JP2001174912A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display device capable of coping with brightness without being affected by ambient brightness, maintaining required brightness and contrast and realizing a high-quality video as a projection type display device whose panel size and system size are small. SOLUTION: This device is equipped with a light source attaining the luminance of the system for securing the required brightness on a display panel corresponding to a bright background or a means for decreasing the brightness and largely raising a contrast value on the display panel by variably controlling the angle range of projected luminous flux supplied to the display panel from the light source and a reflector through a required optical path.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type display device, and more particularly to a front type projection type display device.

[0002]

2. Description of the Related Art First, a conventional projection display device will be described.
This will be specifically described with reference to FIG. Here,
Three liquid crystal reflective display panels are used. here,
1 is a lamp as a light source, 2 is a reflector attached to the lamp 1, 3 is a rod integrator as an optical means for forming a secondary light source image from a light source image of the lamp 1, 4
Is a collimator lens, 5 is a polarization conversion element, 6 is a relay lens, 7 is a color separation dichroic mirror, 8 is PBS
(Polarizing beam splitter). Reference numeral 9 denotes a cross prism, 10 denotes a liquid crystal display panel, 11 denotes a projection lens, and 12 denotes a total reflection mirror.

A light beam emitted from a lamp 1 is reflected by a reflector 2
At the entrance of the integrator 3. Here, the reflector 3 is an elliptical reflector, and its focal point exists at the entrance of the light emitting unit and the integrator. Therefore, the light flux entering the integrator 3 is repeatedly reflected 0 to several times inside the integrator 3 to form a secondary light source image at the exit of the integrator 3. The secondary light source forming method is disclosed in
Although there is a method using a fly's eye described in Japanese Patent No. 1806 or the like, this is not illustrated and described here.

[0004] The light beam from the secondary light source passes through the collimator lens 4 and becomes substantially parallel light, and is incident on a polarization conversion element 5 such as a PBS of a polarization conversion system. P wave is P
The light is reflected by the BS, passes through the λ / 2 plate, becomes (all) S waves, and enters the relay lens 6. Light flux is relay lens 6
By the above, a color separation system such as a dichroic mirror 7, a polarizing plate (not shown), a PBS 8 and a cross prism 9 is formed in an optical path therebetween, and an S wave is formed. Are incident on three liquid crystal display panels 10, respectively.

In a liquid crystal display panel, a liquid crystal shutter is
The voltage is controlled for each pixel in accordance with the image, the S wave is modulated into elliptically polarized light (or linearly polarized light) by the action of the liquid crystal, the P wave component is transmitted by the PBS 8, and the cross prism 9 is transmitted.
After color synthesis in step (1), the light is projected from the projection lens 11. This form is common.

[0006]

However, when trying to reduce the size of the entire system by reducing the panel size, the angle of incidence on the display panel becomes large from the viewpoint of Etendue (product of area and angle). It is known that the contrast of the system is greatly deteriorated (for example, Y. Ito et a
l See SID 97 DiGEST p993, J. Iwai IDW 98 p721, etc.).

Therefore, in order to secure the contrast, a system is designed to reduce the brightness by discarding the light of the component having a large projection angle, and the screen is dark when the system configuration is small. It was a common wisdom of the type display device. For example, at present, when a 100-W class high-pressure mercury lamp is used as a light source and a 1.3-inch liquid crystal display panel is used, a brightness of 1200 ANSI Lumen can be realized.
00ANSILumen is at best.

SUMMARY OF THE INVENTION The present invention has been made to solve this problem. An object of the present invention is to provide a projection type display device having a small panel size and a small system size, which can cope with the brightness of the environment and has a required size. It is an object of the present invention to provide a projection display device capable of maintaining high brightness and contrast and realizing high quality images.

[0009]

Therefore, in the present invention,
In correspondence with a bright background, a light source having a system brightness for ensuring a required brightness on the display panel, or an angle of a projection light beam supplied to the display panel from the light source and the reflector via a required optical path from the light source and the reflector It is characterized in that a means is provided for variably controlling the range so as to greatly increase the contrast value on the display panel as the brightness decreases.

In this case, as an embodiment of the present invention, the variable control means is means for variably controlling the angle range of the light source or the light flux guided from the light source and the reflector to a required optical path. In particular, the variable control means realizes an angle range of a light flux guided from the light source and the reflector to a required optical path by an aperture stop means, or the variable control means performs a required operation from the light source and the reflector. It is effective to realize the angle range of the light flux guided to the optical path by variably controlling the reflection path or the reflectance of the reflector. Further, it is also effective that the variable control means is provided on an entrance side of a projection lens for projecting a light beam onto the display panel, restricts an opening thereof, and variably controls an angle range of the projected light beam. is there.

In the above-mentioned projection display apparatus, the optical path includes a color separation optical system, and the variable control means includes:
In particular, when at least one of a distance from the relay lens group including one or more lenses in the optical path to the display panel and a distance from the relay lens group to the light source is variably controlled, , The light source is 2
Being a secondary light source is a preferred embodiment.

Similarly, in the above-mentioned projection type display device,
The optical path includes a color separation optical system and a relay lens group including one or more lenses, and the variable control unit controls the configuration of the relay lens group to variably control brightness and contrast. Is valid.

In this case, the variable control means is means for restricting the opening of the relay lens group and variably controlling the angle range of the projected light beam. There is an optical unit for forming a light source image, and the relay lens group has a conjugate relationship between the secondary light source image and the display panel. Alternatively, the optical path includes a plurality of light source images from the light source image of the light source. In a preferred embodiment, there is an optical unit for dividing and forming a secondary light source image, and the relay lens group has a conjugate relationship between the secondary light source image and the display panel.

More specifically, in the embodiment of the present invention, the optical means is a rod integrator for forming a secondary light source image from the light source image, and the variable control means is provided on an entrance side of the integrator. Aperture stop means, and the display panel is a reflection type, in particular, a liquid crystal panel, and uses three display panels.

Further, in the above-described configuration of the present invention, it is preferable that the detecting means and the driving means are provided so that the variable control means is automatically controlled by the ambient brightness. In this case, it is useful that the control range of the variable control means is set so that the contrast value on the display panel changes 10 times or more.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the specific structure of the present invention, the brightness and contrast of the projection display device will be described. The so-called contrast is an index indicating how many times the luminance of white display is higher than the luminance of black display, and the contrast value is represented by white luminance / black luminance. In a projection display device, in general, black luminance is small by two digits or more (that is, the contrast is 100 or more), and the value of black is the main factor determining the contrast. On the other hand, the brightness is displayed in units of ANSI Lumen, which is an average of nine points for white luminance.

The inventor of the present invention has intensively studied the specifications required for the actual use of the brightness and the contrast, and as a result, has invented a unique projection type display device, and simply improves the brightness. It is not intended to simply improve the contrast. This will be described below.

In FIG. 1, the horizontal axis represents the white luminance on the screen (display panel) (that is, the white luminance of the projection display device plus the background on the screen), and the vertical axis represents the upper limit of the contrast value. 5 is a graph in which each value is a parameter for each background (that is, room brightness).

Here, 2 looks as the background is a state where the electricity in the room is completely turned off, and
Looks are a state in which only the screen-side electricity is turned off and the rest is turned on, and 400 looks is a state in which all the fluorescent lamps are turned on. As is clear from this, when the electricity is turned on, the actually observed contrast is very low even if the contrast of the system is infinite. This is because, for example, as shown by the point A, since the background is 400 lux, the contrast of the system is infinite, and even if there is a brightness of 1000 lux, the contrast value is 1000 + 400/4.
00 = 3.5, and the contrast value was slightly 3.5.
It's nothing but. By the way, the usual 20
In the case of a projection display device of 00ANSILumen, the white luminance of the system is about 1000 lux at an enlarged projection of 80 inches.

In FIG. 2 to FIG. 4, when the background is 2 lux, 90 lux, and 400 lux, respectively, the brightness (ANSILumen) is plotted on the horizontal axis when the projection on the screen is enlarged to 82 inches. The vertical axis represents the contrast value of the projection display device, and the results of the sensitivity evaluation at that time are shown. The important part to be noted here is the value of the contrast on the screen including the background. Note that a liquid crystal projector and an OHP are used as the projection display device. ○ is a criterion that when it is judged that it is not unclear as a presentation, Δ is a little difficult to see.

As is apparent from FIG. 2, when the background is bright, the brightness is important and the contrast value of the system is not. That is, 2000ANSILume
At n, the system contrast is 4 and 10
Even when comparing the cases of 0 or more, the contrasts on the screen were 2.1 and 3.2, respectively, and there was no large difference.

FIG. 3 generally shows values in an environment used in a presentation, but depending on the brightness, it can be said that a contrast of at most 10 is sufficient. Here, a system background equivalent to the background is allowed (1
2,000 ANSI Lumen, 82 inch magnified projection, white luminance 500 lux, system contrast value 1
At 0, ie, when the background of the system is 50 lux, the contrast value is (500 + 90 / (5
(0 + 90) = 4.2, and even with a system contrast value of 100, the background contrast value is (500 + 90) / (5 + 90) = 6.2, and no significant difference is observed in the sensitivity test).

On the other hand, in a dark environment as shown in FIG. 4, contrast is more important than brightness. Although this depends on the purpose of use, since the background is dark, if the system has a high contrast, it is directly reflected on the image quality and is very easy to see. However, in a normal meeting or the like, the face of the other party cannot be seen and a memo cannot be written, which is inappropriate. That is, an appropriate specification environment is a case where a beautiful moving image is shown or a usage such as a home theater.

As described above, it has been found that the required brightness does not match the contrast depending on the surrounding brightness or usage. That is, when a projection display device is used in a bright place such as a conference, brightness is emphasized. Here, there is no problem even if the contrast is considerably reduced. On the other hand, when a projection display device is used to view an image such as a home theater, contrast is more important than brightness.

(First Embodiment) FIG. 5 shows an example of the configuration of a projection type display device according to the present invention which has the performance satisfying both of them. In the drawings, the same components as those in the related art are denoted by the same reference numerals, and description thereof is omitted.

In the present invention, of the luminous flux applied to the liquid crystal display panel 10, an angle component close to 21 ° is sufficiently taken in, and priority is given to securing absolute brightness first. Because, to secure the brightness, by illuminating the liquid crystal display panel with that brightness,
When trying to secure a brightness equivalent to a 1.3-inch panel from saving as Etendue, the angle at this time is assumed to be approximately 8 ° (described later), and 1.3 × 8 ° = 0.5 × 2.
This is because the angle becomes 0.8 °, and it is necessary to capture the light flux having the angle of 21 ° described above.

In order to capture a 21 ° light flux, the power of the relay lens system is increased to increase θ with respect to the optical system of the 1.3-inch panel. Thus, the focal length is smaller and the overall system is smaller.

Here, the factors that determine the contrast will be described. The contrast is calculated comprehensively based on the contrast of all members on the optical path including the PBS and the display panel, but is rate-limiting at the lowest value. In general, PBS is the key. FIG. 6 shows the incident angle dependence of the transmittance of a general PBS (polarizing beam splitter) used in the present invention.

That is, in order to maintain a contrast of 100, the incident angle is limited to about 8 ° (actually, the light beam distribution is centered on the incident angle of 0 °,
Since the contrast is determined by the integral value, the contrast is increased.) At this time, regarding the brightness, 20
A 0 W ultra-high pressure mercury lamp was used, which provided 1800 ANSI Lumen with sufficient brightness. On the other hand, the contrast of the system was 8. As described above, the value is sufficient for a normal presentation in a bright room.

Next, control means for increasing the contrast and suppressing the brightness will be described. In the present embodiment, a light source (lamp) 1 and a reflector 2 (although only the light source may be used) that provide system brightness for securing a required brightness on the display panel 10 in response to a bright background. The variable control means variably controls the angle range of the projection light beam supplied to the display panel 10 through the optical path, thereby decreasing the brightness and greatly increasing the contrast value on the display panel.

In this embodiment, the variable control means serves as a means for variably controlling the angle range of the light flux guided from the light source 1 and the reflector 2 to a required light path, and the light of an optical system in the light path. A light-shielding plate having a required aperture formed around the center of the axis (or a transparent plate having the aperture region transparent and having an opaque structure or material outside the region or a low light transmittance) outside the region. And the aperture stop means 13 (for example, the angle range of the light beam is changed by moving the light shielding plate in parallel with the optical axis direction).

That is, the outer peripheral portion of the reflector 2 can be freely cut by an aperture, and the angle entering the integrator 3 can be reduced from θ to θ ′.
Make e smaller. With such a configuration,
The angle of the secondary light source at the exit of the integrator 3 becomes small (approximately θ '), and the brightness decreases as much as the cut, but a large angle component near the panel is cut off.
The contrast value increases significantly. For example, 400 ANSI
In the case of Lumen, the angle component of the luminous flux applied to the panel is suppressed to a maximum of 8 °, and the contrast of the system can be set to 200, which is 25 times as compared with the contrast of 8 when bright.

As described above, according to the present invention, by giving a large degree of freedom to the contrast value, an intelligent device can be realized that is adapted to the surrounding environment, even though it is a single device. Furthermore, it is effective to make the surface of the light-shielding plate on the lamp side a total reflection mirror, since the reflected light flux enters the reflector again and helps to improve the brightness.

In this case, the variable control means is realized by using a light-shielding plate having an aperture. However, for example, a reflecting plate or an absorbing plate is provided inside the reflector, and the light flux guided from the light source and the reflector to a required optical path is provided. It is effective as an embodiment of the present invention to realize the angle range by variably controlling the reflection path or the reflectance of the reflector.

Since the display panel used in the present invention is relatively small, a reflection type TN liquid crystal having a large aperture ratio is used. However, the type of the reflection type or liquid crystal is not particularly limited. . For example, although the aperture ratio is small, it goes without saying that there is no difference in the basic concept even if a transmissive structure may be used or a VA liquid crystal or another liquid crystal may be used.

(Second Embodiment) A second embodiment according to the present invention
The embodiment will be specifically described with reference to FIG.
The same components as those of the present invention described above are denoted by the same reference numerals, and description thereof will be omitted. Here, variable control means 17 such as a light-shielding plate having an aperture is provided on the entrance side of the projection lens 11 that projects a light beam onto the display panel, regulates the opening thereof, and variably controls the angle range of the projected light beam. Means. In FIG. 7, the panel 16 includes a DMD
(Digital Micromirror Device), and has a single-plate configuration. Reference numeral 14 denotes a rotating color filter which separates colors in a time-division manner. Reference numeral 15 denotes a concave mirror. For DMD, for example,
Part of SPIE's Thematic Applied Scien, 1995
Larry J. Hornbeck in the ceand Engineering Series
Since n is described in detail, detailed description is omitted here.

Basically, by moving the mirror of the DMD panel and changing the angle, the light enters the projection lens,
By not entering, you create a video. At this time, if the angle of the light beam incident on the DMD panel varies, the contrast is reduced, so that only the light beam within a certain angle is used. Note that the angle of the mirror of the DMD panel is ± 10 ° in the ON state and the OFF state, and therefore, generally, the diameter of the projection lens is set so that the light beam incident on the panel is within 10 ° from the center light beam. It is determined.

However, in the present invention, a design is made so that a larger angle can be taken in, a projection lens having a larger aperture is adopted, and the optical design from the lamp to the display panel is designed to take up an angle of up to 25 °. Further, an aperture stop means such as the light-shielding plate 17 having the above-described aperture is provided at the entrance side opening of the projection lens, and the aperture is made variable.
When brightness is prioritized, the aperture is largely opened to capture a large amount of light.

As a result, in the form of a single plate of 0.85 inches,
From a system with 1200 ANSI Lumen and a contrast of 20, a system with 600 ANSI Lumen and a contrast of 300 could be realized in one projection display device. As described above, in the present invention, by giving a large degree of freedom to the contrast value (in this embodiment, the contrast value is different by a factor of 15), the surrounding environment (background (Brightness of the ground).

As described above, a panel such as a DMD is not necessarily designed so that the central axis of a light beam is perpendicular to the panel. However, in the present invention, by controlling the angle range of the light beam incident on the panel, the projection display can be effectively realized. The same applies to a liquid crystal panel, and it is common to design the center of the light beam to be perpendicular to the panel. However, the essence of the present invention is to control the angle range of the light beam incident on the panel. It does not make any difference.

(Third Embodiment) A third embodiment according to the present invention
The embodiment will be specifically described with reference to FIG. In the above-described projection display device, the optical path includes a color separation optical system, and the variable control unit controls a distance from a relay lens group including one or more lenses in the optical path to a display panel, and the relay. At least one of the distances from the lens group to the light source is variably controlled (in this embodiment, both are controlled), and the light source is a secondary light source from the fly array lens 18.

The light emitted from the light source 1 is converted into parallel light by a parabolic reflector.
8-1. Here, the fly-eye lens is divided into a rectangular matrix, and each rectangular lens forms an image of the light source on the corresponding second fly-eye lens 18-2. The first fly-eye lens has a conjugate relationship with the second fly-eye lens and the display panel via the relay lens, and superimposes the light source image from the first fly-eye lens on the display panel to form an image. By doing so, the unevenness of the light source is eliminated and the light is illuminated uniformly.

In FIG. 8, for simplicity,
Reference numeral 20 denotes a color separation system and reference numeral 21 denotes a color synthesis system. Therefore, the panel can adopt this configuration regardless of the transmission type or the reflection type. In FIG. 8, reference numeral 19 denotes the second fly-eye lens 1.
8-2 and a principal point of the relay lens group 191 composed of one or more relay lenses (here, an example is shown in which the front principal point and the rear principal point coincide with each other, but this is not a limitation. Needless to say, the distance between the principal point 19 and the liquid crystal panel 10 is a, and the distance between the principal point 19 and the secondary light source at the exit of the fly eye 18-1 is b. When the liquid crystal panel and the secondary light source have a conjugate relationship, the distance f can be expressed by 1 / f = 1 / a + 1 / b.

The angle θ applied to the liquid crystal panel is
When the diameter of the relay lens is L, tan ^-1 (L /
2a). Assuming that the size of the secondary light source is B and the size of the panel in a conjugate relationship is A, the enlargement factor M is A / B and a / b. In this embodiment, a =
The basic design is performed so that the liquid crystal panel is irradiated with a luminous flux of about 12 ° at 117 mm and b = 41 mm. The magnification is 2.9 times. The lens diameter is about 50
mm, the diameter of one of the fly eyes divided into 8 × 10 is approximately 6.3 mm × 4.7 mm, and illuminated a display panel 2.9 times as large as the exit of the fly eye 18-1. .

In this embodiment, the display panel is 0.9
18.3 mm x 1 inch reflective liquid crystal panel
This is an area of 3.7 mm. At this time, a 100 W high-pressure mercury lamp was used as a light source, and a system with 1200 ANSI Lumen and a contrast of 4 was realized. Furthermore, in the present invention, the distance between a and b can be changed by moving the liquid crystal panel and the relay lens in conjunction with each other. For example, a = 168m
Assuming that m and b are 37 mm and θ is 8.4 °, the brightness is suppressed to 500 ANSI Lumen, while the contrast can be secured to 200 or more. Such a flexible system can be realized with one projection display device.

Here, both the distance to the relay lens and the distance are changed. However, for example, a lens is formed as a relay lens group and its power (focal length) is changed, that is, f is changed, and Variable control may be performed by changing only the distance on one side, which is only an optical system. To change the focal length, the lens groups may be replaced collectively,
The lens may be partially replaced.

(Fourth Embodiment) In this embodiment, the optical path of the device includes a color separation optical system and a relay lens group including one or more lenses.
It is effective to control the configuration of the relay lens group to variably control brightness and contrast. In particular, the variable control unit is a unit that regulates the opening of the relay lens group and variably controls the angle range of the projection light beam.
In the optical path, there is optical means for forming a secondary light source image from a light source image of a light source, and the relay lens group brings the secondary light source image and the display panel into a conjugate relationship.

Next, the specific configuration will be described with reference to FIG. This embodiment is inefficient in terms of brightness, but can be configured relatively easily in terms of structure. In FIG. 9, the angle seen from the panel is the opening angle at the exit of the relay lens 6 before entering the dichroic mirror, and an aperture stop means 22 having an aperture is provided in this portion. Reduce the substantial angle incident on the panel. However, if the aperture is narrowed at this point, some of the available light that is not angled will also be discarded, and the efficiency will be slightly reduced as compared to other methods.

Using a 1.3-inch liquid crystal panel as a display panel and incorporating a required angle component in the same manner as in the first embodiment, a system in which 1800 ANSI Lumen can be achieved, the relay lens diameter is simply increased from 50 mm. 2 consecutive
The brightness and contrast when changed to 0 mm are as follows. If the relay lens diameter is up to 20mm,
Angle is reduced to 8.2 ° and contrast is 300
To rise. On the other hand, the brightness was darkened by the cut, but it was 300 ANSI Lumen, and the performance as a projection display device in a theater with a screen of a 60-inch class was sufficient.

In the above-described embodiment of the present invention, including this example, the liquid crystal panel and the secondary light source image are conjugated, and the efficiency of brightness is emphasized. In the case of emphasizing, or in the case of emphasizing avoiding unevenness in the display screen, the essence of the present invention is not affected even if the conjugate relationship is not necessarily maintained.

(Fifth Embodiment) The fifth embodiment of the present invention shows an example of controlling the angle component in the above embodiment. This will be described with reference to FIG. Here, the aperture stop means 23 is used as the variable control means on the entrance side of the rod integrator 3 to suppress the factor that the angle component due to the variation in the light source size increases.

In general, since the light source 1 is not a point light source, even if the elliptical reflector 2 is used, it does not converge to one point but has a component of a certain angle φ. This is a factor that the angle component becomes larger than the angle in the case of the point light source, and widening the aperture of the integrator 3 has the effect of increasing the brightness by picking up the component caused by the variation in φ. Have. On the other hand, this also causes an increase in the angle of the secondary light source at the opening on the exit side of the integrator 3 and substantially increases the angle of the light beam irradiated on the panel, thereby lowering the contrast. Here, since the size of the secondary light source is determined only by the opening on the exit side of the integrator 3, there is no relation in this system.

Further, the portion indicated by reference numeral 24 in FIG. 10 which is conjugate with the lamp light source after passing through the polarization conversion system is where the lamp light source 1 forms a plurality of images. This portion also becomes a point image if it is a point light source, but has a spread because it is not actually a point light source. Therefore, by providing an opening in each one and controlling the opening, the light source can be made closer to a point light source, and the angle of the light beam irradiated on the panel can be controlled slightly.

As described above, in this embodiment, the first to the first
Compared with the fourth embodiment, the obtained effect is slightly weaker, but it is an important point of view in implementation, and it is possible to produce a large effect by combining and controlling rather than performing it alone. Can be expected. Therefore, optical means for dividing and forming a plurality of secondary light source images from the light source image of the light source 1 is provided in the optical path of the projection type display device, and the relay lens group is configured to make the secondary light source image and the display panel conjugate. Good to do.

It should be noted that such composite use is
Not only this embodiment, but if the examples of the first to fifth embodiments are combined, the effect is obviously larger, but the control becomes more complicated and the price becomes higher. Become. Therefore, in such a composite design, it is preferable to combine and use only the parts necessary for the system, including the structure of the panel and the structure of the optical system.

(Sixth Embodiment) In the configuration of the present invention described above, it is noted that the detection means and the driving means are provided such that the variable control means is automatically controlled by the surrounding brightness. In this case, it is useful that the control range of the variable control means is set so that the contrast value on the display panel changes 10 times or more.

In this embodiment, a method for automatically controlling the above embodiment will be described. As described in the first embodiment, a system that emphasizes brightness and has less importance on contrast is generally used when the surroundings are bright, while the system that emphasizes contrast requires much brightness. For those who do not, the app will be viewed in a dark environment, if possible, for applications such as home theater. Therefore, if the projection display device itself is configured to automatically change the brightness and contrast in accordance with the surrounding brightness, it is not necessary for a person to manually set each time. ,
There are great benefits. Table 1 shows desired brightness and allowable contrast with respect to the ambient brightness derived from the experimental results in the first embodiment (in this example, when the projection is enlarged to 80 inches).

[0058]

[Table 1] For example, when the surrounding brightness is 2 lux, the brightness is 30
The system automatically changes to a system of about 0 ANSILumen, and when the surrounding environment has 400 lux, a system that emphasizes brightness, for example, 1800 ANSILumen and reduces the contrast. The configuration of this automatic control is shown in the block diagram of FIG. Here, reference numeral 21 denotes a sensor unit for observing illuminance. Reference numeral 22 denotes a memory unit having a correspondence table for associating ambient brightness with a desired system. 23 is the value of the sensor,
A control unit for realizing a system to be corresponded, and 24 is a mechanism unit for executing the system.

For example, assuming that the aperture control in front of the reflector in the first embodiment is mechanically linked with the surrounding environment brightness, the apparatus determines with such a mechanism according to the environment of the projection apparatus. As a result, an intelligent projection device for setting desired brightness and contrast can be realized.

The actual system will be described with reference to FIG. In this figure, the projection display device main body 2
9, a sensor 30 for measuring the ambient brightness is provided to monitor the brightness of the room. The illuminance sensor 30 is a type that converts light into current or voltage and outputs the converted light, and uses a general photodiode. Since the light intensity and the output current are proportional to the photodiode type illuminance sensor, it is converted into a voltage and the signal is transmitted to the control unit. The control unit reads a signal for controlling the opening corresponding to the signal from the correspondence table, and sets the mechanism unit (here, the opening shutter before the reflector) to a desired position.

Here, one mechanical movement is controlled, but in another embodiment, it is also possible to move the mechanical part or control it in a combined manner. On the other hand, sensing the brightness on the screen is more effective because the brightness at the actual viewing position can be sensed. At this time, the reflection of the screen is monitored, and the aperture corresponding to the reflection is variably controlled. In this case, as shown in FIG. 13B, it is preferable to install the sensor unit on the front surface of the projection type display device, but it is not particularly limited to this mode. On the other hand, although the correspondence table has an initial setting, it is preferable that a mechanism capable of changing the setting according to the user's preference is added, and it is preferable that the correspondence table can be set freely according to the environment to be used and according to personal preference. Further, it is preferable that there is a plurality of correspondence tables, and a mechanism that can be freely selected at each time is preferable. Further, the correspondence table can be set manually by using an automatic setting release mechanism. It is necessary in some cases.

[0062]

As described above, according to the present invention, the brightness and the contrast are largely changed by controlling the angle range of the light beam incident on the panel, so that the brightness and the contrast can be adjusted according to the surrounding brightness. In addition, it is possible to provide an easy-to-see projection type display device. Further, since a bright projection display device can be realized with a small panel, it is possible to provide a projection display device which is inexpensive and has a small device body.

Further, according to the projection type display device of the present invention, in a projection type display device having at least a light source such as a lamp having a panel and a reflector, the reflection path or the reflectance of the reflector is controlled to obtain brightness and contrast. , The brightness and contrast can be greatly changed, and an easy-to-see projection display device adapted to the surrounding brightness can be provided.

Further, in the projection type display device of the present invention, in the projection type display device having at least a panel and a projection lens, the opening on the entrance side of the projection lens is controlled to make the brightness and contrast variable. , The brightness and the contrast are greatly changed, and an easy-to-see projection display device adapted to the surrounding brightness can be provided.

According to the projection type display device of the present invention, in a projection type display device having a panel, a light source such as a lamp having a color separation optical system and a reflector, at least one relay provided between the light source and the liquid crystal panel. Having a lens group, variably controlling at least one of a distance from the relay lens group to a panel and a distance from the relay lens to a light source, or controlling an aperture of the relay lens to provide brightness and contrast. , The brightness and contrast can be largely changed, so that it is possible to provide a projection display device that is easy to see and that is adapted to the surrounding brightness.

In the projection display apparatus of the present invention, a projection display apparatus having a panel, a color separation optical system, and a light source such as a lamp has an integrator for forming a secondary light source image from a light source image. By changing the brightness and the contrast by variably controlling the opening on the entrance side of the camera, the brightness and the contrast are largely changed, and it is possible to provide an easy-to-see projection display device adapted to the surrounding brightness.

[Brief description of the drawings]

FIG. 1 is a graph for explaining an embodiment of the present invention.

FIG. 2 is also a graph for explaining an embodiment of the present invention.

FIG. 3 is a graph for explaining an embodiment of the present invention.

FIG. 4 is also a graph for explaining an embodiment of the present invention.

FIG. 5 is a schematic explanatory view of a projection display device showing a first embodiment according to the present invention.

FIG. 6 is a diagram showing the transmittance of the PBS in the same manner.

FIG. 7 is a schematic explanatory diagram of a projection display device showing a second embodiment according to the present invention.

FIG. 8 is a schematic explanatory view of a projection display device showing a third embodiment according to the present invention.

FIG. 9 is a schematic explanatory view of a projection display device showing a fourth embodiment according to the present invention.

FIG. 10 is a schematic explanatory view of a projection display device showing a fifth embodiment according to the present invention.

FIG. 11 is a block diagram showing a configuration for automatic control according to the present invention.

FIG. 12 is a diagram illustrating a conventional example for comparison with the present invention.

13 is a schematic perspective view of the projection display apparatus of FIG. 11 of the present invention.

[Description of Signs] 1 lamp (light source) 2 reflector 3 rod integrator 4, 6, 19 lens 5 polarization conversion system 7 dichroic mirror 8 PBS 9 cross prism 10 liquid crystal panel 11 projection lens 12 total reflection mirror 13, 17, 22, 23 , 24 Shield plate with aperture 14 Rotary filter 15 Concave mirror 16 DMD panel 18 Fly-eye lens 20 Color separation system 21 Color synthesis system 25 Illuminance sensor 26 Memory unit having correspondence table 27 Control unit 28 Mechanism unit 29 Projection display device 30 Illumination sensor

Continued on the front page F term (reference) 2H088 EA14 EA15 EA16 EA18 EA19 GA02 HA13 HA20 HA22 HA24 HA28 JA05 MA04 MA06 2H091 FA10Z FA14Z FA21X FA26Z FA41Z FB07 FC14 FD06 FD12 FD22 FD24 HA07 LA03 LA09 LA18 MA07 A08 EA18 A08 EA08 5C060 BA03 BB01 BC05 BE05 BE10 GA01 HC01 HC14 HC20 HC22 HD05 JA17 JB06

Claims (17)

[Claims] 1. A light source having a system brightness for ensuring a required brightness on a display panel corresponding to a bright background, or supplied from the light source and a reflector to the display panel via a required optical path. A projection type display device comprising means for variably controlling the angle range of a projection light beam to decrease the brightness and greatly increase a contrast value on a display panel. 2. The variable control means according to claim 1, wherein said variable control means variably controls an angular range of a light beam guided from said light source or said reflector to a required optical path. Projection display device. 3. The variable control means according to claim 2, wherein said aperture stop means realizes an angular range of a light beam guided from said light source and said reflector to a required optical path.
3. The projection display device according to 1. 4. The variable control means realizes an angle range of a light flux guided from the light source and the reflector to a required optical path by variable control of a reflection path or a reflectance of the reflector. 3. The projection display device according to 2. 5. The variable control means is provided on an entrance side of a projection lens for projecting a light beam onto the display panel, restricts an opening thereof, and variably controls an angle range of the projected light beam. The projection type display device according to claim 1, wherein: 6. The optical path includes a color separation optical system, and the variable control unit controls a distance from a relay lens group including one or more lenses in the optical path to the display panel.
The projection display device according to claim 1, wherein at least one of a distance from the relay lens group to the light source is variably controlled. 7. The projection display device according to claim 6, wherein the light source is a secondary light source. 8. The optical path includes a color separation optical system and a relay lens group including one or more lenses, and the variable control means controls the configuration of the relay lens group to increase brightness and contrast. The projection display device according to claim 1, wherein the projection display device is variably controlled. 9. The projection type display device according to claim 1, wherein the variable control unit is a unit that regulates an opening of the relay lens group and variably controls an angle range of a projection light beam. 10. The optical path, wherein there is optical means for forming a secondary light source image from the light source image of the light source, and the relay lens group makes the secondary light source image and the display panel conjugate. The projection type display device according to claim 6, wherein the projection type display device is provided. 11. The optical path includes optical means for dividing and forming a plurality of secondary light source images from a light source image of the light source, and the variable control means controls apertures of the plurality of secondary light source images. 2. The projection type display device according to claim 1, wherein the projection type display device variably controls an angle range of the projection light beam. 12. The optical system according to claim 1, wherein the optical unit is a rod integrator for forming a secondary light source image from the light source image, and the variable control unit is an aperture stop provided on an entrance side of the integrator. The projection type display device according to claim 1. 13. The projection type display device according to claim 1, wherein said display panel is of a reflection type. 14. The projection type display device according to claim 13, wherein said display panel is a liquid crystal panel. 15. The projection type display device according to claim 1, wherein three display panels are used. 16. The apparatus according to claim 1, further comprising a detecting unit and a driving unit that automatically controls the variable control unit according to ambient brightness. 3. The projection display device according to 1. 17. The projection type display according to claim 1, wherein a control range of said variable control means is set such that a contrast value changes by a factor of 10 or more. apparatus.