JPH05323049A - Timepiece - Google Patents

Abstract

PURPOSE:To improve decoration value by forming an optical thin film for lowering light reflected at least on one surface of a transparent body to ensure the determination of time. CONSTITUTION:Magnesium fluoride is used as one example of an optical thin film C to form the optical thin film C on the entire surface of a transparent body 7 by a vacuum evaporation means. A light beam incident to the surface of the transparent body 7 is checked from the reflection by the optical thin film C while the quantity of the reflected light beam is reduced significantly so that time shown on a time display section 4 can be determined accurately almost free from dazzling. Moreover, the optical thin film C has a nature of not only reducing the reflected light beam but also of increasing transmission of the light beam with respect to the transparent body 7. For example, the determination of time is ensured even in a room or the like with insufficient quantity of illumination light. This also achieves better appearance of the transparent body 7 itself without impairing color tone and decorativeness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided with a time generating section such as a movement and an electronic circuit, and a time displaying section having a pointer, a liquid crystal display device and the like, and a transparent body is provided at a position covering the time displaying section. More specifically, the present invention relates to an improved timepiece for a transparent body.

[0002]

2. Description of the Related Art Taking a wristwatch as an example, conventionally, a case provided with a belt or the like is provided with a time generating portion such as a movement, and a dial for notifying time information from the time generating portion. The case is provided with a transparent body such as glass so as to protect the plate and the like. Also, as a technique related to this transparent body, there is one disclosed in Japanese Patent Publication No. 63-18147, and in this conventional example, the transparent body is made of glass, and this glass has a small surface such as a diamond cut. A large number of are molded to improve the aesthetic appearance of the glass.

[0003]

Now, considering a conventional timepiece provided with a transparent body, this transparent body is used for indicating the time, or dust or the like attached to the time display portion of a liquid crystal display device or the like. It also has a function of preventing contact with foreign matter and allowing visual recognition from the outside. However, since this transparent body is usually formed by molding glass, resin or the like into a plate shape, for example, when looking into the time display section to know the time in the room, depending on the position of the person, In many cases, the light of room lighting such as a fluorescent lamp reflected on the surface of the transparent body shines on the human eye, and it is often difficult to read the time due to glare. Incidentally, such inconvenience occurs not only in the wall-mounted timepieces but also in wristwatches and table clocks, and this glare is caused not only by the light rays of indoor lighting such as fluorescent lamps but also by the sun rays. However, when the sunlight hits the eyes in this way, it becomes more difficult to visually recognize the time, and an appropriate improvement is desired.

Further, to think about a clock from another viewpoint,
Clocks installed indoors are often used as interior decorations. As such, for decoration purposes, there are also commercially available watches with a decorative pattern such as the outer surface or dial. .. Thinking about wristwatches, wristwatches are often used as accessories, and expensive materials are used for cases, belts, etc. that contain movements, and dials with patterns are also often used. It is also practiced to use a transparent body for glass.
However, even in a timepiece used as interior decoration, the hue of the light rays reflected by the transparent body matches the hue of the light source in the same manner as described above. Even if the colored one is used, the value of the decoration is often halved by reflecting the white light of the fluorescent lamp. Such inconvenience also occurs in a wristwatch or the like, and improvement is desired from the viewpoint of improving aesthetics. By the way, to think about improving aesthetics by using colored glass as a transparent body, the phenomenon of reflecting light rays does not change even when using this kind of glass, and this colored glass absorbs light rays,
Since the light transmittance is lowered, it becomes difficult to check the time, and it cannot be said that the use of colored glass or the like is appropriate.
An object of the present invention is to rationally construct a timepiece that reliably grasps the time even if the transparent body is at an angle that reflects light rays toward the human eye, and that does not impair the value of decoration. There is a point to do.

[0005]

As described at the beginning, the features of the present invention include a time generating unit such as a movement and an electronic circuit, and a time displaying unit including a pointer, a liquid crystal display device, and the like. In a timepiece in which a transparent body is arranged in a position to cover the time display portion, an optical thin film for reducing reflected light is formed on at least one surface of the transparent body, and the action and effect are It is as follows.

[0006]

When magnesium fluoride (MgF ₂ ) is used as an example of the optical thin film C and the optical thin film C is formed on the entire surface of the transparent body 7 as shown in FIG. 1 by means of vacuum vapor deposition as shown in FIG. Since the optical thin film C suppresses the phenomenon of reflection of the light rays incident on the surface of the body 7, the light quantity of the reflected light rays is greatly reduced even when a person visually recognizes the time display unit 4 from the reflection direction of the light rays. Therefore, the time shown on the time display unit 4 can be accurately grasped in a state where it is difficult to feel glare. Further, since the optical thin film C has not only the property of reducing reflected light rays but also the property of increasing the amount of light rays transmitted to the transparent body 7, when the optical thin film C is formed on the transparent body 7 as described above, For example, even when checking the time of a clock in a room or the like where the amount of illumination light is insufficient, the small amount of light is effectively guided to the time display unit 4 to ensure the grasp of the time. Further, since the amount of light rays reflected by the transparent body 7 is reduced, the pattern and color tone of the time display portion 4 are not damaged by the hue of the reflected light. It should be noted that this optical thin film C produces a slight amount of reflected light, and this reflected light can obtain almost all hues in the visible light region by means such as selection of thin film material and setting of film thickness. It is also possible to unify the hue of the reflected light with that of the time display unit 4, the case of the timepiece, the hue, and the like. That is, in the present invention, by forming an optical thin film, which has been conventionally used for an optical lens or the like, on the surface of the transparent body 7 such as a watch glass, the light reflection on the surface of the transparent body 7 is reduced and Since the amount of transmitted light of the body 7 can be increased and the time can be easily grasped, the aesthetic appearance of the transparent body 7 itself can be improved without impairing the color tone and decorativeness of the time display portion 4 and the like. is there.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 2 and 3, a dial 4 (an example of a time display unit) having a minute hand 1, a minute hand 2 and a second hand 3 and a movement 5 (which drives the long hand 1, the minute hand 2 and the second hand 3 respectively). An example of a time generation unit) is housed in a metal case 6, a glass transparent body 7 is fixed to the case 6 by a retaining ring 8 at a position to cover the dial 4, and a back surface of the case 6 is closed. A wristwatch (an example of a timepiece) is provided with the body 9 and the belt 10. As shown in FIG. 1, in this wristwatch, the inner surface and the outer surface of the transparent body 7 are coated with optical thin films C and C for reducing the reflected light, and the dial 4
The visibility of is improved. That is, the optical thin film C uses magnesium fluoride (MgF ₂ ), the transparent body 7 is housed in a vacuum container 11 as shown in FIG. 4, and the thin film material (magnesium fluoride) of the evaporation source 12 is resistance-heated or the like. And the film is formed on the surface of the transparent body 7 by a vapor deposition means to have a film thickness of about 1/4 of the wavelength of visible light. still,
As described above, in order to obtain a film thickness of about ¼ of the wavelength of visible light, the reflectance or the transmittance of the light beam during the vapor deposition process can be measured by a monochromatic photometric method, a dual wavelength photometric method, a wavelength scanning method, or the like. Is measured directly to determine the timing for stopping the vapor deposition. By the way, in this optical thin film C, the wavelength of visible light is assumed to be about 550 nm, which has the highest spectral sensitivity to the naked eye in the wavelength range of visible light, and the optical thin film C is formed with a thickness of 1/4 of this wavelength, Visually satisfactorily reduces reflected light.

The thin film material used for the optical thin film C is
Ideally, the refractive index should be the square root of the refractive index of the transparent body 7, and considering that the refractive index of general glass is about 1.5, the refractive index of magnesium fluoride is 1.3.
In Fig. 9, the reflected light can be satisfactorily reduced because it is close to the square root of 1.22 of the refractive index of 1.5 of the glass. Incidentally, the resistance heating is a means for energizing a resistor such as a tungsten filament and raising the temperature of the thin film material to the evaporation temperature by heat generation of the resistor by Joule heat.
In addition, this vacuum deposition process is performed on both surfaces of the transparent body 7,
Alternatively, both sides of the transparent body 7 are coated with the optical thin film C by means such as inverting the transparent body 7 in a vacuum container. In the transparent body 7 thus formed with the optical thin film C, the reflection of light rays on the surface is reduced, and at the same time, the amount of light rays passing through the transparent body 7 is increased, so that the display content of the dial 4 can be surely grasped. In addition, the color of a slight reflected light beam generated on the surface of the optical thin film C can improve the decorative property and the aesthetic appearance.

[Other Embodiments] In addition to the above embodiments, the present invention is
For example, it can be configured as follows. (A) Applicable to relatively large watches such as wall clocks and table clocks, in addition to those worn like watches. (B) The present invention is applied to a structure in which the time generation unit is composed of an electronic circuit and the time display unit has a liquid crystal display device for notifying the time with digital numbers. (C) As a technique for forming an optical thin film on a transparent body, a technique of evaporating a thin film material by electron beam heating in a vacuum environment or by a flash evaporation method is used. (D) Forming an optical thin film with multiple layers of different thin film materials (a technique called multi-coating with an optical lens),
An optical thin film is formed on one surface of the transparent body. (E) An optical thin film having an arbitrary refractive index is formed by a so-called mixed vapor deposition method of evaporating two or more thin film materials in a mixed state. (F) The thin film material is not limited to magnesium fluoride, but alumina (Al ₂ O ₂ ), titanium oxide (TiO ₂ , Ti
It is possible to use compounds such as O) and silicon dioxide (SiO ₂ ), and it is also possible to use metals such as gold (Au), silver (Ag), and aluminum (Al). (G) Resin is used for the transparent body arranged outside the time display portion, and an optical thin film is formed on this resin.

[0010]

As described above, by forming an optical thin film on a transparent body, even if the transparent body is at an angle at which a light ray is reflected toward the human eye, a person feels dazzling eyes. Make sure to grasp the time by visual confirmation without
Since this optical thin film reduces the reflected light and increases the transmitted light, it is possible to check the time accurately even when checking the time in a relatively dark environment. At the same time that the light enhances the aesthetic appearance, the watch was rationally constructed to further increase the value of the decoration by suppressing the reflection of light.

[0011]

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a transparent body portion.

[Figure 2] Front view of the wristwatch

FIG. 3 is an exploded perspective view of a wristwatch

FIG. 4 is a sectional view of a vacuum vapor deposition device.

[Explanation of symbols]

 4 Time display section 5 Time generation section 6 Case 7 Transparent body C Optical thin film

Claims (4)

[Claims] 1. A time generating section (5) such as a movement and an electronic circuit, and a time display section (4) having a pointer, a liquid crystal display device and the like, and at a position to cover the time display section (4). A timepiece comprising a transparent body (7), wherein the transparent body (7) is provided with an optical thin film (C) for reducing reflected light on at least one surface thereof. 2. The time generating section (5) and the time display section (4) are housed in a case (6), and the timepiece is constructed as a wrist watch, and the optical thin film (C) is placed in the case (6). The timepiece according to claim 1, which is formed by supporting the formed transparent body (7). 3. The optical thin film (C) is formed on the surface of the transparent body (7) by arranging the transparent body (7) in a vacuum container and performing vacuum evaporation to heat and evaporate a thin film material. The timepiece according to claim 1, further comprising: 4. The timepiece according to claim 1, wherein the optical thin film (C) is composed of a plurality of layers of different thin film materials.