DESC:This non-provisional patent application claims priority from the Indian provisional patent application No.: 201741026353 dated 25th July 2017.
TECHNICAL FIELD
The present subject matter is in general related to lens analyzing devices and more particularly, but not exclusively, to an apparatus and a method for measuring Ultraviolet (UV) protection level of lenses.

BACKGROUND
Presently, the ophthalmic lens industry has become concerned with growing evidence that ultraviolet radiation is a major cause of many eye related diseases. This concern has prompted moves towards forming regulations, which would require ultraviolet protection in lenses. Such concern has also led optical manufacturers to find ways to incorporate ultraviolet absorbing compounds into or onto ophthalmic lenses without blocking visible light. The result of such efforts has been the development of anti-reflective or anti-glare coatings, which are essentially invisible.

However, since the anti-reflective coatings are invisible, and the lens absorb ultraviolet radiation, there is no way for a user to visually determine the degree of protection being provided in the lens. Thus, the user is unable to judge the level of UV protection provided in the lens at the time of buying a lens/eyewear.

Existing approaches disclose a method for detecting UV protection level in a lens based on transmission value for the lens in the UV wavelength range for incident light. However, the existing approaches do not consider various exposures of the lens to effectively detect the UV protection level. Also, the existing approaches do not notify a user about actual UV protection level provided in the lens.

The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

SUMMARY
One or more shortcomings of the prior art may be overcome, and additional advantages may be provided through the present disclosure. Additional features and advantages may be realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

Disclosed herein is an apparatus for measuring Ultraviolet (UV) protection level of lenses. The apparatus comprises a housing. The housing comprises a lens receptacle to hold a lens to be tested. Further, the housing comprises a UV Light Emitting Diode (LED) source configured to project UV radiation on the lens. Furthermore, the housing comprises a UV LED receiver configured in reverse bias to receive the UV radiation transmitted through the lens. Additionally, the housing comprises a conditioning circuit, connected to the UV LED receiver, to detect level of reverse bias current generated by the UV LED receiver based on the received UV radiation, and to convert the reverse bias current to an output voltage value. Further, the housing comprises a control unit to measure UV protection level of the lens based on the output voltage value.

Further, disclosed herein is a method for measuring Ultraviolet (UV) protection level of lenses using an apparatus. The method comprises projecting UV radiation emitted from a UV Light Emitting Diode (LED) source configured in the apparatus to a lens to be tested. The lens is placed on a lens receptacle configured in the apparatus. Further, the method comprises receiving, using a UV LED receiver configured in reverse bias in the apparatus, the UV radiation transmitted through the lens. Additionally, the method comprises detecting, using a conditioning circuit connected to the UV LED receiver, level of reverse bias current generated by the UV LED receiver based on the received UV radiation. Thereafter, the method comprises converting the reverse bias current to an output voltage value. Finally, the method comprises measuring, by a control unit configured in the apparatus, UV protection level of the lens based on the output voltage value.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and/or methods in accordance with embodiments of the present subject matter are now described, by way of example only, and regarding the accompanying figures, in which:

FIG. 1 shows an exemplary arrangement of an apparatus for measuring Ultraviolet (UV) protection level of lenses in accordance with some embodiments of the present disclosure;

FIG. 2 shows a flowchart illustrating a method for measuring UV protection level of lenses in accordance with some embodiments of the present disclosure; and

FIG. 3 shows an exemplary model of an apparatus for measuring UV protection level of lenses in accordance with some embodiments of the present disclosure.

It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in computer readable medium and executed by a computer or processor, whether such computer or processor is explicitly shown.

DETAILED DESCRIPTION
In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the specific forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

The terms “comprises”, “comprising”, “includes”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device, or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

The present disclosure relates to an apparatus and a method for measuring Ultraviolet (UV) protection level of lenses. The lenses may be uncut lenses, prescription spectacle or sunglasses. In an embodiment, the apparatus may be operated to measure the UV protection level of the lenses using one or more standard Light Emitting Diode (LEDs), which emit UV radiation of a required wavelength range. One of the UV LEDs is designated as a transmitter. Another UV LED is designated as a receiver and is placed in reverse bias. The transmitter LED emits UV radiation of a specific wavelength. The UV radiation emitted from the transmitter LED transmits through the lens and is received by the receiver LED. The receiver LED generates reverse bias current in proportion to amount of UV radiation incident on the receiver LED. Further, a conditioning circuit connected to the receiver LED converts the reverse bias current to an output voltage value. Subsequently, the UV protection level of the lens is measured based on the output voltage value at the receiver LED. In an embodiment, if the output voltage value at the receiver LED is low, then the lens may have high UV protection level. Similarly, if the output voltage value at the receiver LED high, then the lens may have low UV protection level. Thus, based on the measured output voltage value and a reference voltage value, the apparatus measures the UV protection level of the lens.

In an embodiment, the apparatus of present disclosure makes use of standard UV LEDs as both an emitter of UV light and a receiver of UV light, thereby making the apparatus portable, light-weight, and economical. Also, the apparatus of present disclosure may be calibrated with reference to ambient light, thereby aiding in accurate measurements of the UV protection level of the lenses. In an embodiment, the apparatus of present disclosure notifies percentage value of the UV protection level provided by the lenses, thereby aiding users in comparing various lenses/eyewear and selecting lenses/eyewear having highest UV protection.

In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

FIG. 1 shows an exemplary arrangement of an apparatus 100 for measuring Ultraviolet (UV) protection level of lenses in accordance with some embodiments of the present disclosure.

In an embodiment, the apparatus 100 may include a housing 101. The housing 101 may be an enclosed structure made of a durable material such as, not limiting to, fibre-reinforce plastic, hardened plastic, a metal, an alloy and the like. In an embodiment, the housing 101 may include a UV Light Emitting Diode (LED) source 103, a lens receptacle 107 to hold a lens 105, a UV LED receiver 109, a conditioning circuit 111, and a control unit 113.

In an embodiment, the UV LED source 103 may be a standard LED which emits UV radiation in a range of 395 nm, when powered by a suitable power source. The UV radiation emitted by the UV LED source 103 may be projected on the lens 105 placed in the lens receptacle 107. The lens receptacle 107 may be an adjustable slot within the housing 101, which may be adjusted to hold lenses of varying thickness. In an embodiment, the lens receptacle 107 may be configured between the UV LED source 103 and the UV LED receiver 109 as shown in FIG. 1.

In an embodiment, upon projecting the UV radiation on the lens 105, the lens 105 may reflect and/or block a part of the radiation depending on level of UV protection coating provided on the lens 105. The part of UV radiation which is not blocked by the lens 105 may transmit through the lens 105. In an embodiment, the part of UV radiation which is transmitted through the lens 105 may be received by the UV LED receiver 109.

In an embodiment, the UV LED receiver 109 may be of same standard as that of the UV LED source 103. That is, the wavelength range of the UV LED receiver 109 may be same as the wavelength range of the UV LED source 103 i.e.395 nm. Thus, the UV LED receiver 109 may be responsive only to the UV radiation emitted by the UV LED source 103. In an embodiment, the UV LED receiver 109 may be configured in a reverse bias with a Silicon-On-Insulation (SOI) fabrication. Therefore, the UV LED receiver 109 may generate a reverse bias current in response to receiving the UV radiation transmitted from the lens 105. Level of the reverse bias current generated at the UV LED receiver 109 may be proportional to the amount of UV radiation transmitted from the lens 105. That is, for example, if the amount of transmitted UV radiation is high, then the level of reverse bias current generated at the UV LED receiver 109 may be high. Similarly, if the amount of transmitted UV radiation is low, then the level of reverse bias current generated at the UV LED receiver 109 may be low.

In an embodiment, the conditioning circuit 111 may be connected to the UV LED receiver 109 for detecting the level of reverse bias current generated by the UV LED receiver 109. In an implementation, the conditioning circuit 111 may include a current measurement device such as an ammeter to measure the level of reverse bias current flowing through the conditioning circuit 111. Further, the conditioning circuit 111 may convert the level of reverse bias current to an output voltage value. Thereafter, the control unit 113 may measure the UV protection level of the lens 105 based on the output voltage value.

In an embodiment, the measured UV protection level of the lens 105 may be inversely proportional to the output voltage value at the UV LED receiver 109. That is, if the output voltage value is high, then the measured UV protection level may be a lower value. Similarly, if the output voltage value is low, then the measured UV protection level may be a higher value. In other words, when a higher output voltage value is detected at the UV LED receiver 109, it means that the lens 105 is allowing a large portion of the UV radiation to transmit through, thereby providing less protection from the UV radiation. As an example, if the lens 105 has a good UV protection, the output voltage value may be in a lower range such as 0.2V - 0.3V. And if the lens 105 has no/less UV protection, then the output voltage value may be in a higher range such as 2.0V - 2.2V.

In an embodiment, correlation between the measured output voltage value and the level of UV protection provided by the lens 105 may be made with respect to a reference voltage value detected during calibration of the apparatus 100. In an embodiment, process of calibrating the apparatus 100 includes powering-on the apparatus 100 and placing the lens 105 on the lens receptacle 107 for a predetermined time of say, 8 seconds. During this period, the output voltage value at the UV LED receiver 109 is detected and designated as a reference voltage value for the lens 105. The UV LED source 103 may be activated only upon calibration of the apparatus 100. Thus, the reference voltage value indicates amount of voltage generated at the UV LED receiver 109 due to transmission of ambient UV radiation through the lens 105. That is, the reference voltage value may be used for estimating the level of UV protection provided by the lens 105 for the UV radiation present in ambient light. Further, during actual measurement of the UV protection level of the lens 105, the control unit 113 may subtract the reference voltage value from the output voltage value measured at the UV LED receiver 109 for an accurate measurement of UV protection level.

In an embodiment, based on the reference voltage value and the measured output voltage value, the UV protection level of the lens 105 may be calculated using a predetermined technique such as ‘K- factor’ measurement method. As an example, the K-factor calculation may be performed based as shown in Equation 1 below:

UV protection level = (X1-X2) / [(Y2-Y1) *(Y-Y1)] … (1)

wherein,
‘X1’ is maximum UV lens reference (in percentage)
‘X2’ is minimum UV lens reference (in percentage)
‘Y1’ is maximum lens Analogue to Digital Conversion (ADC) value
‘Y2’ is minimum lens 105 ADC value
‘Y’ is unknown lens 105 ADC value

Further, the percentage value of the UV protection level may be measured using Equation (2) below:

Measured UV range - Min UV range x 100
… (2)
Difference of maximum and minimum UV range

In an embodiment, the measured value of the UV protection level, in percentage value, may be notified to a user and/or an operator of the apparatus 100 using a notification unit (not shown in figure 1) configured in the apparatus 100. However, if the result obtained based on Equation 1 and Equation 2 is below a predetermined threshold value, say below 50%, then the lens 105 may be considered to have no protection for the UV radiation.

FIG. 2 shows a flowchart illustrating a method for measuring Ultraviolet (UV) protection level of lenses in accordance with some embodiments of the present disclosure.

As illustrated in FIG. 2, the method 200 may include one or more blocks illustrating a method of measuring UV protection level of lenses using an apparatus 100 as shown in FIG. 1. The method 200 may be described in the general context of computer executable instructions. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform specific functions or implement specific abstract data types.

The order in which the method 200 is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.

At block 201, the method 200 includes projecting UV radiation emitted from a UV Light Emitting Diode (LED) source 103 configured in the apparatus 100 to a lens 105 to be tested. In an embodiment, the lens 105 may be placed on a lens receptacle 107 configured in the apparatus 100.

At block 203, the method 200 includes receiving the UV radiation transmitted through the lens 105 using a UV LED receiver 109 configured in the apparatus 100. In an implementation, the UV LED receiver 109 may be configured in reverse bias and fabricated with a Silicon-On-Insulator (SOI) layer. In an embodiment, the lens receptacle 107 may be placed between the UV LED source 103 and the UV LED receiver 109 within the apparatus 100.

At block 205, the method 200 includes detecting level of reverse bias current generated by the UV LED receiver 109 based on the received UV radiation, using a conditioning circuit 111 connected to the UV LED receiver 109. Further, the reverse bias current may be converted to an output voltage value using the conditioning circuit 111. In an embodiment, the level of reverse bias current detected by the conditioning circuit 111 may vary in proportion to amount of the UV radiation transmitted through the lens.

At block 207, the method 200 includes measuring, by a control unit 113 configured in the apparatus 100, UV protection level of the lens 105 based on the output voltage value. In an embodiment, the UV protection level of the lens 105 may be inversely proportional to the output voltage value at the UV LED receiver 109. That is, the UV protection level may be a higher value when the output voltage value at the UV LED receiver 109 is low. Similarly, the UV protection level may be a lower value when the output voltage value at the UV LED receiver 109 is high.

In an implementation, the method 200 may include calibrating the apparatus 100 with respect to intensity of ambient light, before imitating the process of measuring the UV protection level of the lens 105. Further, the method 200 may include notifying the measured UV protection level of the lens 105 to a user and/or an operator of the apparatus 100 using a notification unit configured in the apparatus 100.

In an implementation, the control unit 113 may be disposed in communication with one or more input/output (I/O) devices via a I/O interface (not shown in figures) configured in the apparatus 100. The I/O interface may employ communication protocols/methods such as, without limitation, audio, analog, digital, stereo, IEEE-1394, serial bus, Universal Serial Bus (USB), infrared, PS/2, BNC, coaxial, component, composite, Digital Visual Interface (DVI), high-definition multimedia interface (HDMI), Radio Frequency (RF) antennas, S-Video, Video Graphics Array (VGA), IEEE 802.n /b/g/n/x, Bluetooth, cellular (e.g., Code-Division Multiple Access (CDMA), High-Speed Packet Access (HSPA+), Global System For Mobile Communications (GSM), Long-Term Evolution (LTE) or the like), etc.
In some implementation, the control unit 113 may be disposed in communication with a communication network via a network interface (not shown in figures) configured in the apparatus 100. The network interface may employ connection protocols including, without limitation, direct connect, Ethernet (e.g., twisted pair 10/100/1000 Base T), Transmission Control Protocol/Internet Protocol (TCP/IP), token ring, IEEE 802.11a/b/g/n/x, etc. In an implementation, the communication network can be implemented as one of the several types of networks, such as intranet, Local Area Network (LAN), wireless network and such within the organization. Using the network interface and the communication network, the apparatus 100 may connect to one or more user devices and/or display terminals to indicate the measured UV protection level of the lenses.
In some implementations, the control unit 113 may be disposed in communication with a memory unit, for example RAM, ROM and the like, via a storage interface (not shown in figures) configured in the apparatus 100. The storage interface may connect to memory including, without limitation, memory drives, removable disc drives, etc., employing various connection protocols. Further, the memory unit may store a collection of program or database components, including, without limitation, user/application interface, an operating system of the control unit 113, and the like. In some embodiments, the memory unit may be used to store detected level of reverse bias current, output voltage value, a reference voltage value and percentage of UV protection level of the lens 105.

FIG. 3 shows an exemplary model of an apparatus 300 for measuring UV protection level of lenses in accordance with some embodiments of the present disclosure.

In an embodiment, the lens receptacle 107A may be used for placing the lenses such as uncut lenses, flat lenses or laboratory lenses, whose UV protection level may be determined using the apparatus 300. Further, the lenses which are in the form of spectacles or sunglasses may be placed in a separate slot designated for spectacles, as represented by the lens receptacle 107B in FIG. 3. In an embodiment, notification unit 303 may be used for notifying the measured UV protection level to a user and/or an operator of the apparatus 300. As an example, a percentage value of the measured UV protection level may be displayed on a display interface associated with the notification unit 303. Alternatively, the measured UV protection level may also be notified as a voice-based message provided to the user/operator using a speaker associated with the notification unit 303.

Advantages of the embodiment of the present disclosure are illustrated herein.
In an embodiment, the present disclosure discloses an apparatus for measuring Ultraviolet (UV) protection level of lenses.

In an embodiment, the apparatus of present disclosure uses standard UV Light Emitting Diodes (LEDs) as both an emitter of UV light and a receiver of UV light transmitted through the lens, thereby making the apparatus portable, light-weight, and economical.

In an embodiment, the apparatus of present disclosure may be calibrated with reference to ambient light, and hence the apparatus provides accurate measurements of the UV protection level of the lenses.

In an embodiment, the apparatus of present disclosure notifies percentage value of the UV protection level provided by the lenses, thereby aiding users in comparing various lenses/eyewear and selecting lenses/eyewear having highest UV protection.

The terms "an embodiment", "embodiment", "embodiments", "the embodiment", "the embodiments", "one or more embodiments", "some embodiments", and "one embodiment" mean "one or more (but not all) embodiments of the invention(s)" unless expressly specified otherwise.

The terms "including", "comprising", “having” and variations thereof mean "including but not limited to", unless expressly specified otherwise.

The enumerated listing of items does not imply that any or all the items are mutually exclusive, unless expressly specified otherwise. The terms "a", "an" and "the" mean "one or more", unless expressly specified otherwise.

A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate the wide variety of possible embodiments of the invention.

When a single device or article is described herein, it will be clear that more than one device/article (whether they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether they cooperate), it will be clear that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the invention need not include the device itself.

Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the embodiments of the present invention are intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Reference Numerals:
Reference Number Description
100 Apparatus
101 Housing
103 UV LED source
105 Lens
107 Lens receptacle
109 UV LED receiver
111 Conditioning circuit
113 Control unit
300 Exemplary model of the apparatus
107A Lens receptacle for lenses
107B Lens receptacle for spectacles
303 Notification unit
,CLAIMS:1. An apparatus (100) for measuring Ultraviolet (UV) protection level of lenses, the apparatus (100) comprising:
a housing (101), wherein the housing (101) comprises:
a lens receptacle (107) to hold a lens (105) to be tested;
a UV Light Emitting Diode (LED) source (103) configured to project UV radiation on the lens (105);
a UV LED receiver (109) configured in reverse bias, wherein the UV LED receiver (109) receives the UV radiation transmitted through the lens (105);
a conditioning circuit (111), connected to the UV LED receiver (109), to detect level of reverse bias current generated by the UV LED receiver (109) based on the received UV radiation, and to convert the reverse bias current to an output voltage value; and
a control unit (113) configured to measure UV protection level of the lens (105) based on the output voltage value.

2. The apparatus (100) as claimed in claim 1, wherein the UV LED receiver (109) is fabricated with a Silicon-On-Insulator (SOI) layer.

3. The apparatus (100) as claimed in claim 1, wherein the lens receptacle (107) is placed between the UV LED source (103) and the UV LED receiver (109).

4. The apparatus (100) as claimed in claim 1, wherein the level of reverse bias current detected by the conditioning circuit (111) varies in proportion to amount of the UV radiation transmitted through the lens (105).

5. The apparatus (100) as claimed in claim 1, wherein the UV protection level of the lens (105) is inversely proportional to the output voltage value at the UV LED receiver (109).

6. The apparatus (100) as claimed in claim 1, wherein the apparatus (100) is calibrated with respect to intensity of ambient light, before measuring the UV protection level of the lens (105).

7. The apparatus (100) as claimed in claim 1 further comprises a notification unit (303) to notify the measured UV protection level of the lens (105).

8. A method for measuring Ultraviolet (UV) protection level of lenses using an apparatus (100), the method comprising:
projecting UV radiation emitted from a UV Light Emitting Diode (LED) source (103) configured in the apparatus (100) to a lens (105) to be tested, wherein the lens (105) is placed on a lens receptacle (107) configured in the apparatus (100);
receiving, using a UV LED receiver (109) configured in reverse bias in the apparatus (100), the UV radiation transmitted through the lens (105);
detecting, using a conditioning circuit (111) connected to the UV LED receiver (109), level of reverse bias current generated by the UV LED receiver (109) based on the received UV radiation, and converting the reverse bias current to an output voltage value; and
measuring, by a control unit (113) configured in the apparatus (100), UV protection level of the lens (105) based on the output voltage value.

9. The method as claimed in claim 8, wherein the method comprises fabricating the UV LED receiver (109) with a Silicon-On-Insulator (SOI) layer.

10. The method as claimed in claim 8, wherein the method comprises configuring the lens receptacle (107) between the UV LED source (103) and the UV LED receiver (109).

11. The method as claimed in claim 8, wherein the level of reverse bias current in the output detected by the conditioning circuit (111) varies in proportion to amount of the UV radiation transmitted through the lens (105).

12. The method as claimed in claim 8, wherein the UV protection level of the lens (105) is inversely proportional to the output voltage value at the UV LED receiver (109).

13. The method as claimed in claim 8, wherein the method comprises calibrating the apparatus (100) with respect to intensity of ambient light, before measuring the UV protection level of the lens (105).

14. The method as claimed in claim 8 further comprises notifying the measured UV protection level of the lens (105) using a notification unit (303) configured in the apparatus (100).