WO2014126560A1

WO2014126560A1 - A system for venting a touch screen on a medical device

Info

Publication number: WO2014126560A1
Application number: PCT/US2013/025976
Authority: WO
Inventors: Ken Zhen
Original assignee: Draeger Medical Systems, Inc.
Priority date: 2013-02-13
Filing date: 2013-02-13
Publication date: 2014-08-21

Abstract

A device that includes a housing and a resistive touch-screen are described. The touch-screen has an upper and a lower circuit layer, an enclosed space between the upper and lower circuit layers, and an air channel. The housing defines an interior volume. The device includes an air channel that fluidly connects the enclosed space of the resistive touch screen to the interior volume defined by the housing.

Description

SYSTEM FOR VENTING A TOUCHSCREEN

TECHNICAL FIELD

[0001] The subject matter described herein relates generally to the field of electrical devices with touch screens, and more particularly to medical devices with resistive touch screens that are required to be water-tight.

BACKGROUND

[0002] Touch-screen devices that are used in challenging environments where exposure to dirt and fluids are prevalent often use resistive touch screens with polymer upper surfaces. In such devices, it can be desirable for the touch-screen to be water-tight. Water-tight devices that employ resistive touch-screens can be compromised after exposure to extreme temperatures, causing visible waviness in the top layer of the touch screen.

[0003] The waviness in the top layer of touch screens used in water-tight devices with resistive touch-screens is often caused by expansion or contraction of the air or other gas between the top layer and the lower layer. Often the lower layer is glass, or adhered to glass, and will not deform appreciably in response to expanding and contracting air or gas. The top layer, that is often a deformable layer of quite thin glass or a polymer, will expand or deform at times to a point from which it will not recover its initial size or form when the device is exposed to extreme temperatures or pressure, either in a single incident or in repeated incidents. This expansion or contraction of air or gas between the top and bottom layer causes deformation in the top layer that leads to the appearance of waviness in the top layer of the touch screen. Waviness in the top layer of the touch screen can in turn cause customer dissatisfaction due to a degradation in the cosmetic appearance of the touch screen even, as the waviness can remain even after surrounding temperature and pressure have returned to normal and are no longer extreme. Additionally, temporary waviness in the top layer of the touch screen can occur during periods of extreme temperature and/or pressure. This temporary waviness can cause customer dissatisfaction when a user interacts with the touch-screen during such periods of extreme conditions, even though the screen recovers its normal appearance after the extreme conditions have passed.

SUMMARY

[0004] Provided herein is a device that includes a housing and a resistive touch-screen. The housing defines an interior volume. The resistive touch-screen includes an upper and a lower circuit layer, an enclose space between the upper and lower circuit layers, and an air channel that fluidly connects the enclosed space and the interior volume.

[0005] The following features can be present in the device described above in any suitable combination. In some implementations, the device further includes a seal situated between the resistive touch-screen and the device housing. The device can further include at least one opening in the housing that is connected to the interior volume at first end and is connected to the ambient environment at a second end. In some such implementations, the opening can include a channel. The at least one opening in the housing can include a sound opening. In implementations with at least one opening in the housing, the device can further include comprising a membrane vent that allows gas to move through the opening, but prevents liquid from entering the interior volume. In implementations of the device with a seal, the air channel can pass through, under, or over the seal. The device can further include a flexible portion of circuitry that connects the upper and lower circuit layers to a controller. In such implementations, wherein the flexible portion of circuitry partially can define the air channel. The air channel can be further partially defined by a layer of polymer film or tape on top of the flexible portion of circuitry. The housing can also include at least one passage that exists expressly to allow for communication of gas between the interior volume and an environment external to the device.

[0006] In a related aspect, provided herein is a method of fabricating a water-tight hand-held device with a resistive touch-screen. The method includes positioning upper and lower circuit layers within a device housing to form an enclosed space between the upper and lower circuit layers and to define an interior volume, connecting the upper and lower circuit layers with a flexible circuit, partially defining an air channel with the flexible circuit between the enclosed space and interior volume, and creating a water-tight seal with a sealant between the upper and lower circuit layers and the device housing.

[0007] The following features can be present in the method described above in any suitable combination. In some implementations, wherein the device housing includes at least one opening in the housing that is connected to the interior volume at first end and is connected to the ambient environment at a second end. In such implementations, the at least one opening can include a channel. Alternatively, the at least one opening can include a sound opening. The device housing in the method can include a membrane vent that allows gas to move through the opening, but prevents liquid from entering the interior volume. The method can also include positioning a layer of polymer film or tape on top of the flexible portion of circuitry to further partially define the air channel. The device housing can also include at least one passage that exists expressly to allow for communication of gas between the interior volume and an environment external to the device.

[0008] The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

[0009] FIG. 1 is a hand-held electronic device;

[0010] FIG. 2 illustrates a cross sectional view of a hand-held electronic device with a resistive touch screen;

[0011] FIG.3 illustrates a cross sectional view of a water-tight hand-held electronic device with a resistive touch screen showing an implementation of an air channel;

[0012] FIG. 4 is an exploded view of a water-tight hand-held electronic device with a resistive touch screen showing an implementation of an air channel; and

[0013] FIG. 5 illustrates an assembly that includes the top and bottom panes of a resistive touch screen with circuitry configured to provide an air channel from the touch screen.

[0014] Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

[0015] Disclosed herein are hand-held devices that are sealed against the environment, such as water-tight hand-held devices, with a user interface that includes a touch-screen. Such hand-held devices can be used in challenging environments, such as in the field where liquids can splash upon the device or where the device may be accidentally dropped in a container of water. The touch-screen can generally be a resistive touch-screen with a deformable upper-most layer that a user depresses to respond to images or messages displayed on the touch-screen. The bottom of the deformable upper-most layer is a conductive layer or coating, and beneath that is an enclosed space that is bounded by another conductive layer or coating that is supported by a glass backing panel. The combination of the sealed nature of the device and the enclosed space behind the deformable upper-most layer of the touchscreen can make the touch screen susceptible to permanent deformation when the device is exposed to extreme temperatures, especially for a long period of time, if no means of venting the enclosed space is available. This permanent deformation causes waviness in the touch-screen display and can impede the use or performance of the device. To ensure the performance of the hand-held device after exposure to a variety of environments, means and methods of venting the enclosed space within the touchscreen display are needed and are described herein.

HAND-HELD MEDICAL DEVICE

[0016] FIG. 1 illustrates a hand-held electronic device 100. The hand-held electronic device 100 has a housing that encloses a touch-screen 110, a speaker 120, and an interior volume 130 beneath the touch-screen. The housing can also include user interface buttons 140, instrumentation input receptors 150, and recesses for fitting the device into a holder or docking station 160.

[0017] The hand-held electronic device 100 can be used as a patient monitoring device in a hospital, a clinic, an emergency vehicle, or other areas where patients are cared for. When monitoring the condition of a patient, the hand-held electronic device 100 can connect to sensors or monitoring equipment through the instrumentation input receptors 150. A more detailed description of a patient monitoring device can be found in patent application US 7,316,648 filed on June 9, 2004, titled "Portable Patient Monitoring System Including Location Identification Capability," the contents of which are incorporated herein in its entirety by reference.

[0018] FIG. 2 is a cross sectional view of a hand-held electronic device 100 with a touch-screen 110. The touch-screen 110 is surrounded along its edges by a water-tight seal 250 that connects it to the housing 240. Beneath the touch-screen 110 is an interior volume 130 in which circuitry and other components can be contained, along with much empty space that is filled with air or other gas. The touch-screen 110 shown includes a top circuit layer 260; a bottom circuit layer 265; a glass backing panel 270; a spacer 275; spacer dots 276; an enclosed space 280; and clear, conductive coatings 285.

[0019] The touch-screen 110 shown is a conventional resistive touchscreen. The top circuit layer 260 is the surface that a user will touch to interact with the information presented by the user interface. The top circuit layer 260 lies above the bottom circuit layer 265 that is supported by the glass backing panel 270. The top circuit layer 260 and the bottom circuit layer 265 are coated with a clear, conductive material, such as indium-tin oxide (ITO), 285 on the sides of the layer facing each other. These facing sides of the top and bottom circuit layers, along with the spacer 275, define the enclosed space 280. Spacer dots 276 lie above the clear, conductive coating 285 on the bottom circuit layer 265, within the enclosed space 280.

[0020] The device measures the resistance of the touch-screen 110. When a user touches the top circuit layer 290, the resistance changes at the point that a user touches. The resistance can be measured in ways understood by those familiar with touch screen devices. An exemplary system of measuring the resistance of various points located on the touch-screen 110 include the use of four wires, with two wires on each circuit layer, the first wires parallel to the second, and the pairs arranged perpendicular to each other. A controller interprets the resistivity signals to determine where a user has touched.

[0021] In the touch-screen 110 shown in FIG. 2, air or another gas is contained within the enclosed space 280, and this gas expands or contracts as temperature or pressure changes. Because the touch-screen 110 is sealed by the water-tight seal 250, the gas within the enclosed space 280 cannot escape when it expands. This expansion of gas within the enclosed space 280 can cause the top circuit layer 260 to expand. After repeated or prolonged deformation, the top circuit layer 260 can be permanently deformed to a certain degree. Once the ambient conditions have equilibrated to normal levels, such as near 22 degrees Celsius and 1 atmosphere, the trapped gas can no longer exert pressure on the top circuit layer 260, and a waviness can be seen, as the top circuit layer 260 does not return fully to its original configuration. Conversely, if the gas within the enclosed space 280 contracts, such as due to a drop in temperature or an increase in the ambient pressure, the top circuit layer 260 can be forced to deform downwards towards the bottom circuit layer 265 in a manner which may not be elastic once the environment around the device return to normal levels. This downwards deformation can also cause waviness in the top circuit layer 260.

[0022] FIG. 3 is a cross sectional view of a water-tight hand-held electronic device 300 with a vented touch-screen 110. The device is similar to that shown in FIG. 2, with a touch-screen 110 that includes a top circuit layer 260; a bottom circuit layer 265; a glass backing panel 270; a spacer 275; spacer dots 276; an enclosed space 280; clear, conductive coatings 285; and a water-tight seal 250 that connects it to the housing 240. As in FIG. 2, beneath the touch-screen 110 is an interior volume 130 in which circuitry and other components can be contained, along with much empty space that is filled with air or other gas. The device shown in FIG. 3 also includes an integrated air channel 305 that fluidly connects the enclosed space 280 in the touch-screen 110 and the interior volume 130. The integrated air channel 305, as shown, is formed partially by a portion of flexible circuitry 310 that connects the top circuit layer 260 and the bottom circuit layer 265 with a controller that can discern changes in the resistance of the touch screen. The controller can be located within the interior volume 130.

[0023] The integrated air channel 305 can be any suitable size and location to effectively fluidly connect the enclosed space 280 with the interior volume 130. The integrated air channel 305 can pass under or through the sealant 250. The integrated air channel 305 can pass through or under the spacer 275. In a manner that will not compromise the strength of the glass backing panel 270, the integrated air channel 305 can pass through the bottom circuit layer 265 and the glass backing panel 270. The integrated air channel 305 can pass through the spacer 275, the seal 250, and within the housing 240 to the interior volume 130, if it can maintain the water- tightness of the device. The width of the integrated air channel 305 can be 1 mm. The length of the integrated air channel can be as long as needed to fluidly connect the enclosed space 280 and the interior volume 130, such as 4mm, 5mm, or greater. When the integrated air channel 305 is partially defined by a portion of flexible circuitry 310, the integrated air channel 305 can also be bounded by other parts of the device such as the seal 250, the glass backing panel 270, and the bottom circuit layer 265. A layer of polymer sheet, paper, or tape can be used to define the integrated air channel 305 when the integrated air channel passes through or adjacent to the seal 250. When a portion of flexible circuitry 310 partially defines the integrated air channel 300, a layer of polymer sheet or tape, such as Kapton ® (i.e. polyimide) tape, can be applied to the flexible circuitry 310 to separate the integrated air channel 305 from the seal 250.

[0024] The housing of the device shown in FIG. 3 is also different from that in FIG. 2, in that the housing 240 includes a sound channel 320 (that is similar to the speaker 120 in FIG. 1) and a membrane vent 315. The membrane vent 315 includes a material that covers the opening of the sound channel 320 that leads to the interior volume 130. The material of the membrane vent 315 allows gas, such as air, to move through the sound channel 320, but will prevent liquid from entering the interior volume 130, thus maintaining the water-tight nature of the device while allowing for venting of the interior of the device. The membrane vent 315 can include expanded polytetrafluoroethylene (ePTFE), or other hydrophobic material, or material that meets the IEC IPX7 standard, or other material that prevents liquid from passing through but allows gas or air to pass through.

[0025] One or more membrane vents 310 can be found in a water-tight hand-held device, wherein the membrane vent 315 is adjacent a sound channel 320 or speaker opening 120 or adjacent to an opening present in the housing 240 expressly to allow for communication of gas between the interior volume 130 and the environment external to the device.

[0026] The hand-held device that is water-tight can also have a housing 240 that does not include any openings for the communication of air, or other gas, from the interior volume 130 to the ambient environment. In such a device, the interior volume 130 is sufficiently large to absorb any expansion of the gas in the enclosed space 280 or to provide any gas should the gas in the enclosed space 280 contract, when exposure of the device to extreme temperature or pressure is of sufficiently short duration to prevent equilibration of conditions between the enclosed space 280 and the interior volume 130.

[0027] FIG. 4 is an exploded view of a water-tight hand-held electronic device 100 with a resistive touch-screen 110 showing an implementation of an air channel 300. Shown are various portions of the housing 240 with portions of the touch-screen 110 including the upper-most top circuit layer 260 which is surrounded by the seal 250. The top circuit layer 260 is in contact with a portion 400 of the seal 250 that is not seen when the touch-screen 110 is within in the housing 240 (see the right portion of the figure), this portion of the seal 400, coincides with the location of the portion of the flexible circuit 305 that forms the air channel 300. Shown in FIG. 4 is also a piece of tape 306 that can be used to cover the flexible circuitry 310 so that the air channel 300 can be separated from the portion of the seal 400 that is placed over the flexible circuitry 310.

TOUCH SCREEN WITH VENTING SYSTEM

[0028] A touch-screen with a venting system can be found not only in a hand-held medical device, but in any device that is designed to be water-tight. FIG. 5 illustrates an assembly that includes the top and bottom panes of a resistive touch screen 110 with circuitry 305 configured to provide an air channel 300 from the enclosed space 280 within the touch-screen 110. The circuitry 305 connects partially to the top circuit layer (260 in FIG. 3) and partially to the bottom circuit layer (265 in FIG. 3), then meets in one piece that leads to a controller that interprets changes in the resistance between the various points of the touch-screen 110. A gasket 250 seals the enclosed space 280 of the resistive touch-screen 110, and the circuitry 305 and air channel 300 passes from the enclosed space 280 through, under, or over the gasket 250 to an area that can allow venting of the enclosed space 280.

[0029] The air channel 300 can be positioned in any convenient location along the edge of the touch-screen 110. Further, more than one air channel 300 could be a part of a touch-screen 110 with a venting system. The air channel 300 can lead to a fully closed interior volume 130 or an interior volume 130 that is vented to the exterior of the device through a gas-permeable, but liquid impermeable, membrane.

METHODS OF VENTING A RESISTIVE TOUCH SCREEN

[0030] Methods of venting a resistive touch screen include providing an air channel 305 to fluidly connect an enclosed space 280 in a touch-screen 110 to a larger volume, such as the ambient environment or the interior volume 130 shown in figures 1 through 3. In some implementations, the air channel 305 can be

intermittently in fluid contact with both the enclosed space 280 in a touch-screen 110 and a larger volume. Such a configuration can include a switch or valve to open the air channel 305 to the larger volume. In some configurations, the air channel 305 can lead to a larger volume that is enclosed by a housing that can provide intermittent communication of gas from the interior of the housing to the exterior. Such intermittent communication of gas can be accomplished by valves, switches, or covers over ports or membrane covered openings that can be moved to allow or prevent communication of gas from the inside to the outside of a water-tight device. A user may recognize or anticipate a need to vent a touch-screen and can implement an action to open one or more air channels between the enclosed space in a resistive touch-screen and a larger volume. Alternatively, the user can act to allow gaseous communication from within a device to outside of a water-tight device when the need to vent the resistive touch-screen is identified or anticipated.

[0031] The implementations set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[0032] Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and/or variations can be provided in addition to those set forth herein. For example, the implementations described above can be directed to various combinations and subcombinations of the disclosed features and/or combinations and sub-combinations of several further features disclosed above. In addition, the logic flows and steps for use described herein do not require the particular order shown, or sequential order, to achieve desirable results. Similarly, elements located on the front, back, side, top, or bottom of an embodiment or implementation are to be understood as relatively positioned. Other embodiments can be within the scope of the claims.

Claims

WHAT IS CLAIMED IS:

1. A device comprising:

a housing defining an interior volume; and

a resistive touch-screen comprising:

an upper and a lower circuit layer;

an enclosed space between the upper and lower circuit layers; and an air channel that fluidly connects the enclosed space and the interior volume.

2. The device of claim 1, further comprising a seal situated between the resistive touch-screen and the device housing.

3. The device of either claim 1 or claim 2, further comprising at least one

opening in the housing that is connected to the interior volume at first end and is connected to the ambient environment at a second end.

4. The device of claim 3, wherein the at least one opening comprises a channel.

5. The device of claim 3, wherein the at least one opening comprises a sound opening.

6. The device of any of claims 3-5, further comprising a membrane vent that allows gas to move through the opening, but prevents liquid from entering the interior volume.

7. The device of claim 2, wherein the air channel passes through, under, or over the seal.

8. The device of any of claims 1-7, further comprising a flexible portion of circuitry that connects the upper and lower circuit layers to a controller.

9. The device of claim 8, wherein the flexible portion of circuitry partially

defines the air channel.

10. The device of claim 9, wherein the air channel is further partially defined by a layer of polymer film or tape on top of the flexible portion of circuitry.

11. The device of any of claims 1-10, wherein the housing further comprises at least one passage that exists expressly to allow for communication of gas between the interior volume and an environment external to the device.

12. A method of fabricating a water-tight hand-held device with a resistive touchscreen comprising:

positioning upper and lower circuit layers within a device housing to form an enclosed space between the upper and lower circuit layers and to define an interior volume;

connecting the upper and lower circuit layers with a flexible circuit;

partially defining an air channel with the flexible circuit between the enclosed space and interior volume; and

creating a water-tight seal with a sealant between the upper and lower circuit layers and the device housing.

13. The method of claim 13, wherein the device housing comprises at least one opening in the housing that is connected to the interior volume at first end and is connected to the ambient environment at a second end.

14. The method of either claim 12 or claim 13, wherein the at least one opening comprises a channel.

15. The method of claim 14, wherein the at least one opening comprises a sound opening.

16. The method of any of claims 13 - 15, wherein the device housing further comprises a membrane vent that allows gas to move through the opening, but prevents liquid from entering the interior volume.

17. The method of any of claims 12 - 16, further comprising positioning a layer of polymer film or tape on top of the flexible portion of circuitry to further partially define the air channel.

18. The method of any claims of 12 - 17, wherein the device housing further comprises at least one passage that exists expressly to allow for

communication of gas between the interior volume and an environment external to the device.