| JP08068174 | DAYLIGHTING WINDOW |
| JP11028729 | MANUFACTURE OF HEAT INSULATING PANEL |
| JP04092057 | LIGHTING APPARATUS OF UNIT BATH |
IONESCU, Clara (Kerkstraat 108, Gentbrugge, B-9050, BE)
NEAMTU, Daniel (Kerkstraat 108, Gentbrugge, B-9050, BE)
DE KEYSER, Robain (Kerkstraat 108, Gentbrugge, B-9050, BE)
DE MAEYER, Jeroen (Kerkstraat 108, Gentbrugge, B-9050, BE)
MICHIELSSENS, Maarten (Kerkstraat 108, Gentbrugge, B-9050, BE)
WYNS, Bart (Kerkstraat 108, Gentbrugge, B-9050, BE)
IONESCU, Clara (Kerkstraat 108, Gentbrugge, B-9050, BE)
NEAMTU, Daniel (Kerkstraat 108, Gentbrugge, B-9050, BE)
DE KEYSER, Robain (Kerkstraat 108, Gentbrugge, B-9050, BE)
DE MAEYER, Jeroen (Kerkstraat 108, Gentbrugge, B-9050, BE)
MICHIELSSENS, Maarten (Kerkstraat 108, Gentbrugge, B-9050, BE)
| Claims 1. Skylight for spreading daylight in a building, comprising a daylight spreading device (10-12) for installation in a roof opening of the building and a mirror device (1), rotatably mounted above the daylight spreading device and provided for reflecting light to the daylight spreading device, wherein the mirror device comprises a mirror (3), a motor (15) for rotating the mirror device and a controller (5) for controlling the motor, such that the mirror device may be taken to an optimal position, wherein as much light as possible is reflected to the daylight spreading device, characterized in that the controller comprises a measuring device (6-9), arranged for measuring the intensity of the incident light on the mirror wherein the measuring device is provided with a first (6) and a second light sensor (7) and a shade element (8) arranged to create a shadow on the first or second light sensor and a processor (14) for processing the intensity, measured by the light sensors, wherein the controller (5) is provided for determining an optimal adapted position based on the light intensity measured by the first and second light sensor. 2. Skylight according to claim 1 , characterized in that the controller (5) is provided for determining the optimal adapted position when a comparison value calculated on the basis of the light intensities measured by the first and second light sensor, respectively, exceeds a predetermined limit and for periodically determining the comparison value. 3. Skylight according to claim 2, characterized in that the comparison value is equal to the absolute value of a value based on a subtraction of light intensities measured by the first and second light sensor divided by a value based on a sum of light intensities measured by the first and second light sensor. 4. Skylight according to one of the preceding claims, characterized in that the controller (5) is provided to determine the adapted optimal position by rotating the mirror device on the basis of a reference value calculated on the basis of the light intensities measured by the first and second light sensor, respectively. 5. Skylight according to claim 4, characterized in that the reference value is equal to the quotient of a value based on a subtraction of light intensities measured by the first and second light sensor, respectively, and a value based on a sum of light intensities measured by the first and second light sensor, respectively. 6. Skylight according to claims 4 or 5, at least in combination with claim 2, characterized in that the controller (5) is provided for controlling, as long as the comparison value exceeds the predetermined limit, the motor such that the mirror devices rotates according to the reference value, until the reference value does not exceed the predetermined limit. 7. Skylight according to one of the preceding claims, at least in combination with claims 3 or 5 characterized in that the values measured on the basis of a subtraction and sum of the light intensities by the first and second light sensor, respectively, is determined by taking an average of at least two subtractions and sums of at least two pairs of light intensities measured at different points in time by the first and second light sensor, respectively. 8. Skylight according to claim 7, characterized in that the controller is adapted for to finding the adapted optimal position on the basis of the at least two pairs of light intensities measured by the first and second light sensor. 9. Skylight according to claim 7 or 8, at least in combination with claim 2, characterized in that the controller is provided, as long as the comparison value exceeds the predetermined value, to replace at least one of the at least two pairs of values measured by the first and the second light sensor by a pair of values measured by the first and second sensor after or during the rotation of the mirror device. 10. Skylight according to one of the preceding claims, characterized in that the controller is provided for periodically finding the adapted optimal position. 1 1. Skylight according to claim 10, characterized in that the controller is provided for finding the adapted optimal position after an extended period if the measured light intensities are sufficiently different from each other in function of time. 12. Skylight according to one of the preceding claims, at least in combination with claim 2, characterized in that the controller is provided for controlling, when the first and second light sensors are saturated by the radiation of the sun and when by rotating the mirror device the comparison value no longer exceeds the predetermined value, the motor such that it once again continues to rotate the mirror device. 13. Skylight according to one of the preceding claims, characterized in that the first and second sensor (6-7) are arranged next to each other on a printed circuit board (5) and the shade element is formed by a partition (8) in the middle between the first and second sensor. 14. Skylight according to claim 13, characterized in that a protective wall (8) is applied on the printed circuit board (5) at the top of the first and second sensor. 15. Skylight according to one of the preceding claims, characterized in that the measuring device (6-9) and the processor (14) are located on the same printed circuit board (5). 16. Skylight according to one of the preceding claims, characterized in that the mirror (3) is arranged at an angle of 50 to 80° with respect to the surface of the earth. 17. Skylight according to one of the preceding claims, characterized in that the mirror (3) is arranged at an angle of 60 to 70° with respect to the surface of the earth. 18. Skylight according to one of the preceding claims, characterized in that the mirror (3) is arranged at an angle of ca. 65° with respect to the surface of the earth. 19. Skylight according to one of the preceding claims, characterized in that the measuring device (6-9) is substantially perpendicularly arranged with respect to the surface of the earth. 20. Skylight according to one of the claims 1-18, characterized in that the measuring device (6-9) is arranged at angle of substantially 45° with respect to the surface of the earth. 21. Skylight according to one of the preceding claims, characterized in that the mirror device (1 ) comprises a support with a first arm (2) for supporting the mirror (3) and a second arm (4) for supporting the measuring device (6-9) at the top of the mirror. 22. Skylight according to one of the preceding claims, characterized in that the skylight comprises a transparent dome (13), mounted over the mirror device (1 ) to protect it against the weather conditions. 23. Skylight according to one of the preceding claims, characterized in that the daylight spreading device comprises a prismatic lens (10) at the top of the roof opening, a light-shaft (1 1 ) with reflecting walls through the roof opening and a pyramidal lens (12) at the bottom of the roof opening. 24. Skylight according to one of the preceding claims, characterized in that the controller (5) comprises an electronic compass for determining a zero setting in which the mirror device is oriented substantially towards the east. 25. Skylight according to one of the preceding claims, characterized in that the controller (5) is provided for finding an initial optimal position during a complete revolution of the mirror device. 26. Skylight according to claim 25, characterized in that the controller (5) is provided for finding the initial optimal position when the intensity difference measured by the first and second sensor exceeds a predetermined second limit and for periodically determining the adjusted optimal position. 27. Skylight according to one of the preceding claims, characterized in that the controller (5) is provided for adapting the position of the mirror device when the intensity difference measured by the first and second sensor exceeds a predetermined third limit. |
The present invention relates to a skylight according to the preamble of the first claim.
A skylight is for example known from US-B 6,493, 145. The known skylight comprises a light spreading device mounted in a roof opening of the building and a mirror device, rotatably mounted above the daylight spreading device and provided for reflecting light to the light spreading device. The mirror device comprises mirrors, provided for reflecting sunlight through the roof opening, a motor for rotating the mirror device and a driver for driving the motor, such that the mirror device is brought to an optimal position in which as much light as possible is reflected through the roof opening. Control is based on the position of the sun. The optimal position for the mirror device is calculated on the basis of a point in time and a position on the surface of the earth.
The skylight known from US-B-6493145 has the disadvantage that the control is complex and imprecise.
It is an object of the present invention to provide a skylight with a simple control yielding a more accurate optimal position for the mirror device.
This object is achieved according to the invention with a skylight showing all the features of the first claim.
Thereto, the controller comprises a measuring device, provided for measuring the intensity of the incident light on the mirror, wherein the measuring device is provided with a first and a second light sensor and a shade element arranged to create a shadow on the first or second light sensor, and a processor for processing the intensity, measured by the light sensors. The controller is provided for determining an optimal adjusted position based on the light intensity measured by the first and second light sensor.
Specifically, the optimal adjusted position is determined from a difference between the light intensity measured by the first sensor relative to those measured by the second sensor. This difference in light intensity is caused by the shadow of the shade element, cast on the first/second sensor when the position of the mirror device is not optimal.
Thanks to the measuring device and controller according to the invention it is obtained that the optimal position is retrieved and saved on the basis of actual measurements of the incident light intensity on the two sensors, which is a measure of the intensity incident on the mirror. In this way, an erroneous position of the mirror device, which according to the prior art can be caused by an error in the point in time and/or position on the surface of the earth, can be avoided according to the invention, while keeping the control simple. Furthermore, in this way an optimal orientation of the mirror device can also be obtained during the day, taking into account local obstacles or elements creating shadow, such as an antenna box next to the dome, high-rises nearby, a difference in slope on one and the same roof etc. In a preferred embodiment of the present invention the controller is provided with an electronic compass for determining a zero approximately to the east, so that the position of the mirror device is already at dawn substantially optimal.
In a preferred embodiment of the present invention is the controller provided for finding an optimal initial position during a complete rotation of the mirror device. Initially the optimal position can be searched by a complete rotation of the mirror device to implement and to determine at which orientation the measured light intensity is highest. This implementation can serve as an alternative to the electronic compass, or as an addition thereto. In preferred embodiments of the present invention is the controller provided to determine the adjusted optimal position when a comparison value based on the light intensities measured by the first and the second light sensor exceeds a predetermined limit and for periodically determining the comparison value. Such control allows to determine when it is necessary to search a more optimal position by using the existing light sensors.
According to further preferred embodiments of the present invention, the comparison value is equal to the absolute value of a value based on a subtraction of light intensities measured by the first and the second light sensor divided by a value based on a sum of light intensities measured by first and second light sensor, respectively. Such absolute value shows to be a good benchmark for determining when a more optimal position should be sought. It was found that the predetermined limit is preferably 0.01 and preferably the adapted optimal position is only determined if the comparison value is greater than 0.01 , since at such a value a good positioning can be achieved but an excessive repositioning, with accompanying energy consumption, is avoided.
In preferred embodiments of the present invention the controller is provided to determine the adapted optimal position by rotating the mirror device on the basis of a reference value calculated from the light intensities measured by the first and the second light sensor. Such a reference value allows the adapted optimal position to be determined by using the values of the light sensors themselves.
The reference value is further preferably equal to a quotient of a value based on a subtraction of light intensities measured by the first and the second light sensor and a value based on a sum of light intensities measured by the first and the second light sensor. It was found that a good adapted optimal position can be obtained on the basis of such a reference value. Preferably, the mirror device is rotated clockwise on the basis of the reference value if the reference value is greater than 0 and counterclockwise if the reference is less than 0.
More preferably, the controller is provided as long as the comparison value exceeds the predetermined limit, to control the motor such that itself the mirror device rotates according to the reference value, as long as the comparison value does not exceed the predetermined limit. The controller goes, for example, through a cycle as long as the comparison value is greater than the predetermined limit, preferably 0.01 . During each step of the cycle, the mirror device is rotated according to the reference value by the motor controlled by the controller, preferably for a predetermined time or during a predetermined angle. If the comparison value after such a rotation of the mirror device is for example less than the predetermined limit the cycle comes to an end.
The values based on a subtraction of light intensities measured by the first and the second light sensor is preferably determined by a mean of at least two subtractions of at least two pairs of light intensities measured by the first and the second light sensor at different times. The values based on a sum of light intensities measured by the first and the second light sensor is preferably determined by a mean of at least two sums of light intensities measured by the first and the second light sensor at different times. For the sum and subtraction, the same correspondent measured light intensities are used.
For example, some of the by the first and second light sensor substantially simultaneously measured light intensities are recorded in order to calculate average values. Preferably at least 2, but more preferably 5, values of respectively the first and second light sensor are measured at equal times and recorded, to calculate a corresponding times, preferably 5 times, a sum and a subtraction wherein the subtraction is always equal to the light intensity measured by the first light sensor minus the light intensity measured by the second light sensor, after which the average is calculated of the sums and subtractions, respectively, so that an average of the sums, preferably 5, and an average of the differences, preferably 5 is obtained. On this basis, the reference value and comparison value is determined, the comparison value being the absolute value of the reference value.
In embodiments of the present invention the controller is provided, as long as the comparison value exceeds the predetermined limit to replace at least one of the at least two pairs of values measured by the first and second light sensor by a pair of values measured by the first and second sensor during or after rotating the mirror device. Preferably, the controller is provided for replacing preferably periodically the at least one stored values measured by the first and second light sensor at the completion of the cycle by values measured by the first and second sensor after or during rotation of the mirror device in order to adapt the comparison value to the adapted position of the mirror device so that it can be verified whether the mirror system must continue to rotate to take an optimal position. Further preferably, the oldest of the recorded values will thereto be replaced by the last measured values. For example, at the end of each cycle, new values are measured and stored replacing the hitherto oldest stored values.
In a preferred embodiment of the invention the controller is provided for periodically searching the adapted optimal position. More preferably, the time for locating the adapted optimal position is less than 10 minutes, for example 5 minutes. This allows saving energy since a modified position is not continuously searched.
Further preferably, the control is provided to search the adapted optimal position after an extended period if the measured light intensities are sufficiently different from each other in function of time. It was found that in such cases it is avoided that the mirror device follows for example the reflection of a cloud whereas in another position more light can be absorbed. By waiting a longer period it was found that, for example, the cloud moves away and a substantial new position should be sought which might be better.
Preferably, the controller is adapted to measure, before, preferably just before, each, preferably periodically, search of the adapted optimal position, the at least two, preferably 5, pair of substantially simultaneously measured values of light intensities measured by the first and second light sensor. Preferably this is done by measuring during a period shortly before searching the adapted optimal position the light intensities, for example 30 seconds prior to determining the optimal position. This is done further preferably 5 times with 5 to 6 seconds between each measurement during the 30 seconds when searching for the adapted optimal position. In preferred embodiments the controller is provided to control, when the first and second light sensor are saturated by the radiation from the sun and when the comparison value by the mirror device does not any longer exceed the predetermined limit values, the motor so that it rotates the mirror device, preferably for a predetermined time and/or angle. Such a controller also allows to remedy a faulty position caused by the saturation of the light sensors.
The invention will be further elucidated through the following description and the appended figures.
Figure 1 shows a longitudinal section of a preferred embodiment of a skylight according to the invention.
Figure 2 shows a cross section of a preferred embodiment of a skylight according to the invention.
Figure 3 shows a perspective view of a preferred embodiment of a skylight according the invention.
Figure 4 shows a perspective view of a transfer of a preferred embodiment of a skylight according the invention. Figure 5 shows schematically a printed circuit board with an operating system for a preferred embodiment of a skylight according to the invention.
The skylight shown in Figure 1-3 comprises a prismatic lens 10 above the roof opening, a light shaft 1 1 with reflective walls through the roof opening and a pyramidal lens 12 below the roof opening, which together form a daylight spreading device for spreading incident daylight/sunlight falling on the roof top in the building. Above the prismatic lens is a rotatably mounted mirror device 1 , to reflect the incident daylight and/or sunlight through the light shaft 1 1 under a transparent dome 13.
The transparent dome 13 is for example made from high quality transparent polycarbonate (double UV coating), or any other transparent material known in the art. The base of the dome 13 is square, but may optionally also be circular or any other shape considered suitable by the person skilled in the art. The dome preferably forms an airtight seal at the top of the whole and serves as a weatherproof shield for the interior mirror. The dome is preferably attached by a combination of glue and screws as prevention against burglary.
The side panels of the light shaft 1 1 are made from SPO material which receives a highly reflective white coating (based on zirconium as an environmentally friendly alternative to foil reflecting mirror) and the top and bottom of the light shaft are closed by specially tailored optical elements. The top element is the prismatic lens 10, a flat lens made of polycarbonate with a pattern for optimum reception and transmission of light. The bottom element is the pyramid lens 12, a polycarbonate lens in a pyramid shape for optimum light distribution within the building. Besides collecting, enhancing, reflecting and spreading the incoming light, the two lenses 10, 12 also create a stationary layer of air in the shaft 1 1 , causing the system to be thermally insulating. The light distribution device 10-12 can also be formed by any other combination of optical elements known to the skilled person. Preferably a moisture absorbent element is also included in order to combat condensation.
The mirror device 1 comprises a first arm 2 which supports a mirror 3 at an angle of preferably about 65° with respect to the surface of the earth, and a second arm 4 on which a printed circuit board 5 with a measuring device and a processing unit is mounted. The PCB 5 is mounted substantially near the top of the mirror 3 and preferably oriented in a direction substantially perpendicular to the surface of the earth or alternatively in a 45° angle on the surface.
The mirror 3 is preferably a plane mirror. The mirror is preferably placed at a fixed angle of 50 to 80°, more preferably 60 to 70°, most preferably about 65° with respect to the surface of the earth, although other angles are also possible if circumstances require so. In alternative embodiments, the mirror device generally comprises one or more flat or curved mirrors, mounted under the same or at different angles relative to the surface of the earth. In an alternative embodiment, the mirror 3 may also be tiltably mounted on the mirror device 1 , with a tilting mechanism which may also be controlled on the basis of a measurement of the light intensity, such as two sensors with a partition as described herein but with the sensors superimposed instead of parallel.
The printed circuit board (PCB) 5, schematically shown in Figure 5, comprises an operating system with a measuring device 6-9 for measuring the light intensity incident on the mirror 3 and a processor 14 for processing the measured intensity. The measuring device is formed by a first light sensor 6 and a second light sensor 7 next to each other with a partition 8 in the middle between them. This partition 8 is a shade element for creating a shadow on the first or second light sensor, if the position of the mirror device 1 differs from the currently optimal position. In the optimal position the light sensors 6 and 7 measure almost the same intensity. On the PCB 5 a protective wall 9 is also arranged above the first and second sensor 6, 7 for shielding the incident light on that side, which benefits the accuracy of the measurement. The processing unit 14 compares the light intensity measured by the sensors 6 and 7, and concludes from a difference whether the mirror device is to be rotated to the left or to the right, depending on where the measured light intensity is highest. When adapting, the mirror device 1 is rotated until the intensity, measured by the sensors 6, 7 is once more almost equal.
In alternative embodiments, a combination of multiple light sensors may be provided, such as, next to the first and second sensor also a third sensor to accurately distinguish day/night. According to the invention there are at least two sensors, but more than two is also possible.
In the embodiment shown in the figures, the measuring device and the processing unit 6-9 are on the same circuit board 5. This is not essential for the invention and may also be done differently.
The partition 8 and the shielding wall 9 are preferably made of PCB material with a black masking layer, or another essentially non-reflective material known to the skilled person to counter the reflection of the light.
Specifically, the two light sensors 6 and 7 light-sensitive sensors which produce a voltage proportional to the incident light. These include PV cells which can deliver power at incident light, over a resistor of 1 Mohm, leading to a voltage of about 3V at 30Klux. An amplifier may be placed in buffer mode after the sensor to buffer the voltage and absorb the power surge. If the sensors 6 and 7 are optimally directed to the sun or another optimal light spot, both sensors receive substantially the same light and produce an equal voltage. Otherwise - if the position differs from the optimum - one of the sensors will receive more light than the other sensor and two sensors will produce a different voltage. This voltage is used by the processing unit to determine the optimal position.
The processing unit runs an algorithm which is preferably constructed, such that, once a certain minimum (e.g. 300lux or 1000lux) incident light is measured, a light measurement is carried out periodically (e.g. every minute or every five minutes) seeking the optimal point of light. Then the motor is controlled to focus the mirror thereto. At dusk, when the minimum incident light is no longer met, the system is set in readiness for the start of the next cycle. Preferably, an electronic compass is thereto integrated on the printed circuit board 5. Herewith, a zero point can be created in the east, whereto the mirror device can return each 24h and begin a new cycle from this position. Thus each cycle begins in the vicinity of the expected optimal position and the mirror device can quickly be brought to the optimal position.
The motor 15, driving the rotation of the mirror driving device 1 is preferably but not necessarily an electric stepper motor that can rotate in both directions (e.g., speed 0.2 rpm). The motor is for example a DC motor with a control consisting of two half-bridges to control in both directions. The electrical power for the installation is provided by the combination of a solar panel 16 with a rechargeable battery with an autonomy of 3 weeks for example. This way no main power supply should be provided. Obviously, the electric power may also be provided in other ways known in the art, such as for example a main power supply.
The dome preferably is provided with an anti-fogging agent, such as for example a box of active clay, to absorb potential condensation and controlling humidity in the dome. Activated clay is a green variant of silica gel.
The control unit on the printed circuit board 5 is preferably provided with a temperature sensor measuring the temperature inside the dome. The components used are of the industrial class, which means that the allowable temperature range is -20°C to +85°C. If the temperature inside the dome would rise above 85°C, the operation would be shut down for safety reasons.
In the case of several skylights are provided in the building in close proximity to each other, each dome preferably has its own individual operating system so that they operate independently. In this way, it is not necessary to create a link between different domes on the same roof. There are no settings (location coordinates or other) to be entered when installed on the roof. Once the power supply (solar panel and battery) is connected, each skylight operates autonomously and immediately.
Although the present invention has been described with reference to a specific embodiment, it is clear that various modifications can be applied without departing from the scope of the claims. In this sense, the description and the figures should be considered as examples and they should not be understood in a strict sense.
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