DISPLAYS FOR SELF-SERVICE TERMINALS

Disclosed are display systems for self-service terminals. The display systems may include a display panel, a first transparent material and a second transparent material. The second transparent material may be located in between the first transparent material and the display panel. The first transparent material may have a first thermal conductivity and the second transparent material may have a second thermal conductivity. The second thermal conductivity may be greater than the first thermal conductivity.

SUMMARY

Disclosed are display systems for self-service terminals. The display systems may include a display panel, a first transparent material and a second transparent material. The second transparent material may be located in between the first transparent material and the display panel. The first transparent material may have a first thermal conductivity and the second transparent material may have a second thermal conductivity. The second thermal conductivity may be greater than the first thermal conductivity.

DETAILED DESCRIPTION

When a display is operated in an exterior environment, the visible and near-infrared (IR) solar radiation may pass through the front glass of the display and may be absorbed by the front liquid crystal display (LCD) sandwich of the LCD panel. Note that the front glass in the display is transparent to visible and near-IR radiation and is not heated by it. The solar heating of the LCD panel may cause the temperature of the LCD panel to rise beyond a specified working range, which may result in the liquid crystal layer failing to correctly operate such that the image becomes black. This is sometimes referred to as display clearing. The traditional solution for this is to cool the LCD panel by forcing air across its front surface, using forced air thermal convection to cool the surface. This introduces several negative factors. First a sizable air gap is required between the front glass of the display and the surface of the LCD panel, which introduces parallax. Second, the need for the air gap prevents optically bonding of the LCD to the front glass. This introduces air-glass and glass-air material transitions which each cause a reflection of approximately 4% of the light coming from either side. This results in the user seeing stronger reflections obscuring the image, and a slightly lower brightness from the display.

Third, the air passing over the display can carry contaminants that deposit on the LCD and inner surface of the front glass over time, degrading image quality. Fourth, space limitations usually mean that the fans need to be mounted behind the display with complex ducting used to route the air to the air gap in front of the LCD panel. And finial, when the external air temperature is below OC, the air gap allows moisture in the internal air to freeze on the rear surface of the front glass, causing frosting.

As disclosed herein, a thin layer of highly conductive material, such as a sapphire crystal, can be in contact with, and optionally bonded to, the front surface of the LCD panel to conduct the thermal energy away from the LCD layer by thermal conduction. This eliminates the need for the air gap and all the associated negative factors introduced by an air gap. This is possible since the highly conductive transparent material, such as sapphire crystal, is an optically transparent material made of crystallized aluminum oxide, with a thermal conductivity of (34.6 to 40 W/m·K), which is approximately equal to that of steel, and dramatically higher than that of standard glass (1.05 W/m·K), or air (0.026 W/m·K). This high thermal conductivity allows the heat absorbed by the LCD sandwich to conduct through the sapphire crystal layer where it can be dissipated via a heatsink thermally bonded around the border of the sapphire crystal sheet.

Using the systems disclosed herein, the display layer construction, as shown via results of computational fluid dynamics (CFD) simulations, demonstrate that the high thermal conductivity layer can successfully conduct the thermal energy away from the LCD panel, and into the heatsink even under maximum solar load in an ambient temperature of 50 C, dropping the LCD surface temperature from 94.24 C to 72.30 C.

The above discussion is intended to provide an overview of subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The description below is included to provide further information about the present patent application.

Turning now to the figures,FIG.1shows an example schematic of a self-service terminal100. As shown inFIG.1, self-service terminal100may include a processor102and a memory104. Memory104may include a software module106. While executing on processor102, software module104may perform processes for operating the self-service terminal, including, for example, accepting banknotes and checks and dispensing banknotes. Self-service terminal100also may include a user interface108, a communications port110, and an input/output (I/O) device112.

User interface108can include any number of devices that allow a user to interface with self-service terminal100. Non-limiting examples of user interface108include a keypad, a microphone, a display (LCD, touchscreen, or otherwise), etc.

Communications port110may allow self-service terminal100to communicate with various information sources and devices, such as, but not limited to, remote computing devices such as servers or other remote computers maintained by financial institutions, mobile devices such as a user's smart phone, peripheral devices, etc. Non-limiting examples of communications port110include, Ethernet cards (wireless or wired), BLUETOOTH® transmitters and receivers, near-field communications modules, etc.

FIG.2Ashows a rear view of a display unit200consistent with at least one embodiment of this disclosure.FIG.2Bshows a section view of display unit200consistent with at least one embodiment of this disclosure. Display unit200may be a user interface, such as user interface108and/or an I/O device, such as I/O device112.

As disclosed herein, display unit200may include a first transparent material202, a second transparent material204, a display panel206, and a heat sink208. As disclosed herein, first transparent material202may be a clear plastic, clear glass, or other transparent material that is exposed to the elements, such as weather, and allow the user to operate a self-service terminal, such as when display unit is part of a touchscreen display. Non-limiting examples of first transparent material202include, glass (tempered or otherwise) and polymers, such as polycarbonate materials, etc.

First transparent material202may be optically bonded to second transparent material204. For example, a first surface210of second transparent material may be optically bonded to a first surface212of first transparent material202to protect second transparent material from damage. Bonding second transparent material204to first transparent material202results in there not being any voids, which may trap air, in between first transparent material202and second transparent materials204.

Display panel206may be any type of display panel used in self-service terminals. For example, and as disclosed herein, display panel206may be an LCD display used to present information to users during a transaction. While LCD display panels are used as examples herein, other display panel types, such as light emitting diode (LED) display panels may be used without departing from the scope of this disclosure.

Second transparent material204may be a thin layer of material with a high thermal conductivity, such as a material that comprises crystallized aluminum oxide. As an example, second transparent material204may be a sapphire crystal. As disclosed herein, second transparent material204may be optically bonded to display panel206. For example, a first surface214of display panel206may be optically bonded to a second surface216of second transparent material204to conduct thermal energy away from display panel206by thermal conduction. In one example, a transparent thermal paste may be used to bond second transparent material204to display panel206. With or without the use of thermal paste, the contact between second transparent material204and display panel206eliminates the need for the air gap and all the associated negative factors the air gap creates. Stated another way, bonding second transparent material204to display panel206results in there not being any voids, which may trap air, in between display panel206and second transparent materials204.

As disclosed herein, second transparent material204may be an optically transparent material made of crystallized aluminum oxide, such as sapphire, with a thermal conductivity of about 34 to 40 W/m·K, which is approximately equal to that of steel, and dramatically higher than that of standard glass which has a thermal conductivity of about 1 W/m·K or air which has a thermal conductivity of about 0.026 W/m·K. Stated another way, second transparent material204has a thermal conductivity that is at least 1 to 2 orders of magnitude greater than that of glass and/or air.

This high thermal conductivity allows the heat absorbed by display unit200to conduct through second transparent material204where it can be dissipated via heatsink208, which may be thermally bonded around the border of second transparent material204as shown inFIGS.2A and2B.

CFD simulations show the effect of second transparent material204. The simulations disclosed herein had an ambient air temperature of 50 C and a solar load of 1,100 W/m2.

FIGS.3and4each shows the result of a simulation for a 7-inch LCD display optically bonded to a standard front glass, with no Sapphire crystal layer added.FIG.3shows the front glass (i.e., first trans parent material202) surface temperature andFIG.4shows the LCD panel (i.e., display panel206) surface temperature. As shown inFIGS.3and4, the temperatures of the LCD panel and the front glass reach upwards of 94 C.

FIGS.5and6each shows the result of simulations for a display panel having a 2 mm thick layer of sapphire glass (i.e., the second transparent material) thermally bonded to a front of the LCD panel with a heatsink, such as heat sink208, added to aid in dissipation of heat from sapphire glass layer. As shown inFIGS.5and6, the use of sapphire and a heatsink lowers the temperatures to around 79 C. This is a drop in temperature of about 15 C, which is significant and helps avoid display clearing.

FIGS.7and8show the results of simulations for a display panel having a 2 mm thick layer of sapphire glass thermally bonded to a front of the LCD panel with a heatsink and forced convection by blowing air over the heatsink. As shown inFIGS.7and8, the use of sapphire, a heatsink, and forced convection lowers the temperatures to around 72 C. This is a drop in temperature of over 20 C, which is significant and helps avoid display clearing.

FIGS.9and10demonstrate the improvement the sapphire crystal layer makes by showing a simulation repeated as shown inFIGS.8and9, but with the sapphire crystal layer replaced by standard glass. As shown inFIGS.9and10, using standard glass results in temperatures of around 91 C.

These results demonstrate that a thermally conductive layer, such as a sapphire crystal layer, can successfully conduct the thermal energy away from an LCD panel, and in into the heatsink even under maximum solar load in an ambient temperature of 50 C, dropping the LCD surface temperature from 94.24 C to 72.30 C, again, which is a significant decrease in operating temperatures.

Note that for simplicity the simulations used a single fluid volume, so the “interior” (i.e., the air temperature inside the self-service terminal) and “exterior” (i.e., the air temperature outs or ambient air) air temperatures were both 50 C. Implementing a more detailed assembly for the simulation where the interior air temperature was at a maximum of 40 C instead of 50 C would further improve the cooling efficiency of the sapphire glass layer and heatsink, and the LCD surface temp would be approximately a further 10 C cooler.

Examples and Notes

Example 1 is a display system for a self-service terminal, the display system comprising: a display panel; a first transparent material having a first thermal conductivity; and a second transparent material located in between the first transparent material and the display panel, the second transparent material having a second thermal conductivity, the second thermal conductivity being greater than the first thermal conductivity.

In Example 2, the subject matter of Example 1 optionally includes wherein the second transparent material is impregnated with crystallized aluminum oxide.

In Example 3, the subject matter of any one or more of Examples 1-2 optionally include wherein the second transparent material is sapphire.

In Example 4, the subject matter of any one or more of Examples 1-3 optionally include a thermal paste in contact with both the first transparent material and the second transparent material.

In Example 5, the subject matter of any one or more of Examples 1˜4 optionally include a heat sink attached to the second transparent material.

In Example 6, the subject matter of Example 5 optionally includes a thermal paste in contact with both the heat sink and the display panel.

In Example 7, the subject matter of any one or more of Examples 1-6 optionally include order of magnitude.

In Example 8, the subject matter of any one or more of Examples 1-7 optionally include wherein there is not any voids between the display panel and the first and second transparent materials.

Example 9 is a display system for a self-service terminal, the display system comprising: a display panel having a display surface; a first transparent material having a first surface and a first thermal conductivity; and a second transparent material having a first surface in contact with the first surface of the first transparent material and a second surface in contact with the display surface, the second transparent material having a second thermal conductivity, the second thermal conductivity being substantially greater than the first thermal conductivity.

In Example 10, the subject matter of Example 9 optionally includes wherein the second transparent material is impregnated with crystallized aluminum oxide.

In Example 11, the subject matter of any one or more of Examples 9-10 optionally include wherein the second transparent material is sapphire.

In Example 12, the subject matter of any one or more of Examples 9-11 optionally include a thermal paste located in between the first surface of the first transparent material and the first surface of the second transparent material.

In Example 13, the subject matter of any one or more of Examples 9-12 optionally include a heat sink attached to the second transparent material.

In Example 14, the subject matter of any one or more of Examples 12-13 optionally include a thermal paste in contact with both the heat sink and the display panel.

In Example 15, the subject matter of any one or more of Examples 9-14 optionally include order of magnitude.

In Example 16, the subject matter of any one or more of Examples 9-15 optionally include wherein there is not any voids between the first surface of the first transparent material and the first surface of the second transparent material.

Example 17 is a self-service terminal comprising: a display panel; a first transparent material having a first thermal conductivity; a second transparent material comprising crystallized aluminum oxide, the second transparent material located in between the first transparent material and the display panel, the second transparent material having a second thermal conductivity, the second thermal conductivity being greater than the first thermal conductivity; and a heat sink in contact with the second transparent material.

In Example 18, the subject matter of Example 17 optionally includes wherein the second transparent material is a sapphire panel.

In Example 19, the subject matter of any one or more of Examples 17-18 optionally include order of magnitude.

In Example 20, the subject matter of any one or more of Examples 17-19 optionally include wherein there is not any voids between the display panel and the first and second transparent materials.

In Example 21, the display systems, display panels, self-service terminals, of any one or any combination of Examples 1-20 can optionally be configured such that all elements or options recited are available to use or select from.