Illumination correcting method and apparatus for at least one light source board

An illumination correcting apparatus capable of adjusting at least one light source board includes a main unit, a calibrating board and an image capturing device. The main unit is electrically connected to the at least one light source board to adjust an illumination value of the at least one light source board, and includes a calculating module. The calculating module chooses one of the at least one light source board to be a target light source board and calculates a correcting illumination value. The calibrating board is disposed in a light emitting path of the light source board. The image capturing device is electrically connected to the main unit to capture an image and transmit the image to the main unit. The main unit calculates the correcting illumination value in accordance with the illumination of the image, distances between the at least one light source board and the calibrating board, and the target illumination value.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an illumination correcting method and apparatus, and more particularly to an illumination correcting method and apparatus for at least one light source board.

2. Description of Related Art

With reference toFIG. 5, a conventional light source board50, also called a programmable digital controlled light source board, is made of several or hundreds of light emitting modules501. Each of the light emitting modules501is made of multiple light emitting diodes (LEDs). Therefore, each of the light emitting modules501is capable of displaying different colors or different illuminations individually. The light source board50can be designed in different shapes, such as square, round, polygonal, and so on, depending on customers' demands. The light source board50is used in many different fields, such as dynamic display for commercial signs, front light illumination, back light illumination, and so on.

However, when manufacture of the light source board50is completed, the illumination in the light emitting modules501will not be the same. Therefore, a parameter correction in the light emitting modules501of the light source board50will be performed before shipping from the manufacturer to equalize the illumination in each of the light emitting modules501.

When the light source board50has been used for a period of time, the illumination of the light emitting modules501will be gradually attenuated as time goes by. The original illumination parameters set up by the manufacturer of the light source board50are no longer suitable as the reference. When the light emitting modules501are in illumination attenuation situation or are damaged because of lifetime, the light emitting modules501need to be replaced or corrected. The illumination in the new light emitting module501is also different from the overall illumination of the old light emitting module501in the light source board50. Therefore, the original illumination parameters for the light source board50are no longer suitable for use and the illumination parameters need to be readjusted. The readjusting for the illumination parameters are highly time consuming.

Accordingly, a need arises to design a new illumination correcting method and apparatus for light source boards to adjust the illumination of light source boards quickly and efficiently.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide an illumination correcting apparatus capable of adjusting at least one light source board and the illumination correcting apparatus can adjust each of the at least one light source board in accordance with an actual illumination of each of the at least one light source board.

According to the aforementioned objective, the illumination correcting apparatus, which is capable of adjusting at least one light source board, includes a main unit, a calibrating board and an image capturing device. The main unit is electrically connected to the at least one light source board to adjust a respective illumination value of each of the at least one light source board, and includes a calculating module selecting one of the at least one light source board to be a target light source board and calculating a correcting illumination value for the target light source board in accordance with a target illumination value. The calibrating board is disposed in a light emitting path of the at least one light source board. The image capturing device is opposite the calibrating board and is electrically connected to the main unit to capture an image reflected from the at least one light source board to the calibrating board and transmit the image to the main unit. The main unit calculates the correcting illumination value in accordance with an illumination of the image, a respective distance between each of the at least one light source board and the calibrating board, and the target illumination value. The target illumination value is an overall illumination value from the at least one light source board emitting light to the calibrating board.

Another objective of the present invention is to develop an illumination correcting method and the illumination correcting method is not required to perform parameter adjusting. The illumination correcting method is to perform a measurement for an actual situation so as to adjust illumination for each of the at least one light source board.

In order to achieve the aforementioned purpose in the present invention, an illumination correcting method capable of adjusting at least one light source board includes steps of: selecting a target light source board from the at least one light source board; measuring a respective distance between each of the at least one light source board and a calibrating board; acquiring an illumination value from each of the at least light source board via a main unit; measuring an actual illumination value on the calibrating board from the at least one light source board via an image capturing device; calculating a correcting illumination value for the target light source board by a calculating module in accordance with a target illumination value, the illumination value, the actual illumination value, and the distance; wherein the target illumination value is an overall illumination value required on the calibrating board from the at least one light source board. The advantage of the present invention is to perform an illumination adjustment for a current illumination of the at least one light source board and the adjustment is accurate without a complicated parameter adjusting.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings.

With reference toFIG. 1, an illumination correcting apparatus10in the present invention includes a main unit11, a calibrating board12and an image capturing device13. The correcting apparatus10is capable of correcting at least one light source board20. Each of the at least one light source board20is a digital light source board and includes a plurality of light emitting modules201. Each of the light emitting modules201is made of a plurality of light emitting diodes (LEDs). The light emitting modules201are arranged in an array.

The main unit11is a host computer and is electrically connected to the at least one light source board20to control illuminations and colors generated by the light emitting modules201of the at least one light source board20. In addition, since the main unit11is electrically connected to the at least one light source board20, the main unit11may determine a respective illumination value of each of the at least one light source board20in accordance with power consumption and heat generated from each of the at least one light source board20. In a different embodiment, each of the at least one light source board20includes an illumination meter (not shown) that transfers the illumination value to the main unit11. Alternatively, a user can implement an illumination measuring equipment to measure the respective illumination value of each of the at least one light source board20directly. How to measure the illumination value is well known for a person with ordinary skill in the art, and the detailed description is omitted.

The calibrating board12is disposed in a transmitting path of light generated from the at least one light source board20. The light from the at least one light source board20is directly or obliquely transmitted. The calibrating board12can be disposed at a place within a transmitting range of the light from the at least one light source board20. The image capturing device13can be a digital camera such as a camera with a charge-coupled device (CCD). The image capturing device13is opposite the calibrating board12and is electrically connected to the main unit11. The image capturing device13is configured to capture an image on the calibrating board12and the image is generated by the light from the at least one light source board20. The image capturing device13transfers the image to the main unit11to perform an image illumination analysis to obtain an actual illumination value. The main unit11calculates a correcting illumination value of one of the at least one light source board20, which is called a target light source board, in accordance with a target illumination value for all of the at least one light source board20, the illumination value of the target light source board, and the actual illumination value of the image.

Furthermore, the main unit11of the correcting apparatus10includes a calculating module111. The calculating module111performs an illumination analysis for the image and calculates a correcting illumination value required for one of the at least one light source board20(i.e. the target light source board) in accordance with the target illumination value developed by the correcting apparatus10. In the present invention, the calculating module111implements a target-passing function to calculate the correcting illumination value for the target light source board and the function is:

where H is the correcting illumination value of the target light source board;

H1n, H2n, . . . , Hnn are each the respective illumination value of the at least one light source board20;

M is the target illumination value;

Hn is the actual illumination value of the image captured by the image capturing device13;

L1, L2, . . . , Ln are each the respective distance between the at least one light source board20and the calibrating board12;

Minitial1 is a first constant and Minitial2 is a second constant.

The illumination value in each of the at least one light source board20and the distance between each of the at least one light source board20and the calibrating board12can be measured and inputted by the user in the main unit11. And then the illumination value and the distances are to be calculated by the calculating module111.

For example, with reference toFIG. 2, only one light source board30is disposed at one side of the calibrating board12as the target light source board. The image capturing device13captures the image from the calibrating board12and the actual illumination value of the image is 100. The target illumination value is 150. The light source board30is as the target light source board. The target light source board is required to perform the illumination adjustment. The illumination value of the light source board30is 120 and is measured by the main unit11. Alternatively, the illumination value of the light source board30may be measured by an illumination measuring equipment, and it is not limited herein. The correcting illumination value of the light source board30is: H=120+(150−100)/500*688=188.8. The value 688 is the first constant (Minitial1). Therefore, the illumination value of the light source board30is required to be adjusted from 120 to be 188.8.

Alternatively, in another embodiment, with reference toFIG. 3, there are a first light source board40a, a second light source board40band a third light source board40crespectively disposed at a first side, a second side and a third side of the calibrating board12. The illumination value of the first light source board40aat the first side is 80 and the distance between the first light source board40aand the calibrating board12is 600 mm. The illumination value of the second light source board40bat the first side is 120 and the distance between the first light source board40aand the calibrating board12is 500 mm. The illumination value of the third light source board40cat the first side is 110 and the distance between the first light source board40aand the calibrating board12is 300 mm. The target illumination value for the first light source board40a, the second light source board40band the third light source board40cis 150. The second light source board40bat the second side is the target light source board in the present embodiment and the correcting illumination value is: H=120+(150−100)/500*688−((80+(150−100)/600+(110+(150−100)/300))/3.58=1 35. The value 688 is the first constant (Minitial1) and the value 3.58 is the second constant (Minitial2). The first constant and the second constant are obtained by a large number of experiments on the basis of the material and the environment of the first light source board40a, the second light source board40band the third light source board40c. Therefore, the illumination value of the light source board40bat the second side is required to be adjusted from 120 to be 135. Similarly, the target illumination value for the light source board40aat the first side and the light source board40cat the third side is further calculated.

With reference toFIG. 4, an illumination correcting method capable of adjusting at least one light source board in the present invention includes the following steps. In step S401, a target light source board is selected from the at least one light source board20. The target light source board is required to adjust the illumination value. At one embodiment, when the number of the at least one light source board20is more than one and the multiple light source boards need adjustment, the correcting method in the present invention will adjust one of the light source boards20at one time, and the light source board20that is under adjustment is called the target light source board. In different circumstances, different light source boards20need different illumination values to be adjusted in the correcting illumination value. The correcting method in the present invention will set the different illumination values for each one of the source boards20in accordance with different environments. The correcting method in the present invention adjusts the respective illumination value for each light source board20in accordance with the respective distance between each light source board20and the calibrating board12so as to correct illumination of each light source board20. For example, when the quantity of the at least one light source board20is one, the one light source board20is the target light source board. If the number of the at least one light source board20is more than one, one of the source boards20is selected to be the target light source board and the remaining is/are the regular light source board(s)20.

In step S402, the distance between each of the at least one light source board20and the calibrating board12is measured. When the at least one light source board20is more than one, they are located at different positions, so the distances between the light source boards20and the calibrating board12are also different. The illumination strength for different distances is different. Therefore, it is necessary to measure the respective distance between each of the at least one light source board20and the calibrating board12.

In step S403, the main unit11acquires the illumination value for each of the at least one light source board20. Either upon manufacture or after use over time, illuminations generated from the at least one light source board20may change. Therefore, the current illumination value of the at least one light source board20is required for adjusting the illumination of the at least one light source board20. Since the at least one light source board20is electrically connected to the main unit11, the main unit11controls the at least one light source board20to turn on or off. Therefore, the current illumination value(s) of the at least one light source board20can be obtained from the main unit11. Alternatively, in a different embodiment, the user may obtain the current illumination value for each of the at least one light source board20from illumination measuring equipment.

In step S404, an actual illumination value emitted on the calibrating board12from the at least one light source board20is measured by an image capturing device13. The image capturing device13takes a picture of the calibrating board12to obtain an image from all of the at least one light source board20on the calibrating board12and transmits the image to the main unit11to perform illumination analysis of the image so as to obtain the actual illumination value.

In step S405, a correcting illumination value for the target light source board is calculated by a calculating module in accordance with a target illumination value, the illumination value, the actual illumination value, and the distance. The target illumination value is an overall illumination value on the calibrating board12for the at least one light source board20. The illumination value and the distance in each of the at least one light source board20, the actual illumination value on the calibrating board12, and the target illumination value are inputted in the calculating module111, and the correcting illumination value for the target light source board is obtained. The calculating module111is installed within the main unit11, and as the calculating algorithm utilized in the calculating module111is described above, the description thereof is omitted.

At last, in step S406, the illumination of the target light source board is adjusted in accordance with the correcting illumination value by the main unit11. If the correcting illumination value is greater than the current illumination value of the target light source board, it represents that the illumination is not bright enough and the illumination value of the at least one light source board20should be increased by the main unit11. Alternatively, if the illumination is too bright, the illumination value of the at least one light source board20should be decreased by the main unit11. The illumination value for each of the at least one light source board20is adjusted by the correcting method in the present invention. Finally, all of the at least one light source board20is adjusted to have a suitable illumination value. By the aforementioned calculating example, the correcting method in the present invention can be used in the at least one light source board20. The correcting illumination value for each of the at least one light source board20can be calculated sequentially. The at least one light source board20is respectively adjusted to have the required illumination value, so the overall illumination as the requirement for the user can be achieved.

With the aforementioned correcting method, it is unnecessary to set parameters. The illumination value and the distance between the at least one light source board and the calibrating board are measured and the overall illumination value on the calibrating board is captured by the image capturing device from all of the at least one light source board. A target light source board is selected and a target illumination value is set. Therefore, the correcting illumination values for all of the at least one light source board are respectively and sequentially calculated so as to achieve the illumination adjustment for the at least one light source board. By comparing to the conventional parameter adjusting method, the steps in the present invention are simplified without wasting much time to perform parameters adjusting.