DESC:TECHNICAL FIELD
The present subject matter is generally related to anti-fog coating in lens and more particularly, but not exclusively, to method, device and control unit for detecting anti-fog property of a lens or a glass.

BACKGROUND
Ophthalmic lenses are provided with various coatings to provide a plurality of mechanical and/or optical properties. The coating layers are formed on the ophthalmic lens, such as impact-resistant coating layers, abrasion and/or scratch resistant coating layers (hard coatings), Anti-Reflecting coating layers (AR coatings) and the like. The AR coating may be deposited onto the surface of the lens to improve antireflective properties. Similarly, there may be other coatings to reduce fogging in the lenses. Fogging of ophthalmic lenses is troublesome for the wearer and may be unsafe as it will reduce wearer's vision. Fogging may occur when the temperature of the lens is lower than that of its environment.
At present, there are various techniques to provide anti-fogging properties for the lens. However, the existing techniques may not efficiently provide anti-fogging property for the lens. One of the existing techniques use anti-abrasion coatings having anti-fogging properties. The drawback of this technique is that these coatings are very soft and may lead to soiled lenses with generally poor abrasion resistance.
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
Disclosed herein is a device for detecting anti-fogging property of a lens. The device comprises a light source for emitting a light beam on the lens placed in a lens holder of the device. The device also comprises a Light Dependent Resistor (LDR), a fog generating unit and a control unit. The LDR is configured to measure intensity of the light beam refracted through the lens. The fog generating unit is configured to create a fog on the lens. the control unit is configured to, upon creation of the fog on the lens, activate the light source to emit the light beam on the lens and activate the LDR to measure intensity value of the light beam refracted through the lens, at predefined time intervals, starting at a first predefined time. Thereafter, the control unit identifies a second predefined time, from the predefined time intervals, at which the measured intensity value of the light beam matches a predefined calibrated value. Further, the control unit detects the anti-fogging property of the lens based on time duration between the first predefined time and the second predefined time.
Further, the present disclosure discloses a control unit for detecting anti-fogging property of a lens. The control unit comprises a processor and a memory communicatively coupled to the processor, wherein the memory stores the processor-executable instructions, which, on execution, causes the processor to activate a light source associated with the control unit to emit a light beam on a lens formed with a fog. Thereafter, the processor activates a Light Dependent Resistor (LDR) associated with the control unit and the light source to measure intensity value of the light beam refracted through the lens at predefined time intervals starting at a first predefined time. Further, the control unit identifies a second predefined time, from the predefined time intervals, at which measured intensity value of the light beam matches a predefined calibrated value and detects the anti-fogging property of the lens based on time duration between the first predefined time and the second predefined time.

Furthermore, the present disclosure discloses a method for detecting anti-fogging property of a lens. The method comprises activating, by a control unit of a device, a light source associated with the control unit to emit a light beam on the lens placed in a lens holder of the device. Once the light source is activated, the method comprises activating, by the control unit, a Light Dependent Resistor (LDR) to measure intensity value of the light beam refracted through the lens at predefined time intervals starting at a first predefined time. Thereafter, the method comprises identifying, by the control unit, a second predefined time from the predefined time intervals at which measured intensity value of the light beam, by the LDR, matches a predefined calibrated value. Further, the method comprises detecting, by the control unit, the anti-fogging property of the lens based on time duration between the first predefined time and the second predefined time.
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 a device for detecting anti-fog property of a lens in accordance with some embodiments of the present disclosure; and

Fig.2 shows a flowchart illustrating a method for detecting anti-fog property of a lens 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”, “including” 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 a device, method and control unit for detecting anti-fogging property of a lens or a glass. The device may comprise a lens holder configured to hold a lens or a glass for observation. For the purpose of illustration, the present disclosure is illustrated using lens as an example. However, the present disclosure may be applicable for detecting anti-fogging property of any glass or window. The device may also comprise a light source, a Light Dependent Resistor (LDR), a fog generating unit and a control unit. The light source may include one or more Light Emitting Diode (LED) strips. The control unit may activate the light source to emit a light beam on the lens placed in the lens holder upon creation of the fog on the lens. The fog may be created by the fog generating unit. Thereafter, the control unit may activate the LDR to measure intensity value of the light beam refracted through the lens, at predefined time intervals, starting at a first predefined time. The control unit may identify a second predefined time, from the predefined time intervals, at which the measured intensity value of the light beam matches a predefined calibrated value. The predefined calibrated value may be identified by the control unit prior to creation of the fog on the lens. Based on the time duration between the first predefined time and the second predefined time, the control unit may detect the anti-fog property of the lens. If the time duration is less than a first predefined time duration, the control unit may detect high anti-fog property of the lens. If the time duration is more than the first predefined time duration, the control unit may detect low anti-fog property of the lens. In this manner, the present disclosure efficiently detects anti-fog property of a lens based on defog time.
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 of 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 a device for detecting anti-fog property of a lens in accordance with some embodiments of the present disclosure.

The device 100 may comprise a light source 101, a lens holder 103, a Light Dependent Resistor (LDR) 109, a fog generating unit 107 and a control unit 111. The control unit 111may include a processor 113 and a memory 115. The light source 101 may be one or more Light Emitting Diodes (LED). The lens holder 103 may be configured to hold the lens 105 or any glass for observation. As an example, the lens 105 may include, but not limited to, an eyewear lens 105. At first, the lens 105 under observation may be placed in the lens holder 103. Once the lens 105 is placed, the fog is created on the lens 105 using fog generating unit 107. In an embodiment, the fog generating unit 107 may include, but not limited to, a peltier element and a fan. The peltier element and the fan may be switched “On” for a predetermined time for example, 10 seconds to create the fog. Once the fog is created, the peltier element and the fan may be switched “Off”. Thereafter, the processor 113 of the control unit 111may activate the light source 101 to emit light beam on the lens 105. The control unit 111 may also activate the LDR 109 to measure intensity value of the light beam refracted through the lens 105 at predefined time intervals, starting at a first predefined time. As an example, the predefined time intervals may be 10 seconds. The first predefined time may be 1st second. Thereafter, the control unit 111 may identify the second predefined time from the predefined time intervals at which the measured intensity value of the light beam matches the predefined calibrated value.
In an embodiment, the control unit 111 may determine the predefined calibrated value prior to formation of the fog on the lens 105 and store in the memory 115. The control unit 111 may activate the light source 101 to emit light source 101 on the lens 105 for second predefined time duration. As an example, the second predefined time duration may be 20 seconds. Thereafter, the control unit 111 may activate the LDR 109 to measure intensity value of the light beam refracted through the lens 105 during the second predefined time duration. The LDR 109 may measure one or more intensity values during the second predefined time duration. As an example, the LDR 109 may measure 10 intensity values in 20 seconds. The control unit 111 may average the 10 intensity values and identify the predefined calibrated value based on average of the 10 intensity values. The predefined calibrated value may be determined to neglect the ambience lighting. As an example, the predefined calibrated value may be 10 lux.

In an embodiment, the control unit 111 may identify that the measured intensity value matches the predefined calibrated value at the 8th second which is identified as the second predefined time. Based on the time duration between the first predefined time and the second predefined time which is the defog time, the control unit 111 may detect the anti-fog property of the lens 105. In the current scenario, the time duration between the first predefined time and the second predefined time is 7 seconds.

In an embodiment, the control unit 111 may compare the time duration between the first predefined time and the second predefined time to detect the anti-fog property of the lens 105. If the time duration is less than first predefined time duration, then the control unit 111 may detect high anti-fog property of the lens 105. However, if the time duration is more than the first predefined time duration, the control unit 111 may detect low anti-fog property of the lens 105. As an example, the first predefined time duration may be 2 seconds. Since the time duration identified for matching the measured intensity value with the predefined calibrated value for the current lens 105 is 7 seconds which is more than the first predefined time duration which is 2 seconds, the control unit 111 may detect that the lens 105 has low anti-fog property.

Fig.2 shows a flowchart illustrating method for detecting anti-fog property of a lens in accordance with some embodiments of the present disclosure.

As illustrated in Fig.2, the method 200 includes one or more blocks illustrating a method of detecting anti-fog property of a lens 105 by a control unit 111 of a device 100. 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 may include activating, by a control unit 111 of a device 100, a light source 101 associated with the control unit 111. The light source 101 may be activated to emit a light beam on the lens 105 which is placed in a lens holder 103 of the device 100. The light source 101 may be a Light Emitting Diode (LED).

At block 203, the method 200 may include activating, by the control unit 111, a Light Dependent Resistor (LDR) 109. The LDR 109 may be activated to measure intensity value of the light beam refracted through the lens 105 during predefined time interval starting at a first predefined time.

At block 205, the method 200 may include identifying, by the control unit 111, a second predefined time from the predefined time intervals at which measured intensity value of the light beam matches a predefined calibrated value. The predefined calibrated value may be identified by the control unit prior to formation of the fog on the lens 105. The control unit 111 may activate the light source to emit the light beam on the lens 105 prior to formation of the fog for a second predefined time duration. Thereafter, the control unit 111 may activate the LDR 109 to measure one or more intensity values of the light beam refracted through the lens 105 during the second predefined time duration. Once the one or more intensity values are measured, the control unit 111 may identify the predefined calibrated value based on average of the one or more intensity values.

At block 207, the method 200 may include detecting, by the control unit 111, the anti-fog property of the lens 105. The anti-fog property of the lens 105 may be detected based on time duration between the first predefined time and the second predefined time. The control unit 111 may detect high anti-fogging property of the lens 105 when the time duration is less than a first predefined time duration. The control unit 111 may detect low anti-fogging property of the lens 105 when the time duration is more than the first predefined time duration.
Advantages of the embodiment of the present disclosure are illustrated herein.
In an embodiment, the present disclosure provides a method for detecting anti-fog property of a lens.

In an embodiment, the present disclosure provides a compact device for detecting anti-fog property of a lens and hence cost effective

In an embodiment, the present disclosure detects de-fog time based on which anti-fog property is detected and hence the present disclosure accurately detects the anti-fog property.

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.

Referral Numerals:

Reference Number Description

100 Device
101 Light Source
103 Lens holder
105 Lens
107 Fog generating unit
109 Light Dependent Resistor (LDR)
111 Control unit
113 Processor
115 Memory

,CLAIMS:1. A device (100) for detecting anti-fogging property of a lens, the device (100) comprising:
a light source (101) for emitting a light beam on the lens placed in a lens holder (103) of the device (100);
a Light Dependent Resistor (LDR) (109) configured to measure intensity of the light beam refracted through the lens;
a fog generating unit (107) configured to create a fog on the lens; and
a control unit (111) configured to, upon creation of the fog on the lens:
activate the light source (101) to emit the light beam on the lens;
activate the LDR (109) to measure intensity value of the light beam refracted through the lens, at predefined time intervals, starting at a first predefined time;
identify a second predefined time, from the predefined time intervals, at which the measured intensity value of the light beam matches a predefined calibrated value; and
detect the anti-fogging property of the lens based on time duration between the first predefined time and the second predefined time.

2. The device (100) as claimed in claim 1, wherein the control unit (111) detects high anti-fogging property of the lens when the time duration is less than a first predefined time duration.

3. The device (100) as claimed in claim 1, wherein the control unit (111) detects low anti-fogging property of the lens when the time duration is more than the first predefined time duration.

4. The device (100) as claimed in claim 1, wherein the control unit (111) determines the predefined calibrated value by:
activating the light source (101) to emit the light beam on the lens prior to formation of the fog for a second predefined time duration;
activating the LDR (109) to measure one or more intensity values of the light beam refracted through the lens at the second predefined time duration; and
determining the predefined calibrated value based on average of the one or more intensity values.
5. A control unit (111) for detecting anti-fogging property of a lens, the control unit (111) comprising:
a processor; and
a memory communicatively coupled to the processor, wherein the memory stores the processor-executable instructions, which, on execution, causes the processor to:
activate a light source (101) associated with the control unit to emit a light beam on a lens formed with a fog;
activate a Light Dependent Resistor (LDR) (109) associated with the control unit and the light source (101) to measure intensity value of the light beam refracted through the lens at predefined time intervals starting at a first predefined time;
identify a second predefined time, from the predefined time intervals, at which measured intensity value of the light beam matches a predefined calibrated value; and
detect the anti-fogging property of the lens based on time duration between the first predefined time and the second predefined time.

6. The control unit (111) as claimed in claim 5 is associated with a fog generation unit (107) to create the fog on the lens.

7. The control unit (111) as claimed in claim 5 detects high anti-fogging property of the lens when the time duration is less than a first predefined time duration.

8. The control unit (111) as claimed in claim 5 detects low anti-fogging property of the lens when the time duration is more than the first predefined time duration.

9. The control unit (111) as claimed in claim 5 determines the predefined calibrated value by:
activating the light source (101) to emit the light beam on the lens prior to formation of the fog for a second predefined time duration;
activating the LDR (109) to measure one or more intensity values of the light beam refracted through the lens at the second predefined time duration; and
determining the predefined calibrated value based on average of the one or more intensity values.
10. A method for detecting anti-fogging property of a lens, the method comprising:
activating, by a control unit (111) of a device (100), a light source (101) associated with the control unit to emit a light beam on the lens placed in a lens holder (103) of the device (100);
activating, by the control unit (111), a Light Dependent Resistor (LDR) (109) to measure intensity value of the light beam refracted through the lens at predefined time intervals starting at a first predefined time;
identifying, by the control unit (111), a second predefined time from the predefined time intervals at which measured intensity value of the light beam, by the LDR (109), matches a predefined calibrated value; and
detecting, by the control unit (111), the anti-fogging property of the lens based on time duration between the first predefined time and the second predefined time.

11. The method as claimed in claim 10, wherein a high anti-fogging property of the lens is detected when the time duration is less than a first predefined time duration.

12. The method as claimed in claim 10, wherein a low anti-fogging property of the lens is detected when the time duration is more than the first predefined time duration.

13. The method as claimed in claim 10, wherein the predefined calibrated value is determined by:
activating the light source (101) to direct the light beam on the lens placed in the lens holder (103) of the lens prior to formation of the fog for a second predefined time duration;
activating the LDR (109) to measure one or more intensity values of the light passed through the lens at the second predefined time duration; and
determining the predefined calibrated value based on average of the one or more intensity values.