JP4902441B2 - Illumination device and projection display device - Google Patents

Description

  The present invention relates to an illumination device and a projection display apparatus, and is particularly suitable for use in an illumination apparatus and a projection display apparatus having a plurality of light sources.

  In recent years, in projection video display devices (hereinafter referred to as “projectors”), the brightness of illumination light has been increased. As one of the methods for realizing high brightness, it is conceivable to increase the number of lighting devices. For example, in the following Patent Documents 1 and 2, a four-lamp illumination device using four lamps as light emission sources is shown.

  In the four-lamp illumination device, for example, as shown in the lower part of FIG. 12A, four lamps L1 to L4 and mirrors M1 to M4 that reflect light from each lamp in the same direction are used. Here, the optical axes of the lamps L1 and L2 coincide with each other, and the optical axes of the lamps L3 and L4 also coincide with each other. The lamps L1 and L2 are shifted from the lamps L3 and L4 in a direction perpendicular to the drawing sheet.

  From the lamps L1 to L4, substantially parallel light is emitted. The light emitted from each lamp is reflected in the same direction by mirrors M1 to M4 arranged at an inclination of 45 degrees with respect to the lamp optical axis. The upper part of FIG. 6A is a diagram schematically showing a beam cross section of light after being reflected by the mirrors M1 to M4. Here, B1 to B4 indicate beam cross sections of light emitted from the lamps L1 to L4, respectively.

  The middle part (a) of the figure schematically shows the light intensity distribution between adjacent beams. In this case, since the optical axis of each beam is away from the optical axis center of the illumination light, as shown in the upper part of FIG. On the other hand, as shown in the upper part of FIG. 5B, the light intensity near the center of the optical axis can be increased by bringing the optical axis of each beam closer to the center of the optical axis.

  However, when the beam optical axis is brought closer to the center of the optical axis of the illumination light in this way, the light from the other lamp enters one of the opposing lamps as described below, thereby reducing the lamp life. Problems arise.

  That is, in order to bring the optical axis of each beam closer to the center of the optical axis of the illumination light, it is necessary to shorten the distance between the optical axes of each beam in the D1 and D2 directions in the upper part of FIG. In this case, for example, in order to shorten the distance between the optical axes in the D1 direction, it is necessary to shift the lamps L1 to L4 with respect to the mirrors M1 to M4 in the d1 direction as shown in the lower part of FIG. is there. However, if this is done, a part of the light from each lamp (shown as Be in the lower part of FIG. 5B) does not enter the mirror, but goes straight on and enters the opposite lamp. Similarly, when the distance between the optical axes in the D2 direction is shortened, a part of the light is not incident on the corresponding mirror but is incident on the opposite lamp due to the shift of each lamp with respect to each mirror. Will be.

  In order to solve this problem, when the optical axis of each lamp is brought close to the optical axis center of the illumination light, as shown in the lower part of FIG. 5B, a mask S1 for shielding light not reflected by each mirror, S2 is required. However, this causes a problem that the original light quantity of the lamp is lost and the light use efficiency is lowered.

The following Patent Document 3 shows a configuration in which light from a lamp is guided as illumination light using a prism array instead of a mirror.
JP 2002-90877 A JP-A-8-36180 WO2004 / 088413

  It is an object of the present invention to provide an illumination device that can increase the light intensity near the optical axis center of illumination light without impairing the light utilization efficiency, and a projection display device incorporating the illumination device.

  The illumination device according to the present invention includes a first light source unit having a plurality of light sources arranged so that emission directions are inclined by a predetermined angle in the same direction from positions facing each other, and the light from the first light source unit A plurality of light sources arranged such that a part of the incident light is bent and the incident light is bent to form illumination light, and an emission direction is inclined at a predetermined angle in the same direction from a position facing each other. The second light source unit having the first light source unit and the light from the first light source unit not incident on the first bent unit and the light from the second light source unit are incident and the incident light is bent. And having a second bent portion as the illumination light.

  Note that “opposing each other” means that the optical axes face each other in a substantially parallel state as in the lamps L1 and L2 illustrated in the lower part of FIG. However, the present invention is not limited to the case where the optical axes coincide with each other, and includes cases where the optical axes face each other in a shifted state. In the configuration of FIG. 2 in the following embodiment, the lamps 101 and 102 are arranged so that the emission directions are inclined by a predetermined angle in the same direction (X-axis direction) from the “position facing each other”. The lamps 104 and 105 are also arranged so that the emission directions are inclined by a predetermined angle in the same direction (X-axis direction) from the “positions facing each other”. The present invention includes not only the case where the tilt angles of the optical axes are the same but also the case where they are not the same.

  In the present invention, the first and second bent portions can be configured to include a reflective prism array.

  The second bent portion is configured such that the length in the direction parallel to the plane including both the optical axis of the incident light and the optical axis of the bent light is larger than that of the first bent portion. Can be done. Further, the first bent portion has a length in a direction perpendicular to a plane including both the optical axis of the incident light and the optical axis of the light after being bent, smaller than that of the second bent portion. Can be configured. Or a 1st and 2nd bending part can also be made into the mutually same shape.

  In addition, a lens for reducing the effective diameter of the light emitted from the first and second light source units may be disposed between the first and second light source units and the first and second bent portions. .

  A projection display apparatus according to the present invention includes the illumination device having the above-described configuration.

  According to the present invention, since the light sources are arranged so that the emission directions are inclined by a predetermined angle in the same direction from the positions facing each other, light from one opposing light source does not directly enter the other. Therefore, the lifetime of the light source is not undesirably reduced. Also, when the light intensity near the optical axis center of the illumination light is increased by bringing the first light source unit and the second light source unit closer to each other, the first bent portion of the light from the first light source unit is also included. Since the light that has not entered is bent by the second bent portion and used as illumination light, no loss occurs in the light from the first light source portion.

  Therefore, according to the present invention, it is possible to effectively increase the light intensity in the vicinity of the optical axis center of the illumination light without impairing the light use efficiency.

The effects and significance of the present invention and the above-described other configuration examples will become more apparent from the following description of embodiments. However, the following embodiment is merely an example when the present invention is implemented, and the meaning of the term of the present invention or each constituent element is limited to that described in the following embodiment. Is not to be done.

  Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is a configuration example when the lighting device according to the present invention is applied to a projector.

  FIG. 1 shows an optical system of a projector according to the embodiment. In the figure, reference numeral 10 denotes a lighting device having four lamps. As each lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp or the like is used. Light from each lamp is emitted as substantially parallel light by the action of the reflector. The configuration of the illumination device 10 will be described later with reference to FIG.

  Light from the illumination device 10 is incident on a PBS (polarized beam splitter) array 12 and a condenser lens 13 via a fly eye integrator 11. The fly-eye integrator 11 includes first and second fly-eye lenses made up of eyelid-shaped lens groups, and the illumination device 10 has a uniform light amount distribution when entering the liquid crystal panels 18, 24, 33. The light incident from is superimposed.

  The PBS array 12 has a plurality of PBSs and half-wave plates arranged in an array, and aligns the polarization direction of the light incident from the fly eye integrator 11 in one direction. The condenser lens 13 imparts a condensing function to the light incident from the PBS array 13. The light transmitted through the condenser lens 13 enters the dichroic mirror 14.

  The dichroic mirror 14 transmits only the light in the red wavelength band (hereinafter referred to as “R light”) among the light incident from the condenser lens 13, and the blue wavelength band (hereinafter referred to as “B light”) and the green wavelength. The band (hereinafter referred to as “G light”) is reflected. The R light transmitted through the dichroic mirror 14 is reflected by the mirror 15 and enters the condenser lens 16.

  The condenser lens 16 collimates the R light so that the R light enters the liquid crystal panel 18 as substantially parallel light. The R light transmitted through the condenser lens 16 is incident on the liquid crystal panel 18 via the incident side polarizing plate 17. The liquid crystal panel 18 is driven according to the red video signal and modulates the R light according to the driving state. The R light modulated by the liquid crystal panel 18 is incident on the dichroic prism 20 via the emission side polarizing plate 19.

  Of the light reflected by the dichroic mirror 14, G light is reflected by the dichroic mirror 21 and enters the condenser lens 22. The condenser lens 22 collimates the G light so that the G light enters the liquid crystal panel 24 as substantially parallel light. The G light transmitted through the condenser lens 22 is incident on the liquid crystal panel 24 through the incident side polarizing plate 23. The liquid crystal panel 24 is driven according to the green video signal and modulates the G light according to the driving state. The G light modulated by the liquid crystal panel 24 is incident on the dichroic prism 20 via the output side polarizing plate 25.

  The B light transmitted through the dichroic mirror 21 is incident on the condenser lens 26. The condenser lens 26 collimates the B light so that the B light enters the liquid crystal panel 33 as substantially parallel light. The B light transmitted through the condenser lens 26 travels on an optical path composed of relay lenses 27, 29, 31 for adjusting the optical path length and two mirrors 28, 30, and is incident on the liquid crystal panel 33 via the incident side polarizing plate 32. . The liquid crystal panel 33 is driven according to the blue video signal, and modulates the B light according to the driving state. The B light modulated by the liquid crystal panel 33 is incident on the dichroic prism 20 via the emission side polarizing plate 34.

  The dichroic prism 20 color-combines the R light, G light, and B light modulated by the liquid crystal panels 18, 24, and 33, and enters the projection lens 35. The projection lens 35 includes a lens group for forming an image of projection light on the projection surface, and an actuator for adjusting a zoom state and a focus state of the projection image by displacing a part of the lens group in the optical axis direction. It has. The color image light synthesized by the dichroic prism 20 is enlarged and projected on the screen by the projection lens 35.

  Next, the configuration of the illumination device 10 will be described with reference to FIG. FIGS. 4A and 4B are a top view and a front view of the illumination device 10, respectively.

  The illumination device 10 includes four lamps 101, 102, 104, and 105 and two reflective prism arrays 103 and 106.

  Among these, the lamps 101 and 102 are arranged so that the emission direction is inclined by a certain angle in the same direction (X-axis direction) from a position facing each other (position facing the optical axes so as to coincide). That is, the lamps 101 and 102 are arranged such that their optical axes are placed on a common plane parallel to the XY plane. The prism array 103 is arranged so that the incident surface is parallel to the YZ plane. The angle formed by the incident surface of the prism array 103 and the optical axes of the two lamps 101 and 102 are equal. Light incident on the prism array 103 from the lamps 101 and 102 is reflected by the prism array 103 in the same direction (X-axis direction). The prism array 103 is formed with a reflective prism structure. This prism structure is configured by arranging rectangular reflecting surfaces whose longitudinal direction is the Z-axis direction so that they are arranged in a folding screen in the Y-axis direction.

  The lamps 104 and 105 are arranged such that the emission direction is inclined by a certain angle in the same direction (X-axis direction) from a position facing each other (position facing each other so that the optical axes coincide). That is, the lamps 104 and 105 are arranged such that their optical axes are placed on a common plane parallel to the XY plane. The prism array 106 is arranged such that the incident surface is parallel to the YZ plane. The angles formed by the incident surface of the prism array 106 and the optical axes of the lamps 104 and 105 are equal to each other, and the angles formed by these are also equal to the angles formed by the incident surface of the prism array 103 and the optical axes of the lamps 101 and 102. ing. Light incident on the prism array 106 from the lamps 104 and 105 is reflected by the prism array 106 in the same direction (X-axis direction). The prism array 106 is formed with a reflective prism structure. This prism structure is configured by arranging rectangular reflecting surfaces whose longitudinal direction is the Z-axis direction so that they are arranged in a folding screen in the Y-axis direction.

  The plane including the optical axis of the lamps 101 and 102 and the plane including the optical axis of the lamps 104 and 105 are separated by a certain distance in the Z-axis direction in FIG.

  The length Q2 of the prism array 106 is set larger than the effective diameter of light from the lamps 104 and 105. Light from the lamps 104 and 105 is irradiated to the same position in the center of the prism array 106. Therefore, the lights from the lamps 104 and 105 are integrated by the prism array 106 and guided in the same direction (X-axis direction).

  The length Q1 of the prism array 103 is set to be smaller than the effective diameter of the light from the lamps 101 and 102. Light from the lamps 101 and 102 is irradiated to the same position displaced along the Z axis from the center of the prism array 103 to the prism array 106 side. Accordingly, part of the light from the lamps 101 and 102 does not enter the prism array 103 but proceeds to the prism array 106 behind the prism array 103. The length P2 of the prism array 106 is larger than the length P1 of the prism array 103 so that this light enters the prism array 106.

  Of the light from the lamps 101 and 102, light incident on the prism array 103 is integrated by the prism array 103 and guided in the same direction (X-axis direction). Light that is not incident on the prism array 103 is guided in the X-axis direction by the prism array 106. Further, light incident on the prism array 106 from the lamps 104 and 105 is integrated by the prism array 106 and guided in the same direction (X-axis direction). That is, the prism array 106 guides part of the light from the lamps 101 and 102 in the X-axis direction in addition to the light from the lamps 104 and 105.

  FIG. 3A is a diagram illustrating a light incident state with respect to the prism arrays 103 and 106. In the figure, b1 schematically shows an incident area of light incident on the prism array 103 from the lamps 101 and 102, and b2 schematically shows an incident area of light incident on the prism array 106 from the lamps 104 and 105. It is shown as an example. Further, b3 schematically shows an incident area of light incident on the prism array 106 from the lamp 101, and b4 schematically shows an incident area of light incident on the prism array 106 from the lamp 102. is there.

  The light incident on the regions b1 to b4 is guided in the same direction (X-axis direction) by the corresponding prism arrays 103 and 106, respectively. In this case, the optical axis of the light from the lamps 101 and 102 integrated in the region b1 and the optical axis of the light from the lamps 104 and 105 integrated in the region b2 are close to each other. The light intensity near the center is increased. Further, since the light from the lamps 101 and 102 incident on the regions b3 and b4 is also guided to the fly eye integrator 11 of FIG. 1 as illumination light, these lights are not lost.

  FIG. 4 is a verification comparing the light amount loss (shown as “PA method” in the figure) in this embodiment with the light amount loss (shown as “MR method” in the figure) in the configuration example shown in FIG. The result (simulation).

  The vertical axis in the figure is obtained by normalizing the amount of light used as illumination light among the light from each lamp as 100% in the initial state (distance between shortenings = 0).

  The horizontal axis in the figure is the shortened distance when the distance between the optical axes of the lights from the lamps is shortened from the upper stage in FIG. 12A and these optical axes are brought closer to the optical axis center of the illumination light. Here, the shortened distance on the horizontal axis is normalized with the diameter of the reflector of the lamp being 1.

  In the comparative example, a simulation result (diamond plot) when the distance between the optical axes of the beams B1, B2 and B3, B4 is shortened in the direction D2 shown in the upper part of FIG. Two simulation results are shown, which are simulation results (triangular plots) when the distance between the optical axes of the beams B1 and B3 and the beams B2 and B4 is shortened in the direction D1.

  In the present embodiment, a simulation result is shown when the distance between the optical axes of the light from the incident regions b1 and b2 shown in FIG. In this case, the incident area b2 is fixed, and the distance between the optical axes of light from the incident areas b1 and b2 is shortened by bringing the incident area b1 closer to the incident area b2. In the initial state (distance between shortenings = 0), all the light within the effective diameter from the lamps 101 and 102 is incident on the prism array 103, and part of the light is not incident on the prism array 106 on the back side. It has been adjusted.

  Referring to the figure, in the comparative example, as the distance between the optical axes is shortened, the amount of light shielded by the light shielding plates S1 and S2 (see the lower part of FIG. 12B) increases. The amount of light used as light gradually decreases. On the other hand, in the present embodiment, as shown in FIG. 2, the lamps are arranged so as to face obliquely, and light from the opposite lamps does not enter each lamp. Therefore, in the present embodiment, it is not necessary to block the light from each lamp even if the distance between the optical axes is shortened. Therefore, as shown in FIG. 4, there is a loss in the amount of light used as illumination light. Absent.

  As described above, according to the present embodiment, the light intensity in the vicinity of the center of the optical axis of the illumination light can be effectively increased without a light amount loss. In addition, each lamp is disposed so as to face obliquely, and light from the opposite lamp does not enter each lamp, so that the lifetime of the lamp is not undesirably reduced. As described above, according to the present embodiment, an illumination device capable of effectively increasing the light intensity in the vicinity of the center of the optical axis of illumination light and a projection incorporating the illumination device while simultaneously suppressing a decrease in lamp life and a light amount loss. Type image display device can be provided.

  In this embodiment, as shown in FIG. 3A, the shape of the prism array 103 is made smaller than that of the prism array 106. However, as shown in FIG. It is good also as the same shape. In this case, it is not necessary to prepare prism arrays having different shapes and use them appropriately, so that the productivity of the illumination device can be increased as compared with the above. However, from the viewpoint of miniaturization or cost reduction, it is desirable to make the prism array 103 smaller than the prism array 106 as shown in FIG.

  Further, as shown in FIG. 3C, the lamps 101 and 104 and the lamps 102 and 105 are brought close to each other in the Y-axis direction, or as shown in FIG. You may make it mutually approach in an axial direction. If it carries out like this, the dimension of the whole illuminating device can be shrunk | reduced to the Y-axis direction. However, on the other hand, the light reflected by the regions b3 and b4 is likely to enter each lamp, which may cause a reduction in lamp life. Therefore, also in the case of FIGS. 3C and 3D, it is preferable that the lamps facing each other are brought close to each other so that the light reflected in the regions b3 and b4 does not enter each lamp.

<Modification 1>
In the above-described embodiment, the prism arrays 103 and 106 are of the reflection type, but a transmission type prism array may be used instead.

  FIG. 5 is a configuration example in the case of using a transmissive prism array.

  In each of the prism arrays 123 and 126, a transmissive prism structure is formed on the exit surface side. This prism structure is configured by arranging rectangular transmission surfaces whose longitudinal direction is the Z-axis direction so that they are arranged in a folding screen in the Y-axis direction.

  Light from the lamps 121 and 122 and light from the lamps 124 and 125 are incident on the prism arrays 123 and 126 from the back side, respectively. As in the case of FIG. 2, the optical axes of the lamps 121 and 122 and the optical axes of the lamps 124 and 125 are set on a common plane parallel to the XY plane. In addition, the prism arrays 123 and 126 are arranged such that the incident / exit surfaces are parallel to the YZ plane. The angles formed by the optical axes of the respective lights with respect to the incident surfaces of the prism arrays 123 and 126 are the same. Further, the surface including the optical axis of the lamps 121 and 122 and the surface including the optical axis of the lamps 124 and 125 are separated from each other by a certain distance in the Z-axis direction in FIG.

  The light incident on the prism array 103 from the lamps 121 and 122 is incident on the incident area b1 in FIG. 5B, and part of the light is incident on the incident areas b3 and b4, respectively. The light from the lamps 124 and 125 is incident on the incident area b2 in FIG. Light incident on the regions b1 to b4 is directed in the same direction (X-axis direction in FIG. 2) by the corresponding prism arrays 123 and 126, respectively.

  Also in this configuration example, as in FIG. 2, the optical axes of the lights from the lamps 121 and 122 integrated in the region b1 and the optical axes of the lights from the lamps 124 and 125 integrated in the region b2 are close to each other. Therefore, the light intensity near the optical axis center of the illumination light is increased. Moreover, since the light from the lamps 121 and 122 incident on the regions b3 and b4 is also guided to the fly eye integrator 11 of FIG. 1 as illumination light, these lights are not lost. In addition, since the lamps are arranged so as to face obliquely, the lamp life is not reduced by the incidence of light from the opposite lamps.

  In this configuration example, as shown in FIG. 3B, the prism arrays 123 and 126 can have the same shape. Further, as shown in FIGS. 3C and 3D, two opposing lamps can be brought close to each other. In this case, in the configuration example of FIG. 5, since the prism arrays 123 and 126 are transmissive, the light after passing through the regions b3 and b4 is different from the case of FIG. It does not enter the lamp. Therefore, compared with the case of FIG. 2, the opposite lamp | ramp can be made to approach further.

  In the configuration example of FIG. 5, it is desirable to provide a non-reflective coating on the back surfaces of the prism arrays 123 and 126 in order to prevent light reflected by the back surfaces of the prism arrays 123 and 126 from entering the lamp.

  In the configuration example of FIG. 5, the prism arrays 123 and 126 are arranged so that the prism structure is located in the light exit surface side direction, but the prism arrays 123 and 126 are arranged so that the prism structure is located in the light incident surface side direction. However, the same effect can be obtained.

<Modification 2>
In the above embodiment, four lamps are arranged. However, the number of lamps is not limited to four, and can be changed as appropriate.

  FIG. 6 is a diagram illustrating a configuration example when six lamps are arranged. In this configuration example, lamps 107 and 108 and a prism array 109 are further added to the configuration of FIG. Further, the length of the prism array 106 in the Z-axis direction (the length Q2 in FIG. 2B) is smaller than the configuration in FIG.

  The positional relationship of the lamps 107 and 108 with respect to the prism array 109 is the same as the positional relationship of the lamps 104 and 105 with respect to the prism array 106. The plane including the optical axis of the lamps 107 and 108 and the plane including the optical axis of the lamps 104 and 105 are separated by a certain distance in the Z-axis direction in FIG.

  The light incident on the prism array 106 from the lamps 104 and 105 is incident on the incident area b2 in FIG. 5B, and part of the light is incident on the incident areas b6 and b7. Further, the light from the lamps 107 and 108 is incident on the incident region b5 in FIG. The light incident on the regions b1 to b7 is directed in the same direction (X-axis direction in the figure) by the corresponding prism arrays 103, 106, and 109, respectively.

  According to this configuration example, two lamps are added as compared to the configuration in FIG. 2, so that the amount of illumination light can be increased. Also in this configuration example, similarly to the case of FIG. 2, the optical axes of the lights from the lamps 101 and 102 integrated in the region b1, and the optical axes of the lights from the lamps 104 and 105 integrated in the region b2. Since the optical axes of the lights from the lamps 104 and 155 integrated in the region b5 are close to each other, the light intensity in the vicinity of the optical axis center of the illumination light is increased. Further, since the lights from the lamps 101 and 102 and the lamps 104 and 105 incident on the regions b3 and b4 and the regions b6 and b7 are also guided to the fly eye integrator 11 in FIG. 1 as illumination light, the light is lost. There is no. In addition, since the lamps are arranged so as to face obliquely, the lamp life is not reduced by the incidence of light from the opposite lamps.

<Modification 3>
Even when a transmissive prism array is used as shown in FIG. 5, the number of lamps can be changed as appropriate.

  FIG. 7 is a diagram illustrating a configuration example when eight lamps are arranged. In this configuration example, lamps 127, 128, 130, and 131 and prism arrays 129 and 132 are further added to the configuration of FIG. Further, the length of the prism array 126 in the Z-axis direction is smaller than that of the configuration of FIG.

  The positional relationship between the lamps 127 and 128 relative to the prism array 129 and the positional relationship between the lamps 130 and 131 relative to the prism array 132 are the same as the positional relationship between the lamps 124 and 125 relative to the prism array 126. The plane including the optical axes of the lamps 127 and 128 and the plane including the optical axes of the lamps 124 and 125 are spaced apart from each other by a certain distance in the Z-axis direction of the figure, and the plane including the optical axes of the lamps 130 and 131. And the surfaces including the optical axes of the lamps 127 and 128 are further separated by a certain distance in the Z-axis direction in FIG.

  The light incident on the prism array 126 from the lamps 124 and 125 is incident on the incident area b2 in FIG. 5B, and part of the light is incident on the incident areas b6 and b7. Further, the light incident on the prism array 129 from the lamps 127 and 128 is incident on the incident area b5, and part of the light is incident on the incident areas b9 and b10. Further, light from the lamps 130 and 131 is incident on the incident region b5. The light incident on the regions b1 to b10 is directed in the same direction (X-axis direction in the figure) by the corresponding prism arrays 123, 126, 129, and 132, respectively.

  According to this configuration example, since four lamps are added compared to the configuration of FIG. 5, the amount of illumination light can be increased. Also in this configuration example, as in the case of FIG. 5, the light intensity in the vicinity of the optical axis center of the illumination light can be increased. Further, the light incident on the regions b3, b4, b6, b7, b9, b10 is not lost. Further, since the lamps are arranged so as to face obliquely, the lamp life is not reduced by the incidence of light from the opposite lamps.

<Modification 4>
In the above embodiment, the prism array is configured so that the light from each lamp is directed in the same direction. However, as shown in FIG. 8, the prism array is configured so that the light from each lamp is condensed at one point. You can also

  FIGS. 9A and 9B are diagrams showing a configuration example in the case of using the reflective prism arrays 103 and 106 and the transmissive prism arrays 123 and 126, respectively.

  In the configuration example of FIG. 3A, the prism patterns on the prism arrays 103 and 106 are configured so that light from each lamp incident on the regions b1 to b4 of FIG. . Further, in the configuration example of FIG. 5B, the prism patterns on the prism arrays 123 and 126 are configured so that the light from each lamp incident on the regions b1 to b4 of FIG. ing. Specifically, the prism pattern of the prism array in FIGS. 4A and 4B is a concentric ring pattern, and the state of inclination of the light reflecting surface or light transmitting surface of each ring pattern is as follows. It is adjusted so that the light from the lamp is collected at one point.

  According to this configuration example, the light from each lamp can be smoothly taken into the rod integrator by disposing the entrance of the rod integrator at the light collection position of the light from each lamp.

  As shown in FIG. 9A, the prism arrays 123 and 126 may be arranged so that the prism structure is positioned in the light incident surface side direction. Further, as shown in FIG. 9B, a lens for condensing light at one point may be integrally formed on the light emitting surface. In this case, the prism structures of the prism arrays 123 and 126 may be the same as in FIG. Also when the reflective prism array of FIG. 8A is used, a lens may be disposed between the prism array 103 and the rod integrator, thereby condensing the light at one point. In this case, the prism structures of the prism arrays 123 and 126 may be the same as in FIG.

  FIG. 10 is a diagram illustrating a configuration example of an optical system in the case where a rod integrator is used as light uniformizing means.

  The illumination light condensed at one point by the illumination device 10 is made uniform by the rod integrator 40 and then incident on the TIR prism (internal total reflection prism) 44 through the condenser lens 41, the mirror 42, and the condenser lens 43. .

  The light incident on the TIR prism 44 is separated into R light, G light, and B light by the red prism, the green prism, and the blue prism that constitute the TIR prism 44, and is a reflective type composed of DMD (Digital Micro-mirror Device). The light is incident on the light modulation elements 45, 46 and 47. The light paths of the R light, G light, and B light modulated by these light modulation elements 45, 46, and 46 are integrated by the red prism, the green prism, and the blue prism, and light obtained by color-combining each color light is transmitted from the TIR prism 44. The light enters the projection lens 35.

  The configuration of the TIR prism 44 is described in, for example, Japanese Patent Application Laid-Open No. 2006-79080.

  In the configuration example of FIG. 8, for example, the prism patterns on the prism arrays 103 and 106 are configured so that the light from each lamp incident on the regions b1 to b4 in FIG. In addition, the light incident on the regions b3 and b4 in FIG. 3A is brought closer to the center of the optical axis of the illumination light, so that the light from these regions smoothly flows to the fly eye integrator 11 in FIG. The prism pattern on the prism array 106 may be adjusted so that it is captured.

<Modification 5>
In the above embodiment, the light from each lamp is directly incident on the prism array. However, as shown in FIG. 11B, a collimator lens 140 is disposed at the exit position of each lamp, thereby reducing the effective diameter of the light. After the reduction, the light from each lamp may be incident on the prism array. FIG. 11A is a diagram showing a configuration in the case where the collimating lens 140 is not arranged.

First, referring to FIG. 2A, if the angle formed by the incident surface of the prism array 106 and the optical axis of the lamps 101 and 102 is θ, the effective diameter W1 of the light emitted from the lamps 101 and 102, and the prism Assuming that these lights are perfectly collimated between the width W2 of these light incident areas on the array 106,
W2 = W1 / Sinθ (1)
The relationship is established. On the other hand, the light flux width W3 of the light taken into the fly eye integrator 11 is determined by the width W2 of the incident area of these lights as shown in the figure.

  Therefore, when the effective diameter W1 of the light is reduced by the collimating lens 140 as shown in FIG. 4B, W2 is reduced from the relational expression (1), and the prism array 106 can be reduced in size, and at the same time, the width W3. Is reduced and the fly-eye integrator 11 can be reduced in size.

  As described above, according to the configuration example of FIG. 5B, the prism array 106 and the fly-eye lens 11 can be reduced in size, and thus the illumination device 10 and the optical system thereafter can be reduced in size. FIG. 2B shows the configuration when a reflective prism array is used, but the same effect can be obtained when a transmissive prism array is used.

  As mentioned above, although embodiment of this invention and its modified example were demonstrated, this invention is not restrict | limited to the said embodiment and modified example, Moreover, various embodiment of this invention is various besides the above. It can be changed. Note that the illumination device of the present invention can be used for various devices in addition to a projector.

  The embodiment of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims.

The figure which shows the structure of the optical system of the projector which concerns on embodiment The figure which shows the structure of the illuminating device which concerns on embodiment The figure which shows the relationship between the prism array which concerns on embodiment, and a lamp | ramp The figure which shows the verification result of the light utilization efficiency in embodiment and a comparative example The figure which shows the illuminating device which concerns on the example 1 of a change of embodiment. The figure which shows the illuminating device which concerns on the example 2 of a change of embodiment. The figure which shows the illuminating device which concerns on the example 3 of a change of embodiment. The figure which shows the illuminating device which concerns on the example 4 of a change of embodiment. The figure which shows the other structure of the illuminating device which concerns on the example 4 of a change of embodiment. The figure which shows the optical system of the projector which concerns on the example 4 of a change of embodiment. The figure which shows the illuminating device which concerns on the modification 5 of embodiment. The figure which shows the structural example (comparative example) of a 4-lamp type illuminating device

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Light source device 101, 102, 104, 105, 107, 108 ... Lamp 103, 106, 109 ... Prism array 121, 122, 124, 125, 127, 128, 130, 131 ... Lamp 123, 126, 129, 132 ... Prism array 140… collimating lens

Claims (7)

A first light source unit having a plurality of light sources arranged so that the emission directions are inclined by a predetermined angle in the same direction from positions facing each other;
A first bent portion where a part of the light from the first light source portion is incident and the incident light is bent into illumination light;
A second light source unit having a plurality of light sources arranged so that the emission directions are inclined by a predetermined angle in the same direction from positions facing each other;
Second light that is not incident on the first bent portion and light from the first light source portion and light from the second light source portion is incident and the incident light is bent to form the illumination light. Having a bent portion of
A lighting device characterized by that. In claim 1,
The first and second bent portions include a reflective prism array,
A lighting device characterized by that. In claim 1 or 2,
The length of the second bent portion in a direction parallel to a plane including both the optical axis of the incident light and the optical axis of the light after being bent is larger than that of the first bent portion. ,
A lighting device characterized by that. In any one of Claims 1 thru | or 3,
The first bent portion has a length in a direction perpendicular to a plane including both the optical axis of incident light and the optical axis of light after being bent, which is smaller than that of the second bent portion. ,
A lighting device characterized by that. In claim 1 or 2,
The first and second bent portions have the same shape as each other,
A lighting device characterized by that. In claim 1 or 2,
A lens for reducing the effective diameter of the light emitted from the first and second light source units is disposed between the first and second light source units and the first and second bent units.
A lighting device characterized by that.   A projection display apparatus comprising the illumination device according to any one of claims 1 to 6.

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