JP2008209665A - Head-up display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a head-up display device which can suppress the color unevenness of a display image and simultaneously can render the visibility of the display image excellent. <P>SOLUTION: The head-up display device is provided with: a first light source 23 emitting green light L1; a second light source 24 emitting red light L2; a dichroic mirror 29 transmitting the green light L1 and reflecting the red light L2; and a transmission type display element 21 illuminated by illumination light L3 including the green light L1 and the red light L2, the head-up display device irradiates a front glass 13 with display light L emitted from the transmission type display element 21 and allows a user 14 to visually recognize the display image V obtained by the irradiation. Each of the green light L1 and red light L2 emitted from the first and second light sources 23 and 24 is configured to enter the dichroic mirror 29, in such a state that each of them is made into a nearly parallel luminous flux, and a diffusion member 201 is disposed between the dichroic mirror 29 and the transmission type display element 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention irradiates a dedicated reflecting member such as a vehicle windshield or combiner with display light emitted from a transmissive display element such as a liquid crystal display panel, and visually recognizes a display image obtained by the irradiation to a vehicle user. The present invention relates to a head-up display device.

  Conventionally, as this type of head-up display device, for example, one described in Patent Document 1 below is known. The vehicle head-up display device described in Patent Document 1 will be described with reference to FIGS. As shown in FIG. 7, the head-up display device A is a device in which a display device 3 and a reflecting mirror 4 are accommodated in a housing 2 having a light-transmissive window portion 1, and display light emitted from the display device 3. L is reflected by the reflecting mirror 4 and projected (irradiated) onto the windshield or combiner of the vehicle to display a virtual image (display image).

  In this case, as shown in FIG. 8, the display device 3 generates a first light source 5 composed of a green LED that emits green light L1, a second light source 6 composed of a red LED that emits red light L2, and green light L1. A dichroic mirror (transmission reflection member) 7 that transmits red light L2 and reflects the red light L2, and a liquid crystal display panel (transmission display element) 8 that is illuminated by a mixed light L3 in which green light L1 and red light L2 are mixed; have.

  The first and second light sources 5 and 6 are composed of a plurality of light emitting diodes that emit light by being supplied with a predetermined power (current value) from a light source driving circuit (not shown). The second light source 6 is disposed on the right side of the dichroic mirror 7 and is disposed below the dichroic mirror 7 in FIG.

  The dichroic mirror 7 includes a reflective film 7a formed by vapor deposition on the front surface of the glass substrate (the surface facing the back surface of the liquid crystal display panel 8). The traveling direction of the green light L1 and the traveling direction of the red light L2 Are inclined so as to have an inclination of 45 degrees with respect to each other.

  According to such a configuration, the green light L1 emitted from the first light source 5 and the red light L2 emitted from the second light source 6 are mixed through the dichroic mirror 7 and mixed with the mixed light (orange color) on the liquid crystal display panel 8 side. Light) L3, whereby the liquid crystal display panel 8 is transmitted and illuminated with the mixed light L3.

Then, the mixed light L3 that is transmitted through the liquid crystal display panel 8 is emitted from the liquid crystal display panel 8 as display light L. The display light L emitted from the liquid crystal display panel 8 is reflected by the reflecting mirror 4 and applied to the windshield or the like of the vehicle, and the user of the vehicle visually recognizes the display image obtained by the irradiation. Thereby, the user of the vehicle can visually recognize the display image superimposed on the landscape.
JP 2003-295105 A

  By the way, the light emitted from the green LED that is the first light source 5 and the red LED that is the second light source 6 has a large radiation angle (light irradiation region angle) and travels in various directions. For this reason, the light (radiated light) from the green LED (first light source 5) incident on the dichroic mirror 7 is the back surface 7b of the dichroic mirror 7 (surface opposite to the surface on which the reflective film 7a is formed). Are incident with different incident angles. In addition, light (radiated light) from the red LED (second light source 6) incident on the dichroic mirror 7 is incident on the surface of the dichroic mirror 7 on which the reflection film 7a is formed with a different incident angle. Become.

  FIG. 9 shows the light sources 5 and 6 and the dichroic mirror 7 in detail. However, in the following description, only the light sources 5a and 6a shown in FIG. 8 among the light sources 5 and 6 will be described, and description of the light sources 5 and 6 other than the light sources 5a and 6a will be omitted. For example, in the case of the green LED, in FIG. 9, on the back surface 7b of the dichroic mirror 7, an incident position P1 located just above the first light source 5a (on the optical axis B1) and a position slightly deviated from the optical axis B1 The light is incident with the incident angle P2 being different from the incident position P2. More specifically, an angle X1 formed between a perpendicular line (normal line) N extending perpendicularly to the back surface 7b of the dichroic mirror 7 and the incident position P1 is an ideal incident angle of 45 degrees. An angle X2 formed by the perpendicular N and the incident position P2 is smaller than the ideal incident angle, for example, approximately 30 degrees.

  In the case of the red LED, in FIG. 9, the incident position P3 located on the front surface (the surface on which the reflective film 7a is formed) of the dichroic mirror 7 is located immediately above the second light source 6a (on the optical axis B2). The light is incident with the incident angle being different from the incident position P4 that is slightly deviated from the optical axis B2. More specifically, the angle X3 formed between the perpendicular N of the dichroic mirror 7 and the incident position P3 is 45 degrees, which is the ideal incident angle. The angle X4 formed between the perpendicular N of the dichroic mirror 7 and the incident position P4 is It becomes smaller than the ideal incident angle, for example, approximately 30 degrees.

  This means that the light emitted from the first light source 5a (the green LED) has different incident angles with respect to the dichroic mirror 7 at the incident position P1 and the incident position P2, and the second light source 6a (the red LED). This means that the incident angle with respect to the dichroic mirror 7 is different between the incident position P3 and the incident position P4.

  Then, green light L11 (a part of the green light L1) transmitted through the dichroic mirror 7 from the incident position P1 and red light L21 (one of the red light L2) reflected through the dichroic mirror 7 at the incident position P3. Part) is mixed and becomes mixed light L31 (a part of the mixed light L3). At the same time, the green light L12 (a part of the green light L1) transmitted through the dichroic mirror 7 from the incident position P2 and the red light L22 (the red light L2 of the red light L2) reflected through the dichroic mirror 7 at the incident position P4. Are mixed with each other and become mixed light L32 (part of the mixed light L3).

  At this time, the mixed light L31 is composed of illumination light in which the incident angles of the light sources 5a and 6a with respect to the dichroic mirror 7 are mixed at incident positions P1 and P3 corresponding to the ideal incident angle (45 degrees). The mixed light L32 is composed of illumination light mixed at the incident positions P2 and P4 corresponding to approximately 30 degrees instead of 45 degrees of the incident angles of the light sources 5a and 6a with respect to the dichroic mirror 7.

  However, as in the mixed light L31 and the mixed light L32 described above, in the case of light mixed in a configuration in which the incident angles of the light sources 5a and 6a with respect to the dichroic mirror 7 are different, the green color constituting the mixed light L31 A phenomenon occurs in which the balance between the light L11 and the red light L21 and the balance between the green light L12 and the red light L22 constituting the mixed light L32 are lost.

  The reason is that the light from each of the light sources 5a and 6a reaches the dichroic mirror 7 with the ideal incident angle and the light incident on the dichroic mirror 7 with an incident angle different from the ideal incident angle. This is because the transmittance characteristic of the dichroic mirror 7 (that is, the transmittance curve indicating the relationship between the transmittance and the wavelength) is greatly shifted (detailed illustration is omitted here). In other words, the dichroic mirror 7 has such a characteristic that when the incident angle of the light is deviated from the ideal (reference) incident angle of 45 degrees, the transmittance characteristic changes (fluctuates). It is. In this transmittance characteristic (the transmittance curve), it is needless to say that the transmittance is 0%, and the reflectance is 100%.

  Specifically, when the incident angle is 45 degrees, which is the ideal incident angle, the ratio of the green light L11 and the red light L21 constituting the mixed light L31 is a ratio of 5 to 5, whereas the incident angle Is 30 degrees, which is not the ideal incident angle, the phenomenon that the ratio of the green light L12 and the red light L22 constituting the mixed light L32 becomes a ratio of 3 to 7 instead of 5 to 5 occurs. Become.

  Accordingly, the mixed light L3 composed of the mixed light L31 and the mixed light L32 is transmitted through the liquid crystal display panel 8 with color unevenness (the mixed light L32 is slightly reddish than the mixed light L31). The problem is that the display image formed by illuminating and irradiating the front glass or the like with the display light L emitted from the liquid crystal display panel 8 is visually recognized by the user in a state of uneven color. Had.

Further, since the mixed light L3 directly reaches the liquid crystal display panel 8 with color unevenness, for example, the display image is displayed with the user greatly tilting his or her head to the left or right. The display image has a problem that the brightness of the display image is reduced, and the visibility of the display image is reduced in addition to the occurrence of color unevenness of the display image. The room for further improvement was left in the above points.
Accordingly, the present invention is directed to providing a head-up display device capable of suppressing the color unevenness of the display image and improving the visibility of the display image while addressing the above-described problems. .

  The present invention provides a first light source that emits first colored light, a second light source that emits second colored light, and a transmission that transmits the first colored light and reflects the second colored light. A reflective member, and a transmissive display element illuminated with illumination light including the first colored light and the second colored light, and the display light emitted from the transmissive display element is emitted from a vehicle windshield or A head-up display device for irradiating a reflecting member and allowing a user of the vehicle to visually recognize a display image obtained by the irradiation, wherein the first and second colored light emitted from the first and second light sources Light is incident on the transmission / reflection member in a substantially parallel light flux state, and a substantially parallel light beam emitted from the transmission / reflection member between the transmission / reflection member and the transmission-type display element. Illuminating the illumination light Diffusing member for, characterized in that is disposed.

  According to the present invention, the first and second colored lights incident on the transmission / reflection member are converted into substantially parallel light fluxes through the first and second condenser lenses or the first and second reflectors, respectively. It is characterized by becoming.

  ADVANTAGE OF THE INVENTION According to this invention, the initial objective can be achieved, the head-up display apparatus which can make the visibility of a display image favorable while suppressing the color nonuniformity of a display image can be provided.

(First Embodiment) Hereinafter, a first embodiment of the present invention applied to a head-up display device for a vehicle will be described as an example with reference to the accompanying drawings.

  The head-up display device 10 is disposed in the dashboard 12 of the vehicle 11 (see FIG. 1). The display light L projected by the head-up display device 10 is reflected by the windshield 13 of the vehicle 11 toward the user 14 of the vehicle 11. The user 14 can visually recognize the virtual image V superimposed on the landscape. In other words, the head-up display device 10 irradiates the windshield 13 with display light L emitted from a transmissive display element (described later) provided in the head-up display device 10, and a display image (virtual image) obtained by this irradiation. V is visually recognized by the user 14. Thereby, the user 14 can observe the virtual image V superimposed on the landscape.

  The head-up display device 10 has a display device 20, a reflector 30 and the like housed in a housing 40 (see FIG. 2). As shown in FIG. 3, the display device 20 includes a transmissive display element 21, an illumination unit 22 that illuminates the transmissive display element 21, and a dichroic mirror (described later) of the transmissive display element 21 and the illumination unit 22. And a diffusing member 201 disposed on the surface.

  The transmissive display element 21 includes, for example, a TFT (thin film transistor) type liquid crystal display panel in which a polarizing film is provided on the front and back surfaces of a liquid crystal cell in which liquid crystal is sealed in a pair of translucent substrates. The transmissive display element 21 drives an operation circuit (not shown) for measuring the vehicle speed and the engine speed based on output signals from a vehicle speed sensor and an engine rotation sensor provided in the vehicle 11 and drives the liquid crystal based on the calculation result. The measured value of the speed of the vehicle 11 or the engine speed can be displayed as a numerical value by a liquid crystal driving circuit (not shown). Note that the display information displayed by the transmissive display element 21 is not limited to the vehicle speed and the engine speed, and may be travel distance information, navigation information, and outside air temperature information, for example.

  On the other hand, the illumination means 22 includes a first light source 23, a second light source 24, a first wiring board 25, a second wiring board 26, a first condenser lens 27, and a second collector. An optical lens 28 and a dichroic mirror (transmission / reflection member) 29 are provided.

  The first light source 23 includes a plurality of chip-type light emitting diodes that emit green light L1 that is first colored light. In the present embodiment, each of the first light sources 23 has a light irradiation region angle that has a directivity of approximately 60 degrees to the left and right around the first optical axis C1. This means that each of the first light sources 23 has a light irradiation region angle of approximately 120 degrees.

  The second light source 24 is composed of a plurality of chip-type light emitting diodes that emit red light L2 that is second colored light. Further, in the case of the present embodiment, each of the second light sources 24 has a directivity of approximately 60 degrees left and right about the second optical axis C <b> 2, as in the case of the first light source 23. What you have is adopted. This means that each second light source 24 has a light irradiation region angle of approximately 120 degrees.

  The first wiring substrate 25 is made of, for example, a substantially rectangular aluminum substrate having high thermal conductivity, and a plurality of first light sources 23 are mounted at high density.

  The second wiring substrate 26 is made of, for example, a substantially rectangular aluminum substrate having high thermal conductivity, and a plurality of second light sources 24 are mounted at high density. The outer shape of the second wiring board 26 is substantially the same as the outer shape of the first wiring board 25.

  The first condenser lens 27 is made of a light-transmitting synthetic resin, and is formed with a plurality of convex spherical portions 27 a that protrude toward the dichroic mirror 29 corresponding to the individual first light sources 23. And the green radiation light emitted from the 1st light source 23 with the said light irradiation area | region angle is located right above the 1st light source 23 so that the light emission surface of the 1st light source 23 may be opposed. The light is irradiated into the first condenser lens 27 through the light receiving surface 27b.

  Of the green irradiation light, the green irradiation light traveling straight on the first optical axis C1 travels straight without being refracted when passing through the first condenser lens 27 and reaches the spherical portion 27a (see FIG. 4, the other green irradiation light is refracted when passing through the inside of the first condenser lens 27 and reaches the spherical portion 27a (see the optical path S2 in FIG. 4).

  Further, the green irradiation light that reaches the spherical surface portion 27a through the optical path S1 is emitted as straight light from the spherical surface portion 27a and guided to the dichroic mirror 29 side (see the optical path S3 in FIG. 4). Further, the green irradiation light that reaches the spherical portion 27a via the optical path S2 is emitted from the spherical portion 27a as straight light that is substantially parallel to the first optical axis C1, and is guided to the dichroic mirror 29 side ( In FIG. 4, refer to the optical path S4).

  Therefore, when the green radiated light (green light L1) emitted from each first light source 23 is emitted from the first condenser lens 27, it is in the state of being made into substantially parallel luminous fluxes like the optical paths S3 and S4. Thus, the light travels toward the dichroic mirror 29 and enters the dichroic mirror 29. In other words, the green radiated light (green light L1) emitted from each first light source 23 is incident on the dichroic mirror 29 through the first condenser lens 27 in a state of being made into a substantially parallel light flux. Become.

  The second condenser lens 28 is made of a translucent synthetic resin, and is formed with a plurality of convex spherical portions 28 a that protrude toward the dichroic mirror 29 corresponding to the individual second light sources 24. The red emitted light emitted from the second light source 24 with the light irradiation region angle is positioned directly above the second light source 24 so as to face the light emitting surface of the second light source 24. The light is irradiated into the second condenser lens 28 through the light receiving surface 28b.

  Of the red irradiation light, the red irradiation light traveling straight on the second optical axis C2 travels straight as it is without being refracted when passing through the inside of the second condenser lens 28 and reaches the spherical portion 28a (see FIG. 5, the other red irradiation light is refracted when passing through the inside of the second condenser lens 28 and reaches the spherical portion 28a (see the optical path T2 in FIG. 5).

  Further, the red irradiation light that reaches the spherical portion 28a via the optical path T1 is emitted as straight light from the spherical portion 28a and guided to the dichroic mirror 29 side (see optical path T3 in FIG. 5). The red irradiation light that reaches the spherical portion 28a via the optical path T2 is emitted as straight light that is substantially parallel to the second optical axis C2 from the spherical portion 28a and guided to the dichroic mirror 29 side ( In FIG. 5, refer to the optical path T4).

  Therefore, when the red emitted light (red light L2) emitted from each second light source 24 is emitted from the second condenser lens 28, it is in the state of being made into substantially parallel luminous fluxes like the optical paths T3 and T4. Thus, the light travels toward the dichroic mirror 29 and enters the dichroic mirror 29. In other words, the red radiated light (red light L2) emitted from each second light source 24 is incident on the dichroic mirror 29 through the second condenser lens 28 in a substantially parallel light flux state. Become. In addition, the shape of the 2nd condensing lens 28 (each spherical surface part 28a) shall be substantially the same as the shape of the 1st condensing lens 27 (each spherical surface part 27a).

  The dichroic mirror 29 has a reflective film 29a formed by vapor deposition on the front surface of the glass substrate (that is, the surface facing the back surface of the diffusing member 201), and the progress of each green light L1 converted into a substantially parallel light flux. It is inclined and arranged so as to have an inclination of approximately 45 degrees with respect to the direction and the traveling direction of each red light L2 converted into a substantially parallel light beam.

  The dichroic mirror 29 transmits the green light L1 emitted from the first light sources 23 and reflects the red light L2 emitted from the second light sources 24. The green light L1 converted into a substantially parallel light beam that passes through the dichroic mirror 29 and the red light L2 converted into a substantially parallel light beam reflected through the dichroic mirror 29 are mixed with each other by the dichroic mirror 29. Each illumination light (each orange light) L3 is led to the diffusing member 201 side as a substantially parallel light beam.

  Here, when the green light L1 (light having passed through the optical paths S3 and S4) converted into a substantially parallel light flux enters the dichroic mirror 29, the perpendicular N and the optical path S3 extending in the vertical direction with respect to the back surface 29b of the dichroic mirror 29. The angle formed by S4 (incident angle of the green light L1 with respect to the dichroic mirror 29) K1 is 45 degrees, which is an ideal incident angle (see FIG. 4). Similarly, the angle (red light L2) formed between the perpendicular line N of the dichroic mirror 29 and the optical paths T3, T4 when the red light L1 (light having passed through the optical paths T3, T4) converted into a substantially parallel light beam enters the dichroic mirror 29. The incident angle K2 with respect to the dichroic mirror 29 is an ideal incident angle of 45 degrees (see FIG. 5).

  Thus, the incident angles K1 of the green light L1 (optical paths S3 and S4) to the dichroic mirror 29 are all constant, and the incident angles K2 of the red light L2 (optical paths T3 and T4) to the dichroic mirror 29 are all constant. Accordingly, the ratio (balance) between the green light L1 and the red light L2 is kept constant in each illumination light (each orange light) L3 that has been converted into a substantially parallel luminous flux emitted from the dichroic mirror 29.

  Therefore, the color unevenness of the illumination light L3 caused by the incident light on the dichroic mirror 29 in a state where the green light L1 and the red light L2 are not converted into substantially parallel light beams as in the conventional case is the green light in the present embodiment. L1 and red light L2 are incident on the dichroic mirror 29 at the ideal incident angles (incidence angles K1 and K2) in a state of being substantially parallel light beams through the first and second condenser lenses 27 and 28, respectively. The illumination light L3 emitted from the dichroic mirror 29 is guided to the diffusing member 201 side in a state in which the color unevenness is eliminated.

  That is, by adopting a configuration in which the green light L1 and the red light L2 are respectively incident on the dichroic mirror 29 at the ideal incident angle, the green light L1 and the red light L2 constituting the illumination light L3 Since the balance is kept constant irrespective of the position of the dichroic mirror 29 (that is, the incident position of the light on the dichroic mirror 29), the illumination light L3 that has been converted into a substantially parallel light beam emitted from the dichroic mirror 29 has uneven color. In this state, the diffusion member 201 is guided.

  The diffusing member 201 is made of a light-transmitting synthetic resin having milky white color, for example, is formed in a substantially flat plate shape, and is arranged along the back surface of the transmissive display element 21. The diffusing member 201 functions as a light diffusing plate for diffusing the illumination light L3 that has been converted into a substantially parallel luminous flux emitted from the dichroic mirror 29, and for uniformizing the display light L emitted from the transmissive display element 21. It has.

  Any structure can be applied to the diffusing member 201 as long as it diffuses the illumination light L3 and makes the display light L uniform. For example, a lens having a concave surface facing the transmissive display element 21 is applied. It is also possible. In this case, the outer shape of the diffusing member 201 is substantially the same as the outer shape of the transmissive display element 21.

  The transmissive display element 21 positioned in front of the diffusing member 201 illuminates the illumination light L3 having no color unevenness diffused through the diffusing member 201. Further, the illumination light L3 illuminating the transmissive display element 21 is diffused and emitted as display light L with suppressed color unevenness on the front side of the transmissive display element 21, and the display light L is reflected by the reflector 30. Are projected onto the windshield 13 side through a concave mirror, which will be described later, and a window portion, which will be described later, of the housing 40, whereby the user 14 can visually recognize the virtual image V in which color unevenness due to the display light L is suppressed.

  As shown in FIG. 2, the reflector 30 includes a concave mirror 31, a holding member 32, and a stepping motor 33. The concave mirror 31 is formed by depositing a metal (for example, aluminum) on a resin (for example, polycarbonate) to form a reflective surface 31a. The reflection surface 31a is a concave surface, and the display light L without color unevenness emitted from the display device 20 (the transmissive display element 21) is enlarged to display the virtual image V. The concave mirror 31 is bonded to the holding member 32 with a double-sided adhesive tape. The holding member 32 is made of resin (for example, ABS), and the gear portion 34 and the shaft portion 35 are integrally formed. The shaft portion 35 of the holding member 32 is pivotally supported by the housing 40.

  A gear 36 is attached to the rotation shaft of the stepping motor 33, and the gear 36 is engaged with the gear portion 34 of the holding member 32. The concave mirror 31 is supported so as to be rotatable together with the holding member 32, and the concave mirror 31 can be rotated by the stepping motor 33 to adjust the projection direction of the display light L. The user 14 of the vehicle 11 operates a push button switch (not shown) to adjust the angle of the concave mirror 31 so that the display light L is reflected at the eye position (that is, the virtual image V can be visually recognized).

  The housing 40 accommodates the display device 20 and the reflector 30. The housing 40 is provided with a window 41 from which the display light L is emitted. This window part 41 consists of translucent resin (for example, acrylic), and has a curved shape. In addition, the housing 40 is provided with a light shielding wall 42 to prevent a phenomenon (washout) in which external light such as sunlight is incident on the display device 20 and the virtual image V becomes difficult to see. The light shielding wall 42 has a flat plate shape and is formed so as to hang obliquely from the upper part of the housing 40.

  According to this embodiment, the green light L1 and the red light L2 emitted from the first and second light sources 23 and 24 are in a state of being substantially collimated through the first and second condenser lenses 27 and 28. By being respectively incident on the dichroic mirror 29, the transmissive display element 21 is illuminated with the illumination light L3 in which the color unevenness including the green light L1 and the red light L2 is suppressed, and the color unevenness is suppressed. The display light L is irradiated on the windshield 13. Thereby, the user 14 can visually recognize the display image V in which color unevenness is suppressed.

  In addition, a diffusing member 201 is disposed between the dichroic mirror 29 and the transmissive display element 21 for diffusing the illumination light L3 that is emitted from the dichroic mirror 29 into a substantially parallel luminous flux. As a result, the illumination light L3 having no color unevenness that is made into a substantially parallel light flux is diffused in a predetermined angle range through the diffusion member 201, and then the diffused light is irradiated onto the transmissive display element 21, thereby the display light L Will be emitted in a diffused state with no color unevenness.

  With such a configuration, even when the user 14 tries to visually recognize the display image V with the head greatly tilted to the left or right, for example, the display light L is within a predetermined angle range. As a result, the display image V in which color unevenness is suppressed can be viewed well. In other words, even when the user 14 moves slightly from a position where, for example, the display image V in which color unevenness is suppressed can be seen well, and views the display image V from this moved position, the display image V ( Since the change in luminance of the display light L) is suppressed, it is possible for the user 14 to visually recognize a good display form without color unevenness.

  In the present embodiment, the example in which each light source 23, 24 has a directivity of approximately 60 degrees to the left and right with the optical axes C1, C2 as the center has been described. If a lens having a high directivity of about 10 degrees to the left and right with respect to the optical axes C1 and C2 is employed, the first and second condenser lenses 27 and 28 are eliminated. Also good.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. 6. The same or corresponding parts as those in the first embodiment described above will be denoted by the same reference numerals and detailed description thereof will be given. Description is omitted. FIG. 6 shows a side view of a display device according to the second embodiment of the present invention.

  The second embodiment is different from the first embodiment in that first and second reflections are used instead of the first and second condenser lenses 27 and 28 employed in the first embodiment. The bodies 51 and 52 are employed, the radiated light emitted from the first light source 23 is converted into a substantially parallel light flux by the first reflector 51, and the light in the state of being converted into the substantially parallel light flux is incident on the dichroic mirror 29. At the same time, radiation light emitted from the second light source 24 is converted into a substantially parallel light beam by the second reflector 52, and the light in the state of being converted into a substantially parallel light beam is incident on the dichroic mirror 29.

  The first reflector 51 is formed, for example, on a first base 51a made of a metal material or a synthetic resin material having a curved shape, and on the front surface of the first base portion 51a (the surface facing the back surface 29b of the dichroic mirror 29). And a first reflecting portion 51b made of a metal vapor deposition film such as aluminum.

  In FIG. 6, below the first reflector 51, the first wiring board 25 employed in the first embodiment is disposed in the vicinity of the lower end portion 29 c of the dichroic mirror 29. On the first wiring board 25, the first light source 23 is mounted that emits light toward the first reflecting portion 51b.

  The second reflector 52 is formed, for example, on a second base 52a made of a metal material having a curved shape or a synthetic resin material, and on the front surface of the second base 52a (a surface facing the reflective film 29a of the dichroic mirror 29). And a second reflecting portion 52b made of a metal vapor deposition film such as aluminum.

  In FIG. 6, the second wiring board 26 employed in the first embodiment is disposed in the vicinity of the lower end portion 29 c of the dichroic mirror 29 on the right side of the second reflector 52. On the second wiring board 26, the second light source 24 that emits light toward the second reflecting portion 52b is mounted.

  According to the second embodiment, the green radiation light (green light L1) emitted from the first light source 23 is reflected to the dichroic mirror 29 (back surface 29b) side by the first reflecting portion 51a. The reflected light is incident on the dichroic mirror 29 in a substantially parallel light flux as in the optical path S5 shown in FIG. At the same time, the red radiation light (red light L2) emitted from the second light source 24 is reflected to the dichroic mirror 29 (reflection film 29a) side by the second reflection part 52a. The light beam is incident on the dichroic mirror 29 in a substantially parallel light flux as shown in an optical path T5 shown in FIG.

  Accordingly, the green light L1 and the red light L2 emitted from the first and second light sources 23 and 24 are incident on the dichroic mirror 29 in a state of being substantially collimated through the first and second reflectors 51 and 52, respectively. Thus, the transmissive display element 21 is illuminated with the illumination light L3 including the green light L1 and the red light L2 in which color unevenness is suppressed, and the display light L in which color unevenness is suppressed is reflected on the windshield. 13 is irradiated. Thereby, the user 14 can visually recognize the display image V in which the color unevenness is suppressed, and can obtain the same effect as that of the first embodiment.

  In the second embodiment as well, the diffusing member 201 is disposed between the dichroic mirror 29 and the transmissive display element 21, so that the user 14 can display the display image V in which color unevenness is suppressed, for example. Even when the display image V is slightly moved from the position where it can be visually recognized and the display image V is viewed from this moved position, the luminance change of the display image V (display light L) is suppressed. Needless to say, it is possible to visually recognize a good display form.

  In each of the above embodiments, the green light L1 and the red light L2 incident on the dichroic mirror 29 are substantially omitted through the first and second condenser lenses 27 and 28 or the first and second reflectors 51 and 52, respectively. By making the light flux parallel, the illumination light L3 (display image V) with suppressed color unevenness can be obtained with a simple configuration.

  In each of the above embodiments, the example in which the display light L emitted from the transmissive display element 21 is applied to the windshield 13 has been described. For example, the display light L is favorably reflected in the direction of the user 14 on the windshield 13. A combiner film may be provided, or the display light L may be irradiated to a dedicated reflecting member different from the windshield 13.

1 is a schematic view of a head-up display device showing a first embodiment of the present invention. Sectional drawing of the head-up display apparatus which shows embodiment same as the above. The side view of the display apparatus which shows embodiment same as the above. The figure which shows the optical path of the 1st light source which shows embodiment same as the above. The figure which shows the optical path of the 2nd light source which shows embodiment same as the above. The side view of the display apparatus which shows 2nd Embodiment of this invention. Sectional drawing of the head-up display apparatus by a prior art. The side view of the display apparatus by a prior art. The figure which shows the optical path of the 1st, 2nd light source by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 13 Front glass 14 User 21 Transmission type display element 22 Illumination means 23 1st light source 24 2nd light source 27 1st condensing lens 28 2nd condensing lens 29 Dichroic mirror (transmission reflection member)
51 1st reflector 52 2nd reflector 201 Diffusion member L Display light L1 Green light (1st colored light)
L2 Red light (second colored light)
L3 Illumination light V Display image (virtual image)

Claims (2)

A first light source that emits first colored light, a second light source that emits second colored light, a transmission / reflection member that transmits the first colored light and reflects the second colored light, A transmissive display element illuminated with illumination light including the first colored light and the second colored light, and irradiates a vehicle windshield or a reflecting member with display light emitted from the transmissive display element. A head-up display device that allows a user of the vehicle to visually recognize a display image obtained by the irradiation,
The first and second colored lights emitted from the first and second light sources are respectively incident on the transmission / reflection member in a substantially parallel luminous flux, and the transmission / reflection member and the transmission type A head-up display device, characterized in that a diffusing member for diffusing the illumination light, which is converted into a substantially parallel light beam emitted from the transmissive reflecting member, is disposed between the display elements. The first and second colored lights incident on the transmitting / reflecting member are formed into substantially parallel light fluxes through the first and second condenser lenses or the first and second reflectors, respectively. The head-up display device according to claim 1.

Images