JP2020118782A - Image projection device that detects clogging of intake port using a clogging sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image projection device for detecting a blockage of an intake port by using a clogging sensor. SOLUTION: An intake port for taking in outside air, an air filter covering the intake port, a clogging sensor for detecting a clogging degree of the air filter, and a clogging degree detected by the clogging sensor are stored. In an image projection device having a storage unit, a control unit that detects air intake port blockage based on the degree of clogging, and a cooling fan and a light source unit, the control unit has acquired the past clogging condition stored in the storage unit and this time. It is characterized in that it is determined that the intake port is blocked when the amount of increase in the degree of clogging per arbitrary time exceeds a certain level based on the degree of clogging. [Selection diagram] Fig. 3

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image projection device, and more particularly to a projection device that detects clogging of an intake port using a clogging sensor.

In recent years, as an apparatus for observing a magnified projected image, an image projection apparatus has been proposed in which an image based on an image display element is magnified and projected on a screen by a projection optical system. The image projection device has a high temperature part such as a light source, a panel, and an optical element in a housing. In order to prolong their life and secure their performance, it is necessary to cool them to an appropriate temperature. To cool the high temperature part, the fan is rotated and the outside air taken in through the intake port is applied to the high temperature part for cooling. If dust is contained in the inhaled outside air, the dust may adhere to the optical part and affect the image quality. Therefore, the intake port portion is provided with an air filter for removing dust contained in the outside air. When the image projection device is used for a long time, the air filter is clogged with dust, and the cooling performance is deteriorated. Therefore, when the air filter is clogged to some extent, it is necessary to prompt the user to replace or clean the air filter. Further, even if the intake port of the image projection device is blocked by something, the cooling performance will be deteriorated. Therefore, when the intake port is blocked by something, it is necessary to promptly notify the user to prompt the user to cancel the blockage of the intake port.

2. Description of the Related Art Conventionally, a means has been known in which a flow rate sensor or the like is arranged at an intake port portion of an image projection device to detect clogging of an air filter by the air volume passing through the intake port and notify the user. Patent Document 1 discloses a technique capable of gradually notifying a user of the degree of clogging of an air filter and urging the user or a replacement operator to replace or clean the air filter before the degree of clogging increases. Has been done.

Further, there is known a means for detecting the blockage of the intake port by using a temperature sensor arranged in the image projection device. Patent Document 2 has a temperature sensor for detecting a room temperature and a temperature sensor for detecting a temperature of a cooling target, and a difference between a value of the temperature sensor for detecting the room temperature and a temperature sensor value for detecting the temperature of the cooling target is predetermined. A technique is disclosed in which it is determined that the intake port is blocked when the value exceeds a threshold value.

JP 2012-128282 A JP, 2003-43577, A

However, in the conventional technique disclosed in the above-mentioned Patent Document 1, since the case where the intake port is blocked by something is not considered, it is possible to determine whether the intake port is blocked or clogged with dust. Absent. In the case of clogging with dust, the degree of urgency is low and notification is often given so as not to disturb the projection. This may delay the notification to the user, further increase the temperature of the high temperature part, deteriorate the characteristics, and shorten the life of the parts.

In addition, in the method for detecting the blockage of the intake port by the temperature sensor disclosed in Patent Document 2, it cannot be detected until the temperature rises due to the blockage of the intake port. There is a risk that the temperature will rise, the characteristics will deteriorate, and the life of parts will be shortened.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image projection apparatus that can determine whether a filter is clogged with dust or an inlet is blocked by a clogging sensor and promptly notify the user.

In order to achieve the above object, an image projection device according to the present invention is
An intake port that takes in outside air,
An air filter covering the intake port,
A clogging sensor for detecting the degree of clogging of the air filter,
A storage unit that stores the degree of clogging detected by the clogging sensor;
A control unit that detects whether the intake port is blocked by the degree of clogging,
In an image projection device having a cooling fan and a light source unit,
The control unit, based on the past clogging condition stored in the storage unit and the clogging condition acquired this time,
It is characterized in that when the increase amount of the clogging degree per arbitrary time exceeds a certain amount or more, it is judged that the intake port is blocked.

According to the present invention, it is possible to provide an image projection apparatus that can determine whether a filter is clogged by dust or an inlet is blocked by a clogging sensor and promptly notify the user.

It is a block diagram of the image projection apparatus in this invention. 5 is a diagram showing a clogging condition and an elapsed time in Example 1. FIG. FIG. 5 is a diagram showing the degree of clogging and the elapsed time when the intake port is closed during use in the first embodiment. 5 is a specific flow for detecting the blockage of the intake port in the first embodiment. FIG. 8 is a diagram showing a time course of an actual clogging degree and a predicted clogging degree in Example 2. 9 is a specific flow for detecting the blockage of the intake port in the second embodiment. FIG. 5 is a diagram showing a change in the amount of clogging detected when the number of rotations of the cooling fan is increased in the first embodiment. FIG. 8 is a diagram showing a change in the amount of clogging detected when the rotation speed of the cooling fan is decreased in the second embodiment. 9 is a specific flow showing the control for suppressing the temperature rise of the high temperature part when it is detected that the intake port is blocked in the first and second embodiments.

Hereinafter, modes for carrying out the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram of an image projection apparatus according to an embodiment of the present invention.

1, exterior 001, input unit 002, image processing unit 003, optical unit 004, panel unit 005, control unit 006, light source unit 007, clogging detection unit 008, cooling fan 009, storage unit 010, air filter 011, This is an image projection apparatus having an air intake port 012.

The exterior 001 is an exterior that covers the outside of the image projection apparatus, and has an intake port 012.

The input unit 002 is an image input/output unit including an image interface connector such as VGA, DVI, HDMI (registered trademark), which inputs a video signal from a video signal source such as a personal computer or a DVD player, and the video processing unit 003. Output to.

The video processing unit 003 can drive the panel unit 005 as an image forming element by performing resolution conversion, trapezoidal correction, and image quality correction of brightness, contrast, color, etc. on the input video signal. Generate a video signal.

In the optical unit 004, the image lights of a plurality of colors emitted from the panel unit 005 are combined into one by a color combining optical system including a polarization separation element or the like to become full-color image light, and an image is projected on the projection surface from the projection lens. Magnify and project light.

The panel unit 005 receives white light from the light source unit 007 and a plurality of color lights respectively separated from each other by a color separation optical system including a color separation element and a polarization separation element. The panel section 005 modulates the incident color light for each pixel into image light. The panel unit 005 may be a transmissive liquid crystal panel or a reflective liquid crystal panel. Further, other display elements can be used instead of the liquid crystal panel.

The control unit 006 is a controller (control means) including a CPU and the like. The control of the light amount of the light source unit 007, the detection of the degree of clogging of the clogging detection unit 008, the calculation of the predicted degree of clogging, the determination of the closing of the intake port, the rotation speed control of the cooling fan 009, each notification to the user, and the like are performed. As the light source unit 007, a discharge light emitting lamp such as an ultra-high pressure mercury lamp or a xenon lamp is used. A light source other than a lamp such as an LED may be used as the light source.

The light source unit 007 is cooled by the cooling unit 009 because it becomes hot during driving.

The clogging detection unit 008 includes a sensor that detects the degree of clogging of the air filter 011 such as a flow rate sensor. The flow rate passing through the air filter 011 is detected to detect the degree of clogging of the air filter 011.

The cooling fan 009 takes in outside air from the intake port 012 and blows air to the cooling target such as the light source unit 007, the panel unit 005, and the optical unit 004.

The storage unit 010 is a storage device such as a ROM or a RAM. Information such as the degree of clogging detected by the clogging detection unit 008 can be stored in the storage unit 010.

The air filter 011 is provided with a filter that traps dust contained in the outside air taken in through the intake port 012.

The intake port 012 is a hole or a louver opened in the exterior 001 for taking in outside air into the image projection device.

Next, a specific process for detecting the blockage of the intake port, which is a feature of this embodiment, will be described with reference to FIGS. 2 and 3.

FIG. 2 is a diagram showing the degree of clogging of the air filter 011 due to dust and the elapsed time detected by the clogging detection unit 008.

This shows a state in which the degree of clogging of the air filter 011 increases from the state of low clogging to the degree of clogging of the air filter 011 due to dust contained in the outside air over time. The degree of clogging of the air filter 011 gradually increases as long as the degree of contamination of air in the place where the image projection device is used does not change.

FIG. 3 is a diagram showing the degree of clogging of the air filter 011 and the elapsed time when the air intake port 012 is closed during use of the image projection apparatus.

If the air intake port 012 is blocked while the image projection apparatus is in use, the flow rate taken from the air intake port 012 is greatly reduced, and the degree of clogging rapidly increases. When the control unit 006 detects a rapid increase in the degree of clogging, it is possible to detect the blockage of the intake port 012.

FIG. 4 is a specific flow for detecting the blockage of the intake port 012.

It will be described with reference to the flowchart (FIG. 4) of the specific processing of the present invention.

[Step S0]
The control unit 006 acquires the degree of clogging of the air filter 011 by the clogging detection unit 008 and stores it in the storage unit 010.

[Step S1]
Wait until a certain time has passed.

[Step S2]
After a certain time has elapsed, the control unit 006 acquires the degree of clogging of the air filter 011 by the clogging detection unit 008.

[Step S3]
The control unit 006 compares the degree of clogging stored in the storage unit 010 last time with the degree of clogging acquired this time, and determines whether the difference in the degree of clogging is equal to or more than a certain value.

[Step S4]
In step S3, the degree of clogging stored in the storage unit 010 last time is compared with the degree of clogging acquired this time, and if it is determined that the difference in degree of clogging is equal to or greater than a certain value, it is determined that the intake port is blocked. Then, the user is notified that the intake port is blocked.

[Step S5]
In step S3, the degree of clogging stored in the storage unit 010 last time is compared with the degree of clogging acquired this time, and if it is determined that the difference in degree of clogging is not more than a certain value, the degree of clogging acquired this time is stored. It is stored in the part 010.

When the air filter 011 is cleaned and the clogging degree is sharply reduced, the control unit 006 determines that the air filter 011 is cleaned, erases the past clogging degree stored in the storage unit 010, and removes the intake port. Resets the blockage detection process.

Since the schematic configuration of the image projection apparatus in the second embodiment is the same as that in FIG. 1, the same members as those used in the above-described embodiments are designated by the same reference numerals, and the description thereof will be omitted.

Next, a specific process for detecting the blockage of the intake port, which is a feature of this embodiment, will be described with reference to FIG.

FIG. 5 shows a time course of the actual clogging degree of the air filter 011 detected by the clogging detection section 008 and the predicted clogging degree predicted by the control section 006 from the clogging degree of the previously stored air filter 011. FIG.

The control unit 006 stores the degree of clogging of the air filter 011 detected by the clogging detection unit 008 in the storage unit 010 at regular intervals, and determines the amount of increase in the degree of clogging thereafter from the amount of increase in the degree of clogging. Predict. The predicted degree of clogging is defined as the predicted degree of clogging. If the air filter 011 is clogged with dust, the amount of increase in the degree of clogging over time does not deviate significantly from the predicted degree of clogging. However, when the intake port is closed, the degree of clogging rapidly increases, and the predicted degree of clogging greatly deviates. As a result, it is possible to determine whether the clogging is caused by dust or the intake port is blocked.

FIG. 6 is a specific flow for detecting the blockage of the intake port.

It will be described with reference to the flowchart (FIG. 6) of the specific processing of the present invention.

[Step S10]
The control unit 006 acquires the degree of clogging of the air filter 011 by the clogging detection unit 008 and stores it in the storage unit 010.

[Step S11]
Wait until a certain time has passed.

[Step S12]
After a certain time has elapsed, the control unit 006 acquires the clogging degree of the air filter 011 by the clogging detection unit 008 and stores it in the storage unit 010.

[Step S13]
The control unit 006 compares the degree of clogging stored in the storage unit 010 last time with the degree of clogging stored this time, and calculates the predicted degree of clogging from the increase amount.

[Step S14]
Wait until a certain time has passed.

[Step S15]
After a certain time has elapsed, the control unit 006 acquires the clogging degree of the air filter 011 by the clogging detection unit 008 and stores it in the storage unit 010.

[Step S16]
The control unit 006 compares the predicted clogging degree calculated in step S13 with the clogging degree acquired in step S15, and determines whether the difference between the predicted clogging degree obtained in step S15 is larger than the predicted clogging degree. ..

[Step S17]
When it is determined in step S16 that the difference in the degree of clogging acquired in step S15 is larger than the predicted degree of clogging, the control unit 006 determines that the intake port is closed, and notifies the user to that effect.

[Step S18]
If it is not determined in step S16 that the difference between the clogging degree acquired in step S15 is larger than the predicted clogging degree, the control unit 006 determines the estimated clogging degree calculated in step S13 and the clogging acquired in step S15. Correct the predicted clogging condition based on the condition.

If the predicted clogging degree calculated by the control unit 006 at the end is stored in the storage unit 010, the predicted clogging degree calculated by the control unit 006 at the end is read from the storage unit 010, and steps S10 to S13 are performed. The flow of can be omitted.

When the air filter 011 is cleaned and the clogging degree is sharply reduced, the control unit determines that the air filter 011 is cleaned, erases the past clogging degree stored in the storage unit 010, and closes the intake port. Reset the detection process.

In both the first and second embodiments, the mode in which the rotation speed of the cooling fan 009 is constant is shown, but the rotation speed of the cooling fan 009 is changed when the ambient temperature of the image projection apparatus, the projection mode, the brightness of the light source, and the like are changed. May change. When the rotation speed of the cooling fan 009 changes, the detection amount of the clogging degree changes and the change amount of the clogging degree also changes. Therefore, it is necessary to change the threshold value for detecting that the intake port 012 is blocked according to the rotation speed of the cooling fan 009.

FIG. 7 is a diagram showing changes in the detection amount of the degree of clogging when the rotation speed of the cooling fan 009 increases in the form of the first embodiment.

When the rotation speed of the cooling fan 009 increases, the flow rate passing through the air filter 011 increases and the clogging degree seems to decrease. Further, when the rotation speed of the cooling fan 009 increases and the flow rate passing through the air filter 011 increases, the amount of dust passing through the air filter 011 increases, so the amount of change in the degree of clogging also increases. Therefore, it is necessary to increase the threshold value for detecting that the intake port is blocked, depending on how the rotation speed of the cooling fan 009 increases.

FIG. 8 is a diagram showing a change in the detection amount of the degree of clogging when the rotation speed of the cooling fan 009 is decreased in the form of the second embodiment.

When the rotation speed of the cooling fan 009 decreases, the flow rate passing through the air filter 011 decreases and the clogging degree seems to increase. Further, when the rotation speed of the cooling fan decreases and the flow rate passing through the air filter 011 decreases, the amount of dust passing through the air filter 011 decreases, so the amount of change in clogging also decreases. Therefore, it is necessary to raise the threshold value for detecting that the intake port is blocked, depending on the degree of decrease in the rotation speed of the cooling fan.

The method for detecting the blockage of the intake port has been described in the first and second embodiments. When the air intake port 012 of the image projection device is blocked, the amount of outside air taken in from the air intake port 012 decreases, and the cooling capacity decreases. When the cooling capacity decreases, the temperature of the cooling target further increases. There is no problem if the user is notified that the intake port is blocked and the intake port is quickly cleared, but if it takes time to clear the intake port, the temperature of the cooling target rises. Therefore, the image quality may be affected, or an error may prevent the projection from continuing. In the fourth embodiment, control in the case where it takes time to eliminate the blockage of the intake port will be described.

The light source unit 007, the panel unit 005, the optical unit 004, and the like are examples of cooling targets whose temperature rises due to the blockage of the intake port. When the temperature of the cooling target rises due to the blockage of the intake port, as a countermeasure, the light amount of the light source unit 007 is reduced to suppress the heat generation of the light source unit 007 and suppress the temperature rise of the light source unit 007, the panel unit 005, and the optical unit 004. You can expect an effect.

When the intake port of the image projection device is blocked, the amount of outside air taken in from the intake port part 012 is reduced and the cooling capacity is reduced, but if the rotation speed of the cooling fan 009 can be increased, Since it is possible to increase the amount of outside air taken in from the intake port 012, it can be expected that the reduction in cooling capacity is suppressed.

The control that suppresses the temperature rise of the cooling target and the control that suppresses the decrease in the cooling capacity when the intake port 012 of the image projection device is blocked have been described above, but the blockage of the intake port cannot be eliminated. there is a possibility. In that case, if the state where the intake port is blocked is continued, the image quality may be affected, or an error may make it impossible to continue projection. Therefore, when the state where the intake port is blocked continues for a certain period of time, the control unit 006 notifies the user that the power of the image projection device is turned off because the blockage of the intake port is not resolved, and then the power of the image projection device is turned off. Execute the control. In order to give a grace period until the power is turned off, the user may be notified in advance to notify the time until the power is turned off.

FIG. 9 is a specific flow showing the control for suppressing the temperature rise of the cooling target when it is detected that the intake port is blocked.

The specific processing of the present invention will be described with reference to the flowchart (FIG. 9).

[Step S20]
The control unit 006 detects that the intake port is blocked, based on the degree of clogging detected by the clogging detection unit 008.

[Step S21]
Since the blockage of the intake port is detected, the user is notified that the rotation speed of the cooling fan 009 is increased and the light amount of the light source unit 007 is decreased.

[Step S22]
The control unit 006 increases the rotation speed of the cooling fan 009 in order to increase the cooling capacity.

[Step S23]
In order to suppress heat generation of the light source unit 007, the panel unit 005, and the optical unit 004, the light amount of the light source unit 007 is reduced.

The order of step S22 and step S23 is not limited.

[Step S24]
[Step S25]
It is determined whether the intake port is closed during a certain period of time.

[Step S26]
If the blockage of the intake port is not resolved even after a certain period of time thereafter, the user is notified that the power of the image projection device is turned off.

[Step S27]
[Step S28]
It is determined whether the intake port is closed during a certain period of time.

[Step S29]
Since the blockage of the intake port has not been resolved within a certain period of time, the control unit 006 notifies the user that the image projection apparatus is powered off.

[Step S30]
Turn off the power of the image projection device.

[Step S31]
When it is determined in step S24 or step S27 that the blockage of the intake port has been eliminated, the user is notified that the rotation speed of the cooling fan 009 and the light amount of the light source unit 007 are restored.

[Step S32]
The rotation speed of the cooling fan 009 is returned to the rotation speed before being increased.

[Step S33]
The light quantity of the light source unit 007 is returned to the light quantity before it was lowered.

The order of step S32 and step S33 is not limited.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist thereof.

001 exterior, 002 input section, 003 image processing section, 004 optical section,
005 panel unit, 006 control unit, 007 light source unit, 008 clogging detection unit,
009 cooling fan, 010 storage unit, 011 air filter, 012 intake port

Claims (7)

An intake port that takes in outside air,
An air filter covering the intake port,
A clogging sensor for detecting the degree of clogging of the air filter,
A storage unit that stores the degree of clogging detected by the clogging sensor;
A control unit that detects whether the intake port is blocked by the degree of clogging,
In an image projection device having a cooling fan and a light source unit,
The control unit determines that the intake port is blocked when the increase amount of the clogging degree per arbitrary time exceeds a certain amount from the past clogging degree stored in the storage section and the clogging degree acquired this time. An image projection device characterized by: An intake port that takes in outside air,
An air filter covering the intake port,
A clogging sensor for detecting the degree of clogging of the air filter,
A storage unit that stores the degree of clogging detected by the clogging sensor;
A control unit that detects whether the intake port is blocked by the degree of clogging,
In an image projection device having a cooling fan and a light source unit,
From the degree of clogging per arbitrary time stored in the storage unit, the control unit calculates a predicted degree of clogging,
An image projection apparatus, wherein when the acquired clogging degree exceeds a predicted clogging degree by a certain amount or more, it is determined that the intake port is blocked. The image projection apparatus according to claim 1, wherein the control unit changes a threshold value for determining that the intake port is closed, according to the rotation speed of the cooling fan. The control unit notifies the user that the intake port is closed when the control unit determines that the intake port is closed. 5. The method according to claim 1, wherein the control unit notifies the user that the intake port is closed. Image projection device. The image projection apparatus according to claim 1, wherein the control unit performs control to reduce the light amount of the light source unit when it is determined that the intake port is closed. The image projection apparatus according to claim 1, wherein the control unit controls to increase the rotation speed of the cooling fan when it is determined that the intake port is closed. 7. The power supply of the apparatus is turned off when the controller does not improve the clogging for a certain period of time after determining that the intake port is blocked. The image projection device according to the item.