CS261854B2 - Light indicator with increased contrast - Google Patents

Abstract

The light indicator consists of at least one light source (2), a reflector (1) located behind the light source (2) and formed as a concave mirror, a focusing optical element (3) and a shielding body (4) provided with an opening (5) for the passage of light rays. The focusing optical element (3) is a combined lens, to the circumference of which is connected the shell (41) of a cone, in the apex of which an opening (5) is formed and to which coaxial tubular visors (44, 43, 42) of unequal diameter are attached from the outside, the axis of which coincides with the optical axis of the connecting lens. In another embodiment, the focusing optical element is formed by a system of connecting lenses arranged in rows above each other and/or in columns next to each other, with a shielding body in the form of at least two angularly arranged plates being placed in front of each connecting lens.

Description

The light indicator consists of at least one light source (2), a reflector (1) located behind the light source (2) and formed as a concave mirror, a focusing optical element (3) and a shielding body (4) provided with an opening (5) for the passage of light rays. The focusing optical element (3) is a coupled lens, the circumference of which is connected to the cone shell (41), the aperture (5) of which is formed at the apex and to which the coaxial tube apertures (44, 43, 42) whose axis coincides with the optical axis of the lens. In another embodiment, the focusing optical element is formed by a plurality of splice lenses arranged in rows one above the other and / or in columns adjacent to each other, with a shielding body in the form of at least two angularly arranged plates in front of each splice lens.

Giant. l ·

Z810S4

2B1854

The invention relates to an enhanced contrast indicator comprising at least one light source, a reflector placed behind the light source and formed as a concave mirror, a focusing optical element and a shielding body provided with an opening for the passage of the focused light rays.

Indicator means any device providing information to the observer by the effect of light. Typical light indicators are traffic light signals with one light source, two or three light indicators being usually located one below the other or side by side.

On a plate-shaped light indicator, a plurality of identical light sources - "light points" - are placed in columns and / or rows, creating a light field containing several hundreds or even thousands of elementary, usually differently colored light indicators.

The light plate is usually divided into multiple fields composed of light points. Within these light fields, each group contains a plurality of elemental light points such that an indication of an alphanumeric character is possible.

For a picture composed of pixels, a satisfactory image quality condition is that the information content of the individual light points is displayed with minimal distortion. This is achieved by a significant contrast of brightness between on and off light indicators. For example, the effect of contrast may be reduced or increased by the instantaneous background brightness, depending on the time of day or night.

Also, the surface brightness of the light indicator when the background light is off affects the contrast. If the natural or artificial ambient brightness level is low, if the enclosure is unlit, such as a scene in a cinema or in the wild under moonlight, it is sufficient to use low-intensity light sources to ensure clear legibility. In a bright, sunlit area where the light indicator is exposed directly to sunlight, satisfactory contrast can only be achieved with difficulty.

The method of increasing the contrast by increasing the power of the light sources is limited by the conditions of realizing, for example, a light indicator by overheating the light source. Investment costs, energy consumption, rising maintenance costs, etc. are also considered.

In practice, either to isolate the light current emitted from the light source by the shielding bodies or to concentrate the beam current by means of a focusing optical element at one point and then to disperse it, it is used to achieve a significant contrast of the switched-on light indicator and its surroundings.

A common disadvantage of the variously arranged known shielding bodies with auxiliary means, as will be explained and illustrated in detail below, is the unfavorable interaction of the means used, so that the beneficial effect achieved by one part of the means used is undermined by the adverse effects of other means used at the same time. A particularly serious disadvantage of the prior art use of the screening bodies is that a considerable portion of the light beams are absorbed by means of increasing the efficiency of the light source.

The concentration of the light current, the focusing optical means, which is generally a lens, and its subsequent dispersion, have proven to be better for increasing the light effect of the light indicator.

As will be shown and illustrated below, the known arrangement of a light indicator provided with a focusing optical means is not sufficiently effective. The increase in the luminous efficiency of the light indicator depends on the suitability of the arrangement of its individual parts, in particular in connection of the focusing optical element with the shielding body.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light indicator which eliminates or minimizes the effect of external light energy that diminishes the brightness of the light indicator by combining the advantages of the focusing optical element with the effect of the screening body.

This object is achieved in the light indicator of the aforementioned type of the invention, characterized in that the focusing optical element is placed in front of the light source and on the side facing away from the light source a shielding body is connected to its periphery. the axis of the aperture in the shielding body and the axis of the reflector lie on the optical axis of the focusing optical element, and means for controlled light scattering are connected to the shielding body from the outside thereof. The focusing optical element consists of a connecting lens to which a cone-shaped shielding body is connected, the aperture of which is directed in the direction of the light beams, and an aperture is attached to the outer shell of which coaxial visors of different diameters are attached. the axis of the lens and the light source.

In another embodiment, the focusing optical element is formed by a plurality of interconnected lenses arranged in rows side by side or one above the other, wherein a shielding body in the form of at least two angularly arranged plates is arranged in front of each interconnected lens.

The advantage of the solution according to the invention consists in achieving perfect isolation of the rays emitting from the light source from the external light means and by increasing their focusing intensity, thereby increasing the contrast between the light effect of the indicators and the o261854 light source. and broadening the field of view.

The subject matter of the invention will be further elucidated by means of the examples illustrated in the accompanying drawings, in which Figures 1 to 3 are diagrams of the technical problem of achieving a contrast between the light indicator and the light environment in which it operates and known principles of shielding solutions; 4, 5 show the principle of solving the technical problem of the invention by focusing and a shielding body; Figures 6a, 6b show a diagram of a light indicator according to the invention in a first embodiment; Figures 7a, 7b, 7c are diagrams of a light indicator in an embodiment with an array of connecting lenses shaded by plate-shaped shielding bodies; Figures 8a, 8b show another embodiment of a light indicator with a field of coupled lenses and with the possibility of rotating it; FIGS. 9a, 9b are details of another embodiment of a coupled lens.

1 and 2 show schematically a light indicator in one known embodiment. Light from the light source 2 is directed by a reflector 1, for example a parabolic mirror, into the main viewing direction. In the path of approximately parallel running beams, a glass plate 3 uspořád dispersing a portion of the light beams which are incident on it approximately parallel, symmetrically in a circle around the axis of the main direction, is arranged so that a wider viewing angle is obtained.

A shielding body 4 is arranged around the glass plate 3 ‘. The shielding body 4 is generally designed as a cylinder, a prism surrounding the light beam path and preventing the adjacent light points from interacting.

In conventional solutions, the described basic solution is supplemented by a mirror, transparent, translucent, prismatic, grooved plates or shielding bodies, for example wire mesh, screens of various profiles and the like.

The shielding against the external light of the shielding body 4 has only a slight effect in this arrangement.

In the known embodiment shown in FIG. 3, two shielding bodies 4 are used, of which the second shielding body 4 ‘has a lattice shape. This solution achieves a deflection of the beams from the light source 2 and thus a widening of the field of view, but at the same time, only about 25-30% of the light flux 2 of the light source 2 is rectified at the desired spatial angle. very unfavorable. In addition, a daylight indicator without a shading body 4 nelze cannot be used in daylight at all, because the external illumination reaches such a level on the opal bulb that the difference between the surface brightness in the on and off state is barely perceptible. This deficiency cannot be avoided even by painting the grid of the second screening body 4 * with black.

To achieve lossless shielding, as shown in Fig. 4, 5, the effect of a focusing optical element is arranged such that parallel light rays incident from a given direction are centered almost entirely by the focusing optical element of the supplied point forming the focus of the optical system. thereby utilizing all the light efficiency of the light source controlled in a particular direction. The focusing optical elements may be spherical mirrors or lenses.

Referring to FIG. 4, the light energy coming from the reflector 1 directed by the lens 3 into the focus of the lens without obstruction of the aperture 5 located in the focus of the free space, while the shading body 4 forming a black plate aperture substantially reduces the effect of illumination generated by external light energy. This solution is a considerable advance over the solutions of FIGS. 1-3 and the invention is based on its principle.

FIG. 5 shows another example of a known embodiment, which can achieve the same effect as the solution of FIG. 4 without the use of a lens, since the reflector 1 is formed such that light rays reflect from it directly into the focus of the optical system. The reflector 1 has the shape of a parabolic mirror and, when the light source 2 is located in the focus F _p, reflects the beam of parallel light rays. If the light source 2 is outside the focus Fp _{of the} hollow mirror, a further focus occurs along the optical axis in the optical system thus arranged, the light rays reflecting from the surface of the reflector 1 to this second focus convergently. With respect to the optical system, this second focus is real, but does not agree with the focus F _{p of the} parabolic mirror.

This arrangement achieves the same effect as in the arrangement of FIG. 4, in which the light rays coming from the reflector 1 in parallel were directed into the focus of the optical system by the interposed lens 3. All light energy supplied by the light source and reflected by the reflector 1 body, in which lies the opening 5 arranged in the focus.

It is apparent from the diagrams shown in Figures 4 and 5 that the increased light effect of the light indicator is proportional to the cross-section of the aperture 5 in the screening body 4 forming the orifice, and that the light rays supplied by the light source 2 and reflected by the reflector 1 contribute without loss to brightness. hole

5. The immediate outer vicinity of the aperture 5 is formed by a black-painted shielding body 4, which, however, reflects only a small part of the incident light energy from the outside under strong sunlight, thereby rendering a considerable portion of the light source e261854 unnecessarily dispersed.

The lengths of the tubes 42, 43, 44 are selected according to the jet stream, in particular their length can be selected according to the purpose of the light indicator so as not to obstruct the visibility of the light indicator.

In the case of luminous panels providing luminous information, a conventional arrangement remains in which the luminous points are arranged in juxtaposed columns and adjacent rows, and the shading bodies 4 consist of square tubes which thus fill the entire space of the panel in two perpendicular directions. The effect according to the invention can also be achieved in that if the frame of the optical system has a square cross-section, the reflector 1 and the connecting lens 3 of the same circumference are cut from a basic profile, which has a mostly circular cross-section.

In this case, the screening bodies 4, 41 shown in FIG. 6 are modified. The casing is not conical, but has the shape of a pyramid, generally with a square base, the base of the pyramid facing the lens 3 and the aperture 5 formed at the top of the pyramid.

Figures 7a-c show an embodiment of a light indicator. The interconnecting lenses 3 along a plane perpendicular to the optical axis of the reflector 1 are arranged in adjacent columns and rows adjacent to each other. In the same way, it is possible to provide a sheet in which a plurality of bonding lenses 3 form only a single row or column, or wherein on the front surface of a rectangular cross section each complete row or column filling the platelet cylindrical lenses are arranged along a single row or column.

Fig. 7a shows an arrangement in which the shielding bodies 4 are formed in front of each lens 3.

When the lenses 3 form a rotating body and concentrate the beams into the focus, the shielding bodies are formed (FIG. 7aj as conical skirts 45 (FIG. 7b), and a shielding system similar to FIG. 6 is provided in front of each lens. The housing of the shielding bodies may be in the form of a truncated pyramid.

If the lenses 3 are formed, for example, by underlying convex or planconvex cylindrical lens plates, the shielding bodies 45 * shown in FIG. 7c are used. In this arrangement, the diverging ends of the acute angle profiles arranged parallel to the geometric axis of the platelet cylindrical lenses occupy the space between the connecting lenses 3 and the shielding bodies, the opening 5 being formed at the tip of the angular profiles, i.e. the converging ends forming the angular profile.

The angle profile can also be formed at an obtuse angle, so that the shielding bodies 4 are formed by two plates which form an angle other than 180 [deg.] Therebetween. The plates need not be straight. Their plane projections can form a curve or a warped line.

Fig. 8 shows an embodiment with additional direction (Figs. 8a, 8bj. The change of direction is performed by rotating the optical system at any angle about an axis perpendicular to the plane of the drawing. both the shape of the shielding body and the shape of the lenses.

In FIG. 8a, the interconnecting lenses 3 are formed in planar rows below each other as cylindrical lens plates.

Similarly, the shielding bodies 47, 48 are formed in a row opposite the connecting lenses 3. The shielding bodies 47, 48 form an angle of less than 180 ° with converging ends forming apertures 5 and diverging ends closing the space between the connecting lenses 3 and the shielding bodies 47, 48 In the embodiment shown in Fig. 8b, further parallel running bodies 49 are attached to the screening bodies, which are required to additionally change the direction of the light beams.

The alignment effect can be modified by using other plate cylindrical lenses that exhibit a bonding, scattering, sliding or pivoting characteristic. The plate cylindrical lenses may be planconvex or planconcave.

Another embodiment of the lens 3 is shown in FIGS. 9a and 9b, respectively, in two views. Here, three further cylindrical plate lenses, whose geometric axes are formed by the main curve of the curves parallel to the convex surface, are adapted to the convex surface of the lenses 3 lying along the plane so that they lie in a plane perpendicular to the plane along which the lens 3 is arranged. In practice, this can be arranged in such a way that a plurality of, for example, planar-plate cylindrical lens of a suitable size and of a suitable material is arranged along a linear optical axis, after which the plates are bent and adhered to the lens. The resulting shape can also be achieved by a technology that creates the entire system of plate cylindrical lenses as a continuous body, such as a molded plastic body (see Fig. 9J). This embodiment is well suited for both a variety of screening bodies and for plates of cylindrical lenses or for a combination of both systems.

In various embodiments, a plurality of lenses or a plurality of shielding bodies may be colored, and the colors may be combined. It is also possible in front of and behind the lenses or screening bodies to insert a plate or foil that provides a color effect without affecting the directional or shading effect but changes the wavelength of the light rays.

The invention has been described above in terms of the theoretical formation of a mechanism operating according to basic optical laws. In practice, some of these characteristics may represent virtual characteristics that are correct in terms of optics, so far 261854 what in real form - due to technological needs - is somewhat different from virtual characteristics. This is the case, for example, with aperture-function openings in shielding bodies. 4 and 5, it is a prerequisite for the free passage of the light beam that the opening in the focus allows the loss of light energy coming from the reflector 1 to be lost, but at the same time admits the existence of disturbing energy, albeit only to a minor extent. Correctly, the aperture in the aperture in the focus should not be smaller than the expected light beam dimension under production conditions, because if the cross-section were smaller, some of the energy would be wasted. At the same time, it should not be larger than necessary for the safe passage of the beam.

It is apparent from the known dependencies of optical systems that, while maintaining the nominal focusing parameters with respect to the shape and size of the light source 2, the beam cross-section generated can be determined at various light outputs according to the practical dimensional tolerances of the scattering pattern.

If the aperture 5 in the diaphragm is to be actually in a plane containing also the focus of the focusing optical beam 3, it is necessary to select its cross section or height and width larger than the diagonal A, E of the expected maximum light beam (Fig. 6bJ).

In the actual arrangement, the converging ends of the shield body or shield bodies limiting the aperture 9 do not necessarily lie in a plane perpendicular to the optical axis and containing the focus, as shown in FIGS. 4 and 5. For example, said ends may be arranged parallel to this plane but lying at a distance of - | - A X.

Suitably, the aperture 5 in the diaphragm is dimensioned such that in a plane perpendicular to the optical axis of the reflector 1 containing the focus of the reflector 1 and the lens 3, it corresponds to the size which can be expected according to the nominal parameters determining focus.

In general, tolerances arising during production technology cannot be ignored. If measurements are to be made approximately or based on the probability of a scattering pattern, the tolerances will be more important.

Numerous experiments have been carried out with the light indicators according to the invention and it has been found that lossless beam passage while avoiding disturbances can be achieved if the cross-sectional aperture 5 in the aperture is at least 5% larger than the light beam cross-section diagonal, determined by geometric correlations. The interference may be suppressed satisfactorily if it is not exceeded by more than 20 ° / o. In general, the arrangement can be considered acceptable if the cross section of the aperture 5 in the focus does not exceed the maximum cross section of the light beam by more than 10 why.

Accordingly, it is possible within the scope of the invention to provide a number of embodiments and variants that realize the advantages of the invention, namely increasing the contrast of the switched-on light indicator from the environment as desired and under different conditions and increasing the surface brightness of the light indicator.

Claims (4)

SUBJECT i. An enhanced contrast indicator comprising at least one light source, a reflector positioned downstream of the light source and formed as a concave mirror, a focusing optical element, and a shield having an aperture for the passage of the focused light rays, characterized in that the optical element (3) is located in front of the light source (2) and on the side facing away from the light source (2) a shielding body (4) is connected to its periphery, the opening (5) of which focuses the focusing element (3); the axis of the aperture (5J in the screening body (4) and the axis of the reflector (11) lie on the optical axis of the focusing optical element (3J) and are connected to the screening body (4) from the outside to control light scattering. VYNALEZU A light indicator according to claim 1, characterized in that the focusing optical element (3) is formed by a connecting lens to which a cone-shaped shielding body (4J) is connected, in which a aperture is formed in the aperture facing the light beams. (5) and to the housing (41) of which coaxial visors in the form of tubes (44, 43, 42 J and different diameters) are attached from the outside, the axis of which coincides with the optical axis of the lens and the light source (11). Light indicator according to claim 1, characterized in that the focusing element (3) is formed by a system of juxtaposed lenses arranged in rows and / or columns next to each other, and in front of each juxtaposed a body (44J in the shape of at least two mutually) angularly arranged plates (47, 48, 49). 4 leaves plot