KR200476366Y1 - Writing board equipped with LED illumination - Google Patents

Abstract

The idea is to improve the visual acuity and learning effect of the students who need to look at the blackboard for a long time by irradiating the board very uniformly, removing the influence of external light by raising the light intensity of the external light or turning on other lights. To provide a blackboard with LED lighting. According to the present invention, an LED lighting installation board is composed of a board surface having a lateral direction and a longitudinal direction, an upper frame protruding from a board surface on the upper side of the board surface, a lower frame having a longitudinal direction and a lateral direction, And a plurality of LED light source modules installed to illuminate the LEDs.

Description

{Writing board equipped with LED illumination}

The present invention relates to an LED lighting and blackboard field, and more particularly, to a blackboard installed on an upper side of a blackboard and provided with an LED lighting device that uniformly illuminates the entire surface of the blackboard.

There are many known techniques for illuminating a blackboard using LED devices.

A utility model application 2009-806 (a board with a light fixture) incorporates a plurality of fixtures that emit light on the board attached to the frame. In this technique, the main idea is to illuminate the light with the illumination lamps arranged at regular intervals above the blackboard, and it is briefly disclosed that the angles of the arranged illumination lamps are tilted differently, but there is no technical specificity therefor.

Utility Model Application 2009-5410 (Lighting Fixture for Blackboard) is designed to increase the illuminance of the lighting fixture and is designed to be able to use arbitrary angle easily and easily. It is structured to increase the illuminance of the lighting fixture installed on the ceiling. This technology is not attached to the board altogether, but it is only attached to the board and it is only a lighting fixture hanging on the ceiling to illuminate the board. Its purpose is only to enhance the illumination of the lighting fixture. Therefore, there is a fundamental limitation in irradiating uniform light on the board.

Patent Registration No. 1274145 (a lighting apparatus for a blackboard) relates to an LED lighting apparatus for a blackboard, which is provided with a reflector capable of changing an angle in a frame portion, and is intended to uniformly irradiate light toward the blackboard by adjusting an irradiation angle of the light source. However, this technology is also installed separately on the board, and it is only a light that illuminates the board. It does not contain any special technique such as considering the dimming characteristics of the LED in addition to achieving uniform illumination by controlling the reflection angle of the LED illumination. Therefore, there is a limit to the level of uniformity of board surface irradiation, and it is large, heavy, complex, and expensive as a lighting unit of a unit.

There are certain conditions that must be met for the lighting to be applied to the blackboard. Basically, lighting of a certain level or more is essential for the lighting for the blackboard, but it is not good that the lighting is high. Above all, uniformity of dimming (light irradiation) must be ensured. That is, it should be illuminated with uniform illumination over all sides of the chalkboard.

Generally, the board used for lecture is about 4m in length and about 1.5m in height. Arranging a plurality of light sources at an appropriate interval on the upper side of the blackboard in the horizontal direction can relatively easily obtain light uniformity, but it is not easy to uniformly illuminate light from the top to the bottom in the vertical direction.

There are also windows in most of the lecture rooms, and outside light shining through the window through the window is also a problem. To get rid of this external light, the inside of the room is darkened by hitting the hut, and when outside light is left, it is reflected from the chalkboard and enters the eyes of the students.

There are many other things that are needed for blackboard only illumination for convenience. For example, it would be more convenient to have a function that automatically adjusts the brightness of the blackboard lighting according to the brightness change of the outside light.

The purpose of the present invention is to provide a method of illuminating a very uniform light across a board surface and improving the visual acuity of a student who needs to look at the blackboard for a long time by removing the influence of outside light by raising the light intensity of the external light, To provide a blackboard with LED lighting for protection and learning effects.

According to the present invention, the chalkboard with LED lighting is installed vertically protruding from the upper side of the chalkboard having the horizontal and vertical directions, and corresponds to the direction perpendicular to the horizontal direction of the chalkboard surface and the direction protruding from the chalkboard surface An upper frame having a lateral direction and a plurality of LED light source modules mounted on a lower surface (hereinafter referred to as a mounting plane) of the upper frame and mounted to irradiate light in the longitudinal direction of the boardboard surface. In the present apparatus, each of the plurality of LED light source modules includes a substrate having a length in the longitudinal direction longer than the length in the transverse direction, and a plurality of SMD type (surface mount type) LED elements arranged in the substrate in the longitudinal direction and,

The lower surface of the upper frame, that is, the mounting plane, forms an inclined surface that tilts so that the angle formed with the board surface becomes gradually smaller toward the lateral direction from the board surface,

Wherein the first LED light source module among the plurality of LED light source modules is mounted on a side closest to the board surface of the mounting plane of the upper frame, and the n-1th light source module (n is a natural number of 3 or more) And the n-th light source module of the plurality of LED light source modules is disposed on the blackboard side of the n-1-th LED light source module, (Hereinafter, horizontally arranged) in the lateral direction.

This invention considers various technical means in various aspects.

First, the following technologies are considered in terms of sight protection of students or students taking the blackboard for a certain period of time.

First, use the LED as the illumination light source, but use the LED that does not use any LED and selects the characteristics. As a standard for an LED element as a light source, an LED having a CRI (color rendering index) of at least 80 or more is used so as to achieve an effect similar to a natural light source as much as possible using an LED having a high color rendering property. Also, in order to obtain a sufficient amount of light with the LED which is a point light source, the LED device having a minimum wide angle of 120 degrees or more is used. In particular, a surface mounting type (SMD type) LED element equipped with a wide-angle lens is used so as to meet these standards. Since light is irradiated proportionally to the square of the distance, the SMD component with the lowest height is suitable.

A plurality of LED elements are longitudinally arranged on a substrate relatively in the longitudinal direction to constitute an LED light source module. The number of LEDs to be mounted on the substrate, the arrangement interval, the number of array lines, and the like are arbitrary

Second, we will look at LED mounting technology. On the upper side of the chalkboard, there is an upper frame that is generally 'A' shaped, and an LED is mounted below the upper frame. A plurality of SMD type LEDs (aka chip LEDs) are arranged in a single direction to form an LED light source module having a relatively long length. A plurality of the light source modules are arranged in the longitudinal direction, . However, if the light source modules are arranged in a single line, the light irradiated downward from the top of the board is insufficient to be uniformly irradiated in the longitudinal direction of the board. This is because the LED element spreads while light is radiated similarly to other light sources other than the laser, so that the light amount per unit area, that is, the illuminance becomes lower as the distance of reaching the light becomes longer.

In order to solve this problem, the lower surface of the upper frame installed on the upper side of the blackboard, that is, the mounting plane, is tilted toward the boardboard surface in the upward direction along the vertical direction of the boardboard toward the lateral direction away from the boardboard surface Thereby forming an inclined surface. This will be described later in more detail with reference to the drawings. The light source modules are vertically arranged on the upper frame mounting plane formed by the inclined surfaces so that the light source modules are arranged on the farther side from the board (the first light source row) than the longitudinally arranged rows (first light source column) Respectively. However, the mounting plane of the second light source array is inclined so that the irradiation direction thereof is more toward the board side than the irradiation direction of the first light source row, so that the mounting plane can be more uniformly illuminated on the board side than the case where only the first light source row is provided . Further, another third light source array is arranged horizontally on the farther side from the board side than the second light source row. The third light source array is installed such that its mounting plane (the surface on which the third light source row is mounted) is inclined toward the board surface so that the irradiation direction thereof is further toward the boardboard surface than the irradiation direction of the second light source array. Thus, the light uniformity in the longitudinal direction of the board (that is, the vertical direction of the board) is reduced by the lateral arrangement of the first, second, and third light source rows (the respective irradiation directions are gradually stepped toward the board face) .

The light source row is not limited to three columns. Those skilled in the art will be able to arrange more of the light source rows in accordance with the size, usage, installation environment, etc. of the blackboard.

As a result, the uniformity of lighting in the horizontal direction of the board (i.e., the horizontal direction of the board) can be achieved by vertically arranging a plurality of LED light source modules in the longitudinal direction. However, In which a plurality of lines are arranged horizontally, but the farther away from the board the plane is, the larger the angle of the irradiation direction toward the board side becomes.

On the other hand, a light diffusion film (or a film to which a light diffusing chemical agent is added) is applied to an LED element at a distance of not less than a certain distance to suppress the fatigue of eyes due to a high contrast ratio, Install it so that LED light spreads evenly on the board's surface. The LED light source module is installed in a means (lateral light shielding plate) for lateral light shielding to prevent direct light from being illuminated to students (students) located close to the blackboard. This transverse shading plate only irradiates the LED light to within a certain angle and prevents lateral spreading, so students who are close to the blackboard can not see the LED light directly and can prevent glare. It is preferable that the transverse light-shielding plate is formed in a sectional shape of approximately 'c', 'a' and 'I'.

Third, LED elements with different color temperatures were simultaneously adopted to reduce the fatigue of eyes and to enhance the learning effect of students. As described above, not only the eye fatigue can be lowered by using the high-color LED device, but also the LED devices of different color temperature can be additionally used so that the devices of different color temperatures can emit light at a constant amount of light through the electronic circuit It is possible to make light as close to natural light as possible.

Next, consider the technical means of eliminating shadows or reflected light from outside light incident on the board surface at the side of the board.

In order to prevent the eyes from being easily tired by the shadow or reflection light formed on the board due to external sunlight or lighting installed on the ceiling, and to prevent the learning concentration from deteriorating, it is automatically detected that external light is incident, Thereby realizing a function of increasing the luminous intensity of the device.

As one of the methods of detecting external light, when the intensity of a signal output from an optical sensor that senses external light by using an optical sensor such as a CdS sensor exceeds a certain level, external light amount exceeding the allowable level is reflected on the board And controlling the brightness of the LED device. If it is detected that external light exceeding the allowable level is detected, the amount of light can be increased by controlling the predetermined LED elements included in the installed light source module. It is easy for those skilled in the art to increase the light amount of the LED element. For example, PWM control can be performed while dynamically driving an LED element by a pulse.

Another way to increase the light intensity of an LED device is to turn off the LED light source module (hereinafter referred to as a spare light source module) that is preliminarily installed in advance for detecting external light, It is possible to turn on this spare light source module.

In another embodiment, the amount of light of the LED element may be increased proportionately (not always in direct proportion) or the number of turn-on of the spare light source module may be controlled according to the amount of external light sensed.

On the other hand, as an alternative to detecting the amount of external light by the optical sensor, an image sensor such as a CMOS or CCD sensor can be used. The image sensor captures an image including the light amount or position of the external light and processes the image data to recognize the change in light amount of the external light or the external light having exceeded the allowable level to control the brightness of the LED element, Can be turned on.

The foregoing description will become more apparent from the following detailed description of the invention when taken in conjunction with the drawings.

According to the present invention, it is possible to irradiate the light uniformly on the blackboard and prevent reflected light or shadow from being formed on the blackboard even when external light is incident, thereby protecting the eyesight of the learner and enhancing the learning effect do.

1 is a front view and a side view of a blackboard 10 provided with an LED lighting device according to the present invention.
2 is a configuration diagram of the LED light source module 20. Fig.
3 is a view for explaining in detail the mounting plane on which the LED light source module 20 is mounted on the upper frame 12 of the board 10;
4 is a view showing a specific embodiment of the LED light source module 20. Fig.
5 shows another specific embodiment of the LED light source module 20. Fig.
6 (a) and 6 (b) are diagrams of a system for automatically controlling the LED elements by automatically detecting that external light is incident.

Hereinafter, a representative embodiment of the idea of the LED lighting board according to the present invention will be described with reference to the drawings. Those skilled in the art will be able to understand the technical idea of the present invention more easily through the following embodiments, and various modifications and modifications will be possible based on this understanding.

First, the specification of the light source used in the present invention will be described. Although not shown in the drawings, LEDs are used as an illumination light source as described in the item "Solution of the problem". In order to further reduce the fatigue of the eyes and improve the learning effect (attendance effect) of the students, CRI (color rendering) An LED with an index of at least 80 or more was used, and an SMD type LED (aka chip LED) with a minimum light angle of 120 degrees or more and a minimum height of a light emitting source was used. In addition, LED elements with different color temperatures were employed at the same time. By using LED devices with different color temperatures, devices of different color temperatures can emit light at a constant amount of light through an electronic circuit. This allows the board to be illuminated with more natural light than the blend of light of various wavelengths, such as sunlight.

Next, the structure and action of the present invention will be described.

1 is a front view and a side view showing a conceptual configuration of the LED illumination chalkboard 10 according to the present invention. A plurality of LED light source modules 20 are arranged and mounted on a lower surface of the upper frame 12, that is, a mounting plane, generally at the upper side of the blackboard 10, do. In the mounting method, LED light source modules 20 having a relatively long length are arranged by arranging a plurality of SMD type LEDs (aka chip LEDs) in one direction, and a plurality of these light source modules 20 are arranged in the longitudinal direction again Is mounted on the lower surface of the upper frame (12) of the board (10).

The LED light source module 20 is illustrated in Fig. 2, the LED light source module 20 is configured by surface-mounting a plurality of chip LEDs (or SMD type LEDs) on a rectangular substrate. The LED light source modules 20 as shown in FIG. 2 are arranged in a plurality of longitudinal directions, that is, vertically arranged and arranged in the horizontal direction (lateral direction) of the blackboard below the upper frame 20 of the blackboard 10.

Returning to FIG. 1, if the light source modules 20 are arranged in a single line, it is insufficient that the light beams 22 irradiated downward from above the blackboard 10 are uniformly irradiated in the longitudinal direction of the blackboard 10. Not only the light source modules 20 are longitudinally arranged (vertically arranged) but also arranged in a plurality of rows in the width direction (horizontally arranged) for uniform dimming in the longitudinal direction. This will be described in detail later in the drawings.

3 is a side view of the upper frame 12 in detail illustrating a configuration in which the LED light source module 20 is mounted on the lower surface of the upper frame 12 of the blackboard 10 . The lower surface of the upper frame 12, that is, the mounting plane is not parallel to the ground, but forms an inclined surface. The inclination of the inclined surface tilts so that the angle formed with the surface of the board 10 gradually decreases toward the lateral direction away from the surface of the board 10. That is, at a position close to the board (10), the angle between the mounting plane and the board is almost 90 °, and the angle between the mounting plane and the board is smaller than 90 ° It becomes a small angle.

On this mounting plane, the second light source array 20b (the first light source array 20a), which is a sub-array of the light source modules, (Horizontal arrangement). However, the tangent line 20b-p of the mounting plane of the second light source array 20b is set such that the LED illumination direction 20b-i is further closer to the blackboard 20a than the irradiation direction 20a-i of the first light source array 20a 10 so that the light can be evenly dimmed on the board 10 surface as compared with the case where only the first light source unit 20a is provided. Further, another third light source array 20c is arranged laterally on the farther side from the blackboard 10 side than the second light source array 20b. The third light source array 20c is arranged so that the LED illumination direction 20c-i is directed to the blackboard 10 surface more than the illumination direction 20b-i of the second light source array 20b, -p) are inclined toward the board (10). By arranging the first, second and third light source rows 20a, 20b, and 20c (each of which is slightly inclined toward the side of the board 10 stepwise little by little) Light uniformity in the vertical direction (that is, the vertical direction of the blackboard) can be achieved.

Fig. 4 shows a specific embodiment of the LED light source module 20 shown in Fig. In order to suppress the high contrast ratio of the LED, the light diffusion film 24 is provided at a certain distance from the chip LED. The light diffusion film 24 can be implemented as a plastic film to which a chemical solvent that performs a light diffusion function is added. The role of this film is to diffuse the LED light having high contrast to uniformly irradiate the surface of the blackboard 10. The optical acid film 24 may be made of any material as long as it achieves the purpose of light diffusion, and may be manufactured separately from the substrate and assembled together with the substrate as one body.

Fig. 5 shows another specific embodiment of the LED light source module 20 shown in Fig. In order to prevent the light of the LED device from being seen directly on the eyes of a student (student) sitting close to the blackboard 10, the substrate of the LED light source module 20 is inserted into the transverse light shielding plate 26 having a substantially " Indicates installation. Since the LED light is irradiated only within a certain angle by the transverse light shield plate 26, the student who is close to the blackboard can not directly see the LED light, thereby preventing glare. The transverse light-shielding plate 26 may be made of any material so long as it achieves the object of shading, and it may be manufactured separately from the substrate and assembled together with the substrate as one body.

In FIG. 5, if the lengthwise side of the transverse light shielding plate 26 is formed as the bent side 28 curved inward, the lateral light shielding effect is further doubled.

On the other hand, FIG. 5 shows that the transverse shading plate is in the form of a 'C' shape, but it is also obvious that a transverse shading plate in the form of 'A' or 'B' or 'I' shape is also possible.

As another embodiment, an LED light source module having both the light diffusion film 24 of FIG. 4 and the transverse light shield plate 26 of FIG. 5 may be used.

6 (a) and 6 (b) are diagrams for explaining an example of an external light source in order to prevent eyes from being easily tired due to shadows or reflected light formed on the board due to external sunlight, Is automatically detected to automatically turn on the LED element or to increase the brightness.

(a) is a method of detecting external light, in which a signal output from an optical sensor that senses external light 32 is input to the LED driver 40 using a CdS sensor 30, which is a kind of optical sensor, The LED driver 40 determines that the external light 32 having a light amount exceeding the allowable level is reflected on the blackboard, thereby adjusting the brightness of the LED device.

When the LED driver 40 senses that external light exceeding the allowable level is generated, it can increase the amount of light by controlling the predetermined LED elements included in the pre-installed light source module 20. It is easy for those skilled in the art to increase the light amount of the LED element. For example, PWM control can be performed while dynamically driving an LED element by a pulse.

Another method for increasing the light amount of the LED element is to turn off the LED light source module (hereinafter referred to as spare light source module) (not shown) previously installed for detecting external light, The LED driver 40 may be turned on to turn on these spare light source modules.

Furthermore, the LED driver 40 may proportionally increase the amount of light of the LED element or control the number of turn-on of the spare light source module depending on the amount of the detected external light (not necessarily in direct proportion). Which can be easily implemented by those skilled in the art.

(b) uses an image sensor 35 such as a CMOS or a CCD sensor as a method different from the method of detecting the amount of external light by the optical sensor. A vertical bar 37 is provided in front of the sensing surface 36 of the image sensor 35 at a position facing the substantially central portion of the sensing surface 36 and the shadow 38 of the bar 37 produced by the external light 32 And the DSP 50 processes the image data including the position of the shadow 38 and the brightness value per area of the sensor sensing surface 36 to determine whether the external light exceeding the allowable level is generated or the light amount change of the external light The LED driver 40 can control the brightness of the LED element 20 or turn on the spare light source module. This can also be easily carried out by those skilled in the art.

The light source 20 includes a blackboard 10, an upper frame 12, an LED light source module 20, a light beam 22, a first light source array 20a, a second light source array 20b, a third light source array 20c, The light sensor 24, the transverse light shield plate 26, the CdS sensor 30, the external light 32, the image sensor 35, the sensing surface 36, the vertical bar 37,

Claims (7)

An upper frame protruding vertically from an upper side of a board having a horizontal direction and a vertical direction and having a longitudinal direction corresponding to a horizontal direction of the board and a lateral direction corresponding to a direction protruding from the board; And a plurality of LED light source modules mounted on a surface (hereinafter referred to as " mounting plane ") and adapted to irradiate light toward the longitudinal direction of a boardboard surface,
Wherein each of the plurality of LED light source modules includes a substrate having a length in the longitudinal direction longer than the length in the transverse direction and a plurality of SMD type (surface mount type) LED elements arranged in the substrate in the longitudinal direction,
The lower surface of the upper frame, that is, the mounting plane, forms an inclined surface that tilts so that the angle formed with the board surface becomes gradually smaller toward the lateral direction from the board surface,
Wherein the first LED light source module among the plurality of LED light source modules is mounted on a side closest to the board surface of the mounting plane of the upper frame, and the n-1th light source module (n is a natural number of 3 or more) And the n-th light source module of the plurality of LED light source modules is disposed on the blackboard side of the n-1-th LED light source module, (Hereinafter, referred to as " lateral arrangement ") in the lateral direction from the rear side. The board according to claim 1, wherein the LED light source module further comprises a light diffusion film provided in front of the light irradiation part of the LED element. The LED light source module according to claim 1, further comprising a transverse light shielding plate for shielding lateral spreading of the LED element in the light irradiation direction so that the light emitted from the LED element is irradiated only within a predetermined angle , Chalkboard with LED lighting. The board according to claim 1, wherein the LED elements of the LED light source module have different color temperature characteristics. The apparatus according to claim 1, further comprising means for detecting external light incident on the board surface, and means for controlling the brightness of the LED light source module according to the detected amount of external light,
Wherein the external light incidence detection means is an optical sensor,
And the brightness control means includes an LED driver for adjusting the brightness of the LED device when the intensity of the signal output from the optical sensor exceeds a predetermined level, The blackboard with LED lighting is made. The apparatus of claim 1, further comprising: means for detecting that external light is incident on the board surface; and means for controlling the brightness of the LED light source module according to the detected amount of external light,
The external light incidence sensing means is an image sensor for sensing the light amount or position of external light,
The brightness control means includes means for processing the image data captured by the image sensor, and an LED driver for generating external light exceeding an allowable level, or for recognizing a change in light amount of external light and adjusting the brightness of the LED element The blackboard with LED lighting is made. The LED lighting device according to claim 6, further comprising a spare LED light source module preliminarily installed in advance for detecting external light, and being turned on / off by the LED driver blackboard.

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