X-ray system with electrophoretic imaging and solid X-ray absorber

Abstract

An electronradiography imaging chamber providing a real time visual image. An electronradiography imaging chamber with a solid X-ray absorber at one electrode and with electrophoretic particles in the gap between the electrodes, with the particles being selectively moved to a transparent electrode as a result of the electrostatic charge image formed by absorption of incoming X-ray radiation in the solid absorber. An imaging chamber which can be cyclically operated at a relatively high repetition rate, typically 10 to 20 images per second, thereby providing real time viewing of the objects. SUBACKGROUND OF THE INVENTIONThis invention relates to electronradiography and in particular, to X-ray systems providing for real time imaging. The present invention is an improvement on that disclosed in copending application entitled X-RAY SYSTEM WITH ELECTROPHORETIC IMAGING, Ser. No. 571,220, filed Apr. 24, 1975, now U.S. Pat. No. 3,965,352.In the aforesaid copending application, an electronradiography imaging chamber has first and second electrodes mounted in spaced relation with a gap therebetween, with a fluid in the gap. The fluid is an X-ray absorber which emits electrons and positive ions as a function of incoming X-ray radiation. Electrophoretic particles are suspended in the fluid in the gap, and an appropriate electrical power supply is provided for connection across the electrodes. An electrostatic charge image is formed at the edge of the gap during X-ray radiation and this charge image is utilized in selectively depositing electrophoretic particles at one of the electrodes which is transparent for viewing the deposited particles through the electrode. Several arrangements for the electrophoretic particles and the fluid, and several arrangements for viewing of the electrophoretic particle image are disclosed.It is an object of the present invention to provide a new and improved electronradiography imaging chamber which utilizes a solid absorber in place of the previously disclosed fluid absorber.SUMMARY OF THE INVENTIONThe imaging chamber of the present invention includes first and second electrodes in spaced relation with a gap therebetween. An optional dielectric layer may be provided at the surface of one of the electrodes and an absorber sheet is positioned at the surface of the other electrode. Electrophoretic particles are dispersed in a liquid in the gap. The absorber sheet provides for absorption of incoming X-ray radiation and produces electrons and positive ions, and typically is a solid state photoconductor material. An appropriate electrical power supply is provided for connection across the electrodes. An electrostatic charge image is formed at a surface of the solid absorber during X-ray radiation, and this charge image is utilized in the same manner as in the prior art in selectively depositing the electrophoretic particles at one of the electrodes. The image formed by the deposited electrophoretic particles may be viewed in any of the conventional modes. The X-ray exposure and image viewing steps may be repeated cyclically to provide substantially continuous real time imaging.

Description

Claims

1. In an electronradiograph imaging chamber for providing a visual image, the combination of:

first and second electrodes;

means for supporting said electrodes in spaced relation with a gap therebetween, with said first electrode being relatively transparent optically;

a solid absorber sheet including an X-ray absorber and electron and positive ion emitter and positioned at the surface of said second electrode facing said first electrode, with X-ray radiation entering said absorber sheet being absorbed and providing electrons and positive ions therein;

a plurality of electrophoretic particles dispersed in a liquid in said gap; and

means for connecting an electric power source across said electrodes for attracting electrons toward one electrode and positive ions toward the other depending upon the polarity of the power source and forming an electrostatic charge image, with said particles being selectively deposited at said first electrode as a function of said electrostatic charge image forming a visual image viewable through said first electrode.

2. An imaging chamber as defined in claim 1 wherein said absorber sheet is formed of a photoconductor.

3. An imaging chamber as defined in claim 1 wherein said absorber sheet is formed of at least one of selenium, lead oxide, cadmium sulfide, mercury iodide and cesium iodide.

4. An imaging chamber as defined in claim 1 wherein said absorber sheet comprises a dielectric support with a plurality of spaced passages therethrough, with said passages carrying the absorber material.

5. An imaging chamber as defined in claim 1 wherein said second electrode is relatively transparent optically, and including means for directing light through said electrodes with the deposited particles blocking light transmission.

6. An imaging chamber as defined in claim 1 including means for directing light onto said first electrode with the deposited particles reflecting light.

7. An imaging chamber as defined in claim 1 wherein said first electrode includes a support plate with an electrically conducting layer thereon, and including first means for directing light into said plate from an edge with the deposited particles scattering light.

8. An imaging chamber as defined in claim 7 with said light directed into said plate at an angle to produce substantially total reflection of the light internally of the plate except for that scattered by the deposited particles.

9. An imaging chamber as defined in claim 8 including:

second means for directing light onto said first electrode with the deposited particles reflecting light; and

means for selectively energizing said first and second light directing means.

10. An imaging chamber as defined in claim 1 wherein said electrophoretic particles are positively charged.

11. An imaging chamber as defined in claim 1 wherein said electrophoretic particles are negatively charged.

12. An imaging chamber as defined in claim 1 wherein said electrophoretic particles are electrically neutral.

13. An imaging chamber as defined in claim 1 including control means for cyclically actuating said imaging chamber to provide real time visual imaging and including means for energizing an X-ray source for a short portion of each cycle and simultaneously energizing an electric power source for attracting electrons and positive ions, and energizing a light source for viewing the deposited particles for a subsequent portion of the cycle.

14. An imaging chamber as defined in claim 13 wherein said control means includes means for connecting a relatively high voltage supply to said electrodes while the X-ray source is energized and then connecting a relatively low voltage supply to said electrodes.

15. An imaging chamber as defined in claim 14 wherein said control means includes means for connecting a voltage supply of reverse polarity prior to energizing the X-ray source.

16. An imaging chamber as defined in claim 13 wherein said control means includes means for connecting a voltage supply of reverse polarity prior to energizing the X-ray source.

17. An imaging chamber as defined in claim 1 including a dielectric layer at the surface of said first electrode facing said second electrode.