Patent Grant
10660167
Korean Patent Application No. 10-2018-0113438 filed on Sep. 21, 2018, in the Korean Intellectual Property Office, and entitled: “Light Emitting Diode Module, Light Emitting Diode Driver, and Light Emitting Diode Lighting Apparatus,” is incorporated by reference herein in its entirety.
Embodiments relate to a lighting apparatus and, more particularly, relate to a light emitting diode (LED) module, an LED driver, and an LED lighting apparatus.
A light emitting diode (LED) has various advantages such as low power consumption, long lifetime, etc. For this reason, nowadays, an LED device is being widely used as a lighting apparatus, a head lamp for vehicle, a light source for backlight of a display device, and so forth.
The LED device emits a light having a correlated color temperature (CCT). In various application environments, changing the color temperature of the light emitted from the LED device depending on an ambient environment or the requirements of a user is desired. To change the color temperature of the light emitted from the LED device, a color temperature-variable lighting apparatus may use a plurality of LED devices having different color temperatures and a plurality of LED drivers controlling the plurality of LED devices respectively.
However, when the plurality of LED drivers are used, or a separate component which adjusts a channel of a current to be provided to each LED device is required, complexity and cost increases.
According to an example embodiment, a light emitting diode (LED) lighting apparatus includes an LED driver that outputs a driving current, a switch circuit that selects at least one division terminal among a first division terminal to a fourth division terminal and electrically connects the selected at least one division terminal with a driving current terminal receiving the driving current, a first resistor circuit that is connected with the first and second division terminals, a second resistor circuit that is connected with the third and fourth division terminals, a first LED light source that is electrically connected with the first resistor circuit and emits a first light having a first color temperature, and a second LED light source that is electrically connected with the second resistor circuit and emits a second light having a second color temperature higher than the first color temperature.
According to an example embodiment, an LED module includes a first LED light source that receives a first division current through a first division current terminal and emits a first light having a first color temperature based on the first division current, a second LED light source that receives a second division current through a second division current terminal and emits a second light having a second color temperature based on the second division current, and a division circuit that is connected with a driving current terminal receiving a driving current from an external device, the first division current terminal, and the second division current terminal, and divides the driving current into a first division current and a second division current in response to a color temperature control signal from the external device, the division circuit outputting the first division current to the first division current terminal and outputting the second division current to the second division current terminal.
According to an example embodiment, an LED driver includes a driving current generator that generates a driving current controlling external LED devices, a driving current terminal receiving the driving current, a color temperature controller that generates a color temperature control signal corresponding to a target color temperature of a total light from the external LED devices, a switch circuit that selects one of a plurality of first division terminals or one of a plurality of second division terminals in response to the color temperature control signal and electrically connects the selected division terminal with the driving current terminal, a plurality of first resistance elements that is connected between the plurality of first division terminals and a first division current terminal, and a plurality of second resistance elements that is connected between the plurality of second division terminals and a second division current terminal, the first division current terminal and the second division current terminal being respectively connected with the external LED devices.
Features will become apparent to those of skill in the art by describing in detail exemplary embodiments with reference to the attached drawings in which:
Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementations to those skilled in the art.
The LED driver 110 may output a driving current I_drv. For example, the LED driver 110 may include a driving current generator to generate the driving current I_drv. The driving current generator 111 may generate the driving current I_drv for adjusting the amount of a total light emitted from the lighting apparatus 100 under control of a user or a separate external device.
In an example embodiment, the amount of the total light emitted from the lighting apparatus 100 may increase as a magnitude of the driving current I_drv increases. That is, the LED driver 110 may adjust the amount (illuminance) of the total light emitted from the lighting apparatus 100 by adjusting the magnitude of the driving current I_drv. In an example embodiment, the driving current I_drv from the LED driver 110 may be output through one current channel or one driving channel.
The correlated color temperature controller 120 (hereinafter referred to as a “CCT controller”) may control a correlated color temperature (CCT) control signal CTS (hereinafter referred to as a “color temperature control signal”). The color temperature control signal CTS may be a signal for adjusting a color temperature of the total light emitted from the lighting apparatus 100. That is, the color temperature control signal CTS may correspond to a target color temperature of the total light emitted from the lighting apparatus 100. The total light emitted from the lighting apparatus 100 may be light corresponding to a combination of first light emitted from a first LED light source LED1 and second light emitted from a second LED light source LED2. In an example embodiment, the color temperature control signal CTS may be a signal for controlling a switching circuit (to be described with reference to
The switchable division circuit 130 (hereinafter referred to as a “division circuit”) may divide the driving current I_drv from the LED driver 110 into the first and second division currents I_dv1 and I_dv2 in response to the color temperature control signal CTS. For example, the division circuit 130 may adjust magnitudes of the first division current I_dv1 and the second division current I_dv2 in response to the color temperature control signal CTS. In this case, the division circuit 130 may perform the above-described current dividing operation or the above-described current adjusting operation by using a switching circuit and a resistor circuit. A configuration and an operation of the division circuit 130 will be more fully described below.
The LED module 140 may include the first LED light source LED1 and the second LED light source LED2. The first and second LED light sources LED1 and LED2 may respectively receive the first and second division currents I_dv1 and I_dv2, and may be connected to a common terminal CM. In an example embodiment, the common terminal CM may be a ground terminal. The first LED light source LED1 may emit first light in response to the first division current I_dv1 from the division circuit 130. The second LED light source LED2 may emit second light in response to the second division current I_dv2 from the division circuit 130.
In an example embodiment, the first light and the second light may have different color temperatures, respectively. The first light may have a lowest color temperature in a variable color temperature range to be provided by the lighting apparatus 100, while the second light may have a highest color temperature in the variable color temperature range. For example, the first light may be “warm white” of approximately 2700K or lower, and the second light may be “cool white” of approximately 5700K or higher.
The amount of the first light emitted from the first LED light source LED1 may be determined according to the magnitude of the first division current I_dv1. The amount of the second light emitted from the second LED light source LED2 may be determined according to the magnitude of the second division current I_dv2. A color temperature of the total light emitted from the lighting apparatus 100 may be determined according to the amount of first light and the amount of second light. For example, when the amount of first light is greater than the amount of second light, the color temperature of the total light may be closer to the color temperature of first light than that of second light. Similarly, when the amount of first light is less than the amount of second light, the color temperature of the total light may be closer to the color temperature of second light than that of first light.
That is, the lighting apparatus 100 may change or adjust a target color temperature of the total light emitted from the lighting apparatus 100 by adjusting the magnitudes of the first and second division currents I_dv1 and I_dv2 respectively provided to the first and second LED light sources LED1 and LED2 having different color temperatures. In an example embodiment, a variable color temperature range associated with the total light may correspond to a range from a first color temperature of the first LED light source LED1 to a second color temperature of the second LED light source LED2.
As described above, the lighting apparatus 100 according to an embodiment may continuously change a color temperature within the variable color temperature range of the total light emitted by dividing the driving current I_drv provided through one current channel or one driving channel and adjusting the magnitudes of the first and second division currents I_dv1 and I_dv2. In this case, since a color temperature of the total light may be changed by using one LED driver 110, a simpler configuration and/or lower manufacturing may be realized compared with using a plurality of LED drivers. Also, since the first and second division currents I_dv1 and I_dv2 are generated by dividing the driving current I_drv, a number of LEDs may be reduced while the illuminance of the total light may be maintained at a given level or higher. Accordingly, a lighting apparatus according to embodiments may have improved performance and reduced costs.
In an example embodiment, the amount of a light emitted from each of the plurality of LED elements LED_el may vary with a magnitude of the first division current I_dv1. In an example embodiment, the amount of a light emitted from each of the plurality of LED elements LED_el may increase as a magnitude of the first division current I_dv1 increases.
As indicated in the parentheticals in
The first LED light source LED1 and the second LED light source LED2 are illustrated in
Referring to
The first switch circuit 131a is to selectively connect a driving current terminal TDR receiving the driving current I_drv to first division terminals T10 to T1n in response to the color temperature control signal CTS. For example, the first switch circuit 131a may electrically connect any one of the first division terminals T10 to T1n to the driving current terminal TDR receiving the driving current I_drv in response to the color temperature control signal CTS or may block the connection between the first division terminals T10 to T1n and the driving current terminal TDR.
The second switch circuit 131b selectively connects the driving current terminal TDR receiving the driving current I_drv to second division terminals T20 to T2m in response to the color temperature control signal CTS. For example, the second switch circuit 131b may electrically connect any one of the second division terminals T20 to T2m to the driving current terminal TDR receiving the driving current I_drv in response to the color temperature control signal CTS or may block the connection between the second division terminals T20 to T2m and the driving current terminal TDR.
In an example embodiment, the first and second switch circuits 131a and 131b may be implemented with switch elements, e.g., transistors, electric fuses, or the like, or a de-multiplexer to select the first and second division terminals T10 to T1n and T20 to T2m in response to the color temperature control signal CTS. In an example embodiment, the color temperature control signal CTS may be a signal for controlling the first and second switch circuits 131a and 131b. The color temperature control signal CTS may be provided in the form of a digital code for controlling the first and second switch circuits 131a and 131b.
The first resistor circuit 132a may include a plurality of first resistors R11 to R1n respectively connected between the first division terminals T11 to T1n and the first division current terminal TDV1. For example, the resistor R11 of the plurality of first resistors R11 to R1n may be connected between the division terminal T11 and the first division current terminal TDV1, the resistor R12 may be connected between the division terminal T12 and the first division current terminal TDV1, and the resistor R1n may be connected between the division terminal T1n and the first division current terminal TDV1. The division terminal T10 may be directly connected with the first division current terminal TDV1. In an embodiment, the plurality of first resistors R11 to R1n may have different resistance values.
The second resistor circuit 132b may include a plurality of second resistors R21 to R2m respectively connected between the second division terminals T21 to T2m and a second division current terminal TDV2. For example, the resistor R21 of the plurality of second resistors R21 to R2m may be connected between the division terminal 121 and the second division current terminal TDV2, the resistor R22 may be connected between the division terminal T22 and the second division current terminal TDV2, and the resistor R2m may be connected between the division terminal T2m and the second division current terminal TDV2. The division terminal T20 may be directly connected with the second division current terminal TDV2. In an embodiment, the plurality of second resistors R21 to R2m may have different resistance values.
In an example embodiment, the plurality of first resistors R11 to R1n and the plurality of second resistors R21 to R2m may respectively include single resistance elements having different resistance values, or each of the plurality of first resistors R11 to R1n and the plurality of second resistors R21 to R2m may include a plurality of resistance elements, the total resistance value of which is set to be different for each of the first and second resistors R11 to R1n and R21 to R2m. For example, the resistance values of the first resistors R11 to R1n may increase in a linear fashion and the resistance values of the second resistors R21 to R2n may increase in a linear fashion. When n and m are the same, respective resistance values may be equal, e.g., R11 equals R21, R12 equals R22, and so forth. At least one resistance value of the first resistors R11 to R1n may be equal to at least one resistance value of the second resistors R21 to R2n so that a middle color temperature of the variable color temperature range may be realized. There is no resistor provided for the first division terminal T10 or the second division terminal T20.
The first division current terminal TDV1 may be connected with the first LED light source LED1 and may provide the first division current I_dv1 to the first LED light source LED1. The second division current terminal TDV2 may be connected with the second LED light source LED2 and may provide the second division current I_dv2 to the second LED light source LED2.
According to an embodiment, as the first and second switch circuits 131a and 131b perform switching operations in response to the color temperature control signal CTS, the magnitudes of the first and second division currents I_dv1 and I_dv2 may change. For example, a first color temperature control signal CTS-1 may be a signal for adjusting a color temperature of the total light emitted from the lighting apparatus 100 to a first color temperature, and the first color temperature may be a color temperature included in a range from a color temperature of a first light of the first LED light source LED1 to a color temperature of a second light of the second LED light source LED2.
In this case, as illustrated in
In this case, the driving current I_drv may be divided into the first and second driving currents I_drv1 and I_dv2 depending on resistance values of the first and second resistors R11 and R2m. For example, as shown in
In this case, a color temperature of the total light emitted from the lighting apparatus 100 may be closer to the color temperature of the first light. In detail, it is assumed that the first light emitted from the first LED light source LED1 is “warm white” (a CCT being approximately 2700K) and the second light emitted from the second LED light source LED2 is “cool white” (a CCT being approximately 5700K). When the first and second switch circuits 131a and 131b are connected as illustrated in
As described above, a color temperature of the total light emitted from the lighting apparatus 100 may be adjusted by adjusting the magnitudes of the first and second division currents I_dv1 and I_dv2 by using the first and second switch circuits 131a and 131b and the first and second resistor circuits 132a and 132b.
In an example embodiment, the total light emitted from the lighting apparatus 100 may have a color temperature corresponding to any one of the first and second LED light sources LED1 and LED2. For example, as shown in
In this case, as illustrated in
The driving current I_drv may be directly provided to the second LED light source LED2 by the second switch circuit 131b. That is, the magnitude of the second division current I_dv2 may be substantially identical to the magnitude of the driving current I_drv. In contrast, by the first switch circuit 131a, the first division current I_dv1 which is provided to the first LED light source LED1 may be blocked. That is, the first division current I_dv1 may be substantially “0”.
In this case, the first LED light source LED1 may not emit light and only the second LED light source LED2 may emit light. That is, the total light emitted from the lighting apparatus 100 may be identical to the second light, i.e., cool white light.
In a conventional color temperature-variable lighting apparatus, a color temperature of the total light is adjusted by individually controlling currents to be provided to LED light sources having different color temperatures. Since this requires a separate driver or a separate current channel for each of the LED light sources, implementation of conventional color temperature-variable lighting apparatus is complex and costly.
However, as described above, the lighting apparatus 100 may divide and output the driving current I_drv provided through one current channel or one driving channel into the first and second division currents I_dv1 and I_dv2 by using the division circuit 130. In this case, magnitudes of the first and second division currents I_dv1 and I_dv2 may be adjusted by using the first and second switch circuits 131a and 131b and the first and second resistor circuits 132a and 132b included in the division circuit 130, and a color temperature of the total light emitted from the lighting apparatus 100 may be adjusted according to the magnitudes of the first and second division currents I_dv1 and I_dv2.
In addition, the lighting apparatus 100 may output the total light having an intensity that is equal to that of the conventional color temperature-variable lighting apparatus using fewer LED elements. Accordingly, a color temperature-variable lighting apparatus having reduced costs and complexity is provided.
As may be seen in
Referring to
The LED driver 110, the CCT controller 120, the division circuit 130, and the LED module 140 of the lighting apparatus 100 of
In contrast, the CCT controller 220 of the lighting apparatus 200 of
Unlike the lighting apparatus 100 of
Referring to
The LED module 340 may include the first LED light source LED1 and the second LED light source LED2. The LED module 340 is identical to the LED module 140 of
Referring to
Unlike the LED modules 140, 240, and 340 of
As illustrated in
By a switching operation of the switch circuit 431 included in the LED driver 410, the driving current terminal may be electrically connected with any one of the plurality of first resistors of the first resistor circuit 432a in the LED module 440 or any one of the plurality of second resistors of the second resistor circuit 432b in the LED module 440. As such, the magnitudes of the first and second division currents I_dv1 and I_dv2 may be adjusted.
The division circuit 530 may divide the driving current I_drv in response to the color temperature control signal CTS from the CCT controller 520 and may output a plurality of division currents I_dv1 to I_dvk. For example, as in the above description, the division circuit 530 may include pairs of switch and resistor circuits (not illustrated) respectively corresponding to the plurality of LED light sources LED1 to LEDk, and may adjust magnitudes of the plurality of division currents I_dv1 to I_dvk to be provided respectively to the plurality of LED light sources LED1 to LEDk by using the pairs of switch and resistor circuits.
The plurality of LED light sources LED1 to LEDk may respectively receive the plurality of division currents I_dv1 to I_dvk from the division circuit 530 and may emit lights having different color temperatures based on the received division currents I_dv1 to I_dvk. For example, the first LED light source LED1 may receive the first division current I_dv1 from the division circuit 530 and may emit a first light of a first color temperature based on the first division current I_dv1. The second LED light source LED2 may receive the second division current I_dv2 from the division circuit 530 and may emit a second light of a second color temperature higher than the first color temperature based on the second division current I_dv2. The k-th LED light source LEDk may receive the k-th division current I_dvk from the division circuit 530 and may emit a light of a k-th color temperature higher than the second color temperature based on the k-th division current I_dvk.
As described above, a target color temperature of the total light emitted from the lighting apparatus 500 may be adjusted by adjusting the magnitudes of the plurality of division currents I_dv1 to I_dvk.
The lighting apparatuses 100, 200, 300, 400, and 500 described with reference to
The display panel 1100 may include a plurality of display pixels. The plurality of display pixels may be connected with a plurality of gate lines and a plurality of data lines and may be configured to display image information in response to signals of connected lines. In an example embodiment, the plurality of display pixels may be classified into a plurality of groups based on colors to be displayed. The plurality of display pixels may display one of primary colors. The primary colors may include, but not limited to, red, green, blue, and white. For example, the primary colors may further include various colors such as yellow, cyan, and magenta. In an example embodiment, the display panel 1100 may be a liquid crystal display panel.
The DDI 1200 may control various signal lines (e.g., a plurality of data lines or a plurality of gate lines) connected with the display panel 1100 under control of the controller 1500.
The backlight panel 1300 may output a light such that image information may be output through the display panel 1100. In an example embodiment, the backlight panel 1300 may include the LED module or the LED light sources described with reference to
The LED driver 1400 may control the backlight panel 1300. The LED driver 1400 may provide a driving current or a division current to an LED module under control of the controller 1500 such that the backlight panel 1300 emits a light of a target color temperature. The controller 1500 may control the DDI 1200 or the LED driver 1400 such that image information may be displayed through a plurality of pixels included in the display panel 1100.
In an example embodiment, a lighting apparatus according to the embodiments may used in various fields (e.g., an image sensor, a display device, a lighting apparatus, a headlight, etc.) to which LED lighting is applied.
As described above, according to embodiments, a lighting apparatus may control a color temperature over a wide range by adjusting magnitudes of a plurality of division currents obtained by dividing a driving current provided through one current channel. Also, even though fewer LED elements are used, the total light having the same intensity as the related art may be provided. Accordingly, a color temperature-variable lighting apparatus having reduced manufacturing costs and improved performance is provided.
According to embodiments, division currents may be generated by dividing a driving current provided through one current channel, and LED light sources may emit lights having different color temperatures based on the division currents thus generated. As such, a color temperature of the total light emitted from a lighting apparatus may be variously changed. Accordingly, an LED module, an LED driver, and an LED lighting apparatus having reduced cost and improved performance are provided.
Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.
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