# US 8,465,676 B2 · Phosphor for low-voltage electron beam and vacuum fluorescent display apparatus

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- Number: US 8,465,676 B2
- Document ID: US8465676B2
- Status: Granted
- Kind: B2
- Application number: 12/932,136
- Filed: 2011-02-17
- Published: 2011-09-08
- Granted: 2013-06-18
- Earliest claimed: 2010-03-03
- Assignees: Noritake Itron Corporation; Noritake Co., Limited
- Applicants: Koji Kato
- Inventors: Koji Kato
- Web page: https://patentgrep.com/patent/US8465676B2

## CPC

- C09K 11/54: containing zinc or cadmium
- C09K 11/77: containing rare earth metals
- H01J 29/20: characterised by the luminescent material
- H01J 63/04: Vessels provided with luminescent coatings; Selection of materials for the coatings
- H01J 2329/18: Luminescent screens
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)

## Abstract

In order to provide a phosphor for a low-voltage electron beam and a vacuum fluorescent display apparatus in which the phosphor is used, a deposition layer is formed on a surface of a main body of a phosphor shown by the following chemical formula (1), the deposition layer being a plurality of oxide layers sequentially deposited on the surface of the phosphor main body. The phosphor for a low-voltage electron beam contains no cadmium, but has exceptional high-temperature exposure characteristics, as well as prolonged service life and higher brightness. Ca1-xSrxTiO3:Pr,M (1) where M is at least one element selected from Al, Ga, In, Mg, Zn, Li, Na, K, Gd, Y, La, Cs, and Rb; and 0≦x≦1.

## Claims

### Claim 1

A phosphor for a low-voltage electron beam device having a coated deposition layer formed on the phosphor shown by the following chemical formula (1), CaTiO3:Pr,M (where M is at least one element selected from Al, Ga, In, Mg, Zn, Li, Na, K, Gd, Y and La),
wherein the coated deposition layer is a plurality of oxide layers layered on a surface of the phosphor,
wherein the oxide layers are layered in a sequence of oxide (MO1)-oxide (MO2)-oxide (MO3), or, oxide (MO2)-oxide (MO1)-oxide (MO3), with respect to the surface of the phosphor,
wherein the oxide (MO1) is at least one element selected from Gd, Pr, Y, Zn, Ta, and Sr,
wherein the oxide (MO2) is at least one element selected from Si, Al, Mo, Sb, and Ce,
wherein the oxide (MO3) is at least one element selected from Ti, W, and Zr.

### Claim 2 (depends on 1)

The phosphor according to claim 1, wherein the oxide (MO1) is at least one element selected from Gd and Y.

### Claim 3 (depends on 2)

The phosphor according to claim 2, wherein an amount of the oxide (MO1) deposited is 200 to 2000 ppm with respect to the entire amount of the phosphor main body.

### Claim 4 (depends on 1)

The phosphor according to claim 1, wherein oxide (MO2) is at least one element selected from Si and Al.

### Claim 5 (depends on 4)

The phosphor according to claim 4, wherein an amount of the oxide (MO2) deposited is 50 to 2000 ppm with respect to an entire amount of the phosphor main body.

### Claim 6 (depends on 1)

The phosphor according to claim 1, wherein oxide (MO3) is at least one element selected from Ti and W.

### Claim 7 (depends on 6)

The phosphor according to claim 6, wherein an amount of the oxide (MO3) deposited is 400 to 3000 ppm with respect to an entire amount of the phosphor.

### Claim 8 (depends on 7)

The phosphor according to claim 7, wherein the total amount of the oxide (MO2) and the oxide (MO3) deposited is 50 to 3400 ppm with respect to the entire amount of the phosphor.

### Claim 9 (depends on 1)

A vacuum fluorescent display apparatus in which a low-voltage electron beam is injected into a phosphor layer for a low-voltage electron beam to cause the phosphor layer to emit light, the phosphor layer being formed inside a vacuum vessel, wherein the phosphor layer for a low-voltage electron beam is a layer of the phosphor for a low-voltage electron beam of claim 1.

### Claim 10 (depends on 1)

The phosphor for a low-voltage electron beam according to claim 1, wherein the M shown by the chemical formula (1) CaTiO3:Pr,M is at least one element selected from Zn and Li.