JP2005031527A - Picture projection device and picture projection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a picture projection device and a picture projection method by which the entrance of a comparatively small entering body is monitored by using a camera and a sensor having ordinary detecting resolution even in the case of performing projection in a comparatively wide range. <P>SOLUTION: In the picture projection device where projected light corresponding to image information is projected by a projection means 10, two or more monitor areas 14 and 17 for monitoring that the entering body 19 enters a projection area 16 where the projected light is projected are set. Then, the respective areas 14 and 17 are set to be different in size. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image projecting method and an image projecting apparatus that perform image display by projecting projection light corresponding to image information onto a screen or the like.

  In a device using a laser, if the laser light enters the human eye, it may affect the eyes. For this reason, in order to ensure the safety of the laser, the method of use is stipulated in the international standard IEC-60825 by the laser output for the equipment using the laser.

  In the so-called projector that uses a laser to scan the laser and project it onto the screen, the international standard IEC-60825-3 is used as a laser show guidance from the place where the audience can enter the floor surface. It is specified that the distance is 3 m or more in the upward direction and 2.5 m or more in the horizontal direction.

  However, in reality, there are few theaters that can project the laser with sufficient separation from the audience in this way, and projection outside the theater is also limited.

  APR (Automatic Power Reduction) has been proposed as a method for preventing the audience and other human bodies from inadvertently hitting the laser in compliance with the guidance of the international standard IEC60825-3. For example, the light output is reduced or cut off by controlling the output of the light source based on the detection output from the detection means and the detection means from the detection means for detecting the intrusion of the moving body from the projection optical system to the projection area on the screen. A television receiver is proposed (see, for example, Patent Document 1).

  The international standard IEC60825-1 (Amendment 2) stipulates that there is no possibility of traversing a shape having a diameter of 12 mm and a length of 80 mm. This assumes the size of a human finger. Therefore, when the APR system is applied to an image projection apparatus, the minimum detectable dimension is required to be a finger size of 12 mm × 80 mm.

  It is possible to easily consider a sensor and a detection method that can detect an object having such a size by monitoring a narrow range with a sensor placed at a short distance. When a narrow range is detected, a sensor having a resolution with a detection interval of about 10 mm may be used. For example, when detecting with a CCD (Charge Coupled Device) camera, when monitoring a range of 2 m × 1 m, if there is a resolution of about 200 × 100 points, it is possible to monitor points at intervals of 10 mm.

  However, in order to monitor a range surrounding a large screen of 20 m × 10 m, a resolution of 2000 × 1000 points is required, which is difficult to realize in terms of selecting an appropriate sensor device and speed of a signal processing system.

  Also, when monitoring at a low resolution of about 200 × 100 points, a small object of 10 cm or less cannot be detected, and thus the finger size cannot be detected.

Thus, in order to monitor a relatively wide range, the resolution required for the sensor becomes high even when a method other than the above-described CCD is used, so it is difficult to obtain an appropriate device.
Japanese Unexamined Patent Publication No. 4-111585

  The present invention solves the above-mentioned problems, and can monitor the entry of a relatively small intruder using a camera, sensor, etc. having a normal detection resolution even when a relatively wide range of projection is performed. An image projection apparatus and an image projection method are provided.

  In order to solve the above-described problems and achieve the object of the present invention, the present invention provides an image projection apparatus that projects projection light corresponding to image information by a projection means, and an intruder enters the projection area where the projection light is projected. Two or more monitoring areas to be monitored are set, and each monitoring area is set to a different size.

  According to the present invention, in the configuration described above, the monitoring area is defined as the first and second monitoring areas monitored by the first and second monitoring means, respectively, and the second monitoring area is compared with the first monitoring area. And set to a narrow area.

  As described above, in the present invention, in the image projection apparatus that projects the projection light corresponding to the image information by the projection means, the monitoring area for monitoring the intruder to enter the projection area where the projection light is projected is 2. By setting the above, the detection resolution of these two or more monitoring areas is set independently, so that intruders can enter the monitoring area with a relatively low resolution even when an image is projected over a relatively wide range. It is possible to monitor and detect an intruder as small as the size of a human finger of about 12 mm × 80 mm reliably in another monitoring area with a relatively high detection resolution.

  Furthermore, in the present invention, the monitoring area is the first and second monitoring areas monitored by the first and second monitoring means, and the second monitoring area is narrower than the first monitoring area. Thus, by using two monitoring means having the same detection resolution, a smaller intruder, for example, about 12 mm × 80 mm can be reliably detected in the relatively narrow second monitoring area.

  According to the present invention described above, even when projection light is projected over a relatively wide range, the intrusion of an intruder having a size of a relatively small finger can be reliably monitored. Thus, it is possible to reliably perform a process such as dimming or stopping, and to provide an image projection apparatus and an image projection method that are excellent in safety.

Hereinafter, each example of the best mode for carrying out the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following examples, and various other modifications and changes are possible. Needless to say.
[1] First Embodiment FIG. 1 shows a schematic configuration diagram of an image projection apparatus according to an example of the best mode for carrying out the present invention.

  In this case, two or more monitoring areas of different sizes for monitoring the intrusion of the intruder 19 into the projection area 16 projected from the projection means (not shown), the first and second monitoring areas in the illustrated example. 14 and 17.

In this case, by providing two or more monitoring areas and making the areas different, the monitoring means having the same level of detection resolution is used, and in this case the second monitoring area 17 is a relatively narrow monitoring area. A smaller intruder, for example, a finger-sized intrusion of about 12 mm × 80 mm can be reliably monitored.
[2] Second Embodiment Next, FIG. 2 shows a schematic configuration diagram of an example of an image projection apparatus suitable for application to a more specific embodiment of the present invention. As shown in FIG. 2, for example, RGB (red, blue, green) projection light is projected onto a projection area 16 at a predetermined position of the screen 15, for example, a substantially central position, by the projection unit 10, a so-called projector. The first monitoring means 11 composed of a CCD (Charge Coupled Device) camera or the like takes a picture of a first monitoring area 14 wider than the projection area 16, in the example shown, wider than the screen 15, and the image information is controlled by the control means 13. The intruder is monitored by the control means 13.

  Similarly, the second monitoring means 12 is composed of a CCD camera or the like, images the second monitoring area 17 which is narrower than the first monitoring area 14, and sends the image information to the control means 13 to send the control means. 13 monitors the intrusion of smaller intruders.

  Specifically, for example, the first monitoring unit 11 sets a predetermined distance d from the outer edge of the projection area 16 projected on the screen 15, for example, 1 to 2 m that is a range that a person cannot reach by reaching out. The first monitoring region 14 which is a wide range outside the distance d is photographed. The control means 13 takes in the image photographed by the first monitoring means 11 into the memory and stores it as an initial state. The control means 13 compares the current image of the first monitoring means 11 with the captured initial state, and if there is a difference from the initial value in the first monitoring area 14, it is assumed that a moving object such as a person has entered. In the case of a laser projector, for example, a signal for dimming or blocking the laser output is generated. The projection unit 10 dims or blocks the projection light by the dimming or blocking signal from the control unit 13.

  Here, the control means 13 does not compare the changes in the projection area 16 when comparing the initial state and the current image information. This is because the image in the projection area 16 is constantly changing due to changes in the projected video. That is, a change in the image information in the frame-like area of the first monitoring area 14 excluding the projection area 16 is detected by the processing in the control means 13.

  There are various other algorithms for detecting that a person or part of the human body has invaded. For example, a method may be considered in which an edge of extracted image information is extracted and the intrusion is performed when the edge moves.

  In this case, when it is determined that the person has entered the first monitoring area 14, the control means 13 has entered the second monitoring area 17 by the second monitoring means 12 into the first monitoring area 14. It moves to the vicinity of the position where the intruder 19 is located. The second monitoring means 12 is equipped with a so-called telephoto lens having a longer focal length than the first monitoring means 11, and a narrow range between the intruder 19 and the projection area 16 is defined as the second monitoring area 17. Start monitoring. When a part of the body such as a hand or a face enters the second monitoring area 17, the control means 13 performs control so that the projection output of the projection means 10 is dimmed or blocked.

  As described above, by interlocking control of the two monitoring means, it is possible to surely detect an intruder that cannot be realized by one monitoring means, particularly a relatively small intruder such as a part of the human body. it can.

  For example, a method of detecting a finger using a zoom lens with one monitoring camera is also conceivable. However, when zooming, a new intruder is placed in the first monitoring area 14 other than the second monitoring area 17. Cannot be detected. Therefore, it is impossible to detect an intruder having a relatively small shape such as a finger from all directions while monitoring the whole with one monitoring means.

If there are two or more intruders, it is determined from the video imaged by the first monitoring means 11 which is closer to the projection area 16, and the second monitoring area with higher resolution is closer to it. By setting 17, it is possible to monitor an intruder that is more dangerous, ie close to the projection area 17.
[3] Third Embodiment FIG. 3 shows a schematic configuration diagram of an example of an image projection apparatus suitable for application to the third embodiment of the present invention. 3, parts corresponding to those in FIG. 2 are denoted by the same reference numerals, and redundant description is omitted. In this example, the first monitoring means 11 composed of a CCD camera or the like is a relatively wide area having a predetermined distance d with respect to the screen 15, that is, the first monitoring means, as in the example described in the first embodiment. The monitoring area 14 is set to be monitored.

  The first monitoring area 15 is set outside the projection area 14 of the projection means 10 by a predetermined distance d, that is, at least, for example, 1 m or more, and from the outside of the first monitoring area 14, The finger is set not to reach the projection area 16.

  When the first monitoring means 11 detects the intrusion of the intruder 19, the control means 13 includes the second monitoring area 17 by the second monitoring means 12, in this example, the range including the intruder 19. Move to. The second monitoring means 12 is equipped with a so-called telephoto lens having a focal length longer than that of the first monitoring means 11, and has a higher resolution than the first monitoring means 11 in order to monitor a narrow range. Can be obtained. For this reason, it is possible to reliably detect the intrusion of a part of the intruder 19 that cannot be detected by the first monitoring unit 11, for example, a hand or a head.

  Further, the control means 13 may perform image processing on the video output from the second monitoring means 12 to predict the moving direction of the hand or head of the intruder 19. There are various methods for this processing. By comparing the image information for each frame at high speed, it is easy to determine in which direction the intruder 19 is moving and in which direction the hand or finger is moving. Can be detected.

  For example, as shown in FIG. 4, when it is predicted that the direction in which the intruder 19 reaches will reach the projection area as indicated by the arrow m 1, the projection output is dimmed from the control means 13 to the projection means 10. Issue a command to shut off.

  Further, as shown in FIG. 5, when it is predicted that the movement of the intruder 19 does not reach the projection area as indicated by the arrow m2, no command is issued from the control means 13, or the projection light is reduced. It is also possible to perform control to the extent that light is emitted.

As described above, the projection means 19 cannot be stopped just before the intruder 19 puts the fingertip into the projection area 16 with only the integral monitoring means, but the first and second monitoring means 11 and 12 and the control means 13 are By combining them, it is possible to perform control such as detecting an intruder having a relatively small shape such as a finger and stopping the apparatus.
[4] Fourth Embodiment Next, a schematic configuration of an example of an image projection apparatus suitable for the fourth embodiment will be described with reference to FIG. In FIG. 63, the first and second monitoring means 11 and 12 are constituted by, for example, a laser scanning detector. From these monitoring means 11 and 12, the laser is scanned as indicated by broken arrows s1 and s2, respectively, to monitor whether a person or a part of the person enters the area from the projection means 10 to the screen 15. it can.

  In general, there are a time-of-flight method and a phase difference method as a method for measuring a distance by a laser.

  In the time-of-flight method, for example, a pulse laser having a wavelength of 900 nm and a width of about 5 nm is emitted, and the time taken for the reflected light generated when it hits the object to be observed to be captured by the light receiving element is measured. Multiply and measure the distance to the observation object.

  On the other hand, in the phase difference method, a modulated laser emits light, and the distance to the reflecting object is calculated by comparing the phase of the light returned upon hitting the observation object with the emitted light.

  When used for monitoring an intruder in the present invention, sufficient monitoring by the time-of-flight method can be performed. In the time-of-flight method, the first and second monitoring means 11 and 12 including a laser scanning detector emit light while scanning a pulse laser. In order to increase the resolution, the laser spot is narrowed, the emission frequency is increased, and the scanning speed is decreased. However, it is difficult to emit light at a high frequency of about 10 kHz or more because of the limit of the emission frequency of the laser diode. Further, when the scanning speed is slowed down, the amount of laser light irradiated per unit area increases, and this laser may affect the human body and the like.

  Therefore, when a laser scanning detector is used, there is a limit to the resolution with the laser power that can be used safely.

  However, in the present invention, as shown in FIG. 6, the use of two monitoring means composed of laser scanning detectors enables finer monitoring of human intrusion.

  In this case, the first monitoring unit 11 scans, for example, a region below 1 m or more, for example, about 2 m or less below the screen 15 to reach the first monitoring region 14. The first monitoring means 11 monitors a relatively wide area as described above, and the resolution in this case can detect a human head, but cannot detect a finger of about 12 mm × 80 mm.

  When a person or a part of the human body enters the first monitoring area 14, the first monitoring unit 11 generates a detection signal and transmits the position to the control unit 13. The control means 13 moves the second monitoring area 17 by the second monitoring means 12 in accordance with the position of the invading body 19 that has entered, and starts monitoring the 19 that has been made.

  The second monitoring unit 12 can realize a higher resolution because it scans a range narrower than the first monitoring region 14 by the first monitoring unit 11. Further, the second monitoring area 17 is set closer to the projection area 16 by the projection means 10 than the first monitoring area 14, and the intruder 19 reaches the projection area 16. This is detected and a detection signal is issued.

  When a detection signal indicating the intrusion of the intruder 19 is output from the second monitoring unit 12, the control unit 13 performs control to reduce or block the power of the projection unit 10.

As described above, according to the present invention, by controlling the first and second monitoring means composed of two laser scan detectors in an interlocking manner, it can be as much as a finger that could not be detected by one laser scan detector. It is possible to detect intrusions of size.
[5] Fifth Embodiment FIG. 7 shows a schematic configuration of an example of an image projection apparatus suitable for application to the fifth embodiment of the present invention. In this example, a laser scanning detector is used as the first and second monitoring means 11 and 12. In this case, a detector having a so-called raster scan function that performs two-dimensional scanning irradiation is used. .

  In this case, the first monitoring unit 11 scans and monitors the first monitoring region 14 wider than the projection region 16 by the projection unit 10 as indicated by the broken line arrow s1. This area 14 is set at least 1 m or more, for example, about 2 m, outside of the projection area 16 by which a person reaches out, and from the outside of the first monitoring area 14, the hand and head of the intruder 19 are It is set so that it does not reach the projection area 16.

  When the first monitoring means 11 detects the intruder 19, the first monitoring means 11 including a laser scanning detector transmits a detection signal and position information of the intruder 19 to the control means 13. Based on the position information of the intruder 19, the control means 13 moves the second monitor 12 to monitor the area including the intruder 19.

  Since the second monitoring means 12 scans a narrower range than the first monitoring means 11, it is possible to obtain a higher resolution and detect the finger of the intruder 19 and the like.

  Based on the detection signal output from the second monitoring unit 12, the moving direction of the intruder 19 and the moving direction of the hand or head can be predicted by signal processing of the control unit 13. When it is predicted that the intruder 19 reaches the projection area 16 by reaching out, the control means 13 dims or blocks the projection output of the projection means 10.

  As described above, according to the present invention, two or more monitoring areas having different widths are set to monitor the intrusion of the intruder, so that the monitoring area having a relatively high resolution has a width of about 12 mm and a length of about 80 mm. Intrusion of small intruders can be reliably detected.

  Furthermore, when two or more intruders invade, by setting a relatively high resolution monitoring area on the intruder closer to the projection area, it is possible to reliably monitor the intruder with a high possibility of intrusion. It becomes possible to increase safety.

  Each example of the best mode for carrying out the present invention has been described above, but in the first to fifth embodiments, a projector that scans a laser is assumed, but it can also be applied to other high-power projectors. Is self-explanatory. Since projection type projectors such as liquid crystal projectors have high output, it is desirable to avoid viewing a light source through a projection lens even with a normal lamp. Therefore, by applying the present invention to such a large high-power projector, an image projection apparatus with high safety can be provided.

It is a schematic block diagram of an example of the image projection apparatus by this invention. It is a schematic block diagram of an example of the image projection apparatus by this invention. It is a schematic block diagram of an example of the image projection apparatus by this invention. It is explanatory drawing of the intrusion direction of an intruder. It is explanatory drawing of the intrusion direction of an intruder. It is a schematic block diagram of an example of the image projection apparatus by this invention. It is a schematic block diagram of an example of the image projection apparatus by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Projection means 11 1st monitoring means 12 2nd monitoring means 13 Control means 14 1st monitoring area 15 Screen 16 Projection area 17 2nd monitoring area

Claims (7)

In an image projection apparatus that projects projection light corresponding to image information by a projection means,
An image projection apparatus, wherein two or more monitoring areas are set for monitoring whether an intruder enters the projection area where the projection light is projected, and each monitoring area is set to a different size. The monitoring areas are first and second monitoring areas monitored by the first and second monitoring means, respectively.
The image projection apparatus according to claim 1, wherein the second monitoring area is set to be narrower than the first monitoring area. An imaging means is used as the monitoring means,
2. The image projection apparatus according to claim 1, wherein lenses having different focal lengths are used for the photographing means. Using photographing means as the monitoring means,
3. The image projection apparatus according to claim 2, wherein lenses having different focal lengths are used for the photographing means. A laser scanning detector is used as the monitoring means,
2. The image projection apparatus according to claim 1, wherein scanning ranges by the laser scanning detector are set to different widths. A laser scanning detector is used as the monitoring means,
The image projection apparatus according to claim 2, wherein the scanning ranges by the laser scanning detector are set to different widths. In an image projection method for projecting projection light corresponding to image information by a projection means,
An image projection method comprising: setting two or more monitoring areas for monitoring that an intruder enters the projection area where the projection light is projected.

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