JP2008083111A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of reducing the attenuation of light emitted from a light source, suppressing the heat generation in the projector and preventing the invasion of a human body into the space where light rays advance for forming an image. <P>SOLUTION: The light rays emitted from light sources R, G and B composed of lasers or light emitting diodes or the like are made incident on the mirror face of the front side of a scanning mirror SM, reflected and projected on an image forming region on a screen SR. On the other hand, infrared light or millimeter wave emitted from an infrared light source or a millimeter wave light source IRmm is made incident on the mirror face of the back side of the scanning mirror SM and reflected, then projected on a region larger than the image forming region. Thus, a dichroic mirror, which is used for reflecting the infrared light source or the millimeter light source IRmm is unnecessary to be installed between the light sources R, G and B and the scanning mirror SM. Thus, the attenuation of light passing through the dichroic mirror for reflecting the infrared light source or the millimeter wave light source IRmm does not take place. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projector capable of projecting an image on a screen.

Conventionally, a projector PJ as shown in FIG. 7 has been used. First, a conventional projector will be described with reference to FIG.
A conventional projector PJ has a red light source R that emits red light, a green light source G that emits green light, and a blue light source B that emits blue light. The light emitted from the red light source R passes through the dichroic mirrors DM1, DM2, and DM3 and reaches the scanning mirror SM.

  The green light emitted from the green light source G is reflected by the dichroic mirror DM1, passes through the dichroic mirrors DM2 and DM3, and reaches the scanning mirror SM. The blue light emitted from the blue light source B is reflected by the dichroic mirror DM2, passes through the dichroic mirror DM3, and reaches the scanning mirror SM. The light incident on the scanning mirror SM constitutes a predetermined color by overlapping red light, green light, and blue light together.

However, in the conventional projector PJ, each of the red light source R, the green light source G, and the blue light source B uses a laser light source or a light emitting diode light source. Since the output of a laser light source or a light emitting diode light source is high, there is a problem in that when directly projected on a human body, the human body is adversely affected.
Therefore, in order to prevent the occurrence of such a problem, a technique is used in which an area on which infrared rays are projected is formed in an area larger than the image formed on the screen SR by a predetermined range. A projector PJ using this method has an infrared light source IR. The light emitted from the infrared light source IR is reflected by the dichroic mirror DM3 provided between the other light source and the scanning mirror SM and reaches the scanning mirror SM.

According to this, when scanning of the scanning mirror SM is started, an area where infrared rays are projected is formed in an area larger than the image formed on the screen.
JP 2005-309162 A

  According to the conventional projector, dichroic mirrors DM1, DM2, and DM3 are used. The dichroic mirror DM1 is a mirror that transmits red light but reflects green light.

  The dichroic mirror DM2 is a mirror that transmits red and green light but reflects blue light. The dichroic mirror DM3 is a mirror that transmits red, green, and blue light but reflects infrared rays.

  However, the conventional dichroic mirrors DM1, DM2, and DM3 do not completely transmit light. Therefore, the dichroic mirror DM1 does not transmit 100% of red light. Further, the dichroic mirror DM2 does not transmit 100% of red light and blue light. Further, the dichroic mirror DM3 does not transmit 100% of red light, green light, and blue light.

  Therefore, the energy of the light projected on the screen is attenuated by a predetermined amount. Therefore, in order to improve the brightness of the image formed on the screen, it is necessary to increase the energy of each of the red light source R, the green light source G, and the blue light source B. However, this increases the amount of heat generated in the projector PJ.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to reduce the attenuation of light energy based on a dichroic mirror and to allow a human body to enter a space where light with high output is projected. It is to provide a projector that can be prevented.

  In the projector according to the invention, the first light source that emits light having a relatively high output, the second light source that emits light having a relatively low output, and the light emitted from the first light source are incident and reflected. A scanning mirror having one mirror surface and another mirror surface on which light emitted from the second light source is incident and reflected is provided.

  In addition, the projector emits the light emitted from the second light source after being reflected by another mirror surface so that the light reflected by one mirror surface is irradiated to an area outside the area on the screen where the light is projected. It includes a mirror that is incident and reflected, and a sensor that can detect light emitted from a second light source reflected by a screen or a member in the vicinity thereof.

  Further, the controller of the projector determines that an object has entered the path based on the state of the light emitted from the second light source detected by the sensor and stops the emission of the first light source, The intensity of light emitted from one light source is reduced.

  According to the above configuration, the human body enters the space where the light emitted from the second light source is projected before entering the space where the light emitted from the first light source is projected. Therefore, before the human body enters the space where the light emitted from the first light source is projected, it is detected that the human body has entered the space where the light emitted from the second light source is projected. The light emission of the first light source is stopped or the intensity of the light emitted from the first light source is reduced. Accordingly, it is possible to prevent the light emitted from the first light source from being projected onto the human body and adversely affecting the human body.

  Further, unlike a conventional projector, there is no need to provide a dichroic mirror between the light source and the scanning mirror that reflects the light emitted from the second light source and guides it to the scanning mirror. Therefore, attenuation of light emitted from the first light source can be reduced.

  In the projector, the first light source may include a laser beam light source or a light emitting diode light source, and the second light source may include a light source that emits infrared rays or millimeter waves. According to this, the human body is detected by using infrared rays or millimeter waves in order to prevent the human body from being irradiated with high-power light emitted from the laser beam or the light emitting diode.

  The first light source includes a red light source that emits red light, a green light source that emits green light, and a blue light source that emits blue light, and the red light, the green light, and the blue light are combined. Light may be incident on one mirror surface and reflected. According to this, the above-described present invention can be applied to a projector that displays a color image.

Hereinafter, a projector according to an embodiment of the present invention will be described with reference to the drawings.
(Embodiment 1)
As shown in FIG. 1, the projector PJ of the present embodiment includes a red light source R that emits red light, a green light source G that emits green light, and a blue light source B that emits blue light.

  The red light emitted from the red light source R passes through each of the dichroic mirrors DM1 and DM2 and reaches the scanning mirror SM. The light emitted from the green light source G is reflected by the dichroic mirror DM1, passes through the dichroic mirror DM2, and reaches the scanning mirror SM. The dichroic mirror DM1 is a mirror that transmits red light but reflects green light, as in the prior art. Further, the blue light emitted from the blue light source B is reflected by the dichroic mirror DM2 and reaches the scanning mirror SM. The dichroic mirror DM2 is a mirror that transmits red light and green light but reflects blue light.

  The positional relationship among the red light source R, the green light source G, the blue light source B, and the dichroic mirrors DM1 and DM2 may be any as long as a color image can be displayed using the three primary colors of light. .

  The light reaching the scanning mirror SM is a light that represents a predetermined color by superimposing red light, green light, and blue light. When the scanning mirror SM starts scanning light, the light reflected by the surface of the scanning mirror SM is projected onto the screen SR as shown by a broken line in FIG. 1, and an image is formed on the screen SR.

  In the present embodiment, an infrared millimeter wave light source IRmm that emits infrared rays or millimeter waves is provided. The infrared ray or millimeter wave emitted from the infrared millimeter wave light source IRmm is reflected by the mirror surface on the back side of the scanning mirror SM and reaches the fixed mirror FM. The infrared or millimeter wave reflected by the fixed mirror FM is emitted in the same direction as the light reflected by the mirror surface on the front side of the scanning mirror SM.

  The light reflected by the fixed mirror FM is projected onto a region larger than the region where an image is formed by the light reflected by the front mirror surface of the scanning mirror SM. That is, the region where the light reflected by the fixed mirror FM is projected surrounds a region where an image is formed by the light reflected by the mirror surface on the front side of the scanning mirror SM.

  Further, as shown in FIGS. 2 and 3, the scanning mirror SM has a substantially circular mirror surface (front and back) and a frame portion that holds the mirror surface. The frame portion has rotation axes x and y so as to rotate around the X axis and the Y axis, respectively. The scanning mirror SM rotates around the X axis and the Y axis by electromagnetic waves received from the magnet S pole and N pole, respectively. That is, the scanning mirror SM is a two-dimensional scanning mirror.

  In the present embodiment, meandering scanning lines are formed on the screen SR as shown in FIG. An image is formed by the light reflected by the surface of the scanning mirror SM. Further, the infrared or millimeter wave reflected by the fixed mirror FM is reflected by the fixed mirror FM and projected into the area C2. That is, the area C2 where the infrared rays or millimeter waves are projected is larger than the area C1 where the image is formed. An optical system such as the arrangement of each mirror is set so that the above-described relationship is established.

  Therefore, as shown in FIG. 5, the human body enters the space in which infrared rays or millimeter waves travel before entering the space in which the light for forming an image travels by the projector PJ. Therefore, the progress of infrared rays or millimeter waves reflected by the screen SR or its nearby members is hindered.

  Thereby, the sensor S provided in the projector PJ does not detect infrared rays or millimeter waves. Based on this, the controller C that has received a signal from the sensor S determines that the human body has entered the region C2, and reduces or blocks each of the red light source R, the green light source G, and the blue light source B. .

  Therefore, even if each of the red light source R, the green light source G, and the blue light source B is a light source with high output such as a laser light source or a light emitting diode light source, the light emission of the light source is stopped or the light source Since the intensity of light emitted from the laser beam is reduced, it is possible to prevent the human body from being adversely affected by high-power laser light or diode light.

  In the present embodiment, the controller C moves the human body to the path of the infrared or millimeter wave based on the fact that when the sensor S stops detecting the infrared or millimeter wave, the controller C stops receiving a signal from the sensor S. Although the intrusion is detected, the sensor S that can detect infrared rays or millimeter waves may be used to detect that the human body has entered the path of infrared rays or millimeter waves. In short, if the infrared ray or millimeter wave is irradiated from the projector PJ to the area C2 larger than the image forming area C1, and it is possible to detect that the human body has entered the path of the infrared ray or millimeter wave, the sensor S and The controller C may be anything.

  Further, in the projector PJ shown in FIG. 1, red light emitted from the red light source R, green light emitted from the green light source G, and blue light emitted from the blue light source B are respectively infrared rays or millimetres. Since the light does not pass through the dichroic mirror for reflecting the wave, the light enters the scanning mirror SM in a state having energy higher by the attenuation amount in the dichroic mirror for reflecting the infrared or millimeter wave. Therefore, the energy of the red light emitted from the red light source R, the green light source emitted from the green light source G, and the blue light emitted from the blue light source B can be reduced. The amount is reduced.

(Embodiment 2)
Next, the projector according to the second embodiment of the present invention will be described with reference to FIG.

  In the projector PJ of the first embodiment described above, a projector PJ having three light sources of a blue light source, a green light source, and a red light source is used to display a color image, as shown in FIG. .

  On the other hand, the projector PJ of the present embodiment is a projector PJ having only one light source L1, as shown in FIG. The light source L may be a transparent light source, but may be a light source that emits light having a predetermined wavelength, for example, a red light source.

  The projector PJ of the present embodiment has the same structure as that of the projector PJ of the first embodiment except that light emitted from one light source is incident on the scanning mirror SM. Therefore, description of the structure will not be repeated.

  Even in the projector PJ as in the present embodiment, since the dichroic mirror is not provided between the light source L and the scanning mirror SM, the light emitted from the light source L is not attenuated. Therefore, it is possible to reduce the amount of heat generated in the projector PJ.

  Further, in each of the above embodiments, the fixed mirror FM is used, but a movable mirror may be used instead. According to this, it is possible to change the relative positional relationship between a region where light for forming an image is projected and a region where infrared light or millimeter waves are projected.

  Further, in each of the above embodiments, the region where the light for forming the image is projected is included in the region where the infrared ray or millimeter wave is projected. However, if infrared rays or millimeter waves are projected to positions outside at least both sides of the four sides constituting the region where the light for forming the image is projected, the light for forming the image is projected. Infrared rays or millimeter waves may not be projected at positions outside the upper side and the lower side of the four sides constituting the area to be generated. This also prevents the human body from entering the space in which light for forming an image travels. Further, the region where the infrared or millimeter wave is projected may be a very small region. In short, the region where infrared rays or millimeter waves are projected may be any location as long as the human body can be detected before entering the space where the light for forming an image travels.

  In each of the above embodiments, light emitted from a laser light source or light emitted from a light emitting diode is used as light having a relatively high output according to the present invention. Any light may be used as long as it is considered to give light.

  In addition, although infrared rays or millimeter waves are used as light having a relatively low output according to the present invention, this is any light that is generally considered to have no adverse effect on the human body. May be.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure for demonstrating the optical system of the projector of Embodiment 1, Comprising: It is a figure which shows the state provided with the fixed mirror so that the mirror surface of the back side of a scanning mirror might be faced. It is a front view of a scanning mirror. It is the III-III sectional view taken on the line in FIG. It is a figure for demonstrating the area | region in which an image is formed, and the area | region to which infrared rays or a millimeter wave is irradiated. It is a figure for demonstrating the state which a human body tries to invade into the space where the light for forming an image advances. It is a figure for demonstrating the projector of Embodiment 2, Comprising: It is a figure which shows the state provided with the fixed mirror so that the mirror surface of the back side of a scanning mirror might be faced. It is a figure for demonstrating the optical system of the conventional projector, Comprising: It is a figure for demonstrating that the light for forming an image attenuate | damps with a dichroic mirror.

Explanation of symbols

  R, G, B, L light source, DM1, DM2 dichroic mirror, SM scanning mirror, IRmm infrared or millimeter wave light source, FM fixed mirror, SR screen, PJ projector.

Claims (3)

A first light source that emits light having a relatively high output;
A second light source that emits light having a relatively low output;
A scanning mirror having one mirror surface on which light emitted from the first light source is incident and reflected; and another mirror surface on which light emitted from the second light source is incident and reflected;
The light emitted from the second light source after being reflected by the other mirror surface is incident so that the light reflected by the one mirror surface is irradiated to a region outside the region on the screen to be projected. And the mirror reflected
A sensor capable of detecting light emitted by the second light source reflected by the screen or a member in the vicinity thereof;
Based on the state of light emitted from the second light source detected by the sensor, it is determined that some object has entered the path, and the emission of the first light source is stopped, or the first light source is stopped. A projector comprising a controller for reducing the intensity of light emitted from a light source. The first light source comprises a laser beam light source or a light emitting diode light source;
The projector according to claim 1, wherein the second light source includes a light source that emits infrared rays or millimeter waves. The first light source includes a red light source that emits red light, a green light source that emits green light, and a blue light source that emits blue light,
The projector according to claim 1, wherein light obtained by combining the red light, the green light, and the blue light is incident on the one mirror surface and reflected.

Images