JP2017003684A - Head-up display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head-up display device capable of avoiding troubles of a display due to incidence of external light while maintaining visibility of display as much as possible.SOLUTION: A head-up display device 100 has a controller 31 configured to; estimate temperature value of a liquid crystal panel 11a based on ambient temperature around a display 11 acquired by a temperature acquisition unit; estimate an increase in temperature value due to external light SL based on illuminance of the external light SL acquired by an illuminance acquisition unit; compute an expected temperature value of the liquid crystal panel 11a by adding the increase in temperature value to the estimated temperature value of the liquid crystal panel 11a; execute first processing for reducing brightness of a light source 11b when the expected temperature value is determined to be no less than a first threshold; and execute second processing for avoiding irradiation of the display 11 with the external light SL by controlling an actuator 14 when the expected temperature value is determined to be no less than a second threshold that is greater than the first threshold.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a head-up display device.

  Conventionally, a head-up display (Head) that displays vehicle information in front of a windshield or the like so that a vehicle driver can recognize vehicle information (speed, mileage, etc.) with little movement while driving. -Up Display (HUD) device has been proposed. The HUD device includes a display having a transmissive liquid crystal panel, for example, and projects a display light representing a display image emitted from the display onto a transmissive reflection unit such as a windshield so that a virtual image of the display image is superimposed on the landscape. Make it visible to the driver. In such a HUD device, when external light (mainly sunlight) is incident on the display, the temperature of the liquid crystal panel rises, blacking occurs in the liquid crystal in the liquid crystal panel, and display becomes impossible. There was a case that the trouble occurred in the vessel. Further, in recent years, the HUD device has realized a wide angle of view and a so-called augmented reality (AR) display in which a virtual image is displayed over a specific object (such as a forward vehicle or a white line) in a landscape in front of the vehicle. Since the distance display is progressing and the volume of the HUD device needs to be suppressed, the optical magnification (display / display) is high, and the liquid crystal by the external light is easy to collect the external light on the display. There is a greater risk of panel temperature rise.

  In order to deal with such a problem, for example, in the cited document 1, the intensity of light in a specific wavelength band transmitted through a transmission / reflection member constituting the optical system of the HUD device is detected from outside light, and the intensity is a predetermined threshold value. A method is disclosed in which the luminance of the backlight light is reduced or the backlight is extinguished when exceeding the above. Also, in the cited document 2, the brightness of external light from a predetermined area is detected, and when the illuminance data from which the brightness of the external light is detected exceeds a predetermined value, the display light is projected onto the projection member (transmission reflection section). A method of rotating the reflecting mirror that projects the lens to an angular position where external light is not reflected by the display is disclosed.

JP 2013-228442 A JP 2005-331624 A

  Each of the methods disclosed in the cited documents 1 and 2 executes a process for suppressing the temperature rise of the liquid crystal panel when the illuminance of outside light becomes a predetermined threshold value or more. However, since the temperature of the liquid crystal panel is influenced by illumination light from a light source in addition to external light, it is necessary to provide a certain margin for the threshold value. That is, even when the temperature of the liquid crystal panel does not actually reach the temperature at which the blackening phenomenon occurs in the liquid crystal, processing for suppressing the temperature rise of the liquid crystal panel may be executed. Since the processes for suppressing the temperature rise of the liquid crystal panel disclosed in the cited references 1 and 2 are those in which the visibility of the display is reduced or not displayed, further improvement is achieved in that the display is maintained as much as possible. There was room.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a head-up display device capable of avoiding a malfunction of a display device due to incidence of external light while maintaining display as much as possible. .

In order to solve the above-described problem, the head-up display device of the present invention includes a liquid crystal panel and a light source that irradiates the liquid crystal panel with illumination light from behind, and displays a display image on the liquid crystal panel by the illumination light. A display that emits display light indicating the display image from the liquid crystal panel;
A reflective member that reflects the display light toward a transmission / reflection part disposed in front of the viewer;
A head-up display device comprising a control unit that drives and controls the display,
A temperature acquisition unit for acquiring an ambient temperature of the display;
An illuminance acquisition unit for acquiring the illuminance of outside light;
An external light irradiation avoiding unit for avoiding irradiation of the external light to the display device,
The control unit estimates a temperature value of the liquid crystal panel based on the ambient temperature acquired by the temperature acquisition unit, and estimates a temperature increase value due to the external light from the illuminance of the external light acquired by the illuminance acquisition unit. Then, the predicted temperature value of the liquid crystal panel is calculated by adding the temperature rise value to the estimated temperature value of the liquid crystal panel, and when it is determined that the predicted temperature value is equal to or greater than a first threshold value, Performing the first process of reducing the brightness, and controlling the external light irradiation avoiding unit when it is determined that the predicted temperature value is equal to or greater than a second threshold value that is greater than the first threshold value, A second process for avoiding external light from being irradiated on the display is performed.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to avoid the malfunction of the indicator by incident of external light, maintaining a display as much as possible.

It is a figure which shows schematic structure of the head-up display apparatus in embodiment of this invention. It is a figure which shows the liquid crystal panel of embodiment same as the above. It is a flowchart of the trouble avoidance process of embodiment same as the above. It is a figure which shows the mode of the angle adjustment of the concave mirror in embodiment same as the above.

  Hereinafter, an embodiment of a head-up display (hereinafter referred to as HUD) device of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of a HUD device 100 according to the present embodiment. As shown in FIG. 1, the HUD device 100 is mounted on, for example, an automobile, and includes a display 11, a plane mirror 12, a concave mirror 13 (an example of a reflecting member), and an actuator 14 (external light irradiation avoiding unit, An example of an angle adjustment unit), a housing 15, a temperature sensor 21, an illuminance sensor 22, an imaging unit 23, and a control unit 31. The HUD device 100 reflects the display light L representing the display image M displayed on the display area DP by the display device 11 with the plane mirror 12 and the concave mirror 13, and the windshield (transmission reflection) of the vehicle 1 on which the HUD device 100 is mounted. Example of unit) By irradiating 1a, the user can visually recognize the virtual image V. The eye box 2 indicates a viewpoint range in which the user can visually recognize the virtual image V. The contents displayed by the HUD device 100 in this way are, for example, various vehicle information such as the vehicle speed, navigation information that indicates a route, and the like.

  The display 11 is, for example, a transmissive liquid crystal panel including a TFT (Thin Film Transistor) type liquid crystal panel 11a and a light source 11b that is configured by, for example, an LED (Light Emitting Diode) and emits illumination light BL to the liquid crystal panel 11a. It is a display, and the display image M is transmissively displayed on the display area DP of the liquid crystal panel 11a by the illumination light BL. The HUD device 100 normally generates a virtual display surface corresponding to the display area DP in the foreground of the user by reflecting the entire display area DP of the display device 11 with the relay optical system (plane mirror 12 and concave mirror 13). To do. When the display 11 displays the display image M in the display area DP, the virtual image V based on the display image M is displayed on the virtual display surface.

  The plane mirror 12 is formed by forming a reflective film on the surface of a base material made of, for example, a synthetic resin material by means such as vapor deposition, and directs the display light L of the display image M emitted from the display 11 toward the concave mirror 13. It is to be reflected.

  The concave mirror 13 is formed by forming a reflective film on the surface of a base material made of, for example, a synthetic resin material by means such as vapor deposition, and further reflects the display light L reflected by the plane mirror 12 and emits it toward the windshield 1a. To do. The concave mirror 13 has a function as a magnifying mirror, enlarges the display image M displayed on the display 11, and reflects it to the windshield 1a side. That is, the virtual image V visually recognized by the user is an enlarged image of the display image M displayed in the display area DP of the display device 11.

  The actuator 14 includes a motor (not shown), a power transmission member (not shown) such as a gear that transmits the power of the motor to the concave mirror 13, and a support base that supports the motor, the power transmission member, and the concave mirror 13. The concave mirror 13 is rotated around the rotation axis AX. The actuator 14 generates power for rotating the concave mirror 13 around the rotation axis AX, and includes, for example, a stepping motor. The actuator 14 rotates the concave mirror 13 around the rotation axis AX under the control of the control unit 31 described later. The actuator 14 adjusts the angle of the concave mirror 13 by rotating the concave mirror 13, adjusts the position of the eye box 2, and an angle at which the external light SL is not reflected by the concave mirror 13 toward the display 11 as will be described later. It is possible to adjust to.

The housing 15 is composed of an upper case 151 made of, for example, a black light-shielding synthetic resin, and a lower case 152. By engaging the upper case 151 and the lower case 152, the plane mirror 12, the concave mirror 13, The actuator 14, the temperature sensor 21, and the imaging unit 23 are housed inside, and the display 11, the control board on which the control unit 31 is mounted, and the illuminance sensor 22 are attached.
The upper case 151 has an opening 151a that allows the display light L to pass therethrough at a portion facing the windshield 1a, and the opening 151a is covered with a translucent cover 151b. Further, the upper case 151 has a light shielding wall 151c at a location near the plane mirror 12 of the opening 151a, and external light SL incident from the opening 151a (translucent cover 151b) is on the plane mirror 12 side or the display 11 side. To prevent progress. An illuminance sensor 22 is attached in the vicinity of the opening 151 a of the upper case 151.
The lower case 152 includes a plane mirror 12, a concave mirror 13, an actuator 14, a temperature sensor 21, an imaging unit 23, an indicator 11 attached to the outside, and an engaging portion (not shown) that engages a control board. And each member is positioned and fixed. In addition, the lower case 152 has a display port 152a that is opened so that the display image M displayed by the display unit 11 faces the plane mirror 12. The housing 15 is provided with optical paths through which the display light L passes. These optical paths are used to keep the size of the HUD device 100 small and the amount of external light SL that enters the housing 15. In order to suppress this, it is desirable to make it as small as possible.

  The temperature sensor 21 is disposed inside the housing 15, measures the temperature inside the housing 15 as the ambient temperature of the display 11, and transmits temperature information to the control unit 31.

  The illuminance sensor 22 is disposed in the vicinity of the opening 151 a of the upper case 151 of the housing 15, measures the illuminance of the external light SL irradiated to the housing 15, and transmits illuminance information to the control unit 31.

  The imaging unit 23 includes a camera or the like, and always captures at least the first region DP1 of the display region DP of the liquid crystal panel 11a, and transmits the imaging pattern (captured image) to the control unit 31. As shown in FIG. 2, the display area DP of the liquid crystal panel 11a has a first area DP1 where the display image M is not always displayed. In the present embodiment, it is assumed that the first region DP1 is always in a black display state. The imaging unit 23 is installed so that the imaging range 231 includes the first region DP1. In the present embodiment, the imaging range 231 of the imaging unit 23 substantially coincides with the first area DP1, and the first area DP1 is always imaged.

  1 includes a microcomputer including a CPU (Central Processing Unit) and a storage unit 31a such as a ROM (Read Only Memory), a graphic display controller (GDC), an interface, and the like, and is mounted on a control board. . The control unit 31 transmits vehicle speed, engine speed, etc. transmitted from an external device (not shown) such as a vehicle ECU (Electronic Control Unit) or a navigation device via a bus (not shown) such as a CAN (Controller Area Network). Various types of information such as vehicle information and navigation information are acquired, and the transmission / reception of the liquid crystal panel 11a of the display 11 is controlled according to the information, and the light emission of the light source 11b is controlled to display the display image M in a transparent manner. . The control unit 31 is connected to the temperature sensor 21, the illuminance sensor 22, and the imaging unit 23, acquires a temperature sensor value, an illuminance sensor value, and an imaging pattern (captured image), which will be described later, and displays the display 11 accordingly. The light emission of the light source 11b is controlled, and the actuator 14 is controlled to execute a “problem avoidance process” for avoiding the problem of the display 11 due to the temperature rise. That is, the control unit 31 functions as a temperature acquisition unit and an illuminance acquisition unit of the present invention. The “defect avoidance process” executed by the HUD device 100 will be described in detail later. The storage unit 31a is a program for the control unit 31 to execute various calculations, a temperature sensor value, various data tables for calculating the temperature value of the liquid crystal panel 11a from the illuminance sensor value, and a reference pattern (reference image). ), Each threshold data and the like are stored.

  The above is the configuration of the HUD device 100 in the present embodiment. Next, “defect avoidance processing” executed by the HUD device 100 according to the present embodiment will be described with reference to FIG.

  FIG. 3 is a flowchart of the “problem avoidance process” in the present embodiment. The “problem avoidance process” is started when the control unit 31 is turned on, for example, when the ignition switch of the vehicle 1 is turned on.

  First, in step S1 of FIG. 3, the control unit 31 inputs (acquires) temperature information (hereinafter referred to as a temperature sensor value Ts) in the housing 15 from the temperature sensor 21, and the temperature of the liquid crystal panel 11a from the temperature sensor value Ts. Estimate the value Tp. Specifically, the control unit 31 reads the temperature value Tp of the liquid crystal panel 11a corresponding to the temperature sensor value Ts with reference to a data table stored in advance in the storage unit 31a. As described above, the temperature value Tp of the liquid crystal panel 11a is estimated from the temperature sensor value Ts that is the ambient temperature of the liquid crystal panel 11a. If the temperature sensor is directly installed on the surface of the liquid crystal panel 11a, the display is affected. Because. The temperature sensor value Ts may be obtained by averaging a plurality of temperature sensor values Ts input every predetermined period. In addition, the temperature in the housing 15 and the temperature of the liquid crystal panel 11a are considered to be the same, and the temperature sensor value Ts may be used as the temperature value Tp of the liquid crystal panel 11a as it is.

  Next, in step S <b> 2, the control unit 31 inputs (acquires) illuminance information (hereinafter referred to as illuminance sensor value Ls) of the external light SL directed from the illuminance sensor 22 to the housing 15, and external light from the illuminance sensor value Ls. The temperature rise value Tup due to SL is estimated. Specifically, the control unit 31 reads the temperature increase value Tup corresponding to the illuminance sensor value Ls with reference to a data table stored in advance in the storage unit 31a. The illuminance sensor value Ls may be obtained by averaging a plurality of illuminance sensor values Ls input every predetermined cycle.

  Next, in step S3, the controller 31 adds the temperature rise value Tup due to the external light SL estimated in step S2 to the temperature value Tp of the liquid crystal panel 11a estimated in step S1, and the liquid crystal panel 11a after the temperature rise is added. A predicted temperature value Tf is calculated.

  Next, in step S4, the control unit 31 compares the predicted temperature value Tf of the liquid crystal panel 11a calculated in step S3 with the first threshold value X1 stored in the storage unit 31a in advance. As the first threshold value X1, for example, a temperature value that is somewhat lower than the temperature at which the blackening phenomenon occurs in the liquid crystal of the liquid crystal panel 11a is set. If it is determined that the predicted temperature value Tf of the liquid crystal panel 11a is equal to or higher than the first threshold value X1 (Yes in step S4), the control unit 31 proceeds to step S5. If it is determined that the predicted temperature value Tf of the liquid crystal panel 11a is less than the first threshold value X1 (No in step S4), the control unit 31 proceeds to step S14.

  In step S5, the control unit 31 stores the current luminance of the light source 11b of the display 11 in the storage unit 31a, and then executes a first process for reducing the luminance of the light source 11b. Specifically, for example, the luminance of the light source 11b is set to the minimum luminance. Since the illumination light BL from the light source 11b is also a factor that raises the temperature of the liquid crystal panel 11a, the temperature rise of the liquid crystal panel 11a is suppressed by reducing the luminance of the light source 11b. On the other hand, since the brightness of the virtual image V decreases, the visibility of the virtual image V decreases. In addition, the brightness | luminance of the light source 11b by execution of step S5 is not limited to minimum brightness | luminance, You may adjust arbitrarily.

  Next, in step S6, the control unit 31 compares the predicted temperature value Tf of the liquid crystal panel 11a calculated in step S3 with the second threshold value X2 stored in the storage unit 31a in advance. The second threshold value X2 is set to a temperature value that is greater than the first threshold value X1. If it is determined that the predicted temperature value Tf of the liquid crystal panel 11a is equal to or greater than the second threshold value X2 (Yes in step S6), the control unit 31 proceeds to step S7. When it is determined that the predicted temperature value Tf of the liquid crystal panel 11a is less than the first threshold value X2 (No in step S6), the control unit 31 proceeds to step S15.

  In step S7, the control unit 31 acquires an imaging pattern obtained by imaging the first area DP1 of the display area DP from the imaging unit 23, and reads a reference pattern stored in advance in the storage unit 31a. Here, the reference pattern is an imaging pattern that indicates the first region DP when an abnormality such as a blackening phenomenon does not occur in the liquid crystal panel 11a. For example, the imaging unit 23 is the first imaging unit 23 when the HUD device 100 is manufactured. An image pattern obtained by imaging the area DP is stored in advance in the storage unit 31a as a reference pattern.

  Next, in step S8, the control unit 31 acquires the brightness of the imaging pattern acquired in step S7 by known image analysis or the like, and the brightness difference between the brightness of the imaging pattern and the read reference pattern is stored in advance in the storage unit 31a. It is determined whether or not the third threshold value X3 is stored. When the blackening phenomenon actually occurs in the liquid crystal of the liquid crystal panel 11a, the light transmittance is lower than the normal time where the blackening phenomenon does not occur at the place where the blackening phenomenon occurs, and the brightness of the imaging pattern is reduced ( Get dark). Therefore, when it is determined that the brightness difference between the imaging pattern and the reference pattern is greater than or equal to the third threshold value X3 stored in advance in the storage unit 31a (Yes in step S8), the first area DP1 of the liquid crystal panel 11a Since it is estimated that the blackening phenomenon actually occurs, the control unit 31 proceeds to step S9. Further, when it is determined that the brightness difference between the imaging pattern and the reference pattern is less than the third threshold value X3 (No in step S8), a blackening phenomenon actually occurs in the first region DP1 of the liquid crystal panel 11a. Since it is estimated that it is not, the control part 31 transfers to step S10. Note that the third threshold value X3 is, for example, the brightness of the first region DP1 when the light source 11b has the maximum luminance and the first value when the light source 11b has the minimum luminance in order to accurately determine the blackening phenomenon of the liquid crystal. A value larger than the difference from the brightness of the area DP1 is set. Further, since the temperature of the liquid crystal panel 11a is likely to rise at the center, and the blackening phenomenon of the liquid crystal tends to occur from the center and expand toward the periphery, the first region DP1 is the center of the display region DP. It is desirable to be provided.

  In step S <b> 9, the control unit 31 stores the current angle of the concave mirror 13 in the storage unit 31 a, and then controls the actuator 14 to prevent the display device 11 from being irradiated with the external light SL. Execute. Specifically, the control unit 31 controls the actuator 14 so that the external light SL is directed from the concave mirror 13 to the display 11 (liquid crystal panel 11a) via the plane mirror 12 by the concave mirror 13, as shown in FIG. A process of adjusting to an angle that is not reflected (hereinafter referred to as a non-display angle) is executed. Thereby, since the external light SL is no longer applied to the liquid crystal panel 11a, it is considered that the temperature of the liquid crystal panel 11a decreases. The blackening phenomenon of the liquid crystal is improved as the temperature of the liquid crystal panel 11a is lowered for a short time. On the other hand, when the concave mirror 13 is at the non-display angle, the concave mirror 13 does not reflect the display light L toward the windshield 1a, so that the virtual image V cannot be displayed (becomes a non-display state). After executing Step S9, the control unit 31 returns to Step S7 to acquire a new imaging pattern, and compares the brightness of the imaging pattern with the reference pattern.

  In step S10, the control unit 31 determines whether or not the angle of the concave mirror 13 is the non-display angle. When the angle of the concave mirror 13 is the non-display angle (Yes in Step S10), the control unit 31 proceeds to Step S11. When the angle of the concave mirror 13 is not the non-display angle (No in Step S10), the control unit 31 proceeds to Step S15.

  In step S <b> 11, the control unit 31 inputs the illuminance sensor value Ls from the illuminance sensor 22. Next, in step S12, the control unit 31 compares the illuminance sensor value Ls with the fourth threshold value X4 stored in the storage unit 31a in advance. As the fourth threshold value X4, for example, an illuminance value that is large enough to raise the temperature of the liquid crystal panel 11a immediately is set. When it is determined that the illuminance sensor value Ls is less than the fourth threshold value X4 (Yes in Step S12), the control unit 31 proceeds to Step S13. When it is determined that the illuminance sensor value Ls is greater than or equal to the fourth threshold value X4 (No in step S12), the control unit 31 executes steps S11 and S12 again, and delays the transition to step S13. Thereby, the angle of the concave mirror 13 is frequently changed to the non-display angle, and the display and non-display of the virtual image V can be prevented from being frequently switched.

  In step S <b> 13, the control unit 31 controls the actuator 14 and executes a third process that does not avoid the irradiation of the external light SL onto the display 11. Specifically, the control unit 31 controls the actuator 14 to reflect the display light L toward the windshield 1a and store the concave mirror 13 in step S9 and display the virtual image V (hereinafter referred to as display angle). To perform adjustment processing. After executing Step S13, the control unit 31 proceeds to Step S15.

  In step S14, the control unit 31 controls the luminance of the light source 11b so that the user can visually recognize the virtual image V well (hereinafter referred to as normal luminance). The normal luminance is an initial value stored in advance in the storage unit 31 or a luminance value before reduction stored in step S5. The normal luminance may be appropriately changed according to the illuminance of the external light SL. After executing Step S14, the control unit 31 proceeds to Step S15.

  In step S <b> 15, the control unit 31 displays a predetermined display image M on the display device 11.

  The control unit 31 repeatedly executes the above processing until the power is cut off, for example, when the ignition switch of the vehicle 1 is turned off. When the power is shut off, it is desirable that the control unit 31 controls the actuator 14 to adjust the concave mirror 13 to the non-display angle. This is to prevent the external light SL from being applied to the display device 11 when the vehicle 1 is stopped and causing problems. Through the above processing, when the predicted temperature value Tf of the liquid crystal panel 11a based on the temperature increase due to the external light SL increases, the HUD device 100 first decreases the luminance of the light source 11b by the first processing to generate the virtual image V. The temperature rise of the liquid crystal panel 11a is suppressed while maintaining the display. Then, when the predicted temperature value Tf of the liquid crystal panel 11a further increases, it is determined that the blackening phenomenon is actually occurring in the liquid crystal panel 11a from the imaging pattern, and then the external light SL to the display unit 11 by the second processing. Is avoided, and the temperature rise of the liquid crystal panel 11a is further suppressed. When it is determined that the blackening phenomenon of the liquid crystal panel 11a has improved after the second processing, the avoidance of the external light SL on the display 11 is canceled and the virtual image V is displayed again.

  As described above, the HUD device 100 according to the present embodiment includes the liquid crystal panel 11a and the light source 11b that irradiates the illumination light BL from behind to the liquid crystal panel 11a, and transmits the display image M to the liquid crystal panel 11a by the illumination light BL. A display 11 for displaying and emitting display light L indicating a display image M from the liquid crystal panel 11a, and a concave mirror 13 for reflecting the display light L toward the windshield 1a disposed in front of the viewer (user); A head-up display device including a control unit 31 that drives and controls the display unit 11, a temperature acquisition unit (control unit 31) that acquires the ambient temperature (temperature sensor value Ts) of the display unit 11, and external light SL Illuminance acquisition unit (control unit 31) that acquires the illuminance (illuminance sensor value Ls) of the light source, and external light irradiation avoidance unit (actuator 14) that avoids irradiation of the external light SL to the display 11 Further, the control unit 31 estimates the temperature value Tp of the liquid crystal panel 11a based on the ambient temperature acquired by the temperature acquisition unit, and the temperature of the external light SL from the illuminance of the external light SL acquired by the illuminance acquisition unit. The estimated temperature value Tup is estimated, and the estimated temperature value Tf of the liquid crystal panel 11a is calculated by adding the estimated temperature value Tup to the estimated temperature value Tp of the liquid crystal panel 11a. The predicted temperature value Tf is equal to or greater than the first threshold value X1. The first process of reducing the luminance of the light source 11a is executed when it is determined that the predicted temperature value Tf is greater than or equal to the second threshold value X2 that is greater than the first threshold value X1. The light irradiation avoiding unit is controlled to execute a second process for avoiding the external light SL from being applied to the display unit 11. Moreover, the actuator 14 which adjusts the angle of the concave mirror 13 as said external light irradiation avoidance part is provided, and the control part 31 controls the actuator 14 as said 2nd process, and external light SL goes to the indicator 11 through the concave mirror 13. Adjust the angle so that it is not reflected.

  As a result, the HUD device 100 obtains the predicted temperature value Tf of the liquid crystal panel 11a from the ambient temperature of the display 11 and the illuminance of the external light SL, thereby making the actual liquid crystal panel more accurate than the determination based only on the illuminance of the external light SL. 11a can be grasped, and the first process in which the display is maintained prior to the second process in which the virtual image V is in the non-display state is executed, so that the display of the virtual image V is maintained as much as possible. The trouble of the display 11 due to the incidence of the external light SL can be avoided.

In the HUD device 100, the display area DP of the liquid crystal panel 11 includes a first area DP1 where the display image M is not always displayed, and an imaging unit 23 that images at least the first area DP1 of the display area DP; A storage unit 31a that stores a reference image (reference pattern) indicating the first region DP1 in which no abnormality has occurred in the liquid crystal panel 11a, and the control unit 31 includes a first region imaged by the imaging unit 23. The captured image (imaging pattern) indicating DP1 is compared with the reference image stored in the storage unit 31a, and it is determined that the brightness difference between the captured image and the reference image is greater than or equal to a third threshold value X3. If so, the second process is executed.
According to this, the occurrence of the blackening phenomenon of the liquid crystal in the liquid crystal panel 11a can be determined with higher accuracy, and the display of the virtual image V can be maintained as much as possible.

In the HUD device 100, the control unit 31 performs the second processing when it is determined that the brightness difference between the captured image and the reference image is less than a third threshold value X3 after executing the second process. The light irradiation avoiding unit is controlled to execute a third process that does not prevent the display 11 from being irradiated with the external light SL.
According to this, the improvement of the blackening phenomenon in the liquid crystal panel 11a can be accurately determined, and the display of the virtual image V can be resumed at an appropriate timing.

Further, in the HUD device 100, when the control unit 31 determines that the illuminance of the external light SL acquired by the illuminance acquisition unit is equal to or greater than the fourth threshold value X4, the control unit 31 delays the execution of the third process.
According to this, it is possible to prevent frequent switching between display and non-display of the virtual image V, and display visibility can be improved.

  It should be noted that the present invention is not limited to the above-described embodiment, and various modifications (including deletion of constituent elements) can be made without departing from the scope of the invention. In the present embodiment, the actuator 14 that adjusts the angle of the concave mirror 13 is provided as an external light irradiation avoiding unit. However, as the external light irradiation avoiding unit of the present invention, the position of a light shielding shutter (light shielding member) is moved or extended. You may provide the actuator (position adjustment part) controlled by these. In this case, as a second process, the controller 31 blocks the shutter from the external light SL traveling toward the display 11 (for example, on the optical path of the display light L from the display 11 to the opening 15a of the housing 15). Execute the adjustment process. Moreover, the control part 31 performs the process which adjusts a shutter to the position which does not block the external light SL which goes to the indicator 11 as a 3rd process. Moreover, in this embodiment, although the actuator 14 adjusted the angle of the concave mirror 13 as a reflecting member, the actuator 14 may adjust the angle of the plane mirror 12.

  The present invention is suitable for a head-up display device.

1 Vehicle 1a Windshield (Transmission / reflection part)
2 Eye box 11 Display 11a Liquid crystal panel 11b Light source 12 Plane mirror 13 Concave mirror (reflective member)
14 Actuator (external light irradiation avoidance unit, angle adjustment unit)
DESCRIPTION OF SYMBOLS 15 Housing | casing 21 Temperature sensor 22 Illuminance sensor 23 Imaging part 31 Control part 31a Memory | storage part 100 Head-up display apparatus DP display area DP1 1st area | region BL Illumination light L Display light M Display image V Virtual image

Claims (6)

A display that includes a liquid crystal panel and a light source that irradiates illumination light from behind to the liquid crystal panel, displays a display image on the liquid crystal panel by the illumination light, and emits display light indicating the display image from the liquid crystal panel And
A reflective member that reflects the display light toward a transmission / reflection part disposed in front of the viewer;
A head-up display device comprising a control unit that drives and controls the display,
A temperature acquisition unit for acquiring an ambient temperature of the display;
An illuminance acquisition unit for acquiring the illuminance of outside light;
An external light irradiation avoiding unit for avoiding irradiation of the external light to the display device,
The control unit estimates a temperature value of the liquid crystal panel based on the ambient temperature acquired by the temperature acquisition unit, and estimates a temperature increase value due to the external light from the illuminance of the external light acquired by the illuminance acquisition unit. Then, the predicted temperature value of the liquid crystal panel is calculated by adding the temperature rise value to the estimated temperature value of the liquid crystal panel, and when it is determined that the predicted temperature value is equal to or greater than a first threshold value, Performing the first process of reducing the brightness, and controlling the external light irradiation avoiding unit when it is determined that the predicted temperature value is equal to or greater than a second threshold value that is greater than the first threshold value, A head-up display device, wherein a second process for avoiding external light from being radiated to the display is executed. The display area of the liquid crystal panel includes a first area where the display image is not always displayed,
An imaging unit that images at least the first region of the display region; and a storage unit that stores a reference image indicating the first region in which no abnormality has occurred in the liquid crystal panel;
The control unit compares the captured image indicating the first region captured by the imaging unit with the reference image stored in the storage unit, and the brightness difference between the captured image and the reference image is the first. The head-up display device according to claim 1, wherein the second process is executed when it is determined that the threshold value is 3 or more.   The control unit controls the external light irradiation avoiding unit when it is determined that the brightness difference between the captured image and the reference image is less than the third threshold after executing the second process. The head-up display device according to claim 2, wherein a third process that does not avoid irradiation of the external light to the display is performed.   The said control part delays execution of a said 3rd process, when it is judged that the illumination intensity of the said external light which the said illumination intensity acquisition part acquired is more than a 4th threshold value. The head-up display device described in 1. An angle adjusting unit for adjusting the angle of the reflecting member as the external light irradiation avoiding unit;
The said control part controls the said angle adjustment part in a said 2nd process, and adjusts the said reflection member to the angle which is not reflected so that the said external light may go to the said indicator. The head-up display device described in 1. A position adjusting unit for adjusting the position of the light shielding member as the external light irradiation avoiding unit;
2. The head-up display device according to claim 1, wherein in the second process, the control unit adjusts the light-shielding member to a position that blocks the external light toward the display. 3.

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