Image forming module and projector

Abstract

This invention provides an image forming module and projector that can achieve a desired color balance while suppressing the complexity of control. [Solution] The image forming module of the present invention comprises a first light source that emits first light, a second light source that emits second light, a first illumination optical system that generates first illumination light from the first light, a second illumination optical system that generates second illumination light from the second light, a first light modulator that modulates the first illumination light, a second light modulator that modulates the second illumination light, a photosynthesis element, and a control device. The first illumination optical system has a first light guide element that homogenizes the first light and a first parallelizing element that parallelizes the first light. The second illumination optical system has a second light guide element that homogenizes the second light and a second parallelizing element that parallelizes the second light. The control device applies the same current value to the first light source and the second light source, and the light utilization efficiencies of the first illumination optical system and the second illumination optical system are different so that the synthesized light has a desired color balance.

Description

Technical Field

[0001] The present invention relates to an image forming module and a projector.

Background Art

[0002] Conventionally, a projector including a light source that emits colored light, an optical modulation device that modulates the colored light emitted from the light source according to image information to generate image light, and a projection optical system that enlarges and projects the image light emitted from the optical modulation device onto a projection surface such as a screen is known. For example, the projector includes a light source device having a blue light source that emits blue light, an excitation light source that is provided separately from the blue light source and emits blue light, and a phosphor that is excited by the blue light emitted from the excitation light source and emits yellow light. In such a projector, white light including blue light and yellow light is emitted from the light source device, and each colored light included in the white light is converted into image light by a common optical modulation device or optical modulation devices arranged for each colored light.

[0003] For example, Patent Document 1 discloses a projector in which a plurality of light emitting diodes (Light Emitting Diode; LED) are used as light emitting elements of a light source. In the projector disclosed in Patent Document 1, colored light emitted from each LED is overlapped on the same path in the same direction after passing through a block, modulated by an optical modulation element, and enlarged and projected by a projection lens.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In projectors equipped with multiple color-emitting elements, as described above, the output of each color-emitting element is not necessarily the same. Therefore, in order to achieve a predetermined color balance when combining the colors of light, it becomes necessary to control each light-emitting element individually, which presents a challenge in controlling the light source. [Means for solving the problem]

[0006] To solve the above problems, according to one aspect of the present invention, a first light source that emits first light in a first wavelength band, a second light source that emits second light in a second wavelength band different from the first wavelength band, a first illumination optical system that generates first illumination light from the first light emitted from the first light source, a second illumination optical system that generates second illumination light from the second light emitted from the second light source, a first light modulator that modulates the first illumination light emitted from the first illumination optical system according to image information, a second light modulator that modulates the second illumination light emitted from the second illumination optical system according to image information, a photosynthesis element that combines light emitted from the first light modulator and light emitted from the second light modulator to generate composite light, and a control device that controls the driving of the first light source and the second light source, wherein the first illumination optical system emits light from the first light source. An image forming module is provided, comprising: a first light guide element having a first incident end into which the emitted first light is incident and a first exit end for emitting the first light, which uniformizes the in-plane illuminance of the first light, and a first parallelizing element for parallelizing the first light emitted from the first light guide element; the second illumination optical system having a second incident end into which the second light emitted from the second light source is incident and a second exit end for emitting the second light, which uniformizes the in-plane illuminance of the second light, and a second parallelizing element for parallelizing the second light emitted from the second light guide element; and the control device applying the same current value to the first light source and the second light source, wherein the light utilization efficiency of the first illumination optical system and the light utilization efficiency of the second illumination optical system are different so that the synthesized light synthesized by the photosynthesis element has a desired color balance.

[0007] Furthermore, according to another aspect of the present invention, an image forming module is provided, comprising: a first light source that emits first light in a first wavelength band; a second light source that emits second light in a second wavelength band different from the first wavelength band; a first illumination optical system that generates first illumination light from the first light emitted from the first light source; a second illumination optical system that generates second illumination light from the second light emitted from the second light source; a first light modulation device that modulates the first illumination light emitted from the first illumination optical system according to image information; a second light modulation device that modulates the second illumination light emitted from the second illumination optical system according to image information; a photosynthesis element that combines light emitted from the first light modulation device and light emitted from the second light modulation device to generate composite light; and a control device that controls the driving of the first light source and the second light source, wherein the control device applies the same current value to the first light source and the second light source, and the light utilization efficiency of the first light modulation device and the light utilization efficiency of the second light modulation device are different so that the composite light synthesized by the photosynthesis element has a desired color balance.

[0008] Furthermore, according to another aspect of the present invention, a first light source that emits first light in a first wavelength band, a second light source that emits second light in a second wavelength band different from the first wavelength band, a first illumination optical system that generates first illumination light from the first light emitted from the first light source, a second illumination optical system that generates second illumination light from the second light emitted from the second light source, a first light modulation device that modulates the first illumination light emitted from the first illumination optical system according to image information, a second light modulation device that modulates the second illumination light emitted from the second illumination optical system according to image information, and An image forming module is provided, comprising: a photosynthetic element that synthesizes light and light emitted from a second light modulator to generate synthesized light; and a control device that controls the driving of the first light source and the second light source, wherein the first light source includes a first light-emitting element that emits the first light, and the second light source includes a second light-emitting element that emits the second light, and the control device applies the same current value to the first light source and the second light source, and the light-emitting area of ​​the first light-emitting element and the light-emitting area of ​​the second light-emitting element are different so that the synthesized light synthesized by the photosynthetic element has a desired color balance. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the configuration of the projector according to the first embodiment. [Figure 2] This is a diagram showing an example of the configuration of a control device. [Figure 3A] This diagram shows a configuration for adjusting the shapes of the first and second light guide elements. [Figure 3B] This diagram shows a configuration for adjusting the shapes of the first and second light guide elements. [Figure 3C] This diagram shows a configuration for adjusting the shapes of the first and second light guide elements. [Figure 4A] This figure shows an example configuration for adjusting the light transmittance of the first and second parallelizing elements. [Figure 4B] This figure shows an example configuration for adjusting the light transmittance of the first and second parallelizing elements. [Figure 5] This figure shows an example configuration for adjusting the shapes of the first and second parallelizing elements. [Figure 6] This figure shows an example configuration for adjusting the reflectivity of the first and second light guide elements. [Figure 7A] This figure shows examples of configurations that allow for different optical utilization efficiencies of optical modulation elements. [Figure 7B] This figure shows an example configuration in which the aperture ratio of the optical modulation element is varied. [Figure 7C] This figure shows an example configuration in which the light transmittance of the incident polarizing element is varied. [Figure 8] This figure shows an example configuration in which the light-emitting area of ​​the light-emitting element is varied. [Modes for carrying out the invention]

[0010] One embodiment of the present invention will be described below with reference to the drawings. In the following drawings, the dimensions of each component may be shown on a different scale to make them easier to see.

[0011] FIG. 1 is a schematic diagram showing the configuration of a projector 100 according to an embodiment of the present invention. The projector 100 is an image display device including three liquid crystal panels as a light modulation device, and is a so-called three-panel projector. As shown in FIG. 1, the projector 100 includes an image forming module 10 and a projection optical system 20.

[0012] The image forming module 10 includes a blue light source (first light source) 11, a red light source (second light source) 12, a green light source 13, a blue illumination optical system (first illumination optical system) 16, a red illumination optical system (second illumination optical system) 17, a green illumination optical system 18, a blue light modulation device (first light modulation device) 21, a red light modulation device (second light modulation device) 22, a green light modulation device 23, a light combining element 30, and a control device 50.

[0013] The blue light source 11 emits blue light (first light) LB. In the following description, the direction parallel to the optical axis of the blue light LB emitted from the blue light source 11 is defined as the D1 direction. One side in the D1 direction is defined as the -D1 side, and the side opposite to the -D1 side in the D1 direction is defined as the +D1 side. The direction orthogonal to the D1 direction within the plane including the optical axis of the blue light LB is defined as the D2 direction. One side in the D2 direction is defined as the -D2 side, and the side opposite to the -D2 side in the D2 direction is defined as the +D2 side. The direction orthogonal to the D1 direction and the D2 direction is defined as the D3 direction. The blue light LB emitted from the blue light source 11 travels along the D1 direction toward the +D1 side.

[0014] The blue light source 11 includes a substrate 11a and a blue light-emitting element (first light-emitting element) 11b supported by the substrate 11a. The substrate 11a is made of, for example, metal, and also acts as a heat dissipation member that receives heat from the blue light-emitting element 11b that emits blue light LB and releases the heat to the external space. The blue light-emitting element 11b is provided on the +D1 side plate surface among the plate surfaces parallel to the plane including the D2 direction and the D3 direction on the substrate 11a. The blue light-emitting element 11b corresponds to an example of the first light-emitting element of the present invention and emits blue light LB in the blue wavelength band in the visible wavelength band. The blue wavelength band corresponds to the first wavelength band. The blue light LB corresponds to the first light. The light-emitting surface of the blue light-emitting element 11b is arranged substantially parallel to the plane including the D2 direction and the D3 direction, and is the surface on the opposite side of the D1 direction from the surface facing the +D1 side plate surface of the substrate 11a in the blue light-emitting element 11b. The blue light LB diverges from the light-emitting surface of the blue light-emitting element 11b according to a predetermined emission angle about an axis parallel to the D1 direction passing through the center of the light-emitting surface of the blue light-emitting element 11b, and is emitted to the +D1 side. The blue wavelength band is, for example, a wavelength band of 420 nm to 500 nm.

[0015] The blue light-emitting element 11b is composed of, for example, an LED that emits blue light LB. Note that the blue light-emitting element 11b may be composed of one LED or may be composed of a plurality of LEDs as a whole. When the blue light-emitting element 11b is composed of a plurality of LEDs, the plurality of LEDs are arranged in the region occupied by the blue light-emitting element 11b within the plane including the D2 direction and the D3 direction.

[0016] The blue illumination optical system 16 generates blue illumination light (first illumination light) LB1 from the blue light LB emitted from the blue light source 11. The blue illumination optical system 16 includes a first light guide element 161 and a first collimating element 162. The first light guide element 161 has a first incident end 161a on which the blue light LB emitted from the blue light source 11 is incident, a first emission end 161b that emits the blue light LB from the +D1 side, and a first side surface 161s and a first reflection surface 161r that extend between the first incident end 161a and the first emission end 161b in the D1 direction.

[0017] The first incident end 161a extends parallel to the plane including the D2 and D3 directions. The shape of the first incident end 161a when viewed from the D1 direction is similar to the shape of the light-emitting surface of the blue light-emitting element 11b when viewed from the same direction, and is, for example, rectangular.

[0018] The first exit end 161b extends parallel to the plane including the D2 and D3 directions and is larger than the first entrance end 161a. The shape of the first exit end 161b when viewed from the D1 direction is similar to the shape of the modulation surface of the first optical modulation element 210 of the blue light modulation device 21 when viewed from the same direction, and is similar to the modulation surface of the first optical modulation element 210, for example, being rectangular. The size of the first exit end 161b in the plane including the D2 and D3 directions is equivalent to the size of the modulation surface of the first optical modulation element 210 in the plane including the D2 and D3 directions. The first side surface 161s and the first reflective surface 161r connect the periphery of the first entrance end 161a and the periphery of the first exit end 161b in the D1 direction.

[0019] The blue light LB emitted from the blue light source 11 enters the first light guide element 161 from the first incident end 161a. The first light guide element 161 equalizes the in-plane illuminance of the blue light LB, as described later. In the first light guide element 161, the region enclosed by the first incident end 161a, the first exit end 161b, and the first reflective surface 161r is the region through which the blue light LB propagates. The in-plane size of the region enclosed by the first incident end 161a, the first exit end 161b, and the first reflective surface 161r, including the D2 and D3 directions, increases as the light progresses from the -D1 side to the +D1 side in the D1 direction. Furthermore, the shape of the region enclosed by the first incident end 161a, the first exit end 161b, and the first reflective surface 161r changes from the shape of the light-emitting surface of the blue light-emitting element 11b as viewed from the D1 direction to the shape of the modulation surface of the first optical modulation element 210 as you move from the -D1 side to the +D1 side.

[0020] The first side surface 161s of the first light guide element 161, and the first reflective surface 161r provided on the first side surface 161s as described later, form a predetermined angle with respect to a virtual line perpendicular to the first incident end 161a and the optical axis, and move away from the virtual line in a plane including the D2 and D3 directions as moving from the -D1 side to the +D1 side. The blue light LB incident on the first light guide element 161 propagates from the -D1 side to the +D1 side within the region enclosed by the first incident end 161a, the first exit end 161b, and the first reflective surface 161r.

[0021] If the shape of the first optical modulation element 210 when viewed along the D1 direction of the modulation surface is rectangular, then the shape of the light-emitting surface of the blue light-emitting element 11b when viewed along the D1 direction is approximately similar to the modulation surface of the first optical modulation element 210 and is rectangular.

[0022] A portion of the blue light LB incident on the first light guide element 161 propagates directly from the first incident end 161a to the first exit end 161b along a direction that forms an angle smaller than a predetermined angle with respect to the aforementioned imaginary line and optical axis, without ever being incident on the first reflecting surface 161r. The remaining portion of the blue light LB incident on the first light guide element 161 forms an angle greater than or equal to the predetermined angle with respect to the aforementioned imaginary line and optical axis, is incident on the first reflecting surface 161r one or more times from the first incident end 161a, is reflected by the first reflecting surface 161r, and then reaches the first exit end 161b. The path of the blue light LB rays within the region enclosed by the first incident end 161a, the first exit end 161b, and the first reflecting surface 161r differs depending on the angle of incidence to the first incident end 161a, and extends to multiple paths with different numbers of reflections at the first reflecting surface 161r. As a result, the illuminance distribution of the blue light LB propagating in the region enclosed by the first incident end 161a, the first exit end 161b, and the first reflective surface 161r is homogenized in a plane including the D2 and D3 directions. In other words, the first light guide element 161 homogenizes the illuminance distribution of the incident blue light LB in a plane including the D2 and D3 directions. The blue light LB with a homogenized illuminance distribution is emitted from the first exit end 161b towards the +D1 side.

[0023] The first light guide element 161 is a reflector made of a transparent material such as optical glass. The reflector has a frame and is formed as a hollow member. When viewed along the D1 direction, the -D1 end of the reflector frame has the same shape as the first incident end 161a and the light-emitting surface of the blue light-emitting element 11b, and is formed to the same size as the light-emitting surface of the blue light-emitting element 11b, for example, in the shape of a rectangular frame. The +D1 end of the reflector frame has the same shape and size as the first exit end 161b and the modulation surface of the first light modulation element 210, and is formed to the same size as, for example, a rectangular frame with a different size from the -D1 end.

[0024] The reflector is composed of, for example, plate-shaped members made of a transparent material. As described above, if the shape of the first incident end 161a and the first exit end 161b when viewed from the D1 direction is rectangular, the reflector is composed of four trapezoidal plate-shaped members. The length of the side parallel to the D2 or D3 direction on the -D1 side, which corresponds to the upper base of the four plate-shaped members, is set according to the size of the first incident end 161a and the light-emitting surface of the blue light-emitting element 11b in the D2 or D3 direction. The length of the side parallel to the D2 or D3 direction on the +D1 side, which corresponds to the lower base of the four plate-shaped members, is set according to the size of the first exit end 161b and the modulation surface of the first light modulation element 210 in the D2 or D3 direction. Of the four plate-shaped members, one side corresponding to the leg of one of the two plate-shaped members is connected to the side corresponding to the other leg of the other plate-shaped member.

[0025] As described above, if the reflector of the first light guide element 161 is made of a plate-shaped member made of a transparent material, the first side surface 161s, that is, the plate surface of the plate-shaped member facing the external space of the reflector, acts as a reflective surface. In the reflector of the first light guide element 161, in order to increase the reflectivity of the blue light LB incident on the first light guide element 161 from the first incident end 161a near the first side surface 161s, a reflective film 151 made of a dielectric multilayer film or the like is provided on the plate surface of the plate-shaped member constituting the reflector that is opposite to the first side surface 161s, that is, on the inner surface of the plate-shaped member. In this case, the plate surface constituting the inner surface of the reflector in the plate-shaped member acts as the first reflective surface 161r. A portion of the blue light LB incident on the inside of the reflector of the first light guide element 161 from the first incident end 161a is reflected by the reflective film 151 and propagates toward the +D1 side. In addition, in the first light guide element 161, a reflective film 151 may be formed on the plate-shaped member constituting the reflector that faces the external space of the reflector, thereby causing it to act as the first reflective surface 161r.

[0026] The first parallelizing element 162 is, for example, a plano-convex lens and is positioned on the optical path of the blue light LB emitted from the first light guide element 161. The first parallelizing element 162 parallelizes the blue light LB emitted from the first light guide element 161 along the D1 direction. The first parallelizing element 162 is in contact with the first exit end 161b of the first light guide element 161. By the first parallelizing element 162 being in contact with the first exit end 161b, the blue light LB emitted from the first exit end 161b of the first light guide element 161 is efficiently captured by the first parallelizing element 162, and the loss of blue light LB is suppressed. However, the first parallelizing element 162 may be an optical lens other than a plano-convex lens capable of parallelizing the incident blue light LB. Also, the first parallelizing element 162 may be arranged at an appropriate distance from the first light guide element 161 in the D1 direction.

[0027] The blue light modulator 21 modulates the blue illumination light LB1 emitted from the first parallelizing element 162 of the blue illumination optical system 16 according to image information. The blue light modulator 21 includes a first light modulator 210, an incident polarizing element 211, and an exit polarizing element 212.

[0028] The incident polarizing element (first polarizing element) 211 is provided on the optical path of the blue light LB emitted from the first parallelizing element 162 and is positioned on the +D1 side of the first parallelizing element 162. In this embodiment, the incident polarizing element 211 is in contact with the first optical modulation element 210 from the -D1 side, but it may be positioned at an appropriate distance from the first optical modulation element 210 in the D1 direction. The incident polarizing element 211 corresponds to an example of the first polarizing element of the present invention and emits a predetermined polarization of the blue light LB emitted from the first parallelizing element 162 along the D1 direction towards the +D1 side. The predetermined polarization corresponds to an example of the "first polarization component light" of the present invention, for example, P polarization.

[0029] The incident polarizing element 211 is, for example, a reflective polarizer or an absorbing polarizer having a plate surface parallel to the planes including the D2 and D3 directions. The incident polarizing element 211 corresponds to an example of the first polarizing element. If it is desired to suppress reflected light and stray light to the preceding optical elements including the first parallelizing element 162, it is desirable to use an absorbing polarizer as the incident polarizing element 211. The incident polarizing element 211 transmits a predetermined polarization component of the incident blue light LB to the +D1 side and reflects or absorbs other polarization components of the blue light LB.

[0030] The first optical modulation element 210 is positioned on the optical path of the blue light LB emitted from the incident polarizing element 211. The first optical modulation element 210 modulates the blue light LB emitted from the incident polarizing element 211 based on image information input from an image forming apparatus, such as a computer (not shown), which is connected to the first optical modulation element 210 from the outside. The first optical modulation element 210 is, for example, a transmissive liquid crystal panel. The liquid crystal panel constituting the first optical modulation element 210 has a plurality of pixels (not shown). Each pixel is equipped with a switching element. Each pixel modulates the vibration direction of the blue light LB incident from the incident polarizing element 211 by the operation of the switching element in accordance with the electrical signal that generates the blue image, thereby generating blue image light IB. The first optical modulation element 210 emits the image light IB generated by the liquid crystal panel along the D1 direction toward the +D1 side.

[0031] The ejection-side polarizing element 212 is provided on the optical path of the image light IB emitted from the first optical modulation element 210 and is positioned on the +D1 side of the first optical modulation element 210. In this embodiment, the ejection-side polarizing element 212 is in contact with the first optical modulation element 210 from the +D1 side, but it may also be positioned at an appropriate distance from the first optical modulation element 210 in the D1 direction. The ejection-side polarizing element 212 emits a predetermined polarization component of the image light IB emitted from the first optical modulation element 210 along the D1 direction toward the +D1 side. The predetermined polarization component is, for example, S polarization.

[0032] The exit-side polarizing element 212 is, for example, a reflective polarizer or an absorbing polarizer having a plate surface parallel to the planes including the D2 and D3 directions. The exit-side polarizing element 212 transmits a predetermined polarization component of the incident image light IB to the +D1 side and reflects or absorbs the other polarization components of the image light IB to the -D1 side. By using an absorbing polarizer as the exit-side polarizing element 212, it is possible to suppress reflected light and stray light to the first optical modulation element 210.

[0033] The red light source 12 emits red light (secondary light) LR. The red light LR emitted from the red light source 12 travels along the D1 direction toward the -D1 side. The red light source 12 has the same configuration as the blue light source 11, except that the color of the light it emits is different. For this reason, the explanation of the configuration of the red light source 12 will be omitted or simplified.

[0034] The red light source 12 comprises a substrate 12a and a red light-emitting element 12b supported on the substrate 12a. The red light-emitting element (second light-emitting element) 12b is provided on the -D1 side surface of the substrate 12a, which is parallel to the plane including the D2 and D3 directions. The red light-emitting element 12b corresponds to an example of the second light-emitting element of the present invention and emits red light LR in the red wavelength band of the visible wavelength band. The red wavelength band corresponds to the second wavelength band. The red light LR corresponds to the second light. The light-emitting surface of the red light-emitting element 12b is arranged substantially parallel to the plane including the D2 and D3 directions, and is the surface opposite in the D1 direction to the surface of the substrate 12a facing the -D1 side surface of the red light-emitting element 12b. The red light LR diverges from the light-emitting surface of the red light-emitting element 12b, passing through the center of the light-emitting surface of the red light-emitting element 12b and around an axis parallel to the D1 direction, according to a predetermined radiation angle, and is emitted towards the -D1 side. The red wavelength band is, for example, the wavelength band of 610 nm to 700 nm.

[0035] The red light-emitting element 12b is composed of, for example, an LED that emits red light (LR). The red light-emitting element 12b may consist of a single LED or of multiple LEDs combined.

[0036] The red illumination optical system 17 generates red illumination light (second illumination light) LR1 from red light LR emitted from the red light source 12. The red illumination optical system 17 includes a second light guide element 171 and a second parallelizing element 172. The second light guide element 171 has a second incident end 171a into which red light LR emitted from the red light source 12 is incident, a second exit end 171b that emits red light LR from the -D1 side, and a second side surface 171s and a second reflective surface 171r that extend between the second incident end 171a and the second exit end 171b in the D1 direction. The shape of the second incident end 171a is a rectangle, similar to the shape of the light-emitting surface of the red light-emitting element 12b when viewed from the D1 direction. The shape of the second exit end 171b is a rectangle, similar to the modulation surface of the second optical modulation element 220.

[0037] The red light LR emitted from the red light source 12 enters the second light guide element 171 from the second incident end 171a. The size of the propagation region of the red light LR enclosed by the second incident end 171a, the second exit end 171b, and the second reflective surface 171r in the plane including the D2 and D3 directions increases as the light progresses from the +D1 side to the -D1 side in the D1 direction.

[0038] The second side surface 171s of the second light guide element 171, and the second reflective surface 171r provided on the second side surface 171s, form a predetermined angle with respect to a virtual line perpendicular to the second incident end 171a and the optical axis, and move away from the virtual line in a plane including the D2 and D3 directions as moving from the +D1 side to the -D1 side. The second light guide element 171 equalizes the illuminance distribution of the incident red light LR in a plane including the D2 and D3 directions. The red light LR with a uniform illuminance distribution is emitted from the second exit end 171b towards the -D1 side.

[0039] The second light guide element 171, like the first light guide element 161, is a hollow reflector composed of a plate-shaped member made of a transparent material such as optical glass. The reflector of the second light guide element 171 acts as a second reflective surface 171r by providing a reflective film 152 made of a dielectric multilayer film or the like on the inner surface of the plate-shaped member. In addition, in the second light guide element 171, the reflective film 152 may be formed on the plate-shaped member constituting the reflector that faces the external space of the reflector, thereby making it act as a second reflective surface 171r.

[0040] The second parallelizing element 172 is, for example, a plano-convex lens, and parallelizes the red light LR emitted from the second light guide element 171 along the D1 direction. By contacting the second emission end 171b of the second light guide element 171, the second parallelizing element 172 efficiently captures the red light LR and suppresses the loss of red light LR. Note that the second parallelizing element 172 may be an optical lens other than a plano-convex lens, as long as it can parallelize the red light LR. Also, the second parallelizing element 172 may be positioned at an appropriate distance from the second light guide element 171 in the D1 direction.

[0041] The red light modulator 22 modulates the red illumination light LR1 emitted from the second parallelizing element 172 of the red illumination optical system 17 according to image information. The red light modulator 22 includes a second light modulator 220, an incident polarizing element (second polarizing element) 221, and an exit polarizing element 222, all of which are arranged in contact with each other. The incident polarizing element 221 corresponds to an example of the second polarizing element of the present invention, and emits a predetermined polarization of the red light LR emitted from the second parallelizing element 172 along the D1 direction toward the -D1 side. The predetermined polarization corresponds to an example of the "second polarizing component light" of the present invention, for example, P polarization.

[0042] The incident polarizing element 221 is, for example, a reflective polarizer or an absorbing polarizer having a plate surface parallel to the planes including the D2 and D3 directions. The incident polarizing element 221 corresponds to an example of a second polarizing element. If it is desired to suppress reflected light and stray light to the preceding optical elements including the second parallelizing element 172, it is desirable to use an absorbing polarizer as the incident polarizing element 221. The incident polarizing element 221 transmits a predetermined polarization component of the incident red light LR to the -D1 side and reflects or absorbs other polarization components of the red light LR.

[0043] The second optical modulator 220 is positioned on the optical path of the red light LR emitted from the second incident polarizing element 221. The second optical modulator 220 modulates the red light LR emitted from the second incident polarizing element 221 based on image information input from an image forming apparatus, such as a computer (not shown), which is connected to the second optical modulator 220 from the outside. The second optical modulation element 220 is, for example, a transmissive liquid crystal panel. The liquid crystal panel constituting the second optical modulation element 220 has a plurality of pixels (not shown). Each pixel is equipped with a switching element. Each pixel modulates the red light LR incident from the second incident polarizing element 221 by the operation of the switching element in accordance with the electrical signal that generates the red image, thereby generating red image light IR. The second optical modulation element 220 emits the image light IR generated by the liquid crystal panel along the D1 direction toward the -D1 side.

[0044] The ejection-side polarizing element 222 ejects a predetermined polarization component of the image light IR emitted from the second optical modulation element 220 along the D1 direction towards the -D1 side. The predetermined polarization component is, for example, S polarization. The ejection-side polarizing element 222 is, for example, a reflective polarizer or an absorbing polarizer, which transmits the predetermined polarization component of the incident image light IR towards the -D1 side and reflects or absorbs the other polarization components of the image light IR. By employing an absorbing polarizer as the ejection-side polarizing element 222, it is possible to suppress reflected light and stray light to the second optical modulation element 220.

[0045] The green light source 13 emits green light LG along the D2 direction towards the +D2 side. The green light source 13 has the same configuration as the blue light source 11 and the red light source 12, except for the color of the light it emits. Therefore, the configuration of the green light source 13 will be omitted or simplified in this explanation.

[0046] The green light source 13 comprises a substrate 13a and a green light-emitting element 13b. The green light-emitting element 13b is provided on the +D2 side surface of the substrate 13a, which is parallel to the plane including the D1 and D3 directions. The green light-emitting element 13b emits green light LG in the green wavelength band of the visible wavelength band. The light-emitting surface of the green light-emitting element 13b is arranged substantially parallel to the plane including the D1 and D3 directions, and is the surface on the green light-emitting element 13b opposite in the D2 direction to the surface in contact with the +D2 side surface of the substrate 13a. The green light LG diverges from the light-emitting surface of the green light-emitting element 13b around an axis parallel to the D2 direction passing through the center of the light-emitting surface of the green light-emitting element 13b, according to a predetermined radiation angle, and is emitted towards the +D2 side. The green wavelength band is, for example, the wavelength band of 500 nm to 600 nm. The green light-emitting element 13b is composed of, for example, an LED that emits green light LG. The green light-emitting element 13b may consist of a single LED or of multiple LEDs combined.

[0047] The green illumination optical system 18 generates green illumination light LG1 from green light LG emitted from the green light source 13. The green illumination optical system 18 includes a third light guide element 181 and a third parallelizing element 182. The third light guide element 181 has a third incident end 181a, a third exit end 181b, a third side surface 181s, and a third reflective surface 181r. The shape of the third incident end 181a is a rectangle similar to the shape of the light-emitting surface of the green light-emitting element 13b when viewed from the D2 direction. The shape of the third exit end 181b is a rectangle similar to the modulation surface of the third light modulation element 230.

[0048] The size of the propagation region of the green light LG, enclosed by the third incident end 181a, the third exit end 181b, and the third reflecting surface 181r, in the plane including the D1 and D3 directions, increases as it progresses from the -D2 side to the +D2 side in the D2 direction.

[0049] The third side surface 181s of the third light guide element 181, and the third reflective surface 181r provided on the third side surface 181s, form a predetermined angle with respect to a virtual line perpendicular to the third incident end 181a and the optical axis, and move away from the virtual line in a plane including the D1 and D2 directions as moving from the -D2 side to the +D2 side. The third light guide element 181 equalizes the illuminance distribution of the incident green light LG in a plane including the D1 and D2 directions. The green light LG with a uniform illuminance distribution is emitted from the third emission end 181b towards the +D2 side.

[0050] The third light guide element 181, like the first light guide element 161 and the second light guide element 171, is a hollow reflector composed of a plate-shaped member made of a transparent material such as optical glass. The reflector of the third light guide element 181 acts as a third reflective surface 181r by providing a reflective film 153 made of a dielectric multilayer film or the like on the inner surface of the plate-shaped member. In addition, in the third light guide element 181, the reflective film 153 may be formed on the plate surface of the plate-shaped member constituting the reflector that faces the external space of the reflector, thereby making it act as a third reflective surface 181r.

[0051] The third parallelizing element 182 is, for example, a plano-convex lens, and parallelizes the green light LG emitted from the third light guide element 181 along the D2 direction. The third parallelizing element 182 efficiently captures the green light LG by contacting the third emission end 181b of the third light guide element 181, thereby suppressing the loss of green light LG. The third parallelizing element 182 may be an optical lens other than a plano-convex lens, as long as it can parallelize the green light LG. Also, the third parallelizing element 182 may be positioned at an appropriate distance from the third light guide element 181 in the D2 direction.

[0052] The green light modulator 23 modulates the green illumination light LG1 emitted from the third parallelizing element 182 of the green illumination optical system 18 according to image information. The green light modulator 23 has a third light modulator 230, an incident polarizing element 231, and an exit polarizing element 232, which are arranged in contact with each other. A predetermined polarization of the green light LG emitted from the third parallelizing element 182 is emitted along the D2 direction toward the +D2 side. The predetermined polarization is, for example, S polarization.

[0053] The incident polarizing element 231 is, for example, a reflective polarizer or an absorbing polarizer having a plate surface parallel to the planes including the D1 and D3 directions. It is desirable to use an absorbing polarizer as the incident polarizing element 231 if it is desirable to suppress reflected light and stray light to the preceding optical elements, including the third parallelizing element 182. The incident polarizing element 231 transmits a predetermined polarization component of the incident green light LG to the +D2 side and reflects or absorbs other polarization components of the green light LG.

[0054] The third optical modulation element 230 modulates the blue light LB emitted from the third incident polarizing element 231 based on image information input from an external source. The third optical modulation element 230 is, for example, a transmissive liquid crystal panel. The liquid crystal panel constituting the third optical modulation element 230 has multiple pixels, and each pixel is equipped with a switching element. Each pixel modulates the vibration direction of the green light LG incident from the third incident polarizing element 231 by the operation of the switching element in accordance with the electrical signal that generates the green image, thereby generating green image light IG. The third optical modulation element 230 emits the image light IG generated by the liquid crystal panel along the D2 direction towards the +D1 side.

[0055] The ejection-side polarizing element 232 emits a predetermined polarization of the image light IG emitted from the third optical modulation element 230 along the D2 direction towards the +D2 side. The predetermined polarization is, for example, P polarization. The ejection-side polarizing element 232 is, for example, a reflective polarizer or an absorbing polarizer, and transmits a portion of the incident image light IG, including the predetermined polarization, to the +D2 side, and reflects or absorbs the other portion of the image light IG towards the +D2 side. By employing an absorbing polarizer as the ejection-side polarizing element 232, it is possible to suppress reflected light and stray light to the third optical modulation element 230.

[0056] The photosynthesis element 30 is positioned in the region where the optical paths of the image light IB, IR, and IG emitted from the blue light modulator 21, the red light modulator 22, and the green light modulator 23 intersect. The photosynthesis element 30 synthesizes the image light IB, IR, and IG and emits the resulting image light IM along the D2 direction towards the +D2 side.

[0057] The photosynthetic element 30 is, for example, a cross dichroic prism 31. The cross dichroic prism 31 is constructed by aligning the right-angle vertices of four right-angle prisms at the center of the photosynthetic element 30 and bonding the right-angle surfaces together when viewed from the D3 direction, and includes two reflective films 32 and 33.

[0058] The reflective film 32 is positioned such that, when viewed along the D3 direction, it moves from the +D2 side to the -D2 side as it moves from the -D1 side to the +D1 side. The reflective film 33 is positioned such that, when viewed along the D3 direction, it moves from the -D2 side to the +D2 side as it moves from the -D1 side to the +D1 side. The reflective film 32 has optical properties that reflect light in the red wavelength band and transmit light in the blue wavelength band and the green wavelength band. The reflective film 33 has optical properties that reflect light in the blue wavelength band and transmit light in the green wavelength band and the red wavelength band.

[0059] The S-polarized blue image light IB emitted from the exit polarizing element 212 enters the cross dichroic prism 31, passes through the reflective film 32, is reflected by the reflective film 33, and travels to the +D2 side. The P-polarized green image light IG emitted from the exit polarizing element 232 enters the cross dichroic prism 31, passes through the reflective films 32 and 33, and travels straight to the +D2 side. The S-polarized red image light IR emitted from the exit polarizing element 222 enters the cross dichroic prism 31, passes through the reflective film 33, is reflected by the reflective film 32, and travels to the +D2 side. The image lights IB, IG, and IR emitted from the reflective films 32 and 33 of the cross dichroic prism 31 to the +D2 side are combined to generate full-color image light (composite light) IM. The cross dichroic prism 31 emits full-color image light IM along the D2 direction towards the +D2 side. The image light IM corresponds to an example of the "synthetic light" of the present invention.

[0060] The projection optical system 20 is positioned on the optical path of the image light IM emitted from the photosynthetic element 30 of the image forming module 10. The projection optical system 20 projects the image light IM onto a screen SCR located +D2 side of the projection optical system 20, and displays the image light IM on the screen SCR in an enlarged view.

[0061] The projection optical system 20 is composed of, for example, one or more optical lenses arranged along the D2 direction. The optical lenses include, for example, plano-convex lenses, plano-concave lenses, biconvex lenses, biconcave lenses, meniscus lenses, aspherical lenses, free-form lenses, and the like.

[0062] The following describes an example of the configuration of the control device 50 in the image forming module 10 of this embodiment. Figure 2 is a diagram showing an example of the configuration of the control device 50. As shown in Figure 2, the control device 50 of this embodiment comprises a control unit 51, a storage unit 52, and a communication unit 53. The control unit 51 is composed of a processor such as a CPU (Central Processing Unit) and memory (main memory). The control unit 51 functions as a light source drive unit 510 or a panel drive unit 511 when the processor executes a program. The light source drive unit 510 of the control unit 51 controls the driving of each light source 11, 12, and 13. The panel drive unit 511 of the control unit 51 controls the driving of the liquid crystal panels of each optical modulator 21, 22, and 23.

[0063] Furthermore, all or part of the functions of the control unit 51 may be implemented using hardware such as an ASIC (Application Specific Integrated Circuit), PLD (Programmable Logic Device), or FPGA (Field Programmable Gate Array). The above program may be recorded on a computer-readable recording medium. Computer-readable recording media include, for example, portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and semiconductor memory devices (e.g., SSDs: Solid State Drives), as well as storage devices such as hard disks and semiconductor memory devices built into computer systems. The above program may also be transmitted via a telecommunications line.

[0064] The storage unit 52 includes, for example, memory such as an HDD (Hard Disk Drive), SSD (Solid State Drive), EEPROM (Electrically Erasable Programmable Read-Only Memory), ROM (Read-Only Memory), and RAM (Random Access Memory). The storage unit 52 may be an external storage device connected via a digital input / output port such as USB, instead of being built into the control device 50. The storage unit 52 stores various information, images, and operation programs processed by the control device 50. The storage unit 52 may consist of one storage device or multiple storage devices. Furthermore, the multiple storage devices may include storage devices provided by an information processing device separate from the control device 50. In this embodiment, the storage unit 52 stores control programs executed by the control unit 51, and setting data including various setting values ​​related to the operation of the image forming module 10.

[0065] The communication unit 53 is a communication device. The communication unit 53 may be configured, for example, as a network interface. The communication unit 53 communicates data with other external devices via the network in accordance with the control of the control unit 51. The communication unit 53 may be a wireless communication device or a wired communication device.

[0066] By the way, in the image forming module 10 of this embodiment, the light emission characteristics of each light-emitting element 11b, 12b, and 13b in each light source 11, 12, and 13 that emit blue light LB, red light LR, and green light LG are different. Therefore, to achieve a desired color balance (white balance) for the image light IM, which is a composite of image light IB, IG, and IR, it is necessary to individually control the output of each light source 11, 12, and 13. However, individually controlling the output of each light source 11, 12, and 13 complicates the control of the control device. In contrast, the image forming module 10 of this embodiment suppresses the complexity of control by commonizing the control of at least two of the light sources 11, 12, and 13 in the control device 50, while also enabling the generation of an image light IM with a desired color balance. The following describes a method for achieving both the suppression of control complexity and the color balance of the image light IM in the image forming module 10 of this embodiment.

[0067] In the image forming module 10 of this embodiment, the control device 50 unified the control of the blue light source 11 and the red light source 12, which are the two light sources with relatively high luminous efficiency among the three colored light sources: the blue light source 11 and the red light source 12. As a method of unifying the control, the control device 50 applied the same current value to the blue light source 11 and the red light source 12. On the other hand, the control device 50 performed individual control of the green light source 13, which has the lowest luminous efficiency among the three colored light sources. In other words, the control device 50, via the light source drive unit 510, applies the same current value to the blue light source 11 and the red light source 12, and applies a different current value to the green light source 13 than to the blue light source 11 and the red light source 12.

[0068] As described above, the luminous efficiencies of the blue light source 11 and the red light source 12 are not exactly the same. Therefore, when the same current value is applied, the amount of blue light LB emitted from the blue light source 11, which has higher luminous efficiency, will be greater than the amount of red light LR emitted from the red light source 12. For this reason, the amount of blue light LB will be greater than the amount of red light LR. The control device 50 adjusts the light intensity of the green light LG to achieve the desired color balance by setting the current value applied to the green light source 13, which has relatively low luminous efficiency, higher than the current values ​​applied to the blue light source 11 and the red light source 12. In this embodiment, the light intensity of the green light LG is controlled by independent output adjustment of the green light source 13 by the control device 50.

[0069] In this embodiment, the image forming module 10 adjusts the light intensity of blue light LB and red light LR by making the light utilization efficiency of the blue illumination optical system 16 and the light utilization efficiency of the red illumination optical system 17 different, thereby setting the color balance of the image light IM synthesized by the photosynthesis element 30 to a desired balance.

[0070] In the image forming module 10 of this embodiment, the color balance between blue light LB and red light LR can be adjusted by making the light utilization efficiency of the blue illumination optical system 16, into which blue light LB is incident, lower than the light utilization efficiency of the red illumination optical system 17, into which red light LR is incident.

[0071] The following describes a method for adjusting the light utilization efficiency of the blue illumination optical system 16 and the red illumination optical system 17.

[0072] For example, the shapes of the first light guide element 161 and the second light guide element 171 can be adjusted. Figures 3A to 3C show examples of configurations for adjusting the shapes of the first light guide element 161 and the second light guide element 171. It is sufficient that the cross-sectional area of ​​the first incident end 161a of the first light guide element 161 in a plane including the D2 and D3 directions perpendicular to the optical axis of the first parallelizing element 162 is different from the cross-sectional area of ​​the second incident end 171a of the second light guide element 171 in a plane including the D2 and D3 directions perpendicular to the optical axis of the second parallelizing element 172. Here, when the emission area of ​​the blue light LB of the blue light source 11 and the emission area of ​​the red light LR of the red light source 12 are the same, the cross-sectional area of ​​the second incident end 171a is made larger than the cross-sectional area of ​​the first incident end 161a, as shown in Figure 3A. In this case, the absorption efficiency of the red light LR at the second incident end 171a becomes higher than the absorption efficiency of the blue light LB at the first incident end 161a. As described above, the amount of blue light LB is greater than the amount of red light LR, but the absorption efficiency of red light LR at the second incident end 171a is higher than the absorption efficiency of blue light LB at the first incident end 161a, thereby reducing the amount of blue light LB relative to the amount of red light LR, and thus reducing the difference between the amount of blue light LB incident on the first light guide element 161 and the amount of red light LR incident on the second light guide element 171. Therefore, by adjusting the color balance between the blue light LB incident on the blue light modulator 21 and the red light LR incident on the red light modulator 22, the color balance between the image light IB generated by the blue light modulator 21 and the image light IR generated by the red light modulator 22 can be adjusted. Therefore, by making the cross-sectional areas of the first incident end 161a and the second incident end 171a different, the image light IM synthesized by the photosynthesis element 30 can be adjusted to a desired color balance.

[0073] Furthermore, the cross-sectional area of ​​the first exit end 161b of the first light guide element 161 may be different from the cross-sectional area of ​​the second exit end 171b of the second light guide element 171. Here, if the cross-sectional area of ​​the first incident end 161a and the cross-sectional area of ​​the second incident end 171a are the same, then the cross-sectional area of ​​the first exit end 161b is made larger than the cross-sectional area of ​​the second exit end 171b. In this case, as shown in Figure 3B, the illumination area RA of the red light LR emitted from the second exit end 171b of the second light guide element 171 extends beyond the image forming region 220a, which is the optical modulation region of the second optical modulator 220, by a width S2. On the other hand, the illumination area BA of the blue light LB emitted from the first exit end 161b of the first light guide element 161 extends beyond the image forming region 210a, which is the optical modulation region of the first optical modulator 210, by a width S1 which is greater than the width S2. As described above, the amount of blue light LB is greater than the amount of red light LR, but by making the cross-sectional area of ​​the first exit end 161b larger than the cross-sectional area of ​​the second exit end 171b, the amount of blue light LB is reduced relative to the amount of red light LR, thereby reducing the difference between the amount of blue light LB incident on the first optical modulator 210 and the amount of red light LR incident on the second optical modulator 220. Therefore, the color balance between the image light IB modulated by the first optical modulation element 210 and the image light IR modulated by the second optical modulation element 220 can be adjusted. Therefore, by making the cross-sectional areas of the first exit end 161b and the second exit end 171b different, the image light IM synthesized by the photosynthesis element 30 can be adjusted to a desired color balance.

[0074] Furthermore, the length of the first light guide element 161 in the direction along the optical axis of the first parallelizing element 162 may be different from the length of the second light guide element 171. Here, the first light guide element 161 and the second light guide element 171 have equal cross-sectional areas of their light incident surfaces and equal cross-sectional areas of their light emission surfaces, and differ only in length as shown in Figure 3C. As shown in Figure 3C, the length L1 of the first light guide element 161 is longer than the length L2 of the second light guide element 171. Generally, the longer the length of the light guide element, the more uniform the illuminance distribution when emitted. However, as the length increases, the number of internal reflections increases, resulting in light loss. As mentioned above, the amount of blue light LB is greater than the amount of red light LR. However, by making the length L1 of the first light guide element 161 longer than the length L2 of the second light guide element 171, the amount of blue light LB is reduced relative to the amount of red light LR, thereby reducing the difference between the amount of blue light LB incident on the first light modulation element 210 and the amount of red light LR incident on the second light modulation element 220. Therefore, the color balance between the image light IB modulated by the first optical modulation element 210 and the image light IR modulated by the second optical modulation element 220 can be adjusted. Therefore, by making the lengths of the first light guide element 161 and the second light guide element 171 different, the image light IM synthesized by the photosynthesis element 30 can be adjusted to a desired color balance.

[0075] Furthermore, it is conceivable to adjust the light utilization efficiency of the blue illumination optical system 16 and the red illumination optical system 17 by adjusting the light transmittance of the first parallelizing element 162 and the second parallelizing element 172. Figures 4A and 4B show examples of configurations for adjusting the light transmittance of the first parallelizing element 162 and the second parallelizing element 172.

[0076] As shown in Figure 4A, the first parallelizing element 162 has a first light incident surface 162a into which blue light LB emitted from the first light guide element 161 is incident, and a first light emission surface 162b consisting of a convex curved surface that emits blue light LB. The second parallelizing element 172 has a second light incident surface 172a into which red light LR emitted from the second light guide element 171 is incident, and a second light emission surface 172b consisting of a convex curved surface that emits red light LR.

[0077] The first parallelizing element 162 has an anti-reflective coating 163 provided on the first light emission surface 162b. The second parallelizing element 172 has an anti-reflective coating 174 provided on the second light incident surface 172a and an anti-reflective coating 163 provided on the second light emission surface 172b. In other words, the first parallelizing element 162 has an anti-reflective coating only on the light emission side, while the second parallelizing element 172 has an anti-reflective coating on both the light incident side and the light emission side.

[0078] Therefore, the light transmittance of the first light incident surface 162a for blue light LB is different from the light transmittance of the second light incident surface 172a for red light LR. More specifically, the second light incident surface 172a has an anti-reflective coating 174, which suppresses light reflection at the interface, resulting in a higher light capture efficiency compared to the first light incident surface 162a. This reduces the amount of blue light LB relative to the amount of red light LR, thereby reducing the difference between the amount of blue light LB incident on the first parallelizing element 162 and the amount of red light LR incident on the second parallelizing element 172. Therefore, by adjusting the color balance between the blue light LB incident on the blue light modulator 21 and the red light LR incident on the red light modulator 22, the color balance between the image light IB generated by the blue light modulator 21 and the image light IR generated by the red light modulator 22 can be adjusted. Therefore, by making the light transmittances of the first light incident surface 162a and the second light incident surface 172a different, the image light IM synthesized by the photosynthesis element 30 can be adjusted to a desired color balance.

[0079] Furthermore, as shown in Figure 4B, the first parallelizing element 162 has an anti-reflective coating 164 provided on the first light incident surface 162a. The second parallelizing element 172 has an anti-reflective coating 164 provided on the second light incident surface 172a and an anti-reflective coating 175 provided on the second light emission surface 172b. In other words, the first parallelizing element 162 has an anti-reflective coating only on the light incident side, while the second parallelizing element 172 has an anti-reflective coating on both the light incident side and the light emission side.

[0080] Therefore, the light transmittance of the first light emission surface 162b for blue light LB is different from the light transmittance of the second light emission surface 172b for red light LR. More specifically, the second light emission surface 172b has an anti-reflective coating 175, which suppresses light reflection at the interface, resulting in higher light extraction efficiency compared to the first light emission surface 162b. As a result, by reducing the amount of blue light LB relative to the amount of red light LR, the difference between the amount of blue light LB emitted by the first parallelizing element 162 and the amount of red light LR emitted by the second parallelizing element 172 can be reduced. Therefore, by adjusting the color balance between the blue light LB incident on the blue light modulator 21 and the red light LR incident on the red light modulator 22, the color balance between the image light IB generated by the blue light modulator 21 and the image light IR generated by the red light modulator 22 can be adjusted. Therefore, by making the light transmittances of the first light emission surface 162b and the second light emission surface 172b different, the image light IM synthesized by the photosynthesis element 30 can be adjusted to a desired color balance.

[0081] Furthermore, it is conceivable to adjust the light utilization efficiency of the blue illumination optical system 16 and the red illumination optical system 17 by adjusting the shapes of the first parallelizing element 162 and the second parallelizing element 172. Figure 5 shows an example of a configuration in which the shapes of the first parallelizing element 162 and the second parallelizing element 172 are adjusted.

[0082] As shown in Figure 5, the curvature of the first parallelizing element 162 is different from that of the second parallelizing element 172, and the radius of curvature R1 of the first light emission surface 162b of the first parallelizing element 162 is larger than the radius of curvature R2 of the second light emission surface 172b of the second parallelizing element 172. Therefore, the degree of light focusing in the first parallelizing element 162 is smaller than the degree of light focusing in the second parallelizing element 172. Here, we assume that the divergence angle of the blue light LB emitted from the first light guide element 161 and the divergence angle of the red light LR emitted from the second light guide element 171 are approximately the same. In this case, the parallelism of the blue light LB due to the first parallelizing element 162 is lower than the parallelism of the red light LR due to the second parallelizing element 172, so the illumination area of ​​the blue light LB on the illuminated region is larger than that of the red light LR. Therefore, as shown in Figure 3B, the illumination area RA of the red light LR in the image forming region 220a of the second light modulation element 220 extends by a width S2, and the illumination area BA of the blue light LB in the image forming region 210a of the first light modulation element 210 extends by a width S1 which is larger than the width S2. As described above, the amount of blue light LB is greater than the amount of red light LR. However, by making the curvature of the first parallelizing element 162 greater than the curvature of the second parallelizing element 172, the amount of blue light LB can be reduced relative to the amount of red light LR, thereby reducing the difference between the amount of blue light LB incident on the first optical modulator 210 and the amount of red light LR incident on the second optical modulator 220. Therefore, the color balance between the image light IB modulated by the first optical modulator 210 and the image light IR modulated by the second optical modulator 220 can be adjusted. Therefore, by making the curvatures of the first parallelizing element 162 and the second parallelizing element 172 different, the image light IM synthesized by the photosynthesis element 30 can be adjusted to a desired color balance.

[0083] In addition to the radius of curvature, the shapes of the first parallelizing element 162 and the second parallelizing element 172 can also be adjusted by the diameter of the plano-convex lenses that constitute the first parallelizing element 162 and the second parallelizing element 172. Furthermore, the light utilization efficiency of the blue illumination optical system 16 and the red illumination optical system 17 can be adjusted by making the refractive indices of the first parallelizing element 162 and the second parallelizing element 172 different from each other. Alternatively, the light utilization efficiency of the blue illumination optical system 16 and the red illumination optical system 17 can be adjusted by making the shapes and refractive indices of the first parallelizing element 162 and the second parallelizing element 172 different, respectively.

[0084] Furthermore, it is conceivable to adjust the light utilization efficiency of the blue illumination optical system 16 and the red illumination optical system 17 by adjusting the reflectivity of the first light guide element 161 and the second light guide element 171. Figure 6 shows an example configuration for adjusting the reflectivity of the first light guide element 161 and the second light guide element 171. In Figure 6, the difference in reflectivity is represented by the difference in the width of the light rays.

[0085] As shown in Figure 6, the reflectance of the first reflective surface 161r of the first light guide element 161 for blue light LB is different from the reflectance of the second reflective surface 171r of the second light guide element 171 for red light LR, and the reflectance of the first reflective surface 161r is lower than that of the second reflective surface 171r. With this configuration, the second light guide element 171 efficiently reflects and guides the red light LR, so the extraction efficiency of the red light LR by the second light guide element 171 becomes higher than the extraction efficiency of the blue light LB by the first light guide element 161. Therefore, by reducing the amount of blue light LB relative to the amount of red light LR, the difference between the amount of blue light LB emitted by the first light guide element 161 and the amount of red light LR emitted by the second light guide element 171 can be reduced. Therefore, by adjusting the color balance between the blue light LB incident on the blue light modulator 21 and the red light LR incident on the red light modulator 22, the color balance between the image light IB generated by the blue light modulator 21 and the image light IR generated by the red light modulator 22 can be adjusted. By making the reflectivity of the first light guide element 161 and the second light guide element 171 different in this way, the image light IM synthesized by the photosynthesis element 30 can be adjusted to a desired color balance.

[0086] As described above, the image forming module 10 of this embodiment includes a blue light source 11 that emits blue light LB in the blue wavelength band, a red light source 12 that emits red light LR in the red wavelength band, a green light source 13 that emits green light LG in the green wavelength band, a blue illumination optical system 16 that generates blue illumination light LB1 from the blue light LB emitted from the blue light source 11, a red illumination optical system 17 that generates red illumination light LR1 from the red light LR emitted from the red light source 12, a green illumination optical system 18 that generates green illumination light LG1 from the green light LG emitted from the green light source 13, and a blue illumination optical system 16 that generates blue illumination light LB1. The system includes a blue light modulator 21 that modulates according to image information, a red light modulator 22 that modulates red illumination light LR1 emitted from a red illumination optical system 17 according to image information, a green light modulator 23 that modulates green illumination light LG1 emitted from a green illumination optical system 18 according to image information, a photosynthesis element 30 that synthesizes image light IM by combining image light IB emitted from the blue light modulator 21, image light IR emitted from the red light modulator 22, and image light IG emitted from the green light modulator 23, and a control device 50 that controls the driving of the blue light source 11, the red light source 12, and the green light source 13. The blue light illumination optical system 16 has a first input end 161a into which blue light LB emitted from the blue light source 11 is incident, and a first output end 161b that emits blue light LB. It also has a first light guide element 161 that makes the in-plane illuminance of blue light LB uniform, and a first parallelizing element 162 that parallelizes the blue light LB emitted from the first light guide element 161. The red illumination optical system 17 has a second incident end 171a into which red light LR emitted from the red light source 12 enters, and a second exit end 171b that emits red light LR. It also has a second light guide element 171 that makes the in-plane illuminance of the red light LR uniform, and a second parallelizing element 172 that parallelizes the red light LR emitted from the second light guide element 171. The green illumination optical system 18 has a third incident end 181a into which green light LG emitted from the green light source 13 enters, and a third exit end 181b that emits green light LG, and includes a third light guide element 181 that makes the in-plane illuminance of green light LG uniform, and a third parallelizing element 182 that parallelizes the green light LG emitted from the third light guide element 181. The control device 50 applies the same current value to the blue light source 11 and the red light source 12, and the light utilization efficiency of the blue illumination optical system 16 and the light utilization efficiency of the red illumination optical system 17 are different so that the image light IM synthesized by the photosynthesis element 30 has the desired color balance.

[0087] According to the image forming module 10 of this embodiment, the control of the blue light source 11 and the red light source 12 is standardized by applying the same current value to both, thereby suppressing the complexity of the control device 50. Furthermore, the difference in light intensity between the blue light LB and the red light LR that occurs as a result of standardizing the control of the blue light source 11 and the red light source 12 can be adjusted by the light utilization efficiency of the blue illumination optical system 16 and the red illumination optical system 17, thereby adjusting the color balance of the image light IM to a desired balance. Therefore, according to the image forming module 10 of this embodiment, it is possible to suppress the complexity of the control device 50 and set the image light IM to a desired color balance at the same time.

[0088] The projector 100 of this embodiment includes an image forming module 10 and a projection optical system 20 that projects image light IM emitted from the photosynthetic element 30 of the image forming module 10. According to the projector 100 of this embodiment, it is possible to realize a projector that projects image light IM having a desired color balance while suppressing the complexity of control.

[0089] (Second Embodiment) In the first embodiment, the image forming module 10 was given as an example in which the image light IM is set to a desired color balance by making the light utilization efficiency of the blue illumination optical system 16 and the red illumination optical system 17 different. However, in this embodiment, the image forming module sets the image light IM to a desired color balance by making the light utilization efficiency of the blue light modulator 21 and the red light modulator 22 different.

[0090] Hereinafter, a method for adjusting the light utilization efficiency of the blue light modulator 21 and the red light modulator 22 in the image forming module of this embodiment will be described with reference to Figures 7A to 7C. For example, the control device 50 can control the first optical modulation element 210 and the second optical modulation element 220 so that their respective driving voltages are different. For example, as shown in Figure 7A, the panel drive unit 511 of the control device 50 applies different driving voltages to the first optical modulation element 210 and the second optical modulation element 220. The modulation degree of each pixel in the pixel formation region changes according to the driving voltage applied to each optical modulation element 210, 220. The panel drive unit 511 also applies a predetermined driving voltage to the third optical modulation element 230 according to the color balance of the image light IM.

[0091] For example, the panel drive unit 511 applies different drive voltages to the first optical modulation element 210 and the second optical modulation element 220 so that the polarization rotation efficiency of the first optical modulation element 210 is lower than that of the second optical modulation element 220. The modulation light from the first optical modulation element 210 does not rotate sufficiently to the polarization direction along the polarization transmission axis of the output polarizing element 212, thus reducing the transmittance of the output polarizing element 212. On the other hand, the modulation light from the second optical modulation element 220, which has a higher polarization rotation efficiency than the first optical modulation element 210, rotates to the polarization direction along the polarization transmission axis of the output polarizing element 222, thus increasing the transmittance of the output polarizing element 222 relatively. Therefore, the amount of image light IG emitted from the blue light modulation device 21 is less than the amount of image light IR emitted from the red light modulation device 22.

[0092] As described above, the light intensity of the blue light LB is greater than that of the red light LR, but the color balance between the image light IB modulated by the first light modulation element 210 and the image light IR modulated by the second light modulation element 220 can be adjusted. Therefore, by varying the driving voltages of the first light modulation element 210 and the second light modulation element 22, the image light IM synthesized by the photosynthesis element 30 can be adjusted to a desired color balance.

[0093] As described above, the image forming module of this embodiment includes a blue light source 11 that emits blue light LB in the blue wavelength band, a red light source 12 that emits red light LR in the red wavelength band, a green light source 13 that emits green light LG in the green wavelength band, a blue illumination optical system 16 that generates blue illumination light LB1 from the blue light LB emitted from the blue light source 11, a red illumination optical system 17 that generates red illumination light LR1 from the red light LR emitted from the red light source 12, a green illumination optical system 18 that generates green illumination light LG1 from the green light LG emitted from the green light source 13, and the blue illumination light LB1 emitted from the blue illumination optical system 16 for image formation. The system includes a blue light modulator 21 that modulates according to information, a red light modulator 22 that modulates red illumination light LR1 emitted from a red illumination optical system 17 according to image information, a green light modulator 23 that modulates green illumination light LG1 emitted from a green illumination optical system 18 according to image information, a photosynthesis element 30 that synthesizes image light IB emitted from the blue light modulator 21, image light IR emitted from the red light modulator 22, and image light IG emitted from the green light modulator 23 to generate image light IM, and a control device 50 that controls the driving of the blue light source 11, red light source 12, and green light source 13. The control device 50 applies the same current value to the blue light source 11 and the red light source 12. The light utilization efficiency of the blue light modulator 21 and the red light modulator 22 are different so that the image light IM synthesized by the photosynthesis element 30 has a desired color balance.

[0094] In this image forming module, as in the image forming module of the first embodiment, it is possible to suppress the complexity of controlling the control device 50 and generate image light IM with a desired color balance.

[0095] Furthermore, by making the aperture ratio of the first light modulation element 210 and the aperture ratio of the second light modulation element 220 different, the light utilization efficiency of the blue light modulation device 21 and the red light modulation device 22 may be made different.

[0096] Figure 7B shows an example configuration in which the aperture ratios of the first optical modulation element 210 and the second optical modulation element 220 are different. As shown in Figure 7B, the first optical modulation element 210 has an image forming region 210a which is an optical modulation region, and the image forming region 210a includes a plurality of pixels PB partitioned by a black matrix BM1. The second optical modulation element 220 has an image forming region 220a which is an optical modulation region, and the image forming region 220a includes a plurality of pixels PR partitioned by a black matrix BM2.

[0097] Since the width of the black matrix BM1 of the first optical modulator 210 is greater than the width of the black matrix BM2 of the second optical modulator 220, each pixel PB of the first optical modulator 210 is smaller than each pixel PR of the second optical modulator 220. Furthermore, each pixel of the third optical modulator 230 is set to a predetermined size according to the color balance of the image light IM.

[0098] Here, assuming that the number of pixels PB of the first optical modulation element 210 and the number of pixels PR of the second optical modulation element 220 are the same, we can say that the aperture ratio of the first optical modulation element 210 is lower than that of the second optical modulation element 220. In this configuration, the amount of image light IG emitted from the blue light modulator 21 is less than the amount of image light IR emitted from the red light modulator 22.

[0099] As described above, the light intensity of the blue light LB is greater than that of the red light LR, but the color balance between the image light IB modulated by the first light modulation element 210 and the image light IR modulated by the second light modulation element 220 can be adjusted. Therefore, by making the aperture ratios of the first light modulation element 210 and the second light modulation element 220 different, the image light IM synthesized by the photosynthesis element 30 can be adjusted to a desired color balance.

[0100] Furthermore, by making the light transmittance of the incident polarizing element 211, which is located on the light incident side of the first light modulation element 210, different from the light transmittance of the incident polarizing element 221, which is located on the light incident side of the second light modulation element 220, the light utilization efficiencies of the blue light modulation device 21 and the red light modulation device 22 may be made different.

[0101] Figure 7C shows an example configuration in which the light transmittance of the incident polarizing elements 211 and 221 is different. As shown in Figure 7C, the light transmittance of P-polarized blue light LB in the incident polarizing element 211 differs from the light transmittance of P-polarized red light LR in the incident polarizing element 221, and the light transmittance of the incident polarizing element 211 is lower than that of the incident polarizing element 221. With this configuration, the incident polarizing element 221 efficiently transmits red light LR, so that the red light LR acquisition efficiency of the second optical modulator 220 becomes higher than the blue light LB acquisition efficiency of the first optical modulator 210. Therefore, by reducing the amount of blue light LB relative to the amount of red light LR, the difference between the incident light amount of blue light LB in the first optical modulator 210 and the incident light amount of red light LR in the second optical modulator 220 can be reduced. Therefore, by adjusting the color balance between the blue light LB incident on the blue light modulator 21 and the red light LR incident on the red light modulator 22, the color balance between the image light IB generated by the blue light modulator 21 and the image light IR generated by the red light modulator 22 can be adjusted. By making the light transmittance of the incident polarizing elements 211 and 221 different in this way, the image light IM synthesized by the photosynthesis element 30 can be adjusted to a desired color balance.

[0102] In addition, in the image forming module of this embodiment, the configurations for adjusting the light utilization efficiency of the blue illumination optical system 16 and the red illumination optical system 17 in the image forming module 10 of the first embodiment may be combined.

[0103] (Third embodiment) In the first embodiment, the image forming module 10 was given as an example in which the image light IM is set to a desired color balance by making the light utilization efficiency of the blue illumination optical system 16 and the light utilization efficiency of the red illumination optical system 17 different. However, the image light IM may also be set to a desired color balance by making the light emission area of ​​the blue light-emitting element 11b and the light emission area of ​​the red light-emitting element 12b different.

[0104] Figure 8 shows an example configuration in which the light-emitting areas of the blue light-emitting element 11b and the red light-emitting element 12b are different. As shown in Figure 8, the blue light-emitting element 11b includes a light-emitting surface 11c that emits blue light LB, and the red light-emitting element 12b includes a light-emitting surface 12c that emits red light LR. Hereinafter, the area of ​​the light-emitting surfaces 11c and 12c when viewed from above may be referred to as the light-emitting area.

[0105] Here, the luminous efficiency of the blue light-emitting element 11b is higher than that of the red light-emitting element 12b. Therefore, if the light-emitting area of ​​the blue light-emitting element 11b and the light-emitting area of ​​the red light-emitting element 12b are the same, and the same current value is applied to both the blue light-emitting element 11b and the red light-emitting element 12b, the amount of blue light LB emitted will be greater than the amount of red light LR emitted. The light-emitting area of ​​the green light-emitting element 13b is set to a predetermined size according to the color balance of the image light IM.

[0106] In this embodiment, the light-emitting area of ​​the blue light-emitting element 11b is made smaller than the light-emitting area of ​​the red light-emitting element 12b. With this configuration, by reducing the light-emitting area of ​​the blue light-emitting element 11b, which has high luminous efficiency, when the same current value is applied to the blue light-emitting element 11b and the red light-emitting element 12b by the control device 50, the amount of blue light LB emitted from the blue light-emitting element 11b is suppressed while the amount of red light LR emitted from the red light-emitting element 12b is relatively increased. As a result, the difference between the amount of incident light blue LB to the first light modulation element 210 and the amount of incident light red LR to the second light modulation element 220 can be reduced. Therefore, by adjusting the color balance between the blue light LB incident on the blue light modulator 21 and the red light LR incident on the red light modulator 22, the color balance between the image light IB generated by the blue light modulator 21 and the image light IR generated by the red light modulator 22 can be adjusted. Therefore, by making the light-emitting areas of the blue light-emitting element 11b and the red light-emitting element 12b different, the image light IM synthesized by the photosynthetic element 30 can be adjusted to a desired color balance.

[0107] As described above, the image forming module of this embodiment includes a blue light source 11 that emits blue light LB in the blue wavelength band, a red light source 12 that emits red light LR in the red wavelength band, a green light source 13 that emits green light LG in the green wavelength band, a blue illumination optical system 16 that generates blue illumination light LB1 from the blue light LB emitted from the blue light source 11, a red illumination optical system 17 that generates red illumination light LR1 from the red light LR emitted from the red light source 12, a green illumination optical system 18 that generates green illumination light LG1 from the green light LG emitted from the green light source 13, and the blue illumination light LB1 emitted from the blue illumination optical system 16 for image formation. The system includes a blue light modulator 21 that modulates according to information, a red light modulator 22 that modulates red illumination light LR1 emitted from a red illumination optical system 17 according to image information, a green light modulator 23 that modulates green illumination light LG1 emitted from a green illumination optical system 18 according to image information, a photosynthesis element 30 that generates image light IM by combining image light IB emitted from the blue light modulator 21, image light IR emitted from the red light modulator 22, and image light IG emitted from the green light modulator 23, and a control device 50 that controls the driving of the blue light source 11, the red light source 12, and the green light source 13. The blue light source 11 includes a blue light-emitting element 11b that emits blue light LB, the red light source 12 includes a red light-emitting element 12b that emits red light LR, and the green light source 13 includes a green light-emitting element 13b that emits green light LG. The control device 50 applies the same current value to the blue light source 11 and the red light source 12. The light-emitting area of ​​the blue light-emitting element 11b and the light-emitting area of ​​the red light-emitting element 12b are different so that the image light IM synthesized by the photosynthetic element 30 has a desired color balance.

[0108] In this image forming module, as in the image forming module of the first embodiment, it is possible to suppress the complexity of controlling the control device 50 and generate image light IM with a desired color balance.

[0109] In addition, in the image forming module of this embodiment, the configurations for adjusting the light utilization efficiency of the blue light illumination optical system 16 and the red light illumination optical system 17 in the image forming module 10 of the first embodiment, and the configurations for differentiating the light utilization efficiency of the blue light modulator 21 and the red light modulator 22 in the second embodiment may be combined.

[0110] The technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, in the control device 50 of the above embodiment, the control of the blue light source 11 and the red light source 12 was standardized, and the amount of image light IB and IR was adjusted by making the light utilization efficiency of the blue illumination optical system 16 and the light utilization efficiency of the red illumination optical system 17 different, thereby adjusting the balance of image light IB and IR with respect to image light IG and generating image light IM with a desired color balance. However, in the present invention, the control device 50 may standardize the control of the blue light source 11, the red light source 12, and the green light source 13, and generate image light IM with a desired color balance by making the light utilization efficiency of the blue illumination optical system 16, the red illumination optical system 17, and the green illumination optical system 18 different. With this configuration, by standardizing the control of the three light sources 11, 12, and 13, control by the control device 50 can be made simpler and image light IM with a desired color balance can be generated.

[0111] Furthermore, in the above embodiment, an example was given in which the first light guide element 161, the second light guide element 171, and the third light guide element 181 are all composed of hollow reflectors. However, each of the light guide elements 161, 171, and 181 may be composed as a solid reflector made of a transparent material such as optical glass, and a reflective film made of a dielectric multilayer film or the like may be provided on the outer surface to act as a reflective surface.

[0112] Furthermore, the specific details regarding the shape, number, arrangement, and materials of each component of the image forming module and projector are not limited to the above embodiment and can be modified as appropriate.

[0113] A summary of this disclosure is provided below.

[0114] (Note 1) A first light source that emits first light in the first wavelength band, A second light source that emits second light in a second wavelength band different from the first wavelength band, A first illumination optical system that generates first illumination light from the first light emitted from the first light source, A second illumination optical system that generates a second illumination light from the second light emitted from the second light source, A first optical modulator that modulates the first illumination light emitted from the first illumination optical system according to image information, A second optical modulator that modulates the second illumination light emitted from the second illumination optical system according to image information, A photosynthetic element that generates composite light by combining light emitted from the first optical modulator and light emitted from the second optical modulator, The system includes a control device for controlling the driving of the first light source and the second light source, The previous illumination optical system is, A first light guide element having a first incident end into which the first light emitted from the first light source is incident, and a first exit end that emits the first light, and which makes the in-plane illuminance of the first light uniform, The system comprises a first parallelizing element that parallelizes the first light emitted from the first light guide element, The aforementioned second illumination optical system is, A second light guide element having a second incident end into which the second light emitted from the second light source is incident, and a second exit end that emits the second light, and which makes the in-plane illuminance of the second light uniform, The system includes a second parallelizing element that parallelizes the second light emitted from the second light guide element, The control device applies the same current value to the first light source and the second light source, The light utilization efficiency of the first illumination optical system and the light utilization efficiency of the second illumination optical system are different so that the synthesized light produced by the photosynthetic element has a desired color balance. An image forming module characterized by the following features.

[0115] With this image forming module configuration, the control of the first and second light sources is standardized by applying the same current value to both, thereby suppressing the complexity of the control device. Furthermore, the difference in light intensity between the first and second light sources, which occurs as a result of standardizing the control of the first and second light sources, can be adjusted by adjusting the light utilization efficiency of the first and second illumination optics systems to achieve a desired color balance in the composite light. Therefore, this image forming module configuration makes it possible to simultaneously suppress the complexity of the control device and set the composite light to a desired color balance.

[0116] (Note 2) The cross-sectional area of ​​the first incident end of the first light guide element in a plane perpendicular to the optical axis of the first parallelizing element is different from the cross-sectional area of ​​the second incident end of the second light guide element in a plane perpendicular to the optical axis of the second parallelizing element. The image forming module described in Appendix 1, characterized by the features described herein.

[0117] With this configuration, the difference in light intensity between the first and second light can be reduced by adjusting the size of the cross-sectional area of ​​the incident ends of the first and second light guide elements.

[0118] (Note 3) The cross-sectional area of ​​the first exit end of the first light guide element in a plane perpendicular to the optical axis of the first parallelizing element is different from the cross-sectional area of ​​the second exit end of the second light guide element in a plane perpendicular to the optical axis of the second parallelizing element. The image forming module described in Appendix 1 or Appendix 2, characterized by the above.

[0119] With this configuration, the difference in light intensity between the first and second light can be reduced by adjusting the size of the cross-sectional area of ​​the emission ends of the first and second light guide elements.

[0120] (Note 4) The first parallelizing element has a first light incident surface into which the first light emitted from the first light guide element is incident, The second parallelizing element has a second light incident surface into which the second light emitted from the second light guide element is incident, The light transmittance of the first light incident surface for the first light is different from the light transmittance of the second light incident surface for the second light. An image forming module as described in any one of the appendices 1 to 3, characterized by the features described herein.

[0121] With this configuration, the difference in light intensity between the first and second light can be reduced by adjusting the transmittance of the light incident surfaces of the first and second parallelizing elements.

[0122] (Note 5) The first parallelizing element has a first light emission surface that emits the first light, The second parallelizing element has a second light emission surface that emits the second light, The light transmittance of the first light-emitting surface for the first light is different from the light transmittance of the second light-emitting surface for the second light. An image forming module as described in any one of the appendices 1 to 4, characterized by the features described herein.

[0123] With this configuration, the difference in light intensity between the first and second light can be reduced by adjusting the transmittance of the light emission surfaces of the first and second parallelizing elements.

[0124] (Note 6) The first parallelizing element and the second parallelizing element differ in at least one of their shapes and refractive indices. An image forming module as described in any one of the appendices 1 to 5, characterized by the above.

[0125] With this configuration, the difference in light intensity between the first and second light can be reduced by adjusting the shape or refractive index of the first and second parallelizing elements.

[0126] (Note 7) The first light guide element has a first reflective surface that reflects the first light, The second light guide element has a second reflective surface that reflects the second light, The reflectance of the first reflective surface to the first light is different from the reflectance of the second reflective surface to the second light. An image forming module as described in any one of the appendices 1 to 6, characterized by the above.

[0127] With this configuration, the difference in light intensity between the first and second light can be reduced by adjusting the reflectivity of the reflective surfaces of the first and second light guide elements.

[0128] (Note 8) The length of the first light guide element in the direction along the optical axis of the first parallelizing element is different from the length of the second light guide element in the direction along the optical axis of the second parallelizing element. An image forming module as described in any one of the appendices 1 to 7, characterized by the above.

[0129] With this configuration, the difference in light intensity between the first and second light sources can be reduced by adjusting the length of the reflective surfaces of the first and second light guide elements.

[0130] (Note 9) The first optical modulation device includes a first polarizing element that separates a first polarization component from light emitted from the first parallelizing element, and a first optical modulation element that modulates the light emitted from the first polarizing element. The second optical modulation device comprises a second polarizing element that separates the second polarization component of light from the light emitted from the second parallelizing element, and a second optical modulation element that modulates the light emitted from the second polarizing element. The optical utilization efficiency of the first optical modulator is different from that of the second optical modulator. An image forming module as described in any one of the appendices 1 to 8, characterized by the above.

[0131] With this configuration, the difference in light intensity between the first and second light sources can be reduced by adjusting the light utilization efficiency of the first and second light modulators.

[0132] (Note 10) The control device controls the first optical modulation element and the second optical modulation element so that their respective driving voltages are different. The image forming module described in Appendix 9, characterized by the features described herein.

[0133] With this configuration, the difference in light intensity between the first and second light can be reduced by adjusting the driving voltage of the first and second light modulation elements.

[0134] (Note 11) The aperture ratio of the first optical modulation element is different from the aperture ratio of the second optical modulation element. The image forming module described in Appendix 9, characterized by the features described herein.

[0135] With this configuration, the difference in light intensity between the first and second light can be reduced by adjusting the aperture ratio of the first and second light modulation elements.

[0136] (Note 12) The light transmittance of the first polarizing element for the first polarized component of light is different from the light transmittance of the second polarizing element for the second polarized component of light. The image forming module described in Appendix 9, characterized by the features described herein.

[0137] With this configuration, the difference in light intensity between the first and second light can be reduced by adjusting the light transmittance of the first and second polarizing elements.

[0138] (Note 13) The first light source includes a first light-emitting element that emits the first light, The second light source includes a second light-emitting element that emits the second light, The light-emitting area of ​​the first light-emitting element is different from the light-emitting area of ​​the second light-emitting element. The image forming module described in Appendix 9, characterized by the features described herein.

[0139] With this configuration, the difference in light intensity between the first and second light sources can be reduced by adjusting the light-emitting areas of the first and second light sources.

[0140] (Note 14) A first light source that emits first light in the first wavelength band, A second light source that emits second light in a second wavelength band different from the first wavelength band, A first illumination optical system that generates first illumination light from the first light emitted from the first light source, A second illumination optical system that generates a second illumination light from the second light emitted from the second light source, A first optical modulator that modulates the first illumination light emitted from the first illumination optical system according to image information, A second optical modulator that modulates the second illumination light emitted from the second illumination optical system according to image information, A photosynthetic element that generates composite light by combining light emitted from the first optical modulator and light emitted from the second optical modulator, The system includes a control device for controlling the driving of the first light source and the second light source, The control device applies the same current value to the first light source and the second light source, The light utilization efficiency of the first light modulator and the light utilization efficiency of the second light modulator are different so that the synthesized light produced by the photosynthetic element has a desired color balance. An image forming module characterized by the following features.

[0141] This image forming module configuration allows for the unification of control of the first and second light sources, thereby reducing the complexity of the control device. Furthermore, the difference in light intensity between the first and second light sources resulting from the unification of their control can be compensated for by adjusting the light utilization efficiency of the first and second light modulators, allowing the combined light to be adjusted to a desired color balance. Therefore, this image forming module configuration achieves both the reduction of complexity in the control device and the setting of the combined light to a desired color balance.

[0142] (Note 15) A first light source that emits first light in the first wavelength band, A second light source that emits second light in a second wavelength band different from the first wavelength band, A first illumination optical system that generates first illumination light from the first light emitted from the first light source, A second illumination optical system that generates a second illumination light from the second light emitted from the second light source, A first optical modulator that modulates the first illumination light emitted from the first illumination optical system according to image information, A second optical modulator that modulates the second illumination light emitted from the second illumination optical system according to image information, A photosynthetic element that generates composite light by combining light emitted from the first optical modulator and light emitted from the second optical modulator, The system includes a control device for controlling the driving of the first light source and the second light source, The first light source includes a first light-emitting element that emits the first light, The second light source includes a second light-emitting element that emits the second light, The control device applies the same current value to the first light source and the second light source, The light-emitting area of ​​the first light-emitting element and the light-emitting area of ​​the second light-emitting element are different so that the synthesized light produced by the photosynthetic element has a desired color balance. An image forming module characterized by the following features.

[0143] This image forming module configuration allows for the unification of control of the first and second light sources, thereby reducing the complexity of the control device. Furthermore, the difference in light intensity between the first and second light sources resulting from the unification of their control can be compensated for by adjusting the light-emitting areas of the first and second light-emitting elements, thereby adjusting the combined light to a desired color balance. Therefore, this image forming module configuration achieves both the reduction of complexity in the control device and the setting of the combined light to a desired color balance.

[0144] (Note 16) An image forming module described in any one of the appendices 1 to 15, The image forming module comprises a projection optical system that projects light emitted from the photosynthetic element of the image forming module, A projector characterized by the following features.

[0145] This projector configuration makes it possible to realize a projector that projects image light with the desired color balance while suppressing the complexity of control. [Explanation of Symbols]

[0146] 10…Image forming module, 11…Light source, 11…Blue light source (first light source), 11b…Blue light-emitting element (first light-emitting element), 12…Red light source (second light source), 12b…Red light-emitting element (second light-emitting element), 16…Blue illumination optical system (first illumination optical system), 17…Red illumination optical system (second illumination optical system), 20…Projection optical system, 21…Light modulation device, 21…Blue light modulation device (first light modulation device), 22…Red light modulation device (second light modulation device), 30…Photosynthesis element, 50…Control device, 100…Projector, 161…First light guide element, 161a…First entrance end, 161b…First exit end, 161r…First 1 Reflecting surface, 162...First parallelizing element, 162a...First light incident surface, 162b...First light emission surface, 171...Second light guide element, 171a...Second incident end, 171b...Second emission end, 171r...Second reflecting surface, 172...Second parallelizing element, 172a...Second light incident surface, 172b...Second light emission surface, 210...First light modulation element, 211...Incident-side polarizing element (first polarizing element), 220...Second light modulation element, 221...Incident-side polarizing element (second polarizing element), IM...Image light (composite light), LB...Blue light (first light), LB1...Blue illumination light (first illumination light), LR...Red light (second light), LR1...Red illumination light (second illumination light).

Claims

1. A first light source that emits first light in the first wavelength band, A second light source that emits second light in a second wavelength band different from the first wavelength band, A first illumination optical system that generates first illumination light from the first light emitted from the first light source, A second illumination optical system that generates a second illumination light from the second light emitted from the second light source, A first optical modulation device that modulates the first illumination light emitted from the first illumination optical system according to image information, A second optical modulation device that modulates the second illumination light emitted from the second illumination optical system according to image information, A photosynthetic element that generates synthesized light by combining light emitted from the first light modulator and light emitted from the second light modulator, The system includes a control device for controlling the driving of the first light source and the second light source, The first illumination optical system is, A first light guide element having a first incident end into which the first light emitted from the first light source is incident, and a first exit end that emits the first light, and which makes the in-plane illuminance of the first light uniform, The system includes a first parallelizing element that parallelizes the first light emitted from the first light guide element, The second illumination optical system described above is: A second light guide element having a second incident end into which the second light emitted from the second light source is incident, and a second exit end that emits the second light, and which makes the in-plane illuminance of the second light uniform, The system comprises a second parallelizing element that parallelizes the second light emitted from the second light guide element, The control device applies the same current value to the first light source and the second light source, The light utilization efficiency of the first illumination optical system and the light utilization efficiency of the second illumination optical system are different so that the synthesized light produced by the photosynthetic element has a desired color balance. An image forming module characterized by the following features.

2. The cross-sectional area of ​​the first incident end of the first light guide element in a plane perpendicular to the optical axis of the first parallelizing element is different from the cross-sectional area of ​​the second incident end of the second light guide element in a plane perpendicular to the optical axis of the second parallelizing element. The image forming module according to feature 1.

3. The cross-sectional area of ​​the first exit end of the first light guide element in a plane perpendicular to the optical axis of the first parallelizing element is different from the cross-sectional area of ​​the second exit end of the second light guide element in a plane perpendicular to the optical axis of the second parallelizing element. The image forming module according to feature 1.

4. The first parallelizing element has a first light incident surface into which the first light emitted from the first light guide element is incident, The second parallelizing element has a second light incident surface into which the second light emitted from the second light guide element is incident, The light transmittance of the first light incident surface for the first light is different from the light transmittance of the second light incident surface for the second light. The image forming module according to feature 1.

5. The first parallelizing element has a first light emission surface that emits the first light, The second parallelizing element has a second light emission surface that emits the second light, The light transmittance of the first light-emitting surface to the first light is different from the light transmittance of the second light-emitting surface to the second light. The image forming module according to feature 1.

6. The first parallelizing element and the second parallelizing element differ in at least one of their shapes and refractive indices. The image forming module according to feature 1.

7. The first light guide element has a first reflective surface that reflects the first light, The second light guide element has a second reflective surface that reflects the second light, The reflectance of the first reflective surface to the first light is different from the reflectance of the second reflective surface to the second light. The image forming module according to feature 1.

8. The length of the first light guide element in the direction along the optical axis of the first parallelizing element is different from the length of the second light guide element in the direction along the optical axis of the second parallelizing element. The image forming module according to feature 1.

9. The first optical modulation device includes a first polarizing element that separates a first polarization component from light emitted from the first parallelizing element, and a first optical modulation element that modulates the light emitted from the first polarizing element. The second optical modulation device includes a second polarizing element that separates the second polarization component of light from the light emitted from the second parallelizing element, and a second optical modulation element that modulates the light emitted from the second polarizing element. The optical utilization efficiency of the first optical modulator is different from that of the second optical modulator. The image forming module according to feature 1.

10. The control device controls the first optical modulation element and the second optical modulation element so that their respective driving voltages are different. The image forming module according to feature 9.

11. The aperture ratio of the first optical modulation element is different from the aperture ratio of the second optical modulation element. The image forming module according to feature 9.

12. The light transmittance of the first polarizing element for light of the first polarizing component is different from the light transmittance of the second polarizing element for light of the second polarizing component. The image forming module according to feature 9.

13. The first light source includes a first light-emitting element that emits the first light, The second light source includes a second light-emitting element that emits the second light, The light-emitting area of ​​the first light-emitting element is different from the light-emitting area of ​​the second light-emitting element. The image forming module according to feature 9.

14. A first light source that emits first light in the first wavelength band, A second light source that emits second light in a second wavelength band different from the first wavelength band, A first illumination optical system that generates first illumination light from the first light emitted from the first light source, A second illumination optical system that generates a second illumination light from the second light emitted from the second light source, A first optical modulation device that modulates the first illumination light emitted from the first illumination optical system according to image information, A second optical modulation device that modulates the second illumination light emitted from the second illumination optical system according to image information, A photosynthetic element that generates synthesized light by combining light emitted from the first light modulator and light emitted from the second light modulator, The system includes a control device for controlling the driving of the first light source and the second light source, The control device applies the same current value to the first light source and the second light source, The light utilization efficiency of the first light modulator and the light utilization efficiency of the second light modulator are different so that the synthesized light produced by the photosynthetic element has a desired color balance. An image forming module characterized by the following features.

15. A first light source that emits first light in the first wavelength band, A second light source that emits second light in a second wavelength band different from the first wavelength band, A first illumination optical system that generates first illumination light from the first light emitted from the first light source, A second illumination optical system that generates a second illumination light from the second light emitted from the second light source, A first optical modulation device that modulates the first illumination light emitted from the first illumination optical system according to image information, A second optical modulation device that modulates the second illumination light emitted from the second illumination optical system according to image information, A photosynthetic element that generates synthesized light by combining light emitted from the first light modulator and light emitted from the second light modulator, The system includes a control device for controlling the driving of the first light source and the second light source, The first light source includes a first light-emitting element that emits the first light, The second light source includes a second light-emitting element that emits the second light, The control device applies the same current value to the first light source and the second light source, The light-emitting area of ​​the first light-emitting element and the light-emitting area of ​​the second light-emitting element are different so that the synthesized light produced by the photosynthetic element has a desired color balance. An image forming module characterized by the following features.

16. An image forming module according to any one of claims 1 to 15, The image forming module comprises a projection optical system that projects light emitted from the photosynthetic element of the image forming module, A projector characterized by the following features.

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