Display device

Abstract

To enhance the reliability of a display device that displays a three dimensional image.SOLUTION: A display device 10 includes: a first irradiation unit 12 including a first mirror 26 that reflects a first drawing light 18 that has passed through a first shutter 25 toward a drawing space 50 and a first mirror driving unit 27 that changes the orientation of the first mirror 26 to change a first condensing position 28 where the first drawing light 18 is condensed; a second irradiation unit 14 including a second mirror 36 that is disposed on the opposite side of the drawing space 50 from the first mirror 26 and reflects a second drawing light 20 that has passed through a second shutter 35 toward the drawing space 50 and a second mirror driving unit 37 that changes the orientation of the second mirror 36 to change a second condensing position 30 where the second drawing light 20 is condensed; and a control unit 16 for controlling the operation of the first irradiation unit 12 and the operation of the second irradiation unit 14 so that the first shutter 25 and the second shutter 35 are opened and closed in accordance with the operation of the first mirror 26 and the operation of the second mirror 36.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a display device. [Background technology]

[0002] There is a method for generating a three-dimensional image within a display body by irradiating a display body containing a phosphor with excitation light and scanning the focusing position of the excitation light. For example, a configuration has been proposed in which excitation light is irradiated from above and below the display body using multiple irradiation units to improve display accuracy (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-128246 Summary of the Invention [Problem to be solved by the invention]

[0004] When two irradiation units are arranged opposite each other, there is a possibility that light from one irradiation unit may directly enter the inside of the other irradiation unit as stray light, and the incidence of stray light may cause damage to the irradiation unit.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide a technique for improving the reliability of a display device that displays a stereoscopic image. [Means for solving the problem]

[0006] A display device according to one embodiment of the present invention comprises a first irradiation unit including a first shutter that can be opened and closed to pass or block first drawing light, a first mirror that reflects the first drawing light that has passed through the first shutter toward a drawing space, and a first mirror drive unit that changes the orientation of the first mirror to change the first focusing position where the first drawing light is focused; a second irradiation unit that can be opened and closed to pass or block second drawing light, a second mirror that is positioned on the opposite side of the drawing space from the first mirror and reflects the second drawing light that has passed through the second shutter toward the drawing space, and a second mirror drive unit that changes the orientation of the second mirror to change the second focusing position where the second drawing light is focused; and a control unit that controls the operation of the first irradiation unit and the second irradiation unit so that the first shutter and the second shutter are opened and closed in accordance with the operation of the first mirror and the second mirror.

[0007] Any combination of the above components or mutual substitution of the components or expressions of the present invention between methods, devices, systems, etc. are also valid aspects of the present invention. [Effects of the Invention]

[0008] According to the present invention, the reliability of a display device that displays a stereoscopic image can be improved. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram schematically illustrating a configuration of a display device according to a first embodiment. [Figure 2] FIG. 2 is a diagram schematically illustrating an example of the operation of the display device according to the first embodiment. [Figure 3] FIG. 2 is a diagram schematically illustrating an example of the operation of the display device according to the first embodiment. [Figure 4] 5 is a flowchart showing an example of the operation of the display device according to the first embodiment. [Figure 5] 10 is a time chart showing an example of the operation of the display device according to the second embodiment. [Figure 6] FIG. 10 is a diagram schematically illustrating the configuration of a rotary chopper according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Specific numerical values ​​and the like shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. Elements not directly related to the present invention are omitted from the drawings. To facilitate understanding of the description, the dimensional ratios of the components in each drawing do not necessarily correspond to the actual dimensional ratios.

[0011] (First embodiment) 1 is a diagram schematically illustrating the configuration of a display device 10 according to a first embodiment. The display device 10 includes a first irradiating unit 12, a second irradiating unit 14, and a control unit 16. The display device 10 is a so-called volumetric display, and is configured to generate a three-dimensional image 52 in a rendering space 50 located between the first irradiating unit 12 and the second irradiating unit 14.

[0012] The three-dimensional image 52 is composed of a collection of multiple bright spots (or voxels) 54 generated at different three-dimensional positions in the drawing space 50. The multiple bright spots 54 are generated by the first drawing light 18 irradiated from the first irradiator 12 toward the drawing space 50 and the second drawing light 20 irradiated from the second irradiator 14 toward the drawing space 50. For example, if the first drawing light 18 and the second drawing light 20 are femtosecond lasers, the bright spots 54 can be generated by generating plasma at the focusing position of the first drawing light 18 or the second drawing light 20. In this case, a gas (e.g., air) that serves as a plasma generation source is present in the drawing space 50.

[0013] The multiple bright spots 54 may be generated by light emission from a phosphor instead of by light emission from plasma. In this case, a phosphor may be disposed in the drawing space 50, and the multiple bright spots 54 may be generated by exciting the phosphor with the first drawing light 18 or the second drawing light 20. For example, a display body made of transparent glass or resin containing a phosphor may be disposed in the drawing space 50, and the display body may be irradiated with the first drawing light 18 and the second drawing light 20, thereby generating the multiple bright spots 54 within the display body and drawing the three-dimensional image 52.

[0014] The first irradiator 12 irradiates the drawing space 50 with a first drawing light 18. The second irradiator 14 irradiates the drawing space 50 with a second drawing light 20. The first irradiator 12 and the second irradiator 14 are arranged opposite each other with the drawing space 50 in between. The first drawing light 18 and the second drawing light 20 enter the drawing space 50 from opposite sides.

[0015] 1, the direction from the first irradiator 12 to the second irradiator 14 is the +z direction, and the in-plane directions perpendicular to the z direction are the x and y directions. The irradiation direction of the first drawing light 18 toward the drawing space 50 is, for example, the +z direction. The irradiation direction of the second drawing light 20 toward the drawing space 50 is, for example, the -z direction.

[0016] The drawing space 50 can be defined as, for example, an area in which a bright spot 54 can be generated by the first drawing light 18 or the second drawing light 20. In Fig. 1, the outline of the drawing space 50 is schematically shown by a dashed line, but the outline of the drawing space 50 does not need to be clearly defined. The shape of the outline of the drawing space 50 is not particularly limited.

[0017] The first irradiation unit 12 includes a first light source 22 , a first focus adjustment unit 24 , a first shutter 25 , a first mirror 26 , and a first mirror driver 27 .

[0018] First light source 22 generates first drawing light 18. First light source 22 generates, as first drawing light 18, an ultrashort pulse laser having a pulse width of, for example, picoseconds or femtoseconds (for example, 10 fs or more and 100 ps or less). The wavelength of first drawing light 18 is not particularly limited and may be in the infrared range of approximately 800 nm to 1500 nm, the visible range of approximately 400 nm to 800 nm, or the ultraviolet range of approximately 200 nm to 400 nm. The pulse energy of first drawing light 18 is set, for example, to be approximately 1 μJ to 1 mJ so that plasma can be generated at first focusing position 28 where first drawing light 18 is focused.

[0019] The first focus adjustment unit 24 is configured to adjust the focus of the first drawing light 18 and change the z coordinate of the first focusing position 28. The first focus adjustment unit 24 includes, for example, a variable focus lens, and adjusts the focus of the first focusing position 28 by changing the refractive power. Instead of a variable focus lens, the first focus adjustment unit 24 may use a zoom lens configured to be displaceable along the optical path.

[0020] The first shutter 25 is disposed between the first focus adjustment unit 24 and the first mirror 26. The first shutter 25 operates to be openable and closable, and switches between an open state in which the first drawing light 18 passes through and a closed state in which the first drawing light 18 is blocked. For example, in the open state, the first shutter 25 has an opening size that is the same as the effective opening (clear shutter) of the first focus adjustment unit 24.

[0021] The first mirror 26 reflects the first drawing light 18 toward the drawing space 50. The orientation of the first mirror 26 is configured to be variable by a first mirror driver 27. The first mirror driver 27 is configured to change the orientation of the first mirror 26 along two axes, thereby changing a first focusing position 28 of the first drawing light 18 reflected by the first mirror 26 in the x and y directions. The first mirror 26 and the first mirror driver 27 may operate to vector scan the first drawing light 18. The first mirror 26 and the first mirror driver 27 may be configured with a galvanometer mirror or a MEMS (Micro Electro Mechanical Systems) mirror. The first mirror 26 may include a first X mirror for scanning the first drawing light 18 in the x direction and a first Y mirror for scanning the first drawing light 18 in the y direction. The first mirror driver 27 may include a driver for driving the first X mirror and a driver for driving the first Y mirror.

[0022] The second irradiation unit 14 includes a second light source 32, a second focus adjustment unit 34, a second shutter 35, a second mirror 36, and a second mirror drive unit 37. The second irradiation unit 14 can be configured similarly to the first irradiation unit 12.

[0023] The second light source 32 generates the second drawing light 20. The second light source 32 can be configured similarly to the first light source 22, and can generate the second drawing light 20 having the same characteristics (e.g., wavelength, pulse width, pulse energy) as the first drawing light 18. The second light source 32 generates the second drawing light 20 such that plasma can be generated at the second focusing position 30 where the second drawing light 20 is focused. The second light source 32 may generate the second drawing light 20 having characteristics different from those of the first drawing light 18.

[0024] The second focus adjustment unit 34 is configured to adjust the focus of the second drawing light 20 and change the z coordinate of the second light condensing position 30. The second focus adjustment unit 34 can be configured similarly to the first focus adjustment unit 24.

[0025] The second shutter 35 is disposed between the second focus adjustment unit 34 and the second mirror 36. The second shutter 35 operates to be openable and closable, and is switched between an open state in which the second drawing light 20 passes through and a closed state in which the second drawing light 20 is blocked. For example, in the open state, the second shutter 35 has the same opening size as the effective opening (clear shutter) of the second focus adjustment unit 34.

[0026] The second mirror 36 reflects the second drawing light 20 toward the drawing space 50. The second mirror 36 is disposed on the opposite side of the drawing space 50 from the first mirror 26. The orientation of the second mirror 36 is configured to be variable by a second mirror driver 37. The second mirror driver 37 is configured to change the orientation of the second mirror 36 along two axes, thereby changing the first focusing position 28 of the first drawing light 18 reflected by the second mirror 36 in the x and y directions. The second mirror 36 and the second mirror driver 37 may operate to vector scan the second drawing light 20. The second mirror 36 and the second mirror driver 37 may be configured by a galvanometer mirror or a MEMS (Micro Electro Mechanical Systems) mirror. The second mirror 36 may include a second X mirror for scanning the second drawing light 20 in the x direction and a second Y mirror for scanning the second drawing light 20 in the y direction. The second mirror driver 37 may include a driver that drives the second X mirror and a driver that drives the second Y mirror.

[0027] The display device 10 may further include a first drawing lens 38 disposed between the first irradiating unit 12 and the drawing space 50, and a second drawing lens 40 disposed between the second irradiating unit 14 and the drawing space 50. Note that the first drawing lens 38 and the second drawing lens 40 may be omitted.

[0028] The first drawing lens 38 focuses the first drawing light 18 scanned by the first mirror 26 toward the drawing space 50. The first drawing lens 38 may be formed, for example, by a convex lens with fixed refractive power. The first drawing lens 38 may have the role of improving the telecentricity of the first drawing light 18 scanned by the first mirror 26.

[0029] The second drawing lens 40 focuses the second drawing light 20 scanned by the second mirror 36 toward the drawing space 50. The second drawing lens 40 may be formed of, for example, a convex lens with fixed refractive power. The second drawing lens 40 may have a role of improving the telecentricity of the second drawing light 20 scanned by the second mirror 36.

[0030] The first drawing lens 38 and the second drawing lens 40 can be arranged, for example, on a common optical axis 56. For example, the optical axes of the first drawing lens 38 and the second drawing lens 40 can coincide with the optical axis 56 extending in the z direction from the first irradiating unit 12 (e.g., the first mirror 26) toward the second irradiating unit 14 (e.g., the second mirror 36).

[0031] The control unit 16 controls the overall operation of the display device 10. The various functions provided by the control unit 16 can be realized, for example, by a combination of hardware and software. The hardware of the control unit 16 is realized by elements and mechanical devices such as a processor and memory provided in a computer. The software of the control unit 16 is realized by a program executed by a processor, etc.

[0032] The control unit 16 controls the operation of the first irradiator 12 and the second irradiator 14, and variably controls the first condensing position 28 and the second condensing position 30. The control unit 16 controls the operation of the first focus adjuster 24 and the first mirror driver 27, thereby variably controlling the first condensing position 28 in three dimensions. The control unit 16 controls the operation of the second focus adjuster 34 and the second mirror driver 37, thereby variably controlling the second condensing position 30 in three dimensions.

[0033] The control unit 16 generates drawing data indicating the three-dimensional coordinate values ​​of a plurality of bright points 54 that constitute the stereoscopic image 52 to be displayed. The control unit 16 generates the drawing data based on, for example, three-dimensional data of the stereoscopic image 52 provided from an external device. The drawing data indicates, for example, a plurality of coordinate values ​​for drawing the outline of the stereoscopic image 52. The control unit 16 may generate drawing data corresponding to a plurality of frames in order to draw the stereoscopic image 52 as a moving image.

[0034] The control unit 16 classifies the multiple coordinate values ​​included in the drawing data into either first coordinate values ​​or second coordinate values. The drawing data may include multiple first coordinate values ​​indicating first focusing positions 28 to be drawn by the first irradiator 12 and multiple second coordinate values ​​indicating second focusing positions 30 to be drawn by the second irradiator 14. The control unit 16 may, for example, classify the first coordinate values ​​so that the number of first coordinate values ​​is the same as the number of second coordinate values. The control unit 16 may, for example, divide the drawing space 50 into a first region and a second region, and define the coordinate values ​​present in the first region as first coordinate values ​​and the coordinate values ​​present in the second region as second coordinate values.

[0035] The control unit 16 can control the operation of the first irradiator 12 according to a plurality of first coordinate values ​​included in the drawing data. The control unit 16 determines operation parameters indicating the refractive power of the first focus adjuster 24 and the orientation of the first mirror 26 (e.g., angles in the x and y directions) according to the three-dimensional first coordinate values ​​specified as the first focusing position 28, and operates the first focus adjuster 24 and the first mirror driver 27 according to the determined operation parameters. The values ​​of the operation parameters according to the first coordinate values ​​can be determined in advance according to the design of the optical system of the first irradiator 12 and the first drawing lens 38.

[0036] The control unit 16 can control the operation of the second irradiator 14 according to a plurality of second coordinate values ​​included in the drawing data. The control unit 16 determines operating parameters indicating the refractive power of the second focus adjuster 34 and the orientation of the second mirror 36 (e.g., angles in the x and y directions) according to the three-dimensional second coordinate values ​​specified as the second focusing position 30, and operates the second focus adjuster 34 and the second mirror driver 37 according to the determined operating parameters. The values ​​of the operating parameters according to the second coordinate values ​​can be determined in advance according to the design of the optical systems of the second irradiator 14 and the second drawing lens 40.

[0037] The control unit 16 sequentially switches the values ​​of the operating parameters of the first focus adjustment unit 24 and the first mirror drive unit 27 in accordance with the multiple first coordinate values ​​included in the drawing data, thereby sequentially focusing the first drawing light 18 at each of the multiple first focusing positions 28 to generate bright spots 54. The control unit 16 sequentially switches the values ​​of the operating parameters of the second focus adjustment unit 34 and the second mirror drive unit 37 in accordance with the multiple second coordinate values ​​included in the drawing data, thereby sequentially focusing the second drawing light 20 at each of the multiple second focusing positions 30 to generate bright spots 54.

[0038] The control unit 16 controls the operation of the first irradiator 12 and the second irradiator 14 so that the first shutter 25 and the second shutter 35 are opened and closed in accordance with the operation of the first mirror 26 and the second mirror 36. When the orientation of the first mirror 26 satisfies a first condition and the orientation of the second mirror 36 satisfies a second condition, the control unit 16 opens the first shutter 25 and closes the second mirror 36. The first condition is a condition in which the first focusing position 28 is located near the optical axis 56, and in particular, a condition in which the first mirror 26 is oriented such that the first drawing light 18 is incident on the second mirror 36. The first condition can be determined in advance as a condition in which the angle of the first mirror 26 falls within a predetermined first range and the first drawing light 18 is incident on the second mirror 36. The second condition is a condition under which the second mirror 36 is oriented such that the first drawing light 18 that is incident on and reflected by the second mirror 36 is incident on the second shutter 35 as stray light. The second condition may be, for example, a condition under which the second focusing position 30 is located near the optical axis 56, and may be predetermined as a condition under which the angle of the second mirror 36 is within a predetermined second range so that the first drawing light 18 is incident on the second shutter 35. The second condition may also be defined as a condition under which the second mirror 36 is oriented such that the second drawing light 20 is incident on the first mirror 26.

[0039] FIG. 2 is a diagram schematically illustrating an example of operation of the display device 10 according to the first embodiment, showing a case where the first condition is satisfied and the second condition is also satisfied. In the example of operation shown in FIG. 2, the first focusing position 28 is located on the optical axis 56, so the first drawing light 58 that passes through the first focusing position 28 passes through the second drawing lens 40 and is incident on the second mirror 36. In other words, the first condition that the angle of the first mirror 26 is within a predetermined first range is satisfied. Also, in the example of operation shown in FIG. 2, the first drawing light 58 that is incident on the second mirror 36 is reflected by the second mirror 36 and then incident on the second shutter 35. In other words, the angle of the second mirror 36 is within a predetermined second range, so the second condition is satisfied.

[0040] As shown in FIG. 2 , when both the first and second conditions are satisfied, the second shutter 35 is closed to block the second drawing light 20. This prevents the first drawing light 58 reflected by the second mirror 36 from passing through the second shutter 35 and entering the second focus adjustment unit 34 or the second light source 32. If the first drawing light 58 were reflected by the curved surface of the lens of the second focus adjustment unit 34 and concentrated, the second mirror 36 and other components could be damaged by the concentrated light. Furthermore, if the first drawing light 58 were to enter the second light source 32, the second light source 32 could be damaged or its operation could become unstable. When the first and second conditions are satisfied, closing the second shutter 35 prevents malfunctions in the operation of the display device 10 and improves the reliability of the display device 10.

[0041] 3 is a diagram schematically illustrating an example of the operation of the display device 10 according to the first embodiment, where the first condition is satisfied but the second condition is not. Specifically, the first drawing light 58 that passes through the first focusing position 28 is incident on the second mirror 36, but the first drawing light 58 that is reflected by the second mirror 36 does not pass through the effective aperture of the second shutter 35 and deviates to the outside of the aperture of the second shutter 35. This avoids problems caused by the first drawing light 58 being incident on the second focus adjustment unit 34 or the second light source 32, thereby improving the reliability of the display device 10. By opening the second shutter 35 at this time, a bright spot 54 can be generated at the second focusing position 30, thereby improving the drawing accuracy of the stereoscopic image 52.

[0042] When the first condition is not satisfied but the second condition is satisfied, the control unit 16 may open both the first shutter 25 and the second shutter 35. When the first condition is not satisfied and the second condition is not satisfied, the control unit 16 may open both the first shutter 25 and the second shutter 35. This makes it possible to generate bright spots 54 at both the first focusing position 28 and the second focusing position 30, thereby improving the drawing accuracy of the three-dimensional image 52.

[0043] 4 is a flowchart showing an example of the operation of the display device 10 according to the first embodiment. The control unit 16 acquires a first coordinate value included in the drawing data (step S10) and calculates the orientation of the first mirror 26 corresponding to the acquired first coordinate value (step S12). The control unit 16 acquires a second coordinate value included in the drawing data (step S14) and calculates the orientation of the second mirror 36 corresponding to the acquired second coordinate value (step S16). If the calculated orientation of the first mirror 26 satisfies the first condition (Yes in step S18) and if the calculated orientation of the second mirror 36 satisfies the second condition (Yes in step S20), the control unit 16 closes the second shutter 35 (step S22). If the calculated orientation of first mirror 26 does not satisfy the first condition (No in step S18) or if the calculated orientation of second mirror 36 does not satisfy the second condition (No in step S20), control unit 16 opens second shutter 35 (step S24). After executing step S22 or step S24, control unit 16 controls first mirror driver 27 so that first mirror 26 is oriented in the calculated direction (step S26), and controls second mirror driver 37 so that second mirror 36 is oriented in the calculated direction (step S28).

[0044] If the drawing data includes the next coordinate value (Yes in step S30), the control unit 16 repeatedly executes steps S10 to S28 until drawing of the multiple coordinate values ​​included in the drawing data is completed. If the drawing data does not include the next coordinate value (No in step S30), the control unit 16 ends this flow. Note that this flow may be repeatedly executed to continuously display still images or moving images as the 3D image 52.

[0045] According to this embodiment, when the orientation of first mirror 26 satisfies the first condition and the orientation of second mirror 36 satisfies the second condition, the operations of first irradiator 12 and second irradiator 14 are controlled so that second shutter 35 is in the closed state. As a result, it is possible to prevent first drawing light 18 from being incident on second focus adjustment unit 34 or second light source 32 inside second irradiator 14, which is opposite to first drawing light 18, and from affecting the operation of second irradiator 14. This improves the reliability of display device 10.

[0046] (Second embodiment) The display device according to the second embodiment has a configuration similar to that of the display device 10 according to the first embodiment shown in Fig. 1. In the second embodiment, the operations of the first irradiation unit 12 and the second irradiation unit 14 differ from those of the first embodiment. Below, the second embodiment will be described, focusing on the differences from the first embodiment, and a description of the commonalities will be omitted as appropriate.

[0047] 5 is a time chart showing an example of the operation of the display device 10 according to the second embodiment. Fig. 5 schematically shows the operation process of the first shutter 25, the first mirror 26, the second shutter 35, and the second mirror 36. The first shutter 25 operates by alternately repeating a first open period T1a in which it is in an open state and a first closed period T1b in which it is in a closed state. Similarly, the second shutter 35 operates by alternately repeating a second open period T2a in which it is in an open state and a second closed period T2b in which it is in a closed state.

[0048] The first shutter 25 and the second shutter 35 operate so that both are not open at the same time. For example, when the first shutter 25 is open, the second shutter 35 is closed. This prevents the first drawing light 18 from passing through the second shutter 35 and entering the second focus adjustment unit 34 or the second light source 32. Furthermore, when the second shutter 35 is open, the first shutter 25 operates so as to close. This prevents the second drawing light 20 from passing through the first shutter 25 and entering the first focus adjustment unit 24 or the first light source 22.

[0049] The first mirror driver 27 operates to alternately repeat a first change period T1c, during which the orientation of the first mirror 26 is changed, and a first fixation period T1d, during which the orientation of the first mirror 26 is fixed. The first mirror driver 27 fixes the orientation of the first mirror 26 when the first shutter 25 is in the open state, and changes the orientation of the first mirror 26 when the first shutter 25 is in the closed state. This makes it possible to fix the orientation of the first mirror 26 when the first shutter 25 is in the open state and irradiate the first drawing space 50 with the first drawing light 18, thereby stabilizing the position where the bright spot 54 is generated at the first light-collecting position 28 and improving drawing accuracy.

[0050] The second mirror driver 37 operates to alternately repeat a second change period T2c, in which the orientation of the second mirror 36 is changed, and a second fixation period T2d, in which the orientation of the second mirror 36 is fixed. The second mirror driver 37 fixes the orientation of the second mirror 36 when the second shutter 35 is in the open state, and changes the orientation of the second mirror 36 when the second shutter 35 is in the closed state. This makes it possible to fix the orientation of the second mirror 36 when the second shutter 35 is in the open state and irradiate the second drawing light 20 into the drawing space 50, thereby stabilizing the position where the bright spot 54 is generated at the second light-collecting position 30 and improving drawing accuracy.

[0051] In a modification of the second embodiment, a rotary chopper may be used instead of the first shutter 25 and the second shutter 35. FIG. 6 is a diagram schematically illustrating the configuration of a rotary chopper 80 according to the modification. The rotary chopper 80 has a plurality of openings 82 spaced apart in the circumferential direction. The rotary chopper 80 is disposed on the optical path of the first drawing light 18 or the second drawing light 20. The rotary chopper 80 passes the first drawing light 18 or the second drawing light 20 when the openings 82 and the optical path overlap, and blocks the first drawing light 18 or the second drawing light 20 when the openings 82 and the optical path do not overlap. By adjusting the ratio between the opening range θa where the openings 82 are formed and the blocked range θb where the openings 82 are not formed, the ratio between the open period and the closed period when the rotary chopper 80 is rotated at a constant speed can be adjusted.

[0052] The present invention has been described above with reference to the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, and appropriate combinations or substitutions of the configurations shown in each display example are also included in the present invention. [Explanation of symbols]

[0053] 10...display device, 12...first irradiation section, 14...second irradiation section, 16...control section, 18...first drawing light, 20...second drawing light, 28...first focusing position, 30...second focusing position.

Claims

1. a first irradiation unit including a first shutter that can be opened and closed to pass or block a first drawing light, a first mirror that reflects the first drawing light that has passed through the first shutter toward a drawing space, and a first mirror driver that changes an orientation of the first mirror to change a first light-collecting position at which the first drawing light is collected; a second irradiation unit including: a second shutter that can be opened and closed to pass or block the second drawing light; a second mirror that is disposed on the opposite side of the drawing space from the first mirror and that reflects the second drawing light that has passed through the second shutter toward the drawing space; and a second mirror driver that changes an orientation of the second mirror to change a second focusing position at which the second drawing light is focused; a control unit that controls the operation of the first irradiating unit and the second irradiating unit so that the first shutter and the second shutter are opened and closed in accordance with the operation of the first mirror and the second mirror. Display device.

2. the control unit opens the first shutter and closes the second shutter when the orientation of the first mirror satisfies a first condition and the orientation of the second mirror satisfies a second condition. The display device according to claim 1 .

3. the first condition is a condition for determining a direction of the first mirror such that the first drawing light is incident on the second mirror; the second condition is a condition for the second mirror to be oriented in such a way that the second drawing light is incident on the first mirror; The display device according to claim 2 .

4. the control unit closes the second shutter when the first shutter is in an open state, and closes the first shutter when the second shutter is in an open state; The display device according to claim 1 .

5. the control unit fixes the orientation of the first mirror when the first shutter is in an open state, changes the orientation of the first mirror when the first shutter is in a closed state, fixes the orientation of the second mirror when the second shutter is in an open state, and changes the orientation of the second mirror when the second shutter is in a closed state. The display device according to claim 4 .

Images