Eye viewing device for retinal viewing through undilated pupil

• US 6,409,341 B1
• Filed: 11/22/1999
• Issued: 06/25/2002
• Est. Priority Date: 11/24/1998
• Status: Expired due to Term

• Current Assignee: Welch Allyn Incorporated
• Original Assignee: Hand Held Products Incorporated (Honeywell International Inc.)
• Inventors: Slawson, Steven R., Goldfain, Ervin, Krauter, Allan I., Roberts, Chris R., Lagerway, William
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US09/444,161
• Time in Patent Office: 946 Days
• Field of Search: 351/205, 351/206, 351/211, 351/214, 351/215, 351/216, 351/217, 351/221, 351/246, 362/105
• US Class Current: 351/205
• CPC Class Codes: A61B 3/132 in binocular arrangement
• CPC Class Codes: A61B 3/158 of corneal reflection

Abstract

The invention is a low cost, low input power eye viewing device well suited for viewing wide field retinal images through an undilated pupil. Included in the device are a converging light illumination system and an aperture stop. The converging light illumination system provides ease of entry of light rays into an eye, wide field retinal illumination, reduced glare and reduced power consumption. The aperture stop blocks unwanted received glare light not forming part of the retinal image. The device is made especially well suited for retinal viewing through an undilated pupil if the aperture is sized in accordance with the diameter of an undilated pupil.

Claims

1. An eye viewing device for viewing a structure of an eye having a pupil, said device comprising:

an illumination system generating a converging cone of light that converges at an apex and diverges thereafter;

an imaging system having an imaging axis, wherein said illumination system includes a light source positioned off-axis with respect to said imaging axis; and

an aperture stop disposed in said device substantially coaxial with said imaging axis and substantially conjugate to said apex whereby internal and corneal glare in said device is reduced.

2. The eye viewing device of claim 1, wherein an aperture of said aperture stop is sized to substantially correspond to a size of said pupil.

3. The eye viewing device of claim 1, wherein said imaging system includes an objective lens, said objective lens having a first surface closest to said light source curved substantially concentric about a center of an aperture of said aperture stop, whereby internal glare in said device is reduced.

4. The eye viewing device of claim 1, wherein said off-axis positioned light source is positioned outside of an aperture of said aperture stop, whereby said light source has no obscuring effect on images received by said viewing device.

5. The eye viewing device of claim 1, wherein said off-axis positioned light source is positioned outside of a border between received and blocked light defined by said aperture stop, and wherein said imaging system includes an objective lens having a curved first surface curved concentric about a center of said aperture, whereby said light source has no obscuring effect on images received by viewing device, and whereby incident light reflected from said first surface is blocked by said aperture stop.

6. The eye viewing device of claim 1, wherein said imaging system comprises binocular optics adapted to provide binocular viewing.

7. The eye viewing device of claim 1, wherein said device includes a housing including at least one lens holder, and a plurality of lenses, at least one of said lenses being packaged in a lens module which is adapted to be received in said at least one lens holder.

8. The eye viewing device of claim 1, wherein said device includes a housing and wherein said device further comprises:

an eyepiece holder defined by said housing;

an eyepiece having an eyepiece lens, said eyepiece being adapted to be received in said eyepiece holder; and

a video module having an image sensor, said video module being adapted to be received in said eyepiece holder wherein said eyepiece holder is adapted to receive only one of said eyepiece or said video module at a given time.

9. The eye viewing device of claim 1, wherein a retinal field of view of said imaging system is larger than a retinal area of illumination of said illumination system.

10. The eye viewing device of claim 1, wherein a retinal field of view of said imaging system is between about 15 to 30 percent larger than a retinal area of illumination of said illumination system.

11. The eye viewing device of claim 1, wherein said aperture stop is disposed in said device so that said aperture stop is substantially conjugate to said pupil when said illumination system projects substantially a maximum amount of light through said pupil.

12. The eye viewing device of claim 1, wherein an aperture of said aperture stop is sized substantially according to the formula, d=2 m millimeters, where d is the diameter of said aperture and m is the magnification of said pupil in a plane of said aperture stop.

13. The eye viewing device of claim 1, wherein said aperture stop is disposed about said imaging axis.

14. The eye viewing device of claim 1, wherein said light source is a light generating light source selected from the group consisting of a filament based lamp, an arc lamp, a fiber optic light source and a solid state light source.

15. The eye viewing device of claim 1, wherein said light source is provided by a light reflective element.

16. The eye viewing device of claim 15, wherein said light reflective element is a mirror.

17. The eye viewing device of claim 1, wherein said light source is provided by a reflective element, wherein said reflective element redirects light received from a light-generating light source.

18. The eye viewing device of claim 17, wherein said reflective element-provided light source operates in association with a light generating light source and a condenser lens, wherein said condenser lens condenses light from said light generating light source onto said reflective element.

19. The eye viewing device of claim 1, wherein said device is housed in a housing having a first section generally coextensive with said imaging axis and a second section generally transverse to said first section.

20. The eye viewing device of claim 19, wherein said off-axis positioned light source is provided by a reflective element which redirects light emitted by a light generating light source, wherein said light generating light source is disposed in said second section.

21. The eye viewing device of claim 1, wherein said illumination system and said imaging system are incorporated in a single housing.

22. The eye viewing device of claim 1, wherein said imaging system includes an objective lens disposed in a path of illumination light rays generated by said illumination system.

23. The eye viewing device of claim 22, wherein said objective lens is a single element lens.

24. The eye viewing device of claim 22, wherein said objective lens is a plural element lens.

25. The eye viewing device of claim 1, wherein said illumination system includes an objective lens disposed so that said imaging axis intersects said objective lens.

26. The eye viewing device of claim 1, wherein said illumination system and imaging system include a common objective lens.

27. The eye viewing device of claim 26, wherein said common objective lens comprises a single element lens.

28. The eye viewing device of claim 26, wherein said common objective lens comprises a plural element lens.

29. An eye viewing device for viewing a structure of an eye having a retina and a pupil, said device comprising:

an illumination system for illuminating said retina;

an imaging system having an imaging axis, wherein said illumination system includes a light source positioned off-axis with respect to said imaging axis; and

an aperture stop disposed in said device substantially coaxial with said imaging axis and substantially conjugate to said pupil when said device is in an operative position in relation to said eye, whereby internal and corneal glare in said device is reduced.

30. The eye viewing device of claim 29, wherein an aperture of said aperture stop is sized to substantially correspond to a size of said pupil.

31. The eye viewing device of claim 29, wherein said imaging system includes an objective lens, said objective lens having a first surface closest to said light source curved substantially concentric about a center of an aperture of said aperture stop, whereby internal glare in said device is reduced.

32. The eye viewing device of claim 29, wherein said off-axis positioned light source is positioned outside of an aperture of said aperture stop, whereby said light source has no obscuring effect on images received by said viewing device.

33. The eye viewing device of claim 29, wherein said off-axis positioned light source is positioned outside of a border between received and blocked light defined by said aperture stop, and wherein said imaging system includes an objective lens having a curved first surface curved concentric about a center of said aperture, whereby said light source has no obscuring effect on images received by viewing device, and whereby incident light reflected from said first surface is blocked by said aperture stop.

34. The eye viewing device of claim 29, wherein said imaging system comprises binocular optics adapted to provide binocular viewing.

35. The eye viewing device of claim 29, wherein said device includes a housing including at least one lens holder, and a plurality of lenses, at least one of said lenses being packaged in a lens module which is adapted to be received in said at least one lens holder.

36. The eye viewing device of claim 29, wherein said device includes a housing and wherein said device further comprises:

an eyepiece holder defined by said housing;

an eyepiece having an eyepiece lens, said eyepiece being adapted to be received in said eyepiece holder; and

a video module having an image sensor, said video module being adapted to be received in said eyepiece holder wherein said eyepiece holder is adapted to receive only one of said eyepiece or said video module at a given time.

37. The eye viewing device of claim 29, wherein a retinal field of view of said imaging system is larger than a retinal area of illumination of said illumination system.

38. The eye viewing device of claim 29, wherein a retinal field of view of said imaging system is between about 15 to 30 percent larger than a retinal area of illumination of said illumination system.

39. The eye viewing device of claim 29, wherein said illumination system generates converging light converging at an apex, wherein said aperture stop is disposed in said device in a position substantially conjugate to said apex.

40. The eye viewing device of claim 29, wherein an aperture of said aperture stop is sized substantially according to the formula, d=2 m millimeters, where d is the diameter of said aperture and m is the magnification of said pupil in the plane of said aperture stop.

41. The eye viewing device of claim 29, wherein said aperture stop is disposed about said imaging axis.

42. The eye viewing device of claim 29, wherein said light source is a light generating light source selected from the group consisting of a filament based lamp, an arc lamp, a fiber optic light source, and a solid state light source.

43. The eye viewing device of claim 29, wherein said light source is provided by a light reflective element.

44. The eye viewing device of claim 43, wherein said light reflective element is a mirror.

45. The eye viewing device of claim 29, wherein said light source is provided by a reflective element, wherein said reflective element redirects light received from a light-generating light source.

46. The eye viewing device of claim 45, wherein said reflective element-provided light source operates in association with a light generating light source and a condenser lens, wherein said condenser lens condenses light from said light generating light source onto said reflective element.

47. The eye viewing device of claim 29, wherein said device is housed in a housing having a first section generally coextensive with said imaging axis and a second section generally transverse to said first section.

48. The eye viewing device of claim 29, wherein said off-axis light source is provided by a mirror which redirects light emitted by a light generating light source, wherein said light generating light source is disposed in said second section.

49. The eye viewing device of claim 29, wherein said illumination system and said imaging system are incorporated in a single housing.

50. The eye viewing device of claim 29, wherein said imaging system includes an objective lens disposed in a path of illumination light rays generated by said illumination system.

51. The eye viewing device of claim 50, wherein said objective lens is a single element lens.

52. The eye viewing device of claim 50, wherein said objective lens is a plural element lens.

53. The eye viewing device of claim 50, wherein said illumination system includes an objective lens disposed so that said imaging axis intersects said objective lens.

54. The eye viewing device of claim 50, wherein said illumination system and imaging system include a common objective lens.

55. The eye viewing device of claim 54, wherein said common objective lens comprises a single element lens.

56. The eye viewing device of claim 54, wherein said common objective lens comprises a plural element lens.

57. An eye viewing device for viewing a structure of an eye having a pupil, said device comprising:

an illumination system generating a converging cone of light that converges at an apex and diverges thereafter;

an imaging system having an imaging axis, wherein said illumination system includes a reflective element positioned off-axis with respect to said imaging axis; and

an aperture stop disposed in said device substantially coaxial with said imaging axis and substantially conjugate to said apex whereby internal and corneal glare in said device is reduced.

58. The eye viewing device of claim 57, wherein an aperture of said aperture stop is sized to substantially correspond to a size of said pupil.

59. The eye viewing device of claim 57, wherein said imaging system includes an objective lens, said objective lens having a first surface closest to said reflective element curved substantially concentric about a center of an aperture of said aperture stop, whereby internal glare in said device is reduced.

60. The eye viewing device of claim 57, wherein said off-axis positioned reflective element is positioned outside of an aperture of said aperture stop, whereby said reflective element has no obscuring effect on images received by said viewing device.

61. The eye viewing device of claim 57, wherein said off-axis positioned reflective element is positioned outside of a border between received and blocked light defined by said aperture stop, and wherein said imaging system includes an objective lens having a curved first surface curved concentric about a center of said aperture, whereby said reflective element has no obscuring effect on images received by viewing device, and whereby incident light reflected from said first surface is blocked by said aperture stop.

62. The eye viewing device of claim 57, wherein said imaging system comprises binocular optics adapted to provide binocular viewing.

63. The eye viewing device of claim 57, wherein said device includes a housing including at least one lens holder, and a plurality of lenses, at least one of said lenses being packaged in a lens module which is adapted to be received in said at least one lens holder.

64. The eye viewing device of claim 57, wherein said device includes a housing and wherein said device further comprises:

an eyepiece holder defined by said housing;

an eyepiece having an eyepiece lens, said eyepiece being adapted to be received in said eyepiece holder; and

a video module having an image sensor, said video module being adapted to be received in said eyepiece holder wherein said eyepiece holder is adapted to receive only one of said eyepiece or said video module at a given time.

65. The eye viewing device of claim 57, wherein a retinal field of view of said imaging system is larger than a retinal area of illumination of said illumination system.

66. The eye viewing device of claim 57, wherein a retinal field of view of said imaging system is between about 15 to 30 percent larger than a retinal area of illumination of said illumination system.

67. The eye viewing device of claim 57, wherein said aperture stop is disposed in said device so that said aperture stop is substantially conjugate to said pupil when said illumination system projects substantially a maximum amount of light through said pupil.

68. The eye viewing device of claim 57, wherein an aperture of said aperture stop is sized substantially according to the formula, d=2 m millimeters, where d is the diameter of said aperture and m is the magnification of said pupil in a plane of said aperture stop.

69. The eye viewing device of claim 57, wherein said aperture stop is disposed about said imaging axis.

70. The eye viewing device of claim 57, wherein said light reflective element is a mirror.

71. The eye viewing device of claim 57, wherein said reflective element is provided by a mirror, wherein said mirror redirects light received from a light-generating light source.

72. The eye viewing device of claim 71, wherein said mirror-provided light source operates in association with a light generating lightsource and a condenser lens, wherein said condenser lens condenses light from said light generating light source onto said mirror.

73. The eye viewing device of claim 57, wherein said device is housed in a housing having a first section generally coextensive with said imaging axis and a second section generally transverse to said first section.

74. The eye viewing device of claim 73, wherein said reflective element is provided by a mirror which redirects light emitted by a light generating light source, wherein said light generating light source is disposed in said second section.

75. The eye viewing device of claim 57, wherein said illumination system and said imaging system are incorporated in a single housing.

76. The eye viewing device of claim 57, wherein said imaging system includes an objective lens disposed in a path of illumination light rays generated by said illumination system.

77. The eye viewing device of claim 76, wherein said objective lens is a single element lens.

78. The eye viewing device of claim 76, wherein said objective lens is a plural element lens.

79. The eye viewing device of claim 57, wherein said illumination system includes an objective lens disposed so that said imaging axis intersects said objective lens.

80. The eye viewing device of claim 57, wherein said illumination system and imaging system include a common objective lens.

81. The eye viewing device of claim 80, wherein said common objective lens comprises a single element lens.

82. The eye viewing device of claim 80, wherein said common objective lens comprises a plural element lens.

83. An eye viewing device for viewing a structure of an eye having a retina and a pupil, said device comprising:

an illumination system for illuminating said retina;

an imaging system having an imaging axis, wherein said illumination system includes a reflective element positioned off-axis with respect to said imaging axis; and

an aperture stop disposed in said device substantially coaxial with said imaging axis and substantially conjugate to said pupil when said device is in an operative position in relation to said eye, whereby internal and corneal glare in said device is reduced.

84. The eye viewing device of claim 83, wherein an aperture of said aperture stop is sized to substantially correspond to a size of said pupil.

85. The eye viewing device of claim 83, wherein said imaging system includes an objective lens, said objective lens having a first surface closest to said reflective element curved substantially concentric about a center of an aperture of said aperture stop, whereby internal glare in said device is reduced.

86. The eye viewing device of claim 83, wherein said off-axis positioned reflective element is positioned outside of an aperture of said aperture stop, whereby said light source has no obscuring effect on images received by said viewing device.

87. The eye viewing device of claim 83, wherein said off-axis positioned reflective element is positioned outside of a border between received and blocked light defined by said aperture stop, and wherein said imaging system includes an objective lens having a curved first surface curved concentric about a center of said aperture, whereby said reflective element has no obscuring effect on images received by viewing device, and whereby incident light reflected from said first surface is blocked by said aperture stop.

88. The eye viewing device of claim 83, wherein said imaging system comprises binocular optics adapted to provide binocular viewing.

89. The eye viewing device of claim 83, wherein said device includes a housing including at least one lens holder, and a plurality of lenses, at least one of said lenses being packaged in a lens module which is adapted to be received in said at least one lens holder.

90. The eye viewing device of claim 83, wherein said device includes a housing and wherein said device further comprises:

an eyepiece holder defined by said housing;

an eyepiece having an eyepiece lens, said eyepiece being adapted to be received in said eyepiece holder; and

a video module having an image sensor, said video module being adapted to be received in said eyepiece holder wherein said eyepiece holder is adapted to receive only one of said eyepiece or said video module at a given time.

91. The eye viewing device of claim 83, wherein a retinal field of view of said imaging system is larger than a retinal area of illumination of said illumination system.

92. The eye viewing device of claim 83, wherein a retinal field of view of said imaging system is between about 15 to 30 percent larger than a retinal area of illumination of said illumination system.

93. The eye viewing device of claim 83, wherein said illumination system generates a converging cone of light converging at an apex, wherein said aperture stop is disposed in said device substantially conjugate to said apex.

94. The eye viewing device of claim 83, wherein an aperture of said aperture stop is sized substantially according to the formula, d=2 m millimeters, where d is the diameter of said aperture and m is the magnification of said pupil in a plane of said aperture stop.

95. The eye viewing device of claim 83, wherein said aperture stop is disposed about said imaging axis.

96. The eye viewing device of claim 83, wherein said light reflective element is a mirror.

97. The eye viewing device of claim 83, wherein said reflective element is provided by a mirror, wherein said mirror redirects light received from a light generating light source.

98. The eye viewing device of claim 97, wherein said mirror-provided reflective element operates in association with a light generating light source and a condenser lens, wherein said condenser lens condenses light from said light generating light source onto said mirror.

99. The eye viewing device of claim 83, wherein said device is housed in a housing having a first section generally coextensive with said imaging axis and a second section generally transverse to said first section.

100. The eye viewing device of claim 99, wherein said reflective element is provided by a mirror which redirects light emitted by a light generating light source, wherein said light generating light source is disposed in said second section.

101. The eye viewing device of claim 83, wherein said illumination system and said imaging system are incorporated in a single housing.

102. The eye viewing device of claims 83, wherein said imaging system includes objective lens disposed in a path of illumination light rays generated by said illumination system.

103. The eye viewing device of claim 83, wherein said objective lens is a single element lens.

104. The eye viewing device of claim 83, wherein said objective lens is a plural element lens.

105. The eye viewing device of claim 83, wherein said illumination system includes an objective lens disposed so that said imaging axis intersects said objective lens.

106. The eye viewing device of claim 83, wherein said illumination system and imaging system include a common objective lens.

107. The eye viewing device of claim 106, wherein said common objective lens comprises a single element lens.

108. The eye viewing device of claim 106, wherein said common objective lens comprises a plural element lens.

109. An eye viewing device for viewing a structure of an eye having a pupil, said device comprising:

an eyepiece holder defined by said housing;

an eyepiece having an eyepiece lens, said eyepiece being adapted to be received in said holder;

a video module having an image sensor, said video module being adapted to be received in said eyepiece holder wherein said eyepiece holder is adapted to receive only one of said eyepiece or said video module at a given time;

an illumination system generating a converging cone of light that converges at an apex and diverges thereafter;

an imaging system having an imaging axis; and

an aperture stop disposed in said device substantially coaxial with said imaging axis and substantially conjugate to said apex, whereby corneal glare is reduced.

110. The eye viewing device of claim 109, wherein said imaging system includes an objective lens, said objective lens having a first surface closest to said light source curved substantially concentric about a center of an aperture of said aperture stop, whereby internal glare in said device is reduced.

111. The eye viewing device of claim 109, wherein said imaging system includes an objective lens disposed in a path of illumination light rays generated by said illumination system.

112. The eye viewing device of claim 109, wherein said illumination system includes an objective lens disposed so that said imaging axis intersects said objective lens.

113. The eye viewing device of claim 109, wherein said aperture stop is disposed in said device so that said aperture stop is substantially conjugate to said pupil when said illumination system projects substantially a maximum amount of light through said pupil.

114. An eye viewing device for viewing a structure of an eye having a pupil, said device comprising:

an eyepiece holder defined by said housing;

an eyepiece having an eyepiece lens, said eyepiece being adapted to be received in said holder;

a video module having an image sensor, said video module being adapted to be received in said eyepiece holder wherein said eyepiece holder is adapted to receive only one of said eyepiece or said video module at a given time;

an illumination system for illuminating said retina;

an imaging system having an imaging axis; and

an aperture stop disposed in said device substantially coaxial with said imaging axis and substantially conjugate to said pupil when said device is in an operative position in relation to said eye, whereby corneal glare is reduced.

115. The eye viewing device of claim 114, wherein said imaging system includes an objective lens, said objective lens having a first surface closest to said light source curved substantially concentric about a center of an aperture of said aperture stop, whereby internal glare in said device is reduced.

116. The eye viewing device of claim 114, wherein said imaging system includes an objective lens disposed in a path of illumination light rays generated by said illumination system.

117. The eye viewing device of claim 114, wherein said illumination system includes an objective lens disposed so that said imaging axis intersects said objective lens.

118. The eye viewing device of claim 114, wherein said illumination system generates converging light converging at an apex, wherein said aperture stop is disposed in said device in a position substantially conjugate to said apex.