On-board lighting device

Abstract

To provide an on-board lighting device that can secure visibility irrespective of brightness around a vehicle and is suppressed in making an occupant uncomfortable.SOLUTION: An on-board lighting device to be mounted to a vehicle includes: a light source unit 20 configured to be capable of emitting first light having a main wavelength within a range of 480 nm or more and 600 nm or less and second light that is white light; and a control unit 40 for controlling the light source unit 20. The control unit 40 controls the light source unit 20 so as to emit first light when brightness around the vehicle is larger than a reference value and emit second light when the brightness is equal to or smaller than the reference value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an in-vehicle lighting device. [Background technology]

[0002] An example of this type of in-vehicle lighting device is a vehicle lamp unit described in Patent Document 1. The lamp unit described in Patent Document 1 displays signs on the vehicle exterior panels or road surface by irradiating the exterior panels or road surface with visible light. The light source of this lamp unit emits visible light with a wavelength of 360 nm to 830 nm, more preferably 500 nm to 570 nm. Illuminating the exterior panels or road surface with visible light of this wavelength improves visibility, especially during the daytime. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-13722 Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, luminosity, which is the degree of brightness perceived by the human eye, differs between photopic vision during the day and scotopic vision at night. However, in the device described in Patent Document 1, the dominant wavelength of the light source is set to match daytime visibility. Therefore, although excellent daytime visibility is ensured, nighttime visibility may be impaired. [Means for solving the problem]

[0005] Various aspects of an in-vehicle lighting device for solving the above problems will be described. [Aspect 1] An in-vehicle lighting device mounted on a vehicle, a light source unit configured to emit a first light having a dominant wavelength in the range of 480 nm or more and 600 nm or less, and a second light which is white light; a control unit that controls the light source unit, the control unit controls the light source unit to emit the first light when the brightness of the surroundings of the vehicle is greater than a reference value, and to emit the second light when the brightness is equal to or less than the reference value. In-vehicle lighting equipment.

[0006] According to this configuration, when the brightness of the surroundings of the vehicle is greater than a reference value, the first light is emitted. The dominant wavelength of the first light is in the range of 480 nm to 600 nm, and the first light is light close to green. Therefore, the first light has high photopic luminosity, ensuring visibility when the surroundings of the vehicle are bright.

[0007] Incidentally, for example, light close to blue has high scotopic luminosity, but is likely to cause discomfort to the occupants, people around the vehicle, and occupants of other vehicles around the vehicle. In this regard, according to the above configuration, when the brightness around the vehicle is equal to or lower than a reference value, the second light, which is white light, is emitted, thereby ensuring visibility when the vehicle is dark and reducing discomfort to the occupants.

[0008] Therefore, visibility can be ensured regardless of the brightness around the vehicle, and discomfort to the occupants can be reduced. [Aspect 2] The light source unit includes a light source configured to be able to emit the first light and a light source configured to be able to emit the second light, 2. The vehicle-mounted lighting device according to claim 1.

[0009] According to this configuration, the light source that emits the first light and the light source that emits the second light are separate, so that the configuration of each light source can be simplified. [Aspect 3] the light source unit includes a light source having at least three types of light-emitting elements that emit visible light having different dominant wavelengths, the control unit controls a voltage applied to each of the light-emitting elements to selectively emit the first light and the second light from the light source. 2. The vehicle-mounted lighting device according to claim 1.

[0010] According to this configuration, the first light and the second light can be selectively emitted by controlling the voltages applied to the at least three types of light-emitting elements that make up the light source, thereby reducing the number of light sources.

[0011] [Aspect 4] the light source unit includes a light source configured to be able to emit the second light, and a light source configured to be able to emit third light, which is visible light having a dominant wavelength shorter than the dominant wavelength of the first light, the control unit controls the light source unit to emit the second light and the third light when the brightness is equal to or less than the reference value. The in-vehicle lighting device according to any one of the first to third aspects.

[0012] According to this configuration, when the brightness around the vehicle is equal to or lower than a reference value, the second light, which is white light, and the third light, which is visible light with a dominant wavelength shorter than that of the first light, are emitted. This makes it possible to project and display characters, figures, etc., using light close to blue on a background illuminated with white light, for example. This increases the flexibility of the lighting configuration and improves contrast, thereby improving visibility. Furthermore, compared to emitting only the third light close to blue, the amount of third light can be reduced, thereby minimizing discomfort to occupants.

[0013] [Aspect 5] The vehicle is equipped with a sensor that detects the brightness, The control unit controls the light source unit based on the brightness detected by the sensor. The in-vehicle lighting device according to any one of the first to fourth aspects.

[0014] According to this configuration, the light source unit is controlled based on the brightness detected by the sensor mounted on the vehicle, so that the brightness around the vehicle can be detected with high accuracy, and visibility can be ensured accurately regardless of the brightness around the vehicle through the control of the light source unit by the control unit. [Effects of the Invention]

[0015] According to the present invention, visibility can be ensured regardless of the brightness around the vehicle, and discomfort to the occupants can be suppressed. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a block diagram showing the electrical configuration of a first embodiment of an in-vehicle lighting device. [Figure 2] FIG. 2 is a front view showing a light-emitting emblem in the in-vehicle lighting device of the first embodiment. [Figure 3] FIG. 3 is a flowchart showing the processing procedure of the light source unit control processing according to the first embodiment. [Figure 4] FIG. 4 is a graph showing the relationship between the wavelength of light and the photopic luminosity and scotopic luminosity. [Figure 5] FIG. 5 is a block diagram showing the electrical configuration of the in-vehicle lighting device according to the second embodiment. [Figure 6] FIG. 6 is a perspective view showing the periphery of an instrument panel of a vehicle equipped with an in-vehicle lighting device according to the second embodiment. [Figure 7] FIG. 7 is an exploded perspective view of the in-vehicle lighting device according to the second embodiment. [Figure 8] FIG. 8 is a block diagram showing the electrical configuration of the in-vehicle lighting device according to the third embodiment. [Figure 9] FIG. 9 is a diagram schematically showing the emission ranges of the first light source, the second light source, and the third light source of the in-vehicle lighting device according to the third embodiment. [Figure 10]FIG. 10 is a diagram showing a rendering mode using light emitted from the second light source and the third light source in the third embodiment. [Figure 11] FIG. 11 is a plan view showing a modified example of the light-emitting emblem. DETAILED DESCRIPTION OF THE INVENTION

[0017] First Embodiment Hereinafter, a first embodiment of an in-vehicle lighting device will be described with reference to FIGS. As shown in FIG. 1, the in-vehicle lighting device 1 includes a light source unit 20, a sensor 30, and a control unit 40 that controls the light source unit 20.

[0018] <Light source unit 20> 1, the light source unit 20 is configured to emit a first light having a dominant wavelength in the range of 480 nm to 600 nm, and a second light which is white light. The dominant wavelength of the first light is more preferably in the range of 490 nm to 560 nm. In this embodiment, the dominant wavelength of the first light is, for example, 550 nm.

[0019] The light source unit 20 of this embodiment includes a first light source 21 configured to be able to emit a first light, and a second light source 22 configured to be able to emit a second light. The first light source 21 includes a light emitting diode (LED) that emits green light when a predetermined voltage is applied thereto.

[0020] The second light source 22 is a well-known light source that includes a light emitting diode that emits blue light when a predetermined voltage is applied, and a yellow phosphor. As shown in FIG. 2, the light source unit 20 of this embodiment constitutes a light-emitting emblem 10 that is attached to an exterior panel of a vehicle.

[0021] The luminous emblem 10 includes an emblem body 11 made of synthetic resin that is transparent to visible light. The light source unit 20 is attached to the emblem body 11. The light source unit 20 of this embodiment includes a plurality of first light sources 21 and a plurality of second light sources 22. The first light sources 21 and the second light sources 22 are arranged alternately.

[0022] <Sensor 30 and Control Unit 40> 1, the vehicle is equipped with a sensor 30 that detects the brightness. The sensor 30 is, for example, an illuminance sensor configured with a phototransistor having a photodiode and a transistor.

[0023] The sensor 30 of this embodiment is used for controlling automatic switching of the headlamps of a vehicle between on and off. The control unit 40 controls the light source unit 20 to emit the first light when the brightness around the vehicle is greater than a reference value, and to emit the second light when the brightness is equal to or less than the reference value.

[0024] The sensor 30 is electrically connected to the control unit 40. The control unit 40 controls the light source unit 20 based on the brightness detected by the sensor 30. Next, the processing procedure of the control processing of the light source unit 20 executed by the control unit 40 will be described with reference to the flowchart shown in Fig. 3. This control processing is repeatedly executed by the control unit 40 at predetermined time intervals while the light emission conditions of the light emitting emblem 10 are met. Note that the light emission conditions of the light emitting emblem 10 may be met, for example, when the ignition switch of the vehicle is turned on.

[0025] As shown in FIG. 3, when this control process is started, the control unit 40 first reads the brightness of the surroundings of the vehicle detected by the sensor 30 in step S1. Next, in step S2, the control unit 40 determines whether it is daytime. More specifically, the control unit 40 determines whether the brightness detected by the sensor 30 is greater than the reference value (1000 lx). If the determination condition in step S2 is met, the control unit 40 determines that it is daytime and proceeds to step S3. In step S3, the control unit 40 applies a predetermined voltage only to the first light source 21, thereby turning on the first light source 21. Then, this series of processes ends for the time being.

[0026] On the other hand, if the determination condition of step S2 is not satisfied, the control unit 40 determines that it is nighttime and proceeds to step S4. In step S4, the control unit 40 applies a predetermined voltage only to the second light source 22, thereby turning on the second light source 22. Then, this series of processes ends for the time being.

[0027] When the light emitting conditions of the light emitting emblem 10 are no longer met, the application of voltage to the first light source 21 or the second light source 22 is stopped, and the control process is terminated. <Operation of this embodiment> As shown in Figure 4, luminosity, which is the degree of brightness perceived by the human eye, differs between daytime (photopic vision) and nighttime (scotopic vision) (see JIS Z 8785:2019). Specifically, the luminosity perceived by humans during the day (hereinafter referred to as photopic luminosity) has a peak at a wavelength near 555 nm, as shown by the solid line in Figure 4. Furthermore, the luminosity perceived by humans at night (hereinafter referred to as scotopic luminosity) has a peak at a wavelength near 507 nm, which is shorter than the photopic luminosity, as shown by the dashed line in Figure 4.

[0028] In this embodiment, when the brightness of the surroundings of the vehicle is greater than a reference value, the first light is emitted. The dominant wavelength of the first light is in the range of 480 nm to 600 nm, and the first light is light close to green. Therefore, the first light has high photopic luminosity, ensuring visibility when the surroundings of the vehicle are bright.

[0029] Incidentally, for example, light close to blue has high scotopic luminosity, but is likely to cause discomfort to the occupants, people around the vehicle, and occupants of other vehicles around the vehicle. In this regard, according to this embodiment, when the brightness around the vehicle is equal to or lower than a reference value, the second light, which is white light, is emitted, thereby ensuring visibility when the vehicle is in a dark environment while minimizing discomfort to the occupants.

[0030] <Effects of this embodiment> (1) Because of the above-mentioned effects, visibility can be ensured regardless of the brightness around the vehicle, and discomfort to the occupants can be suppressed.

[0031] (2) Since the first light source 21 that emits the first light and the second light source 22 that emits the second light are separate, the configuration of each of the light sources 21 and 22 can be simplified. (3) The light source unit 20 is controlled based on the brightness detected by the sensor 30 mounted on the vehicle. Therefore, the brightness around the vehicle can be detected with high accuracy, and through the control of the light source unit 20 by the control unit 40, visibility can be ensured accurately regardless of the brightness around the vehicle.

[0032] Second Embodiment Hereinafter, the second embodiment of the in-vehicle lighting device will be described with reference to FIGS. 5 to 7, focusing on the differences from the first embodiment.

[0033] <Light source unit 20> As shown in FIG. 5, the light source unit 20 includes a light source 24 having three types of light emitting diodes 24G, 24G, and 24B that emit visible light having different dominant wavelengths.

[0034] The light emitting diode 24R emits red light when a predetermined voltage is applied to it. The light emitting diode 24G emits green light when a predetermined voltage is applied to it. The light emitting diode 24B emits blue light when a predetermined voltage is applied to it. The light emitting diodes 24G, 24G, and 24B correspond to light emitting elements.

[0035] As shown in FIGS. 6 and 7, the vehicle-mounted lighting device 1 of this embodiment is provided on an instrument panel 50 inside the vehicle compartment. The instrument panel 50 includes an upper panel 51 located in front of a passenger seat 54 and a lower panel 52 disposed below the upper panel 51.

[0036] Between the upper panel 51 and the lower panel 52, a space 53 is provided that opens toward a passenger seat 54 and extends in the vehicle width direction. As shown in FIG. 7, the in-vehicle lighting device 1 is disposed in the space 53, and includes a pair of light source units 20, a light guide 25, an outer lens 26, and a housing 27.

[0037] The light guide 25 is rod-shaped and extends in the vehicle width direction, takes in the light emitted from the light source unit 20, propagates the light inside, and emits the light toward the passenger seat 54. The outer lens 26 is made of a resin material that is transparent to visible light, and transmits the light emitted from the light guide 25 .

[0038] The housing 27 is elongated and extends in the vehicle width direction, accommodates the light guide 25, and is open toward the rear. The housing 27 is made of a resin material that is not transparent to visible light.

[0039] The light source units 20 are fixed to both ends of the housing 27. The housing 27 also has an outer lens 26 fixed thereto. <Control unit 40> As shown in FIG. 5, the control unit 40 controls the voltages applied to the light emitting diodes 24R, 24G, and 24B, respectively, to cause the light source 24 to selectively emit the first light and the second light.

[0040] When the brightness of the surroundings of the vehicle is greater than a reference value, the control unit 40 applies a voltage to the light-emitting diode 24G to emit the first light, and when the brightness is equal to or less than the reference value, the control unit 40 controls the light source unit 20 to apply a voltage to the light-emitting diodes 24R, 24G, and 24B to emit the second light, i.e., white light.

[0041] <Actions and Effects of This Embodiment> (4) The first light and the second light can be selectively emitted by controlling the voltage applied to each of the at least three types of light-emitting diodes 24R, 24G, and 24B that constitute the light source 24. Therefore, the number of light sources 24 can be reduced.

[0042] Third Embodiment Hereinafter, the third embodiment of the in-vehicle lighting device will be described with reference to FIGS. 8 to 10, focusing on the differences from the first embodiment.

[0043] <Light source unit 20> As shown in Fig. 8, the device includes a first light source 21 configured to emit a first light, a second light source 22 configured to emit a second light, and a third light source 23 configured to emit a third light, which is visible light having a dominant wavelength shorter than that of the first light. The dominant wavelength of the third light is in the range of 450 nm to 530 nm. More preferably, the dominant wavelength of the third light is in the range of 480 nm to 530 nm. In this embodiment, the dominant wavelength of the third light is, for example, 500 nm.

[0044] 9, the first light source 21, the second light source 22, and the third light source 23 are configured to emit light toward a common predetermined location S. The predetermined location S may be, for example, a road surface or an outer panel of a vehicle.

[0045] The in-vehicle lighting device 1 includes a filter (not shown) on the optical path of the third light source 23. The filter has a mask portion having a shape corresponding to a character 62 (see FIG. 10), a figure, or the like to be projected onto the predetermined location S.

[0046] The control unit 40 controls the light source unit 20 to emit the first light when the brightness around the vehicle is greater than a reference value, and to emit the second light and the third light when the brightness is equal to or less than the reference value.

[0047] <Actions and Effects of This Embodiment> (5) When the brightness around the vehicle is equal to or lower than a reference value, the second light, which is white light, and the third light, which is visible light with a dominant wavelength shorter than that of the first light, are emitted. Therefore, as shown in FIG. 10, it is possible to project and display characters 62 or figures using light that is close to blue on a background 61 illuminated with white light, for example. This increases the degree of freedom in the lighting configuration and improves contrast, thereby improving visibility. Furthermore, compared to emitting only the third light that is close to blue, it is possible to reduce the amount of third light, thereby reducing discomfort to occupants.

[0048] <Modification> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0049] As shown in FIG. 11, a plurality of first light sources 21 may be arranged in a row adjacent to one another, and a plurality of second light sources 22 may be arranged in a row adjacent to one another. In the second embodiment, one of the light source units 20 may be omitted.

[0050] In the third embodiment, the light source 24 of the second embodiment can be used instead of the first light source 21 and the second light source 22. In this case, the light source 24 can selectively emit the first light and the second light. Furthermore, the light source 24 can be used instead of the third light source 23. That is, the light source unit 20 may include two light sources 24. In this case, by controlling the voltages applied to the light-emitting diodes 24R, 24G, and 24B that constitute the two light sources 24, it is possible to generate a variety of colors. Furthermore, the number of types of light sources 24 can be reduced.

[0051] In the second embodiment, three types of light emitting elements may be included in one LED package. In the above embodiments, the brightness around the vehicle is detected by the sensor 30 mounted on the vehicle. However, the brightness around the vehicle may be estimated based on date and time information, vehicle position information, etc.

[0052] In the above embodiments, the light source unit 20 and the control unit 40 are configured separately, but they may also be embodied as a unit in which the light source (LED) and the control unit are integrally provided on an LED circuit board, for example. [Explanation of symbols]

[0053] 1…In-vehicle lighting device 10...Emblem 11...Emblem body 20...Light source unit 21...1st light source 22…Second light source 23…Third light source 24…Light source 24R, 24G, 24B...Light-emitting diodes 25...Light guide 26...Outer lens 27…Housing 30...Sensor 40...Control unit 50...Instrument panel 51...Upper panel 52...Lower panel 53…Space 54…Passenger seat 61…Background 62...characters

Claims

1. An in-vehicle lighting device mounted on a vehicle, a light source unit configured to emit a first light having a dominant wavelength in the range of 480 nm to 600 nm and a second light which is white light; a control unit that controls the light source unit, the control unit controls the light source unit to emit the first light when the brightness of the surroundings of the vehicle is greater than a reference value, and to emit the second light when the brightness is equal to or less than the reference value. In-vehicle lighting equipment.

2. The light source unit includes a light source configured to be able to emit the first light and a light source configured to be able to emit the second light, The vehicle-mounted lighting device according to claim 1 .

3. the light source unit includes a light source having at least three types of light-emitting elements that emit visible light having different dominant wavelengths, the control unit controls a voltage applied to each of the light-emitting elements to selectively emit the first light and the second light from the light source. The vehicle-mounted lighting device according to claim 1 .

4. the light source unit includes a light source configured to be able to emit the second light, and a light source configured to be able to emit third light, which is visible light having a dominant wavelength shorter than the dominant wavelength of the first light, the control unit controls the light source unit to emit the second light and the third light when the brightness is equal to or less than the reference value. The vehicle-mounted lighting device according to any one of claims 1 to 3.

5. The vehicle is equipped with a sensor that detects the brightness, The control unit is configured to control the light source unit based on the brightness detected by the sensor. The vehicle-mounted lighting device according to claim 1 .

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