JP2006171659A - Image projection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a user to watch an image even before a discharge lamp, such as a high voltage mercury lamp, stables, in terms of a projector, a home-use rear projection TV, or the like. <P>SOLUTION: The invention includes, as disclosed in claim 1: a first light source using the discharge lamp composed of a high voltage lamp; a first image forming apparatus for modulating output light from the light source into a projection image; a projection lens for enlarging and projecting the output light from the first image forming component; a first display screen to which projection light is emitted from the projection lens; a second light source that is different in light emission system from the first light source; a second image forming apparatus for modulating output light from the second light source into a display image; a second display screen for displaying the image formed by the second image forming apparatus; and a display switching means for displaying the image onto the second display screen by operating the second light source until the first light source steadily operates after a main switch is turned on. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a projection-type image display device used in a projection-type high-definition television (HDTV) system, a video projector, and the like, and for example, relates to a rear projection television.

The inventor of the present invention previously invented an image display device disclosed in Japanese Patent Application No. 2001-71937. This image display device is disposed at the position of a white light source, a light collecting mirror that collects light from the white light source as a secondary light source, and the secondary light source, and temporally separates the white light into the three primary colors of light. The angle of the reflected light is changed by changing the inclination of the color filter, the condenser lens, the first and second folding mirrors, and the minute mirror of each pixel arranged two-dimensionally to create an on / off state. The apparatus includes a reflective display unit and a projection lens that magnifies and projects an image represented by the reflective display unit on a screen.

FIG. 3 is a structural diagram of the above-described prior art, 40 is an arc (light emitting point) of a white light source, 41 is an elliptical mirror as a condenser mirror, and 42 is a primary color (red, green, blue) in which the annular portion is light. The color filter 43 is divided into a light tunnel, 43 is a light tunnel as an optical component, 44 is a condenser lens, 45 is a plane mirror as a folding mirror, 46 is a spherical mirror as a second folding mirror, and 47 is a reflection described later. DMD (digital micromirror device) as a display means, 48 is a field lens, and 49 is a projection lens.

Here, as described in “Optics” (vol. 25, No. 6, p. 313 to 314, 1996), the DMD 47 is configured by two-dimensionally arranged pixels from minute mirrors. This is a reflective display element that creates an on / off state by controlling the tilt of the micromirror by the electrostatic field effect of the memory element arranged immediately below each pixel and changing the reflection angle of the reflected light.
When the pixel is off, the reflected light from the minute mirror of the pixel does not enter the projection lens. When the pixel is on, the reflected light from the minute mirror of the pixel enters the projection lens 49 and enters the screen. It is necessary to arrange optical parts so as to form an image. The tilt angle of each pixel when the micromirror is on is determined to be about 10 to 12 degrees with respect to the light incident surface of the DMD 47.

JP 08-331469 A JP2004-239992A JP 05-183850 A

Normally, when a discharge lamp such as high-pressure mercury is used as a light source, it may take 30 seconds or more after the main switch is turned on until the brightness of the light source reaches 80%.
In addition, once the lamp is turned off, it cannot be turned on again unless the lamp falls below a certain temperature.
For example, after the TV program is finished and the main switch of the rear projection TV is turned off, the next program suddenly wants to be watched. Even if the main switch is turned on, the lamp remains at a predetermined temperature (for example, 250 degrees). The projection operation cannot be performed for a certain period until it is cooled below.

The rear projector is often used as a television receiver, and the main switch is frequently turned on and off as compared with a normal front projector. For this reason, the lighting and relighting of the lamp as described above is a big problem.
In order to solve these problems, a lamp that can be turned on and off again instantaneously may be used. However, such a lamp has not been developed yet.

In addition, although the above-mentioned Patent Documents 1, 2, and 3 show a display device having a main screen and a reduced screen, they describe an enlarged display and a reduced display. It is intended only for convenience, and is not intended to take measures until the light source of the main screen is stabilized as in the present application.
Further, the display of the child screen is not automatically turned off when the main screen is stably displayed as in the present application.

An object of the present invention is to provide an image projection apparatus that solves such a problem that instantaneous lighting and relighting cannot be performed.

In order to solve the above-mentioned problems, the present invention provides a first light source using a discharge lamp composed of a high-pressure lamp and a first image formation for modulating output light from the light source into a projected image. An apparatus, a projection lens for enlarging and projecting output light from the first image forming component, a first display surface irradiated with projection light from the projection lens, and a light emitting method different from the first light source A second light source, a second image forming apparatus that modulates output light from the second light source into a display image, and a second display surface that displays an image formed by the second image forming apparatus The first display surface and the second display surface have different display areas.

According to a second aspect of the present invention, a first light source using a discharge lamp made of a high-pressure lamp, a first image forming apparatus that modulates output light from the light source into a projected image, and the first image formation A projection lens that magnifies and projects the output light from the component, a first display surface that is irradiated with the projection light from the projection lens,
A second light source that emits light different from the first light source, a second image forming apparatus that modulates output light from the second light source into a display image, and the second image forming apparatus. A second display surface for displaying the displayed image and display switching for displaying the image on the second display screen by operating the second light source until the first light source operates stably after the main switch is turned on. It has the means.

Further, as described in claims 3 to 6, the display switching means is characterized in that after the first light source is stabilized, the second light source is turned off or the video signal is turned off. ,
The second light source is a cold cathode tube, a light emitting diode, or a tungsten lamp, and the second image forming apparatus is a liquid crystal display device, and
The first light source is a high-pressure mercury lamp, and the first image forming apparatus is a digital micromirror device,
Only the second light source and the second image forming apparatus have switches that operate independently.

The apparatus of the present invention enables a user to view an image even during a period until a discharge lamp such as high-pressure mercury is stabilized.

Hereinafter, as an example of the present invention, a rear projection television will be described as an example with reference to the drawings. FIG. 1 is a functional block diagram showing an embodiment of the present invention, and FIG. 2 shows a front view of the apparatus of this embodiment.
The constituent elements other than those shown in FIGS. 1 and 2 are substantially the same as the constituent elements shown in the conventional example, and a description thereof will be omitted.

Reference numeral 1 denotes an image data input terminal, to which analog image data for TV relay designated by the remote controller 23 is input.
A decoder 2 develops image data into luminance signals for each pixel.
Reference numeral 3 denotes an A / D conversion circuit, which converts the decoded analog image data into digital image data.
A video processor 4 includes a video memory 5, a scaler circuit 6 for enlarging and reducing the display image, and a memory controller 7 for controlling writing and reading of the digital image data to and from the video memory.
Reference numeral 8 denotes a first selector which distributes an output signal from the video processor to a first display device having a large screen or a second display device having a small screen.
Reference numeral 9 denotes a first display device, which includes a digital micromirror device (DMD) 10 and a DMD format circuit 10 that drives the DMD 11.
The display surface of the first display device becomes the main screen, and a large screen display is performed.
A second display device 12 includes a liquid crystal device (LCD) 14 and an LCD driver 13 that drives the liquid crystal device (LCD) 14.
The display surface of the second display device is a sub screen, and the video of the designated channel is displayed in a small size until the main screen is displayed after the main switch is turned on.
Reference numeral 15 denotes a display switching unit that controls display switching of the first display device 9 and the second display device 12.
Reference numeral 16 denotes a second selector, which selects which of the first light source 18 and the second light source 20 is driven.
Reference numeral 17 denotes a first light source circuit that drives the first light source 16 composed of a high-pressure mercury lamp.
Reference numeral 19 denotes a second light source circuit that drives the second light source 18 formed of a cold cathode tube.
Reference numeral 21 denotes a CPU which performs data processing in addition to data input / output of the apparatus.
Reference numeral 22 denotes a receiving device that receives a command signal from a remote controller 23 equipped with a main switch 24.

Subsequently, the operation of the above-described apparatus will be described.
When the main switch 23 of the remote controller 23 is turned on, the command signal is input to the receiving device 22.
When the ON signal of the main switch 23 is detected, the display switching means controls the first selector 8 and the second selector to drive the first display device 9 and the second display device 12. Then, the light source circuits 17 and 18 are turned on, and a signal from the video processor is supplied to the DMD format circuit 10 and the LCD driver 13.
Since the first light source takes several tens of seconds until the power becomes constant, an image is not displayed on the first display device, but a cold cathode tube is used as the second light source. Lights up instantaneously, and the second display device displays an image instantly.
When the user selects a channel and operates the remote controller 23, the image data of that channel is input to the video processor and displayed on the second display device.
When the display switching means 15 detects that the light source circuit 17 is stable, the second display device is turned off by the display switching means 15.
Specifically, the signal from the video processor 4 supplied to the LCD driver 13 is blocked by the first selector, and the light source circuit 19 is turned off by the second selector.

The above operation waveforms are shown in FIG.
A period from when the main power switch is turned on until the amount of light output from the first light source reaches 50% is indicated by an arrow.
In this embodiment, the state in which the light amount is 50% or more is regarded as a sufficient light amount, the second light source is turned off, and the first video signal is turned on.
During the period indicated by the arrow A, the first video signal is forcibly turned off.
Here, the state in which the light amount is 50% or more is regarded as a sufficient light amount, but the value of 50% can be changed, and for example, a state in which the light amount is 60% or more may be regarded as a sufficient light amount.

If the user turns the main switch on again immediately after turning off the main switch, the light source circuit 17 is turned off by the second selector until the first light source falls to a predetermined temperature. The state is maintained, and only the light source circuit 19 is turned on. At this time, the signal from the video processor 4 is supplied only to the LCD driver 13 of the second display device 12 by the first selector 8.
When it is detected by a temperature detector (not shown) that the first light source has dropped to a predetermined temperature, the first display device is driven.
Instead of using the temperature detector, the elapsed time may be measured by a timer, and after a predetermined time has elapsed, it may be considered that the temperature has decreased to a predetermined temperature.
When the display switching means 15 detects that the light source circuit 17 is stable, the second display device is turned off by the display switching means 15.

The above operation waveforms are shown in FIG.
When the main power switch is turned off and then turned on again, an arrow B indicates a period from when the main power source is turned on to when the first light source is turned on again.
This period represents a sufficient cooling time required for the high-pressure mercury lamp to be turned on again, and this period is displayed in a part of the second video indicating that the first video is waiting.

2A and 2B are a side view and a front view of the rear projection television of this embodiment.
A first display device and a second display device including optical components from the light source 1 to the projection lens 32 are accommodated in the leg portion 31 of the projection television.
The projection light irradiated from the projection lens 32 of the first display device is reflected by the mirror 33 and irradiated to the screen 34. A projected image is displayed on the screen 34. Therefore, this display surface constitutes the first display surface 35 which is the main screen.
In addition, the second light source 20 of the second display device and the second display surface 36 are disposed in the center of the leg portion 31.
In the figure, 37 is an external connection terminal for inputting / outputting to / from an external device such as a DVD device or a game machine, and 38 is a speaker.

The display surface of the first display device is disposed at the top, and the display surface of the second display device is disposed at the legs.
In the case of a device that does not have a leg portion, the second display device is arranged below the first display device with the right or left side end aligned.
In the case of a design having a leg portion, the first display surface and the second display surface can be designed consistently by aligning the central axis according to the leg portion. By aligning the side edges, the design can be matched.
For example, when a speaker or the like having the same area and its side edge aligned with the side edge of the first display surface is arranged on both the left and right sides of the second display surface, the second display surface is You may arrange in the center.

The present invention is not limited to the above-described embodiment. For example, the first light modulation device may be a liquid crystal panel.
The second light source may be a light emitting diode or a tungsten lamp.

Further, in the above embodiment, the second display device is not displayed after the light source of the first display device is stabilized, but is displayed on the first display device by the user's operation, for example. A video source other than the current video source (first video source), for example, a video of a channel different from the channel displayed on the first display device may be displayed.
Further, a display different from the display for viewing, for example, display of the state of the apparatus such as information on the displayed channel, volume information of sound, information on the life of the light source, and the like may be performed.
In this case, the second display device performs status display after the output light from the light source of the first display device becomes a sufficient amount of light.
The above operation waveforms are shown in FIG.

Further, the second display device may be used as a touch panel, and channel selection and audio volume adjustment may be performed by the second display device.

Furthermore, a start switch for only the second display device may be provided so that only the second display device can be used independently.
This is also provided in the remote control as a sub switch.
When this sub switch is turned on, only the second display device can be used while the first display device is off, and video information can be obtained constantly with low power consumption.
The above operation waveforms are shown in FIG.

The present invention can improve the convenience of a display device using a high-pressure lamp, and thus can be widely used for a projection device from home use to business use.

FIG. 1 is a block diagram showing a main configuration according to an embodiment of the present invention. FIG. 2 is a side view and a front view according to the embodiment of the present invention. FIG. 3 is a block diagram of an optical system of a conventional projector. FIG. 4 is a diagram showing operation waveforms of the embodiment of the present invention. FIG. 5 is a diagram showing operation waveforms of the embodiment of the present invention. FIG. 6 is a diagram showing operation waveforms of another embodiment of the present invention. FIG. 7 is a diagram showing operation waveforms of another embodiment of the present invention.

Explanation of symbols

18: First light source 11: First image forming apparatus (DMD)
32: Projection lens 35: First display surface 20: Second light source 14: Second image forming apparatus (LCD)
36: Second display surface 15: Display switching means

Claims (6)

A first light source using a discharge lamp composed of a high-pressure lamp, a first image forming apparatus that modulates output light from the light source into a projected image, and a projection lens that magnifies and projects output light from the first image forming component A first display surface irradiated with projection light from the projection lens, a second light source of a light emission method different from the first light source, and output light from the second light source as a display image A second image forming apparatus that modulates and a second display surface that displays an image formed by the second image forming apparatus, wherein the first display surface and the second display surface are A rear projector characterized by different display areas. A first light source using a discharge lamp composed of a high-pressure lamp, a first image forming apparatus that modulates output light from the light source into a projected image, and a projection lens that magnifies and projects output light from the first image forming component A first display surface irradiated with projection light from the projection lens, a second light source of a light emission method different from the first light source, and output light from the second light source as a display image The second image forming apparatus to be modulated, the second display surface for displaying the image formed by the second image forming apparatus, and the amount of light output from the first light source after the main switch is turned on A rear projector comprising: a display switching unit that operates the second light source until a predetermined value or more is reached and displays an image on the second display screen. 3. The rear projector according to claim 2, wherein the display switching unit turns off the second light source or turns off the video signal after the first light source is stabilized. 3. The rear projector according to claim 1, wherein the second light source is a cold cathode tube, a light emitting diode, or a tungsten lamp, and the second image forming apparatus is a liquid crystal display device. The rear projector according to claim 1, wherein the first light source is a high-pressure mercury lamp, and the first image forming apparatus is a digital micromirror device. The rear projector according to claim 1, wherein only the second light source and the second image forming apparatus have a switch that operates independently.

Images