JP2002196415A - Projection type image display system and projection type image display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type image display system and a projection type image display capable of surely detecting and controlling the amount of projected light in the case a body enters into an image projection region of a screen. SOLUTION: A power source circuit 32 for a lamp 31 is controlled so as to control the amount of light from a projection lens 35 in the case that a photo detector 37 of a projector 3 can not detect the light emitted from a light emitting means 2 disposed on the section in the outside of image projection region 1b of the screen 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a projection type image display device and a projection type image display device, and more particularly to a safety device therefor.

[0002]

2. Description of the Related Art A projection type image display (projector) using a liquid crystal element or a DMD (digital mirror device) has been developed. The configuration of this projector will be briefly described with reference to the drawings. As shown in FIG. 6, light from a lamp 101, which is a light source, passes through a liquid crystal element 103 driven by a liquid crystal driving circuit 102 and passes through a projection lens 1
The image is projected on the screen 105 through the screen 04. In addition, 1
Reference numeral 06 denotes a power supply circuit of the lamp 101.

[0003] In the past, it has been common practice to project the projector in a darkened room in the past. However, in recent years, there has been a demand to project on a large screen in a bright room. Accordingly, light sources and the like have been improved in response to the above demands. At present, there are many projectors in which the intensity of light projected from a projection lens is very strong. For this reason, if the projector lens 104 is inadvertently looked into the projection lens 104 when it enters between the projection lens 104 and the screen 105 while using the projector, the user may feel extremely dazzling and may hurt his eyes. Was.

Therefore, in order to solve the above-mentioned problems,
It has also been proposed that, when an object enters an area between the projection lens and the screen, the object is detected by the object detection means and the projected image is immediately displayed in darkness (for example, see Japanese Patent Application Laid-Open No. 2000-19637). However, there are problems that the configuration of the object detection means is complicated and that it is difficult to accurately determine the range of object detection from the relationship with the screen.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the range of object detection can be accurately determined, so that an object enters the image projection area of the screen. It is an object of the present invention to provide a projection-type image display device and a projection-type image display device capable of reliably detecting a case and controlling a projection light amount.

[0006]

According to a first aspect of the present invention, there is provided a projection type image display apparatus comprising: a projection type image display for projecting light from a projection lens; and a screen for displaying an image by the projection type image display. In a projection type image display device,
A light-emitting unit arranged outside the image display area of the screen, a detection unit provided in the projection type image display for detecting light from the light-emitting unit of the screen, Control means for controlling the amount of light from the projection lens when no light is detected.

According to a second aspect of the present invention, there is provided a projection type image display device.
2. The projection type image display device according to claim 1, wherein said projection type image display uses a liquid crystal element or a digital mirror device, and said detecting means includes an outer periphery of said liquid crystal element or digital mirror device. It is characterized by being arranged in a part.

According to a third aspect of the present invention, in the projection type image display device according to the second aspect, the plurality of detecting means are arranged on an outer peripheral portion of a liquid crystal element or a digital mirror device. The control means controls the amount of light from a projection lens when at least one of the detection means cannot detect light from the light emitting means.

According to a fourth aspect of the invention, there is provided a projection type image display device.
2. The projection-type image display device according to claim 1, wherein the projection-type image display uses a liquid crystal element, and the detection unit controls a liquid crystal with respect to a half mirror disposed between the liquid crystal element and a projection lens. It is characterized by being arranged at a position symmetrical to the element.

According to a fifth aspect of the present invention, there is provided a projection type image display for projecting light from a projection lens.
Detecting means for detecting light from the light emitting means arranged outside the image display area of the screen for displaying an image by the projection type image display; and light from the light emitting means could not be detected by this detecting means. Control means for controlling the amount of light from the projection lens in such a case.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a projection type image display device and a projection type image display device according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a view showing an embodiment of a projection type image display device and a projection type image display device according to the present invention.
Reference numeral 1 denotes a screen on which an image is displayed, and a plurality of light emitting elements 2 that emit infrared rays are arranged at equal intervals on an outer peripheral portion 1b of an image display area 1a of the screen 1. Reference numeral 3 denotes a projector which is a projection type image display.
FIG. 2 shows the internal configuration of the projector 3. 31 is a lamp as a light source (for example, a high-pressure mercury lamp), 32 is a light source power supply circuit for the lamp 31, 33 is a liquid crystal element, 34
Denotes a liquid crystal drive circuit for the liquid crystal element 32. Reference numeral 35 denotes a projection lens. Further, a control circuit 36 controls the power supply circuit 32 based on the output of the infrared light receiving element 37 built in the outer peripheral portion of the liquid crystal element 32.

FIG. 3 is a plan view showing the liquid crystal element 33 of FIG. 2 in detail, and shows a state in which a plurality of infrared light receiving elements 37 are arranged at equal intervals on the outer peripheral portion 33b of the image display area 33a. That is, the basic configuration of the projector 3 is the same as that of the conventional projector, but is greatly different in that a plurality of infrared light receiving elements 37 are arranged at equal intervals on the outer peripheral portion 33b of the liquid crystal element 33.

Next, the operation of the above device will be described. The infrared light emitted from the infrared light emitting element 2 provided on the outer peripheral portion 1b of the image display area 1a of the screen 1 enters the projector 3 as shown in FIG.

Here, if the screen 1 and the projection lens 3
In the case where a human enters between the screen 1 and 5, the infrared rays from the light emitting element 2 on the outer peripheral portion 1b of the screen 1 are blocked.
No infrared light enters the light receiving element 37. The control circuit 36
When it is detected that at least one of the light receiving elements 37 has not reached the infrared ray, the power supply 32 is controlled to reduce or cut off the light of the lamp 31. In this case, the projection lens 3
Since it is sufficient that the light projected from 5 has a safe intensity, the liquid crystal element 33 may be controlled to control the intensity of the light.
Note that the distance between the light emitting elements 2 of the screen 1 must be set to be sufficiently smaller than the size of a human head.

According to the embodiment described above, the screen 1
Since the light-emitting element 2 is provided on the outer peripheral portion 1b, it is possible to accurately and immediately detect that a person has entered the space between the projection lens 35 and the screen 1, and thereby the lamp as a light source 31 can be reduced or cut off. Therefore, even when the user enters the image display area and carelessly looks into the projection lens 35, it is useful without giving the eyes extreme glare.

In the above embodiment, the liquid crystal element 3
It is also possible to use DMD (digital mirror device) instead of 3.

FIGS. 4 and 5 show still another embodiment of the projection type image display device and the projection type image display device according to the present invention. 2 and FIG. 3 are denoted by the same reference numerals and description thereof will be omitted.

In the present embodiment, the difference from the apparatus of FIG. 2 is that instead of providing the light receiving element around the liquid crystal element, the light receiving element is arranged at a place different from the liquid crystal element as shown in FIGS. It is a point that has been established. That is, the light receiving element 37 is attached to the substrate 42 placed symmetrically with respect to the liquid crystal element 40 with respect to the half mirror 41 disposed between the liquid crystal element 40 and the projection lens 35. The light receiving element 37 is arranged around a portion of the liquid crystal element 40 corresponding to the image display section. Therefore, the substrate 42 and the liquid crystal element 4
0 is at the same optical position as viewed from the projection lens 35, and the light emitted from the light emitting element 2 of the screen 1 is the outer periphery of the portion of the substrate 42 of the projector 3 corresponding to the image display section of the liquid crystal element 40. Projected on the part.

Since the light transmitted through the liquid crystal element 40 is polarized by its nature, it transmits only one polarized light through the half mirror 41 like a polarization beam splitter.
If the other polarized light is reflected, the projection lens 35 is used.
There is almost no attenuation of the light projected from.

As described above, according to this embodiment, the same effects as those of the previous embodiment can be obtained.

By the way, in the above two embodiments, a high-pressure mercury lamp is taken as an example of a light source, but it goes without saying that the present invention is not limited to this and can be applied.

[0023]

As described above, according to the present invention, a projection type image display device capable of reliably detecting a case where an object enters an image projection area of a screen and controlling a projection light amount, and a projection type A type image display can be provided and is useful.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a projection type image display device and a projection type image display device according to the present invention.

FIG. 2 is a diagram showing a configuration of the image display device of FIG.

FIG. 3 is a plan view showing a liquid crystal element of the image display of FIG. 2 in detail.

FIG. 4 is a configuration diagram showing another embodiment of the projection type image display device and the projection type image display device according to the present invention.

FIG. 5 is a plan view showing the arrangement of light receiving elements of the image display of FIG. 4;

FIG. 6 is a configuration diagram showing an example of a conventional projection type image display device.

[Explanation of symbols]

 1: Screen 1b: Screen peripheral part 2: Infrared light emitting element 3: Projection type image display 31: Lamp 32: Light source power supply circuit 33: Liquid crystal element 34: Liquid crystal drive circuit 35: Projection lens 36: Power supply control circuit 37: Infrared ray Light receiving element

Claims (5)

[Claims] 1. A projection type image display device comprising: a projection type image display device for projecting light from a projection lens; and a screen for displaying an image by the projection type image display device, a portion outside the image display area of the screen. A light-emitting means disposed in the projection-type image display, a detecting means for detecting light from the light-emitting means, and a light amount from the projection lens when no light can be detected by this detecting means. A projection-type image display device, comprising: a control unit for controlling. 2. The projection-type image display device according to claim 1, wherein said projection-type image display uses a liquid crystal element or a digital mirror device, and said detecting means includes a liquid crystal element or a digital mirror. A projection type image display device, which is arranged on an outer peripheral portion of a mirror device. 3. The projection type image display device according to claim 2, wherein a plurality of said detecting means are arranged on an outer peripheral portion of a liquid crystal element or a digital mirror device, and said control means is configured such that at least one of said detecting means is said. A projection-type image display device, wherein the amount of light from a projection lens is controlled when light from a light emitting unit cannot be detected. 4. The projection type image display device according to claim 1, wherein said projection type image display uses a liquid crystal element, and said detection means is arranged between the liquid crystal element and a projection lens. A projection-type image display device, wherein the projection-type image display device is provided at a position symmetrical to a liquid crystal element with respect to a half mirror. 5. A projection-type image display for projecting light from a projection lens, wherein detection is performed by detecting light from light-emitting means disposed outside a portion of an image display area of a screen on which an image is projected by the projection-type image display. And a control means for controlling the amount of light from the projection lens when the light from the light emitting means cannot be detected by the detecting means.