JP4394420B2 - Projector with dust removal device - Google Patents

Description

  The present invention relates to a projector that includes an opening of a housing and a projection mirror, and enlarges and projects the display light of an image generated by a video display element onto an external screen, and in particular, removes dust from the reflection surface of the projection mirror and the entire opening. The present invention relates to a projector provided with a dust removing device.

  Projectors for enlarging and projecting display light of an image generated by a video display element onto a screen provided outside are used for various purposes. In recent years, the focus of the projector has been shortened, and the number of projectors that can extremely shorten the projection display distance is increasing.

  Recently, a projector equipped with a projection mirror in a housing having an aperture structure that can achieve a further ultrashort focus has been developed. FIG. 3 is a schematic side view showing an outline of a projector having a projection mirror having a conventional aperture structure. As shown in FIG. 3, a housing opening 33 is provided in the housing 32 of the projector 31, and the housing opening 33 has an emission opening 34 that emits display light. A projection mirror 35 is provided so as to face 34. In use, image display light 36 from an image generated by a video display element (not shown) inside the housing 32 is emitted through the emission opening 34, reflected by the projection mirror 35, and provided outside (not shown). The image is projected on the screen. Although the light source, the image display element, the optical system, and the like constituting the projector 31 are disposed inside the housing 32, they are not shown. The projection mirror 35 may also be used as the lid of the opening 33, and the lid may be closed when the projector 31 is not used.

4A and 4B are external views of the aperture structure projector disclosed in Patent Document 1, in which FIG. 4A is a plan view and FIG. 4B is a side view. An aperture projection type projector as shown in FIG. 4 has also been developed, and this aperture projection type projector reflects the display light modulated by the light source 44, the liquid crystal display element 45, and the image generated by the liquid crystal display element 45. A projection mirror 43 that receives light via a mirror 46 and a reflection mirror 47 and projects it onto an external screen (not shown); and a housing 41 that houses a light source 44, a liquid crystal display element 45, and an illumination optical system. Between the liquid crystal display element 45 and the projection mirror 43 of the body 41, there is an opening 42 for emitting display light from the liquid crystal display element 45 to the projection mirror 43, and at one end is held by the casing 41 by a hinge. The other end of the projection mirror 43 is attached to the upper side wall of the housing 41 so as to be able to fall down and pull up. In the raised state, the projection optical system is configured to fall down. In functioning as a lid for closing the housing opening 42 (see Patent Document 1).
JP-A-11-119343 ([0032] to [0034], FIG. 1)

  In the case of a projector having such an opening structure of the housing and a projection mirror, the projection mirror is exposed at least during use from the structural surface, and therefore dust adheres to the reflective surface and causes image degradation, etc. Will adversely affect. When dust is wiped off, it is necessary to use a soft specially processed cloth so as not to damage the reflecting surface of the projection mirror, and to wipe it off with great care.

  Even in the aperture projection type projector described in Patent Document 1, the projection mirror is exposed during projection, and dust adheres to the image, causing adverse effects such as image degradation. However, Patent Document 1 does not describe any countermeasure against dust adhesion.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a projector having a dust removing device capable of removing dust efficiently and automatically without damaging the reflecting surface of the projection mirror in order to solve the above problems. .

The projector with the dust removing device of the present invention is
The display light of the image generated by the video display element inside the housing is projected from the exit opening to the projection mirror via the housing opening provided in the housing, and reflected by the projection mirror to be externally transmitted. A projector that projects an enlarged image on a screen includes a dust removing device for removing dust attached to the reflecting surface of the projection mirror . The dust removing device includes an ultrasonic vibration unit that vibrates the projection mirror to shake off dust attached to the reflection surface, and a blower fan unit that blows air to the reflection surface of the projection mirror. The blower fan unit includes a blower fan and driving means for driving the blower fan. The blower fan is provided in the vicinity of the emission opening, and the bottom surface of the housing opening and the reflection surface of the projection mirror are continuous surfaces that allow the air blown from the blower fan to flow smoothly.

The blower spout of feed air fan may have an opening control unit capable of controlling the opening degree of the spout.

  In this invention, it has a projection mirror for projecting the display light of the image produced | generated on the video display element on an external screen, and for emitting image display light to a projection mirror between a video display element and a projection mirror In a projector having a housing opening, an ultrasonic vibrator is disposed so that ultrasonic vibration is transmitted to the projection mirror, and dust attached to the projection mirror is shaken off by the ultrasonic vibration. Furthermore, it has a function of blowing off dust adhering to the projection mirror reflecting surface and the entire opening by blowing air from the blower fan.

  In the present invention, an opening structure of the housing and a projection mirror are provided, and image display light of an image generated by the video display element is projected to the projection mirror via the housing opening, and reflected by the projection mirror to the outside. In the projector that enlarges and projects on the provided screen, there is an effect that dust attached to the entire reflection surface of the projection mirror and the housing opening can be automatically removed at once. This is provided with a dust removing device having an ultrasonic vibration unit that vibrates the projection mirror and shakes off dust adhering to the reflection surface, and a blower fan unit that blows air on the reflection surface of the projection mirror, and is reflected by the ultrasonic vibration unit. This is because the dust adhering to the surface is shaken off and the blower fan part blows off the dust. In addition, this has the effect of greatly simplifying maintenance.

  Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic partially transparent side view for explaining a projector with a dust removing device according to an embodiment of the present invention. Although not shown in FIG. 1, a video display element, a light source (lamp), which is configured from a liquid crystal display element, a DMD panel element, or the like, which is necessary for configuring the projector 1, for example, is necessary to configure the projector 1. ), An optical system for guiding the image display light 6 to the emission opening 4 is provided. The projection mirror 5 is disposed on a lid member (not shown) that can close the housing opening 3 of the housing 2 so that the housing opening 3 is closed by the lid member when the projector 1 is not used. Also good.

  When in use, the housing opening 3 and the projection mirror 5 are structurally exposed, and dust adhering to the projection mirror 5 adversely affects image degradation. In the conventional example, dust that has adhered to the reflecting surface of the projection mirror 5 uses a soft specially processed cloth so as not to damage the projection mirror 5, and it is necessary to carefully wipe it off. Moreover, when the projector 1 is installed in a place where it cannot be easily touched by humans, it is very difficult to remove dust.

  In addition, since dust tends to collect in the housing opening 3 and the display light 6 is hardly enlarged on the image display element side of the emission opening 4, the display light 6 emitted from the emission opening 4. There is a problem that the strength of the material is very large, and a thing close to black, such as dust, accumulates and generates heat when hit with this light beam.

  In the present embodiment, in order to prevent dust from adhering to the exposed casing opening 3 and the projection mirror 5 and causing adverse effects such as image degradation, the ultrasonic vibrator 8 A dust removing device including a blower fan 9 is provided. In other words, the ultrasonic vibrator 8 constituting the dust removing device is disposed on the back side of the projection mirror 5, and the dust attached to the reflection surface of the projection mirror 5 is naturally dropped by vibration. Further, a blower fan 9 is arranged on the wall surface side where the emission opening 4 from which the image display light 6 is emitted, and the blower fan 9 blows air from the blowout port 10 to the entire housing opening 3 and the projection mirror. 5 is blown out toward the reflecting surface, and the dust in that portion is blown off. Although not shown in FIG. 1, as will be described later, the dust removing device includes a switch circuit and a blower fan 9 that can detect whether the projector 1 is turned on or off or can manually command the operation. An electric circuit having driving means for driving is provided.

  FIG. 2 is a block configuration diagram for explaining the dust removing device of the projector with the dust removing device according to the embodiment of the present invention. The dust removing apparatus 20 includes a switch circuit 11 having a manual switch 12 and a power on / off detection unit 13, a timer circuit 14, an ultrasonic vibrator driving circuit 15, an ultrasonic vibrator 8, a blower fan drive circuit 24, and a blower fan. 9 is composed. The ultrasonic transducer drive circuit 15 includes a constant voltage circuit 16, an oscillation circuit 17, a drive control circuit 18, a switching circuit 19, and a transformer 23.

  A dust removal operation is commanded by turning on the manual switch 12. When the manual switch 12 is turned on, the timer circuit 14 is set to the “L” level of the ground shown in the figure, and the timer circuit 14 operates to supply current to the ultrasonic transducer driving circuit 15 for a predetermined time.

  The constant voltage circuit 16 of the ultrasonic transducer driving circuit 15 receives the supply of the power supply voltage from the timer circuit 14 and supplies a constant voltage current to the oscillation circuit 17, the drive control circuit 18, and the switching circuit 19. The oscillation circuit 17 includes a crystal resonator 21 and supplies a rectangular wave having a predetermined frequency to the drive control circuit 18. When the current is supplied from the constant voltage circuit 16, the drive control circuit 18 sends a rectangular wave having a predetermined frequency to the switching circuit 19 using the rectangular wave from the oscillation circuit 17. In the switching circuit 19, a current is supplied to the primary winding side of the transformer 23 connected to the collector side of the transistor 22 by switching the transistor 22 in accordance with ON / OFF of the output port of the drive control circuit 18. The Accordingly, the ultrasonic vibrator 8 is vibrated by being supplied with a current from the secondary winding side of the transformer 23.

  As this ultrasonic transducer 8, for example, a known ultrasonic transducer such as an ultrasonic transducer in which electrodes are provided on both surfaces of a piezoelectric element such as ceramic is used.

  The switch circuit 11 includes a manual switch 12 that operates manually and a power on / off detection circuit 13. When the manual switch 12 is turned on, the timer circuit 14 performs a dust removal operation for a predetermined time. The power on / off detection circuit 13 detects, for example, a signal when the power is turned on from the microcomputer of the projector 1 and the like, and the timer circuit 14 performs dust for a predetermined time until the emitted light source lamp reaches a certain brightness. The removal operation is performed. Similarly, power off is detected, and the dust removal operation is performed for a predetermined time by the timer circuit 14 within the cooling time of the lamp of the light source.

  Further, the blower fan drive circuit 24 is supplied with a current for a predetermined time by the timer circuit 14 to drive the blower fan 9, and the air blower fan 9 is supplied from the blower opening 10 to the entire reflecting surface of the housing opening 3 and the projection mirror 5. Spray the air. As a result, the dust shaken off by the vibration of the ultrasonic vibrator 8 and the dust accumulated in the housing opening 3 can be blown away from the reflecting surface of the projection mirror 5 at a time.

  It is desirable to install a filter or an aperture mechanism in the air outlet 10 so that dust does not enter the main body of the projector 1 from the air outlet 10 when the dust removing operation is not performed.

  In this case, it is desirable that the filter has a mesh size that does not hinder the ventilation of the blower fan 9. Further, the opening area of the air outlet 10 may be made variable by an aperture mechanism (not shown) so that dust does not enter inside when the dust removal operation is not performed.

  Moreover, by making the bottom surface structure of the housing opening 3 flat and inclined, it is possible to make a curved line with less resistance from the outlet 10 of the blower fan 9 to the tip of the projection mirror 5. It can be efficiently ejected from the bottom surface of the housing opening 3 along the reflection surface of the projection mirror 5 to the outside of the projector 1.

  As described in detail above, in the present embodiment, air is blown from the blower fan 9 to the entire reflection surface of the housing opening 3 and the projection mirror 5, so that the ultrasonic vibrator 8 causes the reflection surface of the projection mirror 5 to be blown. The dust that has been shaken off and the dust that has accumulated in the housing opening 3 can be blown off at once.

It is a typical partial see-through side view for demonstrating the projector with the dust removal apparatus of embodiment of this invention. It is a block block diagram for demonstrating the dust removal apparatus of the projector with the dust removal apparatus of embodiment of this invention. It is a typical side view which shows the outline | summary of the projector which has a projection mirror by the conventional opening structure. FIG. 11 is an external view of an aperture structure projector disclosed in Patent Document 1. (A) is a top view. (B) is a side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 31 Projector 2, 32, 41 Case 3, 33, 42 Case opening 4, 34 Output opening 5, 35, 43 Projection mirror 6, 36 Image display light 7, 37 Projection mirror cover 8 Ultrasonic transducer DESCRIPTION OF SYMBOLS 9 Blower fan 10 Outlet 11 Switch circuit 12 Manual switch 13 Power ON / OFF detection circuit 14 Timer circuit 15 Ultrasonic vibrator drive circuit 16 Constant voltage circuit 17 Oscillation circuit 18 Drive control circuit 19 Switching circuit 20 Dust removal device 21 Crystal vibration Child 22 Transistor 23 Transformer 24 Blower fan drive circuit 46, 47 Reflection mirror 44 Light source 45 Liquid crystal display element

Claims (2)

The display light of the image generated by the video display element inside the housing is projected from the exit opening to the projection mirror via the housing opening provided in the housing, and is reflected by the projection mirror to be externally transmitted. In the projector that projects on the screen of
A dust removing device for removing dust adhering to the surface of the projection mirror ;
The dust removing device includes an ultrasonic vibration unit that vibrates the projection mirror and shakes off dust attached to a reflection surface, and a blower fan unit that blows air to the reflection surface of the projection mirror,
The blower fan unit includes a blower fan and driving means for driving the blower fan,
The blower fan is provided in the vicinity of the emission opening, and the bottom surface of the housing opening and the reflection surface of the projection mirror are a continuous surface through which air from the blower fan flows smoothly. A projector with a dust removal device. The projector with a dust removing device according to claim 1 , wherein the blower outlet of the blower fan has an opening control unit capable of controlling an opening degree of the outlet.

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