JP2000019636A - Projection type display device and method for controlling projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display device which is capable of detecting objects, such as persons, over a wide range of a projection region and allows the fail-proof regulation of projected images, such as zooming and focusing, at the time of setting the screen of the projection type display device. SOLUTION: The projection type display device 1 has an object detecting means 50 which is disposed to face a projection screen 100 and a projected image control means which controls the projected image on the projection surface 100 according to the output of this object detecting means 50. The object detecting means 50 has an ultrasonic sensor 53 constituted to include a signal transmitting element 51 and a signal receiving element 52. Since the object detecting means 50 has this ultrasonic sensor 53, the setting of the ultrasonic signal from the signal transmitting element 51 over a wide range according to the projection region A is made possible and the detection of the objects over a wide range with the one sensor is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source lamp, an optical system for optically processing a light beam emitted from the light source lamp to form an optical image in accordance with image information, and a method for applying the optical image to a projection surface. The present invention relates to a projection display device including a projection lens for enlarging and projecting, and a method of controlling the projection display device.

[0002]

2. Description of the Related Art Conventionally, a light source lamp, an optical system for optically processing a light beam emitted from the light source lamp to form an optical image according to image information, and a projection for enlarging and projecting the optical image on a projection surface A projection display device having a lens is used. According to such a projection display device, a display screen of a computer or the like can be displayed on a large screen on the projection surface, and a multi-presentation for a large number of people can be performed. In the projection display device described above, since the image is enlarged and projected on the projection surface, it is preferable to increase the light amount of the light source lamp in order to display a clear image.
However, in a projection display device that emits such a strong light beam, looking into the projection lens while a projected image is being displayed may damage the eyes due to the strong light beam.

For this reason, an object detecting means is provided on the side surface of the outer case facing the projection surface, and when the object detecting means detects that an object has entered the area of the projected image, the projected image control means causes the object to be projected on the projection surface. (Japanese Utility Model Application Laid-Open No. 3-94888) has been proposed.

[0004]

However, the conventional projection display device provided with such an object detection sensor and projection image control means has the following problems.

The above-described object detection means is a highly linear sensor that transmits a signal linearly along a boundary of a projection area of a projection image and receives a reflection signal when the signal hits an object. . Therefore, when a person enters the projection area, the person can be detected at the boundary and the projected image can be blocked, but if the person remains inside the projection area, the person can be detected by the object detection means. However, there is a problem that the projected image is restored.

In addition, since the above-described object detection means is configured to start detection upon activation of the projection display device, a screen can be installed in accordance with a projection area of a projection image, zooming of a projection lens, If an attempt is made to adjust the focus or the like, there is a problem that the projection image is blocked by the object detection means and the projection image control means, and such adjustment work cannot be performed substantially.

An object of the present invention is to provide a light source lamp, an optical system that optically processes a light beam emitted from the light source lamp to form an optical image according to image information, and enlarges the optical image on a projection surface. In a projection display device provided with a projection lens for projection, an object such as a person can be detected over a wide range of a projection area, and when setting a screen of the projection display device,
An object of the present invention is to provide a projection display device that can surely adjust a projection image such as zoom and focus. Another object of the present invention is to provide a control method of a projection display device that can surely adjust a projection image such as zoom and focus when setting a screen of the projection display device.

[0008]

According to the present invention, there is provided a projection display apparatus comprising: a light source lamp; an optical system for optically processing a light beam emitted from the light source lamp to form an optical image in accordance with image information; And a projection lens provided with a projection lens for enlarging and projecting the optical image on a projection surface, wherein the object detection means is provided opposite to the projection surface, and the projection is performed according to an output of the object detection means. And a projection image control unit for controlling a projection image displayed on the surface, wherein the object detection unit includes an ultrasonic sensor having a transmission element and a reception element.

Here, the projection image control means is a concept including all means for controlling the projection image on the projection surface when the object detection means detects that an object has entered the projection area of the projection image. is there. For example, as the projection image control means, one that shuts off the power of the light source lamp, one that blocks the light path inside the projection display device, one that reduces the brightness of the light source lamp, and one that turns the projection image on the projection surface black One that switches to an image may be considered.

The ultrasonic sensor is a sensor having a transmitting element and a receiving element, wherein the receiving element detects a reflected wave when an ultrasonic signal transmitted from the transmitting element hits an object. . Specifically, the transmitting element and the receiving element have the same configuration. These elements include a bimorph vibrator in which piezoelectric ceramics and a metal plate are bonded together, and a funnel provided at the center of the bimorph vibrator. And a resonator having the shape of a circle. When a voltage is applied to the piezoelectric ceramics, mechanical vibrations corresponding to the voltage and the frequency are generated, so that ultrasonic waves can be emitted into the air through the resonator. On the other hand, when the piezoelectric ceramics vibrate, electric charges are generated, so that the ultrasonic waves detected via the resonator can be converted into electric signals.

According to the present invention, since the object detecting means includes the ultrasonic sensor, the ultrasonic signal output from the transmitting element can be set in a wide range according to the projection area. A single sensor can detect an object over a wide range. Further, as described above, since the transmitting element and the receiving element have the same structure and a simple configuration,
A circuit for processing a signal can be simplified, and the device does not become complicated.

In the above, a continuous signal level detection system which may employ any one of a continuous signal level detection system, a pulse reflection time detection system, and a Doppler effect detection system as the above-mentioned ultrasonic sensor is described. In this method, a signal is continuously output from a transmitting element, the signal is continuously received by a receiving element, and a change in the signal level of the signal is detected. In such a sensor of the continuous signal level detection method, since the signal is continuously output from the transmitting element, the object can be always detected while the projected image is displayed.

The pulse reflection time detection method is a method in which a pulse signal is output from a transmitting element at a predetermined time interval, the pulse signal is received by a reception signal, and a time difference between transmission and reception is detected. With such a pulse reflection time detection type sensor, since the object is detected based on the transmission / reception time difference, a change in the transmission / reception time difference due to the intrusion of the object is immediately detected, and the object can be detected with high accuracy. it can.

In the case where a pulse reflection time detection type sensor is employed, the transmission interval of the pulse signal output from the transmitting element is determined according to the retina damage threshold of the eye due to the thermal action of the light beam emitted from the projection lens. Is preferably set. Specifically, the transmission interval of the above-mentioned pulse signal is set as follows.

[0015] In general, it is known that the retina damage threshold of an eye due to the thermal effect of a light beam is 292 J / cm ² .

On the other hand, in a projection display device employing a 120 W light source lamp, assuming that about 30% of the light source lamp 120 W is emitted as light energy, the light energy output from the light source lamp is 36 W.

Assuming that the light beam emitted from the light source lamp is emitted from the projection lens with an efficiency of 1 / 7.2 through the optical system and the projection lens, the light energy of the light beam emitted from the projection lens is 5W (36 / 7.2
W).

Further, the irradiation area on the front lens of the projection lens is considered to be substantially equal to the area of the 1.3 ″ light valve constituting the modulation system, and is 5.23 cm ² .

[0019] Therefore, the light amount on the projection lens of the outgoing light beam becomes ^{5W / 5.23cm 2 = 0.96W / cm} 2.

Therefore, when the emitted light beam is directly viewed on the front lens of the projection lens, the time T 0 at which the retina is damaged is calculated as T 0 = 292 / 0.96 / 100 = 3.06 in consideration of these values and the safety factor 100. (Sec), which indicates that retinal damage may occur in 3 seconds of direct viewing. That is, if the transmission interval of the pulse signal is set within 3 seconds, the projection image control means can be operated within 3 seconds, so that the possibility of retinal damage even when looking into the projection lens is greatly reduced. can do.
Note that the time required to reach the retinal damage threshold varies depending on the output of the light source lamp, the efficiency of the optical system and the projection lens, the distance between the eye and the projection lens when looking into the projector, and so on. What is necessary is just to set suitably according to the specification of an apparatus based on the above-mentioned procedure.

The Doppler effect detection method is a method in which a signal continuously output from a transmitting element is received by a receiving element and a change in the frequency of the signal is detected. Then, the reflected wave of the ultrasonic wave is modulated by the Doppler effect. According to such a sensor using the Doppler effect detection method, as in the case of the above-described continuous signal level detection method, a signal is continuously output from the transmitting element, so that while the projected image is displayed, the signal is always output. The object can be set in a detectable state.

In the case where the projection display device has an outer case for housing the light source lamp and the optical system, the above-described transmitting element is provided so as to be retracted from the front surface of the outer case facing the projection surface. Is preferred. In particular,
It is conceivable that the transmitting element is provided so as to be immersed from the front of the outer case.

That is, the above-described ultrasonic sensor has a lower limit of the distance at which an object can be detected. Usually, the lower limit of the distance at which an object can be detected is 6 cm to 20 cm. Therefore, when such an ultrasonic sensor is employed in a projection display device, if the transmitting element is provided so as to recede from the front surface of the outer case by about 6 cm to 20 cm, the entire range from the front surface of the outer case to the projection surface is provided. Can be detected by an ultrasonic sensor. Further, as described above, the transmitting element is 6 cm to 20 c
Since the lens is set back m, even if there is an eye on the front ball of the projection lens, it can be detected by the ultrasonic sensor, and the safety can be further improved.

Further, it is preferable that the above-mentioned projection type display device is provided with a detection start determining means for determining the detection start of the object detecting means. Here, as the detection start determination means, after the projection type display device is started, a timer type determination means for controlling the detection by the object detection means for a predetermined time, and an image adjustment portion such as zoom and focus of the projection type display device are touched. In this state, it is considered that the adjustment-part interlocking type discriminating means for controlling the detection by the object detecting means and the switch-type discriminating means provided with a switch capable of setting whether or not the object detecting means is detected in the projection display device. Can be

That is, since the above-mentioned detection start determining means is provided in the projection type display device, when the screen of the projection type display device is set, the projection image is not interrupted by the object detection means and the projection image control means. In addition, it is possible to adjust the setting of the screen, the zoom and the focus of the projection lens, and the like.

Further, the projection type display device according to the present invention comprises:
A projection display including a light source lamp, an optical system that optically processes a light beam emitted from the light source lamp to form an optical image according to image information, and a projection lens that enlarges and projects the optical image on a projection surface An apparatus, comprising: an object detection unit provided at a position facing the projection surface; and a projection image control unit configured to control a projection image displayed on the projection surface in accordance with an output of the object detection unit. The object detecting means includes a pyroelectric infrared sensor for detecting a human body temperature.

Here, the pyroelectric infrared sensor is a sensor which detects infrared rays emitted from an object and converts them into an electric signal. More specifically, the pyroelectric infrared sensor includes a pyroelectric ceramic that converts infrared light into an electric signal, an optical filter that blocks unnecessary infrared light, a Fresnel lens that defines a detection range of the pyroelectric ceramic, and a pyroelectric ceramic. And a signal processing circuit for amplifying and converting an electric signal output from the electric ceramics.

According to the present invention, since the object detecting means includes the above-described pyroelectric infrared sensor, it is possible to detect a person who has entered the projection area based on the human body temperature. . On the other hand, when the object that has entered the projection area is an object other than a person, the pyroelectric infrared sensor does not detect the intrusion of the object, so that the projection image control means can be operated only in the minimum necessary case. Become. In addition, since it has a Fresnel lens that defines the detection range such as the viewing angle of the pyroelectric infrared sensor, it is possible to set the detection range of the pyroelectric infrared sensor simply by changing the curvature of the Fresnel lens. This is suitable as an object detection unit of a projection display device in which the projection area varies.

Further, a projection display apparatus according to the present invention includes a light source lamp, an optical system for optically processing a light beam emitted from the light source lamp to form an optical image according to image information,
And a projection lens provided with a projection lens for enlarging and projecting the optical image on a projection surface, wherein the object detection means is provided opposite to the projection surface, and the projection is performed according to an output of the object detection means. Projection image control means for controlling a projection image displayed on a surface, wherein the object detection means includes a light emitting unit and a light receiving unit, and the light receiving unit detects the reflection of a signal output from the light emitting unit. A plurality of sensors are arranged, and the optical sensor is arranged to detect an object at least near an outer peripheral edge of a projection area of the projection image and inside the projection area of the projection image. And

Here, the optical sensor includes not only visible light such as laser from the light emitting portion, but also one that emits radio waves, infrared rays, ultraviolet rays, and the like. In short, the light emitting portion outputs a signal with high straightness, It refers to a sensor configured to detect a reflected wave when this signal hits an object by a light receiving unit.

According to the present invention, an object in the vicinity of the outer peripheral edge of the projection area of the projection image and the inside of the projection area of the projection image can be detected by the plurality of optical sensors constituting the object detection means. Therefore, even if a person enters the projection area and the person remains inside the projection area, an object inside the projection area can always be detected, and the projected image is restored and a light beam strong to a person in the projection area. Is not irradiated. Also,
Since the optical sensor outputs a signal with high straightness from the light emitting unit, even if the distance between the projection display device and the projection surface is large,
It is possible to reliably detect an intruding object between them.

In the above, it is preferable that the plurality of optical sensors described above are arranged in a fan shape in accordance with the spread of the luminous flux of the projected image.

Here, to arrange in a fan shape means that the optical sensors are arranged along the spread of the luminous flux of the projected image. For example, a plurality of sensors are arranged in a fan shape above or below the projection lens. When arranging, an optical sensor that detects an object near the outer periphery of the projection area of the projection image is arranged beside the projection lens, and an optical sensor that detects an object inside the area of the projection image is arranged below the projection lens. And so on.

That is, since the plurality of optical sensors are arranged in a fan shape, objects in the projection area can be detected at a fine pitch in accordance with the spread of the luminous flux of the projected image, and the object detection can be performed with higher accuracy. Becomes possible.

According to a control method of a projection display apparatus according to the present invention, which achieves the above object, a light source lamp and a light beam emitted from the light source lamp are optically processed to form an optical image in accordance with image information. An optical system for performing projection and a projection lens for enlarging and projecting the optical image on a projection surface, comprising: an object detection step of detecting that an object has entered a projection area of the projection surface. A projection image control step of controlling a projection image displayed on the projection surface when an object is detected by the object detection step; and a screen setting state of the projection display apparatus, wherein the object detection step and / or Alternatively, there is provided a determining step of not executing the projection image control step.

According to the present invention, since the determination step is provided, when setting the screen of the projection display device,
The projection image such as zooming and focusing can be surely adjusted without executing the object detection step and / or the projection image control step.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

(1) Overall Configuration of the Apparatus FIG. 1 is a block diagram showing the structure of the projection display apparatus according to the first embodiment of the present invention.

The projection display device 1 includes a light source lamp 81
The light flux emitted from the light source is separated into three primary colors of red (R), green (G), and blue (B), and the light flux of each of these colors is modulated according to image information through a modulation element such as a light valve. It is of a type that is enlarged and displayed on the projection plane 100 through the display. The projection display device 1 electrically connects the light source lamp 81 and the optical unit 10 housed inside the outer case 2, the projection lens 6 provided to protrude forward of the outer case 2, and the light source lamp 81 and the optical unit 10. It is configured to include a circuit board to be controlled, a light source lamp 81, an optical unit 10, and a power supply unit (not shown) for supplying power to the circuit board. The projection display device 1 includes:
An object detecting means 50 for detecting an object P in the projection area A of the projection surface 100 and a detection start determining means 60 for determining the start of detection of the object detecting means 50 are provided.

The light source lamp 81 constitutes a light source part of the projection display device 1 and is integrated with a reflector described later by a lamp housing to constitute a light source lamp unit 8 (described later). Although not shown in FIG. 1, the light source lamp unit 8 is configured to be detachable from a lamp replacement lid provided on the bottom surface of the outer case 2.
Everything can be replaced.

The optical unit 10 is a unit for optically processing a light beam emitted from the light source lamp 81 to form an optical image corresponding to image information.
Color separation optical system 924, light modulation system 925, color synthesis optical system 9
10. The illumination optical system 923 and the color separation optical system 924 are housed inside upper and lower light guides where a predetermined optical path is secured. It is sandwiched and held by the light guide. On the other hand, the light modulation system 925 and the color combining optical system 910 are arranged behind the optical path of the color separation optical system 924, and are mounted and fixed on a head body (not shown) to which the projection lens 6 is fixed.

(2) Structure of Optical System Next, the structure of the optical system of the projection display device 1 will be described with reference to the schematic diagram shown in FIG.

The illumination optical system 923 includes a reflection mirror 931 that bends the optical axis 1a of the light beam W emitted from the light source lamp unit 8 toward the front of the device, and a first lens plate 921 that is disposed with the reflection mirror 931 interposed therebetween. And a second lens plate 922. The first lens plate 921 has a plurality of rectangular lenses arranged in a matrix, and divides a light beam emitted from a light source into a plurality of partial light beams. Then, each partial light beam is collected near the second lens plate 922.

The second lens plate 922 has a plurality of rectangular lenses arranged in a matrix, and converts each partial light beam emitted from the first lens plate 921 into a light modulation system 925.
Of liquid crystal light valves 925R, 925G, 92
5B (described later).

As described above, in the projection type display apparatus 1 of this embodiment, the liquid crystal light valve 925 is
Since the R, 925G, and 925B can be illuminated with light having substantially uniform illuminance, a projection image without illuminance unevenness can be obtained.

The color separation optical system 924 includes a blue-green reflecting dichroic mirror 941 and a green reflecting dichroic mirror 9.
42 and a reflection mirror 943. First, in the blue-green reflecting dichroic mirror 941, the blue light beam B included in the light beam W emitted from the illumination optical system 923 is used.
The green light flux G is reflected at a right angle, and travels toward the green reflection dichroic mirror 942.

The red light beam R passes through the blue-green reflecting dichroic mirror 941, is reflected at a right angle by the rear reflecting mirror 943, and is emitted from the emission unit 944 of the red light beam R to the prism unit 910 side. Next, of the blue and green luminous fluxes B and G reflected by the blue-green reflecting dichroic mirror 941, the green reflecting dichroic mirror 94
In 2, only the green light flux G is reflected at a right angle, and is emitted from the emission part 945 of the green light flux G to the color combining optical system side. The blue light beam B that has passed through the green reflection dichroic mirror 942 is transmitted from the light emitting system 946 of the blue light beam B to the light guide system 9.
The light is emitted to the side 27. In this example, the distances from the light emitting portion of the light beam W of the illumination optical system 923 to the light emitting portions 944, 945, and 946 of the color light beams in the color separation optical system 924 are all set to be equal.

The red and green light beams R of the color separation optical system 924
Condensing lenses 951 and 952 are arranged on the emission sides of the G emission sections 944 and 945, respectively. Therefore,
The red and green luminous fluxes R and G emitted from the respective emission sections are incident on these condenser lenses 951 and 952 and are parallelized.

The red and green luminous fluxes R and G thus collimated pass through the incident side polarizing plates 960R and 960G, enter the liquid crystal light valves 925R and 925G, are modulated, and image information corresponding to each color light is modulated. Will be added. That is, the switching of these liquid crystal light valves is controlled by driving means (not shown) according to the image information, whereby each color light passing therethrough is modulated. As such a driving means, a known means can be used as it is. On the other hand, the blue light flux B is guided to the corresponding liquid crystal light valve 925B via the light guide system 927, where it is similarly modulated according to image information. In addition, as the liquid crystal light valves 925R, 925G, and 925B of this example, for example, those using a polysilicon TFT as a switching element can be adopted.

The light guide system 927 includes a light emitting section 94 for the blue light beam B.
6, a condenser lens 954 disposed on the exit side of the light-receiving element 6, an incident-side reflection mirror 971, an exit-side reflection mirror 972, an intermediate lens 973 disposed between these reflection mirrors, and disposed on the front side of the liquid crystal light valve 925B. Condensing lens 95
The blue light flux B emitted from the condenser lens 953 passes through the incident-side polarizing plate 960B, enters the liquid crystal light valve 925B, and is modulated. The length of the optical path of each color light beam, that is, the distance from the light source lamp 81 to each liquid crystal panel is the longest for the blue light beam B, and therefore, the light amount loss of this light beam is the largest. However, by interposing the light guide system 927, the light amount loss can be suppressed.

Next, each liquid crystal light valve 925R, 92
R, G, and B light beams modulated through 5G and 925B, respectively.
Are incident on the prism unit 910 through the exit-side polarizing plates 961R, 961G, and 961B, and are synthesized there. The color image synthesized by the prism unit 910 is enlarged and projected on the projection surface 100 at a predetermined position via the projection lens 6.

(3) Structure of Circuit Board As shown in FIG. 1, a circuit board for electrically controlling the light source lamp 81 and the optical unit 10 includes a control circuit 31, a lamp drive circuit 32, a video signal processing circuit, and the like. 33,
And a modulation element drive circuit 34.

The control circuit 31 includes a lamp driving circuit 32 and a video signal processing circuit 33 based on signal outputs from the object detection means 50, a power switch (not shown), an image adjustment button, and the like.
To output a control signal to the object detecting means 5
0 is also configured to be able to exchange signals with the sensor drive processing circuit 54. This control circuit 31
Is configured to be able to send a control signal to a lamp driving circuit 32 and a video signal processing circuit 33 in response to a signal from the object detection means 50. The control circuit 31 and the video signal processing circuit 33 Is configured.

The lamp drive circuit 32 is a circuit for turning on / off the light source lamp 81, adjusting the luminance, and the like. The video signal processing circuit 33 is a circuit that outputs a video signal input from an RGB input terminal and a video input terminal (not shown) to the modulation element driving circuit 34 according to a control signal of the control circuit 31. The modulation element driving circuit 34 is a circuit that drives the liquid crystal light valves 925R, 925G, and 925B constituting the light modulation system 925 based on the video signal input from the video signal processing circuit 33. It should be noted that known circuits suitable for controlling the light source lamp 81 and the optical unit 10 are employed as these circuits.

(4) Configuration of Object Detecting Means 50 and Detection Start Determination Means 60 Configuration of Transmitting Element 51 and Receiving Element 52 In FIG. 1, the object detecting means 50 includes a transmitting element 51 and a receiving element 52. And a sensor drive processing circuit 54 for driving the transmitting element 51 and the receiving element 52 of the ultrasonic sensor 53. The transmitting element 51 is an element for transmitting an ultrasonic signal, the receiving element 52 is an element for receiving a reflected wave of the ultrasonic signal transmitted from the transmitting element 51, and these elements 51 and 52 are similar to each other. It has a configuration.

For example, as shown in FIG. 3, the transmitting element 51 includes a bimorph vibrator 513 in which a piezoelectric ceramic 511 and a metal plate 512 are bonded, a resonator 514 provided on the bimorph vibrator 513, and a bimorph vibrator 514. It includes a base 515 that supports the vibrator, a case 516 that covers the bimorph vibrator 513 and the resonator 514, and an input / output terminal 517 for inputting and outputting electric signals to and from the bimorph vibrator 513. When an element having such a structure is used as the transmitting element 51,
By inputting an electric signal from the input / output terminal 517 and vibrating the bimorph vibrator 513, an ultrasonic signal is output via the resonator 514. On the other hand, when the bimorph vibrator 513 is used as the receiving element 52, the ultrasonic wave vibrates the bimorph vibrator 513 via the resonator 514, and an electric signal is generated in the bimorph vibrator 513 based on the vibration. A signal is output.

As shown in FIG. 4, the transmitting element 51 and the receiving element 52 having such a configuration are used for measuring the projection lens 6 of the projection display apparatus 1, that is, the projection plane 100.
Is disposed on the front side surface of the exterior case 2 facing the above.

Here, as shown in FIG. 5, the transmitting element 51 is mounted so as to be immersed from the front side surface of the outer case 2, and the immersion amount D of the immersed portion 51A is equal to the transmitting element 51.
Is set in accordance with the lower limit value of the object detectable distance by. Specifically, in the case of the first embodiment, the transmitting element 51
Has a performance of 400 ± 20 kHz and transmission / reception sensitivity of −74 dB or more, and the lower limit of the detectable distance is 6 cm, so the immersion amount D is set to 6 cm. In the vicinity of the opening of the immersed portion 51A, a conical tapered portion 51B whose diameter decreases toward the back is formed, and the wide angle θ of the tapered portion 51B is the same as the range of the light emitted from the projection lens 6. It is desirable that the distance is set to be larger than or larger than that. For example, as shown in FIG.
The detection range 1 is desirably set so as to cover almost the entire projection area A of the projection image by the projection lens 6 in FIG.

On the other hand, as shown in FIG. 6, the receiving element 52 is mounted on substantially the same surface as the front side surface of the outer case 2, and the reflected wave of the ultrasonic signal output from the transmitting element 51 is used as the receiving element. The reception can be performed within a range of a front viewing angle of 52 ° of 180 °.

Configuration of Sensor Drive Processing Circuit The sensor drive processing circuit 54 is a circuit that controls the output of an ultrasonic signal from the transmitting element 51 and converts an electric signal input from the receiving element 52. The sensor drive processing circuit 54 has a different structure depending on the detection method of the ultrasonic sensor 53, and the object detection means 50 according to the first embodiment
In this case, the ultrasonic sensor 53 employs a pulse reflection time detection method.

In the pulse reflection time detection method, as shown in the graph of FIG. 7, the pulse signal S1 is intermittently output from the transmitting element 51 at a predetermined time T, and the pulse signal S1 hits the object. Element 5 for receiving the reflected wave R1
2 and a method of detecting a time difference t between transmission and reception.
Therefore, in order to transmit the pulse signal S1 from the transmitting element 51 every time T and to detect the transmission / reception time difference t when the receiving element 52 receives the reflected wave R1, the sensor drive processing circuit 54 is provided with a timer circuit ( (Not shown in FIG. 1). This timer circuit is configured so that the transmission time interval T of the pulse signal S1 can be changed by the control circuit 31.
The transmission time interval T is set to 3 seconds in order to minimize the possibility of retinal damage due to direct viewing of the light source lamp 81.

Structure of Detection Start Determining Unit 60 The projection display device 1 is provided with a detection start determining unit 60 for determining the start of the object detection by the above-described object detecting unit 50. When the operator of the projection display device 1 adjusts the zoom and focus of the projection lens 6, the detection start determination unit 60 detects the object detection unit 5.
0 is not operated, and a known circuit for detecting the adjustment state of the projection lens 6 is provided. Then, upon detecting that the zoom and focus adjustments by the operator have been completed, the detection start determination means 60 outputs a control signal to start detection to the object detection means 50.

(5) Configuration of Projection Image Control Means The projection image control means, when a signal indicating that the object P has been detected in the projection area A in FIG. The control circuit controls a projection image and includes a control circuit 31 and a video signal processing circuit 33. Then, when the object detection means 50 detects the object P in the projection area A, the control circuit 31 controls the video signal processing circuit 3 based on a signal from the sensor drive processing circuit 54.
3 to output a control signal. The video signal processing circuit 33 displays a black image based on this signal instead of the image signal from the video input terminal. Further, although not shown in FIG. 1, this projection image control means blinks an LED indicator provided on the projection display device 1 to indicate that the projection display device 1 is in an image control state due to the intrusion of the object P. Is made known.

(6) Operation of Projection Display Apparatus 1 Next, the operation of the projection display apparatus 1 having the above-described object detection means 50 and projection image control means will be described with reference to the block diagram of FIG. 1 and the flowchart of FIG. It will be described based on the following.

When the power switch is turned on and the projection display apparatus 1 is started, the object detection means 50 starts detecting an object in the projection area (STEP 1 object detection step). When the operator touches the projection lens 6 to adjust the zoom and focus of the projection lens 6, the detection start determination means 60 determines that the screen of the projection display device 1 is set (STEP 2 determination step), and the control signal Is output to control the object detection by the object detection means 50 (STEP 3).

When the operator zooms the projection lens 6,
When the hand is released from the focus adjustment part, the detection start determination means 60 determines that the screen setting by the operator has been completed (STEP 4), and outputs a control signal to release the restricted state of the object detection means 50, thereby , Object detection means 5
0 returns to the object detection state (STEP 5).

The transmitting element 51 of the object detecting means 50
Is the transmission time interval T (3 in this example) in the graph of FIG.
(Seconds) to transmit an ultrasonic signal S1 to scan the projection area A (STEP 6). During this time, the receiving element 52 receives the reflected wave R1 of the ultrasonic signal S1 and
Detects the transmission / reception time difference t. If the transmission / reception time difference t is detected as a constant value, the sensor drive processing circuit 5
4 determines that the reflected wave R1 is from the projection surface 100 and that no object has entered the projection area A.

When it is detected that a change has occurred in the transmission / reception time difference t, that is, when it is detected that the time difference t has decreased, the sensor drive processing circuit 54 sets the projection area A
It is determined that the object P has entered the inside (STEP 7), and a signal to that effect is output to the control circuit 31.

The control circuit 31 outputs a control signal to the video signal processing circuit 33 based on a signal from the sensor drive processing circuit 54 and outputs a control signal for blinking an LED indicator (not shown) (STEP).
8).

The video signal processing circuit 33 includes the control circuit 3
Based on the control signal from the control unit 1, a video signal composed of a black screen is output to the modulation element driving circuit 34 instead of a video signal input from a video input terminal or the like. The modulation element driving circuit 34 controls the liquid crystal light valves 925R, 925G, 92 based on the video signal from the video signal processing circuit 33.
Modulate 5B. As a result, a black projection image is displayed on the projection surface 100 (STEP 9: projection image control step).

When there is no more object P in the projection area A (STEP 10), the transmission / reception time difference t returns to the original state, and the sensor drive processing circuit 54 that has detected this time difference outputs a signal to that effect to the control circuit 31. . The control circuit 31 outputs a control signal to the video signal processing circuit 33 based on this signal. The video signal processing circuit 33 outputs a video signal from the video input terminal to the modulation element drive circuit 34 based on the control signal, and restores the projected image (STEP 1).
1). Further, the control circuit 31 outputs a control signal for releasing the blinking state of the LED indicator, and returns the LED indicator to the display of the standard state (STEP 12).

The scanning of the projection area A by the object detection means 50 as described above is continued until the power supply of the projection display device 1 is shut off (STEP 13).

(7) Effects of the First Embodiment According to the above-described first embodiment, the following effects can be obtained.

The object detecting means 50 is an ultrasonic sensor 53
Therefore, the ultrasonic signal from the transmitting element 51 can be set in a wide range according to the projection area A, and an object can be detected in a wide range with one sensor. Further, since the transmitting element 51 and the receiving element 52 have the same structure and a simple configuration, the configuration of the sensor drive processing circuit 54 can be simplified, and the structure of the projection display device 1 becomes complicated. Also does not invite.

Since the ultrasonic sensor 53 of the pulse reflection time detection method is employed, if the object P enters the projection area A, the transmission / reception time difference t immediately changes, and the object P is detected with high accuracy. be able to.

Since the transmission time interval T of the transmitting element 51 constituting the ultrasonic sensor 53 is set according to the retinal damage threshold of the eye (3 seconds in this example), the object detecting means 50
Can operate the projection image control means within 3 seconds, and even if a person enters the projection area A and looks directly at the light flux emitted from the projection lens 6, it does not reach the retinal damage threshold due to thermal action. In addition, the possibility of retinal damage due to peeping can be greatly reduced.

The transmitting element 51 is provided so as to be immersed from the front side surface of the outer case 2, and the amount of immersion D is set to the lower limit (6 cm) of the detectable distance of the ultrasonic sensor 53. Object detection can be performed for the entire range from the front side surface 2 to the projection surface.

Since the projection display apparatus 1 includes the detection start determination means 60, the projection image is not blocked by the object detection means 50 and the projection image control means at the time of setting the screen of the projection display apparatus 1. It is possible to set the screen, adjust the zoom, focus, and the like of the projection lens 6.

The projection image control means includes a control circuit 31 and a video signal processing circuit 33, and the object P is located within the projection area A.
Is detected, a video signal composed of a black screen is output. Therefore, compared with the case where the light source lamp 81 is turned off, there is no cool down or the like, and the object P
Is removed from the projection area A, it is possible to immediately switch to the video signal from the video input terminal or the like and return to the original state.

(8) Configuration and Effect of Second Embodiment Next, a second embodiment of the present invention will be described. In the following description, the same or similar parts as those already described will be omitted or simplified.

In the projection type display device 1 according to the first embodiment, the object detecting means 50 includes the ultrasonic sensor 53 having the transmitting element 51 and the receiving element 52. On the other hand, the object detecting unit 250 of the projection display device 201 according to the second embodiment is different from the projection display device 201 in that a pyroelectric infrared sensor 253 is included as shown in FIG.

The projection display device 201 includes four pyroelectric infrared sensors 253, and the four pyroelectric infrared sensors 253 are subjected to drive control and signal processing by a sensor drive processing circuit 254. Although not shown, the pyroelectric infrared sensor 253 includes a pyroelectric ceramic that converts infrared light into an electric signal, an optical filter that blocks unnecessary infrared light, and a Fresnel lens that defines a detection range of the pyroelectric ceramic. And a signal processing circuit for amplifying and converting an electric signal output from the pyroelectric ceramics. Such a pyroelectric infrared sensor 253 is provided in FIG.
As shown in (4), all four are provided on the front side surface of the exterior case 2 of the projection display device 201, and are disposed at four positions, up, down, left, and right of the projection lens 6. The detection ranges of the four pyroelectric infrared sensors 253, such as the viewing angle and the distance, can be changed by changing the curvature of the Fresnel lens. A detection range is set for a viewing angle of 90 ° in the direction and a viewing angle of 63 ° in the vertical direction.

The sensor drive processing circuit 254 outputs a signal to the control circuit 31 when any one of the four pyroelectric infrared sensors 253 detects an object. And an OR circuit. That is, when any of the pyroelectric infrared sensors 253 detects a human body temperature, the sensor drive processing circuit 254 outputs a signal to the control circuit 31 indicating that a person or the like has entered the projection area. Since the structure and operation of the other parts of the projection display device 1 are the same as those of the first embodiment, the description thereof is omitted.

According to the second embodiment, the following effects are obtained in addition to the effects of the first embodiment.

That is, since the object detection means 250 includes the pyroelectric infrared sensor 253, a person who has entered the projection area can be detected based on the human body temperature. On the other hand, when the object that has entered the projection area is an object other than a person, the pyroelectric infrared sensor 253 does not detect the object and can operate the projection image control means only when the necessary minimum. Also, a pyroelectric infrared sensor 253
Is provided with a Fresnel lens that defines the detection range, so that the detection range of the object detection unit 250 can be changed only by changing the curvature of the Fresnel lens, and the object of the projection display device 201 in which the projection area fluctuates. It is suitable as a detecting means.

(9) Configuration and Effect of Third Embodiment Next, a third embodiment of the present invention will be described.

In the projection display device 201 according to the second embodiment, four pyroelectric infrared sensors 253 are employed as sensors constituting the object detecting means 250.

On the other hand, in the projection display device 301 according to the third embodiment, the object detecting means 350 is configured to include an infrared sensor 353 serving as a plurality of optical sensors as shown in FIG. Different.

The infrared sensor 353, which is not shown in FIG. 11, outputs an infrared signal from a light emitting section and detects a reflected wave of the infrared signal reflected on an object at a light receiving section. 353 is subjected to drive control and signal processing by a sensor drive processing circuit 354. Such a plurality of infrared sensors 353 are shown in FIG.
As shown in FIG. 2, it is arranged below the projection lens 6 in a fan shape according to the spread of the luminous flux of the projection image. The light emitting unit of each infrared sensor 353 emits infrared rays IR linearly in accordance with the spread of the light flux in the projection area A, and can detect objects near the outer periphery of the projection area A and inside the projection area A. ing.

The sensor drive processing circuit 354 includes the control circuit 3
1 or a circuit for controlling the driving of each infrared sensor 353 in accordance with a control signal from the detection start determining means 60 and processing a detection signal from a light receiving portion of the infrared sensor 353. When a change occurs in the signal, the signal is output to the control circuit 31, and the subsequent processing is the same as that of the sensor drive processing circuit 254 according to the second embodiment. Note that the structure of other parts and the like is the same as that of the first embodiment, and a description thereof will be omitted.

The projection display device 301 according to the third embodiment has the following effects in addition to the effects of the first embodiment.

That is, the plurality of infrared sensors 353 constituting the object detection means 350 can detect objects near the outer peripheral edge of the projection area of the projection image and inside the projection area of the projection image. Therefore, even if a person enters the projection area and the person remains inside the projection area, an object inside the projection area can always be detected, and the projected image is restored and a strong luminous flux is applied to the person in the projection area. Is not irradiated. In addition, since the infrared sensor 353 outputs a signal with high straightness from the light emitting unit, even if the distance between the projection display device 301 and the projection surface 100 is large, it is possible to reliably detect an intruding object located therebetween. Becomes

Further, since the plurality of infrared sensors 353 are arranged in a fan shape below the projection lens 6, an object in the projection area can be detected at a fine pitch in accordance with the spread of the luminous flux of the projection image. Accuracy of object detection can be improved.

(10) Modifications of the Embodiments The present invention is not limited to the above-described embodiments, but includes the following modifications. That is, in the above-described first embodiment, the ultrasonic sensor 53 employs the pulse reflection time detection method. However, the present invention is not limited to this, and the ultrasonic sensor 53 of the first embodiment may be replaced with the ultrasonic sensor 53 of FIG.
May be used as a sensor of a continuous signal level detection system as shown in the graph of FIG. 13 or may be used as a sensor of a detection system using the Doppler effect as shown in the graph of FIG. When the sensors are changed to these different types, the sensor drive processing circuit 54 in FIG. 1 may be changed so as to be compatible with each type.

If the object detection means of the continuous signal level detection system and the Doppler effect utilization detection system is used, as shown in FIGS. 13A and 13B, the signal is continuously transmitted from the transmitting element. S2 and S3 are output, and the receiving element is in a state of always receiving the reflected waves R2 and R3, so that the object can be always detected while the projected image is being displayed. As shown in FIG. 13B, when the Doppler effect detection method is employed, if the object P does not move inside the projection area at the speed V, the vibration of the reflected wave R3 received by the receiving element 52 will be reduced. Since the number does not change, the object P cannot be detected.

In the above-described first embodiment, the transmitting element 51 of the ultrasonic sensor 53 is provided so as to be immersed in the front side surface of the outer case 2. However, the present invention is not limited to this. It may be arranged on the upper surface of the case 2 so as to retreat from the front side surface. If the transmitting element is arranged at such a position,
Even an ultrasonic sensor having a lower limit of the detectable distance of 20 cm can be adopted as an object detecting means of the projection display device.

Further, in each of the above-described embodiments, each of the object detecting means 50, 25 of the projection display device 1, 201, 301 is used.
Although 0 and 350 employ only one type of sensor 53, 253, and 353, the object detection unit may be configured using a plurality of types of sensors. Specifically, the object detection means is configured to include an optical sensor and an ultrasonic sensor, and the object is detected by an ultrasonic sensor in the vicinity of the projection display device, and the object is detected by the optical sensor in the vicinity of the projection screen. It is possible to do. With this configuration, an object can be detected with high accuracy both in the near and far directions of the projection display device, and a wide detection range and a long-distance detection can be achieved simultaneously.

In each of the above embodiments, the projection image control means is configured to display a black screen by the video signal processing circuit 33. However, the present invention is not limited to this. That is, the image signal processing circuit may be configured to display a gray screen, may be configured to image-process a video signal to darken a projected image, and may further control a projected image control unit. The projection image control means may be constituted by a circuit and a lamp driving circuit, and when an object is detected, the brightness of the light source lamp is reduced or the power of the light source lamp is shut off.

In the projection display device 1 according to the first embodiment, when the operator touches the adjustment part such as the zoom and the focus by the operator, the detection start determination means 60 is automatically activated by the object detection means 50. Although configured as an adjustment-part-linked type discriminating means for restricting object detection, the invention is not limited to this. That is, the detection start determining means is a timer type determining means for restricting object detection by the object detecting means for a predetermined time set by an operator when the power of the projection type display device is turned on, and an operation of the projection type display device. And an operation start switch for restricting object detection by the object detection means after the operator confirms the safety state. Further, the object detection start determination means may be configured to include a detection determination function operation switch exclusively set by the operator to start / stop the operation of the object detection means each time.

Further, in the above-described first embodiment, the object detecting means 50 is provided integrally with the projection display device 1, but is not limited to this. That is, the object detection means and the detection start determination means may be prepared as accessories, and may be configured such that they can be connected to a control circuit for controlling the projection display device by a cable as necessary.

In the third embodiment described above, the infrared sensors 353 constituting the object detecting means 350 are arranged below the projection lens 6 in a fan shape. However, the present invention is not limited to this. That is, an infrared sensor for detecting an object near the outer periphery of the projection area may be arranged on the side of the projection lens, and an infrared sensor for detecting an object in the projection area may be arranged below the projection lens.

In the first embodiment described above, the detection start determining means 60 is configured to control the object detection by the object detecting means 50. However, the present invention is not limited to this. It is sufficient to avoid a state in which the setting screen is not displayed at the time of setting the screen. For example, the execution of the projection image control means may be controlled.

In addition, specific structures, shapes, and the like when implementing the present invention may be other structures and the like as long as the object of the present invention can be achieved.

[0104]

According to the projection display apparatus of the present invention as described above, the object detecting means is constituted by the ultrasonic sensor, the pyroelectric infrared sensor, and the plurality of optical sensors. , An object such as a person can be detected. In addition, since the projection display device includes the detection start determination means, it is possible to surely adjust the projection image such as zoom and focus when setting the screen of the projection display device.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a structure of a projection display device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining a structure of an optical system in the embodiment.

FIG. 3 is a vertical sectional view illustrating a structure of a transmission element included in the ultrasonic sensor according to the embodiment.

FIG. 4 is a front view of the projection display device showing the arrangement of the ultrasonic sensors in the embodiment.

FIG. 5 is a horizontal sectional view showing a mounting structure of a transmitting element to an outer case in the embodiment.

FIG. 6 is a horizontal sectional view showing a mounting structure of a receiving element to an outer case in the embodiment.

FIG. 7 is a graph showing a timing between a signal output of a transmission element and a reception time of a reception element in the embodiment.

FIG. 8 is a flowchart for explaining the operation of the projection display device according to the embodiment.

FIG. 9 is a block diagram illustrating a structure of a projection display apparatus according to a second embodiment of the present invention.

FIG. 10 is a partial front view of a projection display device showing an arrangement of a pyroelectric infrared sensor which constitutes an object detection unit in the embodiment.

FIG. 11 is a block diagram illustrating a structure of a projection display apparatus according to a third embodiment of the present invention.

FIG. 12 is a partial front view of a projection display device showing an arrangement of a pyroelectric infrared sensor constituting an object detection unit in the embodiment.

FIG. 13 is a graph showing a timing between a signal output of a transmission element of a detection method using an ultrasonic sensor and a reception time of a reception element, which is a modification of the first embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 201, 301 Projection display apparatus 2 Outer case 6 Projection lens 10 Optical system 50, 250, 350 Object detection means 51 Transmission element 52 Reception element 53 Ultrasonic sensor 60 Detection start discrimination means 81 Light source lamp 253 Pyroelectric type Infrared sensor 353 Optical sensor (infrared sensor) A Projection area

Claims (13)

[Claims] A light source lamp, an optical system for optically processing a light beam emitted from the light source lamp to form an optical image in accordance with image information, and a projection lens for enlarging and projecting the optical image on a projection surface. A projection display device comprising: an object detection unit provided to face the projection surface; and a projection image control for controlling a projection image displayed on the projection surface in accordance with an output of the object detection unit. A projection type display device comprising: an ultrasonic sensor having a transmitting element and a receiving element. 2. The projection display device according to claim 1, wherein the ultrasonic sensor receives a signal continuously output from the transmitting element by the receiving element, and detects a change in the signal level of the signal. A projection display device, which is a sensor of a continuous signal level detection method for detecting. 3. The projection display device according to claim 1, wherein the ultrasonic sensor receives a pulse signal output from the transmitting element at a predetermined time interval by the receiving element, and transmits and receives the pulse signal. A projection display device, which is a pulse reflection time detection type sensor for detecting a time difference. 4. The projection display device according to claim 3, wherein a transmission interval of the pulse signal output from the transmission element is set to a threshold value of retinal damage to the eye due to a thermal effect of a light beam emitted from the projection lens. A projection display device, which is set according to the conditions. 5. The projection display device according to claim 1, wherein the ultrasonic sensor receives a signal continuously output from the transmitting element by the receiving element, and detects a change in the frequency of the signal. A projection display device, which is a sensor of a detection system using the Doppler effect. 6. The projection type display device according to claim 1, further comprising an outer case for housing said light source lamp and said optical system, wherein said transmitting element faces said projection surface. The projection type display device is provided so as to retreat from the front surface of the outer case. 7. The projection type display device according to claim 1, further comprising a detection start determining means for determining a detection start of said object detecting means. Display device. 8. A light source lamp, an optical system for optically processing a light beam emitted from the light source lamp to form an optical image according to image information, and a projection lens for enlarging and projecting the optical image on a projection surface. A projection display device comprising: an object detection unit provided to face the projection surface; and a projection image control for controlling a projection image displayed on the projection surface in accordance with an output of the object detection unit. A projection type display device comprising: a pyroelectric infrared sensor configured to detect a temperature of a human body. 9. The projection type display device according to claim 8, further comprising a detection start determining means for determining the detection start of said object detecting means. 10. A light source lamp, an optical system for optically processing a light beam emitted from the light source lamp to form an optical image according to image information, and a projection lens for enlarging and projecting the optical image on a projection surface. A projection display device comprising: an object detection unit provided to face the projection surface; and a projection image control for controlling a projection image displayed on the projection surface in accordance with an output of the object detection unit. The object detection means includes a light emitting unit and a light receiving unit, and is configured by arranging a plurality of optical sensors for detecting the reflection of a signal output from the light emitting unit by the light receiving unit. A projection-type display device arranged to detect an object at least near an outer peripheral edge of a projection area of the projection image and inside the projection area of the projection image. 11. The projection display device according to claim 10, wherein the plurality of optical sensors are arranged in a fan shape in accordance with the spread of the luminous flux of the projection image. 12. The projection type display device according to claim 10, further comprising a detection start determining means for determining the detection start of said object detecting means. 13. A light source lamp, an optical system for optically processing a light beam emitted from the light source lamp to form an optical image according to image information, and a projection lens for enlarging and projecting the optical image on a projection surface. A control method for a projection display device, comprising: an object detection step of detecting that an object has entered a projection area of the projection surface; and A projection image control step of controlling a projection image displayed on the screen, and a screen setting state of the projection display apparatus, wherein the object detection step and / or
Or a determining step of not executing the projection image control step.