Picker International, Inc.

Peter S Castro

David L Gilblom

David L Gilbolm

A latent image is formed on a stimulable phosphor plate (10) by irradiating the phosphor plate with x-rays from an x-ray source (14). To develop the stimulable phosphor plate, the plate is irradiated with light of a different wavelength from developer light source (32). The light from the developer light source causes the stimulable phosphor plate to give off light of yet another characteristic wavelength. Light from the stimulable phosphor plate is filtered (38) to remove the wavelength of the developer light and focused (42) on a light sensing element (46) of a time delay and integration video camera (34). The stimulable phosphor plate and the video camera are moved relative to each other and the rate of movement is monitored (60). An array control (50) shifts rows of data or charge values along the light sensing element in coordination with movement of the stimulable phosphor plate such that the light emitted by each incremental element of the stimulable phosphor plate is integrated over a full column of detector elements of the light detector array. The time delay and integration video camera produces a video signal indicative of the latent x-ray shadowgraphic image from the stimulable phosphor plate. In one embodiment (FIG. 1), the developer is in a separate unit. In other embodiments, the time delay and integration camera and the stimulable phosphor plate are in a common darkbox such that the latent image is developed immediately and automatically to produce the video image (FIGS. 3, 4, and 5).

Shadowgraphic x-ray imager with TDI camera and photo stimulable phosphor

One or more time delay and integration camera assemblies (A) are mounted in a housing (100) which is rotated by a motor (40, 106) relative to a vertical axis. A tachometer or encoder (44) produces signals whose frequency or voltage varies in accordance with an angular velocity of the camera assemblies about the vertical axis. A clock generator (46) converts the angular velocity signals into clocking signals for controlling movement of vertical lines of data values (20) along an array (14) of light sensitive elements to a shift register (22). In one embodiment, the clock generator includes a divider (82) which converts the angular velocity signal into a voltage, a comparator (84) which compares the first voltage with a second voltage, and a voltage controlled oscillator (88) which oscillates to generate the clocking signal. A second divider (88) defines a feedback loop between the output of the voltage controlled oscillator and the comparator for generating the second voltage. Each line of data from the array update (64) a corresponding line of a panoramic memory (66). The selectable portion (72) of the data from the panoramic memory is retrieved (70) independently of the memory updating. Scan converters (74) convert retrieved portions of the panoramic memory data into appropriate format for display on video monitor (78). In this manner, the panoramic memory is updated as the array rotates and data is independently retrieved from the panoramic memory to form panable displays.

Panoramic time delay and integration video camera system

A time-delay and integration camera assembly (A) is mounted to view a rotating or other cyclically moving object (B). A lens (30) focuses light from a field of view (10) onto an array (32) of light sensitive elements having N lines of elements. A tachometer (50) monitors rotation of the rotating object and a timing control (54) causes a light sensitive array control (34) to start stepping lines of data along the lines of light sensitive elements toward a shift register (36) as a leading edge (20) of a region of interest (12) enters the field of view. Each time the region of interest moves 1/Nth of the way across the field of view, the lines of data are stepped another time along the lines of light sensitive elements. Digital video signals are sorted (74) among a plurality of image memories (76.sub.1, 76.sub.2, . . . , 76.sub.M) each image memory corresponding to a corresponding region of interest (12.sub.1, 12.sub.2, . . . , 12.sub.M). Scan converters (80) convert the frame image representations in the image memories into a series of human-readable displays. In this manner, the image memory corresponding to each region of interest is updated with each revolution of the object (B) to produce a cinematic video strobe image in a constantly illuminated environment.

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Los Altos, CA, United States of America

Peter S Castro