LED lamp filament and lamp filament lamp

Abstract

The utility model discloses an LED lamp filament and a lamp filament lamp, and relates to the technical field of illumination. The light-emitting unit comprises a first chip string, a second chip string and a third chip string, the first chip string, the second chip string and the third chip string are arranged on the substrate and sequentially connected in series, and each of the first chip string, the second chip string and the third chip string comprises at least one LED chip; the first resistor is connected in parallel with the first chip string and the second chip string; the second resistor is connected with the second chip string and the third chip string in parallel; wherein when the input voltage at the two ends of the lamp filament is lower than the threshold voltage and the lamp filament works, the first chip string and the third chip string are in a normally-on state, and the second chip string is in a non-on state; when the input voltage at the two ends of the lamp filament is higher than the threshold voltage and the lamp filament works, the first chip string, the second chip string and the third chip string are all in a normally-on state. The utility model provides an LED lamp filament and a lamp filament lamp. The problem that a lamp filament using a linear power supply cannot work normally when the input voltage is low is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of lighting, in particular to an LED filament and a filament lamp. Background Art

[0002] An LED filament is formed by fixing multiple LED chips in series on a substrate and then performing die pressing and encapsulation. The voltage of each chip is generally 3.0V, and they are configured in series.

[0003] With the stable development of the LED lighting market, there are more and more requirements for LED filament lamps in the market. At present, the market no longer satisfies the single color temperature constant brightness mode, and most filament lamps have the function of adjustable brightness. However, due to cost issues, most of the power supplies of current filament lamps are linear power supplies. When the linear power supply rectifies and regulates the voltage, the output voltage will fluctuate with the input voltage of the power supply. When the input mains voltage is low, the filament lamp cannot work properly and may experience stroboscopic phenomena, affecting customer use.

[0004] Therefore, it is urgent to develop an LED filament and a filament lamp to solve the problems in the prior art. Summary of the Invention

[0005] The purpose of the utility model is to provide an LED filament and a filament lamp to solve the problem that the filament cannot work properly when the input voltage is low as mentioned in the above background art.

[0006] To achieve the above purpose, the utility model provides the following technical solutions:

[0007] An LED filament, comprising:

[0008] A substrate;

[0009] A light-emitting unit, the light-emitting unit includes a first chip string, a second chip string and a third chip string which are arranged on the substrate and connected in series in sequence, and the first chip string, the second chip string and the third chip string each include at least one LED chip;

[0010] A first resistor, the first resistor is connected in parallel with the first chip string and the second chip string;

[0011] A second resistor, the second resistor is connected in parallel with the second chip string and the third chip string;

[0012] Wherein, when the input voltage at both ends of the filament is lower than the threshold voltage and the filament is working, the first chip string and the third chip string are in a constant brightness state, and the second chip string is in an off state;

[0013] When the input voltage at both ends of the filament is higher than the threshold voltage and the filament is working, the first chip string, the second chip string and the third chip string are all in a constant brightness state.

[0014] Furthermore, filament pins are provided at both ends of the substrate;

[0015] The first end of the first chip string is connected to one of the filament pins;

[0016] The first end of the second chip string is connected to the second end of the first chip string;

[0017] The first end of the third chip string is connected to the second end of the second chip string, and the second end of the third chip string is connected to the other filament pin.

[0018] Furthermore, the first end of the first resistor is connected to the first end of the first chip string, and the second end of the first resistor is connected to the second end of the second chip string;

[0019] The first end of the second resistor is connected to the first end of the second chip string, and the second end of the second resistor is connected to the second end of the third chip string.

[0020] Furthermore, the first chip string and the third chip string include a plurality of LED chips, and the plurality of LED chips are electrically connected by wires.

[0021] Furthermore, the number of LED chips in the second chip string is less than the number of LED chips in the first chip string or the third chip string.

[0022] Furthermore, the LED chips in the first chip string and the third chip string are of the same type and the number of chips is the same.

[0023] Furthermore, the LED chips in the second chip string are the same as or different from the LED chips in the first chip string or the third chip string.

[0024] Furthermore, a first conductive layer and a second conductive layer are further provided on the substrate. The first resistor is provided on the first conductive layer, and the first resistor is electrically connected to the first conductive layer. The second resistor is provided on the second conductive layer, and the second resistor is electrically connected to the second conductive layer.

[0025] Furthermore, the filament pin includes a positive pin and a negative pin. The two ends of the first chip string are respectively connected to the positive pin and the first conductive layer through wires. The two ends of the third chip string are respectively connected to the negative pin and the second conductive layer through wires. The two ends of the second chip string are respectively connected to the first conductive layer and the second conductive layer through wires.

[0026] A filament lamp includes the LED filament described above.

[0027] Compared with the prior art, the beneficial effects of the present utility model are as follows: By providing a first resistor and a second resistor, with the first resistor connected in parallel with the first chip string and the second chip string, and the second resistor connected in parallel with the second chip string and the third chip string; such that when the input voltage across the filament is lower than the threshold voltage and the filament is operating, the first chip string and the third chip string are in a constantly lit state, and the second chip string is in an unlit state, and when the input voltage across the filament is higher than the threshold voltage and the filament is operating, the first chip string, the second chip string, and the third chip string are all in a constantly lit state, thereby achieving the lighting of the filament when the input voltage is relatively low.

[0028] Other features and advantages of the present utility model will be disclosed in detail in the following specific embodiments and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of the overall structure of the present utility model;

[0030] Figure 2 is a schematic diagram of the structure of the substrate of the present utility model;

[0031] Figure 3 is a schematic diagram of the filament structure provided with a fluorescent glue layer;

[0032] Figure 4 is a schematic diagram of the circuit structure of the present utility model;

[0033] Figure 5 is a data relationship diagram of the LED input voltage and input current of the present application.

[0034] Each reference numeral in the figure is: 1, substrate; 21, first chip string; 22, second chip string; 23, third chip string; 3, wire; 41, second conductive layer; 42, first conductive layer; 5, positive electrode pin; 6, negative electrode pin; 7, fluorescent glue layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model.

[0036] The LED filament, as Figure 1 shown, includes:

[0037] A substrate 1, with filament pins provided at both ends of the substrate 1;

[0038] A first chip string 21, the first chip string 21 is provided on the substrate 1, and the first end of the first chip string 21 is connected to one of the filament pins;

[0039] A second chip string 22, the second chip string 22 is disposed on the substrate 1, and a first end of the second chip string 22 is connected to a second end of the first chip string 21;

[0040] A third chip string 23, the third chip string 23 is disposed on the substrate 1, a first end of the third chip string 23 is connected to a second end of the second chip string 22, and a second end of the third chip string 23 is connected to another filament pin;

[0041] A first resistor, a first end of the first resistor is connected to a first end of the first chip string 21, and a second end of the first resistor is connected to a second end of the second chip string 22;

[0042] A second resistor, a first end of the second resistor is connected to a first end of the second chip string 22, and a second end of the second resistor is connected to a second end of the third chip string 23.

[0043] As Figure 4 and Figure 5 shown, in this embodiment, when the input voltage across the filament is the operating voltage, the current across the filament is the operating current IF-1, and the voltage between the first end of the first chip string 21 and the second end of the second chip string 22 is the same as the voltage across the first resistor; the voltage between the first end of the second chip string 22 and the second end of the third chip string 23 is the same as the voltage across the first resistor. In this embodiment, the operating voltage is the threshold voltage, which is the voltage required for the filament to operate normally.

[0044] Specifically, when the input voltage across the filament is the operating voltage, the current across the filament is the operating current IF-1, and the sum of the resistances of the first chip string 21 and the second chip string 22 is the same as the resistance of the first resistor; the sum of the resistances of the second chip string 22 and the third chip string 23 is the same as the resistance of the second resistor.

[0045] In this application, the sum of the resistances of the first chip string 21 and the second chip string 22 is the ratio of the voltage across the two ends to the current; the sum of the resistances of the second chip string 22 and the third chip string 23 is also the ratio of the voltage across the two ends to the current.

[0046] Specifically, when the input current across the filament is less than the operating current, the sum of the resistances of the first chip string 21 and the second chip string 22 is greater than the resistance of the first resistor, and the sum of the resistances of the second chip string 22 and the third chip string 23 is greater than the resistance of the second resistor.

[0047] When the sum of the resistances of the first chip string 21 and the second chip string 22 is greater than the resistance of the first resistor, the current flows through the first resistor and the third chip string 23 in sequence to light up the first chip string 21; when the sum of the resistances of the second chip string 22 and the third chip string 23 is greater than the resistance of the second resistor, the current flows through the first chip string 21 and the second resistor in sequence to light up the third chip string 23.

[0048] In this way, the first chip string 21 and the third chip string 23 of the present application work, and the second chip string 22 does not work, enabling the filament to be lit when a small current is input.

[0049] When the input current at both ends of the filament is greater than the working current, the sum of the resistances of the first chip string 21 and the second chip string 22 is less than the resistance of the first resistor, and the sum of the resistances of the second chip string 22 and the third chip string 23 is less than the resistance of the second resistor, so that the current flows through the first chip string 21, the second chip string 22, and the third chip string 23 in sequence to light up the first chip string 21, the second chip string 22, and the third chip string 23.

[0050] In this way, the current flows through the first chip string 21, the second chip string 22, and the third chip string 23 in sequence, so that the working mode of the present application under normal current or large current conditions is the same as that of an ordinary LED filament.

[0051] The first chip string 21 and the third chip string 23 include a plurality of LED chips, and the plurality of LED chips are electrically connected by a wire 3. The second chip string 22 includes at least one LED chip. Preferably, the number of LED chips in the second chip string 22 is less than the number of LED chips in the first chip string 21 or the third chip string 23. In this way, it helps to reduce the waste of chips under small current conditions. The wire 3 can be a metal wire 3.

[0052] As Figure 2 shown, the filament pins include a positive pin 5 and a negative pin 6. In this embodiment, the positive pin 5 is arranged at one end of the substrate 1 and the negative pin 6 is arranged at the other end of the substrate 1.

[0053] A first conductive layer 42 and a second conductive layer 41 are further arranged on the substrate 1. The first resistor R1 is arranged on the first conductive layer 42, and the first resistor R1 is electrically connected to the first conductive layer 42. The second resistor R2 is arranged on the second conductive layer 41, and the second resistor R2 is electrically connected to the second conductive layer 41.

[0054] In this application, the resistor is connected through a conductive layer. Compared with connecting through a wire, it helps to simplify the manufacturing process. Moreover, due to the relatively long length of the chip string, using a conductive layer for electrical connection optimizes the electrical performance, reduces the line resistance, and helps to keep the resistance value of the circuit where the first resistor R1 or the second resistor R2 is located equal to the resistance value of the circuit in parallel with it.

[0055] Both ends of the first chip string 21 are respectively connected to the positive electrode pin 5 and the first conductive layer 42 through a wire 3. Both ends of the third chip string 23 are respectively connected to the negative electrode pin 6 and the second conductive layer 41 through a wire 3. Both ends of the second chip string 22 are respectively connected to the first conductive layer 42 and the second conductive layer 41 through a wire 3. The first conductive layer 42 and the second conductive layer 41 are not directly electrically connected.

[0056] Furthermore, the chip string is connected to the first conductive layer 42 and / or the second conductive layer 41 through a wire 3, which helps with the convenience of connection.

[0057] In this embodiment, the LED chips in the first chip string 21 and the third chip string 23 are of the same type and the number of chips is the same. The LED chips in the second chip string 22 can be the same or different types of chips as those in the first chip string 21 or the third chip string 23.

[0058] As Figure 3 shown, a fluorescent glue layer 7 is covered on the light-emitting unit, and the fluorescent glue layer 7 can be silicone or epoxy glue.

[0059] The material of the substrate 1 can be ceramic, sapphire, MCPCB or FPC material.

[0060] The LED chip includes a front-mounted chip, a flip-chip or a vertical chip, etc.

[0061] The LED chip includes a blue chip, a red chip, a green chip or a CSP, etc.

[0062] A filament lamp includes the LED filament described above.

[0063] The present utility model provides an LED filament and a filament lamp, which have a simple structure, are convenient to use and have high reliability.

[0064] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above-described exemplary embodiments, and the present utility model can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present utility model. Any reference signs in the claims should not be construed as limiting the claims involved.

Claims

1. An LED filament, characterized in that: include: substrate; A light-emitting unit, the light-emitting unit comprising a first chip string, a second chip string and a third chip string arranged on the substrate and connected in series in sequence, the first chip string, the second chip string and the third chip string all comprising at least one LED chip; A first resistor, the first resistor being connected in parallel with the first chip string and the second chip string; a second resistor, the second resistor being connected in parallel with the second chip string and the third chip string; Wherein, when the input voltage at both ends of the filament is lower than the threshold voltage and the filament is working, the first chip string and the third chip string are in a normally lit state, and the second chip string is in a non-lit state; When the input voltage across the filament is higher than the threshold voltage and the filament is working, the first chip string, the second chip string and the third chip string are all in a constant light state.

2. The LED filament according to claim 1, characterized in that: Both ends of the substrate are provided with filament pins; The first end of the first chip string is connected to one of the filament pins; The first end of the second chip string is connected to the second end of the first chip string; The first end of the third chip string is connected to the second end of the second chip string, and the second end of the third chip string is connected to another filament pin.

3. The LED filament according to claim 2, characterized in that: A first end of the first resistor is connected to a first end of the first chip string, and a second end of the first resistor is connected to a second end of the second chip string; A first end of the second resistor is connected to a first end of the second chip string, and a second end of the second resistor is connected to a second end of the third chip string; When the input voltage at both ends of the filament is the operating voltage, the current at both ends of the filament is the operating current, the sum of the resistance values ​​of the first chip string and the second chip string is the same as the resistance value of the first resistor; the sum of the resistance values ​​of the second chip string and the third chip string is the same as the resistance value of the second resistor.

4. The LED filament according to claim 3, characterized in that: The first chip string and the third chip string include a plurality of LED chips, and the plurality of LED chips are electrically connected through wires.

5. The LED filament according to claim 3, characterized in that: The number of LED chips in the second chip string is less than the number of LED chips in the first chip string or the third chip string.

6. The LED filament according to claim 5, characterized in that: The LED chips in the first chip string and the third chip string are of the same type and have the same number of chips.

7. The LED filament according to claim 6, characterized in that: The LED chips in the second chip string and the LED chips in the first chip string or the third chip string are the same or different types of chips.

8. The LED filament according to claim 3, characterized in that: A first conductive layer and a second conductive layer are also provided on the substrate. The first resistor is provided on the first conductive layer and is electrically connected to the first conductive layer. The second resistor is provided on the second conductive layer and is electrically connected to the second conductive layer.

9. The LED filament according to claim 8, characterized in that: The filament pin includes a positive pin and a negative pin, the two ends of the first chip string are respectively connected to the positive pin and the first conductive layer through wires, the two ends of the third chip string are respectively connected to the negative pin and the second conductive layer through wires, and the two ends of the second chip string are respectively connected to the first conductive layer and the second conductive layer through wires.

10. A filament lamp, characterized in that: The LED filament comprises the LED filament according to any one of claims 1 to 9.

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