Radiation image conversion panel and process for producing the same

• US 20070205380A1
• Filed: 03/02/2007
• Published: 09/06/2007
• Est. Priority Date: 03/02/2006
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Isoda, Yuji
• Granted Patent: US 7,514,698 B2
• Time in Patent Office: Days
• US Class Current: 250/484.400
• CPC Class Codes: C09K 11/7733 with alkali or alkaline earth metals
• CPC Class Codes: G03B 42/02 using X-rays
• CPC Class Codes: G21K 4/00 Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens photographic processes using X-ray intensifiers G03C5/17; discharge tubes comprising luminescent screens H01J1/62; cathode ray tubes for X-ray conversion with optical output H01J31/50

Abstract

The radiation image conversion panel includes a stimulable phosphor layer formed by a vapor-phase deposition and solely formed of columnar crystals, a matrix layer formed under the stimulable phosphor layer, is substantially free of an activator of a stimulable phosphor, and has a columnar crystal region and an underlying non-columnar crystal region and a substrate which supports the matrix layer and the stimulable phosphor layer formed on the matrix layer. The process for producing the radiation image conversion panel forms on the substrate the matrix layer and forms the stimulable phosphor layer by the vapor-phase deposition. The formation of the stimulable phosphor layer is started after a crystal structure of an upper region of the matrix layer has changed from a non-columnar to a columnar.

Claims

1. A radiation image conversion panel comprising:

a stimulable phosphor layer which is formed by a vapor-phase deposition and is solely formed of columnar crystals;

a matrix layer which is formed under said stimulable phosphor layer, is substantially free of an activator of a stimulable phosphor, and has a columnar crystal region and an underlying non-columnar crystal region; and

a substrate which supports said matrix layer and said stimulable phosphor layer formed on said matrix layer.

2. The radiation image conversion panel according to claim 1, wherein said stimulable phosphor layer has an activator concentration-increasing region in which a concentration of said activator increases progressively from an interface with said matrix layer toward an outer surface of said stimulable phosphor layer.

3. The radiation image conversion panel according to claim 2, wherein said activator concentration-increasing region has a thickness ranging from 0.5 μ

m to a value corresponding to a thickness of said stimulable phosphor layer.

4. The radiation image conversion panel according to claim 2, wherein a rate at which said concentration of said activator changes in said activator concentration-increasing region is between 1×

10<sup>−

7</sup> μ

m and 5×

10<sup>−

4</sup> μ

m.

5. The radiation image conversion panel according to claim 1, wherein said underlying non-columnar crystal region of said matrix layer is a spherical crystal layer having a spherical crystal structure.

6. The radiation image conversion panel according to claim 1, further comprising:

a protective layer having sufficient moisture resistance which is formed on said stimulable phosphor layer.

7. A process for producing a radiation image conversion panel having a stimulable phosphor layer, comprising:

forming on or above a substrate a matrix layer which is substantially free of an activator of a stimulable phosphor; and

forming said stimulable phosphor layer by a vapor-phase deposition,

wherein formation of said stimulable phosphor layer is started after a crystal structure of an upper region of said matrix layer has changed from a non-columnar to a columnar.

8. The process for producing a radiation image conversion panel according to claim 7, wherein at a time when said formation of said stimulable phosphor layer has started, said activator of said stimulable phosphor is deposited in a smaller amount than a required value and thereafter said activator is deposited in a progressively increased amount until said required value is reached.