JP4788957B2 - Meter glass shape design method, design device used therefor, and meter device equipped with meter glass designed thereby - Google Patents

Description

  The present invention relates to a design method for a meter glass shape, a design device used for the method, and a meter device including a meter glass designed thereby.

  A so-called meter, which is a conventional technique related to a meter device provided in an instrument panel of a vehicle, in which light is reflected on a meter glass on the front surface of the meter device, and the visibility of the driver's meter device is deteriorated due to the reflected light. Some have prevented the phenomenon of reflection on glass (for example, see Patent Document 1). This is because the line from the driver's eye point to the meter glass is reflected and gathered on the cover of the steering column so that the curved surface of the meter glass is formed and the cover is black matte. It was.

Thereby, the reflection on the meter glass is eliminated, and the meter device with good visibility from the driver can be obtained. On the other hand, however, the cover of the steering column is blackened over a wide range, so it may not meet the driver's preference for the interior of the passenger compartment. In particular, for female drivers, there was a great sense of resistance to black interior items.
Japanese Utility Model Publication No. 58-32318 (FIG. 1)

  Generally, the meter device on the instrument panel of the vehicle is located in front of the driver in the width direction of the vehicle. Since the driver's eye point is located above the meter device, the light reflected on the meter glass enters the driver's eyes, and the reflection phenomenon becomes noticeable.

  Until now, in order to reduce the reflection phenomenon in the meter device, as shown in FIG. 13, the meter cluster 102 is projected below the meter glass 101 formed on the front surface of the meter device 100 and the meter device 100 is visually recognized. The curved surface of the meter glass 101 is formed above the lowest viewpoint LP set as the lowest possible point so that the reflected rays ML and NL deviating from the meter cluster 102 do not reach. Light rays ML and NL from other than the meter cluster 102 are set so as to be reflected on the meter glass 101 and to travel downward from the lowest viewpoint LP.

  Normally, when the position of one end in the vertical direction is set, the meter glass is formed by a curve having a single curvature from the one end so as to satisfy the above-described reflected light condition. For this reason, the meter glass naturally has a shape in which the lower part is deep in the back and the upper part protrudes. For this reason, the meter device is increased in size and cost, and mounting is difficult. As shown in FIG. 14, the meter glass 101 designed in this way has a margin angle β1, with respect to the front end FP of the meter cluster 102, of the incident lines UL1 and UL2 reflected to the lowest viewpoint depending on the position on the surface. β2 varies, and in order to prevent reflection on the meter glass 101 at a position on the meter glass 101, as a result, a large margin is set and the shape is set. This indicates that there are some positions, and the shape was not optimized.

  The present invention has been completed based on the above circumstances, and provides a design method capable of optimal design of the shape of a meter glass, a design device used therefor, and a meter device equipped with the meter glass designed thereby. The purpose is to do.

  The meter glass shape design method of the present invention, the design device used therefor, and the meter device equipped with the meter glass designed thereby, are based on the position data input by the position data input means, and the meter device can be visually recognized. On the meter cluster which sets the lowest viewpoint which is the lower point and the initial reflection point which is one end in the vertical direction of the meter glass, and is provided in the lower front part of the meter glass and prevents reflection on the meter glass A normal line obtained by dividing the angle formed by the incident line connecting the predetermined position and the initial reflection point with the reflection line connecting the lowest viewpoint and the initial reflection point, and then perpendicular to the normal line. Forming a first tangent line, setting a first neighbor point on the tangent line at a position away from the initial reflection point by a predetermined distance, and on the first neighbor point The same calculation as the calculation at the initial reflection point is performed to form the normal line and the tangent line at the first neighboring point, and from the initial reflection point on the tangent line formed on the first neighboring point. A second neighboring point is set in a direction away from the first neighboring point in a direction away from the first neighboring point, and thereafter, the same calculation is repeated to form a plurality of neighboring points, and then the initial reflection point and The meter glass shape is formed by connecting a plurality of the neighboring points by a curve.

  In this way, the shape of the meter glass is set with the same margin at all positions on the meter glass so that no reflection will occur on the meter glass. Become.

The following configuration is preferable as an embodiment of the present invention.
(1) Connect the front end of the meter cluster to the initial reflection point or a plurality of neighboring points to make a boundary line at the initial reflection point or the neighboring point, respectively. Rotate in the direction to make the incident line at the initial reflection point or near point, respectively. As described above, since the margin of the incident line with respect to the front end of the meter cluster is set by the angle, the shape of the meter glass can be designed before the shape of the meter cluster is specifically determined.

  Since the optimum design of the meter glass shape is possible, in particular, the depth dimension of the meter device is not shortened and the size is not increased, and the meter device can be easily mounted at low cost.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. 1 and FIGS. 5 to 7, the right side corresponds to the front of the meter device 2 (the rear of the vehicle). The meter device 2 according to the present embodiment is a combination meter including, for example, a vehicle speedometer and a tachometer, and is accommodated in the instrument panel 1 of the vehicle and is curved on the front surface of the instrument unit 3 having the pointer 4. The meter glass 5 formed by is attached. Further, a flat meter cluster 6 for preventing reflection on the meter glass 5 is formed on the lower front portion of the meter glass 5 so as to protrude forward with a synthetic resin. The surface of the meter cluster 6 is black matted to prevent light reflected from the meter glass 5.

  The design apparatus 10 according to the present embodiment shown in FIG. 2 is for designing the shape of the meter glass 5 on a two-dimensional plane (shown in FIG. 1) extending in the front-rear and vertical directions, and is limited to this. Although it is not a thing, the normal CAD (Computer Aided Design) apparatus is used. The keyboard 11 and the mouse 12 are connected to the control device 15 and correspond to position data input means for inputting position data on a two-dimensional plane to the control device 15. The control device 15 is formed by a microprocessor, and includes a glass shape creation program storage unit 16, a data storage unit 17, a calculation unit 20 (corresponding to the calculation means of the present invention), and an output unit 18. The glass shape creation program storage unit 16 is formed by a ROM, and stores a calculation program for glass shape creation described later. On the other hand, the data storage unit 17 using RAM temporarily stores position data input from the keyboard 11 or the mouse 12.

  The calculation unit 20 is connected to the glass shape creation program storage unit 16 and the data storage unit 17, and in accordance with the calculation program stored in the glass shape creation program storage unit 16, based on the position data stored in the data storage unit 17, Calculation is performed to form a meter glass shape on a two-dimensional plane. The output unit 18 outputs shape data regarding the meter glass shape formed by the calculation unit 20 in accordance with an instruction from the outside. The display unit 13 is not limited to these, but is, for example, a CRT display or a liquid crystal display panel, connected to the output unit 18, and a meter created based on the shape data from the output unit 18. The shape of the glass 5 is displayed. The printer 14 is also connected to the output unit 18 and prints out the shape of the meter glass 5.

  As shown in FIG. 3, the computing unit 20 described above has a reflection line / boundary line creation unit 24 connected to the viewpoint setting unit 21, the meter cluster end point setting unit 22, and the initial reflection point setting unit 23. Yes. The reflection line / boundary line creation unit 24 is connected to the incident line creation unit 25, and is connected to the normal line creation unit 26 together with the incident line creation unit 25. The normal line creation unit 26 is connected to a tangent line creation unit 27, and the tangent line creation unit 27 is connected to a neighborhood point setting unit 28. In addition, the neighborhood point setting unit 28 is connected to an area determination unit 31 connected to the reflection line, boundary line generation unit 24, glass shape curve generation unit 29, and area setting unit 30 described above. Further, the glass shape curve creation unit 29 is also connected to the initial reflection point setting unit 23 described above. It goes without saying that each configuration included in the arithmetic unit 20 has a register that temporarily stores data to be set or data input from another connected configuration.

  Next, based on FIG. 4 thru | or FIG. 7, the design method of the shape of the meter glass 5 by the design apparatus 10 is demonstrated with the function of each structure of the calculating part 20 mentioned above. First, from the keyboard 11 or the mouse 12, for example, position data indicating the position on the two-dimensional plane of the steering device or driver's seat device (not shown) or the instrument panel 1, the margin angle γ, and the value of the predetermined distance S When the value of the margin angle γ and the predetermined distance S may be fixed in advance in the calculation program, the process proceeds from step S401 to step S402 and is temporarily stored in the data storage unit 17. The position data is sent to the calculation unit 20. The calculation unit 20 performs a predetermined calculation according to the calculation program stored in the glass shape creation program storage unit 16 based on the transmitted position data, and the viewpoint setting unit 21, the meter cluster end point setting unit 22 and the initial reflection point. The setting unit 23 is provided at the lowermost viewpoint LP (viewpoint setting step) that is the lowest position where the driver needs to visually check the meter device 2, the meter cluster end point FP that is the front end of the meter cluster 6, and the upper end of the meter glass 5. A certain initial reflection point IR (initial reflection point setting step) is set (shown in FIG. 5).

  Each position on the two-dimensional plane is set by specifying its XY coordinate value, and thereafter, each position set is similarly performed. Further, when the lowest viewpoint LP, the meter cluster end point FP, and the initial reflection point IR are set, these position data may be directly input by the keyboard 11 or the mouse 12. In step S <b> 402, the region setting unit 30 of the calculation unit 20 sets a region (lower edge) for forming the meter glass 5 on the two-dimensional plane based on the position data received from the data storage unit 17.

  Next, the process proceeds to step S403, and based on the position data of the lowest viewpoint LP, the meter cluster end point FP, and the initial reflection point IR, the reflection line / boundary line creation unit 24 performs the lowest viewpoint as shown in FIG. An initial reflection line RL connecting the LP and the initial reflection point IR is formed, and the meter cluster end point FP and the initial reflection point IR are connected by the reflection line / boundary line creation unit 24 (at the initial reflection point IR). An initial boundary line BL is formed. The setting of each line is specified as a linear function on a two-dimensional plane. Thereafter, the process proceeds to step S404, where the incident line creation unit 25 rotates the initial boundary line BL around the initial reflection point IR in the direction of the meter glass 5 (clockwise in FIG. 6) by a predetermined margin angle γ. As shown, an initial incident line IL (at the initial reflection point IR) connecting a predetermined position on the meter cluster 6 and the initial reflection point IR is formed.

  Next, proceeding to step S405, the normal creation unit 26 forms a normal PL that divides the angle formed by the initial incident line IL and the initial reflection line RL into two at an angle α (normal creation step, FIG. 6). Shown). Next, in step S406, the tangent line creation unit 27 forms a tangent line TL perpendicular to the normal line PL (tangent line creation step, FIG. 6). Thereafter, the process proceeds to step S407, where the neighboring point setting unit 28 sets the first neighboring point CP1 at a position away from the initial reflection point IR by a predetermined distance S on the tangent line TL (neighboring point setting step, FIG. 6). ).

  Thereafter, in step S <b> 408, the region determination unit 31 determines whether or not the first neighboring point CP <b> 1 is outside a predetermined region that forms the meter glass 5 set by the region setting unit 30. If it is determined that the first neighboring point CP1 is within the predetermined region, the process returns to step S403, and the lowermost viewpoint LP and the first neighboring point CP1 at the first neighboring point CP1 are similar to the calculation at the initial reflection point IR. Is formed by the reflection line / boundary line creation unit 24, and further, the first boundary line (at the first neighborhood point CP1) that connects the meter cluster end point FP and the first neighborhood point CP1. BL1 is formed (shown in FIG. 7). In step S404, the incident line creation unit 25 rotates the first boundary line BL1 about the first neighboring point CP1 in the direction of the meter glass 5 (clockwise in FIG. 7) by the margin angle γ. A first incident line IL1 at one neighboring point CP1 is formed (shown in FIG. 7).

  Thereafter, according to steps S405 to S407, the same calculation as that at the initial reflection point IR is performed, and the normal line creation unit 26 divides the angle formed by the first incident line IL1 and the first reflection line RL1 into two normal lines ( The tangent line creation unit 27 forms a tangent line (not shown) perpendicular to the normal line on the first neighboring point CP1, and the neighboring point setting unit 28 creates an initial reflection point on the tangent line. A second neighboring point CP2 is set at a position away from the first neighboring point CP1 by a distance S in a direction away from the IR (shown in FIG. 7).

  Thereafter, the same calculation is repeated to form a plurality of neighboring points. In step S408, the (n + 1) th neighboring point is lower than the lower edge of the region forming the meter glass 5 set by the region setting unit 30. If it determines with it being below, it will progress to step S409 and the glass shape curve preparation part 29 will connect the initial reflection point IR and 1st vicinity point CP1-nth vicinity point CPn by a smooth curve, and it will be meter glass. 5 is formed (glass shape curve creation step, FIG. 7 is shown). As a method of connecting a plurality of points on a two-dimensional plane with a curve, a normal spline curve forming method using a CAD device (for example, see Japanese Patent Application Laid-Open No. 5-290106, which is a patent publication). Finally, in step S410, the shape of the formed meter glass 5 is output from the output unit 18 shown in FIG. 2 to the display unit 13 or the printer 14 together with the shapes of other components of the meter device 2. It becomes possible for the designer to confirm the created shape.

  According to the present embodiment, the initial incident line IL formed by rotating the initial boundary line BL connecting the meter cluster end point FP and the initial reflection point IR by the margin angle γ, the lowest viewpoint LP, and the initial reflection. After forming a normal line PL obtained by dividing the angle formed by the initial reflection line RL connecting with the point IR into two, a tangent line TL perpendicular to the normal line PL is formed, and a predetermined distance from the initial reflection point IR on the tangent line TL. A first neighboring point CP1 is set at a position separated by S, and a calculation similar to the calculation at the initial reflection point IR is performed on the first neighboring point CP1 to form a normal line and a tangent line at the first neighboring point CP1. , On the tangent line formed on the first neighboring point CP1, a second neighboring point CP2 is set at a position away from the first neighboring point CP1 by a predetermined distance S in a direction away from the initial reflection point IR, It is later, by repeating the same operations, after forming a plurality of neighboring points CP1 to CPn, to form the shape of the meter glass 5 by connecting the initial point of reflection IR and a plurality of neighboring points CP1 to CPn by curve.

  By doing in this way, in order to prevent reflection on the meter glass 5, from all the positions on the meter glass 5 from the boundary lines BL, BL1 to BLn connected to the meter cluster end point FP, there is a uniform margin. Since the shape of the meter glass 5 is formed so that the incident lines IL, IL1 to ILn entering the inside of the meter cluster 6 by the angle γ are reflected to the lowest viewpoint LP, the optimum design of the shape becomes possible. In particular, the depth dimension of the meter device 2 is shortened and the meter device 2 is not enlarged, and the meter device 2 can be easily mounted at low cost (see FIG. 1). In addition, since a margin angle γ is set between the incident lines IL, IL1 to ILn and the boundary lines BL, BL1 to BLn, incident light that is off the meter cluster 6 is reflected on the meter glass 5. It will surely proceed below the lowest viewpoint LP and will not enter the driver's eyes.

  Also, the meter cluster end point FP and the initial reflection point IR or a plurality of neighboring points CP1 to CPn are connected to form boundary lines BL, BL1 to BLn at the initial reflection point IR or the neighboring points Cp1 to CPn, respectively. ˜BLn is rotated around the initial reflection point IR or a plurality of neighboring points CP1 to CPn by a predetermined angle γ toward the meter glass 5, and incident lines IL at the initial reflection point IR or neighboring points CP1 to CPn, IL1 to ILn. As described above, since the margin of the incident lines IL, IL1 to ILn with respect to the end point FP of the meter cluster 6 is set by the angle γ, the shape of the meter glass 5 is determined before the shape of the meter cluster 6 is specifically determined. Can be designed.

<Embodiment 2>
Next, the second embodiment will be described based on FIGS. 8 to 12 with a focus on differences from the first embodiment. 10 to 12, the right side corresponds to the front of the meter device 2 (the rear of the vehicle). In the present embodiment, the design apparatus 10 includes a calculation unit 40 (shown in FIG. 8) instead of the calculation unit 20. The calculation unit 40 has a margin position setting unit 43 connected to the meter cluster shape creation unit 41. The incident / reflection line creation unit 45 has the same viewpoint setting as that of the margin position setting unit 43 and the first embodiment. The unit 42, the initial reflection point setting unit 44, and the neighborhood point setting unit 48 are connected. Further, the incident reflection line creating unit 45 is also connected to the normal line creating unit 46. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  Next, based on FIG. 9 thru | or FIG. 12, the design method of the shape of the meter glass 5 by this embodiment is demonstrated. First, when position data, margin distance D and predetermined distance S values (the margin distance D and predetermined distance S values may be fixed in advance in the calculation program) are input from the keyboard 11 or mouse 12. (Step S901) Proceeding to Step S902, the meter cluster shape creation unit 41 sets the meter cluster end point FP, and then the shape of the meter cluster 6 is formed (shown in FIG. 10). Thereafter, in step S903, based on the shape of the formed meter cluster 6, the margin position setting unit 43 moves from the meter cluster end point FP toward the meter glass 5 (leftward in FIG. 10) on the meter cluster 6. A margin position SP is set at a position within a predetermined margin distance D (shown in FIG. 10).

  Thereafter, in step S904, as in the first embodiment, based on the position data from the data storage unit 17, the viewpoint setting unit 42, the initial reflection point setting unit 44, and the region setting unit 50 are respectively set to the lowest viewpoint LP and the initial viewpoint. After setting the reflection point IR and the formation area of the meter glass 5, in step S905, the incident reflection line creation unit 45 forms an initial reflection line RL that connects the lowest viewpoint LP and the initial reflection point IR. An initial incident line IL connecting the margin position SP and the initial reflection point IR is formed (shown in FIG. 11).

  Next, proceeding to step S906, the normal line creation unit 46 forms a normal line PL that divides the angle formed by the initial incident line IL and the initial reflection line RL into two at an angle α (shown in FIG. 12). Next, in step S907, the tangent line creation unit 47 forms a tangent line TL perpendicular to the normal line PL (shown in FIG. 12). Thereafter, the process proceeds to step S908, where the neighboring point setting unit 48 sets the first neighboring point CP1 at a position away from the initial reflection point IR by a predetermined distance S on the tangent line TL (shown in FIG. 12). Thereafter, in step S909, the region determination unit 51 determines whether or not the first neighboring point CP1 is outside the predetermined region. If it is determined that the first neighboring point CP1 is within the predetermined region, the process proceeds to step S905. In the same manner as the calculation at the initial reflection point IR, the first reflection line connecting the lowest viewpoint LP and the first vicinity point CP1 at the first vicinity point CP1 is formed by the incident reflection line creating unit 45. A first incident line connecting the margin position SP and the first neighboring point CP1 is formed, and thereafter, a plurality of neighboring points CP1 to CPn are set based on these.

  According to the present embodiment, in the calculation at the initial reflection point IR and all the neighboring points CP1 to CPn, each incident line can be formed only by connecting these positions and the margin position SP. It is possible to reduce calculation steps.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) The margin angle γ, the predetermined distance S, or the margin distance D can be determined to any value according to the size error of the peripheral parts of the vehicle and the meter device.
(2) The meter device of the present invention can be applied not only to vehicles but also to all transportation means such as ships and airplanes.
(3) A design device other than a normal CAD device may be used as the design device.
(4) The initial reflection point may be set at the lower end of the meter glass.
(5) In the present invention, the meter glass is a common name for a transparent plate provided on the front surface of the meter device. The meter device has a transparent plate formed of a material other than glass such as synthetic resin, and the shape of the meter glass. The design method for forming the design method and the design apparatus for executing the design method do not depart from the technical scope of the present invention.

Sectional drawing of the meter apparatus using the meter glass formed by Embodiment 1 The block diagram which shows the whole structure of the design apparatus by this embodiment Configuration diagram of arithmetic unit according to embodiment 1 The flowchart which shows the design method by Embodiment 1. Sectional view showing the lowest viewpoint, initial reflection point and meter cluster end point set by the design method shown in FIG. Sectional drawing which showed the place where the 1st neighborhood point was set by the design method shown in FIG. Sectional drawing which shows the place where the meter glass shape was formed by the design method shown in FIG. Configuration diagram of arithmetic unit according to embodiment 2 The flowchart which shows the design method by Embodiment 2. FIG. 9 is a sectional view showing a margin position on the meter cluster set by the design method shown in FIG. FIG. 9 is a sectional view showing the initial incident line and the initial reflection line set by the design method shown in FIG. Sectional drawing which showed the place where the 1st neighborhood point was set by the design method shown in FIG. Sectional view showing the shape of the meter glass designed by the conventional design method Sectional drawing which showed the relationship between the reflected light on meter glass shown in FIG. 13, and a meter cluster

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Meter apparatus 5 ... Meter glass 6 ... Meter cluster 10 ... Design apparatus 11 ... Keyboard 12 ... Mouse 20, 40 ... Operation part 21, 42 ... Viewpoint setting part 23, 44 ... Initial reflection point setting part 26, 46 ... Normal Creation unit 27, 47 ... Tangent creation unit 28, 48 ... Neighborhood point setting unit 29, 49 ... Glass shape curve creation unit LP ... Bottom viewpoint IR ... Initial reflection point FP ... Meter cluster end point CP1-CPn ... Neighborhood point SP ... Margin Position BL, BL1-BLn ... Boundary line IL, IL1-ILn ... Incident line RL, RL1-RLn ... Reflection line PL ... Normal line TL ... Tangent line γ ... Margin angle D ... Margin distance S ... Predetermined distance

Claims (4)

Position data input means for inputting position data on a two-dimensional plane extending in the front-rear and up-down directions, and a predetermined calculation based on the input position data, provided on the front surface of the meter device on the plane In a meter glass shape design apparatus equipped with a calculation means for determining the meter glass shape,
The calculation means sets, on the two-dimensional plane, a lowest viewpoint that is the lowest point at which the meter device can be visually recognized based on the position data input on the two-dimensional plane by the position data input means. A viewpoint setting unit, an initial reflection point setting unit for setting an initial reflection point on one end in the vertical direction of the meter glass on the two-dimensional plane, provided at a lower front portion of the meter glass, and reflected on the meter glass A normal line formed by dividing an angle formed by an incident line connecting a predetermined position on the meter cluster and the initial reflection point and a reflection line connecting the lowest viewpoint and the initial reflection point into two. A line creation unit, a tangent creation unit that forms a tangent line perpendicular to the normal line, and a first neighborhood point on the tangent line at a predetermined distance from the initial reflection point A side point setting unit, and performing a calculation similar to the calculation at the initial reflection point on the first neighboring point to form the normal line and the tangent line at the first neighboring point; A second neighboring point is set at a position away from the first neighboring point by a predetermined distance in a direction away from the initial reflection point on the tangent line formed on the tangent line. A design apparatus comprising: a glass shape curve creating unit that forms the meter glass shape by connecting the initial reflection point and a plurality of the neighboring points by a curve after forming the neighboring points. The computing means connects the front end of the meter cluster and the initial reflection point or the plurality of neighboring points, respectively, as a boundary line at the initial reflection point or the neighboring points, and the boundary line is the initial reflection point or the The design apparatus according to claim 1, wherein the design device is rotated around a neighboring point toward the meter glass by a predetermined angle to be the incident line at the initial reflection point or the neighboring point, respectively. Based on the position data input step for inputting position data on a two-dimensional plane extending in the front-rear and up-down directions to the design apparatus, and the input position data, the design apparatus performs a predetermined calculation, on the plane, In the design method of the meter glass shape by the design device provided with a calculation process for determining the meter glass shape provided on the front surface of the meter device,
The calculation step includes a viewpoint setting step of setting a lowest viewpoint, which is the lowest point at which the meter device can be visually recognized, on the two-dimensional plane based on the input position data, and one end in the vertical direction of the meter glass. An initial reflection point setting step for setting an initial reflection point which is a part on the two-dimensional plane, a predetermined position on a meter cluster which is provided at a lower front portion of the meter glass and prevents reflection on the meter glass, and the initial A normal generation step for forming a normal line obtained by dividing the angle formed by the incident line connecting the reflection point and the reflection line connecting the lowest viewpoint and the initial reflection point, and a tangent line perpendicular to the normal line; Forming a tangent line to be formed, and a neighboring point setting step for setting a first neighboring point at a position away from the initial reflection point by a predetermined distance on the tangent line, Then, the same calculation as the calculation at the initial reflection point is performed to form the normal line and the tangent line at the first neighboring point, and the initial reflection is performed on the tangent line formed on the first neighboring point. A second neighboring point is set at a position away from the first neighboring point by a predetermined distance in a direction away from the point, and thereafter, the same calculation is repeated to form a plurality of neighboring points, and then the initial reflection is performed. A design method comprising a glass shape curve creating step of forming the meter glass shape by connecting a point and a plurality of neighboring points by a curve. A meter apparatus comprising a meter glass having a shape formed by the design method according to claim 3.

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