CN101019438A - Projection display system - Google Patents

Abstract

Partially polarized light produced by an integrator/polarization conversion system combination and two non-pixilated twisted nematic liquid crystal display cells (TN-LCD) or other light modulators are utilized. By adjusting the voltages on the TN-LCD cells, it is possible to adjust the relative amounts of the greatest two of the colors supplied, of the red, green and blue colors, used by the display without changing the light of the color in the least supply. Because all of the adjustments are done electronically through voltage controls, not mechanically, the 'white' point correction system is both simple and reliable.

Description

Projection display system

The present invention relates to a kind of projection display system.

Projection display system is used in video system and surveillance projected image information.

Many different colors are designated as " white " in video system and surveillance.For example at the cinema in the industry 5400K be designated as " white ", and 6550K is designated as " white " in TV industry.In using, other adopt the scope from 3800K to 9300K to be used as " white ".Therefore, can judge the color of the final image that on monitor, occurs exactly, " white " point of monitor must be adjusted to and be specified " white " point of that application-specific in order to make the terminal use.

In the cathode ray tube (CRT) monitor, can obtain " white " point of appointment by the relative gain of regulating the red, green and blue video amplifier, when all three vision signals (red, green and blue) equate, just can demonstrate required target " white " like this.Can come in this system, to change " white " point by the relative gain that changes the red, green and blue amplifier.Yet there are some shortcomings in this mode that obtains appointment " white " point when carrying out in LCD (LCD).If required gain realizes that in analog domain so this change not only can influence " white " point, and can influence all other color.The gamma correction curve that therefore, need be used for the correction of each target " white " point.If gain-adjusted realizes that in numeric field some dynamic ranges must be left in the basket and not use so.Because eight are regarded as the effectively colored required minimum number of bits that shows usually, the some parts of therefore ignoring dynamic range will cause serious color distortion usually.Even basic resolution is higher, be ten or 12, when vision signal being incorporated in the littler dynamic range also color distortion can appear.

Therefore,, these said methods carry out colour correction though being applicable in the device of for example CRT monitor, however these methods and be not suitable for the color of regulating projection display system.

Employing is called one of 1DC fixing and variable delay winding and proofreaies and correct colour temperature and can cause light on the illumination path color change to take place.This can not allow " white " point is regulated completely, but adjusting is limited in along in the one dimension scope of black body-line.Therefore, if initial or target " white " point not on black body-line, so just can not be regulated " white " point completely.

Thereby for example reach the meeting of target " white " point to the excessive control of " white " some generation with the light quantity of controlling in whole three red, green and blue color channels by the relative intensity of using the ColorLink polariscope to change the red, green and blue color channel.The color space is a two-dimensional space, represents with the x-y hue coordinate usually.Three-dimensional in this system is a lightness dimension.Brightness is also inoperative in " white " point calibration.Therefore, the colour correction system of a bidimensional of needs just can fully control " white " point in the LCD display.

An object of the present invention is to provide a kind of projection display system with improved color adjustment.

This purpose realizes by projection display system of the present invention as claimed in claim 1.

In a preferred embodiment of the invention, need not in analog domain or numeric field, change the color that incoming video signal just can be regulated liquid crystal projection display systems.Therefore, color adjustment can optimally realize and control when operating in projector.In this way, " white " point that can obtain regulating fully, it is not limited to the adjusting along black body-line.In a preferred embodiment, adopt the output of two different color channels to control " white " point of Projection Display, thereby carry out the colour correction of bidimensional.Also adopted by an integration/polarization conversion system combination and two unmanifest (non-pixilated) twisted nematic liquid crystals display boxes (TN-LCD) or partial poolarized light that other optical modulator produced.By regulating the voltage on the TN-LCD box, can regulate the relative quantity that the used color of display is two kinds of colors of Maximum Supply Quantity in redness, green and the blueness, and need not change the light of the color of minimum supply.Because all adjustings all come electronic type by voltage control but not mechanically finish, therefore this " white " point calibration system is simple and reliable.Electrical adjustment can also easily adapt to the variation that the terminal use requires " white " point.

Defined other advantageous embodiment in the dependent claims.

Can know and understand these and other aspect of the present invention with reference to the embodiment that introduces below.In the accompanying drawings:

Similar in the accompanying drawings label is represented corresponding parts.

Fig. 1 has adopted the colored polariscope device of binary channels to control the schematic diagram of light path of the reflection type color mirror drum projector of " white " point in mode of the present invention; With

Fig. 2 is the schematic diagram of light path that adopts three panel transmissive liquid crystal display projectors of colour correction method of the present invention.

With reference now to accompanying drawing,, introduced hereinafter reflective be that the single sided board reflection type liquid crystal shows the preferred embodiments of the present invention that adopt the colour correction method in (LCD) projector and the three panel transmission type LCD projectors.

At first with reference to figure 1, the schematic diagram that has shown the light path of single sided board reflection type color mirror drum projector among the figure, projector has two ECB unit, proofreading and correct " white " point, and the color that need not regulate minimum supply respectively is as blueness or red as red and green or blue and green for two kinds of colors that are used to control Maximum Supply Quantity.This light intensity modulator can be controlled the polarization of redness, green and blue color independently, and provides satisfactory color control by two kinds of colors of regulating maximum surplus capacity.

The method is preferably implemented by a colored polariscope of double-colored ColorLink is set on illumination path as shown in Figure 1, colored polariscope can be from the 55th street of the Boulder of Colorado have been bought No. 2925 the ColorLink company (postcode 80301), and it has introduction in U.S. Patent No. 5751384.For convenience of explanation, this double-colored polariscope 10 is a red/green, suppose that for the purpose of illustration these two kinds of colors are Maximum Supply Quantity, and blueness is the color of minimum supply.This integration/polarization conversion system combination and two unmanifest twisted nematic LCD boxes provide a kind of system, be used for two kinds of colors that voltage by the colored polariscope 10 of electric control is modulated at the Maximum Supply Quantity in three kinds of colors that display uses and promptly be the light intensity of red/green in this example, so that " white " point of adjusting projector.

In the embodiment shown in fig. 1, lamp and reflector 2 have been shown, and the first optical integration plate 3, itself and the second optical integration plate, 4 optical alignments are to provide clear even light distribution on the light polarization transformation system (PCS) 5 that is positioned on the light path of leading to first relay lens 8.Two color channels are promptly red/green ColorLink shutter or filter 10 be positioned at first polarizing beam splitter mirror (PBS) 15 near so that control is passed and is arrived red/green glow of PBS from ColorLink shutter 10.Directly pass PBS15, quarter wave plate 12 and cylindrical lens 13 and arrive color drum 14 from the blue light of ColorLink polariscope 10, color drum 14 is returned blu-ray reflection and is passed lens 13 and quarter wave plate 12.Light polarization can take place be rotated 90 ° owing to passing quarter wave plate 12 for twice, so light is reflected at a PBS15 place now and passes second relay lens 16.

When green, the red passage of ColorLink device all was deactivated, the ColorLink device can not change the polarization of these two kinds of colors, and they follow the path identical with blue light.In this case, all three kinds of colors are reflected on the reflective LCD 30 at the 2nd PBS25 place, and color is modulated individually herein.Then, the color after these modulation is launched by the 2nd PBS25 and projecting lens 35, forms coloured image on the projection screen (not shown).Owing to suppose that in this example amount green and red in this projector is too much with respect to the amount of blueness, therefore to compare with the color of target " white " point, the image that spectators saw is " yellow ".

When a passage in the ColorLink polariscope 10 when for example green channel is partly activated, some green glow generation polarizations and half-twist, some light have stayed because of original polarization.The light that the polarization rotation takes place is reflected at the PBS15 place, and these light lose for system.The green glow that the polarization rotation does not take place sends by PBS15, finally arrives LCD30 and projection screen as described above.Owing to will lose some green glows at the PBS15 place, therefore green glow can be still less in image now.

Similarly, when the red channel in the ColorLink device is partly activated, the ruddiness that arrives LCD30 and projection screen still less, this has just reduced the ruddiness amount in the image.By the green in the control ColorLink device and the activation degree of red channel, can on projection screen, realize target " white " point of relative broad range.

In the three panel projectors that adopted the inventive method for example in the three panel list polarizing beam splitter mirror reflective LCD projectors, improve optical projection system shown in Figure 1 by mirror drum Optical devices shown in replacing with three panel Optical devices.

Yet in three panel transmission type projectors and three panels, three polarizing beam splitter mirror reflective LCD projectors, method of the present invention can be realized by mode shown in Figure 2.In this three panel transmission type LCD projectors, control the light quantity in two passages in three color channels.As mentioned above, control the light quantity in two color channels, these passages have maximum color supply, and it depends on other Optical devices in used particular lamp, applied dichroic filter and the system, and this is known to one skilled in the art.For purposes of illustration, the color channel of Maximum Supply Quantity is the red/green passage, can come two kinds of light of red/green passage are controlled by the unmanifest twisted nematic LCD that employing is arranged in light path.

As shown in Figure 2, pass a pair of counter 3 and 4 and polarization conversion system 5 from the light of lamp and reflector 2 in the mode in embodiment illustrated in fig. 1.The light that passes PCS5 passes first dichronic mirror 41, and it reflexes to second dichronic mirror 51 with blue light and green glow.Ruddiness passes first dichronic mirror 41, and reflected by mirror 43 and pass ruddiness color channel controller 45 as unmanifest twisted nematic liquid crystals shows (TN-LCD) box and has continuous polariscopic LCD46, come the synthetic X-shaped pipe 50 of color that is arranged in light path then, thereby make controlled ruddiness pass projecting lens 60 and arrive unshowned projection screen.

Blue light and green glow are reflexed to second dichronic mirror 51 by first dichronic mirror 41.Second dichronic mirror 51 reflexes to green glow green channel controller 55 as unmanifest TN-LCD box and has continuous polariscopic LCD56, and it makes controlled green glow pass X-shaped pipe 50 and projecting lens 60 and arrives projection screen.Blue light passes second dichronic mirror 51 and sends out, and by a pair of mirror 57 and 58 reflections, passes blue LCD59 and enters into color synthetic X-shaped pipe 50 and projecting lens 60, arrives projection screen at last.

In this embodiment, just can in their color channels separately, control the ruddiness of Maximum Supply Quantity and the amount of green glow, thereby control " white " point of projector respectively by Polarization Controller 45 and 55.

In operation, " white " point control that can regulate fully can electronically be finished by voltage control, need not any mechanical part.In the light path of leading to projector 35 and 60, the Polarization Controller 10 or a pair of 45 and 55 that is used for two kinds of colour bands is positioned, can allow two kinds of colors of maximum surplus capacity in the control system optionally.The controlled minimizing of these colors more than needed can be complementary with the light intensity of the color of minimum supply, thereby " white " point calibration that can regulate fully system is provided.

From to obtaining others of the present invention and feature the research of accompanying drawing, disclosure and appended claims.

Claims (5)

1. projection display system comprises:

Be used to provide the lamp (2) of light beam;

Be used to the prepolarization mirror (3,4 and 5) that receives described light beam and make its partial polarization;

Described partial polarization light beam has still less first primary colors and the supply two kind primary colors bigger than the supply of described first primary colors of supply;

Be used to receive the light polarization modulator (10) of described partial polarization light beam;

Described light polarization modulator makes still less, and described first primary colors of supply therefrom passes, and can be operated the polarization degree of described two kinds of primary colors with the bigger supply of control, and need not change the supply of the polarization of described first primary colors of supply still less in fact with the described primary colors of balance; With

Be positioned to receive from the output of described light polarization modulator (10) second polariscope (15) with image that color balance is provided.

2. projection display system as claimed in claim 1 is characterized in that, described prepolarization mirror is polarization conversion system (5).

3. projection display system comprises:

The lamp that need carry out the light beam of colour correction (2) can be provided;

Be positioned to the prepolarization mirror (3,4 and 5) that can receive described light beam and make its partial polarization;

Be used to the device (41,51) that receives described partial polarization light beam and be divided at least three kinds of mutual exclusive primary colors beamlets;

In the described beamlet at least one is supply still less first primary colors of supply than other two kinds of primary colors;

At least two in other described beamlet is the supply independent primary colors bigger than the supply of described first primary colors;

Be positioned to receive the Polarization Modulation device (45,55) of the partial polarization beamlet of in large supply described primary colors in the described first primary colors supply, thereby the polarization degree of the described beamlet of selectively changing is with balance color supply independently; With

Be positioned to receive second polariscope (50), be used for the beamlet of the described primary colors of bigger supply and the beamlet of described first primary colors of supply are still less carried out color balance from the output of described Polarization Modulation device (45,55).

4. projection display system according to claim 3 is characterized in that, described prepolarization mirror is polarization conversion system (5).

5. projection display system according to claim 3 is characterized in that, described LCD projector comprises three transmission type LCD panels (46,56 and 59).

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