JP5316437B2 - Dot formation order determination method - Google Patents

Description

  The present invention provides a dot formation in which a specified number of dots exist in an area of a predetermined size, dots are dispersed in the area, and additional dots can be inserted later. More particularly, the present invention relates to a dot formation order determination method in the case where a light guide plate forming a planar light emitter is divided into a large number of regions and dots are formed in these regions.

  Specifically, the present invention is arranged on the back surface of a dial of a vehicle instrument, and is suitable for additional processing of a dot composed of a recess that reflects light in a light guide plate that illuminates and transmits numbers on the dial. The present invention relates to a formation order determination method.

  Patent Documents 1 and 2 are known as conventional techniques. Patent Document 1 discloses a planar light emitting body that emits light from a chip of a light emitting diode serving as a point light source such as a liquid crystal backlight in a planar shape, and one radiation surface of a light guide plate on which light from the light emitting diode is incident. The light is emitted in a planar shape from the whole.

  The light guide plate disclosed in Patent Document 1 has a large number of dots on the reflection surface on the back surface, and these dots form a light diffusion pattern. Then, it is intended to obtain a device capable of uniformly emitting light from the light emitting surface by solving the problem that bright lines are generated due to the deficient dot arrangement of the light diffusion pattern.

  Therefore, in the configuration of Patent Document 1, the light guide plate has a radiation surface and a reflection surface facing each other, and light from a point light source provided on one end surface of the light guide plate is uniformly emitted from the radiation surface. Innumerable dots are formed on the reflecting surface.

  In Patent Document 1, a band-like region having a constant dot distribution density is formed. Further, the distribution density of the dots in the band-like region is set so as to sequentially increase by a certain amount as the distance from the light source increases according to the attenuation amount of light incident from the point light source.

  And between two adjacent strip-shaped regions, the vertical line formed by the dots in one strip-shaped region and the vertical line formed by the dots in the other strip-shaped region do not constitute one straight line. In addition, dots are arranged.

  Since the dots are arranged so as not to form one straight line as described above, the vertical lines do not form a straight line over a long distance, and it is possible to prevent the occurrence of a problem bright line. Therefore, uniform light emission from the light emitting surface is possible, and generation of bright lines can be suppressed. However, this Patent Document 1 does not describe anything about correcting a portion where the light emission state is not uniform after the light guide plate is manufactured.

  On the other hand, Patent Document 2 is a method of manufacturing a light guide plate that can obtain high luminance uniformity and appearance, and has an initial prototype process for forming a plurality of initial dots on a reflective surface. In addition, at least one optical characteristic of the appearance is inspected, and if the predetermined optical characteristic is not satisfied, an additional dot is formed in the area that causes the deterioration of the optical characteristic. Process.

  This additional process is repeated until a predetermined optical characteristic is satisfied. Further, in the additional process, additional dots having a smaller diameter and a shallower depth than the peripheral dots formed in the previous process are additionally formed. However, in Patent Document 2, there is a restriction that an additional dot having a smaller diameter and a shallower depth than the previous process must be employed.

Japanese Patent No. 398560 JP 2008-311090 A

  Here, utilizing the techniques of Patent Document 1 and Patent Document 2, the inventor considered completing a vehicle instrument. The above-mentioned vehicular instrument, which is not yet known, guides light from a pair of left and right light emitting diodes serving as a point light source to an inverted U-shaped light guide plate made of acrylic resin, and emits the light guide plate in a planar shape to emit light in a planar manner. A dial is placed on top of the planar light emitter, and the light from the planar light emitter is made visible to the driver via the dial, and the letters on the dial are raised by transmitted illumination. It is.

  The light guide plate that constitutes the planar light emitter of the vehicle instrument reflects light in a right angle direction while light from the light emitting diode existing on one end side enters the planar direction of the planar light emitter. And have to enter the driver ’s view. For this reason, it is necessary to form dots composed of numerous depressions or dimples on the reflection surface of the light guide plate.

  The outline of the light guide plate forming the planar light emitter in the process of completing the present invention will be described below with reference to FIGS. FIG. 21 is a schematic plan view of the light guide plate 2 in the development process. Light from the light emitting diodes 3 and 4 travels in the light guide plate 2 forming the planar light emitter 1 as indicated by arrows A5 and A6, is reflected on the back surface, and is emitted from the front surface. FIG. 22 is a partial cross-sectional view of the light guide plate of FIG. 21 viewed from the direction of arrow A22.

  In FIG. 22, innumerable dots 6 formed on the reflective surface that is the back surface of the light guide plate 2 are formed on the light guide plate 2 as having a certain size in consideration of ease of processing. As the density of 6, that is, the number of dots 6 per unit area is larger, the action of reflecting the light entering in the plane direction and entering the driver's field of view as light in the direction of arrow A 7 is stronger. The other end of the light guide plate 2 on the side of the light emitting diodes 3 and 4, that is, the upper part of FIG. 21 farther from the root where the light source exists must have a higher density of dots 6.

  For this purpose, the inventors divide the surface of the light guide plate 2 into a plurality of areas of, for example, 4 mm square, and determine the number of dots 6 to be formed in each of these areas by computer simulation. The number of dots 6 is considered to be regularly formed in each region.

  FIG. 23 is an explanatory diagram showing the arrangement of the dots 6 in the region 15 in the light guide plate 2 prototyped by the inventors during the development process (unknown) of the present invention. Part (a) of FIG. 23 shows a state in which the light guide plate 2 is partitioned into a large number of regions 15. Part (b) is obtained by aligning dots along the horizontal arrow and the vertical arrow in the nine specific areas 15 among the large number of areas 15, and as a result, the area E1 has a higher density than the area E1. It shows that a small area E2 exists.

  The part (c) in FIG. 23 specifies the number of dots 6 in nine areas. As shown in part (b) of FIG. 23, in the region E1 having a high density, the dots 6 are arranged so densely and regularly that no more dots 6 can be formed.

  Further, in the region E2 portion where the density of the dots 6 is small, for example, 3 × 5, that is, 15 dots 6 are formed in one region 15 of 4 mm square. Although not shown in FIG. 23, the region having the minimum dot density indicates that the dot 6 has zero regions in the region.

  After the shape and dimensions of the dial and the instrument having the light guide plate 2 are determined, a state in which the light from the light emitting diodes 3 and 4 in FIG. The number of dots 6 in each region, that is, the density is determined, and an injection mold made of a metal plate on which the dots 6 are formed is formed based on the density of the dots 6.

  At this time, the metal mold sequentially presses the same cutting tool having a protrusion with a round tip against the surface of the metal plate innumerably to form a dot forming protrusion.

  In this way, a mold in which the density difference of the dots 6 is different for each partitioned area is completed. Next, using this mold, acrylic resin is injection-molded to produce a light guide plate 2 made of transparent resin. The light guide plate 2 is transferred with a projection for forming a dot of a mold. Then, with the reflective surface on which the dots 6 of the light guide plate 2 are formed on the back side, a dial is attached to the front side that is the light emitting surface to form a vehicle instrument.

  In the vehicle instrument thus formed, when the light emitting diodes 3 and 4 are turned on and the light emission state is inspected, there is a light emitting region that cannot be satisfied by the result of the computer simulation. That is, an area where the luminance is low and it is better to further process the dots 6 is found.

  However, in the dot 6 formation method employed in the development stage of the present invention, since the dots 6 are regularly arranged, a region where the dots 6 cannot be formed any more is formed as shown in FIG. 23B. E1 etc. exist. If the dots 6 are forcibly added to the area E1 or the like where the density is high, the dots 6 overlap each other, the light emission state deteriorates, and uniform light emission is not achieved.

  As described above, in the dot arrangement of the light guide plate 2, when the dots 6 are arranged without considering the space of the additional dots 6, if the luminance unevenness occurs, the dots 6 cannot be added later, and the luminance unevenness etc. There was a problem that could not be fixed. There is also a problem that it is difficult to set the number of dots 6 in the region to the designated number.

  For this reason, the present invention relates to a dot having a specified number of dots in a predetermined size area, dots dispersed in the area, and additional dots that can be easily inserted later. It is an object of the present invention to provide a formation order determination method.

  Descriptions of patent documents listed as prior art can be introduced or incorporated by reference as explanations of technical elements described in this specification.

  In order to achieve the above object, the present invention employs the following technical means. That is, according to the first aspect of the present invention, in the quadrangular region where dots are formed on the light guide plate, the dot forming position and order are set, and the coordinate system is set in the region to grid the region. From the pattern in which dots are arranged in all of the small areas that form the respective lattice portions, and the staggered arrangement of dots is thinned out to determine the staggered arrangement pattern, and further from the staggered arrangement pattern A grid-like arrangement step of decimating the arrangement of dots in a grid to determine a grid-like arrangement pattern, and further deciding the arrangement of dots in a zigzag from the grid-like arrangement pattern to determine a zigzag-like arrangement pattern again. A staggered arrangement step, a grid arrangement step and a staggered arrangement step are repeated to determine a single dot to be left last, and a repetition step. It is from a determined dot, characterized in that it comprises a sequence imparting step of imparting order to the dot in the order following the thinning reversed in each of the staggered steps and grid arrangement step by.

  According to the present invention, the staggered arrangement pattern is determined from the pattern in which all dots are arranged, then the lattice-like arrangement pattern is determined, and the staggered arrangement pattern is determined again, and the region is repeated. The dot formation position and the order in which the dots are formed are determined, and according to this determination method, a gap for inserting additional dots can be formed between the dots, and the light emitting state having a desired brightness and a uniform light emission state can be formed. The area of the light plate can be set.

The invention according to claim 2 is a method for setting a dot formation position and order in a quadrangular region where dots are formed on a light guide plate, wherein a plurality of lattice coordinate systems are set in one region. And a pattern in which dots are arranged in all of at least 169 small areas which are each lattice portion of the lattice coordinate system, and dot arrangement is thinned out in a staggered manner to obtain at least 85 staggered arrangement patterns. a step of determining, by thinning out the arrangement of further dots in a grid pattern from staggered arrangement pattern, a lattice-like arrangement determining at least 49 of the grid-shaped arrangement pattern from the grid-like arrangement pattern, further staggered A staggered arrangement step for deciding at least 25 staggered arrangement patterns by thinning out the dot arrangement, and a lattice arrangement step and a staggered arrangement step. The dot thinning is repeated until the number of dots arranged is at least nine, at least five, or one, and the dot arrangement is thinned to determine a single dot arrangement pattern at the center of the area. Contrary to the step and single dot arrangement pattern, the pattern is arranged in order from the dot arrangement pattern to all the small areas, increasing the number of dots in the dot arrangement pattern and assigning the dot arrangement order. It is characterized by including an order giving step.

  According to the present invention, from a pattern in which dots are arranged in all of at least 169 small regions, at least 85 staggered arrangement patterns, at least 49 grid arrangement patterns, and at least 25 zigzag arrangements In the area having at least 169 small areas, the arrangement position of dots is determined as a pattern, at least 5 patterns, and the order of dot arrangement is assigned in the reverse order of the determined order. The dot formation position and the order of formation are determined, and according to this determination method, a gap for inserting additional dots can be made between the dots, and the light guide plate has a uniform light emission state at a desired brightness Can be set.

  According to a third aspect of the present invention, the light guide plate is made of a transparent member, the region is formed of one of a plurality of square regions formed in the light guide plate, and the dots reflect light passing through the light guide plate. And a recess formed on the back surface of the transparent member that leads to the surface of the light guide plate.

  According to this invention, the light that passes through the light guide plate is reflected by the dots formed on the back surface of the transparent member, and the light guide plate in which a plurality of regions are formed can emit light uniformly and in a planar shape. it can.

In the invention of claim 4, the coordinate system consists of an orthogonal coordinate system, the orthogonal coordinate system, it defines a region in a lattice pattern, as characterized by consisting of a collection of small areas which dots are formed in the central Yes.

According to the present invention, the coordinate system consists of an orthogonal coordinate system, the orthogonal coordinate system, defines a region in a lattice pattern, dots because consists of a set of small area formed in the center, to form additional dot It is easy to specify an area and easily adjust the brightness for each area.

  In the invention according to claim 5, the coordinate system has an X-axis and a Y-axis, and the dot arrangement is thinned out along a plurality of lines intersecting both the X-axis and the Y-axis. The thinning out of the dot arrangement in a grid pattern is characterized by thinning out along a plurality of lines extending in the X-axis or Y-axis direction.

  According to the present invention, the staggered dot arrangement is left by thinning into a plurality of lines intersecting both the X axis and the Y axis, and the plurality of lines extending in the X axis or Y axis direction are thinned out. From this, it is possible to leave a grid-like dot arrangement, and by repeating these, the dot formation position and order can be determined.

It is a front view of the dial of the speedometer as a vehicle meter in one embodiment of the present invention. It is a typical partial expanded sectional view of the speedometer seen from the arrow A2-A2 direction of FIG. It is typical sectional drawing of the speedometer seen from the arrow A3 direction of FIG. It is the front view which has arrange | positioned the light-guide plate on the case of the said speedometer. It is the front view which piled up the dial on the light-guide plate of FIG. It is a flowchart of the simulation using the computer in the said embodiment. It is a dot arrangement | positioning figure which shows the state which divided the metal mold | die for forming the light-guide plate used for the said one embodiment into many area | regions, and divided one of these area | regions into the grid | lattice-like small area | region further. FIG. 8 is a dot arrangement diagram showing a state in which the dot arrangement small areas are thinned out from the arrangement of FIG. 7 and the remaining small areas are changed to a staggered dot arrangement small area. FIG. 10 is a dot arrangement diagram in which rows are thinned out every other row from the staggered arrangement of FIG. 8 to determine a grid-like dot arrangement position with gaps in the vertical and horizontal directions. FIG. 10 is a dot arrangement diagram in which a staggered arrangement is made as a whole by thinning out one by one while shifting the position in the column direction and the row direction from the lattice arrangement of FIG. FIG. 11 is a dot arrangement diagram in which a row in which dots are arranged is thinned out from the staggered arrangement in FIG. 10 to form a lattice arrangement. FIG. 12 is a dot arrangement diagram in which the dot formation positions are thinned out from the lattice arrangement of FIG. 11 to form a staggered arrangement. FIG. 12 is a dot arrangement diagram in which a single dot arrangement is obtained by thinning out one row in which dots are arranged from the staggered arrangement of FIG. 11. FIG. 14 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG. 13. FIG. 13 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG. 12. FIG. 12 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG. 11. FIG. 11 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG. 10. FIG. 10 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG. 9. FIG. 9 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG. 8. FIG. 8 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG. 7. It is a typical top view of the light-guide plate in the said development process (unknown). It is the partial cross section figure seen from the arrow A22 direction of the light-guide plate of FIG. It is explanatory drawing which shows the arrangement | sequence of the dot in the area | region in the light-guide plate which an inventor made as an experiment in the said development process.

(One embodiment)
Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 is a front view of a dial of a speedometer as a vehicle instrument that constitutes an embodiment of the present invention. FIG. 2 is a schematic partially enlarged cross-sectional view of the speedometer viewed from the direction of arrows A2-A2 in FIG.

  FIG. 3 is a schematic cross-sectional view of the speedometer viewed from the direction of arrow A3 in FIG. FIG. 4 is a front view in which a light guide plate is disposed on the case of the speedometer. FIG. 5 is a front view of the dial plate 7 superimposed on the light guide plate 2 of FIG. 1 to 5, the speedometer has light emitting diodes 3 and 4 fixed to a case 8 at one end of an inverted U-shaped light guide plate 2 constituting the planar light emitter 1 of FIG. Yes.

  The light from the point light sources of the light emitting diodes 3 and 4 is guided into the transparent light guide plate 2 made of acrylic resin as indicated by arrows A5 and A6 in FIG. The dots 6 (each of which is, for example, a hemispherical depression and may be called a dimple) reflect light to cause the entire light guide plate 2 to emit light in a planar shape. Then, a vehicular instrument in which a character plate 7 in which characters and numerical parts are formed of a transparent portion is superimposed on the surface of the planar light-emitting body 1 (FIG. 2) having the light guide plate 2 so that the characters and numerical parts are transmitted and illuminated. Is configured.

  4 in FIG. 4 is a case having a printed circuit board to which the light emitting diodes 3 and 4 are attached, and 9 in FIG. 3 is a pointer. In the vehicle instrument thus formed, it is desirable that the light guide plate 2 emits light uniformly by the light emitting diodes 3 and 4.

  For this purpose, the number of dots 6 in FIG. 3 to be formed in each of the 4 mm square regions of the light guide plate 2 is simulated in advance by a computer, and the unit area of the light guide plate 2 is determined. The density of dots 6, which is the number of dots 6, is determined for each of a plurality of regions on the light guide plate 2.

  That is, as shown in FIG. 23, the light guide plate 2 is divided for each 4 mm square region 15, and the light reflection from the reflecting surface is adjusted by the difference in the number of dots 6 for each region 15. The light is emitted uniformly from the radiation surface.

  The computer simulation is executed using commercially available software. FIG. 6 is a flowchart of the simulation. In FIG. 6, after dividing the region 15 to be analyzed in step S1 into a grid pattern by the orthogonal coordinate system, in step S2, dots 6 are arranged in each region 15 at the maximum density (169 / each region 15) as an initial condition. In step S3, a simulation of illumination is executed to obtain a target luminance.

  Next, in steps S4 and S5, an illumination simulation is automatically repeated while increasing or decreasing the number of dots 6 so as to approach the target luminance. In step S6, a solution having a minimum residual with the target luminance is obtained. Thereby, the optimum number of dots 6 is obtained for each region 15.

  And since this light-guide plate 2 is an injection molded product which consists of transparent acrylic resin and has the dot 6 which consists of an infinite number of hollows, the metal mold | die for a shaping | molding is not required. On the surface of the metal plate constituting the mold, there is a dot forming portion made of protrusions having a predetermined density as described above. That is, the mold has a projection-like dot forming portion on the contrary to the dots 6 of the light guide plate 2 made of depressions or dimples.

  This protrusion-shaped dot forming portion is formed by pressing the same cutting tool with a rounded tip on the surface of a thin metal plate that becomes a mold one after another using a numerical control device, and raising the surface of the metal plate. Dot forming portions are formed one after another. When the molten acrylic resin is poured into the completed mold, the dots 6 formed by the depressions of the light guide plate 2 are injection-molded corresponding to the countless dot-forming portions of the mold.

  In this case, if the dot forming portions are randomly processed on the mold or the dot forming portions are processed regularly in order from the end portion, the positions of the dots 6 are too biased as described in the development process. In some cases, the dots 6 are too dense to process the additional dot forming portion later.

  For this reason, in this embodiment, the position of the dot forming portion is formed based on a predetermined rule. This will be described below.

  In FIG. 7, the surface of the mold for forming the light guide plate 2 used in the above embodiment is partitioned into a large number of 4 mm square regions 15, and one of these regions 15 is further 13 × 13. = 169 is a dot arrangement diagram showing a state of being divided into 169 lattice-shaped square small regions 21.

  In FIG. 7, a plurality of small regions 21 are formed on the surface of a mold to be manufactured or a light guide plate mass-produced with the mold, but instead of actually drawing vertical and horizontal lines as shown in FIG. An orthogonal coordinate system is set so that the positions of the plurality of small regions 21 are determined on the surface.

  That is, the vertical line 22 and the horizontal line 23 that form lines that intersect with each other in a grid pattern from # 1 to # 13 are virtual lines. In FIG. 7 and the like, # from # 1 to # 13 is omitted, and in the computer simulation, the image surface of the computer display is defined by vertical lines 22 and horizontal lines 23 so that the operator can easily understand. Has been.

  The order of determining the dot arrangement according to the first embodiment will be described below. First, the region 15 in which dots are arranged is partitioned into a square lattice with numbers # 1 to # 13 in the X-axis direction and the Y-axis direction, and a total of 169 small regions 21 as shown in FIG. It is a set of.

  In FIG. 7, all the small areas 21 in the area 15 are set as dot arrangement small areas. That is, FIG. 7 divides one region 15 of the mold of the light guide plate 2 into a set of lattice-like small regions 21 that develop in the Y-axis direction and the X-axis direction of the orthogonal coordinate system. It is a dot arrangement | positioning figure which shows the state made into the dot arrangement | positioning small area | region.

  Next, FIG. 8 is a dot arrangement diagram showing a state in which the dot arrangement small areas are thinned out from the arrangement of FIG. 7 and the remaining small areas 21 are changed to the staggered dot arrangement small areas. Alternatively, FIG. 8 shows that the dot arrangement small areas are thinned out along the 12 lines intersecting both the X axis direction and the Y axis direction from the arrangement shown in FIG. 7, and the remaining dot arrangement small areas are arranged in a staggered dot arrangement. It is what.

  In FIG. 8, a dot arrangement small region 25 painted in black is a dot arrangement small region where dots are formed. The staggered arrangement means a state in which the arrangement positions of dots in adjacent columns or rows are shifted as shown in FIG.

  Next, from the staggered arrangement of FIG. 8, as shown in FIG. 9, the columns are thinned out in a grid pattern every other row, and the dot arrangement positions are determined in a grid pattern with gaps 26 in the vertical and horizontal directions. That is, as can be seen by comparing FIG. 8 and FIG. 9, in FIG. 9, the dot arrangement of the even-numbered rows such as the second row, the fourth row, the sixth row, etc. is thinned out, and as a whole Dot arrangement. Alternatively, it can be said that the lattice-like dot arrangement of FIG. 9 is obtained by thinning out along six lines extending in the Y-axis direction or the X-axis direction from FIG.

  Next, the dot arrangement small areas 25 are thinned out in a zigzag pattern from the lattice arrangement in FIG. 9, and the remaining small areas 21 are converted into the arrangement shown in FIG. That is, this FIG. 10 is thinned out one by one in the first row direction from the lattice arrangement in FIG. 9, for example, and in the next second row, the position is shifted and thinned out one by one. FIG. Alternatively, FIG. 10 can also be said to be a dot arrangement diagram in which a single skip is performed in the row direction, and in the next row, the positions are shifted and skipped one by one, thereby forming a staggered arrangement as a whole.

  Alternatively, FIG. 10 shows the dot formation positions thinned out from FIG. 9 along six lines intersecting both the X-axis direction and the Y-axis direction, and the remaining dot arrangement small regions 25 are staggered as shown in FIG. It can be said that it was arranged.

  Then, one row is thinned out from the staggered dot arrangement of FIG. 10 to obtain the lattice arrangement of FIG. That is, it is thinned out from FIG. 10 along four lines extending in the Y-axis direction or the X-axis direction to form the lattice-like arrangement in FIG.

  Furthermore, from the grid-like arrangement of FIG. 11, one row is thinned out to form the staggered arrangement of FIG. Next, the dot arrangement small areas are thinned out in a lattice pattern from the staggered arrangement in FIG. 12 to obtain the single dot arrangement pattern in FIG.

  The dot arrangement pattern of FIGS. 7 to 13 determined by alternately repeating the staggered arrangement and the lattice arrangement in this manner is reversed from FIG. 13 to FIG. The order of dot arrangement is determined as shown in FIGS. 14, 15, 16, 17, 18, 19, and 20, which show dot formation order patterns that are assigned with this order and arranged. To go.

  That is, FIG. 14 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG. 15 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG. FIG. 16 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG.

  FIG. 17 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG. FIG. 18 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG. FIG. 19 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG. FIG. 20 is a dot sequence diagram corresponding to the dot arrangement diagram of FIG.

  The order in the dot order diagram may be given arbitrarily, but in the first embodiment, the order is given diagonally and clockwise. That is, in FIG. 14, 1 is assigned to a single dot arrangement region, and in FIG. 15, 3 is added to 2 diagonal lines, 4 is further clockwise, and 5 is added to 4 diagonal lines. ing.

  Further, in FIG. 16, 6, 7, 8, and 9 are attached, and in FIG. 17, the dot arrangement order from 10 to 25 is fixed. In the case of FIG. 17 as well, 11 is assigned to the 10th diagonal line at the upper right corner of the figure, and the order is set to 12, 13, 14, 15, 16, 17 in the clockwise direction and further on the diagonal line. It will be confirmed.

  Further, in FIG. 18, the order from No. 26 to No. 49 is given, and the range to which the order is given is further expanded as shown in FIG. 19 and FIG. 20, from 50 to 85 in FIG. 19, and from 86 to 169 in FIG. The dot arrangement order up to is fixed.

  In this way, the dot arrangement order is determined, and the number of dots specified in the computer simulation can be arranged in one area according to the determined order, and as a result, reflection of light by the dots is prevented. The planar light-emitting body 1 by the uniform light-guide plate 2 is obtained.

  Further, no more dots can be added in FIG. 20, but in FIG. 19 and before, a lattice arrangement or a zigzag arrangement with gaps is formed, and a small area that forms a gap 26 in which no dots are arranged, Additional dots can be arbitrarily inserted, and additional dots can be formed without hindrance in the subsequent process.

  As described above, in this embodiment, in the quadrangular area where dots are formed on the light guide plate, the dot formation position and order are set, and the coordinate system is set in the area to form a grid pattern. The initial step of determining the staggered arrangement pattern by thinning out the dot arrangement in a zigzag pattern from the pattern in which the dots are arranged in all of the small areas to be each grid part, and further the grid from the zigzag arrangement pattern The lattice arrangement step of decimating the arrangement of dots in a pattern to determine a grid arrangement pattern, and the staggered arrangement pattern by further decimating the arrangement of dots in a zigzag pattern from the grid arrangement pattern The dot arrangement step, the grid arrangement step, and the staggered arrangement step are repeated, and the dot arrangement is further thinned to determine a single dot arrangement pattern at the center of the region. A step returns Ri, until pattern arranged dots on all the small areas in the reverse of a single dot arrangement pattern traced sequentially includes the sequencing step to continue to grant the order to place a dot.

  As a result, a staggered arrangement pattern is determined from a pattern in which all dots are arranged, then a lattice-like arrangement pattern is determined, and a staggered arrangement pattern is determined again, so that dots in the area are repeated. The formation position and the formation order of can be determined. Further, according to this determination method, it is possible to make a gap for inserting additional dots between the dots, and it is possible to set a region of the light guide plate having a uniform light emission state with a desired brightness.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and can be modified or expanded as follows. For example, in the above-described embodiment, the present invention is applied to the light guide plate of a vehicle meter, but it can also be applied to a light guide plate of another planar light emitter.

  In the above-described embodiment, the number of the small regions 21 is set to 169, but this can be increased or decreased. In one embodiment, an orthogonal coordinate system is used, but an oblique coordinate system may be used.

DESCRIPTION OF SYMBOLS 1 Planar light-emitting body 2 Light guide plate 3, 4 Light emitting diode used as a point light source 6 dots 7 Dial 15 area | region 21 small area 22 vertical line 23 horizontal line 25 dot arrangement | positioning small area 26 gap

Claims (5)

A method for setting the formation position and order of the dots in a rectangular area for forming dots on a light guide plate, and setting a coordinate system in the area to divide the area into a lattice pattern, An initial step of determining a staggered arrangement pattern by thinning out the arrangement of dots in a zigzag pattern from a pattern in which the dots are arranged in all of the small regions
A grid-like arrangement step for determining a grid-like arrangement pattern by further thinning out the arrangement of the dots in a grid form from the staggered arrangement pattern;
A staggered arrangement step of thinning out the dot arrangement in a zigzag pattern from the grid-like arrangement pattern and determining the staggered arrangement pattern again.
Repeating the grid-like placement step and the staggered placement step to determine the last single dot to remain;
A dot ordering step for assigning an order to the dots in the order in which the thinning in each of the staggered placement step and the lattice placement step is traced back from the dots determined by the repetition step; Formation order determination method. In a rectangular region for forming dots on the light guide plate, a method of setting the formation position and order of the dots,
Setting a plurality of grid-like coordinate systems in the one region;
From the pattern in which the dots are arranged in all of at least 169 small regions that are each lattice portion of the lattice-like coordinate system, the dot arrangement is thinned out in a staggered manner to determine at least 85 staggered arrangement patterns. And steps to
A grid-like arrangement step of determining at least 49 grid-like arrangement patterns by further thinning out the arrangement of the dots in a grid form from the staggered arrangement pattern;
From the lattice-like arrangement pattern, a staggered arrangement determining at least 25 staggered arrangement pattern further by thinning out the arrangement of the dot in a staggered manner,
By repeating the thinning in the grid arrangement step and the staggered arrangement step, the dot arrangement is thinned out so that the number of dots arranged is at least nine, at least five, and one. Repeating until a central single dot placement pattern is determined;
Contrary to the single dot arrangement pattern, the pattern is arranged in order from the dot arrangement pattern to all the small areas, and the number of dots in the dot arrangement pattern is increased and the dots are arranged. A dot formation order determination method comprising an order assignment step of assigning an order.   The light guide plate is made of a transparent member, the region is formed of one of a plurality of rectangular regions formed in the light guide plate, and the dots reflect light passing through the light guide plate to reflect the light guide plate. The dot formation order determination method according to claim 1 or 2, comprising a depression formed on the back surface of the transparent member that leads to the front surface of the dot. The coordinate system is composed of an orthogonal coordinate system, the orthogonal coordinate system, the area is divided into a lattice shape, to the dot claims 1, characterized in that it consists of a set of the small regions formed in the center 3 The dot formation order determination method according to any one of the above.   The coordinate system has an X axis and a Y axis, and thinning out the dot arrangement in the zigzag pattern consists of thinning out along a plurality of lines intersecting both the X axis and the Y axis. The thinning of the dot arrangement in the lattice form includes thinning along a plurality of lines extending in the X-axis or Y-axis direction. The dot formation order determination method described.

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