JP2011232478A - Illumination optical device and projection display device comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly efficient, small, and inexpensive illumination optical device for combining lights from a plurality of light sources in one rod integrator and for providing uniform illumination.SOLUTION: A lighting apparatus comprises: a plurality of light sources 102 and 105; a plurality of subsidiary rod integrators 111 and 112 which are provided correspondingly to the plurality of light sources 102 and 105 and which guide irradiation lights entering from the plurality of light sources 102 and 105; and a combining rod integrator 118 for converging emitted lights from the plurality of subsidiary rod integrators 111 and 112. In particular, each of the subsidiary rod integrators 111 and 112 is a glass hexahedral column including an incident surface and an exit surface, and two of four side surfaces excluding at least the incident surface and the exit surface are formed to be parallel and to be oblique to the incident surface and the exit surface.

Description

  The present invention relates to a lighting device using a rod integrator in a multi-lamp composition system, and more particularly to a high-brightness projection display device using an image display element.

  As one method for displaying a large screen, there is known a projection display device that illuminates an image element that forms an optical image corresponding to an image signal with light and projects and enlarges the optical image with a projection lens. A liquid crystal panel or a digital mirror device (DMD) is used as the image element. In such a projection display device, there is a strong demand for higher brightness of a projected image.

  In order to improve the brightness of the projected image in the projection display device, the power consumption of the lamp used for the light source may be increased. However, when the power consumption is increased while ensuring a sufficient lamp life, there is a problem that the shape of the light emitter becomes longer and thicker, and the light utilization efficiency of the optical system decreases. In the case of using an LED other than the lamp, even if an attempt is made to increase the electric power beyond a predetermined power consumption, the limit of the current value allowed by the LED itself is not high, and the life of the light source cannot be ensured. Further, there is a problem that it is difficult to suppress heat generation within a range allowed by the LED light source. Therefore, it has been studied to improve the above-described problem by using a plurality of light sources with relatively low power consumption, and to efficiently improve the brightness of the projection display device.

  Patent Document 1 discloses a configuration in which the illuminance uniformity of illumination light is improved using a rod integrator after synthesizing light emitted from a lamp.

  This will be described with reference to FIG. The light source means 40 includes a first light source 41a and a second light source 41b. The first light source 41a emits a substantially parallel light beam 44a by the first light emitter 42a and the first parabolic mirror 43a. Similar to the first light source 41a, the second light source 41b includes a second light emitter 42b and a second parabolic mirror 43b, and emits a substantially parallel light beam 44b. The directions in which the substantially parallel light beams 44a and 44b are emitted are shown as azimuth axes 45a and 45b.

  The light beam combining means 46 includes a first optical element 47 having two light incident surfaces each having a gently curved surface, and two second optical elements 48a and 48b disposed in close contact with the light incident surfaces. Has been. The light incident surfaces of the second optical elements 48a and 48b are configured as a plane on which incident light from the corresponding light source enters substantially perpendicularly. Further, the light exit surface 49 of the first optical element 47 is a plane perpendicular to the optical axis 50.

  The outgoing light from the first optical element 47 enters a rod integrator 51 having a light incident end face and an outgoing end face. Light emitted from the rod integrator 51 is incident on a light transmission means 52 composed of a plurality of types of lens means. The light transmission means 52 includes a first lens system 53 that substantially collimates the divergent light beam from the rod integrator 51. Note that illustration of other elements included in the light transmission means 52 is omitted.

  The substantially parallel light beam from the first light source 41 a is deflected and condensed by the second optical element 48 a and the first optical element 47 so as to go to the incident point P of the rod integrator 51. This light condensing action also occurs with respect to a substantially parallel light beam from the second light source 41b. The light beams from the two light sources thus condensed are combined toward the incident point P at a predetermined angle.

  The light collected at the incident point P of the rod integrator 51 propagates through the rod integrator 51 while repeating total reflection several times at the glass / air interface, and forms a light emitting surface with high brightness uniformity at the exit end face. Reconfigure.

  By using the rod integrator as described above, a light emitting surface with high uniformity can be reconstructed with a simple configuration, which is effective for realizing high brightness of a projection screen by a plurality of light sources.

  Further, Patent Document 2 discloses a configuration for synthesizing using additional rods 61, 62, 63, 64, 65, 66 as shown in FIGS. 11 and 12 in order to solve the above-described problem. Yes.

JP 2000-250136 A JP 2007-27122 A

  However, in the description of Patent Document 1, since the opening at the entrance end of the rod integrator is too small to arrange a plurality of light sources in parallel, it is difficult to make the condensing points of the light sources coincide on the entrance end surface. . In order to solve this, the light beam synthesizing unit 46 is used. However, the configuration of the light beam synthesizing unit 46 is complicated and it is difficult to manufacture with high accuracy.

  Further, as described in Patent Document 2, when the optical axis of the incident light beam of the additional rods 61 and 62 and the optical axis of the incident light beam of the integration rod 67 are parallel or not perpendicular, A phenomenon occurs in which the angle between the light ray angle of the incident surface and the exit surface of the integrated rod 67 through which the light ray propagates is different. In this case, there is a problem that the angle of the light beam emitted from the integrated rod 67 becomes larger than the angle of the light beam incident on the additional rods 61 and 62, and loss occurs in the subsequent optical system.

  In order to solve the above-described problems, an illumination device according to the present invention includes a plurality of light sources and a plurality of auxiliary rods provided corresponding to the plurality of light sources, respectively, for guiding emitted light incident from the plurality of light sources to a predetermined optical path. An integrator and a synthetic rod integrator that collects light emitted from the plurality of auxiliary rod integrators are provided.

  The auxiliary rod integrator is a hexahedral glass column including an incident / exit surface, and at least two of the four side surfaces excluding the incident / exit surface are formed parallel and oblique to the incident / exit surface. Features.

  Further, the focal point of the light beam emitted from the light source is located on the incident surface of the auxiliary rod integrator, the optical axis of the incident light beam to the synthetic rod integrator, and the optical axis of the incident light beam of the auxiliary rod integrator, It is characterized by being parallel or vertical.

The angle between the optical axis from the light source and the optical axis from the light source is lowered to the inclined surface with respect to the incident / exiting surface of the auxiliary rod integrator and is perpendicular to the inclined surface, θi, and the outermost light of the effective light from the light source And the angle θc between the light source and the optical axis in the air, and the refractive index of the auxiliary rod integrator material is n1,
| N1SIN (2θi−π / 2 + SIN ⁻¹ ((SIN (θc)) / n1) | <1
The relationship is established.

  (However, θc gives a range from −θc to + θc, where − is the direction in which the angle formed with the perpendicular line to the slope becomes smaller, and + is the direction in which the angle becomes larger).

The angle between the optical axis from the light source and the optical axis from the light source is lowered to the inclined surface with respect to the incident / exiting surface of the auxiliary rod integrator and is perpendicular to the inclined surface, θi, and the outermost light of the effective light from the light source And the angle θc between the light source and the optical axis in the air, and the refractive index of the auxiliary rod integrator material is n1,
n1SIN (θi−SIN ⁻¹ (SIN (−θc)) / n1))> 1
The relationship is established.

  (However, θc gives the value of −θc when the direction in which the angle formed with the perpendicular line to the slope becomes smaller is −).

  The angle formed by the incident surface of the auxiliary rod integrator and the obliquely formed surface is 45 °.

  The projection display device of the present invention includes any one of the illumination devices, an image display element that receives the illumination light and modulates incident light according to a video signal, and light modulated by the image display element. And a projection lens that projects the image on the screen.

  According to the above configuration, the emitted light from the light source forms a condensing spot in the vicinity of the incident surface of the auxiliary rod integrator, and efficiently keeps the angle of the incident light in the auxiliary rod integrator while maintaining the angle of the incident light beam. Propagates to the entrance surface. As a result, it is possible to efficiently synthesize light emitted from a plurality of light sources, reduce light loss, and obtain an illumination optical device having a large light output. Using this, a bright projection display device Can be realized.

Configuration diagram of multi-lamp type synthesizing apparatus according to Embodiment 1 1 is a configuration diagram of a projection display device provided with a multi-lamp composition device according to Embodiment 1. FIG. Schematic diagram for explaining total reflection on the exit surface of the auxiliary rod integrator Configuration diagram of a projection display device provided with a multi-lamp synthesizer in Embodiment 2 Configuration diagram of auxiliary rod integrator in Embodiment 2 Configuration diagram of a projection display device provided with a multi-lamp synthesizer in Embodiment 2 Configuration diagram of multi-lamp type synthesizing apparatus according to Embodiment 3 Configuration diagram of a rod integrator for a 4-lamp illuminator Configuration diagram of a rod integrator for a 4-lamp illuminator Configuration diagram showing a conventional projection display device Configuration diagram showing a conventional lighting device Partial configuration diagram of a conventional lighting device

(Embodiment 1)
FIG. 1 and FIG. 2 are configuration diagrams showing a multi-lamp synthesizer and a projection display device including the multi-lamp synthesizer according to Embodiment 1 of the present invention. The first light source unit 101 condenses light emitted from the LED light source 102 mounted on the substrate by a condensing lens 103 disposed in front. Similarly, the second light source unit 104 condenses light emitted from the LED light source 105 mounted on the substrate by a condensing lens 106 disposed in front. The condensing position 107 of the first light source unit 101 and the condensing position 108 of the second light source unit 104 are set on the incident surfaces 113 and 114 of the auxiliary rod integrators 111 and 112, respectively. Further, the reference optical axis 109 of the first light source unit 101 and the reference optical axis 110 of the second light source unit 104 are incident on the incident surfaces 113 and 114 perpendicularly.

  The auxiliary rod integrators 111 and 112 are hexahedrons of optical glass having a high refractive index with incident and exit surfaces that are orthogonal to each other. As shown in FIG. 3, two of the other four surfaces 115a and 115b. Is inclined so that incident light from the incident surface is totally reflected and propagated.

  The sum of the areas of the exit surfaces 116 and 117 of the auxiliary rod integrators 111 and 112 is set equal to the area of the entrance surface 119 of the composite rod integrator 118. At this time, the reference optical axis 109 of the first light source unit 101 and the reference optical axis 110 of the second light source unit 104 that have passed through the auxiliary rod integrators 111 and 112 are perpendicularly incident on the incident surface 119 of the synthesis rod integrator 118.

  In this way, the light incident on the composite rod integrator 118 repeats internal reflection, and uniform light can be emitted from the emission surface 120. In this configuration, since light is propagated only by total reflection, a reflecting mirror coat on the rod is unnecessary. Therefore, heat generation due to cost and absorption can be suppressed.

  As shown in FIG. 2, the light emitted from the emission surface 120 is guided by the relay lens 201 and the field lens 202 and enters the liquid crystal panel 203 which is an image display element. The liquid crystal panel 203 can be controlled independently by an external signal for each pixel arranged two-dimensionally, and is sandwiched between an incident polarizing plate and an output-side polarizing plate that are not shown. By changing the polarization direction of the light transmitted through the incident polarizing plate and incident on the liquid crystal panel in accordance with an external signal for each pixel, the light shielding rate at the output side polarizing plate is changed to display an image. The light transmitted there enters the projection lens 204 and is projected onto a screen not shown.

  Specific features are described below.

  In order to efficiently guide the light from the light source by total reflection as in the above configuration, it is desirable to satisfy the following two relationships.

  1) Of the incident light, the light totally reflected without being emitted from the auxiliary rod integrator emission surface can be emitted from the auxiliary rod integrator by being reflected by the inclined surface and incident again on the emission surface.

  On the other hand, in FIG. 3, if the incident light 121 incident on the exit surface 116 of the auxiliary rod integrator 111 is not totally reflected here, it will be incident on the synthetic rod integrator 118 at a very large angle, so it will not be effective light. . Therefore, when the incident light 121 is totally reflected by the exit surface 116 of the auxiliary rod integrator 111, totally reflected by the side surface 115b which is a slope, and incident on the exit surface 116 again, the incident light 121 passes through here without being totally reflected. is required.

  The incident angle at which the optical axis 109 from the light source is incident on the auxiliary rod integrator side surface 115b is θi, the refractive index of the optical glass constituting the auxiliary rod integrator 111 is n1, and the outermost angle with respect to the reference optical axis 109 incident on the incident surface 113 When the light angle (cone angle) is θc, the following relationship holds. However, here, θc is set to be rotationally symmetric with respect to the optical axis 109, so that θc is directional. Therefore, a range from −θc to + θc is shown, where − is the direction in which the angle formed with the perpendicular line to the side 115b of the auxiliary rod is reduced, and + is the direction in which the angle is also increased.

  At this time, the following relationship holds.

| N1SIN (2θi−π / 2 + SIN ⁻¹ ((SIN (θc)) / n1) | <1
Incidentally, the outermost light angle (cone angle) θc with respect to the reference optical axis 109 incident on the incident surface 113, the optical axis 124 when the optical axis 109 from the light source is emitted, and the side surface 115b which is the inclined surface are all included. It is desirable that the angle formed by the outermost angle light 123 reflected and incident on the exit surface 116 again is equal.

  2) In the auxiliary rod integrator, incident light can propagate without passing through.

  This condition is that the light incident on the incident surface 113 of the auxiliary rod integrator 111 in FIG. 3 is totally reflected and propagated by the side surfaces 115a-115b which are the inclined surfaces of the auxiliary rod integrator 111 in the glass having the refractive index n1. Indicates.

  When the same symbols are defined as above, the following relationship is established.

n1SIN (θi−SIN ⁻¹ (SIN (−θc)) / n1))> 1
For example, actual values are assumed and shown below.

If θi = 45 °, θc = −30 ° to + 30 °, and n1 = 1.8,
According to 1), it is -0.5 to +0.5, and the absolute value is 0.5 or less.
Here, 2) is calculated only for −30 ° because it is only necessary to see the difficulty of total reflection.

  From the above, it can be seen that the emission from the exit surface 116 of the auxiliary rod integrator 111 shown in 1) has no problem. On the other hand, although the total reflection at the side surfaces (slopes) 115a to 115b of the auxiliary rod integrator 111 shown in 2) may partially be lost, it can be said that it is within an allowable range in consideration of cost and the like.

If θi = 55 °, θc = −30 ° to + 30 °, and n1 = 1.8,
According to 1), the absolute value of -1.06 to -0.12 is 1.06 or less.
If θi = 35 °, θc = −30 ° to + 30 °, and n1 = 1.8,
According to 1) the absolute value of +0.12 to +1.06 is 1.06 or less 2) according to 2) 0.73
It can be seen from the figure that the exit from the exit surface 116 of the auxiliary rod integrator 111 in 1) becomes a symmetric value at θi = 45 °.

  Therefore, it is most preferable to set the incident angle at which the optical axis 109 from the light source is incident on the auxiliary rod integrator side surface 115b to 45 °. At this time, it can be seen that there is a degree of freedom in setting the refractive index and the outermost light angle (cone angle).

  The above numerical values indicate what they should be, and it is desirable to satisfy all of them. However, as described above, the device cannot be configured unless it is all established, the size of the device, mechanical interference with other parts, It should be done with all costs and availability in mind.

  If strong priority is given, if θi = 45 ° and 1) is removed, the outermost light angle (cone angle) will be lost on both sides of the part with a large absolute value of + and −, while 2) is the outermost angle. Since the light angle (cone angle) can be lost only in the direction (+ θc) where it is difficult to totally reflect, the configuration is determined assuming that 1) satisfies the first priority and 2) satisfies the condition.

  In the above description, the liquid crystal panel is used as the image display element, but it goes without saying that the present invention can also be applied to a digital mirror device (DMD), which is a reflective device, or a reflective liquid crystal device.

  In this embodiment, the light source is composed of LEDs. However, a reflector having an elliptical reflecting surface on the discharge lamp, a parabolic surface on the discharge lamp, an elliptical surface having a long focal length, or a condenser lens is used. A combined configuration, a laser (LD) light source, a condensing lens, or the like can also be used.

  Here, the auxiliary rod integrators 111 and 112 are symmetrically arranged opposite to each other. However, if the purpose is to prevent interference of the light source unit, one of the auxiliary rod integrators is deleted, and the synthetic rod integrator 118 is directly connected. An incident configuration can also be taken. However, it goes without saying that the optical axes from the respective light source parts are parallel when entering the composite rod integrator 118.

  It should be noted that an air gap (not shown) is required between the exit surface 116 of the auxiliary rod integrator 111 and the entrance surface 119 of the composite rod integrator 118, and it is also clear that this is set.

(Embodiment 2)
FIG. 4 is a configuration diagram showing a projection display device including the multi-lamp combining device according to Embodiment 2 of the present invention.

  It differs from Embodiment 1 in that the incident / exit surfaces of the auxiliary rod integrator are parallel.

  Here, since the configuration from the LED light source unit to the auxiliary rod integrator incident surface is the same as that of the first embodiment, the details are omitted.

  The auxiliary rod integrator is an optical glass hexahedron having parallel incident / exit surfaces as shown in FIG. 5, and the incident / exit surfaces are inclined with respect to the other surfaces as shown in FIG. The inclination is such that most of the light incident on the incident surfaces 213 and 214 along the reference optical axes 209 and 210 is totally reflected by the side surfaces, and the outgoing light beam angle of the composite rod integrator 118 is that of the auxiliary rod integrators 211 and 212. It is installed at an angle at which the total reflection of the exit surface of the auxiliary rod integrator can be used so as to be equal to the incident light beam angle. Also in the second embodiment, θi = 45 ° having the most degree of freedom is set for the same reason as in the first embodiment.

  Further, the sum of the areas of the exit surfaces of the auxiliary rod integrators 211 and 212 is set equal to the area of the entrance surface of the composite rod integrator 118. At this time, the reference optical axis 209 of the first LED and the reference optical axis 210 of the second LED that have passed through the auxiliary rod integrators 211 and 212 are perpendicularly incident on the incident surface of the composite rod integrator 118.

  The light beam emitted from the synthesis rod integrator 118 is guided by the relay lens 201 and the field lens 202, and projected onto a screen (not shown) through the liquid crystal panel 203 and the projection lens 204 as image display elements.

  Even in this configuration, the same can be said for the relations 1) and 2), except that the number of reflections in the auxiliary rod integrators 211 and 212 changes.

  Since there is almost no difference in performance, the first embodiment can be selected depending on the arrangement relationship of the components and the entire apparatus.

  As this application, the configuration of FIG. 6 will be described below.

  Light from the LED 301 that emits green light in the first light source unit 300 is emitted as substantially parallel light by a condensing lens 302 having a light emitting surface of the LED at a focal position, and is reflected by a blue reflecting dichroic mirror 303 and a red reflecting dichroic mirror. The light passes through 304 and is condensed and incident on the incident surface 307 of the auxiliary rod integrator 306 by the condenser lens 305. Light from the LED 308 that emits blue light is emitted as substantially parallel light by the condenser lens 309 having the light emitting surface of the LED at the focal position, reflected by the blue reflecting dichroic mirror 303, and transmitted through the red reflecting dichroic mirror 304. The light is condensed and incident on the incident surface 307 of the auxiliary rod integrator 306 by the condenser lens 305 in the same manner as the green light. Light from the LED 310 that emits red light is emitted as substantially parallel light by a condensing lens 311 having a light emitting surface of the LED at a focal position, reflected by a red reflecting dichroic mirror 304, and auxiliary rod integrator by a condensing lens 305. The light is condensed and incident on the incident surface 307 of 306.

  The auxiliary rod integrator 306 is an optical glass hexahedron having input / output surfaces parallel to the auxiliary rod integrators 211 and 212, and the input / output surfaces are set to be inclined with respect to other surfaces. The inclination is such that most of the light incident on the incident surface 307 along the reference optical axis 312 is totally reflected on the side surface, and the outgoing ray angle of the composite rod integrator 313 is equal to the incident ray angle of the auxiliary rod integrator 306. As described above, the auxiliary rod integrator is installed at an angle at which total reflection of the emission end face of the auxiliary rod integrator can be used. Similar to the above-described embodiment, θi = 45 °, which is the most flexible, is set.

  The synthetic rod integrator 313 is a glass quadrangular prism, and incident light is totally reflected on the inner surface and emitted from the emission surface 315.

  Since the second light source unit 316 has the same configuration as that of the first light source unit 300, a detailed description thereof is omitted.

  In the above configuration, each LED is lit for each color of green, red, and blue by a driving circuit not shown. By doing in this way, the illumination for every single color is enabled by the outgoing light from the outgoing surface 315 of the synthetic rod integrator 313. All the LEDs can be driven to illuminate with white light, or the output can be adjusted for other color outputs.

  By arranging the above-described image display device and projection lens at this illumination position and synchronizing the drive period of the image display device with the light emission color of the LED, color display can be performed.

  Here, it goes without saying that the same configuration can be adopted also in the auxiliary rod integrator in Embodiment 1 in which the entrance surface and the exit surface are orthogonal to each other.

  In addition, a white light source such as a high-pressure mercury lamp can be used in place of the LED, and a color wheel capable of sequentially switching the color light transmitted in the vicinity of the emission surface 315 of the composite rod integrator 313 can be arranged to provide a device capable of performing color display in the same manner. It is clear.

(Embodiment 3)
FIG. 7 is a block diagram showing a multi-lamp combining device according to Embodiment 3 of the present invention.

  The difference from the second embodiment is that there is one auxiliary rod integrator. Since the auxiliary rod integrator is provided for the purpose of avoiding interference between the optical paths from the respective light sources or the constituent parts, as long as the purpose can be achieved with one auxiliary rod integrator as shown in FIG. This configuration can also be selected in terms of efficiency and cost.

  Here, the auxiliary rod integrator has a configuration in which the entrance surface and the exit surface are parallel to each other, but it goes without saying that the auxiliary rod integrator can be configured to use one auxiliary rod integrator according to Embodiment 1 which is in a vertical relationship.

  In addition, the relationship of 1) and 2) in the first embodiment, the point that the degree of freedom of other elements becomes the largest when θi = 45 °, and the like are also effective in the case of using one auxiliary rod integrator.

(Embodiment 4)
In the first, second, and third embodiments, the configuration includes two light source units. However, as shown in FIGS. 8 and 9, it is composed of an incident / exit surface parallel to the synthetic rod integrator 118 and four surfaces inclined thereto. Using four auxiliary rod integrators 401, 402, 403, 404, or 405, 406, 407, 408, it is possible to synthesize light from four light source units not shown.

  At this time, it goes without saying that the total area of the exit surfaces of the auxiliary rod integrators 401, 402, 403, 404 and 405, 406, 407, 408 is equal to the area of the entrance surface of the composite rod integrator 118.

  Here, the auxiliary rod integrator is used obliquely in two directions for the composite rod integrator 118. At this time, the angles 1) and 2) in the first embodiment are satisfied by the angle obtained by combining the angles in each direction. It goes without saying that it is desirable.

  Also here, it is obvious that the auxiliary rod integrator can be configured in a form using the auxiliary rod integrator in the first embodiment in which the incident surface and the outgoing surface are perpendicular to each other.

  The same idea can be applied to a configuration having the number of other auxiliary rod integrators.

  As described above, according to the present invention, since light can be guided only by total reflection, it is possible to provide an apparatus that is highly efficient and advantageous in terms of cost by suppressing absorption loss on the reflection surface.

  The present invention can be used for an illumination device using a plurality of light sources and a projection display device.

DESCRIPTION OF SYMBOLS 100 Multi-lamp type illuminating device 101, 300 1st light source part 102, 105 LED light source 103, 106, 302, 305, 309, 311, 318, 321, 324, 326 Condensing lens 104, 316 2nd LED light source unit 107, 108 LED light source unit condensing position 109, 110, 209, 210 LED light source unit reference optical axis 111, 112, 211, 212, 306, 322 Auxiliary rod integrator 113, 114, 213, 214, 307 Incident surface 115a, 215a of the auxiliary rod integrator Slope 115b facing the incident surface of the auxiliary rod integrator 115b Slope parallel to 115a of the auxiliary rod integrator 116, 117 Emission surface of the auxiliary rod integrator 118, 313 Synthetic rod integrator 119, 314 Synthetic rod Incident surface 120, 315 Combining rod integrator exit surface 201 Relay lens 202 Field lens 203 Liquid crystal panel 204 Projection lens 215b Slope parallel to 215a of auxiliary rod integrator 301, 317 Green LED light source 308, 323 Blue LED light source 310 325 Red LED light source 303, 319 Blue reflective dichroic mirror 304, 320 Red reflective dichroic mirror 401-408 Four-light auxiliary rod integrator 40 Light source means 41a, 41b First and second light sources 42a, 42b First, second Light emitters 43a, 43b first and second parabolic mirrors 44a, 44b substantially parallel light beams 45a, 45b azimuth axis 46 light beam combining means 47 first optical elements 48a, 48b second optical elements 49 light emitting surface 50 light 51 the rod integrator 52 the light transmitting means 53 first lens system 61,62,64,65,66 additional rods 67 and 68 integrated rod

Claims (7)

A plurality of light source, and a plurality of auxiliary rod integrators provided corresponding to the plurality of light sources, respectively, for guiding the radiated light incident from the plurality of light sources to a predetermined optical path;
An illumination device comprising: a synthetic rod integrator that collects light emitted from the plurality of auxiliary rod integrators.   The auxiliary rod integrator is a hexahedral glass column including an incident / exit surface, and at least two of the four side surfaces excluding the incident / exit surface are formed parallel and oblique to the incident / exit surface. The lighting device according to claim 1.   The focal point of the light beam emitted from the light source is located on the incident surface of the auxiliary rod integrator, and the optical axis of the incident light beam to the synthetic rod integrator and the optical axis of the incident light beam of the auxiliary rod integrator are parallel or The lighting device according to claim 1, wherein the lighting device is vertical. The optical axis from the light source and the angle formed by the optical axis from the light source to the inclined surface with respect to the incident / exiting surface of the auxiliary rod integrator and the perpendicular of the inclined surface is θi, and the light and light source of the outermost effective light from the light source When the angle θc formed in the air with the optical axis and the refractive index of the auxiliary rod integrator material are n1,
| N1SIN (2θi−π / 2 + SIN ⁻¹ ((SIN (θc)) / n1) | <1
The lighting device according to claim 2, wherein: The optical axis from the light source and the angle formed by the optical axis from the light source to the inclined surface with respect to the incident / exiting surface of the auxiliary rod integrator and the perpendicular of the inclined surface is θi, and the light and light source of the outermost effective light from the light source When the angle θc formed in the air with the optical axis and the refractive index of the auxiliary rod integrator material are n1,
n1SIN (θi−SIN ⁻¹ (SIN (−θc)) / n1))> 1
The lighting device according to claim 2, wherein:   The illumination device according to claim 2, wherein an angle formed by the incident surface of the auxiliary rod integrator and the obliquely formed surface is 45 °. The lighting device according to any one of claims 1 to 6,
An image display element that modulates incident light according to a video signal when the illumination light is incident;
A projection display device, comprising: a projection lens that projects light modulated by the image display element onto a screen.