JPH0442870Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial field of application> The present invention is a display that has a light emitting section made of a cylindrical cold cathode tube and is used as internal illumination of a display section such as a transmissive liquid crystal display. Regarding lighting equipment,
In particular, the present invention relates to a display lighting device that can be miniaturized and has uniform brightness distribution characteristics.

<Prior Art> Hereinafter, the technology of a conventional display lighting device will be described using a structural diagram of a conventional transmission type liquid crystal display device shown in FIG. 4 as a specific example. Note that FIG. 4A is an exploded perspective view of the structure, and FIG.

In FIG. 4, reference numeral 1 denotes a light emitting section consisting of a cylindrical cold cathode tube. A reflecting part 2 is provided with a reflective surface located on the back and side surfaces of the light emitting part 1 to reflect light from the light emitting part 1. Both ends of the light emitting part 1 in the longitudinal direction are connected to the reflecting part 2 by a holder 3. Fixed. On the other hand, a display section 4 made of, for example, a transmissive liquid crystal segment is provided in front of the light emitting section 1 and is illuminated by direct light from the light emitting section 1 and reflected light from the reflecting section 2 to display information. This display section 4 is connected to a printed circuit board 6 through a rubber connector 5, and a voltage to be displayed is applied according to a command from the main body (not shown), and the contents are displayed. The light emitting section 1 is supplied with power from the connectors 1a at both ends and illuminates the display section. 7 is a casing that houses and supports the entire device.

<Problems to be solved by the invention> By the way, since no consideration has been given to making the reflected light uniform in the reflecting section 2 of this display lighting device, it is difficult to observe the display section 4 from the outside. Sometimes there is a large difference in brightness between the left and right ends and the center, which is not visually pleasing.
In order to prevent this, for example, the light emitting section 1 may be made larger or have more than one light emitting section, but this causes the problem that the entire device becomes larger, the number of parts increases, and the device becomes more expensive.

The present invention was devised in view of the problems of the conventional technology, and the shape of the reflecting surface of the reflecting section is changed in each section to make the reflected light of the light emitting section uniform in the longitudinal direction. It is an object of the present invention to provide a display lighting device that reduces differences in brightness between locations.

<Means for Solving the Problems> The display lighting device of the present invention for achieving the above-mentioned object includes a light emitting section made of a cylindrical cold cathode tube, and reflective surfaces located on the back and side surfaces of the light emitting section. A display lighting device comprising: a reflecting section that reflects light from the light emitting section; and a display section that is illuminated by direct light from the light emitting section and reflected light from the reflecting section. In the longitudinal direction of the light emitting part, the reflective surface of the light emitting part is made concave so as to prevent scattering of the reflected light at both end side parts where the light emission brightness decreases and to direct the reflected light toward the display part, and at the center part where the light emission brightness is increased. In this case, a convex shape is formed so as to direct the reflected light toward the both end side portions, and in a side direction of the light emitting section, an inclined surface is formed that surrounds at least a lower side of the light emitting section and directs the reflected light toward the display section. It is characterized by having a substantially concave shape.

<Examples> Examples of the present invention will be described below with reference to specific drawings. In the following drawings, parts that overlap with those in FIG. 4 are given the same numbers, and the explanation thereof will be omitted.

FIG. 1 is an exploded perspective view of the structure of the display lighting device of the present invention, and FIG. 2 is a sectional view of FIG.

In FIGS. 1 and 2, 20 is a reflecting section. In the longitudinal direction (arrow L) of the light emitting part 1, the reflective surface of the reflecting part 20 prevents the scattering of reflected light at both end side parts 20a where the luminance of light emission decreases, and directs the reflected light λ ₁ toward the display part 4. The reflective surface is spaced apart from the center of the light emitting part 1 and has a concave shape so as to reflect the direct light and reflected light from the light emitting part 1 evenly in the direction of the display part 4 without escaping in the longitudinal direction. In the central portion 20b where the light intensity is stronger, the reflective surface of the structure that is close to or in contact with the light emitting portion ₁ has a convex structure, which has the effect of uniformly reflecting (directing) the reflected light λ 2 to both end side portions 20b.
In addition, in the side direction 20c of the light emitting section, the reflected light λ ₃ encompasses at least the periphery of the lower side of the light emitting section 1.
It has a generally concave shape with an inclined surface facing toward the display section 4. By making the reflective surface of the reflective section 20 have such a structure, the brightness gradient at both end portions in the longitudinal direction decreases gradually, and the difference in brightness of the display section 4 becomes small. Incidentally, in the case of FIG. 1, the light emitting part 1 is attached to two screw holes p at the boundary between the concave part and the convex part of the reflecting part 20 through the holder 3. Further, the reflecting section 20 in this embodiment is constructed by processing and molding a plate-like object.

By the way, the reflecting section of the present invention is not limited to that shown in FIGS. 1 and 2, but may have a shape and configuration as shown in FIG. 3, which shows another embodiment of the present invention. In addition, Figure 3A is a perspective configuration diagram of the reflecting section, Figure 3B is a diagram of the α section viewed from direction A, Figure 3C is
is a diagram of the β cross-section viewed from the B direction, and FIG. D is a diagram of the γ cross-section viewed from the B direction.

The difference from FIGS. 1 and 2 is that the reflecting section 20
0 has a thick wall structure, and a concave shape having an inclined surface that surrounds at least the lower side of the light emitting part 1 and directs reflected light toward the display part 4 on the side surface of the light emitting part 1 is constructed only by a curved line that draws an arc. At the point. With this arc shape, the brightness can be made uniform in the vertical direction of the display section 4, and the brightness distribution can be further improved. In short, in the present invention, the light emitting section 1
The reflecting section may be configured to efficiently distribute high-intensity light in the central portion to both low-intensity end portions and illuminate the display section 4 with uniform reflected light.

It should be noted that the display section of the present invention is not limited to the above-mentioned transmission type liquid crystal display, but can be used in a wide variety of similar configurations, such as aviation instruments with internal lighting and general instruments with internal lighting. Needless to say.

<Effects of the Invention> As described above in detail with reference to the embodiments, the shape of the reflecting part is formed into a convex shape in the longitudinal direction at the center of the light emitting part, and the both end parts in the longitudinal direction are similarly concave. According to the display lighting device of the present invention, in which the side portions of the light-emitting portion are shaped concavely, the brightness at both ends of the light-emitting portion is improved, and the brightness at approximately the center portion is reduced, so that the illumination brightness of the display portion is uniform. be converted into In other words, the brightest area near the center of the display area is
The convex parts of the reflective part make it darker as the reflected light is directed toward the edges, and the darkest ends of the display part become brighter due to the light reflected from the center and the concave parts, so the brightness of the surface of the display part decreases. The difference is reduced. Therefore, it is possible to improve the quality of the display device without increasing the cost, increasing the number of parts, increasing the outer diameter, etc. This has the effect of leading to downsizing of the instrument.

[Brief explanation of the drawing]

Figure 1 is a structural exploded perspective view of the display lighting device of the present invention, Figure 2 is a sectional view of Figure 1, Figure 3 is a diagram showing another embodiment of the present invention, and Figure 4 is a conventional transmission type. FIG. 2 is a structural diagram of a liquid crystal display device. 1... Light emitting part, 2, 20, 200... Reflecting part,
4... Display unit, 5... Rubber connector, 7... Housing.

Claims (1)

[Scope of utility model registration request] a light emitting section made of a cylindrical cold cathode tube; a reflecting section with reflecting surfaces located on the back and side surfaces of the light emitting section to reflect light from the light emitting section; and direct light from the light emitting section and the reflecting section. In the display lighting device comprising a display section illuminated by reflected light from the reflective section, the reflecting surface of the reflecting section has a concave shape at both end portions where luminance of light emission decreases in the longitudinal direction of the light emitting section. A central portion where luminescence brightness is increased is formed into a convex shape that directs the reflected light toward the both end side portions, and in a side direction of the light emitting portion, it encompasses at least a lower side portion of the light emitting portion and directs the reflected light toward the display portion. A display lighting device characterized by having a substantially concave shape having an inclined surface.