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公开(公告)号:GB2323163B
公开(公告)日:2001-08-08
申请号:GB9804448
申请日:1998-03-04
Applicant: HOWARD FOUNDATION
Inventor: BONE RICHARD ANDREW , LANDRUM JOHN THOMAS , HUANG WENLUE , ORTA CARLOS MANUEL
Abstract: A flicker photometer comprises generating means (1, 8, 4) for generating two beams of light of different colours. Both beams are directed to a viewing means (190), and a subject can vary the intensity of light from one beam relative to the other. The colour of the light seen by the subject is caused to alternate. The performance of the photometer is improved by screens which scatter light before it reaches the subject. A first of the screens (186, 188) reflects light from one beam, whilst a second screen (b) is translucent, and thus transmits light from the other. If light of wavelengths to which the eye is less sensitive is passed through the second screen, whilst light of a wavelength to which the eye is more sensitive passes through the first screen, the screens help to make it practicable for the generating means to use a single lamp (1) to produce the light for both beams.
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公开(公告)号:ZA982014B
公开(公告)日:1999-09-10
申请号:ZA982014
申请日:1998-03-10
Applicant: HOWARD FOUNDATION
Inventor: BONE RICHARD ANDREW , LANDRUM JOHN THOMAS , HUANG WENLUE , ORTA CARLOS MANUEL
Abstract: A flicker photometer has beam generating means (1, 8 and 4) for generating two beams of light of different colors. Light from the beams is viewed at the viewing means, and the intensity of light of one beam relative to that of the other beam can be adjusted by adjustment means comprising an attenuating filter (20) which is movably mounted in the path of one beam. Movement of the filter relative to the beam alters the degree to which the beam is attenuated, and is achieved using an electric motor (22). The motor provides a relatively easy means of adjusting the filter position, and can be used to provide coarse and fine adjustments in response to suitable signals from an optical encoder. The motor also enables the filter, along with the beam generating means, to be mounted on a movable table for use in enabling the photometer to accommodate both short and long-sighted subjects.
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公开(公告)号:GB2356701A
公开(公告)日:2001-05-30
申请号:GB0105344
申请日:1998-03-04
Applicant: HOWARD FOUNDATION
Inventor: BONE RICHARD ANDREW , LANDRUM JOHN THOMAS , HUANG WENLUE , ORTA CARLOS MANUEL
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公开(公告)号:AU6507598A
公开(公告)日:1998-09-29
申请号:AU6507598
申请日:1998-03-04
Applicant: HOWARD FOUNDATION
Inventor: BONE RICHARD ANDREW , LANDRUM JOHN THOMAS , HUANG WENLUE , ORTA CARLOS MANUEL
Abstract: A flicker photometer has beam generating means (1, 8 and 4) for generating two beams of light of different colors. Light from the beams is viewed at the viewing means, and the intensity of light of one beam relative to that of the other beam can be adjusted by adjustment means comprising an attenuating filter (20) which is movably mounted in the path of one beam. Movement of the filter relative to the beam alters the degree to which the beam is attenuated, and is achieved using an electric motor (22). The motor provides a relatively easy means of adjusting the filter position, and can be used to provide coarse and fine adjustments in response to suitable signals from an optical encoder. The motor also enables the filter, along with the beam generating means, to be mounted on a movable table for use in enabling the photometer to accommodate both short and long-sighted subjects.
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公开(公告)号:GB2323162A
公开(公告)日:1998-09-16
申请号:GB9804445
申请日:1998-03-04
Applicant: HOWARD FOUNDATION
Inventor: BONE RICHARD ANDREW , LANDRUM JOHN THOMAS , HUANG WENLUE , ORTA CARLOS MANUEL
Abstract: In a flicker photometer to measure the level of macular pigment in the eye of a subject, a light source 1 produces two beams of light of different wavelengths that are alternately directed to the eyepiece 2 via a rotating chopper 18. The intensity of one of the beams is adjusted by the subject until no or minimal flicker is observed by the subject. The intensity adjustment means comprises a wedge-shaped attenuation filter 20 that is positioned in the path of one of the beams by an electric motor 22. In a further embodiment the light source, filter and chopper are located on a table 60 so that is moveable by means of motor 80 or handle 68 so that the photometer can be used with both short and long sighted subjects. The chopper 18 alternately allows transmission 2 of attenuated light via window 6 to the eyepiece or reflects light via its bevelled edge (186,188,figure 18) to the eyepiece. Use of the bevelled edge of the chopper leads to a compact layout.
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公开(公告)号:GB2323162B
公开(公告)日:2001-08-15
申请号:GB9804445
申请日:1998-03-04
Applicant: HOWARD FOUNDATION
Inventor: BONE RICHARD ANDREW , LANDRUM JOHN THOMAS , HUANG WENLUE , ORTA CARLOS MANUEL
Abstract: A flicker photometer has beam generating means (1, 8 and 4) for generating two beams of light of different colors. Light from the beams is viewed at the viewing means, and the intensity of light of one beam relative to that of the other beam can be adjusted by adjustment means comprising an attenuating filter (20) which is movably mounted in the path of one beam. Movement of the filter relative to the beam alters the degree to which the beam is attenuated, and is achieved using an electric motor (22). The motor provides a relatively easy means of adjusting the filter position, and can be used to provide coarse and fine adjustments in response to suitable signals from an optical encoder. The motor also enables the filter, along with the beam generating means, to be mounted on a movable table for use in enabling the photometer to accommodate both short and long-sighted subjects.
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公开(公告)号:ZA9802014B
公开(公告)日:1999-09-10
申请号:ZA9802014
申请日:1998-03-10
Applicant: HOWARD FOUNDATION
Inventor: BONE RICHARD ANDREW , LANDRUM JOHN THOMAS , HUANG WENLUE , ORTA CARLOS MANUEL
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公开(公告)号:ZA9802011B
公开(公告)日:1999-09-10
申请号:ZA9802011
申请日:1998-03-10
Applicant: HOWARD FOUNDATION
Inventor: BONE RICHARD ANDREW , LANDRUM JOHN THOMAS , HUANG WENLUE , ORTA CARLOS MANUEL
CPC classification number: A61B3/02
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公开(公告)号:CA2284120C
公开(公告)日:2006-11-14
申请号:CA2284120
申请日:1998-03-04
Applicant: HOWARD FOUNDATION
Inventor: ORTA CARLOS MANUEL , HUANG WENLUE , LANDRUM JOHN THOMAS , BONE RICHARD ANDREW
Abstract: A flicker photometer has beam generating means (1, 8 and 4) for generating two beams of light of different colours. Light from the beams is viewed at the viewing means, and the intensity of light of one beam relative to that of the other beam can be adjusted by adjustment means comprising an attenuating filter (20) which is movably mounted in the path of one beam. Movement of the filter relative to the beam alters the degree to which the beam is attenuated, and is achieved using an electric motor (22). The motor provides a relatively easy means of adjusting the filter position, and can be used to provide coarse and fine adjustments in response to suitable signals from an optical encoder. The motor also enables the filter, along with the beam generating means, to be mounted on a movable table for use in enabling the photometer to accommodate both short and long-sighted subjects.
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公开(公告)号:ZA982011B
公开(公告)日:1999-09-10
申请号:ZA982011
申请日:1998-03-10
Applicant: HOWARD FOUNDATION
Inventor: BONE RICHARD ANDREW , LANDRUM JOHN THOMAS , HUANG WENLUE , ORTA CARLOS MANUEL
Abstract: A flicker photometer comprises generating means (1, 8, 4) for generating two beams of light of different colours. Both beams are directed to a viewing means (190), and a subject can vary the intensity of light from one beam relative to the other. The colour of the light seen by the subject is caused to alternate. The performance of the photometer is improved by screens which scatter light before it reaches the subject. A first of the screens (186, 188) reflects light from one beam, whilst a second screen (b) is translucent, and thus transmits light from the other. If light of wavelengths to which the eye is less sensitive is passed through the second screen, whilst light of a wavelength to which the eye is more sensitive passes through the first screen, the screens help to make it practicable for the generating means to use a single lamp (1) to produce the light for both beams.
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