JP2019128537A - Light guide plate display device - Google Patents

Abstract

To provide a light guide plate display device having excellent display functions.SOLUTION: The object of the present invention is a light guide plate display device comprising a light guide plate 1 provided with a plurality of segments 51 and a plurality of light sources 4 arranged on the outer circumferential surface of the light guide plate 1 in correspondence to each segment 51, designed so that corresponding segments 51 are made to emit light by light L irradiated from one of the light sources 4 and entering the inside of the light guide plate 1 and a prescribed display pattern is lighted. When a portion of the outer circumferential surface of the light guide plate 1 where the light L from the light sources 4 enters is assumed as a light entry portion 35 and the other portions are assumed as non-light entry portions 36, at least some of the non-light entry portions 36 is formed on a rugged inclined plane 6 inclined at other than a right angle to the light-emitting plane of the light guide plate 1 and composed of a repetition of protrusions and recesses formed along the outer circumferential edge of the light guide plate 1.SELECTED DRAWING: Figure 2A

Description

  The present invention relates to a light guide plate display device such as a 7-segment display that displays a display pattern using a light guide plate.

  Conventionally, seven segments that can be individually turned on and off are provided, and a display as a 7-segment display that emits and displays a display pattern such as Arabic numerals by lighting some of the seven segments. Light plate displays are well known.

  For example, in the following Patent Document 1, a light guide plate provided with a plurality of segments for forming a display pattern, and a plurality of light sources such as a plurality of LEDs disposed in one-to-one correspondence with each segment at an end face of the light guide plate It has. Further, on the back side of the light guide plate, reflecting means for reflecting light forward is provided corresponding to each segment. Then, a light source corresponding to a specific segment to be light-emitting displayed is turned on, light from the light source is incident on the light guide plate, and the incident light is reflected forward by a reflecting means corresponding to the specific segment. Lights only the segment. In this way, the display pattern is emitted and displayed by causing specific segments to emit light.

JP-A-2017-41386

  In the conventional 7-segment display shown in Patent Document 1 described above, although a large amount of light incident from the light source into the light guide plate is reflected by a specific reflection means to cause a specific segment to emit light, a part of the light is specified Through the reflecting means of the light guide plate to reach the end face of the light guide plate. Furthermore, some of the light reaching the end face of the light guide plate is transmitted through the end face of the light guide plate and radiated to the outside, while the remaining light is reflected by the end face of the light guide plate and travels toward the inside of the light guide plate. In this way, some of the light repeatedly reflected in the light guide plate travels in an unexpected direction in the light guide plate, is reflected by an unexpected appropriate reflecting means, and the unspecified segments are inadvertently blurred. Will emit light. When the non-specific segment emits light in this manner, the contrast of the light emitting portion is weakened, the visibility is lowered, and the display pattern cannot be read. Thus, there is a problem that a good display function cannot be obtained.

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a light guide plate display device such as a 7-segment display device or the like capable of improving the visibility of display patterns and having a good display function. .

  In order to solve the above-mentioned subject, the present invention is provided with the following means.

[1] A light guide plate provided with a plurality of segments, and a plurality of light sources arranged corresponding to each segment on the outer peripheral end surface of the light guide plate. A light guide plate display in which any one of the corresponding segments emits light and the predetermined display pattern is caused to emit light by light incident on the
Of the outer peripheral end surface of the light guide plate, when a portion where light from the light source is incident is a light incident portion, and other portions are non-light incident portions, at least a part of the non-light incident portion is the light guide plate. A light guide plate display device, wherein the light guide plate display device is formed on an inclined inclined surface that is inclined at an angle other than a right angle with respect to the light emitting surface and is repeatedly formed along the outer peripheral edge of the light guide plate.

  [2] The light guide plate display device according to the above item 1, wherein the light guide plate is formed in a substantially rectangular shape in a front view, and both end surfaces thereof are configured as the non-light entrance part.

  [3] The light guide plate display device according to item 1 or 2, wherein an inclination angle of the uneven inclined surface with respect to the light emitting surface is set to 30 ° to 60 °.

  [4] The light guide plate display device according to any one of items 1 to 3, wherein the uneven inclined surface has V-shaped unevenness.

  [5] The light guide plate display device according to [4], wherein an inner angle of a tip of the V-shaped convex portion on the inclined surface is set to 30 ° to 90 °.

  According to the light guide plate display device of the invention [1], the non-light-incident portion on the outer peripheral end surface of the light guide plate is formed by the uneven inclined surface that is inclined with respect to the light emitting surface and has unevenness, and therefore, in the light guide plate. When light that has passed through a predetermined segment of incident light reaches the uneven inclined surface of the outer peripheral end face, the light is reflected or refracted and scattered in various directions by the uneven surface, and in the Z direction by the inclined surface. It will reflect or refract. For this reason, reflection of light returning to the inside of the light guide plate is suppressed, and light is transmitted through the uneven sloped surface and efficiently radiated to the outside of the light guide plate, so unexpected surplus light is generated inside the light guide plate. It is possible to suppress the remaining, and to effectively prevent such a defect that the extra segment emits light due to the surplus light. Therefore, only the desired segment can be reliably emitted, the contrast is enhanced, the visibility can be improved, and a good display function can be obtained.

  According to the light guide plate display devices of the inventions [2] to [5], the above effects can be obtained more reliably.

FIG. 1 is a perspective view for explaining the basic structure of a 7-segment display as an embodiment of the present invention. FIG. 2A is a front view showing the periphery of the front light guide plate in the 7-segment display of the embodiment. FIG. 2B is a front view illustrating the periphery of the rear light guide plate in the seven-segment display according to the embodiment. FIG. 3 is an enlarged view showing the uneven slope of the side end face of the light guide plate of the embodiment. FIG. 4 is a schematic cross-sectional view for explaining an inclination angle of the side end face of the light guide plate according to the embodiment with respect to the light emitting surface, and FIG. 4 (a) is a schematic cross-sectional view around the side end face of the front light guide plate; It is a schematic sectional drawing of the side end surface vicinity of a rear light-guide plate. FIG. 5 is a view for explaining a first modification of the uneven slope in the present invention. FIG. 6 is a view for explaining a second modification of the uneven inclined surface in the present invention. FIG. 7 is a front view for explaining the light projection angle with respect to the side end face of the light guide plate. FIG. 8 is a front view for explaining the problem of the light guide plate as a reference example in which both end faces are formed perpendicular to the light emitting surface. FIG. 9 is a graph showing the relationship between the projection angle with respect to the side end face and the transmittance of the side end face in the light guide plates of Examples 1 to 5 and Comparative Examples 1 and 2. FIG. 10 is a graph showing the relationship between the projection angle with respect to the side end face and the transmittance of the side end face in the light guide plates of Examples 6 and 7. FIG. 11 is a graph showing the relationship between the projection angle with respect to the side end face of the light guide plate of Comparative Examples 3 to 5 and the transmittance of the side end face.

  FIG. 1 is a schematic perspective view for explaining the basic structure of a 7-segment display as a light guide plate display according to an embodiment of the present invention, and FIG. 2A is a front view showing the periphery of a front light guide in the 7-segment display of the embodiment. FIG. 2B is a front view showing the area around the rear light guide plate.

  As shown in these figures, the 7-segment display of the present embodiment is configured to emit and display three display patterns as three-digit numbers, and the front light guide plate 1 disposed so as to overlap in the front and rear direction. And a rear light guide plate 2.

  The 7-segment display of this embodiment has three light-emitting display units 5 for forming three display patterns. Each light-emitting display unit 5 is composed of seven segments 51 having the number “8” form. Of the seven segments 51, three segments 51 extending in the horizontal direction (horizontal axis direction) are formed on the front light guide plate 1, and four segments 51 extending in the vertical direction (vertical axis direction) are formed on the rear light guide plate 2. Is formed.

  Each segment 51 is formed of a fine dot pattern formed on the back surface side of the light guide plates 1 and 2 and is irradiated from a predetermined direction among the light introduced to the light guide plates 1 and 2 as described later. Only the light to be reflected is reflected to the front side so that the segment 51 emits light. In the present embodiment, the reflecting means is constituted by a fine dot pattern constituting the segment 51.

  Each light guide plate 1, 2 has an upper end surface 31, a lower end surface 32, and both side end surfaces 33, and is formed in a substantially rectangular shape in front view.

  A plurality of light incident portions 35 that are inclined with respect to the vertical and horizontal axes of the light guide plates 1 and 2 are formed on the upper end surface 31 of each light guide plate 1 and 2. In each light entrance portion 35, a pair of two LEDs (light emitting diodes) 4 as a light source is disposed via a condenser lens 41. In the present embodiment, a portion other than the light incident portion 35 of the upper end surfaces 31 of the light guide plates 1 and 2 is configured as a non-light incident portion 36.

  Further, also in the lower end face 32 of each of the light guide plates 1 and 2, a plurality of two LEDs 4 are arranged via the condenser lens 41. In the present embodiment, in the lower end face 32 of each of the light guide plates 1 and 2, the portion where the LED 4 and the condensing lens 41 are arranged is configured as the light entrance portion 35, and the other portion is not incident. The light unit 36 is configured.

  Further, in the present embodiment, the light source such as the LED 4 is not disposed on the both side end surfaces 33 of the respective light guide plates 1 and 2, and the entire area of the both side end surfaces 33 is configured as the non-light incident part 36.

  Each of the LEDs 4 is disposed corresponding to the predetermined segment 51, and the light L incident on the light guide plates 1 and 2 when any one of the LEDs 4 is turned on passes through the light guide plates 1 and 2 to be the LED 4 And is reflected forward to cause the corresponding predetermined segment 51 to emit light.

  Therefore, the 7-segment display according to the present embodiment turns on any one of the LEDs 4 to cause any of the segments 51 of the segments 51 constituting the light emitting display unit 5 to emit light, thereby achieving a desired number or a simple symbol. And the like can be displayed in a luminous manner.

  By the way, in the 7-segment display of the present embodiment, which will be described in detail later, the side face 33 is specially processed, whereas in the conventional 7-segment display having a very general configuration, the light guide plate The outer peripheral end surface is configured to be a vertical surface with respect to the front surface (light emitting surface) of the light guide plate. Here, first, a problem when the end face of the light guide plate is formed in a vertical plane will be described.

  That is, as shown in FIG. 8, in the 7-segment display in which both side end surfaces 33 of the light guide plate 1 are formed in a plane perpendicular to the light emitting surface, for example, among the LEDs 4 arranged on the upper end surface 31, the third LED 4 from the left. Corresponds to the upper end segment (upper left end segment) 51 of the leftmost light emitting display section 5, and the light L incident into the light guide plate 1 from the third LED 4 corresponds to the corresponding upper left end segment 51. , And is reflected by the reflecting means to cause the upper left segment 51 to emit light. However, as shown by the broken line in the figure, part of the light L passes through the segment 51 at the upper left end without being reflected by the reflection means, and reaches the side end face 33 of the light guide plate 1. Of the light L that has reached the side end face 33 of the light guide plate 1, part of the light L is transmitted through the end face 33 and emitted to the outside, while the remaining light L is reflected by the end face 33 and the inside of the light guide plate 1 Head for. Further, a part of the light L going inward is reflected by the other end face of the light guide plate 1 and goes to the inside of the light guide plate 1. As described above, the light L repeatedly reflected inside the light guide plate 1 travels in an unexpected direction, and is reflected by an unexpected appropriate reflecting means to cause the non-specific segment 51 to emit light. As a result, the contrast between the segment 51 scheduled to emit light and the segment 51 that emits light unexpectedly becomes weak, the visibility is lowered, and the display pattern cannot be read. .

  Therefore, in the present embodiment, the excess light L remaining inside the light guide plates 1 and 2 is not reflected by the end faces of the light guide plates 1 and 2 using the means described below. A good display mechanism can be secured by smoothly radiating to the outside.

  That is, as shown in FIG. 2A, FIG. 2B and FIG. 3, in the light guide plates 1 and 2 of the present embodiment, both end surfaces 33 of the non-light entrance portion 36 are formed on the uneven sloped surface 6. The uneven inclined surface 6 is formed at a knurled surface which is inclined at an angle other than the right angle with respect to the light emitting surfaces (front surfaces) of the light guide plates 1 and 2 and in which the unevenness is repeatedly formed along the side edges. .

  In the present embodiment, as shown in FIGS. 4 (a) and 4 (b), the side end face 33 of the front light guide plate 1 is formed into an inclined surface which is inclined toward the rear light guide plate 2 as shown in FIG. The side end surfaces 33 of the rear light guide plate 2 are formed on inclined surfaces that are inclined toward the front light guide plate 1 and are disposed so as to face each other.

  Here, in the present embodiment, the angle of the side end surface 33 of the light guide plates 1 and 2 with respect to the light emitting surface (front surface) is referred to as the inclination angle θ1 of the uneven inclined surface 6 (end surface). The inclination angle θ1 is displayed as an acute angle. For example, as shown in FIG. 4A, the inclination angle θ1 in the front light guide plate 1 is defined by the inner angle between the side end face 33 and the light emitting face (front face). 4B, the inclination angle θ1 in the rear light guide plate 2 is defined by the outer angle between the side end face and the light emitting face (front face).

  In this embodiment, it is preferable to set the inclination angle θ1 of the light guide plates 1 and 2 to 30 ° to 60 °. When the inclination angle θ1 is set within the above preferable range, when the light L in the light guide plates 1 and 2 reaches the side end face 33, a large amount of light L may be transmitted to the outside As a result, it is possible to suppress the remaining light L from remaining in the light guide plates 1 and 2 and to reliably obtain a good display function. In other words, when the inclination angle θ1 is too large or too small, when the light L in the light guide plates 1 and 2 reaches the side end surface 33, the light L can be sufficiently transmitted to the end surface of the light guide plate. It is impossible to reflect the light L internally, and it becomes difficult to efficiently radiate the excess light L to the outside of the light guide plates 1 and 2, and it may be difficult to obtain a good display function.

  Moreover, in this embodiment, the uneven | corrugated inclined surface 6 in the side end surface 33 of the light-guide plates 1 and 2 is formed in the knurled surface by which unevenness | corrugations were repeatedly formed along the outer periphery, such as a jagged shape, a saw blade shape, and a gear tooth shape. ing.

  In the present embodiment, the unevenness is repeatedly formed along both side edges, because the concave and convex portions are alternately arranged along the direction (vertical direction or vertical axis direction) in which both side edges of the side surface 33 extend. It means that it is formed repeatedly.

  In the present invention, as will be described later, in the case of the non-light-incident part 36, the uneven inclined surface 6 can be formed in addition to the side end surfaces 33. For example, the uneven inclined surface 6 can be formed also on the non-light incident portion 36 of the upper end surface 31 and the lower end surface 32 of the light guide plates 1 and 2, and in this case, the upper end edge and the lower end edge Concave portions and convex portions are alternately and repeatedly formed in the direction in which the edge and the lower end edge extend (left-right direction or horizontal axis direction).

  Further, as shown in FIG. 3, in the present embodiment, the concave portion and the convex portion constituting the concave and convex inclined surface 6 are formed into a V-shaped convex portion and a V-shaped concave portion, and the concave and convex inclined surface 6 is a so-called V-shaped It is formed on the knurled surface (V-shaped surface).

  Here, in the present embodiment, the inner angle θ2 (the opening angle of the bottom of the V-shaped concave portion) of the tip of the V-shaped convex portion on the light guide plate end face 33 is preferably set to 30 ° to 90 °, more preferably It is preferable to set about 50 to 70 degrees. Further, in the present embodiment, it is preferable to set an interval (knurling pitch) P between valley bottoms of adjacent concave portions in the uneven slope surface 6 of the light guide plate side end face 33 to 5 mm to 20 mm. When the above-mentioned internal angle θ2 and the knurling pitch P are set within the above-mentioned preferred range, when the light L in the light guide plates 1 and 2 reaches the side end face 33, the light L is sufficiently outside. It can be made to transmit, the repetition of light reflection in the light guide plates 1 and 2 can be suppressed, and a good display function can be surely obtained. In other words, when the inner angle θ2 and the knurled pitch P are too large or too small, the light L is sufficiently transmitted to the outside when the light L in the light guide plates 1 and 2 reaches the side end face 33. It is difficult to sufficiently emit the excess light L to the outside of the light guide plates 1 and 2 and it may be difficult to obtain a good display function.

  In the present embodiment, the case where the side end surfaces 33 of the light guide plates 1 and 2 are formed on the V-shaped knurled surface (V-shaped uneven surface) has been described as an example. However, the present invention is not limited thereto, and the present invention is not limited thereto. The uneven shape of the knurled surface is not particularly limited. For example, as shown in FIG. 5, the uneven shape of the knurled surface may be a convex circle shape (convex circular knurl surface) formed by arranging semicircular convex portions, or an uneven shape of the knurled surface as shown in FIG. 6. It may be made to form in the shape of a concave circle (concave circle knurl surface) in which semicircular concave portions are formed side by side.

  In the 7-segment display of the present embodiment configured as described above, both end surfaces 33 of the light guide plates 1 and 2 are formed by the uneven inclined surface (inclined knurled surface) 6 which is an inclined surface that is knurled. Therefore, as is apparent from the examples described later, when the light L in the light guide plates 1 and 2 reaches the side end surface 33, the direction of the light L varies depending on the uneven surface (knurled surface) on the side end surface 33. The light is reflected or refracted and scattered, and is reflected or refracted in the Z direction (light guide plate thickness direction) by the inclined surface of the side end face 33. For this reason, the reflection of the light L returning to the inside of the light guide plates 1 and 2 is suppressed, and the light L is transmitted through the side end face 33 toward the Z direction and efficiently radiated to the outside of the light guide plate. Therefore, it is possible to suppress the unexpected surplus light L from remaining in the light guide plates 1 and 2, and to effectively prevent a problem in which an unspecified segment 51 emits light due to the surplus light L. it can. As a result, only the desired segment 51 can be reliably emitted, the contrast is enhanced, the visibility is improved, the display pattern can be read reliably, and a good display function can be obtained.

  Further, in the seven-segment display of the present embodiment, since the light reflection in the light guide plates 1 and 2 is suppressed by processing the shape of the end face of the light guide plate, a process of manufacturing the light guide plates 1 and 2 The processing for suppressing light reflection in the light guide plates 1 and 2 can be performed at the same time in the same process. That is, in the 7-segment display of this embodiment, in order to suppress light reflection in the light guide plates 1 and 2, new processing such as absorbing light by the end surfaces of the light guide plates 1 and 2, for example, light guide plate end surfaces It does not apply black paint or paste black tape. For this reason, in the seven-segment display of this embodiment, there is no need to separately perform processing for suppressing light reflection in the light guide plates 1 and 2. Therefore, the number of processing can be reduced by that amount, and productivity is improved. Improve and reduce costs.

  In the above embodiment, although the case where the light guide plate display device of the present invention is applied to a 7-segment display is described as an example, in the case of a display device using a light guide plate, 7 segment display Even displays other than the display can be applied. For example, the present invention can also be applied to a light guide plate display device such as a segment display having 6 or less segments or 8 or more segments.

  Moreover, in the said embodiment, although the both-sides end surface 33 of the light-guide plates 1 and 2 demonstrated as an example the case where it forms in the inclined knurl surface (uneven | corrugated inclined surface) 6 peculiar to this invention, in this invention, The location formed on the uneven slope 6 is not limited to both end faces. In the present invention, among the outer peripheral end faces of the light guide plates 1 and 2, any position may be formed on the uneven sloped surface as long as the light non-entering part 36 where the light source (LED 4) is not disposed. For example, portions other than the light entrance portion 35 in the upper end surface of the light guide plates 1 and 2 (non-light entrance portion 36), and portions other than the light entrance portion 35 in the lower end surface of the light guide plates 1 and 2 (non-light entrance portion 36) Alternatively, it may be formed on an uneven inclined surface. The point is that at least a part of the non-light entrance portions of the outer peripheral end faces of the light guide plates 1 and 2 may be formed on the uneven sloped surface 6.

  In the present invention, the light incident portion 35 of the outer peripheral end faces of the light guide plates 1 and 2 does not necessarily have to be formed in a vertical plane perpendicular to the light emitting surface, and is formed in an inclined surface inclined with respect to the light emitting surface. You may do so. In the case of an inclined surface, it is preferable to set the inclination angle (see θ1 in FIGS. 4A and 4B) to 30 ° to 60 ° so that light from the light source can be efficiently incident. .

  In order to prove the effect of the present invention, an example including the gist of the present invention and a comparative example deviating from the gist of the present invention were performed by computer simulation as described below.

Example 1
As shown in Table 1, the light guide plate of Example 1 was prepared based on the front light guide plate 1 shown in the above embodiment. In the light guide plate of the first embodiment, the uneven inclined surface 6 as the side end surface 33 is formed on a V-shaped knurl surface having an inclination angle θ1 of 60 °. The internal angle θ2 of the tip convex portion on the V-shaped knurled surface was set to 60 °, and the knurling pitch P was set to 10 mm.

  In the light guide plate of Example 1 having this configuration, the relationship between the projection angle α of the light L with respect to the side end face 33 in the light guide plate, the transmittance at the side end face 33 and the reflectance (reflectance = 100−transmittance) Was measured. The measurement results are shown in Table 2.

  Further, as shown in FIG. 8, the projection angle α is an angle with respect to the normal line (vertical line) of the side end surface 33 in the light L directed to the side end surface 33 inside the light guide plate 1. Furthermore, the transmittance and the reflectance are the transmittance and the reflectance transmitted in the Z direction (light guide plate thickness direction) at the side end surface 33.

Examples 2 to 5
As shown in Table 1, the inclination angle θ1 of the side end face 33 is set to 50 ° in the second embodiment, 45 ° in the third embodiment, and 40 ° in the fourth embodiment, and 30 ° in the fifth embodiment. In the following, in the same light guide plate as in Example 1, the relationship between the projection angle α and the transmittance and reflectance was measured. The measurement results are shown in Table 2.

  <Comparative Example 1>

  As shown in Table 1, the relationship between the projection angle α, the transmittance, and the reflectance in the flat surface in which the side end surface 33 is vertical, that is, in the light guide plate that has the inclination angle θ1 of 90 ° and is not knurled. Was measured. The measurement results are shown in Table 3.

Comparative Example 2
As shown in Table 1, in the light guide plate with the side end face being vertical (inclination angle θ1 = 90 °) and V-shaped knurling similar to that in Example 1, the projection angle α, the transmittance, and the reflection are the same as described above. The relationship with the rate was measured. The measurement results are shown in Table 3.

  FIG. 9 is a graph showing the measurement results of Examples 1 to 5 and Comparative Examples 1 and 2 described above. In this graph, the results of Examples 1 to 5 are indicated by solid lines, the result of Comparative Example 1 is indicated by broken lines, and the result of Comparative Example 2 is indicated by two-dot chain lines.

  As shown in the graph of FIG. 9 and Table 2, in the light guide plates of Examples 1 to 5 including the gist of the present invention, the projection angle α gradually decreases from 55 ° onward, but the projection decreases. Since the influence by the angle α is small and the transmittance is high as a whole (because the reflectance is low), the surplus light L in the light guide plate can be efficiently radiated to the outside of the light guide plate. Therefore, it is possible to prevent light emission from the unspecified segment due to the excessive light L, and to obtain a good display function.

  On the other hand, as shown in the graph of FIG. 9 and Table 3, in the light guide plate of Comparative Example 1 in which the side end face is perpendicular, the transmittance is high up to around 40 ° of the projection angle α, but after that The rate is extremely low. Thus, compared with the light guide plates of Examples 1 to 5, in the light guide plate of Comparative Example 1, the transmittance is high only in the limited range of the projection angle α, and the transmittance as a whole is low ( It is difficult to efficiently radiate excess light L in the light guide plate to the outside of the light guide plate.

  Further, in the light guide plate of Comparative Example 2 in which the side end surface is vertical and formed on the V-shaped knurled surface, the transmittance is extremely low in a portion where the projection angle α is lower than around 25 ° or a portion where the projection angle α exceeds 40 °. It is low. Thus, as compared with the light guide plate of Examples 1 to 5, in the light guide plate of Comparative Example 2, the transmittance as a whole is lower as in Comparative Example 1, and excess light L in the light guide plate is a light guide plate. It is difficult to radiate efficiently to the outside of the

  <Examples 6 and 7>

  As shown in Table 1, the light guide plate in which the side end face 33 is formed on a convex knurl surface (see FIG. 5) having an inclination angle θ1 = 60 ° is used as the light guide plate of Example 6, and in the light guide plate, the projection angle α The relationship between the transmittance and the reflectance was measured. The measurement results are shown in Table 4.

  The light guide plate in which the side end face 33 is formed on the concave knurl surface (see FIG. 6) having an inclination angle θ1 = 60 ° is used as the light guide plate of Example 7, and in the light guide plate, the projection angle α, the transmittance and the reflection are obtained. The relationship with the rate was measured. The measurement results are shown in Table 4.

  FIG. 10 is a graph showing the measurement results of the sixth and seventh embodiments. As shown in this graph and Table 4, in the light guide plates of Examples 6 and 7, as in the light guide plates of Examples 1 to 5 shown in the graph of FIG. Excessive light L in the light plate can be efficiently emitted outside the light guide plate.

  <Comparative Examples 3 to 5>

  As shown in Table 1, the light guide plate (without knurling) in which the inclination angle θ1 of the side end face 33 is set to 60 ° is used as the light guide plate of Comparative Example 3, and the inclination angle θ1 of the side end face 33 is set to 45 °. The light guide plate (without knurling) as the light guide plate of Comparative Example 4, and the light guide plate (without knurling) with the inclination angle θ1 of the side end face 33 set to 30 ° as the light guide plate of Comparative Example 5, In the optical plate, the relationship between the projection angle α, the transmittance, and the reflectance was measured. Each measurement result is shown in Table 5.

  FIG. 11 is a graph showing the measurement results of Comparative Examples 3 to 5 described above. As shown in this graph, in the light guide plate in which the side end face 33 is inclined and is not knurled as in Comparative Examples 3 to 5, the side end face 33 is not knurled as in Comparative Example 1 above. In substantially the same manner as the light guide plate of Comparative Example 1 formed in the vertical plane of the above, the transmittance is extremely low in the portion where the projection angle α exceeds 30 to 40 °. That is, it is difficult to efficiently radiate the excessive light L in the light guide plate to the outside of the light guide plate only by inclining the side end face 33.

  As apparent from the above embodiments, in the light guide plate (light guide plate display device) according to the first to seventh embodiments including the gist of the present invention, the excess light L in the light guide plate is efficiently transmitted to the outside of the light guide plate. It is possible to emit light, and it is possible to reliably emit light only in a predetermined segment, improve visibility, and obtain a good display function.

  The light guide plate display device of the present invention can be suitably used as a 7-segment display for emitting and displaying Arabic numerals and the like.

1, 2: light guide plate 31: upper end face (peripheral end face)
32: Lower end face (peripheral end face)
33: Side end face (peripheral end face)
35: Light entrance 36: Non-light entrance 4: LED (light source)
51: Segment 6: uneven slope L: light θ1: angle of inclination

Claims (5)

A light guide plate provided with a plurality of segments, and a plurality of light sources arranged corresponding to each segment on the outer peripheral end surface of the light guide plate, are irradiated from one of the light sources and enter the light guide plate A light guide plate display device, wherein light causes any one of the corresponding segments to emit light and cause a predetermined display pattern to emit light.
At least a part of the non-light-entering part is the light-guiding plate, where a part of the outer peripheral end face of the light-guiding plate where the light from the light source is incident is a light-incidence part. A light guide plate display device, wherein the light guide plate display device is formed on an inclined inclined surface that is inclined at an angle other than a right angle with respect to the light emitting surface and is repeatedly formed along the outer peripheral edge of the light guide plate.   The light guide plate display device according to claim 1, wherein the light guide plate is formed in a substantially rectangular shape in a front view, and both end surfaces thereof are configured as the non-light entrance part.   The light guide plate display device according to claim 1, wherein an inclination angle of the uneven inclined surface with respect to the light emitting surface is set to 30 ° to 60 °.   The light guide plate display device according to any one of claims 1 to 3, wherein the uneven sloped surface has a V-shaped unevenness. 5. The light guide plate display device according to claim 4, wherein an inner angle of a tip of the V-shaped convex portion in the uneven inclined surface is set to 30 ° to 90 °.

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