, for instance, from {fraction (1/60)} to {fraction (1/15)} seconds, so that a time interval for releasing an electric shutter under the condition in which an exposure time in the first operation and in the second operation is set to a constant period of time, namely a time interval between timings each when an operation for reading out image data is started is obtained by adding a time for pixel shift (TS) to a time for reading (TR). The time for pixel shift (TS) is effected after the time (TF) for transferring charges from the photodiodes to the vertical CCD.
At the timing for executing pixel shift and an operation for imaging in an enlarged dynamic range shown in
FIG. 14
, a time interval between timings each when an operation for reading out image data is started is the same as that shown in
FIG. 13
, but by making an exposure time in the second operation for exposure (E
2
) different from that in the first operation for exposure (E
1
) (for instance, E
1
<E
2
) for executing operations for imaging, the second image data can be used for some pixels which are out of a range to be exposed within a screen used in the first operation for imaging when the pixels are in an appropriate range in a screen used for the second operation for imaging. And for this reason, an image in a wide and dynamic range with a higher resolution can be obtained.
Further, description is made also of a method of obtaining a high resolution image when an all-pixels read-out type of CCD imaging element is not used.
FIG. 15
is a timing chart showing a timing for reading out all pixels in a field read-out type of CCD imaging element according to an example based on the conventional technology.
In this example, in order to read out all pixels using the field read-out type of imaging element, a shutter mechanism which is an optical light-shuttering mechanism is used. At the timing shown in
FIG. 15
, the shutter mechanism is driven at the timing of generation of a mechanical-shutter signal after execution of the operation for imaging, and light to the CCD imaging element is shut. This light-shuttered state is continued until the operation for reading out the pixels is completed.
The operation for reading out pixels is executed twice in one operation for imaging, image data in an odd number of fields is read out in synchronism to a vertical synchronizing signal according to generation of a read-out signal R
1
in a first operation for reading out pixels, and image data in an even number of fields is read out in synchronism to the vertical synchronizing signal according to generation of a read-out signal R
2
in a second operation for reading out pixels.
It should be noted that a photodiode-control signal is generated after the read-out signals are outputted to remove electric charge accumulated in photodiodes (indicating sections in which a plurality of vertical lines are shown on the photodiode-control signal in FIG.
15
). After the electric charge is removed from the photodiodes by means of this photodiode-control signal, the electronic shutter is actuated for exposure.
As described above, in the image input device and the image input system according to the example based on the conventional technology, the electronic shutter can be released to execute operations for imaging only at a time interval between the timings when the operation for reading out image data is started, which makes the device and the system inappropriate for imaging a dynamic object which requires high-speed successive operations for imaging and for imaging an object by a camera held in photographer's hands because these operations must be executed in consideration for shaking of the camera, and for this reason, imaging with the conventional device and system is limited to operations for imaging a still image of a static object, which does not allow full use of the imaging capability.
Nowadays, it has been proposed to use a plurality of sheets of CCD imaging elements and a prism for obtaining a high quality image without any time loss, but in that case the configuration is larger and complicated, and the cost is expensive, which is disadvantageous.
SUMMARY OF THE INVENTION
It is a first object of the present invention to obtain an image input device which can image high quality images regardless of the imaging conditions.
It is a second object of the present invention to obtain an image input device which can image high quality images regardless of the imaging conditions even it is a compact and at a low price.
It is a third object of the present invention to obtain an image input system which can image high quality images regardless of the imaging conditions for any image input device.
It is a fourth object of the present invention to obtain an image input system which can image high quality images regardless of the imaging conditions even if the image input device is compact and at a low price.
With the image input device according to the present invention, when the successive operations for imaging are to be executed, the second operation for imaging is controlled at the timing when the image data obtained in the first operation for imaging is read out from the imaging element, and after start of the second operation for imaging, the light-shuttering operation is controlled at the timing earlier than the timing when the image data obtained in the second operation for imaging is read out from the imaging element, and the light is shuttered to the imaging element with the optical mechanism, so that the control of the second operation for imaging is immediately executed at the timing when the image data obtained in the first operation for imaging is read out without being restricted by the timing when image data is read out from the imaging element.
As a result, time intervals between timings when operations for imaging are executed are reduced and successive operations for imaging are executed at a higher speed, so that imaging conditions are not restricted to an operation for imaging a static object, and operations for imaging a dynamic object and also imaging an object with a camera held in a cameraman's hands can be performed.
With the image input device according to the present invention, when the successive operations for imaging are to be executed, the change of the imaging range is controlled after the fi
Garber Wendy R.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Ricoh & Company, Ltd.
White Mitchell
LandOfFree
Image input device and image input system which controls... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image input device and image input system which controls..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image input device and image input system which controls... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2446686