JP2009186720A - Projection type image display device equipped with dust removing function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection type image display device equipped with a dust removing function capable of cooling devices such as a light source and a power source on the inside without enlarging a place for housing a filter, and achieving prolongation of a period until exchange of the filter while preventing adhesion of dust to an image display element and the periphery of the light source. <P>SOLUTION: The housing 100 includes a partition 101 dividing its inside into a first chamber 102 incorporating at least the light source 104, and an optical unit 106 including liquid crystal panels 113G, 113B and 113R, and a second chamber 103 incorporating at least the power source unit 123. Air passing through a side to which a roll type electrostatic filter 131 is drawn out, out of a portion of a dust capturing part 129 exposed to an opening part 137 of a compact housing 136, is guided to the first chamber 102, and air passing through a side where the electrostatic filter 131 is housed is guided to the second chamber 103. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projection-type image display device having a dust removing function using an electrostatic filter, and more particularly to a projection-type image display device having a function of automatically updating by winding a roll-shaped electrostatic filter. It is.

  Conventionally, a projection type image display device such as a projector condenses intense light from a light source on an image display element such as a liquid crystal panel or DMD (digital mirror device), and modulates this light in accordance with an image signal. The image on the display element is enlarged and projected to obtain a large screen.

  Here, devices such as the image display element, the light source, and the power source of the apparatus that are exposed to strong light generate a large amount of heat, and are thermally destroyed unless they are properly cooled. Accordingly, the projection type image display apparatus adopts a configuration in which outside air is introduced into the apparatus by a fan and the devices in the apparatus are cooled.

  However, since dust is introduced from the outside of the apparatus together with the outside air, and it adheres to the periphery of the image display element and the light source, it becomes a generation source of brightness reduction and color unevenness.

  For this reason, a dust-preventing filter is usually placed at the air intake, but in the case of mainstream urethane filters, clogging occurs in a short time, so it is necessary to clean the filter every several hundred hours It is.

  In addition, the urethane filter physically suppresses intrusion by attracting dust to a small opening, but cannot prevent dust having a size smaller than 10 μm. Therefore, invasion of yellow sand and tobacco particles cannot be prevented.

  On the other hand, while the electrostatic filter has a large opening and suppresses pressure loss, dust collection is performed by static electricity, so even small dust can be captured.

  However, if the capture capacity is exceeded, the effect due to static electricity cannot be obtained, and having a larger opening than the urethane filter is a weak point, and dust is not captured but enters the apparatus.

  In addition, since the electrostatic filter cannot be cleaned, it is necessary to replace it with a new one every several hundred hours.

  However, many of the projection-type image apparatuses represented by projectors are for ceiling suspension applications, and are not in an installation state in which filters can be easily replaced, so that maintenance is difficult.

  For this reason, for example, in an apparatus such as an air purifier, the following structure has been proposed for a similar problem.

  According to Patent Document 1, a structure is proposed in which an electrostatic filter is formed long in a belt shape and is stretched around a rotating roller so that it can be wound up automatically, and a predetermined amount is automatically wound according to the operation time. If this is applied to a projector, it is considered that the filter replacement time can be extended.

Further, Patent Document 2 adopts a similar configuration in which an unused filter housing portion and a used filter housing portion are integrated into a cassette and can be opened by a hinge.
JP-A-5-49830 JP-A-6-269696

  However, in any patent document, it can be used for a long time by winding up the electrostatic filter. However, since the electrostatic filter cannot clean the air when it exceeds the dust trapping capacity, a predetermined time passes. All parts that exceed the dust trapping capacity must be used.

  Therefore, the usage time is automatically determined according to the length of the electrostatic filter and the width of the opening of the opposing device. To further reduce the number of filter replacements, the filter is lengthened and the storage space is expanded. There is a need to.

  However, in the projection type image display apparatus, although air cleaning as in the patent document is necessary, the main purpose is to cool devices such as a light source and a power source in the apparatus. Therefore, the area of the opening through which air is sucked must be increased.

  On the other hand, there is a conflicting problem that a large space cannot be secured in the filter storage place because the set size has no margin.

  The present invention solves the above-mentioned problem, while cooling the devices such as the internal light source and the power source without expanding the storage area of the filter, and while preventing the adhesion of dust around the image display element and the light source An object of the present invention is to provide a projection image display device having a dust removal function that can extend the time until filter replacement.

  A projection-type image display apparatus according to the present invention includes a housing having at least an air inlet, a dust trap disposed in the air inlet, an air intake fan, a light source, an image forming unit, a projection optical system, In the projection-type image display device including a video signal circuit and a power source, the dust trapping unit includes a dust trapping filter unit, and a feed mechanism control unit including a filter feed mechanism and a filter feed amount detection unit. The filter unit includes a roll-shaped electrostatic filter, filter take-up shafts disposed at both ends of the electrostatic filter, and a small housing including a connection portion between the electrostatic filter, the filter take-up shaft, and the filter feed mechanism. The small housing has an opening for allowing air from the housing air inlet to pass between the filter take-up shafts. The filter is pulled out from the state wound on one side of the filter take-up shaft so that the part exposed at the opening is partially updated, and wound up so that it is wound and stored on the other side. The housing includes an inner wall that spatially divides the interior into a first room containing at least a light source part and an image forming part and a second room containing at least a power supply part. Of the portion exposed to the opening of the electrostatic filter, air that passes through the side from which the electrostatic filter is drawn is guided to the first chamber and passes through the storage side of the electrostatic filter. The air to be performed is configured to be guided to the second room.

  Furthermore, the filter storage part in which dust is collected in the small casing can be configured as a substantially sealed structure from the outside.

  Moreover, the feed amount of the electrostatic filter once can be configured to be smaller than the opening width for the air guided to the first room.

  Of the area exposed to the opening of the electrostatic filter, between the area S1 through which the air guided to the first room passes and the area S2 through which the air guided to the second room passes. Can be characterized by the following relationship.

S1 ≧ S2
Further, the air guided to the first air chamber and the second air chamber among the air that has passed through the filter may pass through separate intake fans.

  Of the air that has passed through the filter, the air that is guided to the first room and the second room is guided by separate intake fans.

  Further, the input / output terminal and the power input unit are configured to be provided in the second room, or the input / output terminal and the power input unit are the first room and the second room. It can be configured to be included in a third room provided outside.

  Further, a common exhaust fan may be provided in the first room and the second room.

  The dust collecting performance of the electrostatic filter gradually deteriorates when dust adheres thereto. Therefore, in a roll type filter, if the filter is not renewed all at once but partially in sequence, there is a lot of dust adhering on the filter take-up side, the filter on the drawn side is new and the dust collection performance is excellent. Yes.

  According to the present invention, even if a small amount of dust adheres, the projected image appears as an image, or the brightness of the projected image decreases. Therefore, the first room equipped with an image forming unit that requires high dust collection performance is provided. The air to be introduced must pass through the opening on the filter's drawer side, and cooling is required for heat dissipation, but the ingress of dust that does not significantly affect the heat dissipation is allowed. The air guided to the second chamber provided with is configured to come through the opening on the winding side of the filter.

  In this way, by properly using the openings, it is possible to achieve the necessary dustproof performance with a minimum filter area.

  In particular, as described above, the power supply unit is more resistant to dust than the image forming unit and the light source unit. In consideration of the fact that if the wind speed of the air passing through the dust collecting filter is increased, the dust collecting performance is reduced regardless of the type of the filter. In the present invention, the air is introduced into the first room in which the image forming unit and the light source are stored. The opening area of the filter through which the air to be transmitted permeates is wider than the opening area of the filter through which the air guided to the second room containing the power supply unit passes.

  In particular, if the opening area of the former is an integral multiple of the area of the latter, the entire surface of the latter is updated by updating a part of the former surface in a single feed.

  By doing in this way, the filter that covers the opening to the second room has been used as a filter that covered the opening to the first room, and it is considered that the dust collection performance has deteriorated. However, it is possible to minimize the deterioration by updating the entire surface at once.

  The fact that the dust collection performance of the filter that covered the opening to the first room is deteriorated means that small dust that affects the image forming portion is less likely to adhere, and prevents large dust from entering. Since there is no problem with ventilation, the dust collection performance is sufficient for a place such as the second room that allows entry of small dust, and the filter can be used continuously.

  Therefore, the lifetime of the filter can be greatly extended.

  Needless to say, this is true even if the opening areas of the first and second rooms are equal.

  Embodiments of a projection type image display apparatus according to the present invention will be described below with reference to FIGS.

(Embodiment 1)
FIG. 1 shows an overall configuration diagram of a projection type image display apparatus according to Embodiment 1 of the present invention. In the figure, the whole is enclosed in a housing 100, and the interior is divided into a first room 102 and a second room 103 by a partition wall 101.

  An optical device and a light source are accommodated in the first room 102.

  In the first room 102, the light emitted from the light source 104 is emitted forward by the reflecting mirror 105.

  Incident light to the optical unit 106 is separated into red, green, and blue color light through dichroic mirrors 107 and 108 and total reflection mirrors 109, 110, and 111, and then incident-side polarizing plates 112R, 112G, and 112B, a liquid crystal panel 113R, 113G, 113B and the output side polarizing plates 114R, 114G, 114B are intensity-modulated by an external input signal not shown.

  These lights are combined on one optical path by a combining prism 116 having dichroic reflecting films 115R and 115B, and are incident on a projection lens 117.

  The projection lens 117 is designed and installed so that images on the liquid crystal panels 113R, 113G, and 113B can be enlarged and projected onto a screen (not shown) arranged in front of the apparatus.

  In order to display the image black, the light from the light source 104 needs to be absorbed by the incident-side and emission-side polarizing plates, which causes a high temperature to be emitted.

  Since these polarizing plates are mainly made of an organic material, they are deteriorated unless cooled to an appropriate temperature, resulting in an uncontrollable image, which makes the projection display apparatus unusable.

  On the other hand, since the images on the liquid crystal panels 113R, 113G, and 113B are enlarged and projected to the front of the apparatus, if dust enters the image, a dust image is formed, and the image quality is impaired.

  Further, even if the image does not become clear, if dust adheres to the incident side, output side polarizing plate, or the surface of the synthetic prism, it becomes difficult for light to pass through, and the brightness of the projected image is deteriorated.

  For this reason, it is necessary to prevent dust from entering when taking in outside air.

  Furthermore, in addition to this, a cooling means is required in order to ensure the reliability of the light source tube that reaches 1000 ° C. during light emission and the surrounding mechanical parts.

  Again, it is necessary to avoid the ingress of dust for the same reason as around the liquid crystal panel.

  In the first room 102 for these cooling, outside air is sucked in by the intake fan 119, and this wind is guided by the duct 120 provided at the lower part of the optical unit 106, and is discharged from the opening 120a, and around the liquid crystal panel. Cooling can be focused on.

  In this figure, the wall surface 121 of the duct 120 is used as a partition wall for separating the first chamber 102 and the second chamber 103 together with the partition wall 101 so that air does not come and go.

  In addition, an exhaust fan 122 is provided for releasing the air heated by the heat in the first chamber 102 to the outside.

  Thus, the outside air drawn in by the intake fan 119 flows in the order of the duct 120-the opening 120 a-the optical unit 106-the light source 104-the exhaust fan 122, and cools the device on the air path.

  On the other hand, in the second room 103, a signal processing circuit and a power source unit 123 of a light source are housed.

  This power supply unit 123 has a remarkable self-heating, and will be destroyed if it is not cooled.

  For this reason, it is common to use a heat sink (not shown) in the part that becomes hot.

  Here, there is a possibility that the heat radiation ability may be deteriorated due to the accumulation of dust on the heat sink and the like, leading to deterioration of reliability. However, the influence of the dust adhesion is not the ratio of the light source 104 or the optical unit 106.

  Therefore, the first room 102 is not as sensitive to dust entry in the air as it is, and only a configuration that avoids dust entry is desirable.

  Further, the wall surface forming the second room 103 is provided with an input / output terminal 124 and a power supply unit 125 for receiving a video signal for forming a projected image.

  The input / output terminal 124 and the power supply unit 125 are configured with general parts, and the dust does not sufficiently take into consideration dustproofness. Therefore, it is difficult to avoid the entry of dust from this part.

  Therefore, it is provided on the second room 103 side, which is relatively resistant to dust.

  The second room 103 is provided with an intake fan 126 that sucks outside air and sends it to the power supply unit 123.

  In the present embodiment, the air deprived of heat from the power supply unit 123 and the like is released from the exhaust port 127, but instead of the intake fan 126, an exhaust fan may be arranged at the exhaust port 127. Almost the same cooling can be performed.

  In the present embodiment, a dust trap 129 is provided between the intake port 128 of the housing 100 and the intake fans 119 and 126, and a buffer that does not allow air to pass between the intake port 128 and the dust trap 129. A plurality of materials 130 are provided to prevent air from leaking from the gaps.

  The structure of the dust trapping part 129 will be described below.

  The dust trapping part 129 includes a dust trapping filter part, and a feed mechanism control part including a filter feed mechanism and a filter feed amount detection means. The dust trapping filter part includes a roll-shaped electrostatic filter 131 and a static electricity filter 131. Filter take-up shafts 132a and 132b disposed at both ends of the electric filter 131, electrostatic filter 131 and filter take-up shafts 132a and 132b, a relay rotary shaft 133, a travel amount monitor shaft 134, and a small housing for housing these. And a body 136.

  The small housing 136 includes a partition wall 135 continuously connected to the wall surface 121 of the duct 120 and a filter winding for partitioning the air sucked into the first chamber 102 and the second chamber 103 from the filter passage portion. An opening 137 for allowing the air from the intake port 128 of the housing 100 to permeate between the shafts is provided.

  As shown in FIG. 2, the filter take-up shaft 132 b is provided with a recess 138 at the end, and a connecting portion 139 is connected to the recess 138.

  A gear 141 is fixed to the connecting portion 139 via a shaft 140. The gear 141 is connected to the stepping motor 143 through the small gear 142. This stepping motor 143 is controlled by a drive circuit not shown.

  Further, as shown in FIG. 3, a pressing mechanism 145 is provided so that the electrostatic filter 131 traveling on the travel amount monitor shaft 134 is in close contact.

  The pressing mechanism 145 includes a rotatable roller 147 at the tip of the main body 146 so as to reduce friction with the filter, and the other end rotatably holds a support column 148 fixed to the apparatus main body. .

  Further, the biasing spring 149 is applied to the pressing mechanism main body 146 at both ends through the support column 148, the central portion is applied to the fixing portion of the apparatus main body (not shown), and the roller 147 of the pressing mechanism is interposed via the electrostatic filter 131. It is configured to press against the travel amount monitor shaft 134.

  In this way, the travel amount monitor shaft 134 rotates when the electrostatic filter 131 is wound up.

  According to this configuration, if the thickness of the take-up shaft changes while the filter is being rolled up, the time taken to send the fixed amount of filter changes greatly, but the rotation of the travel amount monitor shaft 134 is always in the filter feed. The number of rotations is adjusted to the amount.

  By making use of this, as shown in FIG. 4, a rotation detection reflection pattern 151 as shown in the figure is provided at the end of the travel amount monitor shaft 134 protruding from the bottom 150 of the small casing 136. The pattern detection sensor 152 is fixed to the apparatus main body wall 153.

  Therefore, the feed amount of the electrostatic filter 131 can be grasped by the pattern detection output of the pattern detection sensor 152.

  By linking this output reading with a timer provided in the stepping motor 143 and a control circuit (not shown), it is possible to always manage the electrostatic filter 131 in an appropriate state.

  The electrostatic filter has a high initial dust collection performance, but when there is a lot of dust attached, the dust collection performance suddenly drops, the ventilation performance deteriorates, and the pressure loss increases. High dust collection performance can be automatically realized by performing the above control even during time use.

  The small casing 136 is detachably attached to the apparatus main body. As described above, the power from the apparatus main body is transmitted by providing the connecting portion with the filter feeding mechanism, and the electrostatic filter 131 is fed by rotating the filter winding shaft 132b included.

  Even so, if the filter is thick and the amount of winding can be secured only slightly, or if the volume for accommodating the necessary filter in the form of a roll cannot be secured, the filter may be used up.

  In this case, the dust collection performance can be recovered by replacing the small case 136 with a new filter.

  Further, depending on the installation situation of the apparatus at the time of replacement, there is a possibility that the small casing 136 may fall off, so that the arm portion 154 extending from the pressing mechanism main body 146 shown in FIG. Such a configuration is adopted so as to prevent excessive omission.

  If the exchanger avoids the arm portion 154, the small housing 136 can be pulled out, and at the same time, the pressing mechanism 145 that presses the travel amount monitor shaft 134 can be avoided without increasing the number of components.

  The small casing 136 has a substantially sealed structure except for a portion through which the filter passes, and suppresses dust from the dust collected filter from being scattered inside.

  As described above, the partition wall 135 is partitioned at a predetermined ratio in the opening area of the filter of the small casing 136. In this embodiment, it is partitioned at 1/2 position for easy understanding.

  When the roll filter is pulled out by the partition wall 135 by a half of the width of the opening 137, the air that permeates the new filter is guided to the first chamber 102.

  In addition, the air that has permeated through the part of the filter that has been used so far is guided to the second chamber 103.

  That is, in the control of the dust trapping part 129, when the filter amount drawn out at a time is smaller than the area of the opening part 137 (in this case, 1/2), the air guided to the first room 102 rather than the second room 103 However, there is less dust contained in the filter due to the difference in the dust collection performance of the filter part.

  Further, there is the following relationship between the area S1 through which the wind guided to the first room 102 passes and the area S2 through which the wind guided to the second room 103 passes.

S1 ≧ S2
This can be compensated by increasing the air blowing capability of the intake fan 126 if there is not enough air for cooling. This is because the second chamber 103 contains relatively dust-resistant components, and thus S2 can be reduced within a practically acceptable range.

  Thereby, the opening 137 can be minimized, and the entire apparatus can be reduced in size and cost.

(Embodiment 2)
FIG. 5 shows an overall configuration diagram of a projection type image display apparatus according to Embodiment 2 of the present invention. In the figure, components similar to those in FIG. 1 in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the figure, the input / output terminal 124 and the power supply unit 125 are provided on the wall surface forming the second chamber 103 in Embodiment 1, but the input / output terminal 124 and the power supply unit 125 do not necessarily need to be cooled. Therefore, as shown in the figure, the interior of the first room 102 can be effectively cooled by providing a third room 156 which is a separate area by partitioning with a wall surface 155.

  In addition, this configuration has an effect such that the distance from the image display element is reduced and noise is not easily applied, and electrical wiring is simplified.

  Further, as shown in FIG. 5, if the exhaust fan 122 has sufficient exhaust capability, the exhaust fan can be shared by the first room 102 and the second room 103.

  In these embodiments, the intake fan 126 is also placed on the windward side of the power supply unit 123 in the second room 103. However, this order may be reversed or provided on the windward side of the power supply unit 123. Is possible.

  Generally, as shown here, it is considered that the arrangement in the leeward position is advantageous in reducing the size and cost of the entire set because local cooling is easier.

  In these embodiments, the pattern detection sensor 151 is used at the end for detecting the rotation of the travel amount monitor shaft 147. However, other types of optical sensors can be applied, and the rotation speed can be mechanically adjusted. It can also be applied to rotation sensors that are read into

  In these embodiments, the two-body image display device that does not include a screen for displaying a projected image in the apparatus main body has been described. However, an integrated type that includes a screen is also effective. In this case, the projection area from the projection lens to the screen increases. However, since this is not an area that requires cooling, it may be a sealed room separate from the first room and the second room. desirable.

  In these embodiments, the image display device is a liquid crystal panel, but it goes without saying that the DLP system using the DMD element supplied by TI can take the same configuration and expect the same effect.

  It goes without saying that the motor to be used can be changed to a cheaper motor instead of the stepping motor 143 used here. However, a suitable speed reduction means according to the rotational speed is necessary.

  The projection-type image display apparatus according to the present invention cools a device such as an internal light source and a power source without increasing the storage space of the filter, and prevents adhesion of dust around the image display element and the light source. It is possible to extend the time until replacement, and is useful for a projection type image display apparatus having a dust removing function.

1 is a configuration diagram of a projection type image display apparatus according to Embodiment 1 of the present invention. Explanatory drawing of filter winding-up part of Embodiment 1 of this invention, a connection, and a drive part Explanatory drawing of the press apparatus structure of Embodiment 1 of this invention Explanatory drawing of the filter winding amount detection structure of Embodiment 1 of this invention Configuration of a projection type image display apparatus according to Embodiment 2 of the present invention

Explanation of symbols

100 Housing 101 Partition 102 First room 103 Second room 104 Light source 105 Reflective mirror 106 Optical unit 107, 108 Dichroic mirror 109, 110, 111 Total reflection mirror 112R, 112G, 112B Incident side polarizing plate 113R, 113G, 113B Liquid crystal panel 114R, 114G, 114B Emission side polarizing plate 115R, 115B Dichroic reflection film 116 Synthetic prism 117 Projection lens 119, 126 Intake fan 120 Duct 121 Wall 122 Exhaust fan 123 Power supply unit 124 Input / output terminal 125 Power supply unit 127 Exhaust port 128 Air intake port 129 Dust trapping part 130 Buffer material 131 Electrostatic filter 132a, 132b Filter take-up shaft 133 Relay rotating shaft 134 Travel amount monitor shaft 135 Partition wall 1 6 Small housing 137 Opening 138 Filter winding shaft concave portion 139 Connection portion 140 Shaft 141 Gear 142 Small gear 143 Stepping motor 145 Pressing mechanism 146 Pressing mechanism main body 147 Roller 148 Post 149 Energizing spring 150 Small housing bottom 151 Rotation detection Reflection pattern 152 Pattern detection sensor 153 Device main body wall 154 Arm 155 Wall surface 156 Third room

Claims (8)

A projection type comprising at least a housing having an air inlet, a dust trap disposed at the air inlet, an air intake fan, a light source, an image forming unit, a projection optical system, a video signal circuit, and a power source In an image display device,
The dust trapping part is composed of a dust trapping filter part, a feed mechanism control part including a filter feed mechanism and a filter feed amount detection means,
The dust trapping filter unit includes a roll-shaped electrostatic filter, filter take-up shafts disposed at both ends of the electrostatic filter, and a connecting portion between the electrostatic filter, the filter take-up shaft, and the filter feed mechanism. A small enclosure with
The small casing has an opening for allowing air from the intake port to pass between the filter winding shafts,
The electrostatic filter is pulled out from the state wound around one of the filter take-up shafts so that the portion exposed at the opening is partially updated, and is wound and stored on the other. The winding is controlled to
The housing includes an inner wall that spatially divides the interior into a first room containing at least a light source part and an image forming part and a second room containing at least a power supply part,
Of the portion exposed to the opening of the electrostatic filter, the air that passes through the side from which the electrostatic filter is drawn is guided to the first chamber and passes through the storage side of the electrostatic filter. Is a projection image display device having a dust removal function, wherein the projection image display device is guided to the second room. 2. The projection type image display device having a dust removing function according to claim 1, wherein the housing portion of the electrostatic filter in the small casing is configured as a substantially sealed structure from the outside. 2. The projection type image display device having a dust removing function according to claim 1, wherein a single feed amount of the electrostatic filter is smaller than an opening width for air guided to the first room. Of the areas exposed to the opening of the filter, the following relationship exists between the area S1 through which the air guided to the first room passes and the area S2 through which the air guided to the second room passes. A projection type image display device having a dust removing function according to claim 3.
S1 ≧ S2 2. The dust removing function according to claim 1, wherein the air guided to the first chamber and the second chamber among the air that has passed through the filter is guided by separate intake fans. Projection-type image display device. The projection with dust removal function according to claim 1, further comprising an input / output terminal and a power input unit, wherein the input / output terminal and the power input unit are provided in the second room. Type image display device. 2. The dust removing function according to claim 1, wherein the input / output terminal and the power input unit are included in a third room provided outside the first room and the second room. A projection type image display apparatus. 2. The projection type image display device having a dust removing function according to claim 1, wherein a common exhaust fan is provided in the first room and the second room.

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