JP2014206706A - Display device, display method, and display program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a driver to clearly recognize the details of display on a head-up display even when the display becomes backlit due to the superposition of sunlight.SOLUTION: When a display device detects a state where a display may become backlit due to the superposition of sunlight, the display device controls to automatically apply voltage to a liquid crystal shutter 42 of a screen part 3 to activate a light blocking function. In this case, the background of the screen part 3 is displayed in black to function as a certain kind of sun visor. Meanwhile, a combiner 41 attached to be overlapped on the front side of the liquid crystal shutter 42 can continue to clearly display projection display images from a head-up display projector 2 by its half mirror function.

Description

  The present invention relates to a display device, a display method, and a display program applied to, for example, a head-up display.

  In recent years, development and popularization of a head-up display that displays a navigation display of an in-vehicle navigation system so as to be superimposed on a front view viewed from a driver's seat through a windshield has been progressing. As one of the display methods of this head-up display, a reflector that is half-mirror treated so as to be transmissive to external light and reflective to internal light is installed in front of the windshield. A projector-type technology has been proposed in which display content is displayed on the side using a laser or the like.

  For example, Patent Document 1 discloses a technique for closing a shutter so that sunlight does not hit a TFT liquid crystal display panel in a HUD display while the HUD display of a head-up display (HUD) is not operating. .

JP 2008-166562 A

  The above prior art is a technique for preventing the TFT liquid crystal display panel from being exposed to sunlight and being damaged while the HUD display is not operating.

  On the other hand, as described above, the reflection plate of the head-up display is configured to transmit external light so that a scenery outside the vehicle can be visually recognized. For this reason, in the time zone in which the sun is low in the early morning or evening, the sun overlaps with the reflector and becomes backlit, and the display content cannot be visually recognized. The above prior art is a technique for when the HUD display is not operating, and the display itself is shielded while the HUD display is operating. Therefore, there has been a demand for clearly viewing the display contents of the head-up display even when the sun overlaps and becomes backlight.

  The problem to be solved by the present invention includes the above-described problem as an example.

  In order to solve the above-mentioned problem, the invention according to claim 1 detects a light amount of external light incident on the display surface and display means for displaying an image by irradiating light from a light source onto the display surface. Detection means; shielding means for shielding external light from being incident on the display surface; and control means for controlling the shielding means in accordance with the detected amount of external light. The display of the image is continued even in a state where the shielding means blocks the incidence of external light on the display surface.

  In order to solve the above-mentioned problem, the invention according to claim 4 is a display method executed by a display device mounted on a moving body, and displays an image by irradiating light from a light source onto a display surface. According to the procedure, the detection procedure for detecting the amount of external light incident near the display surface, the shielding procedure for blocking the incidence of external light on the display surface, and the detected amount of external light, A control procedure for controlling shielding in the shielding procedure, and in the display procedure, the display of the image is continued even in a state in which the incidence of external light to the display surface is blocked in the shielding procedure. .

  In order to solve the above problem, the invention according to claim 5 is a display program to be executed by a calculation means provided in a display device mounted on a moving body, and irradiates the display surface with light from a light source. A display procedure for displaying an image, a detection procedure for detecting the amount of external light incident near the display surface, a shielding procedure for blocking external light incident on the display surface, and the detected external light And a control procedure for controlling shielding in the shielding procedure according to the amount of light, and in the display procedure, even in a state where the incidence of external light on the display surface is blocked by the shielding procedure. Continue displaying images.

It is a figure which shows an example of the display of the vehicle window scenery seen from the inside of a vehicle, and the head-up display which is one Embodiment of this invention. It is the schematic diagram which looked at the aspect of the projection display to the screen part by a head-up display from the side. It is an example of the block diagram of the hardware structural example in a head-up display. It is a figure explaining an example of composition and operation of a liquid crystal shutter. Represents an example of how the liquid crystal shutter is not operating and when it is operating It is a flowchart which shows the example of a procedure of the process performed by CPU in a control part.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of a vehicle window scenery viewed from the inside of a vehicle (moving body) and a display of a head-up display 1 which is an embodiment of the display device of the present invention. In the example shown in FIG. 1, the head-up display projector 2 is fixed to the ceiling roof above the driver's seat located on the right side in the drawing. Further, a screen unit 3 is provided so as to cover the projection range of the head-up display projector 2 on the upper front side of the windshield 101. The head-up display projector 2 and the screen unit 3 are arranged on the front surface of the screen unit 3 based on an image signal output from a navigation unit (not shown) or a vehicle control device that controls a vehicle speed indicator. An image of various information such as the name 201 of the current destination, the distance 202 up to that point, and the guide route 203 is displayed.

  FIG. 2 is a schematic view of the aspect of projection display on the screen unit 3 by the head-up display 1 as seen from the side. The head-up display projector 2 appropriately projects and displays an image on the front surface of the screen unit 3 having a function as a half mirror. Here, the display content of the image is set so as to coincide with the driver's field of view through the windshield 101 of the vehicle 100, so that the driver is guided as if in the front field of view through the windshield 101. It can be visually recognized that a sign indicating the route 203 'is provided. In this way, an image of the guidance path 203 whose position is aligned with the front view itself that the driver visually recognizes through the windshield 101 can be projected and displayed, so that the driver can visually recognize the guidance path 203 without moving the line of sight greatly. Can concentrate on driving.

  In FIG. 2, a light amount sensor 22 described later is provided in the vicinity of the upper end portion of the screen portion 3. The light quantity sensor 22 provided at this position can detect the quantity of external light incident on the screen unit 3 through the windshield 101.

  FIG. 3 shows an example of the system configuration of the entire head-up display 1 of the present embodiment. As shown in FIG. 3, the head-up display 1 includes an image signal input unit 11, a video ASIC 12, a frame memory 13, a ROM 14, a RAM 15, a laser driver ASIC 16, a MEMS control unit 17, and a laser light source unit. 18, MCU 19, MEMS mirror 20, light detection unit 21, and screen unit 3.

  The image signal input unit 11 receives an image signal input from the outside and outputs it to the video ASIC 12.

  The video ASIC 12 is a block that controls the laser driver ASIC 16 and the MEMS control unit 17 based on the input image signal supplied from the image signal input unit 11 and the scanning position information input from the MEMS mirror 20, and is ASIC (Application Specific Integrated). Circuit). The video ASIC 12 includes a video processing unit 12a and a timing controller 12b.

  The video processing unit 12 a separates the image data displayed on the screen unit 3 and the synchronization signal from the input image signal, and writes the image data to the frame memory 13. In addition, the video processing unit 12a reads the image data written in the frame memory 13 and converts it into bit data. Further, the video processing unit 12a converts the converted bit data into a signal representing a light emission pattern of each laser. Here, the light emission pattern signal also includes information on the luminance at which each laser emits light, that is, the light quantity of each laser beam.

  The timing controller 12b controls the operation timing of the video processing unit 12a. The timing controller 12b also controls the operation timing of the MEMS control unit 17 described later.

  In the frame memory 13, the image data separated by the video processing unit 12a is written. The ROM 14 stores a control program and data for operating the video ASIC 12. Various data are sequentially written in the RAM 15 as a work memory when the video ASIC 12 operates.

  The laser driver ASIC 16 is a block that generates a signal for driving a laser diode provided in a laser light source unit 18 described later, and is configured as an ASIC. The laser driver ASIC 16 includes a red laser driving circuit 16r, a blue laser driving circuit 16b, and a green laser driving circuit 16g.

  The red laser driving circuit 16r supplies a current for driving the red laser to the red laser LDr based on the light emission pattern signal output from the video processing unit 12a. The blue laser driving circuit 16b supplies a current for driving the blue laser to the blue laser LDb based on the light emission pattern signal output from the video processing unit 12a. The green laser driving circuit 16g supplies a current for driving the green laser to the green laser LDg based on the light emission pattern signal output from the video processing unit 12a.

  The MEMS control unit 17 controls the MEMS mirror 20 based on a signal output from the timing controller 12b. The MEMS control unit 17 includes a servo circuit 17a and a driver circuit 17b.

  The servo circuit 17a controls the operation of the MEMS mirror 20 based on a signal from the timing controller 12b.

  The driver circuit 17b amplifies the control signal for the MEMS mirror 20 output from the servo circuit 17a to a predetermined level and outputs the amplified signal.

  The laser light source unit 18 emits laser light based on the drive signal output from the laser driver ASIC 16. Specifically, the laser light source unit 18 mainly includes a red laser LDr, a blue laser LDb, a green laser LDg, collimator lenses 31r, 31b, 31g, reflection mirrors 32r, 32b, 32g, and a microlens array. 33 and a lens 34. The laser light source 18 corresponds to the light source described in each claim.

  The red laser LDr emits red laser light, the blue laser LDb emits blue laser light, and the green laser LDg emits green laser light. The collimator lenses 31r, 31b, and 31g convert the red, blue, and green laser beams into parallel light and emit the parallel beams to the reflection mirrors 32r, 32b, and 32g, respectively. The reflection mirror 32b reflects blue laser light. The reflection mirror 32r transmits blue laser light and reflects red laser light. The reflection mirror 32g transmits only the green laser beam and reflects the blue and red laser beams. The green laser light transmitted through the reflection mirror 32g and the blue and red laser light reflected by the reflection mirror 32g are incident on the MEMS mirror 20.

  The MEMS mirror 20 reflects the laser light incident from the reflection mirror toward a microlens array 33 that is an example of an EPE (Exit Pupil Expander). The MEMS mirror 20 basically moves to scan the microlens array 33 under the control of the MEMS control unit 17 in order to display the image input to the image signal input unit 11. Is output to the video ASIC 12 (for example, information such as the angle of the mirror). In the microlens array 33, a plurality of microlenses are arranged, and the laser beam reflected by the MEMS mirror 20 is incident thereon. The lens 34 enlarges and projects the image formed on the radiation surface of the microlens array 33 onto the screen unit 3.

  The MCU 19 is a computer having a CPU, a ROM, and a RAM (not shown) inside, and controls each part of the head-up display 1. In the drawing, only the input of control signals from the MCU 19 to the video ASIC 12 and the light detection unit 21 described later is shown.

  The screen unit 3 includes a combiner 41 and a liquid crystal shutter 42. The combiner 41 and the liquid crystal shutter 42 are thin plates having the same shape and the same size, and are bonded so that they overlap each other. The screen unit 3 is installed in the vehicle interior so that the liquid crystal shutter 42 side faces the windshield 101.

  The combiner 41 has a function as a half mirror as appropriate so as to be light transmissive with respect to external light from the windshield 101 and reflective with respect to internal light from the room. The combiner 41 corresponds to a display surface described in each claim.

  The liquid crystal shutter 42 has a light shielding function that changes the light transmittance by switching the presence or absence of voltage application. The configuration and operation principle of the liquid crystal shutter 42 will be described in detail with reference to FIG. The liquid crystal shutter 42 corresponds to shielding means described in each claim.

  The light detection unit 21 has a function of controlling the light shielding operation of the liquid crystal shutter 42 based on the amount of external light and time information. The light detection unit 21 includes a light amount sensor 22, a power supply unit 23, and a shutter control unit 24.

  The light quantity sensor 22 is composed of a semiconductor element or the like, and has a function of detecting the quantity of external light incident on the screen unit 3 through the windshield 101 as described above. The light quantity sensor 22 corresponds to the detecting means described in each claim.

  The power supply unit 23 has a function of sequentially storing electric power supplied from the vehicle battery and supplying driving power to the liquid crystal shutter 42.

  The shutter control unit 24 is a computer having a CPU, a RAM 15 and a ROM 14 therein, and has a function of controlling the supply of driving power from the power supply unit 23 to the liquid crystal shutter 42. This control process is performed based on the amount of external light detected by the light amount sensor 22, time information acquired from a navigation unit (not shown), and a control signal acquired from the MCU 19. The shutter control unit 24 corresponds to control means described in each claim.

  In the above configuration, each part excluding the screen unit 3 and the light detection unit 21 constitutes the head-up display projector 2, which corresponds to the display means described in each claim.

  Next, the detailed configuration and operation principle of the liquid crystal shutter 42 will be described. 4A and 4B are exploded perspective views of the liquid crystal shutter 42. FIG. 4A shows a case where power is not supplied, and FIG. 4B shows a case where power is supplied. The liquid crystal shutter 42 mainly has a four-layer structure in which two polarizing filters F1 and F2 are disposed on the outer side and two alignment films P1 and P2 are stacked on the inner side.

  The alignment films P1 and P2 are each provided with a fine groove in a certain direction. Further, liquid crystal molecules are injected between the alignment films P1 and P2. In the natural state, the liquid crystal molecules are arranged with gentle regularity in the long axis direction of the molecules. When the liquid crystal is brought into contact with the alignment films P1 and P2, liquid crystal molecules are aligned along the grooves of the alignment films P1 and P2.

  The orientations of the grooves of the alignment films P1 and P2 are 90 ° perpendicular to each other, and the liquid crystal molecules sandwiched between the alignment films P1 and P2 are twisted by 90 ° and arranged. That is, the liquid crystal molecules along the grooves of the alignment film P1 are in the a direction, the liquid crystal molecules along the grooves of the alignment film P2 are in the b direction, and the liquid crystal molecules are twisted by 90 ° between the alignment films P1 and P2. Become.

  Here, when light is transmitted through the liquid crystal, the light is transmitted along the gap where the liquid crystal molecules are arranged. Therefore, as shown in FIG. 4, when the orientation of the grooves of the alignment films P1 and P2 is twisted by 90 °, that is, when the alignment of the liquid crystal molecules is twisted by 90 °, the light wave is centered on the traveling axis. Twist through 90 ° to penetrate. On the other hand, the arrangement of liquid crystal molecules is easily changed by stimulation such as application of voltage. When a voltage is applied, the liquid crystal molecules are aligned in a vertical direction (along the electric field). In this case, the wave of light goes straight along the array of molecules.

  The polarizing filters F1 and F2 block light when arranged so that the polarization directions of the respective lights are orthogonal. On the other hand, if the polarization directions are the same, light is transmitted. Here, as shown in FIG. 4A, when twisted liquid crystals (voltage-unaligned alignment films P1 and P2) are sandwiched between polarizing filters F1 and F2 whose polarization directions are orthogonal to each other so as to block light. The light L entering from the polarizing filter F1 side is twisted by 90 ° along the gap between the liquid crystal molecules and can pass through the polarizing filter F2.

  On the other hand, as shown in FIG. 4B, when a voltage V is applied to the alignment films P1 and P2, the liquid crystal molecules sandwiched between the alignment films P1 and P2 stand upright and can be twisted. For this reason, the light L that has entered from the polarizing filter F1 side passes through the alignment films P1 and P2 as it is and travels toward the polarizing filter F2, and therefore cannot pass through the polarizing filter F2. In this way, the liquid crystal shutter 42 transmits light when no voltage is applied, and when the voltage is applied, the light is blocked and the surface becomes black. In other words, the liquid crystal fulfills a light shutter function (light shielding function) with the application of voltage as a trigger.

  Here, the screen unit 3 used as a display surface of the head-up display 1 is basically configured to transmit outside light so that a scenery outside the vehicle can be visually recognized. However, for this reason, in the time zone in which the sun is at a low position in the early morning or evening, as shown in FIG.

  Therefore, in this embodiment, when detecting a state where the sun can overlap and become backlit, control is performed to automatically apply a voltage to the liquid crystal shutter 42 of the screen unit 3 to activate the light shielding function. In this case, the background of the screen unit 3 is displayed in black as shown in FIG. 5B, thereby functioning as a kind of sun visor. On the other hand, the combiner 41 located in front of the liquid crystal shutter 42 can continue to clearly display the projection image from the head-up display projector 2 by its half mirror function.

  In the example of the present embodiment, the condition for shielding the external light by the liquid crystal shutter 42 is that the amount of external light incident on the screen unit 3 through the windshield 101 is equal to or greater than a predetermined value, and the time at that time On the condition that the sun is in a low time zone. When these two conditions are satisfied at the same time, it is determined that the backlight is incident on the screen unit 3, and the external light is shielded by the liquid crystal shutter 42.

  FIG. 6 is an example of a flowchart showing control contents executed by a CPU (not shown) of the shutter control unit 24 in order to realize the operation mode described above. This flow starts when the vehicle ignition is turned on and power is supplied to the vehicle-mounted electrical component.

  In FIG. 6, first, in step S5, the CPU of the shutter control unit 24 stands by in a loop until the vehicle starts running. When the vehicle starts traveling, the process proceeds to step S10.

  In step S <b> 10, the CPU of the shutter control unit 24 acquires a control signal indicating the control state of the head-up display projector 2 from the MCU 19.

  Next, the process proceeds to step S15, and the CPU of the shutter control unit 24 determines whether or not the head-up display projector 2 is projecting and displaying an image on the screen unit 3 based on the control signal acquired in step S10. . If the image is not projected and displayed on the screen unit 3, the determination is not satisfied and the process returns to step S10 and the same procedure is repeated.

  On the other hand, if the image is projected and displayed on the screen unit 3, the determination is satisfied, and the routine goes to Step S20.

  In step S <b> 20, the CPU of the shutter control unit 24 detects the amount of external light from the light amount sensor 22.

  Next, the process proceeds to step S25, and the CPU of the shutter control unit 24 determines whether or not the amount of external light detected in step S20 is equal to or greater than a predetermined value. If the detected amount of external light is greater than or equal to the predetermined value, the determination is satisfied, and the routine goes to Step S30.

  In step S30, the CPU of the shutter control unit 24 acquires time information at that time from a navigation unit (not shown).

  Next, the process proceeds to step S35, and the CPU of the shutter control unit 24 determines whether or not the current time acquired in step S30 is in a time zone that can be backlit. The backlight period is set, for example, between 6:00 and 7:00 in the early morning or between 16:00 and 17:00 in the evening. In addition, the setting of the backlight time zone may be changed as appropriate according to the season. If the current time is not in the backlight time zone, the determination is not satisfied, and the routine goes to Step S45 described later.

  On the other hand, if the current time is in the backlight time zone, the determination is satisfied, and the routine goes to Step S40.

  In step S40, the CPU of the shutter control unit 24 controls the power supply unit 23 to start voltage application to the liquid crystal shutter 42 and activates its light shielding function.

  Next, the process proceeds to step S45, and the CPU of the shutter control unit 24 newly acquires a control signal from the MCU 19 (not shown), and determines whether or not the projection display of the image image has ended. If the image is still projected and displayed, the determination is not satisfied and the routine goes to Step S50.

  In step S50, the CPU of the shutter control unit 24 determines whether or not the vehicle has finished traveling, in other words, whether or not the engine has been turned off. If the vehicle has not finished running, the determination is not satisfied and the routine returns to step S20 and the same procedure is repeated.

  On the other hand, when the vehicle has finished running, the determination is satisfied, and the routine goes to Step S55.

  On the other hand, when the projection display of the image image is finished in the determination in step S45, the determination is satisfied, and the process proceeds to step S55.

  In step S55, the CPU of the shutter control unit 24 controls the power supply unit 23 to stop the voltage application to the liquid crystal shutter 42 and release the light shielding function. Then, this flow ends.

  On the other hand, if the detected amount of external light is less than the predetermined value in the determination in step S25, the determination is not satisfied and the process proceeds to step S60.

  In step S60, the CPU of the shutter control unit 24 determines whether or not the light shielding function is in operation when a voltage is applied to the liquid crystal shutter 42 at that time. If no voltage is applied to the liquid crystal shutter 42, the determination is not satisfied, and the routine goes to Step S45.

  On the other hand, if a voltage is applied to the liquid crystal shutter 42 at that time, the determination is satisfied, and the routine goes to Step S65.

  In step S65, the CPU of the shutter control unit 24 controls the power supply unit 23 to stop the voltage application to the liquid crystal shutter 42 and release the light shielding function. Then, the process proceeds to step S45.

  In the above, the control procedure for image projection display by the MCU 19 and the video processing unit 12a corresponds to the display procedure described in each claim, the procedure in step S20 corresponds to the detection procedure described in each claim, and the procedure in step S40. Corresponds to the shielding procedure described in each claim, and the processing procedure of the entire flow described in FIG. 6 corresponds to the control procedure described in each claim.

  As described above, the head-up display 1 of the present embodiment is a head-up display projector 2 that displays an image by irradiating the combiner 41 (corresponding to the display surface) with light from the laser light source unit 18 (corresponding to the light source). (Corresponding to display means), a light quantity sensor 22 (corresponding to detection means) for detecting the amount of external light incident near the combiner 41, and a liquid crystal shutter 42 (shielding means) for shielding external light from entering the combiner 41 And a shutter control unit 24 (corresponding to control means) for controlling the liquid crystal shutter 42 in accordance with the detected amount of external light. The head-up display projector 2 includes the liquid crystal shutter 42 as a combiner 41. The display of the image is continued even in the state where the incidence of the external light on is blocked.

  The display method executed by the head-up display 1 includes an MCU 19 and a video processing unit for displaying an image by irradiating light from a laser light source unit 18 (corresponding to a light source) onto a combiner 41 (corresponding to a display surface). The control procedure (corresponding to the display procedure) by 12a, the procedure of step S20 (corresponding to the detection procedure) for detecting the amount of external light incident in the vicinity of the combiner 41, and the step of shielding the entrance of external light to the combiner 41 The procedure of S40 (corresponding to the shielding procedure) and the procedure of the entire flow of FIG. 6 (corresponding to the control procedure) for controlling the shielding by the liquid crystal shutter 42 in accordance with the detected amount of external light are executed. In the control procedure by the MCU 19 and the video processing unit 12a, the image display is continued even in the state where the incident of external light to the combiner 41 is blocked in the procedure of step S40.

  As a result, even when the sun overlaps with the screen unit 3 and is backlit, control is performed to automatically apply a voltage to the liquid crystal shutter 42 of the screen unit 3 to activate the light shielding function. In this case, since the background of the screen unit 3 is displayed in black, it functions as a kind of sun visor, and the driver's field of view can be maintained well. Further, even in this state, by continuing the projection display from the head-up display projector 2, the projection display image on the combiner 41 can be clearly displayed. As a result, even when the sun overlaps and becomes backlit, the driver can clearly see the display content of the head-up display 1.

  In the head-up display 1, the liquid crystal shutter 42 is controlled not to be blocked according to the time zone.

  Here, the light shielding function by the liquid crystal shutter 42 is only to prevent back light when the sun is superimposed on the screen unit 3, and outside light is incident as much as possible in other than the back light state so that the front view is reduced. It should be visible. However, for example, when the light quantity sensor 22 is manually attached, strong external light may be detected even from a high sun position depending on the installation position. Therefore, even when strong external light is detected, the liquid crystal shutter 42 can be prevented from being unnecessarily shielded by controlling the liquid crystal shutter 42 not to be shielded outside, for example, the morning and evening backlight hours.

  In the head-up display 1, the combiner 41 has light transmittance with respect to external light, and the liquid crystal shutter 42 is provided so as to overlap the combiner 41 on the incident side of external light.

  As a result, while the light shielding function of the liquid crystal shutter 42 is released, the entire screen unit 3 combined with the combiner 41 allows the incident from outside light, so that the driver's front view can be secured widely. Further, since the liquid crystal shutter 42 is arranged on the outside light incident side of the combiner 41, even if the light shielding function is in operation, the head-up display projector 2 with respect to the reflective surface of the combiner 41 on the opposite side is operated. Good projection display of the image can be secured.

  In some liquid crystal shutters 42, the ratio of the liquid crystal molecules standing upright is changed by changing the intensity of the applied voltage, and the light transmittance can be variably controlled. In this case, the light transmittance may be appropriately controlled so as to change according to the amount of incident external light. For example, the higher the amount of external light incident, the lower the light transmittance, and the lower the amount of external light incident, the higher the light transmittance. Thereby, the incident amount of the external light through the screen part 3 whole can be maintained constant, and both the shielding function with respect to the backlight and the securing of the front field of view can be achieved.

  In the example of the above embodiment, the case where the screen unit is applied to a projector-type head-up display for a vehicle that hangs the screen from the indoor ceiling and projects an image by irradiation with laser light has been described, but the present invention is not limited thereto. Absent. In addition to the laser light, the present invention may be applied to projection light emitted from an LED or the like as a light source, and the projector itself may be installed so as to be embedded in the dashboard in addition to being suspended from the ceiling. Further, the present invention may be applied to a display device in a broad sense such as using a self-luminous display other than the projector type that performs projection display. Further, in addition to being mounted on a vehicle such as an automobile, it may be mounted on a mobile object in a broad sense such as a ship or an aircraft.

  Note that the flowchart shown in FIG. 6 is not intended to limit the present invention to the illustrated procedure, and the procedure may be added / deleted or the order may be changed without departing from the spirit and technical idea.

  In addition to those already described above, the methods according to the above-described embodiments and modifications may be used in appropriate combination.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

1 Head-up display (equivalent to a display device)
2 Head-up display projector (equivalent to display means)
3 Screen section 12a Video processing section 19 MCU
21 light detection unit 22 light quantity sensor (equivalent to detection means)
23 Power supply unit 24 Shutter control unit (equivalent to control means)
41 Combiner (equivalent to display surface)
42 Liquid crystal shutter (equivalent to shielding means)

Claims (5)

Display means for displaying an image by irradiating the display surface with light from a light source;
Detecting means for detecting the amount of external light incident near the display surface;
Shielding means for shielding external light from entering the display surface;
Control means for controlling the shielding means according to the detected amount of external light;
With
The display means includes
A display device characterized in that the display of the image is continued even in a state where the shielding means blocks external light from entering the display surface. The control means includes
The display device according to claim 1, wherein the shielding unit is controlled not to be shielded according to a time zone. The display surface has optical transparency to the external light;
The display device according to claim 1, wherein the shielding means is a liquid crystal shutter arranged to overlap the display surface on the incident side of the external light. A display method executed by a display device mounted on a moving body,
A display procedure for displaying an image by irradiating light from a light source on the display surface;
A detection procedure for detecting the amount of external light incident near the display surface;
A shielding procedure for shielding external light from entering the display surface;
A control procedure for controlling shielding in the shielding procedure according to the detected amount of external light,
Run
In the display procedure,
A display method characterized in that the display of the image is continued even in a state where the incident of external light to the display surface is blocked by the shielding procedure. A display program to be executed by a calculation means provided in a display device mounted on a moving body,
A display procedure for displaying an image by irradiating light from a light source on the display surface;
A detection procedure for detecting the amount of external light incident near the display surface;
A shielding procedure for shielding external light from entering the display surface;
A control procedure for controlling shielding in the shielding procedure according to the detected amount of external light,
And execute
In the display procedure,
A display program characterized in that the display of the image is continued even in a state where the incidence of external light on the display surface is blocked by the shielding procedure.

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