DE102009025251A1 - CCD device - Google Patents

Abstract

A CCD device comprising a field of pixels arranged in rows and columns defines one image area. A device is provided for quickly determining the position of a reference object on the image surface by clocking charge on one edge of the image surface, combining the charge, collecting charge for a second time period, and another edge in one of the first Clock is clocked at right-angle direction, the charge is summarized and finally the combined charge is read out at the edges. The charge thus represents the intensity distribution of the imaged object in two directions and can be used to determine the position of the object without having to analyze each pixel. This reduces the processing time required to determine the position of the object on the image.

Description

FIELD OF THE INVENTION

The The present invention relates to a CCD device, and more particularly a CCD used to find the location of an object on the image plane can be used.

BACKGROUND OF THE INVENTION

at A typical CCD imager becomes a signal charge which which represents incident radiation, in a pixel field in one Image area collected. After an integration period the signal charge is typically sent to a memory section and then transferred to an output register by using appropriate Clock or drive pulses are applied to control electrodes. The signal charge is then read out of the output register and applied to a charge detection circuit to supply a voltage generate the amount of signal charge. The sensitivity such a device is due to the noise of the conversion process from charge to voltage and from the noise generated by the electronics the subsequent video chain is introduced limited.

An electron multiplying CCD (EMCCD) overcomes this limitation and is described in our previously published UK patent application GB-A-2,371,403 revealed as in 1 is shown. A CCD imager 1 includes a picture surface 2 , a storage section 3 and an output or readout register 4 All of these components are found in a conventional CCD imager. The output register 4 is serially extended so that it is a multiplication register 5 whose output is connected to a charge detection circuit 6 connected is.

During operation of the device, incident radiation becomes at the image surface 2 converted into a signal charge representing the intensity of the radiation impinging on the pixel field forming the image field. After the image acquisition period, driving pulses are applied to control electrodes 7 applied to the pixels of the image area 2 accumulated charge to the storage section 3 transferred to. At the same time, driver signals are also applied to control electrodes 8th at the storage section 3 created to cause charge to be transferred from line to line as indicated by the arrow, with the last line of charge being in elements in the line 3a held parallel to the output register 4 is transmitted.

When a signal charge line in the output register 4 has been transmitted, suitable driving pulses to the electrodes 9 to apply the charge from the elements of the output register sequentially to those of the multiplication register 5 transferred to. In this embodiment, the multiplication register has an architecture similar to the output register in that the doping is responsible for the addition of an electrode for duplication.

To duplicate the charge in each of the elements of the multiplication register 5 to achieve driving pulses with sufficiently high amplitude at control electrodes 10 to transfer both the signal charge from one element to the next adjacent element in the direction shown by the arrow and to increase the level of the signal charge due to the impact ionization by an amount determined by the amplitude of the drive pulses. As each charge packet is transferred through the multiplication register from one element to the next, the signal charge consequently increases. The at the circuit 6 Detected charge is therefore a duplicated version of the signal charge in the output register 4 is accumulated. At each stage of the multiplication register, the signal charge is increased. Each in the output register 4 stored signal charge packet undergoes an identical duplication process while passing through all the elements of the multiplication register 5 wanders through.

The output of the charge detection circuit 6 is also connected to an automatic gain control circuit 11 which are applied to the multiplication register 5 applied voltages to control the gain. In other embodiments, this feedback arrangement is omitted. If desired, the gain can then be controlled manually.

CCD sensors of the type described are suitable for many applications which include the position of an image of an object a CCD frame is detected, with this object in the Image surface of the CCD device can move. An example such an application is in use in imaging of stars using big astronomy telescopes. We however, have found that such facilities may be are unable to provide adequate performance for some Applications, about future generations very big Telescopes, to provide.

Large astronomical telescopes have a need for adaptive optics in the sense that the imaging path must vary to account for variations in the Earth's atmosphere that cause distortion of the image of stars. A large telescope will typically include a deformable mirror for imaging the stars on a detector. In addition, a portion of the reflected light is split using a beam splitter onto a separate detector array used to detect disturbances in the image caused by variations in the earth's atmosphere. The separate detector will typically include a lens array so that the light received by each portion of the mirror is imaged onto a separate detector, often called a wavefront sensor or center of gravity detector. Each such center of gravity detector thus receives a separate image of the considered star from a separate respective part of the primary mirror and thus from a specific optical path through the atmosphere to that part of the mirror. Any variation in the image due to the path through the atmosphere to that part of the mirror can therefore be detected by any such separate center of gravity detector.

Such an exemplary telescopic arrangement is for ease of reference in FIG 2 shown. A telescope 2 For example, light from an observed scene (e.g., a particular portion of the sky, which in the case of large astronomy telescopes comprises weak objects of interest and a bright "guide" star) forms an imaging optic 4 on a large deformable mirror device 6 which transmits the light via an optical path to a main sensor 10 reflected. The main sensor 10 Integrates the light over a suitable period, which is typically a few seconds, to collect the required image. Part of the received light is transmitted via a beam splitter 8th and an optic 14 also to a reference detector arrangement 12 which may be referred to as a wavefront sensor or center of gravity detector. This wavefront sensor detects the position of the imaged guide star for each point of the deformable mirror device and thus provides feedback to a controller 16 which can alter the deformable mirror to ensure that any variation due to the earth's atmosphere is compensated.

3 shows the sensor device 12 comprising an array of lenses, each of which captures an image of the guide star by means of a respective portion of the deformable mirror on a respective sensor 22 provides. If there is any deviation of the image at a particular point on the mirror, then the corresponding image will be on one of the center of gravity detectors 22 move accordingly.

The number of separate images of the guide star for which the center of gravity position must be determined increases with the size of the telescope mirror, requiring approximately one image per every square meter of the mirror surface. For current generations of telescopes, this requirement can be met while maintaining the required frame rate and low noise through the use of known CCD architectures with multiple multiplication registers each reading a group of point images corresponding to a region of the telescope mirror. An example of such a CCD is shown in FIG 4 shown.

The well-known CCD of 4 includes two field sections 21 which generate an image charge from a received image, which then passes to two corresponding half memory sections 23 is clocked. As with the arrangement of 1 then the charge will be in a multiplication register 25 duplicated and output circuits 27 clocked out.

We have established that the existing technologies with the Progression to larger telescope sizes might not be extended in this way that they read a larger one during operation Number of points with low noise in a continuous manner provide information for the deformable mirror to deliver fast settings to thereby to provide a correct image to the main image sensor.

We have generally found that for the purpose of the investigation the position of a continuously moving image of a Object on a CCD sensor a faster image processing arrangement is needed.

SUMMARY OF THE INVENTION

The The invention is defined in the claims to which now Reference is made.

The invention provides an arrangement that allows rapid determination of the position of an image of an object on a CCD sensor in two directions, which may be referred to as X and Y directions, or alternatively as the direction of rows and columns. By providing electrode connections to allow charging of charge either along rows or along columns, charge along two rectangular edges of the image area can be clocked into memory pixels. The use of a process known as "binning" or merging allows very fast transfer of charge into the charge storage pixels at the side and at the top or at the bottom of the image area. Consequently, the charge integrated over a specific period of time can be added up quickly and read out of the image area. This provides a signal which represents the distribution of the intensity of the image of the object in the X and Y directions, and from this the position of the image of the object on the CCD field can be determined. While the exact information of each pixel is lost due to the charge accumulation process, the information about the intensity distribution in the X and Y directions is all that is needed to reliably determine the position of the image of the object on the CCD array.

The Charge storage areas on the side and bottom edge The picture surface can simply be a set of pixels in the picture itself or an extra series of pixels that are not used for imaging. Such Extra series of pixels may be referred to as "summation pixels" or "summation trenches." or, alternatively, the charge can go directly into output registers be summed up and then from the output registers to Amplifiers are clocked out for signal detection. A significant advantage of the embodiment of the invention is that the summary process compared to a conventional reading of the CCD is fast, since the Charge of complete rows or columns added up and the number of charge signals associated with the charge detection circuit to be converted into a voltage is reduced. consequently is the process of generating the signals that make up the position of the image can be derived faster compared to known arrangements.

at the fast frame rates allowed by the invention the signal from the guide star will be very small and the use of EMCCD technology to reinforce this small signals can be beneficial.

The The structure described above provides a means of detection the position of a single point. A field of such structures can be used to determine the positions of a number of such Points can be determined and the structures can be different Be arranged types, for example, such that each line a Provides signal to a single charge detection circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

A Embodiment of the invention will now be described by way of example and with reference to the accompanying figures, in which:

1 a schematic drawing of a CCD imaging device of a known type is;

2 a schematic drawing of a telescopic arrangement, which may embody the invention;

3 is a schematic drawing of the reference sensor or wavefront sensor, which can embody the invention and in the telescope of 2 could be used;

4 Fig. 12 is a schematic drawing of a CCD imager of a known type used for adaptive optics applications;

5 a schematic drawing of a first CCD device embodying the invention;

6 is a schematic drawing of a second CCD device embodying the invention;

7 a schematic drawing of a third CCD device embodying the invention;

8th shows a readout register arrangement which may be used in embodiments of the invention;

9 shows the timing sequence involved in the arrangement of 8th can be used;

10 shows another timing sequence;

11 shows an alternative readout register arrangement that may be used in embodiments of the invention;

12 a timing diagram for the arrangement of 11 shows;

13 another timing diagram for the arrangement of 11 shows;

14 shows another alternative readout register arrangement; and

15 shows a possible clock arrangement of a CCD pixel that may be used in the embodiments of the invention.

PRECISE DESCRIPTION

The present embodiment includes a CCD device such as a CCD imager. The invention is also in one A method for operating a CCD device or for operating a Device containing a CCD device, such as a camera or telescopic arrangement, embodied.

The Embodiment of the invention may be in any application used in which the X and Y position of an image of a Object can be detected quickly using a CCD sensor array got to. However, the main application of the invention is for use in astronomy telescopes and therefore this will be first Application described to facilitate understanding. For large telescopes, as described above, An image of a weak astronomical object often becomes over long integration periods were recorded during which the image of the object on a main detector due to Can move variations in the Earth's atmosphere. The movement of parts of the image produced by different regions of the image Primary mirror is generated, due to the different optical paths through the atmosphere to a large one Telescope be different, and this leads to a Loss of resolution, d. H. a blur of the image. Around to support the determination of such variations in optical paths, often becomes a bright star near the darker object, which is detected, imaged and the bright star becomes the detection used in such variations due to atmospheric conditions. The knowledge of these variations will then change the shape of a deformable mirror within the telescope optics used to compensate for the distortion in real time and thus to reduce the blur of the image. If such a light star not available in the pictured section of the sky is, it can be artificially produced by you let a laser shine in the earth's atmosphere and emissions from a sodium layer in the atmosphere, for example Stimulated 90 km above the earth's surface. Such a Point is usually placed on the telescope in the middle and so are the outer edges of the Telescope mirror actually the elongated point see, because the illuminated section in the sodium layer of the earth's atmosphere will have a certain depth. Consequently, the task of the Reference sensor or wavefront sensor in it, the position of a essentially circular shape for parts of the image towards the center of the mirror or the position an oblong point for parts of the image to determine the edge of the mirror.

The Effects of the Earth's atmosphere cause the Image of the astronomical object quickly across the picture surface of the main detector. Consequently, the reference detector must use the Read out position frequently, and it typically will Reads on the order of 700 to 1000 frames per second needed.

A first CCD device embodying the invention is disclosed in U.S.P. 5 shown. In the embodiment, an architectural form which may be referred to as a rectangular transfer CCD or a 2-D transfer CCD is used. Such electrode structures for CDDs are known and are described in:
DR Smith, AD Holland, A Martin, D Burt, T Eaton, R Steward, "Developments and Testing of a 2-D Transfer CCD" IEEE Trans. Electron Devices, Vol 53, No. 11, (2006), pages 2748- 54 ,

A Variety of possible clock electrode structures for every pixel is possible and of completeness By the way, such an arrangement will be described later. Nevertheless, the key feature is that the charge in both the X and Y directions, or along lines and columns can be clocked down.

In the 5 shown CCD device 22 includes a picture surface 24 with a plurality of pixels, all of which have an electrode arrangement to allow clocking in both the horizontal and vertical directions, or in other words along rows and along columns. clock connections 28 allow clocking in each of the directions, allowing charge along lines to an output register 30 at the side of the image area or along columns to an output register 32 can be clocked at the bottom of the screen. The clock lines 28 and the electrode connections are arranged to charge by combining into the output registers 32 . 30 can be transmitted in both the horizontal and the vertical direction. As is known to those skilled in the art, the act of combining comprises transferring charge from one pixel to another without emptying the charge of a target pixel, thereby reducing the charge of pixels in the target pixel, in this case a pixel in the output register 32 . 30 , is added up.

In operation, the signal in the image section is integrated over the first half of the available integration period. Then it is quickly in one of the readout register, z. As the register at the bottom, transmitted, the signal is shared by all lines together. This is typically achieved by applying drive pulses to 3 of the 4 frame clocks while keeping the fourth static in its "off" state. The signal is then re-integrated over the second half of the available integration period and then quickly into the other readout register, e.g. B. the side register, transmitted, wherein the signal is shared by all columns together. This is typically accomplished by applying pulses to another set of 3 of the 4 frame clocks. Therefore, at the end of the integration period, the two registers contain charge signal patterns representing the summed vertical and horizontal represent profiles of the signal. These signals can be generated using common clock signals 26 be read out and digitally processed by the output amplifiers during the first half of the next integration period to extract the centroid information. Alternatively, the two registers can be clocked independently and each can be read out at any time between respective summary operations.

The embodiment of the invention provides a number of advantages in rapidly determining the position of the signal point of an imaged star on the CCD array. The summary process is very fast. In the example of an integration period of 1 millisecond for the CCD, the summing process may operate at clock frequencies on the order of MHz, so that in an example of 20x20 pixels, the summary period is on the order of 20 microseconds. In addition, the number of charge packets to be read is substantially reduced. For a field of N by N pixels, the number of pixels to be read in a conventional CCD imager is N ² . In the embodiment of the invention, the number of pixels to be read is 2N. This reduces the required data rate and consequently the bandwidth, resulting in a lower readout noise. In addition, the power dissipation associated with fast readout is reduced. The combining process also improves the signal-to-noise ratio because the charge accumulation process does not introduce any additional noise, but the resulting signal is larger while the noise component does not increase. Finally, the process is more efficient because fewer signal calculations need to be performed, as portions of the calculations are naturally performed during the load rollup process. The pixel field in the X and Y directions is reduced to two linear signals representing the sum of the image signals in the X and Y directions by the summing operation. The external digital processing must therefore perform fewer calculations to determine the position of the pixel.

The Calculations performed to determine the position of the pixel can be any suitable calculations The simplest is to be the "center of gravity" of the to determine the object imaged on the CCD. In this context the center of gravity indicates the point in the X and Y directions On both sides of the lighting evenly is distributed. This may be referred to as the centroid or centroid become. Other more complex calculations are possible detecting a reference signal from the detector and Perform a cross-correlation of the reference signal in Include comparison with the detected signal.

A second alternative embodiment is in 6 and includes an image sensor 22 with a picture surface 24 and clock lines 26 . 28 Like previously described. In addition, in this embodiment, a summation trench or register 44 provided that the charge can be clocked before the charge is transferred to the output register 42 is clocked. This additional rollup register allows charge to be summed into the register while charge is being clocked out of the output register from a previous rollup, further increasing the operating speed. This rollup register may be used in the embodiment of FIG 5 be used. In the embodiment of 6 however, the accumulation register is arranged to clock charge in a variant of the output register arrangement in which a single output register has two sections 40 and 42 for receiving charge, which is clocked horizontally or vertically. The charge clocked horizontally along lines is placed in the summation trench at the side of the image area and then in the section 40 the output register clocked. The charge clocked in columns is summed in the summation trench at the bottom of the image area and then in the section 42 the output register. The output register 40 . 42 is then clocked as a whole to read the signal charge from the vertical and then the horizontal summation in a continuous sequence. The advantage of this arrangement is that the CCD has only a single amplifier instead of two amplifiers 46 needed.

The arrangement of 6 has the advantage of requiring only a single amplifier, but also allows the readout period to be extended from the registers to the entire integration period. While charge is integrated in the image area, the previous charge information is read from the registers. Second, it allows the integration of the signals giving the horizontal and vertical profiles of the point to be finer in time than simply between the first and second half of the entire integration period. A number of shorter integration periods may be used wherein charge is alternately combined horizontally and vertically into the summing trenches, while the signals from the previous full integration period are read out by the registers. This technique helps to reduce a skew between the horizontal and vertical profiles in the case of a moving point. This mode can also be used for operation with a pulsed light source (eg. A pulsed laser guide star in adaptive optics applications) in which the signals from the alternating pulses can be summed separately.

Another CCD device embodying the invention is disclosed in U.S. Pat 7 shown. In this arrangement, the CCD includes a device 22 with a picture surface 24 and clock lines 26 . 28 as described above. Similarly, a summation trench 44 and two sections of an output register 40 . 42 provided. However, in this embodiment, the clock signals for the register sections are arranged such that one of the register sections and then the other register section are arranged via the output amplifier 46 is read out. In an alternative embodiment of 6 For example, the horizontal and vertical summation trenches can be independently clocked and the two register sections share common clocks together. In this case, charge would be shifted from one of the accumulation trenches to the corresponding register and read out. Upon completion of this readout, charge would be shifted from the second accumulation trench to its associated register portion for readout. In any case, only one register section would contain a signal so that separation of the horizontal and vertical information is maintained. This embodiment is advantageous when a number of such detectors are combined into one field.

A known clock electrode structure which can be used to control the movement of charge signals in orthogonal directions is shown in FIG 15 shown. In this structure, the movement of charge is controlled by four independent electrode sets. A first set of electrodes 108 has the form of stripes that are vertical in the drawing, and these are connected to a clocked voltage source VG1. A second sentence 114 has the form of stripes that are horizontal in the drawing, and these are connected to a clocked voltage source VG2. Two more sentences 120 . 124 have the shape of separate triangular electrodes and these are connected to clocked voltage sources VG3 and VG4. Channel stop regions 117 are formed in the silicon under the cutting regions of the first and second electrodes. To transfer charge vertically, VG1 is held at a low clock level and a sequence of clock pulses typically used for each three-phase CCD is applied to the other electrodes from VG2, VG3 and VG4. To transmit charge horizontally, VG2 is held at a low clock level and a similar pulse sequence is applied to VG1, VG3 and VG4. The exact sequence of applied pulses determines the direction of charge transfer up / down or left / right as with any standard 3-phase CCD.

In the embodiments of the 5 . 6 or 7 Different readout timing arrangements are possible. In the example of an integration period of 1 millisecond, an integration period of 1/2 millisecond and then combining in the horizontal direction followed by another integration period of 1/2 millisecond and combining in the vertical direction may be used. Alternatively, a toothed approach may be used that combines in alternate directions for smaller subsections of the total integration time span. For example, integrate for 0.25 milliseconds and then unite in one direction, summarize a second integration for 0.25 milliseconds and in the orthogonal direction, and summarize third and fourth integration periods of 0.25 milliseconds and in each direction.

The CCD sensors embodying the invention may have a variety of different field sizes. Typical examples are 16 pixels × 16 pixels and 20 pixels × 20 pixels. The many CCD image areas described with respect to each of these embodiments are typically arranged in groups, for example, 80x80 separate image areas, which may be referred to as sub-apertures. These sub-apertures each depict an object over a respective portion of the mirror. The image surfaces or sub-apertures are constructed from a single silicon CCD device, as now with reference to FIG 8th to 14 is described.

It there is a need for a gap between all Lower aperture image areas, typically of the order of magnitude a spacing of about 6 pixels between blocks of 20x20 Pixels lies. When reading the image signal leads this additional Distance of 6 pixels at wasted time while the Register reads out each of the sub-apertures in turn. We have therefore, the need for efficient arrangements of the output register with respect to each of the sub-apertures detected.

A first such register arrangement for a CCD device embodying the invention is disclosed in U.S.P. 8th shown. In this arrangement, the register follows a "serpentine" path around the subaperture surfaces. At each subaperture, the register is adjacent to one side and either the top or bottom edge. As can be seen, this arrangement provides for a very efficient use of space between the subaperture image areas. The alternate the sub-aperture image areas will clock in different directions. Starting from the upper right lower aperture image area 24 will summarize this in a horizontal direction to the right and in a vertical upward direction. The next subaperture image area will capture an image and then summarize horizontally to the right but vertically down. The image surfaces are arranged with this alternating arrangement of the direction of the clocking. The operation thus consists of an integration period followed by an appropriate clock to the side, an integration period and then a suitable clocking either up or down depending on the Unteraperturbildfläche. After the integration periods, the entire length of the register 50 over the amplifier 44 clocked out. During this cycle time the next integration takes place.

at this architecture will be the horizontally summarized and the vertically grouped images in the first and second Half an integration period of 1.4 milliseconds collected simultaneously in the registers. The reading of the entire field requires a total of 80 × (20 + 20 + N) + Ng cycles, where N is the number of additional ones Is empty pixel per subfield and Ng is the number of prescan pixels, d. H. the number of pixels in the amplifier register structure is.

The basic readout sequence for the so-called serpentine readout array is in 9 shown. In this example, with 80x80 sub-apertures at the 5 MHz clock frequency, read-out is completed in 800 microseconds if the number N of pixels between sub-apertures is about 10. An alternative clock arrangement is in 10 shown.

In the so-called "comb" arrangement of 11 For example, the sub-apertures of a given line have the same orientation and architecture and are summarized in the roll-up register on the same page and at the bottom. In the first half of an integration period of z. B. 1.4 milliseconds collected charge is collected horizontally and then transferred to the register and read during the second half of the integration period. After this reading is completed, the charge from the second half of the integration period is vertically summed and read out during the first half of the next integration period. The timing sequence is in 12 shown. The timing scheme for this arrangement can be summarized for each of the horizontal and vertical directions as 1 Integrate, 2 Summarize, 3 Transmit, and 4 Read. During the transmission and readout stages for one direction, the integration may take place in the opposite direction. An in 13 shown alternative timing arrangement is particularly applicable in the case of pulsed laser guide stars.

Another possible register arrangement is in 14 shown. In this arrangement, all subaperture image areas are 24 spaced apart by a larger amount than the previously described arrangements. Contrary to expectations, this gap can further increase the speed of readout (or reduce the number of charge detection circuits needed) and reduce the need to clear out any empty pixels. The top row of sub-apertures is located back to back to the next row of sub-apertures and the readout register 60 is in two parts 62 and 64 divided, one for each of the adjacent Un teraperturreihen. The pixels from each sub-aperture are merged into the adjacent summing trenches, as previously described, and then the side-by-side and bottom-up summing registers alternately become the respective part 62 . 64 the output register 60 read. The additional columns 66 between all subapertures would obviously leave a space in the pixel sequence. The parts of the output register 62 . 64 but unite at a summation point 68 and so at each gap in the sequence of signals from a series of sub-apertures, the charge from the other row of apertures is displayed. This occurs because of an additional delay in one of the register parts 64 is introduced such that the image pixels effectively at the node 68 be interlinked. This arrangement can significantly reduce any wasted clock time since there are very few, and possibly no, empty pixels that need to be clocked. In summary, the arrangement provides for gearing the charge from adjacent rows of sub-apertures arranged back to back.

The operation modes of the CCD device embodying the invention have been mentioned above but will now be described in more detail. In a "follow" mode, where each subaperture image area 24 the device monitors the image signal received from a respective section of the telescope mirror, the charge in the horizontal and vertical directions is summarized as described above. However, it is also possible to use the device in a normal full-frame mode in which all the pixels are individually clocked and read out to the output register. This advantageously allows the device to generate a reference image and to enable the computation and signal processing on the basis of such reference images, which can then be used in the following mode.

At the Starting a recording session, for example, can be a full frame picture generated by each of the sub-apertures and stored for analysis. This analysis may include that of a suitable correlation function is derived, with which subsequently in the following mode the signals from each sub-aperture are compared. In operation can change the setup between the two modes, so the picture for example, initially from the sub-apertures for analysis can be procured and then in follow-up mode during an image acquisition period for the main sensor changed can be. Once the image has been captured by the main sensor, You can put the sub-apertures in full-frame mode for analysis and to switch back to generating a reference signal.

One another operating mode is possible in situations in which the picture to be followed is known. In the example of the telescope the known image can be a laser-generated "guide star", whose time behavior is known. By pulsing the laser, which generates this guide star, the clock arrangement designed for example for synchronization with this pulsation so that the integration period lasts as long as the Laser pulse exists, and then when caused by the laser pulse Lighting extinguished, the charge is in the summation trenches summarized so that she is ready to return the laser pulse a lighting for a subsequent recording period caused. By summing up cargo during the time span in which no illumination from the guide star is present, blurring due to charge transfer, while the device is lit, it diminishes when not even eliminated.

Various other operating modes are possible, with all the topic the use of the abstract in two different directions of the CCD imaging device is common to an effective position of an image on the CCD field, thereby providing the required Data rate and time required to complete this determination is reduced.

The CCD device may comprise a multiplication register in each embodiment, as shown in FIG 1 is shown. In such an arrangement, the output of the output register is first supplied to a multiplication register and then to an output amplifier.

at The focus applications discussed above is the Output of the CCD is a signal representing the summed charge, which to a means for determining the center of gravity of an imaged Object, such as a DSP or a universal computer delivered becomes.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• GB 2371403 A [0003]

Cited non-patent literature

• - DR Smith, AD Holland, A Martin, D Burt, T Eaton, R Steward, "Developments and Testing of a 2-D Transfer CCD" IEEE Trans. Electron Devices, Vol. 53, No. 11, (2006), pages 2748 -54 [0040]

Claims (25)

CCD device comprising a field of pixels, which are arranged in rows and columns and an image area define, wherein the pixels have clock connections arranged so are that they have a clocking of charge either along lines or allow along columns, the device a first set of memory pixels for receiving charge, the along lines to a first edge of the image area are timed, and a second set of memory pixels for recording Charge passing along columns to a second edge of the image area are clocked, with the clock connections arranged so are that they charge in the first and second set of memory pixels sum up. The CCD device of claim 1, wherein the memory pixels Include pixels that are part of the image area. The CCD device of claim 1, wherein the memory pixels Comprise pixels forming an output register. The CCD device of claim 1, wherein the memory pixels form a separate rollup register. CCD device according to one of the preceding claims, the device being separate output registers for charge which is clocked along rows or columns. CCD device according to claim 1 to 4, wherein the Device comprises a single output register, the two parts has to absorb charge along lines or columns is clocked. A CCD device according to claim 6, wherein the two parts are arranged so that one connected in series with the other is. A CCD device according to claim 6, wherein the two parts with a connection to a common parent node and with Clock connections are arranged to alternately clock each part to enable. A CCD device according to claim 6, wherein the two parts with a connection to a common parent node and with common clock connections but with separately clocked rollup registers are arranged to an independent charge transfer into the two parts of the output register. CCD device according to one of the preceding claims, which includes a plurality of pixel fields comprising a plurality of Provide image surfaces in a regular Patterns are arranged. The CCD device of claim 10, wherein the image areas arranged in rows and columns. CCD device according to claim 11, wherein a continuous Readout register for each image area line or column is provided. The CCD device of claim 12, wherein the continuous Registers in a serpentine shape along each row or column is arranged. The CCD device of claim 12, wherein the continuous Register with a linear section along an edge of the image surfaces and separate sections along right - angled edges of the Image surfaces is arranged. The CCD device of claim 14, wherein adjacent ones Lines of image surfaces are arranged such that their respective continuous registers having an offset with each other are connected, that an indexing the registers the charge for each Image line alternately reads. CCD device according to one of the preceding claims, where the rows and columns are right-angled. A picture device containing the CCD device one of the preceding claims. Focusing device, which is a CCD device according to one of claims 1 to 16 and a means for analysis a signal from the combined charge includes around the center of gravity of an imaged object. Method for operating a CCD device of the Type that has pixels arranged in rows and columns and define an image area comprising: - charge is collected in the pixels as a result of a received image; - charge along lines to a first edge and along columns is clocked to a second edge; - Charge on the first edge and the second edge is summarized; and - the summarized charge is read out. The method of claim 19, wherein the accumulating of charge with clocking charge alternately to the first edge and alternate the second edge. The method of claim 20, wherein the reading The combined charge comprises alternating charge of the first edge and the second edge. A method according to claim 20 or 21, wherein said Collecting charge synchronized with a pulsed light source becomes. Method according to one of claims 19 to 22, in which charge of several image areas in a common Output register is read out. Method according to one of claims 19 to 23, further comprising that the readout of charge is used around the position of an imaged object in the image area to investigate. Method of focusing, the procedure according to any one of claims 19 to 24 and analyzing a signal from the combined charge includes the center of gravity of an imaged object.