JP6811397B2 - Display device, control method of display device, program, and mobile body including display device - Google Patents

Description

The present invention generally relates to a display device, a control method of the display device, a program, and a moving body including the display device. More specifically, the control of the display device and the display device that project a virtual image into an object space by light transmitted through a screen. With respect to moving objects with methods, programs, and display devices.

Conventionally, as a display device for a vehicle, a head-up display device for a vehicle that displays a driving information image necessary for driving as a virtual image at a distance through a windshield is known (see, for example, Patent Document 1).

The display device described in Patent Document 1 includes a scanning means for two-dimensionally scanning light and a screen on which an image is drawn by scanning light from the scanning means. The image formed on the screen is reflected by the windshield of the vehicle via the projection means and reaches the driver's eyes, so that the driver's eyes can see a virtual image far beyond the windshield. .. In the display device described in Patent Document 1, the distance from the driver's eyes to the virtual image can be changed by moving the screen in a direction orthogonal to the surface of the screen.

Japanese Unexamined Patent Publication No. 2009-150947

By the way, in the display device as described above, a reference position (reference position) is determined for the position of the screen, and the screen moves relative to the reference position. Therefore, if the reference position of the screen varies, the distance from the user's (driver's) eye to the virtual image may vary even when the display device displays the same virtual image. In particular, when the reference position shifts each time the screen moves, the shift amount of the reference position is integrated, so that the shift amount of the reference position becomes large and the distance from the user's eyes to the virtual image varies. Can be large.

The present invention has been made in view of the above reasons, and an object of the present invention is to provide a display device capable of reducing variations in the distance from the user's eyes to a virtual image, a control method for the display device, a program, and a moving body including the display device. To do.

The display device according to the first aspect includes a movable screen, a drive control unit, a projection unit, a position detection unit, and a calibration unit . The movable screen can be moved in the moving direction. The drive control unit moves the movable screen relative to a reference position set at a predetermined position in the moving range of the movable screen. The projection unit draws on the movable screen by irradiating the movable screen with light that scans the movable screen, and projects a virtual image into the target space by the light that passes through the movable screen. The position detection unit executes a position detection process for detecting that the movable screen is positioned at a detection position set in relation to the specified position. The calibration unit moves the movable screen to the specified position and resets the reference position on the specified position, at least based on the detection result of the position detection unit. The position detection unit is configured to move the movable screen and execute the position detection process during a non-display period in which the projection unit does not irradiate the movable screen with light.

In the first aspect, the display device according to the second aspect is configured such that the position detection unit moves the movable screen in a control pattern different from that of the drive control unit during the non-display period. There is.

In the display device according to the third aspect, in the first or second aspect, the position detection unit moves the movable screen so that the movable screen passes through the detection position during the non-display period. The position detection process is executed. The calibration unit is configured to move the movable screen to the specified position based on the detection result of the position detection unit and the amount of movement of the movable screen after passing through the detection position.

The display device according to the fourth aspect is configured in any one of the first to third aspects so that the position detection unit detects that the movable screen passes through the detection position.

In the display device according to the fifth aspect, in any one of the first to fourth aspects, a movable display period for irradiating the movable screen with light from the projection unit is intermittently set. The position detection unit is configured to execute the position detection process by using the drive control unit to move the movable screen as a trigger during the movable display period.

In the fifth aspect of the display device according to the sixth aspect, the position detection unit executes the position detection process before the movable display period in which the drive control unit moves the movable screen. It is configured.

In the fifth aspect of the display device according to the seventh aspect, the position detection unit executes the position detection process after the movable display period in which the drive control unit moves the movable screen. It is configured in.

In the fifth aspect, the display device according to the eighth aspect is configured such that the drive control unit executes a return process for returning the movable screen to a reference position each time the movable screen is moved. The position detection unit is configured to execute the position detection process during the non-display period in which the drive control unit performs the return process.

In the display device according to the ninth aspect, in any one of the first to eighth aspects, the position detection unit moves the movable screen within the search range during the non-display period. If it is not detected that the movable screen is located at the detection position, the position detection unit is configured to change the search range, move the movable screen again, and execute the position detection process. There is.

In the display device according to the tenth aspect, in any one of the first to ninth aspects, the movable screen has a surface inclined with respect to the moving direction. The projection unit is configured to irradiate the movable screen with light that scans the surface of the movable screen.

In the tenth aspect of the display device according to the eleventh aspect, the drive control unit is a first virtual image as the virtual image on a first virtual surface in which the inclination angle of the projection unit with respect to the optical axis is smaller than a predetermined value. When forming the movable screen, the movable screen is fixed in the moving direction. When the drive control unit forms the second virtual image as the virtual image on the second virtual surface whose inclination angle with respect to the optical axis of the projection unit is larger than the predetermined value, the drive control unit uses the movable screen in the moving direction. It is configured to move.

The method for controlling the display device according to the twelfth aspect is a method for controlling a display device including a movable screen, a drive control unit, a projection unit, a position detection unit, and a calibration unit . The movable screen can be moved in the moving direction. The drive control unit moves the movable screen relative to a reference position set at a predetermined position in the moving range of the movable screen. The projection unit draws on the movable screen by irradiating the movable screen with light that scans the movable screen, and projects a virtual image into the target space by the light that passes through the movable screen. The position detection unit executes a position detection process for detecting that the movable screen is positioned at a detection position set in relation to the specified position. The calibration unit moves the movable screen to the specified position and resets the reference position on the specified position, at least based on the detection result of the position detection unit. The control method of the display device is to move the movable screen during a non-display period in which the projection unit does not irradiate the movable screen with light, and cause the position detection unit to execute the position detection process.

The program according to the thirteenth aspect is a program for causing a computer to execute the control method of the display device according to the twelfth aspect.

The moving body according to the fourteenth aspect includes a display device according to any one of the first to eleventh aspects and a reflecting member that reflects light from the projection unit.

The present invention has an advantage that the variation in the distance from the user's eyes to the virtual image can be reduced.

FIG. 1 is a conceptual diagram of an automobile including the display device according to the first embodiment. FIG. 2 is a conceptual diagram showing a user's field of view when the same display device is used. FIG. 3 is a conceptual diagram showing the configuration of the above display device. FIG. 4A is a conceptual diagram showing the movement of bright spots on the surface of the screen in the outward path in the same display device, and FIG. 4B is a conceptual diagram showing the movement of bright spots on the surface of the screen in the return path in the same display device. is there. FIG. 5 is a conceptual diagram showing the configuration of the irradiation unit in the above display device. FIG. 6 is a conceptual diagram for explaining the operation of the display device of the same. FIG. 7 is an explanatory diagram schematically showing an operation when projecting a first virtual image on the same display device. FIG. 8 is an explanatory diagram schematically showing an operation when projecting a second virtual image on the same display device. FIG. 9A is a graph showing the time change of the screen position of the same display device, and FIG. 9B is a graph showing the time change of the screen position of the comparative example. FIG. 10A is a graph showing a time change of the position of the screen when the position detection process is executed before the movable display period in the display device according to the second embodiment. FIG. 10B is a graph showing the time change of the position of the screen when the position detection process is executed after the movable display period in the same display device. FIG. 11 is a graph showing a time change of the position of the screen when the position detection process is executed during the non-display period in which the drive control unit performs the return process in the same display device. FIG. 12 is a conceptual diagram showing the configuration of the display device according to the third embodiment.

(Embodiment 1)
(1) Overview As shown in FIG. 1, the display device 10 according to the present embodiment is, for example, a head-up display (HUD) used in an automobile 100 as a moving body.

The display device 10 is installed in the vehicle interior of the automobile 100 so as to project an image from below onto the windshield 101 of the automobile 100. In the example of FIG. 1, the display device 10 is arranged in the dashboard 102 below the windshield 101. When an image is projected from the display device 10 onto the windshield 101, the image reflected by the windshield 101 as a reflecting member is visually recognized by the user 200 (driver).

According to such a display device 10, the user 200 visually recognizes the virtual image 300 projected on the target space 400 set in front of the automobile 100 (outside the vehicle) through the windshield 101. The "virtual image" referred to here means an image in which when the light emitted from the display device 10 is diverged by a reflecting object such as the windshield 101, the diverging light rays actually form an object. Therefore, the user 200 who is driving the automobile 100 can see the virtual image 300 projected by the display device 10 by superimposing it on the real space spreading in front of the automobile 100. Therefore, according to the display device 10, various driving support information such as vehicle speed information, navigation information, pedestrian information, vehicle ahead vehicle information, lane departure information, and vehicle condition information are displayed as a virtual image 300, and the user. It can be visually recognized by 200. As a result, the user 200 can visually acquire the driving support information with only a slight movement of the line of sight from the state in which the line of sight is directed to the front of the windshield 101.

In the display device 10 according to the present embodiment, the virtual image 300 formed in the target space 400 includes at least two types of virtual images, a first virtual image 301 and a second virtual image 302. The "first virtual image" referred to here is a virtual image 300 (301) formed on the first virtual surface 501. The “first virtual surface” is a virtual surface in which the inclination angle α of the display device 10 with respect to the optical axis 500 is smaller than a predetermined value γ (α <γ). Further, the "second virtual image" referred to here is a virtual image 300 (302) formed on the second virtual surface 502. The “second virtual surface” is a virtual surface in which the inclination angle β of the display device 10 with respect to the optical axis 500 is larger than a predetermined value γ (β> γ). The "optical axis" here means the optical axis of the optical system of the projection optical system 4 (see FIG. 3) described later, and means an axis that passes through the center of the target space 400 and along the optical path of the virtual image 300. The predetermined value γ is 45 degrees as an example, and the tilt angle β is 90 degrees as an example.

Further, in the display device 10 according to the present embodiment, the virtual image 300 formed in the target space 400 includes a third virtual image 303 (see FIG. 2) in addition to the first virtual image 301 and the second virtual image 302. The "third virtual image" is a virtual image 300 (303) formed on the second virtual surface 502 in which the inclination angle β with respect to the optical axis 500 is larger than the predetermined value γ, similarly to the second virtual image 302. As will be described in detail later, among the virtual images 300 formed on the second virtual surface 502, the virtual image formed by the light transmitted through the movable screen 1a is the second virtual image 302, which is formed by the light transmitted through the fixed screen 1b. The virtual image formed is the third virtual image 303.

In the present embodiment, the optical axis 500 is along the road surface 600 in front of the automobile 100 in the target space 400 in front of the automobile 100. The first virtual image 301 is formed on the first virtual surface 501 substantially parallel to the road surface 600, and the second virtual image 302 and the third virtual image 303 are formed on the second virtual surface 502 substantially perpendicular to the road surface 600. It is formed. For example, when the road surface 600 is a horizontal plane, the first virtual image 301 is displayed along the horizontal plane, and the second virtual image 302 and the third virtual image 303 are displayed along the vertical plane.

FIG. 2 is a conceptual diagram showing the field of view of the user 200. That is, according to the display device 10 according to the present embodiment, as shown in FIG. 2, the first virtual image 301 visually recognized with a depth along the road surface 600 and the first virtual image 301 standing upright on the road surface 600 at a certain distance from the user 200. It is possible to display the second virtual image 302 and the third virtual image 303 that are visually recognized. Therefore, to the user 200, the first virtual image 301 appears to be on a plane substantially parallel to the road surface 600, and the second virtual image 302 and the third virtual image 303 are on a plane substantially perpendicular to the road surface 600. looks like. As an example, the first virtual image 301 is information indicating the traveling direction of the automobile 100 as navigation information, and it is possible to present an arrow indicating a right turn or a left turn on the road surface 600. The second virtual image 302 is, for example, information indicating the distance to the vehicle in front or a pedestrian, and it is possible to present the distance to the vehicle in front (distance between vehicles) on the vehicle in front. The third virtual image 303 is, for example, current time, vehicle speed information, and vehicle condition information, and it is possible to present such information with, for example, characters, numbers, and symbols, or a meter such as a fuel gauge. ..

(2) Configuration As shown in FIG. 3, the display device 10 according to the present embodiment includes a plurality of screens 1a and 1b, a drive unit 2, an irradiation unit 3, a projection optical system 4, a control circuit 5, and the like. It includes a position sensor 6.

The plurality of screens 1a and 1b include a fixed screen 1b and a movable screen 1a. The fixed screen 1b is fixed at a fixed position with respect to the housing or the like of the display device 10. The movable screen 1a is configured to be movable in the moving direction X (directions indicated by arrows X1-X2 in FIG. 3) with respect to the housing or the like of the display device 10. That is, when the display device 10 is arranged in the dashboard 102, the fixed screen 1b is fixed at a fixed position in the dashboard 102, and the movable screen 1a can move in the dashboard 102 in the moving direction X. is there. Hereinafter, when the movable screen 1a and the fixed screen 1b are not particularly distinguished, each of the plurality of screens 1a and 1b may be referred to as "screen 1".

The screen 1 (each of the movable screen 1a and the fixed screen 1b) has translucency and forms an image for forming a virtual image 300 (see FIG. 1) in the target space 400 (see FIG. 1). That is, an image is drawn on the screen 1 by the light from the irradiation unit 3, and the virtual image 300 is formed in the target space 400 by the light transmitted through the screen 1. The screen 1 is made of, for example, a plate-shaped member having light diffusivity and formed in a rectangular shape. The screen 1 has a front surface 11 and a back surface 12 on both sides in the thickness direction. In the present embodiment, as an example, the surface 11 of the screen 1 has light diffusivity by forming a large number of microlenses on the surface 11 of the screen 1. The screen 1 is arranged between the irradiation unit 3 and the projection optical system 4 with the surface 11 facing the irradiation unit 3, and the surface 11 is an incident surface on which the light from the irradiation unit 3 is incident. ..

The surface 11 of the movable screen 1a is inclined by an angle θ with respect to the reference surface 503. Further, the movable screen 1a is configured to be movable in the moving direction X orthogonal to the reference plane 503. The "reference plane" referred to here is a virtual plane that defines the moving direction of the movable screen 1a, and is not an actual plane. The movable screen 1a is configured to be able to move straight in the moving direction X while maintaining the posture in which the surface 11 is inclined by an angle θ with respect to the reference surface 503. Here, the movable screen 1a has a first end portion 111 and a second end portion 111 at both ends in a direction inclined with respect to the reference surface 503 on the surface 11 (a direction parallel to the surface 11 of the movable screen 1a on the paper surface of FIG. 3). It further has an end 112. The direction connecting the first end portion 111 and the second end portion 112 along the surface 11 of the movable screen 1a is also referred to as a "vertical direction" for the movable screen 1a. The first end portion 111 is the end portion closest to the irradiation portion 3 on the surface 11, and the second end portion 112 is the end portion farthest from the irradiation portion 3 on the surface 11. That is, in the vertical direction, the portion closer to the first end portion 111 of the movable screen 1a is closer to the irradiation portion 3, and the portion closer to the second end portion 112 is farther from the irradiation portion 3.

The surface 11 of the fixed screen 1b is parallel to the reference plane 503. That is, the surface 11 of the fixed screen 1b is substantially orthogonal to the moving direction X of the movable screen 1a. Further, unlike the movable screen 1a, the fixed screen 1b is not mobile and is fixed at a fixed position in the display device 10. In the present embodiment, the fixed screen 1b is arranged so as to be adjacent to the second end portion 112 of the movable screen 1a in the vertical direction of the movable screen 1a. Here, the direction in which the fixed screen 1b and the movable screen 1a are lined up along the surface 11 of the fixed screen 1b (vertical direction in FIG. 3) is also referred to as a "vertical direction" for the fixed screen 1b. The distance from the surface 11 of the fixed screen 1b to the irradiation unit 3 is substantially the same at both ends in the vertical direction of the fixed screen 1b.

The drive unit 2 moves the movable screen 1a in the moving direction X. Here, the drive unit 2 can move the movable screen 1a along the moving direction X in both the first direction X1 and the second direction X2, which are opposite to each other. The first orientation X1 is the orientation indicated by the arrow “X1” in FIG. 3 (to the right in FIG. 3), and the movable screen 1a is oriented away from the irradiation unit 3, in other words, the movable screen 1a is attached to the projection optical system 4. The direction is approaching. The second orientation X2 is the orientation indicated by the arrow “X2” in FIG. 3 (to the left in FIG. 3), and the movable screen 1a approaches the irradiation unit 3, in other words, the movable screen 1a is from the projection optical system 4. It is a direction to leave. The drive unit 2 is composed of, for example, an electrically driven actuator such as a voice coil motor, and operates according to a first control signal from the control circuit 5.

The irradiation unit 3 is a scanning type light irradiation unit, and irradiates the movable screen 1a or the fixed screen 1b with light. That is, the irradiation unit 3 irradiates the movable screen 1a with light that scans the surface 11 of the movable screen 1a so that the irradiation position of the light on the surface 11 of the movable screen 1a changes. Similarly, the irradiation unit 3 irradiates the fixed screen 1b with light scanning on the surface 11 of the fixed screen 1b so that the irradiation position of the light on the surface 11 of the fixed screen 1b changes. Specifically, the irradiation unit 3 has a light source 31 and a scanning unit 32. In the irradiation unit 3, each of the light source 31 and the scanning unit 32 operates according to the second control signal from the control circuit 5.

The light source 31 includes a laser module that outputs laser light. The light source 31 includes a red laser diode that outputs a red (R) laser beam, a green laser diode that outputs a green (G) laser beam, and a blue laser diode that outputs a blue (B) laser beam. Includes. The three-color laser light output from these three types of laser diodes is synthesized by, for example, a dichroic mirror, and is incident on the scanning unit 32.

By scanning the light from the light source 31, the scanning unit 32 irradiates the movable screen 1a or the fixed screen 1b with the light scanning on the surface 11 of the movable screen 1a or the fixed screen 1b. Here, the scanning unit 32 performs a raster scan in which light is two-dimensionally scanned in the vertical and horizontal directions of the surface 11 of the movable screen 1a or the fixed screen 1b. The "horizontal direction" referred to here is a direction parallel to both the surface 11 and the reference surface 503 of the movable screen 1a or the fixed screen 1b, and is orthogonal to the "vertical direction" on the surface 11 (on the paper surface of FIG. 3). Direction perpendicular to each other). The "horizontal direction" is a common direction between the movable screen 1a and the fixed screen 1b.

As shown in FIGS. 4A and 4B, the scanning unit 32 laterally scans the bright spot B1 formed on the surface 11 of the movable screen 1a or the fixed screen 1b in a one-dimensional manner in the lateral direction to form a scanning line. A two-dimensional image is formed by scanning the bright spot B1 in the vertical direction. The scanning unit 32 scans the bright spot B1 so as to reciprocate between both ends of the surface 11 in the vertical direction while repeating such an operation. FIG. 4A shows the movement of the bright spot B1 on the surface 11 of the movable screen 1a or the fixed screen 1b in the “outward path” of scanning the surface 11 of the movable screen 1a from the first end 111 to the second end 112. It is a figure which shows conceptually. FIG. 4B shows the movement of the bright spot B1 on the surface 11 of the movable screen 1a or the fixed screen 1b in the “return path” of scanning the surface 11 of the movable screen 1a from the second end 112 to the first end 111. It is a figure which shows conceptually.

That is, in the present embodiment, the operating state of the irradiation unit 3 includes a first scanning state that is the “outward path” and a second scanning state that is the “return path”. The first scanning state is an operation state of scanning on the surface 11 of the movable screen 1a from the first end portion 111 to the second end portion 112. The second scanning state is an operation state in which scanning is performed on the surface 11 of the movable screen 1a from the second end portion 112 toward the first end portion 111.

Further, in the present embodiment, the movable screen 1a and the fixed screen 1b are arranged side by side in the vertical direction of the movable screen 1a. Therefore, when the irradiation unit 3 is operating in the first scanning state, the bright spot B1 that reaches the second end portion 112 on the surface 11 of the movable screen 1a moves from the movable screen 1a to the fixed screen 1b and continues. Scan on the surface 11 of the fixed screen 1b. Similarly, when the irradiation unit 3 is operating in the second scanning state, the bright spot B1 shifts from the fixed screen 1b to the movable screen 1a and continues to scan on the surface 11 of the movable screen 1a.

Therefore, for example, when the scanning unit 32 reciprocates once in the vertical direction starting from the first end 111 of the movable screen 1a, the light from the irradiation unit 3 first travels on the surface 11 of the movable screen 1a at the first end. Scan from unit 111 to the second end 112. After that, the light from the irradiation unit 3 scans on the surface 11 of the fixed screen 1b from the end portion on the movable screen 1a side in the vertical direction toward the end portion on the opposite side to the movable screen 1a. After that, the light from the irradiation unit 3 scans on the surface 11 of the fixed screen 1b from the end portion on the side opposite to the movable screen 1a in the vertical direction toward the end portion on the movable screen 1a side. After that, the light from the irradiation unit 3 scans on the surface 11 of the movable screen 1a from the second end portion 112 toward the first end portion 111. In this way, the irradiation unit 3 alternately scans the movable screen 1a and the fixed screen 1b.

The scanning unit 32 has, for example, a minute scanning mirror using MEMS (Micro Electro Mechanical Systems) technology. As shown in FIG. 5, the scanning unit 32 includes a mirror unit 321 that reflects laser light, and by rotating the mirror unit 321, the light from the light source 31 is converted into a rotation angle (swing angle) of the mirror unit 321. It reflects in the direction according to. As a result, the scanning unit 32 scans the light from the light source 31. The scanning unit 32 realizes a raster scan that scans light two-dimensionally by rotating the mirror unit 321 around two axes that are orthogonal to each other.

The scanning unit 32 further includes a first lens 322 and a second lens 323. The first lens 322 is arranged between the light source 31 and the mirror unit 321 and incidents parallel light on the mirror unit 321. The second lens 323 is a telecentric lens, and is arranged between the mirror unit 321 and the screen 1. That is, the second lens 323 is an optical system in which the main light beam is parallel to the optical axis in the entire lens, and the light passing through the second lens 323 connects the optical axis (the second lens 323 and the screen 1). It is output parallel to the straight line). FIG. 5 is merely a schematic diagram for explaining the configuration of the irradiation unit 3, and for example, the focus of the light emitted from the irradiation unit 3 is at a position largely deviated from the surface 11 of the screen 1, and the present embodiment. There is a difference from the display device 10 according to the above.

In the projection optical system 4, the light output from the irradiation unit 3 and transmitted through the screen 1 is incident as incident light, and the virtual image 300 (see FIG. 1) is projected onto the target space 400 (see FIG. 1) by the incident light. Here, the projection optical system 4 is arranged so as to line up with respect to the screen 1 in the moving direction X of the movable screen 1a, and is transmitted by the light transmitted through the screen 1 and output from the screen 1 along the moving direction X. The virtual image 300 is projected. As shown in FIG. 3, the projection optical system 4 has a magnifying lens 41, a first mirror 42, and a second mirror 43.

The magnifying lens 41, the first mirror 42, and the second mirror 43 are arranged in this order on the path of light transmitted through the screen 1. The magnifying lens 41 is arranged on the opposite side (first direction X1 side) of the irradiation unit 3 in the moving direction X when viewed from the screen 1 so that the light output from the screen 1 along the moving direction X is incident. Has been done. The magnifying lens 41 magnifies the image 700 (see FIG. 7) formed on the screen 1 by the light from the irradiation unit 3, and outputs the image 700 to the first mirror 42. The first mirror 42 reflects the light from the magnifying lens 41 toward the second mirror 43. The second mirror 43 reflects the light from the first mirror 42 toward the windshield 101 (see FIG. 1). That is, the projection optical system 4 projects the virtual image 300 onto the target space 400 by enlarging the image 700 formed on the screen 1 by the light from the irradiation unit 3 with the magnifying lens 41 and projecting it onto the windshield 101. To do. Here, the optical axis of the magnifying lens 41 is the optical axis 500 of the projection optical system 4.

The projection optical system 4 constitutes the projection unit 40 together with the irradiation unit 3. In other words, the projection unit 40 has an irradiation unit 3 and a projection optical system 4. Therefore, the optical axis of the magnifying lens 41 (including the extension line of the optical axis reflected by the mirror or the like), which is the optical axis 500 of the projection optical system 4, is also the optical axis 500 of the projection unit 40.

The projection unit 40 selectively selects one screen 1 from the plurality of screens 1a and 1b as the target screen, and irradiates the target screen with light that scans the target screen to draw on the target screen. Then, the projection unit 40 projects the virtual image 300 onto the target space 400 by the light passing through the target screen. In the present embodiment, the direction of the light from the light source 31 is changed by the scanning unit 32 of the irradiation unit 3, and which of the movable screen 1a and the fixed screen 1b is irradiated with the light from the light source 31 is determined. It is determined by the irradiation unit 3.

That is, in a state where the movable screen 1a is irradiated with the light from the light source 31 by the scanning unit 32, the movable screen 1a is selected as the target screen by the projection unit 40. In this state, the projection unit 40 draws on the movable screen 1a as the target screen by irradiating the movable screen 1a with light that scans the movable screen 1a. On the other hand, in a state where the fixed screen 1b is irradiated with the light from the light source 31 by the scanning unit 32, the fixed screen 1b is selected as the target screen by the projection unit 40. In this state, the projection unit 40 draws on the fixed screen 1b as the target screen by irradiating the fixed screen 1b with light that scans the fixed screen 1b. In the present embodiment, since the irradiation unit 3 alternately scans the movable screen 1a and the fixed screen 1b, the movable display period for irradiating the movable screen 1a with light from the projection unit 40 is intermittently set. become.

The position sensor 6 is a sensor for detecting the position of the movable screen 1a. What the position sensor 6 detects is the "absolute position" of the movable screen 1a, which is represented with reference to a fixed member such as a housing of the display device 10. The "absolute position" here is the position of the movable screen 1a seen from one fixedly defined point, and is the position on the absolute coordinates with this one point as the origin. Therefore, the absolute position does not change unless the movable screen 1a moves. On the other hand, the drive control unit 51 (see FIG. 3), which will be described later, moves the movable screen 1a relative to the reference position. The "reference position" referred to here is a position set at a specified position in the moving range of the movable screen 1a. The "specified position" here is an arbitrary position defined within the moving range of the movable screen 1a, and is defined as an invariant position on absolute coordinates. That is, when the drive control unit 51 uses a certain position (absolute position) of the movable screen 1a in absolute coordinates as a reference position, the movable screen 1a changes the "relative position" of the movable screen 1a with respect to the reference position. To move. The "relative position" here is a position relative to an arbitrary reference position on absolute coordinates of the movable screen 1a, and is a position on relative coordinates with this reference position as the origin. Therefore, even if the movable screen 1a does not move, the relative position changes if the reference position changes.

In the present embodiment, the position sensor 6 is, for example, an absolute type optical encoder having a light emitting element and a light receiving element. The position sensor 6 detects the position of the movable screen 1a by detecting the position of the slit provided in the holder holding the movable screen 1a based on the state of light received by the light receiving element of the light from the light emitting element. However, the position sensor 6 is not limited to the optical encoder, and may be, for example, a magnetic encoder, a contact type sensor that detects the position based on the conduction state of the contacts, or the like.

The position sensor 6 detects the position of the movable screen 1a in the moving direction X of the movable screen 1a. Here, the position sensor 6 only needs to be able to detect that the movable screen 1a is located at least at the detection position, and it is not essential that the position sensor 6 detects the position of the movable screen 1a over the entire moving range of the movable screen 1a. The "detection position" here is a position on absolute coordinates set in relation to the specified position. In the present embodiment, the specified position itself defined on the absolute coordinates is set as the detection position, and the specified position and the detection position coincide with each other. Therefore, the drive control unit 51, which will be described later, moves the movable screen 1a relative to the detection position as long as the reference position does not deviate from the specified position. In the present embodiment, the position sensor 6 can detect whether or not the movable screen 1a is located at the detection position, as well as the direction of movement of the movable screen 1a in the movement direction X and the amount of movement.

The control circuit 5 controls the drive unit 2, the irradiation unit 3, and the position sensor 6. The control circuit 5 controls the drive unit 2 with the first control signal, and controls the irradiation unit 3 with the second control signal. Further, the control circuit 5 receives a detection signal from the position sensor 6. As will be described in detail later, the control circuit 5 is configured to synchronize the operation of the drive unit 2 with the operation of the irradiation unit 3. In the present embodiment, the irradiation unit 3 has a light source 31 and a scanning unit 32. The control circuit 5 controls both the light source 31 and the scanning unit 32 by the second control signal.

As shown in FIG. 3, the control circuit 5 has functions as a drive control unit 51, a position detection unit 52, and a calibration unit 53. The control circuit 5 receives, for example, a signal from a driving support system mounted on the automobile 100, and determines the content of the virtual image 300 to be projected.

The drive control unit 51 controls the drive unit 2 to move the movable screen 1a relative to the reference position. That is, the drive control unit 51 moves the movable screen 1a on the relative coordinates with the origin at an arbitrary reference position on the absolute coordinates as described above. As will be described in detail later, the drive control unit 51 moves the movable screen 1a in order to project the second virtual image 302 onto the target space 400 by the light transmitted through the movable screen 1a, and the movable screen 1a by the irradiation unit 3 The drive unit 2 is controlled in synchronization with the drawing on.

In the present embodiment, the drive control unit 51 controls the drive unit 2 so as to move the movable screen 1a intermittently. Then, each time the movable screen 1a is moved, the drive control unit 51 performs a return process of moving the movable screen 1a so as to return the movable screen 1a to the reference position. In this way, the drive control unit 51 moves the movable screen 1a relative to the reference position while controlling the drive unit 2 in an open loop. However, the position (absolute position) of the movable screen 1a after the return process may vary. In short, every time the movable screen 1a moves, the position of the movable screen 1a on the absolute coordinates shifts, and as a result, the reference position on the absolute coordinates may vary. The display device 10 according to the present embodiment has the position detection unit 52 and the calibration unit 53 to reduce such variation in the reference position.

The position detection unit 52 executes a position detection process for detecting that the movable screen 1a is positioned at a detection position set in association with the specified position. The position detection unit 52 moves the movable screen 1a and executes the position detection process during the non-display period during which the projection unit 40 (projection optical system 4 and irradiation unit 3) does not irradiate the movable screen 1a with light. It is configured in. That is, the position detection unit 52 has a function of moving the movable screen 1a on absolute coordinates by controlling the drive unit 2. As will be described in detail later, in the present embodiment, the position detection unit 52 moves the movable screen 1a so that the movable screen 1a passes through the detection position during the non-display period, and during that time, the movable screen 1a moves to the detection position. Executes a position detection process for detecting the position of.

The calibration unit 53 moves the movable screen 1a to a predetermined position at least based on the detection result of the position detection unit 52. That is, the calibration unit 53 has a function of moving the movable screen 1a on absolute coordinates by controlling the drive unit 2. As a result, even if the reference position on the absolute coordinates varies, the position detection unit 52 and the calibration unit 53 reset the reference position to the specified position so that the reference position matches the specified position. .. As will be described in detail later, in the present embodiment, the calibration unit 53 moves the movable screen 1a to a specified position based on the detection result of the position detection unit 52 and the amount of movement of the movable screen 1a after passing through the detection position. It is configured as follows.

The control circuit 5 is composed of, for example, a CPU (Central Processing Unit) and a microcomputer whose main configuration is a memory. In other words, the control circuit 5 is realized by a computer having a CPU and a memory, and when the CPU executes a program stored in the memory, the computer executes the control circuit 5 (drive control unit 51, position detection unit 51). It functions as 52 and the calibration unit 53). Although the program is pre-recorded in the memory of the control circuit 5 here, it may be recorded and provided through a telecommunication line such as the Internet or a recording medium such as a memory card.

(3) Operation (3.1) Basic operation First, the basic operation of the display device 10 according to the present embodiment will be described with reference to FIG.

The control circuit 5 controls the irradiation unit 3 and irradiates the movable screen 1a with light from the irradiation unit 3. At this time, the movable screen 1a is irradiated with light that scans the surface 11 of the movable screen 1a from the irradiation unit 3. As a result, an image 700 (see FIG. 7) is formed (projected) on the front surface 11 or the back surface 12 of the movable screen 1a. In the present embodiment, as an example, since the surface 11 of the movable screen 1a has light diffusivity, the image 700 is formed on the surface 11 of the movable screen 1a. Further, the light from the irradiation unit 3 passes through the movable screen 1a and irradiates the windshield 101 from the projection optical system 4 (magnifying lens 41, first mirror 42, and second mirror 43). As a result, the image 700 formed on the movable screen 1a is projected onto the windshield 101 from below the windshield 101 in the interior of the automobile 100.

When the image 700 is projected from the projection optical system 4 onto the windshield 101, the windshield 101 reflects the light from the projection optical system 4 toward the user 200 (driver) in the vehicle interior. As a result, the image 700 reflected by the windshield 101 is visually recognized by the user 200. As a result, the user 200 visually recognizes the virtual image 300 (first virtual image 301 or second virtual image 302) projected in front of the automobile 100 (outside the vehicle) through the windshield 101.

Further, the control circuit 5 controls the drive unit 2 by the drive control unit 51 during the movable display period in which the movable screen 1a is selected as the target screen by the projection unit 40 (projection optical system 4 and irradiation unit 3). , The movable screen 1a is moved in the moving direction X. When the irradiation position of the light from the irradiation unit 3 on the surface 11 of the movable screen 1a, that is, the position of the bright spot B1 is the same, when the movable screen 1a moves in the first direction X1, a virtual image is seen from the eyes (eye points) of the user 200. Distances up to 300 (also referred to as "viewing distance") are shorter. On the contrary, when the position of the bright spot B1 on the surface 11 of the movable screen 1a is the same and the movable screen 1a moves in the second direction X2, the viewing distance to the virtual image 300 becomes long (far). In short, the viewing distance to the virtual image 300 changes depending on the position of the movable screen 1a in the moving direction X, and the closer the movable screen 1a is to the irradiation unit 3, the more the virtual image 300 projected corresponding to the bright spot B1 on the movable screen 1a. The viewing distance to is long. In other words, the farther the irradiation position of the light from the irradiation unit 3 with respect to the movable screen 1a is from the projection optical system 4 in the moving direction X, the longer the viewing distance to the virtual image 300 projected by the light.

Further, the control circuit 5 controls the irradiation unit 3 and irradiates the fixed screen 1b with light from the irradiation unit 3. At this time, the fixed screen 1b is irradiated with light that scans the surface 11 of the fixed screen 1b from the irradiation unit 3. As a result, an image is formed (projected) on the front surface 11 or the back surface 12 (referred to as the front surface 11 in this embodiment) of the fixed screen 1b as in the case of irradiating the movable screen 1a with light, and the image is formed on the windshield 101. Is projected. As a result, the user 200 visually recognizes the virtual image 300 (third virtual image 303) projected on the front side (outside the vehicle) of the automobile 100 through the windshield 101.

(3.2) Specific display operation Next, in the display device 10 according to the present embodiment, a specific operation for projecting the virtual image 300 will be described with reference to FIGS. 7 and 8. FIG. 7 is a diagram schematically showing the operation of the display device 10 when projecting the first virtual image 301, and FIG. 8 is a diagram schematically showing the operation of the display device 10 when projecting the second virtual image 302. It is a representation figure. In FIGS. 7 and 8, the fixed screen 1b and the like are not shown.

When projecting the first virtual image 301, as shown in FIG. 7, the control circuit 5 irradiates the movable screen 1a with light from the irradiation unit 3 while moving the movable screen 1a in the moving direction X (see FIG. 6). The movable screen 1a is fixed in the moving direction X without moving. That is, the control circuit 5 controls the drive unit 2 and the irradiation unit 3 so that the irradiation unit 3 irradiates the movable screen 1a at a fixed position with light. Since the movable screen 1a is tilted with respect to the moving direction X in the first place, even if the movable screen 1a is in a fixed position, the projection optics in the moving direction X depends on the position on the surface 11 of the movable screen 1a in the vertical direction. There is a difference in the distance to the system 4. Therefore, even when the movable screen 1a is fixed, the irradiation position of the light from the irradiation unit 3 on the surface 11 of the movable screen 1a changes in the vertical direction, so that the irradiation unit on the surface 11 of the movable screen 1a The irradiation position of the light from 3 changes in the moving direction X. As a result, the first image 701 is formed (projected) on the movable screen 1a. The "first image" referred to here is an image 700 formed on the front surface 11 or the back surface 12 of the movable screen 1a, and is formed along the front surface 11 of the movable screen 1a, that is, is inclined with respect to the reference surface 503. It is the image 700. When the first image 701 is projected from the projection optical system 4 onto the windshield 101, the user 200 visually recognizes the first virtual image 301 projected in front of the automobile 100 through the windshield 101.

For example, as the light irradiation position from the irradiation unit 3 on the surface 11 of the movable screen 1a approaches the first end portion 111 in the vertical direction, the distance from the projection optical system 4 to the irradiation position in the moving direction X becomes longer. The viewing distance to the virtual image 300 projected by this light becomes long. On the contrary, as the light irradiation position from the irradiation unit 3 on the surface 11 of the movable screen 1a approaches the second end portion 112 in the vertical direction, the distance from the projection optical system 4 to the irradiation position in the moving direction X becomes shorter. The viewing distance to the virtual image 300 projected by this light is shortened. As a result, the first virtual image 301 as the virtual image 300 is formed on the first virtual surface 501 inclined at the inclination angle α with respect to the optical axis 500.

Therefore, if the irradiation unit 3 scans the light from the first end portion 111 to the second end portion 112 in a state where the movable screen 1a is fixed, the user 200 can visually recognize the light along the road surface 600 with a depth. The first virtual image 301 to be created is projected. As shown in FIG. 7, the viewing distance of the first virtual image 301 formed at this time from the eye point Pe1 is such that the movable screen 1a is located on the first end 111 side (upper end side) of the movable screen 1a. It is larger than the second end 112 side (lower end side). In other words, the movable screen 1a is configured so that the optical path length from the drawing point on the first virtual image 301 to the projection optical system 4 is maximized in a state where the light of the irradiation unit 3 irradiates the first end portion 111. ing. The movable screen 1a is configured so that the optical path length from the drawing point on the first virtual image 301 to the projection optical system 4 is minimized in a state where the light of the irradiation unit 3 irradiates the second end portion 112. That is, the first virtual image 301 is a virtual image inclined with respect to the optical axis 500 so that the viewing distance is maximized on the upper end side in the vertical direction (vertical direction in FIG. 2) when viewed from the user 200.

On the other hand, when projecting the second virtual image 302, as shown in FIG. 8, the control circuit 5 moves the movable screen 1a in the moving direction X while irradiating the movable screen 1a with light from the irradiation unit 3. That is, the control circuit 5 controls the drive unit 2 and the irradiation unit 3 so that the moving screen 1a is irradiated with light by the irradiation unit 3. Since the movable screen 1a is tilted with respect to the moving direction X in the first place, when the movable screen 1a is in a fixed position, the projection optical system in the moving direction X depends on the position on the surface 11 of the movable screen 1a in the vertical direction. There is a difference in the distance to 4. Irradiation of the surface 11 of the movable screen 1a by moving the movable screen 1a in the moving direction X in synchronization with the change in the irradiation position of the light from the irradiation unit 3 in the vertical direction so as to cancel this difference in distance. The irradiation position of the light from the unit 3 does not change in the moving direction X. As a result, the second image 702 is formed (projected) on the movable screen 1a. The "second image" referred to here is an image 700 formed on the front surface 11 or the back surface 12 of the movable screen 1a, and is an image 700 formed along the reference surface 503. When the second image 702 is projected from the projection optical system 4 onto the windshield 101, the user 200 visually recognizes the second virtual image 302 projected in front of the automobile 100 through the windshield 101.

For example, when the irradiation position of the light from the irradiation unit 3 on the surface 11 of the movable screen 1a approaches the first end portion 111 in the vertical direction, the movable screen 1a moves in the first direction X1 to move in the moving direction X. The distance from the projection optical system 4 to the irradiation position is substantially constant. On the contrary, when the irradiation position of the light from the irradiation unit 3 on the surface 11 of the movable screen 1a approaches the second end portion 112 in the vertical direction, the movable screen 1a moves in the second direction X2, thereby moving in the moving direction. The distance from the projection optical system 4 to the irradiation position in X is substantially constant. As a result, the second virtual image 302 as the virtual image 300 is formed on the second virtual surface 502 inclined at an inclination angle β (90 degrees as an example) with respect to the optical axis 500.

Therefore, for example, when the movable screen 1a is moving in the second direction X2, if the irradiation unit 3 scans the light from the first end portion 111 to the second end portion 112, it is constant from the user 200. A second virtual image 302 that is viewed upright on the road surface 600 at a distance is projected. As shown in FIG. 8, the viewing distance of the second virtual image 302 formed at this time from the eye point Pe1 is the first end 111 side (upper end side) of the movable screen 1a and the first movable screen 1a. The two ends are substantially equal to the 112 side (lower end side). That is, the second virtual image 302 is a virtual image in which the viewing distance is substantially equal between the upper end side and the lower end side in the vertical direction (vertical direction in FIG. 2) when viewed from the user 200.

Here, in the present embodiment, the scanning range of the irradiation unit 3 in the vertical direction is set narrower when the second virtual image 302 is formed than when the first virtual image 301 is formed. That is, in the image 700 formed on the surface 11 of the movable screen 1a, the size of the second image 702 in the vertical direction of the movable screen 1a is set smaller than that of the first image 701. As a result, for example, as illustrated in FIG. 2, in the field of view of the user 200, the vertical dimension of each second virtual image 302 is smaller than the vertical dimension of the first virtual image 301.

Further, when projecting the third virtual image 303, the control circuit 5 irradiates the fixed screen 1b with light from the irradiation unit 3. Since the fixed screen 1b is in a state of being substantially orthogonal to the moving direction X with respect to the moving direction X, the distance in the moving direction X from the surface 11 of the fixed screen 1b to the projection optical system 4 is the fixed screen 1b in the vertical direction. It is substantially constant regardless of the position on the surface 11. As a result, a third image is formed (projected) along the reference plane 503 on the fixed screen 1b. When this third image is projected from the projection optical system 4 onto the windshield 101, the user 200 visually recognizes the third virtual image 303 (see FIG. 2) projected in front of the automobile 100 through the windshield 101. .. In the present embodiment, the third virtual image 303 formed by the light transmitted through the fixed screen 1b is tilted at an inclination angle β (90 degrees as an example) with respect to the optical axis 500, similarly to the second virtual image 302. It is formed on the virtual surface 502. That is, the third virtual image 303 is a virtual image in which the viewing distance is substantially equal between the upper end side and the lower end side in the vertical direction (vertical direction in FIG. 2) when viewed from the user 200.

The display device 10 according to the present embodiment can project all of the first virtual image 301, the second virtual image 302, and the third virtual image 303 during one cycle in which the scanning unit 32 reciprocates once in the vertical direction of the movable screen 1a. Is. Here, as an example, the first virtual image 301, the third virtual image 303, and the second virtual image 302 are arranged in this order when the scanning unit 32 reciprocates once in the vertical direction starting from the first end portion 111 of the movable screen 1a. The case of being projected by is illustrated. Specifically, the projection unit 40 first irradiates the movable screen 1a with light to project the first virtual image 301 in the “outward path” of scanning the light from the first end portion 111 to the second end portion 112. After that, the fixed screen 1b is irradiated with light to display the third virtual image 303. Then, in the "return path" in which the projection unit 40 scans the light from the second end portion 112 to the first end portion 111, the fixed screen 1b is first irradiated with light to display the third virtual image 303, and then the third virtual image 303 is displayed. The movable screen 1a is irradiated with light to project the second virtual image 302.

That is, when the display device 10 starts the display (projection of the virtual image 300) operation, the display device 10 first performs a process for forming (projecting) the first virtual image 301 in the "outward route". That is, the control circuit 5 operates the irradiation unit 3 in the first scanning state, and the irradiation unit 3 scans the surface 11 of the movable screen 1a from the first end portion 111 to the second end portion 112 (raster). By scanning), the first image 701 is drawn. At this time, the control circuit 5 controls the drive unit 2 by the drive control unit 51 so as to fix the movable screen 1a at the reference position. As described above, in the "outward route", first, the first image 701 is drawn on the movable screen 1a with the movable screen 1a fixed at the reference position. As a result, the first virtual image 301 along the road surface 600 is projected onto the target space 400 during the movable display period in which the movable screen 1a is selected as the target screen by the projection unit 40 in the “outward route”. ..

Next, the display device 10 performs a process for forming (projecting) the third virtual image 303 on the “outward route”. That is, the control circuit 5 operates the irradiation unit 3 in the first scanning state, and in the irradiation unit 3, the fixed screen 1b is directed from the end on the movable screen 1a side to the end on the opposite side to the movable screen 1a. A third image is drawn by scanning (raster scan) on the surface 11. When the outward route is completed, the display device 10 continuously performs a process for forming (projecting) the third virtual image 303 in the "return route". That is, the control circuit 5 operates the irradiation unit 3 in the second scanning state, and the irradiation unit 3 of the fixed screen 1b from the end opposite to the movable screen 1a toward the end on the movable screen 1a side. A third image is drawn by scanning (raster scan) on the surface 11. As described above, in the fixed display period in which the fixed screen 1b is selected as the target screen by the projection unit 40, the third image is drawn on the fixed screen 1b in both the “outward route” and the “return route”. As a result, regardless of whether it is the "outward route" or the "return route", the third virtual image 303 standing upright on the road surface 600 at a certain distance from the user 200 is projected on the target space 400 during the fixed display period.

Next, the display device 10 performs a process for forming (projecting) the second virtual image 302 in the “return path”. That is, the control circuit 5 operates the irradiation unit 3 in the second scanning state, and the irradiation unit 3 scans the surface 11 of the movable screen 1a from the second end portion 112 to the first end portion 111 (raster). By scanning), the second image 702 is drawn. At this time, the control circuit 5 controls the drive unit 2 by the drive control unit 51 so as to move the movable screen 1a in the first direction X1. During drawing of the second image 702, the moving speed of the movable screen 1a that moves in the first direction X1 is constant (constant speed) at a predetermined speed. That is, in the "return path", each time one scanning line is drawn in the lateral direction on the movable screen 1a, the movable screen 1a is moved away from the irradiation unit 3 (closer to the projection optical system 4). The second image 702 will be drawn. As a result, in the "return path", during the movable display period in which the movable screen 1a is selected as the target screen by the projection unit 40, the target space 400 stands upright on the road surface 600 at a certain distance from the user 200. 2 Virtual image 302 is projected.

Therefore, while the irradiation position of the light from the irradiation unit 3 reciprocates once in the vertical direction on the surface 11 of the movable screen 1a and the fixed screen 1b, the target space 400 has the first virtual image 301, the third virtual image 303, and the like. The second virtual image 302 is projected. Since the vertical scanning in the irradiation unit 3 is performed at a relatively high speed, the user 200 can visually recognize that the first virtual image 301, the third virtual image 303, and the second virtual image 302 are displayed at the same time. The frequency of scanning in the vertical direction in the irradiation unit 3 is, for example, 60 Hz or higher.

(3.3) Position Detection Process Next, in the display device 10 according to the present embodiment, refer to FIGS. 9A and 9B for the operations of the position detection unit 52 and the calibration unit 53 for reducing the variation in the reference position. I will explain. In the following, as described in the column of "(3.2) Specific display operation", when the scanning unit 32 reciprocates once in the vertical direction, the first virtual image 301, the third virtual image 303, and the second virtual image 302 However, it is assumed that the images are projected in this order.

FIG. 9A is a graph showing a time change of the position of the movable screen 1a in the moving direction X when the display device 10 according to the present embodiment operates. FIG. 9B is a similar graph for a comparative example in which the functions of the position detection unit 52 and the calibration unit 53 are disabled (that is, the position detection unit 52 and the calibration unit 53 are omitted). In FIGS. 9A and 9B, the horizontal axis is the time axis, and the position of the movable screen 1a is shown on the vertical axis.

In the present embodiment, as shown in FIG. 9A, each frame F1, F2, F3 corresponding to one cycle in which the scanning unit 32 reciprocates once in the vertical direction of the movable screen 1a is in the first period T1 to the seventh period T7. It is divided. When the start time of the "outward route" is set as the starting point of each frame F1, F2, F3, the first period T1, the second period T2, the third period T3, the fourth period T4, the fifth period T5, the sixth period T6, And the seventh period T7 is set in this order from the start point of each frame F1, F2, F3. The first period T1, the fourth period T4, and the seventh period T7 are non-display periods (blanking periods) in which the irradiation unit 3 does not irradiate any of the plurality of screens 1a and 1b with light. Here, the non-display period is a blanking period in which the irradiation unit 3 does not irradiate any of the plurality of screens 1a and 1b with light, for example, in the rotation direction of the mirror unit 321 in the scanning unit 32 in the vertical direction. It is set at the time of reversal (that is, when switching between the outward route and the return route). The second period T2 is a period for projecting the first virtual image 301. The third period T3 and the fifth period T5 are fixed display periods for projecting the third virtual image 303. The sixth period T6 is a movable display period for projecting the second virtual image 302. The switching from the "outward route" to the "return route" is performed in the middle of the fourth period T4 (non-display period). That is, in the present embodiment, the first virtual image 301 and the third virtual image 303 are projected in this order during the "outward route" period Tx, and the third virtual image 303 and the second virtual image 303 are projected during the "return route" period Ty. 302 is projected in this order.

In the example of FIG. 9A, it is assumed that at the start point of the frame F1, the “reference position” that is the reference for the movement of the movable screen 1a by the drive control unit 51 coincides with the specified position Ps1. In the first period T1, which is the non-display period of the frame F1, the position detection process (period T11) and the calibration process (period T12) are executed in the same manner as in the frames F2 and F3, and this point will be described later. At the end of the calibration process (end point of period T12), the movable screen 1a is located at the specified position Ps1. Therefore, after the end point of the first period T1 in the period Tx of the "outward path" of the frame F1, the movable screen 1a is fixed at the reference position (specified position Ps1). That is, in the second period T2 during the "outward route" period Tx, the first image 701 is formed on the movable screen 1a in a state where the movable screen 1a is fixed at the reference position, and the target space 400 has the first image 701. 1 Virtual image 301 is projected.

On the other hand, in the "return path" period Ty of the frame F1, the position of the movable screen 1a in the moving direction X changes according to the timing of drawing the second image 702. Here, the period T61 in the sixth period T6 (movable display period) represents the period during drawing of the second image 702. That is, in a state where the movable screen 1a is moving from the reference position (specified position Ps1) to the first direction X1, the second image 702 is formed on the movable screen 1a, and the second virtual image 302 is formed in the target space 400. It is projected. At this time, the moving speed of the movable screen 1a is constant. Then, each time the second image 702 is formed, the movable screen 1a moves in the second direction X2 and returns to the reference position in the period T62 immediately after the period T61. However, in the example of FIG. 9A, it is assumed that the reference position after the return is a position slightly deviated from the specified position Ps1 to the second direction X2 on the absolute coordinates. Therefore, at the end point of the frame F1 (the start point of the frame F2), the movable screen 1a is located at a position deviated from the specified position Ps1.

In the display device 10 according to the present embodiment, the position detection unit 52 moves the movable screen 1a and executes the position detection process in the first period T1 (non-display period) of the frame F2. Here, the period T11 in the first period T1 represents the period during which the position detection process is executed. At this time, the position detection unit 52 moves the movable screen 1a in the moving direction X with a specified amplitude, so that the movable screen 1a passes through the detection position (specified position Ps1). Then, the position detection unit 52 detects that the movable screen 1a is located at the detection position at the moment when the movable screen 1a passes the detection position (specified position Ps1). That is, in the example of FIG. 9A, it is detected that the movable screen 1a is located at the detection position at the time t0 when the movable screen 1a passes the specified position Ps1.

In the present embodiment, the position detection unit 52 is configured to move the movable screen 1a in a control pattern different from that of the drive control unit 51 during the non-display period. That is, the drive control unit 51 moves the movable screen 1a in order to realize the projection of the second virtual image 302. Therefore, the drive control unit 51 synchronizes the operation of the drive unit 2 with the operation of the irradiation unit 3 as in the period T61 of the sixth period T6, and synchronizes the operation with the operation of the irradiation unit 3 in a predetermined direction (first direction X1) at a predetermined speed. The movable screen 1a is being moved. On the other hand, the position detection unit 52 moves the movable screen 1a in the non-display period regardless of the projection of the virtual image 300. Therefore, the position detection unit 52 can move the movable screen 1a in a control pattern (direction and speed of movement) different from that of the drive control unit 51.

Further, in the first period T1 (non-display period) of the frame F2, the calibration unit 53 executes a calibration process for moving the movable screen 1a to the specified position Ps1 based on the detection result of the position detection unit 52. Here, the period T12 in the first period T1 represents the period during which the calibration process is executed. At this time, the calibration unit 53 moves the movable screen 1a in the moving direction X based on the detection result of the position detecting unit 52 and the amount of movement of the movable screen 1a after passing through the detection position, thereby moving the movable screen 1a. Move to the specified position Ps1. That is, the calibration unit 53 calibrates the reference position by moving the movable screen 1a to the specified position Ps1 which is the regular reference position on the absolute coordinates based on the detection result of the position detection unit 52.

Specifically, the calibration unit 53 determines the direction and amount of movement of the movable screen 1a from the time t0 when the position detection unit 52 detects that the movable screen 1a is located at the detection position, for example, the position sensor 6. Detected from the output of. The calibration unit 53 moves the movable screen 1a to the side opposite to the direction of the detected movement by the amount of movement detected in this way, so that the movable screen 1a is moved to the regular reference position (specified position Ps1). ). In the example of FIG. 9A, since the movable screen 1a is moving from the time point t0 to the first orientation X1 in the frame F2, the calibration unit 53 moves the movable screen 1a in the second orientation X2. Therefore, at the end point of the first period T1 of the frame F2 (the start point of the second period T2), the position of the movable screen 1a is at the regular reference position (specified position Ps1).

Therefore, after the start point of the second period T2 in the period Tx of the "outward path" of the frame F2, the movable screen 1a is fixed to the regular reference position (specified position Ps1). That is, in the second period T2, the first image 701 is formed on the movable screen 1a and the first virtual image 301 is projected on the target space 400 in a state where the movable screen 1a is fixed at the specified position Ps1. ..

Then, in the "return path" period Ty of the frame F2, the movable screen 1a moves to the periods T61 and T62 in the sixth period T6 (movable display period) as in the frame F1. Before the movable screen 1a is moved (before the start of the period T61), the movable screen 1a is in the regular reference position (specified position Ps1), but after the movable screen 1a is moved (after the end of the period T62), it is movable. The screen 1a is located at a position deviated from the specified position Ps1. As a result, the reference position at the end point of the frame F2 is a position deviated from the specified position Ps1 on the absolute coordinates.

After that, in the frame F3 as well as in the frame F2, the reference position is calibrated and reset on the specified position Ps1 by executing the position detection process and the calibration process in the first period T1 (non-display period). Will be done. In the display device 10 according to the present embodiment, by repeating the same operations as the frames F1, F2, and F3 described above, the deviation of the reference position from the specified position Ps1 is corrected for each frame, and the deviation on the absolute coordinates is corrected. The amount of deviation of the reference position from the specified position Ps1 is reduced.

On the other hand, in the comparative example, as shown in FIG. 9B, the deviation of the reference position from the specified position Ps1 is not corrected for each frame, so that the amount of deviation from the reference position from the specified position Ps1 may be large. There is. That is, in the comparative example, as shown in FIG. 9B, as a result of the movable screen 1a moving to the periods T61 and T62 in the period Ty of the "return path" of the frame F1, the reference position at the end point of the frame F1 is in absolute coordinates. It is in a position deviated from the specified position Ps1 above. In the example of FIG. 9B, the reference position at the end point of the frame F1 is a position slightly deviated from the specified position Ps1 in the first direction X1. If the reference position shifts each time the screen moves, the amount of deviation from the reference position from the specified position Ps1 is integrated, so the amount of deviation from the reference position from the specified position Ps1 may gradually increase. There is.

In the second period T2 during the "outward route" period Tx, the first image 701 is formed on the movable screen 1a in a state where the movable screen 1a is fixed at the reference position, and the first virtual image is formed in the target space 400. 301 is projected. Further, in the sixth period T6 (movable display period) of the "return path" period Ty, the second image 702 is formed on the movable screen 1a in a state where the movable screen 1a is moving with reference to the reference position. The second virtual image 302 is projected on the target space 400. Therefore, as in the comparative example, if the variation of the reference position with respect to the specified position Ps1 becomes large, the variation of the distance from the driver's eyes to the virtual image 300 (first virtual image 301 or second virtual image 302) may become large. .. On the other hand, in the display device 10 according to the present embodiment, since the variation in the reference position is reduced, the variation in the distance from the driver's eyes to the virtual image 300 (first virtual image 301 or second virtual image 302) can be reduced. Further, when the variation in the reference position is reduced, the variation in the size of the bright spot B1 (see FIG. 4A) formed on the surface 11 of the movable screen 1a can be suppressed to be relatively small. As a result, in the display device 10, it is possible to suppress a decrease in the resolution of the image 700 formed on the movable screen 1a by the light from the irradiation unit 3, and it is possible to suppress a decrease in the resolution of the virtual image 300.

By the way, in the example of FIG. 9A, it is assumed that the second virtual image 302 is projected only once during the sixth period T6, but the second virtual image 302 is projected a plurality of times during the sixth period T6. May be good. That is, the process for forming the second image 702 (periods T61, T62) is performed a plurality of times (for example, three times), so that the target space 400 has a plurality of second images (for example, three) having different viewing distances. A virtual image 302 is projected (see FIG. 2). In this case, the closer the position where the second image 702 is formed on the movable screen 1a is to the first end portion 111, the longer the viewing distance of the second virtual image 302 becomes. In this way, when the second virtual image 302 is projected a plurality of times during the sixth period T6, the movable screen 1a moves a plurality of times in the sixth period T6, and each time the movable screen 1a moves. , The reference position may deviate from the specified position Ps1. However, in the display device 10 according to the present embodiment, since the reference position is calibrated for each cycle (frame) in which the scanning unit 32 reciprocates once in the vertical direction of the movable screen 1a, the reference position from the specified position Ps1 is calibrated. The deviation is reduced.

(4) Modified Example Embodiment 1 is only one of various embodiments of the present invention. The first embodiment can be modified in various ways depending on the design and the like as long as the object of the present invention can be achieved. Further, the aspect according to the first embodiment is not limited to being embodied by a single display device. For example, the aspect according to the first embodiment may be embodied in a system, a control method of a display device, a computer program, a storage medium in which the program is stored, or the like.

Hereinafter, modifications of the first embodiment will be listed. The modifications described below can be applied in combination as appropriate.

As a first modification of the first embodiment, the position detection unit 52 may be configured so that the search range can be changed. The "search range" referred to here is a moving range of the movable screen 1a when the position detecting unit 52 executes the position detecting process. That is, in the position detection process, the position detection unit 52 first moves the movable screen 1a located at the reference position in the moving direction X with a specified amplitude (search range), so that the movable screen 1a moves to the detection position (specified position). Detects whether or not it is located at Ps1). At this time, if it is not detected that the movable screen 1a is located at the detection position, the position detection unit 52 changes the search range, moves the movable screen 1a again, and executes the position detection process.

As a specific example of changing the search range in the first modification, the position detection unit 52 increases the amplitude of the movable screen 1a in the position detection process to expand the search range in the moving direction X, for example. Alternatively, the position detection unit 52 may change the search range by, for example, changing the movement start position of the movable screen 1a in the position detection process and shifting the search range in the movement direction X. Further, the position detection unit 52 may change the search range by combining the expansion of the search range and the shift of the search range. According to this modification, in the position detection process, the position detection unit 52 can set a relatively small search range when the movable screen 1a is first moved. Therefore, it leads to reduction of power consumption of the drive unit 2 and reduction of operating noise of the drive unit 2 related to the movement of the movable screen 1a in the position detection process.

The non-display period for the position detection unit 52 to execute the position detection process is the fixed display period in which the fixed screen 1b is selected as the target screen in the projection unit 40 (projection optical system 4 and irradiation unit 3). It may be included. That is, even in the fixed display period, the projection unit 40 does not irradiate the movable screen 1a with light, so that the fixed display period is included in the non-display period for executing the position detection process. Good. For example, in the example of FIG. 9A, the position detection unit 52 may execute the position detection process during the third period T3 or the fifth period T5, which is the fixed display period.

Further, the position detection unit 52 is not limited to the non-display period, and for example, when the first virtual image 301 or the second virtual image 302 is projected, the movable screen 1a is positioned at the detection position based on the detection signal from the position sensor 6. You may detect that. That is, if the movable screen 1a passes through the detection position as a result of the drive control unit 51 moving the movable screen 1a, the position detection unit 52 will move the position detection unit 52 based on the detection signal from the position sensor 6 at that time. It can be detected that the movable screen 1a is located at the detection position. In this modification, the position detection unit 52 executes the position detection process during the non-display period only when the movable screen 1a does not pass the detection position as a result of the drive control unit 51 moving the movable screen 1a. Just do it. For example, if it is sufficient to detect that the movable screen 1a is located at the detection position once per predetermined time, the position detection unit 52 only when the movable screen 1a does not pass through the detection position continues for a predetermined time. May execute the position detection process during the non-display period.

Further, the calibration process by the calibration unit 53 is not an essential configuration for the display device 10, and may be omitted as appropriate. In this case, for example, when the position detection unit 52 detects that the movable screen 1a is located at the detection position, the movement of the movable screen 1a by the position detection unit 52 is terminated to reach the detection position (specified position Ps1). The movable screen 1a can be stopped. As a result, the deviation of the reference position from the specified position Ps1 is reduced even if the calibration process is not performed.

Further, in the first embodiment, the specified position Ps1 and the detection position coincide with each other, but the detection position may be set in relation to the specified position Ps1, and for example, a predetermined amount of the first from the specified position Ps1. The position deviated from the direction X1 or the second direction X2 may be the detection position. In this case, if the detection position is specified by the position detection unit 52, the calibration unit 53 can specify the specified position Ps1 based on the detection position and the predetermined amount.

Further, the control circuit 5 may be configured to control the drive unit 2 and the irradiation unit 3, and the function of controlling the drive unit 2 and the function of controlling the irradiation unit 3 may not be integrated. For example, the control unit that controls the drive unit 2 and the control unit that controls the irradiation unit 3 may be provided as separate bodies and configured to be synchronized with each other.

Further, the display device 10 is not limited to the two screens 1 composed of one movable screen 1a and one fixed screen 1b, and may include three or more screens 1. The three or more screens 1 may be composed of, for example, two or more fixed screens 1b and one movable screen 1a, or may be composed of two or more movable screens 1a and one fixed screen 1b. May be good. Further, four or more screens 1 may be formed by two or more movable screens 1a and two or more fixed screens 1b. Even in this case, the position detection unit 52 moves the movable screen 1a during the non-display period in which the projection unit 40 (projection optical system 4 and irradiation unit 3) does not irradiate the movable screen 1a with light, and performs position detection processing. To execute. Then, the calibration unit 53 moves the movable screen 1a to the specified position based on the detection result of the position detection unit 52. As a result, the deviation of the reference position of one or more movable screens 1a from the specified position Ps1 can be reduced.

Further, in the example of FIG. 9A, an example in which the position detection unit 52 executes the position detection process in the first period T1 which is the non-display period of the “outward route” is shown, but the position detection unit 52 is not limited to this example. , The position detection process may be executed during the non-display period. For example, the position detection unit 52 executes the position detection process in the seventh period T7, which is the non-display period of the “return route”, or the fourth period T4, which is the non-display period straddling the “outward route” and the “return route”. May be good. Further, the position detection unit 52 may execute the position detection process in two or more periods of the first period T1, the fourth period T4, and the seventh period T7. Further, the calibration process by the calibration unit 53 does not have to be executed in the same non-display period as the position detection process by the position detection unit 52. For example, the position detection unit 52 executes the position detection process in the first period T1. , The calibration unit 53 may execute the calibration process during the fourth period T4.

Further, the drive control unit 51 is not limited to the configuration in which the movable screen 1a is fixed in the moving direction X when forming the first virtual image 301, and the movable screen 1a is set in the moving direction X when forming the first virtual image 301. You may move it. For example, during the "outbound" period Tx, the drive control unit 51 continues to move the movable screen 1a in the first orientation X1. On the other hand, in the "return path" period Ty, the drive control unit 51 moves the movable screen 1a to the first direction X1 only during the period during drawing of the second image 702, and moves the movable screen 1a during the other periods. Move in the second orientation X2. In this modification, the moving range of the movable screen 1a can be suppressed to be narrower than that in the configuration in which the movable screen 1a is parallel to the reference surface 503.

Further, the movable screen 1a may be parallel to the reference surface 503. Even in this case, the position detection unit 52 moves the movable screen 1a to detect the position during the non-display period in which the projection unit 40 (projection optical system 4 and irradiation unit 3) does not irradiate the movable screen 1a with light. Execute the process. Then, the calibration unit 53 moves the movable screen 1a to the specified position based on the detection result of the position detection unit 52. As a result, the deviation of the reference position of the movable screen 1a from the specified position Ps1 can be reduced. Further, the fixed screen 1b is not limited to the configuration parallel to the reference surface 503, and may be inclined with respect to the reference surface 503 as in the movable screen 1a.

Further, the display device 10 is not limited to the configuration in which the first virtual image 301, the second virtual image 302, and the third virtual image 303 are projected at the same time, and for example, a mode in which only the first virtual image 301 is projected and only the second virtual image 302 are displayed. It may have a mode to project. Similarly, the display device 10 has a mode of projecting only the first virtual image 301 and the third virtual image 303, a mode of projecting only the second virtual image 302 and the third virtual image 303, and a mode of projecting only the third virtual image 303. You may be doing it.

Further, the operating state of the irradiation unit 3 may be only one of the first scanning state (outward path) and the second scanning state (return path). In this case, the first virtual image 301, the second virtual image 302, and the third virtual image 303 are formed in either the first scanning state (outward path) or the second scanning state (return path).

Further, in the first embodiment, the case where the first virtual image 301 is formed only in the first scanning state (outward route) and the second virtual image 302 is formed only in the second scanning state (return route) is shown. Not exclusively. For example, the first virtual image 301 may be formed only in the second scanning state (return path), the second virtual image 302 may be formed only in the first scanning state (outward path), and the first virtual image 301 or the second virtual image 302 may be formed. , It may be formed in both the first scanning state (outward route) and the second scanning state (return route). Further, both the first virtual image 301 and the second virtual image 302 may be formed in both the first scanning state (outward path) and the second scanning state (return path). In this case, for at least a part of the first virtual image 301 and the second virtual image 302, the same virtual image 300 is formed in both the first scanning state (outward path) and the second scanning state (return path), whereby the virtual image 300 is formed. The brightness can be increased. The third virtual image 303 is not limited to the configuration formed in both the first scanning state (outward path) and the second scanning state (return path), but only in the first scanning state (outward path) or in the second scanning state (return path). The third virtual image 303 may be formed only by itself.

Further, the scanning range of the irradiation unit 3 in the vertical direction inclined with respect to the reference surface 503 on the surface 11 of the movable screen 1a is larger when the second virtual image 302 is formed than when the first virtual image 301 is formed. It may be wide.

Further, as shown in FIG. 2, it is not an essential configuration for the display device 10 that a plurality of (three in this case) second virtual images 302 having different viewing distances are projected on the target space 400, but the target space 400. May project only one second virtual image 302.

Further, the drive control unit 51 may control the drive unit 2 so as to suppress sudden acceleration and deceleration of the movable screen 1a in the moving direction X. Specifically, the drive control unit 51 reduces the acceleration applied to the movable screen 1a to a specified value or less, for example, when switching between a state in which the movable screen 1a is stopped and a state in which the movable screen 1a is moving. The control pattern of the drive unit 2 is defined so as to suppress it.

Further, the "display surface" may be any surface on the screen 1 for forming the image 700, and may be not limited to the front surface 11 of the screen 1 but may be, for example, the back surface 12 of the screen 1. Further, the entire surface of the front surface 11 (or the back surface 12) of the screen 1 does not have to be the “display surface”, and the “display surface” may be a part of the front surface 11 (or the back surface 12) of the screen 1. .. In this case, the image 700 is formed only in a part of the front surface 11 (or back surface 12) of the screen 1.

Further, the screen 1 is not limited to a configuration having light diffusivity only on the front surface 11, and may have light diffusivity only on the back surface 12, or on both the front surface 11 and the back surface 12, for example. When the back surface 12 of the screen 1 has light diffusivity, the image 700 is formed on the back surface 12 of the screen 1.

Further, the display device 10 is not limited to the configuration in which the virtual image 300 is projected onto the target space 400 set in front of the traveling direction of the automobile 100, for example, the virtual image is laterally, backward, or upward in the traveling direction of the automobile 100. You may project 300.

Further, the movable screen 1a may be configured to be rotatable so as not only to move straight in the moving direction X but also to change the inclination angle θ of the surface 11 with respect to the reference surface 503, for example.

Further, the projection optical system 4 may or may not include a relay optical system for forming an intermediate image.

Further, the display device 10 is not limited to the head-up display used in the automobile 100, and can be applied to mobile objects other than the automobile 100, such as two-wheeled vehicles, trains, aircraft, construction machinery, and ships. Further, the display device 10 is not limited to a mobile body, and may be used, for example, in an amusement facility, or as a wearable terminal such as a head mounted display (HMD), medical equipment, or a stationary device. May be done.

(Embodiment 2)
The display device 10 according to the present embodiment is different from the first embodiment in that the position detection unit 52 executes the position detection process by using the drive control unit 51 to move the movable screen 1a during the movable display period as a trigger. It is different from the display device 10. Hereinafter, the same configurations as those in the first embodiment will be designated by a common reference numeral and description thereof will be omitted as appropriate.

In the present embodiment, similarly to the first embodiment, the movable display period for irradiating the movable screen 1a with light from the projection unit 40 is intermittently set. The drive control unit 51 does not move the movable screen 1a each time during the movable display period set intermittently in this way, but moves the movable screen 1a only when projecting the second virtual image 302. That is, the second virtual image 302 is not projected every time in the movable display period set intermittently, but the display device 10 is instructed by, for example, the driving support system mounted on the automobile 100. The second virtual image 302 is projected only at the timing. Since the movable screen 1a does not move during the movable display period in which the second virtual image 302 is not projected, the reference position does not deviate from the specified position Ps1 in the first place.

Therefore, in the present embodiment, the position detection unit 52 executes the position detection process by using the drive control unit 51 to move the movable screen 1a during the movable display period as a trigger, whereby the movable screen 1a is executed during the movable display period. The position detection process is executed only when is moved. In other words, when the drive control unit 51 does not move the movable screen 1a during the movable display period, the position detection unit 52 does not execute the position detection process.

Specifically, when the drive control unit 51 moves the movable screen 1a during the movable display period, the position detection unit 52 executes the position detection process in any of the non-display periods before and after the movable display period. .. Hereinafter, the case where the position detection process is executed before the movable display period and the case where the position detection process is executed after the movable display period will be described with reference to FIGS. 10A and 10B. FIG. 10A is a graph showing a time change of the position of the movable screen 1a in the moving direction X when the position detection process is executed before the movable display period. FIG. 10B is a similar graph when the position detection process is executed after the movable display period. In FIGS. 10A and 10B, the horizontal axis is the time axis, and the position of the movable screen 1a is shown on the vertical axis.

First, a case where the position detection unit 52 executes the position detection process before the movable display period in which the drive control unit 51 moves the movable screen 1a will be described. In the example of FIG. 10A, the projection of the second virtual image 302 is performed only in the frame F2 of the frames F1, F2, and F3. That is, the movement of the movable screen 1a by the drive control unit 51 is performed only in the sixth period T6 (movable display period) in the period Ty of the "return path" of the frame F2, and in the period Ty of the "return path" of the frames F1 and F3. It is not performed in the sixth period T6 (movable display period). In this case, as shown in FIG. 10A, in the non-display period (first period T1 of the frame F2) before the sixth period T6 of the frame F2, the position detection process by the position detection unit 52 and the calibration process by the calibration unit 53. Is executed. Therefore, in the movable display period (sixth period T6 of the frame F2) in which the movable screen 1a is moved by the drive control unit 51, the reference position is calibrated and reset on the specified position Ps1.

Next, a case where the position detection unit 52 executes the position detection process after the movable display period in which the drive control unit 51 moves the movable screen 1a will be described. In the example of FIG. 10B, the projection of the second virtual image 302 is performed only in the frame F2 of the frames F1, F2, and F3. That is, the movement of the movable screen 1a by the drive control unit 51 is performed only in the sixth period T6 (movable display period) in the period Ty of the "return path" of the frame F2, and in the period Ty of the "return path" of the frames F1 and F3. It is not performed in the sixth period T6 (movable display period). In this case, as shown in FIG. 10B, the position detection process by the position detection unit 52 and the calibration process by the calibration unit 53 in the non-display period (first period T1 of the frame F3) after the sixth period T6 of the frame F2. Is executed. Therefore, the deviation of the reference position from the specified position Ps1 that occurs in the movable display period (sixth period T6 of the frame F2) in which the movable screen 1a is moved by the drive control unit 51 is corrected after this movable display period. To.

When the position detection process is executed before the movable display period, the position detection unit 52 determines whether or not the second virtual image 302 is projected by, for example, a signal from the driving support system mounted on the automobile 100. Then, it is decided whether or not to execute the position detection process. When the position detection process is executed after the movable display period, the position detection unit 52 determines whether or not to execute the position detection process by interlocking with the drive control unit 51. Therefore, when the position detection process is executed after the movable display period, the process of determining whether or not the position detection process 52 executes the position detection process is performed from the outside of the display device 10 (for example, a driving support system). It is completed inside the display device 10 without requiring the signal of.

Further, as a specific example of executing the position detection process by using the movement of the movable screen 1a by the drive control unit 51 during the movable display period as a trigger, the position detection unit 52 is a non-display in which the drive control unit 51 performs the return process. It may be configured to perform the position detection process during the period. That is, since the drive control unit 51 is configured to execute the return process of returning the movable screen 1a to the reference position each time the movable screen 1a is moved, the position detection unit 52 is configured to perform the return process of the movable screen 1a. The movement can be used for position detection processing. An example of executing the position detection process during the non-display period in which the drive control unit 51 performs the return process will be described with reference to FIG. FIG. 11 is a graph showing the time change of the position of the movable screen 1a in the moving direction X similar to that of FIG. 10B, and the horizontal axis is the time axis and the position of the movable screen 1a is shown on the vertical axis.

In the example of FIG. 11, the projection of the second virtual image 302 is performed only in the frame F2 of the frames F1, F2, and F3. That is, the movement of the movable screen 1a by the drive control unit 51 is performed only in the sixth period T6 (movable display period) in the period Ty of the "return path" of the frame F2, and in the period Ty of the "return path" of the frames F1 and F3. It is not performed in the sixth period T6 (movable display period). In this case, as shown in FIG. 11, the drive control unit 51 moves the movable screen 1a relative to the reference position in the period T61 of the frame F2, and sets the movable screen 1a in the reference position in the period T62 immediately after that. Perform return processing. Then, in the period T62 in which the drive control unit 51 performs the return process, the position detection process by the position detection unit 52 and the calibration process by the calibration unit 53 are executed.

That is, the period T62 is further divided into the periods T621 and T622, the position detection unit 52 executes the position detection process in the period T621, and the calibration unit 53 executes the calibration process in the period T622 in response to the result. Therefore, the deviation of the reference position from the specified position Ps1 that occurs in the movable display period (sixth period T6 of the frame F2) in which the movable screen 1a is moved by the drive control unit 51 is corrected within this sixth period T6. Will be done. That is, the entire sixth period T6 does not correspond to the movable display period in which the projection unit 40 irradiates the movable screen 1a with light, but the period T62 in which the drive control unit 51 performs the return processing is from the projection unit 40. It corresponds to the non-display period in which the movable screen 1a is not irradiated with light. Therefore, the position detection unit 52 can execute the position detection process during this period T62.

As described above, according to the display device 10 according to the present embodiment, the position detection process is executed triggered by the movement of the movable screen 1a by the drive control unit 51 during the movable display period. The frequency of processing can be reduced. That is, in the movable display period in which the second virtual image 302 is not projected, the reference position does not deviate from the specified position Ps1 in the first place, so that the variation in the reference position is not affected even if the position detection process is not performed. As a result, the power consumption of the drive unit 2 and the operation noise of the drive unit 2 related to the movement of the movable screen 1a in the position detection process are reduced. In particular, in the configuration in which the position detection unit 52 executes the position detection process during the non-display period in which the drive control unit 51 performs the return process, compared with the case where the drive unit 2 moves the movable screen 1a only for the position detection process. , The frequency of moving the movable screen 1a can be reduced.

In the second embodiment, the position detection process by the position detection unit 52 is executed in the same frame F2 as the movable display period in which the drive control unit 51 moves the movable screen 1a, or in the non-display period of the next frame F3 in the movable display period. However, it is not limited to this example. For example, the position detection process by the position detection unit 52 may be executed in the non-display period before or after the movable display period in which the drive control unit 51 moves the movable screen 1a.

The configuration (including the modified example) of the display device 10 according to the second embodiment can be appropriately combined with the configuration of the first embodiment (including the modified example).

(Embodiment 3)
As shown in FIG. 12, the display device 10A according to the present embodiment is different from the display device 10 according to the first embodiment in that it has only a movable screen 1a as the screen 1. Hereinafter, the same configurations as those in the first embodiment will be designated by a common reference numeral and description thereof will be omitted as appropriate.

That is, in the present embodiment, the fixed screen 1b (see FIG. 3) is omitted, and the projection unit 40 (projection optical system 4 and irradiation unit 3) draws only on the movable screen 1a. That is, the projection unit 40 always selects the movable screen 1a as the target screen, and irradiates the movable screen 1a with light that scans the movable screen 1a to draw on the movable screen 1a. Then, the projection unit 40 projects the virtual image 300 (first virtual image 301 or second virtual image 302) on the target space 400 by the light transmitted through the movable screen 1a.

The operation of the display device 10A according to the present embodiment is, for example, the same as the operation in which the fixed display period T3 and the fifth period T5 are omitted from the operation shown in FIG. 9A. In this case, the second period T2 is extended by the amount of the third period T3, and the sixth period T6 is extended by the amount of the fifth period T5. Even in this case, the position detection unit 52 does not irradiate the movable screen 1a with light from the projection unit 40 during the non-display period (first period T1, fourth period T4, or seventh period T7). Is moved to execute the position detection process.

In the third embodiment, the display device 10A includes only one movable screen 1a, but the present invention is not limited to this example, and a plurality of movable screens 1a may be provided.

The configuration (including the modified example) of the display device 10A according to the third embodiment can be appropriately combined with the configurations of the first embodiment (including the modified example) and the second embodiment (including the modified example).

The drawings shown in the above embodiments are merely conceptual diagrams for explaining an example of the display device 10, and the shape, size, positional relationship, and the like of each part are appropriately different from the actual display device 10.

(Summary)
As described above, the display devices 10 and 10A according to the first aspect include a movable screen 1a, a drive control unit 51, a projection unit 40, and a position detection unit 52. The movable screen 1a can move in the moving direction X. The drive control unit 51 moves the movable screen 1a relative to the reference position set at the specified position Ps1 in the moving direction X of the movable screen 1a. The projection unit 40 draws on the movable screen 1a by irradiating the movable screen 1a with light that scans the movable screen 1a, and projects the virtual image 300 onto the target space 400 by the light that passes through the movable screen 1a. The position detection unit 52 executes a position detection process for detecting that the movable screen 1a is located at a detection position set in relation to the specified position Ps1. The position detection unit 52 is configured to move the movable screen 1a and execute the position detection process during the non-display period in which the projection unit 40 does not irradiate the movable screen 1a with light.

According to this configuration, the position detection process for detecting the detection position of the movable screen 1a is executed by utilizing the non-display period in which the movement of the movable screen 1a does not affect the projection of the virtual image 300. Therefore, the position detection unit 52 can move the movable screen 1a and detect the detection position of the movable screen 1a without affecting the projection of the virtual image 300. Therefore, when there is a deviation of the reference position from the specified position Ps1, it is possible to detect this deviation and reduce the variation of the reference position. As a result, there is an advantage that the variation in the distance from the eyes of the user 200 to the virtual image 300 due to the variation in the reference position can be reduced.

In the first aspect, the display devices 10 and 10A according to the second aspect are configured such that the position detection unit 52 moves the movable screen 1a in a control pattern different from that of the drive control unit 51 during the non-display period. Has been done. According to this configuration, even if the position detection process cannot be efficiently performed only by moving the movable screen 1a by the drive control unit 51, the position detection unit 52 moves the movable screen 1a to efficiently perform the position detection process. It can be carried out.

The display devices 10 and 10A according to the third aspect further include a calibration unit 53 that moves the movable screen 1a to the specified position Ps1 based on at least the detection result of the position detection unit 52 in the first or second aspect. According to this configuration, when the reference position deviates from the specified position Ps1, the reference position is calibrated by the calibration unit 53, so that the variation in the reference position can be further reduced.

In the display devices 10 and 10A according to the fourth aspect, in the third aspect, the position detection unit 52 moves the movable screen 1a so that the movable screen 1a passes through the detection position during the non-display period, and positions the movable screen 1a. Execute the detection process. The calibration unit 53 is configured to move the movable screen 1a to the specified position Ps1 based on the detection result of the position detection unit 52 and the amount of movement of the movable screen 1a after passing through the detection position. According to this configuration, the movable screen 1a passes through the detection position once in the position detection process and then is returned to the detection position by the calibration unit 53, so that the movable screen 1a suddenly stops at the detection position as compared with the case where the movable screen 1a suddenly stops at the detection position. Therefore, the acceleration applied to the movable screen 1a can be reduced. As a result, the generation of pulse-shaped high-frequency components is suppressed in the drive current of the drive unit 2. This has the advantage that the impact applied to the movable screen 1a and the drive unit 2 can be alleviated, and the generation of noise due to the high frequency component can be suppressed.

In any of the first to fourth aspects, the display devices 10 and 10A according to the fifth aspect are configured such that the position detection unit 52 detects that the movable screen 1a passes through the detection position. According to this configuration, the position detection unit 52 can execute the position detection process with a relatively simple configuration by using the position sensor 6 such as an optical encoder.

In the display devices 10 and 10A according to the sixth aspect, in any one of the first to fifth aspects, the movable display period for irradiating the movable screen 1a with light from the projection unit 40 is intermittently set. The position detection unit 52 is configured to execute the position detection process by using the drive control unit 51 to move the movable screen 1a as a trigger during the movable display period. According to this configuration, the frequency of performing the position detection process can be reduced. That is, in the movable display period in which the drive control unit 51 does not move the movable screen 1a, the reference position does not deviate from the specified position Ps1 in the first place, so that the variation in the reference position is affected even if the position detection process is not performed. do not do. During such a movable display period, the position detection unit 52 does not execute the position detection process, so that the power consumption of the drive unit 2 and the operation of the drive unit 2 related to the movement of the movable screen 1a in the position detection process are reduced. It leads to a decrease in sound.

In the sixth aspect of the display devices 10 and 10A according to the seventh aspect, the position detection unit 52 executes the position detection process before the movable display period in which the drive control unit 51 moves the movable screen 1a. It is configured in. According to this configuration, it is possible to detect the deviation of the reference position from the specified position Ps1 before the start of the movable display period in which the drive control unit 51 moves the movable screen 1a, thereby reducing the variation in the reference position. It is possible.

In the sixth aspect of the display devices 10 and 10A according to the eighth aspect, the position detection unit 52 executes the position detection process after the movable display period in which the drive control unit 51 moves the movable screen 1a. It is configured as follows. According to this configuration, the process of determining whether or not the position detection unit 52 executes the position detection process does not require a signal from the outside (for example, a driving support system) of the display devices 10 and 10A, and the display device does not require a signal. It can be completed inside 10, 10A.

In the sixth aspect, the display devices 10 and 10A according to the ninth aspect are configured such that the drive control unit 51 executes a return process for returning the movable screen 1a to the reference position each time the movable screen 1a is moved. ing. The position detection unit 52 is configured to execute the position detection process during the non-display period in which the drive control unit 51 performs the return process. According to this configuration, the frequency of movement of the movable screen 1a can be reduced as compared with the case where the movable screen 1a is moved only for the position detection process, and the power consumption of the drive unit 2 related to the movement of the movable screen 1a can be reduced. This leads to reduction and reduction of operating noise of the drive unit 2.

In the display devices 10 and 10A according to the tenth aspect, in any one of the first to ninth aspects, the position detection unit 52 moves the movable screen 1a within the search range during the non-display period. If it is not detected that the movable screen 1a is located at the detection position, the position detection unit 52 is configured to change the search range, move the movable screen 1a again, and execute the position detection process. According to this configuration, in the position detection process, the position detection unit 52 can set a relatively small search range when the movable screen 1a is first moved. Therefore, it leads to reduction of power consumption of the drive unit 2 and reduction of operating noise of the drive unit 2 related to the movement of the movable screen 1a in the position detection process.

In the display devices 10 and 10A according to the eleventh aspect, in any one of the first to tenth aspects, the movable screen 1a has a surface 11 inclined with respect to the moving direction X. The projection unit 40 is configured to irradiate the movable screen 1a with light that scans the surface 11 of the movable screen 1a. According to this configuration, if the virtual image 300 has a relatively small inclination angle of the projection unit 40 with respect to the optical axis 500, the moving range of the movable screen 1a can be suppressed to be relatively narrow. When the moving range of the movable screen 1a is narrowed, for example, the drive unit 2 (actuator) for moving the movable screen 1a can be downsized, the power consumption of the drive unit 2 can be reduced, and the operating noise of the drive unit 2 can be reduced. Connect.

In the display devices 10 and 10A according to the twelfth aspect, in the eleventh aspect, when the drive control unit 51 forms the first virtual image 301 as the virtual image 300 on the first virtual surface 501, the moving direction The movable screen 1a is fixed at X. The first virtual surface 501 is a virtual surface in which the inclination angle α of the projection unit 40 with respect to the optical axis 500 is smaller than a predetermined value γ. When the drive control unit 51 forms the second virtual image 302 as the virtual image 300 on the second virtual surface 502 in which the inclination angle β of the projection unit 40 with respect to the optical axis 500 is larger than the predetermined value γ, the drive control unit 51 is in the moving direction X. It is configured to move the movable screen 1a. According to this configuration, the movable screen 1a is fixed to the first virtual image 301 in which the inclination angle α of the projection unit 40 with respect to the optical axis 500 is relatively small, that is, the first virtual image 301 whose angle with respect to the road surface 600 is shallow when viewed from the user 200. It is projected in the state of being projected. Therefore, there is an advantage that the moving range of the movable screen 1a can be narrowed as compared with the case where the movable screen 1a is moved when the first virtual image 301 is projected.

The control method of the display devices 10 and 10A according to the thirteenth aspect is a control method of the display devices 10 and 10A including a movable screen 1a, a drive control unit 51, a projection unit 40, and a position detection unit 52. .. The movable screen 1a can move in the moving direction X. The drive control unit 51 moves the movable screen 1a relative to the reference position set at the specified position Ps1 in the moving range of the movable screen 1a. The projection unit 40 draws on the movable screen 1a by irradiating the movable screen 1a with light that scans the movable screen 1a, and projects the virtual image 300 onto the target space 400 by the light that passes through the movable screen 1a. The position detection unit 52 executes a position detection process for detecting that the movable screen 1a is positioned at a detection position set in relation to the specified position Ps1. In the control method of the display devices 10 and 10A, the movable screen 1a is moved during the non-display period in which the projection unit 40 does not irradiate the movable screen 1a with light, and the position detection unit 52 is made to execute the position detection process.

According to this method, the position detection process for detecting the detection position of the movable screen 1a is executed by utilizing the non-display period in which the movement of the movable screen 1a does not affect the projection of the virtual image 300. Therefore, the position detection unit 52 can move the movable screen 1a and detect the detection position of the movable screen 1a without affecting the projection of the virtual image 300. Therefore, when there is a deviation of the reference position from the specified position Ps1, it is possible to detect this deviation and reduce the variation of the reference position. As a result, there is an advantage that the variation in the distance from the eyes of the user 200 to the virtual image 300 due to the variation in the reference position can be reduced.

The program according to the fourteenth aspect is a program for causing a computer to execute the control method of the display devices 10 and 10A according to the thirteenth aspect. According to this program, even when a general-purpose computer is used, there is an advantage that the variation in the distance from the eyes of the user 200 to the virtual image 300 can be reduced.

The moving body (for example, automobile 100) according to the fifteenth aspect includes the display devices 10 and 10A according to any one of the first to twelfth aspects and a reflective member (for example, a windshield 101) that reflects light from the projection unit 40. And.

According to this configuration, the position detection process for detecting the detection position of the movable screen 1a is executed by utilizing the non-display period in which the movement of the movable screen 1a does not affect the projection of the virtual image 300. Therefore, the position detection unit 52 can move the movable screen 1a and detect the detection position of the movable screen 1a without affecting the projection of the virtual image 300. Therefore, when there is a deviation of the reference position from the specified position Ps1, it is possible to detect this deviation and reduce the variation of the reference position. As a result, there is an advantage that the variation in the distance from the eyes of the user 200 to the virtual image 300 due to the variation in the reference position can be reduced.

The configurations according to the second to twelfth aspects are not essential configurations for the display devices 10 and 10A, and can be omitted as appropriate. Further, the control method of the display devices 10 and 10A according to the thirteenth aspect and the program according to the fourteenth aspect are also the same as those of the display devices 10 and 10A according to the first, second and third embodiments. , Various configurations are applicable.

1a Movable screen 10,10A Display device 11 Surface 40 Projection unit 51 Drive control unit 52 Position detection unit 53 Calibration unit 100 Automobile (moving body)
101 Windshield (reflective member)
300 Virtual image 301 1st virtual image 302 2nd virtual image 400 Target space 500 Optical axis 501 1st virtual surface 502 2nd virtual surface Ps1 Specified position X1-X2 (X) Moving direction

Claims (14)

A movable screen that can move in the direction of movement,
A drive control unit that moves the movable screen relative to a reference position set at a specified position in the moving range of the movable screen.
A projection unit that draws on the movable screen by irradiating the movable screen with light that scans the movable screen and projects a virtual image into the target space by the light that passes through the movable screen.
A position detection unit that executes a position detection process for detecting the position of the movable screen at a detection position set in relation to the specified position, and a position detection unit.
A calibration unit for moving the movable screen to the specified position and resetting the reference position on the specified position is provided, at least based on the detection result of the position detecting unit .
The position detection unit
A display device configured to move the movable screen and execute the position detection process during a non-display period in which the projection unit does not irradiate the movable screen with light. The display device according to claim 1, wherein the position detection unit is configured to move the movable screen in a control pattern different from that of the drive control unit during the non-display period. During the non-display period, the position detection unit moves the movable screen so that the movable screen passes through the detection position, and executes the position detection process.
The calibration unit is configured to move the movable screen to the specified position based on the detection result of the position detection unit and the amount of movement of the movable screen after passing through the detection position.
The display device according to claim 1 or 2. The position detection unit is configured to detect that the movable screen passes through the detection position.
The display device according to any one of claims 1 to 3. The movable display period for irradiating the movable screen with light from the projection unit is intermittently set.
The position detection unit is configured to execute the position detection process by using the drive control unit to move the movable screen as a trigger during the movable display period.
The display device according to any one of claims 1 to 4. The position detection unit is configured to execute the position detection process before the movable display period in which the drive control unit moves the movable screen.
The display device according to claim 5. The position detection unit is configured to execute the position detection process after the movable display period in which the drive control unit moves the movable screen.
The display device according to claim 5. The drive control unit is configured to execute a return process for returning the movable screen to the reference position each time the movable screen is moved.
The position detection unit is configured to execute the position detection process during the non-display period in which the drive control unit performs the return process.
The display device according to claim 5. The position detection unit
During the non-display period
The movable screen is moved within the search range, and if it is not detected that the movable screen is located at the detection position, the search range is changed and the movable screen is moved again to execute the position detection process. Is configured to
The display device according to any one of claims 1 to 8. The movable screen has a surface inclined with respect to the moving direction.
The projection unit is configured to irradiate the movable screen with light that scans the surface of the movable screen.
The display device according to any one of claims 1 to 9. The drive control unit
When forming the first virtual image as the virtual image on the first virtual surface whose inclination angle with respect to the optical axis of the projection unit is smaller than a predetermined value, the movable screen is fixed in the moving direction.
When forming a second virtual image as the virtual image on a second virtual surface whose inclination angle with respect to the optical axis of the projection unit is larger than the predetermined value, the movable screen is configured to move in the moving direction. ing
The display device according to claim 10. A movable screen that can move in the direction of movement,
A drive control unit that moves the movable screen relative to a reference position set at a specified position in the moving range of the movable screen.
A projection unit that draws on the movable screen by irradiating the movable screen with light that scans the movable screen and projects a virtual image into the target space by the light that passes through the movable screen.
A position detection unit that executes a position detection process for detecting the position of the movable screen at a detection position set in relation to the specified position, and a position detection unit.
A control method for a display device including a calibration unit that moves the movable screen to the specified position and resets the reference position on the specified position, at least based on the detection result of the position detecting unit.
During the non-display period in which the projection unit does not irradiate the movable screen with light, the movable screen is moved and the position detection unit is made to execute the position detection process.
How to control the display device. On the computer
A program for executing the control method of the display device according to claim 12. The display device according to any one of claims 1 to 11.
A reflecting member that reflects light from the projection unit is provided.
Mobile body.