The present invention relates to an adjustable mount for an image projector, a piece of furniture with such an adjustable mount and an image projection system with such a piece of furniture.
In recent years image projectors have gained in popularity both for private and commercial use. In particular, short throw projectors, i.e. projectors projecting the image onto the front projection screen in an acute angle are gaining in popularity, because the system of image projector and projection screen does not take up much space, and is less prone to be blocked by a person in front of the screen, as compared traditional projectors projecting onto the front projection screen at an angle much closer to perpendicular.
If the image projected onto the screen needs to have a good and aesthetically pleasing appearance—and it does, the projected image must hit the front projection screen very precisely. Distorted images, and images projected onto the surface next to the front projection screen are to be avoided. Moreover, for an aesthetical appearance and protection it is furthermore desirable if the image projector can be hidden away when not in use. In this respect, however, the acute projection angle poses some problems in precision, and reproducibility thereof, because it takes much less disturbance of the position of the image projector before the image is distorted and improperly projected onto the front projection screen.
On this background, the present invention sets out to provide a mount which allows the image projector to be precisely positioned with respect to the front projection screen, and in particular precisely positioned in a reproducible manner, even when the image projector is located in a movable manner in a piece of furniture, allowing it to be stowed away when not in use.
According to a first aspect of this disclosure, this object is achieved by an adjustable mount for an image projector, the adjustable mount comprising a base, a platform separated from the base by at least three columns with a generally circular cross-section, and a mounting element adapted for engagement with the image projector, where at least some of the columns are adjustable, so as to define a desired spacing between the base and the platform, where said at least three columns are at a first end connected to one of said platform or said base, and remote from said first end pass through apertures in the other of said platform or said base for adjustable engagement, wherein at least some of said apertures have a geometry with a diameter of an inscribed circle larger than the diameter of the column passing through it.
By providing the three apertures for the three respective columns in these shapes and dimensions, i.e. dimensions larger than the nominal diameter of the columns, it becomes possible to accommodate for changes in the angles of the columns with respect to the base, when their effective lengths are changes, and therefore the base and the platform turn away from being in parallel with respect to each other. In particular, some of the three apertures may be provided with much less precision, e.g. as compared to purely circular apertures, in turn leading to cost reduction. So by allowing the columns to change their angles in this way, it becomes easy to adjust the angle of the platform with respect to the front projection screen in a well-defined manner, simply by adjusting the effective lengths of columns.
According to an illustrative example according to the first aspect of this disclosure the apertures comprise a first aperture with a diameter of the inscribed circle corresponding essentially, i.e. nominally, to the diameter of the column passing through it, a second aperture with a diameter of an inscribed circle larger than the diameter of the column passing through it, a third elongate aperture having a length and a width, where the length is longer than the diameter of the column passing through it and where the width corresponds essentially to the diameter of the column passing through it. This still allows some of the three apertures to be provided with much less precision, as compared to purely circular apertures, while securing and maintaining the adjusted angle of the platform with respect to the front projection screen in and even better defined manner. This may still simply be done by adjusting the effective lengths of columns, and it still leads to a significant cost reduction.
According, to an illustrative example, at least one of the first or second aperture, and possibly both, has a circular shape so that the diameter of the inscribed circle corresponds to the diameter of said first and/or second aperture, or in other words when the geometry of the aperture is circular the inscribed circle is coincident with the periphery of the circular aperture. Circular shaped apertures are easy to provide with great precision in a cost-efficient manner, e.g. by drilling or punching.
According to an illustrative example according to the first aspect of this disclosure, the columns comprise a threaded surface and nuts with a matching thread, so as to adjust an effective length of said columns defining said desired spacing. This provides a simple, efficient and intuitive adjustment.
According to another illustrative example according to the first aspect of this disclosure, biasing springs are provided between said base and said platform. By biasing the base and the platform apart, only one adjustment nut is needed per column to adjust the effective length thereof because the base or the platform, as the case may be, is then retained in one direction along the columns by the biasing spring, and in the other by the nut, which is itself displaceable along the column.
According to another illustrative example according to the first aspect of this disclosure, apertures are provided in the base. This allows the adjustment nuts to be easily accessible, even with the image projector in position on the mounting element.
According to yet another illustrative example according to the first aspect of this disclosure, the mounting element extends in parallel to said platform and said mounting element is adapted to be at least displaceable in parallel with respect to said platform, and wherein at least one releasable securing member is provided. This allows the image projector to be moved forward, backward and sideways with respect to the projections screen, and then be fixed at a desired distance and angle, where the size of the projected image matches the size of the front projection screen, upon which the position, angle etc. may be accurately adjusted by adjustment of the effective length of the columns. In other words, providing a possibility of coarse adjustment before fine adjustment.
According to yet another illustrative example according to the first aspect of this disclosure, the base comprises a further access aperture is adapted to adapted to allow access to the at least one releasable securing member. This allows easy access to readjustment coarse adjustment of the image projector.
According to a second aspect of this disclosure the object is achieved by a piece of furniture provided with an adjustable mount according to any one of the examples above. Thereby it becomes possible to arrange the mount in an easy, well-defined, and preferably inconspicuous manner in close relationship to the front projection screen. The latter is in particular the case when according to an illustrative example of the second aspect of this disclosure, said adjustable mount is provided in a drawer movable with respect to a body of said piece furniture between a closed position and an open position.
According to a further example according to the second aspect of this disclosure, the piece of furniture comprises mutually engaging elements adapted to secure the drawer in the open position. This allows the drawn-out drawer to be arrested in a reproducible, accurate and well-defined position, in turn ensuring the correct positioning of the image projector with respect to the front projection screen when in use.
According to another illustrative example of according to the first aspect of this disclosure, said mutually engaging elements comprise magnets. Magnetic attraction provides a good engagement between the elements which, though it may be overcome by the user pushing the drawer back in after use, suffices to maintain the drawer and hence the image projector in the desired well-defined position.
According to an illustrative example according to the third aspect of this disclosure, there is provided a system comprising a front projection screen and a piece of furniture. This allows the front projection screen to be generally matched to the position of the image projector in advance, e.g. in proper size, and allowing supply of a piece of furniture with an already—at least coarsely, adjusted image projector.
According to another illustrative example according to the third aspect of this disclosure, the front projection screen and the piece of furniture are secured to one and the same wall. This makes the image projection system less prone to external disturbances. That is inter alia to say, with both mounted on the same wall or building structure, it becomes less likely that someone moves the furniture and hence the image projector out of position with respect to the front projection screen, e.g. inadvertently bumping into it or shoving is with a vacuum cleaner or the like. Furthermore, being mounted on the same structure they are more likely to move together, e.g. if the weight of a passing person on the floor causes the wall to move, thus minimizing the disturbance.
The principles of this disclosure are described in greater detail based on non-limiting examples and with reference to the drawings, of which:
Turning first to
Turning now to
As can be seen in
Turning now to
The columns 15, 16, 17 are preferably provided with an external thread. The columns 15, 16, 17, or at least a treaded part thereof, extend though three apertures 25, 26, 27. On the opposite side of the baseplate 12 with respect to the platform 21 the thread is engaged by a corresponding internal thread of a respective nut 28, 29, 30. The nuts 28, 29, 30 thus serve as stops for the baseplate 12 at each column 15, 16, 17 when the baseplate 12 is biased away from the platform 21 by the helical coil springs 18, 19, 20. By turning the nuts 28, 29, 30 the effective length of the columns, i.e. the distance between the baseplate 12 and the platform 21 at each column 15, 16, 17 thereby becomes adjustable. Evidently the force of the springs is adapted to the weight of the image projector to be mounted, so as to ensure the spaced apart position of the baseplate 12 and the platform 21. Also, the force of the springs is adapted to ensure that the columns 15, 16, 17 do not displace themselves laterally in those of the apertures 25, 26, 27 that have larger minimum dimensions than the respective column 15, 16, 17 passing through it. In order to not need any excessive spring force for this, friction elements 39 engaging the baseplate 12 (or the platform 21) are provided. As can best be seen in the exploded view of
As an alternative to the spring biasing, threaded nuts (not shown) could be arranged on the threaded columns 15, 16, 17 between the baseplate 12 and the platform 21. By turning these nuts, the effective length of the columns could be adjusted, and the baseplate 12 (or the platform 21 as the case may be) be biased against these nuts, by means of the nuts 28, 29, 30 to firmly secure the position of the platform 21 with respect to the baseplate 12.
The nuts 28, 29, 30 are preferably finger nuts with a knurled or grooved surface for increased friction, or wingnuts for easy manual operation as they serve to adjust the effective length of the columns 15, 16, 17, and hence the height of the platform 21 over the baseplate at the columns 15, 16, 17. Obviously, other kinds of nuts may be used, e.g. conventional hexagonal nuts. Since the effective length of each of the columns 15, 16, 17 may be individually adjusted, the angle of the platform 21 with respect to baseplate 12 may thereby be adjusted so that the image of the image projector 3 mounted on the adjustable 7 is accurately aligned with the front projection screen 3.
However, in order to coarsely adjust the alignment, as well as the size of the image, the adjustable mount 7 has a further adjustment feature in the form of a mounting element 31 adapted to lie in parallel engagement with the platform 21 and on top of it. The mounting element 31 preferably comprises a sufficiently rigid plate, such as a steel plate, adapted in size with the mounting means of the image projector 3. That evidently depends on the image projector 3, but in one possible example the mounting element is a generally rectangular plate with holes 32 in each corner through which mounting screws 33 may be inserted into corresponding threaded bores in the image projector and tightened for secure engagement with the image projector 3.
Having secured the image projector 3 to the mounting element 31, the mounting element 31 may, guided by a number of bolts 34, be displaced in one direction with respect to the platform 21 along one or more elongated slits 35 provided in the mounting element 31, and in a cross-wise direction thereto along at least one elongated slit 36 provided in the platform 21. The length of the at least one elongated slit 36 is preferably longer than the distance between the slits 35, so as also allow rotary motion of the mounting element 31 with respect to the platform 21. When the desired position and angle is reached, the mounting element 31 may be secured in that position and angle on the platform 21 by means of nuts 37 or the like. To easily access these nuts 37 a large central aperture 14 is provided in the baseplate 12, as will inter alia be apparent from
When the coarse positioning has been effected, the fine positioning may be performed by use to the adjustment nuts 28, 29, 30. However, when the effective lengths of the columns 15, 16, 17 are changed during the fine positioning, the change of the angle of the platform 21 with respect to the baseplate 12 will generally have a tendency to change the angle of the individual columns 15, 16, 17 in an uncontrolled manner. That is to say the columns 15, 16, 17 will be forced towards a position where they are not perpendicular to the baseplate 12 in an uncontrolled manner. One way of countering this would be to manufacture the apertures 25, 26, 27 in the baseplate to a high precision matching closely the diameter of the threaded columns 15, 16, 17. High precision and small tolerances are, however, costly in the manufacture, and according to this disclosure this is instead countered by the use of three apertures differing from each other.
Accordingly, as can be seen in
It should be noted though, that even if for reasons of manufacture circular apertures 26, 27 are preferred, they could in fact be substituted with any suitable geometry in particular regular polygonal shapes, such as triangular, square, pentagonal or even star-shaped. In that case it would obviously not be the diameter, which has to be adapted to the diameter of the column 16, 17, but instead the diameter of the inscribed circle. When, in that case, at least one of the first and second apertures is polygonal, the above dimensions would apply equally to the inscribed circles. It must, however, be emphasized that these values are merely examples, exemplifying the relevant precision.
Thus with the above, a new and inventive solution for mounting an image projector 3 in correct position with respect to a front projection screen 1. This solution provides several aspects of increased precision leading to advantages of not only the involved components but also of the overall system itself.
It should be noted though that what has been described is a set of illustrative examples of the components and system, for which the skilled person will easily see variants without departing from the scope of this disclosure. In particular, the skilled person will understand that deviations from the rectangular and triangular shapes if the baseplate 12, mounting element 31 and platform 21 are possible. Locations of holes, slits and apertures may also be altered. E.g. the columns 15, 16, 17 could be rigidly connected to the baseplate 12 and movable with respect to the platform 21.
Furthermore, the bottom 11 of the drawer 5 could be constituted by anything suitable for supporting the base, albeit it is currently preferred that the bottom 11 with base in the form of the baseplate 12 is a contiguous structure allowing objects to be placed and stored next to the image projector 3, such a remote control for the image projector 3, lens cleaning equipment etc. so as to be hidden away together with the image projector 3 when not in use. On the other hand, the bottom 11 of the drawer 5 could itself form the base rather than having a separate embedded baseplate 12.
It should also be noted that the platform 7 may of course also be used without the piece of furniture 4 and the drawer 5, in particular if it is placed in an inconspicuous manner, say below the ceiling of a room, with the projector below it, in which case it would largely be obscured by projector 3 and thus invisible.
Number | Date | Country | Kind |
---|---|---|---|
PA 2017 70363 | May 2017 | DK | national |
The present application is a national stage entry of International Patent Application No. PCT/DK2018/050110, filed May 18, 2018, entitled “AN ADJUSTABLE MOUNT FOR AN IMAGE PROJECTOR.” This application claims the benefit of Danish Patent Application No. PA 2017 70363, filed May 23, 2017, entitled “AN ADJUSTABLE MOUNT FOR AN IMAGE PROJECTOR.”
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/DK2018/050110 | 5/18/2018 | WO | 00 |