JP2008286824A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of suppressing infiltration of dust, or the like. <P>SOLUTION: When the amount of exhaust air exhausted to the outside of a housing 10 by an exhaust fan 50 exceeds the total amount of suction air taken into the housing 10 by a first suction fan 40 and a second suction fan 60, a control part increases the rotational speed of the second suction fan 60 so as to increase the amount of suction air. Thus, drop in the pressure inside the housing 10 is suppressed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projector that projects image light by modulating a light beam emitted from a light source.

A projector is an optical device that modulates a light beam from a light source using a light modulator such as a liquid crystal light valve, and projects the modulated image light onto a screen or the like. It is used for various purposes such as viewing.
As the light source is turned on, the temperature of the internal components such as the light source itself and the light modulator is increased, and the performance and function of these components are reduced. In order to suppress the temperature rise of internal components, many projectors are equipped with an intake fan that cools internal components by taking in outside air and an exhaust fan that exhausts warm air inside the housing to the outside of the housing. Yes.
Since the temperature rise of internal parts varies depending on the usage environment and usage time, the rotational speed of the intake and exhaust fans can be set high so that the internal parts can be properly cooled even when the rise temperature rises. It is necessary to keep. However, if the rotational speed is increased, the noise caused by the rotational noise increases. Therefore, a projector has been proposed in which the intake fan and exhaust fan are individually controlled to reduce the rotational speed more than necessary. (See Patent Document 1).

JP 2003-5289 A

  However, since the projector described in Patent Document 1 controls the intake fan and the exhaust fan individually, there may be a case where the exhaust amount exhausted outside the housing exceeds the intake amount taken into the housing. In such a case, since the pressure in the casing is reduced, outside air is sucked from a gap other than the intake port so as to compensate for an insufficient amount of intake air from the intake fan. Normally, a projector is provided with a dustproof filter at the air inlet and suppresses the intrusion of dust floating in the outside air, but no means for preventing the intrusion of dust is provided in other gaps. For this reason, when the pressure in the housing is reduced, there is a risk that outside air containing dust will be sucked into the housing as it is from the gap. When this dust adheres to an optical component such as a light modulator, there is a problem that the image quality of the projected image is deteriorated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a projector capable of suppressing entry of dust and the like.

  The projector of the present invention includes a light source that emits a light beam, a light modulation unit that modulates the light beam emitted from the light source according to an image signal to form image light, a projection optical unit that projects the image light, A projector including a housing for storing these, a detection unit for detecting a temperature in the housing, first and second intake fans for sucking outside air into the housing, and air in the housing An exhaust fan that exhausts the air out of the housing, and a control unit that controls the rotational speed of the first intake fan and the exhaust fan based on the detection result of the detection unit, the control unit comprising: The exhaust amount of the exhaust fan is compared with the total intake amount of the first and second intake fans, and when the exhaust amount exceeds the total intake amount, the rotational speed of the second intake fan is increased. To increase the intake volume

  According to this configuration, when the exhaust amount exhausted out of the casing by the exhaust fan exceeds the total intake amount taken into the casing by the first and second intake fans, the control unit Increase the intake fan speed by increasing the rotational speed of the intake fan. As a result, the atmospheric pressure in the housing can be increased from the outside, and dust mixed in the outside air from the space between the housings can be prevented from entering the housing. Therefore, it is possible to suppress the deterioration of the image quality of the projected image, and the product life can be extended.

  The projector of the present invention includes a light source that emits a light beam, a light modulation unit that modulates the light beam emitted from the light source according to an image signal to form image light, a projection optical unit that projects the image light, A projector including a housing for storing these, a detection unit for detecting a temperature in the housing, first and second intake fans for sucking outside air into the housing, and air in the housing An exhaust fan that exhausts the air out of the housing, and a control unit that controls the rotational speed of the first intake fan and the exhaust fan based on the detection result of the detection unit, the control unit comprising: When the value obtained by subtracting the total intake amount of the first and second intake fans from the exhaust amount of the exhaust fan is larger than a preset value, the rotational speed of the second intake fan is increased to increase the intake air. It is characterized by increasing the amount.

  According to this configuration, a value obtained by subtracting the total intake amount taken into the housing by the first and second intake fans from the exhaust amount exhausted outside the housing by the exhaust fan is larger than a preset value. When it is large, that is, when the exhaust amount is relatively large, the control unit increases the rotational speed of the second intake fan to increase the intake amount. Accordingly, it is possible to suppress the pressure in the casing from being lowered, and it is possible to suppress the dust mixed in the outside air from entering the casing from the gap between the casings.

  In the projector, it is preferable that the control unit derives the exhaust amount and the total intake amount based on rotation speeds of the first and second intake fans and the exhaust fan.

  According to this configuration, since the control unit derives the exhaust amount and the total intake amount based on the rotational speed of each fan, it is not necessary to newly provide an air amount sensor or the like.

  In the projector, the detection unit includes first and second detection units, and the control unit controls a rotation speed of the first intake fan based on a detection result of the first detection unit, It is desirable to control the rotational speed of the exhaust fan based on the detection result of the second detection unit.

  According to this configuration, the rotation speed of the first intake fan is controlled based on the detection result of the first detection unit, and the rotation speed of the exhaust fan is controlled based on the second detection unit. Can be done more finely.

  In this projector, it is preferable that the housing is provided with a first air intake port through which the first air intake fan takes in outside air, and the first air intake port is covered with a dustproof filter.

  According to this configuration, since the dust-proof filter is disposed at the first intake port through which the first intake fan takes in the outside air, it is possible to suppress the intrusion of dust mixed in the outside air.

  In the projector, it is preferable that the second intake fan cools the inside of the casing with the intake air.

  According to this configuration, the second intake fan suppresses the pressure in the casing from being lowered by the intake air, and cools the inside of the casing, so that the sucked air can be efficiently used. .

  In the projector, a second intake port through which the second intake fan takes in outside air is formed in the housing so as to be separated from the first intake port, and the first and second intake ports are formed. The mouths may be covered with individual dust filters.

  According to this configuration, the first intake port through which the first intake fan takes in outside air and the second intake port through which the second intake fan takes in outside air are formed at positions away from the housing, Since the individual dustproof filter is provided, the degree of freedom of the position where the first and second intake fans are arranged in the housing is increased.

  In the projector, a second intake port through which the second intake fan takes in outside air is formed in the housing in the vicinity of the first intake port, and the first and second intake ports are formed. May be covered with an integral dustproof filter.

  According to this configuration, the first intake port through which the first intake fan takes in outside air and the second intake port through which the second intake fan takes in outside air are formed at positions close to the casing. Therefore, the first and second intake ports can be covered with the integral dustproof filter. Accordingly, since it is not necessary to dispose dustproof filters at the first and second intake ports, the projector can be configured with a small number of parts.

Hereinafter, a projector according to an embodiment of the present invention will be described with reference to the drawings.
The projector according to the present embodiment modulates a light beam emitted from a light source according to an image signal to form image light, and enlarges and projects the image light onto a screen or the like. In order to suppress, the main body can be cooled by taking outside air into the housing.
1 and 2 are views showing the appearance of the projector according to the present embodiment. FIG. 1 is a perspective view seen from the upper front side, and FIG. 2 is a perspective view seen from the lower rear side.

As shown in FIGS. 1 and 2, the projector 1 has a configuration in which a main body is surrounded by a housing 10.
The housing 10 is made of synthetic resin, and includes an upper case 11 that constitutes an upper portion, a lower case 12 that constitutes a lower portion, and a rear case 13 that constitutes a part of a back portion. The upper case 11, the lower case 12, and the rear case 13 are fixed with screws or the like.

The upper case 11 includes an upper surface 11A, a front surface 11B, side surfaces 11C and 11D, and a back surface 11E.
As shown in FIG. 1, a substantially circular opening 15 is formed in the front surface 11 </ b> B of the upper case 11. The opening 15 exposes the front surface of a projection lens 510 that magnifies and projects image light. An opening 16 is formed on the upper surface 11A, and levers 511 and 512 for performing focus adjustment and magnification adjustment operations of the projection lens 510 are exposed from the opening 16. An operation unit 14 is provided on the upper surface 11A. The operation unit 14 includes a plurality of keys for performing various instructions such as a menu key for switching display / non-display of a menu image for performing various settings of the projector 1 and a source switching key for switching an input source.

  As shown in FIG. 2, an opening 24 for attaching the rear case 13 is formed on the back surface 11E of the upper case 11 near the side surface 11D.

  The lower case 12 has a bottom surface 12A, side surfaces 12C and 12D, and a back surface 12E. In the bottom surface 12A, a rectangular opening 21 for accommodating the light source device 110 (see FIG. 3) is formed at a corner near the side surface 12C and the back surface 12E. A lamp cover 22 that covers the opening 21 is detachably provided in the opening 21.

  The rear case 13 is fixed by fitting into a groove (not shown) formed inside the back surface 12E of the lower case 12, and is attached so as to close the opening 24 of the upper case 11. The rear case 13 is formed with a substantially rectangular recess 131 near the upper surface 11 </ b> A of the upper case 11, and the recess 131 is provided with a plurality of holes 132. From the hole 132, a plurality of connection terminals 135 for connection to an external electronic device are exposed.

  On the bottom surface 12A of the lower case 12, a concave first intake port 23 is formed at a corner portion close to the side surface 12D and the back surface 12E. A concave second air inlet 25 is formed at a substantially central portion of the back surface 11E of the upper case 11. The first intake port 23 and the second intake port 25 are provided with a plurality of holes for taking in outside air, respectively, and the main body is cooled by the air taken in from the plurality of holes. In addition, dustproof filters 26 (see FIG. 4) and 28 (see FIG. 3) are arranged in the first air inlet 23 and the second air inlet 25, respectively. The dust filters 26 and 28 are respectively held by the lower case 12 and the upper case 11 by filter frames 27 and 29 having holes for allowing outside air to pass through. Further, an exhaust port 17 is formed in the side surface 11C of the upper case 11, and the warmed air in the housing 10 that has risen as the light source is turned on is discharged from the exhaust port 17 to the outside.

Next, a schematic configuration of the projector 1 will be described.
3 is a plan view showing a schematic configuration of the projector 1, FIG. 4 is a sectional view taken along the line AA, and FIG. 5 is a sectional view taken along the line BB.
As shown in FIG. 3, the projector 1 includes a housing 10, a substantially L-shaped optical unit 30, a first intake fan 40, an exhaust fan 50, a second intake fan 60, and a control board 70. And is configured.

The optical unit 30 modulates the light beam emitted from the light source 111 according to an image signal to form image light, and enlarges and projects the image light.
The first intake fan 40 is configured by a sirocco fan, and is disposed above the first intake port 23 (see FIG. 2) and below the optical unit 30. The first intake fan 40 sucks outside air from the first intake port 23 and cools the optical unit 30.
The exhaust fan 50 is an axial fan, and is disposed inside the exhaust port 17 provided on the side surface 11C of the upper case 11. The exhaust fan 50 exhausts the warm air inside the housing 10 from the exhaust port 17 to the outside of the housing 10.

  The second intake fan 60 is configured by a sirocco fan, and is disposed in the approximate center on the back surface 11E side and in the vicinity of the light source device 110. The second intake fan 60 sucks outside air and cools the inside of the housing 10. As will be described later, the second intake fan 60 rotates at a speed corresponding to the pressure in the housing 10.

  The control board 70 is disposed above the optical unit 30 near the side surface 11D of the upper case 11 (partially omitted in FIG. 3). The control board 70 has a control unit 71 (see FIG. 6). The control unit 71 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and functions as a computer. The control unit 71 operates, for example, the first intake fan 40. The rotational speeds of the exhaust fan 50 and the second intake fan 60 are controlled.

Here, each component of the main body will be described in detail.
The optical unit 30 includes an illumination optical unit 100, a color separation optical unit 200, a relay optical unit 300, liquid crystal light valves 400R, 400G, and 400B that are light modulation units, a cross dichroic prism 450, and a projection optical unit 500. It has.

The illumination optical unit 100 includes a light source device 110, a first lens array 120, a second lens array 130, a polarization conversion element 140, and a superimposing lens 150.
The light source device 110 includes a light source 111, a reflector 112, a light source casing 114 that accommodates and fixes the light source 111 and the reflector 112, and a front glass that covers an opening provided in the light source casing 114 to emit a light beam. 113 etc. are comprised.
The radial light beam emitted from the light source 111 is reflected by the reflector 112 to become a substantially parallel light beam, passes through the front glass 113, and is emitted to the first lens array 120. In this embodiment, an ultrahigh pressure mercury lamp is used as the light source 111, and a parabolic mirror is used as the reflector 112. The light source 111 is not limited to an ultrahigh pressure mercury lamp, and may be a metal halide lamp, for example. Further, the reflector 112 is not limited to a parabolic mirror, and a configuration in which a collimating concave lens is disposed on the exit surface of a reflector made of an ellipsoidal mirror may be employed.

The light beam emitted from the light source 111 is divided into a plurality of minute partial light beams by the first lens array 120, and each partial light beam is three liquid crystal lights to be illuminated by the second lens array 130 and the superimposing lens 150. It is superimposed on the surface of the valves 400R, 400G, 400B. The first lens array 120 and the second lens array 130 are formed by arranging small lenses in a matrix.
The polarization conversion element 140 has a function of aligning a randomly polarized light beam with polarized light having a polarization direction that can be used by the three liquid crystal light valves 400R, 400G, and 400B.

  The color separation optical unit 200 has a function of separating the light beam emitted from the illumination optical unit 100 into light beams of three colors having different wavelength ranges. The first dichroic mirror 210 reflects a red light component (hereinafter referred to as “R light”), a green light component (hereinafter referred to as “G light”), and a blue light component (hereinafter referred to as “B light”). Transparent. The R light reflected by the first dichroic mirror 210 is reflected by the reflection mirror 230, passes through the collimating lens 240R, and illuminates the liquid crystal light valve 400R for R light. The collimating lens 240R collects the plurality of partial light beams from the illumination optical unit 100 so as to illuminate the liquid crystal light valve 400R. Usually, each partial light beam is set to be a substantially parallel light beam. The collimating lenses 240G and 240B disposed in front of the other liquid crystal light valves 400G and 400B also have the same function as the collimating lens 240R.

  The second dichroic mirror 220 reflects G light and transmits B light. For this reason, the G light out of the G light and B light transmitted through the first dichroic mirror 210 is reflected by the second dichroic mirror 220, passes through the collimating lens 240G, and passes through the liquid crystal light valve 400G for G light. Illuminate. On the other hand, the B light passes through the second dichroic mirror 220, passes through the relay optical unit 300, and further passes through the collimating lens 240B to illuminate the B light liquid crystal light valve 400B.

  The relay optical unit 300 includes an incident side lens 310, an incident side reflection mirror 320, a relay lens 330, and an emission side reflection mirror 340. The B light emitted from the color separation optical unit 200 is converged in the vicinity of the relay lens 330 by the incident side lens 310 and is diverged toward the collimating lens 240B (exit side reflection mirror 340). The size of the light beam incident on the collimating lens 240B is set to be approximately equal to the size of the light beam incident on the incident side lens 310. As described above, the relay optical unit 300 is used for the B light because the optical path length of the B light is longer than the optical path lengths of the other color lights. This is to prevent it. The relay optical unit 300 is configured to pass the B light among the three color lights, but is not limited thereto, and may be configured to pass the R light, for example.

Each of the liquid crystal light valves 400R, 400G, and 400B includes a transmissive liquid crystal panel and an incident-side polarizing plate and an emitting-side polarizing plate that are disposed on both sides thereof. The liquid crystal light valves 400R, 400G, and 400B modulate each color light incident on each surface in accordance with the corresponding image signal, form the image light of each color light, and emit it to the cross dichroic prism 450.
The cross dichroic prism 450 combines image light of each color light emitted from the liquid crystal light valves 400R, 400G, and 400B, forms image light representing a color image, and emits the image light to the projection optical unit 500.
The projection optical unit 500 includes a projection lens 510 and enlarges and projects the image light from the cross dichroic prism 450 onto a screen or the like.

Next, each fan (the first and second intake fans 40 and 60, the exhaust fan 50) will be described in detail.
As shown in FIG. 4, the first intake fan 40 is arranged so that its air inlet 41 faces the inner surface of the first inlet 23 of the lower case 12, and sucks outside air from the air inlet 41. (Flow F10) and discharge from the air discharge port 42 (flow F11). A dust-proof filter 26 is disposed at the first air inlet 23, and prevents dust mixed in from the outside air from entering the inside of the housing 10. Since the first intake fan 40 is composed of a sirocco fan having a high static pressure, the outside air can be efficiently sucked even if the dustproof filter 26 is disposed at the first intake port 23.

  A duct 45 is disposed on the air exhaust port 42 side of the first intake fan 40. The duct 45 is made of synthetic resin, and is formed from the air discharge port 42 of the first intake fan 40 to below the liquid crystal light valves 400R, 400G, and 400B. The duct 45 has a box shape, and an opening 45A is formed on one side surface, and three holes 45B (only one is shown) are formed on the top surface. The opening 45A surrounds the air exhaust port 42 of the first intake fan 40, and the three holes 45B are arranged so as to be located below the liquid crystal light valves 400R, 400G, and 400B, respectively (in FIG. 4, Liquid crystal light valves 400R and 400B are not shown). The air discharged from the air discharge port 42 (flow F11) is guided by the duct 45 and discharged from the hole 45B (flow F12), and cools the liquid crystal light valves 400R, 400G, 400B and flows upward ( Flow F13).

  A first detection unit 80 is attached to the upper surface of the cross dichroic prism 450 via an attachment member. The first detection unit 80 is a temperature sensitive element such as a thermistor, and detects the temperature in the vicinity of the liquid crystal light valves 400R, 400G, and 400B.

  Returning to FIG. 3, the exhaust fan 50 removes internal air such as air heated by the cooling of the liquid crystal light valves 400 </ b> R, 400 </ b> G, 400 </ b> B (flow F <b> 21) and air heated by the heat generated by the light source 111 (flow F <b> 22). The air is exhausted outside the housing 10 (flow F23). Since the exhaust fan 50 is configured by an axial fan having a larger air volume than a sirocco fan, the exhaust fan 50 can exhaust efficiently.

  A second detector 90 is attached to the surface of the light source casing 114 near the exhaust fan 50. The second detection unit 90 is a temperature-sensitive element such as a thermistor similarly to the first detection unit 80 and detects the temperature in the vicinity of the light source 111.

  As shown in FIG. 3, the second intake fan 60 is disposed such that the air inlet 61 faces the inner surface of the second intake port 25 of the upper case 11. The second intake fan 60 sucks outside air from the air inlet 61 (flow F30) and discharges it from the air outlet 62 (flow F31). A dust-proof filter 28 is disposed at the second air inlet 25, and the dust-proof filter 28 prevents dust mixed in with the outside air from entering the inside.

  As shown in FIG. 5, the air exhaust port 62 of the second intake fan 60 faces obliquely upward, and discharges the sucked outside air to the inner surface of the upper case 11 above the light source 111 (flow F31). Since this part is close to the light source 111, the temperature is higher than other parts. By cooling this part, it is possible to suppress the upper surface 11A from becoming high temperature. And even if a user touches the upper surface 11A, it becomes possible not to give discomfort.

Here, control of each fan will be described.
FIG. 6 is a block diagram of a control system that controls the rotational speed of each fan.
As shown in FIG. 6, the first detection unit 80, the second detection unit 90, the first intake fan 40, the exhaust fan 50, and the second intake fan 60 are each connected to the control board 70. The control board 70 includes a control unit 71, A / D conversion units 72 and 75, D / A conversion units 73, 76 and 78, and drivers 74, 77 and 79.

The first detection unit 80 detects the temperature in the vicinity of the liquid crystal light valves 400R, 400G, and 400B, and outputs a detection signal corresponding to the detection result. The detection signal output from the first detection unit 80 is input to the control unit 71 via the A / D conversion unit 72.
The control unit 71 generates a control signal (first control signal SO1) based on the input detection signal and outputs the control signal to the driver 74 to control the rotational speed of the first intake fan 40. Specifically, the control unit 71 acquires detection signals from the first detection unit 80 at appropriate intervals, and compares the detected temperature with a predetermined temperature set in advance. When the detected temperature is higher than the predetermined temperature, the first control signal SO1 is generated so that the rotation speed of the first intake fan 40 is increased, and the detected temperature is lower than the predetermined temperature. Sometimes, the first control signal SO1 is generated so that the rotation speed of the first intake fan 40 becomes slow. Then, the control unit 71 outputs the generated first control signal SO1 to the driver 74 via the D / A conversion unit 73. The driver 74 drives the first intake fan 40 by applying a voltage V1 having a rotational speed corresponding to the first control signal SO1.
As described above, the control unit 71 controls the rotational speed of the first intake fan 40 based on the detection result detected by the first detection unit 80.

The second detection unit 90 detects the temperature near the light source 111 and outputs a detection signal corresponding to the detection result. The detection signal output from the second detection unit 90 is input to the control unit 71 via the A / D conversion unit 75.
The control unit 71 generates a control signal (second control signal SO2) based on the input detection signal, and outputs the control signal to the driver 77 to control the rotational speed of the exhaust fan 50. Specifically, the control unit 71 acquires detection signals from the second detection unit 90 at appropriate intervals, and compares the detected temperature with a predetermined temperature set in advance. When the detected temperature is higher than the predetermined temperature, the second control signal SO2 is generated so that the rotational speed of the exhaust fan 50 is increased. When the detected temperature is lower than the predetermined temperature, the exhaust gas is exhausted. A second control signal SO2 is generated so that the rotation speed of the fan 50 becomes slow. Then, the control unit 71 outputs the generated second control signal SO2 to the driver 77 via the D / A conversion unit 76. The driver 77 drives the exhaust fan 50 by applying a voltage V2 having a rotational speed corresponding to the second control signal SO2.
Thus, the control unit 71 controls the rotational speed of the exhaust fan 50 based on the detection result detected by the second detection unit 90.

Further, the control unit 71 generates a third control signal SO3 based on the first control signal SO1 and the second control signal SO2, and outputs the third control signal SO3 to the driver 79, so that the rotational speed of the second intake fan 60 is increased. To control. Based on the third control signal SO3, the driver 79 drives the second intake fan 60 by applying a voltage V3 that has two low-speed and high-speed rotation speeds.
Here, the air volume of each fan, that is, the intake air amount of the first intake fan 40, the exhaust air amount of the exhaust fan 50, and the intake air amount of the second intake fan 60 are determined by the fan performance and the rotational speed. Since the performance of each fan is known, the intake air amount and the exhaust air amount of each fan can be derived from the rotation speed. In addition, since the intake air amount of the second intake fan 60 is set in two stages, the intake air amount also changes in two stages.

The controller 71 controls the rotational speed of the second intake fan 60 at a low speed and a high speed as follows. A method for controlling the rotational speed when the second intake fan 60 is rotated at a low speed will be described.
The controller 71 recognizes the intake air amount of the first intake fan 40 based on the rotational speed of the fan (voltage V1), and recognizes the exhaust amount of the exhaust fan 50 based on the rotational speed of the fan (voltage V2). Further, the controller 71 adds the intake amount of the second intake fan 60 to the intake amount of the first intake fan 40, that is, the total intake amount (low speed) when the second intake fan 60 is rotated. Hour total intake amount) is calculated. Then, the control unit 71 derives a value (outflow value) obtained by subtracting the total intake amount from the exhaust amount of the exhaust fan 50. As a result, when the outflow value is 0 or less, that is, when the exhaust amount is lower than the total intake amount and the atmospheric pressure in the housing 10 is higher than the outside, the control unit 71 rotates the second intake fan 60 at a low speed. Maintain with. On the other hand, when the outflow value is larger than 0, that is, when the exhaust amount exceeds the total intake amount and the atmospheric pressure in the housing 10 is lower than the outside, the control unit 71 rotates the second intake fan 60 at a high speed. .

  On the other hand, the control unit 71 calculates the total intake amount at low speed and derives the outflow value even when the second intake fan 60 is rotating at high speed. As a result, when the outflow value is greater than 0, the control unit 71 maintains the second intake fan 60 at high speed rotation, and when the outflow value is 0 or less, the control unit 71 performs the second intake air intake. The fan 60 is rotated at a low speed.

  As described above, the control unit 71 compares the exhaust amount exhausted outside the housing 10 with the total intake amount sucked into the housing 10 based on the rotation speed of each fan. When the exhaust amount exceeds the total intake amount, that is, when the pressure in the housing 10 decreases, the control unit 71 increases the rotational speed of the second intake fan 60 and incorporates it into the housing 10. Increase intake volume. As a result, the pressure in the housing 10 is prevented from decreasing, and a gap in the housing 10, for example, a gap in the openings 15 and 16 of the upper case 11 as shown in FIGS. Intrusion of outside air from 132 or the like is suppressed.

As described above, according to the projector 1 of the present embodiment, the following effects can be obtained.
(1) According to the projector 1 of the present embodiment, the exhaust amount exhausted outside the casing 10 by the exhaust fan 50 is taken into the casing 10 by the first intake fan 40 and the second intake fan 60. When the total intake air amount exceeds the maximum intake air amount, the control unit 71 increases the intake air amount by increasing the rotational speed of the second intake fan 60. Accordingly, it is possible to suppress the pressure in the housing 10 from being lowered, and it is possible to suppress the dust mixed in the outside air from entering the housing 10 through the gap of the housing 10. Therefore, it is possible to suppress the deterioration of the image quality of the projected image, and the product life can be extended.

  (2) According to the projector 1 of the present embodiment, by providing the second intake fan 60, a large fan whose intake amount always exceeds the displacement is not used as the first intake fan 40. Since it is possible to suppress a decrease in the pressure in the housing 10, it is possible to suppress the intrusion of dust without increasing the size of the projector.

  (3) According to the projector 1 of the present embodiment, since the control unit 71 derives the exhaust amount and the total intake amount based on the rotational speed of each fan, it is not necessary to newly include an air amount sensor or the like. .

  (4) According to the projector 1 of the present embodiment, the dust inlet filter 23 is disposed at the first intake port 23 through which the first intake fan 40 takes in the outside air. Can be suppressed.

  (5) According to the projector 1 of the present embodiment, the first intake fan 40 is composed of a sirocco fan having a high static pressure, so even if the dustproof filter 26 is disposed at the first intake port 23. The liquid crystal light valves 400R, 400G, and 400B can be cooled by efficiently sucking outside air.

  (6) According to the projector 1 of the present embodiment, the exhaust fan 50 is composed of an axial fan having a larger air volume than the sirocco fan, so that the air heated with the cooling of the liquid crystal light valves 400R, 400G, 400B, Internal air such as air warmed by heat generated by the light source 111 can be efficiently exhausted outside the housing 10.

  (7) According to the projector 1 of the present embodiment, the second intake fan 60 suppresses the pressure in the casing 10 from being reduced by the air sucked into the casing 10 and is located above the light source 111. Since the inner surface of the upper case 11 is cooled, the taken-in air can be used efficiently.

  (8) According to the projector 1 of the present embodiment, the first intake port 23 through which the first intake fan 40 takes in outside air and the second intake port 25 through which the second intake fan 60 takes in outside air are: Since the first intake fan 40 and the second intake fan 60 are formed in the separated positions, the degree of freedom of arranging the first intake fan 40 and the second intake fan 60 in the housing 10 is increased.

In addition, you may change embodiment of this invention as follows.
(Modification 1)
The control unit 71 of the embodiment controls the rotation speed of the second intake fan 60 in two stages, low speed and high speed, but controls the rotation of the second intake fan 60 in two stages, ON and OFF. May be. That is, when the exhaust amount exhausted outside the housing 10 exceeds the total intake air amount sucked into the housing 10, the control unit 71 rotates the second intake fan 60 at a predetermined speed. In other cases, the rotation may be stopped. In addition, the rotational speed of the second intake fan 60 is controlled at a rotational speed of three or more stages. For example, fine control may be performed so that the atmospheric pressure in the housing 10 is always higher than the outside. Good.

(Modification 2)
The control unit 71 of the embodiment rotates the second intake fan 60 at a high speed when the value obtained by subtracting the total intake amount from the exhaust amount (outflow value) is larger than 0. When the atmospheric pressure in the housing 10 is slightly lower than the outside so as to prevent the intrusion of dust, the outflow value is compared with a positive value, and if it is larger than this, the second intake fan 60 is rotated at high speed. You may do it. In addition, in order to prevent dust from entering more reliably, the second intake fan 60 is rotated at a high speed when the outflow value is larger than the negative value compared with the negative value in consideration of the variation in performance of each fan. It can also be made to do.

(Modification 3)
The first intake fan 40 of the above embodiment is configured by one, but is not limited to one and may be a plurality. In addition to the fan that cools the light modulation unit, the first intake fan 40 is a fan that cools other optical components, a power supply unit for supplying power, a light source driving circuit for lighting a light source, and the like. The aspect provided may be sufficient.

(Modification 4)
The number of exhaust fans 50 in the embodiment is not limited to one, and may be plural. The exhaust fan 50 includes a power supply unit for supplying power, a light source, in addition to a fan that exhausts internal air such as air warmed by cooling of the light modulation unit and air heated by heat generated by the light source 111. An aspect may be provided that includes a fan for exhausting air warmed by heat generated by a light source driving circuit or the like for lighting.

(Modification 5)
In the embodiment, the control unit 71 controls the rotational speed of each fan based on the temperature in the vicinity of the liquid crystal light valves 400R, 400G, and 400B and the temperature in the vicinity of the light source 111, but is limited to this position. Instead, the first detection unit 80 and the second detection unit 90 may be arranged at other positions and controlled based on the detection result of the positions. Further, the number of detection units may be one or three or more.

(Modification 6)
The second intake fan 60 of the above embodiment cools the inner surface of the upper case 11 above the light source 111 with the intake air, but the power supply for supplying optical components other than the upper case 11 and power. The light source driving circuit for turning on the light source and the light source may be cooled. Moreover, even if it is not cooling the specific cooling object, it should just be the structure which sends air into the inside of a housing | casing.

(Modification 7)
The first air inlet 23 and the second air inlet 25 in the above embodiment are formed apart from each other, and the first air inlet 23 and the second air inlet 25 are respectively provided with individual dustproof filters 26 and 28. However, the first air inlet 23 and the second air inlet 25 may be formed close to each other and covered with an integral dustproof filter.

This aspect will be described with reference to FIG.
FIG. 7 is a cross-sectional view of the rear side portion of the projector 1 as viewed from the rear.
As shown in FIG. 7, the first intake fan 40 and the second intake fan 60 are sirocco fans, and each sirocco fan has air inlets 41 and 61 inside the casing 10 (top surface direction). ) Is attached to face. The lower case 12 is provided with a first air inlet 23 and a second air inlet 25 adjacent to each other between two sirocco fans. Further, the first air inlet 23 and the second air inlet 25 are covered with an integral dustproof filter 128. The dust filter 128 is held in the lower case 12 by a filter frame 129 having a hole through which outside air passes.

  A duct 46 is disposed above the first intake fan 40 so as to cover the first intake port 23 and the first intake fan 40. A duct 47 is disposed above the second intake fan 60 so as to cover the second intake port 25 and the second intake fan 60. The first intake fan 40 draws outside air from the first intake port 23 (flows F40 to F41 to F42), discharges it from the air discharge port 42, and cools the liquid crystal light valves 400R, 400G, and 400B. The second intake fan 60 draws outside air from the second intake port 25 and discharges it into the housing 10 from the air discharge port 62 (flows F40 to F44 to F45 to F46).

  As described above, since the first intake port 23 and the second intake port 25 are formed close to each other, the first intake port 23 and the second intake port 25 are covered with the integral dustproof filter 128. be able to. Accordingly, since it is not necessary to dispose the dustproof filters at the first and second intake ports, respectively, the projector 1 can be configured with a small number of parts, and workability when replacing the dustproof filters is improved. .

(Modification 8)
In the above-described embodiment, the transmissive liquid crystal light valves 400R, 400G, and 400B are used as the light modulation unit. However, the light modulation unit uses a reflective liquid crystal light valve or a device that uses a micromirror. There may be.

The perspective view seen from the upper front side of the projector of this embodiment. The perspective view seen from the lower back side of the projector of this embodiment. FIG. 2 is a plan view illustrating a schematic configuration of the projector according to the embodiment. AA sectional drawing in FIG. BB sectional drawing in FIG. The block diagram of the control system which controls the rotational speed of each fan. Sectional drawing of the projector back side of a modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector, 10 ... Housing | casing, 11 ... Upper case, 12 ... Lower case, 13 ... Rear case, 15, 16 ... Opening part, 17 ... Exhaust port, 23 ... 1st inlet port, 25 ... 2nd intake port Mouth, 26, 28, 128 ... dust filter, 30 ... optical unit, 40 ... first intake fan, 41 ... air inlet, 42 ... air outlet, 45, 46, 47 ... duct, 50 ... exhaust fan, 60 ... Second intake fan, 61 ... Air introduction port, 62 ... Air discharge port, 70 ... Control board, 71 ... Control unit, 72,75 ... A / D conversion unit, 73,76,78 ... D / A conversion unit , 74, 77, 79 ... driver, 80 ... first detection unit, 90 ... second detection unit, 111 ... light source, 400R, 400G, 400B ... liquid crystal light valve, 450 ... cross dichroic prism, 500 ... projection optical unit 510 ... Shooting lens, SO1 ... first control signal, SO2 ... second control signal, SO3 ... third control signal.

Claims (8)

A light source that emits a light beam, a light modulation unit that modulates the light beam emitted from the light source according to an image signal to form image light, a projection optical unit that projects the image light, and a housing that houses these A projector with
A detection unit for detecting a temperature in the housing;
First and second intake fans that draw outside air into the housing;
An exhaust fan for exhausting the air in the housing to the outside of the housing;
A control unit that controls rotational speeds of the first intake fan and the exhaust fan based on a detection result of the detection unit;
With
The control unit compares an exhaust amount of the exhaust fan with a total intake amount of the first and second intake fans, and when the exhaust amount exceeds the total intake amount, the second intake air A projector characterized by increasing the rotational speed of a fan to increase the amount of intake air. A light source that emits a light beam, a light modulation unit that modulates the light beam emitted from the light source according to an image signal to form image light, a projection optical unit that projects the image light, and a housing that houses these A projector with
A detection unit for detecting a temperature in the housing;
First and second intake fans that draw outside air into the housing;
An exhaust fan for exhausting the air in the housing to the outside of the housing;
A control unit that controls rotational speeds of the first intake fan and the exhaust fan based on a detection result of the detection unit;
With
When the value obtained by subtracting the total intake air amount of the first and second intake fans from the exhaust air amount of the exhaust fan is larger than a preset value, the control unit A projector characterized by increasing the intake speed by increasing the rotation speed. The projector according to claim 1 or 2,
The control unit derives the exhaust amount and the total intake amount based on rotational speeds of the first and second intake fans and the exhaust fan. The projector according to any one of claims 1 to 3,
The detection unit includes first and second detection units,
The control unit controls the rotation speed of the first intake fan based on the detection result of the first detection unit, and controls the rotation speed of the exhaust fan based on the detection result of the second detection unit. A projector characterized by that. The projector according to any one of claims 1 to 4,
The projector is characterized in that a first intake port through which the first intake fan takes in outside air is formed in the housing, and the first intake port is covered with a dustproof filter. The projector according to any one of claims 1 to 5,
The projector, wherein the second intake fan cools the inside of the casing with the intake air. The projector according to claim 5,
The casing is formed with a second intake port through which the second intake fan takes in outside air, and is separated from the first intake port. The first and second intake ports are respectively A projector characterized by being covered with an individual dustproof filter. The projector according to claim 5,
The casing is formed with a second intake port through which the second intake fan takes in outside air in the vicinity of the first intake port, and the first and second intake ports are integrated with each other. A projector characterized by being covered with a dustproof filter.

Images