JPH08305295A - Light emitting device - Google Patents

Abstract

PURPOSE: To provide a light emitting device which can display patterns, logos, etc., so that they can be easily seen. CONSTITUTION: A half mirror 6 is formed on time upper surface of a transparent film 7 by deposition, etc., and a white print layer 5 is formed on the upper surface of the half mirror 6. An image print layer 8 where a pattern, etc., is printed is formed on the lower surface of the transparent film 7. A liquid-crystal display device 10 and an electroluminescent panel (EL) 9 are placed on the upper and lower surfaces of the transparent film 7, respectively. While the EL 9 emits light, the light of the EL 9 passes through the image print layer 8, the transparent film 7, the half mirror 6, the white print layer 5, and the liquid-crystal display device 10 and goes outside, allowing the pattern to be seen clearly from above in the figure 1. While the EL 9 emits no light, external light is attenuated by the white print layer 5 and the half mirror 6, making the pattern hard to see from the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device using an electroluminescence element.

[0002]

2. Description of the Related Art An electroluminescence device is used as a backlight of a liquid crystal display device and a dial of an analog timepiece.

Further, conventionally, there is an electronic timepiece or the like in which a film on which a pattern is printed is arranged between a liquid crystal display device and an electroluminescence device and the pattern is displayed through the liquid crystal display device when the electroluminescence device emits light. It is considered.

[0004]

However, when the electroluminescence element is used as a backlight and a pattern is displayed by causing the electroluminescence element to emit light, even when the backlight is turned off, The problem that the pattern on the lower side of the liquid crystal display device (or dial) can be seen by the light from the outside, and the display of the liquid crystal display device is rather difficult to see in the normal state in which the electroluminescence element is turned off. There was a point.

An object of the present invention is to provide a light emitting device which can display a picture, a logo and the like in an easy-to-see manner.

[0006]

The light emitting device of the present invention comprises a white printed layer, a semitransparent layer, a printed layer, and an electroluminescent layer disposed on the lower surface of the printed layer.

For example, a semitransparent layer is arranged on the lower surface of the white printing layer, and a printing layer on which a pattern or the like is printed is arranged on the lower surface of the semitransparent layer. Furthermore, an electroluminescent layer is arranged on the lower surface of the printed layer.

[0008]

According to the present invention, when the electroluminescent layer is emitting light, the light of the electroluminescent element goes out through the printing layer, the semitransparent layer and the white printing layer. As a result, the pattern printed on the print layer can be clearly seen from the outside.

On the other hand, when the electroluminescence layer does not emit light, the light from the outside emits white print,
It is attenuated by the semi-transparent layer, making the printed layer less visible to the outside.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a light emitting device of a first embodiment of the present invention in which an image print layer (described later) on which a pattern or the like is printed and an electroluminescence panel are arranged on the lower surface of a liquid crystal display device. This light emitting device is used as a display unit of an electronic wrist watch.

This light emitting device is arranged on the lower surface of the liquid crystal display device 10, which is composed of an upper deflection plate 1, an upper glass substrate 2 of the liquid crystal display device, a lower glass substrate 3 and a lower deflection plate 4. , White printing layer 5 and half mirror 6
And a transparent film 7 on which an image print layer 8 on which a pattern or the like is printed is formed, and an electroluminescence panel (EL) 9 arranged on the lower surface of the image print layer 8.

The half mirror 6 is a semitransparent layer having different transmittances on the front and back sides, and is formed on the upper surface of the transparent film 7 by fusing or the like. The half mirror 6 is external (see FIG.
The light incident from above) is attenuated more than the light from the electroluminescence panel 9. The white print layer 5 is formed on the half mirror 6. An image print layer 8 on which a pattern or the like is printed is formed on the lower surface of the transparent film 7.

That is, in this embodiment, the white printing layer 5, the half mirror 6, and the image printing layer 8 are integrally formed on the upper and lower surfaces of the transparent film 7. In the light emitting device having such a structure, when the electroluminescence panel 9 is emitting light, the light of the electroluminescence panel 9 is applied to the image printing layer 8, the transparent film 7, the half mirror 6, the white printing layer 5, and the liquid crystal display. Since it goes out through the device 10, the pattern of the image printing layer 8 can be clearly seen from the upper side of FIG.

From the upper side of the half mirror 6 (see FIG.
Upper side), the amount of light incident from the lower side is larger than that of incident light, and since the white printing layer 5 is a thin layer, more light passes through the light-transmitting image printing layer 8 Because it appears in.

On the other hand, when the electroluminescent layer 9 is not emitting light, the light incident from the upper side of the light emitting device of FIG. 1 passes through the liquid crystal display device 10 and is reflected by the white printing layer 5 and the half mirror 6. .

Therefore, when the electroluminescence layer 9 does not emit light, the pattern printed on the image printing layer 8 becomes invisible from the outside, and the display of the liquid crystal display unit 10 becomes easier to see.

Next, FIG. 2 is a circuit block diagram of the electronic wrist watch of the first embodiment. In the first embodiment, if the user operates the electroluminescence panel 9 to emit light, the electroluminescence panel 9 is caused to emit light before the liquid crystal display device 10 is driven, and the image print layer 8 is formed.
Display the pattern printed on. After that, the liquid crystal display device 10 is driven to display the time and the like.

In FIG. 2, the clock signal generated by the oscillating circuit 21 is frequency-divided by the frequency dividing circuit 22 and output to the clock counting circuit 23 and the timer circuit 24 as a clock signal which serves as a reference for clocking time. The timekeeping index circuit 23 counts the timekeeping signal and outputs time data including date and hours, minutes, and seconds to the decoder 25.

The illumination switch 26 is a switch operated by the user when the user wants to turn on the backlight and see the dial of the clock. One end of the illumination switch 26 is grounded and the other end is a set of the flip-flop 27. It is connected to the terminal.

For example, when the lighting switch 26 is turned on by the user, the flip-flop 27 is set and the output Q of the flip-flop 27 becomes high level. When the output of the flip-flop 27 becomes high level, the EL drive circuit 28 operates and the electroluminescence panel 9 starts emitting light.

At the same time, when the timer circuit 24 starts time measurement and the time measured by the timer circuit 24 reaches 3 seconds, a high-level signal is output to the set terminal (S) of the flip-flop 29 and the flip-flop 29. Output Q becomes high level. When the output of the flip-flop 29 becomes high level, the driver 30 starts operating and the decoder 2
The time data output from 5 is displayed on the liquid crystal display device 10.

The circuit operation at this time will be described with reference to FIG. When the user operates the light switch 26 to see the dial of the wristwatch in a dark environment, the switch 26
Is grounded and the set input of the flip-flop 27 becomes high level (FIG. 3 (1)). This circuit is driven by a negative voltage, and the ground level becomes high level.

When the set input of the flip-flop 27 goes high, its output goes high (see FIG.
(2)), the EL drive circuit 28 is driven, and the electroluminescence panel 9 starts emitting light. As a result, in the state where no time is displayed on the liquid crystal display device 10,
Since the electroluminescence panel 9 emits light, the pattern printed on the image printing layer 8 can be clearly seen.

When the lighting switch 26 is turned on, the above-mentioned timer circuit 24 starts measuring time, and the timer circuit 24
When the measurement time of 3 reaches 3 seconds, a 3 second signal is output ((3) in the same figure). The 3-second signal sets the flip-flop 29, and the output of the flip-flop 29 changes to high level ((4) in the same figure). When the output of the flip-flop 29 becomes high level, the driver 30 is driven, and the time data output from the decoder 25 at that time is displayed on the liquid crystal display device 10.

After that, when the time measured by the timer circuit 24 reaches 6 seconds, a 6-second signal is output to the flip-flops 27 and 29.
Is output to the reset terminal and the flip-flops 27 and 29 are reset. When the flip-flop 27 is reset and its output becomes low level, the EL drive circuit 28 stops its operation. Further, when the flip-flop 29 is reset and its output becomes low level, the driver 30 stops its operation and the liquid crystal display device 10 does not display.

That is, in the first embodiment, when the user operates the illumination switch 26, the electroluminescence panel 9 emits light for 3 seconds before the liquid crystal display device 10 is driven, so that the image printing layer 8 is printed. It is possible to effectively show a picture, logo or the like on the liquid crystal display device 10 to the user without disturbing the display.

Next, FIG. 4 is a view showing the internal structure of an electronic wrist watch of the second embodiment in which the light emitting device of the present invention is applied to an analog timepiece, and FIG. 5 is a sectional view of a transparent film having a three-layer structure. is there.

The outer case of this electronic wrist watch is a watch case 41.
It consists of a watch glass 42 and a back cover 43. Inside,
A pointer 44 for displaying hours, minutes, and seconds is arranged, and the pointer 4
A transparent film 45 on which a half mirror, a pattern, etc. are printed is arranged at the lower part of 4. Further, an electroluminescence panel 46 is arranged below the transparent film 45.

FIG. 5 is a sectional view showing the structure of the transparent film 45. As shown in FIG.
A half mirror 51 having a characteristic that the transmittance of light from above is lower than the transmittance of light from below is formed by fusing, and the white printing layer 54 is formed on the upper surface of the half mirror 51.
Are formed. Furthermore, on the upper surface of the white print layer 54,
An hour character 52 indicating a time such as “1:00” and “2:00” of an analog clock is printed.

On the lower surface of the transparent film 45, a pattern 53 corresponding to the above-mentioned image print layer 8 is formed by printing. In the second embodiment, the dial of an analog timepiece is composed of a transparent film 45, and the transparent film 45
Since the white print layer 52, the half mirror 51, and the pattern to be displayed are formed by printing or the like, the light from the outside can be emitted in a state where the electroluminescence panel 46 is not lit.
The pattern printed on the transparent film 45, which is attenuated by the half mirror 51, becomes difficult to see from the outside, and the white print layer 54 can be seen from the outside.

In addition, the electroluminescence panel 46
When the light is emitted, the light of the electroluminescence panel 46 is illuminated by the pattern 53, the half mirror 51, and the white printing layer 52.
The image 53 printed on the transparent film 45 can be clearly seen by the user through the half mirror 51.

Next, a white print layer 61 is formed on the lower surface of the half mirror 62, which is a cross-sectional view of a light emitting device of a third embodiment of the present invention. In this embodiment, a surface medium printed layer 64 for displaying the color of a dial is formed on the upper surface of a base material 63 made of polycarbonate, acrylic or the like, and an hour character 65 indicating the time is further formed thereon. There is.

A half mirror 62 is formed on the lower surface of the polycarbonate 63, and a white printing layer 61 is formed on the lower surface of the half mirror 62. Further, a translucent color film 66 printed with translucent ink such as a fairy tale picture or photograph is arranged on the lower surface thereof, and an EL backlight 67 including an electroluminescence panel is arranged on the lower surface thereof. Are arranged.

In the third embodiment, as in the above-described embodiments, the EL backlight 67 is caused to emit light so that the pattern, logo or the like printed on the translucent color film 66 can be displayed on the half mirror 62 and the white printing layer 61. When the EL backlight 67 is turned off, most of the light from the outside is reflected by the half mirror 62 and further reflected by the white printing layer 61, so that it is printed on the translucent color film 66. The pattern that is displayed disappears from the outside.

Although the transparent film or transparent base material having a multi-layer structure is used in the above-described embodiments, the half mirror and the white printing layer may be formed of different members.
The order of the layers is not limited to the order described in the embodiments.

[0036]

According to the present invention, when a user looks at a dial or a liquid crystal display device, a printed pattern or the like is normally invisible, and the pattern or the like is visible only when the electroluminescence layer is made to emit light. Thus, it is possible to realize a light emitting device in which a normal display is easy to see and a pattern is also easy to see.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a light emitting device of a first embodiment.

FIG. 2 is a circuit block diagram of the electronic timepiece according to the first embodiment.

FIG. 3 is a waveform diagram of the circuit of FIG.

FIG. 4 is a sectional view of an electronic wrist watch according to a second embodiment.

FIG. 5 is a cross-sectional view of a transparent film.

FIG. 6 is a sectional view of a light emitting device of a third embodiment.

[Explanation of symbols]

 5 White printing layer 6 Half mirror 7 Transparent film 8 Image printing layer 9 Electroluminescence panel

Claims (6)

[Claims] 1. A light emitting device comprising a white printing phase, a translucent layer, a printing layer, and an electroluminescent layer disposed on the lower surface of the printing layer. 2. The translucent layer is disposed on the lower surface of the white printed layer, and the printed layer is disposed on the lower surface of the translucent layer.
The light emitting device according to claim 1, wherein an image is printed on the print layer. 3. The light emitting device according to claim 1, wherein the translucent layer has a transmittance of light from the electroluminescent layer higher than a transmittance of light from the outside of the light emitting device. 4. The light emitting device according to claim 1, wherein the semitransparent layer is a half mirror. 5. The light emitting device according to claim 1, 2 or 3, wherein the white printed layer, the semitransparent layer and the printed layer are formed on the same base material. 6. The light emitting device according to claim 1, wherein a liquid crystal display device is arranged on the upper surface of the white printing layer.