GB2577475A

GB2577475A - Casing for a computing device operable as a barcode scanner

Info

Publication number: GB2577475A
Application number: GB1812956.9A
Authority: GB
Inventors: Rainbow Tony
Original assignee: Falcona Solutions Ltd
Current assignee: Falcona Solutions Ltd
Priority date: 2018-08-09
Filing date: 2018-08-09
Publication date: 2020-04-01
Also published as: GB201812956D0

Abstract

A casing (2, fig 3a) for a computing device (10, fig 3a) has a flashlight (12, fig 3a) and a camera (14, fig 3a). The casing has at least one window (4a, 4b, fig 3a) and a first reflective optical element 30 which is positionable to intercept light emitted through the at least one window from within the casing and is arranged when so positioned to reflect light 62 emitted through the at least one window outwardly from the casing at an angle which is other than normal to a plane containing the window. A second reflective optical element 40 is positionable to direct light through the window into the casing and is arranged when so positioned to receive light 28 from a direction which is antiparallel to the direction of the light reflected by the first reflective optical element and to reflect the light into the casing in a direction which is substantially antiparallel to the direction of the light emitted through the window. The reflective optical elements may be prisms and the casing may be a barcode scanner integrated with a smartphone.

Description

Intellectual Property Office Application No. GII1812956.9 RTM Date:21 January 2020 The following terms are registered trade marks and should be read as such wherever they occur in this document: Android Symbian iOS Windows Bing Intellectual Property Office is an operating name of the Patent Office www.gov.uk /ipo Casing for a Computing Device operable as a Barcode Scanner

Technical Field

The present invention concerns a casing for a computing device, a kit comprising a casing for a computing device and an inductive charging cradle, a barcode scanner comprising a casing for a computing device and a computing device contained inside the casing, and a method of operating a barcode scanner.

Background to the Invention

Many examples of computing devices, such as mobile phones and tablet computers, now comprise a flashlight and a camera, which are primarily intended for recording still and/or moving images. However, some such computing devices which comprise a flashlight and a camera may also be used for reading barcodes by being loaded with barcode-reading software as well. Such barcodes may include linear one-dimensional barcodes, as well as more complicated matrix or two-dimensional barcodes, such as quick response (QR) codes.

For example, mobile phones and tablet computers which use the AndroidTM operating system of Google Inc. can read barcodes using the Goggles' application of Google Inc. The Symbian' operating system of Nokia Corporation features a barcode scanner which can be used to read barcodes. The iQSTM operating system of Apple Inc. does not currently include barcode-reading software, but there are more than fifty barcode-reading applications available which are compatible with this operating system. The WindowsTM Phone 8TM operating system of Microsoft Inc. is also able to scan barcodes through the BingTM search app.

It is also known to place computing devices, such as mobile phones and tablet computers, into casings to protect the computing devices from wear and tear and accidental damage during their use. If the computing device comprises a flashlight and a camera, such a casing may typically comprise at least one window to expose the flashlight and the camera of the computing device to the environment when the computing device is inside the casing.

However, since the flashlight and the camera of computing devices which comprise such a flashlight and a camera, are primarily intended for recording still and/or moving images, rather than for reading barcodes, which use is therefore only a subsidiary function of such computing devices, the flashlight and camera are also optimized for recording still and/or moving images and are not particularly well adapted to reading barcodes instead. In particular, the flashlight and camera of such computing devices are typically mounted in or on a generally flat major surface of such a computing device and face forwards perpendicular to that surface, in order to respectively illuminate and record a scene which can be viewed on a visual display of the computing device located on an opposite side of the computing device from that major surface. This entails that the computing device must be held by a user in such a manner as to point the flashlight and camera at a target to be imaged and to view the visual display. For example, in the case of a tablet computer, the computing device may be held in two hands, in the manner of a book. Holding a computing device in this manner, however, is ill-suited to reading barcodes and is particularly uncomfortable and inconvenient if it must be maintained for extended periods of time in order to read more than just a small number of barcodes. Such a general-purpose computing device which comprises a flashlight and a camera is therefore not well suited to dedicated use as a barcode scanner.

Object of the Invention An object of the present invention, therefore, is to provide a casing for a computing device which comprises a flashlight and a camera, a kit comprising a casing for such a computing device and an inductive charging cradle, a barcode scanner comprising a casing for such a computing device and such a computing device contained inside the casing, and a method of operating a barcode scanner.

Description of the Invention

Accordingly, in a first aspect, the present invention provides a casing for a computing device which comprises a flashlight and a camera. The casing comprises at least one window and first and second reflective optical elements. The first reflective optical element is positionable to intercept light emitted through the at least one window from within the casing and is arranged when so positioned to reflect light emitted through the at least one window outwardly from the casing at an angle which is other than normal to a plane containing the at least one window. The second reflective optical element is positionable to direct light through the at least one window into the casing and is arranged when so positioned to receive light from a direction which is substantially antiparallel to the direction of the light reflected by the first reflective optical element and to reflect the light thus received into the casing in a direction which is substantially antiparallel to the direction of the light emitted through the at least one window from within the casing.

Thus, a computing device which comprises a flashlight and a camera may be placed inside such a casing, and the first and second reflective optical elements can respectively be used to redirect light from the flashlight and to redirect light reflected by an object which has been illuminated by the flashlight, in order to respectively illuminate and record an object, such as a barcode, which is not directly facing a surface of the computing device on or in which surface the flashlight and camera are mounted. This has the advantage of allowing the casing with the computing device therein to be held in a much more convenient manner for reading barcodes than the computing device could be held without the casing, and in the same or a similar manner to that in which barcode scanners which are not general-purpose computing devices are conventionally held, such as in a pistol grip. This therefore allows a computing device which comprises a flashlight and a camera to be used for extended periods of time as a dedicated barcode scanner for reading large numbers of barcodes without discomfort to a user. On the other hand, a computing device in such a casing still retains its other computing functions which a conventional dedicated barcode scanner does not have, and may therefore also be used for a wide variety of other applications as well. Moreover, the casing helps to protect the computing device from wear and tear and accidental damage during its use as a barcode scanner. To this end, the casing may additionally comprise one or more shock-absorbing elements on its outer surface which are made of a rubber or other elastomeric material, in order to enhance its ruggedness.

The at least one window of the casing may be either a single window or a plurality of separate windows, at least one of which is associated with the first reflective optical element and at least another of which is associated with the second reflective optical element. The at least one window may be a simple aperture or through-hole without any filling, or may alternatively comprise a transparent filling, such as one made of a glass or a plastics material. The first and second reflective optical elements may be separate from each other or may be integrated with each other into a single reflective optical element, which performs the functions of both the first and second reflective optical elements as just described. Separate first and second reflective optical elements may be present in combination with either a single window or with a plurality of separate windows, and a single integrated reflective optical element may also be present in combination with either a single window or with a plurality of separate windows.

The computing device may, for example, be a mobile phone, a tablet computer, a phablet (i.e. a tablet-sized mobile phone), a laptop computer, or any other computing device which comprises a flashlight and a camera.

In a possible embodiment, the at least one window is to expose the flashlight and the camera of the computing device to the environment when the computing device is inside the casing, the first reflective optical element is positionable to intercept light emitted through the at least one window from within the casing by the flashlight, and the second reflective optical element is positionable to direct light through the at least one window into the casing and into the camera.

In some embodiments, the angle which is other than normal to a plane containing the at least one window is substantially parallel to the plane containing the at least one window. This has the advantage of allowing the casing to be held by a user in a manner similar to that of a handheld television remote control, instead of, for example, in the manner of a camera phone. Such a manner of holding the casing is better adapted to rapidly scanning numerous barcodes, and therefore allows more barcodes to be scanned in a shorter time than would otherwise be achievable using, for example, a camera phone without such a casing.

In some embodiments, the first and second reflective optical elements may be jointly movable by sliding between a first position, in which they at least partially occlude the at least one window, and a second position, in which the at least one window is unobstructed by the first and second reflective optical elements. This has the advantage of allowing the computing device to be used for recording still and/or moving images, as well as for scanning barcodes by sliding the first and second reflective optical elements out of the way of the at least one window.

In some embodiments, at least one of the first and second reflective optical elements may comprise a prism arranged to reflect light emitted through the at least one window from within the casing and/or to reflect light through the at least one window into the casing, respectively, by total internal reflection. Whereas a front-surface mirror could instead be used as at least one of the first and second reflective optical elements, using a prism of the type just described has the advantage that such a prism is more robust in repeated use than a front-surface mirror and is also more resistant to damage of the reflective optical surface of a front-surface mirror, for example by scratching.

If so, in some embodiments, the first reflective optical element may be arranged to reflect the light emitted through the at least one window from within the casing such that it exits the first reflective optical element at an angle which is other than normal to an exit face of the prism. In such a case, however, the casing should further comprise an optical filter arranged to transmit the light emitted through the exit face of the prism. For example, the light emitted through the at least one window from within the casing may exit the first reflective optical element at a relatively narrow acute angle relative to the casing (for example, at an angle of less than about 30 degrees away from the casing), and this may be achieved by the light exiting the first reflective optical element at an angle which is other than normal to an exit face of the prism. This would result in the light which exits the first reflective optical element being refracted at the exit face of the prism. If the light is white light, as is typically the case for light from a flashlight, different wavelengths of the light would therefore be differentially refracted, resulting in dispersion of the light into a spectrum. Providing an optical filter which is arranged to transmit the light emitted through the exit face of the prism results in only a selected waveband of this light being transmitted. This therefore has the advantage of allowing a user to see a more sharply defined single beam of the light transmitted from the flashlight, which is substantially monochromatic, rather than a spread spectrum of light of different colours, thereby allowing the user to direct such a beam accurately onto a barcode, as well as allowing the camera of the computing device to detect the barcode more easily and accurately due to its uniform monochromatic illumination.

If so, the optical filter preferably transmits a waveband of light in the green part of the visible spectrum. By the green part of the visible spectrum is meant light of a wavelength of from about 490 nm to about 580 nm, inclusive, preferably from about 495 nm to about 570 nm, and more preferably from about 500 nm to about 560 nm. This has several advantages, as follows. Firstly, it is in the middle of the visible spectrum for the human eye, so is easy to see.

Secondly, it was found by the present inventors that optical filters in the red or blue parts of the visible spectrum block too much of the white light from the type of flashlight which is typically found in mobile phones, tablet computers and phablets to be easily seen in most circumstances. Thirdly, it also has the advantage that if the light emitted from within the casing is white light, the beam of light which is transmitted by the filter will then be in the middle, geometrically speaking, of the different wavelengths of the light which are differentially refracted at the exit face of the prism.

In some embodiments, the casing may further comprise a refractive optical element which is positionable in front of an exit face of the first reflective optical element to focus light emitted through the at least one window from within the casing into a line. This has the advantage of making the light emitted from within the casing most suitable for reading a linear one-dimensional barcode.

If so, the refractive optical element may be a piano-cylindrical lens. This has the advantage that such a lens comprises a plane face which may be fixed to the exit face of the first reflective optical element to make an integrated whole. In other possible embodiments, however, the refractive optical element may instead be a cylindrical rod. The focal length of any such lens may preferably be chosen to bring the light emitted from within the casing to a focus at a distance of between about 100 mm and 500 mm from the casing.

If the casing does comprise a refractive optical element which is positionable in front of an exit face of the first reflective optical element as well as an optical filter, the refractive optical element may comprise the optical filter. In other words, the refractive optical element may be given the characteristics of an optical filter, for example by colouring the refractive optical element appropriately. This has the advantage of combining the refractive optical element and the optical filter into a single element, thereby reducing the manufacturing cost and complexity of the casing.

In some embodiments, at least one of the first and second reflective optical elements may be mounted in a light-guiding passage which is open at both ends. This has the advantage in the case of the first reflective optical element that whereas the light emitted by a flashlight of a computing device may typically be projected over most of a hemisphere, the light thus emitted may instead be concentrated in such an embodiment into a brighter beam, which a user may therefore direct more accurately onto a barcode, which therefore also allows the camera of the computing device to detect the barcode more easily and accurately. It also has the advantage in the case of the second reflective optical element of obstructing the entry of extraneous environmental light into the second reflective optical element by preferentially allowing only light from the barcode to enter the second reflective optical element.

If so, in some embodiments, the second reflective optical element may be mounted in such a light-guiding passage which is flared in a direction away from the at least one window. This has the advantage of increasing the angle of view of the second reflective optical element, for example allowing it to see more than just a partial or small area of a barcode which is close to the light-guiding passage, whilst still obstructing the entry of extraneous environmental light into the second reflective optical element. If so and if the angle other than normal at which light is reflected by the first reflective optical element is substantially parallel to the plane containing the at least one window, the flaring may preferably also be in a plane which is substantially parallel to the plane containing the at least one window. This is particularly advantageous for reading linear one-dimensional barcodes.

In some embodiments, the casing may comprise two half-clamshells, one of which comprises the at least one window and the first and second reflective optical elements referred to above, and the other of which comprises at least a second window. Such an arrangement has the advantage that the at least second window is then positioned on an opposite side of the casing from the at least one window and the first and second reflective optical elements, making the casing suitable for receiving a computing device with a visual display on one side thereof and a flashlight and camera on the opposite side thereof. Thus the at least second window may be to expose a visual display of the computing device, such as a touch-sensitive display screen, to the environment when the computing device is inside the casing. The two half-clamshells may be fitted together, for example, by clicking them shut or by being screwed together.

In some embodiments, the casing may comprise an inductive charging loop contained therein. The inductive charging loop may be for electrical connection to a power supply input of the computing device when the computing device is inside the casing. This has the advantage of allowing the computing device to be charged and recharged without having to be removed from the casing and without having to provide the casing with a further aperture to expose the power supply input of the computing device to the environment. This increases the durability of the computing device and reduces its susceptibility to ingress of dust and dirt and consequent damage during heavy use.

In a second aspect, therefore, the present invention also provides a kit comprising a casing comprising an inductive charging loop contained inside the casing and an inductive charging cradle, which is adapted to receive the casing.

In a third aspect, the present invention also provides a barcode scanner comprising a casing as described herein and a computing device comprising a flashlight and a camera contained inside the casing, wherein the computing device is loaded with barcode-reading software.

In a fourth aspect, the present invention also provides a method of operating a barcode scanner, the method comprising: providing a casing as described herein; providing a computing device having a flashlight and a camera, wherein the computing device is loaded with barcode-reading software; putting the computing device inside the casing such that the flashlight and the camera of the computing device are exposed by the at least one window of the casing; positioning the first and second reflective optical elements to at least partially occlude the at least one window; using the first and second reflective optical elements to direct light from the flashlight onto a barcode and to direct light reflected by the barcode into the camera; and operating the barcode-reading software to read the barcode.

In a possible embodiment, the method may further comprise moving the first and second reflective optical elements out of the way of the at least one window; and using the camera to record a still or moving image. If so, the flashlight may also be used to illuminate the scene being recorded. This has the advantage that the barcode scanner may therefore also be used as an image recording device.

In some embodiments, if the casing comprises an inductive charging loop contained therein, which inductive charging loop is for electrical connection to a power supply input of the computing device when the computing device is inside the casing, the method may further comprise: electrically connecting the inductive charging loop to the power supply input of the computing device when the computing device is inside the casing; providing an inductive charging cradle adapted to receive the casing; placing the casing with the computing device inside the casing in the inductive charging cradle; and charging the computing device from the inductive charging cradle through the casing via the inductive charging loop contained therein.

Brief Description of the Drawings

Further features and advantages of the present invention will become apparent from the following detailed description, which is given by way of example only and in association with the accompanying drawings, in which: Fig. 1A is a schematic plan view of a first face of an example of a computing device comprising a flashlight and a camera; Fig. 1B is a schematic plan view of a second face, opposite to the first face, of the computing device shown in Fig. 1A; Fig. 2A is a schematic orthographic view of the computing device shown in Figs. 1A and 1B; Fig. 2B is a schematic side elevational view of the computing device shown in Figs. 1A to 2A; Fig. 3A is a schematic plan view of a first face of an embodiment of a casing containing the computing device of Figs. 1A to 2B, wherein the casing is shown in a first state; Fig. 3B is a schematic plan view of the first face of the casing shown in Fig. 3A, wherein the casing is shown in a second state; Fig. 4 is a schematic plan view of a second face, opposite to the first face, of the casing shown in Figs. 3A and 3B; Fig. SA is a schematic side elevational view of a sliding member of the casing shown in Figs. 3A to 4, viewed from the direction of arrow B in Fig. 3B; Fig. 5B is a schematic plan view of a first face of the sliding member shown in Fig. SA; Fig. 5C is a schematic plan view of an underside of the sliding member of Fig. 5A, opposite to the first face shown in Fig. 5B; Fig. 5D is a schematic explanatory diagram of the sliding member shown in Figs. 5A to SC, viewed from the first face thereof; Fig. 6A is a schematic orthographic view of a first reflective optical element and a refractive optical element both contained within the sliding member of Figs. 5A to SD; Fig. 6B is a schematic side elevational view of the first reflective optical element and the refractive optical element shown in Fig. 6A; Fig. 7A is a schematic orthographic view of a second reflective optical element contained within the sliding member of Figs. SA to 5D; Fig. 7B is a schematic side elevational view of the second reflective optical element shown in Fig. 7A; Fig. 8 is a schematic orthographic view of an embodiment of an inductive charging cradle adapted to receive the casing shown in Figs. 3A to 4; and Fig. 9 is a flow diagram schematically representing an embodiment of a method of operating a barcode scanner.

Detailed Description

Figs. 1A and 1B show an example of a computing device 10 which comprises a flashlight 12 and a camera 14. The flashlight 12 and the camera 14 are situated on a first major surface of the computing device 10, which a user of the device would normally consider to be a rear face of the device 10. In this example, the computing device 10 is a mobile phone, but in other possible examples, the computing device 10 could instead be a tablet computer, a phablet (i.e. a tablet-sized mobile phone), a laptop computer or some other computing device comprising a flashlight and a camera. As may be seen in Fig. 1B, the computing device 10 also comprises a touch-sensitive display screen 16 situated on a second major surface of the computing device 10, which is opposite to the first major surface and which a user of the device would normally consider to be a front face of the device 10. In this example, the computing device 10 also comprises a button 18 situated on this second major surface of the computing device 10. The touch-sensitive display screen 16 and button 18 together constitute a user interface of the computing device 10, which a user of the device 10 may use to enter commands to the computing device 10, for example in response to information displayed on the display screen 16.

As shown in Fig. 2A, the computing device 10 may be used to record still and/or moving images with the camera 14. The flashlight 12 may also illuminate the scene being recorded depending on ambient lighting conditions. If so, light from the flashlight 12 is generally projected over most of a hemisphere bounded by the first major surface of the computing device 10 on which the flashlight 12 is mounted. However, the greatest intensity of the light from the flashlight is projected forwards from the first major surface in the direction indicated by the arrow A in Fig. 2B, which is perpendicular or normal to the first major surface. Equally, the camera 14 also points in the direction of the arrow A, so that the centre of the scene captured by the camera is transected by the arrow A. Figs. 3A, 3B and 4 show an embodiment of a casing 2 containing the computing device 10 of Figs. 1A to 2B. Referring firstly to Fig. 3A, it may be seen that the casing 2 comprises a pair of windows 4a and 4b, which respectively expose the flashlight 12 and the camera 14 of the computing device 10 to the environment. The casing 2 also comprises a sliding member 6, which is able to slide in a recess 8 formed in an outer surface 20 of the casing 2. The sliding member 6 is shown in a first position in Fig. 3A, in which the windows 4a, 4b are unobstructed by the sliding member 6, and a second position in Fig. 3B, in which the windows 4a, 4b are occluded by the sliding member 6. Fig. 3B also shows in dashed outline an inductive charging loop 22, which is contained within the casing 2 along with the computing device 10 and which is electrically connected to a power supply input 26 of the computing device 10 via a ribbon cable 24. The inductive charging loop 22 therefore allows the computing device 10 to be charged through the casing 2 without having to remove the computing device 10 from the casing 2. As may be seen in Fig. 4, the casing 2 also comprises a further window 4c on the opposite side of the casing 2 from the windows 4a, 4b and the sliding member 6, which exposes the display screen 16 of the computing device 10 to the environment. This further window 4c may be a simple aperture or through-hole without any filling, or may alternatively comprise a transparent filling, such as one made of a glass or a plastics material, depending on whether the application for which the casing is intended requires the touch sensitivity of the display screen 16 to be retained or not. The casing 2 is formed from two half-clamshells, one of which comprises the pair of windows 4a, 4b and the first and second reflective optical elements 30, 40, and the other of which comprises the further window 4c. The two half-clamshells click firmly together shut, with the computing device 10 and the inductive charging loop 22 inside.

Figs. 5A to SD show the sliding member 6 in greater detail. The sliding member 6 contains first and second reflective optical elements 30, 40. The first reflective optical element 30 is positionable by sliding the sliding member 6 into the position shown in Fig. 3B to intercept light emitted through the window 4a from within the casing 2. When the first reflective optical element 30 is so positioned, it reflects light emitted through the window 4a outwardly from the casing 2 at an angle which is other than normal to a plane containing the at least one window 4a, in other words at an angle other than in the direction indicated by the arrow A in Fig. 2B. This path of the light from the flashlight 12 is represented in the side view of Fig. 5A by the dashed line 62. As may be seen from Fig. 5A, in the illustrated embodiment, the angle other than normal to the plane containing the window 4a is substantially parallel to the plane which contains the window 4a. Thus the casing 2 can be held by a user in a manner similar to that of a handheld television remote control.

Conversely, the second reflective optical element 40 is positionable by sliding the sliding member 6 into the position shown in Fig. 3B to direct light through the window 4b into the casing 2 and therefore into the camera 14. When the second reflective optical element 40 is so positioned, it receives light from a direction which is substantially antiparallel to the direction of the light reflected by the first reflective optical element 30 and reflects the light thus received into the casing 2 in a direction which is substantially antiparallel to the direction of the light emitted through the window 4a from within the casing 2, in other words antiparallel to the dashed line 62 shown in Fig. SA.

Fig. SB is a more detailed view of a first, outer face of the sliding member 6. As may be seen in Fig. SB, this face of the sliding member 6 comprises a finger grip 70 for sliding the sliding member 6 in the directions indicated in Fig. 5B by the double-headed arrow C-C'. The same outer face of the sliding member 6 also contains three apertures 66a, 66b, 66c, which are each mouths at one end of three respective passages. Fig. SC shows the underside of the sliding member 6 of Fig. SA, opposite to the first face thereof shown in Fig. SB. As may be seen in Fig. 5C, this face of the sliding member 6 comprises two apertures 64a, 64b, which are mouths at the other end of only two of the three respective passages just referred to. Fig. SD shows how the apertures in Fig. 5B connect with the apertures in Fig. SC by means of dashed lines, which represent passages in the interior of sliding member 6. As may be seen in Fig. SD, aperture 66a on the first face of the sliding member 6 connects with the aperture 64a on the underside thereof via a light-guiding passage 68a. Aperture 66b on the first face of the sliding member 6 connects with the aperture 64b on the underside thereof via a light-guiding passage 68b. The first reflective optical element 30 is mounted within the light-guiding passage 68a above the aperture 64a and the second reflective optical element 40 is mounted within the light-guiding passage 68b above the aperture 64b. Thus when the sliding member 6 is positioned as shown in Fig. 3B, the apertures 64a and 64b respectively align with the windows 4a, 4b and the first and second reflective optical elements 30, 40 occlude the respective windows 4a, 4b. Aperture 66c, on the other hand, is the mouth of a blind passage 68c, which does not have a mouth on the underside of the sliding member 6. Aperture 66c is provided on the first face of the sliding member 6 for aesthetic reasons, to make the sliding member 6 appear more symmetrical.

As may also be seen from Fig. SD, the light-guiding passage 68b is flared in a direction away from the window 4b. The flaring is in a plane which is substantially parallel to the plane containing the window 4b, in other words, substantially parallel to the plane of the aperture 64b. This increases the angle of view of the camera 14 through the light-guiding passage 68b in the same direction.

Figs. 6A and 6B show the first reflective optical element 30 in greater detail. The first reflective optical element 30 is a prism which has an entry face 32, an exit face 34 and a reflective surface 36 for total internal reflection of light along the path represented by the dashed line 62. In one possible exemplary embodiment, the entry and exit faces 32, 34 may each have dimensions of about 10 mm by about 10 mm square. In this example, the angles labelled a, b, c, d in Fig. 6B are respectively substantially equal to 135, 75, 45 and 105 degrees. The exit face 34 is therefore angled at approximately 15 degrees from perpendicular to the entry face 32. A principal ray which exits the first reflective optical element 30 along the path 62 therefore leaves the exit face 34 of the prism at an angle, f, of about 60 degrees, the angle labelled e therefore being about 120 degrees. The actual values of the angles e and f depend on the refractive index of the first reflective optical element 30. Since the angles e and f are other than normal to the exit face 34 of the prism 30, white light exiting the first reflective optical element 30 will be subject to differential refraction, or dispersion, into a spectrum, with some wavelengths being refracted more than others. The sliding member 6 of the casing 2 therefore further comprises an optical filter 50, which transmits a waveband of light in the green part of the visible spectrum. This optical filter 50 is arranged adjacent the exit face 34 of the prism 30 to transmit the light 62 emitted through the exit face 34. The optical filter 50 filters out light of other wavelengths and only transmits light which, being substantially monochromatic, is also only refracted in a single direction, namely the direction indicated by the dashed line 62.

In the illustrated embodiment, the optical filter 50 is also a piano-convex lens, which is cemented to the exit face 34 of the first reflective optical element 30. This focusses the transmitted light into a line, which is suitable for illuminating a linear, one-dimensional 20 barcode.

Figs. 7A and 7B show the second reflective optical element 40 in greater detail. The second reflective optical element 40 has an entry face 42, an exit face 44 and a reflective surface 46 for total internal reflection of light along the path represented by the dashed line 28. The second reflective optical element 40 is substantially the same in construction as the first reflective optical element 30, with substantially the same angles a, b, c, d, e, f, and substantially the same dimensions. However in this case, light travels in the opposite direction through the second reflective optical element 40, that is in the direction indicated in Figs. 7A and 7B by the dashed line 28. Since light reflected from a barcode which has been illuminated by the flashlight 12 has already been rendered monochromatic by its passage through optical filter 50, there is no need for any further filtering of the light thus reflected to ensure its uniform refraction when it enters the entry face 42 of the second reflective optical element 40.

Fig. 8 shows an embodiment of an inductive charging cradle 70 for the casing 2 shown in Figs. 3A to 4. The inductive charging cradle 70 comprises a recess 72, the shape of which is adapted to receive the casing 2, as well as a mains cable 74, which is able to supply the charging cradle 70 with electrical power from a mains supply. When the casing 2 containing the computing device 10 is placed in the recess 72 of the inductive charging cradle 70, the computing device 10 can be electrically charged or recharged from the mains supply via the inductive charging loop 22 within casing 2 shown in Fig. 3B. The inductive charging cradle 70 and the casing 2 with the inductive charging loop 22 inside it therefore together constitute a kit, which can be used to turn a computing device 10 which has a flashlight 12 and a camera 14 into a dedicated barcode scanner if the computing device 10 is loaded with barcode-reading software.

Thus, an embodiment of a barcode scanner according to the invention comprises a casing 2 of the type described above and shown in Figs. 3A to 4 with a computing device 10 comprising a flashlight 12 and a camera 14 contained inside the casing 2, wherein the computing device is loaded with barcode-reading software.

Fig. 9 is a flow diagram schematically representing an embodiment of a method 80 of operating a barcode scanner. The method 80 comprises providing 81 a casing, such as the casing 2 shown in Figs. 3A to 4. The method 80 also comprises providing 82 a computing device 10 having a flashlight 12 and a camera 14, wherein the computing device 10 is loaded with barcode-reading software. The method 80 comprises putting 83 the computing device 10 inside the casing 2, such that the flashlight 12 and the camera 14 of the computing device 10 are exposed by the respective windows 4a, 4b of the casing 2, and positioning 84 the first and second reflective optical elements 30, 40 to at least partially occlude the windows 4a, 4b, for example by sliding the sliding member 6 to the position shown in Fig. 3B. The method 80 then comprises using 85 the first and second reflective optical elements 30, 40 to direct light from the flashlight 12 onto a barcode and to direct light reflected by the barcode into the camera 14, and operating 86 the barcode-reading software to read the barcode. The embodiment of the method 80 represented in Fig. 9 also comprises moving 87 the first and second reflective optical elements 30, 40 out of the way of the at least one window 4a, 4b, and using 88 the camera 14 to record a still or moving image.

The illustration of a particular order to the blocks in Fig. 9 does not necessarily imply that there is a required or preferred order for the blocks, and the order and arrangement of the block may be varied. Furthermore, it may be possible for some of the blocks to be omitted.

Although embodiments of the present invention have been described above with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed.

Features described in the preceding description may be used in combinations other than in the combinations explicitly described.

Although functions have been described with reference to certain features, those functions may be performable by other features, whether described or not.

Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention which are believed to be of particular importance, it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings, whether or not particular emphasis has been placed thereon.

Claims

Claims 1. A casing (2) for a computing device (10) comprising a flashlight (12) and a camera (14), the casing (2) comprising: at least one window (4a, 4b); a first reflective optical element (30) positionable to intercept light emitted through the at least one window (4a) from within the casing (2), the first reflective optical element (30) being arranged when so positioned to reflect light emitted through the at least one window (4a) outwardly from the casing (2) at an angle other than normal to a plane containing the at least one window (4a); and a second reflective optical element (40) positionable to direct light through the at least one window (4b) into the casing (2), the second reflective optical element (40) being arranged when so positioned to receive light from a direction substantially antiparallel to the direction of the light reflected by the first reflective optical element (30) and to reflect the light thus received into the casing (2) in a direction substantially antiparallel to the direction of the light emitted through the at least one window (4a) from within the casing (2).
2. A casing according to claim 1, wherein: the at least one window (4a, 4b) is to expose the flashlight (12) and the camera (14) of the computing device (10) to the environment when the computing device (10) is inside the casing (2); the first reflective optical element (30) is positionable to intercept light emitted through the at least one window (4a) from within the casing (2) by the flashlight (12); and the second reflective optical element (40) is positionable to direct light through the at least one window (4b) into the casing (2) and into the camera (14).
3. A casing according to claim 1 or claim 2, wherein the angle is substantially parallel to the plane containing the at least one window (4a, 4b).
4. A casing according to any one of the preceding claims, wherein the first and second reflective optical elements (30, 40) are jointly movable by sliding between a first position (Fig. 3B) in which they at least partially occlude the at least one window (4a, 4b) and a second position (Fig. 3A) in which the at least one window (4a, 4b) is unobstructed by the first and second reflective optical elements (30, 40).
S. A casing according to any one of the preceding claims, wherein at least one of the first and second reflective optical elements (30, 40) comprises a prism arranged to reflect light emitted through the at least one window (4a) from within the casing (2) and/or to reflect light through the at least one window (4b) into the casing (2), respectively, by total internal reflection.
6. A casing according to claim 5, wherein the first reflective optical element (30) is arranged to reflect the light emitted through the at least one window (4a) from within the casing (2) to exit the first reflective optical element at an angle (f) other than normal to an exit face (34) of the prism, and the casing (2) further comprises an optical filter (50) arranged to transmit light emitted through the exit face (34) of the prism.
7. A casing according to claim 6, wherein the optical filter (50) transmits a waveband of light in the green part of the visible spectrum.
8. A casing according to any one of the preceding claims, further comprising a refractive optical element (50) positionable in front of an exit face (34) of the first reflective optical element (30) to focus light emitted through the at least one window (4a) from within the casing (2) into a line.
9. A casing according to claim 8, wherein the refractive optical element (50) is a piano-cylindrical lens.
10. A casing according to claim 8 or claim 9, when either claim is dependent on claim 6 or claim 7, wherein the refractive optical element (50) comprises the optical filter.
11. A casing according to any one of the preceding claims, wherein at least one of the first and second reflective optical elements (30, 40) is mounted in a light-guiding passage (68a, 68b) open at both ends.
12. A casing according to claim 11, wherein the second reflective optical element (40) is mounted in such a light-guiding passage (68b) which is flared in a direction away from the at least one window (4b).
13. A casing according to claim 12 as dependent on claim 3, wherein the flaring is in a plane which is substantially parallel to the plane containing the at least one window (4a, 4b).
14. A casing according to any one of the preceding claims, comprising two half-clamshells, one of which comprises the at least one window (4a, 4b) and the first and second reflective optical elements (30, 40), and the other of which comprises at least a second window (4c).
15. A casing according to claim 14, wherein the at least second window (4c) is to expose a visual display (16) of the computing device (10) to the environment when the computing device (10) is inside the casing (2).
16. A casing according to any one of the preceding claims, comprising an inductive charging loop (22) contained therein.
17. A casing according to claim 16, wherein the inductive charging loop (22) is for electrical connection to a power supply input (26) of the computing device (10) when the computing device (10) is inside the casing (2).
18. A kit comprising a casing according to claim 16 or claim 17 and an inductive charging cradle (70) adapted to receive the casing (2).
19. A barcode scanner comprising a casing (2) according to any one of claims 1 to 17 and a computing device (10) comprising a flashlight (12) and a camera (14) contained inside the casing (2), wherein the computing device (10) is loaded with barcode-reading software.
20. A method (80) of operating a barcode scanner, the method comprising: providing (81) a casing (2) according to any one of claims 1 to 17; providing (82) a computing device (10) having a flashlight (12) and a camera (14), wherein the computing device (10) is loaded with barcode-reading software; putting (83) the computing device (10) inside the casing (2) such that the flashlight (12) and the camera (14) of the computing device (10) are exposed by the at least one window (4a, 4b) of the casing (2); positioning (84) the first and second reflective optical elements (30, 40) to at least partially occlude the at least one window (4a, 4b); using (85) the first and second reflective optical elements (30, 40) to direct light from the flashlight (12) onto a barcode and to direct light reflected by the barcode into the camera (14); and operating (86) the barcode-reading software to read the barcode.
21. A method according to claim 20, further comprising: moving (87) the first and second reflective optical elements (30, 40) out of the way of the at least one window (4a, 4b); and using (88) the camera (14) to record at least one of a still and moving image.
22. A method according to claim 20 or claim 21, when either claim is dependent on claim 17, further comprising: electrically connecting the inductive charging loop (22) to the power supply input (26) of the computing device (10) when the computing device (10) is inside the casing (2); providing an inductive charging cradle (70) adapted to receive the casing (2); placing the casing (2) with the computing device (10) inside the casing (2) in the inductive charging cradle (70); and charging the computing device (10) from the inductive charging cradle (70) through the casing (2) via the inductive charging loop (22) contained therein.