# US 5,353,325 A · X-ray fluorograph and radiograph apparatus for obtaining X-ray image having high X-ray latitude

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- Number: US 5,353,325 A
- Document ID: US5353325A
- Status: Granted
- Kind: A
- Application number: 07/983,058
- Filed: 1992-11-30
- Granted: 1994-10-04
- Earliest claimed: 1991-11-29
- Assignees: Hitachi Medical Corporation
- Inventors: Ken Ueda; Hisatake Yokouchi; Keiji Umetani; Yoichi Onodera
- Web page: https://patentgrep.com/patent/US5353325A

## CPC

- H01J 31/50: Image-conversion or image-amplification tubes, i.e. having optical, X-ray, or analogous input, and optical output
- H05G 1/60: Circuit arrangements for obtaining a series of X-ray photographs or for X-ray cinematography
- H01J 2231/50036: X-rays
- H01J 2231/50063: Optical
- H01J 2231/5013: with secondary emission electrodes
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)
- H05G: X-RAY TECHNIQUE (investigating or analysing materials by the use of X-rays G01N23/00; apparatus for X-ray photography G03B42/02; X-ray tubes H01J35/00; TV systems having X-ray input H04N5/321)

## Abstract

An X-ray fluorograph and radiograph apparatus including an X-ray television camera having an avalanche multiplication operation type image pick-up tube having an input/output characteristic in which increment of an output reduces gradually against increase of dose of incident X-rays and a unit for setting X-ray latitude and a multiplication factor of an image pick-up tube to optimum values for inputted radiograph conditions by controlling a voltage value applied to the image pick-up tube and a value of a stop of an optical system, and making it possible to obtain X-ray latitude at 1,000 or more.

## Claims

### Claim 1

An X-ray fluorograph and radiograph apparatus comprising:
(a) an X-ray generator;
(b) a means for controlling generation of X-rays;
(c) a means for converting an X-ray image into a light image;
(d) a television camera including an avalanche multiplication operation type image pick-up tube, and having a non-linear input/output relation in which an increment of an output with respect to an increment of an input of light intensity is controlled so as to reduce gradually with an increasing input light intensity, and having said light image inputted thereto;
(e) a means for setting a radiograph condition; and
(f) a means for controlling said input/output relation of said image pick-up tube on a basis of a set radiographic condition.

### Claim 2 (depends on 1)

An X-ray fluorograph and radiograph apparatus according to claim 1, wherein said image pick-up tube has a film having an area where image read scanning is made by an electron beam which is formed in a rectangular shape of a size having a side 12 mm long or more and made of an amorphous selenium photoconductor.

### Claim 3 (depends on 1)

An X-ray fluorograph and radiograph apparatus according to claim 1, wherein said means for setting a radiograph condition includes:
a means for inputting an X-ray sensitivity and X-ray latitude value; and
a means for selecting a voltage value applied to said image pick-up tube and a stop value of an optical system at optimum values based on said radiograph condition; and
said means for controlling said input/output relation includes a means for controlling a multiplication factor of said image pick-up tube.

### Claim 4 (depends on 3)

An X-ray fluorograph and radiograph apparatus according to claim 3, wherein said means for controlling said multiplication factor comprises:
a means for controlling said multiplication factor by varying a voltage applied to said image pick-up tube; and
a means for controlling said multiplication factor by controlling an increase and decrease of a light amount inputted to said image pick-up tube by said stop value.

### Claim 5 (depends on 4)

An X-ray fluorograph and radiograph apparatus according to claim 4, wherein said image pick-up tube has a multiplication factor of 10 or higher.

### Claim 6 (depends on 1)

An X-ray fluorograph and radiograph apparatus according to claim 1, further comprising a means for displaying an image obtained by said television camera in real time.

### Claim 7 (depends on 1)

An X-ray fluorograph and radiograph apparatus according to claim 1, wherein said means for setting a radiographic condition includes:
a means for controlling a multiplication factor of said image pick-up tube by controlling an increase and decrease of light amount inputted to said image pick-up tube by by said stop value.

### Claim 8 (depends on 1)

An X-ray fluorograph and radiograph apparatus according to claim 1, wherein said means for setting a radiographic condition includes:
a means for controlling a multiplication factor of said image pick-up tube by varying a voltage applied to said image pick-up tube.

### Claim 9 (depends on 1)

An X-ray fluorograph and radiograph apparatus according to claim 1, further comprising a means for converting an output signal of said image pick-up element into a signal having linear input/output relationship.