JP2004348078A - Projection video display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology of a projection video display device which prevents projected light powerful to a person etc., from entering the eyes and avoids giving an unpleasant impression to a viewer. <P>SOLUTION: A video display element is driven in the state of dividing an area to a plurality of areas and the person or the like entering the inside of the projection area of a screen surface is detected by at least any among a plurality of detecting means. Replacement of data is discretely performed by each of the plurality of areas of the video display element based on the detected information and the display state of the screen surface position is changed in correspondence to the position of the person or the like. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a projection display apparatus such as a liquid crystal projector, and more particularly to a technique for controlling the brightness of projection light.
[0002]
[Prior art]
Conventionally, in a projection-type image display device such as a liquid crystal projector that projects light on a front screen surface, when an explainer enters a projection optical path to the screen surface and turns his / her face toward the projection side, a strong There is a danger of damaging the visual system as a result of the light entering the eye, but this is dealt with by giving a warning display or the like.
Examples of the prior art related to the present invention and described in Patent Literature include JP-A-2000-19636 (Patent Document 1), JP-A-2000-305481 (Patent Document 2), and There is one described in JP-A-2001-75170 (Patent Document 3). Japanese Patent Application Laid-Open No. 2000-19636 describes a configuration of a projection display device that detects an object such as a person in a projection area by an ultrasonic sensor and reduces the brightness of the entire projection surface. Japanese Patent Laying-Open No. 2000-305481 describes a configuration in which an image of a display area is imaged by an imaging unit provided in a projection display device, and the brightness of image light in the display area where a person is located is described. Japanese Unexamined Patent Application Publication No. 2001-75170 discloses that a plurality of detection devices are provided outside a projection space region through which projection light passes, and a local space along an outer edge of the projection space region is set as a detection target region. A configuration is described in which when an object in the detection target area is detected, the power of a lamp unit serving as a light emission source is turned off to stop projection.
[0003]
[Patent Document 1]
JP 2000-19636 [Patent Document 2]
JP 2000-305481 A [Patent Document 3]
JP 2001-75170 A
[Problems to be solved by the invention]
Of the above-described conventional techniques, when a display indicating danger is provided, the display is often overlooked. Further, among the patent documents, in the technology described in JP-A-2000-19636 and JP-A-2001-75170, for example, even when a person or the like slightly enters an end portion of a projection surface (screen surface), an image is displayed. Since the overall light intensity is reduced, the viewer is likely to give an unpleasant impression. Further, the technique described in Japanese Patent Application Laid-Open No. 2000-305481 requires an expensive image pickup device, and the circuit configuration is considered to be complicated.
The problem of the present invention is that, in view of the state of the prior art described above, in a projection type video display device, under a low-cost and simple configuration, the screen surface is adjusted according to the position of a person or the like entering the projection area on the screen surface. The purpose is to make it possible to partially change the state of brightness etc., to prevent powerful projection light from entering eyes, etc., and not to give an unpleasant impression to viewers. .
An object of the present invention is to provide a technique capable of solving such a problem.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, basically, as a projection type image display device, the image display element is driven in a state where an area on the element is divided into a plurality of areas, and an area on a screen surface is A person or object entering the inside is detected by at least one of a plurality of detection means at different positions, and data is separately replaced for each of the plurality of regions of the video display element based on the detection information. Alternatively, the display state of the screen surface position corresponding to the position of an object is changed. The data is specific uniform color data, black data, data based on a video signal with a reduced luminance level, and the like.
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 5 are explanatory diagrams of a first embodiment of the present invention. FIG. 1 is a diagram showing an example of the configuration of a projection type video display device according to a first embodiment of the present invention. FIG. 2 is a timing chart for explaining operation signals of the device shown in FIG. 1, and FIG. FIG. 4 is a diagram illustrating an example of a projection image of the apparatus in FIG. 1, and FIG. 5 is a diagram illustrating another example of a projection image in the projection display apparatus of the present invention.
In FIG. 1, reference numeral 1a denotes a projection type video display device as a first embodiment of the present invention, 2 denotes a screen, 3a denotes a CPU as control means, 4 denotes a signal processing unit as display element driving means, and 5 denotes a light source. The optical units 6, 7 for optically processing light from the side are provided with a plurality of ultra-thin detecting means for detecting a person or an object entering an area of a light projection surface (hereinafter, referred to as a screen surface) of the screen 2. The sound wave sensors 10, 11 are sensor drive processing units that drive the ultrasonic sensors 6, 7 and process detection signals. The projection display apparatus 1a includes the plurality of ultrasonic sensors 6, 7, the sensor drive processing units 10, 11, the CPU 3a, the signal processing unit 4, and the optical unit 5. Each of the sensor drive processing units 10 and 11 has the same configuration as each other, and includes a 40 kHz generation unit 101, a first amplification unit 102, a second amplification unit 103, and a pulse generation unit 104.
The optical unit 5 includes an illumination optical system 51, an image display element 52, and a projection lens 53. The illumination optical system 51 includes a lamp 511, a reflector 512, and a condenser lens 513. In the first embodiment, the ultrasonic sensors 6 and 7 are disposed at a plurality of horizontal positions facing the screen surface, that is, right and left positions sandwiching the projection lens 53 in the projection display apparatus 1a. Ultrasonic waves are generated along the outermost contour. Each of the ultrasonic sensors 6 and 7 has a transmission / reception type configuration. When a pulse of 40 kHz is input, the ultrasonic sensors 6 and 7 generate ultrasonic waves and receive the ultrasonic waves. The generation of the 40 kHz pulse is performed by the 40 kHz generation unit 101. The signal processing section 4 drives the video display element 52 based on the video signal in a state where the area on the element 52 is divided into a plurality of areas. The CPU 3 a as a control unit controls the signal processing unit 4 based on detection information (detection signals) of the ultrasonic sensors 6 and 7 input from the sensor drive processing units 10 and 11, and controls a plurality of the video display elements 52. For each area, the data is replaced with data such as specific uniform color data, black data, and data based on a video signal with reduced luminance level (video data with reduced brightness). The control data and control program used by the CPU 3a are stored in a memory (not shown). As the image display element 52, for example, a transmission type liquid crystal panel is used.
[0007]
In the above configuration, the light emitted from the light source unit including the lamp 511 and the reflector 512 is collimated by the condenser lens 513 and applied to the image display element 52. The light applied to the video display element 52 is light-modulated based on the video signal input to the video display element 52 via the signal processing unit 4, and emitted as video light corresponding to the video signal. The image light is color-combined by a prism or the like (not shown), and then enlarged and projected from the projection lens 53 onto the screen 2 as image light of the color-combined optical image. For example, when a person enters the area of the screen surface, one or both of the ultrasonic sensors 6 and 7 detect this, and a detection signal processed by the sensor drive processing units 10 and 11 is input to the CPU 3a. You. The CPU 3a controls the signal processing unit 4 based on the detection signal to specify data of an area corresponding to the screen surface at the position of the intruder among a plurality of areas of the video display element 52, in a predetermined manner. It is replaced with uniform color data, black data, data based on a video signal with a reduced luminance level (video data with reduced brightness), and the like.
[0008]
FIG. 2 is a diagram illustrating timings of operation signals of the ultrasonic sensors 6, 7 and the sensor drive processing units 10, 11 in the configuration of FIG.
In the sensor drive processing units 10 and 11, the 40 kHz pulse is intermittently oscillated in the 40 kHz generation unit 101 at intervals of, for example, 20 Hz (waveform (1)). Pulse generation in this state is performed using a device such as a logic IC or a programmable logic device (hereinafter, referred to as a PLD). The generated 40 kHz pulse is amplified by the first amplifier 102 to have an amplitude of several tens Vpp or more, and is then input to the ultrasonic sensors 6 and 7. The first amplifying unit 102 includes, for example, a high-voltage transistor or a transformer. The ultrasonic sensors 6 and 7 generate ultrasonic waves based on the input 40 kHz pulse. The generated ultrasonic waves are transmitted in a predetermined direction on the screen 2 side. The ultrasonic waves are reflected by the screen 2 and received by the ultrasonic sensors 6 and 7. The ultrasonic sensors 6 and 7 generate and output a 40 kHz pulse based on the received ultrasonic waves. The 40 kHz pulses generated by the ultrasonic sensors 6 and 7 are amplified by the second amplifier 103 in the sensor drive processing units 10 and 11 (waveforms 2 and 3). The waveform (2) is an amplified waveform of a 40 kHz pulse from the ultrasonic sensor 6 (left sensor), and the waveform (3) is an amplified waveform of a 40 kHz pulse from the ultrasonic sensor 7 (right sensor). Both the waveforms (2) and (3) are generated at positions delayed from the waveform (1) by the time from the transmission to the reflection and return. The 40 kHz pulse from the ultrasonic sensor 6 (left sensor) is reflected on the screen 2 and returns to the ultrasonic sensor 6 (left sensor) again. The 40 kHz pulse from the ultrasonic sensor 7 (right sensor) is reflected on the screen surface of the screen 2. It is assumed that the light is reflected by the person 8 in the projection area and returns to the ultrasonic sensor 7 (right sensor) again. The distance from the ultrasonic sensor 7 (right sensor) to the person 8 is shorter than the distance from the ultrasonic sensor 6 (left sensor) to the screen 2. Therefore, the waveform (3) occurs at a position where the delay time with respect to the waveform (1) is shorter than that of the waveform (2). The pulse generation unit 104 in the sensor drive processing units 10 and 11 takes in the waveform (1) and the waveform (2) or the waveform (1) and the waveform (3), and obtains the waveform (4) or the waveform (5). A pulse having a low level is generated only during the period from the generation of ultrasonic waves to the reception thereof. The pulse generator 104 can be configured by a circuit such as a PLD. The pulse of the waveform (4) or the waveform (5) is input to the CPU 3a. The CPU 3a performs an operation based on the pulse and controls the signal processing unit 4.
[0009]
FIG. 3 is an explanatory diagram of a control operation procedure by the CPU 3a in the configuration of FIG. FIG. 4 is a diagram showing an example of a projection image by the control operation.
In FIG.
(1) First, the delay time of a received wave in a state where the person 8 is not interrupted (entered) between the projection display apparatus 1a and the screen 2 (initial state) is measured (step S30). In the method of measuring the delay time of the received wave, the Low level time of the pulse indicated by the waveforms (4) and (5) in FIG. 2 is measured using the counter function of the CPU 3a. The CPU 3a measures the count number during the Low level period, and converts the count number into time. For example, if one count is 0.1 × 10 ⁻⁶ s, the delay time is calculated by multiplying the count number by 10 ⁻⁶ s. In the case of the CPU 3a without the counting function, for example, the pulse is generated by the pulse generation unit 104, and the count number of the low level period of the pulse is sent to the CPU 3a.
(2) Next, the reception wave delay time of the ultrasonic sensor 6 is measured in the normal state, and it is determined whether or not the delay time is shorter than the initial state (step S31).
(3) Similarly, the reception wave delay time of the ultrasonic sensor 7 is measured, and it is determined whether the delay time is shorter than the initial state (steps S32 and S33).
(4) The state transits to four states according to the combination of the results of steps S31 to S33. For example, when the delay time of both the ultrasonic sensors 6 and 7 is shortened, it is determined that the person 8 is located at the center of the screen, and the signal processing unit 4 is controlled to reduce the light intensity on the entire screen surface (step S34). ). For example, it instructs the signal processing unit 4 to mask the entire screen surface with black.
(5) If only the ultrasonic sensor 6 has a shorter delay time, it is determined that the person 8 is located on the left side of the screen (the ultrasonic sensor 6 side), and as shown in FIG. The signal processing unit 4 is controlled so as to reduce the light intensity on the (6) side (step S35).
(6) When only the ultrasonic sensor 7 has a shorter delay time, it is determined that the person 8 is located on the right side of the screen (the ultrasonic sensor 7 side), and the light intensity of the right half of the screen surface (the ultrasonic sensor 7 side) is determined. Is controlled so as to reduce (step S36).
(7) If the delay times of both the ultrasonic sensors 6 and 7 have not changed, the signal processing unit 4 is controlled to stop the black mask on the entire screen (step S37).
[0010]
By repeating the series of controls in steps S31 to S37, the light intensity on the screen surface on the side where the person 8 has interrupted can be reduced.
Although the case where two ultrasonic sensors are used has been described above, three or more ultrasonic sensors may be used. For example, as shown in FIG. 5, the screen may be divided into four parts for control, and four ultrasonic sensors may be arranged corresponding to the respective parts. Even in the case of this configuration, the basic configuration and operation of the projection display apparatus are the same as those in FIGS.
[0011]
According to the first embodiment, the screen state such as the brightness of the screen surface can be partially changed according to the position of a person or the like entering the projection area of the screen surface under a low-cost and simple configuration. The person or the like does not have strong light entering his eyes, and does not give a viewer an unpleasant impression.
[0012]
FIGS. 6 and 7 are explanatory diagrams of a second embodiment of the present invention. In the second embodiment, an infrared sensor is used as detecting means for detecting a person or an object. FIG. 6 is a structural example diagram of a projection type video display device as a second embodiment of the present invention, and FIG. 7 is an explanatory diagram of an infrared distance sensor.
In FIG. 6, reference numeral 1b denotes a projection type image display apparatus as a second embodiment of the present invention, 61 and 71 denote infrared distance sensors as detecting means, and 3b denotes a CPU as control means. Other components that are the same as those in FIG. 1 are denoted by the same reference numerals as in FIG. 1 and description thereof is omitted. As the infrared distance sensors 61 and 71, for example, a PSD (Position Sensitive Detector) type infrared distance sensor having a configuration shown in FIG. 7 is used. In FIG. 7, reference numeral 610 denotes an infrared light emitting diode, 611 denotes a position detecting element (PSD), and 612 and 613 denote lenses. In the infrared distance sensor 61 (the same applies to the infrared distance sensor 71), light emitted from the infrared light emitting diode 610 through the lens 613 is reflected by the object 8, and the reflected light is transmitted to the position detection element (PSD) 611 through the lens 612. Incident. The position detection element 611 is formed of, for example, a PIN photodiode, and the output voltage value changes depending on the position where the reflected light is applied. Thereby, the distance to the position where the infrared rays are reflected is measured.
[0013]
In the configuration shown in FIG. 6, the infrared distance sensors 61 and 71 measure the distance to the screen 2 in a state where the person 8 is not interrupted between the projection display apparatus 1b and the screen 2 (initial state). Convert to The CPU 3b takes in the analog voltage value, converts the analog voltage value into a digital value by an internal AD converter, and stores the digital value. If there is no AD converter in the CPU 3b, an AD converter may be provided outside. Subsequent operations are performed in substantially the same procedure as in the case of FIG. When the distance information from the infrared distance sensors 61 and 71 is shorter than the distance to the screen 2, the CPU 3b determines that the person 8 is between the projection-type image display device 1b and the screen 2, and determines that the person 8 is on the screen. The signal processing unit 4 is controlled so as to reduce the light intensity in the corresponding area above.
[0014]
According to the second embodiment, similarly to the first embodiment, the screen such as the brightness of the screen surface is changed according to the position of a person or the like entering the projection area of the screen surface under a low-cost and simple configuration. Since the state can be partially changed, the person or the like can be prevented from entering strong light into his eyes and not giving a viewer an unpleasant impression. In particular, since the distance information from the infrared distance sensors 61 and 71 can be directly obtained, the device configuration can be further simplified.
[0015]
In each of the above-described embodiments, the signal processing unit 4 is controlled based on the detection signal from the detection unit, and the data of the area corresponding to the screen surface of the position of the person or the like among the plurality of areas of the video display element 52 is determined. Was replaced to change the display state in a state in which the screen surface was divided in the horizontal direction.However, the present invention is not limited to this.For example, the display state is changed in a state in which the screen surface is divided in the vertical direction. The display state may be changed in a state where the screen surface is divided into both the horizontal direction and the vertical direction. Further, the detection means is not limited to the ultrasonic sensor or the infrared distance sensor, but may be a distance sensor such as a laser sensor, or a pyroelectric infrared sensor that detects infrared rays emitted by a person.
[0016]
【The invention's effect】
According to the present invention, in the projection type video display device, the screen state such as the brightness of the screen surface can be partially changed in accordance with the position of the person or the like entering the projection area of the screen surface, and the power of the person or the like can be increased. In addition, it is possible to prevent undesired projection light from entering the eyes and to give an unpleasant impression to the viewer.
[Brief description of the drawings]
FIG. 1 is a configuration example diagram of a projection type video display device as a first embodiment of the present invention.
FIG. 2 is an explanatory timing chart of a detection operation in the apparatus of FIG. 1;
FIG. 3 is an explanatory diagram of a control operation procedure in the device of FIG. 1;
FIG. 4 is a diagram showing an example of a projection image of the apparatus of FIG. 1;
FIG. 5 is a diagram showing another example of a projected image in the projection display apparatus of the present invention.
FIG. 6 is a configuration example diagram of a projection display apparatus as a second embodiment of the present invention.
FIG. 7 is an explanatory diagram of an infrared distance sensor in the device of FIG.
[Explanation of symbols]
1a, 1b: Projection type video display device, 2: Screen, 3a, 3b: CPU, 4: Signal processing unit, 5: Optical unit, 6, 7: Ultrasonic sensor, 10, 11: Sensor drive processing unit, 101 ... 40 kHz generation unit, 102: first amplification unit, 103: second amplification unit, 104: pulse generation unit, 51: illumination optical system, 52: video display element, 53: projection lens, 511: lamp, 512: reflector,
513: condenser lens, 61, 71 ... infrared distance sensor.

Claims (6)

A projection-type image display device that irradiates light from a light source side to an image display element, forms an optical image according to an image signal, and performs enlarged projection on a screen surface to display an image,
Display element driving means for driving the image display element based on an image signal in a state where an area on the element is divided into a plurality of areas,
A plurality of detection means arranged at a plurality of locations facing the screen surface, for detecting a person or an object that has entered the area of the screen surface,
A control unit that controls the display element driving unit based on the detection information of each of the detection units, and performs data replacement for each of a plurality of regions of the video display element;
When at least one of the plurality of detecting means detects a person or an object, the control means causes the data of an area corresponding to the detected detecting means on the video display element to be replaced. A projection type video display device, wherein the display element driving means is controlled to change a display state of a screen surface position corresponding to the position of the person or the object. 2. The projection type video display device according to claim 1, wherein the number of said detection means is made equal to the number of regions divided on said video display element. The projection-type image display device according to claim 1, wherein the plurality of regions divided on the image display element form regions divided in a horizontal direction or a vertical direction on the screen surface. 2. The projection type video display device according to claim 1, wherein the data replaced for each of the plurality of regions of the video display element is any one of specific uniform color data, black data, and data based on a video signal with a reduced luminance level. 2. The projection type image display device according to claim 1, wherein said detecting means is configured to irradiate ultrasonic waves or light to said screen surface and receive ultrasonic waves or light reflected from said screen surface. 2. The projection type image display device according to claim 1, wherein said detection means comprises a pyroelectric infrared sensor.

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