Thermometer without power switch

A thermometer is constituted by a body member and a tip member secured to the body member. A thermal sensor is mounted on the inside of the tip member, adapted for sensing a temperature and producing a temperature signal. A set of leas wires is coupled to the thermal sensor for transmission of the temperature signal. A display unit is disposed on the body member and a processor is disposed to electrically connect the set of lead wires to receive the temperature signal and drive the display unit for display of a corresponding temperature reading. A rear cover is secured to the body member. A mechanical selector is disposed between the processor and the rear cover and the type of temperature scale displayed in the display unit is selected by pushing the mechanical selector from the rear cover.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to the field of thermometers, and more particularly to the field of thermometers with mechanical selector for types of temperature scale conversion.

2. Description of the Related Art

Electronic thermometers generally offer a great number of advantages over conventional glass and mercury thermometers for use in the health care field. Among the advantages of electronic thermometers are the elimination of sterilization procedures for glass thermometers, made possible by the use of disposable covers; elimination of the possibility of broken glass if a thermometer is dropped; a digital temperature display to eliminate temperature reading errors; and with proper circuit design and calibration, higher accuracy and resolution is possible with accurate measurement and display of tenths of a degree Fahrenheit being easily attainable.

Such electronic thermometers typically use a chemical battery as a power supply. However, the electronic thermometers are generally idle for a long time since patients only use the electronic thermometers while they are sick or feel uncomfortable. Thus such electronic thermometers employing a chemical battery as a power supply are not environmentally friendly.

The present inventor proposed to employ a thermometer without battery and switch button to solve this problem in U.S. patent application Ser. No. 12/819,586. However, The type(s) of temperature scale, such as Fahrenheit scale or Celsius scale displayed, may be predetermined by the designer, or it may be selected by the user. Thus, there is a need to provide a new design of thermometer with a mechanical selector for types of temperature scale conversion.

SUMMARY OF THE INVENTION

An exemplary embodiment of the present invention overcomes the above-described problems by providing a thermometer comprising a body member and a tip member secured to the body member. A thermal sensor is mounted on the inside of the tip member, adapted for sensing a temperature and producing a temperature signal. A set of leas wires is coupled to the thermal sensor for transmission of the temperature signal. A display unit is disposed on the body member and a processor is disposed to electrically connect the set of lead wires to receive the temperature signal and drive the display unit for display of a corresponding temperature reading. A rear cover is secured to the body member. A mechanical selector is disposed between the processor and the rear cover and the type of temperature scale displayed in the display unit is selected by pushing the mechanical selector from the rear cover.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIGS. 1 and 2, an embodiment of a thermometer is illustrated. The thermometer is made up of a body member10and a tip member11. Typically, a cover60is secured to the body member10after components of the thermometer have been assembled. The body member10includes a probe portion12and a display portion15. The tip member11is secured to a frond end, such as the probe portion12of the body member10. Preferably, it contains a thermal contact surface surrounding a hollow cavity. In one embodiment, the hollow tip member11is preferably made of metal with good thermal conductivity, such as stainless steel.

A thermal sensor51is placed at the end of the tip member11and mounted on the inside of the thermal contact surface. The thermal sensor senses the temperature of the thermal contact surface and produces a temperature signal. There are a set of lead wires52,54coupled to the thermal sensor51for transmission of the temperature signal.

As shown inFIG. 2, a display unit20is disposed in the display portion15and connected to the lead wires52,54to receive the temperature signal for display of a corresponding temperature reading. Typically, a base plate30may be adapted for supporting the display unit20. In one example, the display unit20may comprise a substrate22; a display23, such as LCD panel, disposed thereon; and a processor24such as integrated circuit chip disposed thereon, coupled to the display23. Processor24is electrically connected to the lead wires52,54to receive the temperature signal; it drives the display23to show a corresponding temperature reading. Preferably, the base plate30has an opening33to expose the display23. Typically, the base plate30is plastic and the substrate22is PCB board.

In one example, the tip member11is made in the form of a tubular shape and closed at a domed, hemispherical or hemiellipsoid shaped end. The contact surface is brought in contact with flesh of a patient so that heat can be transferred from the patient's flesh to the tip member11. In one embodiment, the thermal sensor51is thermistor. The lead wires52,54and the thermistor51are both adhered on the inside of the thermal contact surface with heat conductive glue. The glue is an insulating material with good thermal conductivity, e.g., epoxy resin. Moreover, the lead wires52,54are made up of a pair of electrical lead wires; they are used to connect the thermal sensor51to the processor24for determining a corresponding temperature to display.

A transparent layer40extending from an upper surface thereof at least covers the display unit20under the display aperture13. Preferably, the transparent layer40covers an entire upper surface of the base plate30. And generally, the display23is disposed on the substrate22and under the transparent layer40. The transparent layer40may be a transparent plastic sheet. Preferably, the transparent layer is made of organic glass or polymethyl methacrylate (PMMA).

Referring toFIG. 3, a motion electric power generator is disposed in the body member10, in one example, adjacent to display unit20. Motion electric power generator comprises a tubular cylinder82disposed in the body member and a magnetic core84being free to slide within the tubular cylinder82. A coil of wire86is wrapped around the tubular cylinder82so that the magnetic core84moves through the coil of wire86when sliding through the tubular cylinder82from one end to an opposite end. As shown inFIG. 2, a capacitor26such as chip capacitor is electrically connected to the coil of wire86through the electricity transmission wires70. As magnetic core84moves through tubular cylinder82, it will change the magnet flux flowing through the coil of wire86, increasing the capacitor voltage.

Further, processor24is electrically connected to the capacitor26to obtain electric power and is electrically connected to the set of lead wires52,54to receive the temperature signal and drive the display unit for display of a corresponding temperature reading. In one example, capacitor26stores electrical energy by continuously moving the thermometer back and forth. Processor24is actuated to drive the display23to display a starting signal showing the thermometer is performing a charging action or transmit the starting signal to a speaker (not shown) to generate voice to inform the user the thermometer is performing a charging action, while the capacitor voltage is equal to or higher than a predetermined start voltage. And then the processor24is detecting a change of the capacitor voltage. During a short motion time, processor24starts it's body temperature measuring operation and drive the display23to display an operation signal showing the thermometer is performing a body temperature measuring operation or transmit the operation signal to a speaker (not shown) to generate voice to inform the user the thermometer is performing a body temperature measuring operation, while the capacitor voltage is further increased to a predetermined operation voltage and which is enough to perform at least one or two cycles of body temperature measuring operation.

In such thermometers, capacitor stores energy for the processor to use on demand, so it can be used like a temporary battery to maintain power supply. Thus, there is no need to use a chemical battery which is easy to cause environmental pollution.

Furthermore, a helical spring88may be mounted on one end or both ends of the tubular cylinder82to increase the movement of the magnetic core84.

In another embodiment, there is no need to create battery cover and/or power switch on the surface of the body potion of the thermometers since the thermometers are battery free, and thus such structure may enhance a water-tight seal function as shown inFIG. 1.

Referring now toFIG. 4, there is shown a cross-sectional side view of the mechanical selector for types of temperature scale conversion according to an exemplary embodiment. In this embodiment, the processor24may also comprise a pin SW for types of temperature scale conversion. The mechanical selector61comprises a hole62which is located on a surface of the rear cover60. A channel is disposed within the rear cover60and communicated with the hole62. An elastic member66comprises an elastic main portion66c, a front protrusion portion66aand a rear protrusion portion66b. For example, the front protrusion portion66ais extended from the elastic main portion66ctoward the channel64and the second protrusion portion66bis extended from the elastic main portion66ctoward the processor24.

A connection line24ais disposed to electrically connect the pin SW for keeping a voltage. The voltage of the pin SW may be changed to convert the types of temperature scale by pushing the front protrusion portion66afrom the hole62and the channel64within the rear cover60such that the rear protrusion portion66bis moved to cut the connection line24a. In one example, when the front protrusion portion66cis subjected to a push force such as a use of a needle to insert into the hole, deformation of the elastic main portion66coccurs. When the applied push force is removed, the deformation can be undone by a return force from the elastic main portion66c. Thus, the elastic main portion66cis recovered in an original form and the front protrusion portion66ais moved back to seal the channel64after release of the force. The elastic main portion66cmay be secured to any position68within the body member10, such as the substrate22, the processor24, the base plate30or the rear cover60. The connection line24amay also comprise an end which is disposed to electrically connect a power voltage Vcc.

FIG. 5represents an exemplary embodiment of a cross-sectional side view of the mechanical selector for types of temperature scale conversion. In this example, the connection line24amay also be secured to the substrate22to electrically connect the pin SW and a predetermined voltage such as the power voltage Vcc through the wires24b. The substrate22may also comprise a recession portion for an easy to move the rear protrusion portion66b.