Patent Description:
Most living organisms have been adapted to work in accordance with changes in sunlight. A human body has also been adapted to sunlight for a long time. As a result, the biological rhythm of a human being changes in accordance with the change of sunlight. Especially in the morning cortisol hormone is secreted in the human body under bright sunlight. Cortisol hormone allows more blood to be supplied to each organ of the body to counteract external stimuli such as stress, as a result, pulses and respiration are increased and the human body is awakened from sleep to prepare for outside activities. In the daytime, physical activities are performed under strong sunlight, but melatonin hormone is secreted in the evening and lowers pulse rate, body temperature, and blood pressure, as a result, gets a human body tired and helps to sleep.

However, in modern society, most people do not perform physical activities under sunlight, but mainly work in indoors such as homes and offices. It is normal that most people stay indoors for longer than the hours of physical activity under sunlight, even in the midday.

In the meantime, indoor lighting devices generally exhibit certain spectral power distributions, and these spectral power distributions have many differences from the spectral power distribution of sunlight. For example, in the case of a light emitting device using blue, green, and red light emitting diodes, even though white light can be implemented by a combination of blue, green, and red, the light emitting device does not exhibit a spectral power distribution over a wide wavelength range of visible range as in sunlight, but exhibit a distribution having a peak at a certain wavelength.

In addition, human skin produces vitamin D using ultraviolet rays of sunlight, but indoor lighting devices do not have these ultraviolet components and vitamin D is not produced even if activities are done under indoor lighting devices for a long period.

The <CIT> discloses a light source device with a plurality of light emitting groups emitting white light having a first or a second color temperature. The <CIT> discloses a light source device with a plurality of first light emitting devices emitting white light of a first color temperature, and a plurality second light emitting devices emitting white light of a second color temperature.

Exemplary embodiments of the present disclosure provide a light emitting device to implement spectral power distribution change of sunlight which a human body is adapted to.

Other exemplary embodiments of the present disclosure provide a light emitting device capable of implementing a desired spectral power distribution with spectral power of sunlight adapted to the human body.

Other exemplary embodiments of the present disclosure provide a light emitting device illuminating indoor rooms and providing ultraviolet rays capable of producing vitamin D from human skin similarly to sunlight.

Additional features of the disclosure will be described in the following detailed description, and in part will be obvious from the detailed description, or concepts of the disclosure may be acquired by practice.

The present invention provides a light emitting device according to the appended claims.

A light emitting device in accordance with one exemplary embodiment comprises at least one main light emitting unit including a light emitting diode chip and a wavelength converter to emit white light, wherein the light emitting diode chip comprises an ultraviolet chip, a violet chip or a blue chip, and is adjustable to emit light corresponding to a spectral power distribution of morning sunlight, light corresponding to a spectral power distribution of afternoon sunlight, and light corresponding to a spectral power distribution of evening sunlight.

As used herein, the term "light emitting unit" indicates an individual light emitting source capable of implementing a specific spectral power distribution within a light emitting device. In the case when a light emitting diode chip is arranged without a wavelength converter, the light emitting diode chip becomes a light emitting unit, and in the case when a wavelength converter is applied on a light emitting diode chip, the combination of the light emitting diode chip and the wavelength converter becomes a light emitting unit. In the meantime, a light emitting unit implementing white light by a combination of a light emitting diode chip and a wavelength converter is called a main light emitting unit, and a light emitting unit implementing light other than white light is called an auxiliary light emitting unit.

The following drawings are included to provide a better understanding of concepts of the present invention, are included in and constitute a part of the present disclosure, illustrate exemplary embodiments of the present disclosure, and contribute to explain principles of concepts of the present invention with detailed descriptions.

Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The present disclosure is not limited to the embodiments disclosed herein, and can also be implemented in different forms. In addition, in the drawings, widths, lengths, thicknesses, and the like of elements may be exaggerated for clarity and descriptive purposes. Throughout the specification, like numerals denote like elements.

First, various examples of a light emitting device for implementing light corresponding to changes in spectral power distributions of sunlight will be described with reference to <FIG>.

<FIG> is a schematic cross-sectional view for illustrating a light emitting device in accordance with an example not forming part of the invention.

Referring to <FIG>, the light emitting device may comprise a base <NUM>, light emitting diode chips 20a, 20b, and 20c and wavelength converters 30a, 30b, and 30c.

Like a printed circuit board, the base <NUM> may comprise circuit wirings for supplying electric power to each of the light emitting diode chips 20a, 20b, and 20c.

Each of the light emitting diode chips 20a, 20b, and 20c may be a ultraviolet (UV) chip, a violet chip or a blue chip. The ultraviolet chip may emit light in the wavelength range of <NUM> to <NUM>, but is not particularly limited thereto. In a particular example, the ultraviolet chip may emit ultraviolet light in the wavelength range of <NUM> to <NUM>, as a result, it may contribute to the production of vitamin D from human skins. In the meantime, the violet chip may emit light in the range of <NUM> to <NUM> and the blue chip may emit light in the range of <NUM> to <NUM>.

The light emitting diode chips 20a, 20b, and 20c may be chips having the same peak wavelength, but they are not limited thereto, and may emit light of different peak wavelengths within the above ranges.

The wavelength converters 30a, 30b, and 30c may be coated or adhered onto the chips. The wavelength converters 30a, 30b, and 30c may comprise phosphors emitting fluorescence in relatively wide wavelength ranges. One or more phosphors may be incorporated in each of the wavelength converters 30a, 30b, and 30c.

For instance, phosphors may comprise YAG phosphors, LuAG phosphors, β-sialon (SiAlON), alpha-sialon (SiAlON), CASN, Silicate BAM phosphors, or others, and at least one of these can be selected.

YAG phosphor is generally selected for yellow wavelengths, and it is possible to emit light in a wavelength range from yellowish orange to green by adding Gd and Ga. As Gd is added and its amount increases, a wavelength shifts to a longer wavelength, while as Ga is added and its amount increases, a wavelength shifts to a shorter wavelength.

LuAG-based phosphor is mainly selected for yellowish green wavelengths, and it is possible to emit Cyan color by adding Ga.

Beta sialon (SiAlON) is suitable for emitting light in a green wavelength range, and alpha sialon (SiAlON) is suitable for emitting light in an amber wavelength range. In addition, the CASN (CaAlSiN) -based phosphors are suitable for emitting light in a red wavelength range.

Light corresponding to a spectral power distribution of morning sunlight is implemented by the light emitting diode chip 20a and the wavelength converter 30a. Similarly, light corresponding to a spectral power distribution of daylight (afternoon sunlight) is implemented by the light emitting diode chip 20b and the wavelength converter 30b, and light corresponding to a spectral power distribution of evening sunlight is implemented by the light emitting diode chip 20c and the wavelength converter 30c.

In the present exemplary embodiment, a combination of the light emitting diode chip and the wavelength converter constitutes a "light emitting unit". Here, the light emitting unit represents a unit capable of implementing a particular spectral power distribution individually in a light emitting device. In the meantime, hereinafter, a light emitting unit emitting white light is called a main light emitting unit, and a light emitting unit emitting light of a color other than white light is called an auxiliary light emitting unit. Therefore, light emitting units of this exemplary embodiment are all main light emitting units.

In the present exemplary embodiment, although the light emitting units are illustrated as being mounted on a single base <NUM>, light emitting units may be provided as light emitting modules mounted on different sub-mounts or printed circuit boards, and these light emitting modules may be mounted on the base <NUM>.

In addition, the light emitting units may be molded together by the same molding material, or molded respectively by molding materials which are separated from each other.

Furthermore, the light emitting device may be used for various lighting devices such as light bulbs and tube lighting devices.

In the light emitting device in accordance with the present exemplary embodiment, each light emitting unit independently operates and implements light corresponding to morning sunlight, afternoon sunlight, or evening sunlight.

<FIG> is a schematic cross-sectional view for illustrating a light emitting device in accordance with another example not forming part of the invention.

Referring to <FIG>, the light emitting device comprises a base <NUM>, light emitting diode chips 20a and 20d, and a wavelength converter 30a.

The light emitting diode chip 20a, as described above, may be an ultraviolet (UV) chip, a violet chip or a blue chip. Here, the blue chip can emit light in the range of <NUM> to <NUM>, in particular, it can emit light in the short wavelength range of <NUM> to <NUM>.

The wavelength converter 30a comprises a phosphor, and the phosphor may be selected from the phosphors described in the previous embodiment. A light emitting unit (a main light emitting unit) including the light emitting diode chip 20a and the wavelength converter 30a may implement light corresponding to a spectral power distribution of morning sunlight, afternoon sunlight or evening sunlight, respectively, but is not limited thereto.

In the meantime, the light emitting diode chip 20d is used for a light emitting unit without a wavelength converter. The light emitting diode chip 20d is an auxiliary light emitting unit, which may be selected from a violet chip, a blue chip, a cyan chip, a creen chip, a yellow chip, an amber chip, or a red chip. One of the chips among them may be selected and used, or a combination of two or more chips may be selected and used.

In the present exemplary embodiment, although the light emitting units are illustrated as being mounted on the single base <NUM>, light emitting units may be provided as light emitting modules mounted on different sub-mounts or printed circuit boards, and these light emitting modules may be mounted on the base <NUM>.

In the present exemplary embodiment, the main light emitting unit may emit light corresponding to a spectral power distribution of morning sunlight, afternoon sunlight, or evening sunlight, and light corresponding to spectral power distributions of two different sunlight may be implemented by combining the main light emitting unit and the auxiliary light emitting unit. Alternatively, light corresponding to each of spectral power distributions of morning sunlight, afternoon sunlight, and evening sunlight may be implemented by both of the main lighting unit and the auxiliary lighting unit.

The light emitting device, the base <NUM> comprises light emitting diode chips 20a and 20c and wavelength converters 30a and 30c.

Here, the light emitting diode chip 20a and the wavelength converter 30a constitute a main light emitting unit, and a light emitting diode chip 20e and a wavelength converter 30e constitute an auxiliary light emitting unit.

The light emitting diode chip 20a may be an ultraviolet chip, a violet chip or a blue chip as described in previous embodiments. The light emitting diode chip 20e is a blue chip, and the wavelength converter 30e comprises at least one phosphor selected from cyan, green, yellow, amber, or red phosphor.

In the present exemplary embodiment, it is described that one auxiliary light emitting unit is used, but a plurality of auxiliary light emitting units may be used.

In the present exemplary embodiment, the main light emitting unit may emit light corresponding to a spectral power distribution of morning sunlight, afternoon sunlight, or evening sunlight, and light corresponding to spectral power distributions of two different sunlight may be implemented by combining the main light emitting unit and the auxiliary light emitting unit. Alternatively, light corresponding to each of the spectral power distributions of morning sunlight, afternoon sunlight, and evening sunlight may be implemented by both of the main lighting unit and the auxiliary lighting unit.

Referring to <FIG>, the light emitting device comprises a base <NUM>, light emitting diode chips 20a, 20d, and 20e, and wavelength converters 30a and 30e.

Here, the light emitting diode chip 20a and the wavelength converter 30a constitute a main light emitting unit, the light emitting diode chip 20d constitutes a first auxiliary light emitting unit, and the light emitting diode chip 30e constitutes a second auxiliary light emitting unit.

The light emitting diode chip 20a may be an ultraviolet chip, a violet chip or a blue chip as described in previous embodiments. In the meantime, as described in the embodiment of <FIG>, the light emitting diode chip 20d may be selected from a violet chip, a blue chip, a cyan chip, a green chip, a yellow chip, an amber chip, or a red chip, or any combination thereof.

The light emitting diode chip 20e is a blue chip as described in the embodiment of <FIG>, the wavelength converter 30e is at least one selected from cyan, green, yellow, amber, or red phosphors. A single or a plurality of auxiliary light emitting units including a light emitting diode chip 20e and a wavelength converter 30e may be used for the light emitting device in the present embodiment.

In the present exemplary embodiment, the main light emitting unit may emit light corresponding to a spectral power distribution of morning sunlight, afternoon sunlight, or evening sunlight, and light corresponding to spectral power distributions of two different sunlight may be implemented by combining the main light emitting unit and the first and the second auxiliary light emitting units. Alternatively, light corresponding to each of the spectral power distributions of morning sunlight, afternoon sunlight, and evening sunlight may be implemented by combining the main light emitting unit and the first and/or the second auxiliary light emitting units.

Referring to <FIG>, the light emitting device comprises a base <NUM>, light emitting diode chips 20a, 20b, and 20d, and wavelength converters 30a and 30b.

The light emitting diode chips 20a and 20b may be ultraviolet chips, violet chips or blue chips as described above, and the light emitting diode chip 20d, as described in the embodiment of <FIG>, may be selected from a violet chip, a blue chip, a cyan chip, a green chip, a yellow chip, an amber chip, or a red chip, or any combination thereof.

The wavelength converter 30a and 30b comprise phosphors as described in the embodiment of <FIG>.

In the present exemplary embodiment, the light emitting diode chip 20a and the wavelength converter 30a constitute a first main light emitting unit, and the light emitting diode chip 20b and the wavelength converter 30b constitute a second main light emitting unit, which implement white respectively. For example, the first light emitting unit may implement cool white, and the second light emitting unit may implement warm white.

In the meantime, an auxiliary light emitting unit including the light emitting diode chip 20d emits light in the wavelength range of violet, blue, cyan, green, yellow, amber, or red.

In the present exemplary embodiment, light corresponding to a spectral power distribution of morning sunlight, afternoon sunlight, or evening sunlight may be roughly implemented by a combination of the first light emitting unit and the second light emitting unit, and a spectral power distribution of sunlight may be precisely controlled by the auxiliary light emitting unit. Therefore, light corresponding to each of the spectral power distributions of morning sunlight, afternoon sunlight, and evening sunlight may be implemented by combining the first light emitting unit, the second light emitting unit and the auxiliary light emitting unit.

Referring to <FIG>, the light emitting device comprises a first light emitting unit and a second light emitting unit, similarly to the light emitting device described with reference to <FIG>. However, in the present exemplary embodiment, it is different in that the auxiliary light emitting unit of <FIG> is replaced with the auxiliary light emitting unit described in the embodiment of <FIG>.

That is, the auxiliary light emitting unit comprises a light emitting diode chip 20e and a wavelength converter 30e, the light emitting diode chip 20e is a blue chip, and the wavelength converter 30e comprises at least one of cyan, green, yellow, amber, or red phosphors. As described with reference to <FIG>, one auxiliary light emitting unit may be used, and a plurality of auxiliary light emitting units may be used.

In the present exemplary embodiment, light corresponding to each of the spectral power distributions of morning sunlight, afternoon sunlight, and evening sunlight is implemented by combining the first light emitting unit, and the second light emitting unit and the auxiliary light emitting unit.

Referring to <FIG>, the light emitting device comprises a first light emitting unit, a second light emitting unit and an auxiliary light emitting unit, similarly to the light emitting device described with reference to <FIG>. In addition, the light emitting device in accordance with the present embodiment further comprises auxiliary light emitting units 20e and 30e described with reference to <FIG>.

In the present exemplary embodiment, light corresponding to each of the spectral power distributions of morning sunlight, afternoon sunlight, and evening sunlight is implemented by combining the first light emitting unit, the second light emitting unit and the auxiliary light emitting unit. Light close to the wavelength distribution of sunlight may be implemented by comprising two kinds of auxiliary light emitting units.

Referring to <FIG>, the light emitting device is substantially similar to the light emitting diode described with reference to <FIG>, but is different in that it further comprises an ultraviolet light emitting diode chip 20f.

The ultraviolet light emitting diode chip 20f may emit ultraviolet rays having a wavelength within ranges of <NUM> to <NUM>, and as a result, it may be irradiated on human skins and vitamin D may be produced.

The ultraviolet light emitting diode chip 20f may also be added to the embodiments of <FIG>.

In the meantime, in the exemplary embodiments described above, the light emitting units may be molded together by the same molding material, or molded respectively by molding materials which are separated from each other.

In order to increase power of the light emitting device, it is necessary to arrange a plurality of light emitting units of the same kind on a base. Hereinafter, embodiments in which a plurality of light emitting units are arranged on a printed circuit board will be described in detail.

<FIG> is a plan view for illustrating a light emitting device in accordance with an exemplary embodiment of the present invention.

Referring to <FIG>, the light emitting device <NUM> in accordance with the exemplary embodiment comprises a base <NUM>, first to fourth light emitting groups L1, L2, L3, and L4, each of which comprises one or more light emitting diode chips <NUM>, first to fourth electrode pads <NUM>, <NUM>, <NUM>, and <NUM> and may comprise first to eighth electrode terminals <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>.

The light emitting diode chips <NUM> comprised in the light emitting groups L1, L2, L3 and L4 may be mounted on the base <NUM>, such as a printed circuit board, and electric power may be provided to each of the light emitting groups L1, L2, L3, and L4, through the first to fourth electrode pads <NUM>, <NUM>, <NUM>, and <NUM> and the first to eighth electrode terminals <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>.

Each of the first to fourth light emitting groups L1, L2, L3, and L4 comprises one or more light emitting diode chips <NUM>. As in the present embodiment, in the case where a plurality of light emitting diode chips <NUM> are comprised in each of the light emitting groups L1, L2, L3, and L4, the plurality of light emitting diode chips <NUM> may be electrically connected to one another within the light emitting groups L1, L2, L3, and L4, and the plurality of light emitting diode chips <NUM> may be connected in a serial connection or a parallel connection.

In the present embodiment, the first to fourth light emitting groups L1, L2, L3, and L4 may independently emit light having a predetermined color temperature, respectively. To do this, light emitting diode chips <NUM> comprised in each of the light emitting groups L1, L2, L3, and L4 may be chips having the same peak wavelength. However, the present disclosure is not limited thereto, and it is possible to emit light having different peak wavelengths one another within a predetermined range.

In the meantime, the first to fourth light emitting groups L1, L2, L3, and L4 may emit light having different color temperatures one another. For example, two or more light emitting groups may emit light having the same color temperature, and remaining light emitting groups may emit light having other color temperature.

In accordance with the claimed invention, the first light emitting group L1 and the third light emitting group L3 emit light having the same color temperature, and the second light emitting group L2 and the fourth light emitting group L4 emit light having the same color temperature. At this time, the color temperature of the light emitted from the first and third light emitting groups L1 and L3 and the color temperature of the light emitted from the second and fourth light emitting groups L2 and L4 are different.

The first to fourth light emitting groups L1, L2, L3, and L4 may comprise a wavelength converter comprising a phosphor as needed. The light emitting diode chips <NUM> comprised in the same light emitting group of the first to fourth light emitting groups L1, L2, L3, and L4 may be used to implement light emitting sources implementing the same spectral power distribution or may be used to implement light emitting sources implementing different spectral power distributions. At this time, a wavelength converter may be arranged on the light emitting diode chip <NUM>, and a predetermined spectral power distribution may be shown. The wavelength converters may be independently disposed on the respective light emitting diode chips <NUM>, but it is not limited thereto, and the wavelength converters may be disposed to cover the respective light emitting groups L1, L2, L3, and L4. By combining the light emitting diode chip <NUM> and the wavelength converter, the main light emitting unit and / or auxiliary light emitting unit described in the previous embodiments <NUM> to <NUM> may be formed. For example, light emitting diode chips <NUM> comprised in each of the light emitting groups L1, L2, L3, and L4 may implement main light emitting units or auxiliary light emitting units together with a wavelength converter, thus, the light emitting device <NUM> may change spectral power distributions of light corresponding to power of sunlight and in accordance with changes in spectral power distributions of sunlight.

Furthermore, the light emitting diode chips <NUM> comprised in each of light emitting groups L1, L2, L3, and L4 may emit light having different wavelengths, for example, a blue light emitting diode chip, a green light emitting diode chip, and a red light emitting diode chip may be used in one light emitting group, and light emitted from each light emitting diode chip <NUM> may be mixed and emit white light. As another example, the main light emitting unit and the auxiliary light emitting unit may be comprised in each light emitting group.

And the plurality of light emitting diode chips <NUM> comprised in each of the light emitting groups L1, L2, L3, and L4 serve as light emitting sources, respectively. The plurality of light emitting diode chips <NUM> may be alternately arranged on the bases <NUM>. Alternatively in the case when blue light emitting diode chips, green light emitting diode chips and red light emitting diode chips are used, they may be arranged concentrically adjacent to each other or triangularly arranged.

In the present embodiment, it is described that <NUM> light emitting diode chips <NUM> are comprised in each of the first to fourth light emitting groups L1, L2, L3, and L4, and it is described and illustrated that the first to fourth light emitting groups L1, L2, L3, and L4 are disposed in a circular mounting portion on the base <NUM>. As an example, <NUM> light emitting diode chips <NUM> comprised in the first light emitting group L1 may be arranged in three lines, and a plurality of light emitting diode chips <NUM> in each line may be arranged at predetermined distances. At this time, a light emitting diode chip <NUM> arranged in each line may not be arranged to be flush with a light emitting diode chip <NUM> of an adjacent line thereto, but may be arranged in a position shifted upward or downward. For example, the light emitting diode chips <NUM> arranged in each line may be arranged at the same distance from one another, and the light emitting diode chip <NUM> arranged in one line may be arranged to be flush with a center between two light emitting diode chips <NUM> of an adjacent line thereto. Accordingly, the first light emitting group L1 may be configured in three lines comprising three light emitting diode chips <NUM>, eight light emitting diode chips <NUM> and nine light emitting diode chips <NUM>, respectively, and the light emitting diode chips <NUM> of the respective lines may be arranged alternately with one another. As a result, light emitting units of a same kind may be arranged to be spaced apart at a distance and not to be adjacent to one another, and may implement uniform light.

In addition, <NUM> light emitting diode chips <NUM> comprised in the second light emitting group L2 may be arranged in two lines, and <NUM> light emitting diode chips <NUM> may be arranged in each line at a predetermined distance. At this time, the light emitting diode chips <NUM> arranged in each line may not be arranged to be flush with a light emitting diode chip <NUM> of an adjacent line thereto, but may be arranged in a position shifted upward or downward. For example, the light emitting diode chips <NUM> arranged in each line may be arranged at the same distance from one another, and the light emitting diode chip <NUM> arranged in one line may be arranged to be flush with a center between two light emitting diode chips <NUM> of an adjacent line thereto.

In the third light emitting group L3, like the second light emitting group L2, <NUM> light emitting diode chips <NUM> may be arranged in two lines, and the light emitting diode chips <NUM> arranged in each line may not be arranged to be flush with a light emitting diode chip <NUM> of an adjacent line thereto, but may be arranged in a position shifted upward or downward. For example, the light emitting diode chips <NUM> arranged in each line may be arranged at the same distance from one another, and the light emitting diode chip <NUM> arranged in one line may be arranged to be flush with a center between two light emitting diode chips <NUM> of an adjacent line thereto.

The fourth light emitting group L4, similarly to the first light emitting group L1, may have <NUM> light emitting diode chips <NUM> arranged in three lines.

As described above, when the light emitting diode chips <NUM> are connected in series, the length of a wire W connecting each light emitting diode chip <NUM> may be minimized by arranging the plurality of light emitting diode chips <NUM> comprised in each of light emitting groups L1, L2, L3, and L4 at shifted positions. Further, as described above, even if the number of the light emitting diode chips <NUM> comprised in the light emitting device <NUM> is reduced, a desired color temperature may be implemented by arranging the plurality of light emitting diode chips <NUM>.

According to the invention, two or more kinds of light emitting units are comprised in one light emitting group. It is thus possible to mix light emitted from the light emitting units more uniformly by alternately arranging these light emitting units, and a size of the light emitting device may be reduced. For example, when arranging blue, green, and red light emitting diode chips in each light emitting group L1, L2, L3, and L4, blue, green, and red light emitting diode chips may be arranged at apexes of a triangular structure. Further, another triangular structure adjacent to the triangular structure composed of blue, green, and red light emitting diode chips, as shown in <FIG>, may be arranged in an inverted triangular shape, and light emitting diode chips of the same kind may be arranged so as to be spaced farther apart than different kinds of chips. In particular, pairs of light emitting diode chips of the same kind may be spaced apart from one another by the same distance. As a result, the light emitting diode chips <NUM> may be arranged in a densely packed state, and uniform light may be implemented. Blue, green, and red light emitting diode chips are described as examples, but it is not limited thereto, and three kinds of main light emitting units, or two kinds of main light emitting units and one auxiliary light emitting unit, or one main light emitting unit and two kinds of auxiliary light emitting units may be arranged as described above.

As shown in <FIG>, the first to fourth electrode pads <NUM>, <NUM>, <NUM>, and <NUM> are disposed at the four corners of the base <NUM>, respectively, and are incorporated to electrically connect to an external power supply. To do this, the first to fourth electrode pads <NUM>, <NUM>, <NUM>, and <NUM> may be formed to have predetermined widths.

The first to eighth electrode terminals <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may be incorporated to electrically connect to the first to fourth light emitting groups L1, L2, L3, and L4, respectively, the first to eighth electrode terminals <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> may be formed in a shape surrounding the first to fourth light emitting groups L <NUM>, L <NUM>, L <NUM>, and L <NUM> in the present embodiment.

Referring to <FIG>, the first light emitting group L1 is electrically connected to the second electrode terminal <NUM> and the sixth electrode terminal <NUM>, and the second light emitting group L2 is electrically connected to the third electrode terminal <NUM> and the seventh electrode terminal <NUM>. The third light emitting group L <NUM> is electrically connected to the first electrode terminal <NUM> and the fifth electrode terminal <NUM>, and the fourth light emitting group L4 is electrically connected to the fourth electrode terminal <NUM> and the eighth electrode terminal <NUM>.

In the present embodiment, the first to fourth electrode terminals <NUM>, <NUM>, <NUM>, and <NUM> may be terminals for supplying power to the first to fourth light emitting groups L1, L2, L3, and L4, and the fifth to eighth electrode terminals <NUM>, <NUM>, <NUM>, and <NUM> may be ground terminals. And the first electrode pad <NUM> and the second electrode pad <NUM> may be terminals for supplying power to the first to fourth light emitting groups L1, L2, L3, and L4 , and the third electrode pad <NUM> and the fourth electrode pad <NUM> may be ground terminals. However, it is not limited thereto, and a type of each electrode terminal and electrode pad may be changed as required.

In addition, if necessary, a blue light emitting diode chip, a green light emitting diode chip and a red light emitting diode chip may be electrically connected to electrode pads in a state of being connected to a common terminal, and light emitting groups having different color temperatures of the first to fourth light emitting groups L1, L2, L3, and L4 may be also connected to a common terminal as in the present embodiment.

Further, although it will be described in detail later, a reflector D1 may be disposed to surround the first to fourth light emitting groups L1, L2, L3, and L4, and a partition wall D2 may be disposed among the first to fourth light emitting groups L1, L2, L3, and L4. The reflector D1 may define a light emitting surface of the light emitting device <NUM> by being disposed so as to surround the first to fourth light emitting groups L1, L2, L3, and L4, and may define an area for forming a molding portion Ph on the light emitting surface defined inside the reflector D1. The reflector D1 may reflect light emitted from the first to fourth light emitting groups L1, L2, L3, and L4 to improve a light emission efficiency of the light emitting device <NUM>.

And, the partition wall D2 is disposed among the first to fourth light emitting groups L1, L2, L3, and L4, and incorporated to prevent light emitted from each light emitting group L1, L2, L3 and L4 from being mixed with light emitted from the adjacent light emitting groups L1, L2, L3, and L4.

<FIG> is a view for illustrating electrical connections between light emitting groups and electrodes of the light emitting device in accordance with the present embodiment, and <FIG> is a cross-sectional view of section A of <FIG>.

With reference to <FIG>, electrical connections between light emitting groups and the electrodes of the light emitting device <NUM> in accordance with the present embodiment and a relationship between electrode pads and electrode terminals will be described.

<FIG> is a view in which an insulating layer (not shown) covering the electrodes is removed from the base <NUM> in the light emitting device <NUM> of <FIG>, and electrode shapes forming the electrode pads and the electrode terminals are displayed as the insulating layer is removed. And in <FIG>, positions where each electrode pad and electrode terminal are arranged are indicated by dotted lines.

Referring to <FIG>, a first electrode pad <NUM>, a first electrode terminal <NUM> and a second electrode terminal <NUM> are formed as the insulating layer is formed on a first electrode <NUM>, and a second electrode pad <NUM>, a third electrode terminal <NUM> and a fourth electrode terminal <NUM> are formed as the insulating layer is formed on a second electrode <NUM>. A third electrode pad <NUM>, a fifth electrode terminal <NUM> and a sixth electrode terminal <NUM> are formed as the insulating layer is formed on a third electrode <NUM>, and a fourth electrode pad <NUM>, a seventh electrode terminal <NUM> and an eighth electrode terminal <NUM> are formed as the insulating layer is formed on a fourth electrode <NUM>.

In addition, the first to fourth electrodes <NUM>, <NUM>, <NUM>, and <NUM> may be formed with first to fourth electrode extensions 130a, 140a, 150a, and 160a on their sides, respectively. The first electrode extension 130a is formed extending from the first electrode <NUM> toward the second electrode <NUM>, and the second electrode extension 140a is formed extending from the second electrode <NUM> toward the first electrode <NUM>. At this time, the first electrode extension 130a and the second electrode extension 140a may have a region arranged so as to be adjacent to each other, but may be spaced apart so as to be electrically insulated from each other. In addition, the second electrode extension 140a may be arranged outside of the first electrode extension 130a relative to a position where the light emitting groups L1, L2, L3, and L4 are arranged.

The third electrode extension 150a is formed extending from the third electrode <NUM> toward the fourth electrode <NUM>, and the forth electrode extension 160a is formed extending from the fourth electrode <NUM> toward the third electrode <NUM>. At this time, the third electrode extension 150a and the fourth electrode extension 160a may have a region arranged so as to be adjacent to each other, but may be spaced apart so as to be electrically insulated from each other. In addition, the fourth electrode extension 160a may be arranged outside of the third electrode extension 150a relative to a position where the light emitting groups L1, L2, L3, and L4 are arranged.

As described above, in a state where the first to fourth electrodes <NUM>, <NUM>, <NUM>, and <NUM> are formed, the first light emitting group L1 is electrically connected to the first electrode <NUM> and the third electrode <NUM>, and the second light emitting group L2 is electrically connected to the second electrode <NUM> and the fourth electrode160. And the third light emitting group L3 is electrically connected to the first electrode <NUM> and the third electrode <NUM>, and the fourth light emitting group L4 is electrically connected to the second electrode <NUM> and the fourth electrode portion <NUM>.

Accordingly, in the present embodiment, the first light emitting group L1 and the third light emitting group L3 may be simultaneously controlled and driven, and the second light emitting group L2 and the fourth light emitting group L4 may be simultaneously controlled and driven, but it is not limited thereto, and positions of simultaneously driven light emitting groups L1, L2, L3, and L4 may be changed.

For example, the first light emitting group L1 and the third light emitting group L3 may be configured to emit light at a color temperature of <NUM>, the second light emitting group L2 and the fourth light emitting group L4 may be configured to emit light at a color temperature of <NUM>. As a result, light emitted from each light emitting group L1, L2, L3, and L4 may be mixed to emit light having a color temperature of about <NUM> based on operation of each light emitting group L1, L2, L3, and L4, and it is possible to change the light mixed in an adjustment of a light emitting power or the like of each light emitting group L1, L2, L3, and L4.

In addition, as another example, not falling within the scope of the claimed invention, one of the four light emitting groups L1, L2, L3, and L4 may be configured to emit light at a color temperature of <NUM>, another one to emit light at a color temperature of <NUM>, and the other one to emit light at a color temperature of <NUM>. At this time, light emitting groups to emit light at a color temperature of <NUM> may be two. As described above, various color temperatures may be implemented according to driving conditions by adjusting color temperatures of light emission in each light emitting group L1, L2, L3, and L4.

In the case that the light emitting device <NUM> emits light with those three color temperatures, desired mixed light may be emitted by arranging the four light emitting groups L1, L2, L3, and L4 having color temperatures of <NUM>, <NUM>, <NUM> and <NUM>, respectively, in this sequence. At this time, when the four light emitting groups L1, L2, L3, and L4 have color temperatures of <NUM>, <NUM>, <NUM> <IMG> <NUM>, respectively, the four light emitting groups L1, L2, L3, and L4 may be disposed in parallel to one another in this sequence.

Further, in the case when the four light emitting groups L1, L2, L3, and L4 have color temperatures of <NUM>, <NUM>, <NUM>, and <NUM> respectively, two light emitting groups having a color temperature of <NUM> may be arranged diagonally, and a light emitting group having a color temperature of <NUM> and a light emitting group having a color temperature of <NUM> may be arranged diagonally. In this way, four light emitting groups may be arranged in a square shape.

And, if necessary, in the case of emitting light of three color temperatures, for example, three light emitting groups having color temperatures of <NUM>, <NUM>, and <NUM> may be arranged on a light emitting surface of a light emitting device in a triangular arrangement to emit desired mixed color light. Further, if necessary, three light emitting groups may be arranged in a circle to be adjacent to one another.

And, a driving condition of each light emitting group L1, L2, L3, and L4 may be changed by changing electrical connections between each light emitting group L1, L2, L3, and L4 and each electrode.

Referring again to <FIG>, the second light emitting group L2 is electrically connected to the second electrode extension 140a of the second electrode <NUM> and a fourth electrode extension 160a of the fourth electrode <NUM>, and the third light emitting group L3 is electrically connected to the third electrode extension 130a of the first electrode <NUM> and the first electrode extension 150a of the third electrode <NUM>.

Here, the first electrode extension 130a and the third electrode extension 150a may be disposed adjacent to the third light emitting group L3 to be directly electrically connected through a wire W. In the meantime, the second electrode extension 140a and the fourth electrode extension 160a are not disposed to be adjacent to the second light emitting group L2, but the first electrode extension 130a and the third electrode extension 150a are disposed in between, respectively.

Accordingly, a wire W electrically connecting the second light emitting group L2 and the second electrode extension 140a may electrically connect the second light emitting group L2 and the second electrode extension 140a by passing through an upper region of the first electrode extension 130a. Similarly, a wire W electrically connecting the second light emitting group L2 and the fourth electrode extension 160a may electrically connect the second light emitting group L2 and the fourth electrode extension 160a by passing through an upper region of the third electrode extension 150a.

Referring to <FIG>, to electrically connect the light emitting diode chip <NUM> comprised in the second light emitting group L2 and the second electrode extension 140a, the wire W passes through the upper region of the first electrode extension 130a in a state where it is spaced apart from the first electrode extension 130a by a certain distance or more. In the present embodiment, it is described that the first electrode extension 130a and the second electrode extension 140a may have the same electrical polarity, but it is not limited thereto, the electrode extension 130a and second electrode extension 140a may have different electrical polarities from each other.

Likewise, the wire W may also electrically connect the light emitting diode chip <NUM> comprised in the second light emitting group L2 and the fourth electrode extension 160a, as described above, by passing through the upper region of the third electrode extension 150a.

<FIG> is a cross-sectional view of section B of <FIG>.

<FIG> is a view for illustrating a partition wall D2 to be formed between the second light emitting group L2 and the third light emitting group L3. As shown in <FIG>, the partition wall D2 may be formed between the second and third light emitting groups L2 and L3. The partition wall D2 may be formed to be higher than heights of the light emitting diode chips <NUM> comprised in each of the light emitting groups L <NUM>, L <NUM>, L <NUM>, and L <NUM>. The partition wall D2 may block light emitted from each light emitting group L1, L2, L3 and L4 from being emitted to adjacent light emitting groups L1, L2, L3 and L4. Thus, the light emitting groups L1, L2, L3 and L4 can emit light having their own color temperatures to the outside, respectively, since light emitted from any one of the light emitting groups L1, L2, L3, and L4 is blocked from entering neighboring light emitting groups L1, L2, L3, and L4.

In the meantime, as shown in <FIG>, a molding portion Ph may be formed to cover each of the light emitting groups L1, L2, L3, and L4. The molding portion Ph may be made of a material transmitting light, such as a transparent resin, and may contain one or more kinds of phosphors as required.

<FIG> is a schematic plan view for illustrating a light emitting device in accordance with another exemplary embodiment of the present disclosure.

Referring to <FIG>, the light emitting device <NUM> in accordance with the exemplary embodiment, similar to the light emitting device of <FIG>, may comprise a base <NUM>, first to fourth light emitting groups L1, L2, L3, and L4 comprising one or more light emitting diode chips <NUM> shown in <FIG>, first to fourth electrode pads <NUM>, <NUM>, <NUM>, and <NUM> and first to eighth electrode terminals <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>.

Since the light emitting device <NUM> according to the present embodiment is similar to the light emitting device described with reference to <FIG>, descriptions of the same content will be omitted and differences will be described below in detail in order to avoid redundant description.

The first to fourth light emitting groups L1, L2, L3, and L4 may be disposed in a circular mounting portion on the base <NUM>. The light emitting groups L1, L2, L3, and L4, as shown in <FIG>, may be disposed in lines in parallel to one another, respectively, and each light emitting group L1, L2, L3, and L4 may be disposed alternately with one another. That is, centers of each light emitting group L1, L2, L3, and L4 are not disposed to be flush with one another, but disposed alternately with one another.

As an example, the first light emitting group L1 may be disposed at a leftmost side of the circular mounting portion on the base <NUM>, and may be disposed adjacent to one side of the base <NUM>. And the fourth light emitting group L4 may be disposed on a rightmost side of the circular mounting portion on the base <NUM>, and may be disposed adjacent to another side of the base <NUM> opposite the one side. In addition, the second light emitting group L2 and the third light emitting group L3 may be disposed between the first light emitting group L1 and the fourth light emitting group L4, respectively, and the second light emitting group L2 may be disposed adjacent to the first light emitting group L1, and the third light emitting group L3 may be disposed adjacent to the fourth light emitting group L4. However, it is not limited thereto, if necessary, positions where the light emitting groups L1, L2, L3, and L4 are alternately disposed may be changed in various ways as required.

<FIG> is a view for illustrating electrical connections between light emitting groups and electrodes in accordance with one exemplary embodiment of the present disclosure. In the meantime, the cross section of section A of <FIG> is the same as that shown in <FIG>, and the section of section B of <FIG> is the same as that shown in <FIG>.

Electrical connections between light emitting groups and the electrodes of the light emitting device <NUM> in accordance with the present embodiment are generally similar to those between light emitting groups and the electrodes of the light emitting device described with reference to <FIG>, and further, since a configuration of a partition wall D2 of the light emitting device <NUM> is similar to that described with reference to <FIG>, descriptions of the same content will be omitted and differences will be described below in detail in order to avoid redundant description.

Since the centers of each light emitting group L1, L2, L3, and L4 are disposed to be flush with one another in the embodiment of <FIG>, a length of the wire connecting the second light emitting group L2 and the second electrode extension 140a is different from that of the wire connecting the third light emitting group L3 and the first electrode extension 130a. In contrast, in this embodiment, lengths of wires may be adjusted by arranging the light emitting groups L1, L2, L3, and L4 alternately.

<FIG> is a view for illustrating an example in which a plurality of light emitting diode chips are arranged in each light emitting group of the light emitting device of <FIG>.

Referring to <FIG>, as an example, <NUM> light emitting diode chips <NUM> comprised in the first light emitting group L1 may be arranged in three lines, and a plurality of light emitting diode chips <NUM> may be arranged in each line at a predetermined distance. At this time, the light emitting diode chips <NUM> arranged in each line may be arranged to be flush with a light emitting diode chip <NUM> of an adjacent line thereto. Accordingly, the first light emitting group L1 may be configured with three lines comprising three light emitting diode chips <NUM>, eight light emitting diode chips <NUM> and nine light emitting diode chips <NUM>, respectively, and the light emitting diode chips <NUM> of the respective lines may be arranged to be flush with one another. At this time, the first light emitting group L1 may be biased toward one side of the base <NUM>.

In addition, <NUM> light emitting diode chips <NUM> comprised in the second light emitting group L2 may be arranged in two lines, and <NUM> light emitting diode chips <NUM> may be arranged in each line at a predetermined distance. At this time, the light emitting diode chips <NUM> arranged in each line may be arranged to be flush with a light emitting diode chip <NUM> of an adjacent line thereto. At this time, the second light emitting group L2 may be arranged to be adjacent to and in parallel with the first light emitting group L1.

In the third light emitting group L3, like the second light emitting group L2, <NUM> light emitting diode chips <NUM> may be arranged in two lines, and the light emitting diode chips <NUM> arranged in each line may be arranged to be flush with a light emitting diode chip <NUM> of an adjacent line thereto. At this time, the third light emitting group L3 may be arranged in an adjacent position alternately with the second light emitting group L2.

The fourth light emitting group L4, similarly to the first light emitting group L1, may have <NUM> light emitting diode chips <NUM> arranged in three lines, and the light emitting diode chips <NUM> arranged in each line may be arranged to be flush with a light emitting diode chip <NUM> of an adjacent line thereto. At this time, the fourth light emitting group L4 may be arranged in an adjacent position alternately with the third light emitting group L3.

Furthermore, the light emitting devices in accordance with the exemplary embodiments of the present disclosure may be used for various lighting devices such as light bulbs and tube lighting devices.

Claim 1:
A light emitting device comprising:
a base (<NUM>);
a first light emitting group (L1) disposed on the base (<NUM>); and
a second light emitting group (L2) disposed on the base (<NUM>),
wherein each of the first light emitting group (L1) and the second light emitting group (L2) comprises a plurality of light emitting units, each unit including a light emitting diode chip (<NUM>),
wherein the first light emitting group (L1) emits light having a color temperature different from that of light emitted from the second light emitting group (L2),
the device further comprising:
a third light emitting group (L3) disposed on the base (<NUM>); and
a fourth light emitting group (L4) disposed on the base (<NUM>),
wherein each of the third light emitting group (L3) and the fourth light emitting group (L4) comprises a plurality of light emitting diode chips (<NUM>),
wherein the third light emitting group (L3) emits light having a color temperature different from that of light emitted from the fourth light emitting group (L4),
wherein the second light emitting group (L2) and the third light emitting group (L3) are disposed between the first light emitting group (L1) and the fourth light emitting group (L4), and
wherein the third light emitting group (L3) is disposed between the second light emitting group (L2) and the fourth light emitting group (L4);
wherein the first light emitting group (L1) emits light having the same color temperature as that of the third light emitting group (L3), and
wherein the second light emitting group (L2) emits light having the same color temperature as that of the fourth light emitting group (L4);
characterized in that the plurality of light emitting units in one of the light emitting groups (L1, L2, L3, L4) comprises two or more kinds of light emitting units alternately arranged on the base