Contact lens disinfector with temperature indicator

A unit (10) for disinfecting contact lenses includes a housing, heating means (20) arranged to heat a contact lens case (21) and the contact lenses therein and means (30) for indicating the temperature condition (HOT or COLD) of the lens case. The temperature indicating means includes a viewing window (17) formed in the housing, a prismatic lens (38) within the housing and behind the viewing window, and pivotally mounted indicia (39) behind the prismatic lens that indicates if the lens case is cool enough to handle following the disinfecting heating cycle.

BACKGROUND OF THE INVENTION 
The present invention relates to a contact lens disinfector unit having an 
improved temperature indicator. 
Disinfector units frequently include a lens case which makes broad surface 
contact with a block that is heated by an electric current. After heating 
the lenses at a disinfecting temperature for a sufficient time, the 
application of current to the heating block is terminated and the lens 
case and contact lenses are allowed to cool and then removed for use. 
Disinfector units of the foregoing type have generally controlled the 
application of electric current to the heating block with a thermocoupled 
switch. The thermocouple, after detecting a predetermined temperature of 
the heating block, breaks the switch contact for terminating the 
application of the electric current. Wired in series with the switch may 
be a light bulb. The light bulb lights up when the switch is closed and 
the electric current is being applied to the heating block and is turned 
off when the thermocouple opens the switch to terminate the application of 
the electric current to the heating block. Because of this arrangement, 
the user may not know when the contact lens case has cooled sufficiently 
to be safely removed. The user may therefore either attempt to remove the 
lens case too soon resulting in possible injury, or wait an exceedingly 
long time after the light bulb turns off to be assured that the lens case 
may be safely removed. As a result, such disinfectors are inconvenient to 
use and may result in injury to the user. 
It is therefore an object of the present invention to provide a new and 
improved contact lens disinfector unit which includes a temperature 
indicator for indicating if the contact lens case is hot and unsafe for 
removal or if the lens case has cooled sufficiently for safe removal. 
The present invention therefore provides a contact lens disinfector unit 
for sterilizing contact lenses contained within a contact lens case. The 
contact lens disinfector unit includes a housing, heating means arranged 
to heat the contact lens case and the contact lenses therein to a 
disinfecting temperature and for terminating the application of heat 
thereafter to allow the contact lenses to cool, and temperature indicating 
means for indicating first and second temperatures of the heating means. 
The temperature indicator may include a viewing window formed in the 
housing, prismatic lens means within the housing and behind the viewing 
window, first and second temperature indicia behind the prismatic lens 
means, wherein the prismatic lens means is arranged for movement such that 
the first temperature indicia is viewable through the viewing window when 
the prismatic lens means is at a first angular position relative to the 
viewing window, and the second temperature indicia is viewable through the 
viewing window when the prismatic lens means is at a second angular 
position relative to the viewing window; and actuating means responsive to 
the temperature of the heating means for moving the prismatic lens means 
between the first and second angular positions relative to the viewing 
window.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to FIGS. 1 and 2, the disinfector unit 10 thereshown includes 
a housing comprised of a top cover section 11, a bottom section 12, the 
latter being adapted to house removably a lens case 21. The top cover 
section has openings 13, 14 and 15. In the first opening 13 there is an 
activator button 16 mechanically coupled to a thermocouple switch 22 such 
that depressing the button 16 initiates a disinfecting cycle. The second 
opening 14 is disposed over a light bulb 27 (FIG. 2) which lights when the 
thermocouple switch 22 is closed, thus indicating that the unit 10 is in 
the heating mode. The light bulb 27 is extinguished when the thermocouple 
switch 22 opens upon reaching the proper disinfecting temperature. The 
opening 15 forms a viewing window 17 through which the user may view a 
temperature indicating indicia so as to be informed whether or not the 
contact lens case is sufficiently cool to enable safe removal of the lens 
case 21 from the disinfector unit. 
The top cover section 11 includes a hinged lid portion 18 which is shown in 
a raised position in FIG. 1, allowing the lens case 21 to be inserted or 
withdrawn from the housing. In addition, the top cover section 11 includes 
a circular recess 19 which communicates with the upper surface of a 
heating block 20 in the unit 10. The recess 19 is conventionally 
dimensioned for receiving the lens case 21. The lens case 21 may 
conventionally include a bottom portion 21a removably engaged with an 
upper portion 21b and is internally designed in a known manner to 
accommodate a pair of lenses and a quantity of disinfecting solution. 
Preferably, the lens case 21 and the recess 19 are dimensioned such that 
the bottom surface of the lens case makes surface-to-surface contact with 
the upper surface of the heating block 20. During the disinfecting cycle, 
the heating block 20 provides sufficient heat transfer to the lens case 21 
so as to heat the contact lenses and the disinfecting solution to a 
temperature sufficient to kill pathogenic bacteria on the lenses. 
The disinfector unit 10 further includes a power supply circuit for a 
resistive heating element (not shown) that heats the heating block 20 in a 
known manner. The power supply circuit is adapted to be connected to an 
electric power source by the pins 25 and 26 of a connector 24. Thus, in a 
known manner the disinfecting cycle is initiated by depressing the button 
16 to close the thermocouple switch 22 so as to supply current to the 
heating element that heats the heating block 20. Light 27 is now 
illuminated and remains so until the desired disinfecting temperature has 
been reached following which the switch 22 opens and light 27 goes out. At 
this time, however, the lens case 21 is still too hot to remove from the 
unit 10. 
The heating block 20 includes a surface portion 28 shown in dashed lines 
(FIG. 2) which engages the under surface of the lens case 21 during the 
sterilization of the contact lenses. The heating block includes a rearward 
portion 29 which terminates in upstanding post 31 to which the indicating 
arrangement 30 is operatively connected. The heating block 20 is in 
contact with the resistive heating element mentioned above, and due to the 
surface-to-surface contact with the case 21 applies heat evenly thereto 
for a sufficient period of time during the disinfecting cycle so as to 
raise the temperature of the disinfecting solution to that required for 
disinfecting of the contact lenses. 
Attention is now directed to the temperature indicating arrangement 30 
which is shown in greater detail in FIGS. 3 and 4. The arrangement 
includes a temperature sensitive member 32 in the form of a bi-metallic 
strip which has one end 33 affixed to the upstanding post 31 of the 
heating block 20 and the other end 34 free to move vertically in first and 
second directions. The end 34 will move in a first direction upwardly as 
the temperature of the heating block 20 and lens case 21 rises and 
downwardly in a second direction as the heating block and lens case cools. 
As will be described more fully hereinafter, the reciprocal vertical 
movement of the bi-metallic strip 32 is used to impart pivotal movement to 
a temperature indicia carrying member 35 which in the illustrated 
embodiment is in the form of a flat or planar member. The planar member 35 
is pivotally mounted within a hollow upstanding column or tunnel member 36 
having a plurality of side walls 40, 41, 42 and 43 as best seen in FIG. 2. 
The planar member 35 is pivotally mounted across opposing side walls 40 
and 42 for rocking movement in the member 36. The planar member 35 has a 
rearward extension 44 (FIGS. 3 and 4) which terminates in a pair of 
bifurcated opposing members 45 and 46 which define a space 47 therebetween 
for receiving the free end 34 of the bi-metallic strip 32. The rearward 
extension 44 extends through an opening 48 in the side wall 43 of tunnel 
structure 36. The planar member 35 has an upper surface 37 which carries a 
prismatic lens 38 and temperature indicia 39 therebetween. 
The prismatic lens and temperature indicia form a so-called "vari-vue" 
display that changes when tilted or pivoted. In FIG. 5 a prismatic lens 38 
and first and second temperature indicia 39a and 39b are shown. The pair 
of temperature indicia are formed by a plurality of strips wherein the 
strips 39a of one indicia are alternated with the strips 39b of the other 
indicia. The strips of each respective indicia, when viewed, form a 
complete image, which for example, may be a word to indicate the 
temperature condition of the disinfector unit heating block and lens case. 
For example, the first temperature indicia strips 39a may combine together 
to form the word COLD as illustrated in FIG. 3, and the second temperature 
indicia strips 39b may combine to form the word HOT as seen in FIG. 4. 
When the prismatic lens is tilted or pivoted to a first angular position 
with respect to the viewing window 17, the prismatic lens will be viewed 
at an angle represented by the arrows 50. As a result, only temperature 
indicia strips 39a will be viewable through the window so that the user 
will be informed that the heating block and lens case are sufficiently 
cooled so that the lens case 21 may be safely removed from the disinfector 
unit. When the prismatic lens 38 is pivoted to a second angular position 
relative to the viewing window 17 as illustrated in FIG. 4, the user will 
view the prismatic lens from an angle illustrated by arrows 51. Hence, 
only strips 39b of the second temperature indicia will be seen, which will 
inform the user that the heating block and lens case are too hot to allow 
the lens case to be safely removed. 
At the beginning of a disinfecting cycle, the heating block 20 and contact 
lens case 21 will be cool and the bi-metallic strip 32 will be disposed in 
the COLD position as shown in FIG. 3. As the temperature of the heating 
block and contact lens case rise, the free end 34 of bi-metallic strip 32 
will be displaced upwardly so as to cause the planar member 35 and 
prismatic lens 38 to pivot to the second angular position relative to the 
viewing window 17 as shown in FIG. 4. When the heating block and lens 
reach a temperature considered to be excessively hot for safe removal of 
the lens case 21 from the disinfector unit, the prismatic lens 38 will be 
disposed in the second or HOT position as shown in FIG. 4. 
Upon the cooling of the heating block and lens case following opening of 
the switch 22, the bi-metallic strip 32 at its free end 34 will once again 
be displaced downwardly. When the contact lens case reaches a cool safe 
temperature for removal, the bi-metallic strip will cause the prismatic 
lens 38 to be disposed at its first angular position once again so that 
the first temperature indicia word COLD will be viewable through the 
viewing window 17. 
The tunnel 36 is relatively deep and the indicia-carrying member 35 is 
relatively deeply positioned with the tunnel 36, namely substantially 
recessed from the viewing window 17. As a result the user must view the 
member 35 substantially along the central axis of the tunnel 36 or along a 
path that is only offset at small amounts from the axis of the tunnel 36. 
Consequently, the field of view through the window 17 is narrow so as to 
avoid misreading the indicia as might result if the viewing path were too 
wide.