The invention relates to a portable magnifying camera for the visual disabled person. More particularly, the invention relates to a portable camera for recording and displaying an image of an object such as printed paper, wherein the camera is arranged to be positioned on an object to be recorded wherein the cameras is provided with an outer lower surface which is arranged and intended to be in contact with the object if the camera is positioned on the object, a light sensitive sensor for obtaining an image of at least a portion of the object, a display and processing means for processing the image obtained by means of the sensor and for displaying at least a portion of the recorded image on the display, in possible a magnified form, wherein the camera is provided with at least one lighting unit for lighting the object to be recorded when the camera is positioned on the object.
Such a camera is generally known. The object to be recorded is for example a newspaper which lies on the table. In such a camera, lighting is very important. Important parameters are glare, shadow and gradient on a surface of the object to be recorded. For bigger machines it is possible to place and design the lighting unit in such a way that the intensity of the light is spread evenly over a surface to be recorded. When designing compact magnifiers, the lighting is always a problem because the proximity of the lighting unit causes light spots on the object to be recorded as well as glare. Thus a problem is that light which is emitted by the lighting unit is reflected by a glossy surface to be recorded by the camera towards the sensor so that the sensor can “see” the lighting unit as an image. In the past this has been solved by using indirect or concealed lighting causing a more uniform incidence. In practice this means diffuse reflection: the lighting unit shines on a frosted white surface and then reflects on the object to be recorded. Another well-known solution is adding a diffuser in between the object to be recorded and the lighting unit. This will result in a diffuse light source which will minimize shadow and light spots, thus resulting in an evenly illuminated object to be recorded. A draw-back in this design is however a lot of loss of efficiency. This is caused by the fact that the light is partly blocked by the diffuser. Another draw-back is that the light diffuse surface (reflector or translucent) will act as a new light source although bigger and spreading “softer” light. The proximity problem (glare) in compact design however remains, now with a bigger surface of light. Therefore, on reflective objects to be recorded, like glossy paper, the diffuser will still be reflected as an outline of surface that is overexposed on the object area. This will have an impact on black and white tones on the object. This again will result in problems when enhancing the image in high contrast pictures, for example, when the image is translated in black and white only. The overexposed area will be translated in white, masking the more subtle grey tones “underneath”. A bigger diffusion (for example twice as big as the object area) to prevent this phenomenon is not a solution, because such a diffuser would be too big for a portable camera.
It is an object of the invention to provide a solution to at least one of the above referred to draw-backs.
According to the invention, the camera is arranged such that light rays of the at least one lighting unit which are, in use, submitted to the object are directly submitted to the object, possibly via a mirror and/or a lens, wherein the lighting unit is arranged within the camera on a position relative to the sensor such that if the object which is recorded would be a flat mirror whereon the camera is positioned for recording the reflective surface of the flat mirror (so that the reflective surface of the flat mirror faces the sensor), the lighting unit is located outside a viewing field of the sensor which viewing field is formed in combination with the flat mirror. It further holds that the flat mirror is sufficiently large so that it extends through the full viewing field of the sensor. This means that the full viewing field is mirrored by the flat mirror for defining the position of the lighting unit relative to the sensor. Because the light source is placed in an area where the sensor cannot see it, the problem of glare cannot occur. Also a more even distribution of light on the object can be realized. Of course the mirror itself does not belong to the camera. The mirror is merely used for defining the position of the lighting unit relative to the sensor wherein this position is independent from the presence or absence of the mirror. In other words, because the light source is placed in an area where the sensor cannot see it if the mirror would be present, the problem of glare cannot occur if other objects having a (somewhat) reflective surface are recorded. Alternatively according to the invention the camera is arranged such that light rays of the at least one lighting unit which are, in use, submitted to the object are directly submitted to the object, possibly via a mirror and/or a lens, wherein the lighting unit is arranged within the camera on a position relative to the sensor such that the lighting unit is located outside a viewing field of the sensor which viewing field would be formed in combination with a virtual flat mirror extending in a virtual flat plane extending through the lower outer surface wherein a reflective surface of the mirror faces the sensor. Again it further holds that the virtual flat mirror is sufficiently large so that it extends through the full viewing field of the sensor. This means that the full viewing field is mirrored by the flat mirror for defining the position of the lighting unit relative to the sensor. Because the light source is placed in an area where the sensor cannot see it, the problem of glare cannot occur. Also a more even distribution of light on the object can be realized. Preferably, the camera is provided with at least one light mirror for folding up the light path which extends from the at least one lighting unit to the flat mirror. Because the light path may be folded up, the optical distance between the lighting unit and the object to be recorded can be made bigger without having a negative impact on the size of the portable magnifying camera as such. Such a relatively bigger optical distance between the light and the object, will result in the black and white tones to be eliminated more evenly relative to the situation when there is a relative small optical distance between the lighting unit and the object.
Preferably, it holds that the sensor is provided with an optical axis wherein, in use, the at least one lighting unit is positioned within a lighting unit plane which is perpendicular to the optical axes wherein the lighting unit plane lies between the sensor and a virtual flat plane through which the lower outer surface extends. In this way the portable magnifying camera can be made of a compact design.
According to a preferred embodiment it holds that the camera is provided with a first body portion, a second body portion and a hinge means for connecting the first body portion and the second body portion together wherein the first body portion can move relative to the second body between a folded condition and an unfolded working condition for use of the camera, wherein the second body portion is provided with the sensor and the first body portion is provided with the lighting unit and wherein in the working condition there is a distance between the first body portion and second body portion. In this way the camera can be positioned in a folded condition so that it becomes relatively compact and can be carried easily by the visually handicapped person. For example, the camera may have such a size that it can be positioned in a pocket of a jacket or trousers.
Preferably it holds that the first body portion is arranged to be positioned on the object to be recorded. In that case the first body portion may comprise the outer lower surface. The lighting unit may be arranged to submit light in a direction of the second body portion if the camera is in the folded condition. Preferably, it holds that if the camera is in the unfolded condition, in use, the second body portion extends above the first body portion. In that manner, the portable magnifying camera can be easily positioned on a flat surface which is, for example, provided with a paper to be recorded. Preferably it holds that the real mirror is formed by an outer surface of the second body portion wherein, if the camera is in the unfolded condition, in use, the mirror faces downwardly. Preferably it holds that the second body portion is provided with a display, wherein the display and the mirror lie on opposite sides of the second body part. Preferably it holds that if the camera is in the folded condition, the mirror lies against a surface of the first body part which surface lies opposite the surface of the first body part which forms said outer lower surface.
As indicated above light rays of the lighting unit are transmitted directly to the object, possibly via a mirror and/or a lens. Hence direct transmission of these light rays means that these light rays are not diffused by reflection on, for example, a frosted wall and/or are not diffused by transmission through, for example, a diffuser. Transmission of the light rays through a lens (which provides specular transmission, e.g. conversion and/or diversion of the light beams) or reflection of the light rays on a mirror (which provides specular reflection of the light beams) is however considered as direct transmission of the light rays. In other words: the above mentioned light rays of the lighting unit may be transmitted directly to the object wherein it is also possible that the above mentioned light rays are transmitted to the object via at least one mirror and/or via at least one lens.
It is another object of the invention to provide a portable camera which may be used for different purposes. The portable camera according to this aspect of the invention is characterized in that, the camera is provided with a first body portion, a second body portion and a means for connecting and disconnecting the first body portion and the second body portion, wherein the second body portion is provided with the lighting unit, the sensor and the display and wherein the first body portion is arranged to be positioned on the object to be recorded while the second body portion is connected with the first body portion such that, in use, the first body portion provides a fixed distance between the second body portion and the object to be recorded wherein the first body portion is provided with a side wall surrounding an inner space of the first body portion and a first and second opening lying opposite to each other and each providing visible access to the inner space (if the first body portion and the second body portion are disconnected from each other) wherein if the first body portion and the second body portion are connected together the second opening faces the second body portion and the first opening, in use, faces the object to be recorded such that the sensor can capture an image of the object to be recorded via the second opening, the space and the first opening. Because the first body portion can be disconnected from the second body portion the second body portion can also be used for recording and displaying, for example, an environment of the user or another object if the second body portion is separated from the first body portion. In that mode of use the second body portion need not to be positioned on the object but may simply be hand-held. Because the second body portion is provided with the lighting unit an object or environment to be recorded and displayed by means of the second body portion only, can also be enlightened. It is noted that the portable camera according to this aspect of the invention may, but need not, be also characterized in that the camera is arranged such that light rays of the at least one lighting unit which are, in use, submitted to the object are directly submitted to the object, possibly via a mirror and/or a lens, wherein the lighting unit is arranged within the camera such that if the object which is recorded would be a flat mirror whereon the camera is positioned for recording the reflective surface of the flat mirror, the lighting unit is located outside a viewing field of the sensor which viewing field is formed in combination with the flat mirror.
According to a preferred embodiment the first body portion comprises the outer lower surface. In that case the outer lower surface may comprise the first opening. Preferably the display is inclined relative to the outer lower surface if the second body portion is connected with the first body portion. This provides an easy use if the outer lower portion is positioned on a horizontal surface of an object to be recorded and displayed. According to a special embodiment it holds that if the first body portion is connected to the second body portion a distance between the lighting unit and the outer lower surface is smaller than a distance between the sensor and the outer lower surface. The advantage of the relatively large distance between the sensor and the outer lower surface is that a relative large area of the object can be recorded. The advantage of the relatively small distance between the lighting unit and the outer lower surface is that the object can be lighted efficiently. Preferably the second body portion is provided with a first and second side extending substantially parallel to each other wherein the second side comprises the display and the first side faces the first body portion if the first body portion is connected to the second body portion and/or in that the second body portion has an overall shape of a flat rectangular plate. This enables an easy use of the second body portion if the second body portion is disconnected from the first body portion. Preferably it holds that, the first body portion is provided with a first and second side extending at an angle relative to each other wherein the first side comprises the first opening and the second side comprises the second opening wherein the first side of the second body portion faces the second side of the first body portion if the first body portion is connected to the second body portion. This particular shape of the first body portion provides several advantages: it enables an easy way for the display to be angled relative to the outer lower surface while at the same time the second body portion may have the preferred shape as discussed above. Also the preferred positions of the sensor and the lighting unit relative to the outer lower surface as discussed above can be realised in an easy manner.
According to a advantageous embodiment it further holds that a portion of an inner surface of the first body portion is curved such that, in use, it reflects some of the light emitted by the lighting unit towards the first opening if the first body portion is connected to the second body portion. In this way a more even light distribution over the first opening of the light emitted by the lighting unit can be obtained. This light distribution is at least substantially the sum of the light which is submitted directly from the lighting unit to the first opening and the portion of the light which is reflected by the portion of the curved inner surface towards the first opening. In this respect it preferably holds that the portion of the inner surface is arranged such that the portion of the light emitted by the lighting unit which is reflected by the portion of the inner surface is reflected towards an area of the first opening having a larger distance to the lighting unit than other areas of the first opening, more particularly in that the portion of the inner surface is arranged such that the portion of the light emitted by the lighting unit which is reflected by the portion of the inner surface is reflected towards an area of the first opening having a larger distance to the lighting unit than each other areas of the first opening wherein in particular the area of the first opening having a larger distance to the lighting unit than other areas forms a first halve of the first opening and the other areas form a second halve of the first opening wherein the first halve and the second halve in combination form the first opening. The mentioned areas of the first opening may lie in a virtual plane coinciding with the outer lower surface. Also it may hold that the light rays emitted by the lighting unit which directly illuminates a plane laying in the first opening provide a first distribution of light intensity (for example measured in Lux) in the plane which is not uniform spread over this plane wherein the portion of the inner surface is arranged such that the portion of the light emitted by the lighting unit which is reflected by the portion of the inner surface provides in combination with the light rays which are directly received in the plane a total distribution of light intensity (for example measured in Lux) in the plane which is more uniform spread over this plane than the first distribution. The plane may coincide with the outer lower surface.
Also it may hold that the first opening is provided with a first edge and a second edge laying opposite to each other wherein the lighting unit directly illuminates a plane through the first opening adjacent the first edge with an intensity (for example measured in Lux) which is higher than the intensity by which the plane adjacent the second edge is directly illuminated by the lighting unit and wherein the portion of the inner surface is arranged such that the portion of the light emitted by the lighting unit which is reflected by the portion of the inner surface illuminates the plane adjacent the first edge with an intensity which is lower (including zero intensity) than the intensity by which the plane is illuminated adjacent the second edge by the lighting unit via the portion of the inner surface. Again the plane mat coincide with the outer lower surface. It may also hold that the portion of the inner surface is arranged such that the portion of the light emitted by the lighting unit which is reflected by the portion of the inner surface has a larger intensity on a position laying in the first opening having a larger distance to the lighting unit than other positions laying in the first opening. This intensity may be defined as the intensity of the light at such a position laying in a plane which coincides with the outer lower surface. It may also hold that the portion of the inner surface is arranged such that the portion of the light emitted by the lighting unit which is reflected by the portion of the inner surface increases the intensity of the light more in a first area of the first opening than in a second area of the first opening wherein the intensity of the light in the first area as a result of the light which is directly received from the lighting unit in the first area is lower than the intensity of the light in the second area as a result of the light which is directly received from the lighting unit in the second area, wherein in particular the first area and the second are each form a halve of the first opening and wherein the first area and the second area in combination form the first opening. It may hold that the first area and the second area lay in a plane coinciding with the lower outer surface.
The invention will now be clarified on the basis of the drawing wherein:
In
Furthermore, the camera is provided with a display 10 and processing means 12 for processing the image obtained by means of the sensor 8 and for displaying at least a portion of the recorded image on the display 10 in a possible magnified form. The camera is further provided with at least one lighting unit 14 for lighting the object 4 to be recorded when the camera is positioned on the object. The lighting unit 14 may for example be formed by well-known led's.
According to the invention the lighting unit is located on a special position. As can be seen in
As becomes clear from
On the other hand the light emitted by the lighting unit will lighten directly the object.
As becomes clear from
The camera is arranged such that the light rays of the lighting unit 14 are submitted directly to the object. If there would be any reflection of the light that reaches the object 4 it would be specular reflection only.
In accordance with a preferred embodiment the lighting unit 14 is replaced by a lighting unit 34. Furthermore, in that preferred embodiment the camera is provided with a light mirror 36 for folding up the possible light paths 38 which extends from the at least one lighting unit 34 to the flat mirror 4 (the outer boundaries of the area wherein such folded up light paths extend are indicated by dotted lines 15, 17, 19, 21 and the outer boundaries of the light paths without the light mirror 36 are indicated by dotted lines 23, 25, 19, 21). The light mirror 36 provides specular reflection of the light emitted by the lighting unit that reaches the object. As can be understood from
The sensor 8 is provided with an optical axis 39. The optical axis 39 is the actual axis of the viewing field of the sensor 8 which has the shape of a cone.
As can be seen from
It follows also from
It follows also that the mirror 36 lies between the lighting unit plane 40 and a sensor plane 44 extending through an outer surface 46 of the sensor 8 which outer surface 46 receives the light for recording. The sensor plane 44 is perpendicular to the optical axis 39. In
In
The portable magnifying camera is provided with a first body portion 50, a second body portion 52, and hinge means 54 for connecting the first body portion and the second body portion together. The first body portion can be moved relative to the second body portion between a folded condition as is shown in
Furthermore, the processing means 12 can be arranged in the first body portion 50 and/or the second body portion 52. As becomes clear from
The position of the sensor 8, the mirror 36, the lighting unit 34, and the outer surface 6 in working condition of the practical embodiment as shown in
As is shown in
Based on
The camera according to
The camera is further provided with a first body portion 100, a second body portion 102 and means for connecting and disconnecting the first body portion and the second body portion. The means 104 for connecting and disconnecting the first body portion 100 and second body portion 102 may for example comprise magnets. As schematically indicated, the first body portion 100 may be provided with a first magnet 104A wherein the second body portion 102 is provided with a second magnet 104B wherein in
It is however also possible to disconnect the first body portion and the second body portion from each other so that the second body portion can be used as a hand-held camera. In that case, by means of the sensor 8, an image is captured from the object 4 which is shown on the display 10. This image may be processed by the processing means 12, for example for magnifying the image. At the same time the object 4 may be enlightened by means of the lighting unit 14 for improving the image of the object 4. If the second body portion 102 is hand-held such as shown in
If on the other hand the first body portion and the second body portion are connected to each other, an image of the object 4 can be provided on the display 10 as is shown in
Because, as is shown in
As is shown in
Thus the tilting of the display is realized by the first body portion so that the second body portion when disconnected from the first body portion can have a rectangular shape as discussed above.
As becomes clear from
It becomes clear from
This reflection towards the area 130 may be directly as is shown by light ray 200 of may be indirectly by means of a reflection on another portion 202 of the inner surface as is shown by light ray 204 (see
More particularly it holds that the portion of the inner surface is arranged such that the portion of the light emitted by the lighting unit which is reflected by the portion of the inner surface is reflected towards an area 130 of the first opening having a larger distance to the lighting unit than each other area of the first opening. The above may also hold for other areas such as shown in
It further holds that the portion of the inner surface is arranged such that the portion of the light emitted by the lighting unit which is reflected by the portion of the inner surface has a larger intensity on the position of the first opening having a larger distance to the lighting unit than other positions of the first opening. This position may, for example, lie within the area 130 whereas the other positions lie outside this area.
It further holds that the portion 136 is arranged such that the portion of the light emitted by the lighting unit which is reflected by the portion of the inner surface increases the intensity of the light more in a first area 130 of the first opening than in a second area 132 of the first opening wherein the intensity of the light in the first area as a result of the light which is directly received from the lighting unit in the first area 130 is lower than the intensity of the light in the second area as a result of the light which is directly received from the lighting unit in the second area 132. This also holds for other selections of areas such as shown in
Thereby it is clear that the light reflected by the portion 136 compensates intensity differences between different areas as a result of the direct lighting of these areas by means of the lighting unit 14. In other words it holds that the light rays emitted by the lighting unit which directly illuminates a plane laying in the first opening provide a first distribution of light intensity in the plane 32 which is not uniform spread over this plane wherein the portion of the inner surface is arranged such that the portion of the light emitted by the lighting unit which is reflected by the portion of the inner surface provides in combination with the light rays which are directly received in the plane a total distribution of light intensity in the plane 32 which is more uniform spread over this plane than the first distribution.
This feature of the invention may be further described as follows. The first opening is provided with a first edge 150 and a second edge 152 laying opposite to each other. In fact the first opening is further provided with two opposites edges 154, 156 wherein the edges 150-156 provide the first opening with a rectangular shape. The lighting unit directly illuminates the plane 32 through the first opening adjacent the first edge 150 with an intensity which is higher than the intensity whereby the plane adjacent the second edge 152 is directly illuminated by the lighting unit. Furthermore the portion of the inner surface is arranged such that the portion of the light emitted by the lighting unit which is reflected by the portion of the inner surface illuminates the plane adjacent the first edge 150 with an intensity which is lower than the intensity by which the plane adjacent the second edge 152 is illuminated by the lighting unit via the portion of the inner surface. The portion of the inner surface is arranged such that the portion of the light emitted by the lighting unit which is reflected by the portion of the inner surface is mainly reflected in predetermined directions wherein each of the predetermined directions p (p1, p2) and the outer lower surface enclose an angle γ1, γ2 which is smaller than 90°, preferably smaller than 60° and more preferable smaller than 45° (see
The example is in no matter limited to the disclosed embodiments. Clearly the angle α may have other values as shown in
Also the portable camera may be provided with zoom buttons 140 (
In this example the portable magnifying cameras are arranged for recording streaming video of the object 4 and displaying same on the display 10. This means that if the object is moved relative to the camera, a moving image of the object will be displayed on the display 10. It is however also possible that photos of the object 4 are made and displayed on the display 10.
Furthermore, according to the invention it is possible that the processing means are arranged for recognizing words on the object and converting recognized words into spoken text. The spoken text can be outputted to, for example, a head phone which is connected to the camera. Additionally or alternatively, a Braille display may be operated by means of the camera if the processing means are arranged to recognize words on the object. In accordance with the invention it is also possible that the portable camera is not provided with a display 10. In that case, the processing means 12 may be arranged for converting recognized text on the object into speech as indicated above. Such variations all fall within the scope of the invention.
Number | Date | Country | Kind |
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2006698 | Apr 2011 | NL | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/NL2012/050296 | 4/27/2012 | WO | 00 | 12/17/2013 |