JP5247658B2 - Pointer instrument - Google Patents

Description

  The present invention relates to a pointer instrument.

  Patent Document 1 discloses a timepiece having a light emitting portion in order to improve the visibility of a dial plate in the dark.

JP 2005-091102 A

  In consideration of power consumption and cost, it is desirable that the number of such light emitting portions is small. However, if the number of light emitting parts is small, it is difficult to illuminate the entire dial uniformly. This may deteriorate the visibility of the dial in the dark.

  Therefore, an object of the present invention is to provide a pointer instrument that can irradiate light uniformly on the entire dial plate even if the number of light emitting portions is small.

  The object is to provide a main body having a concave portion, a dial plate and a pointer provided on the bottom surface of the concave portion, a plate-like cover disposed on the front side of the dial plate and having light transmittance, and a plane of the cover. This can be achieved by a pointer instrument that includes a light emitting unit that emits light into the cover so that the direction and the optical axis are aligned, and a frame that has an inner surface that faces at least a part of the edge of the cover.

  As a result, the light emitted from the light emitting unit travels through the cover to the frame that covers the edge of the cover. The light that has reached the frame is reflected by the inner surface of the frame and diffused. Thereby, the light which a light emission part irradiates can be spread over a wide range, and light is irradiated to the whole dial plate. In this way, by utilizing the reflection of the frame, even if the number of light emitting portions is small, the entire dial can be irradiated with light uniformly.

  Even if the number of light emitting parts is small, it is possible to provide a pointer instrument that can irradiate light uniformly over the entire dial.

FIG. 1A is a partial cross-sectional view of a timepiece, and FIG. 1B is an explanatory diagram of a progress state of light emitted from an LED. 2A is a partial cross-sectional view showing the upper side of the timepiece, and FIG. 2B is a partial cross-sectional view showing the lower side of the timepiece. FIG. 3A is an explanatory diagram of an inclined surface having an exposed region, and FIG. 3B is an explanatory diagram of an inclined surface having no exposed region. FIG. 4 is a front view of the dial. FIG. 5 is a rear view of a frame according to a modification. FIG. 6 is a partial cross-sectional view showing the lower side of the watch when there is no frame. FIG. 7 is a partial cross-sectional view showing the lower side of the watch when there is a frame.

  Hereinafter, a watch will be described as an example of a pointer instrument. FIG. 1A is a partial cross-sectional view of the timepiece 1. As shown in FIG. 1A, the timepiece 1 has a main body 10 including a housing 12 and a recess 14. A pointer group 22 and a dial plate 24 are provided on the bottom surface of the recess 14. The pointer group 22 includes an alarm hand, an hour hand, a minute hand, and a second hand. A drive mechanism 20 is provided so as to penetrate the bottom surface of the dial plate 24. The drive mechanism 20 has a plurality of gears arranged coaxially, and a plurality of hands are connected to the plurality of gears. A motor and a battery (both not shown) for driving the drive mechanism 20 are accommodated in the main body 10. A cover 30 is disposed on the front side of the dial 24. The cover 30 is made of a synthetic resin having optical transparency and has a substantially circular flat plate shape. A single LED (light emitting unit) 40 is disposed at the end of the cover 30. The LED 40 is disposed on the upper side of the timepiece 1. The frame 50 is a synthetic resin that does not have optical transparency and has an annular shape. Details of the LED 40 will be described later. The frame 50 sandwiches the cover 30 with the recess 14. Thereby, the cover 30 is held by the timepiece 1.

  FIG. 1B is an explanatory diagram of a traveling state of light emitted from the LED 40. FIG. 1B shows only the cover 30 viewed from the front side of the timepiece 1. The LED 40 emits light into the cover 30. Thereby, the irradiated light travels through the cover 30 and is reflected by the inner surface of the cover 30. Details will be described below.

  2A is a partial cross-sectional view showing the upper side of the timepiece 1, and FIG. 2B is a partial cross-sectional view showing the lower side of the timepiece 1. As shown in FIGS. 2A and 2B, the recess 14 has a bottom surface to which the dial 24 is fixed, and an inner peripheral side surface 16 continuous with the bottom surface. The recess 14 is cylindrical with a bottom surface. The cover 30 has a front surface 32, a back surface 34 positioned on the dial 24 side, and an edge portion 36. The edge portion 36 has an outer peripheral end surface 37 and an inclined surface 38 continuous from the outer peripheral end surface 37 to the back surface 34. The outer peripheral end surface 37 is an end surface located at the most edge of the cover 30. The recess 14 has an inclined surface 18 that is in contact with the inclined surface 38. When the inclined surface 38 of the cover 30 abuts on the inclined surface 18 of the recess 14, the position of the cover 30 with respect to the recess 14 is defined.

  The frame 50 has an inner surface 52 that covers the front 32 side of the edge 36 of the cover 30, and an inner surface 57 that covers at least a part of the outer peripheral end surface 37. The inner side surface 52 is a surface on the back side of the frame body 50. As shown in FIG. 2B, the inner side surfaces 52 and 57 are substantially orthogonal in a sectional view. In addition, as shown to FIG. 2A, the outer peripheral end surface 37 and the inner surface 57 do not oppose in LED vicinity. This is because the LED 40 faces the outer peripheral end surface 37.

  As shown in FIG. 2A, the LED 40 irradiates light into the cover 30 from the edge portion 36 so that the optical axis OA is along the planar direction of the cover 30. The LED 40 and the outer peripheral end surface 37 are in contact with each other. As shown in FIG. 2A, part of the light emitted from the LED 40 travels through the cover 30 and travels to the lower part of the cover 30. As shown in FIG. 2B, the light traveling to the lower part of the cover 30 reaches the edge 36 and is reflected by the inner side surface 52, the inclined surface 18, or the inner side surface 57. The reflected light travels toward the dial plate 24, so that the dial plate 24 is irradiated with light.

  FIG. 6 is a partial cross-sectional view showing the lower side of the timepiece 1 when there is no frame 50. In FIG. 6, the hatching of the cover 30 is omitted. As shown in FIG. 6, the light L reaching the interface on the opposite side of the dial 30 of the cover 30 is divided into the refracted light Lk and the reflected light Lh, and the separation ratio is determined according to the incident angle. For example, in total reflection, the refracted light Lk is 0 and the reflected light Lh is 100%. When there is no inner side surface 52, the refracted light Lk is emitted to the opposite side of the dial plate 24, so that the dial plate 24 is irradiated only by the reflected light Lh.

  On the other hand, when the frame 50 is present as shown in FIG. 2, the refracted light Lk is reflected by the inner side surface 52 of the frame 50 and returns to the cover 30. Therefore, the dial 24 is irradiated with the light reflected by the inner side surface 52 of the frame 50 with the reflected light Lh and the refracted light Lk. For this reason, when the inner surface 52 is present, the dial 24 can be illuminated more brightly than when the inner surface 52 is absent.

  The inner side surface 52 of the frame body 50 does not necessarily have to be in close contact with the front surface 32 of the cover 30. FIG. 7 is a partial cross-sectional view showing the lower side of the timepiece 1 when the frame 50 is present, and is a view showing an example in which light reflected by the inner side surface 52 returns to the cover 30. In FIG. 7, hatching of the cover 30 is omitted. In FIG. 7, there is a gap between the frame body 50 and the front surface 32 of the cover 30. Even if there is a space between the inner side surface 52 and the front surface 32 of the cover 30 as shown in FIG. 7, the refracted light Lk1 that has entered the range of the inner side surface 52 is reflected by the surface of the inner side surface 52. It returns to the dial 24 side again as Lk2. Therefore, the dial 24 is irradiated with the reflected light Lh1 and the light Lk2 reflected by the inner surface 52. For this reason, when the inner surface 52 is present, the dial 24 can be illuminated more brightly than when the inner surface 52 is absent.

  Depending on the surface states of the inner side surface 52 and the inner side surface 57, the rate of attenuation of the reflected light varies. For example, if the surface is uneven, light is scattered and greatly attenuated. Also, the light is attenuated when the color is dark. Therefore, the surfaces of the inner side surface 52 and the inner side surface 57 in this embodiment are formed smoothly. In addition, regardless of the color of the frame 50, the inner side surface 52 and the inner side surface 57 are preferably brighter because the reflectance is higher. The color of the inner side surface 52 and the inner side surface 57 in this embodiment is white.

  Further, as shown in FIG. 2A, a part of the light emitted from the LED 40 is reflected by the inner side surface 52 adjacent to the LED 40 before reaching the lower part of the cover 30. The reflected light is applied to the dial plate 24.

  When the angle at which the light emitted from the LED 40 is incident on the front surface 32 of the cover 30 is smaller than the critical angle of refraction, the light is refracted and transmitted to the opposite side of the dial 24 from the ratio of the light reflected to the dial 24 side. The percentage of light that goes away becomes larger. On the other hand, when the inner side surface 52 is provided, even if the incident angle of light on the inner side surface 52 is smaller than the critical angle of refraction, it is reflected by the surface of the inner side surface 52 and returns to the dial 24 side. Can do.

  This phenomenon is particularly likely to occur near the LED 40. This is because the LED 40 is a point light source, and therefore the incident angle on the inner side surface 52 becomes small in the vicinity of the LED.

  Since the light in the vicinity of the LED 40 is in a very bright state as compared with the light at a position away from the LED 40, if the light is reflected to the dial 24 side without being emitted to the opposite side of the dial 24, the cover Since the total amount of light that travels within 30 increases accordingly, the dial 24 can be illuminated more brightly.

  As described above, the light emitted from the LED 40 is reflected by the inner side surfaces 52 and 57 of the frame body 50 and proceeds to the dial 24. As described above, by utilizing the reflection of the frame 50, the entire dial 24 can be irradiated with light even if the number of the LEDs 40 is small. Therefore, the visibility of the dial 24 in the darkness is improved. Moreover, since the increase in the score of LED40 can be suppressed, power consumption and manufacturing cost can be reduced.

  Further, as shown in FIG. 2B, the inclined surface 38 has a contact area that is in contact with the inclined surface 18 and an exposed area that is exposed from the inclined surface 18. The exposed area is located inside the recess 14 with respect to the contact area. As shown in FIG. 2B, part of the light emitted from the LED 40 reaches the exposed area of the inclined surface 38, and part of the light passes through the inclined surface 38 and proceeds to the inner peripheral side surface 16. Thereby, the light reflected by the inner peripheral side surface 16 reaches the dial plate 24. Similarly, as shown in FIG. 2A, part of the light emitted from the LED 40 and reflected by the inner surface 52 adjacent to the LED 40 also passes through the inclined surface 38 near the LED 40 and reaches the dial 24.

  As described above, a part of the inclined surface 38 is exposed from the recess 14, so that light is allowed to escape from the inclined surface 38 to the dial 24 side. Thereby, the light of LED40 can be efficiently irradiated toward the dial plate 24.

  Further, as shown in FIG. 2B, the outer peripheral end surface 37 is located outside the inner peripheral side surface 16, and the inner side surface 57 covers at least a part of the outer peripheral end surface 37. Further, the inner side surface 52 faces the front surface 32 of the cover 30 and extends to the inner side of the inner peripheral side surface 16 of the recess 14. In other words, the inner surface 52 faces the edge of the dial 24 with the cover 30 in between. Thereby, the light traveling from the LED 40 along the optical axis OA in the cover 30 can be reflected by the inner side surface 57 shown in FIG. 2B and further reflected by the inner side surface 52 to be irradiated on the edge side of the dial plate 24.

  When the outer peripheral end surface 37, the inner side surface 57, and the inner peripheral side surface 16 are located on the same plane, even if the light is reflected by the inner side surface 57 covering the outer peripheral end surface 37 and travels to the dial plate 24, the light is transmitted by the inner side surface 57. Unless the light is reflected in a right angle direction, the light does not reach the edge of the bottom surface of the recess 14, so that it is difficult to irradiate the edge of the dial plate 24, and the entire dial plate 24 may not be irradiated with light uniformly. However, the outer peripheral end surface 37 is thus positioned outside the inner peripheral side surface 16, the inner side surface 57 covers at least a part of the outer peripheral end surface 37, and the inner side surface 52 faces the front surface 32 of the cover 30 and is recessed 14. Since it extends to the inner side of the inner peripheral side surface 16, the entire dial 24 can be irradiated with light uniformly.

  Next, the relationship between the exposed area and area of the inclined surface and the unevenness of light irradiated on the dial 24 will be described. FIG. 3A is an explanatory diagram of an inclined surface having an exposed area, and FIG. 3B is an explanatory diagram of an inclined surface having no exposed area.

  The length D from the inner peripheral side surface 16 of the exposed region of the inclined surface 38 shown in FIG. 3A is 1.5 mm. On the other hand, FIG. 3B shows a timepiece 1a designed so that the inclined surface 38 does not have an exposed region. In the timepiece 1a, the length D of the exposed region of the inclined surface 38 from the inner peripheral side surface 16 is 0 mm. In FIG. 3B, the exposed area of the inclined surface 38 is eliminated by adopting a recess 14 a having a size different from that of the recess 14.

  Using the timepieces 1 and 1a shown in FIGS. 3A and 3B, the LED 40 was turned on in the dark, and the unevenness of the light irradiation to the dial plate 24 was compared. FIG. 4 is a front view of the dial plate 24. As a result of comparing the unevenness of light irradiation to the dial 24 with the timepieces 1 and 1a, a darker region BL was generated near the outer periphery of the dial 24 than in the vicinity of the center. Further, in the timepiece 1a, a region HL that is partially brighter than the other regions is generated near the upper portion of the central portion of the dial 24. Therefore, it is considered that the inclined surface 38 having the exposed region contributes to suppressing unevenness of light irradiated on the dial 24. Note that the above comparison result is not intended to exclude the timepiece 1a from the scope of the present invention.

  FIG. 5 is a rear view of the frame 50a according to the modification. The frame 50a has inner side surfaces 52a and 52b having different reflectivities. The color of the inner surface 52a located on the side closer to the LED 40 is gray. The color of the inner surface 52b located on the side away from the LED 40 is lighter than gray. Therefore, the inner surface 52b has a higher light reflectance than the inner surface 52a. That is, the inner surface of the frame 50 has a higher light reflectance on the side farther from the side closer to the LED 40. Thus, by reducing the reflectance on the bright side close to the LED 40, the bright dial plate 24 close to the LED 40 is prevented from being illuminated brightly, and the reflectance on the side far from the LED 40 is increased to increase the reflectance far from the LED 40. The side can be prevented from being darkly illuminated. Thereby, the entire dial 24 can be irradiated with light uniformly.

  Similarly to the frame 50a, the inner peripheral side surface of the recess may be configured so that the reflectance is partially different. Thereby, the entire dial 24 can be irradiated with light uniformly.

  Alternatively, when a part of the dial 24 is intentionally brightened, the reflectance of the inner side surface or the concave portion of the frame 50 corresponding to that part is made higher than that of the other part, so that a part of the dial 24 Can be brightened.

  In order to illuminate the entire dial plate uniformly, for example, the dial plate is formed of a light-transmitting resin, and this dial plate is used as a light guide plate by irradiating the dial with light from the light emitting portion. It is possible. However, in such a configuration, the dial material is limited to a material that functions as a light guide plate. For example, a metal cannot be used as the dial material. Further, since the dial itself is used as the light guide plate, a dark dial such as black cannot be used. Therefore, in the configuration as described above, the choices of the dial material are narrowed. In the case of an analog timepiece, the rotation shaft to which the hour hand is fixed passes through the center of the dial. For this reason, when only one light emitting part is provided, the light from the light emitting part is irradiated from one direction to the rotation axis, and thus a shadow is generated on the dial plate in the vicinity of the rotation axis. Therefore, with such a configuration, there is a possibility that the entire dial cannot be irradiated with light uniformly.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment, and various modifications can be made within the scope of the gist of the present invention described in the claims.・ Change is possible.

  In the above embodiment, a timepiece is described as an example of a pointer instrument. However, the present invention is not limited to this. For example, a meter may be used as long as it can be measured with a hand.

  In the said Example, although LED was employ | adopted as a light emission part, it is not limited to this, For example, an incandescent lamp and a fluorescent lamp may be sufficient.

DESCRIPTION OF SYMBOLS 1, 1a Timepiece 10 Main body 12 Case 14, 14a Recessed part 16 Inner peripheral side surface 18 Inclined surface 20 Drive mechanism 22 Pointer 24 Dial 30 Cover 32 Front surface 34 Back surface 36 Edge portion 37 Outer peripheral surface 38 Inclined surface 40 LED (light emitting portion)
50, 50a frame body 52, 52a, 52b, 57 inner surface

Claims (6)

A body having a recess;
A dial and a pointer provided on the bottom surface of the recess,
A plate-like cover disposed on the front side of the dial plate and having light transparency;
A light emitting unit for irradiating light into the cover so that the planar direction of the cover and the optical axis are along
A frame body having an inner surface facing at least a part of the edge of the cover ,
The edge of the cover includes an outer peripheral end surface, an inclined surface continuous from the outer peripheral end surface to the back surface facing the dial,
The inclined instrument includes a pointer instrument that includes an exposed region spaced from the inner peripheral side surface of the concave portion inside the inner peripheral side surface of the concave portion . The outer peripheral end surface of the cover is outside the inner peripheral side surface of the recess,
The pointer instrument according to claim 1 , wherein an inner side surface of the frame covers at least a part of an outer peripheral end surface of the cover. The pointer instrument according to claim 1 or 2 , wherein an inner side surface of the frame body covers a front side of an edge portion of the cover and extends to an inner side than an inner peripheral side surface of the recess. The pointer instrument according to claim 1 or 2 , wherein the inclined surface has a contact area in contact with the concave portion. The pointer instrument according to any one of claims 1 to 4 , wherein the inner surface of the frame body is partially different in light reflectivity. The pointer instrument according to any one of claims 1 to 5 , wherein an inner peripheral side surface of the concave portion is partially different in light reflectivity.

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