Canon Kabushiki Kaisha

Canon Inc.

Canon Research Center America, Inc.

Gerald A May

Harry T Garland

Roger D Melen

Michael G Roberts

Neil A Williams

Ken Hunter

Jonathan DeVito

A self-diagnosing image sensor ( ) detects and stores maps of functioning and malfunctioning pixels ( ) in a memory ( ) directly coupled to the sensor ( ). The memory ( ) is coupled to an external monitoring computer ( ) which retrieves the pixel map and adjusts the sensor data received from the image sensor ( ) in accordance with the retrieved pixel map. A defect discriminator ( ) is coupled directly to the image sensor ( ) and to the memory ( ) for detecting whether a pixel ( ) malfunctions, and updates the map accordingly. Additionally, if the number of malfunctioning pixels ( ) in the sensor ( ) exceeds a predefined threshold, an alert message is available to the external monitoring computer or display ( ) to warn the user that the sensor ( ) may be generating inaccurate information. An on-plate pixel processor ( ) performs any necessary interpolation of the date responsive to the pixel map, and a complete image is sent to the remote display ( ), without requiring any further processing.

Self-diagnostic image sensor

A system and method for automatically collimating X-rays. A digital X-ray system ( ) includes a generator ( ), a sensor unit ( ), a control station ( ), and a preview monitor ( ). The generator ( ) generates X-ray radiation that is captured by the sensor unit ( ) as a digital image and transmitted to the control station ( ). The captured image is displayed on the preview monitor ( ). The generator ( ) includes a collimator ( ) that collimates the generated radiation into a primary beam of X-rays. The size and shape of the primary beam can be adjusted by modifying collimation parameters. A short duration beam of X-rays is generated by the generator ( ) and captured ( ) by the sensor unit ( ). This step is repeated as necessary or desired. The resulting digital images are analyzed ( ) by the control station ( ) to calculate a calibration coefficient. Another short duration beam of X-rays is generated and a reference image is captured ( ). The control station ( ) analyzes the reference image and uses the calibration coefficient to collimate the collimator ( ) to achieve a desired goal, such as radiating all or only part of an object being radiated. Once the collimator ( ) is adjusted, the X-ray image of the subject is exposed.

Auto-collimating digital X-ray system

Digital X-ray imaging system,automatically provides an enhanced digital display image,D from a digital camera image,C showing internal structure,S of interest within subject,S. Calibrated radiation attenuators,A placed near the subject appear in the camera image and in the display image. X-ray source,X generates X-ray radiations which are attenuated within the calibrated attenuators to provide calibrated attenuations. The X-ray radiations are also differentially attenuated within the interior of the subject to reveal internal structure therein. Digital X-ray camera,C detects the calibrated radiations to form the camera image of the calibrated greyscale levels. The camera also detects the differentially attenuated radiations to provide the camera image of internal structure of the subject. Each calibrated attenuator appears in the camera image as a collection of adjacent camera pixels exhibiting one of the plurality of calibrated greyscale levels within the camera greyscale. Retriever,retrieves the calibrated greyscale level from the digital camera image of each attenuator pixel collection. Greyscale coordinator,is responsive to the retrieved calibrated greyscale levels for determining mapping assignments defining the relationship between the camera greyscale and the display greyscale which provides the enhanced digital display image. Greyscale mapper,M is responsive to the mapping assignments for mapping the camera greyscale levels of the camera pixels forming the camera image into display greyscale levels of display pixels forming the enhanced display image. Display monitor,D is responsive to the enhanced display image for displaying a pixel image of the internal structure of interest within the subject.

Digital X-ray imaging system with automatic display image greyscale enhancement and method

Diagnostic x-ray images having uniform optical density are generated by selectively scanning (,) lines of pixels (,) in a sensor unit (,) used to capture x-ray images in a digital radiography system (,). By selectively scanning (,) the lines of pixels (,), the exposure time of such pixels can be controlled. The lines of pixels (,) are selectively scanned (,) according to exposure compensation profiles (,) for the anatomic regions of interest. The exposure compensation profiles (,) include an ordered sequence of exposure times which can be loaded into a programmable timer (,) coupled to read out circuitry (,) located in the sensor unit (,). The timer (,) uses this ordered sequence of exposure times to determine which pixel line to access next, and when to initiate that access. The exposure compensation profiles (,) can be generated (,) from empirical data by taking (,) preliminary low dose exposures of the body parts to be examined.

Exposure compensation for digital radiography systems using selective scanning of sensor arrays

A digital x-ray image (,) is divided (,) into regions (,), (,) according to a selected (,) exposure compensation profile. Each region (,),(,) includes pixel values indicative of gray-scale levels in that region. The pixel values are used to index entries in one of a plurality of spatial LUTs (,) assigned (,) to that region. Entries in the selected spatial LUT (,) contain new pixel values indicative of a transform (,) on the original pixel values used to index the spatial LUT (,). Original pixel values are replaced (,) with corresponding pixel values from the spatial LUT (,). Each region of the x-ray image (,) needing compensation is transformed (,), in turn, until the entire image (,) is processed.

Exposure compensation for digital radiography systems using spatial look-up tables

The x-ray exposure of an image pixel array (,) is measured by assigning to certain pixels (,) of the array the task of measuring the level of exposure. A target set (,) of pixels from array (,) is selected and divided into a set of exposure pixels (,) and a set of image pixels (,). Both sets of pixels generate and collect electrical charges in proportion to the amount of x-ray exposure experienced by them. The charges collected by the exposure pixels (,) are continuously read out during the capture of an image and compared with a desired exposure level. Once the desired exposure level is reached, as indicated by the exposure pixels (,), the image pixels (,) are read out and an image is produced.

Exposure control for digital radiography systems using charge build-up in sensor array pixels

A method and system for storing and selectively retrieving information, such as words, from a document set. The method includes generating an image data set representative of the information contained in the document set. The method also involves generating a text data set representative of a text portion of the information contained in the document set. A text-image correspondence (TIC) table is generated that includes data representative of coordinates information corresponding to each phrase of the document set. A search phrase is identified in response to user-specified search criteria and the search phrase is identified in the text image data set. Then, the TIC table is used to identify the coordinates information corresponding to the search phrase identified in the text data set. A display of the portion of the page containing the search phrase is generated using the coordinates information.

Selective document retrieval method and system

A document transport apparatus (100) that may be attached to or integrated with a system (200) for performing a plurality of functions on a single sheet of paper. The apparatus (100) includes one or more elongate tray elements (102), having an end stop element (110) to stop the movement of the sheet of paper as it is delivered to the tray element (102). A rotation element (104), such as a roll bar, is attached to the tray element (102) and proximate to the receiving end (101) of the tray element (102). The rotation element (104) may selectively be activated by a motor (112) attached to the rotation element (104), to rotate the tray element (102) from a first position for receiving a sheet of paper from an output port (206) of one device, to a second position for delivering that same sheet of paper to the input port (208) of another device.

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Saratoga, CA, United States of America

Gerald A May