Image Projection Device

Abstract

To provide an image projection device with which, while suppressing a decrease in the efficiency of using a laser beam, it is possible to smoothly and appropriately suppress a color irregularity of a projection image.SOLUTION: An image projection device 1 comprises: light sources 11-13 for emitting a laser beam in different color; display elements 31a, 31b for modulating the laser beams in respective colors by a video signal; an illumination optical system 20 for guiding the laser beams from the light sources 11-13 to the display elements 31a, 31b; and a projection lens 51 for projecting the laser beams modulated by the display elements 31a, 31b. The illumination optical system 20 includes a first train of optical elements for equalizing the intensity distribution of one laser beam and guiding to the display element 31a (fly-eye lens 22a, cylindrical lens array 24a, diffuser panel 25a, field lens 26a), and a second train of optical elements for equalizing the intensity distribution of the other laser beams and guiding to the display element 31b (fly-eye lens 22b, cylindrical lens array 24b, diffuser panel 25b, field lens 26b).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an image projection device that projects light modulated by a video signal. [Background technology]

[0002] Image projection devices that project images onto a room wall or a screen installed in the room are known. In addition, image projection devices mounted on vehicles project and display images onto the windshield in front of the driver's seat. Patent Document 1 listed below describes an image projection device that projects images using two reflective liquid crystal panels. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-276586 Summary of the Invention [Problem to be solved by the invention]

[0004] An image projection device may use multiple light sources that respectively emit red, green, and blue laser beams. In this case, for example, the laser beams emitted from the light sources are integrated by an illumination optical system and directed to a common display element such as a liquid crystal panel.

[0005] However, in this configuration, if the beam profiles of the laser beams emitted from the respective light sources are different, optimizing the illumination optical system for one of the laser beams will result in color unevenness in the projected image due to the other laser beams.On the other hand, if, for example, the diffusion angle of the diffuser included in the illumination optical system is set large in order to suppress color unevenness in the projected image for all laser beams, power loss will occur in the laser beams from each light source, reducing the utilization efficiency of the laser beams.

[0006] In view of the above, an object of the present invention is to provide an image projection device that can smoothly and appropriately suppress color unevenness in a projected image while suppressing a decrease in the utilization efficiency of laser light. [Means for solving the problem]

[0007] A main aspect of the present invention relates to an image projection device. The image projection device according to this aspect includes at least three light sources that emit laser beams of different colors, at least one display element that modulates the laser beams emitted from the at least three light sources based on a video signal, an illumination optical system that guides the laser beams emitted from the at least three light sources to the display element, and a projection lens that projects the laser beams modulated by the display element. The illumination optical system includes: emitted from one of the at least three light sources a first optical element that homogenizes the intensity distribution of the laser light and guides it to the display element; Emitted from other light sources among the at least three light sources and a second optical element that homogenizes the intensity distribution of the laser light and guides it to the display element. Multiple Laser light intensity distribution Number of peaks in teeth, are equal to each other, and The light is incident on the first optical element. One Laser light intensity distribution Number and difference of peaks in is doing.

[0008] According to the image projection device of this aspect, the first laser light and the other laser light are individually homogenized by the first optical element and the second optical element, respectively, making it easier to optimize the first optical element and the second optical element for the first laser light and the other laser light, respectively. Therefore, compared to when all laser light is homogenized by a single optical element, it is possible to appropriately homogenize the first laser light and the other laser light while suppressing a decrease in the utilization efficiency of the laser light from each light source. [Effects of the Invention]

[0009] As described above, according to the present invention, it is possible to provide an image projection device that can smoothly and appropriately suppress color unevenness in a projected image while suppressing a decrease in the utilization efficiency of laser light.

[0010] The effects and significance of the present invention will become more apparent from the following description of the embodiments, however, the embodiments shown below are merely examples of how the present invention can be implemented, and the present invention is not limited to the embodiments described below. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a plan view showing the configuration of an optical system of an image projection device according to an embodiment. [Figure 2] FIG. 2 is a plan view showing the configuration of an optical system of an image projection device according to a comparative example. [Figure 3] 3(a) to 3(c) are diagrams showing beam profiles of laser light emitted from red, green, and blue light sources, respectively, according to a comparative example. [Figure 4] FIG. 4 is a diagram showing an image obtained by capturing a white projection image according to a comparative example. [Figure 5] FIG. 5 is a block diagram showing the configuration of a circuit unit of an image projection device according to an embodiment. [Figure 6] FIG. 6 is a time chart showing control of three light sources and two display elements according to the embodiment. [Figure 7] FIG. 7 is a plan view showing the configuration of an optical system of an image projection device according to the first modified example. [Figure 8] FIG. 8 is a plan view showing the configuration of an optical system of an image projection device according to the second modified example. [Figure 9] FIG. 9 is a plan view showing the configuration of an optical system of an image projection device according to the third modified example. [Figure 10] FIG. 10 is a plan view showing the configuration of an optical system of an image projection device according to the fourth modified example. [Figure 11] FIG. 11 is a plan view showing the configuration of an optical system of an image projection device according to the fifth modified example. [Figure 12] FIG. 12 is a plan view showing another configuration of the optical system of the image projection device according to the fifth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. For convenience, each drawing is labeled with mutually orthogonal X, Y, and Z axes. The positive direction of the Z axis is the projection direction of laser light modulated by a video signal, and the X axis direction is the vertical direction of the optical system.

[0013] Fig. 1 is a plan view showing the configuration of the optical system of the image projection device 1. In Fig. 1, the optical axis of the optical system is indicated by a dashed dotted line, and the progression of laser light of each color is schematically shown by a dotted line.

[0014] The image projection device 1 includes, as an optical system configuration, light sources 11 to 13, an illumination optical system 20, display elements 31a and 31b, a coupling element 40, and a projection lens unit 50. The image projection device 1 further includes an actuator 60 that vibrates the cylindrical lens arrays 24a and 24b in the Y-axis direction.

[0015] Light sources 11, 12, and 13 emit laser light in the red, green, and blue wavelength bands, respectively. Light sources 11, 12, and 13 are, for example, semiconductor lasers. Light sources 11 and 12 emit laser light in the positive direction of the Z axis, and light source 13 emits laser light in the positive direction of the Y axis. The emission optical axes of light sources 11, 12, and 13 are included in the same plane parallel to the YZ plane. Light source 11 is arranged so that its polarization direction is S-polarized with respect to the polarization plane of polarizing beam splitter 27a, and light sources 12 and 13 are arranged so that their polarization direction is S-polarized with respect to the polarization plane of polarizing beam splitter 27b.

[0016] The illumination optical system 20 guides the laser light of each color emitted from the light sources 11, 12, and 13 to the display elements 31a and 31b. The illumination optical system 20 includes collimator lenses 21a to 21c, fly-eye lenses 22a and 22b, collimator lenses 23a and 23b, cylindrical lens arrays 24a and 24b, diffusers 25a and 25b, field lenses 26a and 26b, polarizing beam splitters 27a and 27b, and a dichroic mirror 28.

[0017] Collimator lenses 21a to 21c converge the laser light emitted from light sources 11 to 13 into approximately parallel light, respectively. Dichroic mirror 28 transmits the laser light in the green wavelength band that has passed through collimator lens 21b, and reflects the laser light in the blue wavelength band that has passed through collimator lens 21c. Dichroic mirror 28 is disposed at a position where the emission optical axes of light sources 12 and 13 intersect. Dichroic mirror 28 aligns the optical axis of light source 13 with the optical axis of light source 12. Therefore, after passing through dichroic mirror 28, the laser light in the green wavelength band and the laser light in the blue wavelength band travel along the same optical path in the positive direction of the Z axis.

[0018] The fly-eye lenses 22a and 22b homogenize the intensity distribution of the incident laser light. The fly-eye lenses 22a and 22b are configured by a microlens array in which a large number of microlenses are arranged in a matrix. The laser light incident on each microlens of the fly-eye lens 22a is diffused via the collimator lens 23a so as to spread over the entire same incident area of ​​the cylindrical lens array 24a. Similarly, the laser light incident on each microlens of the fly-eye lens 22b is diffused via the collimator lens 23b so as to spread over the entire same incident area of ​​the cylindrical lens array 24b. This homogenizes the intensity distribution of the laser light of each color in the incident areas of the cylindrical lens arrays 24a and 24b.

[0019] The collimator lenses 23a and 23b collimate the laser light incident from the fly-eye lenses 22a and 22b, and guide the parallel light to the cylindrical lens arrays 24a and 24b.

[0020] The cylindrical lens arrays 24a and 24b have a number of cylindrical lenses L1, L2, L3 on the entrance surface and a number of cylindrical lenses L4 on the exit surface, respectively. L2 On the entrance surfaces of the cylindrical lens arrays 24a and 24b, a large number of cylindrical lenses L1 are formed so that their generating lines are parallel to the X axis. On the exit surfaces of the cylindrical lens arrays 24a and 24b, a large number of cylindrical lenses L2 are formed so that their generating lines are parallel to the Y axis. L2 is formed.

[0021] When cylindrical lens array 24a is viewed in the Z-axis direction, a rectangular lens portion is formed in the region where cylindrical lens L1 on the incident surface and cylindrical lens L2 on the exit surface intersect. Each lens portion converges the laser light in the Y-axis direction by cylindrical lens L1 on the incident surface and converges the laser light in the X-axis direction by cylindrical lens L2 on the exit surface. Due to this lens action of each lens portion and the lens action of field lens 26a on the subsequent stage, the laser light that has passed through each lens portion is guided to display element 31a so as to spread across the entire display area of ​​display element 31a.

[0022] The converging action of the cylindrical lenses L1 on the incident surface is stronger than the converging action of the cylindrical lenses L2 on the exit surface. As a result, the laser light transmitted through each lens portion becomes a rectangle elongated in the Z-axis direction on the incident surface of the display element 31a. The converging action of the cylindrical lenses L1 on the incident surface and the converging action of the cylindrical lenses L2 on the exit surface are adjusted so that this shape is appropriate for the display area of ​​the display element 31a. In other words, the cylindrical lens array 24a defines the illumination area of ​​the laser light in the red wavelength band on the display element 31a.

[0023] The cylindrical lenses L1 and L2 formed on the entrance and exit surfaces of the cylindrical lens array 24b are adjusted in the same manner. The cylindrical lens array 24b defines the illumination areas of the laser light in the green and blue wavelength bands on the display element 31b.

[0024] The diffusers 25a and 25b diffuse the laser light incident from the cylindrical lens arrays 24a and 24b at a predetermined diffusion angle. A large number of minute lenses are formed with almost no gaps on the incident or exit surfaces of the diffusers 25a and 25b. These lenses diffuse the laser light. Typically, the diffusion angle is set to a few degrees (for example, around 1°). The diffusing effect of the diffusers 25a and 25b further uniforms the intensity distribution of the laser light.

[0025] The polarized beam splitters 27a and 27b reflect the S-polarized component of the laser light incident from the field lenses 26a and 26b, respectively, and guide it to the display elements 31a and 31b, and transmit the P-polarized component of the laser light incident from the display elements 31a and 31b, respectively, and guide it to the coupling element 40.

[0026] The display elements 31a and 31b are reflective liquid crystal panels. The display elements 31a and 31b change the polarization direction of the laser light incident on the display area for each pixel in response to a video signal. This causes the amount of laser light passing through the polarizing beam splitters 27a and 27b to change for each pixel. In this way, the laser light of each color is modulated in response to the video signal.

[0027] The combining element 40 reflects the laser light incident from the polarizing beam splitter 27a side and the laser light incident from the polarizing beam splitter 27b side in the positive direction of the Z axis, and combines the optical paths of the laser light of each color. The combining element 40 is, for example, a cross dichroic prism.

[0028] The projection lens unit 50 projects the modulated laser light of each color incident from the coupling element 40 in the Z-axis direction. The projection lens unit 50 includes a plurality of projection lenses 51 for projecting the laser light of each color, and a lens barrel 52 for holding these projection lenses 51.

[0029] The actuator 60 includes a support portion 61 and a drive portion 62, and vibrates the support portion 61 in the Y-axis direction by driving the drive portion 62. The drive portion 62 is, for example, an electromagnetic actuator that drives the support portion 61 by an electromagnetic force generated between a coil and a magnet. The drive portion 62 may also be configured to drive the support portion by another method.

[0030] 1, laser light in the red wavelength band modulated by the display element 31a based on a video signal and laser light in the green and blue wavelength bands modulated by the display element 31b based on a video signal are each projected by the projection lens 51 via the coupling element 40. As a result, a color projection image is displayed on the rear side of the projection lens unit 50. At this time, the cylindrical lens arrays 24a and 24b are micro-vibrated in the Y-axis direction by the actuator 60. This suppresses speckle noise that occurs in the projection image due to interference of the laser light.

[0031] 1, the intensity distribution of the laser light of each color irradiated onto the display area of ​​display elements 31a and 31b is homogenized by fly-eye lenses 22a and 22b, cylindrical lens arrays 24a and 24b, diffusers 25a and 25b, and field lenses 26a and 26b. That is, the intensity distribution of the laser light in the red wavelength band emitted from light source 11 is homogenized by fly-eye lens 22a, cylindrical lens array 24a, diffuser 25a, and field lens 26a and then guided to display element 31a, while the intensity distribution of the laser light in the green and blue wavelength bands emitted from light sources 12 and 13 is homogenized by fly-eye lens 22b, cylindrical lens array 24b, diffuser 25b, and field lens 26b and then guided to display element 31b.

[0032] In this embodiment, the illumination optical system 20 is provided with a first set of optical elements (fly-eye lens 22a, cylindrical lens array 24a, diffuser 25a, and field lens 26a) for homogenizing the laser light in the red wavelength band, and a second set of optical elements (fly-eye lens 22b, cylindrical lens array 24b, diffuser 25b, and field lens 26b) for homogenizing the laser light in the green and blue wavelength bands. This makes it possible to effectively suppress color unevenness in the projected image while suppressing a decrease in the utilization efficiency of the laser light, as described below.

[0033] FIG. 2 is a plan view showing the configuration of an optical system of an image projection device 2 according to a comparative example.

[0034] In the comparative example, the optical paths of laser light in the red, green, and blue wavelength bands are combined by two dichroic mirrors 28a and 28b. The laser light of each color is then guided to a common display element 31 via a common fly-eye lens 22, collimator lens 23, cylindrical lens array 24, diffuser 25, field lens 26, and polarizing beam splitter 27. The laser light of each color modulated by the display element 31 passes through the polarizing beam splitter 27, enters the projection lens unit 50, and is projected by the projection lens 51. At this time, the cylindrical lens array 24 is micro-vibrated in the Y-axis direction by an actuator 60, thereby suppressing speckle noise in the projected image.

[0035] In the comparative example, the first optical system (fly-eye lens 22, cylindrical lens array 24, diffuser 25, and field lens 26) for uniforming the intensity distribution of each color of laser light is applied to red, green, and blue laser light. Therefore, in the comparative example, these optical systems must be optimized for the three types of laser light: red, green, and blue.

[0036] However, there are cases where the beam profiles of the laser beams emitted from the light sources 11, 12, and 13 are different from each other.

[0037] For example, when generating a white image using red, green, and blue laser beams, the light intensity ratio of the red laser beam needs to be increased compared to the green and blue laser beams. On the other hand, the light source 11 emitting the red laser beam generally experiences a significant decrease in output power with increasing temperature compared to the light sources 12 and 13 emitting the green and blue laser beams. Therefore, in order to maintain the above light intensity ratio even at high temperatures, the maximum output power of the red light source 11 needs to be increased compared to the green and blue light sources 12 and 13.

[0038] To meet such requirements, red light source 11 may be configured, for example, as a multi-emission type laser light source in which three light-emitting elements are arranged side by side in a light-emitting layer. On the other hand, green and blue light sources 12, 13 may be configured, for example, as single-emission type laser light sources in which only one light-emitting element is arranged in a light-emitting layer. In this case, the beam profile of the laser light emitted from red light source 11 will be significantly different from the beam profiles of the laser light emitted from green and blue light sources 12, 13.

[0039] 3(a) to 3(c) are diagrams showing beam profiles (intensity distributions) of laser light emitted from red, green, and blue light sources 11, 12, and 13, respectively, on the observation plane P1 in Fig. 2. For convenience, the color intensity distributions are shown converted to grayscale in Fig. 3(a) to 3(c).

[0040] In this example, three light-emitting units are arranged in light source 11, and therefore the beam profile of the laser light emitted from light source 11 has three peaks aligned in the X-axis direction (indicated by arrows in FIG. 3(a)), as shown in FIG. 3(a). On the other hand, only one light-emitting unit is arranged in light sources 12 and 13, and therefore the beam profiles of the laser light emitted from light sources 12 and 13 each have only one peak in the center (indicated by arrows in FIG. 3(a)), as shown in FIG. 3(b) and (c).

[0041] As shown in Figures 3(b) and 3(c), the beam profiles of the green and blue laser beams are similar to each other. In contrast, the beam profile of the red laser beam is significantly different from the beam profiles of the green and blue laser beams, as shown in Figure 3(a). For this reason, in the configuration of the comparative example in Figure 2, the above-mentioned single system of optical elements (fly-eye lens 22, cylindrical lens array 24, diffuser plate 25, and field lens 26) cannot be optimized for all of the red, green, and blue laser beams, and as a result, color unevenness occurs in the projected image projected from the projection lens 51.

[0042] Fig. 4 is a diagram showing an image captured on the observation plane P2 in Fig. 2 when the light sources 11, 12, and 13 are controlled so as to display a white image in the configuration of the comparative example. For convenience, the color image is shown in Fig. 4 after being converted to grayscale.

[0043] Here, a single set of optical elements (fly-eye lens 22, cylindrical lens array 24, diffuser 25, and field lens 26) for suppressing color unevenness is almost fully optimized for the laser light (beam profile) in the green and blue wavelength bands. Therefore, the green and blue laser light are substantially uniformed by these optical elements, and there is almost no green or blue color unevenness in the white image in FIG. 4.

[0044] However, as shown in Fig. 3(a), the laser light in the red wavelength band emitted from the light source 11 has a beam profile that is significantly different from that of the green and blue laser lights. For this reason, the above-mentioned single optical element cannot be fully optimized for the laser light in the red wavelength band as well as the green and blue wavelength bands. As a result, the white image in Fig. 4 has a strong reddish hue in two regions R1 indicated by dashed lines.

[0045] That is, of the three peaks shown in Fig. 3(a), the central peak is located at approximately the same position as the green and blue peaks, so that the red color unevenness is suppressed at the central position of the white image, just like the green and blue. In contrast, since there are no peaks for the green and blue laser light at the positions of the peaks on both ends shown in Fig. 3(a), the red color unevenness remains in the region R1 of the white image corresponding to these peaks on both ends, making the image appear more reddish.

[0046] 2, in order to suppress the reddish tinge in region R1, for example, a method of increasing the diffusion angle of diffuser plate 25 or a method of adjusting the focal lengths of cylindrical lens array 24 and field lens 26 so that the illumination light spreads over the display region (modulation region) of display element 31 can be used. However, with these methods, the amount of laser light that deviates from the display region of display element 31 increases as the diffusion angle increases or the illumination region expands. Therefore, for each color of laser light, the amount of laser light that is not used for the projected image is lost significantly, resulting in a significant decrease in the utilization efficiency of the laser light.

[0047] 1, in illumination optical system 20, the optical elements of a first system (fly-eye lens 22a, cylindrical lens array 24a, diffuser plate 25a, field lens 26a) through which laser light in the red wavelength band emitted from light source 11 passes are different from the optical elements of a second system (fly-eye lens 22b, cylindrical lens array 24b, diffuser plate 25b, field lens 26b) through which laser light in the green and blue wavelength bands emitted from light sources 12 and 13 pass. Therefore, the optical elements of the second system (fly-eye lens 22b, cylindrical lens array 24b, diffuser plate 25b, field lens 26b) can be optimized for green and blue laser light, while the optical elements of the first system (fly-eye lens 22a, cylindrical lens array 24a, diffuser plate 25a, field lens 26a) can be optimized for red laser light. This makes it possible to appropriately suppress color unevenness for all of the red, green, and blue laser beams while suppressing loss of light quantity.

[0048] For example, the diffusion angle of red diffuser 25a is set larger than the diffusion angle of green and blue diffuser 25b so as to eliminate the strong reddish tinge in region R1 in Fig. 4. Alternatively, the focal lengths of green and blue cylindrical lens array 24b and field lens 26b are set so that the illumination area of ​​the green and blue laser light approximately matches the display area of ​​display element 31b, and the focal lengths of red cylindrical lens array 24a and field lens 26a are set so that the illumination area of ​​the red laser light is wider than the display area of ​​display element 31a.

[0049] Alternatively, the shapes of the cylindrical lenses L1 and L2 of the red cylindrical lens array 24a may be adjusted to a shape that can homogenize the beam profile of the laser light in the red wavelength band on the display area of ​​the display element 31a. In this case, the cylindrical lenses L1 and L2 of the cylindrical lens array 24a may be set to an aspherical shape.

[0050] These adjustments can prevent the reddish tinge from becoming too strong in the region R1 (see FIG. 4) in the projected image, and can effectively reduce color unevenness for all colors.

[0051] When the optical elements of the first system are adjusted as described above, a loss of light intensity occurs in the laser light in the red wavelength band emitted from light source 11, but the loss of light intensity is suppressed in the laser light in the green and blue wavelength bands emitted from light sources 12 and 13. On the other hand, since light source 11 is provided with three light-emitting units as described above and thus has a high maximum emission power, even if some loss of light intensity occurs in the laser light in the red wavelength band, it is possible to guide a sufficient amount of laser light necessary for image display to display element 31a.

[0052] 1, since laser light in the green and blue wavelength bands is guided to one display element 31b, the emission and modulation of the green and blue laser light is performed in a time-division manner. In this case, as will be described below, it is preferable that the duty of the time-division be set in accordance with the maximum emission power of light sources 12 and 13.

[0053] FIG. 5 is a block diagram showing the configuration of a circuit unit of the image projection device 1 according to the embodiment.

[0054] The image projection device 1 includes a control unit 101, light source driving units 102 to 104, display element driving units 105 and 106, and an actuator driving unit 107 as a circuit configuration.

[0055] The control unit 101 includes a processing circuit such as a CPU and a memory, and controls each unit according to a program stored in the memory. 104 drive the light sources 11 to 13, respectively, under the control of the control unit 101. Display element driving units 105 and 106 drive the display elements 31a and 31b, respectively, under the control of the control unit 101. Actuator driving unit 107 drives the actuator 60 under the control of the control unit 101.

[0056] During image projection, the control unit 101 controls the light source driving unit 102 to steadily drive the light source 11, and controls the display element driving unit 105 to steadily drive the display element 31a. The control unit 101 drives the display element 31a based on the video signal to be displayed so as to generate a modulation pattern corresponding to one frame of a red image.

[0057] During image projection, the control unit 101 controls the light source driving units 103 and 104 to drive the light sources 12 and 13 in a time-division manner, and controls the display element driving unit 106 to drive the display element 31b in a time-division manner. green Alternatively, the display element 31b is driven so as to generate a modulation pattern corresponding to a blue image.

[0058] FIG. 6 is a time chart showing the control of the light sources 11 to 13 and the display elements 31a and 31b.

[0059] In Figure 6, the state in which the light source and display elements are driven is shown by high-level pulse waveforms. Also, DR, DG, and DB attached to the waveforms of each display element indicate that the display element is controlled by a modulation pattern corresponding to the red, green, and blue images, respectively.

[0060] When image projection starts at time t0, the control unit 101 causes the light source 11 to emit light steadily at a constant intensity, and steadily drives the display element 31a in accordance with the video signal. In parallel with this, the control unit 101 causes the light sources 12 and 13 to emit light at a constant intensity in a time-division manner, and drives the display element 31b in a time-division manner in accordance with the video signal. Here, the period T1 during which the green laser light is emitted and modulated is longer than the period T2 during which the blue laser light is emitted and modulated. This is because the maximum emission power of the green light source 12 is greater than that of the blue light source. 13 This is because the maximum output power is lower than that of the

[0061] That is, the light intensity ratio of the green and blue laser lights required to display a white image is slightly higher for the green laser light than for the blue laser light. On the other hand, the maximum emission power of the blue light source 13 is higher than the maximum emission power of the green light source 12. For example, the maximum emission power of the blue light source 13 is slightly more than twice the maximum emission power of the green light source 12. For this reason, the period T1 is set longer than the period T2 so that the green and blue laser lights can be irradiated with approximately the same light intensity onto the display element 31b during one duty period consisting of the periods T1 and T2. For example, the period T1 is set to be approximately twice the period T2.

[0062] The frame rates of the green and blue images for the display element 31b are adjusted so that the number of frames of the green image displayed on the display element 31b in the period T1 is the same as the number of frames of the blue image displayed on the display element 31b in the period T2. Furthermore, the frame rates of the green and blue images for the display element 31b are adjusted so that the number of frames of the red image displayed on the display element 31a is the same as the number of frames of the green and blue images displayed on the display element 31b in the periods T1 and T2, respectively, in one duty period consisting of the periods T1 and T2. 31aThe frame rate of the red image is adjusted for the red laser beam. The light emission intensities of the light sources 11 to 13 are set so that the ratio of the total light amounts of the red, green, and blue laser beams emitted in one duty period is equal to the ratio of the light amounts of these laser beams in the white image.

[0063] By the above control, a natural projected image can be generated that is not biased toward any of red, green, and blue.

[0064] During image projection, in parallel with this control, the control unit 101 controls the actuator driving unit 107 to slightly vibrate the cylindrical lens arrays 24a and 24b in the Y-axis direction. This suppresses speckle noise caused by interference of laser light in all red, green, and blue images. This allows high-quality projected images to be displayed.

[0065] <Effects of the embodiment> According to the above embodiment, the following effects are achieved.

[0066] 1, the illumination optical system 20 is individually equipped with a first system of optical elements (fly-eye lens 22a, cylindrical lens array 24a, diffuser 25a, and field lens 26a) that homogenize the intensity distribution of laser light in the red wavelength band and guide it to the display element 31a, and a second system of optical elements (fly-eye lens 22b, cylindrical lens array 24b, diffuser 25b, and field lens 26b) that homogenize the intensity distribution of laser light in the green and blue wavelength bands and guide it to the display element 31b. This allows the first system of optical elements to be optimized for laser light in the red wavelength band, and the second system of optical elements to be optimized for laser light in the green and blue wavelength bands. Therefore, compared to the comparative example shown in Figure 2, where all laser light is homogenized by a single set of optical elements (fly-eye lens 22, cylindrical lens array 24, diffuser plate 25, and field lens 26), all laser light can be homogenized smoothly and appropriately while suppressing a decrease in the utilization efficiency of the laser light from light sources 11, 12, and 13.

[0067] 1, illumination optical system 20 includes diffuser 25a (first diffuser) as a first optical element that homogenizes the intensity distribution of laser light in the red wavelength band and guides it to display element 31a, and diffuser 25b (second diffuser) as a second optical element that homogenizes the intensity distribution of laser light in the green and blue wavelength bands and guides it to display element 31b. Thus, by adjusting the diffusion angles of diffusers 25a and 25b, the intensity distribution of laser light in the red wavelength band and the intensity distribution of laser light in the green and blue wavelength bands can be smoothly homogenized, respectively.

[0068] 1, the illumination optical system 20 includes a cylindrical lens array 24a (first lens array) as a first optical element, and a cylindrical lens array 24b (second lens array) as a second optical element. By adjusting the focal lengths and lens shapes of the cylindrical lens arrays 24a and 24b, the intensity distribution of the laser light in the red wavelength band and the intensity distribution of the laser light in the green and blue wavelength bands can be smoothly uniformed.

[0069] 1, the image projection device 1 includes an actuator 60 that vibrates a support portion 61, and the cylindrical lens arrays 24a and 24b (the corresponding optical elements of the first and second systems) are supported by the support portion 61. This allows the cylindrical lens arrays 24a and 24b to be vibrated simultaneously by one actuator 60, thereby simplifying the configuration and reducing costs.

[0070] As shown in Fig. 1, the image projection device 1 includes a display element 31a (first display element) to which laser light in the red wavelength band is guided, and a display element 31b (second display element) to which laser light in the green and blue wavelength bands is guided. This allows the period for emitting and modulating laser light of each color to be longer than when the emission and modulation of laser light of all colors is performed in a time-division manner, as in the comparative example shown in Fig. 2. This allows the light amount of the projected image to be increased smoothly with simpler control.

[0071] As shown in FIG. 1, laser light (plurality of other laser light) in the green and blue wavelength bands is guided to display element 31b (second display element). Furthermore, as described with reference to FIG. 6, control unit 101 performs time-division emission and modulation of laser light (plurality of other laser light) in the green and blue wavelength bands, and sets the time-division duty (periods T1, T2) according to the maximum emission power of light sources 12, 13, which respectively emit laser light (plurality of other laser light) in the green and blue wavelength bands. This allows green and blue laser light to be irradiated onto display element 31b with approximately the same amount of light during one duty period. Therefore, a projection image with natural colors that is not biased toward green or blue can be generated.

[0072] As shown in FIG. 1, the image projection device 1 includes three light sources 11, 12, and 13 that respectively emit laser beams in the red, green, and blue wavelength bands. A first set of optical elements (fly-eye lens 22a, cylindrical lens array 24a, diffuser 25a, and field lens 26a) is used to homogenize the intensity distribution of the red laser beam emitted from the light source 11. This allows the red laser beam, which has a unique beam profile as shown in FIG. 3(a), to be homogenized appropriately. Furthermore, the green and blue laser beams, which have similar beam profiles as shown in FIGS. 3(b) and 3(c), can be homogenized appropriately while suppressing power loss using a second set of optical elements (fly-eye lens 22b, cylindrical lens array 24b, diffuser 25b, and field lens 26b). This allows for smooth and appropriate suppression of color unevenness in the projected image while suppressing a decrease in the utilization efficiency of the laser beam.

[0073] <Change example 1> In the above embodiment, the display elements 31a and 31b are configured by reflective liquid crystal panels, but in the first modification, transmissive liquid crystal panels are used as the display elements.

[0074] FIG. 7 is a plan view showing the configuration of the optical system of the image projection device 1 according to the first modified example.

[0075] In the configuration of Fig. 7, the polarizing beam splitters 27a and 27b and the display elements 31a and 31b in the configuration of Fig. 1 are replaced with mirrors 29a and 29b and display elements 32a and 32b. The other configuration of Fig. 7 is the same as that of Fig. 1.

[0076] As described above, the display elements 32a and 32b are transmissive liquid crystal panels. The display elements 32a and 32b each have a polarizer on the incident side and the exit side. The light sources 11, 12, and 13 are arranged so that the polarization direction of the laser light they emit matches the polarization direction of the polarizer on the incident side of the display elements 32a and 32b. The mirrors 29a and 29b reflect the laser light that has passed through the field lenses 26a and 26b toward the display elements 32a and 32b, respectively.

[0077] In the configuration of Modification 1, illumination optical system 20 also includes a first system of optical elements (fly-eye lens 22a, cylindrical lens array 24a, diffuser 25a, and field lens 26a) that homogenize the intensity distribution of laser light in the red wavelength band and guide it to display element 32a, and a second system of optical elements (fly-eye lens 22b, cylindrical lens array 24b, diffuser 25b, and field lens 26b) that homogenize the intensity distribution of laser light in the green and blue wavelength bands and guide it to display element 32b. This makes it possible to optimize the first system of optical elements for laser light in the red wavelength band and to optimize the second system of optical elements for laser light in the green and blue wavelength bands. Therefore, compared to the comparative example shown in Figure 2, where all laser light is homogenized by a single set of optical elements (fly-eye lens 22, cylindrical lens array 24, diffuser plate 25, and field lens 26), all laser light can be homogenized smoothly and appropriately on display elements 32a, 32b while suppressing a decrease in the utilization efficiency of laser light from light sources 11, 12, and 13.

[0078] <Change example 2> In the above embodiment, the illumination optical system 20 is completely separated into a system for laser light in the red wavelength band and a system for laser light in the green and blue wavelength bands, and display elements 31a, 32b are provided for each system. In contrast, in Modification Example 2, the system for red laser light is separated from the system for green and blue laser light only by the cylindrical lens array 24a and the diffuser plate 25a, and laser light of all colors is guided to one display element.

[0079] FIG. 8 is a plan view showing the configuration of the optical system of the image projection device 1 according to the second modified example.

[0080] In the configuration of Fig. 8, dichroic mirrors 30a and 30b and mirrors 30c and 30d are added to the configuration of Fig. 2. The configuration and operation from light sources 11, 12, and 13 to collimator lens 23 and the configuration and operation from field lens 26 to projection lens 51 are the same as the configuration of Fig. 2.

[0081] Dichroic mirrors 30a and 30b reflect light in the red wavelength band and transmit light in the green and blue wavelength bands. Therefore, of the laser light in the red, green, and blue wavelength bands that has passed through collimator lens 23, only the laser light in the red wavelength band is reflected in the positive direction of the Y axis by dichroic mirror 30a. The laser light in the red wavelength band is then reflected in the positive direction of the Z axis and the negative direction of the Y axis by mirrors 30c and 30d, respectively, and enters dichroic mirror 30b. Furthermore, the laser light in the red wavelength band is reflected in the positive direction of the Z axis by dichroic mirror 30b and enters field lens 26. The laser light in the green and blue wavelength bands that has passed through collimator lens 23 passes through two dichroic mirrors 30a and 30b and enters field lens 26.

[0082] Between the mirrors 30c and 30d, a cylindrical lens array 24a and a diffuser plate 25a are arranged, similar to those in Fig. 1. Between the dichroic mirrors 30a and 30b, a cylindrical lens array 24b and a diffuser plate 25b are arranged, similar to those in Fig. 1. The cylindrical lens arrays 24a and 24b are integrated and supported by a support portion 61 of the actuator 60.

[0083] 8, the illumination optical system 20 is individually equipped with a first system of optical elements (cylindrical lens array 24a and diffuser plate 25a) that homogenize the intensity distribution of laser light in the red wavelength band and guide it to the display element 31, and a second system of optical elements (cylindrical lens array 24b and diffuser plate 25b) that homogenize the intensity distribution of laser light in the green and blue wavelength bands and guide it to the display element 32b. This makes it possible to optimize the first system of optical elements (cylindrical lens array 24a and diffuser plate 25a) for laser light in the red wavelength band, and to optimize the second system of optical elements (cylindrical lens array 24b and diffuser plate 25b) for laser light in the green and blue wavelength bands. 2, all the laser light can be uniformed smoothly and appropriately on the display elements 32a and 32b while suppressing a decrease in the utilization efficiency of the laser light emitted from the light sources 11, 12, and 13, compared to when all the laser light is uniformed by a single set of optical elements (fly-eye lens 22, cylindrical lens array 24, diffuser plate 25, and field lens 26). This makes it possible to appropriately suppress color unevenness in the projected image.

[0084] 8, the system for red laser light is separated from the systems for green and blue laser light only by the cylindrical lens array 24a and the diffuser plate 25a, and the other parts of the optical system are shared by laser light of all colors. This simplifies the overall configuration of the optical system, reducing the number of parts and costs. Furthermore, since only one display element 31 is provided, the configuration of the image projection device 1 can be simplified and costs can be reduced.

[0085] 8, however, laser light of all colors must be emitted and modulated in a time-division manner because laser light of all colors is irradiated onto one display element 31. In this case, too, the control unit 101 simply sets the periods (duties) for emitting and modulating light of each color so that the light intensity ratio of each light is appropriate when a white image is displayed.

[0086] In addition, in the configuration of FIG. 8, as in the above embodiment, two cylindrical lens arrays 24a and 24b can be driven simultaneously by one actuator 60, which simplifies the configuration of the image projection device 1 and reduces costs.

[0087] <Change example 3> In the third modification, the system for red laser light in the illumination optical system 20 is separated from the systems for green and blue laser light only at the diffuser plate 25a, and laser light of all colors is guided to one display element.

[0088] FIG. 9 is a plan view showing the configuration of the optical system of the image projection device 1 according to the third modified example.

[0089] The configuration of Fig. 9 differs from the configuration of Fig. 8 in the arrangement of the cylindrical lens array 24. That is, only diffusers 25a and 25b are arranged between mirrors 30c and 30d and between dichroic mirrors 30a and 30b, respectively, and a common cylindrical lens array 24 is arranged between the collimator lens 23 and dichroic mirror 30a. The configuration and operation of the optical system other than the dichroic mirrors 30a and 30b, mirrors 30c and 30d, and diffusers 25a and 25b are the same as those in the comparative example of Fig. 2. The configuration and operation of the diffusers 25a and 25b are the same as those in the embodiment of Fig. 1.

[0090] 9, the illumination optical system 20 includes a first optical element (diffuser 25a) that homogenizes the intensity distribution of laser light in the red wavelength band and guides it to the display element 31, and a second optical element (diffuser 25b) that homogenizes the intensity distribution of laser light in the green and blue wavelength bands and guides it to the display element 32b. This allows the first optical element (diffuser 25a) to be optimized for the laser light in the red wavelength band, and the second optical element (diffuser 25b) to be optimized for the laser light in the green and blue wavelength bands. Therefore, compared to the comparative example shown in FIG. 2, where all laser light is homogenized by a single optical element (fly-eye lens 22, cylindrical lens array 24, diffuser 25, and field lens 26), it is possible to smoothly and appropriately homogenize all laser light on the display elements 32a and 32b while suppressing a decrease in the utilization efficiency of the laser light from the light sources 11, 12, and 13. This makes it possible to appropriately suppress color unevenness in the projected image.

[0091] In the configuration of Fig. 9, the system for red laser light is separated from the systems for green and blue laser light only at the diffuser plate 25a, and the other parts of the optical system are shared by laser light of all colors. Therefore, the overall optical system configuration can be further simplified compared to the configuration of Fig. 8.

[0092] 9, as with the configuration of Fig. 8, laser light of all colors is irradiated onto one display element 31, so it is necessary to execute emission and modulation of laser light of all colors in a time-division manner. In this case as well, the control unit 101 simply sets the emission and modulation periods (duties) of light of each color so that the light intensity ratio of each light is appropriate when a white image is displayed.

[0093] <Change Example 4> In the configuration of Modification Example 2, the cylindrical lens array 24b and the diffusion plate 25b are shared by the green and blue laser beams, whereas in Modification Example 4, the cylindrical lens array and the diffusion plate are disposed separately for the laser beams in the red, green, and blue wavelength bands.

[0094] FIG. 10 is a plan view showing the configuration of the optical system of the image projection device 1 according to the fourth modified example.

[0095] In the configuration of FIG. 10, the dichroic mirrors 30a and 30b and the mirrors 30c and 30d in the configuration of FIG. 8 are replaced with dichroic mirrors 30e to 30h and the mirrors 30c and 30d.

[0096] The dichroic mirrors 30e and 30f reflect light in the red and green wavelength bands and transmit light in the blue wavelength band. The dichroic mirrors 30g and 30h transmit light in the red wavelength band. green It reflects light in the wavelength range.

[0097] Therefore, the laser light in the red wavelength band that has transmitted through collimator lens 23 passes through dichroic mirror 30e, dichroic mirror 30g, mirrors 30c and 30d, dichroic mirror 30h, and dichroic mirror 30f in this order, is reflected in the positive direction of the Z axis by dichroic mirror 30f, and enters field lens 26. Similarly, the laser light in the green wavelength band that has transmitted through collimator lens 23 passes through dichroic mirror 30e, dichroic mirror 30g, dichroic mirror 30h, and dichroic mirror 30f in this order, is reflected in the positive direction of the Z axis by dichroic mirror 30f, and enters field lens 26. The laser light in the blue wavelength band that has transmitted through collimator lens 23 passes through dichroic mirrors 30e and 30f in the positive direction of the Z axis, and enters field lens 26.

[0098] Between the mirrors 30c and 30d, a cylindrical lens array 24a and a diffuser 25a are arranged to homogenize the laser light in the red wavelength band on the display element 31. Between the dichroic mirrors 30g and 30h, a cylindrical lens array 24c and a diffuser 25c are arranged to homogenize the laser light in the green wavelength band on the display element 31. Between the dichroic mirrors 30e and 30f, a cylindrical lens array 24d and a diffuser 25d are arranged to homogenize the laser light in the blue wavelength band on the display element 31.

[0099] The cylindrical lens arrays 24 a , 24 c , and 24 d are integrated and supported by a support portion 61 of an actuator 60 .

[0100] 10, cylindrical lens arrays 24a, 24c, and 24d and diffusers 25a, 25c, and 25d are arranged separately for the laser light of the red, green, and blue wavelength bands. Therefore, the first optical element (cylindrical lens array 24a and diffuser 25a) can be optimized for the laser light of each wavelength band, and the two second optical elements (cylindrical lens arrays 24c and 24d and diffusers 25c and 25d) can be optimized for the laser light of the green and blue wavelength bands, respectively. This prevents a decrease in the utilization efficiency of the laser light from light sources 11, 12, and 13, while more smoothly and appropriately uniforming all the laser light on display element 31, thereby more appropriately suppressing color unevenness in the projected image.

[0101] Also, in the configuration of FIG. 10, the three cylindrical lens arrays 24a, 24c, and 24d can be driven simultaneously by one actuator 60, which makes it possible to simplify the configuration and reduce costs.

[0102] 9, in the configuration of Fig. 10, the cylindrical lens array 24 may be disposed between the collimator lens 23 and the dichroic mirror 30e, and only the diffusers 25a, 25c, and 25d may be disposed between the mirrors 30c and 30d, between the dichroic mirrors 30g and 30h, and between the dichroic mirrors 30e and 30f, respectively, thereby further simplifying the configuration of the optical system.

[0103] In the configuration of Figure 10, the cylindrical lens array and diffuser plate through which laser light of one color passes correspond to the optical elements of the first system, and the cylindrical lens array and diffuser plate through which laser light of the other colors passes correspond to the optical elements of the second system.

[0104] <Change Example 5> In the above embodiment, the cylindrical lens arrays 24a, 24b are vibrated by the actuator 60 to suppress speckle noise in the projected image, but speckle noise in the projected image may also be suppressed by vibrating other optical elements.

[0105] For example, as shown in Fig. 11, the diffusers 25a and 25b may be supported by a support portion 61 of the actuator 60, or as shown in Fig. 12, the fly-eye lenses 22a and 22b may be supported by a support portion 61 of the actuator 60. With these configurations, the diffusers 25a and 25b (the corresponding optical elements of the first and second systems) or the fly-eye lenses 22a and 22b (the corresponding optical elements of the first and second systems) can be controlled by a single actuator 60. The same Since the image projection device 1 can be driven simultaneously, the configuration of the image projection device 1 can be simplified and the cost can be reduced.

[0106] <Other change examples> In the above embodiment and modified examples 1 to 5, cylindrical lens arrays 24a to 24d having cylindrical lenses L1 and L2 on the entrance and exit surfaces, respectively, are used as lens arrays for defining the illumination area of ​​the illumination light on the display element. However, the lens array is not limited to this. For example, a lens array may be used in which a number of lenses curved in the X-axis direction and Y-axis direction are aligned in the X-axis direction and Y-axis direction on one of the entrance and exit surfaces. In this case, each lens is adjusted so that its convergence in the Y-axis direction is greater than its convergence in the X-axis direction, similar to the lens portions of cylindrical lens arrays 24a and 24b in the configuration of FIG. 1. Each lens, in conjunction with the action of a subsequent fly's eye lens, defines the illumination area of ​​each color laser light on the display element.

[0107] In addition, in the above embodiment and modified examples 1 to 3, the first system of optical elements (cylindrical lens array 24a, diffuser plate 25a, etc.) that homogenize the intensity distribution of laser light are assigned to laser light in the red wavelength band, but the laser light to which the first system of optical elements are assigned is not limited to this. For example, the first system of optical elements may be assigned to laser light in the green wavelength band emitted from light source 12 with a low maximum emission power, and the second system of optical elements may be assigned to laser light in the red and blue wavelength bands.

[0108] In this case, in order to uniformize the red wavelength band laser light on the display element, the second optical element may, for example, have a large diffusion angle for the diffuser, or the focal lengths of the cylindrical lens array and field lens may be adjusted so that the illumination area is larger than the display area of ​​the display element, resulting in a slight power loss in the blue wavelength band laser light as well as the red wavelength band laser light.

[0109] However, since the first optical element is assigned to the laser light in the green wavelength band, the first optical element can be optimized for the laser light in the green wavelength band, thereby suppressing power loss in the laser light in the green wavelength band.

[0110] In this configuration, different display elements may be assigned to the laser light in the green wavelength band and the laser light in the red and blue wavelength bands, respectively, as shown in Fig. 1. This allows the low-power light source 12 in the green wavelength band to emit light steadily without time division, and the amount of light of the laser light in the green wavelength band can be maintained high.

[0111] In this way, the laser light to be assigned to the optical elements of the first group may be selected from the viewpoint of the maximum emission power of the light source. Also, in the above embodiment, the beam profile of the laser light in the red wavelength band is unique compared to the other laser lights, but if the beam profile of the laser light in a wavelength band other than red is unique, the optical elements of the first group may be assigned to this laser light.

[0112] In addition, in the above-described embodiment and modifications 1 to 5, laser light in three wavelength bands, red, green, and blue, is used, but the types of colors of laser light for generating a projection image are not limited to this. For example, laser light in four or more different wavelength bands may be used to generate a projection image, or laser light in two wavelength bands may be used to generate a projection image. In these cases, a first optical element may be assigned to laser light in one of the wavelength bands, or a first optical element may be assigned to each wavelength band, as in FIG. 10.

[0113] The optical system of the image projection device 1 has the same configuration as the above embodiment. Attitude The configurations are not limited to those shown in Modifications 1 to 5. For example, in Modifications 2 and 3, the optical path of the red wavelength band laser light branched from the main optical path passes through an optical element, is reintegrated into the main optical path, and is guided to a common field lens. However, the optical system from the cylindrical lens array 24a to the polarizing beam splitter 27a in FIG. 1 may be applied to the branched red wavelength band laser light, and the red wavelength band laser light may be guided to the display element 31a assigned specifically for red. In this case, the optical system from the cylindrical lens array 24b to the polarizing beam splitter 27b in FIG. 1 may be applied to the green and blue wavelength band laser light, and the laser light is guided to the display element 31b assigned specifically for green and blue. The laser light of each color modulated by the display elements 31a and 31b is then guided to the projection lens 51 via the coupling element 40.

[0114] In the above embodiment and modifications 1 to 5, a reflective or transmissive liquid crystal panel is used as the display element for modulating the laser light of each color, but the display element used for modulation is not limited to this. For example, a display element of another type, such as a digital mirror device (DMD), may be used as the display element. In this case, the configuration of the optical system may be changed depending on the type of display element. For example, in the configuration of FIG. 1, if a DMD is used as the display elements 31a and 31b, a quarter-wave plate may be disposed between the display elements 31a and 31b and the polarizing beam splitters 27a and 27b.

[0115] In addition, the embodiments of the present invention can be modified in various ways as appropriate within the scope of the technical ideas set forth in the claims. [Explanation of symbols]

[0116] 1. Image projection device 11, 12, 13 light source 20 Illumination optical system 22a Fly-eye lens (first optical element) 22b Fly-eye lens (second optical element) 24a Cylindrical lens array (first lens array, first optical element) 24b, 24c, 24d Cylindrical lens array (second lens array, second optical element) 25a Diffuser (first diffuser, first optical element) 25b, 25c, 25d Diffusers (second diffusers, second optical elements) 26a Field lens (first optical element) 26b Field lens (second optical element) 31 Display element 31a, 32a Display element (first display element) 31b, 32b Display element (second display element) 51 Projection lens 60 Actuator 61 Support part 101 Control section

Claims

1. at least three light sources that emit laser beams of different colors; at least one display element that modulates the laser beams emitted from the at least three light sources based on a video signal; an illumination optical system that guides the laser beams emitted from the at least three light sources to the display element; a projection lens that projects the laser light modulated by the display element, The illumination optical system includes: a first optical element that homogenizes the intensity distribution of the laser light emitted from one of the at least three light sources and guides the laser light to the display element; a second optical element that homogenizes the intensity distribution of the laser light emitted from the other plurality of light sources among the at least three light sources and guides the laser light to the display element, An image projection device characterized in that the number of peaks in the intensity distribution of multiple laser beams incident on the optical element of the second system is equal to each other and different from the number of peaks in the intensity distribution of one laser beam incident on the optical element of the first system.

2. 2. The image projection device according to claim 1, The illumination optical system includes: the first optical element includes a first diffusion plate that diffuses the laser light emitted from the one light source, The second optical element includes a second diffusion plate that diffuses the laser light emitted from the other plurality of light sources. An image projection device comprising:

3. 2. The image projection device according to claim 1, The illumination optical system includes: the first system of optical elements includes a first lens array that defines an illumination area of ​​the laser light emitted from the one light source on the display element, the second system of optical elements includes a second lens array that defines an illumination area of ​​the display element for the laser light emitted from the other plurality of light sources; An image projection device comprising:

4. 4. The image projection device according to claim 1, an actuator that vibrates the support portion; the corresponding optical elements of the first system and the second system are supported by the support portion; An image projection device comprising:

5. 5. The image projection device according to claim 1, The display element includes: a first display element to which the laser light emitted from the one light source is guided; a second display element to which the laser light emitted from the other plurality of light sources is guided, An image projection device comprising:

6. 6. The image projection device according to claim 5, a control unit that controls the at least three light sources, the first display element, and the second display element; the control unit performs emission and modulation of the laser light emitted from the other plurality of light sources in a time-division manner, and sets a duty of the time-division in accordance with a maximum emission power of the other plurality of light sources. An image projection device comprising:

7. 7. The image projection device according to claim 1, the at least three light sources are three light sources that emit laser light in red, green, and blue wavelength bands, respectively; the laser light emitted from the one light source is laser light in the red wavelength band; An image projection device comprising:

Images