JP3298576B2 - Illumination device and projection display device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device having a rod-type integrator having a rod that internally reflects light incident from an incident surface and superimposes and outputs the light on an exit surface.
And a projection display device provided with the lighting device.

[0002]

2. Description of the Related Art In an illumination optical system of a projection display device such as a liquid crystal projector, a fly-eye integrator system and a rod integrator system are known as means for increasing the illuminance ratio of an emitted light beam. The fly-eye integrator method is a method in which a plurality of secondary light source images are created using a lens array, and each secondary light source image is superimposed on an image forming area of an electro-optical device that forms an image. The illuminance ratio can be increased by increasing the number of divisions to increase the number of secondary light source images. On the other hand, the rod integrator method is a method in which light incident from one end face of a rod such as a glass rod is internally reflected inside the rod and is superimposed on an emission surface. Also in this method, the illuminance ratio can be increased by increasing the number of secondary light source images. Here, the number of secondary light source images superimposed on the exit surface increases or decreases depending on the number of internal reflections in the rod, the F value of the light source, and the like.
Reducing the rod cross-sectional area, increasing the length of the rod,
By setting the F value of the light source small, the number of secondary light source images can be increased. The F-number of the light source means a converging angle of light emitted from a light source constituted by a lamp, a reflector, a lens, etc. Can be expressed by the value divided by the maximum diameter of

Comparing such a fly-eye integrator system and a rod integrator system, the rod integrator system can reduce the area in which the secondary light source image is distributed, so that the parallelism of the illuminating light is easily increased, and therefore the liquid crystal panel There is an advantage that it is easy to cope with miniaturization of the electro-optical device.

As a rod used in the rod integrator of the above-described rod integrator type, a solid rod such as a glass rod and a hollow rod having an inner surface mirror-finished are employed. According to a solid rod such as a glass rod, the reflectivity of the internal reflection inside the rod is almost 100%.
%, The light can be used more efficiently than the hollow type.

[0005]

However, in the case of the solid rod described above, if the side surface of the rod becomes dirty or scratched, the condition of total reflection in the rod is disturbed, and light leaks at that portion. There is a problem that utilization efficiency is reduced. Further, an optical component such as a condensing lens is interposed between the exit surface of the rod and an electro-optical device such as a liquid crystal panel. Since the exit surface of the rod and the liquid crystal panel are in a conjugate relationship with the optical component, If dust or the like adheres to the exit surface of the rod,
There is a problem that an image to which dust or the like has adhered is formed at the position of the liquid crystal panel and further formed on the screen.

Further, in the case of a hollow rod, if the light incident surface and the light emitting surface are open, dust and the like may enter the inside, and the light utilization efficiency is reduced as described above. is there.

An object of the present invention is to provide a lighting device and a projection display device which do not lower the light use efficiency in a rod type integrator.

[0008]

In order to achieve the above object, a lighting device according to the present invention comprises a rod having a solid rod which internally reflects light incident from an incident surface and superimposes and outputs the light on an exit surface. A lighting device having a mold integrator, comprising: a cover member that covers a side surface portion of the solid rod; and a transparent member disposed on an incident surface side and an emission surface side of the solid rod. One is fixed to the incident surface of the solid rod, the other is fixed to the output surface of the solid rod, the cover member is fixed to each of the transparent members, the inner surface of the cover member and the It is characterized in that it is arranged with a gap provided between the solid rod and the side surface.

Here, the cover member can be formed of a cylindrical body, and the solid rod is preferably held in such a state that the side portions are kept in contact with the cylindrical body as much as possible.

According to the present invention, since the side surface of the solid rod is covered with the cover member, handling the solid rod together with the cover member improves the handleability of the rod at the time of assembling. At this time, it is possible to prevent the scratches and dirt from adhering to the side surface of the rod. Further, intrusion of dust and the like into the rod side surface can be reduced. Therefore, total reflection in the internal reflection of the solid rod can be maintained, and a decrease in light use efficiency can be prevented.

[0011]

Further, since the transparent member is provided, it is possible to prevent dust and the like from adhering to the light incident surface and the light exit surface of the solid rod. In particular, since the transparent member is provided on the emission surface side, it is possible to prevent dust images from being formed on the liquid crystal panel in a conjugate relationship. Further, intrusion of dust and the like into the side surface of the rod can be more reliably prevented, and the light use efficiency can be further improved.

Further, as the above-mentioned transparent member, a simple transparent plate may be adopted, but by giving various optical functions to the transparent member, the structure of the lighting device can be simplified. Can be. Specifically, as the transparent member,
The following can be adopted.

(1) The incident side transparent member provided on the incident surface side of the solid rod may be a filter that blocks ultraviolet rays and / or infrared rays. By using the transparent member as a filter that blocks ultraviolet rays and / or infrared rays in this manner, it is possible to shield ultraviolet rays and infrared rays from a light source and protect an electro-optical device such as a liquid crystal panel from ultraviolet rays and infrared rays. .

(2) It is conceivable that the incident side transparent member is a light guiding prism for guiding light to the incident surface of the solid rod.
That is, by adopting the light guide prism, it is possible to increase the light incident surface of the light guide prism, thereby improving the light collection efficiency on the incident surface of the rod. In addition, if the light guide prism has a reflecting surface that bends the optical axis of the light beam incident on the incident surface, the optical path from the light source to the lighting device can be bent in a crank shape. It is possible to reduce the size. Further, if the reflection film formed on the reflection surface has a property of transmitting ultraviolet light and / or infrared light, the same action and effect as those of the filter for blocking the ultraviolet light and / or infrared light can be provided. it can.

(3) It is conceivable that the emission-side transparent member provided on the emission surface side of the solid rod is a condenser lens that collects a light beam emitted from the emission surface of the solid rod.
That is, as described above, since the optical components such as the condenser lens are arranged between the rod-type integrator and the electro-optical device, if the condenser lens also serves as a transparent member, the illumination device can be configured. The number of optical parts to be manufactured is reduced, and the structure is simplified.

Further, as the rod support structure of the cover member described above, the following is conceivable.

(1) It is conceivable that the cover member supports the rod at the periphery of the entrance surface and / or the exit surface of the solid rod. Specifically, when the solid rod has a rectangular parallelepiped shape, a structure that supports the solid rod at a corner of a rectangular incident surface or an exit surface may be considered. That is, since the cover member supports the solid rod in this way, it is possible to prevent the side portion of the solid rod and the cover member from coming into contact with each other, so that total internal reflection in the solid rod is maintained. Can be.

When the cover member has such a rod supporting structure, the lighting device is provided with cooling means for cooling the incident surface and / or the exit surface of the solid rod by cooling air. preferable. That is, by providing the cooling means, the rod that is easily overheated by the light beam from the light source can be cooled, and the cooling air is blown onto the incident surface and / or the exit surface of the rod to apply light to the entrance surface and the exit surface of the rod. Adhesion of dust and the like can be prevented.
Further, intrusion of dust or the like into the side surface of the rod can be further reduced, and the light use efficiency can be further improved.

(2) When a transparent member is provided on the entrance surface and / or the exit surface of the solid rod, this transparent member is fixed to the entrance surface and / or the exit surface of the solid rod,
It is conceivable that the cover member supports the solid rod by holding the transparent member. That is, since the cover member holds the transparent member, the rod can be supported inside the cover member in a non-contact state, and the total internal reflection can be maintained as described above. Further, intrusion of dust and the like into the side surface of the rod can be more reliably prevented, and the light use efficiency can be further improved.

(3) It is conceivable to provide a support portion which is in point contact with the side portion of the solid rod inside the cover member. Specifically, a plurality of mechanisms such as screws that advance and retreat in the cross-sectional direction of the rod are provided on the side surface of the cover member, and the tip portion of the screw or the like is brought into point contact with the side portion of the solid rod, so that the rod is inserted inside the cover member. The rod can be supported to maintain the total internal reflection of the rod. Further, by employing such a support structure, the rod can be supported without contacting the cover member regardless of the presence or absence of the transparent member or the like on the rod end surface. Furthermore, by employing a mechanism such as a screw that advances and retreats in the cross-sectional direction of the rod, the positions of the incident surface and the exit surface of the rod can be adjusted.

[0022]

[0023]

[0024]

Further, according to the projection type display device provided with the illumination device of the present invention, since the light use efficiency of the illumination device can be improved, the projected image can be made brighter and the luminance of the light source lamp of the light source system can be increased. By reducing the size, the amount of heat generated by the light source lamp is minimized, and miniaturization and cost reduction of the projection display device are promoted.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) As shown in FIG. 1, a projection display apparatus 10 according to a first embodiment of the present invention
5 is provided. The lighting device 15 has a rod-type integrator, and includes a lamp 1 serving as a light source,
The elliptical reflector 2 serving as the incident side condensing means and a solid glass rod (solid rod) serving as the rod integrator
3, a device for illuminating a first condenser lens 4, a second condenser lens 5, a third condenser lens 6, and a liquid crystal panel 8 having a surface to be illuminated. It is. In the present embodiment, a liquid crystal panel is taken as an example of an electro-optical device having a surface to be irradiated.

The lamp 1 is disposed in the vicinity of the first focal point of the elliptical reflector 2, and a light beam emitted from the lamp 1 is reflected by the elliptical reflector 2 and is reflected by the second ellipse of the elliptical reflector 2.
The light is focused near the focal point and forms a primary light source image G1 on the incident surface of the glass rod 3. The elliptical reflector 2 may be a parabolic reflector, in which case the glass rod 3
A condensing lens for condensing the parallel light flux emitted from the parabolic reflector toward the incident surface of the glass rod 3 may be further provided in the preceding stage.

The glass rod 3 is a columnar glass solid rod. The light beam incident on the glass rod 3 repeats internal reflection in the glass rod 3 to form a plurality of secondary light source images G21, G22, G23,... (See FIG. 2).

FIG. 2 is an explanatory view of the light beam splitting action by the glass rod 3. As shown in FIG. The cross-sectional shape of the glass rod 3 is shown in FIG.
As shown in (b), it is a rectangle having a horizontal a and a vertical b, and the reflecting surfaces (inner surfaces) facing each other are parallel. That is, in FIG. 2, the two reflecting surfaces in the vertical direction are parallel to each other, and the two reflecting surfaces in the horizontal direction are parallel to each other.

The ratio of a to b is substantially equal to the ratio of the shape of the pixel area (display area) of the liquid crystal panel 8 which is the surface to be irradiated.
They are similar. The length of the glass rod 3 is set such that the central ray (optical axis indicated by a dashed line) of the light flux from the secondary light source images G21, G22, G23,... Passes through the center of the exit surface of the glass rod. I have. At this time, this cross-sectional shape is transferred to the entrance surface of the glass rod 3 by the elliptical reflector 2.
If the incident light flux condensed by the glass rod 3 is set to be sufficiently smaller than the spread E (FIG. 3A) of the light flux that can occur when the glass rod 3 is not provided, a part of the light flux A plurality of secondary light source images G21, G22, G23,... Which are reflected on the inner surface of the light source and become virtual images of the primary light source image G1 are generated.

The illustrated primary light source image is G1, which is also a secondary light source image G21 which is a virtual image of a light component emitted without reflection on the inner surface of the glass rod 3. The secondary light source image G22 is a virtual image of a light component reflected once on the inner surface of the glass rod and emitted to the emission surface, and is a light component emitted obliquely to the emission surface. A virtual image is located in an oblique direction deviating from the image G21. Secondary light source image G23
Is a virtual image of a light component reflected twice on the inner surface of the glass rod and emitted to the emission surface, and is a light component emitted obliquely to the emission surface, so that the secondary light source image G21 and the secondary light source A virtual image is located in an oblique direction deviating from the image G22. In this manner, a secondary light source image is formed for each internal reflection number, and light fluxes from the plurality of secondary light source images G21, G22, G23,. The direction of light emission from the rod 3 is also superimposed light from various directions. Therefore, on the emission surface, illumination information with reduced unevenness in brightness and an increased illuminance ratio is formed.

The luminous flux emitted from the exit surface of the glass rod 3 is condensed by a condenser lens 4 and a condenser lens 5 as shown in FIG. 3, and the secondary light source images G21, G22, G23 are respectively provided. , A tertiary light source image G3 corresponding to.
, G32, G33,... Are formed. Condensing lens 5
Is also an imaging lens for condensing the illumination information on the exit surface of the glass rod 3 on the liquid crystal panel 8, and the light flux once condensed as the tertiary light source images G31, G32, G33,.
The light is radiated onto the liquid crystal panel 8 which is the irradiated surface while being deflected by the condenser lens 6 so as to approach a direction parallel to the normal of the pixel region of the liquid crystal panel 8. Here, the condenser lens 6 does not have to be a lens that adjusts the light beam direction.

FIG. 4 shows tertiary light source images G31, G32, G3.
It is a figure for demonstrating the condensing state of 3, ..., and has shown the mode seen from the optical axis direction. Tertiary light source images G31, G3
, G33,... Are the primary light source image G1
, The incident angle, the cross-sectional shape of the glass rod 3, the length, and the like. In particular, the size of the tertiary light source image is the size of the primary light source image, and the distance between the light source images is the glass rod 3.
Depends on the cross-sectional shape of, if the cross-sectional shape is rectangular,
The distance between the light source images in the long side direction is larger than in the short side direction. For example, in the present embodiment, the liquid crystal panel 8 is a rectangle having a long side in the y-axis direction in FIG. 4. Therefore, the cross section of the glass rod 3 having a similar shape to the long side is also a rectangle having a long side in the y-axis direction. The distance y1 between the light source images in the Y-axis direction is z
It is larger than the axial distance z1.

As described above, in the illumination device 15, the illumination information (light flux emitted along the shape of the emission surface) on the emission surface of the glass rod 3 is similarly enlarged by the condenser lens 5, and the liquid crystal panel 8 is enlarged. Will be illuminated. Therefore, although it depends on the size of the cross section of the liquid crystal panel 8 or the glass rod 3, the liquid crystal panel 8 or the condenser lens 6 (the condenser lens 6 collimates incident light and irradiates the liquid crystal panel 8). Creates a space corresponding to the magnification. Naturally, as the distance increases, the conjugation ratio of the condenser lens 5 increases, so that the parallelism of the incident light on the liquid crystal panel 8 increases. In the present embodiment, as shown in FIG. 1, a dichroic mirror 30 as a color separation optical system is arranged by utilizing this space.

The dichroic mirror 30 includes three dichroic mirrors 30R, 30G, and 30B each having a different wavelength selective reflection film that selectively reflects or transmits red light, green light, and blue light. . For example, the dichroic mirror 30R is a mirror that reflects red light and transmits green light and blue light. The dichroic mirror 30G is a dichroic mirror 30G.
A mirror that further separates the green light and the blue light that have passed through R, reflects the green light, and transmits the blue light. The dichroic mirror 30B is a dichroic mirror 30G.
Is a mirror that reflects blue light transmitted through the mirror. The dichroic mirrors 30R, 30G, and 30B are arranged at a predetermined angle to each other, and the reflected light enters the liquid crystal panel 8 from different directions. In the present embodiment, the light passes through the condenser lens 4 before being incident on the liquid crystal panel 8 and undergoes the refraction action, but the separated state of the light beam is maintained. Although the dichroic mirror 30 is composed of three dichroic mirrors, the optically last mirror (30B) may be a total reflection mirror, and a color separation optical system can be configured by using at least two dichroic mirrors. Further, a prism having a wavelength selective reflection film may be used instead of a dichroic mirror. In addition, the order of spectral separation of red light, green light, and blue light may be any order.

FIG. 5 shows a partial cross section of the liquid crystal panel 8 in FIG. As shown in FIG. 5, the liquid crystal panel 8 is an active matrix liquid crystal panel provided with a microlens array 33 for condensing each light beam on a corresponding pixel. A pair of polarizing plates is arranged. The liquid crystal panel 8
Twisted nematic (TN) liquid crystal 36 serving as an electro-optical element is sealed between transparent substrates 34 and 35 such as glass sheets, and one substrate 34 has a common electrode 37 and a black matrix 38 for shielding unnecessary light. Are formed on the other substrate 35, a pixel electrode 39, a thin film transistor (TFT) 40 as a switching element, and the like are formed. When a voltage is applied to the pixel electrode 39 through the TFT 40, the pixel electrode 39 and the common electrode 37 are formed. This is a structure in which the sandwiched liquid crystal 36 is driven.

On the other substrate 35, a plurality of scanning lines and a plurality of data lines are arranged so as to intersect, a TFT 40 is arranged near the intersection, a gate is a scanning line, a source is a data line, and a drain is a drain. It is connected to the pixel electrode 39. Then, the selection voltage is sequentially applied to the scanning lines, and the driving voltage of each pixel is written to the pixel electrode 39 via the TFT 40 of the pixel in the horizontal direction that is turned on in response to the selection voltage. TFT40
Are turned off by the application of the selected voltage, and the applied drive voltage is held in a storage capacitor (not shown). Pixel electrode 3
Numeral 9 is arranged in a region corresponding to the opening of the liquid crystal panel (the opening of the black matrix 38), and each pixel is constituted by the TFT 40 and the pixel electrode 39 (a storage capacitor connected to the pixel electrode as necessary). . The liquid crystal 36 is TN
In addition, various types such as a ferroelectric type, an antiferroelectric type, a horizontal alignment type, and a vertical alignment type can be used.

Further, the microlens array 33 formed on the glass plate by etching or the like and one of the substrates 34 are bonded to each other via a resin layer (adhesive) 41 having a low refractive index. The unit lenses (convex or concave portions of the lens) of the microlens array 33 have a pitch corresponding to three times the pixel pitch in the horizontal direction (scanning line direction) of the liquid crystal panel 8 and reflect the dichroic mirror 30 at different angles. The red light, the green light, and the blue light that are emitted by the light enter the unit lenses of the microlens array 33 at different angles, and the red light, the green light, and the blue light are respectively adjacent to the unit lenses in the horizontal direction. Light is condensed near the pixel electrodes 39 of three pixels corresponding to the lens.

Each unit lens of the microlens array 33 has a focal length such that each color light is focused on the pixel electrodes of three adjacent pixels corresponding to this lens. In FIG. 5, the green light G that travels substantially straight and enters the liquid crystal panel 8 is condensed on the pixel electrode 39 </ b> G by the unit lens of the microlens array 33 and is emitted as it is. On the other hand, the dichroic mirrors 30R and 30B
At an angle corresponding to the angle with respect to 0G, the red light R and the blue light B incident symmetrically with respect to the green light G are:
The light is condensed on the pixel electrodes 39R and 39B by the unit lens, and is emitted at an angle symmetrical to the green light G. It should be noted that, if the order of spectral separation in the dichroic mirror 30 is different, the incident position of the color light on the liquid crystal panel 8 shown in FIG.

As described above, the pixel electrode 3 of the liquid crystal panel 8 is
Each light beam condensed with respect to 9 is modulated and emitted according to a signal applied to the liquid crystal panel 8 and emitted, and is enlarged and projected on a screen 32 in front by a projection lens 31. The three color lights modulated by the three adjacent pixels are projected so as to overlap at the same position on the screen 32 in the above process. The projection display device may be a rear type that projects the screen 32 from the back or a front type that projects the screen 32 from the front.

In the projection display device 10 having the above-described structure, the side surface of the glass rod 3 is covered with a cover member 20.

That is, the cover member 20 is formed as shown in FIG.
As shown in (A) and (B), the plate members 2 facing each other
It is formed by combining 0A and 20B in a square tube shape. The size of the cover member 20 is such that each of the plate members 20A and 20B is arranged with a gap of equal size from the four side surfaces of the glass rod 3, and is formed to be longer than the entire length of the glass rod 3. I have. On the incident side of the glass rod 3, a transparent member 21 is provided with a cover member 20.
And are provided integrally. The transparent member 21 may be a simple transparent member, but may be formed of a UV cut filter that blocks ultraviolet rays, an IR cut filter that blocks infrared rays, or a UV / IR cut filter that blocks both ultraviolet rays and infrared rays. . Further, on the exit side, the condenser lens 4 is disposed slightly away from the exit surface of the glass rod 3, and the transparent member 21 and the condenser lens 4
It is fixed to the cover member 20.

The glass rod 3 is supported on such a cover member 20 by a positioning screw 22. The positioning screw 22 can advance and retreat in the cross-sectional direction of the glass rod 3. For example, in a pair of plate members 20A opposed to each other, two are provided on one plate member 20A and one is provided on the other plate member 20A. These positioning screws 22 are screwed into female screw holes (not shown) formed in each plate member 20A, and the advance / retreat position is changed by changing the screwing position. Note that the positioning screw 22 provided on the plate member 20B can also advance and retreat with a similar structure. The tip of the positioning screw 22 is a sharp supporting portion 22A like a nail tip. Therefore, the glass rod 3 is
Is supported by the support portion 22A of the screw 22 in point contact.

According to the first embodiment, the following effects can be obtained.

(1) Since the side surface of the glass rod 3 is covered with the cover member 20, the glass rod 3 can be handled together with the cover member. Therefore, the handleability of the glass rod 3 is improved at the time of assembling, the scratches and dirt can be prevented from being attached to the side surface of the glass rod 3 at the time of handling, and the intrusion of dust and the like into the rod side surface can be reduced. As a result, total reflection in the internal reflection of the glass rod 3 can be maintained, and a decrease in light use efficiency can be prevented.

(2) The transparent member 21 is provided on the entrance side of the glass rod 3 and the condenser lens 4 is provided on the exit side, respectively.
As a result, it is possible to prevent dust and the like from adhering to the light incident surface and the light exit surface of the glass rod 3. In particular, since the transparent member 21 is provided on the exit surface side, it is possible to prevent the formation of an image such as dust on the liquid crystal panel 8 in a conjugate relationship, and as a result, the image of dust or the like on the screen 32 surface. Can be prevented. Further, intrusion of dust and the like into the side surface of the rod can be more reliably prevented, and the light use efficiency can be further improved.

(3) The transparent member 21 provided on the incident surface side of the glass rod 3 is provided with a UV cut filter for blocking ultraviolet rays, an IR cut filter for blocking infrared rays, or a UV / IR filter for blocking both ultraviolet rays and infrared rays. If formed by a cut filter, the ultraviolet light and infrared light from the lamp 1 can be blocked, and the electro-optical device such as the liquid crystal panel 8 can be protected from the ultraviolet light and infrared light.

(4) Since the transparent member provided on the exit surface side of the glass rod 3 is the condenser lens 4 for condensing the light beam emitted from the exit surface of the glass rod 3, the rod type integrator and the electric Between the optical devices, the number of optical components such as a condensing lens having the exit surface of the glass rod 3 and the liquid crystal panel 8 in a conjugate relationship can be reduced.

(5) The glass rod 3 is attached to the cover member 20.
Since the inside of the glass member 3 is supported by point contact with the support portion 22A of the positioning screw 22 provided on the cover member 20, the influence on the inner surface reflection of the glass rod 3 can be suppressed. Total reflection in reflection can be maintained.

(6) Two positioning screws 22 are provided on one of the plate members 20A opposed to each other, one on the other, and one on the plate member 20B. By moving the set screw forward and backward with respect to the cover member 20, the optical axis of the glass rod 3 and the optical axis of the condenser lens 4 can be finely adjusted to further increase the light use efficiency.

(7) The glass rod 3 is attached to the cover member 20.
The glass rod 3 is supported inside by a point contact with the support portion 22A of the positioning screw 22 provided on the cover member 20, so that the glass rod 3 can be supported regardless of the presence or absence of the transparent member on the end surface of the glass rod 3. .

(8) Since the projection display device 10 includes the illumination device 15 having the glass rod 3 whose side surface is covered with the cover member 20, the light use efficiency of the illumination device 15 can be improved. Therefore, the projection image can be brightened, and the brightness of the light source system lamp 1 can be reduced to minimize the amount of heat generated by the light source lamp 1, thereby reducing the size and cost of the projection display device. .

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS.

The projection type display device 50 of this embodiment is different from the first embodiment in that the light from the lamp 1 is directly incident on the glass rod 3. In this case, the light is made to enter through the light source.

In this embodiment and the third embodiment described below, the same structures and members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted or simplified.

The light guide prism 51 as a transparent member is fixed to the entrance surface of the glass rod 3 of the illumination device 55 with an adhesive or the like, and the condenser lens 4 is fixed to the glass rod 3 on the exit surface. , Glass rod 3, light guide prism 51
And the condenser lens 4 are integrated. The glass rod 3 further includes a reflecting surface 51A that bends the optical axis of a light beam incident on the incident surface of the glass rod 3, and a reflecting film 52 that reflects the light beam is formed on the reflecting surface 51A. By forming the reflective film 52 with a predetermined dielectric multilayer film, a characteristic of transmitting ultraviolet light, a characteristic of transmitting infrared light, or
It can have the property of transmitting both ultraviolet rays and infrared rays.

The side surface portion of the glass rod 3 that reflects the inner surface is covered with a cover member 60. That is, the cover member 60 is formed in the shape of a quadrangular cylinder by the four plate members 60A similarly to the cover member 20, and the inner surface of the end portion holds the light guide prism 51 and the condenser lens 4 therebetween. Thus, the glass rod 3 is supported.

According to the second embodiment, in addition to the effects similar to the above (1), (3), (4), and (8), (9) light is guided to the entrance surface side of the glass rod 3. Since the prism 51 is provided, the light incident surface of the light guide prism 51 can be enlarged, and as a result, the light collection efficiency on the incident surface of the glass rod 3 can be improved.

(10) Since the light guide prism 51 has the reflecting surface 51A for bending the optical axis of the light beam incident on the incident surface, the optical path from the lamp 1 to the lighting device 55 can be bent in a crank shape. As a result, the size of the optical system including the illumination device 55 can be reduced.

(11) Reflection surface 51A of light guide prism 51
By providing a reflective film 52 having a property of transmitting ultraviolet light, a property of transmitting infrared light, or a property of transmitting both ultraviolet light and infrared light, the liquid crystal panel 8 blocks ultraviolet light and infrared light from the lamp 1. And the like can be protected from ultraviolet rays and infrared rays.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS.

The projection type display device 70 of this embodiment is provided with a cooling means 71, and the cooling means 71 allows at least the glass rod 3 constituting the lighting device 75.
Is made to be able to be cooled by the cooling air.

In this embodiment, the glass rod 3 is supported by the cover member 80 at the periphery of the entrance surface and the exit surface. As shown in FIGS. 10A and 10B, the cover member 80 is formed in a square cylindrical shape by two sets of plate members 81 and 82 opposed to each other. In each of the plate members 81 and 82, the ends of the plate members 81 and 82 on the entrance surface and the exit surface side of the glass rod 3 are support portions 81 </ b> A and 82 </ b> A that come into contact with the side surface of the glass rod 3. Part 8
Between 1A and 82A, there are concave portions 81B and 82B separated from the surface of the glass rod 3 by a predetermined dimension. Therefore, it is possible to prevent almost all side surfaces of the glass rod 3 from coming into contact with the cover member 80, and it is possible to maintain total internal reflection inside the glass rod 3.

The transparent member 21 is fixed to the entrance surface of the glass rod 3 with an adhesive to prevent dust and the like from adhering to the entrance surface, and is positioned at a position slightly away from the exit surface on the exit side. The condenser lens 4 is provided.

As shown in FIGS. 9 and 11, above the glass rod 3 and the liquid crystal panel 8 and the like, a fan or the like for cooling by blowing cooling air to at least the exit surface of the glass rod 3 and other illuminating devices 75 is provided. The cooling means 71 is provided to cool the glass rod 3 which is easily overheated by the light flux from the lamp 1 and to blow the cooling air to at least the emission surface of the glass rod 3 so that the emission surface of the glass rod 3 The attachment of dust and the like can be prevented.

According to the third embodiment, in addition to the effects similar to the above (1), (3), (4) and (8), (12) the glass rod 3 Since the peripheral portion of the surface is supported by the cover member 80, it is possible to prevent the side surface portion of the glass rod 3 from coming into contact with the cover member 80, and it is possible to maintain total internal reflection in the glass rod 3. .

(13) At least the exit surface of the glass rod 3 and the cooling means 7 above the other illuminating device 75
1, the glass rod 3 that is easily overheated by the luminous flux from the lamp 1 can be cooled.
By blowing the cooling air onto at least the emission surface of the glass rod 3, it is possible to prevent dust and the like from adhering to the emission surface of the glass rod 3. Therefore, it is possible to prevent dust adhering to the emission surface from being formed on the liquid crystal panel 8 and forming an image such as dust on the screen. Further, intrusion of dust and the like into the side surface of the rod can be more reliably prevented, and the light use efficiency can be further improved.

(Modifications) The present invention is not limited to the above embodiments, and various modifications and changes can be made without departing from the spirit of the present invention.

For example, in each of the above embodiments, the glass rods 3 are all solid, but the invention is not limited to this.
As shown in FIG. 2, a hollow light pipe 83 is used (the outer frame is a reflecting surface composed of glass or the like and the center is a hollow cylindrical column with a hollow center, and in this case, light is reflected on each reflecting surface). May be. The transparent member 21 is provided on the incident surface of the light pipe 83, and the condenser lens 4 is provided on the output surface. In each of the above embodiments, a hollow light pipe 83 as shown in FIG.
In the case where is used, the same effect as in the above-described embodiment can be obtained. If a filter that blocks ultraviolet rays and / or infrared rays is used for the transparent member 21 as described above, the ultraviolet rays and infrared rays from the lamps are blocked, and the electro-optical device such as the liquid crystal panel 8 is exposed to ultraviolet rays and infrared rays. Can be protected from

In each of the above embodiments, the liquid crystal panel 8 is used as an electro-optical device having a surface to be irradiated.
The electro-optical device used in combination with the lighting device of the present invention is not limited to a liquid crystal panel as long as it can generate light representing an image from received light. For example, DMD
(Registered trademark of Texas Instruments, Inc.).

[0072]

As described above, according to the lighting device of the present invention, since the side surface of the solid rod is covered with the cover member, by handling the solid rod together with the cover member,
This improves rod handling during assembly, prevents scratches and dirt from adhering to the side of the rod during handling, and reduces intrusion of dust and the like into the side of the rod. , The total reflection in the internal reflection can be maintained, and a decrease in light use efficiency can be prevented.

Further, according to the projection type display device using the lighting device, the light use efficiency of the lighting device can be improved.
In addition to making the projected image brighter, the brightness of the light source lamp of the light source system is reduced, the heat generation of the light source lamp is minimized, and the miniaturization and cost reduction of the projection display device are promoted.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of a lighting device of the present invention and a projection display device using the lighting device.

FIG. 2 is an explanatory diagram showing light beam division by a glass rod of the illumination device of the embodiment.

FIG. 3 is an explanatory diagram showing a format of a tertiary light source image by the illumination device of the embodiment.

FIG. 4 is a front view showing a tertiary light source image by the illumination device of the embodiment.

FIG. 5 is an explanatory diagram showing a liquid crystal panel in the projection display device of the embodiment.

6A and 6B show a glass rod and the like of the lighting device of the embodiment, wherein FIG. 6A is a longitudinal sectional view, and FIG. 6B is AA in FIG.
It is sectional drawing along the line.

FIG. 7 is a diagram showing a second embodiment of the illumination device of the present invention and a projection display device using the illumination device.

FIG. 8 is a longitudinal sectional view showing a glass rod and the like of the lighting device of the embodiment.

FIG. 9 is a diagram showing a third embodiment of the illumination device of the present invention and a projection display device using the illumination device.

10A and 10B show a glass rod and the like of the lighting device of the embodiment, FIG. 10A is a longitudinal sectional view, and FIG.
It is sectional drawing which followed the B line.

FIG. 11 is a schematic view showing a cooling unit for the lighting device of the embodiment.

FIG. 12 is a perspective view showing a modification of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lamp 2 Elliptical reflector 3 Glass rod (solid rod) 4 Condensing lens 5 Condensing lens 6 Condensing lens 8 Liquid crystal panel 10, 50, 70 Projection display device 15, 55, 75 Illumination device 20 Cover member 21 Transparent member 22 Positioning Screw 30 Dichroic Mirror 31 Projection Lens 32 Screen 51 Light Guide Prism 52 Reflective Film 71 Cooling Means

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shoichi Uchiyama 3-3-5 Yamato, Suwa City, Nagano Prefecture Inside Seiko Epson Corporation (72) Inventor Masafumi Sakaguchi 3-3-5 Yamato, Suwa City, Nagano Prefecture Seiko Epson Corporation (56) References JP-A-9-160034 (JP, A) JP-A-9-43562 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03B 21/14 H04N 5/74

Claims (4)

(57) [Claims] 1. A light incident from an incident surface is internally reflected,
An illumination device having a rod-type integrator having a solid rod that emits light by being superimposed on an emission surface, a cover member that covers a side surface portion of the solid rod, and an incident surface side and an emission surface side of the solid rod. The transparent member, one of the transparent members is fixed to the incident surface of the solid rod, the other is fixed to the emission surface of the solid rod, the cover member, A lighting device fixed to each transparent member and arranged with a gap provided between an inner surface of the cover member and a side surface portion of the solid rod. 2. The illumination device according to claim 1, wherein the incident-side transparent member provided on the incident surface side of the solid rod is a light guide prism that guides light to the incident surface of the solid rod. Lighting device characterized by the following. 3. The lighting device according to claim 1, wherein the light-emitting side transparent member provided on the light-emitting surface side of the solid rod collects a light beam emitted from the light-emitting surface of the solid rod. An illumination device, which is a light-collecting lens. 4. A projection display comprising: the illumination device according to claim 1; and an electro-optical device that modulates light emitted from the illumination device. apparatus.