Patent Description:
With optical articles, such as lenses, the optical article may be subjected to a treatment to enhance the overall performance and function of the optical article. Examples of such treatments include the formation of one or more coatings on a surface of an optical substrate. For example, the coating could include one or more photochromic materials. Optical articles having a photochromic material are configured to transition from an unactivated, or substantially colorless state, to an activated, or colored state in response to exposure to certain wavelengths of electromagnetic radiation (or "actinic radiation"). In the absence of exposure to actinic radiation, photochromic compound(s) in such photochromic materials are reversibly transformed from the activated (colored) state, back to the unactivated (colorless) state. Generally, the reversible transformation of a photochromic compound from the unactivated (colorless) state to the activated (colored) state is faster than the transformation from the activated (colored) state to the unactivated (colorless) state.

When demonstrating the reversible transformation of photochromic lenses, such as when an optician is advising a customer, an ultraviolet light source can be used to activate the photochromic compound(s) and transform the lens from a colorless state to a colored state. This transformation occurs relatively quickly (e.g., <NUM> to <NUM> seconds) such that the transformative effect can be easily and quickly demonstrated. However, the reverse transformation from the colored state to the colorless state cannot be demonstrated as easily due to slower kinetics of switching from the activated state to the unactivated state (e.g., <NUM> to <NUM> minutes). Therefore, it would be desirable to provide a device and/or method for increasing a rate of the reverse transformation of the photochromic lens from the colored state to the colorless state.

<CIT> relates to an inspection unit for photochromic lenses having a housing defining an interior and at least one ultraviolet light source providing ultraviolet radiation into the housing interior. An inspection platform is movable into and out of the housing interior via at least one slide assembly. The inspection platform includes a light table having a translucent viewing area and at least one inspection light source located under the translucent viewing area. <CIT> does not disclose a portion of the sidewall being transparent to allow viewing of the housing interior from the outside of the housing through the sidewall nor does it foresee that the inspection unit includes a heating device configured to heat at least a portion of the interior of the housing.

In accordance with the present invention, provided is a demonstration device for demonstrating at least one thermally-reversible characteristic of an optical article having at least one photochromic material as set forth in appended independent claim <NUM>. Some specific variants of the demonstration device are presented in appended dependent claims <NUM>-<NUM>. The demonstration device includes a housing defining an interior, an inspection platform within the interior of the housing configured for supporting at least a portion of the optical article, at least one ultraviolet light source configured to radiate ultraviolet light into the interior of the housing, at least one inspection light source configured to illuminate at least a portion of the interior of the housing, and at least one heating device configured to heat at least a portion of the interior of the housing.

In accordance with the present invention, the at least one heating device has at least one heat source and at least one fan. The at least one heat source may be an electric heating element thermally connected to a heat exchanger. The at least one heating device may be configured to maintain a temperature within the interior of the housing at a temperature in the range of <NUM> to <NUM>, such as in the range of <NUM> to <NUM>. In some examples or aspects of the present disclosure, the at least one heating device may be convection heating device, a conduction heating device, or a radiation heating device.

In accordance with other examples or aspects of the present disclosure, at least one control device may be operatively connected to at least one of the ultraviolet light source, the inspection light source, or the heating device. The control device may control at least one of an activation of the ultraviolet light source, an intensity of the ultraviolet light source, an activation of the inspection light source, an intensity of the inspection light source, an activation of the heating device, or a temperature of the heating device. The control device may be operatively connected to an input device configured for controlling operation of at least one of the ultraviolet light source, the inspection light source, or the heating device.

In accordance with other examples or aspects of the present disclosure, the housing may have a first portion defining the interior of the housing and a second portion receiving at least one of the ultraviolet light source, the inspection light source, or the heating device. At least a portion of the first portion of the housing is transparent. The at least one ultraviolet light source may be movable between the first portion and the second portion of the housing. The housing may have a door for enclosing the interior of the housing.

In accordance with other examples or aspects of the present disclosure, the inspection platform may have a transparent or translucent viewing stand. The viewing stand may be movable relative to the housing. The at least one inspection light source may be configured to illuminate a side surface or a bottom surface of the viewing stand.

The present invention also relates to a method of demonstrating at least one thermally-reversible characteristic of an optical article having at least one photochromic material as set forth in appended independent claim <NUM>. Some specific variants of the method are presented in appended dependent claims <NUM> and <NUM>. The method includes receiving the optical article within an interior of a housing of a demonstration device, irradiating at least a portion of the optical article with ultraviolet light from an ultraviolet light source to activate a photochromic compound in the photochromic material associated with the optical article, and heating at least a portion of the interior using at least one heating device to unactivate the photochromic compound. The method may further include illuminating at least a portion of the interior using an inspection light source. The method may further include controlling at least one of an activation of the ultraviolet light source, an intensity of the ultraviolet light source, an activation of the inspection light source, an intensity of the inspection light source, an activation of the heating device, or a temperature of the heating device using at least one control device.

The features that characterize the present disclosure are pointed out with particularity in the claims, which are annexed to and form a part of this disclosure. These and other features of the disclosure, its operating advantages, and the specific objects obtained by its use will be more fully understood from the following detailed description in which non-limiting examples of the disclosure are illustrated and described.

As used herein, the singular form of "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

Spatial or directional terms, such as "left", "right", "inner", "outer", "above", "below", and the like, relate to the invention as shown in the drawing figures and are not to be considered as limiting as the invention can assume various alternative orientations.

All numbers used in the specification and claims are to be understood as being modified in all instances by the term "about". By "about" is meant plus or minus twenty-five percent of the stated value, such as plus or minus ten percent of the stated value. However, this should not be considered as limiting to any analysis of the values under the doctrine of equivalents.

Unless otherwise indicated, all ranges or ratios disclosed herein are to be understood to encompass the beginning and ending values and any and all subranges or subratios subsumed therein. For example, a stated range or ratio of "<NUM> to <NUM>" should be considered to include any and all subranges or subratios between (and inclusive of) the minimum value of <NUM> and the maximum value of <NUM>; that is, all subranges or subratios beginning with a minimum value of <NUM> or more and ending with a maximum value of <NUM> or less. The ranges and/or ratios disclosed herein represent the average values over the specified range and/or ratio.

The terms "first", "second", and the like are not intended to refer to any particular order or chronology, but refer to different conditions, properties, or elements.

The term "at least" is synonymous with "greater than or equal to".

As used herein, "at least one of" is synonymous with "one or more of'. For example, the phrase "at least one of A, B, or C" means any one of A, B, or C, or any combination of any two or more of A, B, or C. For example, "at least one of A, B, and C" includes A alone; or B alone; or C alone; or A and B; or A and C; or B and C; or all of A, B, and C.

As used herein, the terms "parallel" or "substantially parallel" mean a relative angle as between two objects (if extended to theoretical intersection), such as elongated objects and including reference lines, that is from <NUM>° to <NUM>°, or from <NUM>° to <NUM>°, or from <NUM>° to <NUM>°, or from <NUM>° to <NUM>°, or from <NUM>° to <NUM>°, or from <NUM>° to <NUM>°, or from <NUM>° to <NUM>°, inclusive of the recited values.

As used herein, the terms "perpendicular" or "substantially perpendicular" mean a relative angle as between two objects at their real or theoretical intersection is from <NUM>° to <NUM>°, or from <NUM>° to <NUM>°, or from <NUM>° to <NUM>°, or from <NUM>° to <NUM>°, or from <NUM>° to <NUM>°, or from <NUM>° to <NUM>°, or from <NUM>° to <NUM>°, inclusive of the recited values.

As used herein, the term "optical" means pertaining to or associated with light and/or vision. For example, according to various non-limiting aspects disclosed herein, the optical element, article or device can be chosen from ophthalmic elements, articles, and devices, display elements, articles, and devices, windows, and mirrors.

As used herein, the term "ophthalmic" means pertaining to or associated with the eye and vision. Non-limiting examples of ophthalmic articles or elements include corrective and non-corrective lenses, including single vision or multi-vision lenses, which may be either segmented or non-segmented multi-vision lenses (such as, but not limited to, bifocal lenses, trifocal lenses and progressive lenses), as well as other elements used to correct, protect, or enhance (cosmetically or otherwise) vision, including without limitation, contact lenses, intra-ocular lenses, magnifying lenses, and protective lenses or visors.

As used herein, the terms "lens" and "lenses" mean and encompass at least individual lenses, lens pairs, partially formed (or semi-finished) lenses, fully formed (or finished) lenses, and lens blanks.

As used herein, the term "photochromic" and similar terms, such as "photochromic material" or "photochromic compound", means any material or compound having an absorption spectrum for at least visible radiation that varies in response to absorption of at least actinic radiation. A photochromic material includes at least one photochromic compound. The photochromic material or compound may be incorporated into a coating or a film applied to at least one surface of an optical article. Additionally, or alternatively, the photochromic material or compound may be incorporated into the body of the optical article, such as by imbibition or casting into the material of the optical article. The term "photochromic lens" means a lens having a photochromic material associated therewith. The terms "photochromic coating" and "photochromic film" include thermally-reversible photochromic materials and compounds. The term "thermally-reversible photochromic compounds/materials" as used herein means compounds/materials capable of converting from a first state, for example a "colorless state", to a second state, for example a "colored state", in response to actinic radiation, and reverting back to the first state in response to thermal energy.

As used herein, the term "actinic radiation" means electromagnetic radiation that is capable of causing a response in a material, such as, but not limited to, transforming a photochromic material from one form or state to another as will be discussed in further detail herein.

As used herein, the terms "visible light" or "visible radiation" means electromagnetic radiation having a wavelength in the range of <NUM> to <NUM>.

As used herein, the terms "ultraviolet", "ultraviolet radiation", and "ultraviolet light" mean electromagnetic radiation having a wavelength in the range of <NUM> to less than <NUM>. The term "UV" means ultraviolet, such as ultraviolet radiation.

The discussion of various examples or aspects may describe certain features as being "particularly" or "preferably" within certain limitations (e.g., "preferably", "more preferably", or "even more preferably", within certain limitations). It is to be understood that the disclosure is not limited to these particular or preferred limitations but encompasses the entire scope of the various examples and aspects described herein.

As used herein, the terms "communication" and "communicate" may refer to the reception, receipt, transmission, transfer, provision, and/or the like, of information (e.g., data, signals, messages, instructions, commands, and/or the like).

As used herein, a "graphical user interface" or "GUI" refers to a generated display with which a user may interact, either directly or indirectly (e.g., through a button, keyboard, mouse, touchscreen etc.).

Various examples or aspects of the disclosure are illustrated in separate drawing figures. However, it is to be understood that this is simply for ease of illustration and discussion. In the practice of the disclosure, one or more examples or aspects shown in one drawing figure can be combined with one or more examples or aspects shown in one or more of the other drawing figures.

With reference to <FIG>, a demonstration device <NUM> is shown in accordance with some examples or aspects of the present disclosure. The demonstration device <NUM> is configured for demonstrating at least one thermally-reversible characteristic of a photochromic optical article, such as an optical article <NUM> having at least one photochromic material, as described herein. The demonstration device <NUM> may be configured as a portable device particularly suitable for use in an office environment. For example, the demonstration device <NUM> can be configured as a portable, table-top device for use in a doctor's office or an eye-care store to demonstrate thermally-reversible characteristics of photochromic optical articles <NUM>.

The optical article <NUM> can be selected from ophthalmic articles or elements, display articles or elements, windows, mirrors, active liquid crystal cell articles or elements, and passive liquid crystal cell articles or elements. Examples of ophthalmic articles or elements include, but are not limited to, corrective and non-corrective lenses, including single vision or multi-vision lenses, which can be either segmented or non-segmented multi-vision lenses (such as, but not limited to, bifocal lenses, trifocal lenses, and progressive lenses), as well as other elements used to correct, protect, or enhance (cosmetically or otherwise) vision, including without limitation, contact lenses, intra-ocular lenses, magnifying lenses, and protective lenses or visors. <FIG> show various examples of a demonstration device <NUM> having various shapes. For ease of description, the demonstration device <NUM> shown in <FIG> will be described in detail.

With reference to <FIG>, the optical article <NUM> has a forward or top surface <NUM>, a rearward or bottom surface <NUM>, and a side surface <NUM> extending between the top surface <NUM> and the bottom surface <NUM>. When the optical article <NUM> is an ophthalmic lens, the bottom surface <NUM> is opposed to the eye of an individual wearing the optical article <NUM>, the side surface <NUM> typically resides within a supportive frame, and the top surface <NUM> faces incident light (not shown) at least a portion of which passes through the optical article <NUM> and into the individual's eye. The optical article <NUM> has at least one photochromic material configured to transition from an unactivated, or substantially colorless state, to an activated, or colored state in response to exposure to actinic radiation. The photochromic material may be applied to at least one surface of the optical article <NUM> in a coating or a film. Alternatively, or in addition, the photochromic material may be incorporated into the body of the optical article <NUM>, such as by imbibition or prior to casting the optical article <NUM>.

With reference to <FIG>, the demonstration device <NUM> includes a housing <NUM> having a sidewall <NUM> defining a hollow interior <NUM>. The housing <NUM> at least partially encloses the components of the demonstration device <NUM>. Some components of the demonstration device <NUM> may be completely enclosed within the housing <NUM>, as discussed herein. The housing <NUM> may be of any suitable rigid material, such as plastic or metal. At least a portion of the sidewall <NUM> is transparent to allow viewing of the housing interior <NUM> from the outside of the housing <NUM> through the sidewall <NUM>.

With continued reference to <FIG>, the housing <NUM> includes a plurality of sides, including a top side <NUM> opposite a bottom side <NUM> with a pair of lateral sides <NUM>, a front side <NUM> (shown in <FIG>), and a rear side <NUM> (shown in <FIG>) connected to each of the top side <NUM> and the bottom side <NUM>. In some examples or aspects, the housing <NUM> is monolithically formed as a single, integral part. In other examples or aspects, the housing <NUM> is formed from a plurality of discrete parts that are removably or non-removably combined together. While the housing <NUM> shown in <FIG> has a substantially oval cross-section in a longitudinal cross plane, the housing <NUM> may have any other shape. For example, with reference to <FIG>, the housing <NUM> may have a substantially circular cross-sectional shape. In some examples, the housing <NUM> may have a substantially rectangular cross-sectional shape, such as shown in <FIG>.

With continued reference to <FIG>, the housing <NUM> may have at least one opening <NUM> providing access to the interior <NUM>. The opening <NUM> may be formed in one or more of the sides of the housing <NUM>. The opening <NUM> may be enclosed by a cover panel or door <NUM>. In some examples or aspects, the door <NUM> may be movable between an open position, where the opening <NUM> is at least partially uncovered to provide access to the interior <NUM>, and a closed position, where the opening <NUM> is closed to enclose the interior <NUM>. In some examples or aspects, the door <NUM> may be mounted on a hinge <NUM> to allow movement between the open position and the closed position. In other examples or aspects, the door <NUM> may be configured for sliding movement relative to one or more sides of the housing <NUM>.

With continued reference to <FIG>, the housing <NUM> may have a first portion 102a and a second portion 102b. The first and second portions 102a, 102b may be removably or non-removably connected together. In some examples or aspects, the interior <NUM> may be defined by one of the first portion 102a or the second portion 102b, while the other of the first portion <NUM> and the second portion 102b receives the components of the demonstration device <NUM> for demonstrating at least one thermally-reversible characteristic of an optical article <NUM> having at least one photochromic material, as discussed herein. At least one of the first portion 102a and the second portion 102b may be made from a transparent material. As used herein, "transparent" means permitting visible light to pass through without diffusing or scattering the light. The door <NUM> may be provided on at least one of the first portion 102a and the second portion 102b.

With continued reference to <FIG>, the demonstration device <NUM> has an inspection platform <NUM> positioned within the interior <NUM> of the housing <NUM>. The inspection platform <NUM> is configured for supporting at least a portion of the optical article <NUM>. In some examples or aspects, the inspection platform <NUM> may be configured for supporting a plurality of optical articles <NUM>. For example, a pair of optical articles <NUM> may be positioned side-by-side on the inspection platform <NUM>. The inspection platform <NUM> may be offset relative to a lower interior surface <NUM> of the housing <NUM>. In some examples or aspects, the inspection platform <NUM> is fixed relative to the housing <NUM>, such as shown in <FIG> In other examples or aspects, such as shown in <FIG>, the inspection platform <NUM> may be movable relative to the housing <NUM>, such as by being slidable and/or rotatable relative to the housing <NUM>. For example, the inspection platform <NUM> may be rotatable relative to the housing <NUM> about an axis <NUM>.

The inspection platform <NUM> has a viewing stand <NUM> defining a support surface <NUM> for supporting at least a portion of at least one optical article <NUM>, such as the bottom surface <NUM> of at least one optical article <NUM>. The viewing stand <NUM> may be made from a transparent or translucent material. As used herein, "translucent" means permitting light to pass through but diffusing or scattering the light.

With reference to <FIG>, the demonstration device <NUM> has at least one inspection light source <NUM> configured for illuminating at least a portion of the interior of the housing <NUM>. In some examples or aspects, the at least one inspection light source <NUM> may be positioned between the lower interior surface <NUM> of the housing <NUM> and the viewing stand <NUM> such that the light emitted from at least one inspection light source <NUM> passes through the transparent or translucent material of the viewing stand <NUM> to illuminate the optical article <NUM>. In further examples or aspects, the at least one inspection light source <NUM> may be placed on a side of the viewing stand <NUM> to illuminate the viewing stand <NUM> from at least one of its edges. The at least one inspection light source <NUM> may be configured for emitting one or more of wavelengths of visible light. In some examples or aspects, the at least one inspection light source <NUM> may be at least one of a fluorescent light source, a halogen light source, an incandescent light source, or an LED light source. The at least one inspection light source <NUM> may be one or more bulbs, lamps, LEDs, and/or light bars/strips. In some examples or aspects, the at least one inspection light source <NUM> may be configured for operating on a 12V DC power circuit, such as a 12V DC edge lit backlight. In other examples or aspects, the at least one inspection light source <NUM> may be configured for operating on a 110V or a 220V AC power circuit, and/or on battery power.

With continued reference to <FIG>, the demonstration device <NUM> has at least one UV light source <NUM> configured to radiate ultraviolet light into the interior <NUM> of the housing <NUM>. The at least one UV light source <NUM> may be configured for activating the photochromic compound(s) in the photochromic material of the optical article <NUM> due to exposure to actinic radiation emitted by the at least one UV light source <NUM>. In some examples or aspects, the at least one UV light source <NUM> may be configured for emitting electromagnetic radiation within the ultraviolet spectrum, such as electromagnetic radiation having wavelength in the range of <NUM>-<NUM>. The at least one UV light source <NUM> may have one or more UV emitters, such as one or more conventional UV lamps and/or one or more UV light-emitting diodes (LEDs). In some examples or aspects, the at least one UV light source <NUM> may be a plurality of 1W 8Type UV LEDs.

In some examples or aspects, the at least one UV light source <NUM> may be mounted proximate to the top side of the housing <NUM> such that it directs UV radiation into the interior <NUM> from the top side of the housing <NUM>. In other examples or aspects, the at least one UV light source <NUM> may be mounted proximate to the bottom side of the housing <NUM> such that it directs UV radiation into the interior chamber <NUM> from the bottom side of the housing <NUM>. In further examples or aspects, the at least one UV light source <NUM> may be mounted to top, bottom, and/or lateral sides of the housing <NUM>. In some examples or aspects, the at least one UV light source <NUM> may be configured for operating on a 12V DC power circuit. In other examples or aspects, the at least one UV light source <NUM> may be configured for operating on a 110V or a 220V AC power circuit, and/or on battery power.

In some examples or aspects, the at least one UV light source <NUM> may be fixedly or non-movably mounted on the housing <NUM>. In other examples or aspects, at least one UV light source <NUM> may be movable relative to the housing <NUM>. For example, as shown in <FIG>, the at least one UV light source <NUM> may be mounted to a movable frame <NUM> that is movable between a first position and a second position relative to the housing <NUM>. In the first position, the movable frame <NUM> may be positioned such that at least one UV light source <NUM> may be configured to irradiate at least a portion of the inspection platform <NUM>, while, in the second position, the movable frame <NUM> is moved such that at least one UV light source <NUM> does not irradiate the inspection platform <NUM>. In this manner, the at least one UV light source <NUM> may be moved to the first position in order to activate the photochromic material of the optical article <NUM> supported on the inspection platform <NUM>. Upon activation of the photochromic compound, the at least one UV light source <NUM> may be moved to the second position to allow for easier viewing of the optical article <NUM> as the photochromic material transitions from the activated state to an unactivated state. The movable frame <NUM> may be slidably movable relative to the housing <NUM> in a direction of arrow A in <FIG>. For example, the movable frame <NUM> may be configured to slidably move the at least one UV light source <NUM> from the first portion 102a of the housing <NUM> toward the second portion 102b. In some examples or aspects, the movable frame <NUM> may be rotatably movable relative to the housing <NUM>. The movable frame <NUM> may have a gripping element <NUM> (shown in <FIG>) for manually moving the frame <NUM> between the first and second positions. In other examples or aspects, the movable frame <NUM> may have a motorized mechanism for moving the frame <NUM> between the first and second positions via a control element, such as a button, actuating one or more electric motors.

With continued reference to <FIG>, the demonstration device <NUM> has at least one heating device <NUM> configured to heat at least a portion of the interior <NUM> of the housing <NUM>. The at least one heating device <NUM> is configured to increase the temperature of the optical article <NUM> within the interior <NUM> of the housing <NUM> relative to ambient temperature surrounding the housing <NUM> in order to speed up the reverse transformation process of the photochromic compound(s) in the photochromic material from the activated (colored) state back to the unactivated (colorless) state. Without intending to be bound theory, kinetics of the reverse transformation of the photochromic compound(s) from the activated to unactivated state increase with an increase in temperature.

In some examples or aspects, the at least one heating device <NUM> may be configured to maintain a predetermined temperature within the interior <NUM> of the housing <NUM>. For example the at least one heating device <NUM> may be configured to maintain the interior <NUM> at a temperature in the range of <NUM> to <NUM>, for example in the range of <NUM> to <NUM>. In various examples or aspects, the at least one heating device <NUM> may be at least one of a conductive heating device, a convective heating device, or a radiative heating device.

With continued reference to <FIG>, the at least one heating device <NUM> has at least one heat source <NUM> and at least one fan <NUM>. The at least one heat source <NUM> may be an electric heating element <NUM> thermally connected to a heat exchanger <NUM>. The at least one fan <NUM> is configured to force air across the heat exchanger <NUM>. Movement of air across the heat exchanger <NUM> heats the air. In some examples or aspects, the at least one heat source <NUM> may be a cartridge heater configured for operating on a 12V DC power circuit. The cartridge heater may have a power of 40W. The at least one fan <NUM> may be a pair of fans, such as a pair of axial fans. The axial fans may have a diameter of <NUM>. In other examples or aspects, the at least one heating device <NUM> may be an infrared heating device, such as an infrared heating lamp.

With continued reference to <FIG>, temperature of the heated air in the interior <NUM> of the housing <NUM> may be controlled by controlling the number and speed of the fans <NUM> and the number and output of the heating elements <NUM>. A temperature control element <NUM>, such as a thermistor, may be provided for actuating at least one of the heating elements <NUM> and the fans <NUM>. In some examples or aspects, the temperature control element <NUM> may be a <NUM> Kohm thermistor.

With continued reference to <FIG>, the demonstration device <NUM> has at least one control device <NUM> operatively connected to at least one of the UV light source <NUM>, the inspection light source <NUM>, or the heating device <NUM>. In some examples or aspects, a single control device <NUM> may be configured to control each of the UV light source <NUM>, the inspection light source <NUM>, and the heating device <NUM>. In other examples or aspects, separate control devices <NUM> may be provided for each of the UV light source <NUM>, the inspection light source <NUM>, and the heating device <NUM>. The at least one control device <NUM> may be configured to control at least one of an activation of the UV light source <NUM> or an intensity of the UV light source <NUM>. The control device <NUM> may be further configured to control at least one of an activation of the inspection light source <NUM> or an intensity of the inspection light source <NUM>. The control device <NUM> may be further configured to control at least one of an activation of the heating device <NUM> or a temperature of the heating device <NUM>. The at least one control device <NUM> may be configured for operating on a 12V DC power circuit. In other examples or aspects, the at least one control device <NUM> may be configured for operating on a 110V or a 220V AC power circuit, and/or on battery power.

In some examples or aspects, the at least one control device <NUM> may be a microprocessor controller, such as an Arduino Nano microprocessor controller. The at least one control device <NUM> may be configured for pulse width modulated (PWM) operation, wherein analog operation of at least one of the UV light source <NUM>, the inspection light source <NUM>, or the heating device <NUM> can be achieved using digital control signals. In some examples or aspects, the at least one control device <NUM> may be configured for continuously modulated control of at least one of the UV light source <NUM>, the inspection light source <NUM>, or the heating device <NUM>. For example, the at least one control device <NUM> may have a proportional-integral-derivative PID controller.

With continued reference to <FIG>, the demonstration device <NUM> has at least one user input device <NUM> configured for inputting user commands to control the operation of at least one of the UV light source <NUM>, the inspection light source <NUM>, or the heating device <NUM>. The user input device <NUM> may include one or more devices capable of receiving information or input from the user. For example, the user input device <NUM> may include one or more buttons or switches <NUM>. Alternatively or additionally, the user input device <NUM> may include one or more computing devices having an electronic visual display capable of displaying a graphical user interface (GUI), such as one or more monitors, touchscreens, or the like. Further, the user input device <NUM> may include or be in communication with one or more input devices capable of receiving input such as a touch screen display, a keyboard, a keypad, a mouse, a button, a switch, and/or the like.

In examples where the user input device <NUM> includes an electronic visual display, such visual display can be configured for receiving user input for controlling the operation of at least one of the UV light source <NUM>, the inspection light source <NUM>, or the heating device <NUM>, and for communicating status information about an operating status or condition of the operation of at least one of the UV light source <NUM>, the inspection light source <NUM>, or the heating device <NUM>. For example, the user input device <NUM> may be an LCD touchscreen used to input commands to control operation of at least one of the UV light source <NUM>, the inspection light source <NUM>, or the heating device <NUM>. For example, the user may input commands to at least one activate/deactivate the UV light source <NUM>, control an intensity of the UV light source <NUM>, activate/deactivate the inspection light source <NUM>, control an intensity of the inspection light source <NUM>, activate/deactivate the heating device <NUM>, or control a temperature of the heating device <NUM>. Furthermore, the user input device <NUM> that is configured as an LCD touchscreen may provide information regarding the operating status or condition of at least one of the UV light source <NUM>, the inspection light source <NUM>, or the heating device <NUM>. For example, the LCD touchscreen may provide information regarding an active/inactive state of the UV light source <NUM>, an intensity of the UV light source <NUM>, an active/inactive state of the inspection light source <NUM>, an intensity of the inspection light source <NUM>, an active/inactive state of the heating device <NUM>, or a temperature of the heating device <NUM>.

Having described the demonstration device <NUM> with reference to <FIG>, an exemplary method of using the demonstration device <NUM> to demonstrate at least one thermally-reversible characteristic of a photochromic optical article, such as the optical article <NUM> with a photochromic material, will now be described.

One or more optical articles <NUM>, such as one or more polymeric ophthalmic lenses having a photochromic material, are received within the interior <NUM> of the housing <NUM>. In some examples or aspects, the one or more optical articles <NUM> may be received within the interior <NUM> of the housing <NUM> by moving the door <NUM> from the closed position to an open position in order to provide an opening for inserting the one or more optical articles <NUM> into the interior <NUM> of the housing <NUM>. Each optical article <NUM> may be supported by at least one surface thereof on the inspection platform. For example, the bottom surface <NUM> of each optical article <NUM> may be supported on the support surface <NUM> of the viewing stand <NUM>. After receiving the optical articles <NUM> within the interior <NUM> of the housing <NUM>, the door <NUM> may be closed to enclose the housing <NUM>. The at least one inspection light source <NUM> may be activated in order to illuminate the optical article <NUM> such that the reversible transformation of color due to activation/inactivation of the photochromic compound(s) in the photochromic material of the optical article <NUM> can be visually observed. Activation of the at least one inspection light source <NUM> may be controlled by the at least one control device <NUM>, such as by receiving user input to activate the at least one inspection light source <NUM> on the user input device <NUM>. Intensity of the at least one inspection light source <NUM> may be controlled by the at least one control device <NUM> in a similar manner.

In order to activate the photochromic compound(s) in the photochromic material of the optical article <NUM> (i. e, transition from colorless to colored), at least a portion of the optical article <NUM> having the photochromic material is irradiated with electromagnetic energy of appropriate wavelength to cause activation. Such irradiation of the optical article <NUM> is performed by activating the at least one UV light source <NUM>. Activation of the at least one UV light source <NUM> may be controlled by the at least one control device <NUM>, such as by receiving user input to activate the at least one UV light source <NUM> on the user input device <NUM>. For example, the user may activate the at least one UV light source <NUM> and set a duration of time during which the at least one UV light source <NUM> is to be active. For example, activation time may be between <NUM> seconds to <NUM> seconds, depending on the intensity of the at least one UV light source <NUM> and/or the type of photochromic compound(s) in the photochromic material of the optical article <NUM>. Intensity of the at least one UV light source <NUM> may be controlled by the at least one control device <NUM> in a similar manner. The at least one inspection light source <NUM> may be active or inactive while the at least one UV light source <NUM> is active.

In examples or aspects where the at least one UV light source <NUM> is movable relative to the housing <NUM>, the at least one UV light source <NUM> may be moved to the first position such that the at least one UV light source <NUM> is positioned to irradiate at least a portion of the optical article <NUM> on the inspection platform <NUM>. In this manner, the at least one UV light source <NUM> activates the photochromic material on the optical article <NUM> supported on the inspection platform <NUM>. Upon activation of the photochromic compound, the at least one UV light source <NUM> may be moved to the second position to allow for easier viewing of the optical article <NUM>.

In order to inactivate the photochromic compound(s) in the photochromic material of the optical article <NUM> (i. e, transition from colored to colorless), the temperature in the interior <NUM> of the housing <NUM> is controlled to be within the predetermined range. As discussed herein, the increased temperature in the interior <NUM> of the housing <NUM> (relative to ambient temperature outside the housing <NUM>) speeds up the reversible transition from the active (colored) state to inactive (colorless) state of the photochromic compound(s) in the photochromic material of the optical article <NUM>. Such heating of the interior <NUM> of the housing <NUM>, and thereby heating of the photochromic compound(s) in the photochromic material of the optical article <NUM>, is performed by activating the at least one heating device <NUM>. Activation of the at least one at least one heating device <NUM> may be controlled by the at least one control device <NUM>, such as by receiving user input to activate the at least one at least one heating device <NUM> on the user input device <NUM>. For example, the user may activate the at least one at least one heating device <NUM> and set a duration of time during which the at least one at least one heating device <NUM> is to be active. Temperature of the at least one at least one heating device <NUM>, or a desired temperature within the interior <NUM> of the housing <NUM>, may be controlled by the at least one control device <NUM> in a similar manner. In some examples or aspects, the at least one heating device <NUM> may be activated after deactivating the at least one UV light source <NUM>. In other examples or aspects, the at least one heating device <NUM> may be activated upon placement of the optical article <NUM> in the interior <NUM> of the housing <NUM>. The increased temperature in the interior <NUM> of the housing <NUM> speeds up the reversible transformation of the photochromic compound(s) in the photochromic material of the optical article <NUM>. from the active (colored) state to inactive (colorless) state.

Claim 1:
A demonstration device (<NUM>) for demonstrating at least one thermally-reversible characteristic of an optical article (<NUM>) having at least one photochromic material, the demonstration device (<NUM>) comprising:
a housing (<NUM>) having a sidewall (<NUM>) defining an interior (<NUM>);
an inspection platform (<NUM>) within the interior of the housing (<NUM>) configured for supporting at least a portion of the optical article (<NUM>);
at least one ultraviolet light source (<NUM>) configured to radiate ultraviolet light into the interior (<NUM>) of the housing (<NUM>); and
at least one inspection light source (<NUM>) configured to illuminate at least a portion of the interior (<NUM>) of the housing (<NUM>); characterized in that
at least a portion of the sidewall (<NUM>) is transparent to allow viewing of the housing interior (<NUM>) from the outside of the housing (<NUM>) through the sidewall (<NUM>); and
the demonstration device further comprising at least one heating device (<NUM>) configured to heat at least a portion of the interior (<NUM>) of the housing (<NUM>), wherein the at least one heating device (<NUM>) comprises at least one heat source (<NUM>) and at least one fan (<NUM>).