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73-416: Completed in 1969, the telescope was upgraded with high-order adaptive optics in 2004 and remains a highly versatile astrophysical observatory that serves as an important test platform for developing new instrumentation and technologies. The Dunn Solar Telescope specializes in solar high-resolution imaging and spectroscopy. These observations allow solar astronomers worldwide to obtain a better understanding of

146-423: A charge amplifier , which converts the charge into a voltage . By repeating this process, the controlling circuit converts the entire contents of the array in the semiconductor to a sequence of voltages. In a digital device, these voltages are then sampled, digitized, and usually stored in memory; in an analog device (such as an analog video camera), they are processed into a continuous analog signal (e.g. by feeding

219-481: A shift register . The essence of the design was the ability to transfer charge along the surface of a semiconductor from one storage capacitor to the next. The concept was similar in principle to the bucket-brigade device (BBD), which was developed at Philips Research Labs during the late 1960s. The first experimental device demonstrating the principle was a row of closely spaced metal squares on an oxidized silicon surface electrically accessed by wire bonds. It

292-482: A CCD is the higher cost: the cell area is basically doubled, and more complex control electronics are needed. An intensified charge-coupled device (ICCD) is a CCD that is optically connected to an image intensifier that is mounted in front of the CCD. An image intensifier includes three functional elements: a photocathode , a micro-channel plate (MCP) and a phosphor screen. These three elements are mounted one close behind

365-468: A Solar Vacuum Tower Telescope was started by the architect and engineer Charles W. Jones in 1963. Construction on the final building started in 1966 under the U.S. Army Corps of Engineers and ended in 1967, at a cost of about $ 3 million, with the architectural firm of Roghlin and Baran, Associates. Richard B. Dunn, for whom the instrument was eventually dedicated, wrote an article in Sky & Telescope about

438-665: A cooling system—using either thermoelectric cooling or liquid nitrogen—to cool the chip down to temperatures in the range of −65 to −95 °C (−85 to −139 °F). This cooling system adds additional costs to the EMCCD imaging system and may yield condensation problems in the application. However, high-end EMCCD cameras are equipped with a permanent hermetic vacuum system confining the chip to avoid condensation issues. The low-light capabilities of EMCCDs find use in astronomy and biomedical research, among other fields. In particular, their low noise at high readout speeds makes them very useful for

511-428: A factor of 2–3 compared to the surface-channel CCD. The gate oxide, i.e. the capacitor dielectric , is grown on top of the epitaxial layer and substrate. Later in the process, polysilicon gates are deposited by chemical vapor deposition , patterned with photolithography , and etched in such a way that the separately phased gates lie perpendicular to the channels. The channels are further defined by utilization of

584-555: A few percent. That image can then be read out slowly from the storage region while a new image is integrating or exposing in the active area. Frame-transfer devices typically do not require a mechanical shutter and were a common architecture for early solid-state broadcast cameras. The downside to the frame-transfer architecture is that it requires twice the silicon real estate of an equivalent full-frame device; hence, it costs roughly twice as much. The interline architecture extends this concept one step further and masks every other column of

657-405: A flexibility to allow for the combination of any many spectral lines, "limited only by practical considerations (e.g., the number of detectors available, space on the optical bench, etc.)". The Interferometric Bidimensional Spectro-polarimeter (IBIS) is a dual interferometer, imaging spectropolarimeter. It uses a series of precise piezoelectric tuning to rapidly scan selected spectral lines within

730-429: A full-frame device, all of the image area is active, and there is no electronic shutter. A mechanical shutter must be added to this type of sensor or the image smears as the device is clocked or read out. With a frame-transfer CCD, half of the silicon area is covered by an opaque mask (typically aluminum). The image can be quickly transferred from the image area to the opaque area or storage region with acceptable smear of

803-592: A gain register is placed between the shift register and the output amplifier. The gain register is split up into a large number of stages. In each stage, the electrons are multiplied by impact ionization in a similar way to an avalanche diode . The gain probability at every stage of the register is small ( P < 2%), but as the number of elements is large (N > 500), the overall gain can be very high ( g = ( 1 + P ) N {\displaystyle g=(1+P)^{N}} ), with single input electrons giving many thousands of output electrons. Reading

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876-401: A large lateral electric field from one gate to the next. This provides an additional driving force to aid in transfer of the charge packets. The CCD image sensors can be implemented in several different architectures. The most common are full-frame, frame-transfer, and interline. The distinguishing characteristic of each of these architectures is their approach to the problem of shuttering. In

949-399: A non-equilibrium state called deep depletion. Then, when electron–hole pairs are generated in the depletion region, they are separated by the electric field, the electrons move toward the surface, and the holes move toward the substrate. Four pair-generation processes can be identified: The last three processes are known as dark-current generation, and add noise to the image; they can limit

1022-417: A p+ doped region underlying them, providing a further barrier to the electrons in the charge packets (this discussion of the physics of CCD devices assumes an electron transfer device, though hole transfer is possible). The clocking of the gates, alternately high and low, will forward and reverse bias the diode that is provided by the buried channel (n-doped) and the epitaxial layer (p-doped). This will cause

1095-409: A reflective material such as aluminium. When the exposure time is up, the cells are transferred very rapidly to the hidden area. Here, safe from any incoming light, cells can be read out at any speed one deems necessary to correctly measure the cells' charge. At the same time, the exposed part of the CCD is collecting light again, so no delay occurs between successive exposures. The disadvantage of such

1168-445: A signal from a CCD gives a noise background, typically a few electrons. In an EMCCD, this noise is superimposed on many thousands of electrons rather than a single electron; the devices' primary advantage is thus their negligible readout noise. The use of avalanche breakdown for amplification of photo charges had already been described in the U.S. patent 3,761,744 in 1973 by George E. Smith/Bell Telephone Laboratories. EMCCDs show

1241-422: A similar sensitivity to intensified CCDs (ICCDs). However, as with ICCDs, the gain that is applied in the gain register is stochastic and the exact gain that has been applied to a pixel's charge is impossible to know. At high gains (> 30), this uncertainty has the same effect on the signal-to-noise ratio (SNR) as halving the quantum efficiency (QE) with respect to operation with a gain of unity. This effect

1314-416: A single slice of the image, whereas a two-dimensional array, used in video and still cameras, captures a two-dimensional picture corresponding to the scene projected onto the focal plane of the sensor. Once the array has been exposed to the image, a control circuit causes each capacitor to transfer its contents to its neighbor (operating as a shift register). The last capacitor in the array dumps its charge into

1387-424: A time. During the readout phase, cells are shifted down the entire area of the CCD. While they are shifted, they continue to collect light. Thus, if the shifting is not fast enough, errors can result from light that falls on a cell holding charge during the transfer. These errors are referred to as "vertical smear" and cause a strong light source to create a vertical line above and below its exact location. In addition,

1460-464: A variety of astronomical applications involving low light sources and transient events such as lucky imaging of faint stars, high speed photon counting photometry, Fabry-Pérot spectroscopy and high-resolution spectroscopy. More recently, these types of CCDs have broken into the field of biomedical research in low-light applications including small animal imaging , single-molecule imaging , Raman spectroscopy , super resolution microscopy as well as

1533-649: Is a multi-slit spectropolarimeter made specifically for the Dunn Solar Telescope to study magnetism on the solar surface. The instrument samples adjacent slices of the solar surface using four parallel slits to achieve high cadence, diffraction-limited , precision spectropolarimetry. Up to four spectral lines at visible and infrared wavelengths, covering four different heights in the solar atmosphere, can be observed simultaneously. It can be optimized to provide simultaneous spectral coverage at visible (3,500 – 10,000 Å) and infrared (9,000 – 24,000 Å) wavelengths through

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1606-410: Is a photoactive region (an epitaxial layer of silicon), and a transmission region made out of a shift register (the CCD, properly speaking). An image is projected through a lens onto the capacitor array (the photoactive region), causing each capacitor to accumulate an electric charge proportional to the light intensity at that location. A one-dimensional array, used in line-scan cameras, captures

1679-432: Is a specialized CCD, often used in astronomy and some professional video cameras , designed for high exposure efficiency and correctness. The normal functioning of a CCD, astronomical or otherwise, can be divided into two phases: exposure and readout. During the first phase, the CCD passively collects incoming photons , storing electrons in its cells. After the exposure time is passed, the cells are read out one line at

1752-402: Is an integrated circuit containing an array of linked, or coupled, capacitors . Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a major technology used in digital imaging . In a CCD image sensor , pixels are represented by p-doped metal–oxide–semiconductor (MOS) capacitors . These MOS capacitors ,

1825-550: Is hung on three bolts, each only 76 millimeters (3.0 in) in diameter. Despite the size and weight, much of the telescope can be controlled and monitored from a single control room, off to one side of the main instrument observing table. The Dunn Solar Telescope has a rotating optical bench, which can be configured to multiple observing setups, depending on the requirements of the science under study. The four most widely used instruments, often used together in one complex observing setup, are: The Facility Infrared Spectropolarimeter

1898-557: Is one of the major advantages of the ICCD over the EMCCD cameras. The highest performing ICCD cameras enable shutter times as short as 200 picoseconds . ICCD cameras are in general somewhat higher in price than EMCCD cameras because they need the expensive image intensifier. On the other hand, EMCCD cameras need a cooling system to cool the EMCCD chip down to temperatures around 170  K (−103  °C ). This cooling system adds additional costs to

1971-555: Is referred to as the Excess Noise Factor (ENF). However, at very low light levels (where the quantum efficiency is most important), it can be assumed that a pixel either contains an electron—or not. This removes the noise associated with the stochastic multiplication at the risk of counting multiple electrons in the same pixel as a single electron. To avoid multiple counts in one pixel due to coincident photons in this mode of operation, high frame rates are essential. The dispersion in

2044-512: Is the probability of getting n output electrons given m input electrons and a total mean multiplication register gain of g . For very large numbers of input electrons, this complex distribution function converges towards a Gaussian. Because of the lower costs and better resolution, EMCCDs are capable of replacing ICCDs in many applications. ICCDs still have the advantage that they can be gated very fast and thus are useful in applications like range-gated imaging . EMCCD cameras indispensably need

2117-422: Is the right choice. Consumer snap-shot cameras have used interline devices. On the other hand, for those applications that require the best possible light collection and issues of money, power and time are less important, the full-frame device is the right choice. Astronomers tend to prefer full-frame devices. The frame-transfer falls in between and was a common choice before the fill-factor issue of interline devices

2190-405: Is used in the construction of interline-transfer devices. Another version of CCD is called a peristaltic CCD. In a peristaltic charge-coupled device, the charge-packet transfer operation is analogous to the peristaltic contraction and dilation of the digestive system . The peristaltic CCD has an additional implant that keeps the charge away from the silicon/ silicon dioxide interface and generates

2263-671: The Kodak Apparatus Division, invented a digital still camera using this same Fairchild 100 × 100 CCD in 1975. The interline transfer (ILT) CCD device was proposed by L. Walsh and R. Dyck at Fairchild in 1973 to reduce smear and eliminate a mechanical shutter . To further reduce smear from bright light sources, the frame-interline-transfer (FIT) CCD architecture was developed by K. Horii, T. Kuroda and T. Kunii at Matsushita (now Panasonic) in 1981. The first KH-11 KENNEN reconnaissance satellite equipped with charge-coupled device array ( 800 × 800 pixels) technology for imaging

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2336-558: The LOCOS process to produce the channel stop region. Channel stops are thermally grown oxides that serve to isolate the charge packets in one column from those in another. These channel stops are produced before the polysilicon gates are, as the LOCOS process utilizes a high-temperature step that would destroy the gate material. The channel stops are parallel to, and exclusive of, the channel, or "charge carrying", regions. Channel stops often have

2409-473: The photodiode to the CCD. This led to their invention of the pinned photodiode, a photodetector structure with low lag, low noise , high quantum efficiency and low dark current . It was first publicly reported by Teranishi and Ishihara with A. Kohono, E. Oda and K. Arai in 1982, with the addition of an anti-blooming structure. The new photodetector structure invented at NEC was given the name "pinned photodiode" (PPD) by B.C. Burkey at Kodak in 1984. In 1987,

2482-595: The 550 and 860 nm range. This creates a time series of high-fidelity imaging, spectroscopy, and polarimetry of the Sun. It has a large circular field-of-view combined with high spectral (R ≥ 200,000), spatial ≃ 0.2″) and temporal resolution (several frames per second). The Rapid Oscillations in the Solar Atmosphere (ROSA) instrument is a single-controlled system of six imaging fast-readout CCD cameras. The full chip on each camera can be read out 30 frames per second, and all

2555-399: The CCD cannot be used to collect light while it is being read out. A faster shifting requires a faster readout, and a faster readout can introduce errors in the cell charge measurement, leading to a higher noise level. A frame transfer CCD solves both problems: it has a shielded, not light sensitive, area containing as many cells as the area exposed to light. Typically, this area is covered by

2628-402: The CCD concept. Michael Tompsett was awarded the 2010 National Medal of Technology and Innovation , for pioneering work and electronic technologies including the design and development of the first CCD imagers. He was also awarded the 2012 IEEE Edison Medal for "pioneering contributions to imaging devices including CCD Imagers, cameras and thermal imagers". In a CCD for capturing images, there

2701-545: The CCD to deplete, near the p–n junction and will collect and move the charge packets beneath the gates—and within the channels—of the device. CCD manufacturing and operation can be optimized for different uses. The above process describes a frame transfer CCD. While CCDs may be manufactured on a heavily doped p++ wafer it is also possible to manufacture a device inside p-wells that have been placed on an n-wafer. This second method, reportedly, reduces smear, dark current , and infrared and red response. This method of manufacture

2774-473: The CCD-G5, was released by Sony in 1983, based on a prototype developed by Yoshiaki Hagiwara in 1981. Early CCD sensors suffered from shutter lag . This was largely resolved with the invention of the pinned photodiode (PPD). It was invented by Nobukazu Teranishi , Hiromitsu Shiraki and Yasuo Ishihara at NEC in 1980. They recognized that lag can be eliminated if the signal carriers could be transferred from

2847-404: The EMCCD camera and often yields heavy condensation problems in the application. ICCDs are used in night vision devices and in various scientific applications. An electron-multiplying CCD (EMCCD, also known as an L3Vision CCD, a product commercialized by e2v Ltd., GB, L3CCD or Impactron CCD, a now-discontinued product offered in the past by Texas Instruments) is a charge-coupled device in which

2920-593: The PPD began to be incorporated into most CCD devices, becoming a fixture in consumer electronic video cameras and then digital still cameras . Since then, the PPD has been used in nearly all CCD sensors and then CMOS sensors . In January 2006, Boyle and Smith were awarded the National Academy of Engineering Charles Stark Draper Prize , and in 2009 they were awarded the Nobel Prize for Physics for their invention of

2993-471: The Sun. Scientists and engineers use the telescope to investigate a range of solar activities, often in concert with satellites or rocket launches, and to develop new technologies for the 4-meter Daniel K. Inouye Solar Telescope . The telescope was inaugurated as the world's premier high spatial resolution optical solar telescope in 1969. With a horizontal rotating 40-foot-diameter (12 m) observing platform, such that instruments do not have to be mounted on

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3066-451: The array's dark current , improving the sensitivity of the CCD to low light intensities, even for ultraviolet and visible wavelengths. Professional observatories often cool their detectors with liquid nitrogen to reduce the dark current, and therefore the thermal noise , to negligible levels. The frame transfer CCD imager was the first imaging structure proposed for CCD Imaging by Michael Tompsett at Bell Laboratories. A frame transfer CCD

3139-692: The basic building blocks of a CCD, are biased above the threshold for inversion when image acquisition begins, allowing the conversion of incoming photons into electron charges at the semiconductor-oxide interface; the CCD is then used to read out these charges. Although CCDs are not the only technology to allow for light detection, CCD image sensors are widely used in professional, medical, and scientific applications where high-quality image data are required. In applications with less exacting quality demands, such as consumer and professional digital cameras , active pixel sensors , also known as CMOS sensors (complementary MOS sensors), are generally used. However,

3212-427: The cameras are triggered from one control system. As such, it provides the ability to image multiple layers of the photosphere and chromosphere simultaneously. At its installation in 2010, it generated up to 12 TB of data per day, making it one of the largest datasets in ground-based solar astronomy at the time. In addition, some older instruments are available, although these are now rarely used: A design for

3285-426: The channel in which the photogenerated charge packets will travel. Simon Sze details the advantages of a buried-channel device: This thin layer (= 0.2–0.3 micron) is fully depleted and the accumulated photogenerated charge is kept away from the surface. This structure has the advantages of higher transfer efficiency and lower dark current, from reduced surface recombination. The penalty is smaller charge capacity, by

3358-447: The charge could be stepped along from one to the next. This led to the invention of the charge-coupled device by Boyle and Smith in 1969. They conceived of the design of what they termed, in their notebook, "Charge 'Bubble' Devices". The initial paper describing the concept in April 1970 listed possible uses as memory , a delay line, and an imaging device. The device could also be used as

3431-423: The completion of the instrument in 1969. As quoted from the article: "In our design we wanted most of all to eliminate problems of local seeing, which are discussed at every meeting on solar instrumentation. Solar astronomers worry about turbulence caused by the slot in the observatory dome, heating of the dome surfaces, heating of the telescope, local convection, and turbulence within the optical system...In our case,

3504-460: The dome was eliminated. We put a window high up on a 135-foot pyramidal tower and then evacuated the air from the entire telescope inside the tower. The latter reduces the effects of local convection and the vacuum eliminates the internal turbulence and seeing problems. Also, it provides the comfort of a heated observing room [...]" The tower telescope was originally dedicated on October 15, 1969, and renamed in 1998 after Richard B. Dunn . A plaque at

3577-515: The facility reads: "Named in honor of one of solar astronomy's most creative instrument builders, this vacuum tower telescope is the masterpiece of Richard B. Dunn's long scientific career at Sacramento Peak Observatory (1998). Construction of the vacuum tower used for the DST significantly impacted future solar instruments: So sharp were the images formed from this type of solar telescope, that almost every large solar telescope built since then has been based on

3650-819: The gain is shown in the graph on the right. For multiplication registers with many elements and large gains it is well modelled by the equation: P ( n ) = ( n − m + 1 ) m − 1 ( m − 1 ) ! ( g − 1 + 1 m ) m exp ⁡ ( − n − m + 1 g − 1 + 1 m )  if  n ≥ m {\displaystyle P\left(n\right)={\frac {\left(n-m+1\right)^{m-1}}{\left(m-1\right)!\left(g-1+{\frac {1}{m}}\right)^{m}}}\exp \left(-{\frac {n-m+1}{g-1+{\frac {1}{m}}}}\right)\quad {\text{ if }}n\geq m} where P

3723-506: The image sensor for storage. In this device, only one pixel shift has to occur to transfer from image area to storage area; thus, shutter times can be less than a microsecond and smear is essentially eliminated. The advantage is not free, however, as the imaging area is now covered by opaque strips dropping the fill factor to approximately 50 percent and the effective quantum efficiency by an equivalent amount. Modern designs have addressed this deleterious characteristic by adding microlenses on

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3796-497: The incident light. Most common types of CCDs are sensitive to near-infrared light, which allows infrared photography , night-vision devices, and zero lux (or near zero lux) video-recording/photography. For normal silicon-based detectors, the sensitivity is limited to 1.1 μm. One other consequence of their sensitivity to infrared is that infrared from remote controls often appears on CCD-based digital cameras or camcorders if they do not have infrared blockers. Cooling reduces

3869-467: The invention and began development programs. Fairchild's effort, led by ex-Bell researcher Gil Amelio, was the first with commercial devices, and by 1974 had a linear 500-element device and a 2D 100 × 100 pixel device. Peter Dillon, a scientist at Kodak Research Labs, invented the first color CCD image sensor by overlaying a color filter array on this Fairchild 100 x 100 pixel Interline CCD starting in 1974. Steven Sasson , an electrical engineer working for

3942-431: The large quality advantage CCDs enjoyed early on has narrowed over time and since the late 2010s CMOS sensors are the dominant technology, having largely if not completely replaced CCD image sensors. The basis for the CCD is the metal–oxide–semiconductor (MOS) structure, with MOS capacitors being the basic building blocks of a CCD, and a depleted MOS structure used as the photodetector in early CCD devices. In

4015-411: The late 1960s, Willard Boyle and George E. Smith at Bell Labs were researching MOS technology while working on semiconductor bubble memory . They realized that an electric charge was the analogy of the magnetic bubble and that it could be stored on a tiny MOS capacitor. As it was fairly straightforward to fabricate a series of MOS capacitors in a row, they connected a suitable voltage to them so that

4088-433: The light and reflects it back up, where it exits the vacuum tube through six quartz optical windows in the floor of an optical laboratory at ground level. The telescope's entire optical system – from the top of the tower to the base of its underground portion, plus the 40-foot-diameter (12 m) observing room floor – is contained within the vacuum tube. The optics are evacuated to eliminate distortion due to convection in

4161-430: The lowest excavated point (the bottom of the sump) is 228 feet (69 m) below ground. Enclosed within the concrete tower is a vertical vacuum tube with 3-foot-thick walls. The optical path starts at a heliostat on top of the tower. An entrance window at the top of the tower, and two mirrors, reflect sunlight down the vacuum tube to the 64-inch primary mirror, 193 feet (59 m) underground. The primary mirror focuses

4234-464: The multiplied electrons back to photons which are guided to the CCD by a fiber optic or a lens. An image intensifier inherently includes a shutter functionality: If the control voltage between the photocathode and the MCP is reversed, the emitted photoelectrons are not accelerated towards the MCP but return to the photocathode. Thus, no electrons are multiplied and emitted by the MCP, no electrons are going to

4307-413: The other in the mentioned sequence. The photons which are coming from the light source fall onto the photocathode, thereby generating photoelectrons. The photoelectrons are accelerated towards the MCP by an electrical control voltage, applied between photocathode and MCP. The electrons are multiplied inside of the MCP and thereafter accelerated towards the phosphor screen. The phosphor screen finally converts

4380-491: The output of the CCD, and this must be taken into consideration in satellites using CCDs. The photoactive region of a CCD is, generally, an epitaxial layer of silicon . It is lightly p doped (usually with boron ) and is grown upon a substrate material, often p++. In buried-channel devices, the type of design utilized in most modern CCDs, certain areas of the surface of the silicon are ion implanted with phosphorus , giving them an n-doped designation. This region defines

4453-447: The output of the charge amplifier into a low-pass filter), which is then processed and fed out to other circuits for transmission, recording, or other processing. Before the MOS capacitors are exposed to light, they are biased into the depletion region; in n-channel CCDs, the silicon under the bias gate is slightly p -doped or intrinsic. The gate is then biased at a positive potential, above

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4526-407: The phosphor screen and no light is emitted from the image intensifier. In this case no light falls onto the CCD, which means that the shutter is closed. The process of reversing the control voltage at the photocathode is called gating and therefore ICCDs are also called gateable CCD cameras. Besides the extremely high sensitivity of ICCD cameras, which enable single photon detection, the gateability

4599-406: The surface of the device to direct light away from the opaque regions and on the active area. Microlenses can bring the fill factor back up to 90 percent or more depending on pixel size and the overall system's optical design. The choice of architecture comes down to one of utility. If the application cannot tolerate an expensive, failure-prone, power-intensive mechanical shutter, an interline device

4672-453: The telescope itself, the Dunn Solar Telescope continues to offer a versatile, user-friendly setup. It has two high-order adaptive optics benches to compensate for blurring by Earth's atmosphere. The whole building from top to bottom is a single instrument. Like an iceberg, only a part of the telescope's bulk is visible above ground. More than half the entire building is underground – the tower extends 136 feet (41 m) feet above ground, while

4745-419: The telescope that would otherwise be caused by the great heat produced by focusing sunlight. The interior vacuum tube, which weighs more than 250 tons, is suspended from the top of the tower by a mercury float bearing that contains 10 tons of mercury. This bearing allows the entire vacuum tube to be rotated, compensating for the apparent rotation of the image as the Sun rises into the sky. The bearing, in turn,

4818-407: The threshold for strong inversion, which will eventually result in the creation of an n channel below the gate as in a MOSFET . However, it takes time to reach this thermal equilibrium: up to hours in high-end scientific cameras cooled at low temperature. Initially after biasing, the holes are pushed far into the substrate, and no mobile electrons are at or near the surface; the CCD thus operates in

4891-456: The total usable integration time. The accumulation of electrons at or near the surface can proceed either until image integration is over and charge begins to be transferred, or thermal equilibrium is reached. In this case, the well is said to be full. The maximum capacity of each well is known as the well depth, typically about 10 electrons per pixel. CCDs are normally susceptible to ionizing radiation and energetic particles which causes noise in

4964-445: The use of a unique dual-armed design. It was "designed to capture the Fe I 6302 Å and Fe I 15648 Å or He I 10830 Å lines with maximum efficiency." The Spectro-Polarimeter for Infrared and Optical Regions performs achromatic lens Stokes polarimetry across several visible and infrared spectral regions. Completed in 2005, it was designed to act as 'experimental oriented' instrument, built with

5037-499: The vacuum tower concept." Daniel K. Inouye Solar Telescope Too Many Requests If you report this error to the Wikimedia System Administrators, please include the details below. Request from 172.68.168.151 via cp1112 cp1112, Varnish XID 392384750 Upstream caches: cp1112 int Error: 429, Too Many Requests at Fri, 29 Nov 2024 05:48:23 GMT Charge-coupled device A charge-coupled device ( CCD )

5110-550: Was a simple 8-bit shift register, reported by Tompsett, Amelio and Smith in August 1970. This device had input and output circuits and was used to demonstrate its use as a shift register and as a crude eight pixel linear imaging device. Development of the device progressed at a rapid rate. By 1971, Bell researchers led by Michael Tompsett were able to capture images with simple linear devices. Several companies, including Fairchild Semiconductor , RCA and Texas Instruments , picked up on

5183-479: Was addressed. Today, frame-transfer is usually chosen when an interline architecture is not available, such as in a back-illuminated device. CCDs containing grids of pixels are used in digital cameras , optical scanners , and video cameras as light-sensing devices. They commonly respond to 70 percent of the incident light (meaning a quantum efficiency of about 70 percent) making them far more efficient than photographic film , which captures only about 2 percent of

5256-450: Was demonstrated by Gil Amelio , Michael Francis Tompsett and George Smith in April 1970. This was the first experimental application of the CCD in image sensor technology, and used a depleted MOS structure as the photodetector. The first patent ( U.S. patent 4,085,456 ) on the application of CCDs to imaging was assigned to Tompsett, who filed the application in 1971. The first working CCD made with integrated circuit technology

5329-466: Was launched in December 1976. Under the leadership of Kazuo Iwama , Sony started a large development effort on CCDs involving a significant investment. Eventually, Sony managed to mass-produce CCDs for their camcorders . Before this happened, Iwama died in August 1982. Subsequently, a CCD chip was placed on his tombstone to acknowledge his contribution. The first mass-produced consumer CCD video camera ,

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