GB2534975A

GB2534975A - Switch

Info

Publication number: GB2534975A
Application number: GB1520485.2A
Authority: GB
Inventors: Ealuri Anoor
Original assignee: Aqualisa Products Ltd
Current assignee: Aqualisa Products Ltd
Priority date: 2014-11-20
Filing date: 2015-11-20
Publication date: 2016-08-10
Also published as: GB2532479A; GB201420642D0; GB201520485D0

Abstract

A switch for a sanitary device comprises a translucent front wall 22 opposite a support 12, on which is mounted a light source 14 and light sensor 16. An opaque shroud 24 defines a first light channel 28 having parallel sides extending between the front wall and the support, wherein at the support the first channel encloses only the light source to prevent light scattering from the light source to a second channel 30 extending between the front wall and the light sensor. The shroud may be a single component and comprise first and second through-holes forming the first and second channels. The second light channel may have one end enclosing only a light detecting portion of the sensor. The light source may irradiate infrared and/or near infrared light. The shroud may be reflective and/or absorbent to infrared and/or near infrared light. A seal 50 may be provided between the front wall 22 and a translucent outer wall 40, and may have first and second apertures 52,54 aligned with the first and second channels. The support may be a circuit board. The switch may be used in an electric shower unit.

Description

SWITCH

The present invention relates to a switch, in particular using a light source, such as infrared or near infrared, and a sanitary device including such a switch, in particular a sanitary device exposed to a wet environment, such as an electric shower unit.

Many sanitary devices for use in wet environments now require the use of user-operable switches, for example for functions of power on and power off It is known to provide conventional mechanical switches, for example operable as push-push switches. However, for use in a wet environment, extra precautions must be taken to seal the switch from that environment and the user.

It is also known to use proximity sensors, for example detecting a user in the vicinity of a lavatory. Such sensors are inappropriate for switches to be selectively operated by a user. In particular, a user's proximity will activate the device, rather than the user operating it, for example with his or her finger, only at the surface of the switch.

In proximity sensors, it was known to provide side-by-side light sources and light detectors that operate to detect reflection of light by the user. Such previous arrangements have had to consider problems resulting from optical leakage between the light source and the light detector. In particular, with a greater amount of leakage, less of the original light is available to detect the user by reflection. As a result, distinguishing reflection of a user above background noise becomes more difficult. It is commonly understood that any transparent overlay above the light source and detector will contribute to optical leakage by refraction and internal reflection. It is therefore commonly understood that the overlay should be minimised and the light source and detector placed as close as possible to the user interface.

In practice, these known requirements/restrictions on the use of an optical sensor make it difficult to use such an optical sensor as a switch in a practical device in a wet environment. In particular, the switch should be sealed within a watertight case and preferably be given a pleasing outer appearance.

It is an object of the present invention to provide a switch that is suitable for use in a sanitary device which might be exposed to a wet environment and which at least partly overcomes the problems discussed above.

According to the present invention, there is provided a switch for a sanitary device including a support, a light source mounted on the support, a light sensor mounted on the support and adjacent the light source, and a translucent front wall opposite the support. The light source may be configured to irradiate light to and through the front wall and the light sensor may be configured to detect the light passing through the front wall to the light sensor. The switch may further include an opaque shroud defining a first light channel extending with substantially parallel sides from the front wall to the support and having one end at the support enclosing substantially only the light source and at least a light irradiating portion of the light source. The shroud may thus be configured so as substantially to prevent light scattering from the light irradiating portion of the light source between the shroud and the support. The shroud may further define a second light channel extending with substantially parallel sides from the front wall to the light sensor.

In this respect, the present invention recognises that issues of optical leakage need not be as significant when using the light source and light sensor to detect immediate proximity, in other words substantially touching, of a user. The switch of the present invention may act as a touch switch, responsive only to touch at an outer surface of the switch or at least location immediately adjacent the outer surface. The first light channel defined by the shroud ensures that substantially no leakage of light occurs between the light source, the support and the translucent front wall. The first light channel may provide substantially a column of light extending to the translucent front wall. Even if some scattering of light then occurs, the resulting losses are not significant compared with the reflection resulting from a part of a user placed immediate adjacent the outer surface.

Preferably, the shroud is a single component extending between the support and the front wall and having first and second through holes forming the first and second light channels respectively.

In this way, the support may be assuredly located with respect to the front wall and the light channels, in particular the first light channel preventing loss of source light is positioned correctly between the support and the front wall.

Although scattering of light that has been reflected and is travelling from the front wall towards the light sensor is of less significance in impeding the performance of the switch, in some embodiments, the second light channel defined by the shroud may also have one end enclosing a light-detecting portion of the light sensor. In this way, the shroud closely defines light paths to and from the front wall with respect to the light source and the light sensor.

The switch preferably operates with infrared or near infrared light. Hence, the light source may be configured to radiate one or both of infrared and near infrared light and a light sensor may be configured to detect one or both of infrared and near infrared light. In this respect, the shroud is preferably one or both of reflective and light absorbent to one or both of infrared and near infrared light.

Contrary to the general understanding of the use of proximity detectors and optical leakage, the present invention recognises that, for use as a switch that operates substantially according to touch, it is possible to increase the thickness of any transparent overlay substantially. Hence, preferably, the switch further includes an translucent outer wall parallel with and adjacent to the front wall and a seal located between the front wall and the outer wall, the seal having a first surface contacting an outer surface of the front wall and a second surface contacting an inner surface of the outer wall.

Even though some refraction will occur at the interfaces and internal reflection is possible, because the light source is provided by means of the first light channel and approaches the translucent front wall as substantial column of light and because the switch is intended only to detect a user in very close proximity with or touching the outer surface of the outer wall, any effects of refraction or internal reflection will not impede functioning of the switch.

Preferably, the seal defines first and second apertures between the first and second surfaces, the first and second apertures being aligned with the first and second light channels respectively.

In this way, the first aperture acts to continue guiding the light from the light source in a generally parallel direction into the outer wall. Similarly, the second aperture acts to limit the effective field of view into the second light channel, thereby more accurately detecting reflected light from a user.

By constructing the seal of a resilient material such as rubber or elastomer, the first and second apertures occur directly at the outer surface of the front wall and the inner surface of the outer wall, thereby limiting any optical leakage.

Contrary to any general understanding of providing an optical proximity detector, it is possible for the outer wall to be constructed of frosted glass. Preferably, the inner surface of the outer wall is frosted.

The support may itself be a printed circuit board to which the light source and the light sensor are electrically connected. For example, the switch may be provided with its own printed circuit board with appropriate components for operating the light source, light sensor and switch. This may then be connected to a main circuit board of a sanitary device to which the switch is fitted.

An opaque mask may be provided including a predefined marking indicating the location of a switch area and including, as part of the marking, a first translucent portion aligned with the first light channel and a second translucent portion aligned with the second light channel In this way, a user is provided with a clear indication of where to touch the switch, for example on the outer surface of the outer wall, to operate a switch.

In some arrangements, the first and second translucent portions may be connected to each other, in other words, contiguous, to form a single translucent portion. For example, the single translucent portion may be an elongate section having dimensions similar to the tip of a typical finger. To indicate clearly that portion, the opaque mask may include other markings, optionally translucent, pointing to that single translucent portion, for example a circular or part-circular pattern around it.

The single translucent portion is preferably no more than 15 mm long and preferably no more than 10 mm long. In one preferred embodiment, the single translucent portion may be substantially 2 mm wide and 10 mm long.

The switch may be incorporated in any appropriate sanitary device, particularly those to be situated in wet environments. The switch is particularly useful in an electric shower unit and the present invention also provides such an electric shower unit including such a switch.

The invention will be more clearly understood from the following description, given by way of example only, with reference to the accompanying drawings, in which: Figure 1 illustrates an electric shower unit embodying a switch of the present invention; Figure 2 illustrates a cross-section through a switch embodying the present invention; Figure 3 illustrates component parts of a switch embodying the present invention on a support; Figure 4 illustrates parts of the switch mounted on a main board; Figure 5 illustrates the top surface of a shroud of a switch embodying the present invention; Figure 6 illustrates an underside of a shroud for use with a switch embodying the present invention; Figure 7 illustrates the underside of a seal for use with an embodiment of the present invention; Figure 8 illustrates a standard symbol that may be used in conjunction with an embodiment of the present invention; Figure 9 illustrates dimensions of a preferred shroud; Figure 10 illustrates schematically a cross-section of the preferred shroud; Figure 11 illustrates schematically a cross-section of a preferred switch; Figure 12 illustrates schematically a cross-section of a preferred switch; and Figure 13 illustrates dimensions of a preferred seal.

The present invention may be useful for any sanitary device that is to be positioned in a wet environment. It provides a switch that can operate as a touch switch positioned at the surface of the sanitary device and can be sealed effectively from the wet environment.

Figure 1 illustrates, as an example of a sanitary device, an electric shower unit 2. The electric shower unit 2 may be configured to receive a water supply and heat that water instantaneously according to a user's requirements for supply from a showerhead. The unit 2 includes an outer case 4 sealing components of the electric shower unit within it and a front face 6. Protruding from the front face 6 is a control knob 8, for example for controlling the outlet temperature of water. Also, in this embodiment, the front face 6 includes the outer portion of a switch 10 embodying the present invention, for example for turning the electric shower unit 2 on and off. The switch 10 may be presented to the user at the outer face 6 by means of a predetermined symbol.

Figure 2 illustrates a cross-section through a switch 10 embodying the present invention.

The switch includes a support 12 as also illustrated in Figure 3 The support 12 may take the form of a PCB (printed circuit board) including other ancillary or peripheral components for the functioning of the switch.

On the support 12, there is located a light source 14 and a light sensor 16. In preferred embodiments, the switch operates using infrared or near infrared wavelengths, for example 850 nm. The light source 14 may be embodied as an IR transmitter, such as an LED. The light sensor 16 may be embodied as an IR receiver. The light source 14 and light sensor 16 are electrically connected to and controlled by components of the PCB 12. In particular, the light source 14 is controlled to emit light and the light sensor 16 is controlled to detect any proportion of that emitted light which is reflected back, for instance from a user.

As illustrated in Figure 2, and also Figure 4, the switch 10, as an integral unit, may be mounted directly to and electrically connected with a main circuit board 20. Of course, other embodiments are possible where the switch 10 is mounted remotely from any main circuit board within the sanitary device.

As illustrated in Figure 2, the support 12 is mounted opposite a translucent front wall 22. The translucent front wall 22 preferably forms part of the outer casing 4 of the sanitary unit 2. Where the outer casing 4 is generally opaque, the front wall 22 may be insert-moulded with the rest the case 4 or secured in place into an opening formed in the case 4. Irrespective, the translucent front wall 22 and the case 4 preferably seal the switch 10 and other components from an external wet environment. For completeness, it will be understood that for some embodiments the translucent front wall 22 need only be translucent to wavelengths used by the light source 14 and light sensor 16.

It is well understood that use of an overlay in front of a proximity sensor using a light source and sensor can significantly affect the performance of the proximity sensor. In particular, the overlay can result in significant amounts of light scattering such that a significant amount of light is reflected back to the sensor even without a user in proximity with the sensor. In contrast to this previous understanding for proximity sensors, the present invention aims to provide a switch that operates like a touch switch and need only be triggered/activated when a user touches or is immediately adjacent the switch. In this regard, the present invention need only provide the transmitted light to a small/restricted part of the outer surface of the sanitary device 2.

As illustrated in Figure 2, there is provided a shroud 24 that extends between the support 12 and the translucent front wall 22. The shroud 24 is also illustrated in Figures 4, 5 and 6. In the illustrated embodiment, the shroud 24 includes a supplementary portion 26 which extends to the main circuit board 20. This may provide additional structural support to the switch 10 or, as will be described below, can channel illumination light from a light source 60.

The shroud 24 defines a first light channel 28 extending between the light source 14 and the translucent front wall 22 and a second light channel 30 extending between the light sensor 16 and transparent front wall 22 The shroud 24 may otherwise be solid. However, in order to save weight and material, as illustrated in Figure 6, the shroud 24 may include walls as required to define the structural features of the shroud 24, but otherwise include open or hollow sections.

The first light channel 28 defined by the shroud 24 fits closely around the light source 14 so as to prevent substantially all light from escaping or scattering from between the shroud 24 and support 12 towards the light sensor 16. The internal surface of the first light channel 28 is at least opaque to the light from the light source 14 and maybe reflective but preferably absorbent of that light. Furthermore, the light source 14 and support 12 may be constructed from materials opaque to the light emitted by the light source 14 so as to prevent light transmission and scattering through the support 12 towards the light sensor 16. The first light channel 28 includes parallel sided wall extending to an outer front surface of the shroud 24 adjacent an inner surface of the translucent front wall 22. In this way, of the light emitted by the light source 14, substantially only light travelling perpendicular to the translucent front wall 22 will pass into and through that front wall 22.

In the illustrated embodiment of Figure 6, the first light channel 28 is formed as a tubular portion extending to and around the light source 14. As illustrated in Figure 5, the first light channel 28 forms a hole 34 in the top surface of the shroud 24 for facing the translucent front wall 22.

It will be understood that, once reflected light has entered back through the transparent front wall 22 into the shroud 24, light scattering is of less concern, because such light is all reflected light and not stray light travelling directly from the light source 14. Hence, in the illustrated embodiment, although the second light channel 30 extends towards the light sensor 16, it is not essential for it to closely fit with the light sensor 16 and support 12. Nevertheless, to restrict reception of stray light from the light source scattered by the front wall 22, the second light channel 30 opens at the top surface of the shroud 34 with an opening 36 adjacent an inner surface of the front wall 22 With the arrangement as described above, despite the use of the translucent front wall 22 as an overlay, it becomes possible to minimise back-scatter of light at the translucent front wall 22 Of course, light entering the translucent front wall 22 will travel not only through the front wall 22 at an angle perpendicular to its surfaces, but also at angles that will internally reflect at its outer surface.

The width across the first light channel 28, for example its diameter, and also the length of the first light channel 28 will assist in restricting light transmission to be more columnar in nature. In a preferred embodiment, the first light channel has a length of 4.6 to 5 mm, preferably substantially 4.8 mm, and, at the top surface, a diameter of 2.7 to 3.1 mm, preferably substantially 2.9 mm.

Also, by restricting the thickness of the translucent front wall 22, the radial scattering of light caused by internal reflection at the outer surface of the front wall 22 will be reduced. The spacing between the first and second light channels 28, 30 and the width, such as diameter, of the second light channel 30 additionally acts to reduce the amount of scattered light entering the second channel. In the preferred embodiment, the second light channel 30 has a diameter of 1.4 to 1.8 mm, preferably substantially 1.6 mm, and the spacing of the centres of the first and second light channels 28, 30 is between 4.8 and 5.2 mm, preferably substantially 5.0 mm. In the preferred embodiment, the second light channel 30 has a length of at least 2.3 mm, preferably 2.5 mm.

Thus, only an object, such as a user's finger, external of the front translucent wall 22 will cause a significant reflection of light from the light source 14 to the light sensor 16 so as to activate the switch.

In the illustrated embodiment, it will be seen that a translucent outer wall 40 is provided in addition to the translucent front wall 22. In particular, it may be desirable to provide a more aesthetically pleasing outer face to a sanitary unit, for instance incorporating glass or frosted glass.

Once again, with the usual understanding of proximity sensors, it would be considered wholly undesirable to place a second overlay in front of the first overlay, thereby increasing the number of interfaces and possibilities for reflection. There are significant difficulties when having to transmit through a frosted/diffusing face located intermediate the transmitter/receiver and the sensing/switching region.

In the illustrated embodiment, a seal 50 is provided between the front wall 22 and outer wall 40.

The seal 50 defines a first aperture 52 aligned with the first light channel 28 and a second aperture 54 aligned with the second light channel 30. Otherwise, at least in the region of the first and second light channels 28, 30, the seal 50 is opaque, at least to wavelengths used by the light source 14 and light sensor 16. Preferably, the seal 50 is absorbent to such light wavelengths. In this way, any light scattering from the top opening of the first light channel 28 and passing through the translucent front wall 22 will be blocked by the seal 50. Only light passing through the first aperture 52 will be able to pass into the translucent outer wall 40.

The thickness of the seal 50, the width of the first aperture 52 and the spacing between the first and second light channels 28 and 30 may be chosen so that any reflection of light at the inner surface of the outer wall 40 will not reach the opening of the second light channel 30 or at least will not reach the light sensor 16 at the far end of the second light channel 30. A preferred arrangement is described below.

The widths of the first aperture 52 and second aperture 54 are substantially the same as the width of the first light channel 28 and second light channel 30, though may be slightly larger. The seal is preferably between 1.5 and 2.5 mm thick.

In the illustrated embodiment, on a first surface of the seal 50 forming the inner side of that seal SO, a peripheral wall 56 may be formed so as to surround the first aperture 52. The outer surface of the front wall 22 may be formed with a corresponding channel for receiving the wall 56. Not only does the wall 56 and corresponding channel act to securely locate the seal 50 in place, but it extends the light-blocking function of the seal 50 towards the shroud 24 in the area of the first light channel 28. In this way, the wall 56 acts to block light scattered by internal reflection at the outer surface of the front wall 22 and the inner surface of the outer wall 40. Of course, the wall 56 need not be entirely peripheral to the aperture 52, but may follow only sufficient of the periphery of the aperture 52 to block light scattering towards the second light channel 30.

As will be appreciated, the second aperture 54 aligned with the second light channel 30 improves the directional sensitivity of the switch. In particular, although some light scattering may occur within the outer wall 40, particularly at its outer surface, only light travelling in a relatively high angle of incidence to the inner surface of the outer wall 40 will be able to reach the light sensor 16, even with some reflectance taking place at the inner surface of the outer wall 40 and the outer and inner surfaces of the front wall 22.

In a preferred embodiment, the outer wall 40 is frosted glass, with frosting on the inner surface.

The outer wall 40 may have a thickness of 2 to 10 mm, preferably 4 to 8 mm, more preferably 5 to 7 mm and more preferably substantially 6 mm.

Figure 7 illustrates an example of the underside of the transparent front wall 22 in the casing of a sanitary device. In this embodiment, for ease of assembly, the seal 50 is provided with a single central first aperture 52, but includes a series of symmetric second apertures around the first aperture 52 with any of those apertures usable as the second aperture 54.

In one preferred embodiment, the supplementary portion 26 described above may define a through-hole by which the switch may be illuminated, preferably by wavelengths not interfering with the light sensor 16. A light source 60, such as an LED, may be positioned on the support 12. As illustrated in Figure 2, as well as Figure 7, an opening 62 may be provided through the seal 50 for allowing light from the source 60 into the outer wall 40 for illumination.

In order to indicate clearly to a user the required position to touch for operation of the switch, a printed pattern can be formed on the inner or outer surface of the outer wall 40. The printed pattern should be translucent to the light used by the light source 14 and light sensor 16 at positions aligned with the first light channel 28 and second light channel 30. Providing aligned translucent apertures in the printed opaque pattern may further enhance the directional nature of the switch.

Where an embodiment uses illumination, such as described above with reference to the light source 60, the translucent portion of the printed pattern may be illuminated, for instance to indicate that the power is "on".

Figure 8 illustrates a standard power on/off symbol, which may be incorporated into an embodiment of the present invention. A first translucent portion 70a aligned with the first light channel 28 is combined with a second translucent portion 70b aligned with the second light channel 30 so as to form a single translucent portion 70. In a preferred embodiment, the translucent portion 70 is substantially 10 mm long and 2 mm wide. As illustrated, this may be combined with another part-circular translucent portion so as to form the complete on/off symbol. Of course, only the translation portion 70 need be translucent to light transmitted from the light source 14. If the symbol is to be illuminated using visible light, then preferably both translucent portions 70 and 80 should be translucent to that visible light.

With the arrangement as described above, little scattering of light is possible and the switch becomes sensitive only to direct reflection at the outer surface of the switch or very close to it. As a result, the switch is also tolerant to moisture and water droplets on the outer surface, which will merely refract light and will not provide sufficient direct internal reflection to activate the switch.

There now follows details of a preferred embodiment with examples of particular arrangements.

As illustrated in Figure 9, to provide an arrangement for the IR transmitter and receiver for the finger touch switch which will work only on the finger contact area, the distance between shroud holes should be 5 mm hole centre to centre, and the hole diameters for the IR transmitter should be 2.9mm and the IR receiver should be I.6mm, the hole tolerances are preferably within 0.1 mm to 0.05mm.

On the shroud part on the PCB, where the IR transmitter and receiver are mounted, the ideal height from the PCB to the face of the shroud is 5mm (see Figure 10). In this respect, the height of the IR receiver component is preferably between 0.55mm and 0.75mm, preferably 0.65mm and the height of the IR transmitter component is preferably between 0.9mm and 1.l mm, preferably 1mm Significant changes in this arrangement will result in a sensor which will not work as a finger touch/contact switch.

The touch switch/contact where the finger touches the surface i is the focal point for the touch contact area. It can be a couple of millimetres higher than the actual surface actuation area (see figure 11) due to tolerances in the mounting stack.

The present invention addresses the challenge of providing an arrangement in which the IR light has to pass through a very small slit of 2mm x lOmm (the single translucent portion) and a stack of 2 layers of materials, the first one of which being a 1.5mm to 2mm transparent plastic and the second of which being a 6mm thick frosted glass. The frosting may be achieved either by sand blasting or chemical etching.

These methods create a roughened surface creating different respective finishes and with different respective surface features. The frosted glass is fitted so that the touch area is a smooth surface for the users. The rough face faces the IR transmitter LED and creates a serious problem of multiple scatter of IR. light. This is blocked out in the arrangement of the present invention by the specific dimensioning and the rubber seal (see figure 13) between the transparent plastic and the frosted glass which has the correct apertures to block the multiple scatter IR light internally and allows guiding of the weak IR. light that is being reflected from touching finger from the focal point only to the IR receiver. The frostiness of the glass and the IR light guiding arrangement severely weakens the IR light return path. Hence, to make the touch switch work reliably, the shroud has to be in alignment with axis of the IR transmitter and receiver or else it ceases to function, see figure 12 for the preferred arrangement.

By using the above mentioned arrangement and guiding the lR light and creating a near sharp focal point for the IR light, it is possible to eliminate false triggering in the touch area by water and water droplets which become transparent to the focal point.

Claims

CLAIMSA switch for a sanitary device including: a support; a light source mounted on the support; a light sensor mounted on the support and adjacent the light source; and a translucent front wall opposite the support; wherein: the light source is configured to irradiate light to and through the front wall; the light sensor is configured to detect the light passing through the front wall to the light sensor; and the switch further includes: an opaque shroud defining a first light channel extending with substantially parallel sides from the front wall to the support and having one end at the support enclosing substantially only the light source and at least a light irradiating portion of the light source so as substantially to prevent light scattering from the light irradiating portion of the light source between the shroud and the support and a second light channel extending with substantially parallel sides from the front wall to the light sensor.
2. A switch according to claim 1 wherein the shroud is a single component extending between the support and the front wall and having first and second throughholes forming the first and second light channels respectively.
3. A switch according to claim 1 or 2 wherein the second light channel defined by the shroud has one end enclosing substantially only a light detecting portion of the light sensor.
4. A switch according to claim 1, 2 or 3 wherein the light source is configured to irradiate one or both of infrared and near infrared light.
5. A switch according to any preceding claim wherein the light sensor is configured to detect one or both of infrared and near infrared light.
6. A switch according to any preceding claim wherein the shroud is one or both of reflective and light absorbent to one or both of infrared and near infrared light.
7. A switch according to any preceding claim further including an translucent outer wall parallel with and adjacent to the front wall and a seal located between the front wall and the outer wall, the seal having a first surface contacting an outer surface of the front wall and a second surface contacting an inner surface of the outer wall.
8. A switch according to claim 7 wherein the seal defines first and second apertures between the first and second surfaces, the first and second apertures being aligned with the first and second light channels respectively.
9. A switch according to claim 7 or 8 wherein the seal is constructed of a resilient material such as rubber or elastomer.
10. A switch according to claim 7, 8 or 9 wherein the outer wall is constructed of frosted glass.
11. A switch according to any preceding claim wherein the support is a printed circuit board to which the light source and the light sensor are electrically connected.
12. A switch according to any preceding claim further including an opaque mask including a predefined marking indicating the location of a switch area and including, as part of said marking, a first translucent portion aligned with the first light channel and a second translucent portion aligned with the second light channel.
13. A switch according to claim 12 wherein the first and second translucent portions are connected to each other to form a single translucent portion.
14. A switch according to claim 13 wherein the single translucent portion is no more than 15mm long, preferably no more than 10mm long and more preferably substantially 2mm x lOmm.
15. An electric shower unit including a switch according to any preceding claim.
16. A switch constructed and arranged substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.
17. An electric shower unit substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.