JP4893780B2 - LIGHTING DEVICE AND PROJECTOR HAVING THE SAME - Google Patents

Description

  The present invention relates to an illuminating device having a light source lamp such as a high-pressure mercury lamp and a projector provided with the same.

In general, a projector includes an illumination device that emits illumination light, an electro-optic modulation device that modulates illumination light from the illumination device in accordance with an image signal, and light modulated by the electro-optic modulation device as a projection image on a screen. And a projection optical system for projecting and displaying on the screen. Such a projector is required to have a bright projected image and a high light intensity of illumination light.
For this reason, in order to obtain higher light intensity, the above-described illumination device has been conventionally used that includes a light source formed by combining a concave mirror with a high-pressure mercury lamp as a light source lamp.

By the way, although the light source lamp (high pressure mercury lamp) used for the conventional illuminating device has a comparatively large light intensity, the light emission characteristic has an emission spectrum peculiar to mercury, and red light (R), green light ( G) and blue light (B) have a problem that it is impossible to obtain illumination light having a good color balance in the visible range because the light intensity in the wavelength range of red light tends to be insufficient. .
Therefore, in order to obtain illumination light with a good color balance, it is conceivable to diminish color components other than the color components in the wavelength range where the light intensity is insufficient. In this case, the brightness in the projected image (light from the light source) There was a problem that the utilization efficiency was reduced.

  Therefore, for example, Patent Literature 1 proposes an illumination device for solving this problem. FIG. 11 is a diagram showing an optical system of the illumination device described in Patent Document 1. As shown in FIG. As shown in FIG. 11, the illumination device 100 absorbs light having a wavelength of 200 to 430 nm and emits light having a wavelength of 570 to 630 nm on an incident side surface 120 i of a translucent rod 120 as an integrator optical system. It is the illuminating device which has arrange | positioned the wavelength conversion optical element 130 to perform. Since the wavelength conversion optical element 130 can increase the intensity of red light that is insufficient in the case of a high-pressure mercury lamp, the color balance of light can be corrected.

JP 2002-90883 A (FIGS. 1 to 6)

  However, in this illuminating device, since the red light emitted by the wavelength conversion optical element 130 becomes isotropic radiated light, the illumination light among the red light emitted incident on the incident side surface 120 i of the translucent rod 120. The light that can be used as is only the light that satisfies the total reflection condition at the interface 120 s of the translucent rod 120. For this reason, there is a problem that the intensity of the insufficient light cannot be sufficiently increased, and as a result, it is not easy to obtain illumination light with a sufficiently good color balance.

  Therefore, the present invention has been made to solve such a problem, and it is possible to sufficiently increase the intensity of insufficient light to obtain illumination light having a sufficiently good color balance and to improve the light utilization efficiency of the light source. It is an object of the present invention to provide an illumination device capable of preventing a decrease and a projector including the illumination device.

  An illuminating device according to the present invention made to achieve the above-described object includes a light source that emits light in a plurality of wavelength regions, and light having a non-uniform light intensity distribution emitted from the light source. And an integrator optical system that converts the light into an intensity distribution, and emits light in a predetermined wavelength region in the vicinity of a position where a plurality of condensed images (light source images) are discretely formed by the integrator optical system. An auxiliary light source is arranged.

For this reason, according to the illumination device of the present invention, light in the wavelength range that is insufficient in the light in the plurality of wavelength ranges emitted from the light source is emitted from the auxiliary light source. Illumination light having a good color balance in the area can be obtained.
In addition, according to the illumination device of the present invention, it is not necessary to diminish a specific color component in order to obtain illumination light with a good color balance, so that it is possible to prevent a decrease in light use efficiency of the light source.

  In the illuminating device of this invention, it is preferable that the said auxiliary light source has a light emitting element and a condensing element. With this configuration, the light emitted from the light emitting element is efficiently guided to the illumination area by the condensing element, and the illumination efficiency is increased.

  In the illumination device of the present invention, the auxiliary light source is a peripheral portion of the optical axis of the light source, and a condensed image (light source image) having a relatively small outer dimension among the condensed images (light source image). ) In the vicinity. With this configuration, the light from the light source is not shielded by the arrangement of the auxiliary light source, so that illumination light with a good color balance can be obtained without reducing the light utilization efficiency.

  Moreover, in the illuminating device of this invention, it is preferable that the said auxiliary light source is made into the some auxiliary light source arrange | positioned in the symmetrical position regarding the optical axis of the said light source. With this configuration, since the angular distribution of illumination light has no anisotropy, uneven brightness due to non-uniformity of the angular distribution of illumination light is prevented from occurring in the illumination target. In particular, when illuminating a display element whose display characteristics are incident angle dependent, display unevenness can be reduced. Further, when this illumination device is used in a three-plate projector provided with a relay optical system, it is possible to effectively prevent color unevenness.

  In the illumination device of the present invention, as the integrator optical system, a light guide that reflects the light incident from the light source at the interface or reflecting surface and emits the light toward the illumination target, and the light emitted from the light guide It is possible to adopt a configuration having a transmission lens that guides the light to the illumination target side. Such an integrator optical system has a simple configuration and is easy to implement. In this system, the formation position of the condensed image by the light source light can be controlled by forming the light guide with tapered rods having similar dimensions of the incident side end face and the exit side end face.

  Moreover, in the illuminating device of this invention, it is preferable that the said transfer lens is a lens array. By configuring in this way, the illumination efficiency can be increased compared to the case where the transfer lens is a single lens.

  Moreover, in the illuminating device of this invention, it is preferable that the said auxiliary light source is arrange | positioned at the at least one side of the entrance side and the exit side of the said transmission lens. With this configuration, when the integrator optical system includes a light guide and a transmission lens, the degree of freedom in arrangement of the auxiliary light source is increased. Here, when the auxiliary light source is disposed on the incident side of the transmission lens, the light emitted from the auxiliary light source can be condensed by the transmission lens. In this case, the auxiliary light source In addition, an optical element (light condensing element) for controlling the radiation angle can be eliminated, and the optical system can be simplified.

  In the illumination device of the present invention, the integrator optical system includes a first lens array that divides the light from the light source into intermediate light, and a second that condenses the intermediate light divided by the first lens array. A configuration having a lens array can be employed. In such an integrator optical system, by changing the light condensing property of each lens in the two lens arrays, the formation position of the condensed image can be freely controlled, so that an area for arranging the auxiliary light source is formed. This makes it easy to obtain illumination light with good color balance without reducing light utilization efficiency.

In the illumination device of the present invention, it is preferable that the auxiliary light source is disposed on at least one of the incident side and the emission side of the second lens array.
With such a configuration, when the integrator optical system includes the first lens array and the second lens array, the degree of freedom in arrangement of the auxiliary light source is increased. Here, when the auxiliary light source is arranged on the incident side of the second lens array, it is possible to configure the second lens array to collect the light emitted from the auxiliary light source. Since the auxiliary light source does not require an optical element (condensing element) for controlling the radiation angle, the optical system can be simplified.

In the illumination device of the present invention, it is preferable that the first lens array and the second lens array are formed by the same lens array, and the lenses of the lens array are arranged so as to correspond to each other. .
With this configuration, it becomes easy to arrange one condensed image and one auxiliary light source for each lens constituting the second lens array. Thereby, a uniform light intensity distribution can be obtained in the illumination target, and improvement in color balance and illumination efficiency can be realized at the same time.

  Moreover, in the illuminating device of this invention, it is preferable that the polarization conversion element is arrange | positioned at the emission side of the said auxiliary light source. With this configuration, when light having a plurality of polarization components is radiated from the auxiliary light source, the light emitted from the light source and the light emitted from the auxiliary light source are converted into P-polarized light and S-polarized light by the polarization conversion element. After being spatially separated, the polarization direction of one polarized light is aligned with the polarization direction of the other polarized light, and each light having substantially the same polarization direction is guided to the illumination target side. Accordingly, when the illumination target is a liquid crystal display device that requires polarized light for image display, it is possible to increase the light use efficiency in the liquid crystal display device and achieve a bright display state.

In the illumination device of the present invention, the polarization conversion element may be configured such that the condensed image (light source image) and the auxiliary light source are arranged corresponding to each polarization separation surface. preferable.
With this configuration, light from the light source and the auxiliary light source is reliably guided to the illumination target side with the polarization direction aligned, and the polarization conversion efficiency can be increased.

  Moreover, in the illuminating device of this invention, it is preferable that the said auxiliary light source is an auxiliary light source which radiates | emits red light. With this configuration, when the light source lamp of the light source is, for example, a high-pressure mercury lamp or a metal halide lamp, the insufficient red light can be supplemented by the auxiliary light source, and illumination light having a good color balance in the visible range can be obtained. .

  In the lighting device of the present invention, it is also preferable that the auxiliary light source is an auxiliary light source that emits blue light. By configuring in this way, when the light source lamp of the light source is, for example, a metal halide lamp or a halogen lamp different from the above, the insufficient blue light is supplemented by the auxiliary light source, and illumination light with a good color balance in the visible range is obtained. Obtainable.

  Moreover, in the illuminating device of this invention, it is preferable that the said auxiliary light source is a LED (light emitting diode) light source. With this configuration, a small auxiliary light source with high luminous efficiency can be used as the auxiliary light source, which facilitates device design. The auxiliary light source is preferably a small element capable of controlling the radiation angle, and in addition to the LED, an electroluminescent element such as a laser, EL or FED can be used.

  A projector according to another invention of the present invention is modulated by the above-described illumination device of the present invention, an electro-optic modulation device that modulates illumination light from the illumination device and displays an image, and the electro-optic modulation device. A projection optical system for projecting light.

  According to the projector of the present invention, the projector is provided with an excellent illumination device having a good color balance and a high light utilization efficiency.

  In the projector according to the aspect of the invention, the electro-optic modulation device may be an electro-optic modulation device that modulates polarized light or an electro-optic modulation device that modulates non-polarized light. Examples of the former include a liquid crystal display element using TN liquid crystal, and examples of the latter include a liquid crystal display element using polymer dispersed liquid crystal and a mirror array element including minute movable mirrors in a matrix. Any type of electro-optic modulator can constitute an excellent projector with good color balance and good light utilization efficiency.

It is a figure which shows the optical system of the projector which concerns on 1st embodiment. It is a figure for demonstrating the arrangement | positioning state of the condensing image formed in the vicinity of the 2nd lens array in 1st embodiment, and an auxiliary light source. It is a figure for demonstrating another arrangement state of the condensing image formed in the vicinity of the 2nd lens array in 1st embodiment, and an auxiliary light source. It is a figure which shows the optical system of the projector which concerns on 2nd embodiment. It is a figure for demonstrating the arrangement | positioning state of the condensing image formed in the vicinity of the 2nd lens array in 2nd embodiment, and an auxiliary light source. It is a figure which shows the optical system of the projector which concerns on 3rd embodiment. It is a figure which shows the optical system of the projector which concerns on 4th embodiment. It is a figure for demonstrating the arrangement | positioning state of the condensing image formed in the vicinity of the condensing lens array in 4th embodiment, and an auxiliary light source. It is a figure which shows the optical system of the projector which concerns on 5th embodiment. It is a figure for demonstrating the arrangement | positioning state of the condensing image formed in the vicinity of the condensing lens array and auxiliary light source in 5th embodiment. It is a figure which shows the optical system of the conventional projector.

DESCRIPTION OF EMBODIMENTS Hereinafter, an illumination device to which the present invention is applied and a projector including the illumination device will be described based on embodiments.
[First embodiment]
FIG. 1 is a diagram showing an optical system of a projector according to the first embodiment of the present invention. FIG. 2 is a diagram for explaining an arrangement state of a condensed image and an auxiliary light source formed in the vicinity of the second lens array in the first embodiment of the present invention. FIG. 3 is a diagram for explaining another arrangement state of the condensed image formed in the vicinity of the second lens array and the auxiliary light source in the first embodiment of the present invention. In the following embodiments, three directions orthogonal to each other are referred to as an X direction, a Y direction, and a Z direction for convenience. Further, a condensed image formed by a first lens array and a condensing lens array, which will be described later, is nothing but a light source image. In each of the following embodiments, the name of the condensed image is used.
In FIG. 1, the projector denoted by reference numeral 1 is roughly composed of an illumination device 2, an electro-optic modulation device 3, and a projection lens 4. The components 2 to 4 of the projector 1 are arranged in order from left to right along the illumination optical axis (optical axis) OC.

The illumination device 2 includes a main light source 5, an integrator optical system 6, an auxiliary light source 7, and a collimating optical system 8. Each component 5-8 of this illuminating device 2 is arrange | positioned along the optical axis OC.
The main light source 5 has a light source lamp 5A and a concave mirror 5B. For example, a high pressure mercury lamp is used as the light source lamp 5A. A parabolic mirror is used as the concave mirror 5B. As a result, the emitted light emitted from the light source lamp 5A is reflected in one direction by the concave mirror 5B, and enters the integrator optical system 6 as light substantially parallel to the optical axis OC.
As the concave mirror 5B, an ellipsoidal mirror or a spherical mirror may be used. In this case, it is preferable to arrange a lens or the like between the main light source 5 and the integrator optical system 6 so that the light emitted from the light source lamp 5A efficiently enters the integrator optical system 6.

The integrator optical system 6 includes a first lens array 6A and a second lens array 6B. The positional relationship between the integrator optical system 6 and the light source 5 is set so that the optical axis OC is positioned on the virtual center axis of the lens arrays 6A and 6B.
The first lens array 6A includes a plurality of light splitting lenses 6a having an outer shape (for example, a rectangular shape that is long in the X direction on the XY plane) that is substantially similar to the display area of the electro-optic modulation device 3 arranged in a matrix. Is formed. Then, the light from the main light source 5 is divided into intermediate light a, and the same number of condensing images as the light splitting lenses 6a are converged at a position where the intermediate light a in a plane perpendicular to the optical axis OC (XY plane in FIG. 1) converges. (Light source image) A is formed.

  The second lens array 6B is configured in substantially the same manner as the first lens array 6A. That is, the second lens array 6B is formed by arranging the same number of condensing lenses 6b as the light splitting lenses 6a in a matrix. Each condensing lens 6b of the second lens array 6B is arranged in one-to-one correspondence with each light dividing lens 6a, that is, in the vicinity of the position where the condensed image A is formed, and from each light dividing lens 6a. Are guided to the electro-optic modulator 3. As a result, the light flux distribution on each light splitting lens 6a is superimposed and coupled on the electro-optic modulation device 3, so that the electro-optic modulation device 3 is illuminated uniformly so as not to cause uneven brightness. Here, an example of the formation state of the condensed image A in the vicinity of the second lens array 6B is shown in FIG. The condensed image A is discretely formed for each corresponding condenser lens 6b.

  As shown in FIG. 1, the auxiliary light source 7 has a light emitting element 7A and a light condensing element 7B and is arranged on the incident side of the second lens array 6B. Further, on the XY plane, as shown in FIG. 2, they are arranged so as not to overlap the condensed image A in a space where the condensed image A does not exist in each condenser lens 6 b. Here, since the position where the condensed image A is formed can be controlled by the condensing characteristic of the light dividing lens 6a in the first lens array 6A, it corresponds by decentering the optical axis of each light dividing lens 6a. The condensing image A is localized in the condensing lens 6b, and the space which can arrange | position the auxiliary light source 7 is ensured.

  As shown in FIG. 2, the size of the condensed image A formed by the main light source 5 is generally large in the vicinity of the optical axis OC and decreases as the distance from the optical axis OC increases. The way of the change depends on the optical characteristics of the concave mirror 5B. Therefore, in the present embodiment, the auxiliary light source 7 is not disposed on the condensing lens 6b in the vicinity of the optical axis OC where the large condensed image A is formed, but from the optical axis OC where the relatively small condensed image A is formed. Although the auxiliary light source 7 is arranged on the remote condenser lens 6b, it is not limited to this. Since the size of the condensed image A depends on the optical characteristics of the main light source 5 and the first lens array 6A, the auxiliary light source 7 may be arranged on all the condensing lenses 6b. In short, the location of the auxiliary light source 7 may be determined in consideration of the relationship between the size of the focused image A and the relative size of the focusing lens 6b. In the present embodiment, all the condensing lenses 6b have the same size and shape. For example, the condensing lens 6b near the optical axis OC where the condensing image A is large is made larger than the condensing lens 6b in the peripheral portion. For example, the auxiliary light source 7 can be disposed in this region.

  The light emitted from the light emitting element 7A is condensed by the light collecting element 7B to become light having a predetermined radiation angle, and then the emission direction is bent toward the center of the electro-optic modulation device 3 by the second lens array 6B. The entire display area of the electro-optic modulation device 3 is illuminated in the same manner as the light from the condensed image A. That is, the light beams emitted from the plurality of auxiliary light sources 7 are superimposed and coupled on the electro-optic modulation device 3 in the same manner as the light beams from the main light source 5. Therefore, the electro-optic modulation device 3 that is the illumination target is illuminated uniformly by the light from the main light source 5 and the light from the plurality of auxiliary light sources 7 so that the brightness is not uneven. The auxiliary light source 7 is composed of a plurality (12) of auxiliary light sources located at positions symmetrical with respect to the optical axis OC of the main light source 5. As a result, the angular distribution of the illumination light has no anisotropy. Therefore, even when the display characteristics of the illumination target (electro-optic modulation device 3) have an incident angle dependency, the illumination light angular distribution is not uniform. It is possible to prevent display unevenness and brightness unevenness.

In the present embodiment, the case where the auxiliary light source 7 is arranged on the incident side of the second lens array 6B has been described. However, the present invention is not limited to this, and the incident light is incident on the emission side of the second lens array 6B. It can also be arranged on both sides of the side and the injection side. For this reason, the freedom degree in arrange | positioning the auxiliary light source 7 is raised.
In the present embodiment, the case where the auxiliary light source 7 faces a part of the condenser lens 6b of the second lens array 6B (the light from the auxiliary light source 7 enters the condenser lens 6b) has been described. As shown in FIG. 3 (only a quarter quadrant is shown), the condenser lens 6b1 is made small so that the auxiliary light source 7 does not face the condenser lens 6b1 (the light from the auxiliary light source 7 does not enter the condenser lens 6b). It is good also as a simple structure.

  As described above, the condensing element 7B has a function of converting light from the light emitting element 7A into light having a predetermined radiation angle. Therefore, when the light radiated from the light emitting element 7A has the predetermined radiation angle in advance, the condensing element 7B can be omitted. However, since the second lens array 6B has a function of bending the traveling direction of the light from the condensing element 7B in the center direction of the electro-optic modulation device 3 that is an illumination target, the condensing lens 6b is provided on the exit side of the auxiliary light source 7. When the configuration does not exist, for example, in the case of FIG. 3 or when the auxiliary light source 7 is disposed on the exit side of the second lens array 6B, it is necessary to add the function of the second lens array 6B to the condensing element 7B. Therefore, it is desirable to provide the condensing element 7B. However, if the light emitted from the light emitting element 7A has radiation characteristics that also considers the function of the second lens array 6B, the condensing element 7B can be omitted regardless of the presence or absence of the second lens array 6B. .

  Furthermore, in the present invention, the positional relationship between the arrangement region of the auxiliary light source 7 corresponding to one condenser lens 6b and the formation region of the condensed image A is not particularly limited, and as shown in FIG. It is good also as a positional relationship that the right and left are reverse to this embodiment (refer FIG. 2).

  For the light emitting element 7A, an LED light source (light emitting diode) that emits red light as light in a predetermined wavelength range is used. Thereby, it is comprised so that the red light insufficient in the light inject | emitted from the main light source 5 may be supplemented. Further, since the LED light source is a small light emitting element with high luminous efficiency, it can be arranged in a small space without blocking the condensed image A, and the design as a lighting device is facilitated. The condensing element 7B is composed of an optical element for controlling the radiation angle, and is configured to superimpose and combine light emitted from the light emitting element 7A. Thereby, the illumination efficiency by the auxiliary light source 7 is improved.

The collimating optical system 8 has a collimating lens (field lens) 8A, and is disposed between the second lens array 6B and the electro-optic modulation device 3, and each light beam from the second lens array 6B is reflected by the light beam. It is converted to be parallel to the central axis. As a result, the angular distribution range of the illumination light beam to the electro-optic modulation device 3 that is the object of illumination is narrowed, so that high image quality can be achieved even when the display characteristics have incident angle dependency.
The configuration of the collimating optical system 8 is not limited to this. For example, an incident side lens is disposed on the incident side (integrator optical system side) of the collimating lens 8A, and the exit side (electro-optic modulator side) is ejected. It may be composed of a plurality of lenses, such as one having a side lens.

The electro-optic modulation device 3 is an electro-optic modulation device such as a transmissive liquid crystal display device, and is disposed on the screen SC side of the collimating optical system 8. Then, the light emitted from the illumination device 2 is made incident, further modulated according to an image signal (image information) (not shown), and the modulated light is emitted to the screen SC side as transmitted light b. Yes.
The projection lens 4 is disposed between the electro-optic modulation device 3 and the screen SC. Then, the modulated light (transmitted light b) emitted from the electro-optic modulation device 3 is projected and displayed on the screen SC as a projection image.

With the above configuration, the light emitted from the illumination device 2 (the main light source 5 and the auxiliary light source 7) is incident on the electro-optic modulation device 3 and modulated, and this modulated light is projected and displayed on the screen SC by the projection lens 4. The At this time, red light that is insufficient in the light of the plurality of wavelength ranges emitted from the main light source 5 (light source lamp 5 </ b> A) of the illumination device 2 is emitted from the auxiliary light source 7 of the illumination device 2.
Therefore, in the present embodiment, it is possible to obtain illumination light with good color balance in the visible range by correcting the light emission characteristics of the light source lamp (high pressure mercury lamp) 5A, and to obtain illumination light with good color balance. In addition, since it is not necessary to diminish a specific color component, it is possible to prevent a decrease in light utilization efficiency of the light source lamp 5A. As a result, a bright projected image with a wide color gamut can be realized. Furthermore, since an LED light source with high luminous efficiency and low heat generation is used as the auxiliary light source 7, even when a bright projection image is displayed, it is not necessary to increase the size of the cooling device or the like as compared with the conventional case, and it is small and low noise. A projector can be realized.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a diagram showing an optical system of the projector according to the second embodiment of the invention. (A) is sectional drawing seen from the upper surface, (b) is sectional drawing seen from the side surface. FIG. 5 is a diagram for explaining the arrangement state of the condensed image and the auxiliary light source formed in the vicinity of the second lens array in the second embodiment of the present invention. In each embodiment described below including this embodiment, the same or equivalent members as those already described are denoted by the same reference numerals, and detailed description thereof is omitted.
The projector (illumination device) in this embodiment includes an integrator optical system having two lens arrays, and a polarization conversion element (polarization conversion optical system) is provided on the emission side of an auxiliary light source that emits light (red light) in a predetermined wavelength range. ) Is characteristic.
The illumination device 41 includes a main light source 5, an integrator optical system 6, an auxiliary light source 7, a collimating optical system 8, and a polarization conversion optical system 42. Note that the polarization conversion optical system employed in this embodiment is a known technique, and is described in detail, for example, in Japanese Patent Application Laid-Open No. 8-304739 by the present inventor.

  The polarization conversion optical system 42 includes a polarization separation unit array 43, a λ / 2 phase difference plate 44, and an exit side lens (superimposition lens) 45, and is disposed on the exit side of the auxiliary light source 7 via the second lens array 6B. Has been. Then, after spatially separating the intermediate light a from the main light source 5 and the red light from the auxiliary light source 7 transmitted through the second lens array 6B into P-polarized light and S-polarized light, the polarization direction of one polarized light Are aligned with the polarization direction of the other polarized light, and the respective lights having substantially the same polarization direction are guided to the illumination target (electro-optic modulation device 3) side. Thereby, the light use efficiency in the electro-optic modulation device 3A (for example, a TN liquid crystal display device) that requires specific polarized light is increased, and a bright display state is achieved.

In this embodiment, since the polarization conversion optical system 42 is used, the arrangement of the auxiliary light source 7 is different from that in the first embodiment. That is, the auxiliary light source 7 is on the incident side of the second lens array 6B, and as shown in FIG. 5, the position where the plurality of condensed images A are discretely formed by the first lens array 6A in the Y direction. It is arranged directly above or directly below. The reason for adopting such an arrangement is that an area (space) SP for polarization conversion is provided in the vicinity (side) of the position where the plurality of condensed images A are discretely formed by the first lens array 6A. It is because it is necessary to form.
The auxiliary light source 7 is arranged on the incident side of the second lens array 6B. However, when the auxiliary light source 7 is a light source that emits light having a single polarization component (for example, a laser), a λ / 2 phase difference is provided. It can be arranged between the plate 44 and the exit side lens 45. In addition, when the condensing element 7B of the auxiliary light source 7 has a function equivalent to that of the emission side lens 45, the auxiliary light source 7 can be disposed on the emission side of the emission side lens 45.

  The polarization separation unit array 43 is formed by arranging a plurality of polarization separation units 43A in a matrix. The polarization separation unit 43A is formed of a square columnar structure having a polarization separation surface 43a1 and a reflection surface 43a2 therein, and the intermediate light a from the main light source 5 and the light from the auxiliary light source 7 are converted into P-polarized light and S-polarized light. It is configured to be spatially separated. Therefore, the polarization separation surface 43a1 and the reflection surface 43a2 are arranged in parallel in the horizontal direction (X direction). Further, the polarization separation surface 43a1 and the reflection surface 43a2 are arranged in a state of being inclined by about 45 ° with respect to the optical axis OC and parallel to each other. The polarization separation unit 43A is arranged so that one of the condensed image A and the auxiliary light source 7 corresponds to the polarization separation surface 43a1. Thereby, the intermediate light a from the main light source 5 and the light from the auxiliary light source 7 incident on the polarization separation unit 43A and the P-polarized light that passes through the polarization separation surface 43a1 without changing the traveling direction on the polarization separation surface 43a1, and The light is reflected by the polarization separation surface 43a1 and separated into S-polarized light that changes the traveling direction to the reflection surface 43a2. Then, the P-polarized light is emitted as it is from the polarization separation unit 43A to the electro-optic modulation device 3A side, and the S-polarized light again changes its traveling direction on the reflecting surface 43a2, and is substantially parallel to the P-polarized light from the polarization separation unit 43A. It is injected.

  In addition, since it is necessary to guide the intermediate light a from the main light source 5 and the light from the auxiliary light source 7 to the region where the polarization separation surface 43a1 of the polarization separation unit 43A exists, these lights enter the central portion of the polarization separation surface 43a1. As described above, the positional relationship between the polarization separation unit 43A and the condenser lens 6b and the lens characteristics of the condenser lens 6b are set.

  The λ / 2 phase difference plate 44 is composed of a plurality of phase difference plates, and is disposed at a portion facing the P exit surface of the polarization separation unit 43A. As a result, when the P-polarized light emitted from the P exit surface of the polarization separation unit 43A (the surface from which the P-polarized light transmitted through the polarization separation surface 43a1 exits) passes through the λ / 2 phase difference plate 44, the polarization direction is changed. It is converted into S-polarized light by receiving a rotating action. On the other hand, since the S-polarized light emitted from the S exit surface of the polarization separation unit 43A (the surface from which the S-polarized light reflected from the polarization separation surface 43a1 exits) does not pass through the λ / 2 phase difference plate 44, the polarization direction is It proceeds without change to the screen SC as it is. As a result, indefinitely polarized light from the main light source 5 and the auxiliary light source 7 is converted into polarized light having substantially the same polarization direction.

The exit side lens (superimposition lens) 45 is formed of a single lens body and is disposed on the exit side of the λ / 2 phase difference plate 44. The exit side lens 45 has a function of bending the traveling direction of each light beam emitted from different positions of the λ / 2 phase difference plate 44 toward the center direction of the electro-optic modulation device 3A that is an illumination target. As a result, the light beam aligned with the S-polarized light in the λ / 2 phase difference plate 44 is superimposed and coupled on the electro-optic modulation device 3. Therefore, the electro-optic modulation device 3A to be illuminated is a single type of polarized light whose light direction is substantially uniform and uniform in order to prevent unevenness of brightness by the light from the main light source 5 and the light from the plurality of auxiliary light sources 7. Illuminated with light. The auxiliary light source 7 is composed of a plurality of (eight in FIG. 5) auxiliary light sources located at positions symmetrical with respect to the optical axis OC of the main light source 5. As a result, the angular distribution of the illumination light has no anisotropy. Therefore, even when the display characteristic of the illumination target (electro-optic modulation device 3A) has an incident angle dependency, the illumination light angular distribution is not uniform. It is possible to prevent display unevenness and brightness unevenness.
Furthermore, the exit side lens 45 does not have to be a single lens body, and may be a lens assembly.

  With the above configuration, the light emitted from the illuminating device 41 (the main light source 5 and the auxiliary light source 7) enters the electro-optic modulation device 3A through the collimating lens 8A and is modulated, and this modulated light is screened by the projection lens 4. Projected and displayed on the SC. At this time, the auxiliary light source 7 emits red light that is insufficient in light of a plurality of wavelength ranges emitted from the main light source 5 (light source lamp 5A).

Therefore, also in this embodiment, the same effect as the first embodiment can be obtained.
In addition, the present embodiment includes a polarization conversion optical system 42 that converts indefinitely polarized light emitted from the main light source 5 and the auxiliary light source 7 into specific polarized light having a uniform polarization direction. In a projector using a required electro-optic modulation device (for example, a TN liquid crystal display device), a brighter projected image can be realized. In the present embodiment and the following embodiments (including the polarization conversion optical system), S-polarized light is obtained as one kind of polarized light from any polarized light, but P-polarized light is obtained. Of course.

[Third embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing an optical system of the projector according to the third embodiment of the invention. (A) is sectional drawing seen from the upper surface, (b) is sectional drawing seen from the side surface.
The projector (illumination device) in the present embodiment is characterized in that the second lens array is disposed on the exit side of the polarization conversion element (polarization conversion optical system).

  The illumination device 61 includes a main light source 5, an integrator optical system 62, an auxiliary light source 7, a collimating optical system 8, and a polarization conversion optical system 42. The integrator optical system 62 includes a first lens array 6A and a second lens array 62B.

  The second lens array 62B is formed by arranging twice as many condensing lenses (superimposing lenses) 62b as the light splitting lenses 6a in a matrix, and each condensing lens 62b is a P exit surface of each polarization separation unit 43A. And S are arranged at positions corresponding to the emission surface. The second lens array 62B bends the traveling direction of the light from the polarization conversion optical system 42 toward the center of the electro-optic modulation device 3 that is the illumination target, and the light from each light splitting lens 6a is placed on the electro-optic modulation device 3. It has a function of overlapping and coupling.

  In addition, since it is necessary to form the area | region (space) SP for performing polarization conversion in the vicinity (side) of the position where the plurality of condensed images A are discretely formed by the first lens array 6A, The auxiliary light source 7 shown in the present embodiment is also arranged in the same manner as the auxiliary light source 7 shown in the second embodiment (see FIG. 5). In other words, the auxiliary light source 7 is disposed on the incident side of the second lens array 62B, directly above or below the position in the Y direction where the plurality of condensed images A are discretely formed by the first lens array 6A. Has been. Accordingly, the intermediate light a having substantially the same polarization direction after polarization conversion and the light from the auxiliary light source 7 are incident on one condenser lens 62b (the intermediate light is incident on the condenser lens 62b at a position where the auxiliary light source 7 does not exist). only a is incident). These lights are superimposed and coupled on the electro-optic modulation device 3A.

  With the above configuration, the light emitted from the illuminating device 61 (the main light source 5 and the auxiliary light source 7) enters the electro-optic modulation device 3A through the collimating lens 8A and is modulated, and this modulated light is screened by the projection lens 4. Projected and displayed on the SC. At this time, the auxiliary light source 7 emits red light that is insufficient in light of a plurality of wavelength ranges emitted from the main light source 5 (light source lamp 5A).

Therefore, also in this embodiment, the same effect as the first and second embodiments can be obtained.
In addition, since the second lens array is disposed on the exit side of the polarization conversion element (polarization conversion optical system), the second lens array also has the function of the exit side lens (superimposing lens) 45 of the second embodiment. Thus, the exit side lens can be omitted, and the optical system can be simplified. In addition, since the condenser lens is made to correspond to each light beam after polarization conversion, each light beam can be superimposed and combined with high accuracy on the electro-optic modulation device 3A that is the illumination target, the illumination efficiency is improved, and brighter projection is achieved. An image can be realized. If the auxiliary light source 7 is a light source that emits specific polarized light (for example, linearly polarized light), the auxiliary light source 7 is disposed between the λ / 2 phase difference plate 44 and the second lens array 62B. Can do. In addition, when the condensing element 7B of the auxiliary light source 7 has a function equivalent to that of the second lens array 62B, the auxiliary light source 7 can be disposed on the emission side of the second lens array 62B.

[Fourth embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a diagram showing an optical system of a projector according to the fourth embodiment of the invention. FIG. 8 is a diagram for explaining an arrangement state of a condensed image and an auxiliary light source formed in the vicinity of the transmission lens 73B in the fourth embodiment of the present invention.
In the projector (illuminating device) according to the present embodiment, the integrator optical system reflects light incident from the light source at the interface or reflecting surface and emits the light to the illumination target side, and the light guiding rod. It has a feature in that it has a transmission lens that guides the emitted light from the illumination target side.
The illumination device 71 includes a main light source 72, an integrator optical system 73, an auxiliary light source 7, and a collimating optical system 8.

The main light source 72 has a light source lamp 72A and a concave mirror 72B. For example, a high-pressure mercury lamp is used as the light source lamp 72A. An elliptical mirror is used as the concave mirror 72B. Thereby, the radiated light beam emitted from the light source lamp 72A is condensed by the concave mirror 72B, and efficiently enters the incident end face of the light guide rod (described later) of the integrator optical system 73.
As the concave mirror 72B, a parabolic mirror or a spherical mirror may be used. In this case, it is preferable to arrange a lens or the like between the main light source 72 and the integrator optical system 73 so that the light emitted from the light source lamp 72 </ b> A efficiently enters the light guide rod of the integrator optical system 73.

The integrator optical system 73 includes a light guide rod 73 </ b> A and a transmission lens 73 </ b> B, and is disposed between the main light source 72 and the collimating optical system 8.
The light guide rod 73A is a light guide having a plurality of interfaces 73a1 for reflecting light from the main light source 72, and has an emission end face having a shape substantially similar to the display region of the electro-optic modulation device to be illuminated. ing. The light guide rod 73A is formed, for example, by forming a transparent prismatic glass body or a reflection mirror into a tubular shape. The light having a non-uniform intensity distribution incident from the main light source 72 is converted into light having a uniform intensity distribution by repeating reflection at the interface 73a1, and is emitted from the emission end face.

In addition, a condensing lens 73a is disposed on the exit end surface portion of the light guide rod 73A, and light beams emitted from the light guide rod 73A by being angularly separated in different directions are emitted by the condensing lens 73a into a plurality of condensed images. A is formed in a matrix in a plane perpendicular to the optical axis OC (XY plane in FIG. 7). As shown in FIG. 8, a plurality of condensed images A are formed discretely. In addition, as described in the first embodiment, the size of the condensed image A to be formed is generally large in the vicinity of the optical axis OC and is small as the distance from the optical axis OC is increased.
Then, by forming the light guide rod 73A as a so-called tapered rod in which the dimensions of the incident end face and the exit end face are different from each other, the formation position of the condensed image A by the light source light can be controlled by the tapered shape.

The transmission lens 73 </ b> B is a single lens and is disposed on the emission side of the auxiliary light source 7. The light from the light guide rod 73 </ b> A (main light source 72) and the auxiliary light source 7 is bent toward the center of the electro-optic modulation device 3 to be illuminated, and the light is superimposed and coupled on the electro-optic modulation device 3. Have.
The transmission lens 73B has been described as being a single lens, but may be a lens array. In this case, the illumination efficiency can be increased compared to the case where the transfer lens 73B is a single lens.

  As shown in FIG. 8, the auxiliary light source 7 is arranged on the incident side of the transfer lens 73 </ b> B so as not to overlap the condensed image A in a space where the condensed image A does not exist. The light emitted from the auxiliary light source 7 is bent by the transmission lens 73B in the direction of emission toward the center of the electro-optic modulation device 3, and the entire display area of the electro-optic modulation device 3 is made the same as the light from the condensed image A. Illuminate. That is, the light beams emitted from the plurality of auxiliary light sources 7 are superimposed and coupled on the electro-optic modulation device 3 in the same manner as the light beams from the main light source 5. Therefore, the electro-optic modulation device 3 that is the illumination target is illuminated uniformly by the light from the main light source 5 and the light from the plurality of auxiliary light sources 7 so that the brightness is not uneven.

  The auxiliary light source 7 is composed of a plurality of (for example, 14) auxiliary light sources located at positions symmetrical with respect to the optical axis OC of the main light source 5. As a result, the angular distribution of the illumination light has no anisotropy. Therefore, even when the display characteristics of the illumination target (electro-optic modulation device 3) have an incident angle dependency, the illumination light angular distribution is not uniform. It is possible to prevent display unevenness and brightness unevenness. The transfer lens 73B is not a single lens but can be a combination lens composed of a plurality of lenses, a lens array in which a plurality of lenses having different characteristics in the XY plane are combined, or the like.

With the above configuration, the light emitted from the illuminating device 71 (the main light source 72 and the auxiliary light source 7) enters the electro-optic modulation device 3 through the collimating lens 8A and is modulated, and the modulated light is screened by the projection lens 4. Projected and displayed on the SC. At this time, the illumination device 71 emits red light that is insufficient in the light of a plurality of wavelength ranges emitted from the main light source 72 (light source lamp 72A).
Therefore, also in this embodiment, the same effect as the first embodiment can be obtained.

  In the present embodiment, the case where the auxiliary light source 7 is disposed on the incident side of the transmission lens 73B has been described. However, the present invention is not limited to this, and the incident side and the emission side of the transmission lens 73B are provided. It can also be arranged on both sides. For this reason, the freedom degree in arrange | positioning the auxiliary light source 7 can be raised.

[Fifth embodiment]
Next, a fifth embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a diagram showing an optical system in the projector according to the fifth embodiment of the invention. (A) is sectional drawing seen from the upper surface, (b) is sectional drawing seen from the side surface. FIG. 10 is a view for explaining the arrangement state of the condensed image and the auxiliary light source formed in the vicinity of the condenser lens array in the fifth embodiment of the present invention.
The projector (illumination device) in this embodiment includes an integrator optical system having a light guide rod and a transmission lens, and a polarization conversion element (polarization conversion) is provided on the emission side of an auxiliary light source that emits light (red light) in a predetermined wavelength range. There is a feature in that an optical system) is arranged.

  The illumination device 81 includes a main light source 72, an integrator optical system 73, an auxiliary light source 7, a collimating optical system 8, and a polarization conversion optical system 82. The configuration and function of the polarization conversion optical system 82 in this embodiment are basically the same as those of the polarization conversion optical system 42 in the second embodiment. A significant difference is the arrangement state of the polarization separation film 43a1 and the reflection surface 43a2. Specifically, in the second embodiment, the polarization separation surface 43a1 and the reflection surface 43a1 are arranged symmetrically on the left and right of the X axis with the optical axis OC as the symmetry axis. However, in this embodiment, all the polarization separation surfaces 43a1 are arranged. And the reflecting surface 43a1 are arranged in the same direction. However, since this difference is only a variation of the polarization conversion optical system and is not the essence of the present invention, a detailed description of the polarization conversion optical system 82 is omitted.

  The auxiliary light source 7 is on the incident side of the condensing lens array 83, and as shown in FIG. 10, directly above the position in the Y direction where the plurality of condensing images A are discretely formed by the light guide rod 73A or It is arranged directly below. As a result, the electro-optic modulation device 3A to be illuminated is a single type of light that is uniform and substantially uniform in polarization so that unevenness in brightness is not caused by light from the main light source 5 and light from the plurality of auxiliary light sources 7. Illuminated with polarized light. Here, the auxiliary light source 7 is composed of a plurality (six in FIG. 10) of auxiliary light sources located at positions symmetrical with respect to the optical axis OC of the main light source 5. The auxiliary light source 7 is arranged on the incident side of the condenser lens array 83. However, when the auxiliary light source 7 is a light source (for example, a laser) that emits light having a single polarization component, a λ / 2 phase difference plate is used. 44 and the exit side lens 73B. In addition, when the condensing element 7B of the auxiliary light source 7 has a function equivalent to that of the emission side lens 73B, the auxiliary light source 7 can be arranged on the emission side of the emission side lens 73B.

  With the above configuration, the light emitted from the illumination device 81 is incident on the electro-optic modulation device 3A and modulated, and this modulated light is projected and displayed on the screen SC by the projection lens 4. At this time, the auxiliary light source 7 emits red light that is insufficient in light of a plurality of wavelength ranges emitted from the main light source 72 (light source lamp 72A).

Therefore, also in this embodiment, the same effect as the fourth embodiment can be obtained.
In addition, the present embodiment includes a polarization conversion optical system 42 that converts indefinitely polarized light emitted from the main light source 5 and the auxiliary light source 7 into specific polarized light having a uniform polarization direction. In a projector using a required electro-optic modulation device (for example, a liquid crystal display device), a brighter projected image can be realized.

As described in the above embodiments, any optical system having a process of discretely forming a plurality of condensed images in the process of reaching the illumination target is related to the form of the integrator optical system and the polarization conversion optical system. It is possible to employ the configuration of the present invention.
In each embodiment, the case where the light source lamps 5A and 72A of the main light sources 5 and 72 are high-pressure mercury lamps has been described. However, the present invention is not limited to this, and other light sources such as metal halide lamps and halogen lamps. A lamp may be used. When a metal halide lamp is used, a light emitting element that emits blue light or red light is used as a light emitting element of an auxiliary light source, and when a halogen lamp is used, a light emitting element that emits blue light is used as a main light source. Specific color light that is insufficient in the luminous flux emitted from the light source can be supplemented, and illumination light with good color balance can be obtained.

  Furthermore, it is desirable to set the shape of the light emitting portion of the light emitting element used as the auxiliary light source in a substantially symmetrical relationship with the display area of the electro-optic modulation device that is the illumination target. Alternatively, when the shape of the light emitting unit is not substantially symmetrical with the display area of the electro-optic modulator, the optical characteristic of the condensing element is controlled to set the substantially symmetrical relation with the display area of the electro-optic modulator. It is desirable. This is because the light emitting part of the light emitting element and the object to be illuminated are in a conjugate relationship by the second lens array or the condensing lens array, so that the illumination efficiency can be improved by introducing the substantially symmetrical relationship described above.

Moreover, in each embodiment, although the case where it applied to the single plate type projector provided with the single electro-optic modulation apparatus 3 was demonstrated, this invention is not limited to this, The three electro-optic modulation apparatus was provided. It can also be applied to a three-plate projector.
In addition, in each of the embodiments, the case where the invention is applied to a projector including the transmissive electro-optic modulation device 3 has been described. However, the present invention is not limited to this, and is of a reflective type (a type that reflects modulated light). The present invention can also be applied to a projector provided with an electro-optic modulation device (for example, a micromirror display element in which a large number of micromirrors are arranged in a matrix, or an LCOS element using liquid crystal).

  DESCRIPTION OF SYMBOLS 1 ... Projector, 2 ... Illuminating device, 3, 3A ... Electro-optic modulation device, 4 ... Projection lens, 5 ... Main light source, 5A ... Light source lamp, 5B ... Concave mirror, 6 ... Integrator optical system, 6A ... 1st lens array, 6a ... light splitting lens, 6B ... second lens array, 6b ... condensing lens, 7 ... auxiliary light source, 7A ... light emitting element, 7B ... condensing element, 8 ... collimating optical system, 8A ... collimating lens, A, A1 to A3 ... Condensed image (light source image), a ... intermediate light, b ... transmitted light, OC ... optical axis, SC ... screen.

Claims (15)

A light source that emits light in a plurality of wavelength ranges;
An integrator optical system that converts light having a non-uniform light intensity distribution emitted from the light source into light having a substantially uniform light intensity distribution;
A plurality of condensed images are formed discretely by this integrator optical system, and the condensed image and the overlapping image are overlapped in a space between the condensed images adjacent to each other and the condensed image. An auxiliary light source that emits light in a predetermined wavelength region is disposed so as not to become light and adjacent to the condensed image .   2. The lighting device according to claim 1, wherein the auxiliary light source includes a light emitting element and a light collecting element. A lighting device according to claim 1 or 2, wherein the auxiliary light source is a peripheral part of the optical axis in the light source, placed near the outer dimensions are relatively small focusing image of the focused beam image The lighting device characterized by being made.   The illuminating device according to claim 1, wherein the auxiliary light source is a plurality of auxiliary light sources arranged at symmetrical positions with respect to an optical axis of the light source.   5. The illumination device according to claim 1, wherein the integrator optical system reflects light incident from the light source at an interface or a reflection surface and emits the light to an illumination target side, and the light guide. An illumination apparatus comprising: a transmission lens that guides light emitted from a light body to an illumination target side.   6. The illumination device according to claim 5, wherein the transfer lens is a lens array.   7. The lighting device according to claim 5, wherein the auxiliary light source is disposed on at least one of an incident side and an emission side of the transmission lens.   5. The illumination device according to claim 1, wherein the integrator optical system divides light from the light source into intermediate light, and intermediate light divided by the first lens array. And a second lens array for condensing light.   9. The illumination device according to claim 8, wherein the auxiliary light source is disposed on at least one of the incident side and the emission side of the second lens array. The illuminating device according to any one of claims 1 to 9 , wherein a polarization conversion element is arranged on an emission side of the auxiliary light source. A lighting device according to claim 10, wherein the polarization conversion element, a feature that each of the condensing Zo及 beauty said auxiliary light source is configured to be arranged corresponding to the respective polarization separating surface Lighting device. A lighting device according to any of claims 1 to 11, the lighting apparatus wherein the auxiliary light source, characterized in that an auxiliary light source that emits red light. A lighting device according to any of claims 1 to 11, the lighting apparatus wherein the auxiliary light source, characterized in that an auxiliary light source that emits blue light. A lighting device according to any one of claims 1 to 13 lighting apparatus, characterized in that said auxiliary light source is a light emission diode light source. The illumination device according to any one of claims 1 to 14 , an electro-optic modulation device that modulates illumination light from the illumination device to display an image, and projects light modulated by the electro-optic modulation device And a projection optical system.

Images