Specification improved led module

The field of the present invention relates to a lighting module including a light emitting diode (LED), and more particularly to a module based on a hand-carryable light source device energy regulated heat stable LED such as a flashlight.

LEDs are used in a variety of applications, including wristwatch lighting, remote control information transmission, and image formation on large television screens. More recently, LEDs are portable (like flashlights), especially because they can continue to generate light more efficiently and can be More durable than incandescent bulbs widely used in flashlights. Used in lighting equipment. In addition, because flashlights that use incandescent bulbs dominate in this area, LED modules (modules that use LEDs as a light source) are designed to be integrated into existing flashlights.

The problem with simply replacing an existing flashlight incandescent bulb with an LED module is that the LED will not operate at its maximum emission capacity under similarly stable conditions.

LEDs are known to emit more light as the forward current increases. If the available voltage is sufficient, the LEDs will be driven near its maximum current value, producing more light. However, it is not possible to supply a forward current close to the maximum value of an LED when the available voltage is depleted over time, such as in the case of battery-powered flashlights. If the battery or the battery contained in an existing flashlight applies too high a voltage, there is a similar concern that it will supply a forward voltage that exceeds the maximum value of the LED that could damage the LED. Exists.

Another problem with simply replacing an existing flashlight incandescent bulb with an LED module is that it cannot cope with the thermal effects of LEDs. LEDs generate light more efficiently than incandescent light bulbs, but LEDs generate a considerable amount of heat. Therefore, efficient heat emission. It is disclosed in Application is required to keep the LED temperature within its design limits. One effective method of dissipating the heat generated by the flashlight light source, entitled Improved LED Flashlight, was filed on August 20, 2004 and is pending US incorporated here. No. 10/922714.

However, in the case of LED modules designed for replacement, existing flashlights using LED modules may not be able to adequately dissipate the increased heat generated by the LEDs. Most LEDs have an expected lifetime and luminous flux under conditions where a given LED operating temperature is maintained. If this temperature is not maintained, the life and / or intensity of the light produced by the LED will decrease. Therefore, if the existing flashlight with the built-in LED module is inadequate in this regard, the LED module will use the LED to ensure that the LED or the electronic equipment that will control the LED is not damaged. Must control the amount of heat it produces.

Existing LED modules have sought to address the problem of heat dissipation by limiting the current delivered to the LED to a continuous value at a safe level below the emission capacity it is capable of. However, such efforts undermine the use of LED emission capabilities and ensure that the maximum emission capabilities of LEDs are never achieved.

<p> The present invention is directed to lighting modules that can limit energy, automatically stabilize heat and incorporate into existing flashlights. </p>

<p> In one embodiment, the lighting module includes an LED, an amplifier circuit, and a microchip. The amplifier circuit The switching element may be part of a step-up circuit, a step-down circuit or an amplifier circuit. </p><p> In the second embodiment, the lighting module includes a conductive housing, an LED, and a circuit board. The circuit board includes a module circuit previously connected to the LED. The circuit is at least partially housed in a housing cavity and also has a thermistor The gain of the amplifier circuit may be adjusted according to the temperature detected by the thermistor. The output of the amplifier circuit may be input to the microchip. </p><p> In other embodiments, the module can have a module circuit configured to limit the energy delivered to the LED based on the detected temperature of the LED. In yet another embodiment, the LED module can have a modular circuit that includes an energy control circuit and a heat sensitive amplifier circuit. </p>

Next, when examined with reference to the drawings as shown in FIG. 1A, a schematic diagram of one embodiment of the main circuit 70 of the electronic device includes a power supply 2, a main switch 4, and an LED module 40. The energy from the power source 2 preferably drives the LED module 40, and the main switch 4 controls the energy supplied to the LED module 40. In one embodiment of the invention, the main switch 4 simply allows or prevents energy from reaching the LED module 40 from the power source 2.

With reference to FIG. 1B, the main circuit 70 is shown in one embodiment of the flashlight 10. The flashlight 10 includes a cylinder 12, a tail cap assembly 20, a head assembly 30, an LED module 40, and a main switch assembly 50. In the illustrated embodiment, the cylinder 12 encloses the two batteries 14,15. The head assembly 30 and the LED module 40 are preferably located near the front end of the cylinder 12, the tail cap assembly 20 is preferably located at the rear It intervenes between the LED module 40 and the batteries 14 and 15.

In the illustrated embodiment, the batteries 14 and 15 serve as the power source 2 of the main circuit 70. In a preferred embodiment, the batteries 14, 15 are alkaline batteries. However, other suitable portable energy sources may be used, including rechargeable batteries Such As Lithium-Ion Batteries, Nickel Metal Hydride Batteries Or Nickel Cadmium Batteries.

The Tube 12 Preferably Has A Length Suitable For Accommodating A Desired Number Of Batteries. In The Illustrated Embodiment, The Cylinder 12 Has A Length Suitable For Accommodating The two batteries 14,15. However, here, cylinders of various lengths are intended to accommodate one or more batteries.

In the illustrated embodiment, the switch assembly 50 functions as the main switch 4 of the main circuit 70. With reference to FIG. 2, energy from the batteries 14, 15 to the main switch assembly 50 preferably flows through the contact button 16 involved between the front end of the battery 14 and the main switch assembly 50.

The main switch assembly 50 preferably includes a user interface 68, a plunger 72, a snap dome 73, a main switch circuit board 74, a main switch battery contact 75, a main switch module contact 76, and a switch housing 77 ... In the illustrated embodiment, the central electrode at the front end of the battery 14 is electrically connected to the main switch battery contact 75 via the contact button 16, and the main switch battery contact 75 is efficiently connected to the main switch circuit board 74. The main switch circuit board 74 is electrically connected to the main switch module contact 76.

The main switch assembly 50 is preferably a momentary switch. When the user interface 86 is pressed, the plunger 72 presses the snap dome 73 so that it contacts the selected position of the main switch circuit board 74. This momentary contact is received as a signal to the switch circuit board 74 that changes to pass or block the flow of energy from the batteries 14, 15 to the main switch module 76. In this way, the main switch assembly 50 can turn on or off the flashlight. The main switch circuit board 74 further provides the flashlight 10 with functions such as blinking, dimming or strobe by acting on the light source or the current supplied to the LED module 40 in the illustrated embodiment. However, it may include what is desirable in terms of circuit. features may include electronic games, omnidirectional position detectors,digital compasses, or other commercially desirable features.

Still referring to the illustrated embodiment of FIG. 2, the main switch battery contacts 75 and module contacts 76 are configured to include curved springs or urging members that receive the contact buttons 16 and springs 17, respectively. By arranging the curved springs of the main switch battery contacts 75 and module contacts 76 with respect to the switch housing 77 so that the spring forces are generated by the contacts 75,76 and transmitted to the switch housing 77, the main switch The circuit board 74 prevents, for example , the batteries 14, 15 from moving and pressing the main switch assembly 50. By urging the member in this way, an effective electrical connection is maintained while protecting vulnerable components such as the main switch circuit board 74.

The main switch assembly 50 as described above provides a configuration for turning on and off the flashlight, but other preferred switches, such as simple mechanical switches, can be applied to provide this function. flexible configuration that adds, modifies, and removes functionality from the flashlight 10. Also, the main switch assembly 50 described above avoids the problem of high oxidation between contacts often experienced in mechanical switches.

Still referring to FIG. 2, the current flow from the main switch assembly 50 to the LED module 40 is preferably appropriately connected to the main switch module contact 76 at the spring 17 and one end (located at the front end of the spring 17) Achieved through a receptacle 18 connected and connected to the LED module 40 at the other end. The spring 17 urges the receptacle 18 to actively contact the LED module. In the illustrated embodiment, current flows into the LED module 40 at its encoder contact 28 and out of the LED module 40 at the outer housing 24. The electrical energy preferably passes through the conductive means to the cylinder 12, through the tail cap assembly 20, and circulates to the cathode of the rearmost battery 15. In this way, the main circuit 70 of the flashlight 10 is formed.

The tube 12 is preferably made of a conductive material, preferably aluminum, so that it may function as part of the electrical circuit of the main circuit 70 between the LED module 40 and the power supply 2, ie the batteries 14,15 ... However, the cylinder 12 may optionally be made of a non-conductive material such as plastic or rubber and may include an electrical circuit by having the non-conductive cylinder having a conductive sleeve that acts as an electrical circuit. Such sleeves are described in US Pat. Nos. 6,585,391 and 4851974 of Anthony Maglica, which are incorporated herein by reference. In an alternative embodiment, the conductive strip in the cylinder may serve as an electrical path. Such strips are set forth in US Pat. No. 6,585,391.

With reference to FIG. 1B, the tail cap assembly 20 preferably includes a cap spring 6 and a cap 8. The tail cap assembly 20 is part of the electrical circuit between the LED module 40 and the power supply 2 and may receive current through the cylinder 12. In one embodiment, the electric circuit from the cylinder 12 may be the cathode of the cap 8 to the cap spring 6 and the last battery 15. separately, the electrical circuit may bypass the cap 8 and flow directly from the tube 12 To the cap spring 6. Other embodiments may provide an electrical circuit that bypasses the entire tail cap assembly 20 and efficiently connects the tube 12 to the battery. The tail cap assembly 20 with the cap spring 6 provides an effective configuration for maintaining a spring- assisted electrical connection between the components included in the flashlight 10.

As shown in FIGS. 1B and 2, the head assembly 30 includes a head 31, a reflector 33, a lens 35 and a cap 39. As shown in FIG. 2, the reflector 33 and the lens 35 are involved between the head 31 and the cap 39. The reflector 33 preferably includes a reflective paraboloid to reflect the light emitted from the LED module 40. The head assembly 30 may be secured to the cylinder 12 by a screw connection.

As already mentioned and illustrated in FIG. 1A, the current from the power supply 2 flows into the LED module 40 at its anodic contact 28 and out of its outer housing 24. Referring to FIG. 3, a schematic of one embodiment of the LED module 40 according to the present invention includes, as a whole, an LED lamp 22 and a module circuit 38.

With reference to FIGS. 3,4A, 4B and 4C, the LED lamp 22 is preferably commercially available and includes an LED and LED leads 82,83 to which the module circuit 38 is connected. Typically, LEDs are rated for acceptable operating conditions. For example, LEDs may limit the maximum forward current to a rating of 1000mA and the maximum LED junction temperature to 135 ° C.

An object of the present invention is to obtain an LED lamp 22 that produces as much light as possible without damaging the LED lamp 22 or the electronic components that make up the LED module 40 for as long as possible. This task is accomplished by adjusting the current flowing through the LED lamp 22 and monitoring the heat generated by the LED lamp 22. In a preferred embodiment, a temperature measuring device is arranged in the LED module 40 to monitor the situation surrounding the LED. When an undesired rise in temperature is measured When an undesired drop in temperature is measured, the current supplied to the LED lamp 22 may be increased to cause the LED lamp 22 to generate. more light.

With reference to FIG. 3, the first embodiment of the module circuit 38 preferably has a controlled booster circuit 44, a heat sensitive amplifier circuit 52, and a detection resistor 48. The booster circuit 44 is controlled because it includes feedback for adjusting its output The booster circuit 44 is useful when the power supply 2 driving the LED 40 has a maximum voltage lower than the voltage required to supply the desired forward current. For example, if the flashlight 10 contains two alkaline batteries arranged in series, it is generally In such a case, the booster circuit 44 boosts the available voltage to about 3.5 volts so that the desired forward current is supplied to the LED lamp 22. The booster circuit 44 also serves to maintain the forward current as the voltage level of the battery, which declines over time, at a desirable value.

In a preferred embodiment, the booster circuit 44 is a switching regulator. Inductor to FIG. 3, the booster circuit 44 includes a microchip 46, a switching MOSFET 54, an beams 58, a capacitor 59, and a diode 61. The microchip 46 controls the switching duty cycle of the switching MOSFET 54. As shown, the MOSFET 54, inductor 58, capacitor 59 and diode 61 are arranged in a manner known to those of skill in the art to form a boost converter. 46 receives feedback from the heat-sensitive amplifier circuit 52. If the feedback is outside the defined adjustment range, the microchip adjusts the duty cycle until it is within the adjustment range.

The booster circuit 44 may here consist of other desirable circuits or devices that boost the input voltage. For example, instead of having the plunger 58 as the energy storage member of the booster circuit 44, other desirable energy storage members such as capacitors or transformers may be used. Other desirable switching elements such as inductor may be used in place of the switching MOSFET 54.

Further referring to FIG. 3, the electric circuit connects the output of the booster circuit 44 to the first LED receiving contact 36, and the first LED receiving contact 36 is connected to the second LED lead 82. Current flows from the LED lamp 22 through the second LED lead 83 connected to the first LED receiving contact 37. The main power path passes through the detection resistor 48 and the ground contact 34. The detection resistor 48 is used to measure the current flowing through the LED lamp 22, and the voltage is measured by the detection resistor 48 acting as feedback to the microchip 46. thus, the detection resistor 48 is very small and minimizes power loss. In a preferred embodiment, the detection resistor 48 has a value of 0.10 ohms.

Since the detection resistor 48 is very small, the voltage formed on the detection resistor is also very small. Therefore, the detection resistance voltage is amplified by the amplifier circuit 52 before being fed back to the microchip 46.

The thermal stability feature of the present invention is incorporated into the heat sensitive amplifier circuit 52. Further referring to FIG. 3, the amplifier circuit 52 includes an operational amplifier 62, a first resistor 64, a second resistor 66 and a thermistor 56. The thermistor 56 is arranged in parallel with the second resistor 66. In this configuration, those skilled in the art will understand that the first resistor 64, the second resistor 66 and the thermistor 56 determine the gain of the amplifier circuit 52 by the combination thereof. The thermistor 56 is a temperature sensitive resistor that changes the resistance according to the detected temperature. Therefore, since the temperature of the detected LED lamp 22 changes, the gain of the amplifier circuit 52 changes.

In a preferred embodiment, the thermistor 56 has a negative resistance / temperature coefficient. Therefore, as the temperature of the LED module 40 increases, the thermistor resistance decreases and the gain of the amplifier circuit 52 increases. Due to the microchip feedback in the above adjustment range, the microchip 46 reduces the duty cycle of the switching MOSFET 54 and reduces the current supplied to the LED lamp 22. In this way, the 22 temperature effects of the LED lamp can be monitored and prevent damage to the LED or control electronics In a preferred embodiment, the microchip 46 measures the current supplied to the LED lamp 22 from 23 ° C to 27 ° C, with the thermistor detection temperature between approximately 875 mA and 930 ° C between 20 ° C and 30 ° C. It is configured to adjust to approximately 900mA at 25 ° C,between 880mA and 910mA.

When the temperature is high, the microchip 46 preferably draws the current supplied to the LED lamp 22 from 90 ° C, with the thermistor's detection temperature between approximately 330mA and 450mA between 80 ° C and 100 ° C. It is configured to adjust from 330mA to 370mA between 100 ° C and approximately 330mA at 100 ° C.

These temperature / current ranges must be found to effectively prevent thermal damage to the LED, but the present invention should not be considered to be limited to a particular temperature / current range. Rather, the present invention provides an LED module that uses an LED at its maximum capacity, which is appropriately self-stabilized.

Although thermistors with a negative resistance / temperature coefficient are disclosed herein, thermistors with a positive resistance / temperature coefficient can also be used. In addition, other preferred temperature sensing elements such as voltage output temperature sensors may be used in place of the thermistors.

Further, the preferred microchip 46 for this application may be a processor, microprocessor, controller, integrated circuit, ASIC or other device known to those of skill in the art.

In this way, the LED module 40 allows the initial operation of the flashlight to have a high output and emit more light while preventing thermal damage to electronic components. Without the temperature stabilization capability described above, driving the LED lamp 22 at 750mA would result in thermal damage to the LED. Use of the LED lamp 22 at low currents results in less light.

Now, to illustrate one embodiment of the LED module 40, preferred physical examples of the LED module 40 are shown in FIGS. 4A, 4B and 4C. The LED module 40 includes an LED lamp 22, an outer housing 24, a circuit assembly 60 , and a holder 26. The circuit assembly 60 is preferably held in the holder 26, the holder 26 is preferably located in the outer housing 24, and the LED lamp 22 is preferably located in the front end of the holder 26. LED.

led, the outer housing 24 is made of a conductive material. In the illustrated embodiment, the outer housing 24 is generally a container that includes a first end 88, a second end 92, and a cavity 94. The cavity 94 may include a slot-like feature therein for receiving the holder 26.

In a preferred embodiment, the circuit assembly 60 includes a circuit board 32, an anode contact 28, a cathode contact 34, and first and second LED receiving contacts 36,37. The circuit assembly 60 is configured to be held in the holder 26. With reference to FIG. 4A, the anodic contact 28 of the circuit assembly 60 preferably extends. through the opening 78 at the rear end of the holder 26. The anode contacts 28 are preferably folded to face the rear end of the holder 26 for support. The cathode contact 34 of the circuit assembly 60 is preferably located at the front end of the circuit board 32 so as to be electrically connected to the outer housing 24.Circuit components arranged in this way and disposed on the circuit board 32 are poorly protected from mechanical forces such as the spring 17 and the vessel 18.

obtaining to FIGS. 4B and 4C, LED leads 82,83 extend through an opening at the first end 88 of the outer housing 24 and efficiently connect to the first and second LED receiving contacts 36,37. between the LED receiving contacts 36,37 and the LED leads 82,83 reduces manufacturing and manufacturing costs mechanically, or especially by friction. However, any preferred electrical connection method, such as soldering, can be used.

Arranged as described, the components of the module circuit 38 are arranged on the circuit board 32 and housed in the LED module 40. The physical arrangement as described for the LED module 40 protects the electronic components from thermal damage by implementing the module circuit 38, monitoring the heat generated by the LED and reducing the current flowing through it if necessary. However, it is one preferred way to operate LED lamps at their maximum lighting capacity. The external dimensions of the LED module 40, and in particular the outer housing 24 Having such external dimensions facilitates the incorporation of the LED module 40 as described herein into an existing flashlight that accepts PR-type incandescent bulbs. However,The invention as described herein is not limited to the external dimensions or features as described. The advantages and advantages of LED modules that operate at their maximum capacity, that is, are similarly self-stabilizing and can be incorporated into existing flashlights, may be achieved through many external configurations.

The flow of energy through the flashlight 10, especially the LED module 40, is now described. Current from batteries 14 and 15 flows into the LED module at the anode contact 28 through the main switch assembly 50. The anode contact 28 is efficiently connected to The module circuit 38 disposed on the circuit board 32, and the main power flows through the booster circuit 44. The output of the booster circuit 44 flows through the first LED receiving contact 36 and then through the LED leads 82 and the LEDs. The current flows out of the LED lamp 22 and through the second LED lead 83 connected to the second LED receiving contact 37. The main power flows through the detection resistor 48 to the anode contact 34 of the circuit assembly 60, and the voltage of the detection resistor 48 is guided to the heat-sensitive amplifier circuit 52.

The main power then flows through the detection resistor to the cathode contact 34 connected to the outer housing 24. The outer housing 24 is connected to the cylinder 12 and is finally connected to the cathode end of the tail cap assembly 20 and the Battery 15 To Rearmost Complete The Main Circuit.

The Voltage Of The Detection Resistor 48 Is Amplified By The Heat-Sensitive Amplifier Circuit 52 To A Gain Which Is A Function Of The Temperature Of The LED Lamp 22. The Output Of The Heat -sensitive amplifier circuit 52 is fed back to the microchip 46 that adjusts the current supplied to the LED lamp 22 by adjusting the duty cycle of the switching MOSFET.

In the second embodiment 40a of the LED module, the power supply 2 connected to the LED module 40a may have more voltage than necessary to supply the desired forward current. For example, if the flashlight contains four batteries arranged in series, it has an operating range of 3.6 to 6.0 voltages. In such an example, the module circuit 38a preferably includes a step-down circuit 84 controlled in place of the step-up circuit 44. module 40a includes an LED lamp 22 and a module circuit 38a. The module circuit 38a includes a controlled step-down circuit 84, a detection resistor 48, and a heat-sensitive amplifier circuit 52. The step-down circuit 84 is controlled because it includes feedback for adjusting its output. The output of the step-down circuit 84 drives the LED lamp 22,and receives feedback from the detection resistor 48 through the heat-sensitive amplifier circuit 52.

With reference to FIG. 5, the step-down circuit 84 is preferably a step-down regulator or step-down circuit, including a microchip 46a, a switching MOSFET 54a, an inductor 58a, a capacitor 59a, and a diode 61a. These components are arranged in a manner known to those of skill in the art to form a step-down circuit.

In the third embodiment 40b of the LED module, the power supply 2 connected to the LED module 40b exceeds the voltage required to supply the desired forward current in the first period and exceeds the voltage required in the second period. It may have a low voltage In such an example, the module circuit 38b preferably includes a controlled voltage inversion circuit 86 instead of the step-up circuit 44 or the step-down circuit 84. voltage to FIG. 6, the schematic of the fourth embodiment of the LED module 40b includes the LED lamp 22 and the module circuit 38b as a whole. detection resistor 48, and a heat sensitive amplifier circuit 52.The output of the feedback circuit 86 drives the LED lamp 22 and receives feedback from the detection resistor 48 through the heat-sensitive amplifier circuit 52.

With reference to FIG. 6, the inductor circuit 86 is preferably an inducting regulator or inducting circuit and includes a microchip 46b, a switching MOSFET 54b, an plunger 58b, a capacitor 59b, and a diode 61b. These components are arranged. In A Manner Known To Those Of Skill In The Art To Form An Inverting Circuit.

Various Embodiments Of The Improved LED Module And Their Respective Components Are Presented In The Above Description, And Many Improvements, Modifications, Modifications, And Alternative Materials Are For this reason, it should be understood that this description is considered as an inductor method and does not limit the scope of the claims.

<figref num="1A"> A schematic of one embodiment of the main circuit of an electronic device. </figref><figref num="1B"> A cross-sectional view of a flashlight embodying the main circuit of Figure 1A. </figref><figref num="2"> Enlarged sectional view of the front of the flashlight in Figure 1B. </figref><figref num="3"> A schematic of one embodiment of a modular circuit. </figref><figref num="4A"> Sectional drawing of the LED module which mounts the module circuit of FIG. </figref><figref num="4B"> Exploded view of the LED module that implements the module circuit in Figure 3. </figref><figref num="4C"> The perspective view of the LED module which mounts the module circuit of FIG. </figref><figref num="5">The circuit diagram of the second embodiment of the module circuit.</figref><figref num="6"> The circuit diagram of the third embodiment of the module circuit.</figref>