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Topic: Frame transfer CCD


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CCD

In the News (Thu 12 Nov 09)

  
  Frame transfer CCD - Wikipedia, the free encyclopedia
A frame transfer CCD is a specialized CCD, often used in astronomy, designed for high exposure efficiency and correctness.
A frame transfer CCD solves both problems: it has a hidden, not normally used area containing as many cells as the area exposed to light.
The downside of such a CCD is the higher cost: the cell area is basically doubled, and more complex control electronics are needed.
en.wikipedia.org /wiki/Frame_transfer_CCD   (344 words)

  
 Charge-coupled device - Wikipedia, the free encyclopedia
CCDs are used in digital photography and astronomy (particularly in photometry, optical and UV spectroscopy and high speed techniques such as lucky imaging).
With a frame transfer CCD, half of the silicon area is covered by an opaque mask (typically aluminum).
CCD cameras used in astrophotography often require very sturdy mounts to cope with vibrations and breezes, along with the tremendous weight that most imaging platforms inherently cause.
en.wikipedia.org /wiki/Charge-coupled_device   (1653 words)

  
 Olympus Microscopy Resource Center: Digital Imaging in Optical Microscopy - Concepts in Digital Imaging - ...
Transfer time from the image-integrating array to the shielded storage array is dependent upon the pixel array sizes, but is typically on the order of 500 microseconds or less.
With the use of a mechanical shutter, a frame-transfer CCD can be used to quickly capture two sequential images, a useful feature in fluorescence microscopy and other applications that require simultaneous acquisition of images generated at different emission and/or excitation wavelengths.
The entire process is repeated until all rows of image data are transferred off the chip, first to a signal output amplifier and then to an analog-to-digital signal converter integrated circuit.
www.olympusmicro.com /primer/digitalimaging/concepts/frametransfer.html   (592 words)

  
 Photomultiplier Tube   (Site not responding. Last check: 2007-10-29)
The frame-transfer CCD uses a two-part sensor in which one-half of the parallel array is used as a storage region and is protected from light by a light-tight mask.
This transfer is accomplished by a series of parallel and serial shifts that displace rows of charge along the chip toward a single corner containing the read-out amplifier.
The size of a pixel in a scientific-grade CCD may be increased by binning, a process in which the charge from a cluster of adjacent photodiodes is pooled and treated as if it came from a larger detector.
www.retrievertech.com /Product/CCD.htm   (1130 words)

  
 Photometrics - Glossary   (Site not responding. Last check: 2007-10-29)
A CCD that has been uniformly reduced to a thickness of approximately 10 µm so that an image can be focused on the back of the parallel register (where there is no gate structure).
When the CCD is exposed to light, the serial register receives charge from the parallel register and shifts it to the output node to form an image.
In CCD imaging technology, the measure of the signal quality at a given pixel, expressed as the ratio of the measured signal to the overall noise at that pixel.
www.photomet.com /library_glossary.html   (3944 words)

  
 Better Digital Imaging Solutions....NOW!
Thinned CCDs exhibit a high sensitivity to photons ranging from the soft x-ray to the near-infrared regions of the spectrum.
After the CCD imager is exposed, it is shifted to and stored in the other half of the CCD, the storage array.
When the CCD is exposed to light, the serial register receives charge from the parallel register and shifts it to readout to form an image.
www.imageteck.net /glossary.htm   (5595 words)

  
 Charge-coupled device   (Site not responding. Last check: 2007-10-29)
Those electrons are shifted along the CCD by regular electronic pulses and "counted" by a circuit which dumps the electrons from each pixel in turn into a capacitor and measures and amplifies the voltage across it, then empties the capacitor.
CCDs with several rows of pixels shift the charge down in the fashion of a vertical shift register and only the last row is read out in a horizontal shift register.
Since a high-resolution CCD chip is very expensive, as of 2004 even a professional photographer could hardly afford a 3CCD high-resolution still camera.
www.freedownloadsoft.com /info/ccd.html   (1149 words)

  
 Jose Mawyin / Stony Brook Laser Teaching Center
The front illuminated Frame Transfer CCDs suffer the same fate as the Full Frame CCDs, that is a reduced QE in the visible with a particularly low QE in the blue.
On a CCD camera the resolution is usually defined in the number of pixels for the x and y dimension of the camera.
The sensor architecture, a full frame digital camera is slower than a frame transfer camera or a interline transfer due to the higher density of the sensor on the chip.
laser.physics.sunysb.edu /~jose/CCDInfo.html   (2215 words)

  
 The CCD architectures commonly used for high performance cameras
The full frame CCD is the simplest form of sensor in which incoming photons fall on the full light sensitive sensor array.
Frame transfer devices have typically faster frame rates than full frames devices and have the advantage of a high duty cycle i.e.
The frame transfer CCD has the sensitivity of the full frame device but are typically more expensive due to the larger sensor size needed to accommodate the frame storage region.
www.andor.com /library/digital_Cameras/index.asp?app=314   (494 words)

  
 GCA_Camdig_Architsens
In the lower part there is a transfer gate that controls the flow of the electronic charge packets to the horizontal linear CCD which supply sequentially the charge packets to the output amplifier sending the signals to the frame grabber interfacing the digital camera and computer.
The transfer of the charge packets along the columns and in the horizontal CCD happens according to the mechanism exposed in the previous paragraph.
However, a new exposure of the CCD can be done at the end of the full transfer of the charge distribution into the matrix memory, that is during the image transfer to the frame grabber.
www.fis.unipr.it /~fermi/PagInternet_English/Digital_Cameras/DigCam_ArchitCCD.html   (1298 words)

  
 CCD's   (Site not responding. Last check: 2007-10-29)
CCD's and CIDs are all under a class of detectors called charge transfer devices - based on silicon after solid state devices were introduced in 1960s; silicon first used to make discrete devices, transistors and diodes which were principally used in research, aerospace, and industrial applications.
A frame transfer CCD can operate continuously without a shutter at television frame rates; if the mask is removed, the entire imager can be used with a shutter as full frame
Thinned CCDs - light normally enters the CCD through the gates of the parallel register - usually made of very thin polysilicon, which is reasonably transparent at long wavelength, but becomes opaque at < 400 nm; gate structure attenuates incoming light.
www.chm.colostate.edu /erf/teaching/c532/ccds.htm   (2449 words)

  
 Progressive Scanning - what is it?
In order to do so, a camera must either have no frame store within the CCD sensor, or have a frame transfer CCD or a full frame interline transfer CCD (this type of camera is most suitable for machine vision).
The latter is a CCD sensor with an interline frame store which has the same resolution as the sensor area.
In short, cameras with a full frame shutter, such as the Sony XC-55, are marketed as progressive scan cameras and have the ability to capture moving objects with full horizontal and vertical resolution.
www.visionelements.co.uk /wpprogscan.htm   (309 words)

  
 E-1 > Frequently Asked Questions
The E-1 Full Frame Transfer CCD transfers image data via a Vertical Charge Register that is a fraction of the size of an Interline highway.
The Full Frame Transfer CCD uses more of the pixel area to actually act as a sensor with a wider aperture for the photodiode and larger pixel capture area.
Located between the shutter and the CCD, the Supersonic Wave Filter uses high-speed ultrasonic vibration to cause most types of dust to simply fall away to be collected and held, preventing it from damaging the photograph.
www.olympusamerica.com /cpg_section/cpg_support_faqs.asp?id=919   (2758 words)

  
 Redlake Glossary
The variable frequency signal EXSYNC triggers line or frame transfer from the sensor to the readout registers and so controls output line or frame rate of the camera.
Frame Rate or Read Out Rate - The speed at which images are captured by an imaging system is called the frame rate and is expressed as number of frames per second EFPS.
Higher frame rates are far better for easier focusing and sample positioning and general ease of use.
www.redlake.com /support/glossary.aspx   (6331 words)

  
 Olympus Microscopy Resource Center: Photomicrography - Frame-Transfer CCD Operation - Interactive Java Tutorials
Use the mouse cursor to shift the slider to the left to observe the CCD at slower shift speeds, or to the right for faster speeds.
The entire process is repeated until all rows of image data are transferred to the output amplifier and off the chip to a analog-to-digital signal converter integrated circuit.
A major advantage of this architecture is the ability of this device to operate without a shutter or synchronized strobe, allowing for an increase in device speed and faster frame rates.
www.olympusmicro.com /primer/java/photomicrography/ccd/frametransfer   (490 words)

  
 Operation   (Site not responding. Last check: 2007-10-29)
The transfer is achieved by reducing the voltage on the gate electrode while the voltage on the neighbouring electrode is raised.
The imaging region of the CCD is continuously exposed to X-rays so that a second integration proceeds while the first is being read from the frame store.
The field of view of CCD detectors cannot yet match that of microchannel plates, although a number of chips can be placed side-by-side in the focal plane to increase coverage.
www.roe.ac.uk /~jcm/thesis/node51.html   (457 words)

  
 Photometrics - Encyclopedia   (Site not responding. Last check: 2007-10-29)
A frame-transfer CCD has its parallel register divided into two distinct areas: the image array, where images are focused, and the storage array, where the integrated image is temporarily stored prior to readout.
Typically, the storage array is identical in size to the image array and is covered with an opaque mask to shield the pixels from light.
Finally, a frame-transfer CCD can be used in conjunction with a mechanical shutter to acquire two images in rapid succession.
www.photomet.com /library_enc_frametrans.shtml   (257 words)

  
 Olympus Australia
The E-1's superb image quality is made possible by a 4/3-type full-frame transfer CCD that boasts an area 4 to 5 times greater than the 1/1.8 and 2/3-type image sensors used in ordinary compact digital cameras.
Unlike the interline transfer CCDs commonly found in digital SLRs, which have light shielded shift registers that leave only a small active pixel area for each photodiode, the full-frame transfer CCD has only a small area masked, allowing it to receive much more light.
To maximise performance of the CCD, new Zuiko Digital lenses are available that have been specifically designed to take advantage of the characteristics of the Four Thirds System.
www.olympusimaging.com.au /e1/imagequality/fullFrame.htm   (130 words)

  
 Kodak Pro DCS620x review: Page 1. Intro [Digital Photography Review]
The advantages to Interline Transfer CCD's are simply that, they can be controlled by software and don't require a mechanical shutter (though are often used in conjunction with one) and can produce a video feed output (a requirement for a live preview LCD feed).
To get around this Interline Transfer CCD manufacturers place a layer of "microlenses" (click here for electron microscope image of microlenses) over the CCD to capture more light and focus it onto the smaller photodiode area which then gives them an better effective fill factor of about 70%.
As Full Frame CCD's are simpler (don't have shift registers and associated electronics around each photodiode) they have a much better Fill Factor (around 70%) and don't require or use microlenses.
www.dpreview.com /reviews/print.asp?review=kodakdcs620x&page=1   (946 words)

  
 2.3.1.1 Description of Physical Principles
The array operates as follows: when an image is focused onto the CCD, photons which penetrate the electrode structure generate electron-hole pairs in the underlying silicon substrate, and the signal charges are stored in the potential wells beneath the electrode structure (gates).
This eliminates the requirement for a mechanical shutter to shield the array during readout, since the data transfer from image to store section is accomplished in a fraction of the time (msecs) taken to read out the data in the array.
Charge transfer within a CCD is subject to inefficiencies caused by the trapping of signal charge at discrete sites in the silicon.
www.astro.psu.edu /xray/docs/sop/node28.html   (1326 words)

  
 Photography - Wikipedia, the free encyclopedia
A camera or camera obscura is the image-forming device and photographic film or a digital storage card is the recording medium, although other methods are available.
For instance, the photocopy or xerography machine forms permanent images but uses the transfer of static electrical charges rather than photographic film, hence the term electrophotography.
Rayographs published by Man Ray and others are images produced by the shadows of objects cast on the photographic paper, without the use of a camera.
en.wikipedia.org /wiki/Photography   (5210 words)

  
 Olympus E-300 Digital SLR Camera (8 Megapixel Entry Level Digital SLR)
In comparison to its Interline Transfer counterparts, which are found in the majority of digital models, the FFT CCD has a larger pixel area, with bigger photodiodes and transfer channels.
Originally developed for motion-picture video cameras, interline transfer CCDs have light shields that mask a substantial portion of the signal transfer area, reducing the size of the light reception area that determines the resulting image quality.
Compared with Interline Transfer, which is used in the majority of digital SLRs, the FFT CCD has a larger pixel area, as well as bigger photodiodes and transfer channels.
www.jjmehta.com /products/olympus_e300.html   (2063 words)

  
 Nikon Instruments - Digital Sight DS-1QM: Introduction   (Site not responding. Last check: 2007-10-29)
New is the “virtual frame transfer" CCD technology that uses in contrary to ordinary low light level imaging cameras, the photosensitive area of the CCD a factor of 2.5 times more efficient.
Comparison of the effective area (in yellow) of a square pixel (dashed line) between virtual frame transfer CCD technology and line transfer CCD technology as used on ordinary low light level cameras.
In the line transfer technology the read out “structure" is obscuring the photosensitive area.
www.nikon-instruments.com /uk/products/digitalimaging/ds-1qm/introduction.html   (315 words)

  
 Photometrics - Encyclopedia   (Site not responding. Last check: 2007-10-29)
In CCD imaging, SNR refers to the relative magnitude of the signal compared to the uncertainty in that signal on a per-pixel basis.
Photoelectrons collected by a CCD exhibit a Poisson distribution and have a square root relationship between signal and noise.
Binning is the process of combining charge from adjacent pixels in a CCD during readout into a single "superpixel." Binning neighboring pixels on the CCD array may allow one to reach a photon-limited signal more quickly at the expense of spatial resolution.
www.photomet.com /library_enc_signal.shtml   (470 words)

  
 Rotating Prism Eglin Camera
The degree of corruption is increased with the intensity of light, the sensitivity of the sensor, and with slower vertical shift rates-the greater the number of photons that can be converted to electric charge while the matrix is being drained, the greater the potential for corruption or smear.
Full frame and frame transfer CCD sensors are used in cameras providing high spatial resolution and/or exceptional light sensitivity.
The most common method for minimizing smear in these CCDs is the use of a shutter, mechanical or electronic, to shield the sensor during charge transfer.
www.epixinc.com /vision_archive/rpvc.htm   (1174 words)

  
 Olympus - Image Quality   (Site not responding. Last check: 2007-10-29)
Often so-called Interline Transfer CCDs are used in digital still cameras, despite the fact they were origin ally developed for film recording.
Compared to this, the CCD integrated in the Olympus E-Series has a considerably higher photodiode aperture ratio (fill factor) and provides a larger transferable signal.
One of the reasons is that pixels are comprised of a photo diode, where the signals are generated, as well as a so called transfer channel, which is used to transport the signals to the processors.
www.olympus.co.uk /consumer/dslr_6839.htm   (442 words)

  
 Handbok of CCD Astronomy   (Site not responding. Last check: 2007-10-29)
Operation analogous to water buckets collecting water, which is then transferred to a separate location to be metered
Typical CCD has three gates/pixel, readout via clocking pixel charge in 3 phases, only transfer charges in vertical direction
Began coating CCD’s which allow them to become sensitive to wavebands silicon is not sensitive to or to enhance the performance
www.du.edu /~rmatson1/AstrCh2outline.htm   (337 words)

  
 Narragansett Imaging Products - Digital Camera Modules
These platforms offer a range of resolutions and frame rates together with a selection of interface options and form factors.
The FTM1010 is a 1 megapixel (1024 x 1024) digital camera module with a frame transfer CCD image sensor that gives true 12-bit images at 15 frames per second.
The FFM4027 is an 11 megapixel (4008 x 2672) digital camera module with a frame transfer CCD image sensor that gives true 12-bit images at 2 frames per second via a cameralink interface.
www.nimaging.com /products/modules   (352 words)

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