Fluorescent display device and control electrode therefor

• US 6,236,158 B1
• Filed: 07/31/1998
• Issued: 05/22/2001
• Est. Priority Date: 08/27/1997
• Status: Expired due to Fees

• Current Assignee: Futaba Denshi Kabushiki Kaisha
• Original Assignee: Futaba Denshi Kabushiki Kaisha
• Inventors: Kikuchi, Yasuyuki
• Primary Examiner(s): Patel, Ashok
• Application Number:
  US09/126,780
• Time in Patent Office: 1,026 Days
• Field of Search: 313/497, 313/495, 313/326, 313/350
• US Class Current: 313/497
• CPC Class Codes: H01J 2329/00 Electron emission display panels, e.g. field emission display panels
• CPC Class Codes: H01J 29/467 Control electrodes for flat display tubes, e.g. of the type covered by group H01J31/123

Abstract

A fluorescent display device capable of eliminating occurrence of EMI. The fluorescent display device includes a mesh-like control electrode. The control electrode has a mesh pattern made of a wire of 30 to 50 μm in diameter into a hexagonal shape so that six sides thereof each are 0.4 mm in length. Also, the mesh pattern is formed so as to have an opening ratio of 74.9%. Such construction effectively eliminates such generation of EMI at a band of 350 to 420 MHz as seen in a conventional fluorescent display device.

Claims

1. A fluorescent display device for use in a head up display comprising:

an envelope evacuated to a high vacuum;

an electron source arranged in said envelope;

a control electrode arranged in said envelope for controlling electrons emitted from said electron source, said control electrode having a hexagonal mesh structure defining plural hexagonal elements each having six sides, each side having a length of at least 0.4 mm; and

anodes each arranged in said envelope and formed thereon with a phosphor which emits light due to impingement of electrons emitted from said electron source thereon.

2. A fluorescent display device as defined in claim 1, wherein said control electrode is made of a wire of 30 to 50 μ

m in diameter.

3. A control electrode for a fluorescent display device including an envelope evacuated to a high vacuum, an electron source arranged in said envelope, and anodes each arranged in said envelope and formed thereon with a phosphor which emits light due to impingement of electrons emitted from said electron thereon, wherein:

said control electrode having a hexagonal mesh structure and arranged in said envelope so as to control electrons emitted from said electron source; and

said hexagonal mesh structure defining plural hexagonal elements each having six sides, each side having a length of at least 0.4 mm.

4. A control electrode as defined in claim 3 wherein said control electrode is made of a wire of 30 to 50 μ

m in diameter.