Flat lighting device and display device using same

Abstract

The present invention can be applied to the technical field pertaining to display devices and, for example, relates to a flat lighting device using a light emitting diode (LED) and a display device including same. A flat lighting device according to an embodiment disclosed herein operates together with a display panel, and comprises: a light-emitting element array including at least one channel to which a plurality of light-emitting elements are connected; a driving element connected to one end of the at least one channel; a power supply unit connected to the other end of the at least one channel to supply power to each of the channels; and a processor which is located between the driving element and the power supply unit and controls the power supply unit by transmitting driving data applied to each of the channels of the light emitting element array to the driving element in accordance with the brightness of the current screen of the display panel, and compensating a set voltage value of the light emitting element array calculated in accordance with the driving data.

Description

Flat lighting device and display device using the same

[0001] The present invention is applicable to a technical field related to display devices, and relates to, for example, a flat lighting device using an LED (Light Emitting Diode) and a display device using the same.

[0002] In recent years, display devices with superior characteristics, such as thinness and flexibility, have been developed in the field of display technology. Currently, the major commercially available displays are represented by LCD (Liquid Crystal Display) and OLED (Organic Light Emitting Diode).

[0003] Meanwhile, a light-emitting diode (LED) is a semiconductor light-emitting device that is well known for converting electric current into light. Starting with the commercialization of a red LED using GaAsP compound semiconductors in 1962, it has been used as a light source for display images in electronic devices, including information and communication devices, along with green LEDs of the GaP:N series.

[0004] Recently, these light-emitting diodes (LEDs) have been gradually miniaturized and manufactured into micrometer-sized LEDs, which are used as pixels or flat lighting in display devices.

[0005] In order for LEDs to be used as flat lighting, a driving element (driving IC) that drives multiple LED strings and a power supply that supplies power to the LEDs can be used.

[0006] These driving elements are combined with a certain number of LED strings forming a channel to detect the driving status of the LEDs and feed back the driving status to the power supply. However, since this feedback is usually reflected after the frame is driven, there may be a delay in the feedback process, which may degrade the display image quality.

[0007] Therefore, measures to improve these problems are required.

[0008] The technical problem to be solved by the present disclosure is to provide a flat lighting device capable of preventing the occurrence of a delay in voltage feedback for driving a light-emitting element array and a display device using the same.

[0009] In addition, the present invention aims to provide a flat lighting device and a display device using the same, which can immediately compensate for the driving voltage of a light-emitting element array through a feedback process using local dimming data, thereby improving the picture quality of a display device.

[0010] A flat lighting device according to one embodiment of the present disclosure is a flat lighting device that operates with a display panel, the flat lighting device including: a light emitting element array including at least one channel in which a plurality of light emitting elements are connected; a driving element connected to one end of the at least one channel; a power supply unit connected to the other end of the at least one channel and supplying power to each channel; and a processor positioned between the driving element and the power supply unit, the processor transmitting driving data applied to each channel of the light emitting element array corresponding to the brightness of a current screen of the display panel to the driving element, and controlling the power supply unit by compensating for a set voltage value of the light emitting element array calculated corresponding to the driving data.

[0011] A display device according to one embodiment of the present disclosure comprises: a display panel unit including a first processor; and a flat lighting device including a second processor linked to the first processor, wherein the flat lighting device comprises: a light-emitting element array including at least one channel in which a plurality of light-emitting elements are connected; a driving element connected to one end of the at least one channel; a power supply unit connected to the other end of the at least one channel and supplying power to each channel; and a second processor positioned between the driving element and the power supply unit, the second processor transmitting driving data applied to each channel of the light-emitting element array corresponding to the brightness of a current screen of the display panel unit to the driving element, and controlling the power supply unit by compensating for a set voltage value of the light-emitting element array received from the first processor and calculated corresponding to the driving data.

[0012] According to one embodiment of the present invention, the following effects are achieved.

[0013] First, according to one embodiment of the present disclosure, rather than compensating the driving voltage of the light-emitting element array after receiving feedback data from the driving element, the feedback value (set voltage value) is calculated using local dimming data and reflected first before receiving the feedback data from the driving element, thereby preventing the occurrence of a delay in voltage feedback.

[0014] In this way, the driving voltage of the light-emitting element array can be immediately compensated through a feedback process using local dimming data, thereby improving the picture quality of the display device.

[0015] Furthermore, according to another embodiment of the present invention, there are additional technical effects not mentioned herein. Those skilled in the art will understand the full scope of the specification and drawings.

[0016] FIG. 1 is a block diagram of a display device according to a first embodiment of the present disclosure.

[0017] FIG. 2 is a flowchart showing the operation of a flat lighting device according to the first embodiment of the present disclosure.

[0018] FIG. 3 is a schematic diagram showing the operation of a flat lighting device according to the first embodiment of the present disclosure.

[0019] FIG. 4 is a block diagram showing the physical connection state of a flat lighting device according to the first embodiment of the present disclosure.

[0020] FIG. 5 is a block diagram of a display device according to a second embodiment of the present disclosure.

[0021] Fig. 6 is a flowchart showing the operation of a flat lighting device according to the second embodiment of the present disclosure.

[0022] Fig. 7 is a schematic diagram showing the operation of a flat lighting device according to the second embodiment of the present disclosure.

[0023] Fig. 8 is a block diagram showing the physical connection state of a flat lighting device according to the second embodiment of the present disclosure.

[0024] Fig. 9 is a schematic diagram showing a block configuration of a flat lighting device according to a second embodiment of the present disclosure.

[0025] Figure 10 is an enlarged view of part A of Figure 9.

[0026] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, a detailed description thereof will be omitted. In addition, it should be noted that the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and should not be construed as limiting the technical ideas disclosed in this specification by the attached drawings.

[0027] Furthermore, for the convenience of explanation, each drawing is described, but it is also within the scope of the present invention for a person skilled in the art to implement another embodiment by combining at least two drawings.

[0028] Additionally, when an element such as a layer, region or substrate is referred to as existing "on" another element, it will be understood that this may be directly on the other element, or that there may be intermediate elements in between.

[0029] The semiconductor light-emitting device mentioned in the specification includes LEDs, micro LEDs, etc., and may be used interchangeably.

[0030]

[0031] FIG. 1 is a block diagram of a display device according to a first embodiment of the present disclosure.

[0032] Referring to FIG. 1, a display device according to a first embodiment of the present disclosure may include a flat lighting device (1) and a display panel portion (2). Here, the display panel portion (2) may include a display panel (not shown) and a processor (50; first processor) for driving the display panel. If the display device implements a TV, the first processor (50) may be implemented as a SoC (System on Chip) for driving the TV.

[0033] A flat lighting device (1) according to the first embodiment of the present disclosure may include a plurality of driving elements (driving ICs; 10) connected to a light-emitting element array (40), a power supply unit (30) that supplies power to the light-emitting element array (40), and a processor (second processor; MCU; 20) connected between the driving elements (10) and the power supply unit (30).

[0034] This flat lighting device (1) is a device that drives a light emitting element array (40) including a plurality of light emitting elements, and may correspond to, for example, a backlight unit (BLU). Hereinafter, the terms flat lighting device (1) and backlight unit are used interchangeably in the description.

[0035] Meanwhile, a plurality of driving elements (driving ICs; 10) connected to the light-emitting element array (40) may be referred to as driving ICs (10). Hereinafter, the terms driving element (10) and driving IC are used interchangeably in the description.

[0036] The driving element (10) may be connected to one end of at least one channel (CH1 to CHn). As an exemplary embodiment, the light emitting element array (40) may include n channels (CH1 to CHn) including a first channel (CH1), an n-1th channel (CHn-1), and an nth channel (CHn). In some cases, the driving element (10) may be provided together with the light emitting element array (40).

[0037] Each channel (CH1 to CHn) of the light emitting element array (40) may be equipped with a plurality of light emitting elements (D1 to Dn). One channel (for example, CH1) may include a light emitting element string in which a plurality of light emitting elements (D1 to Dn) are connected. For example, one channel (for example, CH1) may include a plurality of light emitting elements (D1 to Dn) connected in series with each other.

[0038] The other side of at least one of these channels (CH1 to CHn) can be connected to a power supply (30). Accordingly, the power set in the driving element (10) can be applied to the light emitting element array (40) including at least one channel (CH1 to CHn) by the power supply (30).

[0039] Referring to Fig. 1, a plurality of driving elements (driving ICs; 10) connected to such a light-emitting element array (40) may be connected in parallel to each other in a plurality of numbers (11 to 13). Fig. 1 illustrates a state in which one driving element (e.g., 11) is connected to one channel (e.g., CH1), but this is exemplary, and one driving element may be connected to multiple channels.

[0040] Such a driving element (10) may have a feedback function for a driving voltage for driving a light-emitting element array (40). For example, the driving element (10) may feed back the generation of a headroom voltage to the processor (20). For example, the driving element (10) may feed back a state in which a minimum voltage for supplying current for driving a light-emitting element array (40) at a set brightness is less than a reference value to the processor (20).

[0041] As an exemplary embodiment, a feedback signal according to a headroom voltage generated in each channel (CH1 to CHn) of a light-emitting element array (40) connected to each driving element (10) may be accumulated and transmitted as a feedback signal to an input terminal of a processor (20).

[0042] In the power supply unit (30), a DC-DC converter (e.g., a step-up converter) operates based on such a feedback signal, so that the boosted voltage can be transmitted to the light-emitting element array (40).

[0043] By this configuration, a preset output voltage level is detected for each channel in each driving element (11 to 13), and when a headroom voltage is detected in even one channel, a feedback signal is transmitted from the driving element (10) to the processor unit (MCU; 20). At this time, the transmitted signal is transmitted to the power supply unit (30). In the power supply unit (30), a boost converter that generates a light-emitting element driving voltage (LED Voltage) operates, ultimately increasing the light-emitting element driving voltage (LED Voltage).

[0044] Through this process, it is possible to detect a decrease in the light-emitting element driving voltage (LED Voltage) due to various factors and boost it so that the light-emitting element array (40) can be driven at a constant driving voltage (LED Voltage).

[0045]

[0046] Fig. 2 is a flowchart illustrating the operation of a flat lighting device according to the first embodiment of the present disclosure. Fig. 3 is a schematic diagram illustrating the operation of a flat lighting device according to the first embodiment of the present disclosure.

[0047] Referring to FIG. 2, the driving operation of the light emitting element array (40) is illustrated, which is performed by a plurality of driving elements (driving ICs; 10) connected to the light emitting element array (40), a power supply unit (30) that supplies power to the light emitting element array (40), and a processor (second processor; MCU; 20) connected between the driving elements (10) and the power supply unit (30).

[0048] First, when the operation is started in the processor (20) (Start-Enable), driving data according to the brightness of the current screen, for example, LED current data (rise), can be transmitted to the driving element (10) to drive the light-emitting element array (40) (S1).

[0049] This driving data may be current data applied to the LED. This LED current data may be received from the processor (50) of the display panel unit (2). This LED current data may be local dimming data that divides the light-emitting element array (40) into multiple parts and drives each divided part at different brightnesses.

[0050] For example, when the screen of the display panel unit (20) is brightened, the resulting increased driving data, for example, increased LED current data, can be transmitted to the driving element (10).

[0051] The LED current applied to the light-emitting element array (40) can be increased according to the driving data (LED current data) received from the driving element (10) (S2).

[0052] Accordingly, the light emitting element array (40) is driven by the increased LED current, and the driving element (10) can check whether the voltage for applying the increased LED current is sufficient. For example, the driving element (10) can supply the minimum voltage (V) for driving the light emitting element array (40) with the brightness of the current screen. HEADROOM ) is determined to be less than the reference value (Ref.) (S3), and if this case occurs (Y; VLED voltage insufficient), it can be stored as feedback data (voltage feedback data) (feedback operation; S4).

[0053] In this way, the driving element (10) controls the headroom voltage (V) of the light emitting element array (40). HEADROOM) can be recorded as voltage feedback data. For example, the driving element (10) can record a state in which the minimum voltage for supplying current to drive the light-emitting element array (40) with the current screen brightness is less than a reference value as voltage feedback data.

[0054] Such feedback operation can be checked for N lines (N line; see FIG. 3). For example, referring to FIG. 3, a feedback operation (F / B 1 Transmit) can be performed for the first driving line (1 line) of the light emitting element array (40), and then a feedback operation (F / B 2 Transmit) can be performed for the second first driving line (2 line). In this way, feedback operations are performed sequentially so that a feedback operation (F / BN Transmit) can be performed for the Nth driving line (N line).

[0055] In this way, it is checked whether all feedback operations have been performed for N driving lines (S5), and if all feedback operations have been performed for N driving lines (Y), the feedback data (voltage feedback data) accumulated during the feedback operations for these N driving lines can be transmitted to the processor (20) (S6).

[0056] Then, the processor (20) outputs this feedback data to the power supply (30) (S7) to increase the driving voltage (VLED) of the light-emitting element array (40) (S8).

[0057] Referring to FIG. 3, after such a feedback operation is performed for N frames, feedback data (voltage feedback data) can be transmitted to the processor (20). Accordingly, the operation of outputting the feedback data to the power supply (30) to increase the driving voltage (VLED) of the light emitting element array (40) can be performed after N frames are driven.

[0058]

[0059] FIG. 4 is a block diagram showing the physical connection state of a flat lighting device according to the first embodiment of the present disclosure.

[0060] Referring to FIG. 3, the connection state of four driving elements (driving ICs; 11 to 14) and a processor (MCU; 20) is illustrated as an example. Each driving element (11 to 14) can be connected to each other through a feedback terminal (or communication interface). For example, each driving element (11 to 14) can exchange data with each other through a first line (15). For example, local dimming data for driving a flat lighting device (1) or a backlight unit (BLU) can be transmitted through the first line (15).

[0061] Meanwhile, each driving element (11 to 14) has a feedback terminal (FB), and these feedback terminals (FB) can be connected to each other by separate conductors (16). These conductors (16) can be connected to each other through a second line (17) and connected to a processor (MCU; 20). For example, the feedback terminals (FB) of each driving IC (11 to 14) can be connected to each other by jumper wires.

[0062] Thus, according to the first embodiment, a feedback terminal (FB) may be utilized for feedback operation. In addition, as described above, a large number of wires (jumper wires; 16) and a second line (17) may be required for connecting the feedback terminal (FB).

[0063] In addition, according to the first embodiment, the operation of outputting feedback data to the power supply (30) to increase the driving voltage (VLED) of the light emitting element array (40) can be performed after N frames have been driven, so when a voltage increase is required, a delay may occur until the voltage is increased.

[0064]

[0065] FIG. 5 is a block diagram of a display device according to a second embodiment of the present disclosure.

[0066] Referring to FIG. 5, a display device according to a second embodiment of the present disclosure may include a flat lighting device (100) and a display panel portion (200). Here, the display panel portion (200) may include a display panel (not shown) and a processor (210; first processor) for driving the display panel. If the display device implements a TV, the first processor (210) may be implemented as a SoC (System on Chip) for driving the TV.

[0067] A flat lighting device (100) according to a second embodiment of the present disclosure may include a plurality of driving elements (driving ICs; 110) connected to a light-emitting element array (140), a power supply unit (130) that supplies power to the light-emitting element array (140), and a processor (second processor; MCU; 120) connected between the driving elements (110) and the power supply unit (130).

[0068] This flat lighting device (100) is a device that drives a light emitting element array (140) including a plurality of light emitting elements (D1 to Dn), and may correspond to, for example, a backlight unit (BLU). Hereinafter, the terms flat lighting device (100) and backlight unit will be used interchangeably for explanation.

[0069] Meanwhile, a plurality of driving elements (driving ICs; 110) connected to the light-emitting element array (140) may be referred to as driving ICs (110). Hereinafter, the terms driving element (110) and driving IC are used interchangeably in the description.

[0070] The driving element (110) may be connected to one end of at least one channel (CH1 to CHn). As an exemplary embodiment, the light emitting element array (140) may include n channels (CH1 to CHn), including a first channel (CH1), an n-1th channel (CHn-1), and an nth channel (CHn). In some cases, the driving element (110) may be provided together with the substrate on which the light emitting element array (140) is provided.

[0071] Each channel (CH1 to CHn) of the light emitting element array (140) may be equipped with a plurality of light emitting elements (D1 to Dn). One channel (for example, CH1) may include a light emitting element string in which a plurality of light emitting elements (D1 to Dn) are connected. For example, one channel (for example, CH1) may include a plurality of light emitting elements (D1 to Dn) connected in series with each other.

[0072] The other side of at least one channel (CH1 to CHn) can be connected to a power supply unit (130). Accordingly, the power set in the driving element (110) can be applied to the light emitting element array (140) including at least one channel (CH1 to CHn) by the power supply unit (130).

[0073] Referring to Fig. 5, a plurality of driving elements (driving ICs; 10) connected to such a light-emitting element array (140) may be connected in parallel to each other in a plurality of numbers (110-1 to 110-N). Fig. 5 illustrates a state in which one driving element (e.g., 110-1) is connected to one channel (e.g., CH1), but this is exemplary, and one driving element may be connected to multiple channels (see Fig. 10).

[0074] The processor (120) is located between the driving element (110) and the power supply (130), and can transmit driving data applied to each channel (CH1 to CHn) of the light-emitting element array (140) corresponding to the brightness of the current screen of the display panel unit (200) to the driving element (110). Meanwhile, the processor (120) can control the power supply (130) by compensating for the set voltage value of the light-emitting element array (140) calculated corresponding to the driving data.

[0075] As an exemplary embodiment, driving data for driving the light emitting element array (140) may be current data transmitted from the display panel unit (200). The light emitting element array (140) may be driven by such current data.

[0076] For example, the driving data may be local dimming data transmitted from the display panel unit (200) to partially drive the light-emitting element array (140) at different brightness levels. In this case, different driving data may be applied to at least some of the plurality of driving elements (110-1 to 110-N).

[0077] Meanwhile, the processor (120) can receive voltage feedback data for driving the light emitting element array (140) with respect to the driving data as described above from the driving element (110).

[0078] The driving element (110) may have a feedback function for a driving voltage for driving the light-emitting element array (140). For example, the driving element (110) may feed back the generation of a headroom voltage to the processor (120). For example, the driving element (110) may feed back a state in which a minimum voltage for supplying current for driving the light-emitting element array (140) at a set brightness is less than a reference value to the processor (120).

[0079] As an exemplary embodiment, a feedback signal according to a headroom voltage generated in each channel (CH1 to CHn) of a light-emitting element array (140) connected to each driving element (110) may be accumulated and transmitted as a feedback signal to an input terminal of a processor (120).

[0080] In the power supply unit (130), a DC-DC converter (e.g., a step-up converter) operates based on such a feedback signal, so that the boosted voltage can be transmitted to the light-emitting element array (140).

[0081] By this configuration, a preset output voltage level is detected for each channel in each driving element (110-1 to 110-N), and if a headroom voltage is detected in even one channel, a feedback signal is transmitted from the driving element (110) to the processor unit (MCU; 120). At this time, the transmitted signal is transmitted to the power supply unit (130). In the power supply unit (130), a boost converter that generates a light-emitting element driving voltage (LED Voltage) operates, ultimately increasing the light-emitting element driving voltage (LED Voltage).

[0082] As described above, the processor (120) can transmit driving data applied to each channel (CH1 to CHn) of the light-emitting element array (140) corresponding to the brightness of the current screen of the display panel unit (200) to the driving element (110). Meanwhile, the processor (120) can control the power supply unit (130) by compensating for the set voltage value of the light-emitting element array (140) calculated corresponding to the driving data.

[0083] At this time, if the voltage feedback data transmitted from the driving element (110) is greater than the set voltage value, the processor (120) can compensate for the voltage by the difference between the voltage feedback data and the set voltage value.

[0084] For example, the processor (120) can compare and calculate the voltage feedback data received from the driving element (110) with the set voltage value received from the display panel unit (200), and control the power supply unit (130) to increase the voltage by the difference if the voltage feedback data is greater than the set voltage value.

[0085] Meanwhile, the processor (120) can ignore the voltage feedback data if the voltage feedback data is equal to or less than the set voltage value.

[0086] As an exemplary embodiment, the set voltage value can be calculated from the current-voltage (ILED-VLED) data of the light-emitting element array (140). For example, such current-voltage data can be recorded according to the characteristics of the light-emitting element array. For example, such current-voltage data can be recorded taking into account the dispersion of the light-emitting element array.

[0087] For example, current-voltage data may be stored in a lookup table. Such current-voltage data may be stored in a processor (first processor; 210) of a display panel unit (200) and transmitted to a processor (second processor; 120) of a flat lighting device (100).

[0088] As an exemplary embodiment, the processor may calculate the set voltage value based on the maximum current of the current-voltage data.

[0089] For example, current-voltage data may be recorded for each local dimming block of the light emitting element array (140).

[0090] The operation of compensating the set voltage value of the light emitting element array (140) can be performed for each image frame.

[0091] As described above, the flat lighting device (100) operates together with the display panel unit (200) and may include a light emitting element array (140) including at least one channel (CH1 to CHn) to which a plurality of light emitting elements (D1 to Dn) are connected, a driving element (110) connected to one end of at least one channel (CH1 to CHn), and a power supply unit (130) connected to the other end of at least one channel (CH1 to CHn) to supply power to each channel.

[0092] At this time, the processor (120) is positioned between the driving element (110) and the power supply (130), and transmits driving data applied to each channel of the light-emitting element array (140) corresponding to the brightness of the current screen of the display panel unit (200) to the driving element (110), and controls the power supply (130) by compensating for the set voltage value of the light-emitting element array (140) calculated corresponding to the driving data.

[0093]

[0094] Fig. 6 is a flowchart illustrating the operation of a flat lighting device according to a second embodiment of the present disclosure. Fig. 7 is a schematic diagram illustrating the operation of a flat lighting device according to a second embodiment of the present disclosure.

[0095] Referring to FIG. 6, the driving operation of the light emitting element array (140) is illustrated, which is performed by a plurality of driving elements (driving ICs; 110) connected to the light emitting element array (140), a power supply unit (130) that supplies power to the light emitting element array (140), and a processor (second processor; MCU; 120) connected between the driving elements (110) and the power supply unit (130).

[0096] First, when operation is started in the processor (120) (Start-Enable), driving data according to the brightness of the current screen, for example, LED current data (rise), can be transmitted to the driving element (110) to drive the light-emitting element array (140) (S10).

[0097] This driving data may be current data applied to the LED. This LED current data may be received from the processor (210) of the display panel unit (200). This LED current data may be local dimming data that divides the light-emitting element array (140) into multiple parts and drives each divided part at different brightnesses.

[0098] For example, when the screen of the display panel unit (200) becomes brighter, the resulting increased driving data, for example, increased LED current data, can be transmitted to the driving element (110).

[0099] The LED current applied to the light-emitting element array (140) can be increased according to the driving data (LED current data) received from the driving element (110) (S20).

[0100] Accordingly, the light emitting element array (140) is driven by the increased LED current, and the driving element (110) can check whether the voltage for applying the increased LED current is sufficient. For example, the driving element (10) can supply the minimum voltage (V) for driving the light emitting element array (140) with the brightness of the current screen. HEADROOM ) is determined to be less than the reference value (Ref.) (S30), and if this case occurs (Y; VLED voltage insufficient), it can be stored as feedback data (voltage feedback data) (feedback operation; S40).

[0101] In this way, the driving element (110) controls the headroom voltage (V) of the light emitting element array (140). HEADROOM ) can be recorded as voltage feedback data. For example, the driving element (110) can record a state in which the minimum voltage for supplying current to drive the light-emitting element array (140) with the current screen brightness is less than a reference value as voltage feedback data.

[0102] Such feedback operation can be checked for N lines (N line; see FIG. 7). For example, referring to FIG. 7, a feedback operation (F / B 1 Transmit) can be performed for the first driving line (1 line) of the light emitting element array (140), and then a feedback operation (F / B 2 Transmit) can be performed for the second first driving line (2 line). In this way, feedback operations are performed sequentially so that a feedback operation (F / BN Transmit) can be performed for the Nth driving line (N line).

[0103] In this way, it is checked whether all feedback operations have been performed for N driving lines (S50), and if all feedback operations have been performed for N driving lines (Y), the feedback data (voltage feedback data) accumulated during the feedback operations for these N driving lines can be transmitted to the processor (120) (S60).

[0104] Meanwhile, after the operation (S10) of transmitting LED current data (rising) from the processor (120) to the driving element (110), the processor (120) can output a set voltage value for the driving data (S70).

[0105] As described above, the processor (120) can control the power supply (130) by compensating for the set voltage value of the light emitting element array (140) that is calculated in response to the driving data.

[0106] At this time, the processor (120) can receive driving data of the light emitting element array (140). For example, a set voltage value can be confirmed for the driving data (S71). For example, the set voltage value can be calculated from the current-voltage (ILED-VLED) data of the light emitting element array (140). For example, the current-voltage data can be stored in a look-up table.

[0107] Accordingly, the processor (120) can output a feedback value based on a look-up table. For example, this feedback value may be the set voltage value described above. This set voltage value may be output for each image frame.

[0108] At this time, the processor (120) compares the voltage feedback data received from the driving element (110) with the set voltage value received from the display panel unit (200) and calculates the difference (S73). If the voltage feedback data is greater than the set voltage value, the processor (120) can control the power supply unit (130) to increase the voltage by the difference.

[0109] The processor (120) can output a feedback value (voltage feedback data) for the feedback data (voltage feedback data) accumulated during the feedback operation for the N driving lines received from the driving element (110) (S80). As described above, the feedback value and the set voltage value can be combined in the processor (120) (S73) and transmitted to the power supply (130). In this way, the power supply (130) can be controlled by the value obtained by comparing the feedback value and the set voltage value to increase the driving voltage (VLED) of the light emitting element array (140) (S90).

[0110] As described above, through the comparison operation process, the processor (120) can compensate for the voltage by the difference between the voltage feedback data and the set voltage value if the voltage feedback data transmitted from the driving element (110) is greater than the set voltage value.

[0111] For example, the processor (120) can compare and calculate the voltage feedback data received from the driving element (110) with the set voltage value received from the display panel unit (200), and control the power supply unit (130) to increase the voltage by the difference if the voltage feedback data is greater than the set voltage value.

[0112] Meanwhile, the processor (120) can ignore the voltage feedback data if the voltage feedback data is equal to or less than the set voltage value.

[0113] By this operation, rather than compensating for the driving voltage of the light-emitting element array (140) after receiving feedback data from the driving element (110), the feedback value (set voltage value) is calculated using local dimming data and reflected first before receiving feedback data from the driving element (110), thereby preventing the occurrence of a delay in voltage feedback.

[0114] In this way, the driving voltage of the light emitting element array (140) can be immediately compensated through a feedback process using local dimming data, thereby improving the picture quality of the display device.

[0115]

[0116] Fig. 8 is a block diagram showing the physical connection state of a flat lighting device according to the second embodiment of the present disclosure.

[0117] Referring to FIG. 8, the connection state of four driving elements (driving ICs; 110-1 to 110-4) and a processor (MCU; 120) is illustrated as an example. Each driving element (110-1 to 110-4) can be connected to each other through a communication interface (not shown). Feedback data can be transmitted through this communication interface. For example, each driving element (110-1 to 110-4) can exchange data with each other through a first line (15). For example, local dimming data for driving a flat lighting device (100) or a backlight unit (BLU) can be transmitted through the first line (15).

[0118] For example, each driving element (110-1 to 110-4) can be connected to each other through the input and output terminals of the communication interface.

[0119] Referring to Fig. 8, the feedback operation by headroom voltage detection of each driving element (110-1 to 110-4) is performed during the pause period of communication through the communication interface, so a separate feedback terminal may not be required. Accordingly, a separate wire or jumper wire may not be required to connect these feedback terminals to each other.

[0120] As described above, according to the present embodiment, the driving voltage (VLED) can be controlled by transmitting a feedback signal to the processor (120) in units of (video) frames or periodically within a frame within each driving element (110-1 to 110-4).

[0121] In addition, rather than compensating for the driving voltage of the light-emitting element array (140) after receiving feedback data from the driving element (110), the feedback value (set voltage value) is calculated using local dimming data and reflected first before receiving feedback data from the driving element (110), thereby preventing a delay in voltage feedback.

[0122]

[0123] Fig. 9 is a schematic diagram showing the block configuration of a flat lighting device according to the second embodiment of the present disclosure. Fig. 10 is an enlarged view of part A of Fig. 9.

[0124] Fig. 9 illustrates a block configuration of a flat lighting device according to an embodiment of the present disclosure. Here, the block configuration may correspond to a local dimming block.

[0125] As described above, light emitting elements of at least one channel may be connected to one driving element (110). Referring to FIG. 9, as an exemplary embodiment, light emitting elements of four channels (CH1 to CH4) may be connected to one driving element (110-1). For example, light emitting elements connected to four channels (CH1 to CH4) of one driving element (110-1, 110-2) may be driven with the same brightness. In other words, four channels (CH1 to CH4) of one driving element (110-1) may correspond to a unit local dimming block.

[0126] Each driving element (110-1, 110-2) can be driven by local dimming data for these unit local dimming blocks. In addition, a set voltage value according to these local dimming data can be transmitted to the processor (120) so that voltage feedback can be performed in advance.

[0127]

[0128] The above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention.

[0129] Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of ​​the present invention but to explain it, and the scope of the technical idea of ​​the present invention is not limited by these embodiments.

[0130] The scope of protection of the present invention should be interpreted by the claims below, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

[0131] According to the present disclosure, a flat lighting device and a display device using a semiconductor light-emitting element such as a micro LED can be provided.

Claims

1. In a flat lighting device that operates with a display panel, An array of light-emitting elements comprising at least one channel having a plurality of light-emitting elements connected thereto; A driving element connected to one end of at least one of the channels; A power supply unit connected to the other end of at least one channel and supplying power to each channel; and A flat lighting device including a processor positioned between the driving element and the power supply, transmitting driving data applied to each channel of the light-emitting element array in response to the brightness of the current screen of the display panel to the driving element, and controlling the power supply by compensating for a set voltage value of the light-emitting element array calculated in response to the driving data.

2. In the first paragraph, the driving data is current data transmitted from the display panel unit. Flat lighting device.

3. In the first paragraph, the driving data is local dimming data transmitted from the display panel section to partially drive the light emitting element array at different brightness. Flat lighting device.

4. In the first paragraph, the processor receives voltage feedback data for driving the light emitting element array with respect to the driving data from the driving element. Flat lighting device.

5. In the fourth paragraph, the driving element records the headroom voltage generation of the light emitting element array as the voltage feedback data. Flat lighting device.

6. In the fourth paragraph, the driving element records as the voltage feedback data a state in which the minimum voltage for supplying current to drive the light-emitting element array with the brightness of the current screen is less than a reference value. Flat lighting device.

7. In the fourth paragraph, if the voltage feedback data is greater than the set voltage value, the processor compensates for the voltage by the difference between the voltage feedback data and the set voltage value. Flat lighting device.

8. In the fourth paragraph, the processor ignores the voltage feedback data if the voltage feedback data is equal to or less than the set voltage value. Flat lighting device.

9. In the fourth paragraph, the driving element, In accordance with the above driving data, the driving current transmitted to the light emitting element array is increased, and when the headroom voltage of the light emitting element array is less than a preset value, the voltage feedback data for voltage increase is transmitted to the control unit. Flat lighting device.

10. In the first paragraph, the set voltage value is calculated from the current-voltage data of the light-emitting element array. Flat lighting device.

11. In the 10th paragraph, the current-voltage data is stored in a lookup table. Flat lighting device.

12. In the 10th paragraph, the processor calculates the set voltage value based on the maximum current of the current-voltage data. Flat lighting device.

13. In the first paragraph, the operation of compensating the set voltage value of the light emitting element array is performed for each image frame. Flat lighting device.

14. A display panel section including a first processor; and A flat lighting device comprising a second processor linked to the first processor, The above flat lighting device, An array of light-emitting elements comprising at least one channel having a plurality of light-emitting elements connected thereto; A driving element connected to one end of at least one of the channels; A power supply unit connected to the other end of at least one channel and supplying power to each channel; and A display device including a second processor located between the driving element and the power supply, which transmits driving data applied to each channel of the light-emitting element array in response to the brightness of the current screen of the display panel unit to the driving element, and controls the power supply by compensating for a set voltage value of the light-emitting element array received from the first processor and calculated in response to the driving data.

15. In the 14th paragraph, the driving data is local dimming data transmitted from the first processor to partially drive the light emitting element array at different brightness. Display device.

Images