JP6690664B2 - Lighting equipment - Google Patents

Description

The present disclosure relates to lighting equipment.

  BACKGROUND ART Conventionally, there is known an illuminating device that is mounted on a vehicle and emits illuminating light for capturing an image of an occupant of the vehicle. The illumination device disclosed in Patent Document 1 has a plurality of infrared projectors. Each infrared projector is an LED lamp that emits illumination light as near-infrared light including light having a wavelength in the upper limit of visible light in the form of a point light source in the vicinity of the light emitting portion.

Japanese Patent No. 4640404

  Here, the light of the upper limit wavelength of visible light (780 to 830 nm) included in the near-infrared light has low sensitivity, but can be sensed by being visually recognized by an occupant. Since the infrared projector of Patent Document 1 emits near-infrared light including light having a wavelength of the upper limit of visible light toward the occupant in a point light source shape, the unit of the upper limit of visible light is Luminous intensity per area becomes large and the light is easily perceived by an occupant. Therefore, it has been feared that the light of the upper limit wavelength of visible light may be perceived to impair the appearance of the illuminating device and give a passenger a complicated impression.

The purpose of the one disclosed is to provide a lighting equipment which suppresses complicated impression.

One of the aspects disclosed herein is an illumination device (20, 220) mounted on a vehicle and emitting illumination light for capturing an image of an occupant of the vehicle,
And a surface emitting section (21, 221) for planarly emitting illumination light as near-infrared light including light having a wavelength of the upper limit of visible light,
The surface emitting part is such that at the maximum point (MP) where the luminous intensity of the illuminating light per unit area is the maximum, the luminosity of the illuminating light per unit area is independent of the light of the upper visible wavelength of the occupant. It is set so as to be smaller than the sensing limit value (CV), which is the lower limit value that can be sensed ,
A cover part (30, 230) that covers the surface emitting part and transmits the illumination light;
Cover part, the external light that is incident from the opposite side of the surface emitting part to the cover part, that having a reflective structure that reflects on the opposite side (231) is again surface emitting part.
Further, another one of the disclosed aspects is an illumination device (20, 220) mounted on a vehicle and emitting illumination light for capturing an image of an occupant of the vehicle,
And a surface emitting section (21, 221) for planarly emitting illumination light as near-infrared light including light having a wavelength of the upper limit of visible light,
The surface emitting part is such that at the maximum point (MP) where the luminous intensity of the illuminating light per unit area is the maximum, the luminosity of the illuminating light per unit area is independent of the light of the upper visible wavelength of the occupant. It is set so as to be smaller than the sensing limit value (CV), which is the lower limit value that can be sensed,
A cover part (30, 230) that covers the surface emitting part and transmits the illumination light;
The cover part has a reflection structure part (231) that reflects external light incident on the cover part from the side opposite to the surface light emitting part to the side opposite to the surface light emitting part again.
The surface emitting part is
A near-infrared light emitting element (222) that emits near-infrared light including the upper wavelength of visible light;
A visible light emitting element (226) that emits visible mixed light as visible light;
A surface-emitting optical element that mixes the near-infrared light, which includes light with an upper limit wavelength of visible light emitted from the near-infrared light emitting element, with the visible mixed light emitted from the visible light-emitting element to make it surface-emission (223),
A visible light emission amount changing unit (236) that changes the amount of light emitted by the visible light emitting element so that the amount of light emitted by the visible light emitting element increases as the amount of ambient light decreases.

  According to such an illuminating device, the surface emitting section is configured to emit illumination light as near-infrared light including light having an upper limit wavelength of visible light in a planar manner, so that the emission is dispersed in a planar manner. By doing so, the luminous intensity per unit area can be reduced. Then, even at the maximum location where the luminous intensity per unit area is maximum in the surface emitting portion, the emitted light is dispersed so that the luminous intensity per unit area becomes smaller than the sensing limit value. Therefore, when the occupant looks at the surface emitting part, it becomes difficult to perceive the light of the upper limit wavelength of visible light as an independent light, so it is possible to suppress giving the occupant a complicated impression. Is done.

  It should be noted that the reference numerals in parentheses are illustrative of correspondences with parts of the embodiments described later, and are not intended to limit the technical scope.

It is a front view of the display device for vehicles in a 1st embodiment. It is sectional drawing which shows the pointer etc. in the display apparatus for vehicles of 1st Embodiment. 1 is a block diagram showing a vehicle display device, an imaging system, an imaging device, and a lighting device of a first embodiment. It is sectional drawing which shows the imaging device of 1st Embodiment. It is a figure for demonstrating the illuminating device of 1st Embodiment, Comprising: The cross section of an illuminating device is shown on the left side, and the distribution of illumination light is typically shown on the right side. It is a figure for demonstrating the illuminating device of a comparative example, Comprising: The cross section of an illuminating device is shown on the left side, and the distribution of illumination light is typically shown on the right side. It is a front view of the display device for vehicles in a 2nd embodiment. It is a block diagram which shows the display apparatus for vehicles of 2nd Embodiment, an imaging system, an imaging device, and an illuminating device. It is sectional drawing which shows the illuminating device of 2nd Embodiment, and has shown the case where the surrounding brightness is sufficiently bright. It is sectional drawing which shows the illuminating device of 2nd Embodiment, and has shown the case where the surrounding brightness is dark. It is a flow chart by the visible light emission amount changing unit of the second embodiment. FIG. 9 is a spectrum distribution diagram for explaining one example of Modification 1, showing a case of illumination light of point emission in the comparative example of FIG. 6 in the case where yellow-green light does not exist in the vicinity. FIG. 9 is a spectrum distribution diagram for explaining one example of Modification Example 1, showing a case of plane emission illumination light when yellow-green light does not exist in the vicinity. FIG. 9 is a spectrum distribution diagram for explaining one example of Modification 1, showing a case of illumination light of planar emission when yellow-green light is present in the vicinity. It is sectional drawing which shows the illuminating device of the modification 3.

  Hereinafter, a plurality of embodiments will be described with reference to the drawings. It should be noted that, in each of the embodiments, the corresponding components may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each embodiment, the configurations of the other embodiments described above can be applied to the other part of the configuration. In addition, not only the combination of the configurations explicitly described in the description of each embodiment, but if there is no particular problem in the combination, the configurations of the plurality of embodiments can be partially combined even if not explicitly stated. .

(First embodiment)
The illumination device 20 according to the first embodiment of the present disclosure is mounted on a vehicle and emits illumination light for capturing an image of an occupant of the vehicle. The illumination device 20 constitutes the imaging system 9 together with the imaging device 10 and the like. The imaging system 9 according to the present embodiment captures the face of a vehicle occupant, particularly the driver as an imaging target, and processes the image to monitor the driver's dozing, aside, etc. It is used for Status Monitor, DSM).

  As shown in FIG. 1, the illumination device 20 of the present embodiment is arranged inside a vehicle display device 100 that is integrally formed with the imaging system 9. Therefore, the illumination device 20 is installed together with the vehicle display device 100 on an instrument panel facing a seat on which an occupant as a viewer sits.

  The vehicular display device 100 constitutes a combination meter that combines an analog display by the pointer 60 pointing the index 42 and a digital display by an image displayed by the image display 38. Is displayed. The information displayed includes, for example, vehicle speed, engine speed, remaining fuel amount, engine cooling water temperature, electric motor current value, and other vehicle conditions such as vehicle abnormality. Examples of other information to be displayed include various information such as warnings, road information, visibility assistance information, and electronic mail.

  The vehicle display device 100 as described above includes the image display device 38, the display plate 40, the display light source unit 50, the pointer 60, the imaging system 9, and the like.

  The image display 38 is arranged substantially in the center of the device 100. In the present embodiment, the image display 38 is a transmissive liquid crystal panel using thin film transistors (TFTs), and is an active matrix liquid crystal formed by a plurality of liquid crystal pixels arranged in a two-dimensional direction. It is a liquid crystal display that uses a panel. The image display 38 may be an organic EL display other than the liquid crystal display.

  The display plate 40 is also generally called a dial, and is surrounded by a dial plate that is formed in a tubular shape on the viewing side and a transparent plate that closes the viewing side opening of the viewing plate in the vehicle display device 100. It is an exposed part that is exposed in the space. The display board 40 is formed into a flat plate by partially or wholly printing semitranslucent or light-shielding on the surface of a translucent base material made of a synthetic resin such as a polycarbonate resin or an acrylic resin. Has been formed. Instead of printing, coating may be applied, and an optical resin or an optical filter material that transmits near-infrared light may be held on the display plate 40 by sticking or the like.

  The display plate 40 is arranged on the viewing side of the image display 38. For example, an opening hole 41 is formed in a portion of the display plate 40 that overlaps with the image display 38 so that the image is displayed on the viewing side without interfering with the display plate 40. In the display plate 40, indexes 42 pointed by the pointer 60 are formed in the left and right regions sandwiching the image display 38. The index 42 of the display plate 40 is illuminated by the visible light source unit from the side opposite to the viewing side (hereinafter referred to as the anti-viewing side).

  As shown in FIG. 2, the display light source section 50 is disposed on the side opposite to the viewing side of the display plate 40, and has a plurality of display light emitting elements 51 that emit visible display light. A light emitting diode element, for example, is adopted for each display light emitting element 51, and each display light emitting element 51 is connected to a power source through a conductive pattern on the substrate 70, so that a visible display is made toward the display panel 40. Emits light. In particular, in the present embodiment, as each display light emitting element 51, white light composed of light widely distributed in a wavelength range of about 400 to 800 nm is adopted.

  On the display plate 40, the light-shielding area SA and the display area DA are formed by the above-mentioned printing. The light-shielding area SA occupies a large area of the display plate 40, and shields visible display light from the non-viewing side by forming a dark color (for example, black) by light-shielding printing. The display area DA is adapted to allow visible light source light from the non-viewing side to pass therethrough, with or without semi-transparent printing, and the index 42 is set in the display area DA. As a result, the indicator 42 emits light and is displayed.

  A plurality of hands 60 are provided corresponding to the left and right regions of the display plate 40, respectively. Particularly in the present embodiment, the pointers 60 are provided in the left and right regions, respectively. Each pointer 60 integrally has a connecting portion 61 and an indicating portion 62. The connecting portion 61 is arranged on the side opposite to the viewing side of the display plate 40, and is connected to the rotation shaft of the stepping motor 63 held by the flat plate substrate. The indicator 62 is arranged on the viewing side of the display plate 40 and is needle-shaped so that the indicator 42 can be indicated.

  Each pointer 60 is configured to rotate around the pointer axis according to the output of the stepping motor 63, and by indicating the corresponding index 42, information corresponding to the designated position is displayed. There is. Particularly, in the present embodiment, the speed of the vehicle is displayed by the pointer 60 and the index 42 on the left side, and the engine speed of the vehicle is displayed by the pointer 60 and the index 42 on the right side.

  As shown in FIG. 3, the imaging system 9 includes an imaging device 10, a lighting device 20, and the like. The image capturing device 10 captures an image of a vehicle occupant (particularly, the face of a driver in this embodiment). Specifically, as shown in FIG. 4, the imaging device 10 includes a camera 11, a camera cover unit 13, and an image processing unit 14. The camera 11 is arranged on the side opposite to the viewing side of the display plate 40, for example, beside the image display device 38.

  The camera 11 has a detection element 11a and a lens 11b for forming an image of an imaging target on the detection element 11a. As the detection element 11a, for example, an element such as a CMOS sensor that has good sensitivity from visible light to light of the upper limit wavelength of visible light (including near infrared light) and has a high resolution of an image to be detected is adopted. There is. Here, light having a wavelength in the upper limit of visible light (hereinafter, referred to as visible upper light) means light having a wavelength in the range of 780 to 830 nm which is close to the upper limit and can be visually recognized by humans.

  A near-infrared light transmission filter layer 43 is provided, for example, by printing, at a portion of the display plate 40 that faces the camera 11, so that the camera cover portion 13 that covers the camera 11 from the viewing side is formed in a flat plate shape. The near-infrared light transmission filter layer 43 transmits near-infrared light including the upper visible light, and is set to have a lower transmittance for visible light having a wavelength shorter than that of the upper visible light. This makes it possible to detect near-infrared light including visible upper-light, while the occupant on the viewing side cannot clearly see the camera.

  The image processing unit 14 is realized as a functional block constructed mainly of an electronic circuit in which at least one processor, memory, input / output interface, etc. are mounted on the substrate 70. The processor can execute image processing by executing the computer program stored in the memory based on the signal from the detection element input through the input / output interface. More specifically, the image processing unit generates image data in which the image capturing target is captured, from the signal input from the detection element 11a. The generated image data may be directly output to the outside of the vehicle display device 100 such as an ECU (Electric Control Unit) of the vehicle and analyzed by the ECU, or the image processing unit 14 may output the image data. It is possible to analyze and determine whether the driver is asleep or asleep.

  As shown in FIG. 5, the illumination device 20 illuminates an occupant imaged by the imaging device 10 with illumination light. The lighting device 20 includes a surface emitting unit 21, a lighting cover unit 30, and a lighting control unit 35. In the vehicular display device 100, the surface light emitting unit 21 is arranged in a space defined by a light shielding wall 71 from the visible light source unit on the opposite side of the display plate 40.

  A near-infrared light transmission filter layer 44 is provided at a portion of the display plate 40 that faces the surface light emitting unit 21, so that the illumination cover unit 30 that covers the surface light emitting unit 21 from the viewing side is formed in a flat plate shape. The near-infrared light transmission filter layer 44 transmits near-infrared light including visible upper-limit light as well as the camera cover portion 13, and is set to have a lower transmittance of visible light having a shorter wavelength than the visible upper-limit light. Has been done.

  In addition, in the lighting cover unit 30 of the present embodiment, the visible side surface exposed in the space of the vehicular display device 100 is a surface treatment of an instrument panel, a steering component, or a meter hood that is a peripheral component of the vehicular display device 100. The decorative pattern is made according to the unevenness. The decorative pattern may be applied by printing or sticking a film, and in this case, for example, a decorative pattern such as metal tone, carbon tone, and wood grain tone may be adopted. With such a decorative pattern, the difference in appearance between the lighting cover portion 30 and the peripheral parts described above is reduced, and the presence of the lighting device 20 is less noticeable.

  The surface emitting section 21 includes a near infrared light emitting element 22 and a surface emitting optical element 23. For the near infrared light emitting element 22, for example, a light emitting diode is adopted. The near-infrared light emitting element 22 is held on the viewing side surface of the substrate 70 and is connected to a power source through a conductive pattern on the substrate 70 to emit near-infrared light including upper visible light. Particularly, in the present embodiment, the near-infrared light emitting element 22 having a peak wavelength at 850 nm and a wavelength characteristic with a half width of about 30 to 40 nm is employed.

  The surface-emitting optical element 23 is disposed between the near-infrared light emitting element 22 and the lighting cover portion 30, and is mainly formed of a translucent base material made of synthetic resin such as polycarbonate resin or acrylic resin. It is a prism lens. The surface emitting optical element 23 includes an introducing section 24 for introducing near infrared light including visible upper field light from the near infrared light emitting element 22, and a near infrared light including visible upper field light introduced into the introducing section 24. It has a surface emitting section 25 which makes the surface emitting light and emits it.

  The introduction part 24 is formed so as to project from the surface light emission part 25 to the side opposite to the visual recognition side, and has an introduction surface 24 a facing the near-infrared light emitting element 22 with a slight gap. The introduction surface 24a is formed into a mirror surface and efficiently introduces near-infrared light including the upper visible light emitted from the near-infrared light emitting element 22 into the base material. The near-infrared light including the visible upper field light introduced into the inside of the base material is guided to the viewing side surface emitting section 25 while being reflected by the side wall reflecting surface 24b forming the side wall in the introducing section 24.

  The surface emitting section 25 has a deflective reflection surface 25a arranged on the viewing side of the introduction surface 24a, and a plate section 25b extending from the deflective reflection surface 25a along the extending direction of the illumination cover section 30. The deflecting / reflecting surface 25a reflects the near-infrared light including the visible upper field light guided to the introducing section 24 so as to be deflected in the direction toward the plate section 25b.

  The plate portion 25b is formed in a rectangular plate shape having a facing surface 25c facing the lighting cover portion 30 and a back surface 25d formed on the opposite side of the facing surface 25c with the main body of the plate portion 25b interposed therebetween. There is. The angle between the facing surface 25c and the back surface 25d is adjusted so that the distance between the facing surface 25c and the back surface 25d becomes gradually smaller as the distance from the deflective reflecting surface 25a increases. In the present embodiment, the facing surface 25c and the back surface 25d are roughened by being embossed or the like. In this way, the near-infrared light including the upper visible light is diffused by the facing surface 25c and the back surface 25d, and is turned into surface emission.

  Therefore, the surface light emitting unit 21 planarly emits the illumination light as the near infrared light including the upper visible light. In particular, the surface light emitting unit 21 of the present embodiment emits the illumination light in a plane shape in a rectangular plane shape based on the shape of the plate section 25b. The illumination light emitted in the form of plane light passes through the illumination cover portion 30 and illuminates an occupant of the vehicle.

  The illumination control unit 35 is realized as a functional block constructed mainly of an electronic circuit in which at least one processor, memory, input / output interface, etc. are mounted on the substrate 70. This electronic circuit may be provided separately for the lighting device 20, may be shared with the electronic circuit that realizes the image processing unit 14 of the imaging device 10, and further, the image display 38, It may be shared with a control circuit for controlling the pointer 60 and the like.

  The illumination control unit 35 controls lighting and extinguishing of the near-infrared light emitting element 22 according to on / off of an ignition switch of the vehicle, and when the near-infrared light emitting element 22 is lit, its light emission is performed. Control the amount.

  The light distribution is adjusted by setting the angles of the deflecting / reflecting surface 25a, the facing surface 25c, and the back surface 25d, and the rough surface state of the facing surface 25c and the back surface 25d, and surface emitting of near-infrared light including visible upper field light is performed. The distribution of the luminous intensity (corresponding to the luminance) per unit area (see the right side of FIG. 5) is arbitrarily realized.

  Further, in the present embodiment, in the surface light emitting unit 21, the maximum location MP where the luminous intensity of the illumination light per unit area is maximum is formed in the approximate center of the facing surface 25c. This maximum location MP corresponds to the peak location PP in the above distribution, and in the present embodiment, one maximum location MP is formed. Then, as the distance from the maximum point MP increases, the luminous intensity of the illumination light per unit area gradually decreases.

  Here, the luminous intensity is calculated by weighting the radiation intensity with the luminosity factor for each wavelength, as is generally known. The illumination light of the present embodiment is near-infrared light, but includes light having a wavelength of 780 to 830 nm (that is, visible upper-limit light) having a visibility of greater than 0, and therefore the luminous intensity of the illumination light is also 0. Has a greater value.

  In the surface light emitting unit 21, the luminous intensity of the illumination light per unit area at the maximum location MP is a lower limit value that allows an occupant who visually recognizes the illumination device 20 to relatively perceive the visible upper field light as an independent sense. It is set to be smaller than the limit value CV. Here, the sensing limit value CV is a concept newly disclosed in the present embodiment, and if the luminous intensity of the illumination light per unit area at the maximum location MP is equal to or higher than the sensing limit value CV, the occupant determines that the illuminator 20 When visually recognizing, the emission of visible upper field light can be independently sensed at the maximum point MP. On the other hand, if the luminous intensity of the illumination light per unit area at the maximum point MP is smaller than the sensing limit value CV, the occupant cannot sense the emission of the upper visible light as an independent light.

  The sensing limit value CV is not always a constant absolute value, but depends on the surrounding environment and fluctuates depending on the surrounding environment. For example, when the interior of the vehicle is dark, such as at night, the occupant can easily perceive the visible upper field light as an independent item, and the sensing limit value CV decreases. On the other hand, when the vehicle interior is bright, for example during the daytime, the visible upper field light is present in the ambient external light, and it becomes difficult for the occupant to perceive the visible upper field light as an independent object. The value CV increases.

  In addition, even with the decorative pattern of the lighting cover unit 30 described above, it is difficult for the occupant to perceive the visible upper field light as an independent object due to the camouflage-like camouflage effect, and therefore, compared to the case where the lighting cover unit 30 has no pattern. However, the sensing limit value CV increases.

  In this way, in the lighting device 20 in which the surface emitting section 21 emits planar light, the irradiance in the unit area is small, but by setting the light emitting area wide, the product of the irradiance in the unit area and the light emitting area is obtained. By ensuring the total amount of radiant energy of the illumination light, sufficient illumination light can be provided to illuminate the occupants of the vehicle.

  Therefore, the illumination control unit 35 may change the light emission amount (amount of radiant energy) of the near-infrared light emitting element depending on whether the detection limit value CV is lower or higher. In addition, the total amount of radiant energy of illumination light may be prioritized without changing the amount of light emission.

(Action effect)
The operation and effect of the first embodiment described above will be described below again.

  According to the illuminating device 20 of the first embodiment, the surface emitting section 21 is configured to emit illumination light as near-infrared light including upper visible light in a planar manner, so that the emission is dispersed in a planar manner. As a result, the luminous intensity per unit area can be reduced. Then, even at the maximum portion MP where the luminous intensity per unit area is maximum in the surface light emitting unit 21, the light emission is dispersed so that the luminous intensity per unit area becomes smaller than the sensing limit value CV. Therefore, it becomes difficult for the occupant to perceive the visible upper field light as an independent object when the occupant looks at the surface light emitting unit 21, and therefore, it is possible to suppress giving the occupant a complicated impression. .

  Further, according to the first embodiment, the lighting device 20 further includes the lighting cover unit 30 that covers the surface light emitting unit 21 and transmits the illumination light. By providing such a lighting cover portion 30, the situation where the surface emitting portion 21 is exposed and directly visible is suppressed, so that the presence of the surface emitting portion 21 is less noticeable. Therefore, it is possible to prevent the passenger from having a complicated impression.

  Further, according to the first embodiment, the lighting cover section 30 is provided on the display plate 40 as an exposed component that is exposed on the viewing side in the vehicle display device 100. Since the display device 100 for a vehicle as described above displays information toward the viewing side, the exposed parts thereof are particularly easy to be noticed. It is suitable to illuminate the occupant's face or the like by arranging the surface emitting section 21 at a position covered by the display plate 40 as an exposed component that is easily noticed. Further, even at the maximum point MP of the surface light emitting portion 21, the luminescence is dispersed so that the luminous intensity per unit area becomes smaller than the sensing limit value CV, so that the occupant pays attention to the display board 40 as an exposed component. However, since it becomes difficult to detect the visible upper field light as an independent light, it is possible to prevent the passenger from having a complicated impression.

  In addition, according to the first embodiment, the lighting device 20 includes the surface-emission optical element 23 that surface-emits the near-infrared light including the upper visible light emitted from the near-infrared light-emitting element 22. . By making the surface light emission by such a surface light emission optical element 23, it is possible to easily realize the surface light emission portion 21 that emits a planar light.

  Further, according to the first embodiment, the surface emitting optical element 23 is formed of a translucent base material, and takes in near-infrared light including visible upper light emitted from the near-infrared light emitting element 22 therein. It is a prism lens that emits a planar light while guiding light. By appropriately designing the shape of such a prism lens, it is possible to arbitrarily disperse the visible upper field light from the near-infrared light emitting element 22, so that the luminous intensity per unit area at the above-mentioned maximum point MP can be easily calculated as follows. It can be set to be smaller than the sensing limit value CV.

  Further, according to the imaging system 9 of the first embodiment, the surface light emitting unit 21 is configured to emit the illumination light as near infrared light including the visible upper field light in a planar manner, so that the light emission is performed in a planar manner. By dispersing, the luminous intensity per unit area can be reduced. Then, even at the maximum portion MP where the luminous intensity per unit area is maximum in the surface light emitting unit 21, the light emission is dispersed so that the luminous intensity per unit area becomes smaller than the sensing limit value CV. Therefore, it becomes difficult for the occupant to perceive the visible upper field light as an independent object when the occupant looks at the surface light emitting unit 21, and therefore, it is possible to suppress giving the occupant a complicated impression. .

  Then, it becomes possible for the imaging device 10 to sense and capture visible upper-field light that is difficult to sense as an independent object. By the imaging system 9 making good use of the illumination light, it is possible to suppress deterioration of imaging quality.

  Further, according to the vehicular display device 100 of the first embodiment, the surface light emitting section 21 is adapted to planarly emit the illumination light as the near infrared light including the visible upper field light. The light intensity per unit area can be reduced by dispersing the particles in a uniform shape. Then, even at the maximum portion MP where the luminous intensity per unit area is maximum in the surface light emitting unit 21, the light emission is dispersed so that the luminous intensity per unit area becomes smaller than the sensing limit value CV. Therefore, when the occupant sees the displayed information, it is difficult to detect the visible upper field light as an independent one, even if the illuminating light from the surface light emitting unit 21 is received. Giving to is suppressed.

  The first embodiment will be additionally described by comparison with a comparative example. In the illumination device 920 of the comparative example shown in FIG. 6, the lens 923 collects near-infrared light including the visible upper-field light emitted from the near-infrared light emitting element 922, and emits point light. There is. In such a comparative example, as can be seen from comparison with FIG. 5, there is a portion where the luminous intensity per unit area exceeds the sensing limit value CV. As a result, the occupant will perceive the visible upper field light in the portion exceeding the sensing limit value CV as independent.

(Second embodiment)
As shown in FIGS. 7 to 11, the second embodiment is a modification of the first embodiment. The second embodiment will be described focusing on the points different from the first embodiment.

  In the lighting device 220 of the second embodiment, as shown in FIG. 7, the lighting cover section 230 has a reflection structure section 231 instead of the decorative pattern. As shown in FIGS. 9 and 10, the reflection structure portion 231 re-exposes external light such as sunlight incident on the illumination cover portion 230 from the side opposite to the surface light emitting portion 221 (that is, the viewing side) to the surface again. The light is reflected on the side opposite to the light emitting portion 221.

  The reflective structure portion 231 of the present embodiment is provided by forming a complicated uneven structure 232 on the surface of the lighting cover portion 230 on the viewing side. More specifically, as the complicated uneven structure 232, a structure imitating a diamond cut is adopted. Since the plurality of reflecting surfaces 232a formed in a mirror-like shape in the concavo-convex structure 232 face different directions from each other, external light incident from the side opposite to the surface light emitting portion 221 is again separated from the surface light emitting portion 221. It is reflected in various directions on the opposite side.

  The illumination device 220 according to the second embodiment has a plurality of visible light emitting elements 226 that emit visible mixed light as visible light, in addition to the near infrared light emitting element 222. A light emitting diode, for example, is used for each visible light emitting element 226. Two visible light emitting elements 226 of this embodiment are provided, and are arranged on both sides of the near infrared light emitting element 222. Each visible light emitting element 226 is capable of emitting visible mixed light toward the surface emitting optical element 223 by being connected to a power source through a conductive pattern on the substrate 70. In particular, the visible light emitting element 226 of the present embodiment can emit white light as visible mixed light, but it may emit light of other colors such as green light and reddish color light.

  The surface emitting optical element 223 of the second embodiment is a prism lens mainly formed of a light-transmissive base material made of a synthetic resin such as polycarbonate resin or acrylic resin, and is formed in a block shape. . In the surface-emitting optical element 223, the introduction surface 223a is formed in a planar shape having an area capable of facing the near-infrared light emitting element 222 and each visible light emitting element 226 at the same time. In the surface-emitting optical element 223, the facing surface 223b that faces the illumination cover portion 230 is formed in a planar shape having an area slightly larger than the introduction surface 223a, so that the facing surface 223b overlaps substantially the entire area of the reflecting structure portion 231. There is.

  Such a surface-emission optical element 223 does not have an element for diffusing the illumination light and the visible mixed light because the introduction surface 223a and the facing surface 223b are formed into a mirror surface. However, in the optical path from the introduction surface 223a to the facing surface 223b, a part of the light is reflected by the sidewall reflection surface 223c, so that the near-infrared light emitting element 222 and each visible light emitting element 226 emit the illumination light and the visible mixed light. Surface emission can be achieved as compared with the case of emitting light as it is.

  Further, the illumination control unit 235 of the illumination device 220 has a visible light emission amount changing unit 236, as shown in FIG. The visible light emission amount changing unit 236 controls turning on and off of each visible light emitting element 226, and controls the amount of light emission when each visible light emitting element 226 is turned on.

  Particularly, in the vehicle, the illumination control unit 235 can communicate with the external light sensor 7 and the image processing unit 14 provided on the upper surface of the instrument panel, for example. The external light sensor 7 can detect external light. The camera 11 can also detect external light. By acquiring these detection results from the external light sensor 7 and the image processing unit 14, the brightness around the lighting device 220 can be estimated.

  As shown in the flowchart of FIG. 11, when the detection result of the external light sensor 7 is input to the illumination control unit 235, the visible light emission amount changing unit 236 determines the value (see S10 of FIG. 11), and The amount of light emitted by the visible light emitting element 226 is changed. More specifically, when the amount of detected external light of the external light sensor 7 is equal to or greater than a predetermined amount, the visible light emission amount changing unit 236 sets the amount of light emitted by each visible light emitting element 226 to 0 (that is, each visible light emitting element 226). Is turned off (see S20 in FIG. 11). If the external light detection amount of the external light sensor 7 is less than the predetermined amount, the visible light emission amount changing unit 236 turns on each visible light emitting element 226 (see S30 of FIG. 11), and the external light detection amount of the external light sensor 7 is detected. The amount of light emitted by each visible light emitting element 226 is changed so that the amount of light emitted by each visible light emitting element 226 increases as the amount of light decreases (see S40 in FIG. 11).

  Therefore, when the surroundings are sufficiently bright, for example, in the daytime, each visible light emitting element 226 is turned off as shown in FIG. Therefore, only the near-infrared light emitting element 222 is turned on, and the illumination light as the near-infrared light including the upper visible light emitted from the near-infrared light emitting element 222 emits the surface-emitting optical element 223 and the reflection structure portion. After passing through 231, the planar light emission is performed. At this time, the external light reflected by the reflective structure 231 is mixed with the near infrared light including the visible upper field light. For this reason, it becomes difficult for the occupant to detect the visible upper field light as an independent item, and the detection limit value CV increases. Therefore, the admissibility of making the luminous intensity per unit area at the maximum location MP of the surface light emitting unit 221 smaller than the sensing limit value CV is high.

  On the other hand, when the surroundings are dark, such as at night, as shown in FIG. 10, the amount of outside light (see the broken line arrow in FIG. 10) itself is small, so that the illumination light as near-infrared light including the upper visible light is used. It becomes difficult to mix external light. Therefore, the visible light emission amount changing unit 236 lights each visible light emitting element 226. Then, the illumination light as the near infrared light including the visible upper field light emitted by the near infrared light emitting element 222 and the visible mixed light emitted by each visible light emitting element 226 are mixed by the surface emitting optical element 223. While being illuminated, it is made to emit surface light. In this way, the illumination light as near-infrared light including the visible upper-field light transmitted through the reflecting structure 231 is mixed with the visible mixed light, and it becomes difficult for the occupant to perceive the visible upper-field light as an independent light. Therefore, the sensing limit value CV increases. Therefore, the admissibility of making the luminous intensity per unit area at the maximum location MP of the surface light emitting unit 221 smaller than the sensing limit value CV is high.

  Further, the white light as the visible mixed light is refracted when passing through the reflecting surface 232a of the reflecting structure portion 231, thereby producing a chromatic aberration and producing a complicated optical pattern according to the concavo-convex structure 232. It becomes more difficult to perceive visible upper light as an independent light.

  According to the second embodiment described above, the illumination cover part 230 reflects the external light incident on the cover part 230 from the side opposite to the surface emitting part 221 to the side opposite to the surface emitting part 221 again. It has a reflective structure 231. The external light reflected by the reflective structure portion 231 is mixed with the visible upper field light from the surface light emitting portion 221. Therefore, as a result of making it difficult for the occupant to sense the visible upper field light independently, it is easy to increase the sensing limit value CV so that the luminous intensity per unit area at the maximum location MP is smaller than the sensing limit value CV. This makes it possible to prevent the passenger from having a complicated impression.

  Further, according to the second embodiment, the surface-emitting optical element 223 converts the near-infrared light including the upper visible light emitted from the near-infrared light emitting element 222 into the visible mixed light emitted from the visible light-emitting element 226. Are mixed to obtain surface emission. Since the visible mixed light is mixed with the visible upper field light, it becomes difficult for the occupant to perceive the visible upper field light as an independent result. As a result, the sensing limit value CV is increased and the luminous intensity per unit area at the maximum point MP is increased. Since it is easily possible to make the value smaller than the sensing limit value CV, it is possible to prevent the passenger from having a complicated impression.

  Further, when the amount of ambient light from the surroundings is reduced, the ambient light mixed with the upper visible light from the surface light emitting unit 221 is also reduced due to the reflection at the reflective structure portion 231. As a result, the occupant may easily perceive the visible upper field light as an independent item, and there is a concern that the detection limit value CV may be reduced.

  However, in the second embodiment, the amount of light emitted by the visible light emitting element 226 is changed according to the ambient brightness. Even if the sensing limit value CV is likely to rise or fall depending on the ambient brightness, the sensing limit value CV of the sensing limit value CV is changed by changing the emission amount of the visible mixed light mixed with the upper visible light according to the ambient brightness. Fluctuations can be suppressed. Therefore, the luminous intensity per unit area at the maximum location MP can be made smaller than the sensing limit value CV at all times, so that it is possible to reliably prevent the passenger from having a complicated impression.

  In the second embodiment, the amount of light emitted by the visible light emitting element 226 is changed so that the amount of light emitted by the visible light emitting element 226 increases as the amount of ambient light decreases. Therefore, the decrease of the external light is compensated by the increase of the visible mixed light mixed with the upper visible light from the surface light emitting unit 221, and the decrease of the sensing limit value CV can be suppressed. As a result, the luminous intensity per unit area at the maximum point MP can be easily made smaller than the sensing limit value CV, so that the occupant is prevented from having a complicated impression.

(About specific conditions)
Here, suitable conditions for the luminous intensity of the illumination light per unit area and the color ratio when the visible mixed light is mixed with the visible upper light in each embodiment will be described.

  Here, the daytime environment in the following description is defined as an environment in which the brightness inside the vehicle is 500 lx or more and less than 100,000 lx, and is assumed to be an environment in which the light of the vehicle is not lit during fine weather. The sunrise / sunset / night environment is defined as an environment in which the brightness inside the vehicle is 0 lx or more and less than 500 lx, and the environment in which the vehicle light is on is assumed. Further, it is assumed that the glass front of the vehicle has a transparent color and most of the display board 40 of the vehicle display device 100 has a black color.

First, the luminous intensity of the illumination light per unit area will be described. In the daytime environment, the luminous intensity of the illumination light per unit area is 5 cd / m ² or less at the maximum point MP of the surface emitting portions 21 and 221 that planarly emits the illumination light as near-infrared light including the upper visible light. Therefore, it can be said that the occupant cannot perceive the visible upper field light as an independent item. In the sunrise / sunset / night environment, by setting the luminous intensity of the illuminating light per unit area to 0.5 cd / m ² or less at the maximum point MP of the surface emitting portions 21 and 221, the occupant can see It can be said that the light cannot be perceived as an independent thing.

  The sensing limit value CV is also affected by the luminous intensity of visible display light per unit area by the display light source unit 50 of the vehicle display device 100 and the like. Specifically, by suppressing the luminous intensity of the illumination light per unit area to 5% or less of the luminous intensity of the visible display light per unit area, it becomes difficult to independently detect the upper visible light.

Specifically, in the vehicle display device 100 of each embodiment, the luminous intensity of visible display light per unit area is 100 cd / m ² in the daytime environment (or when the light is not lit), and the sunrise / sunset / night environment is set. (Or when the light is on), it has a dimming function of dimming the luminous intensity of visible display light per unit area to 10 cd / m ² . In response to this, the lighting devices 20 and 220 set the luminous intensity of the illumination light per unit area to 5 cd / m in the daytime environment (or when the light is not lit) so as to satisfy the above condition of 5% or less. ^The light intensity of the illumination light per unit area is reduced to 0.5 cd / m ² or less in a sunrise / sunset / night environment (or when the light is not lit).

  Next, the color ratio when the visible mixed light is mixed with the visible mixed light as in the second embodiment will be described. First, whether the visible mixed light is white light, red light (wavelength is 620 to 780 nm), green light (wavelength is 495 to 570 nm), or blue light (wavelength is 450 to 495 nm). There is a difference in the level at which the visible upper bound light is perceived as independent, depending on the color of the visible mixed light. As a tendency, in the case of mixing red light, it is most effective because the visible upper field light is hardly perceived as an independent light. Then, mixing of green light, mixing of blue light, and mixing of white light are performed in this order.

  When the visible mixed light is white light, the radiant energy of the visible upper bound light is suppressed to 1 or less with respect to the radiant energy 10 of the visible mixed light, thereby independently sensing the visible upper bound light. Will be difficult. When the visible mixed light is blue light, by suppressing the radiant energy of the visible upper bound light to 2 or less with respect to the radiant energy 10 of the visible mixed light, it is difficult to independently sense the visible upper bound light. Becomes When the visible mixed light is green light, the radiant energy of the visible upper bound light is suppressed to 3 or less with respect to the radiant energy 10 of the visible mixed light, so that it is difficult to sense the upper visible light independently. Becomes

  When the visible mixed light is red light, there is almost no difference between the visible mixed light and the visible upper field light in the first place. Therefore, it can be said that there is no restriction on the ratio of the radiant energy of the visible upper bound light to the radiant energy of the visible mixed light.

(Other embodiments)
Although a plurality of embodiments have been described above, the invention is not construed as being limited to those embodiments and can be applied to various embodiments and combinations within the scope not departing from the gist of the invention. .

  Specifically, as a first modification, the lighting device 20 may be arranged adjacent to the indicator 42, the indicator light, the image display 38, etc. formed by the display area DA of the display plate 40. Further, the lighting device 20 may be arranged adjacent to a decorative component that surrounds the rotation range of the pointer 60 and emits light. This makes it possible to make the visible display light more difficult to recognize by utilizing the attractiveness of the display area DA.

  For example, as shown in the spectrum distribution diagram of FIG. 12, when the point light emitting illumination device 920 shown in FIG. 6 is not adjacent to the display area DA, the luminous intensity of the illumination light per unit area is the recognition threshold V0 (sensing threshold). (Corresponding to the limit value CV) is exceeded (indicated by a chain line in FIGS. 12 and 13). As shown in the spectrum distribution diagram of FIG. 13, when the planar light emitting illumination device 20 is not adjacent to the display area DA, the light is dispersed in a planar manner, and as a result, per unit area at the maximum location MP of the illumination light. Is below the recognition threshold V0 (indicated by a broken line in FIG. 14).

  On the other hand, as shown in the spectrum distribution diagram of FIG. 14, in the case where the illumination device 20 is adjacent to the display area DA that emits yellow-green light, as a result of the attractiveness to yellow-green light, the recognition threshold value itself becomes V0. To V1. Therefore, the margin for making the luminous intensity per unit area at the maximum point MP smaller than the sensing limit value CV is improved, and it is possible to suppress the increase in the light emitting area while maintaining the total amount of illuminance energy. As a result, the lighting device 20 can be formed in a more space-saving manner even if the surface light-emitting portion 23 has a structure that emits planar light.

  As a specific example of such a configuration, the illumination device 20 is arranged adjacent to a liquid crystal display that uses yellow-green display light as a backlight or a VFD (Vacuum fluorescent display) that uses a fluorescent display tube. Can be mentioned.

  As a modified example 2 of the second embodiment, as shown in FIG. 15, the reflection structure part 231 is a metal hairline structure formed by printing or the like on a part of the surface of the display plate 40 corresponding to the illumination cover part 230. It may be formed by 233. The metal hairline structure 233 is formed by forming a plurality of fine metallic thin lines capable of reflecting external light concentrically with the pointer axis, and providing a transmissive region capable of transmitting illumination light between the metallic thin lines. . Even with the reflection structure portion 231 formed by the metal hairline structure 233, external light that enters the illumination cover portion 230 from the side opposite to the surface emitting portion 221 can be reflected again toward the side opposite to the surface emitting portion 221. .

  As a modified example 3 of the second embodiment, a reflection ring as a decorative component surrounding the rotation range of the pointer 60 other than the display plate 40 may be adopted in the illumination cover 230. The reflective ring forms an extremely thin metal thin film by plating or vapor-depositing a metal such as tin or silver on the visible side surface of a translucent base material made of a synthetic resin such as polycarbonate resin or acrylic resin. I will do it. Such a metal thin film functions as a magic mirror or a half mirror-like reflection structure 231. Therefore, the reflection ring as the illumination cover portion 230 is formed to reflect the external light incident from the side opposite to the surface light emitting portion 221 to the side opposite to the surface light emitting portion 221, and to transmit the illumination light. There is.

  As a modified example 4 of the second embodiment, the illumination cover portion 230 is configured to form the index 42, and the visible light emitting element 226 that emits visible mixed light is provided with the function of illuminating the index 42. May be.

  As a modified example 5 of the second embodiment, the backlight of the image display device 38 may be replaced with the surface emitting section 221, so that an image is displayed using visible mixed light.

  As a sixth modification, the display plate 40 may be changed to printing in red, white, or the like other than the black printing, and the sensing limit value CV may be increased.

  As a modified example 7, the illumination cover section 30 may not be provided, and the surface-emitting optical element 23 may be exposed in the space surrounded by the dial plate and the transparent plate in the vehicular display device 100. In this case, the reflective structure portion 231 may be formed on the surface-emitting optical element 23.

  As a modified example 8, the surface emitting optical element 23 is not limited to a prism lens, and may be a diffuser plate, or may be a combination with a diffraction grating, a microlens, a mirror array, or the like to which MEMS is applied.

  As a modified example 9, two or more near infrared light emitting elements 22 may be provided for one surface emitting optical element 23.

  As a tenth modification, the surface emitting section 21 may be formed in a planar shape by arranging fine point light sources with a small gap as long as the planar light emitting section 21 emits planar light. Further, the surface light emitting unit 21 may be formed in a planar shape by arranging thin line light sources with a small gap.

  As a modified example 11, two or more maximum points MP where the luminous intensity of the illumination light per unit area is maximum in the surface light emitting section 21 may be formed. Further, the surface emitting section 21 may emit planar light so that the luminosity of the illumination light per unit area is substantially the same in the entire area, and in this case, the entire area corresponds to the maximum point MP. It will be.

  Modification 12 is not limited to the configuration in which the lighting device 20 or the imaging system 9 including the lighting device 20 and the like is arranged inside the vehicle display device 100. For example, the lighting device 20, or the imaging system 9 including the lighting device 20 and the like may be arranged adjacent to the vehicle display device 100 as an independent assembly. Further, for example, the lighting device 20 or the imaging system 9 including the lighting device 20 and the like may be arranged as an independent assembly at a position apart from the vehicular display device 100. Among the configurations that can be adopted here, in the image pickup system 9, only the illumination device 20 is arranged inside the vehicular display device 100, and the image pickup device 10 is arranged outside the vehicular display device, and the image pickup device 10. Is disposed inside the vehicle display device 100, and only the lighting device 20 is disposed outside the vehicle display device 100. Further, in the configuration that can be adopted here, only the surface emitting portion 21 of the lighting device 20 is arranged inside the vehicular display device 100, and the other part of the lighting device 20 and the imaging device 10 are arranged. Included is a configuration to be placed outside the.

  As a thirteenth modification, the lighting device 20, or the imaging system 9 including the lighting device 20 and the like is a device (audio, car navigation, air conditioner, etc. operation panel for displaying or operating various functions of the vehicle. ) May be arranged inside.

  In Modification 14, the imaging target of the imaging device 10 is not limited to the occupant's face. For example, the occupant's hand or arm may be used as the imaging target, and the occupant's gesture operation input or physical condition such as a pulse wave may be determined.

  9 imaging system, 10 imaging device, 20,220 lighting device, 21,221 surface emitting part, 100 vehicle display device, MP maximum location, CV sensing limit value

Claims (7)

A lighting device (20, 220) mounted on a vehicle, which emits illumination light for imaging an occupant of the vehicle,
A surface light emitting part (21, 221) for planarly emitting the illumination light as near infrared light including light having an upper limit wavelength of visible light;
The surface emitting section, in the maximum location (MP) where the luminous intensity of the illumination light per unit area is the maximum, the luminous intensity of the illumination light per unit area is the light of the wavelength of the upper limit of the visible light by the occupant. Is set to be smaller than the lower limit value (CV), which is the lower limit value at which the
A cover part (30, 230) which covers the surface emitting part and transmits the illumination light;
The cover part, the surface of external light coming incident from the side opposite to the light emitting portion, an illumination device that have a reflective structure that reflects on the opposite side (231) is again the surface-emitting portion to the cover portion . The lighting device according to claim 1 , wherein the lighting device is arranged inside a vehicle display device (100) that displays information toward a viewing side.
The said cover part is an illuminating device provided in the exposed component (40) exposed to the said visual recognition side in the said display apparatus for vehicles. The surface emitting unit,
A near-infrared light-emitting element (22, 222) that emits near-infrared light including the upper limit wavelength of the visible light;
The near-infrared light including light having a wavelength of the upper bound of the near-infrared the visible light emitted from the light emitting element, a surface emitting optics for surface emission reduction (23,223), according to claim 1 or with a The lighting device according to 2 . The surface emitting unit,
Further having a visible light emitting element that emits visible mixed light as visible light,
The surface-emitting optical element mixes the visible mixed light emitted from the visible light-emitting element with near-infrared light including light having an upper wavelength of the visible light emitted from the near-infrared light-emitting element. The lighting device according to claim 3 , wherein the lighting device emits surface light. The lighting device according to claim 4 , further comprising a visible light emission amount changing unit (236) that changes an amount of light emitted by the visible light emitting element according to ambient brightness. A lighting device (20, 220) mounted on a vehicle, which emits illumination light for imaging an occupant of the vehicle,
A surface light emitting part (21, 221) for planarly emitting the illumination light as near infrared light including light having an upper limit wavelength of visible light;
The surface emitting section, in the maximum location (MP) where the luminous intensity of the illumination light per unit area is the maximum, the luminous intensity of the illumination light per unit area is the light of the wavelength of the upper limit of the visible light by the occupant. Is set to be smaller than the lower limit value (CV), which is the lower limit value at which the
A cover part (30, 230) which covers the surface emitting part and transmits the illumination light;
The cover part has a reflection structure part (231) that reflects external light incident on the cover part from the side opposite to the surface light emitting part to the side opposite to the surface light emitting part again.
The surface emitting unit,
A near-infrared light emitting element (222) that emits near-infrared light including the upper wavelength of visible light;
A visible light emitting element (226) that emits visible mixed light as visible light;
A surface to be surface-emitted by mixing near-infrared light including light having an upper limit wavelength of the visible light emitted from the near-infrared light emitting element with the visible mixed light emitted from the visible light-emitting element. A light emitting optical element (223),
And a visible light emission amount changing unit (236) for changing the light emission amount of the visible light emitting element so that the light emission amount of the visible light emitting element increases as the amount of the ambient light decreases. apparatus. The surface-emitting optical element is formed of a translucent base material, and while capturing and guiding near-infrared light including the upper limit wavelength of the visible light emitted from the near-infrared light-emitting element, The illumination device according to any one of claims 3 to 6 , which is a prism lens that causes planar light emission.

Images