JP3414212B2 - Projection image display - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type image display device using an integrator optical system as an illumination optical system. As an optical system for uniformly illuminating a rectangular illumination area such as a liquid crystal light valve, an integrator optical system using two lens plates has been conventionally known. It has already been put to practical use as a lighting device for a projection type image display device. [0003] In principle, light from a light source device is divided by a plurality of microlenses on an integrator, and each microlens image is enlarged and projected on a light valve. I do. Thus, even if color unevenness or luminance unevenness occurs in the light from the light source device, the influence on the projected image can be minimized, so that the device is indispensable for high image quality.
Here, the integrator requires at least two lens arrays. Of these, the microlenses on the lens array on the light source device side are similar in shape to the light valve because the image is projected on the light valve. Needless to say, this is desirable. At the same time, in recent years, in order to further improve the light-collecting efficiency, a short-arc type light source having a small interelectrode size among conventional discharge tubes has been commercialized. According to this, since the light source illuminant becomes closer to the point light source, light can be efficiently controlled also in the reflector and the subsequent optical system. However, conventionally, a portion of the electrode wire provided on the reflector side of the light source, which crosses the reflector opening, causes a shadow on the microlens to cause uneven brightness of a projected image. As mentioned earlier, if the light source is short-arced, the shadow outline formed on the microlens becomes clear, so that even if the integrator superimposes many microlens images on the light valve, the image quality of the projected image Deterioration is no longer negligible. Here, the relationship between the direction in which the electrode wires are led out and the arrangement of the microlenses can be cited as a factor that makes image quality degradation noticeable due to shadows on the microlenses in the configuration using an integrator. Generally, in a conventional light source, the light source is drawn out in the longitudinal direction of the light valve. In addition, in recent years, the integrator lens array on the light source device side is also considered to minimize the influence of the electrode wires because the short direction of the light valve is shorter than the long direction. Products that are being pulled in the direction are also offered. [0007] In order to solve the above-mentioned problems, a projection type image display device according to the present invention comprises a light source device, an illumination optical unit, a light valve unit, and a projection optical unit. It is equipped with a discharge-type light source tube, a reflector that emits light emitted from the tube in one direction, and a driver circuit that drives the tube. An electrode line connected to the electrode on the reflector opening side among the two electrodes provided in the tube of the light source device and provided on the axis of rotational symmetry of the reflector, and Across the opening. At this time, a shadow formed by the electrode wire blocking light on the integrator is formed on the microlens of the integrator. At this time, the electrode wire is drawn out so that a shadow is not formed at the same position of a plurality of microlenses. The direction and the arrangement of the microlenses on the integrator are set. According to the present invention, there is provided a projection type image display device comprising a light source device, illumination optical means, light valve means, and projection optical means, wherein the light source device comprises: a bulb of a discharge type light source; A reflector that emits light emitted from the tube in one direction; a driver circuit that drives the tube; and the illumination optical unit includes an integrator optic that includes a number of microlenses substantially similar in shape to a light valve effective part. Means, and among the electrode lines connected to the two electrodes disposed on the axis of rotational symmetry of the reflector and provided in the tube, the electrode line on the microlens by an electrode line crossing the opening of the reflector. In order to prevent the formed shadow from being formed at the same position of a plurality of microlenses, the direction in which the electrode wire is drawn and the The projection type image display device, wherein the arrangement of the microlenses is set. In the projection type image display device according to the present invention, the shadow of the electrode line formed on the microlens constituting the integrator does not overlap when the image is superimposed on the light valve for each microlens. A high quality image can be provided without the shadow of the image being clearly displayed on the projected image. (Embodiment 1) A detailed description is given below with reference to the drawings. FIG. 1 shows the overall configuration of a projection type image display device according to the present invention. Reference numeral 1 denotes a light source device, which is composed of two bulbs and three reflectors. Of both ends of the bulb, a contact 4 is provided at the center of the reflector, and an electrode wire 5 is provided at the opening of the reflector. The light generated from the luminous body generated between the electrodes in the tube, not shown, is emitted to the opening side on the reflecting surface of the inner surface of the reflector and enters the integrator optical system 6. This is the first lens array 7 arranged on the light source side.
, And a second lens array 8 on the light valve side, both of which are composed of a large number of microlenses. In particular, the micro lens on the first lens array 7 has a shape similar to the shape of the effective portion of the light valve described later. The light collected by the integrator optical system 6 illuminates the effective opening of the light valve 9. Here, an image is displayed according to an input signal by a light valve drive circuit not shown. The image displayed here is enlarged and projected by a projection lens 10 on a screen not shown. In such a projection type image display device,
In the conventional configuration as shown in FIGS. 13 and 14, even if the integrator optical system is used, the shadow of the electrode line is formed at the same position for a plurality of microlenses as shown in FIGS. The shadow portion on the microlens image is also superimposed, which also has an adverse effect on the image on the projected image. On the other hand, as shown in FIG. 1, which is an embodiment of the present invention, The electrode wire 5 is oblique to each side of the micro lens of the integrator optical system 6.
Are drawn out. With the configuration according to the present invention, the shadow on the light source side lens array is as shown in FIG. 2, and the shadow portions do not overlap on the light valve (FIG. 3). Can be minimized. In addition, the integrator lens array tends to be sagged around each microlens due to its construction method, causing uneven illuminance around the image as a projected image. Since the shadow of the electrode line is formed, the image quality is degraded from both sides. However, in the present invention, the shadow of the electrode line is always inclined with respect to the microlens. It is clear that Conventionally, the arrangement of the micro lenses on the integrator is a direct arrangement shown in FIG. 4, a staggered arrangement shown in FIG. 5, or a composite type thereof. Further, the aspect ratio of the rectangular micro lens is 4: 3 according to the light valve, and 16:16.
There are mainly two types of the nine types, but there are some types that have a slightly different aspect ratio from the light valve due to the processing relationship of the lens array. It goes without saying that the present invention can basically be treated in the same manner in that basically no shadow of electrode lines formed on a plurality of lens arrays is superimposed on a light bar for any arrangement and aspect ratio. (Embodiment 2) FIG. 6 shows an example in which the device of the above embodiment is applied to a projection type image display device. The projection-type image display device 100 shown in the figure is largely composed of a light source device 101, an integrator optical system 102, a color separation optical system 103, a color combining optical system 104, and a projection optical system 105. The light source device 101 is a discharge lamp that produces high-intensity light by causing an arc between two electrodes to generate an arc. Discharge lamps 106 are provided at both ends with electrode terminals connected to the respective electrodes. This tube 106 is fixed to a reflector 107 having a parabolic reflecting surface which is rotationally symmetric with respect to the axis on the electrode as shown in the figure. Among the above-mentioned electrode terminals, the reflector 10
7, the electrode terminal on the center side is 108, and the electrode terminal on the opening side is 1
09, the electrode terminal 108 on the center side is directly connected to the drive circuit, but the electrode terminal 109 on the opening side is provided with an electrode wire 110, which traverses the opening of the reflector 107. It is drawn out and connected to the drive circuit there. Light emitted from the light source device 101 is made incident on an integrator optical system 102. The integrator optical system 102 includes two lens arrays, is arranged on the light source side, and has a first lens array in which a large number of microlenses 111 having an outer shape similar to the shape of an image display unit of a liquid crystal panel described later are arranged. 112 and a second lens array 113 also composed of many microlenses
Consists of The first lens array 112 includes the light source device 101
Is divided into sub-beams for each microlens, and is condensed on each microlens arranged on the second lens array 113 corresponding to each microlens on the first lens array 112. Each micro lens on the second lens array 113 is connected to the micro lens 11 on the first lens array 112.
One image is formed on an image display unit of a liquid crystal panel, which will be described later. Since this is performed by all of the many microlenses, the images of many microlenses 111 are superimposed. The light beam emitted from the integrator optical system 102 enters the color separation optical system 103. The color separation optical system is mainly a dichroic mirror that allows selection of transmission and reflection by wavelength, a surface mirror with high reflectance, a condenser lens provided so that illumination light is evenly incident on an image display unit of a liquid crystal panel described later, It consists of relay lenses provided in optical paths with different distances from the light source to the panel. First, the light incident on the color separation optical system 103 is transmitted through a red transmitting dichroic mirror 114, and the blue and green lights are reflected. The red light is reflected by the reflection mirror 115, passes through the condenser lens 116, and reaches the first liquid crystal light valve 117. On the other hand, of the blue light and the green light, the green light is reflected by the green reflecting dichroic mirror 118, passes through the condenser lens 116, and reaches the second liquid crystal light valve 119. After the blue light has passed through the green reflecting dichroic mirror 118, the incident side lens 1
20, a reflection lens 123 and a reflection mirror 12 in a relay lens system including a relay lens 121 and an emission side lens 122.
The light is guided to the third liquid crystal light valve 126 by the light guiding means 125 configured in the form of adding 4. Here, the first, second, and third liquid crystal light valves 117, 119, and 126 respectively modulate color light, and dichroic light, which is modulated in accordance with video signals corresponding to each color, is a dichroic optical system 104. The light enters the prism 127. The dichroic prism 127 has a red-reflecting dielectric multilayer film and a blue-reflecting dielectric multilayer film in a cross shape, and synthesizes respective modulated light beams. The light flux synthesized here forms an image on the screen 129 via the projection lens 128 which is the projection optical system 105. In the projection type image display apparatus 100 thus configured, since the shadow of the electrode line 110 is formed on the micro lens 111, the image of the micro lens 111 is superimposed as described above. This shadow also occurs on the projected image. In particular, in the prior art, the electrode wire 1 is arranged in the longitudinal direction or the lateral direction of the micro lens 111 here.
Since the number 10 is pulled out, the former results in a shadow that traverses the projected image right beside, and the latter causes a shadow that traverses the projected image up and down, causing image quality deterioration. Furthermore, each lens array that constitutes the integrator optical system is mainly processed by a glass press, and image deterioration due to the sag generated at the short part of each micro lens at this time causing a shadow part around the projected image is reduced. However, the influence of the shadows of the electrode lines in the conventional configuration and the configuration in the same direction, depending on the configuration of the microlenses, is greatly affected by the influence of the shadows of the electrode lines. Further, according to the above apparatus, since the relay optical system is arranged on the red optical path, the image on which the microlens 111 is superimposed on the projected image has only red inverted up, down, left, and right. Therefore, if the electrode wire 110 is slightly displaced mechanically, the shadow generated on the projected image is yellow, which blocks blue, and purple, which blocks green, almost overlaps, but cyan which blocks red does not. Since the position of the color shadow is generated at a position slightly shifted, color unevenness that is easily recognizable to an observer is still present. Therefore, according to the present embodiment, as shown in FIG. 6, the electrode line 110 is drawn obliquely to each side of the micro lens 111. With such a configuration, it is possible to change the position of the shadow falling on the plurality of microlenses 111, and thereby the microlenses 1
Even when the eleventh image is superimposed, the shadow portions do not overlap and strengthen each other, and can be made less noticeable. In addition, the influence of the sag on the formation of the microlens array does not adversely affect the shadow because the angle is formed. Furthermore, regarding the effect of the reversal of the red light path, the shadow is formed at a position distant from the other colors, so that even if a streak due to the influence of the shadow is formed as in the past, it is difficult for the observer to recognize it. I can do it. However, it is not necessary to draw out a large number of electrode wires 110 obliquely to each side of the microlens 111, and the broken lines are shown in FIGS. 7, 8, 9, 10, 11, and 12. It is necessary to avoid an angle that casts a shadow at the same position on a plurality of microlenses even if it is pulled out obliquely. The angles to be avoided depend on the arrangement of the microlenses, as can be seen in these figures. Needless to say, even if the aspect ratio of the microlens changes. As described above, in the projection type image display device of the present invention, by optimizing the position of the light source electrode line and the arrangement of the microlenses on the integrator optical system, the cost is increased and the design is not largely changed. It is possible to improve brightness unevenness in a projection image of the conventional apparatus, and to greatly improve color unevenness in a three-plate type using three light valves.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing an entire configuration of a projection type image display device according to an embodiment of the present invention. FIG. 2 is an explanatory diagram of a state of a shadow formed on a lens array of the device. FIG. 3 is an explanatory view of a state of a shadow formed on a light valve of the apparatus. FIG. 4 is a view showing micro lenses arranged in an orthogonal direction in an embodiment of the apparatus. FIG. 5 is a staggered arrangement in an embodiment of the apparatus. FIG. 6 is a view showing an overall configuration of a projection type image display apparatus according to an embodiment of the present invention. FIG. 7 is a view showing an arrangement of micro lenses and a state of a shadow formed on a lens array of the apparatus. FIG. 8 is a second explanatory view of the arrangement of microlenses and the shadow formed on the lens array of the apparatus. FIG. 9 is an arrangement of the microlenses of the apparatus and the state of shadow formed on the lens array. Third explanatory view of the situation [Fig. 10] FIG. 11 is a fourth explanatory view of the arrangement of the micro lenses of the apparatus and the state of the shadow formed on the lens array. FIG. 11 is the fifth explanatory view of the arrangement of the micro lenses of the apparatus and the state of the shadow formed on the lens array. 12 is a sixth explanatory view of the arrangement of microlenses and the state of a shadow formed on the lens array of the apparatus. FIG. 13 is a structural explanatory view of a conventional example (1). FIG. 14 is a structural explanatory view of a conventional example (2). FIG. 15 is an explanatory view of a state of a shadow formed on a light valve in the conventional example (1). FIG. 16 is an explanatory view of a state of a shadow formed on a light valve in the conventional example (2). Light source device 2 Tube 3 Reflector 4 Contact 5 Electrode line 6 Integrator optical system 7 First lens array 8 Second lens array 9 Light valve 10 Projection lens 100 Projection type image display device 101 Light source device 102 Integrator optical system 103 Color separation optical system 104 Color synthesis optical system 105 Projection optical system 106 Tube 107 Reflector 108 Electrode terminal on the center side of reflector 109 Electrode terminal on the opening side of reflector 110 Electrode line 111 Micro lens 112 First lens array 113 Second lens array 114 Red transmission dichroic mirror 115 Reflection mirror 116 Condenser lens 117 First liquid crystal light valve 118 Green reflection dichroic mirror 119 Second liquid crystal light valve 120 Incident lens 121 Relay lens 122 Exit lens 123 Reflecting mirror 124 Reflecting mirror 125 Light guide Means 126 Third liquid crystal light valve 127 Dichroic prism 128 Projection lens 129 Screen

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Claims (1)

(57) a reflector for emitting light emitted from the Patent Claims 1] connected to the electrode line has been tube in one direction, Le comprising the light emitted from the reflector of a large number of microlenses
An integrator optical means for illuminating a light valve on which an image is displayed in accordance with an input signal, and a projection lens for enlarging and projecting the image of the light valve. Of the lens array
Obliquely cross the sides of the plurality of microlenses, and
Make sure that the shadows do not overlap when converging with the icro lens
And a projection type image display device connected to the tube .