JP2005173097A - Image display apparatus and method of controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance safety of an image display apparatus using a high intensity light source without necessitating a complex structure and control. <P>SOLUTION: A safety structure is provided against the intrusion of irradiation light which is directed to a plotting region into a passing region when an image is displayed in the plotting region with the irradiation of light on a screen SCN. A confocal optical system is formed by providing an optical system for imaging an intrusion detection pattern on the screen SCN by irradiating with invisible light toward the plotting region and a light receiving system which detects returned light of the intrusion detection pattern. Further, the intrusion to the passing region is detected on the basis of the variation in the detected light quantity with the detection means 12 and an adverse influence on a human body or the like is prevented with the cut off or dimmer control of the irradiation light. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  An object of the present invention is to guarantee the safety of an image display apparatus using high-intensity irradiation light such as laser light. For example, in application to a laser display or the like, reflected (scattered) light from a screen is inherently used. The present invention relates to a technique for preventing an accident in which a laser beam or the like, which is a drawing light, forms an image directly on the fundus during an action such as looking directly into a projection lens.

  A projection-type configuration (projector device) is known as an image display device capable of displaying on a large screen, and an observer can see an image projected by projecting light from a light source onto a screen. For example, regarding a projector using three primary color laser light sources, various systems have been proposed for the purpose of improving brightness and color reproducibility.

  By the way, when using laser light, it is important to ensure its safety. For example, it is necessary to take sufficient measures when a viewer inadvertently enters a laser light projection area (for example, (Refer patent document 1.) The form shown below is known so far.

(1) Detection by image recognition A mode in which a screen is imaged by a CCD camera or the like in the infrared region, and an intruder is detected by image recognition.

(2) Detection of intruders on the screen boundary Illuminate the outline (boundary) of the screen with infrared light, etc. and place a light receiver on the screen boundary or monitor the reflected light at the screen boundary. A form to detect the presence or absence of an object passing through

Japanese National Patent Publication No. 11-501419

  However, the conventional apparatus cannot detect the intrusion of a human body or an object into the laser light irradiation range with sufficient accuracy, or requires an expensive apparatus, complicated mechanism or control for that purpose. There are problems such as.

  For example, in the above form (1), a processing apparatus necessary for image recognition is expensive, and complicated operations such as installation and adjustment of the apparatus are required. In addition, when the reflectance of the intruder to the image projection area is the same as that of the screen, or when the image becomes unclear, the probability of causing a malfunction is increased, or a change in room lighting or external light, etc. It is difficult to find a countermeasure for reducing malfunction or unnecessary operation due to influence.

  And since it is basically detection based on a photographed image (two-dimensional image), an illuminating device is necessary, and when irradiating the entire surface of the screen, there is a case where the output of the illuminating light becomes a safety problem. is there. A method of modulating the illumination light to increase the detection sensitivity is also conceivable, but since it is practically difficult to detect the entire two-dimensional image, in order to improve the detection sensitivity, the intensity of the illumination light Need to be raised.

  In the case of the above form (2), an optical system for illuminating the outline of the screen is necessary. For example, a dedicated optical system or device is required to detect a human body or an intruder that passes through the screen boundary, but the human body or the like has entered the internal drawing range from the screen boundary, or from the drawing range to the outside. It is difficult to accurately determine whether you have left. In addition, in order to sufficiently ensure safety, high accuracy is required for the positional relationship between the screen and the drawing apparatus, and the arrangement thereof is also limited. In addition, for example, it is difficult to detect a hole on the screen and light leaks to the back surface, damage or contamination of the screen, and the image projection is cut off by limiting the area near the intruder. It is difficult to make a configuration that draws the entire image or a partial image as much as possible without causing any problems in securing (for example, when an intrusion is detected, the progress of projection is frequently interrupted due to a false detection, etc. Etc.). And the possibility of malfunctioning with respect to intruders with high reflectivity remains.

  Therefore, an object of the present invention is to improve safety of an image display device using high-intensity light without requiring a complicated configuration or control.

  In order to solve the above-described problem, the image display device according to the present invention provides a safety mechanism against intrusion into the passage region of the irradiation light toward the drawing range when performing image display in the drawing range by light irradiation on the screen. An optical system for forming an intrusion detection pattern on the screen by irradiating a detection wave of non-visible light toward the drawing range or an area including the drawing range. A light receiving system for detecting return light from the intrusion detection pattern to be imaged is provided to form a confocal optical system, and the intrusion detection to the passing area is performed based on the change in the light amount of the detection wave. .

  The image display device control method according to the present invention forms an intrusion detection pattern on a screen by irradiating a detection wave of non-visible light with an optical system toward the drawing range or an area including the drawing range. And detecting the return light reaching the light receiving system through the optical system as reflected light of the intrusion detection pattern imaged on the screen, so that the intrusion into the passing area is performed based on the change in the amount of light. It detects presence / absence or intrusion status.

  Therefore, in the present invention, the property of the confocal optical system, that is, the return light to the light receiving system is generated only when the intrusion detection pattern (linear or dot pattern) is imaged on the screen. By using this, it is possible to accurately detect entry into a space (drawing light passage area) formed between the image display device and the screen. That is, when the light enters the space, the amount of light returning to the light receiving system decreases, so this can be detected immediately and necessary safety measures (blocking of drawing light, reduction of intensity, etc.) can be taken. it can.

  According to the present invention, image recognition processing or the like is not required, and malfunctions and unnecessary operations due to the effects of high reflectance of intruders, image ambiguity, changes in room lighting and outside light, and the like can be reduced. it can. Further, it is possible to accurately determine the intrusion of a human body or an object, and safety can be improved without requiring a complicated configuration or control.

  A configuration in which an invisible light intrusion detection pattern is formed on a one-dimensional image projected using a laser light source at a position immediately above or near the one-dimensional image or at a certain distance from the one-dimensional image. By adopting, it is possible to perform intrusion detection in accordance with the scanning position related to the generation of the drawn image, so that high safety can be ensured. In addition, there are few restrictions on the accuracy and arrangement of the positional relationship regarding the screen and the drawing apparatus.

  When adopting a configuration in which a linear intrusion detection pattern parallel to the formation direction (line direction) of the one-dimensional image is scanned together with the one-dimensional image, a confocal configuration is obtained in the scanning direction of the one-dimensional image. In addition, when adopting a configuration in which an intrusion detection pattern composed of a plurality of detection spots is formed and scanned together with the one-dimensional image, a confocal configuration is formed in the scanning direction and the direction orthogonal to the direction. Therefore, detection can be performed with high accuracy using an optical system with high detection sensitivity. For example, it is possible to detect a cause (such as a hole or a flaw) that hinders image formation on the screen.

  In addition, if the same optical scanning unit is used as the drawing image scanning system and the intrusion detection light scanning system, the configuration is simplified as compared with the configuration using the optical scanning units that are separately and synchronized with each other. It is advantageous for cost reduction.

  When intrusion into the passage area of drawing light is detected, the output of the light source for image display is reduced or blocked, thereby preventing direct irradiation of drawing light to the human body, etc., and ensuring safety, The light source output can be directly controlled and quick response is possible. Further, in the form in which the intensity of the drawing light is reduced or regulated to zero by controlling the light modulation element at the time of intrusion detection, it is not necessary to control the light source output, and it becomes easy to restart after interruption or dimming.

  When intrusion of a human body or the like is detected, it is possible to reduce the intensity of irradiation light to the entire drawing range or a partial area thereof or to set it to zero. In other words, when blocking or dimming the entire drawing range, the circuit configuration is simple and safe, and when blocking or dimming a part of the drawing range, the drawing image is blocked or reduced. The light range can be minimized. In addition, the image projection is blocked by limiting the human body and the vicinity area of the intruder (including the area surrounding the intrusion detection position), or the partial image is drawn within a range where there is no problem in ensuring safety. Can do.

  Further, by modulating the intrusion detection light and detecting the detection signal of the return light from the screen, the detection sensitivity can be improved, which is effective for reducing the light amount.

  The present invention can be applied to an image projection apparatus (for example, an apparatus that forms a one-dimensional image projected using a laser light source on a screen and generates a two-dimensional image by scanning the one-dimensional image). In application to an image display device using an intense light source, the object is to prevent the adverse effects of light irradiation on the human body, etc., and to ensure safety. For example, the following items are provided. .

・ Intrusion detection device and method for drawing range (drawing light irradiation range) using confocal optical system ・ Configuration and method for blocking or dimming drawing light when detecting intrusion of human body etc. ・ Detection wave for intrusion detection In order to be able to respond flexibly to the response speed of the device, the device price, the drawing scanning method, etc. by elaborating on the positional relationship between the (invisible detection light) and the drawing light of the image Configuration form and method-Configuration form for improving intrusion detection sensitivity (modulation of detection light and detection of received light signal).

  The image display device according to the present invention, in its basic configuration, includes an optical system for displaying an image in the drawing range by irradiating the screen with light. For example, in a device (laser display device, etc.) equipped with a light source or projection means for displaying an image by irradiating the screen with laser light, a human body or an object enters the irradiation light passing area from the light source toward the drawing range. Therefore, it is necessary to take sufficient safety measures.

  As for intrusion detection of a human body or the like, there are methods using various detection waves (sound waves or the like). In the case of an optical system using detection light (hereinafter referred to as “intrusion detection optical system”), the optical system. Is provided separately from the drawing display optical system (hereinafter referred to as “drawing optical system”), the device configuration is complicated, adjustment and setting work is troublesome, and intrusion occurs. There is an inconvenience that it is difficult to improve the accuracy of detection.

  Therefore, the present invention basically employs a confocal configuration for intrusion detection, and performs intrusion detection into the irradiation range of the drawing light based on the return light from the screen.

  Note that, in the application of the present invention, any two-dimensional image drawing method may be used, and examples thereof include the following configuration forms.

A drawing optical system that projects a two-dimensional image (or a stereoscopic image, etc.) by an image modulation element (liquid crystal display element, etc.) onto the screen with a projection optical system. A projection and scanning (scanning) of a one-dimensional image onto the screen. A drawing optical system for generating a two-dimensional image.

  FIG. 1 shows a configuration example of an image display apparatus according to the present invention, and shows a main part of an application example to an image projection apparatus (so-called projector) using a laser light source and a one-dimensional light modulation element. .

  The image display apparatus 1 includes various optical elements constituting a drawing optical system and an intrusion detection optical system, and control means for them.

  First, the drawing optical system will be described. The optical system includes a light source 2 and a driving unit 3, a light modulation element 4 and its driving unit 5, a mirror 6, a light scanning unit 7, and a projection system 8.

  The light source 2 is a visible linear light source, and is simply shown as a monochromatic light source in the drawing. However, in actual color image display, of course, light sources corresponding to the three primary colors are provided.

  In this example, a laser light source 2a using a semiconductor laser, a solid-state laser, and the like, and optical components 2b, 2c, and 2d are arranged on the optical axis, and a laser beam is transmitted through the line generator 2b and the cylindrical lenses 2c and 2d in this order. Thus, the light modulation element 4 is irradiated as a one-dimensional linear beam. The output of the laser light source 2a is controlled by the driving means 3 (light source driver).

  A one-dimensional light modulation element is used as the light modulation element 4 and is controlled by receiving a signal from the driving means 5 (modulator driver) (that is, the irradiation light from the light source is modulated based on the image signal).

  In the application of the present invention, any one-dimensional light modulation element may be used. For example, a grating light valve element developed by US Silicon Light Machine (SLM) may be used. This element is configured using a reflective diffraction grating, and a plurality of movable ribbons called membranes are arranged at a predetermined interval, and a fixed ribbon is arranged between the movable ribbons. Then, by applying an appropriate voltage between the common electrode and the movable ribbon, the movable ribbon moves, and a diffraction grating for incident light is configured. That is, in this state (so-called pixel on), first-order diffracted light is generated, and in a state where the movable ribbon is not moved (so-called pixel off), no first-order diffracted light is generated (only regular reflection with respect to incident light). . An image can be displayed with high diffraction efficiency by a configuration using specific diffracted light (a blazed element is preferable for high gradation image display).

  The light modulated using such a one-dimensional light modulation element is passed through a spatial filter such as a schlieren filter (not shown) to sort the first-order diffracted light, and irradiates the light scanning means 7 through the mirror 6. Since the mirror 6 shown in this example has a property of transmitting visible light and reflecting infrared light, only drawing light (visible light) passes through the mirror 6 and reaches the optical scanning means 7.

  A rotary reflecting mirror is used for the optical scanning means 7 and the reflected light is irradiated toward the front screen “SCN” through the projection system 8 (for the sake of simplicity, only the projection lens is shown as a single lens in the figure). Is done. Examples of the scanning method include a form using a galvano mirror, a polygon mirror, or the like. In this example, the galvano mirror 7a and its driving means 7b are used.

  The one-dimensional image by the laser light is developed and projected into a two-dimensional image on the screen by optical scanning and projection. That is, a drawing line indicated by a vertical line “VL” moves on the screen SCN in FIG. 1 in a scanning direction (see arrow “SS”) orthogonal thereto, so that a two-dimensional display image is generated.

  In this example, the projection system 8 is arranged between the optical scanning unit 7 and the screen SCN. However, the present invention is not limited to this, and the optical element is changed such that the positional relationship between the optical scanning unit and the projection system is reversed. It can be implemented in various forms.

  Next, the intrusion detection optical system will be described.

  The intrusion detection optical system has a configuration for forming an image of detection light from the detection light source 9 on the screen SCN and detecting return light from the screen SCN.

  The wavelength of the detection light from the detection light source 9 is invisible light (infrared light, ultraviolet light, etc.) in consideration of the influence on the drawing light. For example, the use of near infrared light or infrared light is preferable. In consideration of the necessity of spatial coherence, for example, a type using a semiconductor laser and a line generation (generation) lens as a linear light source, or a multi-source having a plurality of emitters (radiation sources) is considered. An embodiment using an emitter semiconductor laser or a wide stripe semiconductor laser is preferable, but various light sources (linear filaments, discharge lamps, etc.) can be used as necessary. Of course, the detection light is non-visible light, and its power is set to a sufficiently low level necessary for detection, and there is no influence on the human body.

  In the illustrated example, the detection light source 9 is an infrared linear light source, an infrared light source 9a using a semiconductor laser or the like is disposed, and the optical components 9b to 9d and the slit 9e are positioned on the same optical axis. . A line generator (lens) 9b, a cylindrical lens 9c, a cylindrical lens 9d, and a slit 9e are arranged in this order from the side closer to the infrared light source 9a.

  Separating means 10 and a quarter wavelength plate (λ / 4 plate) 11 are arranged between the light source 9 for detection and the mirror 6. In this example, the light for separating the return light from the screen SCN is separated. A polarization separation mirror (PBS: polarization beam splitter) is used as the separation means 10.

  The light (forward infrared light) transmitted from the detection light source 9 through the separating means 10 and the quarter wavelength plate 11 is reflected by the mirror 6 and then passes through the optical scanning means 7 from the projection system 8 toward the screen SCN. Irradiated.

  As described above, in order to irradiate the detection light (invisible light detection wave) toward the drawing range of the screen SCN or the region including the drawing range and form the intrusion detection pattern on the screen SCN, this example The optical system (projection system) including the light source 9 for detection, the optical components (10, 11, 6), the optical scanning means 7, and the projection system 8 is used. With this optical system, an intrusion detection pattern (for example, a linear pattern or a detection spot array formed by scanning a point image) is formed directly on the screen, in the vicinity thereof, or at a certain distance. The pattern can be scanned with the one-dimensional image.

  For example, a linear intrusion detection pattern is projected along with the one-dimensional image along the vertical line VL shown on the screen SCN of FIG. 1, and moves along the scanning direction SS (intrusion detection pattern for the one-dimensional image). Will be described later in detail). When the same optical scanning unit 7 is used for the scanning system related to the one-dimensional image and the scanning system related to the intrusion detection pattern, the configuration is simplified as compared to the configuration using the optical scanning units that are separately and synchronized with each other. It is advantageous for reducing the number of points and cost.

  The detection light reflected on the screen SCN is detected by the detection means 12 after reaching the separation means 10 along a path opposite to the forward path. That is, the detection light (return infrared light) is reflected by the mirror 6 after passing through the projection system 8 and the optical scanning means 7, then transmitted through the quarter-wave plate 11, and then reflected by the separating means 10 to be detected. The means 12 is reached.

  As the detection means 12, for example, a detection means constituted by arranging a line detector or a point-like detection element in a one-dimensional (linear) manner is used. Examples include a combination of a slit and a detector, a linear imaging element (CCD type, CMOS type, etc.), a linear sensor (line light receiving element), and the like. In this example, the detection light source 9 and the detection means 12 are configured separately. However, when an optical integrated device in which both the optical elements and the optical elements are integrated and packaged is used, miniaturization and high accuracy are achieved. It is advantageous in terms of the above.

  FIG. 2 is a plan view showing an outline of the optical system. In order to clarify that the detection means 12 for detecting light has a confocal configuration (in the case of line illumination, it is not always necessary to have a confocal configuration only in a view from an oblique side as in FIG. This is an example of a configuration when viewed from a direction perpendicular to the plane including the normal direction of the screen surface and the scanning direction (or a direction orthogonal to the plane including the optical axis).

  In the drawing optical system, the laser light source 2a is simply indicated by a circle in the drawing, and the optical components (2b to 2d) are simply indicated by a single lens. These constitute a linear illumination light source for the light modulation element 4.

  Further, in the intrusion detection optical system, elements (the above 9a to 9d) other than the slit 9e (the slit forming direction extends in a direction perpendicular to the paper surface) constituting the detection light source 9 are shown in a square shape in the figure. These are shown in a simplified manner, and these constitute a linear infrared light source for intrusion detection. The detection means 12 is configured by using a slit 12a (the slit is formed in a direction perpendicular to the paper surface) and a photodetector 12b that is simplified by a circle in the drawing.

  For the light receiving system that detects the return light from the intrusion detection pattern imaged on the screen SCN, the return light reflected by the screen is detected by the detection means 12. That is, the reflected light from the screen passes through the projection system 8, the optical scanning unit 7, and the mirror 6 and is transmitted through the quarter-wave plate 11, but the polarization state changes according to the half-wave phase difference generated by the reciprocation. Therefore, the return light separated by the separating means 10 passes through the slit 12a after reflection and reaches the photodetector 12b.

  In this way, in a projection-type device form in which a one-dimensional image is formed using a one-dimensional light modulation element and a two-dimensional image is formed by optical scanning, a one-dimensional image formed on the screen every moment. An invisible light detection pattern is formed on or near the image. By using the light receiving system in which the detecting means 12 is arranged at a position where the confocal configuration is realized with respect to the pattern, the characteristics of the confocal optical system, that is, only when the detection pattern is imaged on the screen, the light receiving system is reached It is possible to accurately detect the intrusion of the drawing light into the passage region by utilizing the fact that the return of light occurs. In the confocal configuration, the light that can enter the photodetector 12b is only the light that is in a confocal position (screen position). For this reason, even if the human body or the intruder has high reflectivity, the return light detected by the light receiving system is greatly reduced because they are always located in front of the screen (on the apparatus side). Therefore, accurate intrusion detection can be performed regardless of the reflectance of the human body or the intruder.

  Regarding the method for separating the detection light and the drawing light, in this example, the mirror 6 has a characteristic of reflecting infrared light and transmitting visible light. However, the present invention is not limited to this, and transmits infrared light and reflects visible light. Of course, a configuration using a mirror is also possible (however, in this case, after the linear beam by the visible light source for drawing is irradiated to the one-dimensional light modulation element, the light reflected by the mirror is applied to the optical scanning means). On the other hand, the optical system is designed so that after the linear beam from the infrared light source for intrusion detection passes through the separating means and the quarter-wave plate, the light passing through the mirror is applied to the optical scanning means. There is a need to.).

  Next, detection of a human body and an intruder with the intrusion detection optical system will be described with reference to FIG.

  FIG. 3 schematically shows the positional relationship of a foreign substance (indicated by a circular object “A” in the figure) with respect to the projection system 8, the optical scanning means 7, and the screen SCN, and the intrusion of a foreign substance is detected below the positional relation. In this case, a graph showing the level change of the detection signal “DS1” of the detecting means 12 in the optical scanning direction is arranged (the scanning direction shown on the horizontal axis is the horizontal direction of the display screen or the time lapse direction). Corresponding.)

  In the state in which the drawing light and the detection light are scanned along the direction indicated by the thick arrow “SS” in the figure by the optical scanning means 7 and imaged on the screen SCN, the level of DS1 is constant. When the detection light is blocked, the DS1 level rapidly decreases. That is, when there is a foreign substance in the drawing light passing area on the screen and the detection light no longer forms an image on the screen, there is no return light to the light receiving system, and in the range indicated by “T1” in the figure, The DS1 level drops to almost zero.

  Accordingly, it is possible to determine whether a foreign substance or the like has entered since the level of the detection signal DS1 of the detection unit 12 is equal to or lower than a predetermined threshold value or the level of the detection signal is out of the allowable range.

  In this example, a threshold “Sh1” indicated by a broken line is defined in advance for DS1, and for example, when it is determined that “DS1 ≦ Sh1”, the presence and position of a human body or an intruder are detected. Is done.

  FIG. 4 exemplifies intrusion detection in a direction orthogonal to the optical scanning direction. The positional relationship between the screen SCN and a foreign object (indicated by a circular object “A” in the figure) viewed from the direction along the image projection direction is schematically shown. In addition, a graph showing the level change of the detection signal “DS2” of the detection means 12 in the direction parallel to the vertical line VL when an intrusion of a foreign object is detected is arranged on the right side. (The axis extending in the vertical direction represents the detection position (detection position of the linear beam) of the detection light in the vertical direction of the screen, and the direction of the axis corresponds to the vertical direction of the display screen.)

  In the state in which the drawing light and the detection light are scanned along the direction indicated by the thick arrow “SS” in the figure by the optical scanning means 7 and imaged on the screen SCN, the level of DS2 is constant. At the position where the detection light is blocked, the DS2 level rapidly decreases. That is, when there is a foreign object in the drawing light passage area on the screen and the detection light does not form an image on the screen, there is no return light to the light receiving system, and in the range indicated by “T2” in the figure. DS2 level drops to almost zero.

  Accordingly, it is possible to determine whether a foreign substance or the like has entered since the level of the detection signal DS2 of the detection unit 12 is equal to or lower than a predetermined threshold value or the level of the detection signal is out of the allowable range.

  In this example, a threshold value “Sh2” (for example, “Sh2 = Sh1”) indicated by a broken line is defined in advance for DS2, and when it is determined that “DS2 ≦ Sh2”, a human body, an intruder, etc. And its position is detected.

  As described above, when a human body or the like enters the space (drawing light passage area) formed between the projection system and the screen, the amount of detection of return light to the light receiving system decreases. Therefore, this is detected to block the irradiation of the drawing light or reduce the light intensity. That is, accidents (irradiation to the fundus etc.) can be prevented in advance by blocking the drawing light or reducing the irradiation intensity.

  In addition, since the occurrence of erroneous detection or the like may be a problem in intrusion detection when the amount of light is reduced, in such a case, a specific frequency component included in the return light detection signal is separated and the level detection is performed. Preferably it is done. That is, as a signal separation method, the detection light may be modulated by signal superimposition of a specific frequency and a specific frequency component may be extracted by detection of the return light.

  In the example shown in FIG. 1, the detection sensitivity is improved by applying a configuration in which modulation is applied to the intrusion detection pattern and the detection signal of the return light by the detection unit 12 is detected.

  The control unit 13 includes a modulation drive unit 14 indicated by a symbol of an AC source in the figure, a detection unit 15 and a determination unit 16, and the processing of the determination unit 16 is performed using calculation means such as a computer, for example. Is called.

  A drive signal of a predetermined frequency generated from the modulation drive unit 14 is supplied to the infrared light source 9a of the light source 9 for detection or a drive circuit for the light source, thereby modulating the light for detection. Further, a signal having the same frequency as described above is transmitted from the modulation driver 14 to the detector 15.

  The received light signal obtained by the detection means 12 is converted into an electric signal, and then sent to the detection unit 15 to be detected, and detection signals (corresponding to DS1 and DS2 above) of the modulation frequency component are sent to the determination unit 16. It is done. Then, for example, the comparison determination with the threshold value is performed as described above, and a control signal corresponding to the comparison result is sent from the determination unit 16 to the driving unit 3 of the light source 2 and the driving unit 5 of the light modulation element 4. .

  Examples of configurations for blocking drawing light and reducing irradiation intensity when intrusion of a human body or the like is detected during image projection onto the screen include the following modes.

(1) Control of light source output (2) Drive control of light modulation element (3) Combined use of (1) and (2).

  First, in the above form (1), the drawing light adversely affects the human body and the intruder by reducing or blocking the output of the image display light source (laser light source 2a in the example of FIG. 1) to the drawing range. Do not hit For example, in FIG. 1, by sending a control signal from the determination unit 16 to the driving means 3 (light source driver in this example), the output of the laser light source 2a is lowered to a safe level when a human body or the like enters. Set the output to zero.

  Moreover, in the said form (2), at the time of invasion of a human body etc., the intensity | strength of drawing light is reduced or made zero by controlling a light modulation element. For example, by sending a control signal from the determination unit 16 to the driving means 5 (modulator driver in this example) in FIG. 1, the intensity of the output light of the light modulation element 4 is brought to a safe level when a human body or the like enters. Decrease or zero (for GLV device, pixel off state, etc.).

  The form (3) can further improve safety by using (1) and (2) in combination, and can cope with a situation such as when either one stops functioning.

  Next, a description will be given of a form in which drawing light is blocked when intrusion of a human body or the like is detected.

  FIG. 5 shows the positional relationship of foreign matter (interfering matter) with respect to the projection system 8, the optical scanning means 7, and the screen SCN. The foreign matter indicated by “A” is shown in a simplified column shape.

  The safety mechanism in the event that a human body or object enters the irradiation light passing area toward the drawing area on the screen is controlled according to the form that uniformly blocks the drawing light and reduces the intensity, and the state of the intrusion. There is a form to change the state. Further, there are a form in which the drawing light intensity is reduced or defined to zero for the entire drawing range, and a form in which the drawing light intensity is reduced or defined to zero for a partial region of the drawing range.

  6 to 10 are diagrams for explaining various light blocking modes (including light blocking and dimming), where the satin portion indicates a blocking (or dimming) region on the screen, and a broken line circle “ “AC” represents the detection range (outer shape) of a foreign object (interfering object).

・ Full screen shading mode (see Fig. 6)
・ Linear area shading mode (see Fig. 7)
・ Shadow shading mode (see Fig. 8 and Fig. 9)
・ Range expansion shading mode (see Fig. 10)
・ Combination of various modes.

  First, in the full screen shading mode, as shown in FIG. 6, sufficient safety measures can be taken by completely blocking the irradiation light on the screen SCN or by darkening the display of the entire screen (full frame). it can. Since a line sensor or the like is not required as detection light detection means (one-dimensional image identification is not necessary), for example, a simple circuit configuration such as a configuration using a slit and a single photodetector can be adopted. Is possible. Further, even if the response time of the sensor constituting the detection means is not fast, if it is less than one frame time, the effect of improving the safety is sufficiently secured, and the preliminary safety is high.

  Further, the line-shaped region light blocking mode is a mode in which the irradiation light directed to a part of the drawing range is blocked or the intensity thereof is reduced, and the output of the drawing light source is blocked or dimmed only at the moment when the intrusion of a human body or the like is detected. Alternatively, a command for blocking or dimming the irradiation light to all pixels may be issued to the driving means 5 for a predetermined time with respect to the light modulation element.

  For example, as shown in FIG. 7, only the vertical line-shaped region including the width of the broken-line circle “AC” and extending in the vertical direction of the screen is the target region for blocking or dimming, and the other regions are used for drawing light. Irradiation continues. Since a line sensor or the like is not required as detection light detection means, a simple circuit configuration can be adopted. Further, the entire display stop state can be avoided by partially blocking or dimming the image.

  The shadow light shielding mode is a mode in which only the foreign matter detection range is targeted, and the irradiation light to the range is blocked or its intensity is reduced. In other words, since the area where the foreign matter detected using the detection light is present appears as a shadow on the screen, for example, as shown in FIG. 8, only a limited area including the broken-line circle “AC” is displayed. Is a target area for blocking or dimming. Although a line sensor or the like is required as detection means for detection light, the light intensity can be limited only in a spatial region (solid angle) where it is desired to avoid light irradiation on a human body or an object, and the drawn image is blocked or reduced. The range of light can be minimized.

  Further, in a form in which the region remains in the optical scanning (scanning) direction (an afterimage type, that is, a form in which the shadow of the detection range of a foreign substance or the like is maintained as a residual image in the optical scanning direction), as shown in FIG. As described above, the limited area including the broken-line circle “AC” is shifted in the direction indicated by the arrow “SS” (scanning direction). That is, the area including the broken-line circle “AC” and the area corresponding to the delay time specified in advance for the area are set as areas to be blocked or dimmed, and the area expands in the scanning direction as time elapses. It will be. As a result, the range can be further expanded to limit irradiation, so that safety can be enhanced.

  The range expansion light shielding mode is a mode in which the light shielding range corresponding to the foreign object detection range is gradually expanded to block the irradiation light to the range or reduce its intensity. For example, as shown in FIG. 10, in the image (frame) at the time when the foreign object is first detected, only a limited area including the broken-line circle “AC” is set as a target area to be blocked or dimmed (initially). The frame is the same as the shade shading mode.) However, since the area is expanded outward as the image frame progresses, the target range expands with time. In this way, as the image frame (or the detection frame) progresses, the light-shielding range corresponding to the detection target range can be expanded to limit irradiation. For example, the boundary of the human body or object that is the detection target is In the case of unclearness, drawing light can be blocked or shielded with sufficient space without relying on detection accuracy. The afterimage type can also be interpreted as being included in a broad range expansion light-shielding mode (that is, a mode in which the light-shielding range is not expanded in the radial direction, but is expanded in a certain direction (scan direction)). Think about it.)

  When returning from the range-enhanced shading mode, return to the original drawing mode on condition of safety confirmation, or perform the original drawing after going through the range reducing mode that gradually reduces the shading range corresponding to the foreign object detection range You can return to mode.

  Of course, each of the above modes can be independently adopted, but in the case of using such a combination of various modes, not only the presence / absence of the intrusion of the human body but also the detailed in accordance with the intrusion situation. Safety measures can be taken. For example, when there are a large number of human bodies or objects detected, the full-screen shading mode is displayed with priority given to safety, and within a range that does not hinder safety in consideration of the number of detections, detection area, etc. The line-shaped region light shielding mode, the shadow light shielding mode, the range expansion light shielding mode, and the like can be used properly.

  Next, the positional relationship between the intrusion detection pattern by the detection light (invisible light) and the drawing line (visible light) will be described with reference to FIGS.

  In a projection type configuration in which a one-dimensional image is formed using a one-dimensional light modulation element, and this is developed and displayed as a two-dimensional image on a screen by optical scanning, the one-dimensional image formed on the screen is displayed. As described below, there is a form in which the scanning light is formed by forming the detection light into a linear image or a spot shape.

・ Line adjacent type (see Fig. 11)
・ Detection line preceding type (see Fig. 12)
・ Bidirectional detection line type (see Fig. 13)
-Detection spot type (see FIG. 14).

  11 to 13, each vertical line indicated by “R” (red), “G” (green), and “B” (blue) indicates a primary color drawing line (visible light line). There are a form in which each drawing line is overlapped and displayed, and a form in which each drawing line is displayed with a slight shift in consideration of ensuring safety, but in either form the intrusion detection pattern is relative to the drawing line. It is necessary to precede the scanning direction.

  First, in the line adjacent type, as shown in FIG. 11, the detection line of the detection light (invisible light) is a vertical line indicated by “DL”, and the line is arranged adjacent to the drawing line. A scan is performed. Then, a vertical line including the detection line is scanned along the direction (scan direction) indicated by the arrow “SS1” to form a two-dimensional image on the screen (the detection line is invisible). The detection line DL is adjacent to the drawing line at the end (right end) in the scanning direction.

  In this example, the unidirectional scanning method is used, and the left edge of the display screen is set as the scanning start position, and the right edge is set as the scanning end position. That is, after the optical scanning is started from the left edge and the vertical line is scanned to the right in the figure, when the right edge is reached, the scanning returns to the left edge again and the optical scanning is repeated (with flyback).

  The detection result of the line sensor or the like constituting the detection means 12 can be immediately reflected in the drawing image blocking or dimming control, and is effective for application to the shadow shading mode or the like.

  In the detection line preceding type, as shown in FIG. 12, the detection line DL is arranged at a position away from the drawing line by a certain distance “d” in the scanning direction (see arrow SS1). That is, since the detection line DL is scanned prior to the visible light line, the time from when the intrusion of a human body or the like is detected using the line until the delay time corresponding to the distance “d” elapses. It is possible to take safety measures such as blocking the drawing line and dimming.

  In this example, the unidirectional scanning method is also employed.

  In the detection line advance type, it is possible to sufficiently secure the time required for the intrusion detection process by causing the detection light to precede the drawing light in the scanning direction.

  In the bidirectional detection line type, a bidirectional scanning method is adopted, and the left edge and the right edge of the display screen are set as a scanning start position and a scanning end position. For example, the optical scanning is started from the left edge, and after the vertical line is scanned in the direction indicated by the arrow SS1 in FIG. 13, when the right edge is reached, the optical scanning is performed along the opposite direction indicated by the arrow SS2 in FIG. Done. When the original left end edge is reached, the operation of starting optical scanning again in the direction of arrow SS1 from the left end edge is repeated (no flyback).

  In this embodiment, since the scanning direction is reversed by reaching the left and right edges of the screen, the detection lines DL1 and DL2 corresponding to each direction are used. That is, the detection line DL1 is used for intrusion detection in the SS1 direction, and the detection line DL2 is used for intrusion detection in the SS2 direction.

  In this case, there are a form in which DL1 and DL2 are arranged adjacent to the drawing line, and a form in which the detection line is scanned in advance in each scanning direction by separating DL1 and DL2 from the drawing line. FIG. 13 exemplifies the latter, and in the case where the drawing light is scanned in both directions, a function equivalent to the detection line preceding type can be realized.

  In the examples of FIGS. 11 to 13, a linear detection pattern (detection line) is used, and a confocal configuration is obtained in the scanning direction, but in a direction orthogonal to the scanning direction (vertical direction in the figure). In order to obtain a confocal configuration, a detection pattern in which a plurality of detection spots are arranged in the vertical direction is used to construct an optical system with a shallower depth of field, that is, a higher detection sensitivity. It becomes possible to do.

  In the detection spot type form, intrusion detection is performed using a plurality of detection spots (see “SP” in FIG. 14) arranged in a line instead of the detection lines.

  For example, as shown in FIG. 14, detection spots SP, SP,... By detection light (invisible light) are arranged on the vertical line at a predetermined interval, and these detection spots are arranged in the vicinity of the drawing line. Has been. Then, the detection spot row and the drawing line are scanned along the direction (scan direction) indicated by the arrow “SS1” to form a two-dimensional image on the screen (the detection spot is invisible).

  In the case of the unidirectional scanning method, as described above, there are a form in which the detection spot row is brought close to the drawing line and a preceding form in which the detection spot row is separated from the drawing line. Further, in application to the bidirectional scanning method, a detection spot row for each scanning direction can be used, and each detection spot row may be arranged on the opposite side across the drawing line (with respect to the drawing line). There are a mode in which the detection spot row is brought close and a preceding type in which the detection spot row is separated from the drawing line.

  In the configuration form in which the detection spot row is formed by scanning the point image of invisible light, the point image scanning position and the detection position in the detection means or the selection of the corresponding detector when using a plurality of detectors are 1 Synchronous control is required to correspond to one-to-one.

  FIG. 15 is an explanatory diagram exemplifying a detection spot type, and shows how detection spots are arranged in the vertical and horizontal directions on the screen. This is effective when it is desired to cover the detection spots in a lattice arrangement in the intrusion detection range in an application form using a two-dimensional light modulation element without performing optical scanning. Further, it is not necessary to combine with the optical scanning optical system, and the intrusion detection optical system can be configured independently.

  As described above, a linear pattern or detection spot group is used for intrusion detection, and in the confocal optical system, the return to the light receiving system is performed only when the detection line or detection spot is imaged on the screen. Utilizing the fact that light is obtained makes it possible to quickly and accurately detect the presence and position of a human body or object that obstructs the detection line or detection spot.

  According to the configuration described above, the following various advantages can be obtained.

・ It is possible to flexibly set the positional relationship between the screen and the main body of the image display device. ・ There is little influence on the intrusion detection due to the reflectance of the intruder.・ Can detect high-reflectivity interfering objects and reflectors, detect screen movement, etc. ・ Can block on the screen or minimize the dimming area. It is possible to cut off or reduce the light to a limited area including the above. ・ Able to realize an inexpensive safety device using a simple optical system when used in combination with the drawing optical system (visible optical system). Advanced calculation processing such as image processing is not necessary.-By detecting the return light from the screen by modulating the detection light, it is possible to detect even weak light and contribute to the improvement of sensitivity.

It is a figure which shows the structural example of the image display apparatus which concerns on this invention. It is explanatory drawing which concerns on the optical system of FIG. It is a figure for demonstrating intrusion detection in the optical scanning direction. It is a figure for demonstrating intrusion detection in the direction orthogonal to the optical scanning direction. It is the schematic which shows the positional relationship of the foreign material (interference thing) with respect to a projection system, an optical scanning means, and a screen. FIG. 7 is a diagram for explaining various light shielding modes together with FIG. 7 to FIG. 10, and FIG. It is explanatory drawing of a linear area | region light shielding mode. It is explanatory drawing of shadow shading mode. It is explanatory drawing of an afterimage type (shadow shading mode). It is explanatory drawing of the range expansion light-shielding mode. FIGS. 12 to 14 are diagrams for explaining the positional relationship between the intrusion detection pattern and the drawing line, and this diagram is an explanatory diagram of a line adjacent type. It is explanatory drawing of a detection line preceding type. It is explanatory drawing of a bidirectional | two-way detection line type. It is explanatory drawing of a detection spot type | mold. It is explanatory drawing which shows another example of a detection spot type | mold.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Image display apparatus, 2a ... Laser light source, 4 ... Light modulation element, 7 ... Optical scanning means, 12 ... Detection means

Claims (13)

In the image display device provided with a safety mechanism against intrusion into the passage area of the irradiation light toward the drawing range while performing image display in the drawing range by light irradiation to the screen,
An optical system for forming an intrusion detection pattern on the screen by irradiating a detection wave of invisible light toward the drawing range or an area including the drawing range, and intrusion detection imaged on the screen An image display apparatus comprising: a light receiving system for detecting return light from the pattern for use, constituting a confocal optical system, and detecting entry into the passage region based on a change in the light amount of the detection wave. The image display device according to claim 1,
Forming a one-dimensional image projected using a laser light source on a screen and generating a two-dimensional image by scanning the one-dimensional image;
The intrusion detection pattern is imaged at a position immediately above or in the vicinity of the one-dimensional image or at a certain distance from the optical system related to the detection wave of invisible light. The image display device according to claim 2,
By the optical system relating to the detection wave of invisible light, a linear intrusion detection pattern or an intrusion detection pattern composed of a plurality of detection spots arranged on the straight line is formed and scanned together with the one-dimensional image An image display device characterized by that. The image display device according to claim 3,
The same optical scanning unit is used for the scanning system related to the one-dimensional image and the scanning system related to the intrusion detection pattern. The image display device according to claim 1,
An image display device characterized by reducing or blocking the output of the light source for image display to the drawing range when an intrusion into the passage area is detected by the detection means constituting the light receiving system. The image display device according to claim 1,
An image display light source that outputs drawing light in the drawing range, and a light modulation element that modulates light from the light source based on an image signal;
An image display device characterized by controlling the light modulation element to reduce or reduce the intensity of the drawing light when intrusion into the passage region is detected by the detection means constituting the light receiving system . The image display device according to claim 5,
An image display device characterized in that, when an intrusion into the drawing range is detected, the intensity of irradiation light to the entire drawing range or a partial region thereof is reduced or set to zero. The image display device according to claim 6,
An image display device characterized in that, when an intrusion into the drawing range is detected, the intensity of irradiation light to the entire drawing range or a partial region thereof is reduced or set to zero. The image display device according to claim 1,
An image display device characterized by modulating the detected wave and detecting a detected wave signal by a detecting means constituting the light receiving system. In the control method of the image display device, which performs image display in the drawing range by light irradiation on the screen, and controls the intensity of the irradiation light by detecting the intrusion of the irradiation light toward the drawing range into the passage region,
An intrusion detection pattern is formed on the screen by irradiating a detection wave of invisible light toward the drawing range or an area including the drawing range by an optical system, and an intrusion detection imaged on the screen is formed. An image characterized in that the presence or absence of intrusion into the passage area is detected based on the change in the amount of light by detecting the return light that reaches the light receiving system through the optical system as reflected light of the pattern for use. Display device control method. In the control method of the image display device according to claim 10,
A one-dimensional image projected using a laser light source is imaged on the screen and scanned in a predetermined direction to generate a two-dimensional image,
A control method for an image display device, wherein the intrusion detection pattern is imaged immediately above or in the vicinity of the one-dimensional image or at a position separated by a certain distance. In the control method of the image display device according to claim 10,
By determining whether or not the detection signal level relating to the detection wave is equal to or less than a predetermined threshold value or out of an allowable range, intrusion and position with respect to the passing region are detected, and the detection result A control method for an image display device, characterized in that the drawing light intensity in the drawing range is reduced or defined to be zero. In the control method of the image display device according to claim 12,
A method for controlling an image display device, wherein when the intrusion into the passage area is detected, the light shielding range is the entire drawing range or a range surrounding the intrusion detection position.

Images