CA1108737A - Optical display arrangements - Google Patents
Optical display arrangementsInfo
- Publication number
- CA1108737A CA1108737A CA296,925A CA296925A CA1108737A CA 1108737 A CA1108737 A CA 1108737A CA 296925 A CA296925 A CA 296925A CA 1108737 A CA1108737 A CA 1108737A
- Authority
- CA
- Canada
- Prior art keywords
- arrangement
- radio
- fluorescent
- active substance
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000003287 optical effect Effects 0.000 title claims description 8
- 239000000941 radioactive substance Substances 0.000 claims abstract description 22
- 239000004973 liquid crystal related substance Substances 0.000 claims abstract description 14
- 239000000463 material Substances 0.000 claims abstract description 12
- 239000002245 particle Substances 0.000 claims abstract description 12
- 229910052722 tritium Inorganic materials 0.000 claims abstract description 9
- YZCKVEUIGOORGS-NJFSPNSNSA-N Tritium Chemical compound [3H] YZCKVEUIGOORGS-NJFSPNSNSA-N 0.000 claims abstract description 8
- 239000000126 substance Substances 0.000 claims abstract description 8
- 238000005286 illumination Methods 0.000 claims abstract description 6
- 238000007373 indentation Methods 0.000 claims description 5
- 230000005855 radiation Effects 0.000 claims description 5
- 239000002253 acid Substances 0.000 claims description 3
- 230000005284 excitation Effects 0.000 claims description 3
- 239000003513 alkali Substances 0.000 claims description 2
- 230000002285 radioactive effect Effects 0.000 claims description 2
- 206010056740 Genital discharge Diseases 0.000 claims 1
- 210000002858 crystal cell Anatomy 0.000 abstract description 6
- 238000000576 coating method Methods 0.000 description 6
- 230000009102 absorption Effects 0.000 description 4
- 238000010521 absorption reaction Methods 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 230000004913 activation Effects 0.000 description 2
- 230000000295 complement effect Effects 0.000 description 2
- 241000792765 Minous Species 0.000 description 1
- 101100004031 Mus musculus Aven gene Proteins 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 230000003213 activating effect Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 210000004027 cell Anatomy 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007943 implant Substances 0.000 description 1
- 239000004922 lacquer Substances 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 239000012857 radioactive material Substances 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 210000002784 stomach Anatomy 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133617—Illumination with ultraviolet light; Luminescent elements or materials associated to the cell
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/04—Luminescent, e.g. electroluminescent, chemiluminescent materials containing natural or artificial radioactive elements or unspecified radioactive elements
-
- G—PHYSICS
- G04—HOROLOGY
- G04G—ELECTRONIC TIME-PIECES
- G04G9/00—Visual time or date indication means
- G04G9/0023—Visual time or date indication means by light valves in general
- G04G9/0029—Details
- G04G9/0035—Details constructional
- G04G9/0041—Illumination devices
Landscapes
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Nonlinear Science (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mathematical Physics (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Liquid Crystal (AREA)
- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
- Electric Clocks (AREA)
Abstract
Abstract of the Disclosure The present invention relates to an arrangement comprising a light valve, in particular a liquid crystal cell, having a light trap in the form of a fluorescent body which is made from a material having a refractive index greater than 1 and containing fluorescent particles and an auxiliary illumination source. The arrangement according to the present invention provides that the auxiliary illumination source contains a radio-active sub-stance as well as a luminous material adapted to be activated by the substance. The radio-active substance may be selected in particular from among weak .beta.-ray emitters, such as for example tritium. The main field of use of the arrangement is in battery-operated indicating instruments, in particular wrist-watches.
Description
The present invention rela-tes to optical display arrange-men-ts comprising a light ~ralve (i.e. a display having at least one display element which is switchable between an opaque or diffusecl state and a transparent state), in particular a liquid crystal cell;
a light trap in the form of a body (hereinafter referred to as a "fluorescent body") which is made of a material having a refractive index greater than 1, which contains fluorescent particles and which is provided with one or more light-emergence windows; and finally an auxiliary illuminating means.
Such displays have already been proposed, for example, in U.S. Patents 4,142,781 issued March 6, 1979 and 4,167,307 issued September 11, 1979. The fluorescent body used in these displays increases the contrast of the display, since it traps incident ambient light by fluorescent scattering and subsequent total reflection, and finally emits it again at a higher level of intensity through the light-emergence windows specifically provided for this purpose.
Since this light trap merely intensifies the image displayed but does not itself generate any light, an auxiliary means of illumin-ation is still required for use when the ambient light is not sufficiently bright, for example, under night conditions.
In such a display, the auxiliary light source provided, ; if it is to be suitable for use with battery-powered devices, should consume as little power as possible and preferably should be operable (for example, in wrist-watches) without any need for manual opera-~ tion, and it is an object of the present invention to provide an `~ optical display arrangement incorporating such an auxiliary light source.
According to the invention, there is provided an optical "~
7 ~ 7 display arranclement comprising a light valve, a liyht -trap in the form of a fluorescent body made of a material having a refractive index greater than 1, which contains fluorescent particles and which is provided with at leas-t one light-emergence window, and an auxiliary illumination means comprlsing a radio-ac-tive substance and a luminous material which is activated by the radiation Erom said substance. A weak ~-ray emitter, such as tritium, for example, is particularly suitable for use as the radio-active substance.
- 10 The light source provided in the arrangement of the invention emits light con-tinuously without any need to press a button to activate it and without requiring any supply of energy, for example, from a battery. In addition, it does not require replacement or regeneration during the normal service life of the display, since its illuminating power, depending only on the half-life of the radio-active material, only declines to an appreciable extent after a relatively long period.
Liquid crystal displays with luminous colours excited by weak ~-emitters are already known per se (see, for example, German Patent Specification No. 2,232,632 of Charrier, laid open January 24, 1974). Moreover, liquid crystal displays are already on the market having miniature bulbs filled with tritium gas. The . ` :
.
:
arrangement of the invention offers considerable advan-tages over these known arrangements~ however, since in the arrangement of th~ invention the light onLy ha~ to be available at the emergence windows and consequently S the radio-activity level which must be ~olerated can be made substantially lower.
In the arrangements of the invention, the fluorescent body is generally plate-shaped and located behind the light valve ~n the viewing direction. With such an arrangement, the auxiliary means of lllumination, such as a mi~iature tritium bulb, ~ay conveniently be disposed either along one or more o~ the side edyes of the fluorescent plate or behind this plate; in the latter case, it should totally cover the face of tbe plate ad~acent to ito ~lternatively~ o cour~e, the light so~rce may be incorporated in the fluorescent plate itself, for example by casking it in when the plate is made.
If a par~icularly space-savins design is r~quired, ~ with uniform illumination of all the elements of the dis-; 20 play, the radio-active substance should be directly incorporated in the fluorescent body in as homogeneously distr~buted a manner as possible~ In this case, it may be worth binding the radio-activ~ substance chemically, for ; example~ to the fluorescent particles. Finally, it may be possibLe to add phosphorescent particIes that can be made to gLow by the radiating substance.
;~ With the arrangement of the lnvent~on, a particularly small amount ot radio-act~ve substance can suffice; i~ the `: :
3~,~
emergence windows of the fluorescent: plate are constltuted b~ a combination of scattering areas on the front f ace of the pl ate and indentations located at corresponding point~
in the rear face ~hereof, the radlo-act~ve substance and the luminous material is applied to the scattering areas only. In this case, the light yield can be made aven higher, if lt is also ensured that the largest possible part o~ ~he fluorescent or other l~minous radlation passes -- through the light val~e. This can be achieve~ by locatlngj 10 the ~luorescent plate~ a~ close as possible to the ~witchable medium and/or lf the light valve is freed from undasirably absorbent component~O In a liquid crystal cell normally using polarisers for its operation~ for example, it i5 particularly ad~antageous to i~plant a pleochroic dye in the liquid crystal layer, since such an additive renders unnecessary that polar~er which is located between the fluorescent body anà the liquid crystal layer and which, in practice, not only polarises but also weakPns the light ~, passing through it by absorptlon.
The invention will now be further descr~ bed with reference to ~he drawing~ ~n which :-Figure 1 is a schematic side sectional view o~ a first embodiment of the invention;
Flgure 2 is a similar ~iew to that of Figure 1 of a second embodiment of the invent~on; and Figur.e 3 is a schematic side-sectional view of a - fluorescent plate for use in a ~hird . embodiment o~ the invention.
In all the Figures~ like parts are indicated by the same refere~nce numeral. ~ 5 .~
.
~ ~ `, .. .. .
:
'3~7 he embodiment shown in Figure 1, includes a light valve in the form of a liquid crystal cell with a single-digit numerical display. In detail, the arrangement illustrated comprises a front linear polariser 1, a front carrier plate 2, a rear carrier plate 3, a rear linear polariser 4, a fluorescent plate 5 and an absorption film 6, all disposed sequentially one behind another in the named order in -the direction of viewing.
On their opposed faces the two carrier plates are pro-vided with electrically conducting coatings, the rear plate 3 with an unbroken coating forming a rear electrode 8, and the front plate 2 with a segmented electrode forming electrode segments 9.
Between the two carrier plates a spacing frame 10 is located, defining with the two plates a sealed chamber filled with a liquid crystal layer 11.
On its four side faces the fluorescent plate 5 carries reflective coatings 12 and it is provided with a plurality of light-emergence windows one disposed behind each individual elec- -trode segment 9 (considered in the direction of viewing). Each of ~ these windows consists of an indentation 13 whlch may be silvered, 20 in the rear face of the plate 5 and of a co-operating scattering area 14 on the front face of the plate and constituted, for example, by a pigment or a roughened flat area of the plate surface. This form of window gives a wide angle viewing zone with relatively high light intensity and provides a practically parallax-free ~` display.
An auxiliary illuminating means in the form of a small lamp 15 filled with tritium gas is attached to one of the four side faces of the plate. On this side the reflective coating is '' , , -:
:: , ~ , :
so cons-ti-tuted that the -tritium light can pass in-to the interior of -the plate but -the fluorescent light is reflected back, -the reflective coating being in the form of a dichroic mirror 16. Naturally, other kinds of optical linking between the small lamp and the pla-te can equally be used.
The liquid crystal cell works on the principle of the so-called "rotary cell". For further details, reference should be made to German Patent Specifica-tion No. 2,158,563 of Wuesthoff et al, laid open June 29, 1972. In the embodiment of Figure 1, the axes of polarisation of the two linear polarisers are arranged at right angles to one another so that the light valve is transparent in the inoperative state and opaque in the activated sta-te. At the same time the activating means (not shown) is so designed that it is always only those electrode segments not required to form the image to be displayed that are supplied with a voltage. This is known as the "principle of complementary activation". These measures give a particularly bright image on a dark background; the part of the display screen not covered by the electrode segments appears almost black since only a very small part of the trapped light leaves the fluorescent plate outside the windows and moreover the light from the background is collected by the absorption film 6. The activated display elements are black since there the valve blocks the passage of light. Finally, the image is particularly intense, since the front face of the fluorescent plate 5 which is covered by the liquid crystal cell can also absorb light.
The embodiment illustrated in Figure 2 differs from the first embodiment in the following ways. The light source is placed, not as in the embodiment of Figure 1, to the side, but behind the .
~luorescent plate 5 and without any optical con-tact -therewith; all -the side faces of -the pla-te 5 are completely silvered; the absorp-tion film 6 is replaced by a filter providecl with a highly reflec-tive coating on its rear face and which only admits light for the excitation of the fluorescent particles (this measure increases the length of the absorption path for the incident and excitation light and thus generally makes it possible to use a lower concen-tration of fluorescent material with a consequent greater ultimate brilliance); complementary activation is not used; the rear linear polariser is eliminated and in its stead, the liquid crystal layer contains a pleochroic dye. In its inoperative state, the li~uid crystal layer exhibits a planar texture wi-th a bias parallel to the axis of polarisation of the linear polariser, whilst in its activated state, it exhibits a homotropic orientation. A focal-conical in-active texture could alternatively be used.
The radio-active substance used need not be present in the gaseous state, it can alternatively be present in chemically bound form in the fluorescent plate, in a film disposed behind the plate or in a layer which fills the indentations in the rear face of the plate, for example. It is, moreover, possible to implant scattering particles of luminous material in the front face of the plate and to surround these particles with a compound containing the radio-active substance. This possibility is illustrated in Figure 3.
Here, the scattering layer 1~ of the fluorescent plate 5 is coated with a tritium lacquer 18. With this form of light source, the light yield from the luminous material is particularly high.
If necessary, for example, in order to keep within a prescribed radiation tolerance level, the radio-active substance ~' ~3~ ~j '5~
can be embedded in a ma-terial that absorbs the undesired radio~
active energy, and is also acid and alkali-resistant, and in particular, is not decomposed by stomach acid.
The inven-tion is not, oi- course, limited to -the embodi-ments illustra-ted, for example, radio-active substances other than tritium can be used, and the light valve, i-luorescen-t body and radio-active adcditional lighting can be combined in other ways.
_ g _ ..
::
.:
.
a light trap in the form of a body (hereinafter referred to as a "fluorescent body") which is made of a material having a refractive index greater than 1, which contains fluorescent particles and which is provided with one or more light-emergence windows; and finally an auxiliary illuminating means.
Such displays have already been proposed, for example, in U.S. Patents 4,142,781 issued March 6, 1979 and 4,167,307 issued September 11, 1979. The fluorescent body used in these displays increases the contrast of the display, since it traps incident ambient light by fluorescent scattering and subsequent total reflection, and finally emits it again at a higher level of intensity through the light-emergence windows specifically provided for this purpose.
Since this light trap merely intensifies the image displayed but does not itself generate any light, an auxiliary means of illumin-ation is still required for use when the ambient light is not sufficiently bright, for example, under night conditions.
In such a display, the auxiliary light source provided, ; if it is to be suitable for use with battery-powered devices, should consume as little power as possible and preferably should be operable (for example, in wrist-watches) without any need for manual opera-~ tion, and it is an object of the present invention to provide an `~ optical display arrangement incorporating such an auxiliary light source.
According to the invention, there is provided an optical "~
7 ~ 7 display arranclement comprising a light valve, a liyht -trap in the form of a fluorescent body made of a material having a refractive index greater than 1, which contains fluorescent particles and which is provided with at leas-t one light-emergence window, and an auxiliary illumination means comprlsing a radio-ac-tive substance and a luminous material which is activated by the radiation Erom said substance. A weak ~-ray emitter, such as tritium, for example, is particularly suitable for use as the radio-active substance.
- 10 The light source provided in the arrangement of the invention emits light con-tinuously without any need to press a button to activate it and without requiring any supply of energy, for example, from a battery. In addition, it does not require replacement or regeneration during the normal service life of the display, since its illuminating power, depending only on the half-life of the radio-active material, only declines to an appreciable extent after a relatively long period.
Liquid crystal displays with luminous colours excited by weak ~-emitters are already known per se (see, for example, German Patent Specification No. 2,232,632 of Charrier, laid open January 24, 1974). Moreover, liquid crystal displays are already on the market having miniature bulbs filled with tritium gas. The . ` :
.
:
arrangement of the invention offers considerable advan-tages over these known arrangements~ however, since in the arrangement of th~ invention the light onLy ha~ to be available at the emergence windows and consequently S the radio-activity level which must be ~olerated can be made substantially lower.
In the arrangements of the invention, the fluorescent body is generally plate-shaped and located behind the light valve ~n the viewing direction. With such an arrangement, the auxiliary means of lllumination, such as a mi~iature tritium bulb, ~ay conveniently be disposed either along one or more o~ the side edyes of the fluorescent plate or behind this plate; in the latter case, it should totally cover the face of tbe plate ad~acent to ito ~lternatively~ o cour~e, the light so~rce may be incorporated in the fluorescent plate itself, for example by casking it in when the plate is made.
If a par~icularly space-savins design is r~quired, ~ with uniform illumination of all the elements of the dis-; 20 play, the radio-active substance should be directly incorporated in the fluorescent body in as homogeneously distr~buted a manner as possible~ In this case, it may be worth binding the radio-activ~ substance chemically, for ; example~ to the fluorescent particles. Finally, it may be possibLe to add phosphorescent particIes that can be made to gLow by the radiating substance.
;~ With the arrangement of the lnvent~on, a particularly small amount ot radio-act~ve substance can suffice; i~ the `: :
3~,~
emergence windows of the fluorescent: plate are constltuted b~ a combination of scattering areas on the front f ace of the pl ate and indentations located at corresponding point~
in the rear face ~hereof, the radlo-act~ve substance and the luminous material is applied to the scattering areas only. In this case, the light yield can be made aven higher, if lt is also ensured that the largest possible part o~ ~he fluorescent or other l~minous radlation passes -- through the light val~e. This can be achieve~ by locatlngj 10 the ~luorescent plate~ a~ close as possible to the ~witchable medium and/or lf the light valve is freed from undasirably absorbent component~O In a liquid crystal cell normally using polarisers for its operation~ for example, it i5 particularly ad~antageous to i~plant a pleochroic dye in the liquid crystal layer, since such an additive renders unnecessary that polar~er which is located between the fluorescent body anà the liquid crystal layer and which, in practice, not only polarises but also weakPns the light ~, passing through it by absorptlon.
The invention will now be further descr~ bed with reference to ~he drawing~ ~n which :-Figure 1 is a schematic side sectional view o~ a first embodiment of the invention;
Flgure 2 is a similar ~iew to that of Figure 1 of a second embodiment of the invent~on; and Figur.e 3 is a schematic side-sectional view of a - fluorescent plate for use in a ~hird . embodiment o~ the invention.
In all the Figures~ like parts are indicated by the same refere~nce numeral. ~ 5 .~
.
~ ~ `, .. .. .
:
'3~7 he embodiment shown in Figure 1, includes a light valve in the form of a liquid crystal cell with a single-digit numerical display. In detail, the arrangement illustrated comprises a front linear polariser 1, a front carrier plate 2, a rear carrier plate 3, a rear linear polariser 4, a fluorescent plate 5 and an absorption film 6, all disposed sequentially one behind another in the named order in -the direction of viewing.
On their opposed faces the two carrier plates are pro-vided with electrically conducting coatings, the rear plate 3 with an unbroken coating forming a rear electrode 8, and the front plate 2 with a segmented electrode forming electrode segments 9.
Between the two carrier plates a spacing frame 10 is located, defining with the two plates a sealed chamber filled with a liquid crystal layer 11.
On its four side faces the fluorescent plate 5 carries reflective coatings 12 and it is provided with a plurality of light-emergence windows one disposed behind each individual elec- -trode segment 9 (considered in the direction of viewing). Each of ~ these windows consists of an indentation 13 whlch may be silvered, 20 in the rear face of the plate 5 and of a co-operating scattering area 14 on the front face of the plate and constituted, for example, by a pigment or a roughened flat area of the plate surface. This form of window gives a wide angle viewing zone with relatively high light intensity and provides a practically parallax-free ~` display.
An auxiliary illuminating means in the form of a small lamp 15 filled with tritium gas is attached to one of the four side faces of the plate. On this side the reflective coating is '' , , -:
:: , ~ , :
so cons-ti-tuted that the -tritium light can pass in-to the interior of -the plate but -the fluorescent light is reflected back, -the reflective coating being in the form of a dichroic mirror 16. Naturally, other kinds of optical linking between the small lamp and the pla-te can equally be used.
The liquid crystal cell works on the principle of the so-called "rotary cell". For further details, reference should be made to German Patent Specifica-tion No. 2,158,563 of Wuesthoff et al, laid open June 29, 1972. In the embodiment of Figure 1, the axes of polarisation of the two linear polarisers are arranged at right angles to one another so that the light valve is transparent in the inoperative state and opaque in the activated sta-te. At the same time the activating means (not shown) is so designed that it is always only those electrode segments not required to form the image to be displayed that are supplied with a voltage. This is known as the "principle of complementary activation". These measures give a particularly bright image on a dark background; the part of the display screen not covered by the electrode segments appears almost black since only a very small part of the trapped light leaves the fluorescent plate outside the windows and moreover the light from the background is collected by the absorption film 6. The activated display elements are black since there the valve blocks the passage of light. Finally, the image is particularly intense, since the front face of the fluorescent plate 5 which is covered by the liquid crystal cell can also absorb light.
The embodiment illustrated in Figure 2 differs from the first embodiment in the following ways. The light source is placed, not as in the embodiment of Figure 1, to the side, but behind the .
~luorescent plate 5 and without any optical con-tact -therewith; all -the side faces of -the pla-te 5 are completely silvered; the absorp-tion film 6 is replaced by a filter providecl with a highly reflec-tive coating on its rear face and which only admits light for the excitation of the fluorescent particles (this measure increases the length of the absorption path for the incident and excitation light and thus generally makes it possible to use a lower concen-tration of fluorescent material with a consequent greater ultimate brilliance); complementary activation is not used; the rear linear polariser is eliminated and in its stead, the liquid crystal layer contains a pleochroic dye. In its inoperative state, the li~uid crystal layer exhibits a planar texture wi-th a bias parallel to the axis of polarisation of the linear polariser, whilst in its activated state, it exhibits a homotropic orientation. A focal-conical in-active texture could alternatively be used.
The radio-active substance used need not be present in the gaseous state, it can alternatively be present in chemically bound form in the fluorescent plate, in a film disposed behind the plate or in a layer which fills the indentations in the rear face of the plate, for example. It is, moreover, possible to implant scattering particles of luminous material in the front face of the plate and to surround these particles with a compound containing the radio-active substance. This possibility is illustrated in Figure 3.
Here, the scattering layer 1~ of the fluorescent plate 5 is coated with a tritium lacquer 18. With this form of light source, the light yield from the luminous material is particularly high.
If necessary, for example, in order to keep within a prescribed radiation tolerance level, the radio-active substance ~' ~3~ ~j '5~
can be embedded in a ma-terial that absorbs the undesired radio~
active energy, and is also acid and alkali-resistant, and in particular, is not decomposed by stomach acid.
The inven-tion is not, oi- course, limited to -the embodi-ments illustra-ted, for example, radio-active substances other than tritium can be used, and the light valve, i-luorescen-t body and radio-active adcditional lighting can be combined in other ways.
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.:
.
Claims (16)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An optical display arrangement comprising a light valve, a light trap in the form of a fluorescent body made of a material having a refractive index greater than 1, which contains fluor-escent particles and which is provided with at least one light-emergence window, and an auxiliary illumination means comprising a radio-active substance and a luminous material which is activated by the radiation from said substance.
2. An arrangement as claimed in claim 1, wherein said radio-active substance is a weak .beta.-ray emitter.
3. An arrangement as claimed in claim 2, wherein said radio-active substance is tritium.
4. An arrangement as claimed in claim 1, 2 or 3, wherein said fluorescent body is in the form of a fluorescent plate disposed behind the light valve considered in the direction of viewing.
5. An arrangement as claimed in claim 1, 2 or 3, wherein said fluorescent body is in the form of a fluorescent plate disposed behind the light valve considered in the direction of viewing and wherein said auxiliary illuminating means is in the form of a lamp disposed on at least one of the side faces of said fluorescent plate.
6. An arrangement as claimed in claim 1, 2 or 3, wherein said fluorescent body is in the form of a fluorescent plate dis-posed behind the light valve considered in the direction of view-ing and wherein said illuminating means is in the form of a lamp or film disposed behind said fluorescent plate considered in the direction of viewing.
7. An arrangement as claimed in claim 1, 2 or 3, wherein said fluorescent body is in the form of a fluorescent plate disposed behind the light valve considered in the direction of viewing and wherein a filter which only lets through excitation light for said fluorescent particles is disposed behind said auxiliary illuminating means; and wherein a highly reflective layer is disposed behind said filter.
8. An arrangement as claimed in claim 1, 2 or 3 wherein said radio-active substance is incorporated in said fluorescent body.
9. An arrangement as claimed in claim 1, 2 or 3 wherein said radio-active substance is incorporated in said fluorescent body and said radio-active substance is uniformly distributed in said fluor-escent body.
10. An arrangement as claimed in claim 1, 2 or 3 wherein said radio-active substance is incorporated in said fluorescent body and said radio-active substance is chemically bound in said fluorescent body.
11. An arrangement as claimed in claim 1, 2 or 3 wherein said radio-active substance is incorporated in said fluorescent body and is chemically bound to said fluorescent particles in said fluores-cent body.
12. An arrangement as claimed in claim 1, 2 or 3, wherein said fluorescent body is in the form of a fluorescent plate disposed behind the light valve considered in the direction of viewing, wherein the or each light-energence window comprises an indentation in the rear face of said plate; wherein said radio-active substance is applied to the or each said scattering area; and wherein said scattering area is formed by luminous particles that are activated by radiation from said radio-active substance.
13. An arrangement as claimed in claim 1, 2 or 3, wherein said fluorescent body is in the form of a fluorescent plate disposed behind the light valve considered in the direction of viewing, wherein the or each light-energence window comprises an indentation in the rear face of said plate; wherein said radio-active substance is applied to the or each said scattering area, said scattering area is formed by luminous particles that are activated by radia-tion from said radioactive substance and wherein said radio-active substance is embedded in a material that absorbs undesired radio-active energy and is acid and alkali-resistant.
14. An arrangement as claimed in claim 1, 2 or 3 wherein said light valve is a liquid crystal layer.
15. An arrangement as claimed in claim 1, 2 or 3 wherein said light valve is a liquid crystal layer which contains at least one pleochroic dye.
16. A wristwatch provided with an optical display arrangement as claimed in claim 1, 2 or 3.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2706375A DE2706375C3 (en) | 1977-02-15 | 1977-02-15 | Display arrangement with a light valve device, in particular a liquid crystal cell |
| DEP2706375.8 | 1977-02-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1108737A true CA1108737A (en) | 1981-09-08 |
Family
ID=6001250
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA296,925A Expired CA1108737A (en) | 1977-02-15 | 1978-02-14 | Optical display arrangements |
Country Status (11)
| Country | Link |
|---|---|
| JP (1) | JPS53101996A (en) |
| AT (1) | AT368294B (en) |
| BE (1) | BE863987A (en) |
| CA (1) | CA1108737A (en) |
| CH (1) | CH621458GA3 (en) |
| DE (1) | DE2706375C3 (en) |
| FR (1) | FR2380609A1 (en) |
| GB (1) | GB1585751A (en) |
| IT (1) | IT1092686B (en) |
| NL (1) | NL7801664A (en) |
| SE (1) | SE7801774L (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2835347A1 (en) * | 1978-08-11 | 1980-02-28 | Fraunhofer Ges Forschung | DISPLAY DEVICE WITH AN ELECTROOPTIC LIGHT VALVE |
| GB2189918B (en) * | 1985-07-23 | 1990-01-04 | John Thomas | Visual display means |
| DE3738414A1 (en) * | 1987-11-12 | 1989-05-24 | Bosch Gmbh Robert | Device for illuminating passive information displays, preferably LCDs |
| KR100498721B1 (en) † | 1996-09-24 | 2005-11-28 | 세이코 엡슨 가부시키가이샤 | Lighting devices and indicators using the devices |
| WO2002054445A2 (en) * | 2000-12-28 | 2002-07-11 | Guy Andrew Vaz | Photon power cell |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT946051B (en) * | 1970-12-04 | 1973-05-21 | Hoffmann La Roche | OPTICAL CELL |
| DE2221441A1 (en) * | 1972-05-02 | 1973-11-15 | Bernt Von Grabe | OPTOELECTRONIC SIGN GENERATOR |
| DE2232632C3 (en) * | 1972-07-03 | 1981-09-17 | Metall-Invent S.A., Zug | Display device |
| JPS50107958A (en) * | 1974-01-31 | 1975-08-25 | ||
| DE7426201U (en) * | 1974-08-01 | 1974-11-14 | Gebrueder Junghans Gmbh | Liquid crystal display devices, in particular for small watches |
| US3950078A (en) * | 1974-10-16 | 1976-04-13 | Timex Corporation | Liquid crystal display |
| US3959655A (en) * | 1975-02-06 | 1976-05-25 | Eastman Kodak Company | Light source for optical sound recording and reproduction apparatus |
| DD120724A1 (en) * | 1975-06-12 | 1976-06-20 | ||
| CH589307A5 (en) * | 1975-06-27 | 1977-06-30 | Bbc Brown Boveri & Cie | |
| JPS526496A (en) * | 1975-07-04 | 1977-01-18 | Toshiba Corp | Liquid crystal indicator |
-
1977
- 1977-02-15 DE DE2706375A patent/DE2706375C3/en not_active Expired
- 1977-12-07 CH CH1495477A patent/CH621458GA3/en unknown
-
1978
- 1978-02-09 FR FR7803643A patent/FR2380609A1/en active Granted
- 1978-02-13 IT IT20211/78A patent/IT1092686B/en active
- 1978-02-13 AT AT0100478A patent/AT368294B/en not_active IP Right Cessation
- 1978-02-14 CA CA296,925A patent/CA1108737A/en not_active Expired
- 1978-02-14 GB GB5772/78A patent/GB1585751A/en not_active Expired
- 1978-02-14 NL NL7801664A patent/NL7801664A/en not_active Application Discontinuation
- 1978-02-15 BE BE185194A patent/BE863987A/en not_active IP Right Cessation
- 1978-02-15 SE SE7801774A patent/SE7801774L/en unknown
- 1978-02-15 JP JP1638178A patent/JPS53101996A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| ATA100478A (en) | 1980-12-15 |
| AT368294B (en) | 1982-09-27 |
| DE2706375C3 (en) | 1982-08-26 |
| IT1092686B (en) | 1985-07-12 |
| BE863987A (en) | 1978-05-29 |
| SE7801774L (en) | 1978-08-15 |
| JPS53101996A (en) | 1978-09-05 |
| CH621458GA3 (en) | 1981-02-13 |
| FR2380609B1 (en) | 1982-07-16 |
| FR2380609A1 (en) | 1978-09-08 |
| NL7801664A (en) | 1978-08-17 |
| CH621458B5 (en) | 1981-08-14 |
| DE2706375A1 (en) | 1978-08-17 |
| IT7820211A0 (en) | 1978-02-13 |
| GB1585751A (en) | 1981-03-11 |
| DE2706375B2 (en) | 1978-11-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 19980908 |