WO2019031355A1 - Backlight unit and electronic device - Google Patents

Backlight unit and electronic device Download PDF

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Publication number
WO2019031355A1
WO2019031355A1 PCT/JP2018/028877 JP2018028877W WO2019031355A1 WO 2019031355 A1 WO2019031355 A1 WO 2019031355A1 JP 2018028877 W JP2018028877 W JP 2018028877W WO 2019031355 A1 WO2019031355 A1 WO 2019031355A1
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WO
WIPO (PCT)
Prior art keywords
constant current
led
backlight unit
circuit
voltage generation
Prior art date
Application number
PCT/JP2018/028877
Other languages
French (fr)
Japanese (ja)
Inventor
齊藤　浩二
森　泰樹
正樹 植畑
和也 近藤
一久 吉本
晃祐 川本
Original Assignee
シャープ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by シャープ株式会社 filed Critical シャープ株式会社
Publication of WO2019031355A1 publication Critical patent/WO2019031355A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S2/00—Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V19/00—Fastening of light sources or lamp holders
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
    • F21V29/50—Cooling arrangements
    • F21V29/502—Cooling arrangements characterised by the adaptation for cooling of specific components
    • F21V29/503—Cooling arrangements characterised by the adaptation for cooling of specific components of light sources
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
    • F21V29/50—Cooling arrangements
    • F21V29/502—Cooling arrangements characterised by the adaptation for cooling of specific components
    • F21V29/508—Cooling arrangements characterised by the adaptation for cooling of specific components of electrical circuits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
    • F21V29/50—Cooling arrangements
    • F21V29/70—Cooling arrangements characterised by passive heat-dissipating elements, e.g. heat-sinks
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods

Definitions

  • the present invention relates to a backlight unit and an electronic device.
  • a liquid crystal module (LCM: Liquid Crystal Module) 204 of a conventional laptop PC (Personal Computer: personal computer) 201 includes a backlight unit 202, a display control substrate 203, and a liquid crystal panel (not shown). including.
  • a plurality of LEDs 210, a flexible printed circuit (FPC) 207 on which a plurality of LEDs 210 are mounted, and a light guide plate 206 are stored in a bezel 205.
  • the display control board 203 includes a plurality of LED driver ICs (Integrated Circuits) 240, a power supply IC 251, a Tcon (Timing Controller: Timing Controller) 252, and an EEPROM (Electrically Erasable Programmable Read-Only Memory: A non-volatile memory 253 such as a trademark) and an input connector 254 are provided.
  • the light emitted from the plurality of LEDs 210 enters the light guide plate 206 from one side surface of the light guide plate 206, emits from the main surface of the light guide plate 206 out of the light guide plate 206, and illuminates a liquid crystal panel (not shown).
  • the backlight unit 202 has three LED arrays 212.
  • an LED string 211 is configured by connecting eight LEDs 210 in series, and four LED strings 211 are configured in parallel.
  • the LED driver IC 240 is provided in one-to-one correspondence with the LED array 212.
  • the LED driver IC 240 includes, in the LED array 212, the channels ch201 to ch204 to which the cathodes of the LED rows 211 are connected, the constant current circuit 220 for supplying a constant current to each LED row 211, and the anodes of the LED rows 211. And a booster circuit 230 for generating a voltage to be supplied.
  • the LED driver IC 240 is connected between the coil 232 and the anode of the diode 231, and the cathode of the diode 231 is connected to the anode of each LED row 211.
  • the boosting circuit 230 of the LED driver IC 240, the coil 232, and the diode 231 constitute a boosting circuit block 233 that supplies a boosted voltage to the anode of each LED string 211.
  • the backlight unit 202 needs to be a direct light type, not a side light type.
  • Patent Document 1 discloses a direct type backlight unit.
  • the direct type backlight unit has more LEDs.
  • the number of LED driver ICs 240 provided corresponding to the LED arrays 212 and in which the constant current circuit 220 and the booster circuit 230 are integrated also increases.
  • the area of the display control board 203 shown in FIG. 17 also needs to be increased.
  • the Y dimension Y200 of the liquid crystal module which is the length to the opposite side) also becomes large.
  • An object of one embodiment of the present invention is to obtain a direct-type backlight unit while suppressing an increase in size of a display control substrate.
  • a back light unit concerning one mode of the present invention is a direct-back type back light unit, and a substrate and a plurality of LED arranged on the above-mentioned substrate were connected Or a plurality of LED arrays, and one or more constant current ICs provided on the base material corresponding to the LED arrays and supplying constant current to the LEDs included in the LED arrays, the LED array comprising A plurality of LED strings including a plurality of LEDs connected in series, and the constant current IC includes a plurality of constant current circuits connected to each of the plurality of LED strings.
  • FIG. 2 is a cross-sectional view illustrating the configuration of the electronic device according to the first embodiment.
  • FIG. 2 is a plan view illustrating a configuration of a liquid crystal module of Embodiment 1.
  • FIG. 6 is a plan view illustrating a configuration of a backlight unit and a display control board in the electronic device of Embodiment 1.
  • FIG. 2 is a diagram illustrating a circuit of a backlight unit and a voltage generation circuit block in the electronic device of Embodiment 1.
  • FIG. 2 is a diagram illustrating a configuration of a constant current IC of Embodiment 1.
  • FIG. 7 is a diagram illustrating a configuration in which a voltage generation IC is provided on a main control substrate in the electronic device of Embodiment 1.
  • FIG. 7 is a diagram illustrating a configuration of an electronic device of a second embodiment.
  • FIG. 7 is a diagram illustrating a configuration of an electronic device of a third embodiment.
  • FIG. 7 is a circuit diagram of a backlight unit and an LED driver according to a first comparative example. It is a figure showing the composition of the electronic equipment of the 2nd comparative example. It is a figure showing the composition of the liquid crystal module of the conventional notebook PC. It is a circuit diagram of a backlight unit and an LED driver in a conventional notebook PC.
  • FIG. 6 is a diagram for explaining the operation of the voltage generation circuit block of the first embodiment. It is a figure showing the voltage in the voltage generation circuit block of FIG. It is sectional drawing showing the structure of the liquid crystal module for televisions.
  • first comparative example and the second comparative example As in the conventional side light type backlight module shown in FIGS. 17 and 18, a constant current circuit and a booster circuit are integrally provided for each LED array. It is a liquid crystal module having a direct type backlight module provided with an LED driver IC.
  • FIG. 14 is a diagram illustrating the configuration of the electronic device 101 of the first comparative example.
  • the liquid crystal module 104 of the electronic device 101 such as a notebook PC includes a backlight unit 102, a display control substrate 103, and a liquid crystal panel (not shown).
  • a bezel 105 stores a plurality of LEDs 110, a base material 107 such as an FPC on which the plurality of LEDs 110 are mounted, and a diffusion plate 106.
  • the plurality of LEDs 110 are provided in a matrix on the base material 107, and a diffusion plate 106 is provided to cover the plurality of LEDs 110.
  • the display control board 103 is provided with a plurality of LED driver ICs 140, a power source IC 151, a Tcon 152, a nonvolatile memory 153 such as an EEPROM, an input connector 154 and the like.
  • the light emitted from the plurality of LEDs 110 enters the diffusion plate 106 from the back surface of the diffusion plate 106, exits from the main surface of the diffusion plate 106 to the outside of the diffusion plate 106, and illuminates a liquid crystal panel (not shown).
  • FIG. 15 is a circuit diagram of a backlight unit and an LED driver according to a first comparative example.
  • the backlight unit 102 has eight LED arrays 112.
  • an LED string 111 is configured by connecting four LEDs 110 in series, and sixteen LED strings 111 are configured in parallel.
  • the LED driver IC 140 is provided in one-to-one correspondence with the LED array 112. That is, eight LED driver ICs 140 are also provided.
  • the LED driver IC 140 includes the channels ch101 to ch116 to which the cathode of each LED array 111 is connected in the LED array 112, the constant current circuit 120 for supplying a constant current to each LED array 111, and the anode of each LED array 111. And a booster circuit 130 for generating a voltage to be supplied.
  • the LED driver IC 140 is connected between the coil 132 and the anode of the diode 131, and the cathode of the diode 131 is connected to the anode of each LED string 111.
  • the boosting circuit 130 of the LED driver IC 140, the coil 132, and the diode 131 constitute a boosting circuit block 133 that supplies a boosted voltage to the anode of each LED array 111.
  • the area of the display control board 103 needs to be greatly enlarged.
  • the lower side of the display control board 103 (the side facing the backlight unit 102) from the upper side of the backlight unit 102 (the side opposite to the side facing the display control board 103).
  • the Y dimension Y100 of the liquid crystal module which is the length to the side opposite to
  • FIG. 16 is a diagram illustrating the configuration of the electronic device 101A of the second comparative example.
  • the electronic device 101A is provided not on the display control substrate 103 but on the base 107 so as to be adjacent to one side surface of the diffusion plate 106 instead of providing the eight LED drivers 140.
  • the circuit configuration of the backlight unit and the LED driver of the electronic device 101A is the same as the circuit configuration of the backlight unit and the LED driver shown in FIG.
  • the lower side of the display control board 103 (the side facing the backlight unit 102) and the upper side of the backlight unit 102 (the side opposite to the side facing the display control board 103)
  • the Y dimension Y100A of the liquid crystal module which is the length to the opposite side) does not increase, and can be approximately the same as the Y dimension Y200 of the liquid crystal module shown in FIG.
  • the area of the backlight unit 102 is increased, or Alternatively, when provided on both the front and back sides of the base material 107, the thickness of the backlight unit 102 becomes thick.
  • the eight LED drivers 140 and the peripheral circuits including the eight coils 132 and the diodes 131 corresponding to them are not provided on both the front and back sides of the substrate 107
  • the peripheral circuit including the coil 132 and the diode 131 corresponding to a part of the LED driver 140 among the eight LED drivers 140 can not be provided on the base material 107, and must be provided on the display control substrate 103. .
  • the coil 132 and the diode 131 corresponding to a part of the LED driver 140 among the eight LED drivers 140 are provided on the display control board 103, and the coil 132 and the diode corresponding to the other part LED driver 140
  • the substrate 131 is provided on the substrate 7
  • the electrical characteristics between the LED drivers 140 change, and the luminance of each LED array 112 can not be controlled with high accuracy.
  • FIG. 1 is a cross-sectional view illustrating the configuration of the electronic device 1 according to the first embodiment.
  • the electronic device 1 is various electronic devices having a display area of an image.
  • the electronic device 1 may be a television, but is preferably a mobile electronic device such as a notebook PC, a tablet terminal, a mobile phone terminal or the like.
  • the electronic device 1 will be described as being a notebook PC.
  • the electronic device 1 includes a liquid crystal module 4, a main control substrate 9 which is a mother board, and a bezel 5 (see FIG. 2) for storing a backlight unit of the liquid crystal module 4.
  • the main control board 9 comprehensively controls the operation of the electronic device 1.
  • the main control board 9 is made of resin, metal or the like, and various circuits are provided.
  • the liquid crystal module 4 includes a liquid crystal panel 8, a backlight unit 2, and a display control substrate 3.
  • the backlight unit 2 is disposed on the back side of the liquid crystal panel 8 and illuminates the liquid crystal panel 8 from the back side.
  • the liquid crystal panel 8 is configured such that a TFT substrate provided with TFT elements (Thin Film Transistors) for each pixel and a counter substrate face each other with a liquid crystal layer interposed.
  • TFT elements Thin Film Transistors
  • the display control board 3 controls the driving of the backlight unit 2 and the liquid crystal panel 8 by outputting a drive signal to the backlight unit 2 and the liquid crystal panel 8 according to an instruction from the main control board 9.
  • the display control board 3 is made of resin, metal or the like, and various circuits are mounted.
  • FIG. 2 is a plan view showing the configuration of the liquid crystal module 4 of the first embodiment.
  • the liquid crystal panel 8 has a display area 81 in which pixels are arranged in a matrix and displays an image, and a frame area 4 a which is an area around the display area 81.
  • the frame area 4 a is an area from the edge of the display area 81 to the outermost edge of the backlight unit 2 or the liquid crystal panel 8.
  • the frame area 4 a refers to an area from the edge of the display area 81 to the edge of the bezel 5 (that is, the edge of the backlight unit 2).
  • an area above the display area 81 is referred to as an upper frame 4aT
  • an area below the display area 81 is referred to as a lower frame 4aD
  • an area to the right of the display area 81 is right
  • the area to the left of the display area 81 is referred to as a left frame 4aL.
  • a landscape type is generally adopted in liquid crystal modules for notebook PCs.
  • the mounting area of the source driver SD is secured in the lower frame 4aD of the liquid crystal module 4, and the display control substrate 3 is disposed outside the lower frame 4aD.
  • a region outside the display area 81 may be referred to as a panel frame. Further, which of the backlight unit 2 and the liquid crystal panel 8 is the outermost edge varies depending on the application of the liquid crystal module 4.
  • FIG. 3 is a plan view showing the configuration of the backlight unit 2 and the display control board 3 in the electronic device 1 of the first embodiment.
  • the liquid crystal panel 8 of the liquid crystal module 4 is not shown.
  • the backlight unit 2 is a direct type backlight unit, and can emit light by the local dimming method.
  • the backlight unit 2 includes a substrate 7, a plurality of LEDs 10 (light emitting elements) mounted on the substrate 7, a diffusion plate 6 provided on the plurality of LEDs 10, and a plurality of substrates mounted on the substrate 7. It includes a current IC and a bezel 5 that houses the base 7 and the diffusion plate 6.
  • the substrate 7 is, for example, an FPC.
  • the base 7 is not limited to the FPC, and may be a substrate or the like made of a material such as resin or metal.
  • the display control substrate 3 is electrically connected to the base 7, and outputs various signals to the backlight unit 2 and the liquid crystal panel 8 through the connection portion.
  • the display control board 3 is provided with a power supply IC 51, a Tcon 52, a non-volatile memory 53 such as an EEPROM, an input connector 54 and the like. Furthermore, the display control board 3 is provided with one or more voltage generation circuit blocks 33 for supplying a desired voltage to the LED 10.
  • the voltage generation circuit block 33 includes a voltage generation IC 30, a diode 31 and a coil 32.
  • the voltage generation IC 30 may include the function of the diode 31. In this case, the diode 31 is unnecessary.
  • FIG. 4 is a diagram showing a circuit of the backlight unit 2 and the voltage generation circuit block 33 in the electronic device 1 of the first embodiment.
  • the backlight unit 2 includes one or more LED arrays 12 and one or more constant current ICs 20 for supplying a constant current to the LEDs 10.
  • the LED array 12 is connected in series to one voltage generation circuit block 33.
  • a voltage generation IC 30 for generating a voltage to be supplied to the anode of the LED 10 is connected between the anode of the diode 31 and the coil 32.
  • the voltage generation IC 30 is provided on the display control substrate 3 which is a substrate different from the substrate 7 on which the constant current IC 20 is provided.
  • the voltage generation IC 30 includes a boost circuit, a step-down circuit or a step-up / step-down circuit for supplying a desired current to the LED 10.
  • each LED array 12 is configured by connecting in parallel a plurality of LED strings 11 connected in series.
  • the LED array 11 is configured by connecting four LEDs 10 in series
  • each LED array 12 is configured by connecting 16 LED arrays 11 in parallel.
  • eight LED arrays 12 are provided side by side.
  • the anodes of the LED arrays 11 are configured by connecting the anodes of the LED arrays 11 to each other.
  • the anode of each LED array 12 is connected to the cathode of the diode 31.
  • the constant current IC 20 is provided to the LED array 12 in a one-to-one correspondence.
  • eight LED arrays 12 are provided, so eight constant current ICs 20 are also provided.
  • FIG. 5 is a diagram illustrating the configuration of the constant current IC 20 according to the first embodiment.
  • the constant current IC 20 has a control signal input circuit 21, a constant current circuit block control circuit 22 (constant current control circuit), a plurality of constant current circuits C1 to C16, and a plurality of channels ch1 to ch16.
  • each LED row 11 is connected to each of the channels ch1 to ch16.
  • the constant current circuits C1 to C16 are provided corresponding to the channels ch1 to ch16 (in other words, corresponding to the respective LED columns 11). Constant current circuits C1 to C16 are connected to the channels ch1 to ch16, respectively. The constant current circuits C1 to C16 are circuits for causing a constant current to flow in each LED row 11.
  • the control signal input circuit 21 is an interface input circuit that receives an input of a control signal.
  • the control signal input circuit 21 obtains a control signal such as SCS, SCLK, or SDI from the control circuit provided on the display control board 3, the control signal input circuit 21 outputs an instruction signal to the constant current circuit block control circuit 22 based on the control signal. Do.
  • the constant current circuit block control circuit 22 individually controls the current supplied to each of the constant current circuits C1 to C16 based on the control signal acquired from the control signal input circuit 21. In other words, the current supplied to each LED row 11 is controlled for each LED row 11. In this way, local dimming can be performed to adjust the luminance for each of the LED rows 11.
  • the constant current IC 20 can be configured to access using, for example, an interface standard such as SPI (Serial Peripheral Interface).
  • SPI Serial Peripheral Interface
  • the interface standard for accessing the constant current IC 20 is arbitrary, and is not limited to SPI.
  • a voltage supplied to the anode of each LED array 11 according to the current flowing in the constant current circuits C1 to C16 (that is, the current flowing in each LED array 11) between each constant current IC 20 and the voltage generation IC 30 A control circuit may be provided which outputs a voltage adjustment signal for adjusting the voltage to the voltage generation IC 30.
  • the voltage generation IC 30 can adjust the voltage supplied to each of the LED rows 11 to increase the luminous efficiency of each LED 10.
  • FIG. 19 is a diagram for explaining the operation of the voltage generation circuit block 33.
  • FIG. 20 is a diagram showing voltages in the voltage generation circuit block 33 of FIG.
  • the voltage generation IC 30 of the voltage generation circuit block 33 is a boost IC.
  • the configuration and operation of the voltage circuit block 33 shown in FIGS. 19 and 20 are an example, and other aspects can be adopted.
  • the voltage generation circuit block 33 further includes a first capacitance Cin on the input side disposed upstream of the coil 32 and a second capacitance Cout on the output side connected to the cathode of the diode 31.
  • the voltage generation IC 30 has a switch 30 a connected between the coil 32 and the diode 31.
  • the voltage on the input side of the voltage generation circuit block 33 is a voltage vin
  • the voltage on the output side (the side connected to the backlight unit 2) is a voltage Vout.
  • FIG. 6 is a cross-sectional view of the backlight unit 2 of the first embodiment.
  • the base material 7 is arrange
  • the diffusion plate 6 is provided above the plurality of LEDs 10 so as not to overlap with the constant current IC 20.
  • the base 7 on which the constant current IC 20 and the plurality of LEDs 10 are mounted is the bezel 5 in which the back surface which is the surface opposite to the mounting surface of the constant current IC 20 and the plurality of LEDs 10 is made of metal.
  • the heat generated from the constant current IC 20 and the plurality of LEDs 10 can be dissipated to the bezel 5 through the base 7. Therefore, the heat dissipation efficiency can be increased.
  • the constant current IC 20 and the plurality of LEDs 10 may be mounted directly on the surface of the bezel 5 instead of on the substrate 7. According to this, since the heat generated from the constant current IC 20 and the plurality of LEDs 10 is directly dissipated to the bezel 5, it is possible to further enhance the radiation efficiency.
  • FIG. 21 is a cross-sectional view showing a configuration of a liquid crystal module 304 for television.
  • the liquid crystal module 304 has a direct type backlight unit in which the FPC 307 on which the LED array 12 is mounted and the diffusion plate 6 disposed above the LED array 12 are stored in the bezel 305. Further, the side wall of the bezel 505 in the lower frame is inclined, and the outer surface of the side wall of the inclined bezel 505 (the surface opposite to the side on which the diffusion plate 6, the LED array 12 and the FPC 307 are stored) A display control board 303 on which an LED driver IC 340, a coil 332 and the like are mounted is disposed.
  • the display control substrate 303 on which the LED driver IC 340, the coil 332, and the like are mounted can be disposed on the outer surface of the side wall of the inclined bezel 505.
  • the said structure since a certain amount of thickness is required, it can not apply to the liquid crystal module for manufacturing a notebook PC with severe thickness restrictions.
  • FIG. 7 is a diagram showing the configuration of a display control board used in a conventional notebook PC.
  • FIG. 8 is an enlarged view of a part of the display control board of FIG.
  • the display control board 203 is provided with a connector 250, an LED driver IC 240, a diode 231 and a coil 232.
  • An FPC 207 extending from the backlight unit 202 to the display control board 203 is connected to the connector 250.
  • the number of pins of the connector 250 is ten, and the coil 232 has a size of 4 mm ⁇ 4 mm and a thickness of about 1.2 mm.
  • the width Y 203 of the display control board 203 is about 8 mm.
  • an area including a part of the LED driver IC 240 (a part including the constant current circuit 220) and the peripheral circuit is a constant current circuit block 229.
  • a region including another part of the LED driver IC 240 (a portion including the booster circuit 230) and a peripheral circuit having the diode 231 and the coil 232 is a booster circuit block 233.
  • the peripheral circuits of the constant current circuit block 229 and the peripheral circuits of the booster circuit block 233 shown in FIG. 8 are merely examples, and differ depending on the type and application of the liquid crystal module.
  • the peripheral circuits of the booster circuit block 233 require a larger number of circuit components than the peripheral circuits of the constant current circuit block 229.
  • the diode 231 and the coil 232 included in the peripheral circuit of the booster circuit block 233 have a large area compared with other circuit components, and further, the vicinity of another part of the LED driver IC 240 (part including the booster circuit 230). Need to be
  • the display control board 203 Assuming that a large number of sets of the booster circuit block 233 and the constant current circuit block 229 are provided on the display control board 203 as the number of LEDs to be controlled increases, the display control board 203 is increased in width Y203, etc. The area of the substrate 203 needs to be increased.
  • booster circuit blocks 233 having this large area are provided in the backlight unit 202, it is necessary to greatly enlarge the lower frame of the backlight unit 202 or to greatly expand the thickness of the backlight unit 202. There is. Alternatively, it is necessary to provide the display control substrate 203 with the diodes 231 and the coils 232 included in the peripheral circuits of some of the plurality of booster circuit blocks 233 among the plurality of booster circuit blocks 233.
  • the constant current circuit block 229 has a smaller area than the booster circuit block 233.
  • the backlight unit 2 of the present embodiment corresponds to the substrate 7, the plurality of LED arrays 12 disposed on the substrate 7, and the respective LED arrays 12.
  • a plurality of constant current ICs provided on the substrate 7 are provided.
  • Each constant current IC includes a plurality of constant current circuits C1 to C16 connected to the cathodes of the respective LED strings of the corresponding LED array 12.
  • constant current circuits C 1 to C 16 for supplying a constant current to the respective LED strings 11 included in the LED array 12 are collectively provided in the constant current IC 20.
  • the constant current circuit is provided on the substrate 7.
  • the display control board 3 is provided with a voltage generation circuit block 33 for supplying a desired voltage to the anode of each LED row of the LED array 12.
  • the area of the display control board is increased compared to the case where the LED driver in which the constant current circuit and the booster circuit are integrated as shown in FIGS. 17 and 18 are provided on the display control board. It can be suppressed. That is, according to the above configuration, it is possible to configure the direct type backlight unit 2 while suppressing an increase in the area of the display control substrate 3.
  • the backlight unit 2 is a direct type backlight unit not provided with the voltage generation circuit.
  • the heat generation source can be dispersed, so that heat generation can also be suppressed.
  • the voltage generation circuit has a larger power loss than a constant current circuit, and thereby generates a large amount of heat.
  • GND can be sufficiently obtained, and power loss can be reduced.
  • relatively large circuit parts can be selected for the size and thickness of the current generating circuit and peripheral circuits, so the boosting efficiency is improved. Also, heat generation can be reduced.
  • the maximum thickness of the circuit component in the case of being provided on a display control substrate for a television is about 12 mm
  • the maximum thickness of the circuit component in the case of being provided on a display control substrate for a notebook PC is about 1.2 mm
  • the maximum thickness of the circuit component in the case of being provided on the FPC of the notebook PC is about 0.9 mm.
  • the number of pins of the connector is considered.
  • the number of pins of the connector is designed to be about 10 to 16.
  • the number of pins of the connector 250 shown in FIGS. 7 and 8 is ten, of which two are connected to the anodes of the plurality of LED arrays 12 and six are connected to the cathodes of the LED array 12.
  • 2 is NC (No Connection: not connected).
  • the liquid crystal module 4 for example, it is assumed that one screen is divided into 128 and local dimming is performed, and the one screen is driven by eight 16ch constant current ICs and two voltage generation ICs.
  • the number of pins is 2 for anode, 4 for GND, 1 for logic power supply, 4 for SPI, 1 for EN and 2 for NC, the total number of pins is 16 It will be enough.
  • the installation area of the connector for connecting the FPC provided on the display control substrate can be reduced.
  • the number of voltage generation ICs 30 is smaller than the number of constant current ICs 20.
  • the LED driver IC 240 When the LED driver IC 240 is provided outside the backlight unit 202 as shown in FIGS. 17 and 18, since the booster circuit and the constant current circuit are integrated, the booster circuit and the constant current circuit are fixed in the liquid crystal module. The same number of current circuits were present.
  • the voltage generation IC 30 can be smaller than the constant current circuits C1 to C16. . Furthermore, the voltage generation IC 30 can be less than the constant current IC 20. This can reduce the cost.
  • the load on the voltage generation IC 30 can also be reduced. Therefore, it is possible to drive more constant current ICs (that is, each LED controlled by the constant current IC) with less voltage generation IC.
  • one or more voltage generation ICs 30 may be provided not on the display control board 3 but on the main control board 9.
  • FIG. 10 is a diagram illustrating the configuration of the electronic device 1 of the second embodiment.
  • the number of voltage generation ICs 30 may be an integer (but one or more) of the number of constant current ICs 20.
  • FIG. 10 shows an example in which two voltage generation ICs 30 that are one fourth of the eight constant current ICs 20 are provided.
  • the load of the voltage generation IC 30 can be equally divided by setting the number of voltage generation ICs 30 to be an integral number (but one or more) of the number of constant current ICs 20. Therefore, the peripheral circuits included in the voltage generation IC 30 As a result, it is possible to select an optimal and inexpensive peripheral circuit.
  • FIG. 11 is a diagram illustrating the configuration of the electronic device 1 of the third embodiment.
  • FIG. 12 is a diagram illustrating configurations of a constant current IC 20 and a voltage generation IC 30 included in the electronic device 1 of the third embodiment.
  • FIG. 13 is a diagram showing how a plurality of constant current ICs are connected in parallel to a voltage generation IC.
  • two circuits including two constant current ICs 20 and one voltage generation IC 30 are provided.
  • the number of the constant current IC 20, the voltage generation IC 30, and the circuit including them is not limited to the number shown in FIG.
  • the constant current IC 20 includes, in addition to the constant current circuits C1 to C16 and the channels ch1 to ch16, the channels ch17 to ch20, the abnormality detection circuit 24, and the abnormality condition notification signal input circuit 25. And an abnormal condition notification signal output circuit 26.
  • the constant current IC 20 may include the constant current circuit block control circuit 22 and the control signal input circuit 21 shown in FIG.
  • the abnormal state notification signal input circuit 25 is connected to the channel ch17 and the channel ch18.
  • the abnormal state notification signal output circuit 26 is connected to the channel ch19 and the channel ch20.
  • the abnormality detection circuit 24 detects an abnormal state of the constant current circuits C1 to C16 by monitoring each of the constant current circuits C1 to C16.
  • the abnormal state is, for example, an abnormal current, an abnormal voltage, or an abnormal temperature.
  • the abnormality detection circuit 24 monitors the current flowing in each of the constant current circuits C1 to C16, compares it with a predetermined upper limit current value set in advance, and compares it with the upper limit current value. If it is large, it is judged as an abnormal current.
  • the channel ch20 of the first stage constant current IC20 is connected to the channel ch17 of the second stage constant current IC20.
  • the channel ch 20 of the second stage constant current IC 20 is connected to the voltage generation IC 30.
  • the channel ch19 of the first stage constant current IC20 is connected to the channel ch18 of the second stage constant current IC20.
  • the channel ch19 of the second stage constant current IC 20 is connected to the voltage generation IC 30.
  • the abnormal state detection circuit 24 When the abnormal state detection circuit 24 detects an abnormal state of any of the constant current circuits C1 to C16, it outputs an abnormal state notification signal DATA, which is a signal notifying an abnormal state, to the abnormal state notification signal output circuit 26.
  • an abnormal state notification signal DATA which is a signal notifying an abnormal state
  • the abnormality detection circuit 24 of the first stage constant current IC 20 detects an abnormal state of any of the constant current circuits C1 to C16, it outputs an abnormal state notification signal DATA to the abnormal state notification signal output circuit 26. .
  • the abnormal state notification signal output circuit 26 of the first stage constant current IC 20 outputs the abnormal state notification signal DATA from the channel ch 19 and outputs the clock signal CLK from the channel ch 20.
  • the abnormal condition notification signal DATA output from the channel ch19 of the first stage constant current IC20 is input to the abnormal condition notification signal input circuit 25 of the second stage constant current IC20 through the channel ch18
  • the clock signal CLK output from the channel ch20 of the first stage constant current IC20 is input to the abnormal state notification signal input circuit 25 of the second stage constant current IC20 through the channel ch17.
  • the abnormal state notification signal input circuit 25 of the second stage constant current IC 20 outputs the abnormal state notification signal DATA and the clock signal CLK inputted thereto to the abnormal state notification signal output circuit 26 of the second stage constant current IC 20. Output to
  • the abnormal state notification signal output circuit 26 of the second stage constant current IC 20 outputs the input abnormal state notification signal DATA from the channel ch 19 and outputs the clock signal CLK from the channel ch 20.
  • both the abnormal state notification signal DATA output from the channel ch19 of the second stage constant current IC20 and the clock signal CLK output from the channel ch20 of the second stage constant current IC20 are abnormal state notification signal receiving circuits. It is input to 35.
  • the abnormal condition notification signal receiving circuit 35 outputs the input abnormal condition notification signal DATA and the clock signal CLK to the voltage generation operation control circuit 36.
  • the voltage generation IC stops the generation of the voltage. Thereby, the voltage supplied to the anode of each LED array 12 is also stopped, and each LED array 12 is turned off. That is, the current flowing in the constant current circuits C1 to C16 of the first and second stage constant current ICs 20 is also stopped.
  • a path in which the channel ch19 of the first stage constant current IC20 and the channel ch18 of the second stage constant current IC20 are connected, and the channel ch19 of the second stage constant current IC20 and the voltage generation IC 30 are connected Is a path for transmitting and receiving an abnormal state notification signal which is a signal notifying an abnormal state.
  • the area allocated for installing a connector for connecting the FPC and the display control board is very small, and it is necessary to reduce the number of pins of the connector.
  • the path which transmits / receives an abnormal condition notification signal which is a signal which notifies an abnormal condition among a plurality of constant current IC20 and voltage generation IC30 is connected in series.
  • an abnormal condition notification signal which is a signal which notifies an abnormal condition among a plurality of constant current IC20 and voltage generation IC30
  • the number of wires can be reduced by connecting in series a path for transmitting and receiving an abnormal state notification signal which is a signal notifying an abnormal state between the plurality of constant current ICs 20 and the voltage generation IC 30.
  • a backlight unit is a direct-type backlight unit, comprising: a substrate; and one or more LED arrays to which a plurality of LEDs disposed on the substrate are connected; And one or more constant current ICs for supplying constant current to the LEDs included in the LED array corresponding to the array, and the LED array includes a plurality of LEDs connected in series.
  • the constant current IC includes a plurality of constant current circuits connected to each of the plurality of LED strings.
  • a plurality of constant current circuits for supplying a constant current to the plurality of LED rows included in the LED array are collectively provided in the constant current IC. Therefore, among the constant current IC and the circuit for supplying a desired voltage to the anodes of the plurality of LED strings, the constant current IC is provided on the base material and desired for the anodes of the plurality of LED strings.
  • the circuit for supplying the voltage V.sub.2 can be provided on another substrate different from the above substrate.
  • the constant current IC is a control signal input circuit that acquires a control signal input to the constant current IC, and an instruction from the control signal input circuit And a constant current control circuit for adjusting the current flowing from each of the LED rows to each of the constant current circuits based on a signal. According to the above configuration, it is possible to adjust the current flowing for each of the LED strings in the LED array. Thereby, the brightness can be adjusted for each of the LED rows in the LED array.
  • the backlight unit, the display control substrate, and the display control substrate are disposed, and include a voltage generation IC and peripheral circuit components And a voltage generation circuit block for supplying a voltage to the anodes of the columns.
  • the number of the voltage generation ICs may be smaller than the number of the constant current ICs. This can reduce the cost.
  • the number of voltage generation ICs may be an integer (but one or more) of the number of the constant current ICs. According to the above configuration, since loads of a plurality of voltage generation ICs can be equally divided, it is possible to select an optimal and inexpensive peripheral circuit as a peripheral circuit included in the voltage generation IC.
  • the plurality of constant current ICs and the voltage generation IC connect in series a path for transmitting and receiving an abnormal state notification signal which is a signal notifying an abnormal state. It may be done. According to the above configuration, the number of wires can be reduced.
  • the backlight unit stores the base material, the one or more LED arrays, and the one or more constant current ICs
  • the bezel is in contact with a surface of the base opposite to the side on which the one or more LED arrays and the one or more constant current ICs are disposed in the base.
  • the backlight unit stores the one or more LED arrays and the one or more constant current ICs, and is made of metal.
  • a bezel may be provided, and the substrate may be part of the bezel.
  • the heat radiation efficiency can be increased.

Abstract

According to the present invention, a direct backlight unit is obtained, while suppressing increase in the size of a display control substrate. A direct backlight unit (2) according to the present invention is configured such that a constant current IC (20) having a plurality of constant current circuits (C1-C16) is provided on a substrate (7) which is provided with an LED (10).

Description

バックライトユニット及び電子機器Backlight unit and electronic device
　本発明はバックライトユニット及び電子機器に関する。 The present invention relates to a backlight unit and an electronic device.
　図１７に示すように、従来のノート型ＰＣ（Personal Computer：パーソナルコンピューター）２０１の液晶モジュール（LCM：Liquid Crystal Module）２０４は、バックライトユニット２０２と、表示制御基板２０３と、図示しない液晶パネルとを含む。 As shown in FIG. 17, a liquid crystal module (LCM: Liquid Crystal Module) 204 of a conventional laptop PC (Personal Computer: personal computer) 201 includes a backlight unit 202, a display control substrate 203, and a liquid crystal panel (not shown). including.
　サイドライト型のバックライトユニット２０２は、ベゼル２０５に、複数のＬＥＤ２１０と、複数のＬＥＤ２１０が搭載されたＦＰＣ（Flexible Printed Circuits：フレキシブルプリント回路基板）２０７と、導光板２０６とが格納されている。 In the side light type backlight unit 202, a plurality of LEDs 210, a flexible printed circuit (FPC) 207 on which a plurality of LEDs 210 are mounted, and a light guide plate 206 are stored in a bezel 205.
　表示制御基板２０３には、複数のＬＥＤドライバＩＣ（Integrated Circuit：集積回路）２４０と、電源ＩＣ２５１と、Ｔｃｏｎ（Timing Controller：タイミング・コントローラー）２５２と、ＥＥＰＲＯＭ（Electrically Erasable Programmable Read-Only Memory：（登録商標））等の不揮発性メモリ２５３と、入力コネクタ２５４等が設けられている。 The display control board 203 includes a plurality of LED driver ICs (Integrated Circuits) 240, a power supply IC 251, a Tcon (Timing Controller: Timing Controller) 252, and an EEPROM (Electrically Erasable Programmable Read-Only Memory: A non-volatile memory 253 such as a trademark) and an input connector 254 are provided.
　複数のＬＥＤ２１０から出射した光は導光板２０６の一側面から導光板２０６内に進入し、導光板２０６の主面から導光板２０６外へ出射し、液晶パネル（不図示）を照明する。 The light emitted from the plurality of LEDs 210 enters the light guide plate 206 from one side surface of the light guide plate 206, emits from the main surface of the light guide plate 206 out of the light guide plate 206, and illuminates a liquid crystal panel (not shown).
　図１８に示すように、バックライトユニット２０２は３個のＬＥＤアレイ２１２を有する。各ＬＥＤアレイ２１２は、８個のＬＥＤ２１０が直列に接続されることでＬＥＤ列２１１が構成され、そのＬＥＤ列２１１が４個並列に並んで構成されている。 As shown in FIG. 18, the backlight unit 202 has three LED arrays 212. In each LED array 212, an LED string 211 is configured by connecting eight LEDs 210 in series, and four LED strings 211 are configured in parallel.
　ＬＥＤドライバＩＣ２４０は、ＬＥＤアレイ２１２と一対一対応で設けられている。ＬＥＤドライバＩＣ２４０は、ＬＥＤアレイ２１２における、各ＬＥＤ列２１１のカソードが接続されるチャネルｃｈ２０１～ｃｈ２０４と、各ＬＥＤ列２１１に定電流を流すための定電流回路２２０と、各ＬＥＤ列２１１のアノードに供給する電圧を生成する昇圧回路２３０とを有する。 The LED driver IC 240 is provided in one-to-one correspondence with the LED array 212. The LED driver IC 240 includes, in the LED array 212, the channels ch201 to ch204 to which the cathodes of the LED rows 211 are connected, the constant current circuit 220 for supplying a constant current to each LED row 211, and the anodes of the LED rows 211. And a booster circuit 230 for generating a voltage to be supplied.
　コイル２３２とダイオード２３１のアノードとの間にＬＥＤドライバＩＣ２４０が接続され、ダイオード２３１のカソードは、各ＬＥＤ列２１１のアノードと接続されている。 The LED driver IC 240 is connected between the coil 232 and the anode of the diode 231, and the cathode of the diode 231 is connected to the anode of each LED row 211.
　ＬＥＤドライバＩＣ２４０の昇圧回路２３０と、コイル２３２と、ダイオード２３１とで、各ＬＥＤ列２１１のアノードに昇圧した電圧を供給する昇圧回路ブロック２３３を構成している。 The boosting circuit 230 of the LED driver IC 240, the coil 232, and the diode 231 constitute a boosting circuit block 233 that supplies a boosted voltage to the anode of each LED string 211.
　また、近年、ノート型ＰＣ等のモバイル型の電子機器においても、テレビと同様に画質の高品質化が要求されており、バックライトモジュールをローカルディミング（領域毎に発光）させる方式が要求されている。ローカルディミング方式にて発光させるには、バックライトユニット２０２をサイドライト型ではなく、直下型の構成にする必要がある。 Also, in recent years, even in mobile electronic devices such as notebook PCs, high quality image quality is required as in television, and a method for locally dimming the backlight module (emitting light for each area) is required. There is. In order to emit light by the local dimming method, the backlight unit 202 needs to be a direct light type, not a side light type.
　特許文献１には、直下型のバックライトユニットが開示されている。 Patent Document 1 discloses a direct type backlight unit.
日本国公開特許公報「特開２０１２‐１８６３５０号公報（２０１２年９月２７日公開）」Japanese Patent Publication No. 2012-186350 (published on September 27, 2012)
　しかし、サイドライト型のバックライトユニットと比べて、直下型のバックライトユニットはＬＥＤの個数が多くなる。 However, as compared with the sidelight type backlight unit, the direct type backlight unit has more LEDs.
　例えば、図１８においてＬＥＤアレイ２１２の個数が多くなると、ＬＥＤアレイ２１２に対応して設けられている、定電流回路２２０と昇圧回路２３０とが一体化されたＬＥＤドライバＩＣ２４０の個数も多くなる。 For example, when the number of LED arrays 212 in FIG. 18 increases, the number of LED driver ICs 240 provided corresponding to the LED arrays 212 and in which the constant current circuit 220 and the booster circuit 230 are integrated also increases.
　ＬＥＤドライバＩＣ２４０の個数が多くなると、図１７に示した表示制御基板２０３の面積も大きくする必要がある。表示制御基板２０３の面積が大きくなると、バックライトユニット２０２の上辺（表示制御基板２０３と対向する辺とは逆側の辺）から表示制御基板２０３の下辺（バックライトユニット２０２と対向する辺とは逆側の辺）までの長さである液晶モジュールのＹ寸法Ｙ２００も大きくなる。 As the number of LED driver ICs 240 increases, the area of the display control board 203 shown in FIG. 17 also needs to be increased. When the area of the display control substrate 203 is increased, the upper side of the backlight unit 202 (the side opposite to the side facing the display control substrate 203) and the lower side of the display control substrate 203 (the side facing the backlight unit 202) The Y dimension Y200 of the liquid crystal module which is the length to the opposite side) also becomes large.
　しかし、テレビとは異なり、ノート型ＰＣ等のモバイル型の電子機器においては、利便性の観点から、表示制御基板のサイズの制約が厳しい。 However, unlike televisions, mobile electronic devices such as notebook PCs are severely restricted in the size of display control boards from the viewpoint of convenience.
　特許文献１においても、定電流制御部と昇圧回路部とが一対一で対応して設けられているため、ＬＥＤの個数が増加すると、それに伴い、定電流制御部と昇圧回路部とを配置するための表示制御基板のサイズが大きくなる。 Also in Patent Document 1, since the constant current control unit and the booster circuit unit are provided in one-to-one correspondence, when the number of LEDs increases, the constant current control unit and the booster circuit unit are arranged accordingly The size of the display control board is increased.
　本発明の一態様は、表示制御基板のサイズの増大を抑制しつつ直下型のバックライトユニットを得ることを目的とする。 An object of one embodiment of the present invention is to obtain a direct-type backlight unit while suppressing an increase in size of a display control substrate.
　上記の課題を解決するために、本発明の一態様に係るバックライトユニットは、直下型のバックライトユニットであって、基材と、上記基材に配置された複数のＬＥＤが接続された一又は複数のＬＥＤアレイと、上記ＬＥＤアレイに対応して上記基材に設けられ、当該ＬＥＤアレイに含まれるＬＥＤに定電流を流すための一又は複数の定電流ＩＣとを備え、上記ＬＥＤアレイは、複数のＬＥＤが直列に接続された複数のＬＥＤ列を含み、上記定電流ＩＣは、上記複数のＬＥＤ列それぞれに接続された複数の定電流回路を含むことを特徴とする。 In order to solve the above-mentioned subject, a back light unit concerning one mode of the present invention is a direct-back type back light unit, and a substrate and a plurality of LED arranged on the above-mentioned substrate were connected Or a plurality of LED arrays, and one or more constant current ICs provided on the base material corresponding to the LED arrays and supplying constant current to the LEDs included in the LED arrays, the LED array comprising A plurality of LED strings including a plurality of LEDs connected in series, and the constant current IC includes a plurality of constant current circuits connected to each of the plurality of LED strings.
　本発明の一態様によれば、表示制御基板のサイズの増大を抑制しつつ直下型のバックライトユニットを得るという効果を奏する。 According to one aspect of the present invention, it is possible to obtain a direct type backlight unit while suppressing an increase in the size of the display control substrate.
実施形態１に係る電子機器の構成を表す断面図である。FIG. 2 is a cross-sectional view illustrating the configuration of the electronic device according to the first embodiment. 実施形態１の液晶モジュールの構成を表す平面図である。FIG. 2 is a plan view illustrating a configuration of a liquid crystal module of Embodiment 1. 実施形態１の電子機器のうち、バックライトユニット及び表示制御基板の構成を表す平面図である。FIG. 6 is a plan view illustrating a configuration of a backlight unit and a display control board in the electronic device of Embodiment 1. 実施形態１の電子機器における、バックライトユニット及び電圧生成回路ブロックの回路を表す図である。FIG. 2 is a diagram illustrating a circuit of a backlight unit and a voltage generation circuit block in the electronic device of Embodiment 1. 実施形態１の定電流ＩＣの構成を表す図である。FIG. 2 is a diagram illustrating a configuration of a constant current IC of Embodiment 1. （ａ）は実施形態１のバックライトユニットの構成の一例を示す断面図であり、（ｂ）は実施形態１のバックライトユニットの構成の他の例を示す断面図である。(A) is sectional drawing which shows an example of a structure of the backlight unit of Embodiment 1, (b) is sectional drawing which shows the other example of a structure of the backlight unit of Embodiment 1. FIG. 従来のノート型ＰＣに使用されている表示制御基板の構成を表す図である。It is a figure showing the composition of the display control board used for the conventional notebook PC. 図７の表示制御基板の一部を拡大した図である。It is the figure which expanded a part of display control board of FIG. 実施形態１の電子機器において、電圧生成ＩＣを主制御基板に設けた構成を表す図である。FIG. 7 is a diagram illustrating a configuration in which a voltage generation IC is provided on a main control substrate in the electronic device of Embodiment 1. 実施形態２の電子機器の構成を表す図である。FIG. 7 is a diagram illustrating a configuration of an electronic device of a second embodiment. 実施形態３の電子機器の構成を表す図である。FIG. 7 is a diagram illustrating a configuration of an electronic device of a third embodiment. 実施形態３の電子機器が備える定電流ＩＣ及び電圧生成ＩＣの構成を表す図である。It is a figure showing the composition of constant current IC and voltage generation IC with which electronic equipment of Embodiment 3 is provided. 複数の定電流ＩＣが電圧生成ＩＣに並列で接続されている様子を表す図である。It is a figure showing a mode that several constant current IC is connected in parallel with voltage generation IC. 第１比較例の電子機器の構成を表す図である。It is a figure showing the composition of the electronic equipment of the 1st comparative example. 第１比較例に係るバックライトユニット及びＬＥＤドライバの回路図である。FIG. 7 is a circuit diagram of a backlight unit and an LED driver according to a first comparative example. 第２比較例の電子機器の構成を表す図である。It is a figure showing the composition of the electronic equipment of the 2nd comparative example. 従来のノート型ＰＣの液晶モジュールの構成を表す図である。It is a figure showing the composition of the liquid crystal module of the conventional notebook PC. 従来のノート型ＰＣにおける、バックライトユニット及びＬＥＤドライバの回路図である。It is a circuit diagram of a backlight unit and an LED driver in a conventional notebook PC. 実施形態１の電圧生成回路ブロックの動作を説明する図である。FIG. 6 is a diagram for explaining the operation of the voltage generation circuit block of the first embodiment. 図１９の電圧生成回路ブロック内の電圧を表す図である。It is a figure showing the voltage in the voltage generation circuit block of FIG. テレビ向けの液晶モジュールの構成を表す断面図である。It is sectional drawing showing the structure of the liquid crystal module for televisions.
　〔比較例〕
　まず、第１比較例及び第２比較例の構成について説明する。第１比較例及び第２比較例は、図１７及び図１８に示した従来のサイドライト型のバックライトモジュールと同様に、ＬＥＤアレイ毎に、定電流回路と昇圧回路とが一体として設けられたＬＥＤドライバＩＣを設けた、直下型のバックライトモジュールを有する液晶モジュールである。 Comparative Example
First, the configurations of the first comparative example and the second comparative example will be described. In the first comparative example and the second comparative example, as in the conventional side light type backlight module shown in FIGS. 17 and 18, a constant current circuit and a booster circuit are integrally provided for each LED array. It is a liquid crystal module having a direct type backlight module provided with an LED driver IC.
　図１４は、第１比較例の電子機器１０１の構成を表す図である。図１４に示すように、ノート型ＰＣ等の電子機器１０１の液晶モジュール１０４は、バックライトユニット１０２と、表示制御基板１０３と、図示しない液晶パネルとを含む。 FIG. 14 is a diagram illustrating the configuration of the electronic device 101 of the first comparative example. As shown in FIG. 14, the liquid crystal module 104 of the electronic device 101 such as a notebook PC includes a backlight unit 102, a display control substrate 103, and a liquid crystal panel (not shown).
　直下型のバックライトユニット１０２は、ベゼル１０５に、複数のＬＥＤ１１０と、複数のＬＥＤ１１０が搭載されたＦＰＣ等の基材１０７と、拡散板１０６とが格納されている。複数のＬＥＤ１１０は、基材１０７上にマトリクス状に設けられており、複数のＬＥＤ１１０の上方を覆って拡散板１０６が設けられている。 In the direct-type backlight unit 102, a bezel 105 stores a plurality of LEDs 110, a base material 107 such as an FPC on which the plurality of LEDs 110 are mounted, and a diffusion plate 106. The plurality of LEDs 110 are provided in a matrix on the base material 107, and a diffusion plate 106 is provided to cover the plurality of LEDs 110.
　表示制御基板１０３には、複数のＬＥＤドライバＩＣ１４０と、電源ＩＣ１５１と、Ｔｃｏｎ１５２と、ＥＥＰＲＯＭ等の不揮発性メモリ１５３と、入力コネクタ１５４等が設けられている。 The display control board 103 is provided with a plurality of LED driver ICs 140, a power source IC 151, a Tcon 152, a nonvolatile memory 153 such as an EEPROM, an input connector 154 and the like.
　複数のＬＥＤ１１０から出射した光は拡散板１０６の裏面から拡散板１０６内に進入し、拡散板１０６の主面から拡散板１０６外へ出射し、液晶パネル（不図示）を照明する。 The light emitted from the plurality of LEDs 110 enters the diffusion plate 106 from the back surface of the diffusion plate 106, exits from the main surface of the diffusion plate 106 to the outside of the diffusion plate 106, and illuminates a liquid crystal panel (not shown).
　図１５は第１比較例に係るバックライトユニット及びＬＥＤドライバの回路図である。図１５に示すように、バックライトユニット１０２は８個のＬＥＤアレイ１１２を有する。各ＬＥＤアレイ１１２は、４個のＬＥＤ１１０が直列に接続されることでＬＥＤ列１１１が構成され、そのＬＥＤ列１１１が１６個並列に並んで構成されている。 FIG. 15 is a circuit diagram of a backlight unit and an LED driver according to a first comparative example. As shown in FIG. 15, the backlight unit 102 has eight LED arrays 112. In each LED array 112, an LED string 111 is configured by connecting four LEDs 110 in series, and sixteen LED strings 111 are configured in parallel.
　ＬＥＤドライバＩＣ１４０は、ＬＥＤアレイ１１２と一対一対応で設けられている。つまり、ＬＥＤドライバＩＣ１４０も８個設けられている。 The LED driver IC 140 is provided in one-to-one correspondence with the LED array 112. That is, eight LED driver ICs 140 are also provided.
　ＬＥＤドライバＩＣ１４０は、ＬＥＤアレイ１１２における、各ＬＥＤ列１１１のカソードが接続されるチャネルｃｈ１０１～ｃｈ１１６と、各ＬＥＤ列１１１に定電流を流すための定電流回路１２０と、各ＬＥＤ列１１１のアノードに供給する電圧を生成する昇圧回路１３０とを有する。 The LED driver IC 140 includes the channels ch101 to ch116 to which the cathode of each LED array 111 is connected in the LED array 112, the constant current circuit 120 for supplying a constant current to each LED array 111, and the anode of each LED array 111. And a booster circuit 130 for generating a voltage to be supplied.
　コイル１３２とダイオード１３１のアノードとの間にＬＥＤドライバＩＣ１４０が接続され、ダイオード１３１のカソードは、各ＬＥＤ列１１１のアノードと接続されている。 The LED driver IC 140 is connected between the coil 132 and the anode of the diode 131, and the cathode of the diode 131 is connected to the anode of each LED string 111.
　ＬＥＤドライバＩＣ１４０の昇圧回路１３０と、コイル１３２と、ダイオード１３１とで、各ＬＥＤ列１１１のアノードに昇圧した電圧を供給する昇圧回路ブロック１３３を構成している。 The boosting circuit 130 of the LED driver IC 140, the coil 132, and the diode 131 constitute a boosting circuit block 133 that supplies a boosted voltage to the anode of each LED array 111.
　第１比較例に係る液晶モジュールによると、ＬＥＤアレイ１１２を８個設けると、それに対応してＬＥＤドライバ１４０も８個設ける必要がある。 In the liquid crystal module according to the first comparative example, when eight LED arrays 112 are provided, it is necessary to provide eight LED drivers 140 correspondingly.
　このため図１４に示すように、８個のＬＥＤドライバ１４０を搭載させるために、表示制御基板１０３の面積を大幅に大きくする必要がある。この結果、第１比較例の構成によると、バックライトユニット１０２の上辺（表示制御基板１０３と対向する辺とは逆側の辺）から表示制御基板１０３の下辺（バックライトユニット１０２と対向する辺とは逆側の辺）までの長さである液晶モジュールのＹ寸法Ｙ１００も大幅に大きくなる。 Therefore, as shown in FIG. 14, in order to mount eight LED drivers 140, the area of the display control board 103 needs to be greatly enlarged. As a result, according to the configuration of the first comparative example, the lower side of the display control board 103 (the side facing the backlight unit 102) from the upper side of the backlight unit 102 (the side opposite to the side facing the display control board 103). The Y dimension Y100 of the liquid crystal module, which is the length to the side opposite to
　図１６は、第２比較例の電子機器１０１Ａの構成を表す図である。電子機器１０１Ａは、図１４に示した電子機器１０１において、８個のＬＥＤドライバ１４０を、表示制御基板１０３に設けるのではなく、拡散板１０６の一側面に隣接するように、基材１０７に設けた構成である。すなわち、電子機器１０１Ａは、図１７に示したサイドライト型のバックライトモジュール２０２において複数のＬＥＤ２１０が配置されていた領域に、８個のＬＥＤドライバ１４０を設けた構成である。 FIG. 16 is a diagram illustrating the configuration of the electronic device 101A of the second comparative example. In the electronic device 101 shown in FIG. 14, the electronic device 101A is provided not on the display control substrate 103 but on the base 107 so as to be adjacent to one side surface of the diffusion plate 106 instead of providing the eight LED drivers 140. Configuration. That is, the electronic device 101A has a configuration in which eight LED drivers 140 are provided in the area where the plurality of LEDs 210 are arranged in the side light type backlight module 202 shown in FIG.
　なお、電子機器１０１Ａのバックライトユニット及びＬＥＤドライバの回路構成は、図１５に示したバックライトユニット及びＬＥＤドライバの回路構成と同じである。 The circuit configuration of the backlight unit and the LED driver of the electronic device 101A is the same as the circuit configuration of the backlight unit and the LED driver shown in FIG.
　図１６に示すように、電子機器１０１Ａの構成によると、図１４に示した電子機器１０１と比べて、表示制御基板１０３の面積が増大することを抑制することができる。 As shown in FIG. 16, according to the configuration of the electronic device 101A, an increase in the area of the display control substrate 103 can be suppressed as compared with the electronic device 101 shown in FIG.
　この結果、電子機器１０１Ａの構成によると、バックライトユニット１０２の上辺（表示制御基板１０３と対向する辺とは逆側の辺）から表示制御基板１０３の下辺（バックライトユニット１０２と対向する辺とは逆側の辺）までの長さである液晶モジュールのＹ寸法Ｙ１００Ａは大きくならず、図１７に示した液晶モジュールのＹ寸法Ｙ２００と同程度とすることができる。 As a result, according to the configuration of the electronic device 101A, the lower side of the display control board 103 (the side facing the backlight unit 102) and the upper side of the backlight unit 102 (the side opposite to the side facing the display control board 103) The Y dimension Y100A of the liquid crystal module which is the length to the opposite side) does not increase, and can be approximately the same as the Y dimension Y200 of the liquid crystal module shown in FIG.
　しかし、図１５に示したように、昇圧回路１３０の近傍に、昇圧回路１３０の周辺回路であるコイル１３２とダイオード１３１とを設ける必要がある。すなわち、ＬＥＤドライバ１４０の個数分だけ、ＬＥＤドライバ１４０の近傍にコイル１３２及びダイオード１３１を設ける必要がある。後述するように、コイル１３２とダイオード１３１は、設置面積が比較的大きい。 However, as shown in FIG. 15, it is necessary to provide a coil 132 and a diode 131, which are peripheral circuits of the booster circuit 130, in the vicinity of the booster circuit 130. That is, it is necessary to provide the coil 132 and the diode 131 in the vicinity of the LED driver 140 by the number of the LED drivers 140. As described later, the coil 132 and the diode 131 have relatively large footprints.
　このため、８個のＬＥＤドライバ１４０と、それらに対応する８個のコイル１３２及びダイオード１３１を含む周辺回路と、を全てバックライトユニット１０２に設ける場合、バックライトユニット１０２の面積を大きくするか、又は、基材１０７の表裏両面に設けた場合は、バックライトユニット１０２の厚さが厚くなる。 Therefore, in the case where the eight LED drivers 140 and the peripheral circuits including the eight coils 132 and the diodes 131 corresponding to them are all provided in the backlight unit 102, the area of the backlight unit 102 is increased, or Alternatively, when provided on both the front and back sides of the base material 107, the thickness of the backlight unit 102 becomes thick.
　または、バックライトユニット１０２の面積を大きくせず、８個のＬＥＤドライバ１４０と、それらに対応する８個のコイル１３２及びダイオード１３１を含む周辺回路とを基材１０７の表裏両面に設けない場合は、８個のＬＥＤドライバ１４０のうち、一部のＬＥＤドライバ１４０に対応するコイル１３２及びダイオード１３１を含む周辺回路が、基材１０７に設けることができず、表示制御基板１０３に設けなければならなくなる。 Alternatively, when the area of the backlight unit 102 is not increased and the eight LED drivers 140 and the peripheral circuits including the eight coils 132 and the diodes 131 corresponding to them are not provided on both the front and back sides of the substrate 107, The peripheral circuit including the coil 132 and the diode 131 corresponding to a part of the LED driver 140 among the eight LED drivers 140 can not be provided on the base material 107, and must be provided on the display control substrate 103. .
　このように、８個のＬＥＤドライバ１４０のうち、一部のＬＥＤドライバ１４０に対応するコイル１３２及びダイオード１３１を表示制御基板１０３に設け、他の一部のＬＥＤドライバ１４０に対応するコイル１３２及びダイオード１３１を基材７に設けると、ＬＥＤドライバ１４０間での電気的特性が変わり、精度よく、各ＬＥＤアレイ１１２の輝度を制御することができない。 As described above, the coil 132 and the diode 131 corresponding to a part of the LED driver 140 among the eight LED drivers 140 are provided on the display control board 103, and the coil 132 and the diode corresponding to the other part LED driver 140 When the substrate 131 is provided on the substrate 7, the electrical characteristics between the LED drivers 140 change, and the luminance of each LED array 112 can not be controlled with high accuracy.
　〔実施形態１〕
　図１は実施形態１に係る電子機器１の構成を表す断面図である。 Embodiment 1
FIG. 1 is a cross-sectional view illustrating the configuration of the electronic device 1 according to the first embodiment.
　電子機器１は、画像の表示エリアを有する種々の電子機器である。電子機器１は、テレビであってもよいが、ノート型ＰＣ、タブレット端末、携帯電話端末等のモバイル型の電子機器でることが好ましい。一例として、電子機器１は、ノート型ＰＣであるものとして説明する。 The electronic device 1 is various electronic devices having a display area of an image. The electronic device 1 may be a television, but is preferably a mobile electronic device such as a notebook PC, a tablet terminal, a mobile phone terminal or the like. As an example, the electronic device 1 will be described as being a notebook PC.
　図１に示すように、電子機器１は、液晶モジュール４と、マザーボードである主制御基板９と、液晶モジュール４のバックライトユニットを格納するベゼル５（図２参照）とを含む。主制御基板９は電子機器１の動作を総合的に制御する。主制御基板９は樹脂又は金属等から構成され、各種回路が設けられている。 As shown in FIG. 1, the electronic device 1 includes a liquid crystal module 4, a main control substrate 9 which is a mother board, and a bezel 5 (see FIG. 2) for storing a backlight unit of the liquid crystal module 4. The main control board 9 comprehensively controls the operation of the electronic device 1. The main control board 9 is made of resin, metal or the like, and various circuits are provided.
　液晶モジュール４は、液晶パネル８と、バックライトユニット２と、表示制御基板３とを含む。バックライトユニット２は液晶パネル８の背面側に配置され、当該背面側から液晶パネル８を照明する。液晶パネル８は、液晶層を介在させて、ＴＦＴ素子（Thin Film Transistor）が画素毎に設けられたＴＦＴ基板と、対向基板とが対向配置されて構成されている。 The liquid crystal module 4 includes a liquid crystal panel 8, a backlight unit 2, and a display control substrate 3. The backlight unit 2 is disposed on the back side of the liquid crystal panel 8 and illuminates the liquid crystal panel 8 from the back side. The liquid crystal panel 8 is configured such that a TFT substrate provided with TFT elements (Thin Film Transistors) for each pixel and a counter substrate face each other with a liquid crystal layer interposed.
　表示制御基板３は、主制御基板９からの指示により、バックライトユニット２及び液晶パネル８に駆動信号を出力することで、バックライトユニット２及び液晶パネル８の駆動を制御する。表示制御基板３は樹脂又は金属等から構成され、各種回路が搭載されている。 The display control board 3 controls the driving of the backlight unit 2 and the liquid crystal panel 8 by outputting a drive signal to the backlight unit 2 and the liquid crystal panel 8 according to an instruction from the main control board 9. The display control board 3 is made of resin, metal or the like, and various circuits are mounted.
　図２は実施形態１の液晶モジュール４の構成を表す平面図である。図２に示すように、液晶パネル８は、画素がマトリクス状に配置され画像を表示する表示エリア８１と、表示エリア８１の周辺の領域である額縁エリア４ａとを有する。額縁エリア４ａは、表示エリア８１のエッジから、バックライトユニット２又は液晶パネル８の最外形エッジまでの領域である。ここでは、額縁エリア４ａは、表示エリア８１のエッジから、ベゼル５のエッジ（すなわちバックライトユニット２のエッジ）までの領域を指すものとする。 FIG. 2 is a plan view showing the configuration of the liquid crystal module 4 of the first embodiment. As shown in FIG. 2, the liquid crystal panel 8 has a display area 81 in which pixels are arranged in a matrix and displays an image, and a frame area 4 a which is an area around the display area 81. The frame area 4 a is an area from the edge of the display area 81 to the outermost edge of the backlight unit 2 or the liquid crystal panel 8. Here, the frame area 4 a refers to an area from the edge of the display area 81 to the edge of the bezel 5 (that is, the edge of the backlight unit 2).
　図２に示すように、額縁エリア４ａのうち、表示エリア８１より上方の領域を上額縁４ａＴと称し、表示エリア８１より下方の領域を下額縁４ａＤと称し、表示エリア８１より右側の領域を右額縁４ａＲと称し、表示エリア８１より左側の領域を左額縁４ａＬと称する。 As shown in FIG. 2, in the frame area 4a, an area above the display area 81 is referred to as an upper frame 4aT, an area below the display area 81 is referred to as a lower frame 4aD, and an area to the right of the display area 81 is right The area to the left of the display area 81 is referred to as a left frame 4aL.
　ノート型ＰＣ用の液晶モジュールでは、ランドスケープ型が一般的に採用されている。例えば、液晶モジュール４のうち、下額縁４ａＤに、ソースドライバＳＤの実装領域を確保しており、表示制御基板３は下額縁４ａＤの外側に配置される。 A landscape type is generally adopted in liquid crystal modules for notebook PCs. For example, the mounting area of the source driver SD is secured in the lower frame 4aD of the liquid crystal module 4, and the display control substrate 3 is disposed outside the lower frame 4aD.
　なお、液晶パネル８のうち、表示エリア８１よりも外側の領域をパネル額縁と称する場合がある。また、バックライトユニット２と液晶パネル８とのうちどちらが最外形エッジとなるかは、液晶モジュール４の用途によって様々である。 In the liquid crystal panel 8, a region outside the display area 81 may be referred to as a panel frame. Further, which of the backlight unit 2 and the liquid crystal panel 8 is the outermost edge varies depending on the application of the liquid crystal module 4.
　（電子機器１の構成）
　図３は、実施形態１の電子機器１のうち、バックライトユニット２及び表示制御基板３の構成を表す平面図である。図３では、液晶モジュール４のうち液晶パネル８の図示を省略している。 (Configuration of electronic device 1)
FIG. 3 is a plan view showing the configuration of the backlight unit 2 and the display control board 3 in the electronic device 1 of the first embodiment. In FIG. 3, the liquid crystal panel 8 of the liquid crystal module 4 is not shown.
　図３に示すように、バックライトユニット２は、直下型のバックライトユニットであり、ローカルディミング方式による発光が可能である。バックライトユニット２は、基材７と、基材７に搭載された複数のＬＥＤ１０（発光素子）と、複数のＬＥＤ１０上に設けられた拡散板６と、基材７に搭載された複数の定電流ＩＣと、基材７及び拡散板６を格納するベゼル５とを含む。 As shown in FIG. 3, the backlight unit 2 is a direct type backlight unit, and can emit light by the local dimming method. The backlight unit 2 includes a substrate 7, a plurality of LEDs 10 (light emitting elements) mounted on the substrate 7, a diffusion plate 6 provided on the plurality of LEDs 10, and a plurality of substrates mounted on the substrate 7. It includes a current IC and a bezel 5 that houses the base 7 and the diffusion plate 6.
　基材７は、例えば、ＦＰＣである。なお、基材７は、ＦＰＣに限定されず、樹脂又は金属等の材質から構成される基板等であってもよい。 The substrate 7 is, for example, an FPC. The base 7 is not limited to the FPC, and may be a substrate or the like made of a material such as resin or metal.
　表示制御基板３は、基材７と電気的に接続されており、当該接続部分を通して、バックライトユニット２及び液晶パネル８に各種の信号を出力する。 The display control substrate 3 is electrically connected to the base 7, and outputs various signals to the backlight unit 2 and the liquid crystal panel 8 through the connection portion.
　表示制御基板３には、電源ＩＣ５１と、Ｔｃｏｎ５２と、ＥＥＰＲＯＭ等の不揮発性メモリ５３と、入力コネクタ５４等が設けられている。さらに、表示制御基板３には、ＬＥＤ１０に所望の電圧を供給するための一又は複数の電圧生成回路ブロック３３が設けられている。電圧生成回路ブロック３３は、電圧生成ＩＣ３０と、ダイオード３１と、コイル３２とを含む。なお、電圧生成ＩＣ３０にダイオード３１の機能が含まれていてもよい。この場合、ダイオード３１は不要である。 The display control board 3 is provided with a power supply IC 51, a Tcon 52, a non-volatile memory 53 such as an EEPROM, an input connector 54 and the like. Furthermore, the display control board 3 is provided with one or more voltage generation circuit blocks 33 for supplying a desired voltage to the LED 10. The voltage generation circuit block 33 includes a voltage generation IC 30, a diode 31 and a coil 32. The voltage generation IC 30 may include the function of the diode 31. In this case, the diode 31 is unnecessary.
　図４は、実施形態１の電子機器１における、バックライトユニット２及び電圧生成回路ブロック３３の回路を表す図である。 FIG. 4 is a diagram showing a circuit of the backlight unit 2 and the voltage generation circuit block 33 in the electronic device 1 of the first embodiment.
　バックライトユニット２は、一又は複数のＬＥＤアレイ１２と、ＬＥＤ１０に定電流を流すための一又は複数の定電流ＩＣ２０とを含む。 The backlight unit 2 includes one or more LED arrays 12 and one or more constant current ICs 20 for supplying a constant current to the LEDs 10.
　本実施形態では、１個の電圧生成回路ブロック３３に、ＬＥＤアレイ１２が直列に接続されている。電圧生成回路ブロック３３においては、ダイオード３１のアノードとコイル３２との間に、ＬＥＤ１０のアノードに供給する電圧を生成する電圧生成ＩＣ３０が接続されている。 In the present embodiment, the LED array 12 is connected in series to one voltage generation circuit block 33. In the voltage generation circuit block 33, a voltage generation IC 30 for generating a voltage to be supplied to the anode of the LED 10 is connected between the anode of the diode 31 and the coil 32.
　上述のように、電圧生成ＩＣ３０は、定電流ＩＣ２０が設けられた基材７とは異なる基板である表示制御基板３に設けられている。電圧生成ＩＣ３０は、ＬＥＤ１０に所望の電流を流すための、昇圧回路、降圧回路又は昇降圧回路を含む。 As described above, the voltage generation IC 30 is provided on the display control substrate 3 which is a substrate different from the substrate 7 on which the constant current IC 20 is provided. The voltage generation IC 30 includes a boost circuit, a step-down circuit or a step-up / step-down circuit for supplying a desired current to the LED 10.
　例えば、各ＬＥＤアレイ１２は、直列に複数個接続されたＬＥＤ列１１が複数個並列に接続されることで構成されている。例えば、４個のＬＥＤ１０が直列に接続されることでＬＥＤ列１１が構成され、ＬＥＤ列１１が１６個並列に接続されることで各ＬＥＤアレイ１２が構成されている。例えば、ＬＥＤアレイ１２は８個並んで設けられている。 For example, each LED array 12 is configured by connecting in parallel a plurality of LED strings 11 connected in series. For example, the LED array 11 is configured by connecting four LEDs 10 in series, and each LED array 12 is configured by connecting 16 LED arrays 11 in parallel. For example, eight LED arrays 12 are provided side by side.
　各ＬＥＤアレイ１２において、各ＬＥＤ列１１のアノード同士は互いに接続されることで、各ＬＥＤアレイ１２のアノードが構成されている。各ＬＥＤアレイ１２のアノードは、ダイオード３１のカソードと接続されている。 In each LED array 12, the anodes of the LED arrays 11 are configured by connecting the anodes of the LED arrays 11 to each other. The anode of each LED array 12 is connected to the cathode of the diode 31.
　定電流ＩＣ２０は、ＬＥＤアレイ１２に一対一対応で設けられている。本実施形態では、ＬＥＤアレイ１２が８個設けられているため、定電流ＩＣ２０も８個設けられている。 The constant current IC 20 is provided to the LED array 12 in a one-to-one correspondence. In the present embodiment, eight LED arrays 12 are provided, so eight constant current ICs 20 are also provided.
　図５は、実施形態１の定電流ＩＣ２０の構成を表す図である。定電流ＩＣ２０は、制御信号入力回路２１と、定電流回路ブロック制御回路２２（定電流制御回路）と、複数の定電流回路Ｃ１～Ｃ１６と、複数のチャネルｃｈ１～ｃｈ１６とを有する。 FIG. 5 is a diagram illustrating the configuration of the constant current IC 20 according to the first embodiment. The constant current IC 20 has a control signal input circuit 21, a constant current circuit block control circuit 22 (constant current control circuit), a plurality of constant current circuits C1 to C16, and a plurality of channels ch1 to ch16.
　チャネルｃｈ１～ｃｈ１６それぞれには、各ＬＥＤ列１１のカソードが接続されている。 The cathode of each LED row 11 is connected to each of the channels ch1 to ch16.
　定電流回路Ｃ１～Ｃ１６は、チャネルｃｈ１～ｃｈ１６に対応して（換言すると、各ＬＥＤ列１１に対応して）設けられている。チャネルｃｈ１～ｃｈ１６には、それぞれ、定電流回路Ｃ１～Ｃ１６が接続されている。定電流回路Ｃ１～Ｃ１６は、各ＬＥＤ列１１に定電流を流す回路である。 The constant current circuits C1 to C16 are provided corresponding to the channels ch1 to ch16 (in other words, corresponding to the respective LED columns 11). Constant current circuits C1 to C16 are connected to the channels ch1 to ch16, respectively. The constant current circuits C1 to C16 are circuits for causing a constant current to flow in each LED row 11.
　制御信号入力回路２１は、制御信号の入力を受け付けるインターフェース入力回路である。制御信号入力回路２１は、表示制御基板３に設けられた制御回路からＳＣＳ、ＳＣＬＫ、ＳＤＩ等の制御信号を取得すると、当該制御信号に基づいて、定電流回路ブロック制御回路２２へ指示信号を出力する。 The control signal input circuit 21 is an interface input circuit that receives an input of a control signal. When the control signal input circuit 21 obtains a control signal such as SCS, SCLK, or SDI from the control circuit provided on the display control board 3, the control signal input circuit 21 outputs an instruction signal to the constant current circuit block control circuit 22 based on the control signal. Do.
　定電流回路ブロック制御回路２２は、制御信号入力回路２１から取得した制御信号に基づいて、定電流回路Ｃ１～Ｃ１６それぞれに流す電流を個別に制御する。換言すると、各ＬＥＤ列１１に流す電流を、ＬＥＤ列１１毎に制御する。これにより、ＬＥＤ列１１毎に輝度を調整するローカルディミングを行うことができる。 The constant current circuit block control circuit 22 individually controls the current supplied to each of the constant current circuits C1 to C16 based on the control signal acquired from the control signal input circuit 21. In other words, the current supplied to each LED row 11 is controlled for each LED row 11. In this way, local dimming can be performed to adjust the luminance for each of the LED rows 11.
　定電流ＩＣ２０は、例えば、ＳＰＩ（Serial Peripheral Interface：シリアル・ペリフェラル・インタフェース）等のインターフェース規格を用いてアクセスする構成とすることができる。なお、定電流ＩＣ２０にアクセスするためのインターフェース規格は任意であり、ＳＰＩに限定されるものではない。 The constant current IC 20 can be configured to access using, for example, an interface standard such as SPI (Serial Peripheral Interface). The interface standard for accessing the constant current IC 20 is arbitrary, and is not limited to SPI.
　また、各定電流ＩＣ２０と、電圧生成ＩＣ３０との間に、定電流回路Ｃ１～Ｃ１６に流れる電流（すなわち、各ＬＥＤ列１１に流れる電流）に応じて、各ＬＥＤ列１１のアノードに供給する電圧を調整する電圧調整信号を電圧生成ＩＣ３０に出力する制御回路を設けてもよい。これにより、電圧生成ＩＣ３０は、ＬＥＤ列１１毎に供給する電圧を調整し、各ＬＥＤ１０の発光効率を上げることができる。 In addition, a voltage supplied to the anode of each LED array 11 according to the current flowing in the constant current circuits C1 to C16 (that is, the current flowing in each LED array 11) between each constant current IC 20 and the voltage generation IC 30 A control circuit may be provided which outputs a voltage adjustment signal for adjusting the voltage to the voltage generation IC 30. As a result, the voltage generation IC 30 can adjust the voltage supplied to each of the LED rows 11 to increase the luminous efficiency of each LED 10.
　（電圧生成回路ブロック３３の動作）
　図１９は電圧生成回路ブロック３３の動作を説明する図である。図２０は、図１９の電圧生成回路ブロック３３内の電圧を表す図である。ここでは、電圧生成回路ブロック３３の電圧生成ＩＣ３０は昇圧ＩＣであるものとする。なお、図１９及び図２０に示す電圧回路ブロック３３の構成及び動作は一例であり、他の態様も採りえる。 (Operation of voltage generation circuit block 33)
FIG. 19 is a diagram for explaining the operation of the voltage generation circuit block 33. In FIG. FIG. 20 is a diagram showing voltages in the voltage generation circuit block 33 of FIG. Here, it is assumed that the voltage generation IC 30 of the voltage generation circuit block 33 is a boost IC. The configuration and operation of the voltage circuit block 33 shown in FIGS. 19 and 20 are an example, and other aspects can be adopted.
　一例として、電圧生成回路ブロック３３は、さらに、コイル３２の上流側に配置された入力側の第１容量Ｃｉｎと、ダイオード３１のカソードに接続された出力側の第２容量Ｃｏｕｔとを有する。また、電圧生成ＩＣ３０はコイル３２とダイオード３１との間に接続されているスイッチ３０ａを有する。電圧生成回路ブロック３３の入力側の電圧を電圧ｖｉｎとし、出力側（バックライトユニット２はと接続されている側）の電圧を電圧Ｖｏｕｔとする。 As an example, the voltage generation circuit block 33 further includes a first capacitance Cin on the input side disposed upstream of the coil 32 and a second capacitance Cout on the output side connected to the cathode of the diode 31. In addition, the voltage generation IC 30 has a switch 30 a connected between the coil 32 and the diode 31. The voltage on the input side of the voltage generation circuit block 33 is a voltage vin, and the voltage on the output side (the side connected to the backlight unit 2) is a voltage Vout.
　図１９及び図２０に示すように、スイッチ３０ａをオンにすると、電圧生成回路ブロック３３の入力側の電圧Ｖｉｎによって、コイル３２及びスイッチ３０ａを通り電流Ｉ_Ｌ（ｏｎ）が流れる。このときコイル３２にエネルギーが蓄積される。このスイッチ３０ａがオンされているときは、負荷（すなわち、バックライトユニット２）へ第２容量Ｃｏｕｔに蓄えられた電荷による電流Ｉ_Ｌ（ｏｎ）が流れる。 As shown in FIGS. 19 and 20, when the switch 30a is turned on, a current I_L (on) flows through the coil 32 and the switch 30a by the voltage Vin on the input side of the voltage generation circuit block 33. At this time, energy is stored in the coil 32. When the switch 30a is turned on, a current I_L (on) due to the charge stored in the second capacitor Cout flows to the load (that is, the backlight unit 2).
　次いで、スイッチ３０ａをオフにすると、コイル３２流れている電流を保持するために、蓄えられたエネルギーを放出して、コイル３２から流れた電流Ｉ＿Ｌ（ｏｆｆ）は、ダイオード３１を通り、これにより第２容量Ｃｏｕｔの電荷が充電されると共に、電流Ｉ＿Ｌ（ｏｆｆ）が負荷（すなわち、バックライトユニット２）へ流れる。 Then, when the switch 30a is turned off, the stored energy is released to hold the current flowing through the coil 32, and the current I_L (off) from the coil 32 passes through the diode 31, thereby While the charge of 2 capacity Cout is charged, current I_L (off) flows into a load (namely, back light unit 2).
　このように、スイッチ３０ａのオンオフにより、電圧生成回路ブロック３３に接続されたバックライトユニット２へ電力供給がされる。 Thus, power is supplied to the backlight unit 2 connected to the voltage generation circuit block 33 by turning on and off the switch 30a.
　（バックライトユニット２のベゼル５の構成）
　図６は実施形態１のバックライトユニット２の断面図である。 (Configuration of bezel 5 of backlight unit 2)
FIG. 6 is a cross-sectional view of the backlight unit 2 of the first embodiment.
　図６の（ａ）に示すように、金属で構成されているベゼル５上に、基材７を配置し、この基材７上に定電流ＩＣ２０と複数のＬＥＤ１０とを実装する。そして、複数のＬＥＤ１０の上方であって、定電流ＩＣ２０と重ならないように拡散板６を設ける。 As shown to (a) of FIG. 6, the base material 7 is arrange | positioned on the bezel 5 comprised with the metal, and the constant current IC 20 and several LED10 are mounted on this base material 7. As shown in FIG. Then, the diffusion plate 6 is provided above the plurality of LEDs 10 so as not to overlap with the constant current IC 20.
　このように、定電流ＩＣ２０及び複数のＬＥＤ１０が実装されている基材７は、定電流ＩＣ２０及び複数のＬＥＤ１０の実装面とは反対側の面である裏面が、金属で構成されているベゼル５と接触している。これにより、定電流ＩＣ２０及び複数のＬＥＤ１０から発生した熱を、基材７を介して、ベゼル５に放熱することができる。このため、放熱効率を上げることができる。 Thus, the base 7 on which the constant current IC 20 and the plurality of LEDs 10 are mounted is the bezel 5 in which the back surface which is the surface opposite to the mounting surface of the constant current IC 20 and the plurality of LEDs 10 is made of metal. In contact with Thus, the heat generated from the constant current IC 20 and the plurality of LEDs 10 can be dissipated to the bezel 5 through the base 7. Therefore, the heat dissipation efficiency can be increased.
　又は、図６の（ｂ）に示すように、定電流ＩＣ２０と、複数のＬＥＤ１０とを、基材７上ではなく、直接ベゼル５の表面に実装してもよい。これによると、定電流ＩＣ２０及び複数のＬＥＤ１０から発生した熱が直接ベゼル５に放熱されるため、より、放熱効率を上げることができる。 Alternatively, as shown in (b) of FIG. 6, the constant current IC 20 and the plurality of LEDs 10 may be mounted directly on the surface of the bezel 5 instead of on the substrate 7. According to this, since the heat generated from the constant current IC 20 and the plurality of LEDs 10 is directly dissipated to the bezel 5, it is possible to further enhance the radiation efficiency.
　図２１は、テレビ向けの液晶モジュール３０４の構成を表す断面図である。液晶モジュール３０４は、ベゼル３０５内に、ＬＥＤアレイ１２が搭載されたＦＰＣ３０７と、ＬＥＤアレイ１２の上方に配置された拡散板６とが格納された直下型のバックライトユニットを有する。また、下額縁におけるベゼル５０５の側壁は傾斜しており、この傾斜するベゼル５０５の側壁の外側面（拡散板６、ＬＥＤアレイ１２及びＦＰＣ３０７が格納されている側とは反対側の面）に、ＬＥＤドライバＩＣ３４０及びコイル３３２等が搭載された表示制御基板３０３が配置されている。このように、テレビの製造に用いられる液晶モジュール３０４においては、傾斜させたベゼル５０５の側壁の外側面に、ＬＥＤドライバＩＣ３４０及びコイル３３２等が搭載された表示制御基板３０３を配置することができる。しかし、当該構成によると、ある程度の厚みが必要となるため、厚みの制約が厳しいノート型ＰＣを製造するための液晶モジュールに適用することはできない。 FIG. 21 is a cross-sectional view showing a configuration of a liquid crystal module 304 for television. The liquid crystal module 304 has a direct type backlight unit in which the FPC 307 on which the LED array 12 is mounted and the diffusion plate 6 disposed above the LED array 12 are stored in the bezel 305. Further, the side wall of the bezel 505 in the lower frame is inclined, and the outer surface of the side wall of the inclined bezel 505 (the surface opposite to the side on which the diffusion plate 6, the LED array 12 and the FPC 307 are stored) A display control board 303 on which an LED driver IC 340, a coil 332 and the like are mounted is disposed. As described above, in the liquid crystal module 304 used for manufacturing a television, the display control substrate 303 on which the LED driver IC 340, the coil 332, and the like are mounted can be disposed on the outer surface of the side wall of the inclined bezel 505. However, according to the said structure, since a certain amount of thickness is required, it can not apply to the liquid crystal module for manufacturing a notebook PC with severe thickness restrictions.
　（主な効果）
　図７は、従来のノート型ＰＣに使用されている表示制御基板の構成を表す図である。図８は、図７の表示制御基板の一部を拡大した図である。 (Main effect)
FIG. 7 is a diagram showing the configuration of a display control board used in a conventional notebook PC. FIG. 8 is an enlarged view of a part of the display control board of FIG.
　図７に示すように、表示制御基板２０３に、コネクタ２５０、ＬＥＤドライバＩＣ２４０、ダイオード２３１及びコイル２３２が設けられている。そして、バックライトユニット２０２から表示制御基板２０３に延びるＦＰＣ２０７がコネクタ２５０に接続されている。 As shown in FIG. 7, the display control board 203 is provided with a connector 250, an LED driver IC 240, a diode 231 and a coil 232. An FPC 207 extending from the backlight unit 202 to the display control board 203 is connected to the connector 250.
　例えば、コネクタ２５０のピン数は１０本であり、コイル２３２は、サイズが４ｍｍ×４ｍｍで厚みが１．２ｍｍ程度である。例えば、表示制御基板２０３の幅Ｙ２０３は８ｍｍ程度である。 For example, the number of pins of the connector 250 is ten, and the coil 232 has a size of 4 mm × 4 mm and a thickness of about 1.2 mm. For example, the width Y 203 of the display control board 203 is about 8 mm.
　図８に示すように、ＬＥＤドライバＩＣ２４０の一部（定電流回路２２０を含む部分）と周辺回路とを含む領域が定電流回路ブロック２２９である。また、ＬＥＤドライバＩＣ２４０の他の一部（昇圧回路２３０を含む部分）と、ダイオード２３１及びコイル２３２を有する周辺回路とを含む領域が昇圧回路ブロック２３３である。なお、図８に示す定電流回路ブロック２２９の周辺回路及び昇圧回路ブロック２３３の周辺回路は、一例であり、液晶モジュールの機種及び用途等によって異なる。 As shown in FIG. 8, an area including a part of the LED driver IC 240 (a part including the constant current circuit 220) and the peripheral circuit is a constant current circuit block 229. Further, a region including another part of the LED driver IC 240 (a portion including the booster circuit 230) and a peripheral circuit having the diode 231 and the coil 232 is a booster circuit block 233. The peripheral circuits of the constant current circuit block 229 and the peripheral circuits of the booster circuit block 233 shown in FIG. 8 are merely examples, and differ depending on the type and application of the liquid crystal module.
　図８に示すように、昇圧回路ブロック２３３の周辺回路には、定電流回路ブロック２２９の周辺回路と比べて、多数の回路部品が必要であることが分かる。特に、昇圧回路ブロック２３３の周辺回路に含まれるダイオード２３１及びコイル２３２は、他の回路部品と比べて面積が大きく、さらに、ＬＥＤドライバＩＣ２４０の他の一部（昇圧回路２３０を含む部分）の近くに設ける必要がある。 As shown in FIG. 8, it can be understood that the peripheral circuits of the booster circuit block 233 require a larger number of circuit components than the peripheral circuits of the constant current circuit block 229. In particular, the diode 231 and the coil 232 included in the peripheral circuit of the booster circuit block 233 have a large area compared with other circuit components, and further, the vicinity of another part of the LED driver IC 240 (part including the booster circuit 230). Need to be
　制御するＬＥＤの数の増加に伴い、この昇圧回路ブロック２３３と定電流回路ブロック２２９とのセットを、表示制御基板２０３に多数設けるとすると、表示制御基板２０３の幅Ｙ２０３を大きくする等、表示制御基板２０３の面積を大きくする必要がある。 Assuming that a large number of sets of the booster circuit block 233 and the constant current circuit block 229 are provided on the display control board 203 as the number of LEDs to be controlled increases, the display control board 203 is increased in width Y203, etc. The area of the substrate 203 needs to be increased.
　また、この面積が大きい昇圧回路ブロック２３３を、多数、バックライトユニット２０２に設けるとすると、バックライトユニット２０２の下額縁を大幅に大きくしたり、バックライトユニット２０２の厚みを大幅に広げたりする必要がある。または、複数の昇圧回路ブロック２３３のうち、一部の昇圧回路ブロック２３３の周辺回路に含まれるダイオード２３１及びコイル２３２を、表示制御基板２０３に設ける必要がある。 Further, if a large number of booster circuit blocks 233 having this large area are provided in the backlight unit 202, it is necessary to greatly enlarge the lower frame of the backlight unit 202 or to greatly expand the thickness of the backlight unit 202. There is. Alternatively, it is necessary to provide the display control substrate 203 with the diodes 231 and the coils 232 included in the peripheral circuits of some of the plurality of booster circuit blocks 233 among the plurality of booster circuit blocks 233.
　一方、定電流回路ブロック２２９は、昇圧回路ブロック２３３と比べて面積が小さい。 On the other hand, the constant current circuit block 229 has a smaller area than the booster circuit block 233.
　そこで、図３～図５に示したように、本実施形態のバックライトユニット２は、基材７と、基材７に配置された複数のＬＥＤアレイ１２と、各ＬＥＤアレイ１２に対応して基材７に設けられた複数の定電流ＩＣとを備える。そして、各定電流ＩＣは、対応するＬＥＤアレイ１２の各ＬＥＤ列のカソードと接続された複数の定電流回路Ｃ１～Ｃ１６を含む。 Therefore, as shown in FIGS. 3 to 5, the backlight unit 2 of the present embodiment corresponds to the substrate 7, the plurality of LED arrays 12 disposed on the substrate 7, and the respective LED arrays 12. A plurality of constant current ICs provided on the substrate 7 are provided. Each constant current IC includes a plurality of constant current circuits C1 to C16 connected to the cathodes of the respective LED strings of the corresponding LED array 12.
　このように、バックライトユニット２は、ＬＥＤアレイ１２に含まれる各ＬＥＤ列１１に定電流を流すための定電流回路Ｃ１～Ｃ１６をまとめて定電流ＩＣ２０に設けている。 As described above, in the backlight unit 2, constant current circuits C 1 to C 16 for supplying a constant current to the respective LED strings 11 included in the LED array 12 are collectively provided in the constant current IC 20.
　つまり、ＬＥＤアレイ１２に所望の定電流を流すために必要な、定電流回路と電圧生成回路とのうち、定電流回路は基材７に設けている。 That is, among the constant current circuit and the voltage generation circuit necessary for supplying a desired constant current to the LED array 12, the constant current circuit is provided on the substrate 7.
　そして、ＬＥＤアレイ１２の各ＬＥＤ列のアノードに所望の電圧を供給するための電圧生成回路ブロック３３は表示制御基板３に設けている。 The display control board 3 is provided with a voltage generation circuit block 33 for supplying a desired voltage to the anode of each LED row of the LED array 12.
　これにより、図１７及び図１８に示したような、定電回路と昇圧回路とが一体として構成されているＬＥＤドライバを、表示制御基板に設ける場合と比べて、表示制御基板の面積の増大を抑制することができる。すなわち、上記構成によると、表示制御基板３の面積の増大を抑制しつつ、直下型のバックライトユニット２を構成することができる。 Thereby, the area of the display control board is increased compared to the case where the LED driver in which the constant current circuit and the booster circuit are integrated as shown in FIGS. 17 and 18 are provided on the display control board. It can be suppressed. That is, according to the above configuration, it is possible to configure the direct type backlight unit 2 while suppressing an increase in the area of the display control substrate 3.
　換言すると、バックライトユニット２は、定電流回路と電圧生成回路とのうち、電圧生成回路を備えていない直下型のバックライトユニットである。 In other words, of the constant current circuit and the voltage generation circuit, the backlight unit 2 is a direct type backlight unit not provided with the voltage generation circuit.
　加えて、液晶モジュール４によると、定電流回路と電圧生成回路とを別々の基板に設けることで、熱の発生源を分散化できるため、発熱の抑制も可能である。 In addition, according to the liquid crystal module 4, by providing the constant current circuit and the voltage generation circuit on different substrates, the heat generation source can be dispersed, so that heat generation can also be suppressed.
　また、電圧生成回路は、定電流回路よりも電力ロスが大きく、これにより、発熱量も大きい。この電圧生成回路を、基材７ではなく、別の基板である表示制御基板３に設けることで、十分にＧＮＤをとることができ、電力ロスを低減することができる。加えて、基材７ではなく、別の基板である表示制御基板３であれば、電流生成回路および周辺回路のサイズ及び厚みとも比較的大きな回路部品を選定することができるため、昇圧効率をアップさせ、また、発熱も低減することができる。 In addition, the voltage generation circuit has a larger power loss than a constant current circuit, and thereby generates a large amount of heat. By providing this voltage generation circuit on the display control substrate 3 which is not a substrate 7 but another substrate, GND can be sufficiently obtained, and power loss can be reduced. In addition, if it is not the base 7 but the display control board 3 which is another board, relatively large circuit parts can be selected for the size and thickness of the current generating circuit and peripheral circuits, so the boosting efficiency is improved. Also, heat generation can be reduced.
　一例として、テレビ用の表示制御基板に設ける場合の回路部品の厚みの最大は１２ｍｍ程度であり、ノート型ＰＣ用の表示制御基板に設ける場合の回路部品の厚みの最大は１．２ｍｍ程度であり、ノート型ＰＣのＦＰＣに設ける場合の回路部品の厚みの最大は０．９ｍｍ程度である。 As an example, the maximum thickness of the circuit component in the case of being provided on a display control substrate for a television is about 12 mm, and the maximum thickness of the circuit component in the case of being provided on a display control substrate for a notebook PC is about 1.2 mm The maximum thickness of the circuit component in the case of being provided on the FPC of the notebook PC is about 0.9 mm.
　ここで、コネクタのピン数について検討する。 Here, the number of pins of the connector is considered.
　通常、ローカルディミングを採用しない液晶モジュールにおいては、コネクタのピン数は１０～１６本位で設計されている。図７及び図８に示したコネクタ２５０のピン数は１０本であり、そのうち、２本が複数のＬＥＤアレイ１２のアノードと接続されており、６本がＬＥＤアレイ１２のカソードと接続されており、２本がＮＣ（No Connection：未接続）である。 Usually, in a liquid crystal module that does not employ local dimming, the number of pins of the connector is designed to be about 10 to 16. The number of pins of the connector 250 shown in FIGS. 7 and 8 is ten, of which two are connected to the anodes of the plurality of LED arrays 12 and six are connected to the cathodes of the LED array 12. , 2 is NC (No Connection: not connected).
　直下型のバックライトモジュールとし、ローカルディミングを採用する場合、従来の構造のように、ＬＥＤドライバ（電圧生成回路＋定電流回路）をバックライトモジュールの外部に設けたとする。１画面を１２８分割してローカルディミングを行うとし、その１画面を３２ｃｈのＬＥＤドライバ４個で駆動させる場合、ピン数は、アノード用に８本、カソード用に１２８本、２本をＮＣとすると、合計１３８本のピンが必要となる。 In the case of adopting a direct-type backlight module and adopting local dimming, it is assumed that an LED driver (voltage generation circuit + constant current circuit) is provided outside the backlight module as in the conventional structure. Assuming that one screen is divided into 128 and local dimming is performed, and the one screen is driven by four 32 ch LED drivers, the number of pins is assumed to be 8 for anode and 128 for cathode, and 2 for NC. A total of 138 pins are required.
　一方、本実施形態の液晶モジュール４の場合、例えば、１画面を１２８分割してローカルディミングを行うとし、その１画面を、１６ｃｈの定電流ＩＣが８個と、電圧生成ＩＣ２個とで駆動させる場合、ピン数は、アノード用に２本、ＧＮＤ用に４本、ロジック電源用に１本、ＳＰＩ用に４本、ＥＮ用に１本、２本をＮＣとすると、合計１６本のピン数で済むことになる。 On the other hand, in the case of the liquid crystal module 4 according to the present embodiment, for example, it is assumed that one screen is divided into 128 and local dimming is performed, and the one screen is driven by eight 16ch constant current ICs and two voltage generation ICs. In the case where the number of pins is 2 for anode, 4 for GND, 1 for logic power supply, 4 for SPI, 1 for EN and 2 for NC, the total number of pins is 16 It will be enough.
　このように、本実施形態の液晶モジュール４によると、必要なピン数を削減することができるため、表示制御基板に設けられた、ＦＰＣを接続するコネクタの設置面積を小さくすることができる。 As described above, according to the liquid crystal module 4 of the present embodiment, since the required number of pins can be reduced, the installation area of the connector for connecting the FPC provided on the display control substrate can be reduced.
　また、液晶モジュール４では、電圧生成ＩＣ３０の個数は、定電流ＩＣ２０の個数よりも少ない。 In the liquid crystal module 4, the number of voltage generation ICs 30 is smaller than the number of constant current ICs 20.
　図１７及び図１８に示したような、バックライトユニット２０２の外部にＬＥＤドライバＩＣ２４０を設けている場合、昇圧回路と定電流回路とが一体型であるため、液晶モジュール内に、昇圧回路と定電流回路とが同数存在していた。 When the LED driver IC 240 is provided outside the backlight unit 202 as shown in FIGS. 17 and 18, since the booster circuit and the constant current circuit are integrated, the booster circuit and the constant current circuit are fixed in the liquid crystal module. The same number of current circuits were present.
　一方、本実施形態のように、複数の定電流回路Ｃ１～Ｃ１６を定電流ＩＣ２０に含めてバックライトユニット２に設けた場合、電圧生成ＩＣ３０は、定電流回路Ｃ１～Ｃ１６より少なくすることができる。さらに、電圧生成ＩＣ３０は、定電流ＩＣ２０よりも少なくすることができる。これにより、コストダウンを行うことができる。 On the other hand, when a plurality of constant current circuits C1 to C16 are included in the constant current IC 20 and provided in the backlight unit 2 as in the present embodiment, the voltage generation IC 30 can be smaller than the constant current circuits C1 to C16. . Furthermore, the voltage generation IC 30 can be less than the constant current IC 20. This can reduce the cost.
　加えて、１個の定電流ＩＣが制御するＬＥＤの個数も相対的に減るため、電圧生成ＩＣ３０の負荷を低減することもできる。このため、少ない電圧生成ＩＣでより多くの定電流ＩＣ（すなわち、定電流ＩＣが制御する各ＬＥＤ）を駆動することができる。 In addition, since the number of LEDs controlled by one constant current IC is also relatively reduced, the load on the voltage generation IC 30 can also be reduced. Therefore, it is possible to drive more constant current ICs (that is, each LED controlled by the constant current IC) with less voltage generation IC.
　また、図９に示すように、一又は複数の電圧生成ＩＣ３０（すなわち、電圧生成回路ブロック３３）を、表示制御基板３ではなく主制御基板９に設けてもよい。 Further, as shown in FIG. 9, one or more voltage generation ICs 30 (that is, the voltage generation circuit block 33) may be provided not on the display control board 3 but on the main control board 9.
　〔実施形態２〕
　図１０は、実施形態２の電子機器１の構成を表す図である。図１０に示すように、電圧生成ＩＣ３０の個数を、定電流ＩＣ２０の個数の整数（但し１以上）分の１としてもよい。図１０では、８個の定電流ＩＣ２０に対し、４分の１である２個の電圧生成ＩＣ３０が設けられている例を示している。 Second Embodiment
FIG. 10 is a diagram illustrating the configuration of the electronic device 1 of the second embodiment. As shown in FIG. 10, the number of voltage generation ICs 30 may be an integer (but one or more) of the number of constant current ICs 20. FIG. 10 shows an example in which two voltage generation ICs 30 that are one fourth of the eight constant current ICs 20 are provided.
　このように、電圧生成ＩＣ３０の個数を、定電流ＩＣ２０の個数の整数（但し１以上）分の１とすることで、電圧生成ＩＣ３０の負荷を均等割りできるため、電圧生成ＩＣ３０に含まれる周辺回路として、最適かつ安価な周辺回路を選定することが可能となる。 Thus, the load of the voltage generation IC 30 can be equally divided by setting the number of voltage generation ICs 30 to be an integral number (but one or more) of the number of constant current ICs 20. Therefore, the peripheral circuits included in the voltage generation IC 30 As a result, it is possible to select an optimal and inexpensive peripheral circuit.
　〔実施形態３〕
　図１１は、実施形態３の電子機器１の構成を表す図である。図１２は、実施形態３の電子機器１が備える定電流ＩＣ２０及び電圧生成ＩＣ３０の構成を表す図である。図１３は複数の定電流ＩＣが電圧生成ＩＣに並列で接続されている様子を表す図である。 Third Embodiment
FIG. 11 is a diagram illustrating the configuration of the electronic device 1 of the third embodiment. FIG. 12 is a diagram illustrating configurations of a constant current IC 20 and a voltage generation IC 30 included in the electronic device 1 of the third embodiment. FIG. 13 is a diagram showing how a plurality of constant current ICs are connected in parallel to a voltage generation IC.
　図１１に示す例では、２個の定電流ＩＣ２０と１個の電圧生成ＩＣ３０とを含む回路が２個設けられている。しかし、定電流ＩＣ２０、電圧生成ＩＣ３０及びそれらを含む回路の個数は図１１に示す個数に限定されるものではない。 In the example shown in FIG. 11, two circuits including two constant current ICs 20 and one voltage generation IC 30 are provided. However, the number of the constant current IC 20, the voltage generation IC 30, and the circuit including them is not limited to the number shown in FIG.
　図１１及び図１２に示すように、定電流ＩＣ２０は、定電流回路Ｃ１～Ｃ１６およびチャネルｃｈ１～ｃｈ１６に加え、さらに、チャネルｃｈ１７～ｃｈ２０と、異常検出回路２４と、異常状態通知信号入力回路２５と、異常状態通知信号出力回路２６とを含む。なお、定電流ＩＣ２０は、図５に示した、定電流回路ブロック制御回路２２と、制御信号入力回路２１とを含んでもよい。 As shown in FIGS. 11 and 12, the constant current IC 20 includes, in addition to the constant current circuits C1 to C16 and the channels ch1 to ch16, the channels ch17 to ch20, the abnormality detection circuit 24, and the abnormality condition notification signal input circuit 25. And an abnormal condition notification signal output circuit 26. The constant current IC 20 may include the constant current circuit block control circuit 22 and the control signal input circuit 21 shown in FIG.
　異常状態通知信号入力回路２５は、チャネルｃｈ１７及びチャネルｃｈ１８と接続されている。異常状態通知信号出力回路２６は、チャネルｃｈ１９及びチャネルｃｈ２０と接続されている。 The abnormal state notification signal input circuit 25 is connected to the channel ch17 and the channel ch18. The abnormal state notification signal output circuit 26 is connected to the channel ch19 and the channel ch20.
　異常検出回路２４は、定電流回路Ｃ１～Ｃ１６それぞれを監視することで、定電流回路Ｃ１～Ｃ１６の異常状態を検出する。この異常状態とは、例えば、異常電流、異常電圧、又は、異常温度等である。 The abnormality detection circuit 24 detects an abnormal state of the constant current circuits C1 to C16 by monitoring each of the constant current circuits C1 to C16. The abnormal state is, for example, an abnormal current, an abnormal voltage, or an abnormal temperature.
　異常検出回路２４は、例えば異常電流を検出する場合は、各定電流回路Ｃ１～Ｃ１６に流れる電流を監視して、予め設定されている所定の上限電流値と比較し、その上限電流値よりも大きい場合は異常電流と判定する。 For example, when detecting an abnormal current, the abnormality detection circuit 24 monitors the current flowing in each of the constant current circuits C1 to C16, compares it with a predetermined upper limit current value set in advance, and compares it with the upper limit current value. If it is large, it is judged as an abnormal current.
　第１段目の定電流ＩＣ２０のチャネルｃｈ２０は、第２段目の定電流ＩＣ２０のチャネルｃｈ１７と接続されている。第２段目の定電流ＩＣ２０のチャネルｃｈ２０は電圧生成ＩＣ３０と接続されている。 The channel ch20 of the first stage constant current IC20 is connected to the channel ch17 of the second stage constant current IC20. The channel ch 20 of the second stage constant current IC 20 is connected to the voltage generation IC 30.
　第１段目の定電流ＩＣ２０のチャネルｃｈ１９は、第２段目の定電流ＩＣ２０のチャネルｃｈ１８と接続されている。第２段目の定電流ＩＣ２０のチャネルｃｈ１９は電圧生成ＩＣ３０と接続されている。 The channel ch19 of the first stage constant current IC20 is connected to the channel ch18 of the second stage constant current IC20. The channel ch19 of the second stage constant current IC 20 is connected to the voltage generation IC 30.
　異常検出回路２４は、定電流回路Ｃ１～Ｃ１６の何れかの異常状態を検出すると、異常状態を知らせる信号である異常状態通知信号ＤＡＴＡを異常状態通知信号出力回路２６に出力する。 When the abnormal state detection circuit 24 detects an abnormal state of any of the constant current circuits C1 to C16, it outputs an abnormal state notification signal DATA, which is a signal notifying an abnormal state, to the abnormal state notification signal output circuit 26.
　例えば、第１段目の定電流ＩＣ２０の異常検出回路２４が、定電流回路Ｃ１～Ｃ１６の何れかの異常状態を検出すると、異常状態通知信号出力回路２６に、異常状態通知信号ＤＡＴＡを出力する。 For example, when the abnormality detection circuit 24 of the first stage constant current IC 20 detects an abnormal state of any of the constant current circuits C1 to C16, it outputs an abnormal state notification signal DATA to the abnormal state notification signal output circuit 26. .
　すると、第１段目の定電流ＩＣ２０の異常状態通知信号出力回路２６は、チャネルｃｈ１９から異常状態通知信号ＤＡＴＡを出力すると共に、チャネルｃｈ２０からクロック信号ＣＬＫを出力する。 Then, the abnormal state notification signal output circuit 26 of the first stage constant current IC 20 outputs the abnormal state notification signal DATA from the channel ch 19 and outputs the clock signal CLK from the channel ch 20.
　そして、第１段目の定電流ＩＣ２０のチャネルｃｈ１９から出力された異常状態通知信号ＤＡＴＡはチャネルｃｈ１８を通って第２段目の定電流ＩＣ２０の異常状態通知信号入力回路２５へ入力されると共に、第１段目の定電流ＩＣ２０のチャネルｃｈ２０から出力されたクロック信号ＣＬＫはチャネルｃｈ１７を通って第２段目の定電流ＩＣ２０の異常状態通知信号入力回路２５へ入力される。 Then, the abnormal condition notification signal DATA output from the channel ch19 of the first stage constant current IC20 is input to the abnormal condition notification signal input circuit 25 of the second stage constant current IC20 through the channel ch18, The clock signal CLK output from the channel ch20 of the first stage constant current IC20 is input to the abnormal state notification signal input circuit 25 of the second stage constant current IC20 through the channel ch17.
　すると、第２段目の定電流ＩＣ２０の異常状態通知信号入力回路２５は、入力された異常状態通知信号ＤＡＴＡ及びクロック信号ＣＬＫを、第２段目の定電流ＩＣ２０の異常状態通知信号出力回路２６へ出力する。 Then, the abnormal state notification signal input circuit 25 of the second stage constant current IC 20 outputs the abnormal state notification signal DATA and the clock signal CLK inputted thereto to the abnormal state notification signal output circuit 26 of the second stage constant current IC 20. Output to
　そして、第２段目の定電流ＩＣ２０の異常状態通知信号出力回路２６は、入力された異常状態通知信号ＤＡＴＡを、チャネルｃｈ１９から出力すると共に、チャネルｃｈ２０からクロック信号ＣＬＫを出力する。 Then, the abnormal state notification signal output circuit 26 of the second stage constant current IC 20 outputs the input abnormal state notification signal DATA from the channel ch 19 and outputs the clock signal CLK from the channel ch 20.
　ついで、第２段目の定電流ＩＣ２０のチャネルｃｈ１９から出力された異常状態通知信号ＤＡＴＡ及び第２段目の定電流ＩＣ２０のチャネルｃｈ２０から出力されたクロック信号ＣＬＫは共に、異常状態通知信号受信回路３５へ入力される。 Then, both the abnormal state notification signal DATA output from the channel ch19 of the second stage constant current IC20 and the clock signal CLK output from the channel ch20 of the second stage constant current IC20 are abnormal state notification signal receiving circuits. It is input to 35.
　すると、異常状態通知信号受信回路３５は、入力された異常状態通知信号ＤＡＴＡ及びクロック信号ＣＬＫを電圧生成動作制御回路３６へ出力する。 Then, the abnormal condition notification signal receiving circuit 35 outputs the input abnormal condition notification signal DATA and the clock signal CLK to the voltage generation operation control circuit 36.
　そして、電圧生成動作制御回路３６に、異常状態通知信号ＤＡＴＡ及びクロック信号ＣＬＫが入力されると、電圧生成ＩＣは、電圧の生成を停止する。これにより、各ＬＥＤアレイ１２のアノードへ供給される電圧も停止し、各ＬＥＤアレイ１２は消灯する。すなわち、第１段目及び第２段目の定電流ＩＣ２０の定電流回路Ｃ１～Ｃ１６に流れる電流も停止する。 Then, when the abnormal state notification signal DATA and the clock signal CLK are input to the voltage generation operation control circuit 36, the voltage generation IC stops the generation of the voltage. Thereby, the voltage supplied to the anode of each LED array 12 is also stopped, and each LED array 12 is turned off. That is, the current flowing in the constant current circuits C1 to C16 of the first and second stage constant current ICs 20 is also stopped.
　この第１段目の定電流ＩＣ２０のチャネルｃｈ１９と第２段目の定電流ＩＣ２０のチャネルｃｈ１８とが接続され、第２段目の定電流ＩＣ２０のチャネルｃｈ１９と電圧生成ＩＣ３０と接続されている経路が、異常状態を知らせる信号である異常状態通知信号を送受信する経路である。 A path in which the channel ch19 of the first stage constant current IC20 and the channel ch18 of the second stage constant current IC20 are connected, and the channel ch19 of the second stage constant current IC20 and the voltage generation IC 30 are connected Is a path for transmitting and receiving an abnormal state notification signal which is a signal notifying an abnormal state.
　ここで、ノート型ＰＣの分野等では、ＦＰＣと表示制御基板とを接続するコネクタを設置するために割り当てられる面積が非常に小さく、コネクタのピン数を少なくする必要がある。 Here, in the field of laptop PCs, etc., the area allocated for installing a connector for connecting the FPC and the display control board is very small, and it is necessary to reduce the number of pins of the connector.
　また、バックライトモジュールの下額縁のサイズの極小化のため、ＦＰＣ上の配線本数も極力少なくする必要がある。 In addition, in order to minimize the size of the lower frame of the backlight module, it is necessary to reduce the number of wires on the FPC as much as possible.
　そこで、本実施形態では、複数の定電流ＩＣ２０及び電圧生成ＩＣ３０間で、異常状態を知らせる信号である異常状態通知信号を送受信する経路が直列接続されている。これにより、図１２の破線Ｚに示すように、複数の定電流ＩＣ２０と電圧生成ＩＣ３０とを接続する配線が２本で済む。 So, in this embodiment, the path which transmits / receives an abnormal condition notification signal which is a signal which notifies an abnormal condition among a plurality of constant current IC20 and voltage generation IC30 is connected in series. As a result, as shown by the broken line Z in FIG. 12, only two wires are required to connect the plurality of constant current ICs 20 and the voltage generation IC 30.
　一方、図１３に示すような、複数の定電流ＩＣ２０のチャネルｃｈ１９及びチャネルｃｈ２０それぞれが、電圧生成ＩＣと接続されている場合、複数の定電流ＩＣ２０と電圧生成ＩＣとを接続する配線が多くなる。図１３の例では、破線Ｚ２００に示すように４本必要となる。 On the other hand, when each of the channels ch19 and ch20 of the plurality of constant current ICs 20 is connected to the voltage generation IC as shown in FIG. 13, the number of wirings connecting the plurality of constant current ICs 20 and the voltage generation IC increases. . In the example of FIG. 13, four are required as indicated by the broken line Z200.
　このように、複数の定電流ＩＣ２０及び電圧生成ＩＣ３０間で、異常状態を知らせる信号である異常状態通知信号を送受信する経路が直列接続されていることで、配線の本数を減らすことができる。 Thus, the number of wires can be reduced by connecting in series a path for transmitting and receiving an abnormal state notification signal which is a signal notifying an abnormal state between the plurality of constant current ICs 20 and the voltage generation IC 30.
　〔まとめ〕
　本発明の態様１に係るバックライトユニットは、直下型のバックライトユニットであって、基材と、上記基材に配置された複数のＬＥＤが接続された一又は複数のＬＥＤアレイと、上記ＬＥＤアレイに対応して上記基材に設けられ、当該ＬＥＤアレイに含まれるＬＥＤに定電流を流すための一又は複数の定電流ＩＣとを備え、上記ＬＥＤアレイは、複数のＬＥＤが直列に接続された複数のＬＥＤ列を含み、上記定電流ＩＣは、上記複数のＬＥＤ列それぞれに接続された複数の定電流回路を含むことを特徴とする。 [Summary]
A backlight unit according to aspect 1 of the present invention is a direct-type backlight unit, comprising: a substrate; and one or more LED arrays to which a plurality of LEDs disposed on the substrate are connected; And one or more constant current ICs for supplying constant current to the LEDs included in the LED array corresponding to the array, and the LED array includes a plurality of LEDs connected in series. The constant current IC includes a plurality of constant current circuits connected to each of the plurality of LED strings.
　上記構成によると、上記ＬＥＤアレイに含まれる複数のＬＥＤ列に定電流を流すための定電流回路を複数個まとめて上記定電流ＩＣに設けている。このため、上記定電流ＩＣと、上記複数のＬＥＤ列のアノードに所望の電圧を供給するための回路とのうち、上記定電流ＩＣは上記基材に設け、上記複数のＬＥＤ列のアノードに所望の電圧を供給するための回路は上記基材とは異なる別の基板に設けることができる。 According to the above configuration, a plurality of constant current circuits for supplying a constant current to the plurality of LED rows included in the LED array are collectively provided in the constant current IC. Therefore, among the constant current IC and the circuit for supplying a desired voltage to the anodes of the plurality of LED strings, the constant current IC is provided on the base material and desired for the anodes of the plurality of LED strings. The circuit for supplying the voltage V.sub.2 can be provided on another substrate different from the above substrate.
　これにより、定電回路と昇圧回路とが一体として構成されているＬＥＤドライバを、上記表示制御基板に設ける場合と比べて、表示制御基板等の別の基板の面積の増大を抑制することができる。すなわち、上記構成によると、表示制御基板等の別の基板の面積の増大を抑制しつつ、直下型のバックライトユニットを構成することができる。 Thereby, it is possible to suppress an increase in the area of another substrate such as a display control substrate as compared with the case where the LED driver in which the constant current circuit and the booster circuit are integrally configured are provided on the display control substrate. . That is, according to the above configuration, it is possible to configure the direct type backlight unit while suppressing an increase in the area of another substrate such as a display control substrate.
　本発明の態様２に係るバックライトユニットは、上記態様１において、上記定電流ＩＣは、当該定電流ＩＣへ入力される制御信号を取得する制御信号入力回路と、上記制御信号入力回路からの指示信号に基づいて、上記各ＬＥＤ列から各定電流回路へ流す電流をそれぞれ調整する定電流制御回路とを含んでもよい。上記構成によると、上記ＬＥＤアレイにおけるＬＥＤ列毎に流れる電流を調整することができる。これにより、上記ＬＥＤアレイにおけるＬＥＤ列毎に輝度を調整することができる。 In the backlight unit according to aspect 2 of the present invention, in the above aspect 1, the constant current IC is a control signal input circuit that acquires a control signal input to the constant current IC, and an instruction from the control signal input circuit And a constant current control circuit for adjusting the current flowing from each of the LED rows to each of the constant current circuits based on a signal. According to the above configuration, it is possible to adjust the current flowing for each of the LED strings in the LED array. Thereby, the brightness can be adjusted for each of the LED rows in the LED array.
　本発明の態様３に係る電子機器は、上記態様１又は２において、上記バックライトユニットと、表示制御基板と、上記表示制御基板に配置され、電圧生成ＩＣ及び周辺回路部品を含み、上記各ＬＥＤ列のアノードに電圧を供給するための電圧生成回路ブロックとを備えていてもよい。 In the electronic device according to aspect 3 of the present invention, in the above aspect 1 or 2, the backlight unit, the display control substrate, and the display control substrate are disposed, and include a voltage generation IC and peripheral circuit components And a voltage generation circuit block for supplying a voltage to the anodes of the columns.
　上記構成によると、上記表示制御基板に複数の定電流回路を設ける必要がないため、比較的設置面積が大きい電圧生成回路ブロックを複数、上記表示制御基板に設けても、当該表示制御基板の面積が増大することを抑制することができる。 According to the above configuration, since it is not necessary to provide a plurality of constant current circuits on the display control substrate, even if a plurality of voltage generation circuit blocks having a relatively large installation area are provided on the display control substrate, the area of the display control substrate Can be suppressed.
　本発明の態様４に係る電子機器は、上記態様３において、上記電圧生成ＩＣの個数は、上記定電流ＩＣの個数よりも少なくてもよい。これにより、コストダウンを行うことができる。 In the electronic device according to aspect 4 of the present invention, in the aspect 3, the number of the voltage generation ICs may be smaller than the number of the constant current ICs. This can reduce the cost.
　本発明の態様５に係る電子機器は、上記態様３又は４において、上記電圧生成ＩＣの個数は、上記定電流ＩＣの個数の整数（但し１以上）分の１であってもよい。上記構成によると、複数の電圧生成ＩＣの負荷を均等割りできるため、電圧生成ＩＣに含まれる周辺回路として、最適かつ安価な周辺回路を選定することが可能となる。 In the electronic device according to aspect 5 of the present invention, in the above aspect 3 or 4, the number of voltage generation ICs may be an integer (but one or more) of the number of the constant current ICs. According to the above configuration, since loads of a plurality of voltage generation ICs can be equally divided, it is possible to select an optimal and inexpensive peripheral circuit as a peripheral circuit included in the voltage generation IC.
　本発明の態様６に係る電子機器は、上記態様３～５において、上記複数の定電流ＩＣ及び上記電圧生成ＩＣ間で、異常状態を知らせる信号である異常状態通知信号を送受信する経路が直列接続されていてもよい。上記構成によると、配線の本数を減らすことができる。 In the electronic device according to aspect 6 of the present invention, in the above aspects 3 to 5, the plurality of constant current ICs and the voltage generation IC connect in series a path for transmitting and receiving an abnormal state notification signal which is a signal notifying an abnormal state. It may be done. According to the above configuration, the number of wires can be reduced.
　本発明の態様７に係る電子機器は、上記態様３～６において、上記バックライトユニットは、上記基材、上記一又は複数のＬＥＤアレイ及び上記一又は複数の定電流ＩＣを格納し、金属から構成されているベゼルを備え、上記基材における、上記一又は複数のＬＥＤアレイ及び上記一又は複数の定電流ＩＣが配置されている面とは反対側の面と、上記ベゼルとは接触していてもよい。 In the electronic device according to aspect 7 of the present invention, in the above aspects 3 to 6, the backlight unit stores the base material, the one or more LED arrays, and the one or more constant current ICs, The bezel is in contact with a surface of the base opposite to the side on which the one or more LED arrays and the one or more constant current ICs are disposed in the base. May be
　本発明の態様８に係る電子機器は、上記態様３～６において、上記バックライトユニットは、上記一又は複数のＬＥＤアレイ及び上記一又は複数の定電流ＩＣを格納し、金属から構成されているベゼルを備え、上記基材は上記ベゼルの一部であってもよい。 In the electronic device according to aspect 8 of the present invention, in the above aspects 3 to 6, the backlight unit stores the one or more LED arrays and the one or more constant current ICs, and is made of metal. A bezel may be provided, and the substrate may be part of the bezel.
　上記構成によると放熱効率を上げることができる。 According to the above configuration, the heat radiation efficiency can be increased.
　本発明は上述した各実施形態に限定されるものではなく、請求項に示した範囲で種々の変更が可能であり、異なる実施形態にそれぞれ開示された技術的手段を適宜組み合わせて得られる実施形態についても本発明の技術的範囲に含まれる。さらに、各実施形態にそれぞれ開示された技術的手段を組み合わせることにより、新しい技術的特徴を形成することができる。 The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.
１　電子機器
２　バックライトユニット
３　表示制御基板
４　液晶モジュール
４ａ　額縁エリア
５　ベゼル
６　拡散板
７　基材
８　液晶パネル
９　主制御基板
１０　ＬＥＤ
１１　ＬＥＤ列
１２　ＬＥＤアレイ
２０　定電流ＩＣ
２１　制御信号入力回路
２２　定電流回路ブロック制御回路
２４　異常検出回路
２５　異常状態通知信号入力回路
２６　異常状態通知信号出力回路
３０　電圧生成ＩＣ
３１　ダイオード
３２　コイル
３３　電圧生成回路ブロック
３５　異常状態通知信号受信回路
３６　電圧生成動作制御回路
８１　表示エリア REFERENCE SIGNS LIST 1 electronic device 2 back light unit 3 display control board 4 liquid crystal module 4 a frame area 5 bezel 6 diffusion plate 7 base 8 liquid crystal panel 9 main control board 10 LED
11 LED array 12 LED array 20 constant current IC
21 control signal input circuit 22 constant current circuit block control circuit 24 abnormality detection circuit 25 abnormal state notification signal input circuit 26 abnormal state notification signal output circuit 30 voltage generation IC
31 diode 32 coil 33 voltage generation circuit block 35 abnormal state notification signal reception circuit 36 voltage generation operation control circuit 81 display area

Claims (8)

  1. 　直下型のバックライトユニットであって、
    　基材と、
    　上記基材に配置された複数のＬＥＤが接続された一又は複数のＬＥＤアレイと、
    　上記ＬＥＤアレイに対応して上記基材に設けられ、当該ＬＥＤアレイに含まれるＬＥＤに定電流を流すための一又は複数の定電流ＩＣとを備え、
    　上記ＬＥＤアレイは、複数のＬＥＤが直列に接続された複数のＬＥＤ列を含み、
    　上記定電流ＩＣは、上記複数のＬＥＤ列それぞれに接続された複数の定電流回路を含むことを特徴とするバックライトユニット。     It is a direct type backlight unit,
    A substrate,
    One or more LED arrays to which a plurality of LEDs disposed on the substrate are connected;
    And one or more constant current ICs provided on the base material corresponding to the LED array, for supplying a constant current to the LEDs included in the LED array,
    The LED array includes a plurality of LED strings in which a plurality of LEDs are connected in series;
    A backlight unit comprising: a plurality of constant current circuits connected to each of the plurality of LED strings.
  2. 　上記定電流ＩＣは、当該定電流ＩＣへ入力される制御信号を取得する制御信号入力回路と、
    　上記制御信号入力回路からの指示信号に基づいて、上記各ＬＥＤ列から各定電流回路へ流す電流をそれぞれ調整する定電流制御回路とを含むことを特徴とする請求項１に記載のバックライトユニット。     The constant current IC includes a control signal input circuit that acquires a control signal input to the constant current IC.
    2. The backlight unit according to claim 1, further comprising: a constant current control circuit for adjusting the current flowing from each of the LED rows to each of the constant current circuits based on an instruction signal from the control signal input circuit. .
  3. 　請求項１又は２に記載のバックライトユニットと、
    　表示制御基板と、
    　上記表示制御基板に配置され、電圧生成ＩＣ及び周辺回路部品を含み、上記各ＬＥＤ列のアノードに電圧を供給するための電圧生成回路ブロックとを備えていることを特徴とする電子機器。     A backlight unit according to claim 1 or 2.
    Display control board,
    An electronic apparatus comprising: a voltage generation circuit block disposed on the display control substrate, including a voltage generation IC and a peripheral circuit component, for supplying a voltage to an anode of each of the LED rows.
  4. 　上記電圧生成ＩＣの個数は、上記定電流ＩＣの個数よりも少ないことを特徴とする請求項３に記載の電子機器。 The electronic device according to claim 3, wherein the number of the voltage generation ICs is smaller than the number of the constant current ICs.
  5. 　上記電圧生成ＩＣの個数は、上記定電流ＩＣの個数の整数（但し１以上）分の１であることを特徴とする請求項３又は４に記載の電子機器。 5. The electronic device according to claim 3, wherein the number of the voltage generation ICs is an integer (1 or more) of the number of the constant current ICs.
  6. 　上記複数の定電流ＩＣ及び上記電圧生成ＩＣ間に、異常を知らせる信号である異常信号を送受信する経路が直列に接続されていることを特徴とする請求項３～５の何れか１項に記載の電子機器。 A path for transmitting and receiving an abnormal signal, which is a signal notifying an abnormality, is connected in series between the plurality of constant current ICs and the voltage generation IC, according to any one of claims 3 to 5. Electronic devices.
  7. 　上記バックライトユニットは、上記基材、上記一又は複数のＬＥＤアレイ及び上記一又は複数の定電流ＩＣを格納し、金属から構成されているベゼルを備え、
    　上記基材における、上記一又は複数のＬＥＤアレイ及び上記一又は複数の定電流ＩＣが配置されている面とは反対側の面と、上記ベゼルとは接触していることを特徴とする請求項３～６の何れか１項に記載の電子機器。     The backlight unit includes a bezel that stores the base, the one or more LED arrays, and the one or more constant current ICs, and is made of metal.
    The bezel is in contact with the surface of the base opposite to the surface on which the one or more LED arrays and the one or more constant current ICs are disposed. The electronic device according to any one of 3 to 6.
  8. 　上記バックライトユニットは、上記一又は複数のＬＥＤアレイ及び上記一又は複数の定電流ＩＣを格納し、金属から構成されているベゼルを備え、
    　上記基材は上記ベゼルの一部であることを特徴とする請求項３～６の何れか１項に記載の電子機器。     The backlight unit includes a bezel that stores the one or more LED arrays and the one or more constant current ICs, and is made of metal.
    The electronic device according to any one of claims 3 to 6, wherein the base material is a part of the bezel.
PCT/JP2018/028877 2017-08-08 2018-08-01 Backlight unit and electronic device WO2019031355A1 (en)

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