JP2000139711A - Water level indicator for liquid container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evenly illuminate the whole water level tube and make it easy to confirm a water level even if it is positioned in any level by making course the back face of a light-conductive body in a light-reflecting part, in a water level indication device for a liquid container. SOLUTION: The inlet side of a liquid-feed pump 5 is connected to the bottom face of an inner container 3 and a water level tube 6 used for a liquid feed pipe in common is connected to the outlet side, and the upper end part of the tube is connected to a discharge pipe 8 through a safety valve set 7. A transparent prismatic light-conductive body 9 such as an acrylic resin is provided between the back side of the water level tube 6 and the front face of the inner container 3, and an illuminant 11 such as a light-emitting diode is installed at the lower side of the lower end face thereunder. The light-conductive body 9 has a certain inclined angle θ at which the body tilts to the front face side as the back face 12 goes far from the illuminant 11. The back face 12 is coursely processed to form the whole face as a diffused reflection face. Hence, light emitted out of the illuminant 11 shines on the back face 12 and diffusely reflects to the front face side. One can see the diffusely reflected light (a) from the outside through the water level tube 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a water level display device for a liquid container such as an electric pot.

[0002]

2. Description of the Related Art In a water level display device of a liquid container, a transparent rod-shaped light guide is provided along the back of a water level tube so that the water level can be confirmed even in darkness at night or the like. A graduation kerf is formed at regular intervals, and light emitted from a light source installed on the end face of the light guide is reflected to the front side by the kerf so that the reflected light can be seen from the front of the water level tube. Some are known (for example, Japanese Utility Model Publication No. 3-49627).

[0003]

However, in the above-mentioned apparatus, since the cut grooves provided in the light guide are formed at regular intervals, the light seen through the water level tube is scattered and is difficult to see. There are drawbacks.

Accordingly, the present invention provides a water level indicator for a liquid container that enables uniform illumination of the entire water level tube and that turns on the illumination light source only when necessary so as not to waste power. It is an object to provide a device.

[0005]

In order to solve the above problems,
The present invention provides a transparent prismatic light guide along the water level tube behind the water level tube, forming a light reflecting portion on the back surface of the light guide,
In a liquid level display device of a liquid container in which light emitted from a light source disposed on an end face of the light guide is reflected to the front side in the light reflection section, the light reflection section is formed on a rear surface of the light guide with a rough surface. This is a configuration formed by the above.

[0006] The back surface of the light guide may have a tilt angle that is inclined toward the front side as it moves away from the light source, or the back surface of the light guide is parallel to the front surface, and the optical axis of light introduced into the light guide is parallel to the front surface. It may be configured to be inclined with respect to the back surface.

In addition, the light source is turned on when any of the operation buttons provided on the liquid container is operated, or a human sensor is turned on when a person approaches the light source. It is possible to adopt a configuration having a timer for turning off the light source after a certain period of time after turning on the light source.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the electric pot of the embodiment includes a pot main body 1 and a lid 2 which is openably and closably attached thereto.

An inner container 3 is housed inside the pot body 1, and the hot water is heated by a heater 4 mounted on the bottom surface of the inner container 3. An inlet side of the liquid supply pump 5 is communicated with the bottom surface of the inner container 3, and a water level tube 6 serving as a liquid supply pipe is connected to an outlet side thereof. The upper end of the water level pipe 6 is connected to a discharge pipe 8 via a safety valve set 7.

A prismatic light guide 9 made of a transparent material such as an acrylic resin is provided between the back of the water level tube 6 and the front of the inner container 3, and a light source 11 such as a light emitting diode is provided below the lower end surface thereof. Is installed.

As shown in FIG. 1B, the light guide 9 has an inclination angle θ that is inclined at a constant angle toward the front as the back 12 moves away from the light source 11. In addition, the back 1
2 is roughened and the whole is a diffuse reflection surface. For this reason, the light emitted from the light source 11 hits the rear surface 12 and is irregularly reflected toward the front side, and the irregularly reflected light a can be seen from the outside through the water level tube 6.

FIG. 1C shows a modification of the light guide 9. In this case, the back surface 12 is parallel to the front surface, and forms a square pole as a whole. The back surface 12 is roughened as in the above case, but in this case, the light source 11 is installed so that the optical axis of the light source 11 has an inclination angle φ with respect to the back surface 12. The light sources 11 may be provided at both upper and lower ends as shown, or may be provided at only one of them. In any case, light is diffusely reflected on the back surface 12 toward the front surface.

The above-mentioned light source 11 may be energized at all times while power is supplied to the electric pot. However, in order to save unnecessary power consumption, a hot water supply button, a re-boiling button, and a lock release button are used. Or the like, or only when any one of the operation buttons 13 is operated, or by mounting an infrared sensor 14 so that the light is automatically turned on when it is detected that a person approaches. .

FIGS. 2A and 2B show a specific example of the mounting structure of the light guide 9 described above. A recess 15 is provided at the lower end of the light guide 9, and the light source 11 is housed in the recess 15,
An insertion portion 16 is provided at the upper end. Liquid supply pump 5
A receiving portion 18 is provided at a joint 17 between the water level tube 6 and the lower end of the water level tube 6. The lower end of the water level tube 6 is inserted into the receiving portion 18, and the insertion portion 16 is provided on a shoulder member 19 of the pot body 1. It is inserted into the recess 21. The light guide 9 is supported between the receiving part 18 of the joint and the fitting recess 21 of the shoulder member 19.

FIGS. 3A and 3B are flowcharts of the microcomputer of the control unit 22 of the electric pot. FIG.
As shown in (a), when one of the operation buttons 13 is turned on in step 1, the light source 11 is turned on in step 2, and the timer is started in step 3. Then, when a predetermined time has elapsed (step 4), the light source 11 is turned off in step 5.

When the infrared sensor 14 is provided, the light source 11 may be turned on when the approach of a person is detected by this (step 6).

FIG. 3 (b) shows that the light source 11 is turned on when a person approaches (step 1) (step 2).
This is the same as the case described above, but in this case, when it is sensed that the person has left (step 3), a timer is started (step 4), and after a certain time has elapsed (step 5), the light source 11 is turned off ( Step 6).

[0018]

As described above, according to the present invention, since the irregular reflection portion is formed by roughening the back surface of the light guide provided behind the water level tube, the entire water level tube is uniformly illuminated. This makes it easy to confirm the water level at any position.

Further, since the light source for illumination of the water level tube is turned on only when necessary, and is turned off in other cases, unnecessary power consumption can be reduced.

[Brief description of the drawings]

FIG. 1A is a schematic sectional view of an embodiment. FIG. 1B is a perspective view of a light guide. FIG. 1C is a side view of a modification of the light guide.

FIG. 2 (a) is a partial cross-sectional view showing a specific structure of the above, and (b) is a partially enlarged cross-sectional view of FIG.

FIG. 3A is a flowchart of a microcomputer according to the embodiment; FIG. 3B is another flowchart;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pot main body 2 Lid 3 Inner container 4 Heater 5 Liquid supply pump 6 Water level pipe 7 Safety valve set 8 Discharge pipe 9 Light guide 11 Light source 12 Back 13 Operation button 14 Infrared sensor 15 Concave part 16 Insert part 17 Joint 18 Reception part 19 Shoulder member 21 fitting recess 22 control unit

Continued on the front page F term (reference) 2H038 AA09 AA41 3K014 AA00 AA01 LA00 LA01 PD00 4B002 AA12 BA22 BA51 BA59 CA12 CA45 4B055 AA34 BA42 CA17 CA85 CB22 CD01 CD22 CD32 CD44 CD51 GA14 GB44 GC21 GC36 GD02

Claims (6)

[Claims] A transparent prismatic light guide is provided along the water level tube behind the water level tube, a light reflecting portion is formed on the back surface of the light guide, and light is emitted from a light source disposed on an end face of the light guide. Wherein the light reflecting portion is formed by roughening the back surface of the light guide. Water level indicator. 2. The liquid level display device for a liquid container according to claim 1, wherein the back surface of the light guide has an inclination angle that is inclined toward the front surface as it goes away from the light source. 3. A back surface of the light guide is parallel to a front surface,
The water level display device for a liquid container according to claim 1, wherein the optical axis of the light introduced thereto is inclined with respect to the back surface. 4. The liquid level display device for a liquid container according to claim 1, wherein the light source is turned on when any one of operation buttons provided on the liquid container is operated. 5. The liquid level display device for a liquid container according to claim 1, further comprising a person sensor that turns on the light source when a person approaches. 6. The apparatus according to claim 1, further comprising a timer for turning off the light source after a predetermined time after the light source is turned on.
6. The water level display device for a liquid container according to any one of claims 1 to 5.