projector

Abstract

The present application provides a projector capable of improving cooling performance. The projector has: an external casing that sucks external air into an inside via a filter; a light source disposed in the external casing; an image forming unit that converts light from the light source into image light; a suction fan that has a suction port that sucks the external air; an antechamber that communicates with the filter and the suction port; a pressure sensor disposed in the antechamber; and a control unit that performs drive control on the suction fan, the control unit performing the following controls: a first measurement process that starts the suction fan and measures the pressure of the antechamber using the pressure sensor at a rotational speed at the time of start; a second measurement process that makes the rotational speed of the suction fan lower than the rotational speed at the time of start and measures the pressure of the antechamber using the pressure sensor; and a determination process that determines the clogging of the filter based on the difference between the pressure value of the first measurement process and the pressure value of the second measurement process.

Description

TECHNICAL FIELD

[0001] The present application relates to a projector. BACKGROUND

[0002] A projector is disclosed in Patent Document 1, which has an air intake fan for introducing air from an air intake port into a housing, an air exhaust fan for exhausting air in the housing, a dust filter installed at the air intake port, and a pressure sensor for detecting the pressure in the housing, and detects the clogging state of the dust filter based on the output of the pressure sensor. The pressure sensor is disposed between the air intake fan and the air exhaust fan.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2009-188040

[0004] However, in the projector described in Patent Document 1, since it takes time until the pressure in the entire housing becomes constant, in the case where the dust filter is clogged, there is a problem that it takes time until the inside of the housing is cooled. That is, it is required to be able to quickly detect the clogging of the dust filter to improve the cooling performance in the housing, and to be able to shorten the time from power-on to projection of an image. SUMMARY

[0005] A projector has an outer housing that sucks external air into the inside via a filter, a light source that is disposed in the outer housing, an image forming device that is disposed in the outer housing and converts light from the light source into image light, a suction fan that is disposed in the outer housing and has a suction port that sucks the external air, an antechamber that is disposed in the outer housing and communicates with the filter and the suction port, a pressure sensor that is disposed in the antechamber, and a control section that drives controls the suction fan, the control section performing a first measurement process that starts the suction fan and measures the pressure in the antechamber using the pressure sensor at the rotational speed at the time of start, a second measurement process that makes the rotational speed of the suction fan lower than the rotational speed at the time of start and measures the pressure in the antechamber using the pressure sensor, and a determination process that determines the clogging of the filter based on the difference between the pressure value of the first measurement process and the pressure value of the second measurement process.

[0006] Further, the projector has: an outer casing that sucks outside air into an inside via a filter; a light source that is disposed in the outer casing; an image forming device that is disposed in the outer casing, converts light from the light source into image light; a suction fan that is disposed in the outer casing, has a suction port that sucks the outside air; an antechamber that is disposed in the outer casing, communicates with the filter and the suction port; a pressure sensor that is disposed in the antechamber; and a control section that drives controls the suction fan, the control section executes: a first measurement process that drives the suction fan, makes the pressure of the antechamber negative, and measures with the pressure sensor; a second measurement process that drives the suction fan, makes the pressure of the antechamber simulate outside air pressure, and measures with the pressure sensor; and a determination process that determines clogging of the filter based on a difference between the pressure value of the first measurement process and the pressure value of the second measurement process. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a perspective view showing a structure of the projector.

[0008] Figure 2 is a plan view showing a structure from a light source unit to a projection optical unit.

[0009] Figure 3 is a sectional view along the line A-A' shown in Figure 2 .

[0010] Figure 4 is a plan view showing an inside of the projector from an upper surface side.

[0011] Figure 5 is a plan view showing a structure of a part of the projector.

[0012] Figure 6 is a plan view showing a structure from a light source unit to a projection optical unit.

[0013] Figure 7 is a perspective view showing a structure of a part of the projector.

[0014] Figure 8 is a side view showing an inside of the projector from a side surface side.

[0015] Figure 9 is a block diagram showing a structure of the projector.

[0016] Figure 10 is a flowchart showing a driving method of the suction fan.

[0017] Figure 11 is a timing chart showing the driving method of the suction fan.

[0018] Figure 12 is a timing chart showing a driving method of the suction fan.

[0019] Figure 13 is a timing chart showing a driving method of the suction fan.

[0020] Figure 14 is a timing chart showing a driving method of the suction fan.

[0021] Figure 15 is a timing chart showing a driving method of the suction fan.

[0022] Explanation of Reference Signs

[0023] 10: control section; 11: image processing section; 12: light modulating element driving section; 13: light modulating element; 14: light source driving section; 15: fan driving section; 16: operation section; 17: display section; 18: sound output section; 19: storage section; 20: detection section; 21: determination section; 100: outer casing; 100a: front surface; 100b: back surface; 101: speaker unit; 102: power supply unit; 103: duct; 103a: a portion; 200: air inlet; 201: filter; 202: prechamber; 203: suction fan; 203a, 203b, 203c, 203d: suction fan; 203x: suction port; 204: pressure sensor; 205, 206, 207: fan; 208: exhaust fan; 210: air outlet; 300: projection optical unit; 400: light source unit; 401: light source; 500: light guide optical unit; 600: image forming unit as an image forming apparatus; 601, 601B, 601G, 601R: liquid crystal panel as a light modulating panel; 602: cross dichroic prism; 1000: projector. DETAILED DESCRIPTION

[0024] In each of the following drawings, three axes perpendicular to each other are described as an X axis, a Y axis, and a Z axis. The direction along the X axis is set as an "X direction", the direction along the Y axis is set as a "Y direction", and the direction along the Z axis is set as a "Z direction", the direction of the arrow is a + direction, and the direction opposite to the + direction is set as a - direction. Note that the +Z direction is sometimes referred to as "up" or "above", and the -Z direction is sometimes referred to as "down" or "below", and the observation from the +Z direction is sometimes referred to as a plan view or a plan. In addition, the surface on the +Z direction side is described as an upper surface, and the surface on the -Z direction side opposite thereto is described as a lower surface. In the present embodiment, the direction from the front surface 100a to the back surface 100b of the outer casing 100 described later is defined as a +Y direction of the Y axis, the direction of the exhaust port 210 of the X axis perpendicular to the Y axis is defined as a +X direction, and the direction of the projection port of the Z axis perpendicular to the Y axis and the X axis is defined as a +Z direction.

[0025] First, referring to Figures 1-3 The structure of the projector 1000 will be described.

[0026] As Figure 1 shown, the projector 1000 has an outer casing 100, an air inlet 200 disposed on the front face 100a side of the outer casing 100, and a projection optical unit 300 that projects image light L toward the back face 100b side of the outer casing 100. A mirror for reflecting the image light L is disposed in the projection optical unit 300.

[0027] As Figure 2 shown, the projector 1000 has a light source unit 400, a light guide optical unit 500, an image forming unit 600 as an image forming device, and the projection optical unit 300. The light source unit 400, the light guide optical unit 500, the image forming unit 600, and the projection optical unit 300 are disposed along a system optical axis and project the image light L.

[0028] The light source unit 400 is configured, for example, to include a solid-state light source such as a laser semiconductor having a high luminance, a wavelength conversion element that wavelength-converts a portion of the laser light as excitation light, a fluorescent body, an integrating lens, and a polarization conversion element. In addition, the light source 401 can also be an LED light source, an ultrahigh-pressure mercury lamp, a halogen lamp, or the like white light source. The polarization conversion element has a function of making the P-polarization component and the S-polarization component of the light emitted from the light source 401 coincide.

[0029] The light guide optical unit 500 is configured, for example, to include a dichroic mirror as a light separating element, a mirror, and a relay lens.

[0030] The image forming unit 600 is a portion that generates image light from the light emitted from the light source unit 400 and has three liquid crystal panels 601R, 601G, 601B as light modulation panels and a cross dichroic prism 602 as a light combining element.

[0031] As Figure 3 shown, the projection optical unit 300 is mounted to the outer casing 100. In addition, the projection optical unit 300 can also have a lens shift mechanism. The combined image light L is projected onto a screen by a projection lens, and an image is enlarged and displayed.

[0032] Next, referring to Figures 4-8 The flow of external air G introduced into the projector 1000 will be described.

[0033] As Figure 4As shown above, the projector 1000 includes a light source unit 400, an image forming unit 600, and a projection optics unit 300 within its outer casing 100. A speaker unit 101 is disposed on the right side of the front side 100a of the outer casing 100, specifically on the +X direction side relative to the projection optics unit 300. A power supply unit 102 is disposed on the right side of the rear side 100b of the outer casing 100, specifically on the +X direction side relative to the projection optics unit 300 and on the +Y direction side relative to the speaker unit 101.

[0034] As described above, an air inlet 200 is provided on the left side of the front 100a of the outer housing 100, that is, on the -X direction side of the outer housing 100 relative to the projection optical unit 300. A filter 201 for capturing dust and other particles contained in the outside air is provided in the air inlet 200. Inside the outer housing 100, closer to the filter 201, a front chamber 202 is provided, which has multiple suction fans, specifically four suction fans 203a, 203b, 203c, and 203d in this embodiment.

[0035] The anterior chamber 202 is the space separating the filter 201 and the intake 203x of the suction fan 203, forming a simulated external air pressure forming chamber. The intake 203x is the front end portion of the suction fan 203. Additionally, the suction fan 203 has an exhaust port for expelling the drawn-in external gas G. A pressure sensor 204 for measuring the pressure inside the anterior chamber 202 is disposed in a portion of this anterior chamber 202.

[0036] Three suction fans 203a, 203c, and 203d blow external air into the three liquid crystal panels 601 that constitute the image forming unit 600. The remaining suction fan 203b blows external air into the projection lens and polarization conversion element that constitute the projection optics unit 300. The external air is supplied through a duct.

[0037] like Figure 5 As shown, the exhaust port (not shown) of the suction fan 203 is connected via pipe 103 to three liquid crystal panels 601R (red), 601G (green), and 601B (blue) constituting the image forming unit 600. Specifically, Figure 4 The three suction fans 203a, 203c, and 203d shown blow air to each LCD panel 601 through a separate pipe 103.

[0038] Further, the suction fans 203a, 203b, 203c, 203d can also not determine the objects to be cooled as described above. For example, a part of the suction fans 203 can be connected to one duct 103, branched into three from the middle of the one duct 103, and air can be supplied to each of the liquid crystal panels 601. A part 103a of the duct 103 is configured to be able to supply air to the polarization conversion element.

[0039] In addition, the suction fans 203 are not limited to being composed of four, and can be composed of only one. In this case, for example, air can be supplied only to the liquid crystal panel 601, for example, the blue liquid crystal panel 601B, which is most required to be cooled as a heat source. In addition, the front chamber 202 and the pressure sensor 204 can be provided for each of the suction fans 203, although the suction inlets 203x of the suction fans 203 are opened in the one front chamber 202.

[0040] As shown in Figure 4 A part of the air K1 that has cooled the image forming unit 600 by being supplied from the suction fans 203 is drawn by the fan 205. The air K1 blown from the fan 205 cools the light source unit 400 and is discharged to the outside from the exhaust port not shown in the outer casing 100 on the left side of the outer casing 100, that is, in the -X direction with respect to the light source unit 400. In addition, the air K2 that has cooled the image forming unit 600, the power supply unit 102, the projection optical unit 300, and the like is discharged from the exhaust port 210 of the outer casing 100 on the right side of the outer casing 100, that is, in the +X direction of the outer casing 100, via the fans 206, 207, and 208.

[0041] As shown in Figure 5 The pressure sensor 204 is disposed in the space between the filter 201 and the suction inlets 203x of the suction fans 203.

[0042] Next, the flow of the air K when viewed from the top and the sectional view will be described with reference to Figures 6-8

[0043] As shown in Figure 6 As viewed from the top, the outside air G is introduced into the outer casing 100 via the filter 201 disposed at the air inlet 200 of the projector 1000.

[0044] As shown in Figure 7 When the projector 1000 is viewed obliquely, the outside air G enters the inside of the outer casing 100 from the air inlet 200 disposed at the lower left of the front surface 100a of the outer casing 100. The introduced outside air G enters the front chamber 202 through the filter 201.

[0045] The filter 201 is disposed below the suction fans 203, that is, in such a manner as to oppose the suction fans 203 in the -Z direction. As​Figure 8 As shown, when the projector 1000 is viewed from the side, external air G enters the inside of the casing 100 from an air inlet 200 provided on the lower side of the front face 100a of the casing 100. The introduced external air G enters the front chamber 202 through a filter 201. Further, a suction fan 203, which is provided so that a suction inlet 203x communicates with the front chamber 202, can be provided in the front chamber 202 or outside the front chamber 202. In addition, the suction inlet 203x can be provided on the side of a wall of the front chamber 202 or in the wall.

[0046] Next, the structure of the projector 1000 will be described with reference to Figure 9 The structure of the projector 1000 will be described.

[0047] The projector 1000 has a control section 10 that controls the overall operation of the projector 1000, an image processing section 11, a light modulating element drive section 12, a light modulating element 13, a light source 401, and a light source drive section 14 that drives the light source 401.

[0048] Further, the projector 1000 has a suction fan 203 that introduces air from the outside via the air inlet 200 described above, an exhaust fan 208 that exhausts air inside the casing 100 to the outside via an exhaust port 210 (see Fig. 2) formed in the casing 100, and a fan drive section 15 that drives the suction fan 203 and the exhaust fan 208. Figure 4

[0049] Further, the projector 1000 has an operation section 16 that includes switches and the like for inputting various operation signals to the control section 10, a display section 17 that indicates the state of the projector 1000, a sound output section 18, and a nonvolatile storage section 19 that holds various data and programs.

[0050] Further, the projector 1000 has a detection section 20 that detects the output of the pressure sensor 204 and a determination section 21 that determines whether the filter 201 is clogged based on the pressure value of the front chamber 202 detected by the detection section 20 and a threshold value.

[0051] The control section 10 is composed of a microcomputer including a CPU, a ROM, a RAM, and the like, and controls the overall operation of the projector 1000, such as the operation of the image processing section 11, the light source drive section 14, the fan drive section 15, the display section 17, the operation section 16, the sound output section 18, the storage section 19, the detection section 20, and the determination section 21, in accordance with various programs stored in the ROM.

[0052] ​The light modulation element 13 is composed of liquid crystal light valves comprising three liquid crystal panels 601R, 601G, and 601B that modulate the light emitted from the light source 401, respectively modulating red light R, green light G, and blue light B.

[0053] The light emitted from the light source 401 is separated into different colors by the light guiding optical unit 500, modulated by a liquid crystal light valve (not shown) containing the corresponding liquid crystal panel 601, and then combined by the cross-shaped dichroic prism 602 before being amplified and projected by the projection optical unit 300.

[0054] The image processing unit 11 supplies the generated frame image signal to the light modulation element driving unit 12, for example. In addition, if the operation unit 16 is operated, the control unit 10 drives the light source driving unit 14 to light up the light source 401, and drives the fan driving unit 15 to rotate the suction fan 203 and the exhaust fan 208.

[0055] Therefore, external air is introduced into the outer casing 100, and air inside the outer casing 100 is exhausted to the outside, thereby cooling the interior of the outer casing 100. Additionally, the control unit 10 activates the image processing unit 11, which performs various processes on the input image signal to generate a frame image signal, which is then supplied to the light modulation element drive unit 12. Based on the frame image signal, the transmittance of each pixel of the light modulation element 13 is controlled.

[0056] Next, refer to Figures 10 to 13 The driving method for the exhaust fan 203 will be explained below. The driving method for the projector 1000 used in a low-lying area will also be explained below.

[0057] like Figure 10 As shown, in step S11, when the user turns on the power to the projector 1000, the control unit 10 causes the fan drive unit 15 to start the suction fan 203. Specifically, as... Figure 11 As shown, the suction fan 203 is started at the startup speed. In order to ensure stable operation of the suction fan 203, the speed at this startup speed is higher than the normal driving speed.

[0058] In addition, Figure 11 In the timing diagram showing the operation of the suction fan 203, the horizontal axis represents the passage of time, and the vertical axis corresponds to the rotational speed of the suction fan 203. The vertical axis increases as the rotational speed increases. Similarly, in the timing diagram showing the operation of the pressure sensor 204, the horizontal axis represents the passage of time, and the vertical axis represents the pressure. The vertical axis decreases as the pressure decreases.

[0059] Further, the rotation speed is a rotation speed required to stably drive the suction fan 203 at the time of starting the suction fan 203. The rotation speed is suppressed to be lower than the maximum driving of the suction fan 203, and becomes a rotation speed at which noise is suppressed. If noise is not considered, the suction fan 203 can also be driven at the maximum. During the period of starting at which the rotation speed of the suction fan 203 is increased to increase the driving force, the outside air G is introduced into the ante-chamber 202 via the filter 201. In Figure 11 At this time, the operation of the pressure sensor 204 is atmospheric pressure. The operation of the suction fan 203 is the minimum rotation speed.

[0060] In step S12, the control section 10 causes the light source driving section 14 to light the laser as the light source 401. Here, the laser is used as the light source 401. Specifically, as shown in FIG. 4, the suction fan 203 is maintained at the start speed. The operation of the pressure sensor 204 of the ante-chamber 202 becomes a pressure value that is reduced from atmospheric pressure. By starting the light source 401, the liquid crystal panel 601, the polarization conversion element, the phosphor, and the like serve as heat sources and the temperature rises with the light from the light source 401. The phosphor has a function of performing fluorescent conversion on excitation light. Figure 11

[0061] In step S13, the control section 10 causes the detection section 20 to measure the first measurement, i.e., pressure measurement 1, as the first measurement process. Specifically, the suction fan 203 is maintained in a state of the start speed. The pressure of the ante-chamber 202 at this time is measured using the pressure sensor 204, and a reference value is obtained.

[0062] In step S14, the control section 10 causes the fan driving section 15 to reduce the rotation speed of the suction fan 203 to the minimum rotation speed. Specifically, as shown in FIG. 5, after the pressure measurement 1, the suction fan 203 is made to be the minimum driving speed. The minimum driving speed is driving for making the ante-chamber 202 to be the outside air pressure, i.e., a pressure equivalent to atmospheric pressure. If the suction fan 203 is stopped, in order to start, it is necessary to perform start driving again, and thus the driving is as low as possible. The pressure of the ante-chamber 202 at this time becomes an analog outside air pressure equivalent to atmospheric pressure. Further, the period of rotation at the minimum rotation speed is taken as a stable driving period. Figure 11 In step S15, the control section 10 causes the detection section 20 to measure the second measurement, i.e., pressure measurement 2, as the second measurement process. As described above, the pressure of the ante-chamber 202 is an analog outside air pressure, i.e., an analog atmospheric pressure. As a threshold value of clogging of the filter 201, the threshold value is set based on the pressure value obtained by the pressure measurement 2.

[0063]

[0064] ​​In step S16, the control unit 10 instructs the arithmetic processing unit (not shown) to calculate the difference between the pressure value measured by pressure measurement 2 and the pressure value measured by pressure measurement 1 (pressure difference = pressure measurement 2 - pressure measurement 1).

[0065] In step S17, as a determination process, the control unit 10 instructs the determination unit 21 to determine whether the pressure difference calculated in step S16 is greater than a threshold. If it is less than the threshold and therefore the filter 201 is not clogged, the process proceeds to step S19. If it is greater than the threshold and therefore the filter 201 is clogged, the process proceeds to step S18.

[0066] like Figure 11 As shown, when the filter 201 is not clogged and the process proceeds to step S19, the control unit 10 instructs the fan drive unit 15 to increase the speed of the suction fan 203 from the minimum drive speed to a normal drive speed. This speed is required to maintain the cooling function of the liquid crystal panel 601, polarization conversion element, and light source 401, which are heat sources. This normally controlled speed is lower than the startup speed. At this time, the operation of the pressure sensor 204 indicates a pressure value indicating that a negative pressure has been applied from atmospheric pressure.

[0067] like Figure 12 As shown, when the filter 201 becomes clogged and the process proceeds to step S18, the control unit 10 causes the fan drive unit 15 to continuously drive the suction fan 203 at a speed higher than the startup speed for a fixed period of time as the acceleration time. Figure 12 The speed is displayed as the acceleration speed. This is because, after the suction fan 203 starts, the temperature of the driving light source 401, such as the LCD panel 601, continues to rise. Therefore, by driving the suction fan 203, the temperature rise of the LCD panel 601 is stopped, thus enabling temperature management.

[0068] During this acceleration period, the speed will preferentially increase to a higher speed than the startup speed, compared to the increased noise of the suction fan 203. Full-speed rotation drive is also possible.

[0069] At this point, the pressure value of the pressure sensor 204 located in the anterior chamber 202 further decreases to negative pressure. Thus, in the event of a blockage, by setting a higher rotation speed, the temperature rise of the heat source can be quickly suppressed.

[0070] Furthermore, in the case of filter 201 clogging, such as Figure 12 As shown, the pressure value in pressure measurement 1 is lower than the pressure value in pressure measurement 1 when there is no blockage. That is, the negative pressure increases. Therefore, the pressure difference calculated in step S16 is determined to be greater than the threshold in step S17.

[0071] By using the startup driving action of the suction fan 203 that requires a higher rotational speed than the normal driving rotational speed, the amount of suction of the external air is large, so the clogging can be determined significantly. Also, for the pressure of the front chamber 202 in the pressure determination 2, even if there is clogging, since the suction fan 203 is driven at a low speed, there is no difference from the pressure in the state where there is no clogging, and it is determined as the analog external air pressure.

[0072] Also, as shown in Figure 12 When the acceleration time elapses, the rotational speed of the suction fan 203 is decreased from the acceleration speed to the driving rotational speed of the suction fan 203 in the clogging state, that is, the clogging driving rotational speed. In other words, after the suction fan 203 is driven at a higher rotational speed than the clogging driving rotational speed, that is, the acceleration speed, it is decreased to the clogging driving rotational speed. At this time, the rotational speed of the suction fan 203 is in an environment where the heat source is likely to rise, so it is driven at a higher rotational speed than the normal control rotational speed where there is no clogging. Also, the rotational driving in the clogging state is not limited to one rotational speed, and it is preferable to prepare a plurality of rotational driving according to the clogging degree.

[0073] Also, although not shown in Figure 10 , in the case where it is determined that the filter 201 is clogged, it is preferable to determine whether to continue using the projector 1000 or to suspend the use. Suspension means a state where the cooling function to the heat sources, the liquid crystal panel 601, the polarization conversion element, and the light source 401, cannot be maintained, and it is determined based on a threshold value. That is, Figure 12 the drawing shown in is a case where the level at which the cooling function to the heat sources can be maintained under the control of the suction fan 203.

[0074] In the case of suspension, for example, the power of the projector 1000 is turned off or a warning is issued.

[0075] Also, in the case where the projector 1000 can be used although the clogging is relatively large, as shown in Figure 13 , the suction fan 203 can also be driven in such a manner that the acceleration speed is directly maintained after the acceleration time elapses.

[0076] Also, in the pressure determination 1, the startup driving action of the suction fan 203 that requires a higher rotational speed than the normal driving rotational speed is used, and in the pressure determination 2, the driving of the suction fan 203 is not stopped, so the time until the projection image is projected is not delayed by the clogging determination processing determination.

[0077] Next, the driving method of the suction fan 203 in the case where the projector 1000 is used at a high altitude will be described with reference to Figure 14 and Figure 15 . Also, the parts different from the case where the projector 1000 is used at a low altitude described above will be described in detail. The high altitude is, for example, an environment exceeding 2000 m.

[0078] In the case of highlands, the air pressure becomes low, and thus the cooling process of the heat source is preferably performed using a driving method that matches the highlands. Figure 14 A driving method in the case where there is no clogging at highlands is indicated.

[0079] Figure 15 A driving method in the case where there is clogging at highlands is indicated.

[0080] As Figure 14 indicated, when the projector 1000 is started to start the suction fan 203, the value of the pressure sensor 204 becomes a negative pressure compared to lowlands. In addition, Figure 14 the dashed line in the operation of the pressure sensor 204 indicates a pressure value in the case where there is no clogging at lowlands.

[0081] Thus, in the first measurement, which is pressure measurement 1, as the first measurement process, the pressure value becomes a negative pressure compared to lowlands. In addition, in the second measurement, which is pressure measurement 2, as the second measurement process, likewise, the pressure value becomes a negative pressure compared to lowlands.

[0082] Further, a highland mode determination threshold value that compares the pressure value of pressure measurement 2, which is the simulated external air pressure, that is, the simulated atmospheric pressure, is set in advance. In other words, if the pressure value of pressure measurement 2 is a negative pressure compared to the highland mode determination threshold value, the driving method of the suction fan 203 in the highland mode is performed. The absolute value of the atmospheric pressure greatly changes in highlands and lowlands, and thus the determination of highlands or lowlands can be performed only by the pressure value of pressure measurement 2.

[0083] Regarding the determination of whether there is clogging, the value of the difference between pressure measurement 1 and pressure measurement 2 is compared to a threshold value, as in the case of lowlands. In Figure 14 the case where there is no clogging, the value of the difference is less than the threshold value, and it is a case where there is no clogging.

[0084] When it is determined that there is no clogging and that it is in highlands, the driving of the suction fan 203 is performed at a first highland mode driving rotation speed that is higher than the normal driving rotation speed in lowlands. This is because, in highlands, the temperature of the heat source easily rises, and further cooling is required. In this way, the determination of whether it is highlands and the clogging determination can be accurately performed using the pressure sensor 204.

[0085] Next, with reference to Figure 15 , the driving method of the suction fan 203 in the case where there is clogging is described.

[0086] As Figure 15As shown, in the case where clogging occurs at high altitudes, the pressure value of the pressure measurement 1 indicates a value lower than in the case of low altitudes. The threshold value of whether clogging occurs is set based on the value of the simulated external air pressure, that is, the simulated atmospheric pressure, of the pressure measurement 2, and in the case where the value of the difference between the pressure measurement 1 and the pressure measurement 2 is greater than the threshold value, it is determined that clogging occurs.

[0087] If it is determined that clogging occurs and it is determined that the projector 1000 can be used, the suction fan 203 is driven at the acceleration speed for the acceleration time, and then, is driven at the second high-altitude mode driving rotation speed based on the clogging state. The second high-altitude mode driving rotation speed is a rotation speed higher than the clogging driving rotation speed of the low-altitude mode.

[0088] As described above, the projector 1000 of the present embodiment has: an outer casing 100 that sucks external air G into the inside via a filter 201; a light source 401 that is disposed in the outer casing 100; an image forming unit 600 that is disposed in the outer casing 100, converts light from the light source 401 into image light; a suction fan 203 that is disposed in the outer casing 100, has a suction port 203x that sucks external air G; an antechamber 202 that is disposed in the outer casing 100, communicates with the filter 201 and the suction port 203x; a pressure sensor 204 that is disposed in the antechamber 202; and a control section 10 that drives controls the suction fan 203. The control section 10 performs: a first measurement process that starts the suction fan 203, and measures the pressure of the antechamber 202 at the rotation speed at the time of the start using the pressure sensor 204; a second measurement process that makes the rotation speed of the suction fan 203 a rotation speed lower than the rotation speed at the time of the start, and measures the pressure of the antechamber 202 using the pressure sensor 204; and a determination process that determines clogging of the filter 201 based on the difference between the pressure value of the first measurement process and the pressure value of the second measurement process.

[0089] According to this structure, it is possible to measure a pressure value that reflects the clogging state of the filter 201 by the first measurement process, it is possible to measure a pressure value close to the pressure of the external air G by the second measurement process, and it is possible to determine clogging of the filter 201 based on the difference between the above two pressure values by the determination process. Further, since the pressure sensor 204 is disposed in the antechamber 202, the pressure value of the antechamber 202, which is a limited region, is measured, so the time until the pressure becomes constant is short compared to the case where the pressure value of the entire outer casing 100 is measured, and it is possible to measure the pressure value in advance. Thus, it is possible to accurately determine clogging from the time of the start of the suction fan 203 in a short time, and for example, it is possible to perform a cooling process based on the determination. Also, since it is possible to quickly perform the cooling process, it is possible to project image light in a short time from the time of the start of the suction fan 203.

[0090] Further, in the projector 1000 of the present embodiment, it is preferable that the control section 10 performs the following control: when it is determined in the determination processing that it does not correspond to the clogging, the suction fan 203 is driven normally, the suction fan 203 is driven at a normal driving rotation speed higher than the rotation speed in the second measurement processing, and when it is determined in the determination processing that it corresponds to the clogging, the suction fan 203 is driven for clogging, the suction fan 203 is driven at a clogging driving rotation speed higher than the normal driving rotation speed. According to this structure, in the case where it is determined that it is clogging, by driving the suction fan 203 at the clogging driving rotation speed higher than the normal driving rotation speed, it is possible to maintain the cooling performance, and it is possible to use the projector 1000.

[0091] Further, in the projector 1000 of the present embodiment, it is preferable that the control section 10 performs the following control: when it is determined in the determination processing that it is clogging, after driving the suction fan 203 at a rotation speed higher than the clogging driving rotation speed, it is lowered to the clogging driving rotation speed. According to this structure, in the case where it is determined that it is clogging, by reaching the rotation speed higher than the clogging driving rotation speed, it is possible to quickly suppress the temperature rise of the heat source.

[0092] Further, in the projector 1000 of the present embodiment, it is preferable that the control section 10 performs the following control: when it is determined in the determination processing that it is clogging, after driving the suction fan 203 at a rotation speed higher than the clogging driving rotation speed, it is lowered to the clogging driving rotation speed. According to this structure, in the case where it is determined that it is clogging, by reaching the rotation speed higher than the clogging driving rotation speed, it is possible to quickly suppress the temperature rise of the heat source.

[0093] Further, in the projector 1000 of the present embodiment, it is preferable that the control section 10 has a threshold value that determines high and low, the control section 10 compares the pressure value of the second measurement processing with the threshold value, and in the case where it is determined that it is high, the suction fan 203 is driven at a rotation speed higher than the rotation speed of low. According to this structure, the pressure value of the second measurement processing that is the simulated atmospheric pressure is compared with the threshold value, and if it is high, the suction fan 203 is driven at a higher rotation speed, and thus it is possible to maintain the cooling performance, and it is possible to use the projector 1000.

[0094] Further, in the projector 1000 of the present embodiment, it is preferable that the control section 10 has a threshold value that determines high and low, the control section 10 compares the pressure value of the second measurement processing with the threshold value, and in the case where it is determined that it is high, the suction fan 203 is driven at a rotation speed higher than the rotation speed of low. According to this structure, the pressure value of the second measurement processing that is the simulated atmospheric pressure is compared with the threshold value, and if it is high, the suction fan 203 is driven at a higher rotation speed, and thus it is possible to maintain the cooling performance, and it is possible to use the projector 1000.

[0095] Further, in the projector 1000 of the present embodiment, it is preferable that another suction fan 203 different from the suction fan 203 be provided, the other suction fan 203 having another suction port 203x that communicates with the front chamber 202. According to this structure, the other suction fan 203 also communicates with the common front chamber 202, and sucks the outside air G via the common filter 201, so even in the case of using the other suction fan 203, it is possible to measure the clogging of the filter 201.

[0096] Further, the projector 1000 of the present embodiment is provided with: an outer casing 100 that sucks the outside air G into the inside via the filter 201; a light source 401 that is disposed in the outer casing 100; an image forming unit 600 that is disposed in the outer casing 100, and that converts light from the light source 401 into image light; a suction fan 203 that is disposed in the outer casing 100, and that has a suction port 203x that sucks the outside air G; a front chamber 202 that is disposed in the outer casing 100, and that communicates with the filter 201 and the suction port 203x; a pressure sensor 204 that is disposed in the front chamber 202; and a control section 10 that drives controls the suction fan 203. The control section 10 performs: a first measurement process of driving the suction fan 203, making the pressure of the front chamber 202 negative, and measuring with the pressure sensor 204; a second measurement process of driving the suction fan 203, making the pressure of the front chamber 202 simulate the outside air pressure, and measuring with the pressure sensor 204; and a determination process of determining the clogging of the filter 201 based on the difference between the pressure value of the first measurement process and the pressure value of the second measurement process.

[0097] According to this structure, it is possible to measure the pressure value that reflects the clogging state of the filter 201 by the first measurement process, to measure the pressure value close to the pressure of the outside air G by the second measurement process, and to determine the clogging of the filter 201 based on the difference between the above two pressure values by the determination process. Further, since the pressure sensor 204 is disposed in the front chamber 202, and the pressure value of the front chamber 202, which is a limited area, is measured, the time until the pressure becomes constant is short compared to the case of measuring the pressure value of the entire outer casing 100, and it is possible to measure the pressure value in advance.

[0098] Hereinafter, a modification of the above embodiment will be described.

[0099] As described above, upon detecting clogging, it is not limited to changing the driving method of the suction fan 203, and for example, it is possible to perform a notification process that urges the user to replace or clean the filter 201. As the notification process, it is possible to cite notifying using the display section 17 of the projector 1000, or notifying to a connection device based on wireless means. Further, it is possible to display using an LED or the like, or to notify by sound through the sound output section 18.

Claims

1. A projector, wherein the projector has: an outer case that sucks outside air into the inside via a filter; a light source that is disposed in the outer case; an image forming device that is disposed in the outer case, converts light from the light source into image light; a suction fan that is disposed in the outer case, has a suction port that sucks the outside air; an antechamber that is disposed in the outer case, communicates with the filter and the suction port; a pressure sensor that is disposed in the antechamber; and a control section that drives controls the suction fan, the control section executes: a first measurement process that starts the suction fan, measures the pressure of the antechamber at the time of start with the pressure sensor at a rotational speed at the time of start; a second measurement process that makes the rotational speed of the suction fan lower than the rotational speed at the time of start, measures the pressure of the antechamber with the pressure sensor; and a determination process that determines the clogging of the filter based on the difference between the pressure value of the first measurement process and the pressure value of the second measurement process.

2. The projector according to claim 1, wherein the control section executes: when it is determined that it does not correspond to clogging in the determination process, normally drives the suction fan, drives the suction fan at a normally driving rotational speed that is higher than the rotational speed in the second measurement process, when it is determined that it corresponds to clogging in the determination process, clogging drives the suction fan, drives the suction fan at a clogging driving rotational speed that is higher than the normally driving rotational speed.

3. The projector according to claim 2, wherein the control section executes: when it is determined that it is clogging in the determination process, after driving the suction fan at a rotational speed that is higher than the clogging driving rotational speed, reduces to the clogging driving rotational speed.

4. The projector according to any one of claims 1 to 3, wherein the control section executes: during the period from when the suction fan is started to the first measurement process, lights up light from the light source, during the stable driving of the light source, executes the second measurement process.

5. The projector according to any one of claims 1 to 3, wherein the control section has a threshold value that determines high and low, the control section compares the pressure value of the second measurement process with the threshold value, in the case where it is determined that it is the high, drives the suction fan at a rotational speed that is higher than the rotational speed of the low.

6. The projector according to any one of claims 1 to 3, wherein the image forming device has a light modulation panel, the suction fan has a discharge port, the discharge port is connected to the light modulation panel by a duct.

7. The projector according to any one of claims 1 to 3, wherein the projector has other suction fans that are different from the suction fan, the other suction fans have other suction ports, the other suction ports communicate with the antechamber.

8. A projector, wherein the projector has: an outer case that sucks outside air into the inside via a filter; a light source that is disposed in the outer case; an image forming device that is disposed in the outer case, converts light from the light source into image light; a suction fan that is disposed in the outer case, has a suction port that sucks the outside air; an antechamber that is disposed in the outer case, communicates with the filter and the suction port; a pressure sensor that is disposed in the antechamber; and a control section that drives controls the suction fan, the control section executes: a first measurement process that starts the suction fan, measures the pressure of the antechamber at the time of start with the pressure sensor at a rotational speed at the time of start; a second measurement process that makes the rotational speed of the suction fan lower than the rotational speed at the time of start, measures the pressure of the antechamber with the pressure sensor; and a determination process that determines the clogging of the filter based on the difference between the pressure value of the first measurement process and the pressure value of the second measurement process. An image forming apparatus configured in the outer casing, converts light from the light source into image light; A suction fan configured in the outer casing, having a suction port that sucks the outside air; A front chamber configured in the outer casing, communicating with the filter and the suction port; A pressure sensor configured in the front chamber; and A control section that drives and controls the suction fan, The control section performs the following processes: A first measurement process that drives the suction fan, makes the pressure of the front chamber negative, and measures with the pressure sensor; A second measurement process that drives the suction fan, makes the pressure of the front chamber simulate the outside air pressure, and measures with the pressure sensor; And A determination process that determines the clogging of the filter according to the difference between the pressure value of the first measurement process and the pressure value of the second measurement process.

Images