JP2015087525A - Light source device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device capable of preventing illuminance reduction caused by dust and dispensing with the maintenance of a structure for capturing the dust and to provide a projector.SOLUTION: A light source device 12R includes a light emitting element, an optical element on which light from the light emitting element is made incident, an electrode part 34 capturing the dust floating toward the optical element, a housing 19 storing the optical element and the electrode part 34, a power supply applying a voltage to the electrode part 34, a dust discharge device 35 sucking the dust and discharging the dust to the outside of the housing 19, and a controller controlling the power supply and the dust discharge device 35.

Description

  The present invention relates to a light source device and a projector.

  Conventionally, a high-intensity discharge lamp has been used as a light-emitting element of a light source device in a projector. In recent years, a light source and an optical path configuration using a laser diode (LD) that generates less heat than a discharge lamp have been proposed. (Patent Documents 1 and 2). Patent Document 3 discloses that electrostatic charge is used to capture dust charged to a polarity opposite to the polarity of an electrode.

JP 2011-13317 A JP 2011-76781 A JP 2008-18340 A

  However, in the case of a configuration using a laser diode, dust or the like contained in the air introduced into the projector due to cooling or the like adheres to the surface of each lens constituting the optical system due to the light dust collecting effect, and the illuminance decreases. There is a problem of end up.

  In the configuration of Patent Document 3, since the surface of the electrode that captures dust is coated with an adhesive, the dust trapped on the surface of the electrode is not scattered even when the power is turned off. However, there is a problem that it is necessary to replace the electrode, and it takes time and effort for maintenance.

  One aspect of the present invention is a light source device and a projector that are made in view of the above-described problems of the prior art and that can prevent a decrease in illuminance due to dust and eliminate the need for maintenance of a structure for capturing dust. One of the purposes is to provide it.

  In order to solve the above problems, a light source device according to one aspect of the present invention includes a light emitting element, an optical element on which light from the light emitting element is incident, and an electrode unit that captures dust floating toward the optical element. A housing that houses the optical element and the electrode unit, a voltage applying unit that applies a voltage to the electrode unit, a dust discharging device that sucks and discharges the dust to the outside, and And a control device for controlling the voltage applying means and the dust discharging device.

According to the light source device of one aspect of the present invention, dust floating toward the light emitting element can be captured on the surface of the electrode portion by applying a voltage to the electrode portion by the voltage applying means. In addition, the dust discharging device sucks the dust in the housing including the dust trapped on the surface of the electrode portion and discharges it to the outside of the housing, so that the dust can be prevented from re-floating in the housing. Maintenance such as replacing the electrode is not necessary.
In this way, floating dust is captured on the electrode portion and discharged to the outside of the housing by the dust discharging device, thereby preventing dust from adhering to the light emitting element due to the light dust collecting effect. It is possible to prevent a decrease in illuminance of the light source device due to dust.

  In addition, when the light source device is stopped, the control device turns off the light emitting element and stops the voltage application to the electrode unit by the voltage applying unit, and then operates the dust discharging device for a predetermined time. Is preferably maintained.

  According to this configuration, the light emitting element is first turned off by the control device, and after the voltage application means stops the voltage application to the electrode unit, the dust discharging device is maintained in an operating state for a predetermined time. The trapped dust can be efficiently discharged out of the housing.

  Moreover, at the time of starting the light source device, it is preferable that the control device turns on the light emitting element after the voltage applying unit starts to apply a voltage to the electrode unit.

According to this configuration, the voltage application unit can lighten the light emitting element after the voltage application to the electrode portion is started, thereby capturing dust floating in the housing in advance before the light emitting element is turned on. it can. Thereby, generation | occurrence | production of optical dust collection can be prevented.
Further, dust can be captured if a voltage is applied to the electrode portion, but it is preferable to operate the dust discharging device before the light emitting element is turned on. As a result, dust that has not yet been captured on the electrode part and is floating can be discharged to the outside of the housing, so that dust removal efficiency is increased.

  In addition, it is preferable that the electrode portion includes an electrode disposed in a direction along an optical path of a light beam emitted from the light emitting element or in a direction intersecting the optical path, and the electrode does not block the optical path.

  According to this configuration, by arranging the electrode (electrode part) so as not to block the optical path of the light emitted from the light emitting element, it is possible to prevent a decrease in illuminance due to the electrode.

  Moreover, it is preferable that the said electrode part contains the 1st electrode and 2nd electrode which are arrange | positioned on both sides of the said optical path on both sides of the said optical path.

  According to this configuration, dust can be efficiently removed from the vicinity of the light emitting element by disposing the first electrode and the second electrode on both sides of the optical path across the optical path of the light emitted from the light emitting element. .

  The casing includes a chamber, the electrode unit is provided in the chamber, the dust discharging device includes a duct and a fan provided in the duct, and the opening of the duct is formed in the first portion. It is preferable to be provided so as to communicate with the space between the electrode and the second electrode.

  According to this configuration, by providing an opening in the duct near the first electrode and the second electrode, even if voltage application to the first electrode and the second electrode is stopped, they are captured on the first electrode and the second electrode. The dust can be efficiently discharged outside the casing through the duct without being scattered in the casing (chamber). Further, since the dust is forcibly discharged out of the housing by the fan, a clean environment can be realized over a wide range.

  The first electrode and the second electrode are arranged so as to intersect with the optical path, and the first electrode and the second electrode are provided with holes for allowing the light from the light emitting element to pass therethrough. Is preferred.

  According to this configuration, since the light flux emitted from the light emitting element can be surrounded by the first electrode and the second electrode, dust can be more effectively removed from the vicinity of the light emitting element (on the optical path of the light). Can do.

  A projector according to an aspect of the present invention projects the light source device described above, a light modulation device that modulates light emitted from the light source device according to image information, and modulated light from the light modulation device as a projection image. A projection optical system.

  According to this configuration, dust floating toward the light modulation device can be captured on the electrode. Thereby, adhesion of dust to the light modulation device due to the light dust collection effect can be prevented.

  A projector according to an aspect of the present invention projects the light source device described above, a light modulation device that modulates light emitted from the light source device according to image information, and modulated light from the light modulation device as a projection image. A projection optical system, an electrode portion that captures dust floating toward the light modulation device, a main housing that houses the light source device, the light modulation device, the projection optical system, and the electrode portion, A dust discharging device that sucks dust and discharges it to the outside of the main housing; and a control device that controls the voltage applying means and the dust discharging device.

  According to the projector of one aspect of the present invention, dust floating toward the light modulation device can be captured on the electrode portion. Thereby, adhesion of dust to the light modulation device due to the light dust collection effect can be prevented. Further, since the dust is forcibly discharged to the outside of the main housing of the projector by the dust discharging device even when the voltage application to the electrode portion is stopped, it is possible to prevent the dust from re-floating in the main housing. . Thereby, the illumination fall by dust can be prevented.

Moreover, it is preferable that the dust discharge device is configured by a duct communicating with the internal space of the main housing and a fan provided in the housing.
According to this configuration, by using the fan provided in the main casing of the projector, it is not necessary to newly provide a dust discharge fan, and the apparatus configuration is simplified.

FIG. 2 is a schematic diagram illustrating a schematic configuration of a projector according to the first embodiment. The figure which shows the structure of a red light source device. The perspective view which shows the structure of the light source part periphery of a light source device. (A), (b) The figure which shows the other shape of an electrode. (A), (b) The figure which shows the other shape of an electrode. (A), (b) The figure which shows the other shape of an electrode. FIG. 10 is a diagram illustrating an overall configuration of a projector according to a second embodiment. The figure which shows the internal structure of the light source device in 2nd Embodiment. The perspective view which looked at the lower light guide in 2nd Embodiment from upper direction. FIG. 10 is a diagram illustrating an overall configuration of a projector according to a third embodiment. The perspective view which shows the position of the duct in 3rd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[Projector of the first embodiment]
First, an example of the projector 10 shown in FIG. 1 will be described as an embodiment of the present invention. FIG. 1 is a schematic diagram illustrating a schematic configuration of the projector 10. FIG. 2 is a diagram illustrating a configuration of a red light source device. FIG. 3 is a perspective view showing a configuration around the light source unit of the light source device.

  As shown in FIG. 1, the projector 10 is a projection type image display device that displays a color image on a screen SCR. Further, the projector 10 includes a liquid crystal light valve (liquid crystal panel) corresponding to red light (R) as the light modulation device 11R, a liquid crystal light valve corresponding to green light (G) as the light modulation device 11G, and a light modulation device 11B. And a liquid crystal light valve corresponding to blue light (B).

  Furthermore, the projector 10 includes a plurality of laser light sources (semiconductor lasers) capable of obtaining light with high luminance and high output as the light source unit 150R of the light source device 12R corresponding to red light (R). The light source unit 150G of the light source device 12G corresponding to green light (G) includes a plurality of laser light sources (semiconductor lasers) that can obtain light with high luminance and high output. As the light source unit 150B of the light source device 12B corresponding to blue light (B), a plurality of laser light sources (semiconductor lasers) capable of obtaining light with high luminance and high output are provided.

Specifically, the projector 10 includes a light source device 12R that emits red light (R) that is first color light, a light source device 12G that emits green light (G) that is second color light, and a third color light. A light source device 12B that emits blue light (B).
Further, the projector 10 modulates red light (R), green light (G), and blue light (B) according to image information, and outputs red light (R), green light (G), and blue light (B). A light modulation device 11R, a light modulation device 11G, and a light modulation device 11B that form image light corresponding to each of them are provided.
Further, the projector 10 synthesizes image light from each of the light modulation devices 11R, 11G, and 11B, a projection optical system 14 that projects the image light from the synthesis optical system 13 toward the screen SCR, and Is roughly provided.

  The light source device 12R, the light source device 12G, and the light source device 12B are respectively a semiconductor laser (light emitting element) 15R that emits laser light corresponding to red light (R), green light (G), and blue light (B), a semiconductor laser ( It has the same configuration except that it includes a light emitting element) 15G and a semiconductor laser (light emitting element) 15B. Therefore, in the following description, the light source device 12R will be described, and the description of the light source device 12G and the light source device 12B will be omitted.

  As shown in FIGS. 2 and 3, the light source device 12R includes a light source unit 150R, a homogenizing optical system 16 that uniformizes the illuminance distribution of the laser light emitted from the light source unit 150R, and dust in the housing 19. And a dust discharge unit 20 for capturing and discharging.

  The light source unit 150 </ b> R is an array light source formed by arranging a plurality of semiconductor lasers 15 </ b> R on the substrate 41. The semiconductor laser 15 </ b> R emits coherent light toward the microlens array 18. The light source unit 150R is not limited to a configuration in which a plurality of semiconductor lasers 15R are arranged, and may have a configuration including one semiconductor laser 15R.

  The homogenizing optical system 16 includes a microlens array (optical element) 18, a first condenser lens (optical element) 21, a second condenser lens (optical element) 22, a diffusion plate 23, a collimator lens (optical element). ) 24 and a field lens (optical element) 26. The homogenizing optical system 16 has a function of making the intensity distribution of the light incident on the image forming region of the light modulation device 11R uniform by condensing and diffusing the laser light from each semiconductor laser 15R. Thereby, the light modulation device 11R is illuminated with light having a uniform illuminance distribution.

  The microlens array 18 includes a lens substrate on which a plurality of microlenses 18a are two-dimensionally arranged. The microlens array 18 is positioned in the optical path so that the plurality of microlenses 18a are respectively positioned at positions corresponding to the plurality of semiconductor lasers 15R. That is, the microlens array 18 is provided so that one microlens 18a corresponds to one semiconductor laser 15R. The light emitted from each semiconductor laser 15R is collected by the corresponding microlens 18a.

  The first condenser lens 21 is formed in such a size that all light transmitted through each microlens 18a of the microlens array 18 enters. The light transmitted through each micro lens 18 a is converged by the first condenser lens 21 and is emitted toward the second condenser lens 22.

  The diffusion plate 23 is made of, for example, a computer generated hologram (CGH). The light transmitted through the second condenser lens 22 is diffused by the diffusion plate 23 and is emitted to the collimator lens 24. The collimator lens 24 and the field lens 26 collimate the light beam incident on the light modulation device 11R.

  The dust contained in the air is present in the housing 19, and when the dust is exposed to strong light from the semiconductor laser 15R, the microlens array 18 and the first lens constituting the optical system are formed by the light dust collection effect. There is a risk of moving and adhering toward the surfaces of the condenser lens 21, the second condenser lens 22, and the collimator lens 24. Since the semiconductor laser 15R has a short wavelength, the energy density is high. When such laser light having a high light output is condensed and used, light dust collection becomes particularly remarkable.

  Therefore, the light source device 12R in the present embodiment includes a dust discharge unit 20 for capturing and removing dust in the housing 19. As shown in FIGS. 1 to 3, the dust discharge unit 20 is configured to apply a voltage to the electrode portions 34, a plurality of electrode portions 34 that capture dust, a dust discharge device 35 that discharges dust to the outside of the housing 19, and the electrode portions 34. A power supply (voltage applying means) 36 to be applied, and a dust discharge device 35 and a control device 37 for controlling the power supply 36 are provided.

  A plurality of chambers (internal spaces) 5 are formed in the casing 19 of the light source device 12R depending on the assembled state of the parts. In this embodiment, three chambers 5 are formed. One is a chamber 5a formed by the substrate 41 of the light source unit 150R and the first condenser lens 21, and the semiconductor laser 15R, the microlens array 18, and the electrode unit 34 are provided therein. One is a chamber 5 b formed by the first condenser lens 21 and the second condenser lens 22, and an electrode portion 34 is provided therein. The remaining one is a chamber 5c formed by the second condenser lens 22 and the field lens 26, and an electrode portion 34, a diffusion plate 23, and a collimator lens 24 are provided therein.

  Each electrode part 34 is composed of a pair of first electrode 34A and second electrode 34B composed of a positive electrode and a negative electrode. Each electrode part 34 is provided at a position that does not block the optical path of each light emitted from each semiconductor laser 15R of the light source part 150R. Specifically, each of the plurality of electrode portions 34 is provided in the vicinity of the microlens array 18, the first condenser lens 21, the second condenser lens 22, and the collimator lens 24 provided in the housing 19. It has been. The pair of first electrode 34A and second electrode 34B are arranged so as to sandwich the optical path of all the light beams emitted from each of the semiconductor lasers 15R of the light source unit 150R. In the present embodiment, the first electrode 34A and the second electrode 34B are plate-like electrodes, and are installed so that the electrode surfaces face each other. However, the shapes and sizes of the electrodes 34A and 34B are not limited to those shown in the figure.

  The electrode part 34 is provided for each chamber 5. The electrode unit 34 is disposed on at least one of the light incident side and the light emitting side of the microlens array 18. The electrode unit 34 is disposed on at least one of the light incident side and the light emission side of the first condenser lens 21. The electrode unit 34 is disposed on at least one of the light incident side and the light emission side of the second condenser lens 22. The electrode unit 34 is disposed on at least one of the light incident side and the light emitting side of the collimator lens 24.

  The first electrode 34 </ b> A and the second electrode 34 </ b> B are configured to be charged to opposite polarities when a voltage is applied from the power source 36. Here, it is assumed that the voltage is applied so that the first electrode 34A is positively charged and the second electrode 34B is negatively charged. Since dust floating in the air moves while repeatedly colliding and contacting, it is often charged positively or negatively. Therefore, dust charged to any polarity moves along the lines of electric force emitted from the first electrode 34A and the second electrode 34B, and is captured by the surfaces of the electrodes 34A and 34B, respectively. .

  The dust discharging device 35 includes a duct 38 provided so as to communicate with each chamber 5 in the housing 19, and a dust discharging fan 39 provided in the duct 38.

  Specifically, by providing the opening 38 </ b> A of the duct 38 in the chamber 5 in which the electrode part 34 is disposed, dust captured by the electrode part 34 can be collected via the duct 38. The opening 38A of the duct 38 is desirably provided at a position where dust captured on the electrodes 34A and 34B can be efficiently collected. Specifically, the openings 38 </ b> A of the duct 38 are preferably disposed in the vicinity of the electrode portions 34 disposed in the chamber 5. For example, in the chamber 5a, an opening 38A of the duct 38 is provided so as to communicate with a space formed by the microlens array 18, the first condenser lens 21, and the electrode portion 34.

  In the chamber 5 b formed by the first condenser lens 21 and the second condenser lens 22, the opening 38 </ b> A is formed by the first condenser lens 21, the second condenser lens 22, and the electrode part 34. It is provided in the vicinity of the second condenser lens 22 so as to communicate with the space.

  In the chamber 5 c formed by the second condenser lens 22 and the field lens 26, the opening of the duct 38 is communicated with the space between the second condenser lens 22, the collimator lens 24, and the electrode portion 34. 38A is provided.

  The opening 38A is a rectangular hole that is provided between the first electrode 34A and the second electrode 34B that are opposed to each other, and whose longitudinal direction extends in the direction connecting the first electrode 34A and the second electrode 34B.

  Further, if an opening 38A is provided in a region including directly below each of the electrodes 34A and 34B, after the application of voltage to the electrodes 34A and 34B is stopped, the dust trapped on the electrodes 34A and 34B is dropped as it is. It will enter the duct 38. Thereby, even when the dust discharge fan 39 does not operate for some reason, it is possible to prevent the dust from floating again in the housing 19.

  The opening 38 </ b> A of the duct 38 is configured by a through hole formed in the housing 19. Therefore, a through hole that has been conventionally provided for reducing the weight of the housing can also be used as the opening 38 </ b> A of the duct 38.

  The size and shape of the opening 38A of the duct 38 formed in the housing 19 are not limited to those illustrated.

  The dust discharge fan 39 may be provided for each color light source device 12R, 12G, 12B. Alternatively, one dust discharge fan 39 common to the three light source devices 12R, 12G, and 12B may be provided.

  The control device 37 controls the driving of the dust discharge fan 39 in the power source 36 and the dust discharge device 35. The timing of voltage application to the electrode unit 34 by the power source 36, the magnitude of the voltage, and the timing of driving and stopping the dust discharge fan 39 are controlled by the control device 37.

  At the time of activation of the light source device 12R, the control device 37 starts applying a voltage to the first electrode 34A and the second electrode 34B by the power source 36. Thereafter, the plurality of semiconductor lasers 15R of the light source unit 150R are turned on.

  If a voltage is applied to the first electrode 34A and the second electrode 34B before the semiconductor laser 15R is turned on, dust floating in the housing 19 is attached to the lens surface by the electric field generated between the electrodes 34A and 34B. It is previously captured on the surface of each electrode 34A, 34B. Therefore, the operation of the dust discharging device 35 may be after the voltage application to the electrodes 34A and 34B is started. However, it is desirable to operate the dust discharging device 35 before turning on the semiconductor laser 15R. Thereby, the dust can be discharged out of the housing 19 before the floating dust is exposed to the laser beam. Of course, the dust discharging device 35 may be operated before the voltage application to the electrode portion 34 is started.

  When the light source device 12R is stopped, the control device 37 first turns off the plurality of semiconductor lasers 15R and turns off the light source unit 150R. Next, after stopping the application of voltage to the first electrode 34A and the second electrode 34B, the dust discharging device 35 is maintained in an operating state for a predetermined time.

  Even after the application of voltage to the electrodes 34A and 34B is stopped, the dust discharging device 35 is driven, so that the dust trapped on the surfaces of the electrodes 34A and 34B is not scattered in the housing 19. Efficient suction and discharge.

  According to the projector 10 of the present embodiment, for each of the electrode portions 34 provided in the vicinity of the microlens array 18, the first condenser lens 21, the second condenser lens 22, and the collimator lens 24, respectively. When a voltage is applied, dust floating in the light source device 12R is attracted toward the electrodes 34A and 34B by an electric field generated between the electrodes 34A and 34B. For this reason, while applying a voltage to each electrode part 34, dust can be adsorbed and captured on the surface of each electrode 34A, 34B. An electric field between the first electrode 34A and the second electrode 34B of the electrode portion 34 that generates a force that attracts the dust with a force stronger than the force that moves the dust toward each lens by the light dust collection effect. Thus, the charged dust is attracted to the surfaces of the electrodes 34A and 34B without going to the lens surface. Thus, even when a high-power laser light source is used by applying predetermined voltages to the electrodes 34A and 34B of the electrode portion 34 to capture floating charged dust, the lens It is possible to prevent dust from adhering to the surface.

  In the present embodiment, dust can be removed from the surfaces of the electrodes 34A and 34B by stopping the application of voltage to the electrodes 34A and 34B. This eliminates the need for maintenance such as replacement of the electrodes 34A and 34B. Further, even if the application of voltage to the electrodes 34A and 34B is stopped, the dust in the housing 19 including the dust captured by the electrode portion 34 is sucked by the dust discharging device 35 and discharged to the outside of the housing 19. Can do. That is, even after the application of the voltage to the electrode portion 34 is stopped, the dust trapped on the surfaces of the electrodes 34A and 34B can be sucked and discharged without being scattered in the housing 19.

  In this manner, dust floating in the housing 19 is captured on the electrodes 34A and 34B and discharged to the outside of the housing 19 by the dust discharging device 35, whereby the lens surface due to the light dust collection effect is applied. It is possible to eliminate the problem that the adhesion of dust is prevented and the illuminance of the light source device 12R is lowered.

  In the present embodiment, the dust discharge fan 39 forcibly discharges the dust to the outside of the housing 19, so that a clean environment can be realized over a wide range. If the air in the housing 19 is discharged, uncharged dust that has not been captured by the electrode part 34 can also be removed.

  As described above, the dust trapped on the electrodes 34A and 34B is discharged through the duct 38 by stopping the application of voltage to the electrodes 34A and 34B. For this reason, it is not necessary to provide adhesiveness for attaching (capturing) dust to the surfaces of the electrodes 34A and 34B, and it is not necessary to replace the electrodes 34A and 34B. Therefore, a maintenance-free dust trapping structure can be realized.

  Further, the projector 10 is usually provided with a cooling device, and is configured to cool the light source device 12R, the light source device 12G, and the light source device 12B that generate heat by taking outside air into the housing body 27. . Therefore, the cooling air flows around the casing 19 of the light source device 12R, the casing 19 of the light source device 12G, and the casing 19 of the light source device 12B. Since air passes through a filter (not shown) provided in the housing body 27 of the projector 10, large dust does not enter the light source device 12R, the light source device 12G, and the light source device 12B. However, it is possible that small dust that can pass through the filter enters the inside of each housing 19.

  However, the grease used when mounting the semiconductor laser 15R exists between the semiconductor laser 15R and the substrate 41 (FIG. 3), and the grease is vaporized by the heat generated by the semiconductor laser 15R and floats as dust. is there.

  Thus, even if large dust is not contained in the air flowing from the outside of the casing body 27 (FIG. 1), dust generated from the inside of each casing 19 of the light source devices 12R, 12G, and 12B, that is, grease It is possible that dust is generated from the inside of each casing 19 due to the outgas from the adhesive or the like. The projector 10 in the present embodiment can efficiently capture and discharge the dust, even if it is dust due to the outgas generated inside, to the outside.

  In addition, the projector 10 may be provided with an exhaust fan that inhales the heated air in the housing body 27 and discharges it to the outside. The exhaust fan may be attached to the dust discharge device 35. It may be used as the dust discharge fan 39. As a result, it is not necessary to newly provide a dust discharge fan, so that the configuration of the apparatus is simplified, and labor and cost for installing the dust discharge fan can be reduced.

  The shapes of the electrodes 34A and 34B constituting the electrode part 34 are not limited to those described above. FIGS. 4A and 4B are diagrams showing an example of the shape and arrangement of electrodes. FIGS. 5A and 5B are diagrams showing an example of the shape and arrangement of electrodes. 6A and 6B are diagrams showing an example of the shape and arrangement of electrodes.

  As shown in FIGS. 4A and 4B, as the electrode portion 34, a pair of electrodes 42A and 42B composed of a positive electrode and a negative electrode may be juxtaposed along the optical path. In this case, a hole 43 through which all the light beams emitted from the microlens array 18, the first condenser lens 21, the second condenser lens 22, and the collimator lens 24 are formed in each of the electrodes 42A and 42B. In addition, the electrodes 42A and 42B have a shape that does not block the transmitted light flux. The electrodes 42A and 42B are frame-like electrodes each having one hole 43 through which the partial light beams emitted from the semiconductor lasers 15R are collectively transmitted.

  Alternatively, as shown in FIGS. 5A and 5B, plate-like electrodes 45A and 45B each having a plurality of holes 44 through which the light beams emitted from the semiconductor lasers 15R are transmitted may be used. The electrodes 45A and 45B are arranged in parallel on one surface side of the microlens array 18, the first condenser lens 21, the second condenser lens 22, and the collimator lens 24 (not shown) so as to have opposite polarities. A voltage is applied to. Thereby, since the periphery of the light beam transmitted through each microlens 18a can be surrounded by the electrodes 45A and 45B, dust can be more effectively removed from the vicinity of the microlens array 18.

Further, as shown in FIGS. 6A and 6B, for example, a plurality of electrodes 46A and a plurality of electrodes 46B having a plurality of holes 47 through which the light beams of the respective semiconductor lasers 15R are transmitted may be used. The plurality of electrodes 46 </ b> A and 46 </ b> B are alternately arranged in parallel in a direction (X direction) intersecting the optical path, for example, in a posture that faces one surface of the microlens array 18. A voltage is applied so that adjacent electrodes 46A and 46B have opposite polarities. Thereby, the plurality of electrodes 46A and 46B can be installed in a space-saving manner as electrode portions having a high dust collection effect.
Here, the parallel arrangement direction of the plurality of electrodes 46A and 46B composed of the positive electrode and the negative electrode may be the horizontal direction (X direction) or the vertical direction (Y direction) in the installation posture of the projector 10.

Further, it is not necessary to unify the configurations of the electrode portions arranged in the vicinity of the microlens array 18, the first condenser lens 21, the second condenser lens 22, and the collimator lens 24 (not shown). The shape of the electrode composed of the positive electrode and the negative electrode can be appropriately changed according to the shape and size of the corresponding lens.
In the present embodiment, the electrode unit 34 is disposed on either the incident side or the exit side of the microlens array 18, the first condensing lens 21, the second condensing lens 22, and the collimator lens 24. The electrode portions 34 may be provided on both the side and the emission side.

[Projector of Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
FIG. 7 is a diagram showing the overall configuration of the projector. FIG. 8 is a diagram showing the internal structure of the optical unit 102. Specifically, FIG. 8 is a diagram in which the upper light guide 25B is removed from the light guide 25 of the optical unit 102 in FIG.

  As shown in FIG. 7, the projector 100 according to the present embodiment includes an optical unit 102 having an L shape in plan view and a projection lens 101 connected to one end of the optical unit 102. The optical unit 102 is a light source device in the present invention.

  As shown in FIG. 8, the projector 100 includes a light source unit 103 that introduces a light beam into the optical unit 102, in addition to the electro-optical device 240 and the projection lens 101 in which the optical unit 102, the light modulation device, and the color synthesis light source device are integrated. The power supply unit 104 that supplies power supplied from the outside to the constituent members of the projector 100, the control device 105 that drives the liquid crystal panels 241R, 241G, and 241B as light modulators and other constituent elements, and the projector 100 A cooling unit having a cooling fan that blows cooling air to the constituent members, and a dust discharge unit 106 that collects and discharges dust in the optical unit 102 are configured.

  The optical unit 102 forms an optical image according to image information from the outside under the control of the control device 105 together with the electro-optical device 240. The optical unit 102 includes a light guide 25 as a housing formed in a container shape, and a plurality of optical components accommodated in the light guide 25.

  As shown in FIG. 8, the plurality of optical components housed in the light guide 25 includes an integrator illumination optical system 210, a color separation optical system 220, and a relay optical system 230. In these optical components, a light beam is introduced from the light source unit 103 installed on the other end side of the flat L-shape of the optical unit 102.

  The light source unit 103 has substantially the same configuration as the light source unit described in the previous embodiment, and includes a plurality of semiconductor lasers arranged in an array on a substrate. Here, a plurality of semiconductor lasers corresponding to each of the RGB lights are arranged.

  The integrator illumination optical system 210 is an optical system for making the luminous flux emitted from the light source unit 103 uniform in the plane perpendicular to the optical axis of the luminous flux. The integrator illumination optical system 210 includes a first lens array 211, a second lens array 212, a polarization conversion element 213, and a superimposing lens 214.

  The first lens array 211 and the second lens array 212 have a configuration in which a plurality of microlenses are arranged in a matrix. Each microlens condenses light beams emitted from a plurality of semiconductor lasers and emits them in the optical axis direction. The first lens array 211 and the second lens array 212, together with the superimposing lens 214, convert the images of the microlenses of the first lens array 211 and the second lens array 212 to the liquid crystal panels 241R, 241G, and 241B, which are light modulation devices. It has a function of forming an image on each image forming area.

  The color separation optical system 220 includes two dichroic mirrors 221 and 222 and a reflection mirror 223. The plurality of partial light beams emitted from the integrator illumination optical system 210 are separated into three color lights of red (R), green (G), and blue (B) by the two dichroic mirrors 221 and 222. The relay optical system 230 includes an incident side lens 231, a relay lens 233, and reflection mirrors 232 and 234. The relay optical system 230 has a function of guiding blue light, which is color light separated by the color separation optical system 220, to the liquid crystal panel 241B.

In the dichroic mirror 221 of the color separation optical system 220, among the light beams emitted from the integrator illumination optical system, the green light component and the blue light component are transmitted, and the red light component is reflected. The red light reflected by the dichroic mirror 221 is reflected by the reflection mirror 223, passes through the field lens 224, and reaches the red liquid crystal panel 241R.
The field lens 224 converts each partial light beam emitted from each lens array 211, 212 into a light beam parallel to the central axis (principal light beam). The same applies to the field lens 224 provided on the light incident side of the other liquid crystal panels 241G and 241B.

  Of the blue light and green light transmitted through the dichroic mirror 221, the green light is reflected by the dichroic mirror 222, passes through the field lens 224, and reaches the liquid crystal panel 241G for green light. On the other hand, the blue light passes through the dichroic mirror 222, passes through the relay optical system 230, passes through the field lens 224, and reaches the liquid crystal panel 241B for blue light.

  Note that the relay optical system 230 is used for blue light because the optical path length of the blue light is longer than the optical path lengths of the other color lights, thereby preventing a reduction in light use efficiency due to color divergence or the like. It is to do. That is, this is to transmit the partial light beam incident on the incident side lens 231 to the field lens 224 as it is.

  The electro-optical device 240 modulates the incident light beam according to image information to form a color image. The electro-optical device 240 includes three incident-side polarizing plates 242 to which the respective color lights separated by the color separation optical system 220 are incident, and a liquid crystal panel 241R as a light modulation device disposed at the subsequent stage of each incident-side polarizing plate 242. , 241G, 241B, the exit side polarizing plate 243, and a cross dichroic prism 244 as a color synthesizing optical device.

  The liquid crystal panels 241R, 241G, and 241B use, for example, polysilicon TFTs as switching elements, and the liquid crystal is hermetically sealed in a pair of transparent substrates arranged opposite to each other. Then, the liquid crystal panels 241R, 241G, and 241B modulate the light beam incident through the incident side polarizing plate 242 in accordance with the image information and emit the modulated light beam. The liquid crystal panels 241R, 241G, and 241B are housed and held by a holding frame (not shown) having an opening that serves as an image forming area of the liquid crystal panels 241R, 241G, and 241B.

  The incident-side polarizing plate 242 transmits only polarized light in a certain direction among the color lights separated by the color separation optical system 220 and absorbs other light beams. A polarizing film is attached to a substrate such as sapphire glass. It has been done. The exit side polarizing plate 243 is also configured in substantially the same manner as the incident side polarizing plate 242, and transmits only polarized light in a predetermined direction among the light beams emitted from the liquid crystal panels 241R, 241G, and 241B, and absorbs other light beams. The polarization axis of the polarized light to be transmitted is set so as to be orthogonal to the polarization axis of the polarized light to be transmitted by the incident side polarizing plate 242.

  The cross dichroic prism 244 forms a color image by synthesizing an optical image emitted from the emission-side polarizing plate 243 and modulated by each color light. The cross dichroic prism 244 is provided with a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light in a substantially X shape along the interface of four right-angle prisms. Three color lights are synthesized by the multilayer film.

  The dust discharge unit 106 includes a plurality of electrode portions 107 arranged along the optical path of light emitted from the light source portion 103 and a dust discharge device 108 provided on the light guide 25. The electrode unit 107 is provided in the vicinity of the first lens array 211, the second lens array 212, the superimposing lens 214, the plurality of incident side lenses 231, the relay lens 233, and the field lens 224, respectively. The first electrode 107A and the second electrode 107B constituting each electrode part 107 are on the peripheral side of each lens and at positions that do not block the optical path of each light beam from the light source part 103, that is, in the vicinity of each of them across the optical path. They are arranged facing each other.

  The dust discharge device 108 includes a plurality of ducts 109 provided in the light guide 25 and a dust discharge fan 110 provided in common to each duct 109. FIG. 9 is a plan view of the lower light guide 25A as viewed from above. As shown in FIG. 9, the opening 109 </ b> A of each duct 109 is a through hole formed in the lower light guide 25 </ b> A, and is provided in the vicinity of each electrode portion 107. A hole formed for reducing the weight of the light guide 25 may be used as the opening 109A of each duct 109.

  The dust discharge fan 110 is connected to the duct 109. The dust discharge fan 110 may be installed somewhere on the duct 109, for example, or may be provided at the end (exhaust port 207) of the duct 109 opposite to the opening 109A.

  As described in the first embodiment, the electrode unit 107 and the dust discharge fan 110 are subjected to voltage application and stop under the control of the control device 105, and the dust discharge fan 110 is started and stopped as described in the first embodiment. This is performed at a predetermined timing.

  According to the present embodiment, the light beam emitted from the light source unit 103 is separated into three color lights (R, G, B) and then incident on the corresponding light modulation device. It is possible to effectively suppress the light dust collection effect in the vicinity of a plurality of lenses existing in the lens. In the vicinity of each lens, an electrode portion 107 that generates an electric field that generates a force that attracts dust with a force stronger than the force that moves the dust toward each lens by the light dust collection effect is disposed. Excellent dust collection and high trapping effect can be obtained.

  In addition, since the openings 109A are formed so that the ducts 109 communicate with the plurality of chambers 5 in which the lenses and the electrode portions 107 exist, air containing dust around the lenses and dust captured by the electrode portions 107 can be efficiently written. It can be discharged out of the guide 25. One end side of the duct 109 is connected to an opening 109 </ b> A formed in the light guide 25, and the other end side of the duct 109 is connected to an exhaust port 207 provided on the wall surface of the main housing 204 of the projector 100. It is desirable. Thereby, dust can be discharged to the outside quickly and reliably.

[Projector of the third embodiment]
Next, a projector according to a third embodiment of the invention will be described with reference to FIG.
FIG. 10 is a diagram illustrating an overall configuration of the projector 200 according to the present embodiment.
The projector 200 according to the present embodiment basically has the same configuration as the projector according to the first embodiment described above, but only the configuration of the dust discharge unit 202 of the light source unit 201 is different. Therefore, the dust discharge unit 202 will be mainly described in detail.

  The dust discharge unit 202 in this embodiment includes an electrode unit 203 provided in the vicinity of three light modulation devices corresponding to RGB color lights, and a fan 205 (dust discharge device) provided in the main housing 204 of the projector 200. ) And mainly.

  Each electrode unit 203 is provided outside the light guide 25 and between the liquid crystal panels 241R, 241G, and 241B, which are light modulation devices, and the incident-side polarizing plate 242 corresponding thereto. These electrode portions 203 are attached to the outer wall of the light guide 25, but may be provided in the main housing 204 of the projector 200 that houses the light source unit 201.

  The projector 200 is provided with an exhaust fan 205 for exhausting air (hot air) in the main housing 204. In the present embodiment, the exhaust fan 205 is also used as a dust discharge fan. In the following description, the dust discharge fan 205 is also referred to.

  When the dust discharge fan 205 (exhaust fan) in the present embodiment is driven, the air in the main housing 204 is sucked, and the air around the electrode portion 203 including dust collected by the electrodes 203A and 203B is also taken. It flows and is discharged to the outside of the main casing 204 through the exhaust port 206.

FIG. 11 is a perspective view showing the position of the duct.
In order to discharge the air around the electrode unit 203 more efficiently, for example, as shown in FIG. 11, a duct 208 having a size corresponding to all the electrode units 203 (dust discharging device) is provided in the vicinity of the electrode unit 203. Is provided. By providing a duct 208 that allows the dust discharge fan 205 to communicate with the space in which each electrode portion 203 exists, it is possible to quickly suck and discharge dust-containing air without diffusing into the main housing 204. . Since the air around the liquid crystal panels 241R, 241G, and 241B is heated by the heat generated by the liquid crystal panels 241R, 241G, and 241B accompanying the continuous use of the projector 200, the liquid crystal panel 241R, Air cooling effects such as 241G and 241B are also obtained.

  According to the configuration of the present embodiment, dust floating toward the liquid crystal panel 241R, the liquid crystal panel 241G, and the liquid crystal panel 241B is generated in the electrode portion 203 provided in the vicinity of each of the liquid crystal panel 241R, the liquid crystal panel 241G, and the liquid crystal panel 241B. Can be captured. In this manner, among the components of the projector 200, by collecting and removing dust in the space in the area where the image is to be formed, it is possible to obtain an image with good brightness with no decrease in illuminance. Further, since the exhaust fan provided in the main housing 204 of the projector 200 is used as the dust discharge fan 205, it is not necessary to newly provide a dust discharge fan in addition to the exhaust fan. This simplifies the apparatus configuration and reduces the labor and cost of installing a dust discharge fan.

  Further, the air around the liquid crystal panel 241R, liquid crystal panel 241G, and liquid crystal panel 241B is forcibly sucked and discharged through the duct 208, so that the liquid crystal panel 241R, liquid crystal panel 241G, liquid crystal panel 241B, etc. are not shown. It will be exposed to the external cold air which flowed into the main housing 204 from the air intake port. Thus, not only dust removal but also the heat generating liquid crystal panel 241R, liquid crystal panel 241G, liquid crystal panel 241B and the like can be effectively cooled. In addition, the inflow of dust into the main housing 204 is prevented by a filter attached to the air inlet.

  Further, FIG. 11 shows a configuration in which one duct 208 having an opening having a size that can correspond to all three electrode portions is provided, but the shape and number of the ducts 208 are not limited thereto. The position of the duct 208 is not limited to the upper side of the image forming area, and the duct 208 may be provided below the image forming area. Note that the downward direction means the direction in which gravity works.

  Note that the second embodiment and the third embodiment may be combined. Floating in the main housing of the projector by providing a dust discharge unit in the vicinity of the light modulator that exists outside the housing of the light source device, as well as in the vicinity of each lens where the light dust collecting effect tends to occur in the light source device It is also possible to suppress the light dust collecting effect of the dust. Thereby, the illuminance can be prevented from lowering by dust inside and outside the light source device, so that the projector can perform a good display.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

DESCRIPTION OF SYMBOLS 10 ... Projector, 5 ... Chamber (space), 11R ... Light modulation device, 12R ... Light source device, 15R ... Semiconductor laser (light emitting element), 18 ... Micro lens array (optical element), 19 ... Case, 21 ... 1st , 22 ... second condenser lens (optical element), 24 ... third condenser lens (optical element), 26 ... field lens (optical element), 34A, 34B ... electrode, 35 ... Dust discharging device, 38 ... Duct, 38A ... Opening, 39 ... Dust discharging fan (Dust discharging device fan),

Claims (10)

A light emitting element;
An optical element on which light from the light emitting element is incident;
An electrode part for capturing dust floating toward the optical element;
A housing for housing the optical element and the electrode unit;
Voltage applying means for applying a voltage to the electrode part;
A dust discharging device that sucks the dust and discharges it to the outside of the housing;
A control device for controlling the voltage applying means and the dust discharging device;
A light source device comprising: When the light source device is stopped, the control device turns off the light emitting element and stops the voltage application to the electrode unit by the voltage applying unit, and then maintains the dust discharging device in an operating state for a predetermined time. The light source device according to claim 1. 3. The light source device according to claim 1, wherein, at the time of start-up, the control device turns on the light-emitting element after the voltage application unit starts voltage application to the electrode unit. The electrode portion includes an electrode disposed in a direction along the optical path of a light beam emitted from the light emitting element or in a direction intersecting the optical path,
The light source device according to claim 1, wherein the electrode does not block the optical path. The light source device according to claim 4, wherein the electrode unit includes a first electrode and a second electrode disposed on both sides of the optical path with the optical path interposed therebetween. The housing has a chamber;
The electrode part is provided in the room,
The dust discharge device has a duct and a fan provided in the duct,
The light source device according to claim 5, wherein an opening of the duct is provided so as to communicate with a space between the first electrode and the second electrode. The said 1st electrode and the said 2nd electrode are arrange | positioned crossing the said optical path, The hole for allowing the said light from the said light emitting element to pass through is provided in the said 1st electrode and the said 2nd electrode. 5. The light source device according to 5. The light source device according to any one of claims 1 to 7,
A light modulation device that modulates light emitted from the light source device according to image information;
A projection optical system that projects the modulated light from the light modulation device as a projection image;
Projector with The light source device according to any one of claims 1 to 7,
A light modulation device that modulates light emitted from the light source device according to image information;
A projection optical system that projects the modulated light from the light modulation device as a projection image;
An electrode part for capturing dust floating toward the light modulation device;
A main housing that houses the light source device, the light modulation device, the projection optical system, and the electrode unit;
A dust discharging device that sucks the dust and discharges it to the outside of the housing;
A projector comprising: a control device that controls the voltage applying means and the dust discharging device. The dust discharging device includes a duct communicating with an internal space of the main housing;
The projector according to claim 8, comprising a fan provided in the housing.

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