JP7248527B2 - Projection type image display device and obstacle detection method - Google Patents

Description

TECHNICAL FIELD The present invention relates to technology for a projection-type image display device (projector) and the like, and to technology such as obstacle detection in a projector.

As a prior art example, Japanese Patent No. 6070871 (Patent Document 1) can be cited. Japanese Patent Application Laid-Open No. 2002-200002 describes that a projector includes a detection unit that detects an obstacle that blocks image light.

Japanese Patent No. 6070871

There may be an obstacle between the output part (for example, lens) of the projection optical system in the projector and the area of the screen. For example, an obstacle such as paper may be placed near the exit section. In that case, the image light from the output section is blocked by the obstacle, and the image light is reflected or absorbed, which may cause an undesirable problem such as an increase in the temperature around the projection optical system. If the user does not notice the obstacle or does not take measures such as removing the obstacle, such a problem will be left unsolved.

As a prior art example of an obstacle detection method, there is a method of detecting an obstacle using a sensor such as an infrared sensor.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a technology for a projection-type image display device or the like, which is capable of more appropriately detecting obstacles and dealing with problems, thereby improving usability of the device for the user. .

A representative embodiment of the present invention has the following configuration. A projection-type image display apparatus according to one embodiment includes a light source, a display element that transmits or reflects light from the light source, and a projection optical system that projects the light from the display element onto a display surface to display an image. an obstacle sensor for detecting an obstacle near the output portion of the projection optical system; and a controller for controlling display of the image, wherein the obstacle sensor includes an infrared sensor and a far infrared sensor. Including, the control unit makes detection determination of the obstacle based on the detection result of the infrared sensor and the detection result of the far infrared sensor.

According to the representative embodiments of the present invention, obstacles can be more suitably detected and problems can be dealt with in the technology of the projection type image display device, and the user's usability of the device can be improved. can.

1 is a diagram showing a configuration example of a projection-type image display device according to Embodiment 1 of the present invention; FIG. 4 is a diagram showing a configuration example of an obstacle sensor and a control unit in the first embodiment; FIG. 1 is a diagram showing characteristics of an infrared sensor in Embodiment 1. FIG. 1 is a diagram showing characteristics of a far-infrared sensor in Embodiment 1. FIG. FIG. 2 is a diagram showing infrared characteristics in Embodiment 1; 4 is a diagram showing a processing flow regarding an obstacle detection function in Embodiment 1. FIG. 4 is a diagram showing obstacle detection determination in the first embodiment; FIG. FIG. 4 is a diagram showing an example of a combination of handling processes in Embodiment 1; 4 is a diagram showing an example of detection continuation determination in Embodiment 1. FIG. FIG. 3 is a perspective view showing an example 1 of arrangement of obstacle sensors in the first embodiment; FIG. 2 is a configuration diagram of arrangement example 1 viewed from the side in embodiment 1; FIG. 10 is a front view of the screen regarding arrangement example 1 in the first embodiment; FIG. 7 is a perspective view showing an example 2 of arrangement of obstacle sensors in the first embodiment; FIG. 10 is a configuration diagram of the arrangement example 2 viewed from the side in the first embodiment; FIG. 10 is a diagram of the arrangement example 2 of the first embodiment as viewed from the front of the screen; 4 is a diagram showing an example of exhaust in Embodiment 1. FIG. FIG. 4 is a diagram showing an exhaust direction in Embodiment 1; FIG. 10 is a diagram showing a display example 1 of a message in Embodiment 1; FIG. 10 is a diagram showing a display example 2 of a message in Embodiment 1; FIG. 10 is a diagram showing a third display example of a message in Embodiment 1; FIG. 10 is a diagram showing a display example 4 of a message in Embodiment 1;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In principle, the same reference numerals are given to the same parts in all the drawings, and repeated explanations are omitted.

(Embodiment 1)
A projection type image display device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 21. FIG.

[Projection type image display device (projector)]
FIG. 1 shows a functional block configuration as a configuration example of a projection type image display device according to Embodiment 1. As shown in FIG. Projector 1, which is a projection type image display apparatus according to Embodiment 1, includes projection optical system 101, display element 102, display element driving section 103, illumination optical system 104, light source 105, power supply 106, operation input section 107, nonvolatile memory. 108 , memory 109 , control unit 110 and obstacle sensor 120 . Further, the projector 1 includes a cooling unit 115, a display unit 130, a speaker 131, an image adjustment unit 132, a storage unit 133, a communication unit 134, an orientation sensor 135, a camera 136, a video signal input unit 141, an audio signal input unit 142, a video A signal output unit 143, an audio signal output unit 144, and the like are provided. These components are interconnected through a bus or the like.

A light source 105 generates light for image projection, and is configured using a high-pressure mercury lamp, a xenon lamp, an LED light source, a laser light source, or a combination thereof. The power supply 106 is connected to an external power supply, converts AC current input from the external power supply into DC current, and supplies necessary power to each part such as the light source 105 . The illumination optical system 104 collects the light from the light source 105 , makes it more uniform, and irradiates the display element 102 with the light.

The display element driving section 103 sends a driving signal generated according to the video signal to be referred to to the display element 102 . The video signal referred to by the display element driving section 103 may be a video signal generated by the control section 110 or may be an input video signal input from the outside via the video signal input section 141 . Further, this video signal may be a video signal after image adjustment is performed by the image adjustment unit 132 on the input video signal. Also, a signal obtained by superimposing an OSD (on-screen display) image signal on these video signals may be used as a reference video signal. The OSD image signal is generated by control unit 110 using data such as images stored in nonvolatile memory 108 and storage unit 133 .

The display element 102 is an element that transmits or reflects light from the illumination optical system 104 and modulates the light at that time to generate an image. Micromirror Device (registered trademark) panels and the like are used. The display element 102 modulates light according to a driving signal from the display element driving section 103 to generate an image.

The projection optical system 101 is an enlarged projection optical system that enlarges and projects an image generated by the display element 102 onto the display surface 200, and includes at least one of a lens and a mirror. The display surface 200 is, in other words, a screen, an image projection surface, or the like. The image light from the projection optical system 101 is projected onto a partial area 201 of the display surface 200 and becomes a display image.

The cooling part 115 is a part that cools each part that can be in a high temperature state, such as the light source 105, the power supply 106, or the display element 102, by an air cooling method or a liquid cooling method as necessary, and includes, for example, an exhaust fan. .

Control unit 110 corresponds to a processor or controller that controls the entire projector 1 and each unit. The control unit 110 includes, for example, a CPU, etc., and implements functions by software program processing. The memory 109 stores various data and information handled by the control unit 110, such as video data and control information. The nonvolatile memory 108 retains various data and information used in the projector function for a long period of time. The memory 109 or the like may store image data for generating a graphical user interface (GUI) or the like.

The operation input unit 107 includes operation buttons or an operation panel and a remote control light receiving unit, and is a portion for inputting user's operations. The remote control light-receiving unit receives a signal from a remote control, which is an attached device. Signals from the remote controller to the remote controller light receiving section are transmitted by, for example, infrared rays.

The display 130 is a part that displays information as an interface for the user, and includes, for example, a sub-monitor and an LED indicator. The sub-monitor is composed of a liquid crystal display or the like, and displays information such as characters. The LED indicator includes a plurality of LEDs, each LED is associated with a state (for example, power on/off), and the state is expressed by lighting, extinguishing, blinking, or the like. Note that some LEDs of the LED indicator may be defined as LEDs representing the obstacle detection state.

The speaker 131 is an audio output device, and outputs, for example, built-in operation sounds and warning sounds, and can output audio based on audio data input to the audio signal input unit 142 .

The image adjustment unit 132 is a part that performs image processing on video data input through the video signal input unit 141, for example. This image processing includes, for example, scaling processing, brightness adjustment processing, contrast adjustment processing, gamma adjustment processing, and Retinex processing. Scaling processing is processing such as enlargement, reduction, and deformation of an image. Brightness adjustment processing is processing for changing luminance. Contrast adjustment processing is processing for changing the contrast curve of an image. Gamma adjustment processing is processing for changing a gamma curve that indicates the gradation characteristics of an image. Retinex processing is processing that decomposes an image into light components and changes weighting for each component.

The storage unit 133 records various data such as videos, images, and sounds. For example, such various data may be recorded in the storage unit 133 in advance at the time of product shipment. Further, in the storage unit 133, such various data acquired from the outside through the communication unit 134 may be recorded. Various data recorded in the storage unit 170 can be output as projection images through the display element 102, the projection optical system 101, and the like. The audio data can be output as audio from the speaker 131 .

The communication unit 134 communicates with an external device, a network, a server, or the like via a wired or wireless communication interface, and exchanges various data such as control information and contents.

The orientation sensor 135 is a sensor that detects the state of the orientation when the projector 1 is installed, and is configured by a gravity sensor, a gyro sensor, or the like. The control unit 110 may perform control using information regarding the posture state detected by the posture sensor 135 . For example, the control unit 110 may rotate the direction of the image displayed on the display element 102 according to the posture state so that the displayed image is in a direction that does not cause discomfort according to the posture state. In addition, the control unit 110 may control the local strength of cooling by the cooling unit 115, the change of the threshold value for cooling error detection, and the like so as to be suitable for the posture state. Further, the control unit 110 may perform control related to the obstacle detection function, for example, control of switching between on and off of the function, according to the posture state.

Camera 136 may comprise a visible light camera. In this case, the visible light camera is used to capture an image around the projector 1 or the display surface 200 and record or output it to the outside. The control unit 110 may perform control using the image of the camera 136 . Camera 136 may comprise an infrared camera. In this case, the infrared camera may detect a pointing position on display surface 200 indicated using a pointing device that emits or reflects infrared light. In addition, it is also possible to detect a person or the like standing in front of the display surface 200 using the camera 136 and use it for anti-glare control such as reducing the light output of the projected image.

The video signal input unit 141 inputs a video signal from the outside via a wired or wireless interface. Audio signal input unit 142 inputs an audio signal from the outside via a wired or wireless interface. The video signal output unit 143 outputs video signals to the outside via a wired or wireless interface. The video signal output unit 143 may have a function of outputting the video signal input from the first external device via the video signal input unit 141 to the second external device as it is. The video signal output unit 143 may have a function of outputting a video signal based on the video data recorded in the storage unit 133 or a video signal based on the video captured by the camera 136 to the outside.

The audio signal output unit 144 outputs audio signals to the outside via a wired or wireless interface. The audio signal output unit 144 may have a function of outputting the audio signal input from the first external device via the audio signal input unit 142 to the second external device as it is. The audio signal output unit 144 may have a function of outputting an audio signal or the like based on the audio data recorded in the storage unit 133 to the outside. The video signal input section 141 and the audio signal input section 142 may be configured as an integrated signal input interface. The video signal output section 143 and the audio signal output section 144 may be configured as an integrated signal output interface. The video signal input section 141, the audio signal input section 142, the video signal output section 143, and the audio signal output section 144 may be configured as an integrated signal input/output interface. These integrated interfaces may have communication capabilities to communicate control signals bi-directionally. This communication function may be provided separately from the communication unit 134 . As illustrated above, the projector 1 can be equipped with various functions.

The obstacle sensor 120 is arranged near the projection optical system 101 . The obstacle sensor 120 is a sensor that detects an obstacle in an area near the projection optical system 101 including an area through which image light passes. Specifically, in Embodiment 1, obstacle sensor 120 includes both an infrared sensor and a far-infrared sensor. The controller 110 of the projector 1 combines the detection result of the infrared sensor and the detection result of the far-infrared sensor to determine whether or not an obstacle is detected. Obstacle sensor 120 may be configured as an obstacle sensor in which an infrared sensor and a far-infrared sensor are integrated. The obstacle sensor 120 may be configured as a plurality of obstacle sensors in which infrared sensors and far-infrared sensors are separated. Details of the obstacle sensor 120 will be described later.

[Obstacle sensor and controller]
FIG. 2 shows a configuration example of the obstacle sensor 120 and the control unit 110. As shown in FIG. Obstacle sensor 120 includes infrared sensor 10 and far infrared sensor 20 . The obstacle sensor 120 may also include a circuit for driving the sensor, a circuit for processing the sensor signal, and the like. The infrared sensor 10 is a sensor whose main detection wavelength range is near-infrared rays. The far-infrared sensor 20 is a sensor whose main detection wavelength range is far-infrared rays. The infrared sensor 10 is an active sensor including an infrared light emitter and an infrared detector. The far-infrared sensor 20 is a passive sensor including an infrared detector.

The infrared sensor 10 outputs an infrared sensor signal A1 as the first signal. The infrared sensor signal A1 is, for example, a signal representing a voltage corresponding to the amount of infrared rays detected. The far-infrared sensor 20 outputs a far-infrared sensor signal A2 as the second signal. The far-infrared sensor signal A2 is, for example, a signal representing the detected temperature.

The control unit 110 performs processing related to an obstacle detection function in addition to the processing for controlling each unit described above. Note that a control unit that performs processing related to the obstacle detection function may be provided separately from the control unit 110 .

The control unit 110 receives the infrared sensor signal A1 from the infrared sensor 10, performs detection processing, and obtains a processed signal. This detection process is, for example, a process of determining the presence or absence of an obstacle based on the voltage of the infrared sensor signal A1. The control unit 110 receives the far-infrared sensor signal A2 from the far-infrared sensor 20, performs detection processing, and obtains a processed signal. This detection process is, for example, a process of determining the presence or absence of an obstacle based on the temperature of the far-infrared sensor signal A2. Note that a processing unit that performs such detection processing may be mounted in the obstacle sensor 120 .

The control unit 110 considers both of the signals after the above-described detection processing, makes an obstacle detection judgment comprehensively, and obtains a detection judgment result signal. This signal is a signal indicating whether or not an obstacle is detected, and is a signal indicating a state in which an obstacle is detected or a state in which an obstacle is not detected.

The control unit 110 performs the first handling process according to the result of obstacle detection determination, that is, the content of the signal. The handling process is a process related to handling an obstacle, such as warning the user of the presence of the obstacle and prompting the user to take action such as removing the obstacle. In the first embodiment, there are two stages of correspondence processing, that is, first correspondence processing and second correspondence processing. The control unit 110 controls operations such as sound output from each unit in FIG.

Control unit 110 determines whether or not a state in which an obstacle has been detected continues in relation to the result of the obstacle detection determination. Control unit 110 obtains a detection continuation determination result signal.

The control unit 110 performs the second handling process according to the content of the signal indicating the obstacle detection continuation determination result. The second response process is a second response process for the first first response process, or a response process different in type from the first response process.

[Characteristics of infrared sensor]
An infrared sensor detects an object based on reflected infrared light. There are two types of infrared sensors: an active type that emits infrared rays by itself and detects reflected light, and a passive type that detects reflected infrared rays emitted from other devices or other infrared emitting units. In Embodiment 1, the infrared sensor 10 is of an active type unless otherwise specified, and the far infrared sensor 20 is of a passive type unless otherwise specified. The infrared sensor 10 is an active sensor having an infrared light emitting portion and an infrared light receiving portion. The far-infrared sensor 20 is a passive sensor having an infrared light receiving portion that receives infrared rays in a far-infrared region, which is a longer wavelength region than the infrared light receiving portion of the infrared sensor 10 corresponds to.

FIG. 3 shows an example of an object detection range of an infrared sensor as a characteristic of the infrared sensor. Graph (A) is particularly for explaining the difference in detection characteristics of white/black obstacles by the infrared sensor 10 . In the graph of (A), the horizontal axis indicates the horizontal relative detection distance, and the vertical axis indicates the vertical relative detection distance. A white dot indicates the detection range when the obstacle is a white object as shown in (B). The black dot indicates the detection range when the obstacle is a black object as shown in (C). In the graph of (A), the distance on the vertical axis and the distance on the horizontal axis are each normalized with the furthest distance in the white object detection range being 1. Here, horizontal and vertical means that the direction from the projection optical system 101 of the projector 1 to the display surface 200 is vertical, and the left and right directions of the main body of the projector 1 with respect to the display surface 200 are horizontal.

In object detection by an infrared sensor, the detectable distance differs between a white object such as (B) and a black object such as (C). This is because a white object and a black object have different light reflectances and absorbances. The example of (B) shows that the absorption is 10 and the reflection is 90 when the total amount of infrared rays irradiated to a white object is 100. The example of (C) shows that if the total amount of infrared rays irradiated to a black object is 100, the absorption is 90 and the reflection is 10. In this way, the infrared sensor is less likely to reflect infrared rays in the case of a black object such as (C), and the detection range is narrower than the detection range in the case of a white object such as (B). end up For this reason, in the case of a configuration in which an obstacle is detected using only an infrared sensor as an example of conventional technology, the detection accuracy of a black object is lower than that of a white object, depending on the position of the obstacle.

As described above, infrared sensors are suitable for detecting white objects as obstacles based on their detection characteristics. However, infrared sensors have difficulty detecting black objects that are less bright. Therefore, in Embodiment 1, the far-infrared sensor 20 is used in combination with the infrared sensor 10 as the obstacle sensor 120 . Far-infrared sensors are more likely to detect black-and-white objects than white objects based on their detection characteristics.

[Characteristics of far-infrared sensor]
FIG. 4 shows the characteristics for the far infrared sensor. Graph (A) shows an example of an object detection range by a far infrared sensor. This graph is for explaining the difference in characteristics between the detection range of a white object and the detection range of a black object of the far-infrared sensor, and is normalized in the same manner as in FIG. In object detection by a far-infrared sensor, a black object such as (C) has a longer detectable distance than a white object such as (B). This is because a white object and a black object have different light emissivity and absorptance. The example of (B) shows that, if the total amount is 100, the far-infrared radiation emitted from the white object is 10. The example of (C) indicates that the far-infrared radiation emitted from the black object is 90 degrees. Thus, in the case of a black object such as (C), far-infrared radiation is large, and the detection range is wider than the detection range in the case of a white object such as (B). In Embodiment 1, by using the infrared sensor 10 and the far-infrared sensor 20 in combination, the obstacle detection range can be broadened comprehensively, and the black object detection accuracy can also be improved.

[Characteristics of infrared rays]
FIG. 5 shows an explanatory diagram of characteristics related to infrared rays. FIG. 5 schematically shows the wavelength regions of ultraviolet, visible, near-infrared, middle-infrared, and far-infrared rays. Near-infrared rays have a wavelength range of approximately 0.78 μm to 2.5 μm. Far infrared rays have a wavelength range of about 4.0 μm to 1 mm. An infrared sensor is a sensor that can mainly detect near-infrared wavelengths. A far-infrared sensor is a sensor that can mainly detect the wavelength region of far-infrared rays. Infrared sensor 10 and far infrared sensor 20 in Embodiment 1 apply such a sensor.

In general, when an object absorbs light, its temperature rises and it emits infrared rays. The emitted wavelength shifts to longer wavelengths at lower temperatures. The amount of infrared radiation emitted is proportional to the amount of absorption. Using this feature, the far-infrared sensor can detect infrared rays in the far-infrared region emitted from an object and measure the surface temperature of the object. The presence or absence of an object can also be detected based on the detection result of the object surface temperature. That is, the far-infrared sensor has both a temperature measurement function and an object detection function due to its ability to detect far-infrared rays.

In the example of Embodiment 1, the infrared sensor 10 sets the infrared output wavelength of the infrared light emitting portion and the detection wavelength of the infrared light receiving portion in the near-infrared wavelength region around 940 nm. The infrared light emitting section is composed of, for example, a pulse-driven IR-LED. The infrared light receiving section detects reflected light from an obstacle with a light receiving element. In the infrared sensor 10, the light emission pulse of the infrared light emitting portion and the light receiving element of the infrared light receiving portion are synchronized, and non-synchronized infrared rays are not detected. The infrared sensor 10 is configured using a filter that cuts visible light, and transmits only infrared rays.

In the example of Embodiment 1, the far-infrared sensor 20 has a detection wavelength range of 8 μm to 14 μm. An infrared light receiving portion in the far infrared sensor 20 is configured using a bandpass filter that allows far infrared rays to pass through. The light source 106 emits light in the visible region of RGB, and the wavelength region is 400 nm to 780 nm.

[Processing flow]
FIG. 6 shows a processing flow relating to processing including obstacle detection handling processing as main processing of the obstacle detection function of the projector 1 . FIG. 6 has steps S1 to S7, which will be described in the order of the steps. In step S1, the controller 110 (FIG. 2) of the projector 1 combines the obstacle detection processing result signal from the infrared sensor 10 and the obstacle detection processing result signal from the far-infrared sensor 20 to perform obstacle detection processing. conduct. Details of the obstacle detection process will be described later (FIG. 7).

When the controller 110 of the projector 1 detects an obstacle based on the signal resulting from the obstacle detection process (S1-YES), the controller 110 performs a first response process in step S2. Details of the first correspondence process will be described later (FIG. 8). If the projector 1 does not detect an obstacle based on the signal resulting from the obstacle detection process (S1-NO), the process returns to the beginning of the flow.

In step S3, the control unit 110 of the projector 1 performs a first detection continuation determination process, which is a process of determining whether or not the obstacle detection state continues after the first response process. The details of the first detection continuation determination process will be described later (FIG. 9).

When the projector 1 determines that the obstacle detection continues based on the signal resulting from the first detection continuation determination process (S3-YES), the second response process is performed in step S4. Details of the second correspondence process will be described later (FIG. 8). When the projector 1 determines that the obstacle detection is not continued based on the signal resulting from the first detection continuation determination process (S3-NO), the process returns to the beginning of the flow via step S7.

After the second response process, the control unit 110 of the projector 1 performs a second detection continuation determination process for determining whether or not the obstacle detection state continues in step S5. Details of the second detection continuation determination process will be described later (FIG. 9). When the projector 1 determines that the obstacle detection continues based on the signal resulting from the second detection continuation determination process (S5-YES), the process proceeds to step S6. When the projector 1 determines that the obstacle detection is not continued based on the signal resulting from the second detection continuation determination process (S5-NO), the process returns to the beginning of the flow via step S7.

In step S6, the projector 1 turns off the light source 105, shifts to standby mode, and ends the flow.

In step S7, the projector 1 restores the brightness of the light source 105 to normal if the light source brightness reduction process is being performed in the first handling process or the second handling process. Further, if the projector 1 issues an error notification in the first response process or the second response process, it cancels the error notification. Also, if the projector 1 displays a message in the first response process or the second response process, the message display is erased. In addition, when the projector 1 outputs the warning sound in the first response process or the second response process, it cancels the output of the warning sound.

[Obstacle detection judgment]
FIG. 7 shows details of obstacle detection determination by the control unit 110 in step S1. The control unit 110 combines the detection result of the infrared sensor 10 and the detection result of the far-infrared sensor 20 to make an obstacle detection judgment as a whole system. The table in FIG. 7 shows the binary values of the detection results of the infrared sensor 10 in two columns, the binary values of the detection results of the far-infrared sensor 20 in two rows, and the intersecting items in the matrix indicate combinations of these values. indicates the value of the comprehensive obstacle detection judgment result according to Here, the binary value is 0 when no obstacle is detected, and 1 when an obstacle is detected. If either one of the detection result of the infrared sensor 10 and the detection result of the far-infrared sensor 20 indicates that an obstacle is detected (value=1), the control unit 110 performs comprehensive detection by the obstacle detection function. It is assumed that an obstacle detection determination result is a state in which an obstacle is detected (value=1). As illustrated, this obstacle detection determination can be regarded as a logical sum (OR). When both the detection result of the infrared sensor 10 and the detection result of the far-infrared sensor 20 indicate that no obstacle is detected (value=0), the projector 1 determines that no obstacle is detected. state (value=0).

[Corresponding process]
FIG. 8 shows specific examples of the first handling process in step S2 and the second handling process in step S4. Various processes can be considered for the contents of the first handling process 1 and the second handling process, but in the first embodiment, a specific example as shown in FIG. 8 is applied. The table in FIG. 8 shows examples 1 to 5 as specific examples of combinations of the first correspondence processing and the second correspondence processing.

In example 1, the first response process is the light source brightness reduction process, and the second response process is the warning process. Light source luminance reduction processing is processing for reducing the luminance of the light source 105 in FIG. It is a process to reduce. If the amount of light output from the projection optical system 101 is reduced, the temperature around the projection optical system 101 rises due to light reflection or light absorption by the obstacles, even if the user does not take action such as removing the obstacles. problem may be resolved.

Warning processing includes processing to superimpose and display a message such as a warning or guide on the projection image, processing to display a message on the sub-monitor of the display 130, processing to output a warning sound from the speaker 131, or processing to detect other errors. Notification processing and the like. Other error notification processing may be processing for notifying the error on the sub-monitor or LED indicator of the display 130, or processing for transmitting the error notification to the remote controller or the user's wireless terminal device. The wireless terminal device may be a device such as a user's smart phone that communicates with the projector 1 . The error notification may be a change in the light emission color of the LED indicator or light emission control of a specific LED. The projector 1 performs at least one of those warning processes. The projector 1 may perform two or more warning processes in combination, or may perform each warning process sequentially.

A specific example of the message displayed in the warning process may be a message to the effect that "an obstacle has been detected near the output unit of the projection optical system 101", or a message "an obstacle has been detected near the output unit of the projection optical system 101". It may be a message to the effect that the user is urged to remove the obstacle since it has been detected. It should be noted that a message to the effect that "the light source will be turned off automatically after that if the obstacle detection state continues" may be used. The projector 1 may perform control to automatically turn off the light source 105 when the obstacle detection state continues for a certain amount of time or longer after performing the warning process. These indications may be combined. A mark or the like may be displayed instead of the message. Display of a message, mark, or the like makes it easier for the user to recognize the situation and to take action.

Further, a specific example of the warning sound output in the warning process may be a simple beep sound or a verbal message voice. In the case of message voice, the content of the message may be output by voice. In the case of a message voice, messages in a plurality of languages may be stored in the storage device of the projector 1, and an appropriate language may be selected according to the language setting of the menu display to output the message voice.

For example, there may be a large obstacle in front of the output portion of the projection optical system 101, and the obstacle may block most of the image light. In that case, even if OSD processing is performed to superimpose a message on the projected image, the user may not be able to visually recognize it. Even in such a case, outputting a warning sound is preferable because it can notify the user of the warning. Therefore, it is more preferable to display a message on the projection image and output a warning sound.

As described above, in example 1, only the light source brightness reduction process is performed in the first response process, and the warning process is not performed. This has the advantage that there is a possibility that the problem will be resolved without any action by the user, and that the probability of bothering the user is lower.

In Example 2, the first response process is the first warning process, and the second response process is the second warning process. For both the first warning process and the second warning process, specific examples of the warning process of Example 1 may be used alone or in combination. Simply, the first warning process and the second warning process may be the same. Alternatively, the scale of the second warning process may be larger than the scale of the first warning process. For example, the display size of the message of the second warning process may be larger than the display size of the message of the first warning process. The number of messages displayed for the second warning process may be increased. The volume of the warning sound for the second warning process may be higher than the volume of the warning sound for the first warning process. The content of the message for the second warning process may be changed to a content that urges the user to take action more strongly than the content of the message for the first warning process.

Alternatively, the warning sound of the first warning process is a non-verbal sound such as a beep, the warning sound of the second warning process is a verbal message sound, and the warning sound of the second warning process is the first warning process. It may be changed so that the content of the warning is conveyed to the user more strongly than the warning sound of .

Alternatively, the types of warning processes may be increased so that the second warning process encourages the user to respond more strongly than the first warning process. For example, in the first warning process, a message is displayed without outputting the warning sound, and in the second warning process, the message is displayed and the warning sound is output. As a result, it is possible to increase the probability that the problem will be resolved by the user's response before performing a response such as turning off the light source. In the first embodiment, "the problem is solved by the user's response" means, for example, that the user removes an obstacle in the vicinity of the output unit of the projection optical system 101 by moving or the like, and the obstacle caused by the obstacle This means that problems such as temperature rise around the projection optical system 101 due to light reflection or light absorption of image light are resolved.

As described above, in example 2, the user is warned twice before turning off the light source. As a result, there is an advantage that the problem is more likely to be solved by the user's response before turning off the light source. In the above example, the warning process is performed twice, but the present invention is not limited to this, and it is also possible to perform a stepwise response process a plurality of times.

Example 3 is based on the processing of Example 2, and performs light source brightness reduction processing together with the first warning processing. Thus, example 3 realizes both the advantages of example 1 and the advantages of example 2. The advantage of Example 1 is that if the amount of light output from the projection optical system 101 is reduced, problems such as a temperature rise around the projection optical system 101 due to obstacles can be resolved without any action by the user. including benefits. Advantages of Example 2 include that multiple warnings to the user increase the probability that the problem will be resolved before the light source is turned off. The details of each process are the same as in Examples 1 and 2.

Example 4 is based on the processing of Example 2, and adds a process of switching the projected image from the image desired by the user to the black screen display image when performing the second warning process. It is a thing. The black screen display image is an image in which all the pixels of the projection image are black. When displaying a warning message, the message may be superimposed on the black screen display image. The image is not limited to the black screen display image, and may be an image or the like in which the brightness of the original image of the user is reduced as a whole.

By switching the projected image from the user's image to the black screen display image, the following advantages (1) and (2) are obtained. (1) Since the black display area in the projected image increases, the total amount of image light output from the projection optical system 101 can be reduced. As a result, it is possible to suppress temperature rise around the projection optical system 101 due to light reflection or light absorption by the obstacle. (2) Since the projected image becomes a black screen display image, the user's image is not displayed, so the user's attention to the warning process increases, and the user can be strongly urged to respond to the obstacle. The processing is the same as in Example 2 except that the projected image is switched to the black screen display image.

Example 5 is based on the processing of Example 4, and performs light source luminance reduction processing together with the first warning processing. This allows both the advantages of Example 1 and Example 4 to be realized. The details of each process are the same as in Examples 1 and 4.

In any combination, during the second correspondence process, a countdown timer may be displayed on the projected image or on the sub-monitor of the display 130 to display the remaining time until the light source is turned off. This makes it possible to more strongly prompt the user to take action. Instead of or in addition to the countdown timer display, a warning sound including a message explaining the remaining time until the light source is turned off may be output.

According to the first handling process and the second handling process described above, it is possible to more preferably increase the probability of solving problems such as temperature rise around the projection optical system 101 due to obstacles before the light source is turned off.

[Detection continuation determination process]
FIG. 9 shows a specific example of obstacle detection continuation determination processing by the control unit 110 in steps S3 and S5. Although various processes are conceivable for the first detection continuation determination and the second detection continuation determination, several specific examples in the first embodiment will be shown. The table in FIG. 9 shows two examples (determination example 1 and determination example 2) regarding the first detection continuation determination and the second detection continuation determination.

Judgment example 1 is as follows. In the first detection continuation determination of step S3, the projector 1 determines that the state of "obstacle detected" as a result of the obstacle detection determination process of step S1 continues for a predetermined period of time T1 after step S1. As a comprehensive judgment, it is judged that the "obstacle detected" state continues. In FIG. 9, this state is described as a detection continuation state.

Further, if the state of the projector 1 changes to "no obstacle detected" within the predetermined period T1, for example, if the detection result after the period T1 is "no obstacle detected" , as a comprehensive judgment of the system, it is judged that the state has changed to "no obstacle detected", in other words, the obstacle detection is not continuing. In FIG. 9, this state is described as a detection discontinued state.

In addition, in the second detection continuation determination in step S5, the projector 1 causes the "obstacle detected" state as a result of the obstacle detection determination processing to continue for a predetermined period T2 after step S3 in the first detection continuation determination. In this case, as a comprehensive determination of the system, it is determined that the state in which the "obstacle has been detected" continues, that is, the detection continues state.

Further, when the projector 1 changes to the "obstacle not detected" state within the period T2, as a comprehensive judgment of the system, the state changed to the "obstacle not detected" state, that is, the detection discontinued state I judge.

In Determination Example 1, the length of the period T1 and the length of the period T2 may be longer or shorter, or may be the same. However, if the length of the period T1 between the first response process and the second response process is longer than the period T2, the second response process, which is a stronger warning process than the first response process, can be used. It is preferred because it has the advantage of having a higher chance of solving the problem before proceeding.

In determination example 2, the following determination process is added to the determination process of determination example 1 in the first detection continuation determination. The added judgment process is that when the temperature detected by the far-infrared sensor 20 during the period T1 exceeds the first threshold value, the "obstacle detected" state continues without waiting for the period T1 to elapse. This is a process for determining that the state is a detection continuation state, which is a state in which the The far-infrared sensor 20 is capable of detecting temperature as described above, and can consider temperature rise as well as determination based on the period. Therefore, by adding such determination processing, it is possible to more quickly determine that the second response processing should be performed.

Further, in the second detection continuation determination, the following determination process is added to the determination process of the first determination example. The added determination process is that when the temperature detected by the far-infrared sensor 20 during the period T2 exceeds the second threshold, the state of "an obstacle is detected" continues without waiting for the lapse of the period T2. This is a process for determining that the state is a detection continuation state, which is a state in which the With the addition of this determination process, it can be determined that the light source extinguishing process (step S6) should proceed more quickly.

Either of the first threshold value and the second threshold value related to the temperature may be larger or may be the same. However, since the second detection continuation determination is the final determination when proceeding to the light source extinguishing process, it is preferable to proceed more carefully. Therefore, it is desirable to set the second threshold higher than the first threshold.

A more detailed processing example of the detection continuation determination is as follows. A processing example is shown below the table in FIG. On the time axis, it has a period T1 from time t1 to time t2 and a period T2 from time t2 to time t3. Time t1 is the first detection time corresponding to step S1, and is, for example, "a state in which an obstacle has been detected" (value=1). Time t2 is the second detection time corresponding to step S3, and is the time when period T1 has elapsed from time t1. For example, detection determination is not performed between time t1 and time t2. At time t2, for example, it is also assumed that an "obstacle is detected" (value=1). In this case, the projector 1 determines that the detection continues state since the same state continues during the period T1 as in determination example 1 above.

Another processing example is as follows. The period T1 further has a plurality of unit times. The projector 1 always performs the detection judgment of step S1 for each unit time. The projector 1 determines that the detection continues state when all the detection results for each unit time during the period T1 are "a state in which an obstacle is detected" (value=1). The projector 1 judges the detection discontinuation state when the detection result for each unit of time in the period T1 indicates "a state in which no obstacle is detected" (value=1).

Alternatively, as another example of processing, the projector 1 detects that a predetermined number or more of the plurality of detection results for each unit time in the period T1 are in a state in which an obstacle is detected (value=1). In this case, it may be determined that the detection continues.

[Obstacle sensor: Arrangement example 1]
FIG. 10 shows a perspective view of an example of the external configuration of the projector 1 of Embodiment 1, and an example of a specific arrangement of the obstacle sensors 120 in the main body 50 of the projector 1 (arrangement example 1). X, Y, and Z are shown as descriptive directions. The X direction and the Y direction are two orthogonal directions forming a horizontal plane. The Z direction is the vertical direction and corresponds to the height direction of the main body 50 . The direction of projection from the projection lens 3, which is the output portion of the projection optical system 101, onto the screen (display surface 200) is roughly the Y direction, which is diagonally upward.

The projector 1 in FIG. 10 is for an ultra-short-throw projection type image display device. FIG. 10 is a perspective view mainly of the upper surface F1 of the main body 50 viewed obliquely from above on the side of the display surface 200, which is a screen, and on the side of the front surface F2. The front surface F2 is a vertical surface facing the display surface 200 in the Y direction. In arrangement example 1, an infrared sensor 10 and a far-infrared sensor 20 that constitute an obstacle sensor 120 are arranged in front of the exit surface 3 a of the projection lens 3 .

The body 50 has a generally rectangular parallelepiped shape. In this example, a display 130 is provided in a region near the front surface F2 in a portion of the upper surface F1, and has an LED indicator 130A as a part of the display 130. FIG. A speaker 131 is provided in a part of the upper surface F1, in a region close to the rear surface F3 and the side surface F5.

The upper surface F1 has a concave portion 51 and a convex portion 52 in a partial region closer to the back surface F3, with the horizontal plane as the basis. The back surface F3 is a vertical surface on the far side from the display surface 200 . The recessed portion 51 is a portion that becomes a recess on the lower side with respect to the horizontal plane of the upper surface F1, and has a slope in this example. This slope is a slope that descends toward the projection lens 3 and the convex portion 52 . Further, a part of the slope of the concave portion 51 in front of the projection lens 3 is a concave portion 51b in which the obstacle sensor 120 is arranged. The convex portion 52 is a portion that rises upward adjacent to the concave portion 51 and accommodates a portion of the projection lens 3 .

The projection lens 3, which constitutes the output part of the projection optical system 101, is arranged at the central position in the X direction, part of the convex part 52, in the region of the main body 50 on the side closer to the rear surface F3. The exit surface 3 a , which is a part of the projection lens 3 , is a curved surface and protrudes forward from a portion of the convex portion 52 near the slope of the concave portion 51 .

The projection lens 3 is configured using a lens made of glass, a lens made of plastic, or the like. For example, if the lens forming the exit surface 3a is made of a plastic lens, it is likely to be affected by temperature rise. Therefore, it is desirable to detect obstacles by providing the infrared sensor 10 and the far-infrared sensor 20 in the vicinity of the lens forming the emission surface 3a.

In Arrangement Example 1, the infrared sensor 10 and the far-infrared sensor 20 that constitute the obstacle sensor 120 are arranged in the recess 51 b on the front side of the projection lens 3 . As a result, the obstacle sensor 120 does not block the image light from the exit surface 3a. In particular, in arrangement example 1, one infrared sensor 10 and one far infrared sensor 20 are arranged side by side near the center in the X direction.

FIG. 11 shows a configuration diagram of the configuration of the projector 1 in FIG. 10 on the YZ plane viewed from the side of the screen and the side surface F4 of the main body 50. As shown in FIG. Side F4 is a right vertical surface facing display surface 200, which is a screen. As shown, the infrared sensor 10 and the far infrared sensor 20 are arranged near the projection lens 3 and on the image projection direction side. In this example, the lower surface F0 of the main body 50 of the projector 1 is installed on a horizontal installation surface FA such as a table. Since it is an ultra-short projection type, the distance between the front surface F2 of the main body 50 and the display surface 200 is small.

In the example of FIG. 11, the projection optical system 101 is composed of an optical lens 4A, an optical lens 4B, a projection lens 3, and the like. Light from the display element 102 is projected through the optical lens 4A, the optical lens 4B, and the projection lens 3 in this order. FIG. 11 also shows the optical axis L1 of the image light emitted from the projection lens 3 and the ends L2 and L3 of the range, which are obliquely upward as shown.

FIG. 11 shows an example of the detection range of the obstacle sensor 120, that is, the detection range of the infrared sensor 10 and the detection range of the far-infrared sensor 20, as an image of a cone. In Arrangement Example 1, the direction of the detection axis, which is the center axis of the cone of the detection range of each of the infrared sensor 10 and the far-infrared sensor 20, is substantially vertical as indicated by the arrow. “Substantially vertical” refers to the vertical direction when the projector 1 is stationary, and is the vertical Z direction in the example of FIG. 11 . In other words, this detection axis is perpendicular to the installation surface FA of projector 1 . Expressed another way, the detection axis is parallel to the display surface 200 . In the example of FIG. 11, the direction of this detection axis is perpendicular to the plane of the concave portion 51b of the upper surface F1. As a result, the obstacle sensor 120 can suitably detect an obstacle on the front side of the projection lens 3 .

The position of the infrared sensor 10 and the position of the far-infrared sensor 20 are not limited to the example shown in FIG. As a modification, the infrared sensor 10 and the far-infrared sensor 20 may be arranged at positions on the left and right sides of the exit surface 3a in the X direction, for example, at a part of the convex portion 52 in FIG.

As a modification, the detection axes of the infrared sensor 10 and the far-infrared sensor 20 are not limited to the vertical direction, and may be slightly tilted from the vertical direction. The direction of inclination of the detection axis may be the direction of inclination toward the projection lens 3 side, the direction of inclination toward the screen side, or the direction of inclination left or right in the X direction.

As a modification, the infrared sensor 10 and the far-infrared sensor 20 may be arranged on the slope of the recess 51. In that case, the detection axes of the infrared sensor 10 and the far-infrared sensor 20 are substantially perpendicular to the slope. good too.

FIG. 12 shows a schematic configuration of the configuration of the projector 1 in FIGS. 10 and 11 on the rear F3 side, in the direction in which the front of the display surface 200 is viewed from the user's viewpoint. A partial area 201 of the display surface 200, which is a screen, is an area on which an image is projected. 12 and 10, the detailed shape and the like on the rear surface F3 side of FIG. 11 are shown in a simplified manner.

[Obstacle sensor: Arrangement example 2]
FIG. 13 shows an arrangement example 2 of the obstacle sensor 120. As shown in FIG. Arrangement Example 2 differs from Arrangement Example 1 in that the obstacle sensor 120 has a total of four infrared sensors 10 and one far-infrared sensor 20 . In arrangement example 2, the number of infrared sensors 10 is increased as compared with arrangement example 1, and they are also arranged in positions different from arrangement example 1. FIG. In the concave portion 51, one infrared sensor 10 and one far-infrared sensor 20 are arranged at positions near the center in the X direction in front of the exit surface 3a of the projection lens 3, as in Arrangement Example 1. . In addition, two infrared sensors 10 are arranged at different positions on the left and right in the X direction with respect to that position. As a result, detection by the infrared sensor 10 can cover a wider range in the X direction of the front surface of the projection lens 3 .

Furthermore, one infrared sensor 10 is arranged at a position above the exit surface 3 a of the projection lens 3 in the convex portion 52 . As a result, detection by the infrared sensor 10 can cover a wider range in the Z direction of the front surface of the projection lens 3 .

In Arrangement Example 2, one far-infrared sensor 20 is arranged near the central infrared sensor 10 in front of the projection lens 3 as in Arrangement Example 1. Any position may be used, and a plurality of them may be arranged. For example, a total of a plurality of far-infrared sensors 20 may be provided in front of or above the projection lens 3 .

When a plurality of infrared sensors 10 are provided as in Arrangement Example 2, the controller 110 of the projector 1 performs detection and judgment in step S1 as follows. When the detection result of at least one of the plurality of infrared sensors 10 is the above-described "obstacle detected" state (value=1), control unit 110 determines that an obstacle is detected by infrared sensor 10. It is judged to be in a state of In the table of FIG. 7, this case corresponds to the column of the "obstacle detected" state (value=1) among the two columns of the infrared sensor 10. FIG.

Also, when a plurality of far-infrared sensors 20 are provided, the control unit 110 similarly determines that the detection result of at least one of the plurality of far-infrared sensors 20 is in the above-described "obstacle detected" state (value = 1 ), it is determined that the far-infrared sensor 20 has detected an obstacle. In the table of FIG. 7, this case corresponds to the row of the "obstacle detected" state (value=1) among the two rows of the far-infrared sensor 20. FIG.

FIG. 14 is a configuration diagram of the arrangement example 2 of FIG. 13 as viewed from the side face F4. The infrared sensor 10, which is arranged above the projection lens 3, has the direction of the detection axis of the detection range indicated by the cone roughly in the Y direction, which is forward toward the screen. Specifically, the detection axis of the upper infrared sensor 10 is directed obliquely downward from the horizontal as shown. In the ultra-short projection type as in this example, the optical axis L1 of the projected image from the projection lens 3 is oriented obliquely upward. On the other hand, the direction in the Z direction in the direction of the detection axis of the upper infrared sensor 10 is set downward from the horizontal. As a result, the direction of the detection axis of the infrared sensor 10 does not intersect with the area 201 of the display surface 200, and detection is less likely to be affected by images projected onto the screen. Therefore, with this configuration, it is possible to avoid erroneous detection by the infrared sensor 10 based on the projected image on the screen. The direction of the detection axis of the upper infrared sensor 10 is not limited to this, and may be substantially horizontal, in other words, substantially perpendicular to the vertical plane of the convex portion 52 .

FIG. 15 is a schematic configuration diagram in the direction in which the screen is viewed, corresponding to the arrangement example 2 of FIGS. 13 and 14. In FIG. As shown, an obstacle sensor 120 including multiple infrared sensors 10 in the X direction forms a wide detection range.

[Influence of exhaust]
FIG. 16 shows, as a comparative example, an explanatory diagram of the predetermined exhaust direction of the projector 1x and its influence. In particular, FIG. 16 shows a case where, as the exhaust direction, the exhaust from the cooling unit 115 of the projector is exhaust in the Y direction from the front surface F2 toward the screen side. A projector generally includes an air cooling system to cool a light source, a power supply circuit, optical components, and the like, and has a configuration in which air is exhausted to dissipate heat. The projector 1 of the first embodiment and the projector 1x of the comparative example also include the cooling unit 115 described above, and the cooling unit 115 includes an exhaust fan or the like for air cooling.

Here, in the case of the projector 1x of the comparative example, which is the ultra-short projection type and the ultra-short focus type, as shown in FIG. Due to the influence of 202 and the like, it is possible that exhaust air from the front surface F2 hits the wall 202, changes direction, and passes above the top surface F1 of the projector 1x. Assume that in the projector 1x of the comparative example, an obstacle sensor 120x including a far-infrared sensor is arranged on the upper surface F1, as in the arrangement example 1. FIG. 16, in the comparative example, the exhaust passes in front of the cone in the detection range of the obstacle sensor 120x, in this example, above. If the exhaust air of the projector 1x is hot, such a situation may cause the obstacle sensor 120x to make false detections, in other words, reduce its accuracy.

Therefore, FIG. 17 is an explanatory diagram of a more preferable exhaust direction as a preferable configuration example considering the influence of the exhaust in the projector 1 according to the first embodiment. This exhaust includes, for example, exhaust after cooling the light source 105 by the cooling unit 115, exhaust after cooling various circuits such as a power supply circuit, exhaust after cooling the display element 102, and after cooling optical components. exhaust, and/or the like. In FIG. 17, the obstacle sensor 120 is simply shown as one sensor, particularly the far infrared sensor 20 . In FIG. 17, illustration of exhaust ports on each surface of the main body 50 is omitted. When implementing the exhaust function by the cooling unit 115, an exhaust port may be appropriately provided.

First, each exhaust direction will be described with reference to FIG. In FIG. 17, exhaust directions d1, d2, d3, d4, and d5 are shown as exhaust direction candidates from each surface and position of the main body 50 . The exhaust direction d1 is exhaust upward in the Z direction from the upper surface F1 of the main body 50 on which the obstacle sensor 120 is installed. The exhaust direction d2 is exhaust from the front surface F2, which is the side surface of the main body 50 facing the screen, toward the screen in the Y direction. The exhaust direction d3 is exhaust to the side opposite to the exhaust direction d2, and is exhaust from the rear surface F3 of the main body 50 opposite to the front surface F2 toward the rear in the Y direction toward the side opposite to the screen. The exhaust direction d4 is one-way exhaust from the right side surface F4 of the main body 50 to the right side of the screen in the X direction. The exhaust direction d5 is exhaust in the direction opposite to the exhaust direction d4, and is one-way exhaust from the left side surface F5 of the main body 50 toward the left side of the screen in the X direction. Of the four side surfaces in the Z direction of the main body 50, the front surface F2 and the rear surface F3 are front and rear side surfaces in the Y direction, and the side surfaces F4 and F5 are left and right side surfaces in the X direction.

As shown in FIG. 16, when the air is exhausted toward the screen side as in the exhaust direction d2, there is a possibility that the far-infrared sensor 20 may cause erroneous detection due to the influence of the high-temperature exhaust. Therefore, it is desirable to employ an exhaust direction other than the exhaust direction d2. Further, even when the air is exhausted from the upper surface F1 on which the obstacle sensor 120 is installed, as in the exhaust direction d1, the exhaust direction is close to the detection range of the far-infrared sensor 20, so the far-infrared sensor 20 May cause false positives. Therefore, it is desirable to employ an exhaust direction other than the exhaust direction d1.

Therefore, it is preferable that the projector 1 of the arrangement example 1 in which the far-infrared sensor 20 is provided on the upper surface F1 employ an exhaust direction other than the exhaust direction d2 and the exhaust direction d1. Specifically, the projector 1 of the first embodiment adopts any one of the exhaust direction d3, the exhaust direction d4, and the exhaust direction d5, or a combination thereof, regarding the mounting of the exhaust direction by the cooling unit 115. FIG. The hottest possible exhaust air from a projector is after the light source has been cooled. Therefore, it is particularly desirable to adopt the above-described exhaust direction for the exhaust direction after cooling the light source 105 .

[Message display]
Next, a configuration example of a message display, which is one of specific examples of the above-described warning processing (FIG. 8), will be described. FIG. 18 shows an example of message display (referred to as display example 1) in the projector 1 of the first embodiment. FIG. 18 shows a schematic diagram of a front view of an area 201 on which an image is projected on a display surface 200, which is a screen, from the projection lens 3. As shown in FIG. In the example of FIG. 18 , a plurality of infrared sensors 10 and one far-infrared ray sensor 20 are provided as obstacle sensors 120 like arrangement example 2 . In FIG. 18, the front portion of the projection lens 3 is shown as an obstacle sensor 120a and an infrared sensor 10a, and the portion above the projection lens 3 is shown as an obstacle sensor 120b and an infrared sensor 10b.

Assume that the projector 1 detects the obstacle OB1 based on the detection results of these sensors, for example, by the method described above. In this example, there is an obstacle OB1 on the front right side of the projection lens 3 position. In this case, as an example of warning processing, the projector 1 displays a message such as "Please remove the obstacle near the projection lens" in the projected image area 201 as shown in FIG. display a message 180 prompting Message 180 is a static message image. In the example of FIG. 18, the message 180 is displayed in one central location (area AR2b) of the area 201. FIG. The display position of this message 180 may basically be any position in the area 201 of the projected image.

However, as in arrangement example 2, when a plurality of infrared sensors 10 are arranged as obstacle sensors 120 on the left and right sides in the X direction facing the screen, the obstacle OB1 reaches the center of the area 201. Moreover, the probability of being detected by either the left or right infrared sensor 10 is high. For example, the obstruction OB1 on the right side blocks the image light, which may make it difficult for the user to see the projection image in the area AR3 on the right side of the area 201 .

Therefore, when the message 180 is displayed in one place in the area 201, it is better to display the message 180 in the central position as shown in the drawing than in the edge of the area 201. This is more preferable because it is less likely to be detected and more likely to be easily visible to the user.

FIG. 19 similarly shows display example 2 of the message display. In the display example 2, for example, when the obstacle OB2 is detected, the projector 1 simultaneously displays the message 180 such as "Please remove the obstacle near the projection lens" in the area 201 of the projected image. . In the example of FIG. 19, the area 201 roughly has 3×3=9 areas, and the same message 180 is displayed in each area. In the X direction, there are three areas AR1, AR2 and AR3 corresponding to the three infrared sensors 10. FIG. The example of FIG. 19 shows the case where there is an obstacle OB2 in front of the projection lens 3 over the center and right sides. Due to the obstruction OB2 blocking the image light, it becomes difficult to see the projected image in the central area AR2 and the right area AR3 of the area 201 .

In the example of FIG. 19, the message 180 is also displayed in the light shielded portion (areas AR2 and AR3) blocked by the obstacle OB2. is blocked by the image, so it is not actually reflected. However, the image on the display element 102 is configured to display a plurality of messages 180 as shown in FIG. With this configuration, even if a portion of the image for warning processing is blocked by the obstacle OB2, the possibility that the user can visually recognize the message 180 only in the unblocked portion is increased, which is preferable.

In the example of FIG. 19 , infrared sensors 10 are arranged as obstacle sensors 120 at three locations on the front side of the projection lens 3 and one location on the upper side of the projection lens 3 . When the message 180 is simultaneously displayed in a plurality of locations in the area 201 of the projected image as in the example of FIG. 19, even if the center of the area 201 (for example, the area AR2b) is shaded, the user may be able to visually recognize the message 180. increase. Therefore, even in the case of a simple configuration in which one infrared sensor 10 and one far infrared sensor 20 are arranged only at one central location on the front side of the projection lens 3 as in Arrangement Example 1, there is a possibility that the user can visually recognize them. High message display can be realized.

FIG. 20 shows display example 3 of the message display. In display example 3, the projector 1 displays a message 180 such as "Please remove any obstacles near the projection lens" so as to move within the area 201 of the projected image. This message 180 is a moving message video. In the example of FIG. 20, the message 180 moves zigzag as indicated by the arrow from the upper left corner of the area 201, in other words, along a trajectory like raster scanning. When the movement of message 180 reaches the lower right corner of area 201, it returns to the initial upper left corner and the zigzag movement is repeated in the same way.

With this configuration, even if part of the image light is blocked by the obstacle OB1, there is a time period during which the message 180 is displayed in the unblocked portion, increasing the possibility that the user can visually recognize the message 180. Therefore, it is preferable. In addition, since the message 180 moves, there is also an advantage that the user's attention to the message 180 can be improved compared to when the message 180 is stationary.

FIG. 21 shows display example 4 of the message display. In Display Example 4, the projector 1 has a configuration in which the infrared sensors 10 in the obstacle sensor 120 are arranged at a plurality of locations as in Arrangement Example 2, and detects an obstacle OB1, for example. Then, the projector 1 estimates a portion of the projection image blocked by the obstacle OB1, and displays the message 180 in the region 201 excluding the estimated shaded portion. For example, the detection result of the infrared sensor 10 on the right side in front of the projection lens 3 is "obstacle detected", and the detection result of the other infrared sensor 10 is "no obstacle detected". Suppose there is In that case, the projector 1 comprehensively determines that the obstacle OB1 has been detected. At the same time, the projector 1 estimates that the position of the obstacle OB1 is within the area connecting the projection lens 3 and the area AR3. It is estimated that there is a high possibility that light is blocked. Therefore, the projector 1 moves and displays the message 180 in the range of the areas AR1 and AR2 of the area 201 excluding the area AR3, for example, similarly to the display example 3. FIG. With this configuration, even if a portion of the projected image is blocked by the obstacle OB1, the message 180 is displayed in the unblocked portion, which increases the possibility that the user can visually recognize the message 180, which is preferable.

When displaying the message 180 within the areas AR1 and AR2, which are non-light-shielding areas, other methods may be applied instead of the moving method. Following Display Example 1, the message 180 may be statically displayed at one location within the estimated non-shading region, or following Display Example 2, the message 180 may be displayed at a plurality of locations within the estimated non-shading region. may be displayed at the same time. Also, the message 180 may be enlarged and displayed in the entirety of the estimated non-light-shielding area. In these cases, control is simpler and configuration is easier.

Further, in FIGS. 6 and 8, when the message display in the first response process (step S2) and the message display in the second response process (step S4) are performed, The same display example may be used, or different display examples may be used in combination. Specific examples of using a combination of different display examples for the message display in the first response process and the message display in the second response process are as follows. For example, Display Example 1 may be applied to the first response process, and Display Example 2 may be applied to the second response process. Since the second response process is the state immediately before the light source 105 is turned off, the number of messages 180 displayed in the area 201 is increased compared to the number of messages displayed in the first response process. As a result, it is possible to more strongly prompt the user to take action against the obstacle in the second handling process, which is more preferable. Further, for example, display example 1 or display example 2 may be applied in the first correspondence process, and display example 3 or display example 4 may be applied in the second correspondence process. Since the second response process is a state immediately before the light source 105 is turned off, a message display with a higher degree of attention that moves the display position is used instead of the message display with a fixed position in the first response process. As a result, the user can be strongly urged to take action against the obstacle, which is more preferable.

In the above description, a message, in other words, a character image, is used as an example of a display object in the warning process of the response process. A mark indicating the prompting, or an animation or video for explaining the fact may be used. Of course, the above display may be accompanied by the output of a specific sound.

[Obstacle detection mode]
The projector 1 of Embodiment 1 has an obstacle detection function capable of detecting an obstacle using the obstacle sensor 120 described above. This projector 1 has a mode in which this obstacle detection function is enabled and a mode in which it is disabled, and these modes can be set and switched. In basic settings, this obstacle detection function is always in a valid mode, but it is also possible to set it to an invalid mode by user setting.

[Effects, etc.]
As described above, according to the projector 1 of Embodiment 1, obstacles in the vicinity of the output section can be more preferably detected and the problem can be dealt with, thereby improving usability of the apparatus for the user. According to Embodiment 1, an obstacle can be detected with higher accuracy, and the user can be appropriately urged to take action by the handling process according to the detection, thereby preventing or solving problems such as temperature rise.

The output portion of the projection optical system 101 is the portion from which the image light is output from the main body 50 to the outside, and in the first embodiment, it is the output surface 3a of the projection lens 3 as shown in FIG. Not limited to this, in other embodiments, the output portion of the projection optical system 101 may be a mirror, a mirror cover glass, or the like. Although the projector 1 of Embodiment 1 is of the ultra-short projection type, the obstacle detection method according to the present invention can be similarly applied to projectors of other types as well.

Although the present invention has been specifically described above based on the embodiments, the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the scope of the invention. The invention is not limited to the number, shape, size, or other configuration of the elements described above. The present invention can be configured such that other components are added to the components described above, and some components are deleted.

DESCRIPTION OF SYMBOLS 1... Projector 3... Projection lens 3a... Output surface 10... Infrared sensor 20... Far-infrared sensor 50... Main body 51... Concave part 51b... Concave part 52... Convex part 120... Obstacle sensor F1... Upper surface, F2... Front surface, F3... Rear surface, F4... Side surface, F5... Side surface, 130... Indicator, 130A... LED indicator, 131... Speaker.

Claims (16)

a light source;
a display element that transmits or reflects light from the light source;
a projection optical system that projects light from the display element onto a display surface to display an image;
an obstacle sensor that detects an obstacle in the vicinity of the exit portion of the projection optical system;
a control unit that controls display of the video;
with
the obstacle sensor includes an infrared sensor and a far infrared sensor,
The control unit makes a detection judgment of the obstacle based on the detection result of the infrared sensor and the detection result of the far infrared sensor.
Projection type image display device. In the projection type image display device of claim 1,
At least one of the detection result of the infrared sensor and the detection result of the far-infrared sensor is a detection result indicating that the obstacle has been detected. If it is determined that the obstacle has been detected comprehensively,
Projection type image display device. In the projection type image display device of claim 1,
The infrared sensor is an active sensor having an infrared light emitting portion and an infrared light receiving portion,
The far-infrared sensor is a passive sensor having an infrared light receiving portion that receives infrared light in a far-infrared region that is a longer wavelength region than the infrared light receiving portion of the infrared sensor corresponds to.
Projection type image display device. The projection type image display device according to claim 1,
The control unit
When it is determined that the obstacle is detected as a result of the detection determination,
As control of the first obstacle handling process according to the result of the detection judgment,
control to reduce the brightness of the light source;
control to display a message on the image projected from the projection optical system;
Control for outputting a warning sound from a speaker included in the projection video display device;
Control for notifying an error by a display device included in the projection type image display device; and
Control for notifying an error from the projection display device to a remote controller or a wireless terminal;
Control at least one of
Projection type image display device. The projection type image display device according to claim 1,
The control unit
After determining that the obstacle has been detected as a result of the detection determination, performing a first continuation determination for determining whether the state in which the obstacle has been detected continues,
performing a first obstacle handling process according to the result of the first continuation determination;
After determining that the state in which the obstacle has been detected continues as a result of the first continuation determination, a second continuation determination is made to determine whether or not the state in which the obstacle has been detected continues. ,
performing a second obstacle handling process according to the result of the second continuation determination;
Projection type image display device. In the projection type image display device according to claim 5,
The first continuation determination is for determining whether or not the state in which the obstacle is detected as a result of the detection determination has continued in a first period,
The second continuation determination is for determining whether or not the state in which the obstacle is detected as a result of the detection determination has continued in a second period,
the length of the first period is greater than or equal to the length of the second period;
Projection type image display device. In the projection type image display device according to claim 6,
The control unit
When the first continuation determination is made, if the temperature detected by the far-infrared sensor exceeds the first threshold within the first period, the obstacle is detected without waiting for the first period to elapse. judging that the state is continuing, moving to the first obstacle handling process,
At the time of the second continuation determination, if the temperature detected by the far-infrared sensor among the obstacle sensors exceeds a second threshold larger than the first threshold during the second period, Determining that the state in which the obstacle has been detected continues without waiting for the passage of time, and moving to the second obstacle handling process;
Projection type image display device. In the projection type image display device according to claim 5,
The control unit controls the second obstacle handling process according to the result of the second continuation determination,
control for switching an image projected from the projection optical system to a black screen display image;
control to display a message on the image projected from the projection optical system;
Control for outputting a warning sound from a speaker included in the projection video display device;
Control for notifying an error by a display device included in the projection type image display device; and
Control for notifying an error from the projection display device to a remote controller or a wireless terminal;
Control at least one of
Projection type image display device. The projection type image display device according to claim 1,
an output unit of the projection optical system is arranged on an upper surface of the projection type image display device,
The obstacle sensor includes at least one or more infrared sensors and one or more far-infrared sensors arranged near the emitting portion on the upper surface,
Projection type image display device. In the projection type image display device according to claim 9,
the direction of the central axis of the detection range of at least one infrared sensor is perpendicular to the installation surface of the projection display device;
The direction of the central axis of the detection range of at least one far-infrared sensor is perpendicular to the installation surface of the projection-type image display device,
Projection type image display device. In the projection type image display device according to claim 9,
The infrared sensor includes at least two infrared sensors arranged at different positions on the upper surface in the left and right directions toward the display surface with respect to the position of the emitting part,
Projection type image display device. In the projection type image display device according to claim 9,
The infrared sensor includes an infrared sensor arranged above the output unit,
The direction of the central axis of the detection range of the infrared sensor arranged on the upper side is the direction toward the display surface and the horizontal direction or a direction downward from the horizontal,
Projection type image display device. In the projection type image display device according to claim 9,
A cooling unit for cooling a portion including the light source,
The exhaust direction of the exhaust after cooling the light source by the cooling unit is
A direction from the rear surface of the projection display device, which is the opposite side of the display surface, toward the opposite side of the display surface, or
A direction from either one of the left and right directions toward the display surface to one of the left and right directions toward the display surface,
Projection type image display device. The projection type image display device according to claim 1,
The control unit performs control to display a message or a mark relating to handling of the obstacle on the image projected from the projection optical system based on the result of the obstacle detection determination,
The message or the mark is displayed stationary at a predetermined position in the area of the projected image on the display surface, or simultaneously displayed as multiple messages or multiple marks at multiple positions within the area. , or displayed while moving through multiple positions within said area,
Projection type image display device. The projection type image display device according to claim 1,
The obstacle sensor has a plurality of infrared sensors arranged at a plurality of positions as the infrared sensor,
The control unit estimates an area blocked by the obstacle in the area of the projected image on the display surface based on the plurality of detection results of the plurality of infrared sensors, and based on the detection determination result of the obstacle. controls to display a message or mark related to handling the obstacle on the image projected from the projection optical system;
The message or the mark is displayed in an area of the projected image other than the blocked area, according to the result of the estimation.
Projection type image display device. A method for detecting an obstacle in a projection-type image display device, comprising:
The projection type image display device comprises:
a light source;
a display element that transmits or reflects light from the light source;
a projection optical system that projects light from the display element onto a display surface to display an image;
an obstacle sensor that detects an obstacle in the vicinity of the exit portion of the projection optical system;
a control unit that controls display of the video;
with
the obstacle sensor includes an infrared sensor and a far infrared sensor,
The control unit, based on the detection result of the infrared sensor and the detection result of the far infrared sensor, making a detection judgment of the obstacle,
Obstacle detection method.

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