Technical Field The present invention relates to a car gauge, and more particularly, to a car gauge which is provided with a prism that can make an efficient reach of a light from a light source at rear of a dial in the gauge to the needle, allowing to obtain a highly illuminated needle.

Background Art In general, car gauges display information on running, and other operating conditions of the car so that the driver can drive the car with safety and make maintenance of the car with ease.

Referring to Figs. 11 and 12 showing a speedometer for indicating a car speed (or a revolution gauge, a hydraulic pressure gauge, a fuel gauge, or water temperature gauge, or etc.) as examples, a background art gauge 10 is provided with a dial 11 having various numerals (characters) and scale marks and a transparent prism 20 at rear of the dial 11. Below the prism 20, there is a needle 40 having a shaft 40A at one end thereof inserted in a shaft 51 of a needle moving unit 50 and a third reflecting part 42. The prism 20 has an end portion having a light receiving part 21 and a first reflecting part 21 A and a middle portion having a second reflecting part 22. There is a light source 30 adjacent to the light receiving part 21 of the prism 20. The unexplained reference numeral 60 is a cap for covering one end of the needle.

When a driver lights the light source 30 in the background art gauge 10 by switching a combination switch during a night drive, light from the light source 30 illuminates the dial 11 in the gauge 10 and, on the same time, transmitted to the needle 40 through the light receiving part

21 in the prism 20, to observe the gauge 10 with ease. That is, as shown in section in Fig. 12, a light from the light source 30 is, incident to the light receiving part 21 in the prism 20, directed to the first reflecting part 21 A, reflected in a horizontal direction at the first reflecting part 21 A, reflected again in a vertical direction at the second reflecting part 22, and incident to the third reflecting part 42 in the needle 40. The light incident to the third reflecting part 42 is reflected at a bottom of the needle 40 and directed upward, illuminating the needle for an easy observation of the driver.

However, the background art needle 40 can not be highly illuminated because the needle is impossible to transmit a large amount of light as the light receiving part 21 for transferring light is formed only at one portion of the base 20A, and has a non-uniform luminance as well as a heavy loss of light as the light reflected at the second reflecting part 22 in the prism 20 is incident to the third reflecting part 42 in the needle 40 with much dispersion and a discontinuity of luminance between portions provided with and without the light receiving part 21. Moreover, the black face window W provided as a front face of the gauge 10 in an attempt to make the gauge 10 a high quality leads to require a brighter needle 40 for better observation of the needle 40, for which a small sized lamp 30 has been provided in the needle 40 as a light source 30 as shown in Fig. 13.

This however leads to require a separate component for supplying power to the light source 30 provided in the needle 30, that causes a complicated structure with a drop of a productivity and a cost high.

Disclosure of the Invention Accordingly, the present invention is directed to a car gauge that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a car gauge which allows an effective

transmission of light from a light source to a needle for an excellent reading of the gauge by a driver and to embody an elegant and highly illuminated needle.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the car gauge having a transparent prism in rear of a dial 11 so that a light from a light source illuminates a needle fitted over the dial 11 through the prism, includes the prism 20 having a reflecting means for converging the light from the light source 30 toward a center part 8 thereof, a shaft 40A mounted in a through hole 23 in the prism 20 and having a concave part 40B at a top part thereof, and a needle 40 having a third reflecting part for fitting at the center part 0, the third reflecting part being fitted over the concave part 40B of the shaft 40A for reflecting the light directed toward the center part 6 from the prism 20 toward the needle 40.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Brief Description of the Drawings The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part ofthis specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention:

In the drawings: Fig. 1 illustrates an exemplary gauge having the present invention applied; Fig. 2 illustrates a top view of an exemplary gauge having a black face window in accordance with a preferred embodiment of the present invention with a partial cut away view; Fig. 3 illustrates a disassembled perspective view of the present invention; Fig. 4 illustrates a section of a system in accordance with a first preferred embodiment of the present invention; Fig. 5 illustrates an operation according to the first embodiment of the present invention shown in Fig. 4; Fig. 6 illustrates a section of a system in accordance with a second preferred embodiment of the present invention; Fig. 7 illustrates a section of a system in accordance with a third preferred embodiment of the present invention; Fig. 8 illustrates a section of a system in accordance with a fourth preferred embodiment of the present invention; Fig. 9 illustrates a section of a system in accordance with a fifth preferred embodiment of the present invention; Fig. 10 illustrates a plan view of an exemplary prism in accordance with a fifth preferred embodiment of the present invention; Fig. 11 illustrates a perspective view of a background art needle system in a gauge; Fig. 12 illustrates a section of a background art system; and, Fig. 13 illustrates a section of another exemplary background art system.

Best Mode for Carrying Out the Invention

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The same reference numerals will be given to parts having the same functions. Fig. 1 illustrates an exemplary gauge having the present invention applied, and Fig. 2 illustrates a top view of an exemplary gauge having a black face window in accordance with a preferred embodiment of the present invention with a partial cut away view wherein it is shown that a gauge 10 provided in an instrument panel in front of a car driver seat has a dial 11 with various scale marks, a black face window W on top of the dial 11, and a transparent prism in rear of the dial 11.

Fig. 3 illustrates a disassembled perspective view of a system of the present invention, and Fig. 4 illustrates a section of a system in accordance with a first preferred embodiment of the present invention, wherein it is shown that the prism 20 includes a base 20A having a radial cut away portion, and a light receiving part 21 on an outer circumference of the base 20A. There is a light source 30 below and adjacent to the light receiving part 21. The light source 30 may be replaced with a plurality of bulbs. The base 20A of the prism 20 has a concave portion A 22A on the central portion thereof formed by a slight upwardly projection toward the center of the base 20A, a through hole 23 at the center in a up and down direction, and a second reflecting part 22 of a convex portion under the convex portion A. There is a needle moving unit 50 under the center portion of the base 20A of the prism 20, and there is a shaft 51 of the needle moving unit 50 in the through hole 23, on top of which a transparent shaft 40A is fitted, which is connected to a needle 40 provided over a dial 11. The shaft 40A has a recessed portion 40B on top, and the needle 40 has a concave portion B 41 on one side of a lower end fitted on the top of the shaft 40A. There is a sloped third reflecting part 42 over the concave portion B 41 adapted to be positioned on a central portion 8 of the shaft 40A, for increased light reached to the needle to

improve illumination of the needle and keeping light always constant even when the needle rotates. On the other hand, the second reflecting part 22 is formed of a convex portion, for focusing light incident thereto to reduce loss of the light. And, there is a cap 60 covered on one end of the needle 40 fitted on the shaft 40A. A portion of the cap 60 over the third reflecting part 42 in the needle 40 is cut away to form an open part 61, for extending exposed portion of the needle 40 to maximize illumination of the needle 40.

The operation of the present invention having the aforementioned system will be explained. Fig. 5 illustrates an operation according to the first embodiment of the present invention shown in Fig. 4.

Referring to Fig. 5, when the driver turns on a switch (not shown), turning on the light source 30, the dial 11 is illuminated and, on the same time, a portion of light incident to the light receiving part 21 in the prism 20. The light through the light receiving part 21 is incident to the first reflecting part 21 A, reflected at the first reflecting part 21 A to travel in a horizontal direction in the base 20A, and incident to the second reflecting part 22. The light incident to the second reflecting part 22 is reflected again at an angle upwardly, converged, and incident to the third reflecting part 42 on the central portion 0. As explained, since the third reflecting part 42 is located on the central portion 0 of the shaft 40A and the light reflected at the second reflecting part 22 is transmitted to the central portion 6 of the third reflecting part 42 without a loss, allowing reflection of much amount of light toward the needle 40, the needle can be highly illuminated. In this instance, though the concave part B is provided on an under side of the needle 40 under the third reflecting part for showing an example of adjusting the light too much focused onto the third reflecting part 42, to collimate the light reflected at the second reflecting part 22, the concave part B 41 may be replaced with a flat part.

Fig. 6 illustrates a section of a system in accordance with a second preferred embodiment of the present invention, including a second reflecting part 22 with an underside slope on the center of the base 20A of the in the prism 20, and a shaft 40A having a first refracting part 40C and a second refracting part 40D respectively formed convex on top and bottom thereof separate from the needle 40.

The second embodiment is operative as follows. A light from the light source 30 is incident to the light receiving part 21, reflected at a slope in the first reflecting part 21A, passes through the base 20A, and is incident to the second reflecting part 22, reflected at the second reflecting part 22 in a vertical direction, and incident to the first refracting part 40C in the shaft 40A. The light incident to the first refracting part 40C is made to incident to the second refracting part 40D at a proper angle by the convex portion, and the light incident to the second refracting part 40D is focused onto a center of the concave part B 41 underside of the needle 40. As explained in connection with Fig. 5, the light incident to the concave part B 41 is directed upwardly, and incident to the third reflecting part 42, reflected at the third reflecting part 42 toward the needle 40, illuminating the needle 40. In the second embodiment shown in Fig. 2, the light reflected at the second reflecting part 22 in the prism 20 passes through the first, and second refracting parts 40C and 40D in the shaft 40A with refractions at proper angles, and is incident toward the needle 40, thereby making an operation identical to the embodiment explained in connection with Fig. 5.

Fig. 7 illustrates a section of a system in accordance with a third preferred embodiment of the present invention, including a base 20A of the prism 20 having a second reflecting part 22 of a downward convex portion on the center and a concave portion 22A over the second reflecting part 22, a shaft 40A formed as a unit with the needle 40 fitted on a shaft 51 of a needle

moving unit 50, a concave part B 41 at a starting portion of the needle 40, and a third reflecting part 42 over the concave part B 41.

The operation of the third embodiment having the aforementioned system will be explained. The light from the light source 30 passes through the light receiving part 21 and the first reflecting part 21 A, is reflected at the convex portion of the second reflecting part upwardly sloped at an angle, incident to the concave portion B 41 in the needle 40. The light incident to the concave portion B 41 is refracted upwardly in a vertical direction, incident to the third reflecting part 42, reflected at the third reflecting part 42 toward the needle 40, thereby implementing a highly illuminated needle like the first, and second embodiments.

Fig. 8 illustrates a section of a system in accordance with a fourth preferred embodiment of the present invention, including a base 20A of the prism 20 having a second reflecting part 22 of a downward sloped convex portion on a center, and a shaft 40A formed separate from a needle 40. The shaft 40A has a flat recess part 40E sloped downwardly inwardly to a center on a top surface, and the needle 40 having a flat recess part 40F sloped upwardly to a center opposite to the flat recess part 40E on the center of the needle 40 and a third reflecting part 42 over the flat recess part 40F.

In the fourth embodiment having the aforementioned system, the light from the lamp 30 is, received through the light receiving part 21, reflected at the first reflecting part 21 A, incident to the second reflecting part 22, reflected at the second reflecting part 22 upwardly at an angle, passes through the recess part 40E in the shaft 40A, and converged onto the flat recess part 40F in the needle 40. The light converged and incident onto the flat recess part 40F in the needle 40 is upwardly refracted in a vertical direction, incident to the third reflecting part 42, and reflected at the third reflecting part 42 toward the needle 40, thereby implementing a highly illuminated

needle like the first, second, and third embodiments. That is, in the first, second, third, and fourth embodiments, a highly illuminated needle 40 can be implemented by receiving a large amount of light by means of the light receiving part 21 enlarged wider and converging to a center when the light is transmitted to the third reflecting part 42 in the needle 40 through the first, and second reflecting parts 21A and 22, increasing illumination of the needle significantly.

Fig. 9 illustrates a section of a system in accordance with a fifth preferred embodiment of the present invention, and Fig. 10 illustrates a plan view of an exemplary prism in accordance with a fifth preferred embodiment of the present invention, including a base 20A of the prism 20 having fitting recesses 20B, and LEDs L fitted in the fitting recesses 20B. That is, fitting recesses 20B are formed cutting away portions of the base 20A, in each of which the LED L is fitted, and a light receiving convex part 20C is formed in front of the LED L, i. e., at an end of the fitting recess 20B for receiving a light from the LED L. As shown in Fig. 10, preferably, a plurality of the fitting recesses 20B are formed radially in the base 20A in the disc form of prism 20, for fitting a plurality of LEDs L therein. In the fifth embodiment having the aforementioned system, light from the LED L is directly incident to the light receiving convex part 20C, and illuminates the needle through the second, and third light receiving parts 22 and 42.

As alternatives to the fifth embodiment, either different color LEDs L may be provided for easy distinguishing of gauges from a zone to another zone, or the fitting recesses 20B and the LEDs L may be formed and directly fitted therein at the position of the light receiving part 21 in Fig 4 and etc., while keeping the prism 20 as it was.

Since the present invention as has been explained by means of different embodiments can improve an efficiency of lighting in a gauge having a black face window W applied thereto, the present invention can implement a highly illuminated needle and allows to provide a high quality

gauge. And, the highly illuminated needle helps easy reading of the gauges that help a safe running, and the embodiment of high quality gauges help to provide a high quality car that improves market price of the car. And, a productivity and reliability of the gauge are improved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the car gauge of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.