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Patent EP0334297A2 successfully refreshed from Google Patents.
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EP0334297A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Wrist carried wireless instrument

Assignee: Seiko Epson Corp
•
Filing: 1989-03-21
•
Granted: —
•
Expires: 2009-03-21
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Abstract

Abstract A wrist carried wireless instrument comprises a case including circuits and a loop antenna (1) formed outside of the case. An antenna resonance circuit is formed by said loop antenna (1) and at least two capacitors (C1, C2) connected in series between the ends of said loop antenna (1). The connecting point (A) between the two capacitors (C1, C2) is held at a ground electric potential and the capacitors (C1, C2) are arranged such that their connecting point (A) is near to the intermediate value of the impedance formed by the capacitors. By this construction of the antenna resonance circuit the influence of the human body on the sensitivity of the antenna is greatly reduced.

Inventors

  • 👤 Shunsuke Koyama

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-07 22:39
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/24; H04B7/26; H01; H01Q; H01Q1/00; H01Q1/27; H01Q1/273; H01Q7/00

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 95 words
A wrist carried wireless instrument comprising a case including circuits and a loop antenna (1) formed outside of the case, wherein an antenna resonance circuit is formed by said loop antenna (1) and at least two capaci­tors (C₁, C₂) connected in series between the ends of said loop antenna (1), and wherein the connecting point (A) bet­ween the two capacitors (C₁, C₂) is held at a ground elec­tric potential and the capacitors (C₁, C₂) are arranged such that their connecting point (A) is near to the inter­mediate value of the impedance formed by the capacitors.
Claim 2
Dependent Claim 95 words
A wrist carried wireless instrument comprising a case including circuits and a loop antenna (1) formed outside of the case, wherein an antenna resonance circuit is formed by said loop antenna (1) and at least two capaci­tors (C₁, C₂) connected in series between the ends of said loop antenna (1), and wherein the connecting point (A) bet­ween the two capacitors (C₁, C₂) is held at a ground elec­tric potential and the capacitors (C₁, C₂) are arranged such that their connecting point (A) is near to the inter­mediate value of the impedance formed by the capacitors.
Claim 3
Dependent Claim 30 words
The instrument as claimed in claim 1, wherein both ends of the at least two capacitors (C₁, C₂) are connected to balanced input terminals of a front-end RF amplifier (7).
Claim 4
Dependent Claim 62 words
A wrist carried wireless instrument comprising a case for supporting wireless instrument circuitry, a loop antenna extending outside of said case, an antenna reso­nance circuit formed by said loop antenna and at least one capacitor, and an RF amplifier which is a front end ampli­fier, wherein both ends of said capacitor are connected to balanced input terminals of said RF amplifier, respective­ly.
Claim 5
Dependent Claim 62 words
A wrist carried wireless instrument comprising a case for supporting wireless instrument circuitry, a loop antenna extending outside of said case, an antenna reso­nance circuit formed by said loop antenna and at least one capacitor, and an RF amplifier which is a front end ampli­fier, wherein both ends of said capacitor are connected to balanced input terminals of said RF amplifier, respective­ly.
Claim 6
Dependent Claim 21 words
The instrument as claimed in any of claim 1 or 3, wherein the loop antenna (1) has a wrist surrounding form.

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