WO2023145854A1 - Head-up display device - Google Patents

Head-up display device Download PDF

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Publication number
WO2023145854A1
WO2023145854A1 PCT/JP2023/002573 JP2023002573W WO2023145854A1 WO 2023145854 A1 WO2023145854 A1 WO 2023145854A1 JP 2023002573 W JP2023002573 W JP 2023002573W WO 2023145854 A1 WO2023145854 A1 WO 2023145854A1
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Prior art keywords
light source
signal
adim
microcomputer
lighting signal
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PCT/JP2023/002573
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French (fr)
Japanese (ja)
Inventor
正則 遠藤
健人 廣木
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日本精機株式会社
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Publication of WO2023145854A1 publication Critical patent/WO2023145854A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
    • H05B47/10—Controlling the light source
    • H05B47/16—Controlling the light source by timing means
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
    • H05B47/20—Responsive to malfunctions or to light source life; for protection
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection

Definitions

  • the present invention relates to a head-up display device.
  • the head-up display device described in Patent Document 1 includes an LED (Light Emitting Diode) and a microcomputer that outputs a first PWM signal and acquires the cathode voltage of the LED.
  • This microcomputer detects a luminance abnormality failure when determining that a specific point specified by the cathode voltage and the duty ratio of the first PWM signal exists within the high luminance abnormality range.
  • the present invention has been made in view of the above-mentioned actual situation, and it is an object of the present invention to provide a head-up display device that has a simpler configuration and can more quickly determine the luminance abnormality of the light source.
  • a head-up display device includes a display, a light source that lights so as to emit light to the display, a driver that lights the light source, a light source current or a light source.
  • a microcomputer that supplies the light source current or the light source voltage commanded by the lighting signal to the light source by outputting a lighting signal that commands a voltage to the driver, and feeds back the output lighting signal as a feedback lighting signal.
  • the microcomputer includes a luminance abnormality determination unit that determines whether or not there is luminance abnormality in the light source by comparing the output lighting signal and the input feedback lighting signal.
  • the head-up display device it is possible to more quickly determine the brightness abnormality of the light source with a simpler configuration.
  • FIG. 1 is a schematic diagram of a vehicle equipped with a head-up display device according to an embodiment of the present invention
  • FIG. 1 is a schematic diagram of a head-up display device according to one embodiment of the present invention
  • FIG. 1 is a block diagram of a head-up display device according to an embodiment of the invention
  • FIG. 3(a) to 3(c) are diagrams showing waveforms of an ADIM signal and an ADIM feedback signal when there is no luminance abnormality according to an embodiment of the present invention
  • FIG. 3(a) and 3(b) are diagrams showing waveforms of an ADIM signal and an ADIM feedback signal when there is a luminance abnormality according to an embodiment of the present invention
  • FIG. 3(a) and 3(b) are diagrams showing waveforms of an ADIM signal and an ADIM feedback signal when there is a luminance abnormality according to an embodiment of the present invention
  • FIG. 4 is a flow chart showing the procedure of luminance abnormality determination processing according to one embodiment of the present invention.
  • head-up display device 100 is installed in a dashboard of vehicle 200 .
  • the head-up display device 100 emits display light L representing an image toward a windshield 201, which is an example of a projected member of the vehicle 200.
  • the display light L is reflected by the windshield 201 and reaches the viewer 1 (mainly the driver of the vehicle 200). Thereby, the virtual image V is displayed so that it can be visually recognized by the viewer 1 .
  • the head-up display device 100 includes a display section 10, a plane mirror 20, a concave mirror 30, a housing 60, and a control section .
  • the display unit 10 emits display light L representing an image under the control of the control unit 70 .
  • the display unit 10 includes a display 14 and an illumination device 18 .
  • the plane mirror 20 reflects the display light L emitted by the display unit 10 toward the concave mirror 30 .
  • the concave mirror 30 magnifies and reflects the display light L reflected by the plane mirror 20 toward the windshield 201 (see FIG. 1).
  • the plane mirror 20 may be a concave mirror.
  • the housing 60 is made of non-translucent resin or metal and has a substantially hollow rectangular parallelepiped shape. Each component of the head-up display device 100 is housed in the housing 60 .
  • An opening 61 is formed in the housing 60 at a position facing the windshield 201 .
  • the housing 60 includes a curved plate-shaped window 50 that closes the opening 61 .
  • the window part 50 is made of translucent resin such as acrylic through which the display light L is transmitted.
  • the display 14 is a TFT (Thin Film Transistor) type liquid crystal display panel controlled by the control unit 70 .
  • the display 14 emits display light L upon receiving light from the illumination device 18 .
  • the illumination device 18 is located behind the display 14 and illuminates the display 14 with illumination light.
  • the illumination device 18 includes a plurality of light sources 18 a that emit light to the display 14 under the control of the controller 70 .
  • Each light source 18a consists of an LED.
  • the display unit 10 includes a plurality of light sources 18a, a display 14, and a signal conditioning circuit 73.
  • the control unit 70 includes a microcomputer (microcomputer) 71 , a light source driver IC 72 and an input voltage switching circuit 78 .
  • the input voltage switching circuit 78 is provided between the power supply voltage Vc and the light source driver IC 72, and receives a control signal Sc from the microcomputer 71 and switches between an ON state and an OFF state.
  • a voltage from the power supply voltage Vc is applied to the light source driver IC 72 .
  • the input voltage switching circuit 78 is in the OFF state, application of voltage from the power supply voltage Vc to the light source driver IC 72 is stopped.
  • the light source driver IC 72 is a switch circuit that receives the power supply voltage Vc and boosts a first PWM (Pulse Width Modulation) signal Spwm1 described later from the microcomputer 71 to generate a second PWM signal Spwm2.
  • the second PWM signal Spwm2 becomes a signal synchronized with the first PWM signal Spwm1.
  • the light source driver IC 72 supplies the light source current Iled to the plurality of light sources 18a via the second PWM signal Spwm2.
  • An anode terminal of the light source 18 a is connected to the light source driver IC 72 .
  • a cathode terminal of the light source 18 a is connected to the microcomputer 71 via the signal adjustment circuit 73 .
  • the signal adjustment circuit 73 receives the voltage across the light source 18a (anode voltage and cathode voltage Vct), generates a PWM feedback signal Sfp that is a feedback signal of the second PWM signal Spwm2, and sends the generated PWM feedback signal Sfp to the microcomputer 71. output to The signal adjustment circuit 73 generates a binarized PWM feedback signal Sfp by comparing the cathode voltage of the light source 18a and the threshold.
  • the signal conditioning circuit 73 has capacitors, resistors and switching elements.
  • the microcomputer 71 is used as a processing unit such as a CPU (Central Processing Unit) that executes an operation program, a ROM (Read Only Memory) that stores the operation program of this processing unit, and a work area for this processing unit.
  • a RAM Random Access Memory
  • the microcomputer 71 includes, as functional blocks, a light control section 71a, a luminance abnormality determination section 71b, and a display control section 71c that controls the display device 14.
  • the light control unit 71a controls lighting of the light source 18a via the light source driver IC72.
  • the dimming unit 71a receives the required brightness signal Sa from the outside and turns on the light source 18a with the required brightness included in the required brightness signal Sa.
  • the required brightness signal Sa increases in proportion to, for example, an external light intensity detection value indicating ambient brightness included in vehicle information from an in-vehicle ECU (Electronic Control Unit).
  • the dimming unit 71a outputs an enable signal Sen to the light source driver IC 72 to permit the light source driver IC 72 to operate.
  • the light adjustment unit 71a disables the operation of the light source driver IC 72 by stopping the output of the enable signal Sen after the luminance abnormality determination described later.
  • the dimming unit 71a adjusts the luminance of the light source 18a by adjusting the duty ratio of the first PWM signal Spwm1 and the duty ratio of the ADIM (analog dimming input) signal Sadim.
  • the higher the on-duty ratio of the ADIM signal Sadim the higher the peak current value of the light source current Iled.
  • the frequency of the first PWM signal Spwm1 is set to, for example, 1 kHz to several hundred kHz.
  • the frequency of the ADIM signal Sadim is set to, for example, several tens of kHz, preferably 50 kHz.
  • the dimming unit 71a fixes the duty ratio of the ADIM signal Sadim to a specified value and generates the first PWM signal Spwm1 having a duty ratio corresponding to the required brightness.
  • the dimming unit 71a fixes the duty ratio of the first PWM signal Spwm1 to the lower limit and adjusts the duty ratio according to the required brightness. to generate the ADIM signal Sadim.
  • the lower limit of the duty ratio of the first PWM signal Spwm1 is set to 0.2%, for example.
  • the luminance abnormality determination unit 71b determines whether or not there is luminance abnormality in the light source 18a.
  • the ADIM signal Sadim as shown in FIG. 4(a), has a pulse waveform that is periodically turned on for the on-time Ton1.
  • the ADIM feedback signal Sfb ideally has the same waveform as the ADIM signal Sadim. , the waveform of the ADIM signal Sadim is rounded.
  • the brightness abnormality determination unit 71b determines that the ADIM feedback signal Sfb is ON. Then, when the ADIM feedback signal Sfb, which is raw data, becomes equal to or lower than the OFF threshold value THoff, the ADIM feedback signal Sfb is determined to be OFF. As a result, the ADIM feedback signal Sfb is binarized as shown in FIG. 4(c).
  • the on-threshold THon is set to a value different from the off-threshold THoff, i.e., to a value larger than the off-threshold THoff.
  • the on-threshold THon and the off-threshold THoff may be set to the same value.
  • the luminance abnormality determination unit 71b determines that the difference between the on-time Ton1 of the ADIM signal Sadim and the on-time Ton2 of the ADIM feedback signal Sfb is equal to or less than a preset specified value Tk. Sometimes, it is determined that the light source 18a has no luminance abnormality. When the luminance abnormality determination unit 71b determines that the light source 18a has no luminance abnormality, the light control unit 71a continues lighting control of the light source 18a.
  • the brightness abnormality determination unit 71b determines the ON time Ton1 of the ADIM signal Sadim and the ON time Ton2 of the ADIM feedback signal Sfb.
  • the difference ⁇ T is equal to or greater than the specified value Tk, it is determined that the light source 18a has an abnormality in brightness. Possible causes of this luminance abnormality are, for example, a failure of the microcomputer 71 or a failure of the light source 18a.
  • FIGS. 5(a) and 5(b) and FIGS. 6(a) and 6(b) determines the ON time Ton1 of the ADIM signal Sadim and the ON time Ton2 of the ADIM feedback signal Sfb.
  • the on-time Ton2 of the ADIM feedback signal Sfb is longer than the on-time Ton1 of the ADIM signal Sadim, and the difference ⁇ T between the on-times Ton1 and Ton2 is equal to or greater than the specified value Tk.
  • the on-time Ton2 of the ADIM feedback signal Sfb is shorter than the on-time Ton1 of the ADIM signal Sadim, and the difference ⁇ T between the on-times Ton1 and Ton2 is greater than or equal to the specified value Tk.
  • step S101 determines whether or not the light source 18a has a luminance abnormality.
  • step S101 determines whether or not the light source 18a has a luminance abnormality.
  • the light control unit 71a determines that the light source 18a has an abnormality in brightness (step S101; YES), it executes shutdown processing in steps S102 to S104. Specifically, the dimming unit 71a stops outputting the enable signal Sen to the light source driver IC 72 (step S102). Next, the dimming unit 71a stops outputting the ADIM signal Sadim to the light source driver IC 72 (step S103). Next, the dimming unit 71a turns off the input voltage switching circuit 78 through the control signal Sc (step S104). Through steps S102 to S104, the light sources 18a are turned off and the illumination device 18 is shut down in three separate systems. Therefore, it is possible to shut down the lighting device 18 more reliably.
  • the brightness of the light source 18a is abnormally increased, and it is suppressed that the driver is dazzled.
  • the enable signal Sen is fixed at the Hi level
  • the light source 18a cannot be turned off by the processing of step S102. You can turn off the light.
  • the display control unit 71c ends the display on the display 14 when the lighting device 18 is shut down.
  • the head-up display device 100 includes a display 14, a light source 18a that lights so as to emit light to the display 14, a light source driver IC 72 that is an example of a driver that lights the light source 18a, and a light source current Iled.
  • the ADIM signal Sadim which is an example of a lighting signal to be instructed
  • the light source driver IC 72 By outputting the ADIM signal Sadim, which is an example of a lighting signal to be instructed, to the light source driver IC 72, the light source current Iled commanded by the ADIM signal Sadim is supplied to the light source 18a, and the output ADIM signal Sadim is an example of a feedback lighting signal.
  • a microcomputer 71 that feeds back as an ADIM feedback signal Sfb.
  • the microcomputer 71 includes a brightness abnormality determination section 71b that determines whether there is a brightness abnormality in the light source 18a by comparing the output ADIM signal Sadim and the input ADIM feedback signal Sfb.
  • a brightness abnormality determination section 71b that determines whether there is a brightness abnormality in the light source 18a by comparing the output ADIM signal Sadim and the input ADIM feedback signal Sfb.
  • the luminance abnormality determining unit 71b compares the on-time Ton1, which is an example of the first on-time of the ADIM signal Sadim, and the on-time Ton2, which is an example of the second on-time of the ADIM feedback signal Sfb. When the difference ⁇ T of the on-time Ton2 is equal to or greater than a preset specified value Tk, it is determined that there is a luminance abnormality.
  • the microcomputer 71 turns off the light source 18a when the luminance abnormality determination unit 71b determines that there is luminance abnormality.
  • the luminance abnormality determination unit 71b determines that there is luminance abnormality, the light source 18a is turned off. Therefore, excessive increase in luminance of the light source 18a and, in turn, dazzling the viewer 1 are suppressed.
  • the light source 18a is an LED.
  • the microcomputer 71 feeds back an ADIM signal (analog dimming signal) Sadim for commanding the light source current Iled as an ADIM feedback signal Sfb.
  • ADIM signal analog dimming signal
  • Sadim analog dimming signal
  • a change in the light source current Iled tends to affect the luminance of the light source 18a. Therefore, by using the ADIM signal Sadim for commanding the light source current Iled to determine the luminance abnormality, it is possible to suppress the discomfort given to the viewer 1 due to the luminance abnormality.
  • the microcomputer 71 includes a first shutdown section that stops outputting the enable signal Sen that permits the operation of the light source driver IC 72 to the light source driver IC 72, and a second shutdown section that stops outputting the ADIM signal Sadim to the light source driver IC 72. and a third shutdown section for stopping the application of the power supply voltage Vc to the light source driver IC 72 .
  • the microcomputer 71 sequentially operates the first shutdown section, the second shutdown section, and the third shutdown section to turn off the light source 18a. With this configuration, the light source 18a can be turned off more reliably when the luminance abnormality determination unit 71b determines that there is luminance abnormality.
  • step S102 ⁇ step S103 ⁇ step S104 In the shutdown processing of the above embodiment, the processing was executed in the order of step S102 ⁇ step S103 ⁇ step S104, but this order can be changed as appropriate. Also, steps S102 to S104 may be performed simultaneously. Furthermore, any two of the three steps S102 to S104 may be omitted. In addition, the output of the first PWM signal Spwm1 may be stopped as shutdown processing. Also, the ADIM feedback signal Sfb may be a signal that has passed through the light source driver IC 72 .
  • the display control unit 71c may switch the display 14 to the non-transmissive state (black display state) when the luminance abnormality determination unit 71b determines that the light source 18a has abnormality in luminance. As a result, dazzling the viewer 1 viewing the virtual image V is suppressed.
  • the lighting signal is the ADIM signal Sadim and the feedback lighting signal is the ADIM feedback signal Sfb.
  • the lighting signal is the ADIM signal Sadim and the feedback lighting signal is the ADIM feedback signal Sfb.
  • the display 14 was a liquid crystal display panel, but it is not limited to this, and may be a reflective display such as a DMD (Digital Micromirror Device) element.
  • DMD Digital Micromirror Device
  • step S101 when the microcomputer 71 determines that the light source 18a has a luminance abnormality (step S101; YES), the plurality of light sources 18a is turned off. The presence may be notified to the viewer 1 through notification means such as an indicator.
  • the head-up display device 100 is mounted on the vehicle 200 in the above embodiment, it may be mounted on a vehicle other than the vehicle 200, such as an airplane or a ship. Further, the projected member is not limited to the windshield 201, and may be a dedicated combiner.

Abstract

Provided is a head-up display device with which it is possible to more quickly assess an abnormality in the brightness of a light source even with a simpler configuration.　This head-up display device (100) comprises: a display (14); a light source (18a) that lights up so as to emit light toward the display (14); a light source driver IC (72) that causes the light source (18a) to light up; and a microcomputer (71) that outputs, to the light source IC (72), an ADIM signal (Sadim) for issuing a command regarding a light source current (Iled), as a result of which the light source current (Iled) commanded by the ADIM signal (Sadim) is supplied to the light source (18a), and the outputted ADIM signal (Sadim) is fed back and inputted as an ADIM feedback signal (Sfb). The microcomputer (71) is provided with a brightness abnormality assessment unit (71b) for comparing the outputted ADIM signal (Sadim) and the inputted ADIM feedback signal (Sfb) to thereby assess whether there is an abnormality in the brightness of the light source (18a).

Description

ヘッドアップディスプレイ装置head-up display device
　本発明は、ヘッドアップディスプレイ装置に関する。 The present invention relates to a head-up display device.
　例えば、特許文献１に記載のヘッドアップディスプレイ装置は、ＬＥＤ（Light Emitting Diode)と、第１ＰＷＭ信号を出力し、ＬＥＤのカソード電圧を取得するマイコンと、を備える。このマイコンは、カソード電圧と第１ＰＷＭ信号のデューティ比により特定される特定点が高輝度異常範囲内に存在する旨判別したときに輝度異常故障を検出する。 For example, the head-up display device described in Patent Document 1 includes an LED (Light Emitting Diode) and a microcomputer that outputs a first PWM signal and acquires the cathode voltage of the LED. This microcomputer detects a luminance abnormality failure when determining that a specific point specified by the cathode voltage and the duty ratio of the first PWM signal exists within the high luminance abnormality range.
国際公開第２０２０／２３５６８３号WO2020/235683
　上記特許文献１に記載の構成では、ＬＥＤのカソード電圧を監視しているため、ＬＥＤに実際に電圧が印加されるまで異常を検出できなかった。また、ＬＥＤの駆動ラインを直接監視する構成は、その構成がＬＥＤの正常な点灯を妨げないよう、設計上構成が複雑になるおそれがあった。 In the configuration described in Patent Document 1 above, since the cathode voltage of the LED is monitored, an abnormality cannot be detected until a voltage is actually applied to the LED. In addition, the configuration for directly monitoring the drive line of the LED may be complicated in terms of design so that the configuration does not interfere with the normal lighting of the LED.
　本発明は、上記実状を鑑みてなされたものであり、より簡易な構成でありながらも、より迅速に光源の輝度異常を判定することができるヘッドアップディスプレイ装置を提供することを目的とする。 The present invention has been made in view of the above-mentioned actual situation, and it is an object of the present invention to provide a head-up display device that has a simpler configuration and can more quickly determine the luminance abnormality of the light source.
　上記目的を達成するため、本発明の観点に係るヘッドアップディスプレイ装置は、表示器と、前記表示器に光を出射するように点灯する光源と、前記光源を点灯させるドライバと、光源電流又は光源電圧を指令する点灯信号を前記ドライバに出力することにより、前記点灯信号により指令された前記光源電流又は前記光源電圧を前記光源に供給し、出力した前記点灯信号を帰還点灯信号として帰還入力するマイコンと、を備え、前記マイコンは、出力された前記点灯信号及び入力された前記帰還点灯信号を比較することにより前記光源の輝度異常の有無を判定する輝度異常判定部を備える。 In order to achieve the above object, a head-up display device according to an aspect of the present invention includes a display, a light source that lights so as to emit light to the display, a driver that lights the light source, a light source current or a light source. A microcomputer that supplies the light source current or the light source voltage commanded by the lighting signal to the light source by outputting a lighting signal that commands a voltage to the driver, and feeds back the output lighting signal as a feedback lighting signal. and the microcomputer includes a luminance abnormality determination unit that determines whether or not there is luminance abnormality in the light source by comparing the output lighting signal and the input feedback lighting signal.
　本発明によれば、ヘッドアップディスプレイ装置において、より簡易な構成でありながらも、より迅速に光源の輝度異常を判定することができる。 According to the present invention, in the head-up display device, it is possible to more quickly determine the brightness abnormality of the light source with a simpler configuration.
本発明の一実施形態に係るヘッドアップディスプレイ装置が搭載された車両の模式図である。1 is a schematic diagram of a vehicle equipped with a head-up display device according to an embodiment of the present invention; FIG. 本発明の一実施形態に係るヘッドアップディスプレイ装置の概略図である。1 is a schematic diagram of a head-up display device according to one embodiment of the present invention; FIG. 本発明の一実施形態に係るヘッドアップディスプレイ装置のブロック図である。1 is a block diagram of a head-up display device according to an embodiment of the invention; FIG. （ａ）～（ｃ）は本発明の一実施形態に係る輝度異常がないときのＡＤＩＭ信号及びＡＤＩＭフィードバック信号の波形を示す図である。3(a) to 3(c) are diagrams showing waveforms of an ADIM signal and an ADIM feedback signal when there is no luminance abnormality according to an embodiment of the present invention; FIG. （ａ）、（ｂ）は本発明の一実施形態に係る輝度異常があるときのＡＤＩＭ信号及びＡＤＩＭフィードバック信号の波形を示す図である。3(a) and 3(b) are diagrams showing waveforms of an ADIM signal and an ADIM feedback signal when there is a luminance abnormality according to an embodiment of the present invention; FIG. （ａ）、（ｂ）は本発明の一実施形態に係る輝度異常があるときのＡＤＩＭ信号及びＡＤＩＭフィードバック信号の波形を示す図である。3(a) and 3(b) are diagrams showing waveforms of an ADIM signal and an ADIM feedback signal when there is a luminance abnormality according to an embodiment of the present invention; FIG. 本発明の一実施形態に係る輝度異常判定処理の手順を示すフローチャートである。4 is a flow chart showing the procedure of luminance abnormality determination processing according to one embodiment of the present invention.
　本発明に係るヘッドアップディスプレイ装置の一実施形態について、図面を参照して説明する。
　図１に示すように、ヘッドアップディスプレイ装置１００は、車両２００のダッシュボード内に設置される。ヘッドアップディスプレイ装置１００は、車両２００の被投射部材の一例であるフロントガラス２０１に向けて像を表す表示光Ｌを出射する。表示光Ｌはフロントガラス２０１で反射して視認者１（主に車両２００の運転者）に到達する。これにより、虚像Ｖが視認者１により視認可能に表示される。 An embodiment of a head-up display device according to the present invention will be described with reference to the drawings.
As shown in FIG. 1 , head-up display device 100 is installed in a dashboard of vehicle 200 . The head-up display device 100 emits display light L representing an image toward a windshield 201, which is an example of a projected member of the vehicle 200. As shown in FIG. The display light L is reflected by the windshield 201 and reaches the viewer 1 (mainly the driver of the vehicle 200). Thereby, the virtual image V is displayed so that it can be visually recognized by the viewer 1 .
　図２に示すように、ヘッドアップディスプレイ装置１００は、表示部１０と、平面鏡２０と、凹面鏡３０と、筐体６０と、制御部７０と、を備える。 As shown in FIG. 2, the head-up display device 100 includes a display section 10, a plane mirror 20, a concave mirror 30, a housing 60, and a control section .
　表示部１０は、制御部７０による制御のもと、像を表す表示光Ｌを出射する。表示部１０は、表示器１４と、照明装置１８と、を備える。 The display unit 10 emits display light L representing an image under the control of the control unit 70 . The display unit 10 includes a display 14 and an illumination device 18 .
　平面鏡２０は、表示部１０が出射した表示光Ｌを凹面鏡３０に向けて反射させる。凹面鏡３０は、平面鏡２０で反射した表示光Ｌをフロントガラス２０１（図１参照）に向けて拡大させつつ反射させる。
　なお、平面鏡２０は、凹面鏡であってもよい。 The plane mirror 20 reflects the display light L emitted by the display unit 10 toward the concave mirror 30 . The concave mirror 30 magnifies and reflects the display light L reflected by the plane mirror 20 toward the windshield 201 (see FIG. 1).
Note that the plane mirror 20 may be a concave mirror.
　筐体６０は、非透光性の樹脂又は金属で形成されるとともに、中空の略直方体をなす。筐体６０内には、ヘッドアップディスプレイ装置１００の各構成が収納されている。
　筐体６０には、フロントガラス２０１に対向する位置に開口部６１が形成されている。筐体６０は、開口部６１を塞ぐ湾曲板状の窓部５０を備える。窓部５０は、表示光Ｌが透過するアクリル等の透光性の樹脂からなる。 The housing 60 is made of non-translucent resin or metal and has a substantially hollow rectangular parallelepiped shape. Each component of the head-up display device 100 is housed in the housing 60 .
An opening 61 is formed in the housing 60 at a position facing the windshield 201 . The housing 60 includes a curved plate-shaped window 50 that closes the opening 61 . The window part 50 is made of translucent resin such as acrylic through which the display light L is transmitted.
　表示器１４は、制御部７０により制御されるＴＦＴ（Thin Film Transistor）型の液晶表示パネルである。表示器１４は、照明装置１８からの光を受けて表示光Ｌを出射する。 The display 14 is a TFT (Thin Film Transistor) type liquid crystal display panel controlled by the control unit 70 . The display 14 emits display light L upon receiving light from the illumination device 18 .
　照明装置１８は、表示器１４の裏側に位置し、表示器１４に照明光を照明する。照明装置１８は、制御部７０による制御のもと表示器１４に光を出射する複数の光源１８ａを備える。各光源１８ａは、ＬＥＤからなる。 The illumination device 18 is located behind the display 14 and illuminates the display 14 with illumination light. The illumination device 18 includes a plurality of light sources 18 a that emit light to the display 14 under the control of the controller 70 . Each light source 18a consists of an LED.
　次に、表示部１０及び制御部７０の電気的構成について説明する。
　図３に示すように、表示部１０は、複数の光源１８ａと、表示器１４と、信号調整回路７３と、を備える。制御部７０は、マイコン（マイクロコンピュータ）７１と、光源ドライバＩＣ７２と、入力電圧切替回路７８と、を備える。 Next, electrical configurations of the display unit 10 and the control unit 70 will be described.
As shown in FIG. 3, the display unit 10 includes a plurality of light sources 18a, a display 14, and a signal conditioning circuit 73. The control unit 70 includes a microcomputer (microcomputer) 71 , a light source driver IC 72 and an input voltage switching circuit 78 .
　入力電圧切替回路７８は、電源電圧Ｖｃと光源ドライバＩＣ７２の間に設けられ、マイコン７１からの制御信号Ｓｃを受けてオン状態とオフ状態の間で切り替わる。入力電圧切替回路７８がオン状態にあるとき、電源電圧Ｖｃからの電圧が光源ドライバＩＣ７２に印加される。入力電圧切替回路７８がオフ状態にあるとき、電源電圧Ｖｃからの光源ドライバＩＣ７２への電圧印加が停止される。 The input voltage switching circuit 78 is provided between the power supply voltage Vc and the light source driver IC 72, and receives a control signal Sc from the microcomputer 71 and switches between an ON state and an OFF state. When the input voltage switching circuit 78 is on, a voltage from the power supply voltage Vc is applied to the light source driver IC 72 . When the input voltage switching circuit 78 is in the OFF state, application of voltage from the power supply voltage Vc to the light source driver IC 72 is stopped.
　光源ドライバＩＣ７２は、電源電圧Ｖｃを受けて、マイコン７１からの後述する第１ＰＷＭ(Pulse Width Modulation)信号Ｓｐｗｍ１を昇圧させた第２ＰＷＭ信号Ｓｐｗｍ２を生成するスイッチ回路である。第２ＰＷＭ信号Ｓｐｗｍ２は、第１ＰＷＭ信号Ｓｐｗｍ１に同期した信号となる。光源ドライバＩＣ７２は、第２ＰＷＭ信号Ｓｐｗｍ２を介して複数の光源１８ａに光源電流Ｉｌｅｄを供給する。光源１８ａのアノード端子は光源ドライバＩＣ７２に接続されている。光源１８ａのカソード端子は、信号調整回路７３を介してマイコン７１に接続されている。 The light source driver IC 72 is a switch circuit that receives the power supply voltage Vc and boosts a first PWM (Pulse Width Modulation) signal Spwm1 described later from the microcomputer 71 to generate a second PWM signal Spwm2. The second PWM signal Spwm2 becomes a signal synchronized with the first PWM signal Spwm1. The light source driver IC 72 supplies the light source current Iled to the plurality of light sources 18a via the second PWM signal Spwm2. An anode terminal of the light source 18 a is connected to the light source driver IC 72 . A cathode terminal of the light source 18 a is connected to the microcomputer 71 via the signal adjustment circuit 73 .
　信号調整回路７３は、光源１８ａの両端の電圧（アノード電圧及びカソード電圧Ｖｃｔ）を入力し、第２ＰＷＭ信号Ｓｐｗｍ２のフィードバック信号であるＰＷＭフィードバック信号Ｓｆｐを生成し、生成したＰＷＭフィードバック信号Ｓｆｐをマイコン７１に出力する。信号調整回路７３は、光源１８ａのカソード電圧と閾値の比較により２値化したＰＷＭフィードバック信号Ｓｆｐを生成する。信号調整回路７３は、コンデンサ、抵抗及びスイッチング素子を有する。 The signal adjustment circuit 73 receives the voltage across the light source 18a (anode voltage and cathode voltage Vct), generates a PWM feedback signal Sfp that is a feedback signal of the second PWM signal Spwm2, and sends the generated PWM feedback signal Sfp to the microcomputer 71. output to The signal adjustment circuit 73 generates a binarized PWM feedback signal Sfp by comparing the cathode voltage of the light source 18a and the threshold. The signal conditioning circuit 73 has capacitors, resistors and switching elements.
　マイコン７１は、動作プログラムを実行するＣＰＵ（Central Processing Unit）等の処理部と、この処理部の動作プログラム等が記憶されるＲＯＭ（Read Only Memory）と、この処理部のワークエリアとして利用されるＲＡＭ（Random Access Memory）と、を備える。
　マイコン７１は、機能ブロックとして、調光部７１ａと、輝度異常判定部７１ｂと、表示器１４を制御する表示制御部７１ｃと、を備える。 The microcomputer 71 is used as a processing unit such as a CPU (Central Processing Unit) that executes an operation program, a ROM (Read Only Memory) that stores the operation program of this processing unit, and a work area for this processing unit. A RAM (Random Access Memory) is provided.
The microcomputer 71 includes, as functional blocks, a light control section 71a, a luminance abnormality determination section 71b, and a display control section 71c that controls the display device 14. FIG.
　調光部７１ａは、光源ドライバＩＣ７２を介して光源１８ａを点灯制御する。調光部７１ａは、外部からの要求輝度信号Ｓａを受けて、要求輝度信号Ｓａに含まれる要求輝度で光源１８ａを点灯させる。要求輝度信号Ｓａは、例えば、車載されるＥＣＵ（Electronic Control Unit）からの車両情報に含まれる周囲の明るさを示す外光強度検出値に比例して高くなる。
　調光部７１ａは、表示部１０の電源がオンされると、イネーブル信号Ｓｅｎを光源ドライバＩＣ７２に出力することにより、光源ドライバＩＣ７２の動作を許可する。調光部７１ａは、後述する輝度異常判定後に、イネーブル信号Ｓｅｎの出力を停止することにより、光源ドライバＩＣ７２の動作を不可とする。 The light control unit 71a controls lighting of the light source 18a via the light source driver IC72. The dimming unit 71a receives the required brightness signal Sa from the outside and turns on the light source 18a with the required brightness included in the required brightness signal Sa. The required brightness signal Sa increases in proportion to, for example, an external light intensity detection value indicating ambient brightness included in vehicle information from an in-vehicle ECU (Electronic Control Unit).
When the display unit 10 is powered on, the dimming unit 71a outputs an enable signal Sen to the light source driver IC 72 to permit the light source driver IC 72 to operate. The light adjustment unit 71a disables the operation of the light source driver IC 72 by stopping the output of the enable signal Sen after the luminance abnormality determination described later.
　調光部７１ａは、第１ＰＷＭ信号Ｓｐｗｍ１のデューティ比及びＡＤＩＭ（アナログ調光入力）信号Ｓａｄｉｍのデューティ比を調整することにより、光源１８ａの輝度を調整する。第１ＰＷＭ信号Ｓｐｗｍ１のオンデューティ比が高くなるほど、光源電流Ｉｌｅｄが光源１８ａに供給される時間が長くなり、光源１８ａの輝度が高くなる。ＡＤＩＭ信号Ｓａｄｉｍのオンデューティ比が高くなるほど、光源電流Ｉｌｅｄのピーク電流値が高くなる。
　第１ＰＷＭ信号Ｓｐｗｍ１の周波数は、例えば、１ｋＨｚ～数百ｋＨｚに設定される。ＡＤＩＭ信号Ｓａｄｉｍの周波数は、例えば、数十ｋＨｚ、好ましくは、５０ｋＨｚに設定されている。 The dimming unit 71a adjusts the luminance of the light source 18a by adjusting the duty ratio of the first PWM signal Spwm1 and the duty ratio of the ADIM (analog dimming input) signal Sadim. The higher the on-duty ratio of the first PWM signal Spwm1, the longer the time during which the light source current Iled is supplied to the light source 18a, and the higher the brightness of the light source 18a. The higher the on-duty ratio of the ADIM signal Sadim, the higher the peak current value of the light source current Iled.
The frequency of the first PWM signal Spwm1 is set to, for example, 1 kHz to several hundred kHz. The frequency of the ADIM signal Sadim is set to, for example, several tens of kHz, preferably 50 kHz.
　調光部７１ａは、要求輝度が通常輝度範囲内にあるときには、ＡＤＩＭ信号Ｓａｄｉｍのデューティ比を規定値に固定しつつ、要求輝度に応じたデューティ比の第１ＰＷＭ信号Ｓｐｗｍ１を生成する。通常輝度範囲内では要求輝度が高くなるほど、第１ＰＷＭ信号Ｓｐｗｍ１のオンデューティ比が高く設定される。 When the required brightness is within the normal brightness range, the dimming unit 71a fixes the duty ratio of the ADIM signal Sadim to a specified value and generates the first PWM signal Spwm1 having a duty ratio corresponding to the required brightness. Within the normal luminance range, the higher the required luminance is, the higher the on-duty ratio of the first PWM signal Spwm1 is set.
　調光部７１ａは、要求輝度が通常輝度範囲よりも低い範囲に設定される低輝度範囲内にあるときには、第１ＰＷＭ信号Ｓｐｗｍ１のデューティ比を下限値に固定しつつ、要求輝度に応じたデューティ比のＡＤＩＭ信号Ｓａｄｉｍを生成する。低輝度範囲内では要求輝度が高くなるほど、ＡＤＩＭ信号Ｓａｄｉｍのオンデューティ比が高く設定される。第１ＰＷＭ信号Ｓｐｗｍ１のデューティ比の下限値は、例えば、０．２％に設定されている。 When the required brightness is within the low brightness range set to be lower than the normal brightness range, the dimming unit 71a fixes the duty ratio of the first PWM signal Spwm1 to the lower limit and adjusts the duty ratio according to the required brightness. to generate the ADIM signal Sadim. Within the low luminance range, the higher the required luminance is, the higher the on-duty ratio of the ADIM signal Sadim is set. The lower limit of the duty ratio of the first PWM signal Spwm1 is set to 0.2%, for example.
　輝度異常判定部７１ｂは、マイコン７１から出力されるＡＤＩＭ信号Ｓａｄｉｍ、及びこのＡＤＩＭ信号Ｓａｄｉｍのフィードバック信号であるＡＤＩＭフィードバック信号Ｓｆｂに基づき、光源１８ａの輝度異常の有無を判定する。
　ＡＤＩＭ信号Ｓａｄｉｍは、図４（ａ）に示すように、周期的にオン時間Ｔｏｎ１にわたってオンするパルス波形からなる。ＡＤＩＭフィードバック信号Ｓｆｂは、理想的にはＡＤＩＭ信号Ｓａｄｉｍと同じ波形であるが、実際の生データでは、光源ドライバＩＣ７２のコンデンサ、抵抗及びスイッチ等の電子部品により、図４（ｂ）に示すように、ＡＤＩＭ信号Ｓａｄｉｍに対して波形がなまる。 Based on the ADIM signal Sadim output from the microcomputer 71 and the ADIM feedback signal Sfb, which is a feedback signal of the ADIM signal Sadim, the luminance abnormality determination unit 71b determines whether or not there is luminance abnormality in the light source 18a.
The ADIM signal Sadim, as shown in FIG. 4(a), has a pulse waveform that is periodically turned on for the on-time Ton1. The ADIM feedback signal Sfb ideally has the same waveform as the ADIM signal Sadim. , the waveform of the ADIM signal Sadim is rounded.
　輝度異常判定部７１ｂは、図４（ｂ）、（ｃ）に示すように、生データであるＡＤＩＭフィードバック信号Ｓｆｂがオン閾値ＴＨｏｎ以上となると、ＡＤＩＭフィードバック信号Ｓｆｂをオンと判定する。そして、生データであるＡＤＩＭフィードバック信号Ｓｆｂがオフ閾値ＴＨｏｆｆ以下となると、ＡＤＩＭフィードバック信号Ｓｆｂをオフと判定する。これにより、図４（ｃ）に示すように、ＡＤＩＭフィードバック信号Ｓｆｂが２値化される。
　なお、本例では、オン閾値ＴＨｏｎは、オフ閾値ＴＨｏｆｆと異なる値、すなわち、オフ閾値ＴＨｏｆｆよりも大きい値に設定されているが、これに限らず、オフ閾値ＴＨｏｆｆよりも小さい値に設定されてもよいし、オン閾値ＴＨｏｎとオフ閾値ＴＨｏｆｆが同一値に設定されていてもよい。 As shown in FIGS. 4B and 4C, when the ADIM feedback signal Sfb, which is raw data, becomes equal to or greater than the ON threshold value THon, the brightness abnormality determination unit 71b determines that the ADIM feedback signal Sfb is ON. Then, when the ADIM feedback signal Sfb, which is raw data, becomes equal to or lower than the OFF threshold value THoff, the ADIM feedback signal Sfb is determined to be OFF. As a result, the ADIM feedback signal Sfb is binarized as shown in FIG. 4(c).
In this example, the on-threshold THon is set to a value different from the off-threshold THoff, i.e., to a value larger than the off-threshold THoff. Alternatively, the on-threshold THon and the off-threshold THoff may be set to the same value.
　輝度異常判定部７１ｂは、図４（ａ）、（ｃ）に示すように、ＡＤＩＭ信号Ｓａｄｉｍのオン時間Ｔｏｎ１とＡＤＩＭフィードバック信号Ｓｆｂのオン時間Ｔｏｎ２の差分が予め設定される規定値Ｔｋ以下であるときには光源１８ａに輝度異常がないと判定する。調光部７１ａは、輝度異常判定部７１ｂにより光源１８ａに輝度異常がないと判定されると、光源１８ａの点灯制御を継続する。 As shown in FIGS. 4A and 4C, the luminance abnormality determination unit 71b determines that the difference between the on-time Ton1 of the ADIM signal Sadim and the on-time Ton2 of the ADIM feedback signal Sfb is equal to or less than a preset specified value Tk. Sometimes, it is determined that the light source 18a has no luminance abnormality. When the luminance abnormality determination unit 71b determines that the light source 18a has no luminance abnormality, the light control unit 71a continues lighting control of the light source 18a.
　一方、輝度異常判定部７１ｂは、図５（ａ）、（ｂ）及び図６（ａ）、（ｂ）に示すように、ＡＤＩＭ信号Ｓａｄｉｍのオン時間Ｔｏｎ１とＡＤＩＭフィードバック信号Ｓｆｂのオン時間Ｔｏｎ２の差分ΔＴが規定値Ｔｋ以上であるときには光源１８ａに輝度異常があると判定する。この輝度異常の原因としては、例えば、マイコン７１の故障、又は光源１８ａの故障等が考えられる。
　図５（ａ）、（ｂ）の例では、ＡＤＩＭフィードバック信号Ｓｆｂのオン時間Ｔｏｎ２がＡＤＩＭ信号Ｓａｄｉｍのオン時間Ｔｏｎ１よりも大きく、オン時間Ｔｏｎ１，Ｔｏｎ２の差分ΔＴが規定値Ｔｋ以上となる。
　図６（ａ）、（ｂ）の例では、ＡＤＩＭフィードバック信号Ｓｆｂのオン時間Ｔｏｎ２がＡＤＩＭ信号Ｓａｄｉｍのオン時間Ｔｏｎ１よりも小さく、オン時間Ｔｏｎ１，Ｔｏｎ２の差分ΔＴが規定値Ｔｋ以上となる。
　調光部７１ａは、輝度異常判定部７１ｂにより光源１８ａに輝度異常があると判定されると、後述するシャットダウン処理を実行する。 On the other hand, as shown in FIGS. 5(a) and 5(b) and FIGS. 6(a) and 6(b), the brightness abnormality determination unit 71b determines the ON time Ton1 of the ADIM signal Sadim and the ON time Ton2 of the ADIM feedback signal Sfb. When the difference ΔT is equal to or greater than the specified value Tk, it is determined that the light source 18a has an abnormality in brightness. Possible causes of this luminance abnormality are, for example, a failure of the microcomputer 71 or a failure of the light source 18a.
In the examples of FIGS. 5A and 5B, the on-time Ton2 of the ADIM feedback signal Sfb is longer than the on-time Ton1 of the ADIM signal Sadim, and the difference ΔT between the on-times Ton1 and Ton2 is equal to or greater than the specified value Tk.
In the examples of FIGS. 6A and 6B, the on-time Ton2 of the ADIM feedback signal Sfb is shorter than the on-time Ton1 of the ADIM signal Sadim, and the difference ΔT between the on-times Ton1 and Ton2 is greater than or equal to the specified value Tk.
When the luminance abnormality determination unit 71b determines that the light source 18a has abnormality in luminance, the light control unit 71a executes shutdown processing, which will be described later.
　次に、図７のフローチャートを参照しつつ、マイコン７１により実行される輝度異常判定処理について説明する。この輝度異常判定処理は、マイコン７１が光源１８ａを点灯制御している期間に繰り返し実行される。
　調光部７１ａは、光源１８ａが点灯されると、光源１８ａに輝度異常があるか否かを判定する（ステップＳ１０１）。調光部７１ａは、光源１８ａに輝度異常がないと判定すると（ステップＳ１０１；ＮＯ）、ステップＳ１０２～Ｓ１０４の処理を経ずに、この輝度異常判定処理を終了する。 Next, the brightness abnormality determination process executed by the microcomputer 71 will be described with reference to the flowchart of FIG. This luminance abnormality determination process is repeatedly executed while the microcomputer 71 controls the lighting of the light source 18a.
When the light source 18a is turned on, the dimming unit 71a determines whether or not the light source 18a has a luminance abnormality (step S101). When the light control unit 71a determines that there is no brightness abnormality in the light source 18a (step S101; NO), it ends this brightness abnormality determination process without going through the processes of steps S102 to S104.
　一方、調光部７１ａは、光源１８ａに輝度異常があると判定すると（ステップＳ１０１；ＹＥＳ）、ステップＳ１０２～Ｓ１０４に係るシャットダウン処理を実行する。詳しくは、調光部７１ａは、光源ドライバＩＣ７２へのイネーブル信号Ｓｅｎの出力を停止する（ステップＳ１０２）。次に、調光部７１ａは、光源ドライバＩＣ７２へのＡＤＩＭ信号Ｓａｄｉｍの出力を停止する（ステップＳ１０３）。次に、調光部７１ａは、制御信号Ｓｃを通じて、入力電圧切替回路７８をオフ状態とする（ステップＳ１０４）。このステップＳ１０２～Ｓ１０４により、それぞれ別個の３系統にて、光源１８ａが消灯されて、照明装置１８がシャットダウンされる。よって、より確実に、照明装置１８のシャットダウンが可能となる。これにより、例えば、光源１８ａの輝度が異常に高まり、運転者を眩惑することが抑制される。例えば、イネーブル信号ＳｅｎがＨｉレベルで固定されるように故障した場合には、上記ステップＳ１０２の処理では光源１８ａを消灯できないが、このようなケースでも、上記ステップＳ１０３，Ｓ１０４の処理により光源１８ａを消灯できる。
　また、表示制御部７１ｃは、照明装置１８のシャットダウン時に、表示器１４での表示を終了する。 On the other hand, when the light control unit 71a determines that the light source 18a has an abnormality in brightness (step S101; YES), it executes shutdown processing in steps S102 to S104. Specifically, the dimming unit 71a stops outputting the enable signal Sen to the light source driver IC 72 (step S102). Next, the dimming unit 71a stops outputting the ADIM signal Sadim to the light source driver IC 72 (step S103). Next, the dimming unit 71a turns off the input voltage switching circuit 78 through the control signal Sc (step S104). Through steps S102 to S104, the light sources 18a are turned off and the illumination device 18 is shut down in three separate systems. Therefore, it is possible to shut down the lighting device 18 more reliably. As a result, for example, the brightness of the light source 18a is abnormally increased, and it is suppressed that the driver is dazzled. For example, if there is a failure such that the enable signal Sen is fixed at the Hi level, the light source 18a cannot be turned off by the processing of step S102. You can turn off the light.
Further, the display control unit 71c ends the display on the display 14 when the lighting device 18 is shut down.
　（効果）
　以上、説明した一実施形態によれば、以下の効果を奏する。
　（１）ヘッドアップディスプレイ装置１００は、表示器１４と、表示器１４に光を出射するように点灯する光源１８ａと、光源１８ａを点灯させるドライバの一例である光源ドライバＩＣ７２と、光源電流Ｉｌｅｄを指令する点灯信号の一例であるＡＤＩＭ信号Ｓａｄｉｍを光源ドライバＩＣ７２に出力することにより、ＡＤＩＭ信号Ｓａｄｉｍにより指令された光源電流Ｉｌｅｄを光源１８ａに供給し、出力したＡＤＩＭ信号Ｓａｄｉｍを帰還点灯信号の一例であるＡＤＩＭフィードバック信号Ｓｆｂとして帰還入力するマイコン７１と、を備える。マイコン７１は、出力されたＡＤＩＭ信号Ｓａｄｉｍ及び入力されたＡＤＩＭフィードバック信号Ｓｆｂを比較することにより光源１８ａの輝度異常の有無を判定する輝度異常判定部７１ｂを備える。
　この構成によれば、ＡＤＩＭフィードバック信号Ｓｆｂを輝度異常の判定に用いることにより、光源電流Ｉｌｅｄ又は光源電圧を輝度異常の判定に用いる場合に比べて、より迅速に光源１８ａの輝度異常を判定することができる。また、ＡＤＩＭフィードバック信号Ｓｆｂを監視しても、光源電流Ｉｌｅｄ又は光源電圧に影響を及ぼさないため、光源電流Ｉｌｅｄへの影響を小さくする構成が不要となる。よって、より簡易な構成を実現できる。
　さらに、輝度異常の判定にあたって、電流検出用増幅器を用いる必要がなく、より簡易な構成を実現できる。 (effect)
According to the embodiment described above, the following effects are obtained.
(1) The head-up display device 100 includes a display 14, a light source 18a that lights so as to emit light to the display 14, a light source driver IC 72 that is an example of a driver that lights the light source 18a, and a light source current Iled. By outputting the ADIM signal Sadim, which is an example of a lighting signal to be instructed, to the light source driver IC 72, the light source current Iled commanded by the ADIM signal Sadim is supplied to the light source 18a, and the output ADIM signal Sadim is an example of a feedback lighting signal. and a microcomputer 71 that feeds back as an ADIM feedback signal Sfb. The microcomputer 71 includes a brightness abnormality determination section 71b that determines whether there is a brightness abnormality in the light source 18a by comparing the output ADIM signal Sadim and the input ADIM feedback signal Sfb.
According to this configuration, by using the ADIM feedback signal Sfb to determine the luminance abnormality, the luminance abnormality of the light source 18a can be determined more quickly than when the light source current Iled or the light source voltage is used to determine the luminance abnormality. can be done. Moreover, since monitoring the ADIM feedback signal Sfb does not affect the light source current Iled or the light source voltage, a configuration for reducing the effect on the light source current Iled is not required. Therefore, a simpler configuration can be realized.
Furthermore, it is not necessary to use a current detection amplifier in determining luminance abnormality, and a simpler configuration can be realized.
　（２）輝度異常判定部７１ｂは、ＡＤＩＭ信号Ｓａｄｉｍの第１オン時間の一例であるオン時間Ｔｏｎ１及びＡＤＩＭフィードバック信号Ｓｆｂの第２オン時間の一例であるオン時間Ｔｏｎ２を比較し、オン時間Ｔｏｎ１及びオン時間Ｔｏｎ２の差分ΔＴが予め設定される規定値Ｔｋ以上であるときに輝度異常があると判定する。マイコン７１は、輝度異常判定部７１ｂにより輝度異常があると判定されると、光源１８ａを消灯する。
　この構成によれば、ＡＤＩＭ信号Ｓａｄｉｍのオン時間Ｔｏｎ１及びＡＤＩＭフィードバック信号Ｓｆｂのオン時間Ｔｏｎ２を比較することにより、簡単に光源１８ａの輝度異常を判定することができる。
　また、輝度異常判定部７１ｂにより輝度異常があると判定されると、光源１８ａが消灯される。このため、光源１８ａの輝度が過度に高まること、ひいては、視認者１を眩惑することが抑制される。 (2) The luminance abnormality determining unit 71b compares the on-time Ton1, which is an example of the first on-time of the ADIM signal Sadim, and the on-time Ton2, which is an example of the second on-time of the ADIM feedback signal Sfb. When the difference ΔT of the on-time Ton2 is equal to or greater than a preset specified value Tk, it is determined that there is a luminance abnormality. The microcomputer 71 turns off the light source 18a when the luminance abnormality determination unit 71b determines that there is luminance abnormality.
According to this configuration, by comparing the on-time Ton1 of the ADIM signal Sadim and the on-time Ton2 of the ADIM feedback signal Sfb, it is possible to easily determine the luminance abnormality of the light source 18a.
Further, when the luminance abnormality determination unit 71b determines that there is luminance abnormality, the light source 18a is turned off. Therefore, excessive increase in luminance of the light source 18a and, in turn, dazzling the viewer 1 are suppressed.
　（３）光源１８ａは、ＬＥＤである。マイコン７１は、光源電流Ｉｌｅｄを指令するＡＤＩＭ信号（アナログ調光信号）ＳａｄｉｍをＡＤＩＭフィードバック信号Ｓｆｂとして帰還入力する。
　光源電流Ｉｌｅｄの変化は、光源１８ａの輝度に影響を及ぼしやすい。このため、光源電流Ｉｌｅｄを指令するＡＤＩＭ信号Ｓａｄｉｍを輝度異常の判定に用いることにより、輝度異常によって視認者１に与える違和感を抑制することができる。 (3) The light source 18a is an LED. The microcomputer 71 feeds back an ADIM signal (analog dimming signal) Sadim for commanding the light source current Iled as an ADIM feedback signal Sfb.
A change in the light source current Iled tends to affect the luminance of the light source 18a. Therefore, by using the ADIM signal Sadim for commanding the light source current Iled to determine the luminance abnormality, it is possible to suppress the discomfort given to the viewer 1 due to the luminance abnormality.
　（４）マイコン７１は、光源ドライバＩＣ７２の動作を許可するイネーブル信号Ｓｅｎの光源ドライバＩＣ７２への出力を停止する第１シャットダウン部と、光源ドライバＩＣ７２へのＡＤＩＭ信号Ｓａｄｉｍの出力を停止する第２シャットダウン部と、光源ドライバＩＣ７２への電源電圧Ｖｃの印加を停止する第３シャットダウン部と、を備える。マイコン７１は、輝度異常判定部７１ｂにより輝度異常があると判定されると、上記第１シャットダウン部、上記第２シャットダウン部及び上記第３シャットダウン部を順番に動作させて光源１８ａを消灯する。
　この構成によれば、輝度異常判定部７１ｂにより輝度異常があると判定された場合に、より確実に、光源１８ａを消灯することができる。 (4) The microcomputer 71 includes a first shutdown section that stops outputting the enable signal Sen that permits the operation of the light source driver IC 72 to the light source driver IC 72, and a second shutdown section that stops outputting the ADIM signal Sadim to the light source driver IC 72. and a third shutdown section for stopping the application of the power supply voltage Vc to the light source driver IC 72 . When the brightness abnormality determination section 71b determines that there is brightness abnormality, the microcomputer 71 sequentially operates the first shutdown section, the second shutdown section, and the third shutdown section to turn off the light source 18a.
With this configuration, the light source 18a can be turned off more reliably when the luminance abnormality determination unit 71b determines that there is luminance abnormality.
　なお、本発明は以上の実施形態及び図面によって限定されるものではない。本発明の要旨を変更しない範囲で、適宜、変更（構成要素の削除も含む）を加えることが可能である。以下に、変形の一例を説明する。 The present invention is not limited by the above embodiments and drawings. Modifications (including deletion of components) can be made as appropriate without changing the gist of the present invention. An example of modification will be described below.
　（変形例）
　上記実施形態のシャットダウン処理においては、ステップＳ１０２→ステップＳ１０３→ステップＳ１０４の順番で処理が実行されていたが、この順番は適宜変更可能である。また、ステップＳ１０２～Ｓ１０４は同時に実行されてもよい。
　さらに、３つのステップＳ１０２～Ｓ１０４のうち何れか２つが省略されてもよい。
　また、シャットダウン処理として第１ＰＷＭ信号Ｓｐｗｍ１の出力を停止してもよい。
　また、ＡＤＩＭフィードバック信号Ｓｆｂは、光源ドライバＩＣ７２を通った信号であってもよい。 (Modification)
In the shutdown processing of the above embodiment, the processing was executed in the order of step S102→step S103→step S104, but this order can be changed as appropriate. Also, steps S102 to S104 may be performed simultaneously.
Furthermore, any two of the three steps S102 to S104 may be omitted.
In addition, the output of the first PWM signal Spwm1 may be stopped as shutdown processing.
Also, the ADIM feedback signal Sfb may be a signal that has passed through the light source driver IC 72 .
　上記実施形態において、表示制御部７１ｃは、輝度異常判定部７１ｂにより光源１８ａに輝度異常があると判定されると、表示器１４を非透過状態（黒表示状態）に切り替えてもよい。これにより、虚像Ｖを視認する視認者１を眩惑することが抑制される。 In the above embodiment, the display control unit 71c may switch the display 14 to the non-transmissive state (black display state) when the luminance abnormality determination unit 71b determines that the light source 18a has abnormality in luminance. As a result, dazzling the viewer 1 viewing the virtual image V is suppressed.
　上記実施形態においては、点灯信号はＡＤＩＭ信号Ｓａｄｉｍであり、帰還点灯信号はＡＤＩＭフィードバック信号Ｓｆｂであったが、これに限らず、点灯信号は第１ＰＷＭ信号Ｓｐｗｍ１であり、帰還点灯信号は検出信号Ｓｏｎであってもよい。 In the above embodiment, the lighting signal is the ADIM signal Sadim and the feedback lighting signal is the ADIM feedback signal Sfb. may be
　上記実施形態においては、表示器１４は、液晶表示パネルであったが、これに限らず、ＤＭＤ（Digital Micro mirror Device）素子等の反射型表示器であってもよい。 In the above embodiment, the display 14 was a liquid crystal display panel, but it is not limited to this, and may be a reflective display such as a DMD (Digital Micromirror Device) element.
　上記実施形態において、マイコン７１は、光源１８ａに輝度異常があると判定すると（ステップＳ１０１；ＹＥＳ）、複数の光源１８ａを消灯していたが、複数の光源１８ａを消灯せずに、輝度異常がある旨をインジケータ等の通知手段を通じて視認者１に通知してもよい。 In the above embodiment, when the microcomputer 71 determines that the light source 18a has a luminance abnormality (step S101; YES), the plurality of light sources 18a is turned off. The presence may be notified to the viewer 1 through notification means such as an indicator.
　上記実施形態においては、ヘッドアップディスプレイ装置１００は車両２００に搭載されていたが、車両２００以外の飛行機、船等の乗り物に搭載されていてもよい。また、被投射部材はフロントガラス２０１に限らず、専用のコンバイナであってもよい。 Although the head-up display device 100 is mounted on the vehicle 200 in the above embodiment, it may be mounted on a vehicle other than the vehicle 200, such as an airplane or a ship. Further, the projected member is not limited to the windshield 201, and may be a dedicated combiner.
１　視認者１０　表示部１４　表示器１８　照明装置１８ａ　光源２０　平面鏡３０　凹面鏡５０　窓部６０　筐体６１　開口部７０　制御部７１　マイコン７１ａ　調光部７１ｂ　判定部７１ｃ　表示制御部７２　光源ドライバＩＣ７３　信号調整回路７８　入力電圧切替回路１００　ヘッドアップディスプレイ装置２００　車両２０１　フロントガラスＬ　表示光ΔＴ　差分Ｖ　虚像Ｓａ　要求輝度信号Ｓｃ　制御信号Ｖｃ　電源電圧Ｔｋ　規定値Ｓｆｂ　ＡＤＩＭフィードバック信号Ｓｅｎ　イネーブル信号Ｓｏｎ　検出信号Ｔｏｎ１，Ｔｏｎ２　オン時間Ｉｌｅｄ　光源電流ＴＨｏｎ　オン閾値ＴＨｏｆｆ　オフ閾値Ｓｐｗｍ１　第１ＰＷＭ信号Ｓｐｗｍ２　第２ＰＷＭ信号Ｓａｄｉｍ　ＡＤＩＭ信号 1 Viewer 10 Display unit 14 Display unit 18 Lighting device 18a Light source 20 Plane mirror 30 Concave mirror 50 Window 60 Housing 61 Opening 70 Control unit 71 Microcomputer 71a Dimming unit 71b Judging unit 71c Display control unit 72 Light source driver IC 73 Signal adjustment circuit 78 Input voltage switching circuit 100 Head-up display device 200 Vehicle 201 Windshield L Display light ΔT Difference V Virtual image Sa Required luminance signal Sc Control signal Vc Power supply voltage Tk Specified value Sfb ADIM feedback signal Sen Enable signal Son Detection signals Ton1, Ton2 ON time Iled 　Light source current THon 　On threshold THoff 　Off threshold Spwm1 　First PWM signal Spwm2 　Second PWM signal Sadim 　ADIM signal

Claims (4)

  1. 　表示器と、
    　前記表示器に光を出射するように点灯する光源と、
    　前記光源を点灯させるドライバと、
    　光源電流又は光源電圧を指令する点灯信号を前記ドライバに出力することにより、前記点灯信号により指令された前記光源電流又は前記光源電圧を前記光源に供給し、出力した前記点灯信号を帰還点灯信号として帰還入力するマイコンと、を備え、
    　前記マイコンは、出力された前記点灯信号及び入力された前記帰還点灯信号を比較することにより前記光源の輝度異常の有無を判定する輝度異常判定部を備える、
    　ヘッドアップディスプレイ装置。     a display;
    a light source that lights so as to emit light to the indicator;
    a driver for lighting the light source;
    By outputting a lighting signal instructing a light source current or a light source voltage to the driver, the light source current or the light source voltage commanded by the lighting signal is supplied to the light source, and the output lighting signal is used as a feedback lighting signal. and a microcomputer for feedback input,
    The microcomputer includes a luminance abnormality determination unit that determines whether or not there is luminance abnormality in the light source by comparing the output lighting signal and the input feedback lighting signal.
    Head-up display device.
  2. 　前記輝度異常判定部は、前記点灯信号の第１オン時間及び前記帰還点灯信号の第２オン時間を比較し、前記第１オン時間及び前記第２オン時間の差分が予め設定される規定値以上であるときに輝度異常があると判定し、
    　前記マイコンは、前記輝度異常判定部により輝度異常があると判定されると、前記光源を消灯する、
    　請求項１に記載のヘッドアップディスプレイ装置。     The luminance abnormality determination section compares a first on-time of the lighting signal and a second on-time of the feedback lighting signal, and determines that a difference between the first on-time and the second on-time is equal to or greater than a preset specified value. It is determined that there is luminance abnormality when
    The microcomputer turns off the light source when the luminance abnormality determination unit determines that there is luminance abnormality.
    The head-up display device according to claim 1.
  3. 　前記光源は、ＬＥＤであり、
    　前記マイコンは、前記光源電流を指令する前記点灯信号であるアナログ調光信号を前記帰還点灯信号として帰還入力する、
    　請求項１又は２に記載のヘッドアップディスプレイ装置。     the light source is an LED,
    The microcomputer feedback-inputs the analog dimming signal, which is the lighting signal for commanding the light source current, as the feedback lighting signal.
    The head-up display device according to claim 1 or 2.
  4. 　前記マイコンは、
    　前記ドライバの動作を許可するイネーブル信号の前記ドライバへの出力を停止する第１シャットダウン部と、
    　前記ドライバへの前記点灯信号の出力を停止する第２シャットダウン部と、
    　前記ドライバへの電源電圧の印加を停止する第３シャットダウン部と、を備え、
    　前記マイコンは、前記輝度異常判定部により輝度異常があると判定されると、前記第１シャットダウン部、前記第２シャットダウン部及び前記第３シャットダウン部のうち何れか２以上を順番又は同時に動作させる、
    　請求項１に記載のヘッドアップディスプレイ装置。     The microcomputer
    a first shutdown unit that stops outputting an enable signal that permits operation of the driver to the driver;
    a second shutdown unit that stops outputting the lighting signal to the driver;
    A third shutdown unit that stops applying the power supply voltage to the driver,
    The microcomputer causes any two or more of the first shutdown section, the second shutdown section, and the third shutdown section to operate sequentially or simultaneously when the luminance abnormality determination section determines that there is luminance abnormality.
    The head-up display device according to claim 1.
PCT/JP2023/002573 2022-01-31 2023-01-27 Head-up display device WO2023145854A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018018774A (en) * 2016-07-29 2018-02-01 株式会社小糸製作所 Lightning circuit and lamp fitting for vehicle
WO2020003559A1 (en) * 2018-06-29 2020-01-02 ローム株式会社 Light-emitting element drive device
WO2020235683A1 (en) * 2019-05-23 2020-11-26 日本精機株式会社 Head-up display device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018018774A (en) * 2016-07-29 2018-02-01 株式会社小糸製作所 Lightning circuit and lamp fitting for vehicle
WO2020003559A1 (en) * 2018-06-29 2020-01-02 ローム株式会社 Light-emitting element drive device
WO2020235683A1 (en) * 2019-05-23 2020-11-26 日本精機株式会社 Head-up display device

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