DESC:TECHNICAL FIELD
[0001] The present invention relates generally to integrally lit panels.

BACKGROUND
[0002] Typically, illuminated panels are provided in vehicles to enable a user to clearly see the labels provided in the vehicle. For example, illuminated panels are provided in the cockpit of aircrafts to enable the pilot to see various labels provided in the cockpit, typically for controls provided therein. The illumination in the panels plays a vital role during night. The illumination should be bright enough to enable the pilot to see and read the labels without putting strain on his eyes. Further, the illuminated panels should be compatible with devices used in that vehicle. For example, if the panel is to be used in the cockpit, the panel should be compatible with devices used in the cockpit such as Night Vision Goggles (NVG). More specifically, the illuminated panels should be visible enough in case the pilot is using night Vision Goggles. To achieve this, the panels are required to be illuminated with certain colors which are compatible with NVG devices.
[0003] Conventionally, these panels are designed with Light Emitting Diodes (LED) to illuminate them. However, the LEDs based panels are bulky. Further, use of LEDs in the panels requires additional circuitry to illuminate them which increases the overall thickness of the panels. Further, the LED based panels lead to non uniformity of light and emission of light rays from corners of the panels which may cause distraction for the pilot as well as makes it difficult for the pilot to see and read the labels using NVG. To alleviate the drawbacks of the LED panels, a panel having an electro-luminescent (EL) lamp is used. However, even the EL lamp panel possesses certain drawbacks. One of the major drawbacks is that in EL based panels, the supply bus wires run at corners of the EL lamp making that area non-illuminated. Further, light rays may emit out from the peripheral area of the EL lamp and cover sheets, which cause disturbance to read the labels. Thus, labels can not be placed near the peripheral area of the EL lamp. This results in increase in the size of EL based panels.
[0004] Therefore, there is felt a need of an integrally lit panel that alleviates the aforementioned drawbacks of conventional illuminated panels.

SUMMARY
[0005] The present invention envisages an integrally lit panel. The panel comprises a base, an electroluminescent (EL) lamp, and a cover sheet. The base has a pocket configured thereon. The EL lamp is arranged in the pocket. The cover sheet is mounted on the EL lamp. The cover sheet has labels printed thereon which are illuminated by the EL lamp. A channel is defined between walls of the base and peripheral surface of the cover sheet. A potting material is filled in the channel to arrest light rays emitted from peripheral surface of the EL lamp.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
[0006] The detailed description is described with reference to the accompanying figures. The same numbers are used throughout the drawings to reference like features and modules.
[0007] Figure 1 illustrates an isometric exploded view of an integrally lit panel, in accordance with an embodiment of the present invention.
[0008] Figure 2 illustrates an isometric rear view of the integrally lit panel of Figure 1 depicting electrical connections.
[0009] Figure 3 illustrates another isometric rear view of integrally lit panel of Figure 1 depicting the electrical connections after sealing with potting material.
[0010] Figure 4 illustrates an isometric view of a corner of the integrally lit panel of Figure 1.
[0011] Figure 5 illustrates a front view of the integrally lit panel of Figure 1.
[0012] Figure 6 illustrates a front view of the integrally lit panel of Figure 1 when it is illuminated.

DETAILED DESCRIPTION
[0013] In the following description, for purpose of explanation, specific details are set forth in order to provide an understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these details. One skilled in the art will recognize that embodiments of the present invention, some of which are described below, may be incorporated into a number of systems.
[0014] However, the systems and methods are not limited to the specific embodiments described herein. Further, structures and devices shown in the figures are illustrative of exemplary embodiments of the present invention and are meant to avoid obscuring of the present invention.
[0015] It should be noted that the description merely illustrates the principles of the present invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present invention. Furthermore, all examples recited herein are principally intended expressly to be only for explanatory purposes to help the reader in understanding the principles of the invention and the concepts contributed by the inventor to furthering the art and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass equivalents thereof.
[0016] The present invention relates to an integrally lit panel. The panel is provided with labels which can be read in day light as well as during low or no light conditions. The panel is compatible with various devices, such as Night Vision Goggles.
[0017] The panel comprises a base, an electroluminescent (EL) lamp, and a cover sheet. The base has a pocket configured thereon. The EL lamp is arranged in the pocket, and is configured to illuminate labels printed on the cover sheet. The EL lamp can be in the form of a sheet or a panel. The cover sheet is mounted on the EL lamp such that a channel is defined between walls of the base and peripheral surface of the cover sheet. A potting material is filled in the channel to arrest light rays emitted from peripheral surface of the EL lamp. In an embodiment, the EL lamp and the cover sheet are attached to each other via double sided adhesive tapes. The cover sheet has labels printed thereon which are illuminated by the EL lamp. The labels are reverse printed in white color to facilitate reading of the labels in day light condition when the EL lamp is in OFF state. The base is provided with a groove configured on a rear side of the base to provide a passage for wires of the electroluminescent lamp. In another embodiment, the base can have more than one groove depending upon the requirement of the EL lamp. Wires are connected to a rear side of the electroluminescent lamp in an ‘L’ shaped configuration. After connecting the wires, the groove is filled with potting material to strengthen the connection.
[0018] The panel of the present invention and its various embodiments are now described in more detail with reference to accompanying Figures 1 to 6.
[0019] Referring to Figure 1 to 6, an integrally lit panel (100) is shown. The panel (100) comprises a base (110), an electroluminescent (EL) lamp (120), and a cover sheet (130).
[0020] The base (110) may be of any material. In an embodiment, the base (110) may be made of aluminium. Aluminium base (110) has higher strength to density ratio. The base (110) has a plurality of walls extending from an operative top surface of the base (110). A pocket (112) is formed on the operative top surface of the base (110). The dimensions of the pocket (112) are determined such that the EL lamp (120) can be received in the pocket (112). The depth of the pocket (112) is determined as per the thickness of the EL lamp (120). The EL lamp (120) is securely pasted in the pocket (112) of the base (110). In an embodiment, mounting holes (114) are provided on the base (110) and on the cover sheet (130) for mounting purposes.
[0021] The base (110) has a groove (116) configured on a rear side of the base (110) to provide a passage for wires (124) of the EL lamp (120).
[0022] The EL lamp (120) is typically in a form of thin sheet or panel. The EL lamp (120) is arranged in the pocket (112). To provide electrical energy to the EL lamp (120), supply wires (124) are soldered to connect with EL lamp (120). The connection of the supply wires (124) is shown in Figure 2. The supply wires (124) are connected to Flex PCB connections of EL Lamp (120) on the rear side of the EL lamp (120). The groove (116) facilitates the supply wires (124) to connect with the EL lamp (120). In an embodiment, the wires (124) are connected in L-shaped configuration to prevent the stress on the connection. Further, the connection is strengthened and sealed with sealing compound or potting material (126). The potting material (126) is filled in the groove (116) after connecting the supply wires (124) to the EL lamp (120). The sealed connection is shown in Figure 3.
[0023] The cover sheet (130) is mounted on the EL lamp (120). In an embodiment, the EL lamp (120) and the cover sheet (130) are attached to each other via double sided adhesive tapes to prevent ingress of moisture and dust. The corners are sealed with potting material, making the panel (100) IP67 compliant. More specifically, the electroluminescent lamp (120) is sandwiched between the base (110) and the cover sheet (130).
[0024] The dimensions of the cover sheet (130) are smaller than the dimensions of the base (110) such that a channel (118) is defined between the walls of the base (110) and the peripheral surface of the cover sheet (130) when the cover sheet (130) is mounted on the EL lamp (120). The dimensions of the channel (118) are determined on the basis of overall dimensions of the base (110) and the cover sheet (130). In an embodiment, the width of the channel (118) varies from 0.5 mm to 0.8 mm.
[0025] A potting material (117) is filled in the channel (118) to arrest any light rays emitted from the peripheral area of the EL lamp (120). This allows the placement of labels (122) near peripheral area of the cover sheet (130). As the light rays emitted from the corners of the EL lamp (120) are arrested, the labels (122) near the peripheral area of the cover sheet (130) can be easily read without any disturbance. In an embodiment, the labels (122) can be placed up to 3 mm from the periphery of the cover sheet (130). This also reduces overall size of the panel (100) as more area is now available for the placement of the labels (122). Further, the thickness of the supply bus running through the corners of the EL lamp (120) and lamination of the EL lamp (120) is also reduced to increase the illuminated area. The placement of the labels (122) and the channel (118) filled with the potting material are shown in Figure 5.
[0026] In an embodiment, the potting material is epoxy resin. In another embodiment, the potting material is HYSOL ES1000 or DP-270 Black. However, any other suitable material can also be used as a potting material.
[0027] The cover sheet (130) can be made of any suitable material. In an embodiment, the cover sheet (130) is made of thin transparent polycarbonate sheet. In another embodiment, the cover sheet (130) is made of matt finish scratch proof polycarbonate sheet to make the top surface of the panel (100) antireflective and scratch proof. The cover sheet (130) has labels printed thereon. The EL lamp (120) illuminates the panel (100), more specifically, the labels (122) printed on the cover sheet (130).
[0028] The labels are reverse printed on the cover sheet (130). The labels can be printed using any suitable ink. In an embodiment, the labels (122) are printed with white colour so that the labels (122) are visible in day light when the EL lamp (120) is in OFF state. The rear surface of the cover sheet (130), which faces the EL lamp (120), is painted with black color/ink at remaining area other than the area where labels are to be printed. The labels are printed with white color on the rear side of the cover sheet (130). White sheets are pasted on the label area. The labels can also be painted in white ink. For safeguarding the labels, double sided transparent adhesive tape can be applied on the cover sheet (130), which also facilitates pasting of the cover sheet (130) on the EL lamp (120).
[0029] The reverse printing of the labels (122) prevents settling of the dust observed in conventionally printed labels. Conventionally, the labels are printed on a cover sheet by painting the front surface of the cover sheet in black and the legends are etched using laser itching or other processes leaving a legend groove in the cover sheet. With the passing of time, dust settles down in these legend grooves and legend may become dull. The reverse printing of the labels (122) on the cover sheet (130) does not allow settling of dust thereon.
[0030] The electroluminescent lamp (120) has output compatible with Night Vision Goggles. The electroluminescent lamp (120) has adequate brightness when powered with AC source. In an embodiment, the electroluminescent lamp (120) preferably is a green colour EL lamp, i.e., it emits green coloured light rays. Thus, the panel (100) is compatible with NVG Gen-III devices. An illuminated panel (100) is shown in Figure 6.
[0031] In an embodiment, a plurality of through holes (132) is provided on the panel (100) to provide access control switches.
[0032] The panel (100) can be used in various automobile applications. The panel (100) is particularly useful in cockpits of aircrafts. The panel (100) is very thin. In an embodiment, thickness of the panel (100) is 3 mm. The panel (100) is also light in weight which makes it ideal for use in aviation applications as compared to conventional LED based panels.
[0033] During the day time, the electroluminescent lamp (120) is kept in OFF state. The labels are visible as they are printed in white colour. During low light conditions or at night, the electroluminescent lamp (120) is illuminated and the labels appear in NVG compatible green colour.
[0034] The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the substance of the invention may occur to person skilled in the art, the invention should be construed to include everything within the scope of the invention.

LIST OF REFERNCE NUMERALS
100 – Integrally lit panel
110 – Base
112 – Pocket
114 – Mounting holes
116 – Groove
117, 126 – Potting material 118 – Channel
120 – EL lamp
122 – Labels
124 – Supply wires
130 – Cover sheet
132 – Through holes

,CLAIMS:
1. An integrally lit panel comprising:
a base having a pocket formed thereon;
an electroluminescent (EL) lamp arranged in said pocket;
a cover sheet mounted on said electroluminescent lamp, said cover sheet having labels printed thereon illuminated by said electroluminescent lamp;
a channel defined between walls of said base and peripheral surface of said cover sheet; and
a potting material filled in said channel to arrest light rays emitted from peripheral surface of said electroluminescent lamp.

2. The panel as claimed in claim 1, wherein said labels are reverse printed on said cover sheet.

3. The panel as claimed in claim 1 or 2, wherein said labels are printed in a white color.

4. The panel as claimed in claim 1, wherein said base has a groove on a rear side of said base to provide a passage for wires of the electroluminescent lamp.

5. The panel as claimed in claim 4, wherein said wires are connected to a rear side of the electroluminescent lamp in an ‘L’ shaped configuration.

6. The panel as claimed in claim 4, wherein said groove is filled with a potting material after connecting said wires to said electroluminescent lamp.

7. The panel as claimed in any one of the preceding claims 1 – 6, wherein said electroluminescent lamp and the cover sheet are attached to each other via double sided adhesive tapes.

8. The panel as claimed in any one of the preceding claims 1 – 7, wherein said electroluminescent lamp is a green colour electroluminescent lamp.