JP2000105284A - Time piece with luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly illuminate the whole time display part of a time piece in a dark site with excellent visibility by laminating a hologram sheet on a display part side surface or a face reverse to a display part of a transparent member to diffract, toward the display part, illumination light guided from a luminaire arranged in a side face of the transparent member into the transparent member. SOLUTION: A luminaire 6 comprising an LED or the like is arranged inside a shell case 8 in a side face of a transparent cover 5 fixed in a front face of a time display part to protect an inside of a time piece. Illumination light from the luminaire 6 is guided from the transparent cover 5 to its inside to serve as guided illumination light 20, and it is dispersed as illumination light 21 diffracted toward the display part of the time piece by a hologram sheet 10 laminated on the transparent cover 5, so as to illuminate the display part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timepiece with lighting equipment.

[0002]

2. Description of the Related Art Conventionally, in order to make it easy to read the time of a clock at night or in a dark place, a method of applying a luminescent material such as a phosphorescent paint or a luminous paint to a part of a time display portion of the clock such as a dial or a hand has been conventionally used. Was adopted. In addition, with the digitization of timepieces, a method of illuminating a time display unit with a point-emission illuminator such as a micro lamp or a light emitting diode (LED) has been generalized.

Further, in recent years, as described in US Pat. No. 4,775,964, a watch using an electroluminescent (EL) element as a lighting device has been put to practical use. Since the EL element is flat and thin and emits surface light, the entire time display portion can be uniformly illuminated, and there is an advantage that the timepiece becomes compact. In the case of a timepiece having a liquid crystal display section, it can be used as a backlight for liquid crystal. on the other hand,
2. Description of the Related Art Clocks that have an alarm function and generate an alarm sound at a set time or the like and turn on a light to notify an alarm occurrence time are generally known.

[0004]

Each of the above-mentioned conventional lighting methods has a problem. That is, in the method using the light emitting material, the visibility of the time display was insufficient because the light emission duration was short and the light emission intensity was low. Further, in the method using a point-emission type lighting device such as a micro lamp or an LED, it is difficult to uniformly illuminate the entire surface of the time display unit because local illumination is provided. For example, FIG. 6 is a cross-sectional view showing an example of a conventional pointer-type timepiece with lighting equipment. A time display unit including a dial 1, an hour hand 2, a minute hand 3, and a second hand 4 is housed in a body case 8 together with a movement mechanism unit 7. A transparent cover 5 as a transparent member is fixed to the front of the time display section to protect the inside of the timepiece.

An illuminator 6 composed of LEDs is arranged on the inner side wall of the body case 8 and the like, and illuminates the time display section with the illumination light. However, as described above, in the point-emission illuminator, the vicinity thereof is illuminated brightly, but it becomes darker as the distance from the illuminator increases, making it difficult to uniformly illuminate the entire time display portion.

Although the EL element has the above-mentioned advantages, it has a problem that it is expensive. In a conventional watch with lighting, E
A dial made of a transparent material is provided on the front surface of the L element, and the dial is illuminated from the back surface. Therefore, there is a problem that the material of the dial is limited and opaque ones cannot be used. In addition, there is an unnaturalness in that the front side such as a pointer becomes slightly darker because of illumination from the back side.

[0007] Further, since lighting equipment such as EL consumes large power, when it is necessary to generate an alarm sound at the same time as lighting, the battery voltage may drop, and the operation of the clock circuit becomes unstable. Battery life.

Further, when an alarm is issued by turning on a light, it is necessary to have a brightness of the light which can be visually recognized even in the light. On the other hand, since this illumination is also used as illumination at night or in the dark, it is too bright as it is, and the battery life is unnecessarily consumed. Therefore, in many cases, the brightness is set to an intermediate value. However, the illumination is too bright in the dark, the light is too dark to emit an alarm, and both functions may be incomplete. Both the lighting function and the alarm function are important functions, and sacrificing either one has impaired the marketability of the watch.

In order to solve these problems, Japanese Patent Laid-Open No.
Japanese Patent Publication No. 138262 discloses a lighting device (LED) with low illuminance.
It is proposed that a lighting device (incandescent lamp) with high illuminance be provided, and that the lighting device and the alarm be used properly. However, in this method, since two types of lighting fixtures are provided, there is a problem in space, and there is a problem in that compactness is hindered. In addition, a dedicated circuit has to be provided for each lighting fixture having different operating conditions.

In Japanese Patent Application Laid-Open No. 8-220264, a display drive unit control means is provided which has two input signals, an illumination signal for operating a lighting device and a sound signal for operating an alarm sound generator. Also, it has been proposed that the alarm does not sound even when the alarm set time comes during the operation of the lighting device, and the display unit blinks to perform the alarm operation. However, this method merely flashes the lighting equipment for dark lighting, and is not always sufficient as a caution effect when an alarm occurs. An object of the present invention is to provide a timepiece with a lighting device that solves these problems of the related art.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a display section for displaying time, a lighting device for illuminating the display section, and a display section on the front side of the display section. In a timepiece with a lighting device provided with at least a transparent member provided, a lighting device is arranged on a side surface of the transparent member, and a hologram sheet is laminated on a surface of the transparent member on a display portion side or a surface opposite to the display portion. Further, there is provided a timepiece with a lighting device, wherein the illumination light emitted from the lighting device and guided through the transparent member is diffracted toward the display unit.

Further, an alarm sound generator is added, a lighting device having a plurality of emission colors is provided, and the hologram sheet has a function of diffracting light of a plurality of emission colors. The timepiece with the lighting device, wherein the color of the illumination light changes with time, is provided. Further, the present invention provides the illuminated timepiece described above, wherein the diffraction efficiency of the hologram sheet increases as the distance from the illuminator increases.

[0013]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of a timepiece with lighting equipment of the present invention. The same components as those in FIG. 6 are denoted by the same reference numerals. A time display unit including a dial 1, an hour hand 2, a minute hand 3, and a second hand 4 is housed in a body case 8 together with a movement mechanism unit 7. A transparent cover 5, which is a transparent member, is fixed to the front of the time display section to protect the inside of the timepiece.

An illuminator 6 composed of an LED is arranged in the body case 8, and the illuminating light is guided from the side surface of the transparent cover 5 into the inside, and becomes the illuminating light 20 to be guided. The illumination light 20 to be guided is diffracted by the hologram sheet 10 disposed on the transparent cover 5 toward the time display unit.
It is diffused as 1 and illuminates the time display.

FIG. 1 shows, as an example, a state in which one light beam emitted from the lighting device 6 is repeatedly reflected in the transparent cover 5 and diffracted by the hologram sheet 10. For this reason, it is shown that the light is diffracted by the hologram sheet only discretely. However, as described later, the illuminator actually emits light that is spread at various angles, so that illumination can be performed over a wide range. When the illumination light is repeatedly reflected in the transparent cover 5, if the total reflection condition is satisfied, the light can be guided to a distant place without losing the light amount on the reflection surface.

Further, the present invention uses an illuminator having a plurality of luminescent colors, and when it is necessary to simultaneously perform the illumination and the alarm operation, instead of generating an alarm sound, the luminescent color differs from that in the normal illumination. Change the lighting. For example, normal illumination is performed in green and red when an alarm occurs, so that battery consumption can be reduced and the alerting effect when an alarm occurs can be significantly improved. As a method of changing the emission color, the color may be changed to light or blink, or a plurality of colors may alternately blink. The use of colorful colors can also improve the fashionability of the watch.

Next, another embodiment of the present invention will be described with reference to FIG.
It will be described in detail based on. Here, LE of two-color emission
The lighting fixture 6 made of D is arranged inside the body case, and the illuminating light is guided inside from the side surface of the transparent cover 5 to become the illuminating light 20 to be guided. The illumination light 20 to be guided is the illumination light 2 diffracted toward the time display unit by the hologram sheet 10 that diffracts the light of two wavelengths arranged on the transparent cover 5.
1, the light is diffracted diffusively, and the time display unit can be illuminated.

At the time of normal illumination, one light emitting color (for example, green) LED is turned on. An alarm sound may be generated at the time of an alarm at the time of light. However, when lighting and an alarm are performed simultaneously at night or the like, the LED of the other emission color (for example, red) is turned on instead of emitting an alarm sound. Or, both may be blinked alternately. Also, LEDs of three or more colors may be used. In this case, hologram sheet 1
0 diffracts three or more emission colors.

From the viewpoint of miniaturization, it is preferable to mount a plurality of LED chips of different emission colors in a single mold as a plurality of light emitting LEDs. If space is available, a plurality of separate LEDs having different emission colors may be used. As described above with reference to FIG. 1, even when light of a plurality of luminescent colors is repeatedly reflected in the transparent cover 5 and diffracted by the hologram sheet 10, light of the plurality of luminescent colors from the illuminating tool is various. Since the light is emitted at an angle, it can be illuminated with different colors over a wide range.

FIG. 2 is a conceptual diagram for explaining how the illumination light is guided. Specifically, the angle of incidence θ on the interface between the transparent cover 5 and the hologram sheet 10, which are the reflecting surfaces shown in FIG.
(Shown as θ _a and θ _{b in the} figure) preferably satisfies the expression (1). The same holds true for monochromatic illumination light and multicolor illumination light. In FIG. 2, 20a and 20b are illumination light to be guided, and θ _a and θ _b are incident angles of the respective illumination light. sin θ ≧ 1 / n (1) where n is the refractive index of the transparent cover. When the transparent cover is made of glass or transparent resin, n is about 1.5. Therefore, θ is expressed by equation (2) from equation (1). θ ≧ 42 °... (2) The illumination light from the illuminator has a spread, and if the range of the spread of the incident angle due to the spread is expressed as θ _a ≦ θ ≦ θ _b , θ in this range becomes ( It suffices to satisfy the expression 2).

It is preferable that the hologram sheet diffracts the incident light toward the time display section. In order to illuminate a wider range, it is preferable to have a diffusing function so that diffracted light is diffused. Further, it is preferable that the diffraction wavelength of the hologram matches the wavelength of the light emitted from the lighting device 6. In order to obtain a hologram that diffracts light of wavelengths corresponding to a plurality of emission colors, a plurality of separate hologram sheets that diffract light of wavelengths corresponding to different emission colors may be laminated, or one hologram may be used. A hologram having a plurality of characteristics may be multiplex-recorded therein.

Although a transmission type hologram is shown in FIG. 1, a similar effect can be obtained with a reflection type hologram. That is, when the hologram sheet 10 is arranged on the surface of the transparent cover 5 on the display unit side, a transmission type hologram is used, and when the hologram sheet 10 is arranged on the surface of the transparent cover 5 opposite to the display unit side. May use a reflection type hologram. If the diffraction efficiency of the hologram is uniform over the entire surface, the intensity of the diffracted light becomes weaker as the distance from the illumination device increases. Therefore, it is preferable that the diffraction efficiency of the hologram increase as the distance from the illumination device increases.

According to the present invention, even with light from a point light source type lighting device, the entire time display portion can be uniformly illuminated by guiding the light inside the transparent cover. In addition, since the time display unit is illuminated from the front rather than from the back side as in the EL element, it is possible to provide a comfortable illumination.
In addition, since there is no restriction on the material of the dial and opaque ones can be used, design and fashion can be improved.

The type of hologram used in the present invention is preferably a volume phase hologram having good transparency and high diffraction efficiency. Illumination can also be performed with an embossed hologram or the like, but is not optimal for illumination of a watch because the transparency is impaired. As the hologram photosensitive material, a photopolymer, gelatin dichromate, a silver salt-based material, a photoresist and the like can be used.

As a mode of disposing the hologram sheet 10 on the transparent cover 5, a method of attaching the hologram sheet 10 to the surface of the transparent cover on the time display side as shown in FIGS. 1 and 2 can be exemplified. Further, in consideration of protection of the hologram sheet, a transparent protective cover 11 may be provided as shown in FIG. Here, FIG.
It is a partial expanded sectional view of a timepiece with a lighting fixture of the present invention. In particular, in the case of a hologram photosensitive material that is weak to humidity such as gelatin dichromate, the form in which the hologram sheet 10 is sealed between the transparent cover 5 and the protective cover 11 is preferable.

The material of the transparent cover is preferably transparent and resistant to damage in view of preventing absorption loss of the light to be guided and ensuring visibility of the dial. Examples thereof include a glass plate and a transparent resin plate provided with a hard coat. Also, those colored from the viewpoint of fashionability can be used. In that case, a material having a small light absorption with respect to the wavelength of the light to be guided is preferable.

The adhesive or pressure-sensitive adhesive for adhering the hologram and the base material is preferably one that can adhere with required strength and ensure long-term reliability. Those having high transparency and low scattering are particularly preferable because of low loss of light. From the viewpoint of downsizing of the timepiece and the life of the battery, it is preferable that the illuminator is small, has low power consumption, and has high luminous efficiency. Examples of the point-emission type lighting device include an LED, a semiconductor laser, and a small incandescent lamp. Further, a surface-emitting light-emitting element such as an EL element may be used.

The degree of spread of light of the point emission type lighting device is various. If the directivity is too narrow to illuminate the entire time display unit, a plurality of illuminators may be used. It is also effective to increase the spread in the plane of the transparent cover and narrow the spread in the plane perpendicular to the transparent cover.
For this purpose, a combination of a lighting device having a uniform spread and a cylindrical lens can be exemplified. Further, the shape of the light incident surface of the transparent cover may be cylindrical. In the LED, the spread of light can be controlled by making the shape of the mold lens asymmetric. In addition, since the LD spreads light in two directions due to astigmatism, the light may be used.

As a method of guiding the illumination light from the lighting device 6 into the transparent cover 5, an edge light method in which the light is incident from the side surface of the transparent cover 5 as shown in FIG. 1 can be exemplified. Further, a prism coupling method or the like in which a prism or the like is brought into contact with the surface of the transparent cover and light is incident through the prism can also be adopted. This method should be appropriately selected according to the configuration and space inside the timepiece, and is not limited to the above method.

The present invention is particularly effective in a small portable timepiece such as a wristwatch, but can be similarly applied to a table clock and a wall clock. Further, in the above-mentioned timepiece with lighting equipment, the time display section may be a pointer type one including a pointer and a dial, an electronic type using a liquid crystal display element, or a combination thereof.

[0031]

[Example 1] In Example 1, the configuration shown in FIG. 1 was employed. As described above, the time display unit including the dial 1, the hour hand 2, the minute hand 3, and the second hand 4 is housed in the body case 8 together with the movement mechanism 7. A transparent cover 5 is fixed to the front of the time display section to protect the inside of the timepiece.

An illuminating device 6 made of an LED is arranged inside the body case, and the illuminating light is guided from the side of the transparent cover 5 to the inside to become the illuminating light 20 to be guided. The illuminating light 20 guided is the hologram sheet 10 disposed on the transparent cover 5.
As a result, the light was diffracted diffusively toward the time display portion as indicated by 21, and the time display portion was uniformly illuminated.

The emission wavelength of the LED used in Example 1 was about 560
It is a green emission color in nm. FIG. 4 is a schematic diagram illustrating the directivity of light emission of the lighting fixture of Example 1. The spread angle at which the light intensity becomes half is ± 15 ° from the front. That is, most of the emitted light exists within the range of ± 15 °. In Example 1, this light is 60 ° ± 15 ° with respect to the hologram sheet,
That is, the light was guided so that the incident angle was within the range of θ _a = 45 ° and θ _b = 75 °. This angle range is (2)
In order to satisfy the expression, most of the light was guided in the transparent cover in a total reflection manner.

The hologram sheet was provided with a function of diffracting light near 560 nm incident at 60 ° in the transparent cover in the direction of the display plate at a time (perpendicular to the surface of the transparent cover). Specifically, the light having a wavelength of about 560 nm oscillated from the dye laser device is separated into two light beams, one of which is a spherical wave incident at 60 °, the other is a diffused light which is incident vertically, and both of them are in a hologram photosensitive material. And interference fringes were recorded. An acrylic photopolymer was used as the hologram photosensitive material. The hologram was sealed in a glass substrate with a thermosetting adhesive.

Example 2 In Example 2, the configuration shown in FIG. 1 was adopted, but the illumination tool 6 and the hologram sheet 10 were different from Example 1. A lighting device 6 composed of two-color light emitting LEDs having two chips for red and green mounted in one mold is arranged inside the body case, and the illumination light is guided from the side of the transparent cover 5 to the inside. , And the illumination light 20 to be guided.
The guided illumination light 20 was diffusively diffracted by the hologram sheet 10 disposed on the transparent cover 5 toward the time display unit as indicated by 21, and the time display unit was uniformly illuminated.

The emission wavelength of the LED used in Example 2 was about 560
nm green emission and about 630 nm red emission. FIG. 5 is a schematic diagram showing the directivity of light emission of Example 2. This indicates the directivity of light emission in a cross section parallel to the transparent cover surface. FIG. 4 shows the directivity in the plane of FIG. In the cross section parallel to the transparent cover surface, the traveling directions of the light emitted from the red LED and the green LED are slightly different,
In the paper of FIG. 1, the directivities of the two are almost the same, and the spread angle at which the light intensity becomes half is ± 15 ° from the front.
That is, most of the emitted light exists in a range of ± 15 °. In Example 2, this light was applied to the hologram sheet by 6
0 ° ± 15 °, that is, the incident angles θ _a = 45 ° and θ _b = 7
The light was guided so as to be incident within a range of 5 °. Since this angle range satisfies the expression (2), most of the light was guided in the transparent cover in total reflection.

The hologram sheet was provided with a function of diffusing diffracting light near the wavelengths of 560 nm and 630 nm incident at 60 ° in the transparent cover in the direction of the display panel at a time (perpendicular to the surface of the transparent cover). Specifically, after light having a wavelength of about 560 nm oscillating from a dye laser device and light having a wavelength of 647 nm oscillating from a Kr laser device are coaxially superposed, the light is separated into two light beams, and one light beam is split into two light beams.
The hologram photosensitive material was multiplex-recorded by causing a spherical wave to be incident at an angle of 0 ° and a diffused light to be incident perpendicularly, and making the two interfere with each other in one hologram photosensitive material. An acrylic photopolymer was used as the hologram photosensitive material. The hologram sheet was sealed in a glass substrate with a thermosetting adhesive.

[0038]

According to the present invention, it is possible to uniformly illuminate the entire time display portion of the clock in a dark place with good visibility. Moreover,
It is possible to illuminate from the front side instead of the back side of the time display unit like the EL element. In addition, there is no restriction on the material of the dial, and opaque ones can be used. In addition, battery consumption can be reduced, and the effect of alerting when an alarm occurs can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a timepiece with lighting equipment of the present invention.

FIG. 2 is a conceptual diagram illustrating a state of guiding illumination light.

FIG. 3 is a partially enlarged sectional view of a timepiece with a lighting device of the present invention.

FIG. 4 is a schematic diagram showing directivity of light emission of a lighting fixture in the embodiment.

FIG. 5 is a schematic diagram showing directivity of light emission of a lighting device in another embodiment.

FIG. 6 is a cross-sectional view showing an example of a conventional pointer-type timepiece with lighting equipment.

[Explanation of symbols]

 1: Dial 2: Hour hand 3: Minute hand 4: Second hand 5: Transparent cover 6: Illumination tool 7: Movement mechanism 8: Body case 10: Hologram sheet 11: Protective cover 20, 20a, 20b: Illuminated light Light 21: Diffracted illumination light

Claims (3)

[Claims] 1. A timepiece with an illuminator, comprising at least a display unit for displaying time, an illuminator for illuminating the display unit, and a transparent member disposed on the front side of the display unit. A lighting device is arranged on the side surface, a hologram sheet is laminated on the surface of the transparent member on the display unit side or on the surface opposite to the display unit, and illumination light emitted from the lighting device and guided through the transparent member is displayed on the display unit. A clock with lighting equipment, characterized in that it is diffracted toward. 2. An alarm sound generator is added, an illuminator having a plurality of luminescent colors is provided, and the hologram sheet has a function of diffracting light of a plurality of luminescent colors. The timepiece with a lighting device according to claim 1, wherein the color of the illumination light changes with time. 3. The timepiece with a lighting device according to claim 1, wherein the diffraction efficiency of the hologram sheet increases as the distance from the lighting device increases.