JP4703228B2 - Video display device - Google Patents

Description

  The present invention relates to a video display device such as a DLP (Digital Light Processing) projector, and more particularly to a video display device including a rotary color filter.

  In a projection-type image display device, light emitted from a light source passes through a rotary color filter (color wheel) and enters a light valve, and an image generated by the light valve is projected onto a screen by a projection lens. Is done. Optical components (including color filters and light valves) from the light source to the projection lens constitute an optical unit and are accommodated in a box-shaped unit case. The color filter is fixed to the main shaft of the motor and rotates at a high speed. The color filter and the motor are sealed in a color wheel case having a window that transmits light so that surrounding dust does not adhere to the color filter with this rotation (see, for example, Patent Document 1).

JP 2002-90886 A (page 4-5, FIG. 1-2)

  In general, the color wheel case is fixed to the bottom surface of the unit case with screws. The unit case is fixed on a position adjustment base for adjusting the position of the image projected on the screen, and is accommodated in the cabinet of the image display device. In addition, a partition plate for partitioning the optical unit and the screen is provided in the cabinet so that leakage light from the light source is not applied to the screen.

  If the motor rotates at a high speed for a long time, abnormal noise may be generated due to the wear life of the bearing, or the rotation may stop. In such a case, the motor must be replaced. When exchanging the motor, first, the unit case of the optical unit is removed from the position adjustment base and taken out of the cabinet. Next, the cover of the unit case is removed, and the color wheel case is removed from the bottom surface of the unit case. Next, the cable is removed from the circuit board, the color wheel case is divided into two parts, a main body and a lid, and the motor is taken out and replaced with a new motor (a color filter is fixed in advance).

  Here, the insertion path of the tool for rotating the screw for removing the cover of the unit case and the tool for rotating the screw on the bottom surface of the unit case is blocked by the partition plate described above. Therefore, the motor cannot be replaced only after the unit case is removed from the position adjustment table and taken out of the cabinet. Furthermore, after the unit case is reattached to the position adjustment table, the position adjustment table must be operated in order to adjust the relative positional relationship between the optical unit and the screen, which increases the time required for motor replacement.

  The circuit board and the cable are accommodated in a shield case so that high-frequency noise generated in the circuit board does not leak to the outside of the cabinet through the cable. Therefore, when removing the cable from the circuit board, the cover must be removed from the shield case, and the replacement work becomes more complicated. In particular, since the cover of the shield case is attached to the lower side of the unit case (the side facing the position adjustment stand), remove the cover from the shield case only after removing the unit case from the position adjustment stand. I can't.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to facilitate motor replacement and shorten the time required for motor replacement.

  An image display device according to the present invention includes a light source, a color filter that transmits light emitted from the light source, a motor that rotates the color filter, a light valve that modulates light transmitted through the color filter, and modulation by the light valve. Optical system for projecting the emitted light onto a screen, a light source, a color filter, a motor, a light valve, a projection optical system and a device housing for housing the screen, a unit case provided inside the device housing, and a unit An opening formed in the case, a holder that holds the color filter and the motor, and is provided in the unit case so as to be insertable / removable through the opening, and provided in the apparatus housing opposite the opening of the unit case Operating opening.

  The video display device according to the present invention also includes a light source, a color filter that transmits light emitted from the light source, a motor that rotates the color filter, a light valve that modulates light transmitted through the color filter, and a light valve. A projection optical system that projects the light modulated by the light onto the screen, a light source, a color filter, a motor, a light valve, a projection optical system and a device housing that houses the screen, and a unit case provided inside the device housing; , An opening formed in the unit case, a circuit board that controls the drive of the motor in synchronization with the light valve, and provided inside the unit case and in the vicinity of the opening, and connected to the circuit board via a cable Connected relay board.

  According to the present invention, since the holder (holding the motor) can be removed from the opening of the unit case without removing the unit case from the apparatus housing, the motor can be easily replaced. Further, unlike the case where the unit case is taken out from the apparatus housing, it is not necessary to readjust the position of the unit case after the motor replacement, so that the time required for the motor replacement can be shortened.

  In addition, according to the present invention, since the cable can be removed from the relay board via the opening of the unit case, the motor can be easily replaced. In addition, since it is not necessary to remove a cover or the like of a case (for example, a shield case) that accommodates the circuit board, the time required for motor replacement can be shortened.

The best mode for carrying out the invention will be described below.
1 and 2 are a longitudinal sectional view and a sectional view showing the internal structure of the optical unit of the video display apparatus according to Embodiment 1 of the present invention. 3 to 5 are perspective views of the optical unit of the video display device.

  As shown in FIGS. 1 and 2, the optical unit 22 includes a light source 1 and a color filter 4 that transmits light emitted from the light source 1. A condensing lens (not shown) is provided between the light source 1 and the color filter 4. The light source 1 is, for example, a discharge lamp. Here, the light source 1 emits light in the horizontal direction. The color filter 4 is, for example, a glass disk, and has three color regions in which a thin film that transmits light of a specific wavelength band is deposited in the circumferential direction. The color filter 4 is attached to the main shaft of the motor 3 (FIG. 2), and rotates about a rotation axis that is substantially parallel to the incident direction of light from the light source 1. As the color filter 4 rotates at high speed, the light emitted from the light source 1 is separated into three colors.

  The optical unit 22 further includes mirrors 5 and 6 for substantially reversing the traveling direction of the light transmitted through the color filter 4, the prism 7 on which the reflected light from the mirrors 5 and 6 is incident, and the reflected light of the prism 7 is incident. And a light valve 8. The light valve 8 spatially modulates incident light based on a video signal (that is, generates a video). The light valve 8 and the color filter 4 are controlled in synchronization with each other by a control board 15 (FIG. 1) described later.

  The optical unit 22 further includes a projection optical system 9 that projects light modulated by the light valve 8. Here, the direction of the optical axis A of the projection optical system 9 is a substantially vertical direction (see FIG. 3). That is, the projection optical system 9 emits light vertically upward toward a mirror 25 (FIG. 11) described later disposed above the optical unit 22.

  The motor 3, the color filter 4, the mirrors 5 and 6, the prism 7, and the light valve 8 are attached to the inside of the bottom case 17. The bottom case 17 is a substantially box-shaped member whose upper side is opened, and the upper side thereof is covered with an upper case 21. Further, the projection optical system 9 described above is attached to the upper case 21. The bottom case 17 and the upper case 21 constitute a unit case that houses the motor 3, the color filter 4, the mirrors 5 and 6, the prism 7, and the light valve 8. The light source 1 is attached to the light source case 1 a (FIG. 12) attached to the bottom case 17.

  The basic operation of the optical unit 22 will be described with reference to FIG. The light 2 emitted from the light source 1 is converged by a condenser lens (not shown), passes through the color filter 4 rotated by the motor 3, and is reflected by the mirror 5 and the mirror 6 fixed to the bottom case 17, respectively. The light enters the light valve 8 through 7. The light modulated by the light valve 8 is projected onto the screen 26 (FIG. 11) by the projection optical system 9, and a color image is displayed on the screen 26.

  Next, the mounting structure of the color filter 4 and the motor 3 will be described. As shown in FIG. 3, the motor 3 having the color filter 4 fixed to the main shaft is fixed to a holder 31. A sensor substrate 33 having a sensor for detecting the rotational speed of the motor 3 is fixed to the holder 31.

  The bottom case 17 is provided with a guide 40 that guides the holder 31 in a direction substantially orthogonal to the optical axis (vertical axis) of the projection optical system 9. Note that the guide direction of the guide 40 is substantially orthogonal to the rotation axis of the color filter 4. In addition, an opening 30 for extracting the holder 31 from the bottom case 17 along the guide 40 is formed on the side surface of the bottom case 17. The opening 30 is covered with a removable cover 36. By removing the cover 36, the holder 31 can be extracted from the bottom case 17.

  In the state illustrated in FIG. 3, the holder 31 holding the color filter 4 and the motor 3 is extracted from the bottom case 17 through the opening 30 in the direction indicated by the arrow 34. In the state shown in FIG. 4, the holder 31 is inserted into the bottom case 17 in the direction indicated by the arrow 35 through the opening 30. In the state shown in FIG. 5, the holder 31 is completely inserted into the bottom case 17, and the opening 30 is closed with the cover 36. Insertion / removal directions indicated by arrows 34 and 35 are substantially orthogonal to the optical axis direction 36 of the projection optical system 9.

  The cover 36 is fixed to the side surface of the bottom case 17 with a screw 37 (FIG. 5) in a state of being in close contact with the periphery of the opening 30. When the opening 30 is closed by the cover 36, a notch 38 (FIGS. 3 to 4) formed at one end of the cover 36 is sandwiched between the side surface of the bottom case 17 and the hook 39 attached to the bottom case 17. Is done. Thereby, the gasket 36a (FIG. 2) fixed to the back surface of the cover 36 is in close contact with the periphery of the opening 30 to block the space between the opening 30 and the cover 36 and prevent dust from entering.

  6 to 9 are perspective views showing the holder 31 and the guide 40. 6 and 7, the state in which the holder 31 is inserted into the guide 40 and the state in which the holder 31 is extracted from the guide 40 are referred to as a light incident side with respect to the color filter 4 (hereinafter simply referred to as an incident side). It is the perspective view seen from. 8 and 9, the state in which the holder 31 is inserted into the guide 40 and the state in which the holder 31 is extracted from the guide 40 are the light emission side from the color filter 4 (hereinafter simply referred to as the emission side). It is the perspective view seen from.).

  As shown in FIGS. 7 and 9, the guide 40 has a pair of upper and lower upper walls 43 and 44 that are parallel to each other. The upper wall 43 and the lower wall 44 extend substantially horizontally and are formed long in a direction substantially orthogonal to the traveling direction of light from the light source 1. A side wall 50 extends downward from the incident side end of the upper wall 43, and a side wall 51 extends upward from the incident side end of the lower wall 44. Between the side walls 50 and 51, a side wall 40a that is slightly displaced to the incident side is formed. In the side wall 40a, an opening 40b through which light from the light source 1 passes is formed. A facing wall 48 extends downward from the end on the exit side of the upper wall 43 so as to face the side wall 50, and faces the side wall 51 from the end on the incident side of the lower wall 44. An opposing wall 49 extends upward. The space between these opposing walls 48 and 49 is open.

  Long plate springs (pressing members) 52 and 53 are attached to the side walls 50 and 51, respectively. The leaf spring 52 has a central portion fixed to the side wall 50 and both end portions bent to form contact portions 54 and 55. The contact portions 54 and 55 of the leaf spring 52 protrude from the notches 56 and 57 formed at both ends of the side wall 50 to the inside of the guide 40 (between the side wall 50 and the opposing wall 48). Similarly, the leaf spring 53 is fixed to the side wall 51 at the center and bent at both ends to form contact portions 58 and 59. The contact portions 58 and 59 of the leaf spring 53 protrude from the notches 60 and 61 formed at both ends of the side wall 51 to the inside of the guide 40 (between the side wall 51 and the opposing wall 49).

  The holder 31 has a pair of upper and lower upper walls 41 and 42 that are parallel to each other. The upper wall 41 and the lower wall 42 are formed long in a direction substantially orthogonal to the traveling direction of light from the light source 1. A side wall 47 is formed on the emission side of the upper wall 41 and the lower wall 42. A facing wall 45 extends downward from the incident side end of the upper wall 41 so as to face the side wall 47, and from the incident side end of the lower wall 42 to face the side wall 47. The opposing wall 46 extends upward. The space between the two opposing walls 45 and 46 is open. Further, a vertical wall 35 extending between the upper wall 41 and the lower wall 42 is formed at the side end of the side wall 47.

  As shown in FIGS. 8 and 9, the motor 3 is fixed to a motor mounting portion 47 b formed on the side wall 47 of the holder 31 with a screw 36. In the side wall 47, an opening 47a for allowing the light transmitted through the color filter 4 to pass therethrough is formed. One end of a cable 14 for transmitting a signal from the control circuit 15 is connected to the motor 3, and the cable 14 is drawn out of the holder 31 through an opening 47 a of the side wall 47. The interval between the upper wall 41 and the lower wall 42 is set so that the gaps between the upper wall 41 and the lower wall 42 and the color filter 4 are small. A sensor substrate 33 (FIG. 7) for detecting the rotation of the motor 3 is also attached to the side wall 47.

  As shown in FIG. 7, the upper wall 41, the lower wall 42, the opposing walls 45, 46 and the side wall 47 of the holder 31 are defined by the upper wall 43, the lower wall 44, the side walls 50, 51 and the opposing walls 48, 49 of the guide 40. Then, it is guided in a direction orthogonal to the optical axis of the projection optical system 9. Since the color filter 4 is surrounded by the upper wall 41, the lower wall 42, the opposing walls 45 and 46, and the side wall 47 of the holder 31, even if the user holds the holder 31 by hand, the color filter 4 remains on the surface of the color filter 4. Fingerprints and the like are not attached, and the color filter 40 is not damaged by contacting the periphery of the opening 30 or the guide 40.

  In the state where the holder 31 is inserted into the guide 40, the motor 3 and the color filter 4 are surrounded by the upper wall 41, the lower wall 42, the side wall 47 and the vertical wall 35 of the holder 31 and the side walls 40 a, 50, 51 of the guide 40. Enclosed. Thereby, adhesion of dust or the like to the color filter 4 is prevented. Further, the contact portions 54 and 55 of the leaf spring 52 of the guide 40 urge the opposing wall 45 of the holder 31, and the contact portions 58 and 59 of the leaf spring 53 urge the opposing wall 46 of the holder 31. The holder 31 is held in a state of being pressed against the guide 40 by the elastic force of the leaf springs 52 and 53.

  In addition, the guide 40 is being fixed to the bottom face of the bottom case 17, as shown in FIG. The height from the bottom surface of the bottom case 17 to the upper case 21 depends on the thickness of the upper wall 41 and the lower wall 42 of the holder 31 and the thickness of the upper wall 43 and the lower wall 44 of the guide 40 on the diameter of the color filter 4. It is set to be slightly higher than the added amount.

  FIG. 10 is a perspective view showing the holder 31, the guide 40, and the cover 36 taken out. FIG. 10 is a view of the cover 36 viewed from the back side in the insertion direction of the holder 31 (that is, the inside of the bottom case 17).

  As shown in FIG. 10, stoppers 62a and 62b are formed at the ends of the upper wall 43 and the lower wall 44 of the guide 40 in the holder insertion direction, respectively. When the holder 31 is inserted along the guide 40, the end portions 63a and 63b of the upper wall 41 and the lower wall 42 of the holder 31 come into contact with the stoppers 62a and 62b. Further, when the cover 36 is fixed to the bottom case 17 with the screw 37 (FIG. 5), the leaf spring 64 fixed to the inside of the cover 36 comes into contact with the vertical wall 35 (FIGS. 6 to 9) of the holder 31. Is biased in the insertion direction. Thereby, the holder 31 is fixed in the state pressed with respect to the guide 40 in the insertion direction. Therefore, when the holder 31 is attached to the optical unit 22 for motor replacement or the like, the holder 31 can be positioned with respect to the bottom case 17 of the optical unit 22 only by tightening one screw 37 (FIG. 5).

  With respect to the shape and material of the leaf spring 64 and the above-described leaf springs 52 and 53 (FIGS. 6 to 7), the natural frequency when each presses the holder 31 is lower than the rotational frequency of the motor 3. Is set to Thereby, the vibration generated when the motor 3 rotates at high speed is attenuated by the leaf springs 52 and 53 and the leaf spring 64, and the propagation of the vibration to the structure such as the bottom case 17 is suppressed. As a result, noise caused by rotational vibration of the motor 3 outside the optical unit 22 is reduced.

  Here, when replacing the motor, in addition to removing the motor 3, it is necessary to remove a cable for transmitting a control signal from the circuit board 15 to the motor 3. The configuration for this will be described below.

  As shown in FIG. 1, the circuit board 15 having a control circuit for controlling the motor 3 and the light valve 8 is fixed to the lower surface of the bottom case 17 so that the generated high-frequency electromagnetic waves do not leak outside. It is attached inside the shield case 65. The shield case 65 is a box-shaped container whose bottom is opened, and its lower surface is covered with a shield cover 65a.

  In addition, one end of a cable 66 that transmits a signal for rotating the motor 3 in synchronization with the driving of the light valve 8 is connected to the circuit board 15. A relay board 67 to which the other end of the cable 66 is connected is attached to the bottom case 17. The cable 14 connected to the motor 3 is detachably attached to the relay board 67. Electric power and a rotation synchronization signal for rotationally driving the motor 3 are sent from the circuit board 15 to the motor 3 through the cable 66, the relay board 67 and the cable 14.

  As shown in FIG. 4, the relay substrate 67 is disposed inside the bottom case 17 and in the vicinity of the opening 30. Therefore, when replacing the motor 3, the cable 14 can be easily detached from the relay board 67 through the opening 30 by removing the cover 36 from the opening 30 of the bottom case 17.

  A cable 66 connecting the relay board 67 in the bottom case 17 and the circuit board 15 in the shield case 65 passes through the through hole 68 (FIG. 1) of the bottom case 17 and the through hole of the shield case 65, and The case 17 and the shield case 65 are not exposed to the outside.

  The bottom case 17, the upper case 21, the cover 36, and the gasket 36a are all formed of a conductive member (for example, aluminum). Therefore, even if high-frequency electromagnetic waves generated in the circuit board 15 propagate to the cable 14 via the cable 66, the cable 14 is surrounded by a conductive member. Electromagnetic waves are prevented from leaking to the surface.

  FIG. 11 is a longitudinal sectional view showing the basic configuration of the video display apparatus according to Embodiment 1 of the present invention, in which the above-described optical unit 22 is mounted. FIG. 12 is an enlarged rear view showing a part of the video display device shown in FIG.

  As shown in FIG. 11, the image display device projects the position adjusting table 24 to which the above-described optical unit 22 is fixed, the mirror 25 provided on the upper part of the optical unit 22, and the image reflected by the mirror 25. A screen 26 and a cabinet (device casing) 23 for housing them. The light emitted upward from the projection optical system 9 of the optical unit 22 is reflected by the mirror 25 and projected onto the screen 26, whereby the image is enlarged and projected onto the screen 26. The position adjusting table 24 adjusts the position of the image projected on the screen 26 by adjusting the position of the optical unit 22. Further, a partition plate 27 is provided between the optical unit 22 and the screen 25 so that the light leaked from the light source 1 in the optical unit 22 is not directly applied to the screen 26.

  As indicated by the alternate long and short dash line X in FIG. 12, the light emission direction from the light source 1 (FIG. 1 or the like) of the optical unit 22 is substantially parallel to the horizontal direction of the screen 26 (FIG. 11). Moreover, the extraction direction 34 (FIG. 3) of the holder 3 from the optical unit 22 is a direction toward the side opposite to the screen 26 side, that is, the back side of the cabinet 23.

  As shown in FIG. 12, a maintenance opening (operation opening) 69 is provided on the back surface of the cabinet 23 at a position corresponding to the cover 36 that closes the opening 30 (FIG. 3 and the like) of the optical unit 22. . The maintenance opening 69 is closed by a cover 70 that can be opened and closed. The maintenance opening 69 and the cover 70 are provided for taking in and out the parts when replacing the parts.

  When abnormal noise is generated from the motor 3 due to the wear life of the ball bearing of the motor 3 or the rotation stops, the cover 70 is first opened and the maintenance opening 69 is opened. Next, the screw 37 of the bottom case 17 of the optical unit 22 is loosened from the maintenance opening 69, and the cover 36 is removed. Thereby, the opening part 30 (FIG. 3) of the bottom case 17 is open | released.

  Next, as shown in FIG. 4, the cable 14 is removed from the relay substrate 67 through the opening 30 of the bottom case 17. After removing the cable 14, the holder 31 is extracted from the bottom case 17 along the guide 40 as shown in FIG. 3. Next, the motor 3 (with the color filter 4 fixed) is removed and replaced with a new motor 3 with a new color filter 4 fixed in advance.

  After attaching the new motor 3 to the holder 31, the holder 31 is inserted along the guide 40 from the opening 30 of the bottom case 17. Next, the cable 14 is connected to the relay substrate 67, and the cover 36 is fixed to the bottom case 17 with screws 37. Thereafter, when the cover 70 of the maintenance opening 69 is closed, the replacement operation of the motor 3 is completed.

  In the above-described replacement work of the motor 3, when the cover 70 of the maintenance opening 69 for taking in and out the parts at the time of parts replacement is opened, the screw 37 can be visually recognized on the front surface, and a tool for loosening the screws. Since 20a (for example, a driver) can be easily inserted from the maintenance opening 69, the holder 31 can be taken out of the optical unit 22 without removing the optical unit 22 from the position adjusting table 24.

  Further, since it is not necessary to remove the optical unit 22 from the position adjusting table 24, the positional relationship between the screen 26 and the projection optical system 9 does not change before and after the motor replacement, and therefore the position adjusting table 24 after the motor 3 is replaced. There is no need to readjust. As a result, the motor replacement work can be facilitated and the time required for motor replacement can be shortened.

  Next, specific numerical examples for reducing noise caused by rotational vibration of the motor 3 will be described. The natural frequencies of the leaf springs (the leaf springs 52, 53, and 64 described above) are as follows: gravity acceleration is g, leaf spring biasing force is W, leaf spring longitudinal elastic modulus is E, leaf spring section modulus is When the distance from the fixed point of the leaf spring to the action point is L, it is expressed by the following formula (1).

As a specific numerical example, each of the leaf springs 52, 53, and 64 has an urging force of 4.4 N (450 g), a longitudinal elastic modulus of 1.8 × 10 ¹¹ Pa (19000 kg / mm ² ), and a section modulus. 0.0135, and the distance from the fixed point to the action point is 12 mm. The rotation frequency of the motor 3 is set to 120 Hz. From the above formula (1), the natural frequency (f) of each of the leaf springs 52, 53, and 64 is about 64 Hz, which is sufficiently lower than the rotational frequency of the motor 3. With this configuration, the leaf springs 52, 53, and 64 do not resonate with the rotational vibration of the motor 3, and the vibration generated when the motor 3 rotates at high speed is attenuated. As a result, propagation of vibration to the structure such as the bottom case 17 is suppressed, and noise caused by rotational vibration of the motor 3 is reduced.

  As described above, in the present embodiment, the holder 31 on which the motor 3 is mounted can be extracted from the bottom case 17 of the optical unit 22 through the opening 30, so that the optical unit 22 is removed from the position adjustment table 24. The motor can be replaced without removing it, and the work for replacing the motor is facilitated. In addition, since it is not necessary to readjust the position adjusting table 24 after replacing the motor 3, the time required for replacing the motor can be shortened.

  In addition, since the direction in which the holder 31 is inserted and removed is a direction substantially orthogonal to the optical axis of the projection optical system 9, the user can remove the holder 31 horizontally (more specifically, on the back side of the cavity 23). The holder 31 can be easily pulled out.

  Furthermore, since the holder 31 is guided by the guide 40, a configuration that allows the holder 31 to be inserted and removed can be realized with a simple configuration.

  In addition, since the color filter 4 is covered with the holder 31 and the guide 40 in a state where the holder 31 is inserted into the bottom case 17, it is possible to prevent dust from adhering to the color filter 4.

  In addition, since the holder 31 is pressed against the guide 40 by the leaf springs 52, 53, 64, it is possible to prevent the holder 31 from rattling and to accurately position the color filter 4 and the motor 3. it can.

  Further, since the natural frequency of the leaf springs 52, 53, 64 is set sufficiently lower than the rotation frequency of the motor 3, vibration due to the high speed rotation of the motor 3 is attenuated by the leaf springs 52, 53, 64, and noise is generated. Can be reduced.

  In the present embodiment, because the cable 14 can be removed from the relay board 67 through the opening 30 of the bottom case 17 of the optical unit 22, the cable 14 can be removed when replacing the motor. It is not necessary to remove the shield cover 65a from the shield case 65. Therefore, motor replacement can be performed easily, and the time required for motor replacement can be shortened.

  Furthermore, since the cable 14 connecting the relay substrate 67 and the motor 3 is surrounded by a conductive unit case (the bottom case 17 and the upper case 21), leakage of electromagnetic waves to the outside is suppressed.

  Note that the configuration in which the relay substrate 67 is arranged in the vicinity of the opening 30 in the bottom case 17 is not a video display device in which the holder 31 can be inserted and removed from the opening 30 of the bottom case 17 as in the present embodiment. It can also be applied to other video display devices.

  Finally, in order to facilitate understanding of the effects of the present embodiment, a video display device according to a comparative example with respect to the present embodiment will be described. FIG. 13 is a cross-sectional view illustrating an optical unit of a video display device according to a comparative example, and FIG. 14 is a cross-sectional view illustrating a video display device according to a comparative example.

  In the optical unit 22 shown in FIG. 13, the color filter 4 and the motor 3 are sealed inside splittable unit cases 12 and 13 having a transparent window portion 11. A cable 14 for supplying electric power to the motor 3 is drawn out from the unit cases 12 and 13 and connected to the circuit board 15. The unit cases 12 and 13 are fixed to the bottom surface of the bottom case 17 with screws 20. That is, the unit cases 12 and 13 can be detached from the bottom case 17 by removing the upper case 21 from the bottom case 17.

  In the image display device according to this comparative example, the tool 20a (FIG. 14) for rotating the screw for removing the upper case 21 from the bottom case 17 and the screw for removing the unit cases 12, 13 from the bottom case 17 are rotated. The insertion path of the tool to be operated is blocked by a partition plate 27 between the screen 26 and the optical unit 22. For this reason, the motor 3 cannot be replaced unless the optical unit 22 is removed from the position adjusting table 24 and taken out of the cabinet 23. Furthermore, after the optical unit 22 is attached to the position adjustment table 24, the position adjustment table 24 must be readjusted.

  Further, the cable 14 is accommodated in a shield case 29 (FIG. 11) so that high frequency noise generated in the circuit board 15 does not leak outside the cabinet 23 via the cable 14, and the opening of the shield case 29 is shielded. Covered by a cover 28. Accordingly, the shield cover 28 must be removed from the shield case 29 when the motor 3 is replaced. Since the shield cover 28 is disposed between the optical unit 22 and the position adjustment table 24, the shield cover 28 cannot be removed from the shield case 29 unless the optical unit 22 is removed from the position adjustment table 24. The time required for motor replacement becomes longer.

  Thus, in the video display device according to the comparative example, the replacement work of the motor 3 is complicated, and the time required for replacement of the motor 3 becomes long.

  On the other hand, in the present embodiment, by opening the cover 70 of the cabinet 23 and opening the cover 36 of the bottom case 17 of the optical unit 22, the holder 31 on which the motor 3 is mounted is extracted from the opening 30 of the bottom case 17. be able to. In this manner, the holder 31 can be extracted without removing the optical unit 22 from the position adjusting table 24, so that the work for replacing the motor is facilitated. In addition, since it is not necessary to adjust the position adjusting table 24 after replacing the motor 3, the time required for replacing the motor can be shortened.

  The present invention is not limited to the video display device described in the above-described embodiment, and can be applied to various video display devices. The present invention is, for example, a video display device that operates 24 hours a day and is used for a long period of time, and can be a business problem if the motor replacement time (time during which video is not displayed) is prolonged (for example, for monitoring) This is particularly useful for video display devices used in

It is sectional drawing which shows the internal structure of the video display apparatus concerning one embodiment of this invention. It is a top view which shows the internal structure of the video display apparatus concerning one embodiment of this invention. It is a perspective view of the video display device concerning one embodiment of this invention, and is a perspective view showing the state where the holder was taken out from the opening of the bottom case. It is a perspective view of the video display device concerning one embodiment of this invention, and is a perspective view showing the state where the holder was inserted in the opening of the bottom case. It is a perspective view of the video display device concerning one embodiment of this invention, and is a perspective view showing the state where the opening of the bottom case was closed with the cover. It is a perspective view which shows the state in which the holder of the video display apparatus concerning one embodiment of this invention was inserted in the guide. It is a perspective view which shows the state from which the holder of the video display apparatus concerning one embodiment of this invention was taken out from the guide. It is a perspective view which shows the state in which the holder of the video display apparatus concerning one embodiment of this invention was inserted in the guide. It is a perspective view which shows the state from which the holder of the video display apparatus concerning one embodiment of this invention was taken out from the guide. It is a perspective view which shows the holder of the video display apparatus which concerns on one embodiment of this invention, a guide, and a cover. 1 is a side sectional view showing a video display apparatus according to an embodiment of the present invention. It is a rear view which expands and shows a part of video display device concerning one embodiment of this invention. It is sectional drawing which shows the video display apparatus concerning a comparative example. It is a sectional side view which shows the video display apparatus concerning a comparative example.

Explanation of symbols

  3 motor, 4 color filter, 8 light valve, 9 projection optical system, 14,66 cable, 15 circuit board, 17 bottom case, 21 upper case, 22 optical unit, 23 cabinet, 26 screen, 30 opening, 31 holder, 36 cover, 40 guide, 52, 53, 64 spring member, 65 shield case, 67 relay board, 69 opening for maintenance, 70 cover.

Claims (9)

A light source;
A color filter that transmits light emitted from the light source;
A motor for rotating the color filter;
A light valve that modulates light transmitted through the color filter;
A projection optical system that projects light modulated by the light valve onto a screen;
An apparatus housing that houses the light source, the color filter, the motor, the light valve, the projection optical system, and the screen;
A unit case provided inside the device housing;
An opening formed in the unit case;
A holder that holds the color filter and the motor, and is provided in the unit case so as to be inserted / removed through the opening;
An image display device comprising: an operation opening provided in the device casing so as to face the opening of the unit case.   The video display apparatus according to claim 1, wherein a direction in which the holder can be inserted and removed is a direction substantially orthogonal to the optical axis of the projection optical system.   The video display device according to claim 1, further comprising a guide for guiding the holder in the direction in which the holder can be inserted and removed.   The video display according to claim 3, wherein the unit case and the guide are configured to cover the color filter and the motor in a state where the holder is inserted into the unit case. apparatus.   5. The video display device according to claim 1, further comprising a pressing member that presses the holder against the guide in a state where the holder is inserted into the unit case. 6. . The pressing member is at least one spring member;
The video display device according to claim 5, wherein a natural frequency of the spring member is lower than a rotation frequency of the motor. A light source;
A color filter that transmits light emitted from the light source;
A motor for rotating the color filter;
A light valve that modulates light transmitted through the color filter;
A projection optical system that projects light modulated by the light valve onto a screen;
An apparatus housing that houses the light source, the color filter, the motor, the light valve, the projection optical system, and the screen;
A unit case provided inside the device housing;
An opening formed in the unit case;
A circuit board that controls driving of the motor in synchronization with the light valve;
An image display device comprising: a relay substrate provided in the unit case and in the vicinity of the opening, and connected to the circuit substrate via a cable.   The video display device according to claim 7, wherein a portion surrounding the cable in the unit case is formed of a conductive member.   The video display device according to claim 7, further comprising a holder that holds the color filter and the motor and is provided in the unit case so as to be inserted and removed through the opening.

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