JPH04325323A - Head-up display - Google Patents

Abstract

PURPOSE:To set the display light of a head-up display to the invariably conspicuous display intensity by calculating and adjusting the display intensity against the unprescribed background intensity from the display intensity manually set against the preset background intensity via a pilot. CONSTITUTION:The information display light L emitted from an optical information display means D is polarized and fed to a front glass C through a polarizing plate E and an optical member A. Part of the incident information display light L penetrates the front glass C and is sent to the outside, and the remainder is reflected and sent to eyes of a pilot. The intensity change pattern against the background intensity is set to the taste of the pilot by a setting means 18. A microcomputer M calculates the display intensity from the preset equation in response to the intensity signal inputted from the setting means 18. The intensity of the information display light L displayed on the optical information display means D is controlled by the rotation position of a polarizing plate E, and it is adjusted to the display intensity conspicuous for the pilot.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention provides various information ( For example, speed information, brake information, time information, etc.)
Regarding a head-up display that displays overlapping images. Using such a head-up display eliminates the need for the driver to take his or her eyes away from the outside world and look at the instruments, thereby making it possible to prevent unexpected accidents that may occur while the driver takes his or her eyes away from the outside world.

0002

2. Description of the Related Art In the conventional head-up display, a combiner such as a half mirror or a hologram element is usually placed in front of the driver's visual field, and the combiner transmits light rays emitted from the external scenery toward the driver. The information display light incident on the combiner from inside the cockpit is reflected or diffracted in the direction of the operator. 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 generally 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 above-mentioned conventional head-up display, when the brightness of the displayed optical information is kept constant and applied to a railway vehicle, etc., it is difficult to distinguish between when driving in a tunnel, when driving at night, and when driving on the ground during the day. The brightness of the outside world around the vehicle varies greatly depending on the time of day, so even if the display brightness is easy to see in a relatively bright place, it may be too bright in a relatively dark place, making it difficult to see the outside world in front of the vehicle, or causing problems in a dark place. If the display brightness is set to zero, the problem arises that optical information becomes almost invisible in bright places.

[0004] Conventionally, therefore, a sensor is provided to detect the background brightness (ie, background brightness) in the field of view in which the driver visually recognizes the optical information of the head-up display, and the display brightness is varied according to the brightness of the outside world. Conventionally, display brightness control means as shown in FIGS. 8 and 9 have been used.

The device shown in FIG. 8 is provided with a brightness setting means VR that can be manually set by the operator, and performs manual brightness control using a manually set brightness signal Vm set by the brightness setting means and automatic brightness control using a background brightness signal Va. The switching is performed using a switch Sw. When an appropriate display brightness cannot be obtained with the automatic brightness control, the operator switches the switch Sw to perform manual brightness control, and the brightness setting means V
By adjusting R, the display brightness signal Vo is set.

In the system shown in FIG. 9, a switch Sw switches between a background brightness signal Va and a constant voltage E, and a brightness setting means VR sets a display brightness signal Vo desired by the driver.

In the conventional example shown in FIGS. 8 and 9, when switching between automatic brightness control and manual brightness control using the switch Sw, it may not be possible to obtain an appropriate display brightness. That is, when the manually set brightness signal Vm in FIG. 8 or the constant voltage E in FIG. 9 is higher than the background brightness signal Va, when switching from automatic brightness control to manual brightness control, the display brightness becomes too high (display becomes too bright), making it difficult to see the outside world. Furthermore, when the background brightness signal Va is higher than the manually set brightness signal Vm in FIG. 8, when switching from automatic brightness control to manual brightness control, the necessary display brightness cannot be obtained (the display becomes too dark). ) Optical display information becomes difficult to see.

In other words, as mentioned above, in the method of switching between automatic brightness control and manual brightness control while using a head-up display, the display brightness changes rapidly when switching, making it difficult to see the displayed information. There was a problem. ,

Furthermore, since the display brightness that the user of a head-up display, that is, the operator feels is easy to see, differs depending on individual differences, uniform display brightness control for each operator may result in a display that is easy to see for a certain operator. Even so, it may be difficult for other operators to see. In other words, according to the inventor's research, there is a large difference in display brightness that the pilot feels is easy to see when the background is dark, depending on the pilot's visual acuity. (becomes more pronounced as the background becomes darker). On the other hand, even when the background is bright, there is variation in display brightness that is perceived as easy to see due to individual differences, but this variation is thought to be due to the driver's preference rather than visual acuity.

[0010] In view of the above-mentioned problems, the present invention enables each operator to always set the information display light of the head-up display to a display brightness that he or she feels is easy to see, regardless of whether the background brightness is dark or bright. The task is to do so.

[0011]

[Means for Solving the Problems] Next, the invention of the present application devised to solve the above problems will be explained. Therefore, the symbols of the elements of the embodiments are enclosed in parentheses. The reason for explaining the present invention in correspondence with the reference numerals of the embodiments described later is to facilitate understanding of the present invention, and is not to limit the scope of the present invention to the embodiments. In order to solve the above problems, the head-up display (H) of the present invention includes an optical information display means (D) having a display surface on which information is displayed, and an information display light (L) emitted from the display surface. Optical member (A) that emits light in a predetermined direction
an information projection device (K) equipped with an information projection device (K), and an information display light (J) that transmits light (J) emitted from a scene in front toward a rear viewing position and projected from the information projection device (K);
a combiner (C) for directing the L) to the viewing position;
Information display light (L) visually recognized by the pilot (P)
background brightness detection means (17) for detecting the background brightness of the vehicle; and display brightness adjustment means for adjusting the brightness of the information display light (L) visually recognized by the operator (P) according to the detected background brightness. (U) In the head-up display, the display brightness adjustment means (U) is configured to adjust the display brightness for a predetermined display brightness setting background brightness in a background high brightness area where the background brightness is bright and for a background brightness where the background brightness is dark. manual brightness setting means (18) for manually setting display brightness for a predetermined display brightness setting background brightness in a brightness area; and from each of the display brightnesses manually set for the predetermined display brightness setting background brightness, display brightness calculating means for calculating a display brightness with respect to a background brightness other than the predetermined display brightness setting background brightness, and information display light that is visually recognized by the operator (P) according to the calculated display brightness. The display is characterized in that it is configured to adjust the brightness of the display.

Various calculation formulas can be adopted for the "display brightness calculation means", but for example, the horizontal axis of the coordinate axes is the background brightness, the vertical axis is the display brightness, and the above coordinates are plotted on the coordinate axes. Each of the manually set display brightnesses is plotted with respect to each predetermined display brightness setting background brightness of the background high brightness area and the background low brightness area. Then, a formula representing a straight line connecting these plot points can be employed as the calculation formula. In addition, select three or more of the predetermined background brightness settings for display brightness, plot each manually set display brightness on the coordinate axes, and use a formula representing a polygonal line connecting those plot points or each plot point. A formula representing a curve (spline curve) that smoothly connects can be employed as the calculation formula.

[0013]

[Operation] The operator (P) using the head-up display (H) of the present invention having the above-mentioned features can use the manual brightness setting means (18) of the display brightness adjustment means (U) to
For setting a predetermined display brightness in a high-brightness area with a bright background and a dark background.For setting a predetermined display brightness in a low-brightness area with a dark background and a dark background.You can manually adjust the display brightness relative to the background brightness according to your preference. Can be set. The display brightness calculation means calculates a background brightness other than the predetermined display brightness setting background brightness from each display brightness manually set by the operator (P) with respect to a predetermined display brightness setting background brightness. The display brightness is calculated using a predetermined calculation formula. The brightness of the information display light (L) visually recognized by the operator (P) is adjusted according to the calculated display brightness.

[0014]

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, there is a lower body part 5 of the railway vehicle 1 and a ceiling 6.
A windshield C as a combiner is arranged between the two. As shown in FIG. 1, this windshield C is arranged so as to be inclined downward as it goes forward.

An information projection device K of a head-up display H is disposed on the instrument panel 4 of the driver's cab 2. The information projecting device K has a casing 10. Inside this casing 10, as shown in FIGS. 3 and 4, an optical member A and an optical information display means D are arranged. This optical information display means D is composed of a transmissive liquid crystal display panel (polarized light transmissive display panel) D1 that emits polarized light, and a light source D2 disposed on the back thereof. The liquid crystal display panel D1 is driven by a liquid crystal drive circuit 11, and necessary information (for example, speed information, brake pressure information, etc.) is displayed on its display surface. Also,
The light source D2 includes a reflecting mirror 12 and a metal halide lamp 13 supported by the reflecting mirror 12.

The optical member A is composed of a lens system A1, a mirror A2, a convex lens A3, etc., and is arranged so that the information display light L emitted from the optical information display means D is incident on the windshield C. has been done. A polarizing plate E is disposed between the optical member A and the optical information display means D, and the polarizing plate E has a
A gear 14 is provided at a portion where the central angle is slightly larger than degrees. The casing 10 includes 180
The gear 14 is placed on the outer periphery, which allows for a center angle that is slightly larger than the degree.
A groove (not shown) is formed to allow rotation of the
The gear 14 is rotatable together with the polarizing plate E within an angle slightly larger than 90 degrees.

A stepping motor S is disposed on the upper outer surface of the casing 10.
A pinion 15 fixed to the output shaft of is engaged with the gear 14. Then, when the stepping motor S rotates and the polarizing plate 14 rotates in a range of 0 to 90 degrees, the polarization direction of the information display light L passing through the liquid crystal display panel D1 and the polarization direction of the polarizing plate E become different. The shift, or phase shift, varies between 0 and 90 degrees. At this time, the brightness of the information display light L is adjusted.

The stepping motor S is configured to be operated by a motor drive circuit 16, and the motor drive circuit 16 is controlled by a microcomputer M. The light amount of the external scene light J, that is, the background brightness is detected by a light amount sensor (background brightness detection means) 17, and the background brightness signal detected by the light amount sensor 17 is input to the microcomputer M. The microcomputer M includes a central processing unit CPU, a memory Me, an interface I/F, and the like.

The microcomputer M includes manual brightness setting means 1.
8 are connected. This display brightness setting means 18 is for manually setting the display brightness for a predetermined display brightness setting background brightness in a background high brightness area where the background brightness is bright, a background low brightness area where the background brightness is dark, and a background medium brightness area. belongs to. As shown in FIG. 5, the background brightness for setting the predetermined display brightness is 3000 (candela/square meter) in the background high brightness area, 0.3 (candela/square meter) in the background low brightness area,
In the background medium brightness region, 30 (candela/square meter) is adopted.

As can be seen from FIG. 5, for the display brightness setting background brightness value of 3000 (candela/square meter) adopted in the background high brightness area, the manual brightness setting means 18 sets the background brightness to 6000. ~2
The display brightness can be set within a range of 0,000 (candela/square meter). Further, the background brightness value for display brightness setting adopted in the background low brightness area is 0.
．． 3 (candela/m2), the manual brightness setting means 18 allows the display brightness to be set in the range of 3 to 30 (candela/m2). In addition, for the display brightness setting background brightness value of 30 (candela/m2) adopted in the background medium brightness region, the manual brightness setting means 18 sets the value in the range of 30 to 300 (candela/m2). Display brightness can be set.

Each setting display brightness signal outputted from the manual brightness setting means 18 is input to the microcomputer M. The microcomputer M determines the equation of the polygonal line shown in FIG. 5 in accordance with the display brightness signals input from the manual brightness setting means 18. Then, the microcomputer M calculates display brightness from the polygonal line equation according to the background brightness signal input from the optical sensor 17. In other words, microcomputer M
has a function as display brightness calculation means. The microcomputer M outputs a control signal for the stepping motor S to the motor drive circuit 16 in accordance with the calculated display brightness.

The control signal for the stepping motor S that is output from the microcomputer M in accordance with the calculated display brightness is determined by the polarization direction of the information display light L and the polarization of the polarizing plate E as the calculated display brightness increases. The stepping motor S is driven so that the deviation in direction, that is, the deviation in phase, is reduced. Further, the control signal drives the stepping motor S so that the deviation between the polarization direction of the information display light L and the polarization direction of the polarizing plate E becomes smaller as the calculated display brightness is lower. The display brightness adjusting means U is constituted by the components indicated by the reference numerals 14 to 18 and M.

The windshield 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 windshield C is arranged so as to reflect a part of the external light J incident from an external scene, etc., and transmit the remaining part toward the operator P. That is, the windshield C of this embodiment itself has a function as a combiner. In addition, the combiner is
It is also possible to configure it separately from the windshield. An information projecting device K is constituted by the optical member A and the optical information display means D, and the information projecting device K is composed of the windshield C functioning as the combiner, the information projecting device K, the display brightness adjusting device U, etc. Display H (
(see Figures 1 and 3).

Next, the operation of the embodiment of the present invention having the above-described configuration will be explained. External light rays J proceeding toward the windshield C from the outside world on the left side of Figure 1, part of which is reflected by the windshield C to the outside world, and the rest of the light passes through the windshield C and travels 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 information display light L emitted from the optical information display means D of the information projecting device K is polarized light, and as can be seen from FIG. The amount of transmitted light is adjusted according to the rotational position of E. The information display light L that has passed through the polarizing plate E and the optical member A is incident on the windshield C. The information display light L incident on the windshield C is
A part of the light passes through the windshield C and is emitted to the outside world, but the rest is reflected and reaches the eyes of the operator P. This allows the operator P to visually recognize the information display light L. and,
The brightness of the information displayed on the optical information display means D, that is, the brightness of the information display light L, is controlled by the rotational position of the polarizing plate E.

Next, a method of controlling the rotational position of the polarizing plate E will be explained with reference to FIG. In FIG. 7, control of the rotational position of the polarizing plate E is executed by a program (polarizing plate rotational position control flow execution program) stored in the memory Me of the microcomputer M. When the polarizing plate rotation position control flow is started by the program, the display brightness manual setting value set by the manual brightness setting means 18 is read in step S1. Next step S
In step 2, a display brightness calculation formula is determined. This display brightness calculation formula is a polygonal line equation shown in FIG.

Next, in step S3, the optical sensor 1
7. Read the background brightness detected in step 7. Next step S4
In step S5, the display brightness is calculated from the display brightness calculation formula and the background brightness, and the rotational position of the stepping motor S, that is, the rotational position of the polarizing plate E is detected. Next, in step S6, it is determined whether the rotational position of the polarizing plate E is correct, that is, whether the polarizing plate E is at a rotational position corresponding to the calculated display brightness. If yes (Y), step S1
If the answer is NO (N), the process moves to the next step S7.

In step S7, the stepping motor S is driven to a rotating position corresponding to the calculated display brightness. That is, when the amount of external scene light J detected by the light amount sensor 14 is greater than the display brightness corresponding to the detected rotational position of the stepping motor S (rotation position of the polarizing plate E) (the When the calculated display brightness is high), the stepping motor S is driven so that the phase shift in the polarization direction (the polarization direction of the transmitted light of the liquid crystal display panel D1 and the polarization direction of the polarizing plate E) becomes small. At this time, the brightness of the information display light L becomes high. Further, the polarizing plate E is driven by a stepping motor S so that when the amount of external scene light J detected by the light amount sensor 14 is small, the phase shift in the polarization direction becomes large. At this time, the information display light L
The brightness of will be lower.

Next, in step S8, it is determined whether the polarizing plate rotation position control flow has been completed. No (N)
In this case, the process returns to step S1. If yes (Y), the process ends.

An embodiment of the head-up display of the present invention having the above-mentioned features includes a polarization transmission type display panel that emits polarized light and a polarizing plate disposed parallel to the display panel and rotatably supported. Therefore, when the vibration direction of the polarized light emitted from the polarized light transmissive display panel and the vibration direction of the light transmitted through the polarizing plate are set in the same direction, a high-brightness display will be obtained, and the vibration of the polarized light emitted from the polarized light transmissive display panel will be When the direction and the vibration direction of the light transmitted through the polarizing plate are shifted by 90 degrees, a display with low brightness is obtained. Since the display brightness is changed simply by rotating the polarizing plate, the display brightness can be adjusted at high speed.

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, in the embodiment described above, the manual brightness setting means 18 can be provided with more setting levers in order to more precisely set the brightness. In that case, the pattern of brightness changes relative to the background brightness can be adjusted to suit the driver's preference. In addition, the present invention
It is also possible to apply the present invention to a head-up display using an RT display or an LED display. Furthermore, in the above embodiments, the polarizing plate can be placed at any position along the optical path from the light source to the person viewing the display. The display brightness can also be adjusted by adjusting the brightness of the light source itself, instead of by adjusting the rotational position of the polarizing plate. For example, when using an LED display, brightness can be adjusted by changing the duty ratio of blinking. Furthermore, the present invention can also be applied to head-up displays for vehicles other than railway vehicles.

[0031]

Effects of the Invention The head-up display of the present invention having the above-mentioned characteristics has a display brightness for a predetermined display brightness setting in a background high-brightness area where the background brightness is bright, and a background low brightness where the background brightness is low (dark). The display brightness relative to the predetermined display brightness setting background brightness in the area can be manually set according to the operator's preference. Therefore, the driver using the head-up display can always view the information display light of the head-up display at a display brightness that he or she feels is easy to see, even if the background brightness changes over a wide range.

[Brief explanation of drawings]

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 sectional view of the main parts of the same embodiment.

FIG. 4 is an enlarged perspective view of the same embodiment.

FIG. 5 is an explanatory diagram of display brightness relative to background brightness in the same example.

FIG. 6 is an explanatory diagram of the function of the brightness adjustment part.

FIG. 7 is an explanatory diagram of the operation of the polarizing plate rotation position control flow.

FIG. 8 is an explanatory diagram of a conventional display brightness adjustment means.

FIG. 9 is an explanatory diagram of a conventional display brightness adjustment means.

[Explanation of symbols]

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; a combiner that transmits light emitted from a scene toward a rear viewing position and directs information display light projected from the information projecting device toward the viewing position; A head-up display comprising a background brightness detection means for detecting background brightness, and a display brightness adjustment means for adjusting the brightness of information display light visually recognized by the operator according to the detected background brightness, The display brightness adjustment means adjusts the display brightness for a predetermined display brightness setting background brightness in a background high brightness area where the background brightness is bright and the display brightness for a predetermined display brightness setting background brightness in a background low brightness area where the background brightness is dark. Calculating display brightness for background brightness other than the predetermined display brightness setting background brightness from a manual brightness setting means that manually sets the display brightness and each display brightness manually set for the predetermined display brightness setting background brightness. A head-up display comprising: display brightness calculation means, and configured to adjust the brightness of information display light visually recognized by the operator according to the calculated display brightness.