JPH025579A - Led lamp - Google Patents

Abstract

PURPOSE:To obtain an LED lamp whose luminance and light distribution property are excellent enough for the use in an outdoor sign board by a method wherein two or more LED chips possessed of the same color and property are provided to positions symmetrical about an axis of a reflecting mirror so as to make optical axes of the LED chips cross each other on the axis of the reflector mirror. CONSTITUTION:Two LED chips 4 and 5 are provided to positions symmetrical about the geometrical axis of a lamp and separate from the axis by a distance previously calculated so as to make their optical axes cross each other on the axis of the lamp. That is, one of the LED chips is fixed to a position which is inside the distance between the optical center position and the focal point of a lens section, at the distance to enable light rays radiated from the lens to have a prescribed directional angle, and enables the extension of a direct line which connects a center of the lens to be one of centers of a required light distribution property, and the other LED chip is fixed to a position symmetrical to that of the former about a geometrical axis of the LED lamp. Practically, as the performance of a reflecting mirror 3 and a lens (concave lens) is not ideal, some corrections are necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a rung that uses a light emitting diode (LED) as a light source.

[Prior art and its drawbacks] In the early 1970s, there was a widespread movement to replace the light source of incandescent bulbs with LEDs in light-emitting display devices that use lamps to express characters, figures, or signals. Due to improved efficiency and improved light-transmitting resin, it has been put into practical use in many fields.

However, LED lamps are still not as good as light bulbs in terms of luminous efficiency, brightness, and light distribution characteristics (they have become practical due to the control of light distribution characteristics centered on the optical axis by the materials that make up LED lamps). ), an LED that can be seen from a wide range and has sufficient brightness to rival an incandescent light bulb.
The lamp has not been put into practical use.

Public relations display boards and road information boards generally require a wide field of view in the horizontal direction, but do not require a wide field of view in the vertical direction, so the light distribution is sufficiently narrow in the vertical direction and wide in the horizontal direction. There is a demand for an LED lamp that has characteristics and can efficiently emit light without emitting unnecessary light in the vertical direction.

Conventionally, an LED pump having this type of light distribution characteristic has not been put into practical use. Attempts to achieve this characteristic using existing techniques result in the following problems, each of which has its own drawbacks.

(1) A plurality of ED clamps with narrow light distribution characteristics are installed closely together. Mounting an LED lamp with the direction of the optical axis slightly widened left and right requires a large number of manufacturing parts and installation man-hours, and requires the use of complicated jigs, resulting in high costs.

Also, 1. = Space is required to install multiple E D lamps, and the brightness per display board surface becomes relatively brighter.Especially when viewed from the center of impact, two or more L F, This is because within the area that can be set up for the D-rang, there is only one ()) that appears to be shining.

(2) Collecting fine prisms, 1. Configure Pa7zu 1
7. Control light distribution characteristics. , 2, and 2 are theoretically possible, but the design, manufacturing, and molding are complicated, and the cost becomes significantly high, making them impractical.

FIG. 5 is an example of a two-color LED lamp whose structure is similar to the LED lamp according to the present invention. In the figure, 1 is a lens part molded from transparent epoxy resin, and 2 is a light guide part molded from the same material. -t to L, E D
The chip 4.5 is held and the generated light is guided from the chip to the lens section 1. 3 is an anti-AT mirror having a concave surface close to a parabolic surface molded on the top of the terminal 6, and 4 is a red light emitting L E I) chip, the cathode side of which is near the axis of the reflecting mirror 3. Fixed and electrically connected. 5 is a green light emitting 1-4 ED chip, which is also connected to the reflecting mirror 3 near the axis. Red light emitting L E L) Dep・l, 41 anode wire is connected to terminal 7 with a gold wire, green light emitting light, +vo chip...The anode side of step 5 is connected to terminal 8 in the same way. , its electrical circuit is constructed as shown in FIG. Apply a (''-) potential to the end 76,
@'If you apply (=) potential to f7 and flow several milliamps of DC current, it will turn red, and if you apply (+~) potential to terminal 6,
When terminal 8 is given (-), it emits green light. This is possible by lighting up the LED lights 45 at the same time.

The 1-7 ED lamp shown in FIG. 5 is similar to the present invention in that two 1-7 ED chips 4 and 5 are provided on the concave surface of the reflecting mirror 3, but their purpose will be explained later. The requirements for the geometrical (optical) structure are therefore quite different.

That is, the LED rung (not shown in Fig. 5) is equipped with two LED chimps that emit light of different colors, and these 1-7ED depths can be switched on to change the emitted color, or be lit simultaneously to emit mixed colors. For this purpose, it goes without saying that the LED chips are made to have the same light distribution characteristics when turned on, and to obtain the same field of view. As a result of our efforts in the design to accommodate the two F and ED zimbs, we have designed two L E lenses, one for the F, one for the F, and one for the reflector to align the optical axes of the two ED zimbs as much as possible.
The D chips are placed as close as possible.

Therefore, this two-color LED lamp (1↓) cannot meet the above requirements in terms of light distribution characteristics and brightness.

[Technical Problems to be Solved] This invention takes into consideration the drawback of conventional LED lamps, namely, that their light distribution characteristics are insufficient to provide sufficient illumination over a sufficiently wide area12. The object of the present invention is to provide an LED lamp with sufficient brightness and light distribution characteristics that can be used for applications such as lighting and other applications.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the LED lamp according to the present invention includes a lens portion at the tip and a reflecting mirror having a concave surface in the direction of the lens portion near the base. , L on the concave surface of the reflecting mirror
Place the ED chip and connect the Eri lens part and the base with the cylindrical light guide part! ~In the LED lamp,
The present invention is characterized in that a plurality of LED chips having the same color and characteristics are provided at symmetrical positions with respect to the axis of the reflecting mirror so that the optical axes of the respective LED chips intersect on the axis of the reflecting mirror.

[Function] When multiple LED chips are lit at the same time, each L
Since light is emitted from the ED chip along the optical axis that intersects on the axis of the reflecting mirror, the light distribution characteristics are expanded in a specific direction as a result.

[Embodiment of the present invention] FIG. 1 shows an example of an LED lamp according to the present invention. Second
The figure shows a cross section taken along the line ■-■ of an example of an LED lamp. In the figure, the same reference numerals as those in FIG. 5 indicate the same members as those in FIG. 5, except that 4 and 5 are red LED lamps with the same characteristics.

In this invention, the two LED chips 4.5 are
At a pre-calculated distance from the geometric axis of the lamp,
The optical axis is provided at a symmetrical position with respect to the axis so that the optical axis intersects with the axis.

In other words, the arrangement is such that the light emitted from the lens has a predetermined directivity angle within the distance between the optical center position of the lens section and the focal point, and the extension of the straight line connecting the center of the lens is required. One LED chip is fixed at a position that is the center of one of the light characteristics, and another LED chip is fixed at a position symmetrical to the geometrical axis of the LED lamp. In reality, correction is required because the performance of the reflecting mirror 3 and the performance of the lens (convex lens) are not ideal.

FIG. 3 shows the light distribution characteristics of this example on an extended cross section of FIG. In fact, the light distribution characteristic shown by the solid line F, which is the sum of these two light distribution characteristics, is obtained. That is, two chips 7, 4,
In the direction parallel to the plane formed by connecting the optical axes of 5, a wide light distribution characteristic can be obtained in the vertical direction.

Similarly, FIG. 4 shows the light distribution characteristics on the cross section of FIG. 3, and no vertical spread occurs in the drawing.

[Effects of the Invention] As described above, according to the present invention, for example, the width is wide in the lateral direction,
It is possible to realize an LED lamp having a light distribution characteristic that is narrow in the vertical direction, wide in a specific direction, and narrow in the direction of the pond.

Moreover, since no light is emitted in unnecessary directions, the efficiency is high, and therefore, a display device using light emitting diodes with high brightness and visible from a wide range can be easily realized.

In addition, the manufacturing technology is easy, and low costs are possible through mass production.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an LED lamp according to the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, FIG. 3 is an explanatory diagram showing the light distribution characteristics of the LED lamp, and FIG. FIG. 4 is an explanatory diagram showing light distribution characteristics along line IV-IV in FIG. 3; FIG. 5 is a plan view of a conventional LED rung, and FIG. 6 is a circuit diagram showing only an extracted electric circuit. DESCRIPTION OF SYMBOLS 1...Lens part, 2...Light guide part, 3...Reflector, 4.5...LED chip, 6.7.8...Terminal.

Claims (1)

[Claims] A lens portion is provided at the tip, a reflecting mirror having a concave surface in the direction of the lens portion is provided near the base, and an LED chip is disposed on the concave surface of the reflecting mirror, so that the lens portion and the base are formed into a cylindrical shape. An LED lamp connected by a shaped light guiding section, wherein the LED chips are a plurality of LED chips with the same emission color and uniform characteristics, and the optical axis of each LED chip intersects on the axis of the reflecting mirror. The LED lamp is characterized by being provided at symmetrical positions around the axis of the reflecting mirror.