JP2011170066A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector that includes optical modulators in which prevention of adhesion of dust, fuzz, etc. to the surfaces of the optical modulators caused by static electricity is improved by enhancing a destaticizing effect. <P>SOLUTION: Antistatic conductive films 603 are provided on both the front surface and the back surface of each of the optical modulators 50R, 50G, ad 50B. Each conductive film 603 is grounded via a lead wire 804 connected to a thermistor 801 disposed near the corresponding optical modulator. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light modulation device and a projector including the light modulation device. More specifically, the present invention relates to a technique for preventing dust, debris, and the like from adhering to the surface of a light modulation device.

  Conventionally, it has been known that static electricity is charged on the surface of a liquid crystal panel, and the image quality is deteriorated due to the static electricity causing dust, mark, etc. to adhere to the surface of the liquid crystal panel and appearing on a projection screen. In addition, the liquid crystal panel surface is close to the imaging plane and forms an image on the projection screen, so that the influence on the image is great. In order to prevent this, a method of providing a conductive film on the surface of the liquid crystal panel and grounding the conductive film has been proposed.

  For example, there is a projector in which a conductive film provided on the surface of a liquid crystal panel is grounded via a GND line provided on a flexible cable (for example, see Patent Document 1).

JP 20042333501 A

  In Patent Document 1, the conductive film provided on the surface of the dust-proof glass is electrically grounded using the GND line provided on the flexible cable. However, another method for connecting the conductive film and the flexible cable is used. Flexible cables are required and the flexible cables must be connected to each other, increasing the number of assembly steps. Moreover, since the strength of the connection portion between the flexible cables is low, there is a problem that durability is low.

  The present invention has been made in view of the above points, and provides a projector that can reliably prevent dust, injuries, and the like from adhering to the surface of a light modulation device such as a liquid crystal panel with a simpler configuration. With the goal.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A projector according to this application example drives and controls a light modulation device that modulates a light beam emitted from a light source, a projection lens that projects light modulated by the light modulation device, and the light modulation device. The light modulation device includes a liquid crystal display body and a holding body for holding the liquid crystal display body, and a conductive film is provided on a surface of the liquid crystal display body. The conductive film is grounded through a lead wire that connects an electrical component disposed in the vicinity of the light modulation device and the control board.

  According to this application example, since the conductive film is grounded using the lead wire that connects the electrical component disposed in the vicinity of the light modulation device and the control board, the conductive film can be grounded with a simple configuration. In addition, since lead wires are used, reliability is improved. Therefore, it is possible to reliably suppress deterioration in image quality due to dust, mark, etc. adhering to the light modulation device with a simple configuration.

  Application Example 2 In the projector according to the application example, the conductive film is grounded through the holding body.

  According to this application example, since the conductive film is grounded via the holder of the light modulation device, the conductive film can be grounded more easily, and the manufacturing process of the light modulation device and the projector can be simplified as compared with the prior art. It becomes possible.

  Application Example 3 In the projector according to the application example, the electrical component is a thermistor.

  According to this application example, by using the lead wire connected to the thermistor arranged in the vicinity of the light modulation device and connected to the thermistor in the vicinity of the light modulation device for monitoring the environmental temperature. It is possible to connect more easily than using a lead wire.

  Application Example 4 In the projector according to the application example, it is preferable that the thermistor is mounted on a substrate, and the light modulation device is grounded via the substrate.

  According to this application example, the thermistor has a structure in which the thermistor is mounted after being mounted on the substrate. Even if the substrate has a plurality of light modulation devices by connecting the substrate to the plurality of light modulation devices, the structure Can be simplified.

FIG. 2 is a diagram illustrating an appearance of a projector according to the present embodiment. The figure which shows arrangement | positioning of each component within the exterior case of FIG. (A) The figure which takes out and shows the part of an optical lens unit and a projection lens unit, (B) The schematic block diagram of an optical system. 1 is a front view of a light modulation device according to an embodiment of the present invention. AA sectional drawing of FIG. FIG. 5 is an exploded perspective view of the light modulation device in FIG. 4. The figure which shows an example of a structure of the transparent conductive film with a non-reflective function. The figure which shows the connection structural example of a transparent conductive film and a thermistor.

(First embodiment)
Next, a preferred embodiment of the present invention will be described with reference to the drawings, taking as an example a projector as an embodiment of a light modulation device according to the present invention.

  FIG. 1 is an external view of the projector according to the present embodiment. The outer case 2 of the projector 1 of this example has a rectangular parallelepiped shape. The exterior case 2 includes an upper case 3, a lower case 4, and a front case 5. A portion on the front end side of the projection lens unit 6 protrudes from the center of the front case 5.

  FIG. 2 shows an arrangement of each component in the projector 1. As shown in FIG. 2, a power supply unit 7 is disposed inside the projector 1 on the side opposite to the projection lens unit 6. A light source lamp unit 8 and an optical unit 9 are arranged at a position adjacent to the front side of the apparatus with respect to the power supply unit 7. Further, the base end side of the projection lens unit 6 is located in the center of the front side of the optical unit 9.

  On the other hand, an interface board 11 on which an input / output interface circuit is mounted is disposed on one side of the optical unit 9 in the front-rear direction of the apparatus, and a video board 12 on which a video signal processing circuit is mounted in parallel with the interface board. Is arranged. Further, a control board 13 for device drive control is disposed above the light source lamp unit 8 and the optical unit 9, and speakers 14R and 14L are disposed at the left and right corners on the front end side of the device, respectively.

  Air intake fans 15A and 15B for cooling the inside of the apparatus are arranged above and below the optical unit 9. Further, an exhaust fan 16 is disposed on the side of the apparatus that is the back side of the light source lamp unit 8. An auxiliary cooling fan 17 for sucking the cooling airflow from the intake fan 15A into the power supply unit 7 is disposed at a position facing the ends of the interface board 11 and the video board 12 in the power supply unit 7. Yes.

  Among these fans, the intake fan 15B mainly functions as a cooling fan for the liquid crystal panels 40R, 40G, and 40B as light modulation elements provided in light modulation devices 50R, 50G, and 50B described later. Yes. The intake fan 15A can be used for cooling the liquid crystal panels 40R, 40G, and 40B. The intake fans 15A and 15B are connected to the control board 13 via lead wires (not shown).

  Hereinafter, the configuration of the optical unit 9 and the optical system will be described with reference to FIG.

  FIG. 3A shows a portion of the optical unit 9. As shown in FIG. 3A, the optical unit 9 has an optical element other than the prism unit 20 constituting the color synthesizing means sandwiched between an upper light guide 901 and a lower light guide 902 from above and below. It has a retained configuration. The upper light guide 901 is fixed to the lower light guide 902 with fixing screws. The lower light guide 902 is also fixed to the lower case 4 with a fixing screw.

  The prism unit 20 is fixed to the back surface of the thick head plate 30 which is a die-cast plate by a fixing screw. On the front surface of the head plate 30, the base end side of the projection lens unit 6 as projection means is similarly fixed by a fixing screw. Therefore, in this example, the prism unit 20 and the projection lens unit 6 are fixed so as to be integrated with the head plate 30 interposed therebetween.

  FIG. 3B shows a schematic configuration of an optical system incorporated in the projector 1. The optical system of this example includes a light source lamp 805, a uniform illumination optical system 923 having integrator lenses 921 and 922 that are uniform illumination optical elements, and a light flux W emitted from the uniform illumination optical system 923 as red, green, Three light modulation devices 50R, 50G, and 50B each having a color separation optical system 924 that separates blue light beams R, G, and B, and liquid crystal panels 40R, 40G, and 40B as light modulation elements that modulate the light beams. (A detailed configuration will be described in detail below), a prism composite 22 as a color combining optical system for combining modulated color light beams, and a projection lens unit 6 for enlarging and projecting the combined light beams on the projection surface, Consists of In addition, a relay optical system 927 that guides the blue light beam B to the corresponding liquid crystal panel 40B among the color light beams separated by the color separation optical system 924 is provided.

  The uniform illumination optical system 923 further includes a reflection mirror 931 so that the optical axis 1a of the emitted light from the light source lamp 805 is bent at a right angle toward the front of the apparatus. With this reflection mirror 931 sandwiched, the integrator lenses 921 and 922 are arranged so as to be orthogonal to the front and rear.

  The color separation optical system 924 includes a blue-green reflecting dichroic mirror 941, a green reflecting dichroic mirror 942, and a reflecting mirror 943. First, in the blue-green reflecting dichroic mirror 941, the blue light beam B and the green light beam G included in the light beam W that has passed through the uniform illumination optical system 923 are reflected at right angles, so that the green reflecting dichroic mirror 942 side. Head for. The red light beam R passes through the blue-green reflecting dichroic mirror 941, is reflected at a right angle by the rear reflecting mirror 943, and is emitted from the red light beam emitting portion 944 to the color synthesis optical system side. Next, in the green reflection dichroic mirror 942, only the green light beam G is reflected at right angles out of the blue and green light beams B and G reflected by the blue-green reflection dichroic mirror 941, and the color is emitted from the emission portion 945 of the green light beam. The light is emitted to the side of the combining optical system. The blue light beam B that has passed through the green reflecting dichroic mirror 942 is emitted from the blue light beam emitting portion 946 to the relay optical system 927 side. In this example, the distances from the light beam emitting portion of the uniform illumination optical element to the light beam emitting portions 944, 945, and 946 in the color separation optical system 924 are all set to be substantially equal.

  Condensing lenses 951 and 952 are disposed on the emission side of the emission portions 944 and 945 of the red and green light beams of the color separation optical system 924, respectively. Therefore, the red light beam and the green light beam emitted from each emitting part are incident on these condenser lenses 951 and 952 and are collimated.

  The collimated red and green luminous fluxes R and G are aligned in the polarization direction by the polarizing plates 60R and 60G, then enter the light modulation devices 50R and 50G, and are modulated by the liquid crystal panels 40R and 40G, respectively. Corresponding image information is added. That is, the liquid crystal panels 40R and 40G are switching-controlled by an image signal corresponding to image information by a driving unit (not shown), thereby modulating each color light passing therethrough. As such driving means, known means can be used as they are.

  On the other hand, the blue light beam B is guided to the corresponding light modulation device 50B through the relay optical system 927 and further aligned in the polarization direction by the polarizing plate 60B, where it is similarly modulated according to the image information. Is given.

  The relay optical system 927 includes a condenser lens 974, an incident-side reflection mirror 971, an emission-side reflection mirror 972, an intermediate lens 973 arranged between these mirrors, and a condenser lens 953 arranged on the near side of the liquid crystal panel 40B. Consists of As for the length of the optical path of each color beam, that is, the distance from the light source lamp 805 to each light modulator, the blue beam B is the longest, and therefore the light amount loss of this beam is the largest. However, the light loss can be suppressed by interposing the relay optical system 927.

  The light beams of the respective colors modulated through the respective light modulation devices 50R, 50G, 50B are incident on the polarizing plates 61R, 61G, 61B, and the light transmitted therethrough is incident on the prism composite 22 where they are combined. In this example, a color composition optical system is configured by using a prism composition 22 composed of a dichroic prism. The synthesized color image is enlarged and projected on the projection plane 10 at a predetermined position via the projection lens unit 6.

  Next, the light modulation devices 50R, 50G, and 50B and the grounding structure will be described.

  4 is a front view of the light modulation device according to the embodiment of the present invention, FIG. 5 is a cross-sectional view taken along the line CC of FIG. 4, and FIG. 6 is an exploded perspective view of the light modulation device of FIG. Since the light modulation devices 50R, 50G, and 50B have the same configuration, the light modulation device 50G will be described below as an example. Further, in FIG. 5, the left side is the entrance surface side, the right side is the exit surface side, the right side in FIG. 6 is the entrance surface side, and the left side is the exit surface side.

  The light modulation device 50G includes a holding frame 500 as a holding body and a plate spring member 510, and houses a liquid crystal display body 70G therein. The holding frame 500 is made of metal and has a substantially rectangular shape, and has an opening 502 for light passage at the center thereof. Screw holes 504 for screw-fixing the light modulation device 50G to the prism composite 22 (see FIG. 3B) via a fixing member (not shown) are screwed at the four corners of the holding frame 500. Hooks 501 for engaging with the plate spring members 510 are provided on the left and right side surfaces of the holding frame 500.

  As shown in FIG. 4, a GND line 505 is connected to the holding frame 500 by soldering. The GND line 505 is composed of a lead wire or the like, and has a function of electrically connecting a conductive film, which will be described later, provided on the liquid crystal display body 70G and the GND of the projector 1. The GND line 505 is similarly connected to the light modulation devices 50R and 50B.

  The plate-like spring member 510 is made of sheet metal, has a light passage opening 512 at the center, and has a frame-like portion 514 bent at the left and right ends so as to protrude toward the light beam incident side. The plate-like spring member 510 has a configuration in which the constituent members are integrally coupled by engaging the frame-like portion 514 with the hook 501 provided on the holding frame 500 from the light beam exit side. At the time of engagement, the holding frame 500 and the plate spring member 510 are configured to be electrically connected.

  The liquid crystal display body 70G includes a liquid crystal panel 40G as a light modulation element, and two dust-proof glasses 600 and 602 disposed on the incident side surface and the emission side surface of the liquid crystal panel 40G, respectively. In this example, a liquid crystal panel 40G having a configuration in which liquid crystal (not shown) is sealed between a TFT substrate 42 and a counter substrate 44 facing the TFT substrate 42 is used.

  The incident-side dust-proof glass 600 is set to have substantially the same outer shape as the counter substrate 44 of the liquid crystal panel 40G, and is adhered and fixed to the incident-side surface of the liquid crystal panel 40G. This prevents dust and the like from adhering. Even if dust or the like adheres to the incident-side surface of the incident-side dust-proof glass 600 itself, the projected image is not affected by increasing the distance from the liquid crystal surface of the liquid crystal panel 40G. I am doing so.

  Further, the dust-proof glass 602 on the emission side is set to have substantially the same outer shape as the TFT substrate 42 of the liquid crystal panel 40G, and is adhered and fixed to the surface on the emission side of the liquid crystal panel 40G so as to be on the emission side of the liquid crystal panel 40G. It prevents dust from adhering to the surface. Even if dust or the like adheres to the exit side surface of the exit side dust-proof glass 602 itself, the projected image is not affected by increasing the distance from the liquid crystal surface of the liquid crystal panel 40G. I have to.

  As shown in FIG. 5, an antistatic conductive film 603 is formed on the entire outer surface of each of the entrance-side dust-proof glass 600 and the exit-side dust-proof glass 602. The conductive film 603 is transparent, and in this embodiment, a conductive film having a non-reflection function in addition to the antistatic function is used.

FIG. 7 is a diagram illustrating an example of the configuration of a conductive film with a non-reflective function. As shown in FIG. 7, a conductive film 603 with a non-reflective function is formed on a dustproof glass 600, 602 with SiO ₂ (29 nm), ZrO ₂ (33 nm), SiO ₂ (21 nm), conductive ITO (for example, ITO ( It has a multilayer structure in which Indium Tin Oxide (63 nm) and SiO ₂ (29 nm) are laminated in this order. In the multilayer structure, a non-reflective function is realized by a material film excluding ITO, and a transparent conductive film is realized by ITO. By providing such a conductive film 603 on the surface of the dust-proof glass 600, 602, electrostatic charging on the surface of the dust-proof glass 600, 602 is prevented. In addition, the non-reflecting function can improve the light transmittance and increase the light utilization efficiency, thereby enabling a clear image to be obtained. Note that the structure of the conductive film 603 with a non-reflective function shown here is an example and is not limited to this structure.

  As described above, the holding frame 500 and the plate-like spring member 510 are disposed so as to sandwich the liquid crystal display body 70G, and the conductive film 603 provided on the dust-proof glass 600 on the incident side and the holding frame 500 come into contact with each other electrically. The conductive film 603 provided on the dust-proof glass 602 on the output side and the plate-like spring member 510 are fixed so as to contact and electrically connect. In the case where an adhesive is used for fixing the holding frame 500 and the liquid crystal display 70G, a conductive adhesive is used. By using a conductive adhesive, conduction between the holding frame 500 and the conductive film 603 can be reliably obtained.

  FIG. 8 is a diagram illustrating an example of the configuration of the light modulation devices 50R, 50G, and 50B and the prism composite 22. As shown in FIG. 8, the light modulation devices 50R, 50G, and 50B are fixed to the prism composite 22. Each of the optical modulation devices 50R, 50G, and 50B is connected with a GND line 505 to each holding frame 500, and each GND line 505 is coupled together, and a connector 506 for connection is provided at the tip.

  A thermistor unit 800 is installed in the prism composite 22 in the vicinity of the light modulation devices 50R, 50G, and 50B. The thermistor unit 800 includes a thermistor 801 that monitors the temperature around the light modulation devices 50R, 50G, and 50B, a thermistor substrate 802 on which the thermistor 801 is mounted, and a connector 803 that connects the GND line 505. The thermistor 801 monitors the temperature around the light modulators 50R, 50G, and 50B, and monitors whether the light modulators 50R, 50G, and 50B are driven in an appropriate temperature range. Since the thermistor 801 needs to be disposed in the vicinity of the light modulation devices 50R, 50G, and 50B, it is disposed on the prism composite 22. Further, since the thermistor 801 is a chip component, it is mounted on the thermistor substrate 802.

  In the thermistor substrate 802, a lead wire 804 that connects the thermistor 801 and the control substrate 13 via the thermistor substrate 802 is also connected. The thermistor substrate 802 is provided with a wiring pattern for electrically connecting the connector 803 and the GND line of the lead wire 804. The GND line of the lead wire 804 is electrically connected to the GND of the control board 13. With the above configuration, the conductive film 603 is grounded to the GND of the control board 13 of the projector 1 via the holding frame 500, the plate spring member 510, the GND line 505, the thermistor board 802, and the lead wire 804.

  By grounding the conductive film 603 in this way, static electricity that is to be charged in the display region of the liquid crystal display 70G flows from the conductive film 603 to the holding frame 500 or the plate spring member 510, and the GND line 505, the thermistor substrate. It is escaped to GND of the control board 13 of the projector 1 via 802. For this reason, it is possible to prevent the adhesion of dust, chips and the like to the surface of the liquid crystal display body 70G due to the electrostatic charge on the surface of the liquid crystal display body 70G. As a result, it is possible to prevent the deterioration of the image quality due to the adhesion of dust, scratches, etc.

  In the present embodiment, the conductive film 603 is grounded by using the lead wire 804 that connects the thermistor 801 and the control board 13 disposed in the vicinity of the light modulation devices 50R, 50G, and 50B. With the structure, the conductive film 603 can be grounded, and the grounded state can be maintained. The thermistor 801 is an electrical component that is disposed closest to the light modulation devices 50R, 50G, and 50B, and can be connected more easily than using other electronic components.

  In the present embodiment, the thermistor 801 is mounted on the prism composite 22 after being mounted on the thermistor substrate 802. By connecting the connector 803 for connecting the GND line 505 to the thermistor substrate 802, the connection can be further facilitated.

  Since the projector 1 including the light modulation devices 50R, 50G, and 50B configured as described above prevents dust and dirt from adhering to the surfaces of the liquid crystal display bodies 70R, 70G, and 70B. Therefore, it is possible to prevent the deterioration of the image quality of the projected image due to the adhesion, etc., to provide a better projected image more easily, and to extend the life of the projector 1.

  In the present embodiment, the lead wire 804 of the thermistor unit 800 is used for electrical grounding of the conductive film 603. However, if the lead wire 804 of the thermistor unit 800 is disposed in the vicinity of the light modulation devices 50R, 50G, and 50B, other electrical components are used. May be used. For example, when the wind speed sensor is arranged in the vicinity of the light modulation devices 50R, 50G, and 50B, it may be connected to a lead wire connected to the wind speed sensor, or connected to a lead wire connected to the intake fan 15B. May be.

  In the present embodiment, the GND lines 505 are combined into one, but may be individually connected to the thermistor substrate 802. Also, the thermistor 801 is mounted on the thermistor substrate 802 and the GND line 505 is connected to the thermistor substrate 802. The thermistor formed integrally with the lead wire is adopted, and the thermistor lead wire and the GND line are used. 505 may be directly connected.

  In the present embodiment, the GND line 505 of the holding body is connected to the holding frame 500 by soldering. However, another connection method may be used.

  In the above embodiment, an example in which the present invention is applied to a projector using a transmissive liquid crystal panel has been described. However, the present invention can also be applied to a projector using a reflective liquid crystal panel. It is. Further, as will be described later, the light modulation element is not limited to the liquid crystal panel. Here, “transmission type” means that a light modulation element such as a liquid crystal panel transmits light, and “reflection type” means that a light modulation element such as a liquid crystal panel reflects light. Means type.

  In a projector employing a reflective light modulation element, a dichroic prism such as the prism composite 22 is used as a light separating means for separating light into three colors of red, green, and blue, and is modulated. It may also be used as light combining means for combining three colors of light and emitting it in the same direction. Further, a polarization beam splitter may be disposed between the light modulation element and the color synthesizing unit. Even when the present invention is applied to a reflective projector, substantially the same effect as that of a transmissive projector can be obtained.

  Further, as the projection type projector, there are a front projection type projector that performs projection from the direction of observing the projected image and a rear projection type projector that projects from the opposite side to the direction of observing the projected image. The configuration shown in the form can be applied to any of them.

  In the above embodiment, the case where the light modulation device of the present invention is applied to a so-called three-plate projector using three liquid crystal panels has been described as an example. However, two or four liquid crystal panels are used. The present invention can also be applied to a plate type or four plate type projector.

  DESCRIPTION OF SYMBOLS 1 ... Projector, 22 ... Prism compound body, 40R, 40G, 40B ... Liquid crystal panel (light modulation element), 42 ... TFT substrate, 44 ... Opposite substrate, 46 ... Flexible cable, 50R, 50G, 50B ... Light modulation device, 62 ... Display area, 500 ... Holding frame, 505 ... GND line, 600, 602 ... Dust-proof glass, 603 ... Conductive film, 800 ... Thermistor unit, 801 ... Thermistor, 802 ... Thermistor substrate, 803 ... Connector, 804 ... Lead line.

Claims (4)

A projector comprising: a light modulation device that modulates a light beam emitted from a light source; a projection lens that projects light modulated by the light modulation device; and a control board on which a control circuit that drives and controls the light modulation device is mounted Because
The light modulation device includes a liquid crystal display body and a holding body for holding the liquid crystal display body,
A conductive film is provided on the surface of the liquid crystal display,
The conductive film is grounded through a lead wire that connects the electrical component disposed in the vicinity of the light modulation device and the control board,
A projector characterized by that. The projector according to claim 1.
The projector according to claim 1, wherein the conductive film is grounded through the holding body. The projector according to claim 1 or 2,
The projector according to claim 1, wherein the electrical component is a thermistor. The projector according to claim 3.
The thermistor is mounted on a substrate;
The projector, wherein the light modulation device is grounded via the substrate.

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