JP2015125377A - On-vehicle projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle projection device that can sharply project a light irradiation pattern including an image even on a place inside a passenger compartment with irregularities.SOLUTION: An on-vehicle projection device 10 is provided with a light source that emits coherent light having a visible wavelength, a collimator lens, and a hologram optical element. The coherent light passes through the collimator lens to be converted into collimating light; the hologram optical element generates the diffraction of light; and then a light irradiation pattern 12a is projected on a steering wheel 4 inside a passenger compartment 1. Projection light 11a converted by the hologram optical element has the substantially infinite depth of focus, and the light irradiation pattern 12a can be sharply projected on the steering wheel 4 and the area therebelow.

Description

  The present invention relates to an in-vehicle projection device that projects a light irradiation pattern including an image into a vehicle interior of a vehicle.

  Patent Document 1 discloses an invention relating to an in-vehicle information display device using an irradiation device.

  The irradiation device can irradiate various places in the passenger compartment with the collected visible light as a spot or a predetermined area.

  In the irradiation device, a visible light beam emitted from the beam irradiation device is guided by an optical fiber, and the visible light beam is irradiated to a plurality of locations in the vehicle interior. By moving the irradiation place of the visible light beam, it is possible to guide the place to be watched by the user and to instruct the place to be operated by the user by irradiating the visible light beam to the switches in the vehicle. ing.

  It is also possible to display information by displaying characters, symbols, pictures, etc. on the dashboard with a visible light beam.

  A system combining a galvanometer mirror and a DLP (registered trademark) digital projector is used as a structure for irradiating a visible light beam to multiple locations in a vehicle interior and displaying characters, symbols, pictures, etc. with the visible light beam Has been. The digital projector projects an image or the like using a digital mirror device.

JP 2008-195375 A

  The in-vehicle information display device described in Patent Document 1 uses a galvano mirror and a digital mirror device to move the reflection direction of the visible light beam, thereby moving the irradiation position of the spot. This is a structure that draws and displays characters, symbols, and patterns by moving the reflection direction of. However, in this apparatus, since characters, symbols, and patterns are drawn by turning on / off each pixel of the digital mirror device, the resolution of the pattern is limited according to the operation accuracy of the digital mirror device. In addition, since it is configured in combination with a projection lens, the focal length for forming a projected image is determined within a certain range.

  In addition, when attempting to project characters, symbols, and patterns on uneven areas, the farther away from the focal point of the visible light irradiation device, the more the display lines become blurred, making it difficult to display clear information on the uneven parts. .

  The present invention solves the above-described conventional problems, and provides an in-vehicle projection device capable of clearly projecting an irradiation pattern including an image in a passenger compartment and displaying information clearly on an uneven portion. It is an object.

The present invention relates to an in-vehicle projection device that projects information into a vehicle interior.
A light source that generates coherent light having a visible wavelength, a collimator lens that converts the coherent light into collimated light, and a hologram optical element that projects a light irradiation pattern including a predetermined image by causing interference in the collimated light. And is provided.

  Since the on-vehicle projector of the present invention projects a light irradiation pattern with a hologram optical element, it can project a clear image including at least one of letters, numbers, figures, and symbols into the vehicle interior.

  In the present invention, the hologram optical element can be configured such that a depth of focus at which the light irradiation pattern can be formed is set longer than a spatial distance in the projection direction of the light irradiation pattern in the vehicle interior.

  Using a hologram optical element makes it possible to increase the distance at which the light irradiation pattern can be imaged in the irradiation direction, enabling clear image formation even where there are large irregularities or where there are steps before and after. Become. That is, it is possible to make the depth of focus substantially infinite by using the hologram optical element.

  In the present invention, the hologram optical element may have a diffraction grating fixed inside and project a light irradiation pattern of a fixed image.

  In this case, the plurality of light sources, the collimating lens corresponding to each light source, and the hologram optical element are individually provided, and each hologram optical element projects a light irradiation pattern of a different fixed image. A reflection member that sends projection light of different light irradiation patterns in the same projection direction, and a projection control unit that selectively turns on the plurality of light sources. preferable.

  In this in-vehicle projection device, it is possible to select and project light irradiation patterns of different images at the same location in the vehicle interior.

  For example, the plurality of light sources generate coherent light having different wavelengths, and the reflecting member selects transmission and reflection of coherent light according to the wavelength.

  Alternatively, the polarization directions of coherent light emitted from the plurality of light sources are different, and the reflection member selects transmission and reflection of coherent light according to the polarization direction.

  In the vehicle-mounted projection device of the present invention, the hologram optical element may be a variable optical element that can change the image content of the light irradiation pattern.

  Furthermore, the vehicle-mounted projection device of the present invention may be provided with a projection direction adjusting device that changes the irradiation direction of the light irradiation pattern projected by the hologram optical element.

  By providing the projection direction adjusting device, the projection location of the light irradiation pattern can be moved to an arbitrary location in the vehicle interior, or the light irradiation pattern can be selected and projected at a plurality of locations.

  The present invention projects a light irradiation pattern of an image prompting installation of an electronic device at a predetermined location when a passenger is in the passenger compartment, and displays the image of the light irradiation pattern when the passenger gets off. It can be configured to warn of misplacement of electronic equipment by switching.

  For example, it is determined whether the passenger has got on or off the vehicle by turning on or off an ignition switch or an accessory switch. Alternatively, it is determined by detecting a sensor in the passenger compartment whether the passenger has boarded or got off. The electronic device is, for example, a portable information terminal.

  Since the in-vehicle projector of the present invention uses a hologram optical element to diffract coherent collimated light to generate and project a light irradiation pattern, the range in which the light irradiation pattern can be imaged on the projection optical path The (depth of focus) can be made substantially infinite, and this range can be made longer than on the projection optical path in the interior of the automobile. Therefore, an image can be projected clearly, for example, an image including at least one of letters, numbers, figures, and symbols drawn with a thick line can be projected, and clear information display can be performed.

  In addition, it is possible to project a clear image on a place where there is a large unevenness in the passenger compartment or a place where the depth difference is large.

Explanatory drawing which shows the state by which the light irradiation pattern is projected on the steering wheel in a vehicle interior by the vehicle-mounted projection apparatus of this invention, Explanatory drawing which shows the operation state in which the light irradiation pattern is projected on the steering wheel, Explanatory drawing which shows the operation state in which the light irradiation pattern is projected on the steering wheel, Explanatory drawing which shows the operation state in which the light irradiation pattern is projected on the steering wheel, (A) (B) (C) is explanatory drawing which shows other embodiment of the reflective member which selects projection light, Explanatory drawing which shows the state by which the light irradiation pattern is projected on the center console box of a vehicle interior, (A) (B) is explanatory drawing which shows the example of projection of the light irradiation pattern to a console box, Explanatory drawing showing an example of the configuration of the projection unit, Explanatory drawing which shows the other example of a structure of a projection part, The block diagram which shows the structural example of the vehicle-mounted projection apparatus of this invention,

  FIG. 1 shows the internal structure of a passenger compartment 1 of an automobile. A vehicle compartment 1 shown in FIG. 1 is provided with an instrument panel 3 in a region below the windshield 2, and a display 3 a is provided on the instrument panel 3. In the driver's seat, a steering wheel 4 is disposed in front of the instrument panel 3.

  A dashboard 5 is arranged in front of the middle between the driver's seat and the passenger seat, and an in-vehicle electronic device 6 is provided here. The in-vehicle electronic device 6 is an audio device, a navigation device, other communication devices, or the like. A center console box 7 is disposed in front of the dashboard 5 and a shift lever 8 is provided in front of the center console box 7. On the center console box 7, in front of the shift lever 8, a portable device installation area 9 is provided as an electronic device installation area.

  As shown in FIG. 1, an in-vehicle projector 10 is installed on a windshield 2 in a passenger compartment 1.

  The in-vehicle projection apparatus 10 is provided with a projection unit 20. In the example shown in FIG. 1, projection light 11 a is given from the projection unit 20 toward the swinging wheel 4, and the steering wheel 4, a driver's leg positioned below the steering wheel 4, a part of the seat, a floor surface, or the like The light irradiation pattern 12a is projected and displayed.

  The structure of the projection unit 20 for projecting the light irradiation pattern 12a toward the steering wheel 4 is shown in FIGS.

  The projection unit 20 is provided with a first light irradiation unit 21a, a second light irradiation unit 21b, and a third light irradiation unit 21c. FIG. 8 shows details of the structure of the first light irradiation unit 21a. The first light irradiation unit 21 a has a case 22 in which a first light source 23 a and a collimating lens 24 are accommodated. The first light source 23a is a laser light emitting element that emits coherent light having a visible wavelength, and a visible light laser having a green visible wavelength is emitted. This visible light laser is converted into collimated light 25 a by a collimating lens 24.

  2, 3, and 4 are also provided with a second light source 23 b and a collimator lens 24 (none of which are shown). The second light source 23b is a laser light emitting element that emits coherent light having a visible wavelength, and a visible light laser having a red visible wavelength is emitted. The third light illumination unit 21c is provided with a second light source 23c and a collimator lens 24 (both not shown). The third light source 23c is a laser light emitting element that emits coherent light having a visible wavelength, and emits a visible light laser having a blue visible wavelength.

  A first hologram optical element 26a is disposed in front of the first light irradiation unit 21a. The first hologram optical element 26a has a diffraction grating fixed inside, and generates projection light 11a that is hologram light for projecting the first light irradiation pattern 12a of the fixed image. As shown in FIG. 8, the projection light 11a transmitted through the first hologram optical element 26a becomes divergent light whose beam area gradually increases as it goes forward.

  When the coherent collimated light 25a is transmitted through the first hologram optical element 26a, light is diffracted by the diffraction grating formed and fixed inside the element, and the object irradiated with the projection light 11a is shown in FIGS. A first light irradiation pattern 12a as shown in FIG. The first light irradiation pattern 12a is displayed with a green visible light laser, and is displayed as an image in which the characters “Relax” and the symbol “!” Are combined.

  The range in which the light irradiation pattern 12a can be imaged in the projection direction so that a clear image can be projected to any object in the passenger compartment 1 when the projection light 11a generated by the first hologram optical element 26a hits any object in the passenger compartment 1 The (depth) is set to be longer than the maximum value of the depth distance of the indoor space in the direction in which the projection light 11a is projected in the passenger compartment 1. That is, the depth of focus at which the light irradiation pattern 12a can be imaged by the first hologram optical element 26a is set to be longer than the total length of the indoor space in the direction in which the projection light 11a is projected in the passenger compartment 1, The depth of focus is set to be infinite.

  The first holographic optical element 26a for projecting an image in which the characters “Relax” and the symbol “!” Are combined at an almost infinite depth of focus is a computer-generated holography technology. ) To record the diffraction grating structure inside the element.

  As shown in FIGS. 2, 3, and 4, the second hologram optical element 26b is disposed in front of the second light irradiation unit 21b. The coherent red laser light emitted from the second light source 23b provided in the second light irradiation unit 21b passes through the second hologram optical element 26b and becomes the second projection light 11b. The second hologram optical element 26b has the same structure and function as the first hologram optical element 26a, and the second projection light 11b transmitted through the second hologram optical element 26b becomes divergent light, and the second light irradiation. The depth of focus at which the pattern 12b can be formed becomes almost infinite.

  However, as shown in FIG. 3, the second light irradiation pattern 12 b displayed when the second projection light 11 b is irradiated onto the object in the passenger compartment 1 includes the characters “Caution” and “!”. The second light irradiation pattern 12b is displayed by red laser light.

  As shown in FIGS. 2, 3, and 4, a third hologram optical element 26c is arranged in front of the third light irradiation unit 21c. The coherent blue laser light emitted from the third light source 23c provided in the third light irradiation unit 21c is transmitted through the third hologram optical element 26c and the third projection light 11c which is divergent light. Become. In the third projection light 11c, as shown in FIG. 4, the third light irradiation pattern 12c displayed when the object in the passenger compartment 1 is irradiated is that the door of the vehicle is not completely closed. It is a figure for warning. The third light irradiation pattern 12c is displayed in blue. The depth of focus for imaging the third light irradiation pattern 12c is also almost infinite.

  As shown in FIGS. 2, 3, and 4, the projection unit 20 selects any one of the first projection light 11a, the second projection light 11b, and the third projection light 11c. A dichroic mirror (dichroic prism) 27 is provided. The dichroic mirror 27 includes a first mirror surface 27a and a second mirror surface 27b that intersect each other. The first mirror surface 27a and the second mirror surface 27b exhibit one of transmission and reflection functions depending on the wavelength of light. As shown in FIG. 2, the first mirror surface 27a and the second mirror surface 27b transmit light having a green wavelength. As shown in FIG. 3, the red wavelength light is reflected by the first mirror surface 27a, and as shown in FIG. 4, the blue wavelength light is reflected by the second mirror surface 27b.

  The in-vehicle projection apparatus 10 shown in FIG. 1 includes a projection control unit 31 (see FIG. 10) together with the projection unit 20. The projection control unit 31 is notified of vehicle setting information, driving information, and physical information obtained from the driver, and controls which light irradiation pattern is selected according to the situation.

  When the projection control unit 31 determines that the driver is in a tension state based on the driver's physical information, the first light irradiation unit 21a is selected and included in this as shown in FIG. The first light source 23a is turned on. As a result, the green first light irradiation pattern 12 a including the characters “Relax” is projected onto the steering wheel 4.

  If the projection control unit 31 determines that the traveling speed of the vehicle is too high or the distance from the vehicle traveling ahead is too short, as shown in FIG. When selected, the second light source 23b included therein is turned on. As a result, the red second light irradiation pattern 12b including the letters “Caution” is projected onto the steering wheel 4 to alert the driver. When it is desired to further alert the driver, the second light source 23b is controlled to blink, and the second light irradiation pattern 12b is blinked.

  When the projection control unit 31 determines that the vehicle door is not completely closed, as shown in FIG. 4, the third light irradiation unit 21c is selected, and the third light source 23c included therein is selected. Is lit. As a result, the third light irradiation pattern 12c including a figure for warning that the door is not closed is displayed on the steering wheel 4 in blue.

Since the light irradiation patterns 12a, 12b, and 12c are generated by diffraction of light by the hologram optical elements 26a, 26b, and 26c, an image is drawn by turning the digital micromirror on / off by reflecting the beam with a galvanometer mirror. Compared to a conventional projection apparatus, it is possible to display a bright image with less light loss.

  Further, the projection light beams 11a, 11b, and 11c generated by the hologram optical elements 26a, 26b, and 26c have almost infinite depth of focus for forming the light irradiation patterns 12a, 12b, and 12c. As shown, the image of the light irradiation patterns 12a, 12b, and 12c can be clearly projected on the surface of the steering wheel 4 having an uneven surface, and the steering wheel 4 is projected by the projection light 11a projected at a position off the steering wheel 4. It is possible to clearly project and display a part of the light irradiation pattern on the driver's leg located on the lower side, the seat of the driver's seat, or the floor surface.

  In the above embodiment, the dichroic mirror 27 is used as a reflecting member for selecting the display lights 11a, 11b, and 11c. However, in the embodiment shown in FIG. 5, a polarization beam combiner 28 is used as the reflecting member. . The polarization beam combiner 28 selects reflection and transmission according to the polarization direction of the input light.

  The polarization beam combiner 28 shown in FIG. 5A has a reflecting surface 28a. The polarization direction of the visible light laser emitted from the first light source 23a of the first light irradiation unit 21a is different from the polarization direction of the visible light laser emitted from the second light source 23b of the second light irradiation unit 21b. ing. The reflecting surface 28a is configured to transmit the polarized light of the visible light laser from the first light source 23a and reflect the polarized light of the visible light laser from the second light source 23b.

  When the first light source 23a of the first light irradiation unit 21a is turned on by the control of the projection control device 31, the projection light 11a that has passed through the first hologram optical element 26a passes through the reflecting surface 28a and passes through the vehicle interior. 1 is projected inside. When the second light source 23b of the second light irradiation unit 21b is turned on, the projection light 11b transmitted through the second hologram optical element 26b is reflected by the reflecting surface 28a and projected inside the passenger compartment 1.

  The polarization beam combiner 28 shown in FIG. 5B has a reflecting surface 28b. The reflecting surface 28b is configured to transmit the polarized light of the visible light laser from the first light source 23a and reflect the polarized light of the visible light laser from the third light source 23c provided in the third light irradiation unit 21c. Has been. When the first light source 23a is turned on under the control of the projection control device 31, the projection light 11a transmitted through the first hologram optical element 26a is transmitted through the reflecting surface 28b and projected into the passenger compartment 1, When the third light source 23c is turned on, the projection light 11b transmitted through the third hologram optical element 26c is reflected by the reflecting surface 28b and projected onto the interior of the passenger compartment 1.

  A polarization beam combiner 28 shown in FIG. 5C has a reflecting surface 28a and a reflecting surface 28b. When the first light source 23 a is turned on by the control of the projection control device 31, the projection light 11 a that has passed through the first hologram optical element 26 a passes through the reflecting surface 28 a and the reflecting surface 28 b and enters the interior of the passenger compartment 1. Projected. When the second light source 23b is turned on, the projection light 11b transmitted through the second hologram optical element 26b is reflected by the reflecting surface 28a and projected to the interior of the passenger compartment 1, and the third light source 23c is turned on. Then, the projection light 11c transmitted through the third hologram optical element 26c is reflected by the reflecting surface 28b and projected onto the interior of the passenger compartment 1.

  Next, in the embodiment shown in FIG. 6, the projection light 13 is irradiated from the in-vehicle projector 10 to the center console box 7, and the light irradiation pattern 14 is projected onto the portable device installation area 9.

  The projection unit 20 of the in-vehicle projection device 10 is provided with the same two light irradiation units 21 a and 21 b and two hologram optical elements 26 a and 26 b as shown in FIG. 2 or FIG. 5A, and the dichroic mirror 27. Alternatively, a polarization beam combiner 28 is provided. However, the first hologram optical element 26a projects an image of the first light irradiation pattern 14a shown in FIG. 7A, and the second hologram optical element 26b shows the second light shown in FIG. 7B. The light irradiation pattern 14b is projected. FIG. 6 shows a state in which the first light irradiation pattern 14 a is projected on the center console box 7.

  The in-vehicle projector 10 shown in FIG. 6 has the device configuration shown in the block diagram of FIG. When the projection control unit 31 recognizes that the passenger (driver) has boarded, the projection unit 20 projects the first light irradiation pattern 14a shown in FIG. 6 and FIG. Is done. The first light irradiation pattern 14a is projected by a green visible light laser, for example.

  As shown in FIG. 6, by irradiating the first light irradiation pattern 14 a, the passenger (driver) is prompted to install the portable device 36 in the portable device installation area 9. The portable device 36 is a portable information terminal, for example, a mobile phone. Whether or not the passenger has boarded is determined by whether or not the switch 35 such as an ignition switch or an accessory switch of the automobile shown in FIG. 10 is switched. Alternatively, the determination is made by detecting whether or not a person has boarded using any of the sensors 32 arranged at a plurality of locations in the vehicle.

  The presence of the portable device 36 in the portable device installation area 9 is detected by any of the sensors 32, and further communication is possible by checking the ID and the like by communication between the portable device 36 and the transceiver in the vehicle. If it is determined that the mobile device 36 is a portable device 36, the light source of the light irradiation unit is turned off, and the first light irradiation pattern 14a shown in FIG. 7A disappears.

  Next, when the occupant is about to leave the passenger compartment 1, if the projection control unit 31 recognizes that the portable device 36 is still placed in the portable device installation area 9, the projection device 20 moves the portable device. The light irradiation pattern 14b shown in FIG. This light irradiation pattern 14b is projected in red. Further, the red light irradiation pattern 14b may be blinked. This projection warns the passenger that the portable device 36 has been left behind.

  Whether or not the passenger is about to leave the passenger compartment 1 is determined based on whether or not a switch 35 such as an ignition switch or an accessory switch has been switched. Alternatively, the determination is made by detecting whether a person is about to get off using any of the sensors 32. Whether or not the portable device 36 is left in the portable device installation area 9 is determined based on the presence or absence of communication between the portable device 36 and the vehicle transceiver, or by any one of the sensors 32 detecting the portable device 36. It is judged by whether it is.

  In the above-described embodiment, the fixed image is projected by the hologram optical elements 26a, 26b, and 26c. However, as the hologram optical element, different types can be obtained by changing the structure of the diffraction grating by the control operation from the projection control unit 31. It is also possible to use a variable optical element capable of generating the image and project a plurality of types of light irradiation patterns with one hologram optical element.

  A hologram optical element that generates light irradiation patterns of a plurality of images can be configured by a liquid crystal element that establishes a plurality of types of diffraction gratings inside the element by a computer-generated holography technique.

  As a light irradiation unit, as shown in FIG. 9, the collimated light emitted from the light source 23a and converted by the collimating lens 24 is reflected by the polarization beam combiner 28 and applied to the hologram optical element 29 using the reflective liquid crystal. The converted light that is given and reflected by the hologram optical element 29 may be transmitted through the polarization beam combiner 28 and projected as display light.

  The reflection type hologram optical element 29 may generate a light irradiation pattern of a fixed image or may change an image.

  Further, the in-vehicle projector 10 of the present invention is provided with a projection direction adjusting device 34 using a galvanometer mirror or the like as shown in FIG. 10 to change the place where the light irradiation pattern is projected inside the passenger compartment 1. Or may be moved.

  Further, a safety device 33 shown in FIG. 10 is preferably provided. When this safety device 33 is provided, a light is emitted from a light source when a person tries to look directly into the projection unit 20 and it is detected using infrared rays or the like that a person has approached the projection unit 20 to some extent. The emission intensity of the visible light laser is reduced, and adverse effects on human eyes can be prevented.

DESCRIPTION OF SYMBOLS 1 Car compartment 2 Windshield 3 Instrument panel 4 Steering wheel 5 Dashboard 7 Center console box 9 Portable equipment installation area 10 In-vehicle projector 11a, 11b, 11c Projection light 12a, 12b, 12c, 14a, 14b Light irradiation pattern 20 Projection unit 21a, 21b, 21c Light irradiation unit 23a, 23b, 23c Light source 24 Collimate lens 26a, 26b, 26c Hologram optical element 27 Die quick mirror 28 Polarization beam combiner 31 Projection control unit 32 Sensor 35 Switch 36 Portable device

Claims (12)

In a vehicle-mounted projection device that projects information into the passenger compartment,
A light source that generates coherent light having a visible wavelength, a collimator lens that converts the coherent light into collimated light, and a hologram optical element that diffracts the collimated light and projects a light irradiation pattern including a predetermined image into the vehicle interior. And an in-vehicle projection device.   The in-vehicle projector according to claim 1, wherein the hologram optical element has a depth of focus at which the light irradiation pattern can be imaged longer than a spatial distance in a projection direction of the light irradiation pattern in the vehicle interior.   The in-vehicle projection apparatus according to claim 1, wherein the hologram optical element has a diffraction grating fixed inside and projects a light irradiation pattern of a fixed image. A plurality of the light sources, the collimating lens corresponding to each of the light sources and the hologram optical element are individually provided;
Each hologram optical element projects a light irradiation pattern of a different fixed image,
The in-vehicle projection apparatus according to claim 3, further comprising: a reflection member that transmits projection light having different light irradiation patterns in the same projection direction; and a projection control unit that selectively turns on the plurality of light sources.   The in-vehicle projector according to claim 4, wherein the plurality of light sources generate coherent light having different wavelengths, and the reflecting member selects transmission and reflection of coherent light according to the wavelength.   The in-vehicle projector according to claim 4, wherein polarization directions of coherent light emitted from the plurality of light sources are different, and the reflection member selects transmission and reflection of coherent light according to the polarization direction. .   The in-vehicle projector according to claim 1, wherein the hologram optical element is a variable optical element that can change an image content of a light irradiation pattern.   The in-vehicle projection apparatus according to claim 1, further comprising a projection direction adjusting device that changes an irradiation direction of a light irradiation pattern projected by the hologram optical element.   When the passenger is in the passenger compartment, the light irradiation pattern of the image prompting the installation of the electronic device is projected at a predetermined location, and when the passenger gets off, the image of the light irradiation pattern is switched to The in-vehicle projector according to any one of claims 1 to 8, which warns of misplacement of equipment.   The in-vehicle projection apparatus according to claim 9, wherein whether the passenger gets on or off the vehicle is determined by turning on or off an ignition switch or an accessory switch.   The in-vehicle projection device according to claim 9, wherein whether the passenger gets on or off the vehicle is determined by detection of a sensor in the passenger compartment.   The in-vehicle projection apparatus according to claim 9, wherein the electronic device is a portable information terminal.

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