JP6884539B2 - Projection type display device - Google Patents

Description

The present invention relates to a projection type display device.

The projection type display device has many objects to be cooled built in, and it is necessary to control the temperature to an appropriate temperature by using a cooling device such as a fan. On the other hand, the projection type display device has been used in various places in recent years, and may be used in isolation from the environment in which the user lives. In that case, the environment in which the device is installed may not be controlled to an appropriate temperature for human life, and the device itself may be used in a state of being exposed to a high temperature environment.

Therefore, conventionally, by arranging a temperature sensor inside the device near the cooling air intake port (intake port), the intake temperature used for cooling the inside of the device is detected and the temperature is adjusted to the ambient temperature. Generally, the system is built so that the cooling capacity can be exhibited.

Patent Document 1 discloses a cooling device that determines the rotation speed of a fan based on the difference between the outside air temperature and the heating element temperature.

Japanese Unexamined Patent Publication No. 2008-172118

However, in the configuration disclosed in Patent Document 1, there is a possibility that the outside air temperature may be erroneously detected depending on the installation posture of the projection type display device. Specifically, when the temperature sensor (intake air temperature sensor) provided inside the projection type display device is placed on the upper side in the gravity direction of a high heating element such as a light source, the temperature around the temperature sensor due to the rise of hot air. May be higher. In particular, when the exhaust fan is stopped after the light source of the projection type display device is turned off, the residual heat moves upward, so that the detected value of the temperature sensor becomes higher than the actual outside air temperature. Therefore, when trying to turn on the light source again, the projection type display device may mistakenly recognize that the environment is higher than the actual environment temperature, and perform abnormal operations (protection operation) such as overcooling and avoiding lighting of the light source. is there.

Therefore, the present invention provides a projection type display device capable of appropriately performing a protective operation such as avoiding lighting of a light source regardless of the installation posture.

The projection type display device as one aspect of the present invention is a projection type display device that projects an image using light from a light source, and is a cooling system that takes in outside air from an intake port and discharges internal heat from an exhaust port. The control means includes a means, a temperature detecting means for detecting a temperature, and a control means for performing a protection operation when the temperature detected by the temperature detecting means is higher than a reference temperature, and the control means is the temperature detecting means. When the first temperature detected at the first time is higher than the second temperature detected at the second time after the first time, the power of the projection type display device is turned on. A second reference temperature higher than the first reference temperature is set as the reference temperature, and the reference temperature is changed to the first reference temperature after a lapse of a predetermined time. When the first temperature is lower than the second temperature, the first reference temperature lower than the second reference temperature is set as the reference temperature after the power of the projection type display device is turned on .

Other objects and features of the present invention will be described in the following examples.

According to the present invention, it is possible to provide a projection type display device capable of appropriately performing a protective operation such as avoiding lighting of a light source regardless of the installation posture.

It is a flowchart which shows the control method in Example 1. FIG. It is a flowchart which shows the control method in Example 2. FIG. It is a block diagram of the projection type display device in each Example. It is a block diagram of the peripheral area of the temperature sensor provided in the projection type display device in each Example. It is explanatory drawing of the detection temperature of the temperature sensor in each Example. It is a block diagram of the control board in each Example.

Hereinafter, examples of the present invention will be described in detail with reference to the drawings.

First, the configuration of the projection type display device according to the first embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG. 3 is an overall configuration diagram of the projection type display device 100 (projector). FIG. 4 is a configuration diagram of a peripheral region of the temperature sensor 8 (intake air temperature sensor) provided in the projection type display device.

1 is a light source (light source lamp). Reference numeral 2 denotes an optical system (projection optical system) in which image information is added to the light from the light source 1 and projected onto an external screen (projection surface). Reference numeral 3 denotes an exhaust fan (exhaust means) for exhausting the air inside the projection type display device 100 to the outside. Reference numeral 4 denotes a cooling fan (cooling means) that takes in cooling air (outside air) from the outside of the projection type display device 100 through an intake port 6 described later and cools an optical element or the like constituting the optical system 2. Reference numeral 5 denotes an exhaust port provided on the exterior of the projection type display device 100. Reference numeral 6 denotes an intake port provided on the exterior of the projection type display device 100. Reference numeral 7 denotes a cooling duct that connects at least the cooling fan 4 and the intake port 6. Reference numeral 8 denotes a temperature sensor (temperature detecting means) arranged inside the projection type display device 100 and in the vicinity of the intake port 6. The arrow W in FIG. 3 indicates the airflow flowing inside the projection type display device 100.

A control board 10 (control unit) is provided inside the projection type display device 100. The control board 10 acquires and records the temperature (detection result) detected by the temperature sensor 8 (intake air temperature sensor), calculates, controls each element such as the exhaust fan 3, the cooling fan 4, and the light source 1, and the elapsed time. And so on. FIG. 6 is a block diagram of the control board 10 (control unit). In this embodiment, the control board 10 includes a time measuring means 11 (timer), a storage means 12 (memory), a calculation means 13, and a control means 14. The time measuring means 11 measures the elapsed time from a certain time. The storage means 12 stores the elapsed time measured by the time measuring means 11 in association with the temperature (detected temperature) detected by the temperature sensor 8. The calculation means 13 performs a predetermined calculation (subtraction or the like) using the two detection temperatures stored in the storage means 12. When the temperature detected by the temperature sensor 8 is higher than the reference temperature (predetermined temperature, set value), the control means 14 performs a predetermined protection operation (warning display, output reduction of the light source 1, forced extinguishing, etc.). Details of each of these elements will be described later.

The temperature sensor 8 needs to accurately detect the temperature of the cooling air used for cooling. Therefore, it is preferable that the temperature sensor 8 is arranged at a position where the outside air temperature can always be detected (such as in the vicinity of the intake port 6). For example, the temperature sensor 8 is arranged in the cooling duct 7 (including a configuration in which the temperature sensor 8 is attached to the wall surface of the cooling duct 7), so that the outside air is used for cooling with higher accuracy. It becomes possible to detect the temperature of. That is, by driving the cooling fan 4, when the outside air that has entered from the intake port 6 passes through the cooling duct 7, the outside air passes in the vicinity of the temperature sensor 8. Therefore, the temperature of the outside air (cooling air) used for cooling can be detected with high accuracy.

On the other hand, the light source 1 is a high heat generating portion such that the light emitting portion becomes close to 1000 ° C. when lit. When the light source 1 is lit, the surroundings of the light source 1 are also affected by this and become hot. Therefore, by driving the exhaust fan 3, high-temperature air is exhausted from the exhaust port 5 to the outside of the projection type display device 100, and heat is suppressed from being trapped inside the projection type display device 100.

In recent years, due to the diversification of applications of projection-type display devices, the number of situations in which they are used in various postures has increased, and users are required not to be restricted by the posture of projection-type display devices. Here, a case where the projected light from the projection type display device 100 is installed so as to be projected upward (when the projection light is installed so as to be at a high position in FIG. 3) will be described. When the projection type display device 100 is installed in such an attitude, the temperature sensor 8 is arranged at a position higher than the light source 1 (a position higher in the direction of gravity).

Warm air becomes lighter and has the property of going upward by natural convection. Therefore, the air warmed by the light source 1 reaches the vicinity of the temperature sensor 8. As a result, there is a possibility that the temperature sensor 8 that should normally detect the intake outside air temperature may erroneously detect the outside air temperature due to the influence of the heat inside the projection type display device 100 (light source 1). There is a possibility that the temperature due to the influence will be erroneously detected as the outside air temperature). In particular, when the light source 1 is turned off and the cooling fan 4 and the exhaust fan 3 are stopped in order to stop the use of the projection type display device 100, new outside air is introduced (intake) and exhausted into the inside of the projection type display device 100. Heat (exhaust) stops. As a result, the influence of the above-mentioned natural convection appears remarkably, and the temperature detected by the temperature sensor 8 may rise.

With reference to FIG. 5, when the projection type display device 100 is installed in a posture of projecting upward (when the projection type display device 100 is installed so as to be in a high position in FIG. 3), the projection type display device 100 is turned OFF / ON. The temperature detected by the temperature sensor 8 due to operation will be described. FIG. 5 is an explanatory diagram of the detected temperature of the temperature sensor 8. In FIG. 5, the vertical axis represents the detected temperature (temperature) of the temperature sensor 8, and the horizontal axis represents the elapsed time (time). The solid line A shows the temperature detected by the temperature sensor 8, and the broken line B shows the outside air temperature.

In FIG. 5, the time S1 is the time when the power of the projection type display device 100 is turned off. The time S2 is the time when the cooling-down operation of the projection type display device 100 is completed. The time S3 is the time when the power of the projection type display device 100 is turned on.

When the cooling-down operation ends at time S2 and the rotations of the cooling fan 4 and the exhaust fan 3 stop, the detected temperature of the temperature sensor 8 shown by the solid line A rises with respect to the outside air temperature shown by the broken line B. I will go. When the power is turned on again at time S3 while the detection temperature of the temperature sensor 8 is rising, the cooling fan 4 and the exhaust fan 3 start rotating. Therefore, the outside air is reintroduced, and the outside air flows in the vicinity of the temperature sensor 8. As a result, the detection temperature of the temperature sensor 8 decreases and becomes equal to the outside air temperature (the detection temperature of the temperature sensor 8 approaches the outside air temperature).

The projection type display device 100 needs to cool each component arranged inside the display device 100 to an appropriate temperature. Therefore, when the detection temperature of the temperature sensor 8 exceeds a predetermined temperature (reference temperature), it is common to control the fan rotation speed, control the output of the light source 1, display a warning, or forcibly turn off the light source 1. Is the target. For example, consider a case where the projection type display device 100 is installed and used near the upper limit where the environmental temperature is within the assumed range. At this time, if the detection temperature of the temperature sensor 8 rises due to the influence of the internal residual heat, the projection type display device 100 performs thermal protection processing (protection operation) such as forced extinguishing of the light source 1 which is normally unnecessary. There is. On the other hand, in order to avoid a protective operation such as forcibly turning off the light source 1, the predetermined temperature (reference temperature) used for determining whether or not the protective operation can be executed is shifted to the higher temperature side by the effect of residual heat (set a high reference temperature). ) Is possible. However, in this case, since it can be actually used in an unexpected high temperature environment depending on how the user uses it, there is a possibility that each component inside the projection type display device 100 will be damaged and the life of each component will be shortened. .. Therefore, in this embodiment, the projection type display device 100 (control means 14) changes the reference temperature according to the change in the temperature (detection temperature) detected by the temperature sensor 8.

The control method of the projection type display device 100 in this embodiment will be described with reference to FIG. FIG. 1 is a flowchart showing a control method in this embodiment. Each step of FIG. 1 is executed by each part of the control board 10.

First, in step S101, the control means 14 turns on the power of the projection type display device 100 based on the user's instruction (operation). Subsequently, in step S102, the control means 14 acquires the detection temperature T11 (the first temperature detected at the first time (time S4 in FIG. 5)) of the temperature sensor 8, and the storage means 12 acquires the detection temperature T11. Remember. Subsequently, in step S103, the control means 14 counts a predetermined time (elapsed time) using the time measuring means 11 (timer mounted on the control board 10), and the storage means 12 stores the elapsed time. Subsequently, in step S104, after a predetermined time has elapsed from step S102, the control means 14 is detected at the detection temperature T12 of the temperature sensor 8 (second time after the first time (time S5 in FIG. 5)). The second temperature) is acquired, and the storage means 12 stores the detection temperature T12.

Subsequently, in step S105, the calculation means 13 calculates the difference (ΔT = T11-T12) between the detection temperature T11 acquired in step S102 and the detection temperature T12 acquired in step S104. If this difference (calculation result) is a positive value (ΔT> 0), the process proceeds to step S106. At this time, since the detection temperature of the temperature sensor 8 is lowered after the fan is driven, the temperature sensor 8 may not detect the accurate outside air temperature as described above. Therefore, in step S106, the control means 14 sets the temperature Ta1 (second reference temperature) higher than the originally assumed temperature Tb1 (first reference temperature) as the reference temperature. On the other hand, if the difference (calculation result) is a negative value or zero (ΔT ≦ 0), the process proceeds to step S111. At this time, the control means 14 determines that the temperature sensor 8 has accurately detected the outside air temperature, and sets the temperature Tb1 (first reference temperature) that should be originally assumed as the reference temperature. In this embodiment, the calculation means 13 performs an averaging process on the detected temperature in consideration of the variation and instability of the detected temperature of the temperature sensor 8, and obtains a predetermined value from the calculation result (difference) in step S105. The process of subtraction may be performed.

Subsequently, in step S107, the control means 14 acquires the detection temperature T13 (the third temperature detected at the third time) of the temperature sensor 8, and the storage means 12 stores the detection temperature T13. Subsequently, in step S108, the control means 14 compares the temperature Ta1 (second reference temperature) set in step S106 with the detection temperature T13 detected in step S107. When the detected temperature T13 is larger than the temperature Ta1 or the detected temperature T13 is equal to the temperature Ta1 (Ta1 ≦ T13), the process proceeds to step S109. In step S109, the control means 14 displays a warning (protection operation).

On the other hand, when the detected temperature T13 is smaller than the temperature Ta1 (Ta1> T13), the process proceeds to step S110. In step S110, the control means 14 uses the time measuring means 11 to measure the elapsed time from setting the temperature Ta1 in step S106. After a predetermined time has elapsed after setting the temperature Ta1, the process proceeds to step S111. Here, the predetermined time is the time required to eliminate (or sufficiently reduce) the influence of residual heat. In step S111, the control means 14 changes the reference temperature from the temperature Ta1 to the temperature Tb1. That is, when the control means 14 sets the temperature Ta1 (second reference temperature) as the reference temperature, the control means changes the reference temperature from the temperature Ta1 (second reference temperature) to the temperature Tb1 (first reference temperature) after a lapse of a predetermined time. ).

Subsequently, in step S112, the control means 14 acquires the detection temperature T14 (the fourth temperature detected at the fourth time) of the temperature sensor 8, and the storage means 12 stores the detection temperature T14. Subsequently, in step S113, the control means 14 compares the temperature Tb1 (first reference temperature) set in step S111 with the detection temperature T14 detected in step S112. If the detected temperature T14 is larger than the temperature Tb1 or the detected temperature T14 is equal to the temperature Tb1 (Tb1 ≦ T14), the process proceeds to step S114. In step S114, the control means 14 displays a warning (protection operation). On the other hand, when the detected temperature T14 is smaller than the temperature Tb1 (Tb1> T14), the process returns to step S112, and steps S112 and S113 are repeated.

As described above, in the present embodiment, the control means 14 has the first temperature (T11) detected at the first time and the second temperature detected at the second time after the first time. The reference temperature is changed according to the difference from (T12). More preferably, the control means 14 sets the first reference temperature (Tb1) as the reference temperature when the first temperature is smaller than the second temperature. On the other hand, when the first temperature is higher than the second temperature, the control means 14 sets a second reference temperature (Ta1) higher than the first reference temperature as the reference temperature. Further, preferably, the temperature sensor 8 detects the first temperature after the power of the projection type display device 100 is turned on (after driving the cooling fan 4), and detects the first temperature and then the second temperature. To detect.

According to this embodiment, the influence of residual heat from the heating element inside the projection type display device 100 can be removed (sufficiently reduced) and the outside air temperature can be recognized more accurately, so that the thermal protection operation can be performed. Can be optimized.

Next, the projection type display device according to the second embodiment of the present invention will be described. In the first embodiment, the control using the detected value (detected temperature) by the temperature sensor 8 is performed immediately after the power is turned on, but in the present embodiment, the detected value acquired in the standby state immediately before the power is turned off is used. Take control. The same effect as in the first embodiment can be obtained by such control. Since the projection type display device of this embodiment has the same structure as the projection type display device 100 described in the first embodiment with reference to FIG. 3, the description thereof will be omitted.

The control method of the projection type display device 100 in this embodiment will be described with reference to FIG. FIG. 2 is a flowchart showing a control method in this embodiment. Each step of FIG. 2 is executed by each part of the control board 10. The description common to that of FIG. 1 will be omitted for each step of FIG.

First, in step S201, the control means 14 turns off the power of the projection type display device 100 based on the user's instruction (operation). Subsequently, in step S202, the control means 14 acquires the detection temperature T21 (first temperature detected at the first time) of the temperature sensor 8, and the storage means 12 stores the detection temperature T21. Subsequently, in step S203, the control means 14 turns on the power of the projection type display device 100 based on the user's instruction (operation). Subsequently, in step S204, the control means 14 acquires the detection temperature T22 of the temperature sensor 8 (the second temperature detected at the second time after the first time), and the storage means 12 acquires the detection temperature T22. Remember.

Subsequently, in step S205, the calculation means 13 calculates the difference (ΔT = T21-T22) between the detection temperature T21 and the detection temperature T22. When this difference (calculation result) is a positive value (ΔT> 0), the process proceeds to step S206, and the control means 14 has a temperature Ta2 (second reference temperature) higher than the temperature Tb2 (first reference temperature) as the reference temperature. Reference temperature) is set. On the other hand, when the difference (calculation result) is a negative value or zero (ΔT ≦ 0), the process proceeds to step S211 and the temperature Tb2 (first reference temperature) is set as the reference temperature.

In step S207, the control means 14 acquires the detection temperature T23 (the third temperature detected at the third time) of the temperature sensor 8, and the storage means 12 stores the detection temperature T23. Subsequently, in step S208, the control means 14 compares the temperature Ta2 (second reference temperature) with the detected temperature T23. When the detection temperature T23 is larger than the temperature Ta2 or the detection temperature T23 is equal to the temperature Ta2 (Ta2 ≦ T23), the process proceeds to step S209, and the control means 14 displays a warning (protection operation).

On the other hand, when the detected temperature T23 is smaller than the temperature Ta2 (Ta2> T23), the process proceeds to step S210, and the control means 14 uses the time measuring means 11 to set the temperature Ta2 in step S206. To measure. After a predetermined time has elapsed after setting the temperature Ta2, the process proceeds to step S211 and the control means 14 changes the reference temperature from the temperature Ta2 to the temperature Tb2. That is, when the control means 14 sets the temperature Ta2 (second reference temperature) as the reference temperature, the control means changes the reference temperature from the temperature Ta2 (second reference temperature) to the temperature Tb2 (first reference temperature) after a lapse of a predetermined time. ).

Subsequently, in step S212, the control means 14 acquires the detection temperature T24 (the fourth temperature detected at the fourth time) of the temperature sensor 8, and the storage means 12 stores the detection temperature T24. Subsequently, in step S213, the control means 14 compares the temperature Tb2 (first reference temperature) with the detection temperature T24. When the detection temperature T24 is larger than the temperature Tb2 or the detection temperature T24 is equal to the temperature Tb2 (Tb2 ≦ T24), the process proceeds to step S214, and the control means 14 displays a warning (protection operation). On the other hand, when the detected temperature T24 is smaller than the temperature Tb2 (Tb2> T24), the process returns to step S212, and steps S212 and S213 are repeated.

As described above, in the present embodiment, the temperature sensor 8 detects the first temperature after the power of the projection type display device 100 is turned off (after the light source 1 is turned off), detects the first temperature, and then powers the power. Detects a second temperature after is turned on. According to this embodiment, the influence of residual heat from the heating element inside the projection type display device 100 can be removed (sufficiently reduced) and the outside air temperature can be recognized more accurately, so that the thermal protection operation can be performed. Can be optimized.

The projection type display device of each embodiment determines whether the detection temperature of the temperature sensor is the original outside air temperature or a false detection temperature affected by the residual heat, regardless of the posture of the projection type display device. Can be determined. Therefore, according to each embodiment, it is possible to provide a projection type display device capable of appropriately performing protective operations such as warning display and avoidance of lighting of a light source regardless of the installation posture. This is particularly effective when the projection display device is installed so that the temperature detecting means is located higher than the light source.

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

For example, in each embodiment of the present invention, the projection type display device that performs the above-mentioned control has been described, but the present invention is not limited to such a projection type display device. A projection type display device having a cooling means for sucking outside air from an intake port, a temperature detecting means for detecting a temperature, and a control means for performing a protective operation when the temperature detected by the temperature detecting means is higher than a reference temperature. It may be a program for. Then, this program has a step of changing the reference temperature according to the change in temperature detected by the temperature detecting means.

4 Cooling fan (cooling means)
8 Temperature sensor (Temperature detection means)
14 Control means 100 Projection type display device

Claims (7)

A projection display device that projects an image using light from a light source.
Cooling means that takes in outside air from the intake port,
A temperature detecting means for detecting the temperature and
It has a control means that performs a protective operation when the temperature detected by the temperature detecting means is higher than a reference temperature.
When the first temperature detected by the temperature detecting means at the first time is higher than the second temperature detected at the second time after the first time , the control means is used. A second reference temperature higher than the first reference temperature is set as the reference temperature after the power of the projection type display device is turned on, and the reference temperature is set to the first reference temperature after a lapse of a predetermined time. change,
When the first temperature is lower than the second temperature, the control means is lower than the second reference temperature as the reference temperature after the power of the projection type display device is turned on. A projection type display device characterized by setting a reference temperature. The temperature detecting means is
After the power of the projection type display device is turned on, the first temperature is detected and the temperature is detected.
Projection display device according to claim 1, characterized in that to detect the second temperature after detecting the first temperature. The temperature detecting means is
After the power of the projection type display device is turned off, the first temperature is detected.
Projection display device according to claim 1, characterized in that to detect the second temperature from the detection of the first temperature after the power is turned on. The projection type display device according to any one of claims 1 to 3 , wherein the control means displays a warning as the protective operation. The projection type display device according to any one of claims 1 to 4 , wherein the control means reduces the output of the light source as the protection operation. The projection type display device according to any one of claims 1 to 5 , wherein the temperature detecting means is arranged in the vicinity of the intake port. The projection-type display device according to any one of claims 1 to 6 , wherein the projection-type display device is installed so that the temperature detecting means is installed at a position higher than that of the light source.

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