We present some design details and characterization results for a VGA CMOS image sensor designed for high sped inspection applications. The sensor has 16 analog outputs, which can each operate at 50 MHz data rate, and can capture images at 1600 frames per second. The image sensor has exposure control functionality, antiblooming capability and a on-rolling shutter architecture to implement snap-shot image capture mode. The pixel architecture incorporates 5 transistors on a 15.3 micron pitch with 50 percent fill factor.
DALSA and Philips Digital Video Systems have developed a high performance pinned-photo-diode CCD linescan sensor for scanning of motion picture film. This application requires a sensor with performance optimized for a high dynamic range optical input, with high speed operation. The sensor is named the IL-P2-2048. It is based on the existing DALSA IL- P1-2048 linescan sensor design with a number of significant changes--the full well has been increased to in excess of 300,000 electrons, with a maximum video swing of more than 1000 mV with two bi-directional outputs operating at > 21 MHz video rate. Of importance is the introduction of pinned- photo diode pixels (10 X 10 micron pitch) which possess extremely low fixed pattern noise, low pixel-response non- uniformity, and low image lag. The sensor also has pixel select gates to enable the user to select the full resolution or a reduced number of pixels for use in different imaging formats; the pixel selection is nevertheless dynamic and can be user selectable. The output circuitry has excellent linearity from a few mV to the full signal swing of 1000 mV. In this paper the authors present the design and test results of the sensor.
Charge-coupled devices have found widespread use in many imaging applications and demonstrate many advantages over other detector technologies such as high speed, low power, low noise, and small physical size. Nevertheless, `off-the-shelf' CCD architectures are frequently not feasible for many unique applications, requiring custom CCD designs and processing. In this paper the authors discuss a CCD sensor developed specifically for a near- infrared linescan-type application. The authors discuss the architecture, design, and performance of the sensor, as well as current work in the project.
The applicability of large-area full-frame CCD image sensor technology to large optical format aerial reconnaissance applications has been recently demonstrated. The requirements of low-contrast, high-resolution imaging at high frame rates have generated the need for a manufacturable, multitap, small-pitch, wafer-scale CCD image sensor technology. The added requirement of incorporation of electronic motion compensation at the focal plane has generated the need for multisegmented full-frame area array architectures. Characterization results from the newly developed 5040 X 5040 element, eight-tap, full-frame image sensor with multisegmentation for electronic motion compensation are discussed. Experimental determination of resistive-capacitive time constants for metal strapped vertical clock busses on wafer-scale sensors is discussed.
CCD devices fabricated on low-resistivity silicon epi (30 - 60 (Omega) -cm) exhibit satisfactory imaging characteristics in the visible spectrum but inferior imaging characteristics in the near infrared and x ray regions. This is a result of the greater penetration depth of the photons, which tend to travel beyond the depletion regions under the CCD gates causing optical crosstalk and poor responsivity. This represents a performance limiting issue for acousto-optical applications and scientific imaging. CCD devices fabricated on high-resistivity silicon epi (>= 1000 (Omega) -cm) with increased epi layer thickness will exhibit superior imaging performance for near-infrared and x-ray photons. This is because the width of the depletion regions is much greater compared to devices on conventional substrates. DALSA has fabricated CCD structures on high-resistivity substrates and has examined their performance, in particular imaging behavior in the near-infrared region of the spectrum. We also examine the behavior of the nonimaging circuitry associated with the CCD such as the output amplifiers.
Focal planes constructed of high speed, high resolution CCD image sensors are suitable for airborne reconnaissance applications, but have mainly consisted of linear and TDI array configurations. Until recently large format area arrays have been limited to staring applications, characterized by long integration times and slow readout rates. Large area reconnaissance focal planes require opto-mechanical systems for motion compensation across the imaging plane. A unique CCD architecture has been developed to provide electronic image motion compensation using variable speed vertical clocking segments. This architecture has been applied to very large full frame CCD sensors having 2048 X 2048 and 5040 X 5040 pixel formats.
Reconnaissance systems incorporating solid-state image sensors have advantages over film- based systems in their ability to provide real-time images and transmit digital data to a remote location. In this application area array sensors have advantages over linear and TDI type sensors in eliminating the need for the aircraft to travel in a straight line as is required for 'push broom' imaging. DALSA has previously developed a single output 2048 X 2048 area array which evolved to a four output high speed image sensor suitable for airborne reconnaissance. In this paper we discuss a four output 5120 X 5120 image sensor; this sensor is a prototype for an 8 output imager suitable to replace film recording media for airborne reconnaissance. We review the performance of the existing 5120 X 5120 array and discuss the design modifications implemented on the second generation device to match reconnaissance requirements, improve performance and enhance yield.
Large format charge coupled device area arrays (1 million pixels or more) have proven to be useful in scientific, medical and industrial imaging applications. DALSA has developed a 1024 X 1024 pixel single output, full-frame area array incorporating 3-poly 3-phase buried channel NMOS CCD shift registers and a 10 micrometers X 10 micrometers pixel pitch. The device was fabricated with an additional buried channel implant (notch) in the pixel columns to increase charge storage capacity. In this paper the authors discuss the design and initial performance evaluation of the device. Preliminary measurements of the pixel charge storage capacity indicate 70,000 e- without notch and 140,000 e- with notch. The results indicate that the sensor should be suitable for a variety of applications such as high resolution machine vision, still photography, and scientific imaging.
A 26.2 million pixel CCD Imager Sensor has been successfully designed and fabricated. The device uses a full frame architecture with 5,120 X 5,120 pixels organization. With a pitch of 12 microns in both dimensions, the overall image zone is 61.44 mm X 61.44 mm. The charge storage capacity of each photosite is greater than 130,000 electrons and the minimum detectable charge is 50 electrons when correlated double sampling is used. The device is also capable of reduced dark current operation of 60 pA/cm2 when operated in the surface inversion mode. The device has four outputs, each of which can operate up to 12 MHz.
High speed, high resolution CCD image sensors are suitable for airborne reconnaissance applications, but have mainly consisted of linear and TDI arrays. To date large format area arrays have been limited to staring applications, characterized by long integration times and slow readout rates. The authors have developed a 2048 (H) by 2048 (V) pixel, fast framing CCD array for aerial reconnaissance. The array incorporates high speed design features to provide operation in excess of 10 frames per second. Process modifications have been used in the design of a high signal capacity photoelement. A 12 micron square pixel pitch results in a relatively small focal plane diagonal of 34 millimeters. In this paper, we present the design and detailed performance evaluation of the array.
KEYWORDS: Charge-coupled devices, Surveillance, Electrons, Modulation transfer functions, Capacitance, Image sensors, Clocks, Airborne reconnaissance, Imaging systems, Signal to noise ratio
Time-Delay and Integration (TDI) CCD sensors have been proven to increase the effective sensitivity in imaging applications where the image is scanned across the focal plane. This paper describes the development of a 6032 element, 32-stage TDI imager for airborne reconnaissance applications. The device is fabricated using a 3-poly 3-phase NMOS process, incorporating buried channel CCDs throughout. It is one-side buttable to produce an array of over 12,000 contiguous elements and is capable of read rates of over 4000 lines per second. For fast readout, the design incorporates dual horizontal CCDs for a total of four outputs in the abutted configuration. The architecture also allows dynamic selection in the number of TDI stages.
Time-delay and integration (TDI) CCD sensors have been proven to increase the effective sensitivity in linescan imaging applications. This paper describes the design and initial test results of a 6032 element, 32-stage TDI imager for airborne reconnaissance applications. The device is fabricated using a 3-poly 3-phase NMOS process, incorporating buried channel CCDs throughout. It is one-side buttable to produce an array of over 12,000 contiguous elements and is capable of read rates of over 4000 lines per second. For fast readout, the design incorporates dual horizontal CCDs for a total of four outputs in the abutted configuration. The architecture also allows dynamic selection in the number of TDI stages.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.