Ophthalmic lighting apparatus

An ophthalmic lighting apparatus for operable attachment to ophthalmic articles, such as ophthalmic refractors, which articles are capable of supporting and deploying a protruding reading card rod, a reading card holder and accordingly a reading card during an ophthalmic examination. An illumination member is operably attached to one or more of the components of the reading card assembly for providing a controlled and standardized amount of light to the reading card. A position sensitive switch is interposed between a power source and the illumination member for automatically switching a light source upon movement of the reading card rod from a vertically protruding pre-ophthalmic examination position to a substantially horizontal protruding ophthalmic examination position.

BACKGROUND OF THE INVENTION 
The present invention relates to ophthalmic examination equipment and, more 
particularly, to an ophthalmic lighting apparatus for operable attachment 
to an ophthalmic article, such as an ophthalmic refractor, of the type 
which has an attachment element capable of supporting a reading card rod, 
and accordingly a reading card holder and reading card, so as to provide 
controlled and standardized illumination of at least a portion of the 
reading card during the ophthalmic examination. 
Lighting devices used for illuminating reading cards of the type operably 
attached to ophthalmic articles such as ophthalmic refractors have been 
known in the art for many years. Many of such lighting devices are 
typically in the form of conventional multi-positionable lamps 
independently positioned and physically isolated from the ophthalmic 
article itself, which ophthalmic refractor, for example, utilizes a 
reading card assembly. The position and illumination of such independent 
light sources are, unfortunately, rarely maintained at a specific 
recommended illumination level, much less a predetermined, calibrated, 
distance away from the reading card during the actual ophthalmic 
examination. Accordingly, one of several problems associated with the use 
of such conventional independent lamps, is that the brightness of the 
light projected onto the reading card typically exceeds the ten to twenty 
foot candle illumination protocol recommended for an ophthalmic reading 
test. Accordingly, the results of the reading test may often be 
inconsistent, and in many cases, in error--with some patients complaining 
that their reading glasses "worked better" during examination than in use; 
due to over illumination of the reading test card. In addition, inasmuch 
as the lamps are not maintained in a predetermined, calibrated, 
orientation with respect to the reading card, the intensity of light 
projected onto the reading card may vary from examination to examination, 
with the wrong intensity of light otherwise recommended for such an 
examination being projected onto the reading card--thereby potentially 
resulting in an inaccurate diagnosis by the examiner. 
It is accordingly not uncommon for an optometrist or ophthalmologist to 
prescribe corrective lenses to a patient, for reading, based upon the 
results of a reading examination given in association with a 
non-calibrated, non protocol-conforming conventional light projector, only 
to later find out that such lenses do not adequately correct the patients 
vision when he or she is attempting to read in a "real world" environment. 
Furthermore, inasmuch as many conventional style lamps are 
multi-positionable, and, accordingly, constantly re-adjusted (i.e. by 
swinging the lamp into proximate position for the examination, followed by 
making further manual adjustments thereto followed by raising the lamp and 
swinging it out of the way after the examination) breakage and/or other 
forms of malfunction of the lamp are not uncommon. 
It is thus an object of the present invention to provide an ophthalmic 
lighting apparatus which is maintained at a predetermined, calibrated, 
position away from the reading card, so as to ensure that the industry 
recommended amount of light is being projected onto the reading card 
during every ophthalmic examination given. 
It is also an object of the present invention to provide an ophthalmic 
lighting apparatus which is operably attached to a portion of an 
ophthalmic article, such as a reading card holder attached to an 
ophthalmic refractor, so that constant reorientation of the lighting 
apparatus, with respect to the reading card, is not required. 
It is still further an object of the present invention to provide an 
ophthalmic lighting apparatus which includes a position sensitive switch 
which automatically results in the projection of light when the apparatus 
is in an ophthalmic examination position and automatically shuts of the 
light when the lighting apparatus is in a pre-ophthalmic examination 
position--while isolating wall current electrical conductors from contact 
with the metal refractor. 
These and other objects of the present invention will become apparent in 
light of the present specification and drawings. 
SUMMARY OF THE INVENTION 
The present invention comprises an ophthalmic lighting apparatus for 
operable attachment to ophthalmic articles, such as ophthalmic refractors, 
which articles are of the type having a reading card assembly including a 
reading card rod attachment element capable of operably supporting a 
protruding reading card rod, along with a reading card holder and a 
reading card supported by the reading card holder in front of the 
ophthalmic article for use in association with ophthalmic examinations; 
for providing controlled and standardized illumination to at least a 
portion of the reading card during the ophthalmic examination. 
The ophthalmic lighting apparatus includes apparatus attachment means for 
operably securing the ophthalmic lighting apparatus to at least a portion 
of said reading card assembly. Illumination means are operably attachable 
along the reading card rod in a facilitated manner for projecting a 
desired, calibrated amount of light towards and onto the reading card 
during the ophthalmic examination to, in turn, obviate the need to utilize 
externally positioned non-calibrated illumination devices. 
Power means are operably attached to the illumination means for providing 
electricity to the illumination means, to, in turn, enable the projection 
of the desired amount of light toward and onto the reading card. In 
addition, switch means are operably interposed between the power means and 
the illumination means for alternatively opening and closing the flow of 
electricity from the power means to the illumination means. 
A housing means has an exterior surface and an interior surface defining a 
component protection region which operably surrounds and shields at least 
a portion of one or more of the power means, the illumination means and 
the switch means within the component protection region. In addition, 
positioning means are operably interposed between the illumination means 
and reading card, for operably maintaining the illumination means at a 
desired distance away from the reading card. 
In the preferred embodiment of the invention, the switching means comprises 
a position sensitive switch. This switch automatically opens the flow of 
electricity from the power means to the illumination means when the 
reading card rod, and, in turn, the reading card, are in an extended 
deployed, ophthalmic examination position. Conversely, the position 
sensitive switch closes the flow of electricity from the power means to 
the illumination means when the reading card rod, reading card holder and 
reading card are in a pre-ophthalmic examination position. The position 
sensitive switch itself preferably comprises a mercury switch. In this 
embodiment, the switch will be in an open-flow position when the reading 
card rod is in a substantially horizontal protruding examination position, 
and closed to power flow when the reading card rod is raised to a 
substantially vertical, protruding pre-examination position--thereby 
preventing the flow of electricity to the illumination means. 
In a preferred embodiment of the invention, the power means includes a 
battery for providing electricity to the illumination means so as to 
preclude the need to attach the ophthalmic lighting device to conventional 
socket current during use thereof, thereby insulating a typically metallic 
refractor from direct contact with dangerous, high current 110 volt 
conductor wires. The low current battery power means further includes 
electricity conduit means operably connected to the switching means and 
the illumination means. 
In the preferred embodiment of the invention, the illumination means 
comprises a light bulb which is operably exposed to the reading card for 
illuminating the reading card during the ophthalmic examination through 
the projection of light thereupon. The light bulb may further include 
magnifying lens means which are operably positioned adjacent the light 
bulb. The magnifying lens means are positioned in exposed relationship to 
the reading card for intensifying light projected from the light bulb 
toward and onto the reading card. It is also contemplated that the 
illumination means may further include light diffusion means which are 
operably associated with the light bulb and/or the magnifying lens means. 
The light diffusion mean are positioned in exposed relationship to the 
reading card for operable directing and concentrating the light emitted 
from the light bulb and, alternatively, the magnifying lens means toward 
and onto the reading card. The light diffusion means may comprise a fiber 
optic element. 
In another embodiment of the invention, the apparatus attachment means is 
removably secured to at least a portion of the ophthalmic article. This 
bracket may be slidably engageable over at least a portion of a 
conventional reading card holder for standardized removable securement 
thereto. 
In the preferred embodiment of the invention, the illumination means 
projects an intensity of light of between ten and twenty foot candles onto 
the reading card when the switch means, the reading card rod, reading card 
holder and reading card, are in the substantially horizontal ophthalmic 
examination position. The intensity of projected light is a function of 
the power means, the illumination means and the distance at which the 
illumination means is maintained away from the reading card by the 
positioning means.

DETAILED DESCRIPTION OF THE DRAWINGS 
While this invention is susceptible of embodiment in many different forms, 
there is shown in the drawings and will herein be described in detail, one 
specific embodiment with the understanding that the present disclosure is 
to be considered as an exemplification of the principles of the invention 
and is not intended to limit the invention to the embodiment illustrated. 
Ophthalmic lighting apparatus 10 is shown in FIG. 1 and FIG. 2 in its 
intended environment, and specifically, as integrally, yet removably 
attached to a conventional reading card assembly which comprises a reading 
card 109, reading card holder 110 and a reading card rod 106 for use with 
a conventional ophthalmic article, such as ophthalmic refractor 100. As 
shown, reading card holder 110, (and accordingly, ophthalmic lighting 
apparatus 10) is operably secured to ophthalmic refractor 100 through 
cooperation with reading card rod 106. Reading card rod 106 has a first 
end 107 and a second end 108. First end 107 of reading card rod 106 is 
operably inserted within slot 90 of conventional reading rod attachment 
element 105 which is pivotally attached to ophthalmic refractor 100. 
Restraint screw 81 fixedly restrains rod 106 within slot 90. Second end 
108 of reading rod 106 is operably inserted and secured within reading 
card rod receiving slot 114 of reading card rod acceptance bracket 115 on 
reading card holder 110, as shown more fully in FIG. 4. 
Ophthalmic lighting apparatus 10 is shown in FIG. 3 as comprising housing 
means 40 and 40', illumination means 20, power means 25, switch means 28, 
positioning means 46 and apparatus attachment means 15 which is integrally 
connected to first end 47 of positioning means 46. Illumination means 20, 
which serves to illuminate a relevant portion of reading card 109 (FIG. 
4), may include a light bulb and magnifying lens (not shown) as well as 
fiber optic element 23. Fiber optic 23 is operably positioned above the 
bulb/magnifying lens assembly within illumination means 20 so that the 
light being emitted from the light bulb is first magnified and then 
transmitted through the fiber optic where it is then diffused and directed 
to and concentrated on, a relevant portion of reading card 109 (FIG. 4). 
Although the bulb/magnifying assembly is not shown, a commercially 
suitable assembly, such as a light bulb capable of drawing three volts of 
electricity at 0.006 amps of current, coupled with a magnifying lens 
capable, for example, of twenty times magnification of the light projected 
from the bulb, can be used. An example of such a light bulb/magnifying 
lens combination is commercially available from Hamai Corporation under 
its catalog number LNS-BP4-20K. In addition, any suitable plastic fiber 
optic element may be utilized. 
Power means 25, which serves to electrically power illumination means 20, 
is shown in FIG. 3 and FIG. 5 as including battery 26 and resistor 27. 
Battery 26 is operably connected to illumination means 20, resistor 27, as 
well as switch means 28, by electrical conduit, such as electrical 
conduits 29 and 30. Use of a battery, as opposed to common current from a 
typical electrical outlet is desired inasmuch as such a self-contained 
power source substantially reduces the risk of electrical shock which 
could otherwise occur from a short in the electrical connection from a 
standard 110 volt outlet--especially inasmuch as the patient being 
examined usually has his or her face pressed against a portion of the 
metal casing of ophthalmic refractor 100. Although battery 26 is 
contemplated to be a readily available 9 volt transistor radio battery, 
and, resistor 27 is contemplated to be a commercially available resistor 
having approximately ten ohms of resistance, many other types of batteries 
and resistor combinations are also contemplated--provided that such a 
combination enables the desired amount of light to be projected onto 
reading card 109 from illumination means 20 during the ophthalmic 
examination. 
Switch 28, which is interposed between battery 26 and illumination means 20 
(FIG. 3 and FIG. 5), serves to allow, or preclude the flow of electricity 
from battery 26 to illumination means 20. It is preferred that switch 28 
comprise a position sensitive switch, such as a mercury switch, so as to 
automatically open and close the flow of electricity to illumination means 
20, depending upon the orientation of ophthalmic lighting apparatus 10. 
Indeed, when ophthalmic lighting apparatus 10, and accordingly reading 
card rod 106, are in a substantially vertical protruding orientation, as 
shown in FIG. 1, then the apparatus will be in its pre-ophthalmic 
examination position. Accordingly, when in such a position, switch 28 will 
preclude the flow of electricity to illumination means 20. Conversely, 
when ophthalmic lighting device 10, and accordingly reading card rod 106, 
are in a substantially horizontal protruding orientation, as shown in FIG. 
2, then the apparatus will be in an ophthalmic examination position, so 
that switch means 28 will automatically allow the flow of electricity to 
illumination means 20. Simply re-orientating the apparatus from the 
pre-examination position to the examination position will automatically 
cause switch means 28 to permit electric power to flow to illumination 
means 20. Such a position sensitive switch is available from Micro-Dynamic 
Corporation under its catalog number 5- 2-10--although any other suitable 
position sensitive switch can be used for such automatic "on" and "off" 
switching. 
Housing means 40 and 40', as shown in FIG. 3, each include an exterior 
surface, such as exterior surface 41, and an interior surface (not shown) 
which defines a component protection region (also not shown). In addition, 
housing means 40' which enshrouds battery 26, includes conduit aperture 43 
which facilitates unobstructed passage of electrical conduit, such as 
connectors 29 and 30 from battery 26 to illumination means 20, as well as 
to switching means 28. The housing means serves to protect the inner 
componentry, and more specifically, the illumination means 20, power means 
25, and switch means 28 from potential damage which could result from 
exposure to the external contact, while serving to preclude injury which 
could result from even nominal electrical shock. Furthermore, housing 
means 40 which substantially covers illumination means 20, switching means 
28 and resistor 27, additionally includes an illumination projection 
portal 52, as shown more fully in FIG. 1 and FIG. 2. This illumination 
projection portal enables at least a portion of fiber optic 23 to extend 
past exterior surface 41 of housing means 40, so as to facilitate the 
unobstructed projection of the necessary amount of light from illumination 
means 20 onto reading surface 102 (FIG. 4) of reading card 109. 
Positioning means 46, as shown in FIG. 3 and FIG. 4, includes first end 47 
and second end 48. Second end 48 is operably attached to support member 
60, which supports illumination means 20, power means 25 and switch means 
28, while first end 47 is operably attached to apparatus attachment means 
15 which is removably secured to reading card holder 110--so as to 
maintain illumination means 20 at a predetermined, calibrated, distance 
away from the relevant portion of reading card 109 (FIG. 2). Accordingly, 
such maintained, interposed orientation of positioning means 46 ensures 
that the amount of light being projected from illumination means 20 onto 
reading card 109, can be set to a desired constant, even if adjustable, 
examination after examination. Although any desired amount of illumination 
can be achieved, it is preferable that positioning means 46 have a length 
which, along with the foot candle capacity of the illumination means, 
enables the projection of light onto reading card 109 to be between the 
recommended industry standard of ten to twenty foot candles. 
Apparatus attachment means 15, which enables removable securement of 
apparatus 10 to reading card holder 110, comprises bracket 16 having top 
surface 55, bottom surface 56, outer periphery 17 and an inner shaped 
periphery 18. As can be seen, inner periphery 18 has a configuration 
substantially similar to the outer periphery of standardized reading card 
rod acceptance bracket 115, so as to enable use of apparatus 10 as a 
readily attachable accessory on existing card holder elements. 
Accordingly, bracket 16 will operably fit over and around reading card rod 
acceptance bracket 115 with very little free play. Additional securement 
of the apparatus to the card holder may be obtained, by utilization of 
commercially available fastening members, such as screws, wing nuts, allan 
screws or thumb screws in attachment means 15. After bracket 16, and 
accordingly ophthalmic lighting apparatus 10, have been operably attached 
to card holder 110, reading card rod 106 is slid into slot 114 of reading 
card rod acceptance bracket 115, of card holder 110, so as to facilitate 
operable cooperation with ophthalmic refractor 100 during an examination, 
or, pre-examination orientation. Once properly inserted, reading card rod 
106 will be positioned adjacent to bottom side 77 of apparatus 10 to 
further provide stability thereto. In addition, inasmuch as the transverse 
cross-sectional thickness of bracket 16 does not extend above the base of 
the reading card rod receiving slot 114 (FIG. 4) when bracket 16 is 
operably attached to reading card rod acceptance bracket 115, reading card 
rod 106 will be able to be inserted within acceptance slot 114 without any 
obstruction. 
The foregoing description and drawings merely explain and illustrate the 
invention and the invention is not limited thereto except insofar as the 
appended claims are so limited, as those skilled in the art who have the 
disclosure before them will be able to make modifications and variations 
therein without departing from the scope of the invention.