DEVICE FOR PREVENTING PSEUDO LIGHTING PHENOMENON OF SIGNAL LAMP

Abstract: This device is installed between the cover lens of a signal lamp main body and the light source in order to prevent pseudo lighting phenomenon. This device (B) comprises a pair of plates of spherical lens matrices (200) each plate being formed by the following way: a large number of spheres are arranged on a plane in matrix, and so pressed and deformed that they are brought into contact with each other without gaps between them but with the spherical tops intact, these spherical tops serving as spherical lens elements. The device (B) further comprises a light shielding member (300) disposed between the plates as a spacer, having light transmitting slits which respectively receive lens planes of the spherical lens elements from the corresponding side, and determining the corresponding foci of the spherical lens elements of one of the plates in the vicinities of the vertexes of the lens planes of the spherical lens elements of the other plate. The solar rays which enter through the cover lens are once focused in the light transmitting slits by means of the composite spherical lens elements of the plate on the cover lens side, and then, diffused by the composite spherical lens elements of the plate on the light source side to reach the signal lamp body. The reflected rays which are reflected in the signal lamp and tend to exit are thus reduced. At the same time, the reflected rays are blocked by the light shielding member. Therefore, the contrast between the inside and outside of the signal lamp becomes remarkably clear.

Description: [Field of the Invention] This invention relates to a device for preventing effectively signal lamps from presenting a false lighting phenomenon caused by the sun light, particularly by the rising sun, setting sun, and the like, so that the state of lights, on and off, can be determined more distinctly. [Description of the Prior Art] In the current automobile society, for instance, the role of the traffic lights is extremely important in order to control road traffics smoothly. Such traffic lights must be reliably recognizable by a driver under any circumstances. As is well known, the traffic lights are of a self-emissive type using electric bulbs. Therefore, if its surrounding brightness is low, the relative luminance is high, making the lighting condition reliably recognizable, but if the surroundings are considerably bright, the relative luminance is low, making it difficult for an observer to recognize the condition reliably in some cases. If the sun shines directly on the surface of the traffic lights, such cases may take place actually. In other words, if the sun is in a lower position as it rises or sets, the sun light is incident upon the interior of the signal lamps and reflected, thus presenting a condition that the traffic lights are misidentified as if the lights were on. This is the so-called false lighting phenomenon, which is a subject that must be solved with respect to the signal lamps. As means for solving a false lighting phenomenon of the kind, there has been known a shielding lens used for the signal lamps such as disclosed in Japanese Unexamined Utility Model Publication No. Hei-3-54100. This prior art is such that many numbers of cylindrical condenser lens elements having a given curvature are arranged on the reverse side of lenses formed by a translucent material, and at the same time, there are formed on the surface side of the translucent lenses the diffuse lenses each of converging sections of which is made a light transmission section corresponding to each of the condenser lens elements, and that the shielding lenses in which shielding films are coated between the diffuse lenses are provided between the front lenses of the signal lamps and the light sources. In other words, while the light from the electric bulb serving as the light source is condensed by the condenser lens elements for irradiation, the sun light is diffused in the interior of the signal lamps by the diffuse lenses, at the same time being shielded by use of the shielding films in order to prevent the false lighting from taking place. Nevertheless, in the shielding lens, when the sun light is radiant right in front of the signal lamps while the signal lamps are turned off, the sun light which is incident upon the interior of the diffuse lens elements continuously arranged on a concave surface is allowed by the shielding element to enter the interior of the signal lamps in a straight line. Then, after the sun light is reflected by the reflection mirror in the signal lamp, it is again radiated through the condenser lens elements. As a result, a false lighting phenomenon takes place, and at the same time, the surface reflection occurs itself on the surface of the diffuse lens elements. Thus, by the synergistic effect with the false lightning phenomenon, it becomes difficult to identify the on and off condition of the lights. Consequently, as far as the sun light is incident upon the shielding lenses at a certain angle, this disclosed example demonstrates an excellent effect in preventing a false lighting phenomenon, but there is still a problem that it is difficult to prevent a false lighting phenomenon from taking place when the sun light is incident upon the signal lamps from its front at the time of the sun rise, sun set, and the like. From EP-A-142 955 a device is known comprising a pair of complex spherical lenses and a shielding element having light transmitting holes, intervened between said pair of lenses. In short, for the prevention of a false lighting phenomenon, various improvements have been attempted, but under the present circumstances, there has been developed no signal lamps capable of effectively solving the problem of a false lighting phenomenon because of the conflicting functions required: whereas the sun light, an external light, should be cut off as much as possible, the inner light from the internal light source should be emitted as effectively as possible. Therefore, it is an objective of this invention to provide a device capable of emitting the inner light as effectively as possible while shielding the sun light as much as possible for preventing signal lamps from presenting a false lighting phenomenon. [Disclosure of the Invention] A device for preventing a false lighting phenomenon according to this invention, which is arranged between a light source in the main body of a signal lamp and a cover lens, is to provide as its primary feature a pair of complex spherical lenses formed by many numbers of spheres arranged in matrix on planes, and configured in a chain form in which the contact points, front, rear, left, and right sides, of each of the spheres adhere closely to each other by being squeezed without any gaps while the upper and lower spherical surfaces are left intact so that the upper and lower spherical surfaces are utilized as the spherical lenses, and also, provide a shielding element serving as a spacer intervening between the pair of complex spherical lenses, having the light transmitting holes arranged in such a way that the lens surfaces of the spherical lenses are received in said light transmitting holes from both sides of said shielding element and positioning the focuses of the spherical lens on one side in the vicinity of the vertices of the lens surfaces of the spherical lenses on the other side. According to a device for preventing a false lighting phenomenon of this invention, the directly radiated beam of the sun is at first refracted by each of the spherical lenses of the complex spherical lenses on the cover lens side (external side) even when it is incident upon them right from the front, thus causing it to focus in the light transmitting holes of the shielding element so that it is contracted to be extremely small, and then, refracted again by the spherical lenses of the complex spherical lenses on the light source side (internal side) of the signal lamps, thus allowing the sun light to enter in a state that it is diffused. In this way, since the sun light is incident in a diffused state, the reflected light is reduced when it is reflected in the signal lamps and emitted therefrom. At the same time, the reflected light is cut off by the shielding element. Therefore, the contrast of brightness becomes greater in the interior and exterior of the signal lamps. In this respect, there exists the sun light reflected on the outer surface of the complex spherical lenses on the outer side, though its surface reflection is extremely limited. However, there is no flat portion associated with the surface of the complex spherical lenses. The surface is a collective element of convex surfaces configured substantially hemispheric, hence making it possible to reflect it after being greatly diffused. As a result, its luminance is made extremely small. On the other hand, when the light source is turned on in the signal lamp which uses this device for preventing a false lighting phenomenon, the light beam from the light source is refracted by each of the spherical lenses of the complex spherical lenses on the internal side so that it is in focus in the light transmitting holes, thus being contracted to be extremely small. Then, the light beam is in a state that it is emitted while being refracted and expanded through each of the spherical lenses of the complex spherical lenses on the external side. As a result, it is possible to obtain a good visibility from the outside without observing any shadow of the shielding element. The complex spherical lenses of a device for preventing a false lighting phenomenon of the kind can be formed of an acrylic resin without any problem. In other words, if more considerations should be given to the apparatus with respect to the economy and weight, the acrylic resin is suitably used because of its light weight and excellent workability. If the transmittance should be considered more important, a glass material is suitably used. Also, if the shielding element is prepared by a metallic board having light transmitting holes made by a punching, it is possible to obtain a shielding element having a good workability and a higher strength as well. In other words, the interior of the signal lamp provided with the device for preventing a false lighting phenomenon is heated to a temperature of as high as 120 °C at the maximum due to the heat generated by the light source when it is turned on. However, with the provision of a shielding element of the kind which is disposed between the complex spherical lenses and formed integrally with them, it is possible to obtain a sufficient strength that can withstand such a high temperature, while preventing the focus of each spherical lens of the complex spherical lenses from being deviated. Further, it is preferable to arrange the inner sides of the light transmitting holes and/or the faces other than the light transmitting holes of the shielding element to be colored in black or the like because with this coloring arrangement, an excellent shielding capability can be obtained in a better condition. Also, if a mirror section is provided on the inner side of each of the light transmitting holes on the light source side of the signal lamp, the light beam from the light source is amplified by the reflection on each mirror section so that the luminance is further enhanced. In this case, compared to the one having no mirror sections, the light beam is converged so that its visual angle can be controlled. Therefore, it becomes more convenient to adopt such signal lamps at an intersection where its crossing angles are narrower. The second feature of the device for preventing a false lighting phenomenon according to this invention resides in that the device is provided between a light source in the main body of a signal lamp and a cover lens for preventing the signal lamp from presenting a false lighting phenomenon, is to provide a pair of complex spherical lenses formed by many numbers of spheres arranged in matrix on planes, and configured in a chain form in which the contact points, front, rear, left, and right sides, of each of the spheres adhere closely to each other by being squeezed without any gaps while the upper and lower spherical surfaces are left intact so that the upper and lower spherical surfaces are utilized as the spherical lenses, and also, provide a shielding element serving as a spacer intervening between the pair of the complex spherical lenses, having the light transmitting slits arranged in such a way that the lens surfaces of the spherical lenses are received in said light transmitting slits from both sides of said shielding element, and positioning the focuses of spherical lenses on one side in the vicinity of the vertices of the lens surfaces of the spherical lenses on other side. According to such a device for preventing a false lighting phenomenon, the directly radiated beam of the sun is at first refracted by each of the spherical lenses of the complex spherical lenses on the cover lens side (external side) even when it is incident upon them right from the front, thus causing it to focus in the light transmitting slits of the shielding element so that it is contracted to be extremely small, and then, refracted again by the spherical lenses of the complex spherical lenses on the light source side (internal side) of the signal lamp, thus allowing the sun light to enter in a state that it is diffused. In this way, since the sun light is incident in a diffused state, the reflected light is reduced when it is reflected in the signal lamps and emitted therefrom. At the same time, the reflected light is sufficiently cut off by the cross bars of the shielding element. Therefore, the contrast of brightness becomes greater in the interior and exterior of the signal lamp. In this respect, there exists the sun light reflected on the outer surface of the complex spherical lenses on the outer side, though its surface reflection is extremely limited. However, there is no flat portion associated with the surface of the complex spherical lenses. The surface is a collective element of convex surfaces configure substantially hemispheric, hence making it possible to reflect it after being greatly diffused. As a result, its luminance is made extremely small. On the other hand, when the light source is turned on in the signal lamp which uses this device for preventing a false lighting phenomenon, the light beam from the light source is refracted by each of the spherical lenses of the complex spherical lenses on the internal side so that it is in focus in the light transmitting slits, thus being contracted to be extremely small. Then, the light beam is in a state that it is emitted while being refracted and expanded through each of the spherical lenses of the complex spherical lenses on the external side. As a result, it is possible to obtain a good visibility from the outside without observing any shadow of the shielding element. With respect to the light transmitting slits of a device for preventing a false lighting phenomenon of the kind, if its size is made to be able to receive three pieces of the spherical lenses of the complex spherical lenses from its corresponding side, it is possible to obtain a sufficient preventive effect against a false lighting, while enhancing the brightness because the transmittance is increased when the signal lamps are turned on. This arrangement is preferable because the visibility is further improved. Also, if the portions other than the light transmitting slits of the shielding element are arranged to remain as the cross bars and vertical bars, and allow the central portion of the cross bars to be rectangular to the vertical bars, while the vertical and cross bars being provided corresponding to the lens boundary sections of each spherical lens of the complex spherical lenses at the same time, it is possible for the cross bars to demonstrate its shielding function sufficiently and make its shadow almost invisible. Also, the strength of the shielding element is made greater by the presence of the vertical bars. Further, if the shielding element is formed of a plastic molding, not only its good workability is obtainable, but also, its economy becomes significant because it can be made in a light weight. With a shielding element of the kind which is disposed between the complex spherical lenses and formed integrally with them, it is possible to obtain a strength sufficiently withstanding a high temperature, and to prevent the focus of each spherical lens of the complex spherical lenses from being deviated. Then, if the shielding element is colored in black or the like or a mirror section is provided for the portions in the inner side of the light transmitting slits close to the light source in the signal lamp, it is possible to obtain the same effects as described above. Also, it is more preferable to arrange a pair of complex sphere lenses of a device for preventing a false lighting phenomenon of the kind so that the pair of them can be fixed to each other particularly in the central portion thereof because its strength is enhanced in the central portion facing the light source of signal lamps where the temperature becomes highest. In this respect, it is to be understood that the term "signal lamp" used in the specification and claims means not only a traffic signal lamp, but also a wider conception including aeronautical marker lights and the like. [Brief Description of the Drawings] Fig. 1 is a side view showing the complex spherical lenses according to this invention. Fig. 2 is a side view showing a device for preventing a false lighting phenomenon according to a first embodiment of the this invention. Fig. 3 is a plan view showing a shielding element according to the first embodiment of the this invention. Fig. 4 is a cross-sectional view showing the principal part of the device for preventing a false lighting phenomenon according to the first embodiment of this invention. Fig. 5 is a cross-sectional view showing a shielding element according to a second embodiment of this invention. Fig. 6 is a side view showing the device for preventing a false lighting phenomenon according to the second embodiment of this invention. Fig. 7 is a partially sectional side view showing the main body of a signal lamp in which is installed the device for preventing a false lighting phenomenon according to the first and second embodiments of this invention. Fig. 8 is an explanatory view illustrating a state when the sun light is directly radiated on the device for preventing a false lighting phenomenon according to the first and second embodiments of this invention. Fig. 9 is an explanatory view illustrating a state when the lights are turned on for the signal lamps provided with the device for preventing a false lighting phenomenon according to the first embodiment of this invention. Fig. 10 is an explanatory view illustrating a state when the lamps are turned on for the signal lamps provided with the device for preventing a false lighting phenomenon according to the second embodiment of this invention. Fig. 11 is a side view showing a device for preventing a false lighting phenomenon according to a third embodiment of this invention. Fig. 12 is a plan view showing the shielding element according to the third embodiment of this invention. Fig. 13 is a cross-sectional view showing the principal part of the device for preventing a false lighting phenomenon according to the third embodiment of this invention. Fig. 14 is a cross-sectional view showing the principal part of a shielding element according to a fourth embodiment of this invention. Fig. 15 is a side view showing a device for preventing a false lighting phenomenon according to the fourth embodiment of this invention. Fig. 16 is a partially sectional side view showing the main body of the signal lamp in which is installed the device for preventing a false lighting phenomenon according to the third and fourth embodiments of this invention. Fig. 17 is an explanatory view illustrating a state when the sun light is directly radiated on the device for preventing a false lighting phenomenon according to the third and fourth embodiments of this invention. Fig. 18 is an explanatory view illustrating a state when the lights are turned on for the signal lamps provided with the device for preventing a false lighting phenomenon according to the third embodiment of this invention. Fig. 19 is an explanatory view illustrating a state when the lights are turned on for the signal lamps provided with the device for preventing a false lighting phenomenon according to the fourth embodiment of this invention. [Best Mode for Carrying out the Invention] Hereinafter, the description will be made of the embodiments according to this invention with reference to the accompanying drawings. First Embodiment As shown in Fig. 1, a device A for preventing a false lighting phenomenon according to this embodiment comprises a pair of complex spherical lenses 2 and 2 formed of an acrylic resin or a glass material, and is of such a structure that many numbers of spheres are arranged in matrix on planes, and configured in a chain form in which the contact points, front, rear, left and right sides, of each of the spheres adhere closely to each other by being squeezed without any gaps while the upper and lower spherical surfaces left intact so that the upper and lower spherical surfaces are utilized as spherical lenses 1, 1, ..., and a shielding element 3 as shown in Fig. 3, and that the complex spherical lenses 2 and 2 are arranged to face each other with the shielding element 3 intervening between them as shown in Fig. 2. When observing the complex spherical lenses 2 in the vertical direction (in the direction indicated by arrows in Fig. 1), each of the spherical lenses 1, 1, ..., presents a state that each of those formed substantially in square is arranged in matrix without any gaps. Also, as a material for the complex spherical lenses 2, an acrylic resin or a glass material is suitable, but the material is not necessarily limited to either one of them. It may be possible to use some other materials having transmittance, such as materials usable for eye glasses, hard or soft contact lenses. The shielding element 3 is formed of a metal board in this embodiment, and as shown in Fig. 3, it is structured in such a manner that the light transmitting holes 4, 4, ... having a substantially circular section are made by punching in the positions corresponding to each of the spherical lenses 1, 1, ..., and that the faces other than the light transmitting holes 4, 4, ..., and/or the inner face of the light transmitting holes 4, 4, ... are colored in black. Then, as shown in Fig. 4, the lens surfaces a, a, ... of the spherical lenses 1, 1, ... are fitted into each of the light transmitting holes 4, 4, ... from the corresponding sides, respectively, and the shielding element 3 is disposed between the complex spherical lenses 2 and 2 in a state that a specific fine space b is maintained between its vertices. In this way, the strength of the apparatus A for preventing a false lighting phenomenon is enhanced by allowing the shielding element 3 to intervene between the complex spherical lenses 2 and 2. At this time, the thickness of the shielding element 3 is adjusted so that the focus of each spherical lens 1 of the complex spherical lenses 2 on one side is positioned close to the vertex of the lens surface a of each spherical lens 1 on the other side in the space b. For example, the thickness is adjusted so that the space b is 1.3 to 1.4 mm when the radius of curvature of the lens surface a of the spherical lens 1 is 3.5 mm. Second Embodiment A device A-1 for preventing a false lighting phenomenon according to this embodiment is of such a structure that the external surface 5 of a shielding element 3-1 having the same configuration as that of the first embodiment is frosted in black, and at the same time, a mirror section 6 is formed in each of the inner side of the light transmitting holes 4, 4, ... on the light source side of signal lamps as shown in Fig. 5. Then, as shown in Fig. 6, in each of the light transmitting holes 4, 4, ... of the shielding element 3-1, the lens surfaces a, a, ... of the spherical lenses 1, 1, ... are fitted from the corresponding sides, respectively, and the shielding element 3-1 is disposed between the complex spherical lenses 2 and 2 in a state that a specific fine space b is maintained between its vertices in the same manner as in the first embodiment. An Example of Installation of the Devices of the First and Second Embodiments to the Main Body of a Signal Lamp The main body 7 of signal lamps to which the device for preventing a false lighting phenomenon according to the above-mentioned first and second embodiments is installed is provided, as shown in Fig. 7, with a curved-face mirror 8 configured almost in the form of a bowl having a mirror portion 8a on the inner surface thereof, a light source 9 (using an electric bulb in this example) supported in a light source supporting section 8b provided in the center of the bottom of the curved-face mirror 8, and a cover lens 10. The cover lens 10 is a lens each colored in red, blue, yellow, and others, respectively, in a case of signal lamps, for example. On the circumferential edge of the lens surface, a flange 10a is extendedly provided. On the other hand, a flange 8c, and a side wall 8d which is extendedly arranged substantially at right angles to the flange 8c are provided on the aperture end of the curved-face mirror 8. Then the flange 10a of the cover lens 10 is fixed to the side wall 8d of the curved-face mirror 8 while the circumferential edge of the apparatus A or A-1 for preventing a false lighting phenomenon is disposed between the flange 8c of the curved-face mirror 8 and the flange 10a of the cover lens 10. In this way, the apparatus A or A-1 for preventing a false lighting phenomenon is installed between the cover lens 10 and the light source 9. Now, the description will be made of such a case where the light of the rising sun, the setting sun, or other sun light radiates directly on the main body 7 of the signal lamp in which a device A or A-1 for preventing a false lighting phenomenon of the kind is installed. To describe in detail, as shown in Fig. 8, the sun light c incident upon the device A or A-1 for preventing a false lighting phenomenon is refracted by each of the spherical lenses 1, 1, ... of the complex spherical lenses 2 on the external side to focus in the space b so that it is contracted to be extremely small, and then, refracted again by each of the spherical lenses 1, 1, ... of the complex spherical lenses 2 on the internal side, thus being incident on the interior of the main body 7 of a signal lamp in a state that it is diffused. Since the sun light is incident in such a diffused state, the light reflected on and emitted from the mirror section 8a of the curved-face mirror 8 is reduced, and at the same time, the reflected light is cut off by the shielding element 3 or 3-1. Therefore, the brightness contrast between the interior of the main body 7 of the signal lamp and the exterior of the main body 7 of the signal lamp is great. In addition, there exists the sun light which is reflected on the outer surface of the complex spherical lenses 2 on the external side, though the amount is extremely limited. However, there is no flat portion on the surface with respect to the complex spherical lenses 2. The surface is formed collectively by the convex surfaces of hemisphere. Consequently, the sun light is reflected while being greatly diffused, and its luminance is extremely small. Also, a light reflected on the surface of the kind is reduced in proportion to the radius of curvature of the lens surface of the spherical lenses 1. If such a surface reflection still presents a problem, the radius of curvature of the lens surface of the spherical lenses 1 should only be adjusted. On the other hand, when the light source 9 is turned on in the main body 7 of the signal lamp using the device A for preventing a false lighting phenomenon as shown in Fig. 9, the light beam d from the light source 9 is refracted in each of the spherical lenses 1, 1, ... of the complex spherical lenses 2 on the internal side to focus in the space b, thus being contracted to be extremely small. Then it is in a state of being emitted while it is refracted and expanded in each of the spherical lenses 1, 1, ... of the complex spherical lenses 2 on the external side. Therefore, it is possible to obtain a good visibility without any shadow of the shielding element 3 being observed from the outside. Also, as shown in Fig. 10, when the light source 9 is turned on in the main body 7 of signal lamps which uses the device A-1 for preventing a false lighting phenomenon, the light beam d from the light source 9 is refracted in each of the spherical lenses 1, 1, ... of the complex spherical lenses 2 on the internal side to focus in the space b, thus being contracted to be extremely small. Then, the light beam is in a state that it is emitted while being refracted in each of the spherical lenses 1, 1, ... of the complex spherical lenses 2 on the external side. Further in this case, the light beam d from the light source 9 is in a state that it is amplified by the reflection by the mirror section 6 formed in the shielding element 3-1 on the light source 9 side, and passes each of the light transmitting holes 4 of the shielding element 3-1. Also, compared to the case where no mirror section 6 is formed, the light beam is converged so that the visual angle can be controlled, hence making its use more convenient at an intersection having a narrower intersecting angles. Third Embodiment As shown in Fig. 11, a device B for preventing a false lighting phenomenon according to this embodiment comprises a pair of complex spherical lenses 200 and 200 formed by an acrylic resin or a glass material, and is of such a structure that many numbers of spheres are arranged in matrix on planes, and configured in a chain form in which the contact points, front, rear, left and right sides, of each of the spheres adhere closely to each other by being squeezed without any gaps while the upper and lower spherical surfaces left intact so that the upper and lower spherical surfaces are utilized as spherical lenses 100, 100, ..., and a shielding element 300 as shown in Fig. 12, and that the complex spherical lenses 200 and 200 are arranged to face each other with the shielding element 300 intervening between them. When observing the complex spherical lenses 200 in the vertical direction (the same as in Fig. 1), each of the spherical lenses 100, 100, ... presents a state that each of those formed in substantially square is arranged in matrix without any gaps. Also, as a material for the complex spherical lenses 200, an acrylic resin or a glass material is suitable, but the material is not necessarily limited to either one of them. It may be possible to use some other materials having transmittance, such as materials usable for eye glasses, hard or soft contact lenses. The shielding element 300 is a molded product using plastic, and as shown in Fig. 12, it is structured in such a manner that the light transmitting slits 402, 402, ... in a size receiving each three lens surfaces of the spherical lenses 100, 100, ... and cross bars 400, 400, ... are formed in the positions corresponding to the lens boundary sections at intervals of three lens surfaces of the spherical lenses 100. The shielding element is colored in black all over. Also, in this shielding element 300, a vertical bar 401 is provided in a position rectangular to the central part of each of the cross bars 400, 400, ... in order to enhance the strength of the shielding element. This vertical bar 400 is provided as an reinforcing member so that the focus relations between each of the spherical lenses 100, 100, ... are more reliably prevented from being deviated due to the deformation of the device B for preventing a false lighting phenomenon by a high temperature when the light source is turned on in the main body of the signal lamp. In this respect, a vertical bar 401 of the kind is arranged in the positions corresponding to the lens boundary sections of each of the spherical lenses 100. Also, in the central part of the shielding element 300, a fixture 301 is arranged. This fixture 301 is provided with five fixing holes 301a, 301a, ... corresponding to the lens boundaries of the spherical lenses 100, and through these fixing holes 301a, the extruded male and female bosses (not shown) which are arranged and positioned to each other on the boundary sections of the complex spherical lenses 200 and 200 are allowed to engage and are adhesively bonded for fixation. Further, on this fixture 301, a plurality of light transmitting holes 301b are arranged in the positions corresponding to the lens surfaces of the spherical lenses 100 so that the lens surfaces of the spherical lenses 100 can be inserted. In this way, the fixation is made in the central part of the complex spherical lenses 200, thus enhancing the strength of the central part which is heated to the highest temperature in a signal lamp when the light source is turned on. Then, as shown in Fig. 13, three each of the lens surfaces a', a', ... of the spherical lenses 100, 100, ... are fitted into each of the light transmitting slits 402, 402, ... from the corresponding side, respectively, and the shielding element 300 is disposed between the complex spherical lenses 200 and 200 in a state that a specific fine space b' is maintained between its vertices. In this way, the strength of the device B for preventing a false lighting phenomenon is enhanced by arranging the shielding element 300 to intervene between the complex spherical lenses 200 and 200. At this time, the thickness of the shielding element 3 is adjusted so that the focus of each spherical lens 100 of the complex spherical lenses 200 on one side is positioned close to the vertex of the lens surface a of the spherical lens 100 on the other side in the space b'. For example, the thickness of the shielding element 300 is adjusted so that the space b' is 1.3 to 1.4 mm when the radius of curvature of the lens surface a' of the spherical lens 100 is 3.5 mm. Fourth Embodiment A device B-1 for preventing a false lighting phenomenon according to this embodiment is such that as shown in Fig. 14, mirror sections 600 are arranged at intervals of approximately 1/3 of the thickness from the light source side of the signal lamp in the inner face of each of the light transmitting slits 402, 402, ... of the shielding element 300-1 having the same configuration as represented in the third embodiment. Then, as shown in Fig. 15, three each of the lens surfaces a', a', ... of the spherical lenses 100, 100, ... are fitted into each of the light transmitting slits 402, 402, ... of the shielding element 300-1 from the corresponding side, respectively, and the shielding element 300-1 is disposed between the complex spherical lenses 200 and 200 in a state that a specific fine space b' is maintained between its vertices in the same manner as in the third embodiment. An Example of Installation of the Device of the Third and Fourth Embodiments to the Main Body of a Signal Lamp The main body 700 of a signal lamp to which the device for preventing a false lighting phenomenon according to the above-mentioned third and fourth embodiments is installed is provided, as shown in Fig. 16, with a curved-face mirror 800 configured almost in the form of a bowl having a mirror portion 800a on the inner surface thereof, a light source 900 (using an electric bulb in this example) supported in a light source supporting section 800b provided in the center of the bottom of the curved-face mirror 800, and a cover lens 110. The cover lens 110 is the same as the one used for the above-mentioned embodiment. On the circumferential edge of the lens surface, a flange 110a is extendedly provided. On the other hand, a flange 800c, and the side wall 800d which is extendedly arranged at substantially right angles to the flange 800c are provided on the aperture end of the curved-face mirror 800. Then the flange 110a of the cover lens 100 is fixed to the side wall 800d of the curved-face mirror 800 while the circumferential edge of the device B or B-1 for preventing a false lighting phenomenon is disposed between the flange 800c of the curved-face mirror 800 and the flange 110a of the cover lens 110. In this way, the device B or B-1 for preventing a false lighting phenomenon is installed between the cover lens 110 and the light source 900. In this respect, the traffic signal lamps are often installed in a position which is usually looked up from the lower direction. For such a use, therefore, the device B or B-1 for preventing a false lighting phenomenon should preferably be inclined downward at a specific angle in relation to the installation height of the signal lamps. Thus the light beam emitted from the light source 900 in the way which will be described later is in a state that it has the optical axis close to the line of sight to make the visibility more enhanced. On the other hand, the sun light is diffused as described later, and at the same time, reflected by the curved-face mirror 800 in a state that it is incident upon the mirror diagonally. As a result, it is projected to the above and below the interior of the main body 700 of a signal lamp, thus making it difficult for the reflected light of the sun light to appear directly on the complex spherical lenses 200. Hence the prevention of a false lighting phenomenon can be carried out more reliably (this is also applicable to the above-mentioned first and second embodiments). Now, the description will be made of such a case where the light of the rising sun, the setting sun, or other sun light radiates directly on the main body 7 of a signal lamp in which a device B or B-1 for preventing a false lighting phenomenon of the kind is installed. To describe in detail, as shown in Fig. 17, the sun light c' incident upon the device B or B-1 for preventing a false lighting phenomenon is refracted by each of the spherical lenses 100, 100, ... of the complex spherical lenses 200 on the external side to focus in the space b' so that it is contracted to be extremely small, and then, refracted again by each of the spherical lenses 100, 100, ... of the complex spherical lenses 200 on the internal side, thus being incident on the interior of the main body 700 of a signal lamp in a state that it is diffused. Since the sun light is incident in such a diffused state as this, the light reflected on and emitted from the mirror section 800a of the curved-face mirror 800 is reduced, and at the same time, the reflected light is cut off by the cross bars 400 of the shielding element 300 or 300-1. Therefore, the brightness contrast between the interior of the main body 700 of a signal lamp and the exterior of the main body 700 of a signal lamp is great. In addition, there exists the sun light which is reflected on the outer surface of the complex spherical lenses 200 on the external side, though the amount is extremely limited. However, there is no flat portion on the surface with respect to the complex spherical lenses 200. The surface is formed collectively by the convex surfaces of hemisphere. Consequently, the sun light is reflected while being diffused greatly, and its luminance is extremely small. Also, a light reflected on such surface of the kind is reduced in proportion to the radius of curvature of the lens surface of the spherical lenses 100. If such a surface reflection still presents a problem, the radius of curvature of the lens surface of the spherical lenses 100 should only be adjusted. On the other hand, when the light source 900 is turned on in the main body 700 of a signal lamp using the device B for preventing a false lighting phenomenon as shown in Fig. 18, the light beam d' from the light source 900 is refracted in each of the spherical lenses 100, 100, ... of the complex spherical lenses 200 on the internal side to focus in the space b', thus being contracted to be extremely small. Then it is in a state of being emitted while it is refracted and expanded in each of the spherical lenses 100, 100, ... of the complex spherical lenses 200 on the external side. Therefore, it is possible to obtain a good visibility without any shadow of the cross bars 400 the shielding element 300 being observed from the outside. Also, as shown in Fig. 19, when the light source 900 is turned on in the main body 700 of a signal lamp using the device B-1 for preventing a false lighting phenomenon, the light beam d' from the light source 900 is refracted in each of the spherical lenses 100, 100, ... of the complex spherical lenses 200 on the internal side to focus in the space b', thus being contracted to be extremely small. Then the light beam is in a state that it is emitted while being refracted in each of the spherical lenses 100, 100, ... of the complex spherical lenses 200 on the external side. Further in this case, the light beam d' from the light source 900 is in a state that it is amplified by the reflection by the mirror section 600 formed in the shielding element 300-1 on the light source 900 side, and passes each of the light transmitting slits 402 of the shielding element 300-1. Also, compared to the case where no mirror section 600 is formed, the light beam is converged so that the visual angle can be controlled, hence making its use more convenient at an intersection having a narrower intersecting angles. [Industrial Utilizability] As described above, while a device for preventing a false lighting phenomenon according to this invention is capable of effectively preventing a false lighting phenomenon from taking place, it can maintain the visibility as in the conventional art when signal lamps are turned on. Therefore, the apparatus is remarkably suitable for use as traffic lights, aeronautical marker lights, and the like, and is capable of contributing to the provision of a higher safety in the traffics, aviation, and the like.

Claims: A device for preventing a false lighting phenomenon provided between a light source of the main body of a signal lamp and a cover lens, comprising: a pair of complex spherical lenses formed by many numbers of spheres arranged in matrix on planes, and configured in a chain form in which the contact points, front, rear, left and right sides, of each of the spheres adhere closely to each other by being squeezed without any gaps while the upper and lower spherical surfaces are left intact so that the upper and lower spherical surfaces are utilized as spherical lenses; and a shielding element intervened between said pair of complex spherical lenses, and having light transmitting holes arranged in such a way that the lens surfaces of the spherical lenses are received in said light transmitting holes from both sides of said shielding element, said shielding elements functioning as a spacer positioning the focuses of the spherical lenses on one side correspondingly in the vicinity of the vertices of the lens surfaces of the spherical lenses on the other side. The device for preventing a false lighting phenomenon according to Claim 1, wherein said shielding element is formed by a metal board having light transmitting holes made by punching. The device for preventing a false lighting phenomenon according to Claim 1 or 2, wherein the inner side of said light transmitting holes and/or the surfaces other than said light transmitting holes of said shielding element are colored in black. The device for preventing a false lighting phenomenon according to any of Claims 1 to 3, wherein a mirror section is provided for the inner side of each of said light transmitting holes on the light source side of the signal lamps. The device for preventing a false lighting phenomenon according to Claim 1, wherein said complex spherical lenses are formed of an acrylic resin or a glass material. A device for preventing a false lighting phenomenon provided between a light source of the main body of signal lamps and a cover lens comprising: a pair of complex spherical lenses formed by many numbers of spheres arranged in matrix on planes, and configured in a chain form in which the contact points, front, rear, left and right sides, of each of the spheres adhere closely to each other by being squeezed without any gaps while the upper and lower spherical surfaces are left intact so that the upper and lower spherical surfaces are utilized as spherical lenses; and a shielding element intervened between said pair of complex spherical lenses, and having light transmitting slits arranged in such a way that the lens surfaces of the spherical lenses are received in said light transmitting slits from both sides of said shielding element, said shielding elements functioning as a spacer for positioning the focuses of the spherical lenses on one side correspondingly in the vicinity of the vertices of the lens surfaces of the spherical lenses on the other side. The device for preventing a false lighting phenomenon according to Claim 6, wherein the light transmitting slits of said shielding element receive three spherical lenses of the complex spherical lenses from the corresponding side. The device for preventing a false lighting phenomenon according to Claim 6 or 7, wherein the portions other than the light transmitting slits of said shielding element remain as cross bars and vertical bars, and intersect the vertical bar in the central parts of the cross bars, and at the same time, the vertical and cross bars are arranged to face the lens boundary of each of the spherical lenses of said complex spherical lenses. The device for preventing a false lighting phenomenon according to any of Claims 6 to 8, wherein said shielding element is colored in shades of black. The device for preventing a false lighting phenomenon according to any of Claims 6 to 9, wherein said shielding element is provided with a mirror section on the inner side, especially on the closer portion to the light source of a signal lamp, of the light transmitting slits thereof. The device for preventing a false lighting phenomenon according to any of Claims 6 to 10, wherein said pair of complex spherical lenses are arranged to be fixed to each other at least in the central part thereof. The device for preventing a false lighting phenomenon according to any of Claims 6 to 11, wherein said complex spherical lenses are formed of an acrylic resin or a glass material. The device for preventing a false lighting phenomenon according to any of Claims 6 to 12, wherein said shielding element is a molded product of plastic.

Inventors: ITONAGA TAKASHI, TOMOSADA TOSHIO, ITONAGA, TAKASHI, TOMOSADA, TOSHIO
Applicants: SINGOH DENZAI KABUSHIKI KAISHA
Application year: 1993
Main classification: G08G1
IPC codes: F21S2, F21S8, G08G1, F21V5, G02B3