WO2013068770A2

WO2013068770A2 - Optical viewing system for a utility meter

Info

Publication number: WO2013068770A2
Application number: PCT/GB2012/052807
Authority: WO
Inventors: Matthew Middleton
Original assignee: Metermimic Limited
Priority date: 2011-11-11
Filing date: 2012-11-12
Publication date: 2013-05-16
Also published as: WO2013068770A3

Abstract

The present invention relates to an optical viewing system for use in automatic meter reading systems. The optical viewing system comprises an optical device arranged to provide an optical viewing path therethrough for viewing usage information from a utility meter. The system further comprises a meter window optical enhancement material (such as acrylic) arranged to be positioned between a meter window and the optical device to provide an optical path between a meter window and the optical device.

Description

Optical Viewing System for a Utility Meter

Due to the quest for efficiency and a better use of resources, there is currently a trend towards automatic meter reading (AMR) in the utility industry to replace meters being read by an individual affiliated to the utility industry. The problem the utility companies are faced with, is, not only the investment required replacing the existing analogue meters with AMR devices, but the investment in training required to install the new devices and the disruption caused by having to cut off the supply to do so. Not only is the extra investment a concern, but also the fact that the existing analogue meters are based on technologies that have been improved and perfected during many years and proven to work in the most extreme conditions. Furthermore analogue meters, in particular for the case of water or gas meters, do not require a power source to providing accurate and continuous readings, which is potentially a problem with most AMR devices. Additionally there is the problem of disposal of the old meters, many of which contain mercury, which is an environmental hazard.

The utility industry has currently installed millions of analogue metering devices for metering water, electricity and gas consumption. Manual reading of meters is time consuming and expensive. There are solutions in the market place of automatic meter reading but the majority relate to changing the original meters for a 'new' automatic meter, which again is time consuming and expensive.

The invention is based on taking advantage of the existing stock of analogue metering devices and using a non-invasive sensor system (i.e. not dismounting, invading or penetrating the existing device in any way) to convert the analogue meters into highly versatile AMR devices.

Ideally these existing meters can be adapted by using reed switches, magnetic sensors or optical sensors to read the consumption. The current invention will deal with the latter, i.e. the challenges faced when trying to adapt meters with optical sensors. Utility meters in general and water meters in particular are subject to harsh environments. Some are fitted in underground pits where the meters are sometimes covered with mud or the pits are flooded with water. This sort of environment makes it very difficult for an optical sensor to work properly, as either the sensor itself, the meter window, or the space between the sensor and the window become clouded in that environment and effective automatic meter reading via optical means can no longer take place. A lot of scratching and 'pitting' is caused to meters commonly when manual readings are taken as the dirty surfaces are scraped by the operators in their efforts to view the registers and record the meter readings.

This sort of environment and the scratching and pitting caused by the operators, affects the transparency of the windows on the meters. Windows can get very dirty and the dirt and sand present in that environment can cause them to be scratched, which reduces the transparency of the window considerably, even to the bare eye.

In many cases the windows become translucent and no longer transparent, which makes it almost impossible to take readings, as the numbers behind them cannot be read.

Background in relation to Optical sensors for utility meters

1. Various automatic meter reading add-on systems are available, some with optical designs but are related to specific meter types and specific groups of meters. 2. Most optical designs consist of a camera looking at digits via a mirror or prism.

These devices often primarily cover the meter digits so that a manual reading cannot be taken unless the design incorporates an add-on mechanical device i.e. a lid that can be flipped up (moved) so that a manual reading can take place.

3. Most optical designs are not designed to work in harsh environments which can cause ingress of water and other contaminants into the optical path rendering these devices inoperable. 4. Many optical designs which rely on prisms which distort the view of the meter digits when viewed through the prism from outside the device making manual reading difficult.

5. In principle, an automatic meter reader can work passively, just relying on

background light but illumination is a requirement for optoelectronic devices. In addition, many meters will be located in dark environments making illumination essential.

6. An inherent difficulty in the design of optical sensor devices relates to the variation of ambient light in all meter situations, therefore effective designs should incorporate their own controlled illumination to provide consistent electronic image capture.

7. Another problem with optical meter reading devices is the back-refection of light from the device mirror and/or window. The reflections from plastic or glass can be stronger than the light reflection from the meter digits, this can denigrate the image required for monitoring and can lead to a 'no -reading', which would be unacceptable.

8. Also with optical monitoring devices, a major problem they encounter is again of reflection off the surface that the device is attached to i.e. the meter glass.

9. Most automatic metering devices available consist of a single assembly which is then attached by various means, this leads to inconsistency and inaccurate positioning of the devices.

10. Another major problem is in the attachment of the device to the meter in confined spaces i.e. in underground meter boundary boxes. Also it must be noted that installations of the system can take place in environmentally harsh conditions.

The present invention provides an improved system.

According to the present invention there is an optical viewing system comprising an optical device arranged to provide an optical viewing path therethrough for viewing usage information from a utility meter, the system further comprising a meter window optical enhancement material arranged to be positioned between a meter window and the optical device to provide an optical path between a meter window and the optical device.

The presently claimed invention provides significant advantages over prior art

arrangements. The provision of a meter window optical enhancement material has a significant benefit in that the optical enhancement material effectively fills in the gaps caused by scratching and pitting and effectively improves the transparency of the window to the meter. Through the optical device therefore the meter reading can be easily read by either an image capture device such as a camera or by a person reading the meter. The optical device beneficially comprises a material having a substantially constant refractive index value. An optical path is provided which effectively removes the chance of moisture or dirt ingress.

The optical enhancement material is beneficially arranged to provide a seal in between the optical device and a meter window in situ for substantially excluding air in the optical path between a meter window and the optical device. The optical path therefore from the meter window into the optical device is substantially beneficially airless and is substantially beneficially waterless meaning that there is no chance of water, condensation or dust ingress which would obscure the reading of the meter. This is particularly beneficial in automatic meter reading system for accurate receipt of meter usage data.

Prior art arrangements suffer from reflection off the meter window, however the present invention is preferably arranged such that the optical enhancement material preferably has a similar and beneficially substantially the same refractive index as the meter window material (usually glass). The reflection effect is therefore eliminated.

The meter window optical enhancement material is beneficially adhered to the optical device. The meter window optical enhancement material is beneficially arranged to adhere to a meter window.

The optical enhancement material is beneficially substantially transparent. The optical enhancement material is beneficially substantially of the same refractive index as the optical device. This ensures that light is not refracted as it transfers from the optical enhancement material to the optical device.

The optical enhancement material is beneficially a layer provided on a meter facing face of the optical device. This provides significant advantages during application to an existing meter. A protective layer can be removed from the optical enhancement material layer and subsequently the optical device is brought into the vicinity of the meter window such that the optical enhancement material communicates with the meter window. The optical enhancement material is beneficially a flowable material and preferably has a thickness greater than 0.5mm. The thickness range of the optical enhancement material is preferably between substantially 0.5 and 4mm.

The optical enhancement material beneficially comprises a polymer, wherein the polymer preferably includes modified or unmodified acrylic or may include polycarbonate. The use of acrylic is beneficial as this also acts as an adhesive. A polyethylene film may be provided to protect the acrylic material which may be removed prior to location on to the meter window. The acrylic may, for example, be approximately 1mm in thickness in an alternative embodiment, a polyester film may be included. In one embodiment the polyester film may be encapsulated between layers of acrylic. The acrylic may be modified. Suitable acrylic material is known in the art.

The optical device beneficial comprises a prism. The prism is beneficially arranged to provide a first and second viewing zone, such that the meter usage information can be viewed simultaneously by a human operator and an image capture device. In one embodiment the prism may simply be utilised to reflect light to accommodate location in an environment in which a meter is provided meaning that a user can view the meter easily from an angle which would otherwise mean the meter usage would be impossible to read. More beneficially, however, the prism is arranged to enable simultaneous viewing in two different positions. This means that simultaneous viewing can be achieved by a human operator and an image capture device. The prism beneficially comprises a first reflective surface for enabling the first and second viewing zone.

The optical device beneficially comprises a meter facing face arranged in situ to sit generally parallel to a meter window. The first reflective surface is beneficially provided at an angle of substantially less than 45 degrees relative to the meter facing face. Such an angle is beneficial as this improves visible reading of the meter to be achieved whilst also improves capability for the viewing and capturing of the meter reading by the image capture device.

The first reflective surface is beneficially at an angle of substantially between 30 and 40 degrees relative to the meter facing face, and even more beneficial is at an angle of substantially 35 degrees relative to the meter facing face. It has been determined that an angle of substantially 35 degrees relative to the meter facing face provides optimal reading by both a human and by an image capture device. The prism beneficially includes a second reflective surface arranged to reflect light from the first reflective surface for providing an optical path to the second viewing zone.

In one embodiment a second optical device is arranged to be positioned between the first optical device and the optical enhancement material. This can be utilised to improve flexibility of the system for use with different types of meters having different spacing requirements due to the location in which the meter is positioned. This optical device may be an extension material so may comprise a substantially transparent material the same as the prism to allow light to pass therethrough.

A bracket arrangement is beneficially provided for securing the optical device to a meter window. As will be described herein a number of alternative bracket arrangements are considered suitable. This depends on the configuration of the meter and the surrounding environment in which the meter is located.

The optical viewing system beneficially further comprises an image capture device for capturing images of the utility meter reading, the optical device configured to

accommodate the image capture device. The optical viewing system beneficially further comprises a processor and data storage element. This system beneficially further comprises a transmitter for transmitting images from the image capture device to a further location.

As will be appreciated the present invention is beneficially an automatic meter reading (AMR) optical viewing system.

The invention relates to an automatic optical or optoelectronic sensor system that can monitor (or read) metering devices by recognising and transferring their counter images at timed intervals in the form of electronic data and overcomes weaknesses in current market offerings. A substantially single refractive index is preferably achieved by matching of the refractive index value of the optical enhancement material and the optical device is making it suitable for water, gas and electricity meters.

Also, according to the present invention there is a method of viewing usage information of a utility meter comprising the steps of providing an optical device and positioning a meter window optical enhancement material between a meter window and the optical device to provide an optical viewing path between a meter window and the optical device.

The present invention also extends to a process for restoring the optical transparency of a meter window by applying an optical enhancement material to a meter window and applying sufficient pressure on an optical device such that the optical enhancement material adapts to any irregularities in the meter window surface. The optical enhancement material is therefore provided between the optical device and the optical enhancement material. The optical device beneficially comprises a prism. The optical device is beneficially secured relative to the utility meter.

Also according to one aspect of the present invention there is an optical sensor for use in an automatic meter reading (AMR) system adapted to read a meter provided with a meter window which reveals usage information, the said sensor comprising a main prism characterised by having: a meter window facing face, a first reflective surface positioned at a first angle to the said meter window facing face, a viewing prism (3) overlaid and attached on the said first reflective surface of the main prism arranged to permit, in use, substantially direct reading of the meter consumption data by a human operator facing the meter window, and, whereby the first reflective surface enables an image detection device to receive a reflected image of the usage information through the meter window, whilst simultaneously enabling a human operator facing the meter to also read usage information.

Preferably the main prism is further characterised by comprising a second reflective surface parallel to the first reflective surface.

Preferably the main prism is further characterised by comprising a surface provided with formations for attaching and/or aligning an image detector, either directly or via a holder for an image detector.

Preferably the main prism is further characterised by comprising a recess adapted to fully or partially enclose illumination means arranged, in use, to illuminate the meter window.

Preferably the main prism is further characterised by comprising a channel-shaped recess adapted to fully or partially enclose illumination means arranged, in use, to illuminate the meter window. Preferably the main prism is further characterised by comprising a semi-circular section channel- shaped recess adapted to fully or partially enclose illumination means arranged, in use, to illuminate the meter window.

The main prism is further preferably characterised by comprising at least an individual cavity-shaped recess adapted to fully or partially enclose illumination means arranged, in use, to illuminate the meter window. The main prism is preferably further characterised by a substantially transparent adhesive layer adhered thereto at the meter facing face.

The main prism is preferably further characterised by having attached thereto an extension prism provided with two parallel faces for modifying the distance between the meter window and the meter window facing face of the main prism.

The attachment between the extension prism and the main prism and the attachment between the extension prism and the meter window may be realised with a substantially transparent adhesive layer acting between the faces of the face and the window.

The adhesive layer may comprise acrylic material.

In one embodiment the adhesive layer may have a thickness of between 0.5mm and 5mm.

An image detection device holder may be connected to the surface provided with formations.

The extension prism may comprise prongs, walls, arms or other formations to aid alignment and/or location of the extension prism with respect to the meter window facing portion of the main prism.

An image detection device holder may comprise internal formations for locating a filter. The optical sensor may be detachably mounted to a bracket comprising prongs, walls, arms or other formations to aid alignment and/or location of the extension prism or the meter window facing portion of the main prism, with respect to the meter window.

The bracket may be provided with an adhesive layer comprising a foam core for adhering the bracket to the meter.

The bracket may be provided with ruler marks or indicia, as a visual aid for positioning of the bracket by the operator. The bracket may comprise a substantially 'C shaped base.

The bracket may comprise at least one hole or slot for engaging a strapping means, such as a cable, strap or tie.

The bracket may comprise a bracing member attached thereto.

The bracket may consist of a kit comprising a bracket base and a bracket bracing member. As aspect of the present invention may an assembly comprising an AMR system comprising an optical sensor as hereinbefore described in combination with a utility meter provided with a meter window which reveals usage information, wherein the meter window and a prism portion of the optical sensor are attached together with a transparent adhesive layer.

One aspect of the invention comprises a kit of parts for an optical sensor for an automatic meter reading system comprising a main prism defined by a meter window facing face, and a first reflective surface positioned at a first angle to the said meter window facing face, a viewing prism overlaid and attached on the said first reflective surface of the main prism and arranged to permit, in use, substantially direct reading of the meter consumption data by a human operator facing the meter window, and, one or more extension prisms, each comprising two parallel faces spaced from one another and arranged to be attached, in use, one to the meter window and the other to the meter window facing face of the main prism, wherein the spacing between the faces of the said one or more extension prisms can have (a) predetermined dimension(s) for adapting the optical sensor to (a) predetermined meter model(s).

The system provides features that: • facilitate the 'ease of attachment' required for the physical fitting of the unit as a separate device to the existing meter in environmentally unfriendly conditions and confined spaces,

• facilitate the ease of adaptation of the optical sensor to different kinds of meters,

• provides a substantially clean and single refractive index solid material line of sight between the optical sensor camera and the meter window where the potential impact (e.g. ingress) of foreign matter (e.g. water) occluding the line of sight or the meter window is substantially eliminated and,

• simultaneously provides means for manually reading (by an operator) the counter behind the meter window, without need of interfering with the AMR device.

• the invention also incorporates an assembly of optoelectronic sensor and bracket system for accurate device positioning on the majority of service meters.

The present invention will now be described by way of example only with reference to the accompanying drawings in which:-

Figure 1 is a schematic side view of an optical viewing system according to an exemplary embodiment of the present invention including the provision of two viewing zones, with a second viewing zone having an optical path allowing viewing of the meter usage in parallel to the meter window.

Figure 2 is a schematic side view of an optical viewing system according to an exemplary embodiment of the present invention similar to Figure 1. However in this embodiment an image capture device is arranged to capture meter usage information substantially perpendicular to the meter window.

Figure 3 is a schematic side view of an optical viewing system according to an exemplary embodiment of the present invention including a supplementary optical device 7.

Figure 4 is a schematic side view of the optical viewing system of Figures 1 & 2 showing an enlarged camera and camera holder/locator and arrows indicating the positioning of the camera and holder/locator with respect to the respective optical devices. Figure 5 is a schematic perspective enlarged view of the camera and holder/locator (as shown in Figure 4). Figure 6 is a schematic side view of an optical viewing system according to an alternative embodiment of the present invention.

Figure 7 is a schematic view of a supplementary optical device as shown in the

embodiment as described with respect to Figure 3.

Figure 8 is a schematic plan and perspective view of a bracket for correct positioning of an optical device for use according to an exemplary embodiment of the present invention.

Referring to Figure 1 there is an optical device (1) which will be referred to herein as a prism as its purpose is to transfer light and beneficially reflect light. The prism (1) beneficially therefore comprises a substantially transparent material that may be glass or polymer. The prism (1) is designed in such a way to allow operation of a line of view for a camera (2) pointing at a right angle to the plane of the meter window (10) via a camera holder/locater (12). Furthermore, an operator identified by reference numeral (8) is allowed to take manual readings due to light reflected from the first reflective surface (3). Accordingly, the first reflective surface (3) is provided which enables light to be reflected both to the operator (8) enabling manual readings and also the camera (2) which may take automatic readings. The optical device comprises a meter facing face (5) which is beneficially substantially planar. This meter facing face (5) is beneficially in parallel to the meter window (10) and positioned in between the meter facing face (5) and the meter window (10) is a meter window optical enhancement material hereinafter referred to as the adhesive (11). This adhesive (11) provides significant benefits. The transparency of the meter window (10) is significantly improved as such a window (10) is typically degraded by scratches and indentation to an extent where the meter is difficult to read. The layer of adhesive (11) is beneficially flowable and is capable of filling in the scratches and indentations on the surface of the meter window. The optical transparency of the window is substantially restored to an extent where the meter is significantly easier to read. The adhesive (11) is beneficially provided in the form of a transparent adhesive tape. This tape is adhered to the meter facing face (5) of the prism (1). Accordingly, dirt and moisture is incapable of being found between the meter facing face (5) and the adhesive (11). The adhesive formulation is beneficially in a flowable form, and the opposing side of the adhesive (11) which secures to the meter window (10) is covered with a protective layer prior to use. This protective layer is removed and the prism is then pushed onto the meter window (10) causing the adhesive material to flow into the scratches and pits provided on the meter window (10). The adhesive formulation is beneficially acrylic based, and may be pure acrylic in one embodiment. Acrylic provides a highly transparent material having a light refraction index similar to that of glass, i.e. light transmission is greater than 80% of the visible light scope. Acrylic provides a good initial tack, lasting ultimate bonding strength, good sealing and good insulating properties. It is also resistant to aging and UV radiation hence suitable for long term use. A polyethylene liner is beneficially removed immediately prior to attachment. A further benefit of this adhesive (11) is that it can be used to attach to either a flat window or a concave window. The thickness of the adhesive which may be in the form of a tape is beneficially sufficient to allow plenty of flowable adhesive material to fill in any scratches and surface irregularity on the meter window (10). The thickness may be anything between 0.5mm to upward of 3mm. Increasing the thickness is particularly beneficial for meter windows of different shapes, in particular the more concaved shapes.

In one embodiment the optical viewing system may be provided as a separate prism (1) and adhesive (11). In such an embodiment an installer may be required to remove protective layers from both sides of the adhesive (11), and either apply the adhesive layer firstly to the meter window (10) or to the meter facing face (5).

The adhesive is beneficially made of a width that is greater than the width of the meter window. As such overlapping the edges of the meter window in order to provide an additional safety margin for any leaks or surface that may occur at the edges of the adhesive material is achieved. It will be appreciated that the application of sufficient pressure on the adhesive to allow the flowable material to flow into and adapt to any irregularities on the meter window (10) should be provided. Referring again to Figure 1 the angle of the first reflective surface (3) has been carefully chosen and designed to ensure that meter readings can be taken by both a human (8) and a camera (2). It will be appreciated that the respective positions of the viewing zones of the human (8) and the camera (2) may be switched. The angle of the first reflective surface (3) relative to the angle of the meter facing face (5) is beneficially substantially 35°. Such an angle provides the best reflective properties for viewing by both the human (8) and the camera (2). It has been found that an angle of less than 45° achieves good meter reading ability by both the human and camera, and between 30 and 40 ° even more beneficially and preferably 35°.

The prism (1) beneficially comprises a recess (9) wherein the recess (9) is preferably channel shaped, and more preferably of semi-circular section. A strip light source such as LED is beneficially provided and is even more beneficially provided in the recess or alternatively individual light sources are provided in each semi-circular section. The light source is provided to illuminate the meter digits, dials or indicia, whilst minimising undesirable reflections.

As can also be seen in Figure 4 there is provided at least one protrusion (14) arranged to be received in corresponding at least one aperture (16) in the prism (1). These apertures (16) ensure that relative movement of the camera holder/locator (12) in the prism is prevented through receipt of the protrusions (14), and also ensures accurate positioning and alignment.

The prism also includes a second reflective surface (18) which is provided for reflection of light to receive the meter reading at the camera (2).

The meter counter image is therefore imaged onto the camera (2) via the adhesive (11), the main body of the prism (1) and into the camera holder/locator (12) thus eliminating all extraneous contaminants due to the optical path for the image effectively being through a material that excludes air. The light reflected from the meter window (10) is effectively that emitted from the light source provided at (9). It is beneficial to provide a second reflective surface (18) as shown in Figure 1 as this means that the camera (2) can be located onto a board for a convenient location in a housing (not shown) that accommodates the prism and a board for ease of location into the environment in which the meter is found. It will be appreciated that this board includes a processor and transmitter for transmitting captured images to a data logger unit which is provided separate to the optical viewing system. The arrangement of Figure 1 is extremely beneficial as there are no moving parts required for manual viewing the meter nor are any moving parts required for image capture.

Referring now to Figure 2, the prism (1) as compared to the embodiment of Figure 1 has been modified such that the camera (2) is positioned to receive an image of the meter reading without a requirement for a second reflective prism surface. In this embodiment the camera is positioned perpendicular to the plane of the meter window (10). Whether the embodiment of Figure 2 or Figure 1 is utilised depends on the space available around the meter within the meter pit or enclosure or depending on other constraints. In this embodiment a flexible connection may be required from the camera (2) to the processor for subsequent transmission of the images to a data logger.

Referring to Figure 3, the embodiment of Figure 2 is shown, however in this embodiment a supplementary optical device (7) has been added which has been overlaid on the prism (1). This can be used to adapt the optical viewing system to different kinds of meters. In conjunction with the camera locator (12) the exact dimensions can be set to optimise the view and the focus of the camera on the meter digits or indicia of the meter (6). This supplementary optical device (7) and an exemplary embodiment thereof is shown in Figure 7 which effectively shows an extension optical device (7) or extension prism. In order to assist location and alignment of the supplementary optical device (7) with the meter facing face (5) of main prism (1), shown in Figure 7 is the supplementary optical device (7) which may be provided with an upstanding wall (7a) extending substantially at right angles to the face of the supplementary optical device (7) and will seat against the meter facing face (5) of the main prism (1). Arms (7b) may be provided extending from the wall (7a) arranged to embrace the meter facing face (5) of the main prism (1) and to limit the relative movement between the supplementary optical device (7) and the main prism (1) in at least one direction along the plane of the meter window facing face (5). Alternative

embodiments not shown could include a partial or full peripheral wall, or upright posts arranged to allow the meter window facing face (5) of the main prism (1) to effectively plug into the supplementary optical device (7). The option of adding supplementary optical devices (7) for fitting to the main prism for specific meter types provides greater versatility to the main prism (1). This extension prism (7) can also be changed to suit specific requirements, for example, monitoring of increased/decreased number of digits or larger/smaller sized meter digits.

Referring now to Figure 4, the communication between the camera holder/locater (12) and the respective embodiments of the present invention shown in Figures 1 and 2, for example, is shown. The camera holder/locator (12) as previously described may comprise one or more protrusions (14) which can be accommodated in corresponding receiving apertures (16) which are provided in the prism (1). The camera (2) seats into the camera holder/locator (12). This is shown more clearly in Figure 5. Also shown in both Figures 4 and 5 is a bottom ledge 17 for supporting or locating a filter (18), preferably an

interchangeable filter. This holder (12) is arranged to allow for light spectrum filter (18) to be fitted for specific optical monitoring requirements and can be used in conjunction with the various LED light options that can be adopted.

Referring now to Figure 6, a further embodiment of the present invention is shown which comprises a viewing prism (20) which is attached to the main prism (1) for manual reading. The remaining features are the same as the embodiment described, for example, with reference to Figure 1. In certain embodiments and for certain meters a viewing prism (20) may be utilised in order to ensure that an operator taking manual readings can actually view the meter reading due to the limitation placed on the line of sight by the meter pit. This will be necessary due to the constraints of the location in which the meter is positioned.

Referring now to Figure 8, a position bracket is shown for ensuring accurate positioning of the optical device onto the meter window (10). In one embodiment the bracket is generally 'C shaped as shown in Figure 8 and is shaped to provide at least two meter window (10) abutting surfaces (42) to aid alignment. The surfaces are provided with upstanding walls (44) which partially surround the sides of the meter window facing section of the prism (1) or (7) as the case may be. At least one, but preferably at least two of the abutment surfaces (42) are provided with indicia means such as graduated rule marks to assist the operator in assessing any displacement required in case the bracket needs to be slightly repositioned to enable the prism (1) to be correctly aligned with the meter window (10) and the meter digit or the meter characters or indicia. The indicia provided on the bracket may be plural indicia provided at right angles on corresponding surfaces (e.g. in X/Y axis fashion).

The bracket may be provided with an adhesive tape or layer (11) (not shown in Figure 8) on the surface that is designed to contact the meter window (10). The adhesive is preferably of a thickness of between 0.5mm and 6mm in order to conform more easily to any curvature or surface irregularity on the meter window.

The incorporation of the attachment bracket system allows for accurate placement and positive fitting to the meter of the prism (1) that is particularly important when, for example, by the nature of the meter, the digits are further away from the glass, it may be a requirement to position the prism (1) differently compared to a meter where the prism (1) has to be positioned directly above the meter indicia. This system therefore gives increased versatility for the fitting to many types and sizes of meters and gives the opportunity for fitting in confined spaces.

A means to secure the optical viewing system to the meter are beneficially provided. They may comprise, for example, a strap or tie which attach over the housing of the optical viewing system. In an embodiment wherein there is use of a bracket then the strap or tie, for example, are used to apply substantially constant pressure on the optical viewing system and therefore on the adhesive material that lies between the meter window (10) and the meter window facing face of the main prism or extension prism (1, 7). This pressure allows the adhesive to flow and adapt to the shape of the meter window or any surface irregularities on the window.

It will be further appreciated that in some embodiments it is not essential to provide a bracket and instead the optical viewing system is applied directly to the meter window face and means to attach the optical viewing system to the meter window face is provided such as again, a strap or tie. In one embodiment the strap or tie can be applied over the optical viewing system and around the meter, but the skilled addressee would find other forms of attachment also suitable. The optical view system as a whole beneficially comprises a housing which has not been shown which incorporates the prism, camera holder, LED, light PCB strip and optical processing board which include a processor and means to transfer image data to a data logger which may be remote. The first light path is between the camera and the meter window via the camera holder (12) held within the prism (1) and reflects off the surface or surfaces depending on the specific embodiment. A second light path outside the device housing is also shown for visually reading the meter readings by a human observer. A third light path (not shown) is provided for internal illumination required for the meter image from the light source provided around position (9). A direct line from the light source through the prism (1) to the meter digit surface is beneficially provided and as a result of design requirement for an even light intensity across the required image. The external faces of the prism (1) at the channel (9) and also optionally at the external devices of the prism have a rough surface which can optionally be coated as part of the enhancement of the even spread of light across the meter digit surfaces.

It is beneficial in the present invention that once the optical viewing system has been installed the image required for transmission for all intents and purposes travels through a substantially single refractive index material all the way from the meter window to the image capture device thus eliminating surface reflection problems.

The present invention is beneficially utilised in an automatic meter reading system. In one embodiment in such a system images of the indicia of the meter are recorded in a data storage device in the optical viewing system. After a pre-determined time period or once a sufficient number of images have been captured this data is transmitted to a data logger which is beneficially physically remote from the optical viewing system. The present invention has been described by way of example only and it will be appreciated by the skilled addressee that modifications and variations may be made without departing from the scope of protection afforded by the appended claims.

Claims

Claims:

1. An optical viewing system comprising an optical device arranged to provide an optical viewing path therethrough for viewing usage information from a utility meter, the system further comprising a meter window optical enhancement material arranged to be positioned between a meter window and the optical device to provide an optical path between a meter window and the optical device.

2. An optical viewing system according to claim 1 wherein the optical enhancement material is arranged to provide a seal inbetween the optical device and a meter window in situ for substantially excluding air in the optical path between a meter window and the optical device.

3. An optical viewing system according to any preceding claim wherein the meter window optical enhancement material is adhered to the optical device, and preferably wherein the meter window optical enhancement material is arranged to adhere to a meter window.

4. An optical viewing system according to any preceding claim wherein the optical enhancement material is substantially transparent.

5. An optical viewing system according to any preceding claim wherein the optical enhancement material has substantially the same refractive index value as the refractive index value of the optical device.

6. An optical viewing system according to any preceding claim wherein the optical enhancement material is a layer provided on a meter facing face of the optical device.

7. An optical viewing system according to any preceding claim wherein the optical enhancement material is a flowable material and preferably has a thickness greater than 0.5mm.

8. An optical viewing system according to any preceding claim wherein the optical enhancement material comprises a polymer, wherein the polymer preferably includes acrylic or may include polycarbonate.

9. An optical viewing system according to any preceding claim wherein the optical device comprises a prism arranged to provide a first and second viewing zone, such that meter usage information can be viewed simultaneously by a human operator and an image capture device.

10. An optical viewing system according to claim 9 wherein the prism comprises a first reflective surface for enabling the first and second viewing zone.

11. An optical viewing system according to any preceding claim wherein the optical device comprises a meter facing face arranged in situ to sit generally parallel to a meter window.

12. An optical viewing system according to claims 10 and 11 wherein the first

reflective surface is provided at an angle of substantially less than 45 degrees relative the meter facing face.

13. An optical viewing system according to claim 12 wherein the first reflective surface is at an angle of substantially between 30 and 40 degrees relative to the meter facing face, and even more preferably is at an angle of substantially 35 degrees relative to the meter facing face.

14. An optical viewing system according to any of claims 9 - 13 wherein the prism includes a second reflective surface arranged to reflect light from the first reflective surface for providing an optical path to the second viewing zone.

15. An optical viewing system according to any preceding claim further comprising a second optical device arranged to be positioned between the first optical device and the optical enhancement material.

16. An optical viewing system according to any preceding claim further comprising a bracket arrangement for securing the optical device to a meter window.

17. An optical viewing system according to any preceding claim further comprising an image capture device for capturing images of the utility meter reading, the optical device configured to accommodate the image capture device.

18. An optical viewing system according to claim 17 further comprising a processor and data storage element.

19. An optical viewing system according to any of claims 17 - 18 further comprising a transmitter for transmitting images from the image capture device to a further location.

20. An automatic meter reading optical viewing system according to any preceding claims.

21. A method of viewing usage information of a utility meter comprising the steps of providing an optical device and positioning a meter window optical enhancement material between a meter window and the optical device to provide an optical path between a meter window and the optical device.

22. A process for restoring the optical transparency of a utility meter window

comprising the steps of applying an optical enhancement material to a meter window and applying pressure from an optical device such that the optical enhancement material adapts to any irregularities in the meter window.