DE1287119B - Arrangement for increasing the light intensity and improving the color purity on the projection screen of a projection color television set - Google Patents

Description

1 2

The invention relates to an arrangement of different grid spacing, and its grid to Increasing the light intensity and improving the lines are perpendicular to the lines of the two Color purity on the projection screen of a pro-first grid. There are more on the inlet panel jection color television set with a leaf placed parallel to the grid lines of the fourth grid electrical charges deformable light- 5 fende translucent areas arranged with controlling medium on which two the light in the other opaque areas on the outside Direction diffractive lattice of different diaphragm are aligned in such a way that the through Lich grid spacing are recorded, the light control medium passing through undiffracted first grid with the larger grid spacing of a light of the third color component to the most impenetrable Color component with a shorter wave- i ° visible areas of the outlet diaphragm impinges. Prelude and the second grating with the smaller grating are preferably those of the third color component at a distance a second color component with an ordered transparent area of such a dimension longer Wavelength is assigned, and with a sioned that through the to an opaque between a light source and the light control area adjoining first transparent area inlet aperture arranged in the medium, whose through 15 diffracted by the fourth grating in the first order visible areas with the opaque areas light of the third color component passes through that one between the light control medium and that through the next, second transparent area Projection screen arranged outlet aperture of the - essentially that of the fourth grid in the second art are aligned that the light diffracted by the light control and third order of the third color medium undiffracted light passing through passes to the component and that passes through the opaque one Areas of the outlet aperture, the third transparent area that emerges from, and in which the light is diffracted in the fourth order by an opaque fourth grating rich first through third color component adjoining the outlet diaphragm, The visible area and the subsequent second are preferably those which are transparent to the first two in color Area of such a width and 25 components and that of the third color component compared to the opaque area, transparent areas assigned in this way are each stocky are that through the first transparent intersection slits of equal width and the two rich the first color component and the third color diffracted from the first grating in the first order Light of the first color component and the opaque areas associated with the component 30 bars of the same width as one another, diffracted in the first order by a third grid. With the arrangement according to the invention, light from the two color components will pass through

and that the slits in the outlet diaphragm are better utilized through the second transparent one, the area of the second grating in the first order so that more light of the second color component diffracted by the light control medium passes through under the corresponding light modulation, the third grating of the two 35 conditions reaches the projection screen without the first-mentioned grids due to beats that the different color channels of the device appear, are contaminated in an undesirable manner according to patent application, dung G 42799 VIII a / 21 a ¹ (German interpretation document If no light-diffractive deformations on

1 270 598). the light control medium are available, then

The object of the invention is that at 4 ° all of the light shines in the zeroth order, Arrangement according to the main patent application is therefore unbowed and falls on the opaque the projection screen the light intensity even more bars of the outlet aperture. When an electron beam to increase and to further combine the color purity with a light diffraction grating with an approximately sinusoidal improve. Draws the outline on the light control medium, then

This is achieved according to the invention in that 45 becomes that which impinges on the light control medium that additional light in the first, second and higher order gelich through the first transparent area that diffracted in the second order by the third grating. In the first order, a maximum of 67% If diffracted light of both color components passes through, all of the light must be contained in what is produced by the that depends on the depth of deformation through the second transparent area. The deeper the deformation In addition, the 5 ° from the first grating in the second order, the greater the proportion of the in the second diffracted light of the first color component through-order diffracted light. Commits the maximum value and that through the second translates about 47%. With even deeper deformations In the third transparent area following the third order, the light component increases and That rich of the second grid in the second order reaches about a maximum of 38%. The maxi-diffracted light of the second color component and the 55 times light output for the first-order gevom light diffracted in the first grating in the third order is therefore only 67%. The maximal the first color component passes through. Luminous efficiency for the first and second order

The ratio of the lattice spacing of the second diffracted light is 93% and for the first Grating to the grating spacing of the first grating is first and third order diffracted light 69%. The light in part 3: 4. The first color component 60 is the yield of the three first orders combined blue and the second color component red. is 98%. That in a higher than the third order

In addition to the so-called blue and red grids, diffracted light can therefore be and neglect the influence due to the superposition of these two grids, formed third, so-called floating grid is opposite to the arrangement according to the main patent In general, a fourth grid on the light registration is except for the subject matter of the invention The control medium is recorded, as is a third, primarily first-order diffracted light NEN color component is assigned. This fourth the second order and partly the third Grid has exploited a light diffracted by the blue and red grid order.

An embodiment of the invention will be described with reference to figures.

F i g. 1 schematically shows a projection color television set with the arrangement according to the invention;

2A to 2F schematically show the light control medium with the different light diffraction gratings;

F i g. Figure 3 is a section taken along line 3-3 of Figure 1 showing the inlet aperture with its lenses;

F i g. Figure 4 is a section on line 4-4 of Figure 4. 1 and shows the one arranged in front of the inlet aperture Lens plate;

F i g. Fig. 5 is a section taken on line 5-5 of Fig. 1 showing the light exit aperture;

F i g. 6 shows the instantaneous light yield as a function of the deformation depth on the Light control medium for the individual diffraction orders;

F i g. 7 shows the instantaneous light yield as a function of the deformation depth on the Light control medium for the sum of several diffraction orders;

F i g. 8 shows the average light output as a function of the deformation depth on the Light control medium for several diffraction orders in common;

Fig. 9A is a section of that with several vertical slots and webs provided outlet diaphragm according to FIG. 5; there are those from the red grid produced diffraction fringes of different orders for the red and blue light are shown;

Fig. 9B is similar to Fig. 9A and shows the dated blue gratings produced diffraction fringes of blue and red light;

Figure 9C is similar to Figures 9A and 9B and shows the diffraction stripes of the third, so-called beating grating for the red-blue or magenta-red one Light;

9D shows a section from a with a plurality of horizontal slots and webs provided side part of the outlet diaphragm according to FIG. 5; the diffraction strips of the green light generated by the green grid are shown.

The projection color television set shown in FIG includes an optical channel with a light control medium 10 and an electrical channel with an electron beam source 11, the beam 12 of which is directed over the light control medium 10. That from Light coming from a light source 13 is projected onto the light control medium. A projection lens system 14 with a light screen provided with several openings can contain several lenses, which cooperate on the light outlet side with the light control medium in such a way that the from Light control medium let through light falls on a projection screen 15 and there as an image is recovered.

The light source 13 with two electrodes 20 is located on the light inlet side of the light control medium 10 and 21, which are connected to a supply voltage source 22. The two electrodes 20 and 21 are located at the focal point of an elliptical reflector 25. The vertically oriented central part of an approximately circular filter 26 leaves essentially only the red and blue components of the electrodes generated white light. The side parts adjoining the middle part on both sides essentially only transmit the green component of the white light. A roughly circular one Lens plate 27 contains numerous small lenses arranged horizontally and vertically. Another approximately circular lens plate, which is designed as a light inlet aperture 28, has on its one There are also numerous small lenses on the outer surface. The light control medium 10 is located in the second Focus of the elliptical reflector 25. The central part of the light inlet aperture 28 contains several vertical slots separated by webs. On both sides of the middle part are in the Inlet panel several horizontally extending slots separated by further webs. The individual little ones Lenses of the lens plate 27 convert the light coming from the arc source 13 into several small light sources, the number of which corresponds to the number of small lenses. Thereby the light source mapped onto the individual separate lenses at the clear slots in the inlet aperture 28. The lenses of the inlet aperture 28 correspondingly form the lenses on the lens plate 27 on the active area of the light control medium away. Due to the filter 26, only the red and blue components fall on the perpendicular running slits and the green light component on the horizontally running slits of the Inlet panel 28.

The projection lens system 14 arranged on the light outlet side is divided into a lens system 30 with an outlet aperture 31 and a lens system 32. The middle part of the outlet aperture 31 also has several horizontally extending slots separated by webs. The at that Middle part on both sides adjoining side parts accordingly contain several separated by webs, horizontally running slots. If the light control medium 10 is not deformed, that forms Lens system 30 the light falling through the slits of the inlet aperture 28 to corresponding opaque Web of the outlet aperture 31 from. When the light control medium 10 is deformed, the light becomes flexed and passes through the slots in the outlet aperture 31 and is by the lens system 32 thrown on the projection screen 15.

A section from FIG. 2A is schematically shown in FIG a grid on the light control medium 10 can be seen. The diffraction grating 34 shown is the red one Color component assigned. The overall size of the grid in this embodiment has a height of about 20.8 mm and a width of 28 mm. The horizontal lines 33 indicate that of the green color component assigned diffraction gratings. The red diffraction grating is modulated by the speed Electron beam is generated, which with a sampling frequency of 15 735 Hz line by line over the Light control medium is directed. A fixed carrier oscillation is used for speed modulation Frequency of about 16 MHz. This creates a grid with a line spacing of about 0.0334 mm. As a result of the speed modulation with the high-frequency carrier oscillation, the moves Beam stepwise, and the charge distribution is applied as it is schematically in Fig. 2A and shown in section in Fig. 2B.

Figures 2C and 2D show the corresponding for the blue diffraction grating 35. The carrier oscillation modulating the speed of the same electron beam has a frequency of about 12 MHz, so

that the blue grid has a larger grid spacing.

FIGS. 2 E and 2F show the green diffraction grating 33 in more detail. Point to both sides of the grid lines dashed lines 36 schematically indicate the concentration of the charges in the direction of the grid lines. The green diffraction grating is due to the modulation of the electron beam with a very high Frequency of about 48 MHz in the vertical direction,

are assigned to the green color component in the two side parts (Fig. 3).

In Fig. 3, the inlet aperture 28 is shown. the

source 60, a green carrier frequency source 61, a green modulator 62 to which the green video signal and the green carrier signal are fed, and a push-pull amplifier 64, the output signal 5 of which is fed to the vertically deflecting plates 43. A vertical deflection unit 63 is also connected to the plates 43 and the plates 41 via capacitors 49 c and 49 d.

As mentioned earlier, uses the red and the blue

so vertical to the deflection direction of the electron io light channel the vertical slits and webs and the Beam generated. The amplitude of the 48 MHz carrier green channel the horizontal slits and ridges in oscillation changes inversely proportionally with the light shields. The raster area of the light Amplitude of the green video signal. The control medium can have a rectangular shape, chosen frequency is higher than that of the red or its ratio of height to width is 3: 4 blue carrier oscillation, so that an undesirable 15 can. The distance between the slots from center to center Interaction with the other carrier vibrations is therefore three in the horizontal arrangement gen is avoided. Quarter the distance of the slots from center to

In the case of a truthful representation of a center in the vertical arrangement. The small Color picture element must have three properties of the lenses of the plates in question are in the same Light, namely the luminosity, the hue and the 20 ways. With them the ratio is of Saturation can be reproduced. The luminosity is height to width also 3: 4. The little lenses of both the lightness, the hue, the color and the saturation plates, which yes in horizontal rows and vertical ones the saturation of the color. For correct re-columns are arranged, point one from the plate if the luminosity had been given a single dependent focal length would be sufficient. The filter can have three ab-grid lines. To accurately reproduce the color shade, have 25 sections that correspond to the red and blue color and the saturation, however, are at least three to three components in the central part of the inlet aperture and the four grid lines necessary.

For the speed modulation of the electron beam 12, the one in FIG. 1 device shown in
an evacuated flask 40 the electron beam 30 vertical slits 70 affect the red and blue source 11 with a cathode (not shown), a color component of the image to be projected. The control electrode (not shown) and an anode horizontal slots 71 in the edge sector of the inlet (not shown), two vertically deflecting plate aperture on either side of the central part act with 41, two horizontally deflecting plates 42, a light control medium and the light outlet aperture set of deflection electrodes 43 for vertical focus 35 in such a way that the green color componentization, a set of deflection electrodes 44 for the horizontal light to be projected is influenced. The zontal focusing and the light control medium ratio of the distances from the center to the center of the 10. The cathode, the control electrode, the anode and horizontal slots 71 to the distances of the vertie a transparent intercepting electrode 48, which the light kale slots 70 is 3: 4. The vertical control medium 10 carries, are fed by a supply 40 and horizontal dashed lines 72 and 73 counterpart 46. The rectangular areas formed by the electrodes 41 and 42 are the boundaries for the individual small lenses that are present on the surface of the diaphragm 28 occupied by high impedances 68 a to 68 d to earth. It works. The electrodes 43 and 44 serve as the focus center of these small lenses is in each case in the center and deflection of the electron beam with respect to one of the limited areas. Hch of the light control medium and are attached to a fo- In Fig. 4, the lens plate 27 is shown, the

Kissing voltage unit 47 connected. horizontal rows and vertical columns of small ones

The two carrier vibrations that the red and lenses 74 have. All the small lenses on this plate Generate blue grids, will act in addition to the horizontal with one in the inlet aperture 28 arranged zontal Deflection voltage the horizontally deflecting small lens together, fed to the plates 42. The high-frequency, from the in F i g. 5 has light outlet aperture 31 shown

green video signal modulated carrier wave several vertical transparent slits 75 and unwill in addition to the vertical deflection voltage, the transparent webs 76 in the middle part and several vertical deflecting plates 41 fed. The horizontal clear slots 77 and opaque light control medium 10 is an oil of corresponding 55 visible webs 78 in their two edge parts. Viscosity, which is on a transparent holding body F i g. 6 shows the light output for the

45 is applied, which is a transparent conductive
Layer, e.g. B. of indium oxide, carries.

In Fig. 1 are also a horizontal deflection unit
58, a red and blue video signal source 50 and 60, respectively
51, a red and blue carrier frequency source 52
or 54, a red and blue modulator 53 or 55,
an adder circuit 56 and a push-pull amplifier
shown of the horizontally deflecting plates
feeds. The horizontal deflection unit 58 is flat 65 diffracted light zero, first, second and third if to the plates 44 and via capacitors 49 a order, the light yield in curves 80 to and 49 b is connected to the plates 42. · 83 shown. If the light control medium does not

Furthermore, Fig. 1 shows a green video signal- is deformed, all the light occurs as in zeroth

light diffracted by the light control medium depending on a deformation function Z:

Ζ = 2π (η-ΐ) Α / λ.

Here, A denotes the depth of the deformations, λ the wavelength of the incident light and η the refractive index of the light control medium. For the

Order diffracted light, i.e. as non-diffracted light. However, this is always done by the light control medium light passing through is slightly deflected by the refraction in the medium, since the refractive index of this medium differs from that of the Vacuum or air. Appropriately, the medium is chosen so that his Refractive index roughly with that of the other optical materials used in the device, for example glass, matches. When mapping the slots of the inlet aperture on the webs of the outlet aperture low refractive effects are allowed. If the deformation or modulation depth for If a given grid is raised, more and more light appears in the various orders the diffraction figure. With increasing orders, the maximum value of the luminous efficacy increases increasingly from. As you can see from the graphs, the light output is in the first, second and third order approximately 67.47 and 37 ° / a, respectively.

7 shows diagrams of the light yield as a function of the deformation function Z for various combinations of diffraction orders. Here the light output is plotted along the ordinate in percent and Z along the abscissa. A curve 85 shows how the luminous efficiency increases in the first order until it reaches the maximum value of about 67% and then decreases. A curve 86 shows the light yield for the sum of the light diffracted in the first and second order, which increases until a maximum value of approximately 93% is reached and then decreases. Similarly, a curve 87 shows the light yield of the diffraction gratings for the first and third diffraction orders. This light yield increases until it reaches a maximum value of 69 % and then decreases. Finally, a curve 88 shows the light yield for the sum of the first, second and third orders. This light output increases up to a peak value of about 98% and then decreases. A curve 89 shows the light yield for the sum of all orders with the exception of the zeroth order.

F i g. 8 shows a family of curves for the average luminous efficacy for the various combinations of diffraction orders as a function of Z. The average luminous efficacy is plotted along the ordinate in percent and the auxiliary variable Z, which is proportional to the deformation amplitude, is plotted along the abscissa. In order for the device to work properly, the light control medium must maintain the diffraction deformations until scanning of the field is complete. Ideally, the deformations should be retained undamped at all points until new deformations are recorded at the individual points. In practice, such an ideal situation cannot be fulfilled, since the charges flow away from the medium and thus the diffraction grating decreases significantly. Under the practical conditions, the deformations should decrease to a small value during the scanning of the television picture, so that the new deformations can be impressed on the light control medium. The curves for the average light output of Figure 8 are based on the deformation decrease to approximately the third part of the initial value during a field scan. Curves 90 to 93 show the average luminous efficacy for first-order diffraction, for first-order and second-order diffraction together, for first and third-order diffraction together, and for first, second and third-order diffraction together.

9A shows a part of the webs and slots, namely four webs 94 to 97 and three slots 98 to 100 in the central part of the outlet aperture 31 (FIGS. 1 and 5). This figure is intended in particular to illustrate how the red and blue light fall in different orders on the vertical webs and slots of the outlet diaphragm during diffraction. The horizontal shift of the various orders for the red and blue color components in relation to the slots and webs of the outlet diaphragm is shown on the abscissa. When the light control medium is not modulated, the distance between the lines B ₀ , R _{0 contains} a certain relationship to the width of the slits in the inlet aperture 28 (FIG. 3). Since the longer wavelengths are deflected more strongly by a diffraction grating with fixed line spacing, the first-order red light R ₁ is deflected more than the first-order blue light _B1. The increasingly higher orders of the diffracted light are also increasingly deflected by the factor of the order. Thus, the red second order component R _{2 is} deflected twice as far as the red first order component R _1; the same applies for blue light second OrdnungB. ₂ What for them

different color components is said, also applies to the individual wavelengths within a color component; the long-wave red light is deflected more strongly than the short-wave red light. Accordingly becomes the spatial spread of the image of the light source with higher order and for larger ones Wavelengths get bigger. The light source, which has a certain width in the zero order image, has a correspondingly greater width in the higher-order images; the degree of increase depends not only on the order, but also on the color component. For better The overview is the enlarged width of the higher order diffraction fringes in FIGS. 9A to 9D not specified.

The line spacing of the red diffraction grating, the blue diffraction grating, the mean wavelength of the red light and the mean wavelength of the blue light have a special relationship to one another. The mean wavelength of a color component means a wavelength lying in the middle of the color component spectrum used. Such a mean wavelength represents the predominant wavelength of a color component or primary color that impinges on the light control medium. Since all wavelengths of a primary color component are not transmitted in the same way by the optical elements on the outlet side of the light control medium, the predominant wavelengths which impinge on the projection screen differ from the predominant wavelengths of the primary color incident on the light control medium; however, these predominant wavelengths hardly differ from the previously defined mean wavelength. Typically, the mean wavelength of the blue color component is 465 nanometers and that of the red color component is 620 nanometers.
The ratio of the line spacing in the blue

909503/1235

9 10

Diffraction grating can be made to the line spacing of the red diffraction without compromising the sighting grating is preferably equal to the ratio lent to the purity of the various, nor the same mean wavelength of red light can be closed to the colors that are let through in the middle leren wavelength of blue light chosen. For the must, so that a higher proportion of diffracted light the typical value mentioned above is this value. The greater width for the ratio 1.33. This corresponds to a ratio of the vertical outlet slot can be 75% of the common Carrier frequencies that represent the red and blue diffraction widths of a slot and an adjacent ridge create a grid of 4: 3. A ratio of the mid-amount.

The two diffraction gratings with different wavelengths of 4: 3 are used for the device according to line spacing, but with orien-F i g in the same direction. 1 elected. The absolute value of the carrier-oriented lines in the same range of the light diffraction frequencies, which generate the line spacing of the red and medium. B. determined by the line spacing by the difference between the two fringing capacities of fine grids in the light control sequences of the corresponding primary grids. Medium and also subject to certain requirements. The grid frequencies of the first two grids are correct, e.g. B. that the beat frequencies are selected so that the difference frequency is half the video tape and is therefore none lower than each of the two frequencies. That evoke through the desired, visible image. the beating generated grating, the line spacing of which If the ratio of the line spacing of the is greater than that of the two other grids, the blue grating to the line spacing of the red grating 20 therefore directs the diffracted light in the various ord-4: 3 and the vertical bars the outlet - decreases less than the other two grids; dazzle the different orders of the blue light diffracted from the red the extent of the deflection depends on the line spacing of the diffraction grating, this grating and the wavelength of the light. However, let the red light pass through, then it is evident from Fig. 9C how, according to the invention blue in the first, second and third order, the diffracted light B ₁ , B ₀ and B ₃ through the beating grating can be applied to the first , light diffracted by the second different orders is advantageous from the third web 95, 96 or 97; uses the red light. In Fig. 9C, the same central part of the first order lights R ₁ falls into the second slit 99 and the outlet aperture with the same slits and webs as the red light of the second order R _{2 can be seen} in the third in FIGS. 9A and 9B. The red and slit 100. 30 blue light are collectively referred to as magenta M in Fig. 9B is the ^: distribution of the various draws. In FIGS. 9A and 9B, magenta orders of the red and blue light fall above the zero order light M ₀ on the opaque outlet aperture for the blue component to the web 94. Magenta light first order M ₁ , orderly diffraction gratings can be seen. The abscissa gives second order magenta light M ₂ and in this case the horizontal shift of the 35 white third order magenta light M ₃ falls in red and blue components in the different first slit 98. At least part of the blue diffraction orders with respect to the slits and first order light B ₁ and part of the red bars on the outlet aperture. Because the line spacing in third order light R ₃ will be blocked. How the blue grid is larger than the red one, it has been found out in the, that such a barrier in light diffracted in different orders is less essentially complementary, so that the magenta-red is deflected. The zeroth order light R ₀ , B ₀ remains unaffected by light passing through the first slit. The blue light of the first order B ₁ falls red and blue light approximately in the desired Anjedoch now essentially in the first slit 98, share. Like the fig. 7 and 8 the blue light of the second order B _{2 can be taken} into the second, the device, in which in addition to the slit 99 and the blue light of the third order B ₃ in 45 light of the first order, the light of the second also leaves the third slit 100. The red light of the first order and third order is used, a considerable amount R ₁ and the red light of the second order R ₉ falls on the light intensity compared to a device now on the first web 95 or on the second web, in which only that First order light

96. The blue light of the fourth order S ₄ and the red light is used.

Third-order light R ₃ impinges on the third web 50. FIG. 9D shows a section from a side part

97. Although, in addition to the blue, red light can also be seen from the outlet aperture. There are different falls on the blue diffraction grating, the webs 101 to 104 block the red 105 to 107 separated from each other by successive slits webs and slits on the outlet aperture. Light along the abscissa and let only the blue pass through. _{This is the vertical shift of the green light G 0} to G ₄ diffracted into the different orders of the first, second and third orders by the blue grating and the first and second order of the red light diffracted by the red grating opposite the slits and webs of the outlets diffracted red light aperture 31 (F i g. 1 and 5) shown. The green ones are let through. The way in which grids assigned to primary color components can be seen from FIG. 7 and FIG. 8 results in a device in which the maximum modulation of the light control medium 60 is formed from horizontal grid lines of an image field. The distance between the bars from center to center corresponds to a depth, which roughly corresponds to the depth for the maximum light output in the outlet diaphragm for the green light channel, a large three quarters of the distance between the bars in the red and light intensity for the red and blue components and blue channel. Accordingly, a good color choice is made in a device. As a result, the purity of FIG. 1 is retained with a grid height of 20.8 mm and both colors. If small light sources, 65 at a mean green wavelength of 530 nano, so the lens plates with the small lenses in the meter the green light of the first order G _{1 is used} in the light inlet part of the device of Fig. 1 slot 105, about a third of the green light of the second, The slots of the outlet aperture can be wide order G ₂ in the slot 106 ~ and about a third

of the green light of the third order G ₃ also into the slot 106. The width of the slots 105 to 107 is chosen so that this green light can easily pass through.

Claims (5)

5 claims: 1. Arrangement for increasing the light intensity and improving the color purity on the projection screen of a projection color television set with a light-controlling medium which can be deformed by applied electrical charges and on which two grating diffracting the light in the same direction and having different grating spacing are recorded, the first grating having the larger grating spacing a first color component with a shorter wavelength and the second grating with the smaller grid spacing is assigned to a second color component with a longer wavelength, and with an inlet aperture arranged between a light source and the light control medium, the transparent areas of which with the opaque areas between the The outlet screen arranged on the light control medium and the projection screen are aligned in such a way that the undiffracted light passing through the light control medium strikes the opaque areas of the outlet screen d in which the first transparent area adjoining an opaque area on the outlet diaphragm and the subsequent second transparent area are of such a width and offset from the opaque area in such a way that the light diffracted by the first grating in the first order through the first transparent area of the first color component and the light of the two color components diffracted by a third grating in the first order and that the light of the second color component diffracted in the first order by the second grating passes through the second transparent area, the third grating of the first two grids is generated due to beating phenomena, according to patent application G 42799 VIII a / 21 a ¹ (German Auslegeschrift 1270 598), characterized in that the first transparent area (98 in Fig. 9A to 9C) additionally that of the third grid in the second order diffracted light of both F arb Components (M ₂ ) passes that through the second transparent area (99) additionally the second order diffracted by the first grating (35 in Fig. 2C and 2D) light of the first color component (B ₂ ) passes and that through the second The third transparent area (100) following the transparent area, the second-order diffracted light of the second color component (R ₂ ) by the second grating (34 in FIGS. 2A and 2B) and the third-order diffracted light of the first color component (B ₃ ) passes through. 2. Arrangement according to claim 1, characterized in that the first color component is blue and the second color component is red and that the ratio of the grid spacing of the second Grid (34) to the grid spacing of the first grid (35) is 3: 4. 3. Arrangement according to claim 2, in which a grid assigned to a third color component is recorded with a fixed, but different grid spacing from the two first grids and with grid lines perpendicular to the first three grids, and the further grid running parallel to the grid lines of the fourth grid translucent areas on the inlet screen are aligned with further opaque areas on the outlet screen in such a way that the undiffracted light of the third color component which passes through the light control medium impinges on the opaque areas of the outlet screen, characterized in that the transparent areas assigned to the third color component (77 in Fig . 5) on the outlet diaphragm (31) are dimensioned in such a way that through the first transparent area (105) adjoining an opaque area (101 in FIG. 9D) the fourth grille (33 in FIG. 2 E and 2F) first order diffracted light the third n color component (G ₁ ) passes that through the next, second transparent region (106) _{essentially the light of the third color component (G 2} and G ₃ ) diffracted in the second and third order by the fourth grating passes and that through the following, third transparent area (107) the light of the third color component (G ₄ ) diffracted by the fourth grating in the fourth order passes. 4. Arrangement according to claim 3, characterized in that the two first color components and the transparent areas assigned to the third color component each have equal width slots (75 or 77) and the opaque areas assigned to the first two color components and the third color component are mutually equally wide webs (76 and 78). For this purpose 2 sheets of drawings