JPH04242785A - Head-up display - Google Patents

Abstract

PURPOSE:To prevent the burning of an optical information display means without using a cold mirror or a hot mirror. CONSTITUTION:The optical axial direction of the light emitting surface of an optical member A for projecting an information indicating light toward a combiner C is turned in vertical direction, and a screen D1 is disposed in an area on and adjacent to the optical axis of the optical member A which a sunlight S entering the optical member A never reaches.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention enables the driver of a track running vehicle (including general railway vehicles, monorails, new transportation systems, etc.) running on a defined track to operate the vehicle while looking at the scene in the outside world ahead. In particular, the present invention relates to a head-up display for a vehicle that displays various information (for example, speed information, brake information, time information, etc.) superimposed on the external scene in front of the driver. If such a head-up display is used, the driver does not have to take his eyes away from the scene ahead to look at the instruments, so it is possible to prevent unexpected accidents that may occur while the driver takes his eyes away from the scene ahead. can.

0002

2. Description of the Related Art The conventional head-up display normally has a combiner such as a half mirror or a hologram element placed in front of the user's field of view, and the combiner directs light rays emitted from the scene in front of the user in the direction of the user. The information display light is transmitted through the combiner and is configured to reflect or diffract the information display light incident on the rear surface of the combiner toward the driver. The information projecting device that makes the information display light enter the combiner includes an optical information display means such as a CRT, a plasma display, or a light emitting diode display, and an optical system that makes the light emitted from the optical information display means enter the combiner. It is equipped with a member. The optical member is usually composed of a lens system, a reflecting mirror, etc., and is configured so that the information display light can be visually recognized by the driver in the front field of view.

0003

[Problems to be Solved by the Invention] In the conventional head-up display, the distance from the visual position (eye position) behind the combiner to the scene in front of the combiner,
If the distance from the visible position to the position where the display information is visually recognized (the position of the virtual image of the display information, that is, the position of the information display image) differs greatly, the eyes will get tired, so it is important to make sure that the distances are the same. It is set to be. In particular, with head-up displays used in track-driving vehicles, the distance from the viewing position (driver's eye position) to the scene in front of the combiner is quite long. The distance to the position of the image) is also set long. Therefore, the information display light that reaches the visible position is substantially collimated by the optical member.

In order to substantially collimate the information display light in this manner, conventionally, when sunlight passes through the combiner and enters, the optical member condenses the sunlight and forms the display surface of the optical information display means. A sun image may be formed in the vicinity of the optical information display means, which may cause the optical information display means to be burnt out. To prevent this, conventionally, a so-called cold mirror that reflects only visible rays and transmits infrared rays, which is heat rays, is used as a reflecting mirror constituting the optical member.
Alternatively, a so-called hot mirror that transmits visible light but reflects infrared rays is used in the optical path of the optical member to prevent infrared rays from reaching the optical information display means.

[0005] In general, head-up displays used in track-running vehicles and the like are located far from the user, so in order to ensure the necessary size of the displayed information image, the optical information display means must be A large display surface is also required. For this reason, the cold mirror or hot mirror described above also needs to have a relatively large area, but since these are manufactured by coating the glass surface with multiple layers of dielectric material, it is difficult to obtain a large area mirror, which increases costs. becomes. Moreover, since the amount of light condensed is large, even if the cold mirror or hot mirror is used, there is a risk that the temperature will rise in the solar imaging area.

[0006] By the way, considering the railway vehicles operated in Japan, the southernmost point is at about 31 degrees north latitude in Kagoshima Prefecture, and even at the midsummer time of the summer solstice, when the sun is at its highest altitude, the sun is about 7 degrees from the vertical direction. It is tilted .5 degrees to the south. Additionally, the slope of a railway track is generally said to be at most 33 per mil (33/1000), which is approximately 1.9 degrees, so in a railway vehicle, the slope is approximately 5 degrees in the longitudinal direction from the vertical direction of the vehicle. The sun is never located within .6 (=7.5-1.9) degrees. Therefore, if the optical axis of the information display light emitted from the optical member toward the combiner is oriented vertically, even when the railway vehicle is tilted the most forward or backward, sunlight will be perpendicular to the optical axis of the optical member. There is no incident on . In this case, the position where the sunlight incident on the optical member converges is a position away from the optical axis of the optical member. In other words, sunlight does not reach within a region of a predetermined area located on the optical axis side of the position where the sunlight incident on the optical member converges.

[0007] Furthermore, so-called cants are provided inward on curved sections of railway tracks in order to cancel out the centrifugal force when a vehicle runs. Therefore, a vehicle traveling on a curved section with a small radius may lean left or right by more than the maximum longitudinal inclination angle due to the gradient, but such sharp curved sections only exist in limited sections, and In this case, since the inclination direction of the vehicle changes from moment to moment as the vehicle travels, the sun image will not remain on the display surface of the optical information display means for a long time and the display surface will not be burnt out.

[0008] Therefore, if the direction of the optical axis of the light emitting surface of the optical member that emits the information display light toward the combiner is arranged vertically, there will be a region where the solar image does not remain for a long time. By placing the display surface in the area, it should be possible to prevent damage to the display surface from sunlight. In view of the above-mentioned circumstances and results of consideration, the present invention has been made based on the following:
It is an object of the present invention to prevent burnout of an optical information display means without using a cold mirror or a hot mirror, which causes an increase in cost.

[0009]

[Means for Solving the Problems] In order to solve the above problems, the head-up display of the present invention includes an optical information display means having a display surface on which information is displayed, and an information display light emitted from the display surface. An information projector equipped with an optical member that projects light in a predetermined direction, and an information projector that is installed to be inclined in front of the operator and directs light rays from the outside world forward so that the operator can visually recognize the scene of the outside world in front of the operator. A head-up display for a track running vehicle, comprising a combiner that transmits information display light projected from the information projection device backward and reflects the information display light projected from the information projection device in a direction visible to a driver, The direction of the optical axis of the light exit surface of the optical member that projects the information display light is oriented in the vertical direction, and sunlight that is on the optical axis of the optical member and in an area adjacent thereto and that is incident on the optical member does not reach the optical member. The display screen is characterized in that the display surface is arranged in the area.

0010

[Operation] In the head-up display of the present invention having the above-mentioned features, the direction of the optical axis of the light exit surface of the optical member that projects the information display light toward the combiner is oriented in the vertical direction. In this case, there is a region on the optical axis of the optical member and an adjacent portion thereof where the solar image does not remain for a long time. Further, according to the present invention, since the solar image is disposed on the optical axis of the optical member and in an area adjacent to the optical axis where the solar image does not remain for a long time, damage to the display surface due to sunlight can be prevented.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, a driver's cab 2 is installed at the front end of a railway vehicle 1. In this driver's cab 2, an instrument panel 4 is arranged in front of a seat 3 for a pilot P. Further, in front of the driver's cab 2, a windshield 7 is disposed between the lower part 5 of the car body of the electric train 1 and the ceiling 6.

[0012] The instrument panel 4 of the driver's cab 2 is provided with an information projection device K of a head-up display. This information projecting device K has a casing B shown in FIG. Inside this casing B, an optical member A, a light shielding plate N, and an optical information display means D are arranged. This optical information display means D is composed of a transmissive liquid crystal display panel D1 and a light source D2 disposed on the back surface thereof.

The liquid crystal display panel D1 is driven by a liquid crystal drive circuit (not shown), and necessary information (for example, speed information or brake pressure information) is displayed on its display surface. Further, the light source D2 includes a reflecting mirror 10.
and a metal halide lamp 11 supported by the lamp.

The light shielding plate N disposed between the liquid crystal display panel D1 and the optical member A is composed of a black colored metal plate, and the liquid crystal display panel D1 is disposed in the center of the light shielding plate N.
The hole is the same size as the display section.

The optical member A is composed of a lens system A1, a mirror A2, a convex lens A3, etc., and is arranged so as to emit the information display light L emitted from the optical information display means D upward in the vertical direction. ing. The optical axis Ax of the portion that emits the information display light L upward in the vertical direction (i.e., the light emitting surface of the optical member A) is oriented in the vertical direction when the railway vehicle 1 is in a horizontal position. It is set.

As mentioned above, the light exit surface (
That is, since the optical axis Ax of the convex lens A3 (top surface of the convex lens A3) is set in the vertical direction, the incident angle (angle with the optical axis Ax) of the sunlight S (see FIG. 3) on the convex lens A3 is approximately 5.
．． It cannot be less than 6 degrees. In this case, the solar image will be formed at a certain distance from the optical axis of the optical member A. Therefore, the display surface of the liquid crystal display panel D1 is arranged on the optical axis of the optical member A and in an area adjacent thereto, where the solar image is not formed. The liquid crystal display panel D1 is composed of a display surface and a circuit-forming portion outside the display surface, and when a solar image is formed on the circuit-forming portion, the temperature of that portion increases, causing an adverse effect. Therefore, the light shielding plate N prevents a solar image from being formed on the circuit forming portion.

The light exit surface of the optical member A (convex lens A3
A combiner C made up of a half mirror is disposed above the top surface. This combiner C is arranged so as to transmit a part of the information display light L incident from the optical member A and reflect the remaining part towards the operator P. Further, the combiner C is arranged so as to reflect a part of the external light J transmitted through the windshield 7 from an external scene, etc., and transmit the remaining part toward the operator P. Although the combiner C and the windshield 7 are constructed separately in this embodiment, it is also possible to provide the windshield 7 itself with a function as a combiner. The optical member A and the optical information display means D constitute an information projection device K, and the combiner C, the information projection device K, etc. constitute a head-up display H (see FIGS. 1 and 3). has been done.

Next, the operation of the embodiment of the present invention having the above-described configuration will be explained. External light rays J from the outside world on the left side of FIG. 1 pass through the windshield 7 and enter the combiner C. Part of the external light beams J is reflected by the combiner C to the outside world, and the rest passes through the combiner C and goes straight. It reaches the eyes of Person P. This allows the operator P to visually recognize the scene in the outside world as it is.

On the other hand, the operating information displayed on the liquid crystal display panel D1 of the information projecting device K is converted into information display light by the illumination light from the light source D2, passes through the optical member A, and enters the combiner C. . A part of the information display light L passes through the combiner C and is emitted to the outside world, but the remaining part is reflected and reaches the driver's P's eyes. Since this information display light L is collimated by the optical member A, its display image is as far away as the scene in front, and the driver P can check the driving information while looking at the front outside the vehicle.

As mentioned above, the light exit surface (
That is, since the optical axis Ax of the upper surface of the convex lens A3 is set in the vertical direction, the incident angle θ (see FIGS. 1 and 3) of sunlight S (see FIG. 3) on the convex lens A3 is about 5. 6
It will never be less than a degree. Therefore, sunlight S is
The light is not blocked by the light shielding plate N and does not reach the liquid crystal display panel D1.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various design changes can be made without departing from the scope of the invention described in the claims. It is possible to do this. For example, instead of a liquid crystal display panel, a CRT display tube, a plasma display, a light emitting diode display, etc. may be used as the optical information display means. Also, when using a small display area as an optical information display means,
If there is no heat-sensitive member such as a circuit board disposed on the outer periphery, the light shielding plate may be omitted. Further, in the above embodiment, the optical member A is provided with the mirror A2, and the light shielding plate N, the liquid crystal display panel D1, the light source D2, etc. are arranged on the side, but the instrument panel 4 may have a sufficiently large dimension in the height direction. If so, it is also possible to omit the mirror A2 and arrange the liquid crystal display panel D1 and the like entirely below the lens A3. Furthermore, in addition to a colored metal plate, the light shielding plate N can also be made of a heat-resistant material such as ceramic with low light reflectance, and it is also possible to incorporate a heat pipe etc. to release heat. It is. Further, by rotating the casing according to the inclination of the railway vehicle, it is also possible to maintain the optical axis of the light exit surface of the optical member vertically at all times. Furthermore, the present invention can be applied to vehicles other than general railway vehicles, such as monorail cars, new transportation systems, etc., whose tilting posture is predetermined.

[0022]

Effects of the Invention In the above-described head-up display of the present invention, the direction of the optical axis of the light exit surface of the optical member that projects information display light toward the combiner is directed in the vertical direction, and Since the display surface is arranged on the optical axis and in an area adjacent to the optical axis where sunlight that enters the optical member does not reach, optical Burnout of the information display means can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a state in which an embodiment of the head-up display of the present invention is installed in a railway vehicle.

FIG. 2 is a partial plan view of the same embodiment.

FIG. 3 is a side cross-sectional view of essential parts of the same embodiment.

[Explanation of symbols]

A Optical member C Combiner (windshield) D. Optical information display means D1 Liquid crystal display panel D2 Light source H Head-up display J External scene light K　Information projection device L Information display light N　Light shielding plate P Driver

Claims (1)

[Claims] 1. An information projecting device comprising: an optical information display means having a display surface on which information is displayed; an optical member projecting information display light emitted from the display surface in a predetermined direction; The driver is provided at an angle in front of the driver, and transmits light rays from the outside world from the front to the rear so that the driver can visually recognize the scene of the outside world in front of the driver, and also transmits the information display light projected from the information projector. In a head-up display for a track running vehicle that includes a combiner that reflects in a direction visible to the operator, the direction of the optical axis of the light output surface of the optical member that projects information display light toward the combiner is The display surface of the optical information display means is oriented in the vertical direction, and is arranged on the optical axis of the optical member and in an area adjacent to the optical axis and in an area where sunlight incident on the optical member does not reach. Head-up display for tracked vehicles.