Wristwatch radio communication device having an improved noise shielding structure

• US 5,564,096 A
• Filed: 12/01/1994
• Issued: 10/08/1996
• Est. Priority Date: 02/09/1990
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Hama, Norio, Kurosawa, Shyogo
• Primary Examiner(s): Pham, Chi H.
• Application Number:
  US08/348,505
• Time in Patent Office: 677 Days
• Field of Search: 455/274, 455/283, 455/298, 455/300, 455/301, 455/344, 455/347, 455/351, 340/825.44, 343/718, 343/720, 368/282, 361/814, 361/816, 361/818, 361/736, 361/737, 361/746, 361/748, 361/752, 361/753, 361/799, 174/35 R, 174/35 MS
• US Class Current: 455/300
• CPC Class Codes: G02F 1/133334 Electromagnetic shields
• CPC Class Codes: G04G 21/04 using radio waves radio-controlled time-pieces G04R
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H04B 1/086 Portable receivers
• CPC Class Codes: H04B 1/385 Transceivers carried on the body, e.g. in helmets
• CPC Class Codes: H04M 1/0202 Portable telephone sets, e.g. cordless phones, mobile phones or bar type handsets constructional features of telephone transmitters or receivers, e.g. of speakers or microphones H04M1/03

Abstract

A portable radio communication device such as wristwatch receiver and/or transmitter is provided with an effective noise shielding structure. The portable radio communication device includes a high frequency analog circuitry for receiving and transmitting radio signals and further includes digital circuitry for data processing and display. The noise shielding structure protects high frequency noise from being transmitted to the analog circuitry from the digital circuitry and from other outside sources. The noise shielding structure is made of electrically conductive material. In another aspect of the invention, at least one circuit board constructed of a multi-layered construction having at least one inner printed wire pattern is provided. The inner printed wire pattern is set at ground potential with respect to the high frequency output from the analog circuitry. In this manner the inner printed wire pattern serves as a noise shielding member. In addition, the invention obtains effective noise shielding without increasing the size or the manufacturing cost of the device.

Claims

1. A wristwatch device, comprising:

a body portion having a first side for facing a user'"'"'s wrist and a second side essentially opposite from said first side;

a wristband portion for fastening around a user'"'"'s wrist attached to said body portion;

a loop antenna embedded in said wristband portion for receiving data transmitted over the air and having ends operatively coupled to said body portion intermediate said first and second sides thereof, said loop antenna together with a projection between said loop antenna ends through said body portion defining an enclosed area, when fastened around a user'"'"'s wrist; and

a digital circuit for data decoding and display and serving as a noise source, said digital circuit being positioned in said body portion in the region of the second side thereof so that said digital circuit lies outside said enclosed area defined by said loop antenna to effectively reduce the effect on the operation of the loop antenna of the noise produced by said digital circuit.

2. The wristwatch device of claim 1, further including an analog circuit for receiving from said loop antenna signals including said data and positioned in said body portion in the region of the first side thereof so as to be within said enclosed area defined by said loop antenna.

3. The wristwatch device of claim 1, and including a support structure supporting said analog circuit in said body portion so that said analog circuit faces said first side of said body portion and supporting said digital circuit so that said digital circuit faces said second side of said body portion.

4. The wristwatch device of claim 1, including a pager device responsive to data transmitted over the air and received by said loop antenna, said pager device including said digital circuit and said analog circuit;

and said wristwatch device further including a digital timekeeping device positioned in said first cover portion.

5. A wristwatch device, comprising:

a body portion, said body portion including a front cover portion having a display and a rear cover portion opposite said front cover portion;

a plurality of substrates having a plurality of layers supported in said body portion,

a digital circuit acting as a noise source mounted in said body portion on one of said substrates toward said front cover and positioned in said front cover portion;

an analog circuit mounted in said body portion on one of said substrates toward said rear cover and positioned in said rear cover portion;

a wristband portion for fastening around a user'"'"'s wrist attached to said body portion; and

wherein said plurality of substrates including inner layer conductive patterns, wherein said analog circuit is surrounded by said inner layer conductive patterns and said rear cover portion to form an electrically shielded space, said rear cover portion contacting said user'"'"'s wrist when the wristband portion is fastened about the user'"'"'s wrist so that the noise from said digital circuit is prevented from entering said analog circuit.

6. The wristwatch device of claim 5, wherein said digital circuit is surrounded by said inner layer conductive patterns and said front cover portion to form an electrically shielded space.

7. The wristwatch device of claim 6, wherein said wristband portion incorporates an antenna.

8. The wristwatch device of claim 7, wherein said antenna is a loop antenna so that the noise from said digital circuit is reduced.

9. The wristwatch device of claim 8, wherein said device is a pager.

10. The wristwatch device of claim 9, wherein said rear cover portion is essentially formed of a conductive metal material.

11. A wristwatch device, comprising:

a body portion, said body portion including a front cover portion having a display and a rear cover portion opposite said front cover portion;

a least two substrates supported in said body portion;

a digital circuit acting as a noise source mounted on one of said substrates on the side of said front cover portion;

an analog circuit mounted on the other of said substrates on the side of said rear cover portion; and

a shield element supported between said two substrates constructed to effectively reduce the noise from said digital circuit reaching said analog circuit.

12. A wristwatch device, comprising:

a body portion including a first surface having a display portion and a second surface essentially parallel to said first surface;

a first circuit board positioned in said body portion toward said first surface, said first circuit board comprising a digital circuit;

a second circuit board positioned in said body portion toward said second surface, said second circuit board comprising an analog circuit; and

a shield member positioned between said first and second circuit boards, whereby noise from said digital circuit is effectively shielded from said analog circuit.

13. The wristwatch device of claim 12, wherein said analog circuit includes a second digital circuit.

14. The wristwatch device of claim 12, wherein said display is a liquid crystal display.

15. The wristwatch device of claim 12, wherein said analog circuit includes a high frequency analog circuit.

16. The wristwatch device of claim 12, wherein said digital circuit includes at least one of a phase locked loop circuit and a data reading circuit.

17. A wireless instrument, comprising:

a body portion including a first surface having a display portion and a second surface essentially parallel to said first surface;

a first circuit board positioned in said body portion toward said first surface, said first circuit board comprising a digital circuit;

a second circuit board positioned in said body portion toward said second surface, said second circuit board comprising an analog circuit; and

a shield member positioned between said first and second circuit boards, whereby noise from said digital circuit is shielded from said analog circuit.

18. The wireless instrument of claim 17, wherein said analog circuit includes a second digital circuit.

19. The wireless instrument of claim 17, wherein said display is a liquid crystal display.

20. The wireless instrument of claim 17, wherein said analog circuit includes a high frequency analog circuit.

21. The wireless instrument of claim 17, wherein said digital circuit includes at least one of a phase locked loop circuit and a data reading circuit.

22. A portable small-sized apparatus, comprising:

a body portion including a first surface having a display portion and a second surface essentially parallel to said first surface;

a first circuit board positioned in said body portion toward said first surface, said first circuit board comprising a digital circuit;

a second circuit board positioned in said body portion toward said second surface, said second circuit board comprising an analog circuit; and

a shield member positioned between said first and second circuit boards, whereby noise from said digital circuit is effectively shielded from said analog circuit.

23. The portable small-sized apparatus of claim 22, wherein said analog circuit includes a second digital circuit.

24. The portable small-sized apparatus of claim 22, wherein said display is a liquid crystal display.

25. The portable small-sized apparatus of claim 22, wherein said analog circuit includes a high frequency analog circuit.

26. The portable small-sized apparatus of claim 22, wherein said digital circuit includes at least one of a phase locked loop circuit and a data reading circuit.

27. A wristwatch device, comprising:

a body portion including a first surface having a display portion and a second surface essentially parallel to said first surface;

a circuit board positioned in said body portion, said circuit board comprising a digital circuit on a side thereof facing toward said first surface and an analog circuit on a side thereof facing toward said second surface, said digital circuit including at least one of a phase locked loop circuit and a data reading circuit; and

a ground layer essentially positioned on said circuit board between said digital circuit and said analog circuit.

28. A wireless instrument, comprising:

a body portion including a first surface having a display portion and a second surface essentially parallel to said first surface;

a circuit board positioned in said body portion, said circuit board comprising a digital circuit positioned on one side thereof facing said first surface and an analog circuit positioned on the other side thereof facing toward said second surface, said digital circuit including at least one of a phase locked loop circuit and a data reading circuit; and

a ground layer essentially positioned on said circuit board between said digital circuit and said analog circuit.

29. A wireless instrument, comprising:

a body portion including a first surface having a display portion and a second surface essentially parallel to said first surface;

a circuit board positioned in said body portion, said circuit board comprising a digital circuit positioned on one side thereof facing toward said first surface and an analog circuit positioned on the other side thereof facing said second surface, said digital circuit including at least one of a phase locked loop circuit and a data reading circuit; and

a ground layer essentially positioned on said circuit board between said digital circuit and said analog circuit.

30. A wristwatch device, comprising:

a body portion including a first surface and a second surface essentially parallel to said first surface;

a circuit board positioned in said body portion, said circuit board including a digital circuit on a side thereof facing toward said first surface and an analog circuit on a side thereof facing toward said second surface, said digital circuit including at least one of a phase locked loop circuit and a data reading circuit; and

a ground layer essentially positioned on said circuit board between said digital circuit and said analog circuit.

31. A wireless instrument, comprising:

a body portion including a first surface and a second surface essentially parallel to said first surface;

a circuit board positioned in said body portion, said circuit board including a digital circuit positioned on one side thereof facing said first surface and an analog circuit positioned on the other side thereof facing toward said second surface, said digital circuit including at least one of a phase locked loop circuit and a data reading circuit; and

a ground layer essentially positioned on said circuit board between said digital circuit and said analog circuit.

32. A portable small-sized apparatus, comprising:

a body portion including a first surface and a second surface essentially parallel to said first surface;

a circuit board positioned in said body portion, said circuit board including a digital circuit positioned on one side thereof facing toward said first surface and an analog circuit positioned on the other side thereof facing said second surface, said digital circuit including at least one of a phase locked loop circuit and a data reading circuit; and

a ground layer essentially positioned on said circuit board between said digital circuit and said analog circuit.

33. A wristwatch device, comprising:

a body portion including a first surface having a display portion and a second surface essentially parallel to said first surface;

a first circuit board positioned in said body portion toward said first surface, said first circuit board including digital circuit means for data decoding and for driving said display portion and serving as a noise source;

a second circuit board positioned in said body portion toward said second surface, said second circuit board including analog circuit means for receiving data; and

shield means for effectively shielding said noise from said digital circuit means from said analog circuit means, said shield means positioned between said first and second circuit boards.

34. The wristwatch device of claim 33, wherein said analog circuit means includes a second digital circuit.

35. The wristwatch device of claim 33, wherein said display portion is a liquid crystal display.

36. The wristwatch device of claim 33, wherein said analog circuit means includes a high frequency analog circuit.

37. The wristwatch device of claim 33, wherein said digital circuit means includes at least one of a phase locked loop circuit and a data reading circuit.

38. A wristwatch device, comprising:

a body portion including a first surface having a display portion and a second surface essentially parallel to said first surface;

a circuit board positioned in said body portion, said circuit board including digital circuit means for data decoding and for driving said display portion and serving as a noise source, said digital circuit means positioned on a side of said circuit board facing toward said first surface and analog circuit means for receiving data, said analog circuit means positioned on a side of said circuit board facing toward said second surface; and

ground means for grounding said digital circuit means and said analog circuit means, said ground means essentially positioned on said circuit board between said digital circuit means and said analog circuit means.

39. The wristwatch device of claim 38, wherein said analog circuit means includes a second digital circuit.

40. The wristwatch device of claim 38, wherein said display portion is a liquid crystal display.

41. The wristwatch device of claim 38, wherein said analog circuit includes a high frequency analog circuit.

42. The wristwatch device of claim 38, wherein said digital circuit includes at least one of a phase locked loop circuit and a data reading circuit.

43. A wireless instrument, comprising:

a body portion including a first surface having a display portion and a second surface essentially parallel to said first surface;

a first circuit board positioned in said body portion toward said first surface, said first circuit board including digital circuit means for data decoding and for driving said display portion and serving as a noise source;

a second circuit board positioned in said body portion toward said second surface, said second circuit board including analog circuit means for receiving data; and

shield means for effectively shielding said noise from said digital circuit means from said analog circuit means, said shield means positioned between said first and second circuit boards.

44. The wireless instrument of claim 43, wherein said analog circuit means includes a second digital circuit.

45. The wireless instrument of claim 43, wherein said display portion is a liquid crystal display.

46. The wireless instrument of claim 43, wherein said analog circuit means includes a high frequency analog circuit.

47. The wireless instrument of claim 43, wherein said digital circuit means includes at least one of a phase locked loop circuit and a data reading circuit.

48. A wireless instrument, comprising:

a body portion including a first surface having a display portion and a second surface essentially parallel to said first surface;

a circuit board positioned in said body portion, said circuit board including digital circuit means for data decoding and for driving said display portion and serving as a noise source, said digital circuit means positioned on a side of said circuit board facing toward said first surface and analog circuit means for receiving data, said analog circuit means positioned on a side of said circuit board facing toward said second surface, said digital circuit means including at least one of a phase locked loop circuit and a data reading circuit; and

ground means for grounding said digital circuit means and said analog circuit means, said ground means essentially positioned on said circuit board between said digital circuit means and said analog circuit means.

49. A portable small-sized apparatus, comprising:

a body portion including a first surface having a display portion and a second surface essentially parallel to said first surface;

a first circuit board positioned in said body portion toward said first surface, said first circuit board including digital circuit means for data decoding and for driving said display portion and serving as a noise source;

a second circuit board positioned in said body portion toward said second surface, said second circuit board including analog circuit means for receiving data; and

shield means for effectively shielding said noise from said digital circuit means from said analog circuit means, said shield means positioned between said first and second circuit boards.

50. The portable small-sized apparatus of claim 49, wherein said analog circuit means includes a second digital circuit.

51. The portable small-sized apparatus of claim 49, wherein said display portion is a liquid crystal display.

52. The portable small-sized apparatus of claim 49, wherein said analog circuit means includes a high frequency analog circuit.

53. The portable small-sized apparatus of claim 49, wherein said digital circuit means includes at least one of a phase locked loop circuit and a data reading circuit.

54. A portable small-sized apparatus, comprising:

a body portion including a first surface having a display portion and a second surface essentially parallel to said first surface;

a circuit board positioned in said body portion, said circuit board including digital circuit means for data decoding and for driving said display portion and serving as a noise source, said digital circuit means positioned on a side of said circuit board facing toward said first surface and analog circuit means for receiving data, said analog circuit means positioned on a side of said circuit board facing toward said second surface, said digital circuit means includes at least one of a phase locked loop circuit and a data reading circuit; and

ground means for grounding said digital circuit means and said analog circuit means, said ground means essentially positioned on said circuit board between said digital circuit means and said analog circuit means.