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 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 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 mirror driving unit 27 and the operation of the second mirror driving unit 37 so that the orientation of the second mirror 36 satisfies a second condition when the orientation of the first mirror 26 satisfies a first condition.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 mirror that reflects first drawing light toward a drawing space and a first mirror driver 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 is arranged on the opposite side of the drawing space from the first mirror and includes a second mirror that reflects second drawing light toward the drawing space and a second mirror driver 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 mirror driver and the second mirror driver so that the orientation of the second mirror satisfies a second condition when the orientation of the first mirror satisfies a first condition.

[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] 10A and 10B are diagrams schematically illustrating the operation of a display device according to a comparative example. [Figure 3] 10A to 10C are diagrams illustrating the operation of the display device according to the embodiment. [Figure 4] 5 is a flowchart showing an example of the operation of the display device according to the first embodiment. [Figure 5] FIG. 10 is a diagram schematically illustrating the configuration of a display device according to a second embodiment. [Figure 6] 10 is a time chart showing an example of the operation of the display device according to the second embodiment. [Figure 7] FIG. 10 is a diagram schematically illustrating the configuration of a display device according to a third embodiment. [Figure 8]8(a) and 8(b) are diagrams schematically showing the configuration and operation of the first polygon mirror according to the third embodiment. [Figure 9] 10 is a time chart showing an example of the operation of the display device according to the third embodiment. 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 aperture 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 aperture 25 is disposed between the first focus adjustment unit 24 and the first mirror 26. The first aperture 25 has, for example, the same opening size as the effective opening (clear aperture) of the first focus adjustment unit 24. The first aperture 25 blocks the second drawing light 20 that enters the first irradiation unit 12 from the second irradiation unit 14 as stray light, and prevents the second drawing light 20 from entering the lens 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 aperture 35, a second mirror 36, and a second mirror driver 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 aperture 35 is disposed between the second focus adjustment unit 34 and the second mirror 36. The second aperture 35 has, for example, the same opening size as the effective opening (clear aperture) of the second focus adjustment unit 34. The second aperture 35 blocks the first drawing light 18 that enters the second irradiation unit 14 from the first irradiation unit 12 as stray light, and prevents the first drawing light 18 from entering the lens 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] When the orientation of the first mirror 26 satisfies the first condition, the control unit 16 controls the operation of the first mirror driver 27 and the second mirror driver 37 so that the orientation of the second mirror 36 satisfies the second condition. 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 so that the first drawing light 18 is incident on the second mirror 36. The first condition can be predetermined as a condition in which the angle of the first mirror 26 is within a predetermined first range, so that the first drawing light 18 is incident on the second mirror 36. The second condition is a condition in which the second mirror 36 is oriented so that the first drawing light 18, which is incident on and reflected by the second mirror 36, does not pass through the second aperture 35 as stray light. The second condition can be predetermined as a condition in which the angle of the second mirror 36 is outside a predetermined second range, so that the first drawing light 18 does not pass through the second aperture 35.

[0039] 2 is a diagram schematically illustrating the operation of a display device 10 according to a comparative example, showing a case where the first condition is satisfied but the second condition is not satisfied. For clarity, the second drawing light 20 is not shown in FIG. 2. In the comparative example of 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.

[0040] In the comparative example of FIG. 2 , the first drawing light 58 incident on the second mirror 36 passes through the second aperture 35 after being reflected by the second mirror 36. In other words, the angle of the second mirror 36 is within the predetermined second range, so the second condition is not satisfied. An example of a case where the orientation of the second mirror 36 is within the second range is when the second focusing position 30 is located near the optical axis 56. In this case, the first drawing light 58 passing through the second aperture 35 may be incident on the second focus adjustment unit 34 or the second light source 32. If the first drawing light 58 is reflected and focused by the curved surface of the lens of the second focus adjustment unit 34, the focusing may damage the second mirror 36 or other components. Furthermore, if the first drawing light 58 is incident on the second light source 32, the second light source 32 may be damaged or its operation may become unstable. In this way, if the operation of the comparative example that does not satisfy the second condition is permitted when the first condition is satisfied, problems may occur in the operation of the display device 10, which may reduce the reliability of the display device 10.

[0041] 3 is a diagram schematically illustrating the operation of display device 10 according to an embodiment, showing a case where both the first condition and the second condition are satisfied. That is, first drawing light 58 that has passed through first focusing position 28 is incident on second mirror 36, but first drawing light 58 that has been reflected by second mirror 36 does not pass through second aperture 35 and deviates to the outside of the opening of second aperture 35. In this case, problems caused by first drawing light 58 being incident on second focus adjustment unit 34 or second light source 32 can be avoided, thereby improving the reliability of display device 10.

[0042] The second condition may be defined as a condition under which the second mirror 36 is oriented such that the second drawing light 20 does not enter the first mirror 26. When the second mirror 36 is oriented such that the second drawing light 20 does not enter the first mirror 26, even if the first drawing light 18 enters the second mirror 36, it is reflected along a different optical path from the second drawing light 20, and therefore the first drawing light 18 can be prevented from passing through the second aperture 35.

[0043] When the first condition is satisfied, the control unit 16 operates the second irradiator 14 so that the second condition is also satisfied, thereby avoiding the operation of the comparative example of FIG. 2 and achieving the operation of the embodiment of FIG. 3. When the first condition is satisfied by the orientation of the first mirror 26, the control unit 16 controls the orientation of the second mirror 36 so that the second condition is satisfied. In other words, when the angle of the first mirror 26 is within a predetermined first range, the control unit 16 controls the angle of the second mirror 36 so that it is outside a predetermined second range. When the first condition is not satisfied, the control unit 16 may operate the second irradiator 14 so that the second condition is satisfied, or may operate the second irradiator 14 so that the second condition is not satisfied.

[0044] 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 the calculated orientation of the second mirror 36 satisfies the second condition (Yes in step S20), the control unit 16 controls the first mirror driver 27 so that the first mirror 26 is oriented in the calculated direction (step S22) and controls the second mirror driver 37 so that the second mirror 36 is oriented in the calculated direction (step S24).

[0045] If the orientation of the first mirror 26 does not satisfy the first condition in step S18 (No in step S18), the control unit 16 skips step S20 and executes steps S22 and S24. If the calculated orientation of the second mirror 36 does not satisfy the second condition in step S20 (No in step S20), the control unit 16 acquires another second coordinate value included in the drawing data (step S26), calculates the orientation of the second mirror 36 corresponding to the acquired other second coordinate value (step S28), and returns to step S20. The control unit 16 repeats steps S26 and S28 until the calculated orientation of the second mirror 36 satisfies the second condition in step S20. If the calculated orientation of the second mirror 36 satisfies the second condition (Yes in step S20), the control unit 16 executes steps S22 and S24.

[0046] 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.

[0047] According to this embodiment, when the orientation of the first mirror 26 satisfies the first condition, the operations of the first irradiator 12 and the second irradiator 14 are controlled so that the orientation of the second mirror 36 satisfies the second condition. As a result, it is possible to prevent the first drawing light 18 from entering the opposing second irradiator 14 and affecting the operation of the second irradiator 14. This improves the reliability of the display device 10.

[0048] (Second embodiment) 5 is a diagram schematically illustrating the configuration of a display device 10A according to a second embodiment. The second embodiment differs from the first embodiment in that the first drawing light 18 and the second drawing light 20 are configured to be raster scanned rather than vector scanned. The following description of the second embodiment will focus on the differences from the first embodiment, and will omit a description of the commonalities as appropriate.

[0049] The display device 10A includes a first irradiator 12A, a second irradiator 14A, and a controller 16A. The first irradiator 12A includes a first light source 22, a first intensity modulator 23, a first focus adjuster 24, a first aperture 25, a first mirror 26, and a first mirror driver 27. The second irradiator 14A includes a second light source 32, a second intensity modulator 33, a second focus adjuster 34, a second aperture 35, a second mirror 36, and a second mirror driver 37. The display device 10A may further include a first drawing lens 38 and a second drawing lens 40.

[0050] The first irradiation unit 12A differs from the first irradiation unit 12 according to the first embodiment in that it further includes a first intensity modulation unit 23. The first intensity modulation unit 23 modulates the intensity of the first drawing light 18. For example, the first intensity modulation unit 23 can modulate the light intensity of the first drawing light 18 for each pulse in synchronization with the pulse of the first drawing light 18 output from the first light source 22. The first intensity modulation unit 23 is configured, for example, by an electro-optic modulator (EOM). The first intensity modulation unit 23 may be a shutter that turns on and off the pulse output of the first drawing light 18. The first intensity modulation unit 23 is disposed, for example, between the first light source 22 and the first focus adjustment unit 24. The first intensity modulation unit 23 may be disposed between the first focus adjustment unit 24 and the first mirror 26 or between the first focus adjustment unit 24 and the first aperture 25.

[0051] The second irradiation unit 14A differs from the second irradiation unit 14 according to the first embodiment in that it further includes a second intensity modulation unit 33. The second intensity modulation unit 33 may be configured similarly to the first intensity modulation unit 23. The second intensity modulation unit 33 modulates the intensity of the second drawing light 20. For example, the second intensity modulation unit 33 may modulate the light intensity of the second drawing light 20 for each pulse in synchronization with the pulse of the second drawing light 20 output from the second light source 32. The second intensity modulation unit 33 may be configured, for example, by an electro-optical modulator (EOM). The second intensity modulation unit 33 may be a shutter that turns on and off the pulse output of the second drawing light 20. The second intensity modulation unit 33 is disposed, for example, between the second light source 32 and the second focus adjustment unit 34. The second intensity modulation unit 33 may be disposed between the second focus adjustment unit 34 and the second mirror 36, or between the second focus adjustment unit 34 and the second aperture 35.

[0052] Like the control unit 16 according to the first embodiment, the control unit 16A controls the overall operation of the display device 10. Like the control unit 16, the functions provided by the control unit 16A can be realized, for example, by cooperation between hardware and software.

[0053] The control unit 16A can control the operation of the first irradiation unit 12A according to a plurality of first coordinate values ​​included in the drawing data. For example, the control unit 16A operates the first mirror driver 27 so that the first drawing light 18 is raster scanned at a constant cycle. For example, the control unit 16A operates the first focus adjuster 24 so that the focus of the first condensing position 28 changes in accordance with the raster scanning cycle. The control unit 16A selectively generates bright spots 54 at each of a plurality of first coordinate values ​​included in the drawing data by operating the first intensity modulator 23 according to the coordinate values ​​of the first condensing position 28. For example, the control unit 16A operates the first intensity modulator 23 so that the light intensity of the first drawing light 18 is set to a first intensity when the first condensing position 28 matches the first coordinate value included in the drawing data, and the light intensity of the first drawing light 18 is set to a second intensity lower than the first intensity when the first condensing position 28 does not match the first coordinate value included in the drawing data. Here, the first intensity is equal to or greater than the light intensity required to generate the bright spot 54, and the second intensity is less than the light intensity required to generate the bright spot 54.

[0054] The control unit 16A can control the operation of the second irradiation unit 14A according to the multiple second coordinate values ​​included in the drawing data. For example, the control unit 16A operates the second mirror driver 37 so that the second drawing light 20 is raster scanned at a constant cycle. For example, the control unit 16A operates the second focus adjuster 34 so that the focus of the second condensing position 30 changes in accordance with the raster scanning cycle. The control unit 16A selectively generates bright spots 54 at each of the multiple second coordinate values ​​included in the drawing data by operating the second intensity modulator 33 according to the coordinate values ​​of the second condensing position 30. For example, the control unit 16A operates the second intensity modulator 33 so that the light intensity of the second drawing light 20 is set to a first intensity when the second condensing position 30 matches the second coordinate value included in the drawing data, and the light intensity of the second drawing light 20 is set to a second intensity lower than the first intensity when the second condensing position 30 does not match the second coordinate value included in the drawing data.

[0055] As in the first embodiment, when the orientation of the first mirror 26 satisfies the first condition, the control unit 16A operates the first mirror driver 27 and the second mirror driver 37 so that the orientation of the second mirror 36 satisfies the second condition. For example, the control unit 16A matches the operation cycles (e.g., raster scan cycles) of the first mirror 26 and the second mirror 36, and keeps the relative angle between the first mirror 26 and the second mirror 36 constant. This makes it possible to simultaneously perform raster scans of both the first drawing beam 18 and the second drawing beam 20 while maintaining a state in which both the first condition and the second condition are satisfied.

[0056] Fig. 6 is a time chart showing an example of the operation of the display device 10A according to the second embodiment. Fig. 6 shows the changes over time in the x-direction angle θ1x and the y-direction angle θ1y of the first mirror 26, and the changes over time in the x-direction angle θ2x and the y-direction angle θ2y of the second mirror 36.

[0057] The x-direction angle θ1x of the first mirror 26 changes at a constant speed during the first X-scan period T1x from a predetermined lower limit angle θ1a to a predetermined upper limit angle θ1b, and the operation during the first X-scan period T1x is repeated. The y-direction angle θ1y of the first mirror 26 changes at a constant speed during the first Y-scan period T1y from a predetermined lower limit angle θ1d to a predetermined upper limit angle θ1e, and the operation during the first Y-scan period T1y is repeated. The first Y-scan period T1y includes multiple first X-scan periods T1x, and in the example of FIG. 6, it includes 20 first X-scan periods T1x.

[0058] The x-direction angle θ2x of the second mirror 36 changes at a constant speed during the second X scan period T2x from a predetermined lower limit angle θ2a to a predetermined upper limit angle θ2b, and the operation during the second X scan period T2x is repeated. The y-direction angle θ2y of the second mirror 36 changes at a constant speed during the second Y scan period T2y from a predetermined lower limit angle θ2d to a predetermined upper limit angle θ2e, and the operation during the second Y scan period T2y is repeated. The second Y scan period T2y includes multiple second X scan periods T2x, and in the example of FIG. 6, it includes 20 second X scan periods T2x.

[0059] The operation cycle of the second mirror 36 is the same as the operation cycle of the first mirror 26. That is, the first X scan period T1x and the second X scan period T2x have the same length, and the first Y scan period T1y and the second Y scan period T2y have the same length. However, the operation timing (or phase) of the second mirror 36 differs from the operation timing (or phase) of the first mirror 26, and there is a shift of a predetermined period ΔTa. The length of the predetermined period ΔTa is shorter than the first X scan period T1x or the second X scan period T2x. The length of the predetermined period ΔTa is, for example, between 1 / 3 and 2 / 3 of the first X scan period T1x or the second X scan period T2x.

[0060] By shifting the operation timing of the first mirror 26 and the second mirror 36, it is possible to operate the first mirror 26 and the second mirror 36 so that the second condition is also satisfied at the timing when the first condition is satisfied. The timing when the first condition is satisfied is when the x-direction angle θ1x of the first mirror 26 is within a first range θ1 near the central angle θ1c in FIG. 6. The timing when the second condition is not satisfied is when the x-direction angle θ2x of the second mirror 36 is within a second range θ1 near the central angle θ2c in FIG. 6. In the example of FIG. 6, the timing when the first condition is satisfied is shifted from the timing when the second condition is not satisfied, so it is possible to operate the first mirror 26 and the second mirror 36 so that the second condition is always satisfied when the first condition is satisfied.

[0061] In the second embodiment, the first mirror 26 may include a first X polygon mirror for scanning the first drawing light 18 in the x direction and a first Y polygon mirror for scanning the first drawing light 18 in the y direction. The second mirror 36 may include a second X polygon mirror for scanning the second drawing light 20 in the x direction and a second Y polygon mirror for scanning the second drawing light 20 in the y direction. In this case, the operation cycles (or rotation cycles) of the first X polygon mirror and the second X polygon mirror can be matched, and the operation timings (or rotation phases) of the first X polygon mirror and the second X polygon mirror can be made different. Similarly, the operation cycles (or rotation cycles) of the first Y polygon mirror and the second Y polygon mirror can be matched, and the operation timings (or rotation phases) of the first Y polygon mirror and the second Y polygon mirror can be made different. This allows for an operation similar to that shown in FIG. 6 to be realized.

[0062] In the second embodiment, each of the first mirror 26 and the second mirror 36 may be configured by a combination of a polygon mirror and a galvanometer mirror. For example, a polygon mirror or a galvanometer mirror may be used to scan the first drawing light 18 or the second drawing light 20 in the x direction. In this case, a galvanometer mirror or a polygon mirror may be used to scan the first drawing light 18 or the second drawing light 20 in the y direction.

[0063] In this embodiment as well, when the orientation of the first mirror 26 satisfies the first condition, the operations of the first irradiator 12A and the second irradiator 14A are controlled so that the orientation of the second mirror 36 satisfies the second condition. As a result, it is possible to prevent the first drawing light 18 from entering the opposing second irradiator 14 and affecting the operation of the second irradiator 14. This improves the reliability of the display device 10.

[0064] (Third embodiment) FIG. 7 is a diagram schematically illustrating the configuration of a display device 10B according to a third embodiment. In the third embodiment, similar to the second embodiment, the display device is configured to raster scan the first drawing light 18 and the second drawing light 20. In the third embodiment, polygon mirrors are used as the first mirror 26B and the second mirror 36B. The polygon mirror has a reflective surface and a non-reflective surface, and its operation is controlled so that when one of the first drawing light 18 and the second drawing light 20 is reflected by the reflective surface, the other of the first drawing light 18 and the second drawing light 20 is incident on the non-reflective surface and is not reflected. The following description of the third embodiment will focus on the differences from the above-described embodiments, and a description of the commonalities will be omitted as appropriate.

[0065] The display device 10B includes a first irradiator 12B, a second irradiator 14B, and a controller 16B. The first irradiator 12B includes a first light source 22, a first intensity modulator 23, a first focus adjuster 24, a first aperture 25, a first mirror 26B, and a first mirror driver 27B. The second irradiator 14B includes a second light source 32, a second intensity modulator 33, a second focus adjuster 34, a second aperture 35, a second mirror 36B, and a second mirror driver 37B. The display device 10B may further include a first drawing lens 38 and a second drawing lens 40.

[0066] The first mirror 26B includes a first polygon mirror 60 for scanning the first drawing light 18. The first polygon mirror 60 is configured to scan the first drawing light 18 in, for example, the x direction. The first mirror 26B may further include a galvanometer mirror or polygon mirror (not shown in FIG. 7) configured to scan the first drawing light 18 in a direction different from that of the first polygon mirror 60 (for example, the y direction). The first mirror driver 27B rotates the first polygon mirror 60 to change the orientation of the reflective surface of the first polygon mirror 60 onto which the first drawing light 18 is incident.

[0067] The second mirror 36B includes a second polygon mirror 70 for scanning the second drawing light 20. The second polygon mirror 70 is configured to scan the second drawing light 20 in, for example, the x direction. The second mirror 36B may further include a galvanometer mirror or polygon mirror (not shown in FIG. 7) configured to scan the second drawing light 20 in a direction different from that of the second polygon mirror 70 (for example, the y direction). The second mirror driver 37B rotates the second polygon mirror 70 to change the orientation of the reflective surface of the second polygon mirror 70 onto which the second drawing light 20 is incident.

[0068] 8(a) and 8(b) are diagrams schematically illustrating the configuration and operation of a first polygon mirror 60 according to the third embodiment. The first polygon mirror 60 has a plurality of first reflecting surfaces 62 and a plurality of first non-reflecting surfaces 64. The first reflecting surfaces 62 and the first non-reflecting surfaces 64 are provided on the side surfaces of a polygonal prism (polygon). The first reflecting surfaces 62 are surfaces on which mirrors that specularly reflect the first drawing light 18 are formed. The first non-reflecting surfaces 64 are surfaces that do not substantially reflect the first drawing light 18 and are configured to absorb or scatter the first drawing light 18. The first reflecting surfaces 62 and the first non-reflecting surfaces 64 are arranged alternately in the rotation direction of the polygonal prism (polygon). In the example of FIGS. 8(a) and 8(b), the first polygon mirror 60 has an octagonal prism shape and has four first reflecting surfaces 62 and four first non-reflecting surfaces 64 that are arranged alternately.

[0069] 8(a) shows the timing at which the first drawing light 18 is incident on the first reflecting surface 62. The first drawing light 18 is reflected by the first reflecting surface 62 and travels toward the first drawing lens 38. The first drawing light 18 is scanned in the x direction by the rotation of the first polygon mirror 60 changing the orientation of the first reflecting surface 62.

[0070] 8(b) shows the timing at which the first drawing light 18 is incident on the first non-reflective surface 64. The first drawing light 18 is absorbed or scattered by the first non-reflective surface 64, and is therefore not specularly reflected toward the first drawing lens 38. The first drawing light 18 is not scanned in the x direction even if the orientation of the first non-reflective surface 64 changes due to the rotation of the first polygon mirror 60.

[0071] When the first polygon mirror 60 is rotated at a constant speed, a first irradiation period in which the first drawing light 18 is reflected by the first reflecting surface 62 and irradiated into the drawing space 50 and a first non-irradiation period in which the first drawing light 18 is not irradiated into the drawing space 50 because it is incident on the first non-reflecting surface 64 are alternately repeated.

[0072] The second polygon mirror 70 can be configured similarly to the first polygon mirror 60. The second polygon mirror 70 has a plurality of second reflective surfaces and a plurality of second non-reflective surfaces, which are arranged alternately in the rotation direction of the polygonal prism (polygon). When the second polygon mirror 70 is rotated at a constant speed, a second irradiation period in which the second drawing light 20 is reflected by the second reflective surfaces and irradiated onto the drawing space 50 and a second non-irradiation period in which the second drawing light 20 is incident on the second non-reflective surfaces and is therefore not irradiated onto the drawing space 50 are alternately repeated.

[0073] Fig. 9 is a time chart showing an example of the operation of the display device 10B according to the third embodiment. Fig. 9 shows the change over time in the x-direction angle θ1x of the first reflective surface 62 or the first non-reflective surface 64 of the first polygon mirror 60, and the change over time in the x-direction angle θ2x of the second reflective surface or the second non-reflective surface of the second polygon mirror 70. Fig. 9 also shows the change over time in the y-direction angle θ1y of the mirror that scans the first drawing light 18 in the y direction, and the change over time in the y-direction angle θ2y of the mirror that scans the second drawing light 20 in the y direction.

[0074] The first polygon mirror 60 alternates between a first irradiation period (or a first X-scan period T1x) during which the first drawing light 18 is incident on the first reflecting surface 62 and a first non-irradiation period T1n during which the first drawing light 18 is incident on the first non-reflecting surface 64. The second polygon mirror 70 alternates between a second irradiation period (or a second X-scan period T2x) during which the second drawing light 20 is incident on the second reflecting surface and a second non-irradiation period T2n during which the second drawing light 20 is incident on the second non-reflecting surface. In Figure 9, the timing at which the drawing light is incident on a reflecting surface is indicated by a solid line, and the timing at which the drawing light is incident on a non-reflecting surface is indicated by a dashed line.

[0075] The operation cycle of the second polygon mirror 70 is the same as the operation cycle of the first polygon mirror 60. That is, the lengths of the first X scan period T1x and the second X scan period T2x are the same, and the lengths of the first non-irradiation period T1n and the second non-irradiation period T2n are also the same. However, the operation timing (or phase) of the second polygon mirror 70 differs from the operation timing (or phase) of the first polygon mirror 60, and there is a shift of a predetermined period ΔTb. The length of the predetermined period ΔTb can be, for example, equal to or greater than the length of the first X scan period T1x or the second X scan period T2x, and can be equal to or less than the length of the first non-irradiation period T1n or the second non-irradiation period T2n.

[0076] According to this embodiment, a first X scan period T1x during which the first drawing light 18 is applied to the drawing space 50 can be set as a second non-irradiation period T2n during which the second drawing light 20 is not applied to the drawing space 50. In the first X scan period T1x, if the orientation of the first reflecting surface 62 of the first mirror 26B satisfies the first condition, the orientation of the second reflecting surface of the second mirror 36B satisfies the second condition, and therefore it is possible to prevent the first drawing light 18 from entering the opposing second irradiating unit 14 and affecting the operation of the second irradiating unit 14. This improves the reliability of the display device 10B.

[0077] According to this embodiment, during the second X scan period T2x in which the second drawing light 20 is applied to the drawing space 50, a first non-irradiation period T21 can be set in which the first drawing light 18 is not applied to the drawing space 50. If the orientation of the second reflecting surface of the second mirror 36B does not satisfy the second condition during the second X scan period T2x, the orientation of the first reflecting surface 62 of the first mirror 26B does not satisfy the first condition, and therefore it is possible to prevent the second drawing light 20 from entering the opposing first irradiator 12B and affecting the operation of the first irradiator 12B. This improves the reliability of the display device 10B.

[0078] 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]

[0079] 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 mirror that reflects the first drawing light toward a drawing space, and a first mirror driver that changes an orientation of the first mirror to change a first light collection position where the first drawing light is collected; a second irradiation unit including: a second mirror arranged on the opposite side of the drawing space from the first mirror, the second mirror reflecting second drawing light toward the drawing space; and a second mirror driving unit changing an orientation of the second mirror to change a second light collecting position at which the second drawing light is collected; a control unit that controls operations of the first mirror driving unit and the second mirror driving unit so that the orientation of the second mirror satisfies a second condition when the orientation of the first mirror satisfies a first condition. Display device.

2. the second irradiation unit further includes a second focus adjustment unit that changes a focus of the second light collection position, and a second aperture that is disposed between the second focus adjustment unit and the second mirror and that passes the second drawing light, 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 that the second mirror is oriented in such a way that the first drawing light reflected by the second mirror does not pass through the second aperture; The display device according to claim 1 .

3. the control unit operates the first mirror driving unit and the second mirror driving unit so that operation cycles of the first mirror and the second mirror coincide with each other and operation timings of the first mirror and the second mirror are shifted.

3. The display device according to claim 1 or 2.

4. the first mirror includes a first polygon mirror, the second mirror includes a second polygon mirror, the control unit operates the first mirror driving unit and the second mirror driving unit so that the rotation periods of the first polygon mirror and the second polygon mirror are the same and the rotation phases of the first polygon mirror and the second polygon mirror are shifted from each other.

3. The display device according to claim 1 or 2.

5. the first polygon mirror has a first reflecting surface and a first non-reflecting surface, and the first drawing light is alternately incident on the first reflecting surface or the first non-reflecting surface by rotation of the first polygon mirror; the second polygon mirror has a second reflective surface and a second non-reflective surface, and the second drawing light is alternately incident on the second reflective surface or the second non-reflective surface by rotation of the second polygon mirror; the control unit operates the first mirror driving unit and the second mirror driving unit so that the second drawing light is incident on the second non-reflective surface when the first drawing light is incident on the first reflective surface, and the first drawing light is incident on the first non-reflective surface when the second drawing light is incident on the second reflective surface. The display device according to claim 4 .

Images