JP3950407B2 - Display and light collector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device and a light collecting portion, and more particularly, to a display device including a display light guide body in which the shape of a display character is three-dimensionally formed, and a light collecting portion used in the display device.
[0002]
[Prior art]
Conventionally, from the viewpoint of design design, there has been considered a display device that irradiates light from the back of a display light guide in which the shape of the display character is formed in three dimensions and displays the display character in three dimensions. Yes. However, for example, when a point light source such as an LED is used as a light source for irradiating light from the back surface, a portion of the display character that is in a direction away from the LED becomes darker.
[0003]
For example, as shown in FIG. 10, as a display character, a segment shape forming a number is formed in the display light guide 10, and the LED 20 is an abbreviation in the longitudinal direction Y1 on the back surface of the display light guide 10. When arranged at the center C, the emission luminance in the longitudinal direction Y1 of the segment becomes darker as the distance from the center C increases. For this reason, there is a problem that the display character cannot be seen three-dimensionally and the effect of rendering is impaired.
[0004]
It is also conceivable to use a liquid crystal display (LCD) to create a surface light source that faces the display character. However, there is a problem in that the brightness of the liquid crystal itself is low and the light emission luminance of the display character is reduced overall. It was.
[0005]
In particular, in the case of a segment shape, it is also conceivable to use a fluorescent display tube (VFT) to produce a surface light source according to the segment shape. However, the VFT has a gap between the phosphor that is the light emitting surface and the front glass. For this reason, as shown in FIG. 11A, when viewed from the front, the VFT 30 is positioned directly behind the segment shape formed in the display light guide 10, but when the line of sight is shifted to the left, for example, FIG. As shown in FIG. 4, there is a problem that the position of the VFT 30 is shifted from the back of the segment shape.
[0006]
[Problems to be solved by the invention]
Accordingly, the present invention pays attention to the above-described problems, and provides a display device in which the entire display character three-dimensionally formed on the display light guide can emit light even when a point light source is used. And
[0007]
[Means for Solving the Problems]
  The invention according to claim 1, which has been made to solve the above problems, includes a display light guide body in which the shape of the display character is three-dimensionally formed, a point light source provided on the back surface of the display light guide body, A light collecting unit provided between the point light source and the display light guide and having a parabolic light reflecting surface with a straight line as an axis perpendicular to the back surface of the display light guide;In the display light guide, a display segment shape is formed as the display character, and the light reflecting surface is perpendicular to the surface formed by the parabola and the axis. The movement is performed while continuously changing the inclination of the parabola so that the shape drawn by the end of the parabola substantially matches the shape of the end of the segment in the longitudinal direction. The same shape as the surface to be formedIt exists in the display characterized by this.
[0008]
According to the first aspect of the present invention, the shape of the display character is three-dimensionally formed on the display light guide. A point light source is provided on the back surface of the display light guide. Between the point light source and the display light guide, a condensing unit having a radial light reflection surface with a straight line perpendicular to the back surface of the display light guide as an axis of symmetry is provided. Therefore, if a point light source is arranged at the focal point of the parabola formed by the light reflecting surface, the light incident on the light reflecting surface from the point light source is reflected by the light reflecting surface and is reflected on the back surface of the display light guide. Can be ejected almost vertically. That is, it is possible to emit light substantially perpendicularly to a portion that is not directly in front of the point light source with respect to the display character formed on the display light guide.
[0021]
  Also,Claim1According to the described invention, the display light guide is formed with a display segment shape as a display character. The light-reflecting surface moves the parabola in a direction perpendicular to the plane formed by the parabola and the axis, and the shape drawn by the end of the parabola is almost the same as the shape of the end of the segment in the longitudinal direction. As shown, when it moves while continuously changing the inclination of the parabola, it has the same shape as the surface formed. Therefore, if the light reflecting surface is arranged so that the end of the parabola that forms the light reflecting surface is positioned on the back of the end in the longitudinal direction of the segment, the light reflecting surface is placed on the back of the segment in the longitudinal direction. While arranging, the light reflecting surface does not need to be arranged on the back surface other than the portion where the segment shape is formed.
[0022]
  The invention according to claim 2 is a display light guide in which the shape of the display character is three-dimensionally formed, a point light source provided on the back surface of the display light guide, the point light source, and the display light guide. And a condensing part having a parabolic light reflecting surface with a straight line as an axis perpendicular to the back surface of the display light guide.In the display light guide, a display segment shape is formed as the display character, and the light reflecting surface is perpendicular to the surface formed by the parabola and the axis. The movement is performed while intermittently changing the inclination of the parabola so that the shape drawn by the end of the parabola substantially matches the shape of the end of the segment in the longitudinal direction. The same shape as the surface to be formedIt exists in the display characterized by this.
[0023]
  According to the second aspect of the present invention, the shape of the display character is three-dimensionally formed on the display light guide. A point light source is provided on the back surface of the display light guide. Between the point light source and the display light guide, a condensing unit having a radial light reflection surface with a straight line perpendicular to the back surface of the display light guide as an axis of symmetry is provided. Therefore, if a point light source is arranged at the focal point of the parabola formed by the light reflecting surface, the light incident on the light reflecting surface from the point light source is reflected by the light reflecting surface and is reflected on the back surface of the display light guide. Can be ejected almost vertically. That is, it is possible to emit light substantially perpendicularly to a portion that is not directly in front of the point light source with respect to the display character formed on the display light guide. Also,Claim2According to the described invention, the display light guide is formed with a display segment shape as a display character. The light-reflecting surface moves the parabola in a direction perpendicular to the plane formed by the parabola and the axis, and the shape drawn by the end of the parabola is almost the same as the shape of the end of the segment in the longitudinal direction. As shown, the shape is the same as the surface formed when the parabola is moved while being intermittently changed.
[0024]
Therefore, if the light reflecting surface is arranged so that the end of the parabola that forms the light reflecting surface is positioned on the back of the end in the longitudinal direction of the segment, the light reflecting surface is placed on the back of the segment in the longitudinal direction. While arranging, it is not necessary to arrange a light reflecting surface in a portion other than directly below the segment shape. Moreover, an arbitrary cross section when the light reflecting surface is cut by a plane parallel to the back surface of the display light guide is perpendicular to the longitudinal direction.
[0031]
  Claim3The described invention is a condensing unit provided between a display surface on which a segment-shaped portion emits light by light from the back surface and a point light source disposed on the back surface of the display surface, and the parabola is the parabola. And the parabola such that the shape drawn by the end of the parabola substantially coincides with the shape of the segment in the longitudinal direction by the movement. When the movement is performed while continuously changing the inclination of the light, a light reflecting surface having the same shape as the surface to be formed is provided.
[0032]
  Claim3According to the described invention, the light reflecting surface moves the parabola in a direction perpendicular to the surface formed by the parabola and the axis, and the shape drawn by the end of the parabola by the movement is the longitudinal direction of the segment. It is the same shape as the surface formed when it is moved while continuously changing the inclination of the parabola so as to substantially match the shape of the side end. Therefore, if the light reflecting surface is arranged so that the end of the parabola that forms the light reflecting surface is positioned on the back of the end in the longitudinal direction of the segment, the light reflecting surface is placed on the back of the segment in the longitudinal direction. While arranging, it is not necessary to arrange a light reflecting surface in a portion other than directly below the segment shape.
[0033]
  Claim4The described invention is a condensing unit provided between a display surface on which a segment-shaped portion emits light by light from the back surface and a point light source disposed on the back surface of the display surface, and the parabola is the parabola. And the parabola such that the shape drawn by the end of the parabola substantially coincides with the shape of the segment in the longitudinal direction by the movement. When the movement is performed while intermittently changing the inclination, the light condensing part has the same shape as the surface to be formed.
[0034]
  Claim4According to the described invention, the light reflecting surface moves the parabola in a direction perpendicular to the surface formed by the parabola and the axis, and the shape drawn by the end of the parabola by the movement is the longitudinal direction of the segment. It is the same shape as the surface formed when it moves while changing the parabola's inclination intermittently so as to substantially match the shape of the side end.
[0035]
Therefore, if the light reflecting surface is arranged so that the end of the parabola that forms the light reflecting surface is positioned on the back of the end in the longitudinal direction of the segment, the light reflecting surface is placed on the back of the segment in the longitudinal direction. While arranging, it is not necessary to arrange a light reflecting surface in a portion other than directly below the segment shape. Moreover, an arbitrary cross section when the light reflecting surface is cut by a plane parallel to the display surface is perpendicular to the longitudinal direction.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
First embodiment
Hereinafter, a display incorporating the light collecting unit of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an embodiment in which the display of the present invention is applied to a digital speedometer. As shown in the figure, the display device includes a display light guide 10 in which a display segment shape and a character shape representing a speed unit (km / h) are three-dimensionally formed as display characters ( The display light guide 10 in which the character shape is formed is not shown).
[0037]
For example, 16 segment shapes are formed, and the display light guide 10 is provided with a separate baht for each of the 16 segment shapes. The 16 segments are arranged to represent, for example, the number “188”. Eighteen LEDs 20 are arranged on the back surface of the display light guide 10. Sixteen of the eighteen LEDs 20 are arranged on the substrate 30 so as to be positioned on the back of the sixteen segment shapes. Further, the remaining two are arranged on the substrate 30 so as to be positioned on the back surface of the character shape.
[0038]
Between the said display light guide 10 and LED20, the box-shaped condensing part 40 for condensing the light from LED20 to the display light guide 10 and the display light guide 10 from the condensing part 40 are displayed. A light diffusing plate 50 for diffusing the light emitted toward the surface is provided. Further, on the front surface of the display light guide 10, a shielding plate 60 having a cutout portion 61 cut out along the outer periphery of a segment shape or a character shape and a decorative plate 70 having a similar cutout portion 71 are arranged. Yes.
[0039]
The condensing part 40 is formed of a light blocking member, and has 16 through-holes 41a penetrating from the back to the front at positions facing each segment shape, and from the back to the position facing the character shape. A through hole 41b penetrating therethrough is provided. And the condensing light guide 42 is inserted in the through-holes 41a and 42b, respectively.
[0040]
Next, the detailed shape of the condensing light guide 42 inserted into the above-described through hole 41a will be described with reference to FIGS. 2 is a perspective view of the condensing light guide 42, FIG. 3A is a side view of the display light guide 10, the condensing light guide 42, and the LED 20 of FIG. 2, and FIG. FIG. 4 is a front view of the light collecting light guide 42 and the display light guide 10.
[0041]
As shown in FIG. 2, a part of the outer surface of the condensing light guide 42 is formed in a parabolic shape. And the outer surface formed in this parabolic shape is the light reflecting surface 42a in the claims. The shape of the light reflecting surface 42a is the same as the shape described below. First, as shown in FIG. 2 and FIG.₁Parabola L around the axis_{twenty one}And L_{twenty two}Suppose there is. This parabola L_{twenty one}And L_{twenty two}Is the axis L as shown in FIG.₁And the distance L between the edge₃₁, L₃₂Is the longest distance L from the longitudinal center of the segment shape to the longitudinal end.₄₁, L₄₂It is getting longer.
[0042]
The light reflecting surface 42a has a parabola L as shown in FIG._{twenty one}, L_{twenty two}Without changing its shape, parabola L_{twenty one}, L_{twenty two}And axis L₁The shape is the same as the surface formed when the segment shape is moved by the width W in the short direction of the segment shape (see FIG. 3B) in the direction Y2 perpendicular to the surface formed by.
[0043]
As shown in FIG. 3A, the display light guide 10 has a parabolic line L in the short direction of the segment shape._{twenty one}And L_{twenty two}And the back side of the axis L₁It is arrange | positioned at the front side of the condensing light guide 42 so that it may become perpendicular | vertical. Further, as shown in FIG. 3 (b), the condensing light guide 42 is disposed so that the light reflecting surface 42a covers the entire back surface of the segment shape when viewed from the front.
[0044]
Further, as shown in FIG. 1, the light condensing unit 40 is provided with a flange 43 having a screw hole. When the screw hole provided in the flange 43 is aligned with the screw hole 31 provided in the substrate 30 and is fixed with a screw, the parabola L formed by the reflection surface 42a of the condensing light guide 42 provided in the condensing part 40 is formed._{twenty one}, L_{twenty two}The condensing part 40 can be fixed to the board | substrate 30 in the state by which LED20 is arrange | positioned 1 each at the focus of this, and two LED20 is arrange | positioned on the back surface of the through-hole 41b. As described above, the LED 20 can be easily attached to the back surface of the light collecting unit 40 simply by fixing the light collecting unit 40 to a predetermined position of the substrate 30, and assembling becomes easy.
[0045]
Further, the above-described blocking plate 60 is formed in a lid shape that covers the light collecting portion 40, and the convex portion 44 in which the hole 62 is provided in the light collecting portion 40 with the light diffusion plate 50 and the display light guide 10 sandwiched therebetween. Can be fixed to the light collecting unit 40.
[0046]
The operation of the display device having the above-described configuration will be described below with reference to FIG. 4A shows an X of the condensing light guide 42 in FIG.₁-X₁FIG. 4B is a cross-sectional view taken along the line, and FIG.₁₁-Z₁₁Cross section, Z₁₂-Z₁₂Cross section, Z₁₃-Z₁₃It is sectional drawing.
First, when the LED 20 is turned on, the light from the LED 20 is transmitted through a condensing light guide 42 provided in the condensing unit 40.
[0047]
As shown in FIG. 4A, a parabola L formed by the light reflecting surface 42a._{twenty one}, L_{twenty two}If the LED 20 arranged at the focal point is arranged, the light LL transmitted from the LED 20 through the condensing light guide 42 and incident on the light reflecting surface 42a is reflected by the light reflecting surface 42a, and the axis L₁The light can be emitted substantially parallel to the direction, that is, substantially perpendicular to the back surface of the display light guide 10.
[0048]
By the way, when the width W of the segment shape in the short direction is smaller than or substantially the same as the width of the LED 20, as shown in FIG. 4B, the light LL from the LED 20 is reflected on the light reflecting surface 42a. Incident in the longitudinal direction when viewed from the side. As described above, the light reflecting surface 42a has the parabola L._{twenty one}, L_{twenty two}Without changing its shape, parabola L_{twenty one}, L_{twenty two}And axis L₁Are formed in the same shape as the surface formed when moved in the direction Y2 perpendicular to the surface formed.
[0049]
Therefore, as described above, the display light guide 10 has a segment shape whose short direction is a parabola L._{twenty one}And L_{twenty two}And the back side of the axis L₁4b, the light reflection surface 42a is cut by a plane parallel to the back surface of the display light guide 10, as shown in FIG. 4 (b). An arbitrary cross section at the time becomes perpendicular to the longitudinal direction Y1. For this reason, the light LL emitted from the LED 20 emitted in the longitudinal direction when viewed from the front is reflected by the light reflecting surface 42a and then proceeds to the front without shifting in the lateral direction, that is, the display light guide 10 Can be injected perpendicularly to the back of the.
[0050]
Therefore, light can be emitted vertically to the display character of the display light guide 10 that is not directly in front of the LED 20, for example, to both end portions in the longitudinal direction, and a point light source such as the LED 20 can be used. The entire display character formed three-dimensionally on the display light guide 10 can be made to emit light uniformly.
[0051]
Moreover, since the said through-hole 41a is formed from the light shielding member, the light from LED20 which injected from the back side opening part of the through-hole 41a does not leak outside the through-hole 41a, but the front of the through-hole 41a. It is emitted only from the side opening. For this reason, the light from the LED 20 can be prevented from being guided to other segment shapes that do not face the LED 20, and when the LED 20 is turned on, even other segments that do not correspond to the LED 20 emit light. This can be prevented.
[0052]
Further, as shown in FIG. 1, the light emitted from the light collecting unit 40 toward the back surface of the display light guide 10 by the light diffusion plate 50 between the display light guide 10 and the light collecting unit 40 is The light from the LEDs 20 can be evenly emitted to the display light guide 10 by being diffused.
[0053]
Further, among the light emitted from the display light guide 10 toward the front, the light from the portion where the segment shape is formed is emitted to the front through the cutout portion 61 of the blocking plate 60. On the other hand, light from portions other than the segment shape is blocked by the blocking plate 60. For this reason, the contrast between the segment shape and the other portions can be increased.
[0054]
Second embodiment
In the above-described embodiment, as shown in FIG. 2, the light reflecting surface 42 a is provided with the outer surface of the condensing light guide 42 having a parabolic shape. However, for example, as shown in FIG. 5, it is also conceivable to provide a light reflecting surface 42a by forming a groove 42b by the light condensing light guide 42 and forming the inner surface forming the groove 42b in a parabolic shape. In this case, if the light reflection surface 42a is subjected to a reflection process, more light is emitted to the back surface of the condensing light guide 42, and the brightness of the segment is increased.
[0055]
Third embodiment
In the first embodiment described above, as shown in FIG. 3B, the light reflecting surface 42 a is arranged so as to cover the entire segment shape formed by the display light guide 10. For this reason, the parabola L which forms the light reflection surface 42a_{twenty one}, L_{twenty two}Is the distance L₃₁, L₃₂However, as shown in FIG. 3A, the longest distance L from the longitudinal center of the segment shape to the longitudinal end.₄₁, L₄₂It was getting longer.
[0056]
However, when the light reflecting surface 42a is formed in this way, a light reflecting member is also formed on the back surface of the display light guide 10 (indicated by the oblique lines in FIG. 3B) other than the portion where the segment shape is formed. . For this reason, when the segments have to be arranged close to each other, the light reflecting surfaces 42a arranged on the back surfaces of the segments interfere with each other as shown by the oblique lines in FIG.
[0057]
Therefore, as shown in FIG. 6B, a parabola L forming the light reflecting surface 42a._{twenty one}, L_{twenty two}Distance L₃₁, L₃₂Is approximately equal to the shortest distance from the approximate longitudinal center of the segment shape to the longitudinal end so that the light reflecting surfaces 42a do not interfere with each other.
[0058]
However, in this case, the light reflecting surface 42a is not provided on the back surface of the portion indicated by the oblique line of the display light guide 10, and the portion indicated by the oblique line may become dark. Therefore, it is conceivable to provide a light reflecting surface 42a having a shape as shown in FIG. FIG. 7A shows a perspective view of the condensing light guide 42 in the third embodiment, and FIG. 7B shows a front view of the display light guide 10 and the condensing light guide 42 in the third embodiment. Show.
[0059]
As shown in the figure, a straight line perpendicular to the back surface of the display light guide 10 is defined as the symmetry axis L.₁Parabola L_{twenty one}, L_{twenty two}Suppose there is. The light reflecting surface 42a is a parabola L_{twenty one}, L_{twenty two}A parabola L_{twenty one}, L_{twenty two}And axis L₁Are moved by a width W in the short direction of the segment shape in the direction Y2 perpendicular to the plane formed by_{twenty one}, L_{twenty two}The parabola L so that the shape drawn by the end of the segment substantially matches the shape of the longitudinal end of the segment shape._{twenty one}, L_{twenty two}The shape is the same as the surface formed when it is moved while continuously changing its inclination.
[0060]
In the display light guide 10, the short direction of the segment shape is a parabola L._{twenty one}And L_{twenty two}And the back side of the axis L₁It is arrange | positioned at the front side of the condensing light guide 42 so that it may become perpendicular | vertical. Further, as shown in FIG. 7 (b), when viewed from the front, the parabola L just below the longitudinal end of the segment shape._{twenty one}, L_{twenty two}The condensing light guide 42 is disposed so that the end of the light is positioned.
[0061]
If comprised as mentioned above, the light reflection surface 42a does not need to be arrange | positioned except the part in which the segment shape is formed, arrange | positioning the light reflection surface 42a in the back surface of the longitudinal direction side end of a segment shape. For this reason, the end of the segment shape does not become dark, and even if a plurality of segments are arranged close to each other, the light reflecting surfaces 42a corresponding to each segment do not interfere with each other.
[0062]
Fourth embodiment
In the third embodiment described above, the light reflecting surface 42a is a parabola L._{twenty one}, L_{twenty two}Was made to have the same shape as the surface formed when it was moved by changing its inclination continuously. However, in such a light reflecting surface 42a, an arbitrary cross section when cut by a plane parallel to the back surface of the display light guide 10 is not perpendicular to the longitudinal direction Y1.
[0063]
For this reason, the light from the LED 20 emitted in the longitudinal direction when viewed from the front is reflected by the light reflecting surface 42a and then shifted in the short direction, and does not proceed directly to the front, that is, the display light guide 10 There is a problem that the brightness of the segment viewed from the front is lowered because the light cannot be emitted perpendicularly to the back surface of the screen.
[0064]
Therefore, it is conceivable to provide a light reflecting surface 42a having a shape as shown in FIG. FIG. 8A shows a perspective view of the condensing light guide 42 in the fourth embodiment, and FIG. 8B shows a front view of the display light guide 10 and the condensing light guide 42 in the fourth embodiment. Show.
[0065]
That is, in the third embodiment, the light reflecting surface 42a is a parabola L._{twenty one}, L_{twenty two}A parabola L_{twenty one}, L_{twenty two}While continuously changing the inclination, the shape was the same as the surface formed when moving in the direction of the arrow Y2. In contrast, in the fourth embodiment, the light reflecting surface 42a has a parabola L as shown in FIG._{twenty one}, L_{twenty two}A parabola L_{twenty one}, L_{twenty two}The surface is formed in the same shape as the surface formed when moving in the direction of the arrow Y2 while intermittently changing the inclination of.
[0066]
In the fourth embodiment, the parabola L as in the third embodiment._{twenty one}, L_{twenty two}Of the parabola L by the above movement._{twenty one}, L_{twenty two}The shape drawn by the end of the segment is changed so as to substantially match the shape of the end of the segment shape in the longitudinal direction. Further, in the fourth example, as in the third embodiment, the display light guide 10 has a segment shape whose short direction is a parabola L._{twenty one}And L_{twenty two}And the back side of the axis L₁It is arrange | positioned at the front side of the condensing light guide 42 so that it may become perpendicular | vertical. Further, as shown in FIG. 8 (b), when viewed from the front, a parabola L just below the longitudinal end of the segment shape._{twenty one}, L_{twenty two}The condensing light guide 42 is disposed so that the end of the light is positioned.
[0067]
As described above, the parabola L intermittently_{twenty one}, L_{twenty two}By changing the slope of the parabola L_{twenty one}, L_{twenty three}Parabola L without changing the shape of_{twenty one}, L_{twenty three}As in the case of moving, an arbitrary cross section when cut by a plane parallel to the back surface of the display light guide 10 is perpendicular to the longitudinal direction Y1. For this reason, the light from the LED 20 emitted in the longitudinal direction Y1 when viewed from the front can be reflected directly on the light reflecting surface 42a, and can proceed directly to the front without shifting in the lateral direction. The light can be emitted perpendicularly to the back surface of the light body 10.
[0068]
Further, as in the third embodiment, the light reflecting surfaces 42a are not disposed on portions other than the portions where the segment shapes are formed while the light reflecting surfaces 42a are disposed on the back surfaces of both ends of the segment shape.
[0069]
Fifth embodiment
Furthermore, in the first to fourth embodiments described above, a display segment shape is used as the display character, and the light reflecting surface 42a is replaced by a parabola L._{twenty one}, L_{twenty two}Was formed in the same shape as the surface formed when moved in the direction of arrow Y2. However, when a display character showing a high beam or the like is used as the display character, for example, as shown in FIG.₁Parabola L around_{twenty one}It is also conceivable to use a light reflecting surface 42a having the same shape as the surface formed when the lens is rotated.
[0070]
【The invention's effect】
  As explained above, the claims1, 2According to the described invention, if a point light source is arranged at the focal point of the parabola formed by the light reflecting surface, the light incident on the light reflecting surface from the point light source is reflected by the light reflecting surface, and the display light guide It can be emitted almost perpendicularly to the back of the body. In other words, light can be emitted almost perpendicularly to the portion of the display light guide that is not directly in front of the point light source. Thus, a display device can be obtained in which the entire display character formed uniformly emits light.
[0076]
  Also,Claim1According to the described invention, if the light reflecting surface is arranged so that the end of the parabola that forms the light reflecting surface is positioned on the back surface of the end in the longitudinal direction of the segment, the back surface of the end in the longitudinal direction of the segment shape Since the light reflecting surface is not disposed on the back surface other than the portion where the segment shape is formed, the end of the segment shape is not darkened, and the plurality of segments are close to each other. Even if it is arranged, it is possible to obtain a display device in which the light reflecting surfaces corresponding to the segments do not interfere with each other.
[0077]
  Claim2According to the described invention, if the light reflecting surface is arranged so that the end of the parabola that forms the light reflecting surface is positioned on the back surface of the end in the longitudinal direction of the segment, the back surface of the end in the longitudinal direction of the segment shape When a light reflecting surface is placed on the other side of the segment shape, it is not necessary to place the light reflecting surface on any part other than the segment shape, so that the edges of the segment shape do not become dark and more than one segment is placed close to each other Even so, the light reflecting surfaces corresponding to each segment do not interfere with each other. Moreover, since the arbitrary cross section when the light reflecting surface is cut by a plane parallel to the back surface of the display light guide is perpendicular to the longitudinal direction, the point light source emitted toward the longitudinal direction of the segment when viewed from the front After the light from the light is reflected by the light reflecting surface, it is possible to obtain a display device that can be emitted directly in front, that is, perpendicularly to the back surface of the display light guide.
[0081]
  Claim3According to the described invention, if the light reflecting surface is arranged so that the end of the parabola that forms the light reflecting surface is positioned on the back surface of the end in the longitudinal direction of the segment, the back surface of the end in the longitudinal direction of the segment shape When a light reflecting surface is placed on the other side of the segment shape, it is not necessary to place the light reflecting surface on any part other than the segment shape, so that the edges of the segment shape do not become dark and more than one segment is placed close to each other Even so, it is possible to obtain a condensing part in which the light reflecting surfaces corresponding to each segment do not interfere with each other.
[0082]
  Claim4According to the described invention, if the light reflecting surface is arranged so that the end of the parabola that forms the light reflecting surface is positioned on the back surface of the end in the longitudinal direction of the segment, the back surface of the end in the longitudinal direction of the segment shape When a light reflecting surface is placed on the other side of the segment shape, it is not necessary to place the light reflecting surface on any part other than the segment shape, so that the edges of the segment shape do not become dark and more than one segment is placed close to each other Even so, the light reflecting surfaces corresponding to each segment do not interfere with each other. Moreover, since the arbitrary cross section when the light reflecting surface is cut by a plane parallel to the display surface is perpendicular to the longitudinal direction, the light from the point light source emitted toward the longitudinal direction of the segment when viewed from the front is reflected. After the light is reflected by the light reflecting surface, it is possible to obtain a light collecting portion that can be emitted directly in front, that is, perpendicularly to the display surface.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment in which a display of the present invention is applied to a digital speedometer.
FIG. 2 is a perspective view of a condensing light guide 42 in the first embodiment.
3A is a side view of the display light guide 10, the light collection light guide 42, and the LED 20 of FIG. 2, and FIG. 3B is a light collection light guide 42 and the display light guide. 10 is a front view of FIG.
4A is a diagram illustrating X of the light collecting light guide 10 in FIG. 2; FIG.₁-X₁FIG. 4B is a cross-sectional view of a line, and FIG. 4B shows the Z of the condensing light guide 10 of FIG.₁₁-Z₁₁Cross section, Z₁₂-Z₁₂Cross section, Z₁₃-Z₁₃It is sectional drawing.
FIG. 5 is a perspective view of a condensing light guide 42 in a second embodiment.
FIG. 6 is a diagram for explaining a problem that occurs in the first embodiment.
FIG. 7A is a perspective view of the condensing light guide 42 in the third embodiment, and FIG. 7B is a display light guide 10 and the condensing light guide 42 in the third embodiment. FIG.
FIG. 8A is a perspective view of the condensing light guide 42 in the fourth embodiment, and FIG. 8B is a display light guide 10 and the condensing light guide 42 in the fourth embodiment. FIG.
FIG. 9 is a perspective view of a display device according to a fifth embodiment.
FIG. 10 is a diagram illustrating an example of a conventional display device.
FIG. 11 is a diagram illustrating an example of a conventional display device.
[Explanation of symbols]
10 Display light guide
20 LED (point light source)
40 Condenser
41a Through hole
42 Condensing light guide
42a Light reflecting surface
50 Light diffusion plate
60 Shield plate
L_{twenty one}, L_{twenty two}  parabola
L₁        axis

Claims (4)

A display light guide in which the shape of the display character is three-dimensionally formed;
A point light source provided on the back surface of the display light guide;
A light condensing part provided between the point light source and the display light guide and having a parabolic light reflecting surface with a straight line as an axis perpendicular to the back surface of the display light guide ; and
In the display light guide, a segment shape for display is formed as the display character,
The light reflecting surface moves the parabola in a direction perpendicular to a surface formed by the parabola and the axis;
When the movement is performed while continuously changing the inclination of the parabola so that the shape drawn by the end of the parabola substantially matches the shape of the end of the segment in the longitudinal direction by the movement, A display device having the same shape as the surface to be formed . A display light guide in which the shape of the display character is three-dimensionally formed;
A point light source provided on the back surface of the display light guide;
A light condensing part provided between the point light source and the display light guide and having a parabolic light reflecting surface with a straight line as an axis perpendicular to the back surface of the display light guide ; and
In the display light guide, a segment shape for display is formed as the display character,
The light reflecting surface moves the parabola in a direction perpendicular to a surface formed by the parabola and the axis;
When the movement is performed while intermittently changing the inclination of the parabola so that the shape drawn by the end of the parabola substantially matches the shape of the end of the segment in the longitudinal direction by the movement, A display device having the same shape as the surface to be formed . A light collecting unit provided between a display surface on which the segment-shaped portion emits light from the back surface and a point light source disposed on the back surface of the display surface;
Moving the parabola in a direction perpendicular to the plane formed by the parabola and the axis;
Formed when the movement is performed while continuously changing the inclination of the parabola so that the shape drawn by the end of the parabola substantially matches the shape of the segment in the longitudinal direction by the movement. A light condensing unit comprising a light reflecting surface having the same shape as the surface to be formed. A light collecting unit provided between a display surface on which the segment-shaped portion emits light from the back surface and a point light source disposed on the back surface of the display surface;
Moving the parabola in a direction perpendicular to the plane formed by the parabola and the axis;
Formed when the movement is performed while the inclination of the parabola is intermittently changed so that the shape drawn by the end of the parabola substantially matches the shape of the segment in the longitudinal direction by the movement. Condensing part characterized by having the same shape as the surface to be formed.

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