CN111682016A

CN111682016A - LED lamp filament and bulb lamp using same

Info

Publication number: CN111682016A
Application number: CN202010062698.5A
Authority: CN
Inventors: 江涛; 张志超
Original assignee: Jiaxing Super Lighting Electric Appliance Co Ltd
Current assignee: Jiaxing Super Lighting Electric Appliance Co Ltd
Priority date: 2019-01-22
Filing date: 2020-01-19
Publication date: 2020-09-18
Also published as: CN212319432U

Abstract

The application relates to the field of illumination, and discloses an LED filament which comprises an LED section, wherein the LED section comprises at least two LED chips, and the LED chips are electrically connected with each other through a lead; the conductor section comprises a conductor connecting two adjacent LED sections, and the length of the conductor is greater than that of the lead; the LED comprises an LED section, an electrode, and a light conversion layer, wherein the electrode is electrically connected with the LED section, and the light conversion layer at least covers the LED section and part of the electrode, so that one part of the electrode is exposed. The application also discloses an LED bulb lamp containing the LED filament. The LED lamp has the characteristics of uniform light emission and good heat dissipation effect.

Description

LED lamp filament and bulb lamp using same

Technical Field

The application relates to the field of lighting, especially relates to an LED filament, has still related to and has used the ball bubble lamp of LED filament.

Background

The LED has the advantages of environmental protection, energy conservation, high efficiency and long service life, so the LED generally receives attention in recent years and gradually replaces the status of the traditional lighting lamp. However, the light emitted by the conventional LED light source has directivity, unlike the conventional lamp, which can illuminate in a wide angle range, so that the application of the LED to the conventional lamp has a corresponding challenge depending on the kind of the lamp.

In recent years, an LED filament capable of making an LED light source emit light similar to a traditional tungsten filament bulb lamp and achieving 360-degree full-angle illumination is increasingly emphasized in the industry. The LED filament is manufactured by connecting a plurality of LED chips in series and fixing the LED chips on a narrow and long glass substrate, wrapping the whole glass substrate with silica gel doped with fluorescent powder, and then electrically connecting. In addition, there is also a soft filament of LED, which is similar to the above filament structure, and the glass substrate is partially replaced by a flexible substrate (hereinafter referred to as FPC), so that the filament can have a certain degree of bending. However, the soft filament made of the FPC has a thermal expansion coefficient different from that of the silica gel coating the filament, and the displacement and even the degumming of the LED chip can be caused by long-term use; or the FPC is not favorable for flexible change of the process conditions and the like.

The applicant has disclosed a soft filament (for example, some embodiments of chinese patent publication No. CN 106468405A), in which a soft filament structure without a carrier substrate is provided to replace the conventional structure that a chip is mounted on a substrate first and then coated with phosphor/package, so as to provide a flexible and wavelength-converting fluorescent package. However, when the arrangement of the chips in the filament is delicate, if the adjacent LED chips are connected by the metal routing, stress is too concentrated on a specific part of the filament due to bending of the filament, and the metal routing connecting the LED chips is easily damaged or even broken, so that there is still room for improving the quality of some embodiments.

In the prior art, most of LED lamps adopt a blue LED chip and yellow fluorescent powder to combine to emit white light, but the emission spectrum of the LED lamp is weaker in light in a red light region, the color rendering index is lower, low color temperature is difficult to realize, certain green fluorescent powder and certain red fluorescent powder are generally added to improve the color rendering index, but the relative conversion rate of the red fluorescent powder is lower, so that the total luminous flux of the LED lamp is generally reduced, namely the luminous efficiency is reduced.

In addition, the LED filament is generally disposed in the LED bulb, and in order to present an aesthetic feeling in appearance and to make an illumination effect of the LED filament more uniform and wide, the LED filament may be bent to present various curves. However, the LED filament has LED chips arranged therein, and the LED chips are relatively hard objects, so that the LED filament is difficult to bend into a desired shape. Further, the LED filament is also prone to cracking due to stress concentration during bending.

The present application further optimizes the above applications to further address various manufacturing processes and product requirements.

Disclosure of Invention

It is specifically noted that the present disclosure may actually encompass one or more inventive aspects that may or may not have been presently claimed, and that several inventive aspects that may be present herein may be collectively referred to herein as "the present application" during the course of writing the description to avoid obscuring the unnecessary distinction between such inventions.

This summary describes many embodiments with respect to the "present application". The term "present application," however, is used merely to describe some embodiments disclosed in the specification (whether or not in the claims), rather than a complete description of all possible embodiments. Certain embodiments of various features or aspects described below as "the present application" may be combined in different ways to form an LED bulb or portion thereof.

The application discloses LED filament, LED filament includes:

the LED section comprises at least two LED chips, and the LED chips are electrically connected with each other through a wire;

the conductor section comprises a conductor connecting two adjacent LED sections, and the length of the conductor is greater than that of the lead;

an electrode electrically connected to the LED segment, an

The light conversion layer at least covers the LED section and part of the electrode, so that part of the electrode is exposed, the light conversion layer comprises a top layer and a base layer which are respectively positioned on two sides of the LED chip, the top layer comprises a fluorescent powder composition, the fluorescent powder composition comprises first fluorescent powder with a peak wavelength value of 490-500 nm and a FWHM of 29-32 nm under the excitation of blue light, second fluorescent powder with a peak wavelength value of 520-540 nm and a FWHM of 110-115 nm under the excitation of blue light, and third fluorescent powder with a peak wavelength value of 660-672 nm and a FWHM of 15-18 nm under the excitation of blue light; and the fourth fluorescent powder has a wavelength peak value of 600-612 nm and a FWHM of 72-75 nm under the excitation of blue light.

Preferably, the weight percentage of each phosphor in the phosphor composition is: 5.45-5.55% of first fluorescent powder, 70-88% of second fluorescent powder, 0.6-7% of third fluorescent powder and the balance of fourth fluorescent powder.

Preferably, the range of D50 of the first phosphor and the fourth phosphor is 16 to 20 μm.

Preferably, the top layer further comprises glue, and the weight ratio of the fluorescent powder composition to the glue is 0.2-0.3: 1.

Preferably, the peak wavelength value of the blue light chip is 450-500 nm, and the FWHM is 15-18 nm.

Preferably, the LED filament is supplied with no more than 8w of electric energy, and when the LED filament is lightened, at least 4lm of white light is emitted per millimeter of the length of the LED filament.

The application also discloses LED ball bubble lamp, LED ball bubble lamp includes:

a lamp housing; the lamp shell is filled with gas, the gas comprises nitrogen and oxygen, and the content of the oxygen is 1-10% of the volume of the lamp shell;

the lamp holder is connected with the lamp shell;

the core column extends from the lamp holder into the lamp shell; and

the LED bulb lamp is positioned in a space coordinate system (X, Y, Z), wherein the Z axis is parallel to the core column, the diameter of the lamp holder is R1, the maximum diameter of the lamp shell is R2, the maximum width of the LED filament in the Y axis direction on the YZ plane or the maximum width of the LED filament in the X axis direction on the XZ plane is R3, and R1 is more than R3 and more than R2.

Preferably, the gas contains impurities in an amount of 0.1 to 5% by volume of the lamp envelope.

Preferably, the LED filament has at least two first bending points and at least one second bending point when bent, the first bending points and the second bending points are spaced apart, and the height of any one of the first bending points on the Z axis is greater than that of any one of the second bending points.

Preferably, the distance between two adjacent first bending points on the Y axis or the X axis has a maximum value D1 and a minimum value D2, and D2 is in the range of 0.5D1 to 0.9D 1.

Through the technical scheme, the method has the following or any combination of technical effects: (1) by adjusting the content of the first fluorescent powder, the second fluorescent powder, the third fluorescent powder and the fourth fluorescent powder in the fluorescent powder composition, the LED filament can obtain better luminous performance; (2) the proportion of the fluorescent powder composition and the glue is adjusted, so that the sedimentation of the fluorescent powder can be greatly reduced, and the light refraction rule tends to be consistent; (3) the inflation gas contains a small amount of impurities, and light emitted by the LED lamp filament is emitted or refracted by the impurities, so that the light emitting angle is increased, and the light emitting effect of the LED lamp filament is improved; (4) by designing the relationship among the diameter of the lamp holder, the maximum diameter of the lamp shell and the maximum width of the LED filament in the Y-axis direction on the YZ plane or the maximum width in the X-axis direction on the XZ plane, the radiating effect of the bulb lamp can be effectively improved.

Drawings

FIG. 1 is a schematic structural diagram of one embodiment of an LED filament of the present application;

fig. 2A-2D are schematic, side, another side, and top views, respectively, of an LED bulb according to an embodiment of the present application;

fig. 3 is a schematic diagram illustrating an output light spectrum of an LED bulb lamp according to an embodiment of the present application;

fig. 4 is a schematic diagram illustrating an output light spectrum of an LED bulb lamp according to an embodiment of the present application;

fig. 5 is a schematic diagram of an output light spectrum of an LED bulb lamp according to an embodiment of the present application.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below.

Fig. 1 is a schematic structural diagram of an embodiment of an LED filament according to the present application, and as shown in fig. 1, the LED filament 400 has: a light conversion layer 420;

LED segments

402, 404; the

electrodes

410, 412; and a conductor segment 430 for electrically connecting between two

adjacent LED segments

402, 404. The LED segments 402,404 include at least two LED chips 442 electrically connected to each other by wires 440. In the present embodiment, the conductor segment 430 includes a conductor 430a connecting the

LED segments

402 and 404, wherein the shortest distance between two LED chips 442 respectively located in two

adjacent LED segments

402 and 404 is greater than the distance between two adjacent LED chips in the LED segment 402/404, and the length of the conducting wire 440 is less than the length of the conductor 430 a. Therefore, the conductor segments are prevented from being broken by the stress generated when the two LED segments are bent. The light conversion layer 420 is coated on at least two sides of the LED chip 442/

electrodes

410, 412. The light conversion layer 420 exposes a portion of the

electrodes

410, 412. The light conversion layer 420 may have at least a top layer 420a and a bottom layer 420b as the upper layer and the lower layer of the filament, respectively, in this embodiment, the top layer 420a and the bottom layer 420b are located on two sides of the LED chip 442/the

electrodes

410 and 412, respectively. In one embodiment, if no more than 8w of electrical power is supplied to the filament, the filament emits at least 4lm of white light per millimeter of filament length when lit. In one embodiment, the filament comprises at least 2 LED chips per millimeter, and the temperature of the LED filament is not more than the junction temperature of the LED filament when the LED filament is lighted for 15000 hours in an ambient environment at 25 ℃.

The phosphor composition as a part of the top layer 420b includes a first phosphor, a second phosphor, a third phosphor and a fourth phosphor, wherein the first phosphor has a wavelength peak of 490-500 nm and a half-peak width (FWHM) of 29-32 nm under excitation of blue light; under the excitation of blue light, the peak value of the wavelength of the second fluorescent powder is 520-540 nm, and the half-peak wave width (FWHM) is 110-115 nm; under the excitation of blue light, the peak value of the wavelength of the third fluorescent powder is 660-672 nm, and the half-peak wave width (FWHM) is 15-18 nm; under the excitation of blue light, the peak wavelength value of the fourth fluorescent powder is 600-612 nm, the full width at half maximum (FWHM) is 72-75 nm or 620-628 nm, the full width at half maximum (FWHM) is 16-18 nm or 640-650 nm, and the full width at half maximum (FWHM) is 85-90 nm. The range of the central particle diameter (D50) of any one of the first fluorescent powder, the second fluorescent powder, the third fluorescent powder and the fourth fluorescent powder is 15-20 mu m, the range of the D50 of the second fluorescent powder and the third fluorescent powder is preferably 15-16 mu m, and the range of the D50 of the first fluorescent powder and the fourth fluorescent powder is preferably 16-20 mu m. When the blue light excites the phosphor, the thickness of the top layer having the same phosphor concentration will affect the half-peak bandwidth of the phosphor, and in this embodiment, the thickness of the top layer 420b is 80-100 μm. The weight percentage of each fluorescent powder in the fluorescent powder composition is as follows: the first fluorescent powder is 5.45-5.55%, the second fluorescent powder is 70-88%, the third fluorescent powder is 0.6-7%, and the balance is the fourth fluorescent powder, the top layer selects the fluorescent powder with different peak wavelengths under the condition of blending a certain ratio of the fluorescent powder to the glue, and the measured optical properties are shown in table 1 under the conditions that the peak wavelength of a blue light LED chip is 451nm, the FWHM is 16.3nm, and the current is 30 mA:

TABLE 1

As shown in the No. 1-4 of Table 1, the contents of the third phosphor and the fourth phosphor in the phosphor composition have an effect on the luminous efficiency (Eff), the average color rendering index (Ra) and the saturated red color (R9). As can be seen from Nos. 1 and 2, when the content of the fourth phosphor having a peak wavelength of 670nm was increased, Eff was increased, and Ra and R9 were decreased; when the phosphor having a peak wavelength of 630nm was used in place of the phosphor having a peak wavelength of 652nm, it can be seen from the numbers No.3 and 4 in Table 1 that when the content of the fourth phosphor having a peak wavelength of 670nm was increased, Eff decreased, and Ra and R9 increased. Therefore, according to actual needs, when the fourth fluorescent powder with different wavelength peak values is selected, the use amounts of the third fluorescent powder and the fourth fluorescent powder are adjusted to obtain better luminous performance.

Ratio of phosphor to glue

The same fluorescent powder is selected, the proportion of the fluorescent powder composition to the glue is prepared, as shown in table 2, as can be seen from table 2, the proportion of the fluorescent powder composition to the glue is different, the Eff, the Ra, the R9 and the CCT are different, the more the fluorescent powder composition accounts for the glue, the more the Eff, the Ra and the CCT are reduced, and the R9 has the tendency of increasing after being reduced; in addition, when the fluorescent powder composition is matched with glue (such as silica gel) to serve as the top layer of the LED filament, in the process of manufacturing the top layer, the fluorescent powder can be remarkably settled due to the fact that the specific gravity of the fluorescent powder composition is larger than that of the silica gel, and white light LED color temperature drift is caused, when the specific gravity of the fluorescent powder composition is larger, the fluorescent powder is more settled, the color temperature drift is more serious, and therefore the weight ratio of the fluorescent powder composition to the glue in the top layer is 0.2-0.3: 1, preferably 0.25-0.3: 1. In one embodiment, a certain amount of hollow glass beads can be added into the phosphor composition, when the phosphor is settled, the glass beads float upwards, the backscattering/emission degree of light during the floating process is reduced, and the backscattering/emission degree is offset with the effect of the phosphor settled on light scattering, so that the color temperature drift phenomenon can be relieved, and in addition, the influence of adding the glass beads on the initial brightness of the white light LED is small because the absorption of the beads on visible light is small. The mass ratio of the glass beads to the fluorescent powder composition is 1: 5-15, and the weight ratio of the glass beads to the fluorescent powder composition is preferably 1: 10-15.

TABLE 2

In one embodiment, an LED filament is provided, wherein the LED filament is made of the phosphor composition and a blue light chip, the blue light chip has a wavelength peak of 450 to 500nm and a half-peak width of 15 to 18 nm.

Referring to fig. 2A and fig. 2B to 2D, fig. 2A is a schematic diagram of an LED bulb 40h according to an embodiment of the present application, and fig. 2B to 2D are a side view, another side view and a top view of the LED bulb 40h of fig. 2A, respectively. In the present embodiment, as shown in fig. 2A to 2D, the LED bulb lamp includes a lamp housing 12, a base 16 connected to the lamp housing 12, a stem 19 disposed in the lamp housing 12, and a single LED filament 100. The stem 19 includes a bottom portion connected to the burner 16 and a top portion (or called a vertical rod 19a) extending into the lamp envelope 12, for example, the top portion of the stem may be located at about the center of the inside of the lamp envelope 12. The LED filament 100 includes a filament body and two

filament electrodes

110 and 112, the two

filament electrodes

110 and 112 are located at two opposite ends of the filament body, and the filament body is the other part of the LED filament 100 excluding the

filament electrodes

110 and 112.

In the manufacturing process of the traditional bulb lamp, in order to avoid oxidation fracture failure caused by combustion of tungsten filaments in air, a glass structure sleeve of a horn core column is designed to be sintered and sealed at an opening of a glass lamp housing, then the inside air of the lamp housing is pumped into nitrogen by a port connection vacuum pump of the horn core column, the combustion oxidation of the tungsten filaments inside the lamp housing is avoided, and finally the port of the horn core column is sintered and sealed. Therefore, the vacuum pump can pump the air in the lamp housing into full nitrogen or the combination of nitrogen and helium in a proper proportion through the core column so as to improve the heat conductivity of the gas in the lamp housing and remove the water mist hidden in the air. In one embodiment, the ratio of nitrogen to oxygen or the ratio of nitrogen to air can be replaced by a proper ratio, the content of oxygen or air is 1-10% of the volume of the lamp shell, preferably 1-5%, when the base layer contains saturated hydrocarbon, the saturated hydrocarbon can generate free radicals under the action of light, heat, stress and the like during the use of the LED bulb lamp, the generated free radicals or activated molecules are combined with oxygen to form peroxide free radicals, and the lamp shell is filled with oxygen, so that the heat resistance and the light resistance of the base layer containing the saturated hydrocarbon can be improved.

In the preparation process of the LED bulb lamp, in order to improve the refractive index of the lamp housing 12 to the light emitted by the LED filament, some foreign matters, such as rosin, may be attached to the inner wall of the lamp housing 12. The average thickness of the foreign matter deposition in each square centimeter of the inner wall area of the lamp shell 12 is 0.01-2 mm, and the preferred thickness of the foreign matter is 0.01-0.5 mm. In one embodiment, the amount of the foreign materials in the inner wall area of the lamp housing 12 per square centimeter is 1% to 30%, preferably 1% to 10%, of the amount of the foreign materials in the entire inner wall of the lamp housing 12. The foreign matter content can be adjusted by, for example, vacuum drying the lamp envelope. In another embodiment, a portion of impurities may be left in the inflation gas of the lamp housing 12, the content of the impurities in the inflation gas is 0.1% to 20%, preferably 0.1% to 5%, of the volume of the lamp housing 12, and the content of the impurities may be adjusted by, for example, vacuum drying the lamp housing, because the inflation gas contains a small amount of impurities, the light emitted by the LED filament is emitted or refracted by the impurities, the light emitting angle is increased, and the light emitting effect of the LED filament is improved.

The LED bulb lamp is located in a space coordinate system (X, Y and Z), wherein a Z axis is parallel to the core column 19, the LED filament 100 is provided with at least two first bending points and at least one second bending point when being bent, the first bending points and the second bending points are arranged at intervals, the height of any first bending point on the Z axis is larger than that of any second bending point, in one embodiment, the distance between every two adjacent first bending points on the Y axis or the X axis is equal, and the LED filament is neat and attractive in appearance. In one embodiment, the distance between two adjacent first bending points on the Y axis or the X axis has a maximum value D1 and a minimum value D2, D2 is in the range of 0.5D1 to 0.9D1, and the luminous flux distribution on each plane is relatively consistent. When the diameter of the lamp base 16 is R1 (see fig. 2B), the maximum diameter of the lamp housing 12 or the maximum horizontal distance between the lamp housing 12 in the YZ plane is R2 (see fig. 2B), the maximum width of the LED filament 100 in the Y-axis direction in the YZ plane (see fig. 2B) or the maximum width in the X-axis direction in the XZ plane is R3 (see fig. 2C), and R3 is between R1 and R2, that is, R1 < R3 < R2, when the LED filament is bent, the distance between adjacent first bending points and/or adjacent second bending points in the Z-axis direction is wider, which is beneficial to improving the heat dissipation effect of the LED filament. In the manufacturing process of the LED bulb lamp, the LED filament 100 may be placed in the inner space of the lamp housing 12 in a folding manner, and then the filament 100 is stretched in the lamp housing 12 in a manual or mechanical manner, so that the maximum length of the filament 100 on the XZ plane satisfies the above relation.

As shown in fig. 2A to 2D, in the present embodiment, there is one conductor segment 130 of the LED filament 100, and there are two LED

segments

102 and 104, and every two

adjacent LED segments

102 and 104 are connected by the conductor segment 130, and the LED filament 100 is curved in an arc shape in a bending state at a highest point, that is, the

LED segments

102 and 104 are curved in an arc shape at the highest point of the LED filament 100, and the conductor segment is also curved in an arc shape at a low point of the LED filament. The LED filament 100 may be defined as a succession of segments following each bent conductor segment 130, with the

individual LED segments

102, 104 forming corresponding segments.

Moreover, since the LED filament 100 employs a flexible base layer, and the flexible base layer preferably employs an organic silicon modified polyimide resin composition, the

LED segments

102 and 104 themselves also have a certain degree of bending capability. In the present embodiment, the two LED segments 102 are bent to form an inverted U shape, and the conductor segment 130 is located between the two LED segments 102, and the bending degree of the conductor segment 130 is the same as or greater than that of the LED segments 102. That is to say, two LED segments 102 are bent at the filament high point to form an inverted U shape and have a bending radius R1, and conductor segment 130 is bent at the filament LED filament 100 low point and has a bending radius R2, where R1 is greater than R2. By the configuration of the conductor segments 130, the LED filament 100 can be bent with a small turning radius in a limited space. In one embodiment, the bending points of the

LED segments

102 and 104 are at the same height in the Z-direction. The height of this rod 19a corresponds to the height of the conductor section 130. For example, the lowest portion of the conductor segment 130 may be connected to the top of the rod 19a, so that the overall shape of the LED filament 100 is not easily deformed. In various embodiments, the conductor segments 130 can be connected to each other through a through hole in the top of the upright rod 19a, or the conductor segments 130 can be glued to the top of the upright rod 19a and connected to each other, but is not limited thereto. In one embodiment, the conductor segment 130 and the vertical rod 19a can be connected by a guide wire, for example, a guide wire is led out from the top of the vertical rod 19a to connect the conductor segment 130.

As shown in fig. 2B, in the present embodiment, in the Z direction, the height of the conductor segment 130 is higher than the two

electrodes

110 and 112, and the two LED segments 102 extend upward from the two

electrodes

110 and 112 to the highest point, and then bend and extend downward to the conductor segment 130 connecting the two LED segments 102. As shown in fig. 2C, in the present embodiment, the profile of the LED filament 100 in the XZ plane is similar to a V shape, that is, the two LED segments 102 extend upward and outward in an oblique manner, and after being bent at the highest point, extend downward and inward in an oblique manner to the conductor segment 130. As shown in fig. 2D, in the present embodiment, the profile of the LED filament 100 in the XY plane has an S-shape. As shown in fig. 2B and 2D, in the present embodiment, the conductor segment 130 is located between the

electrodes

110 and 112. As shown in fig. 2D, in the present embodiment, the bending point of the LED segment 102, the bending point of the LED segment 104, and the

electrodes

110 and 112 are located on a circumference with the conductor segment 130 as a center on the XY plane.

Referring to fig. 3, fig. 3 is a schematic view of an output light spectrum of an LED bulb lamp according to an embodiment of the present application. In this embodiment, the LED bulb may be any one of the LED bulbs disclosed in the previous embodiments, and the LED bulb is provided with any one single LED filament disclosed in the previous embodiments. The spectrum diagram shown in fig. 3 can be obtained by measuring the light emitted by the LED bulb through a spectrum measuring instrument. From the spectrum diagram, the spectrum of the LED bulb lamp is mainly distributed between wavelengths of 400nm and 800nm, and three peaks P1, P2 and P3 appear at three positions in the range. The peak P1 is between about 430nm and 480nm, the peak P2 is between about 580nm and 620nm, and the peak P3 is between about 680nm and 750 nm. In intensity, the intensity of peak P1 is less than the intensity of peak P2, and the intensity of peak P2 is less than the intensity of peak P3. As shown in fig. 3, such a spectral distribution is close to that of a conventional incandescent filament lamp, and also close to that of natural light. In one embodiment, a light emission spectrum diagram of a single LED filament is shown in fig. 4, and it can be seen from the spectrum diagram that the spectrum of the LED bulb lamp is mainly distributed between wavelengths of 400nm and 800nm, and three peaks P1, P2, and P3 appear at three positions in the range. The peak P1 is between about 430nm and 480nm, the peak P2 is between about 480nm and 530nm, and the peak P3 is between about 630nm and 680 nm. Such a spectral distribution is close to that of a conventional incandescent filament lamp and also close to that of natural light.

Referring to fig. 5, fig. 5 is a light emission spectrum diagram of an LED bulb lamp according to an embodiment of the present application, and it can be seen from the diagram that the spectrum distribution of the LED bulb lamp has three peaks P1 ', P2 ' and P3 ' similar to those shown in fig. 4 between wavelengths of 400nm and 800nm, except that the intensity of P1 ' is greater than P1, and the half-wave peak width of P3 ' is greater than P3. The LED bulb lamp has an average color rendering index Ra (R1-R8) of more than 95, saturated red (R9) of more than or equal to 90, and the luminous efficiency (Eff) of an LED filament is more than or equal to 100 lm/w.

The term "one LED filament" or "one LED filament" refers to a single LED filament structure that is formed by connecting the aforementioned conductor segments and LED segments together or is composed of only LED segments, has the same and continuous light conversion layer (including the same and continuously formed top layer or bottom layer), and is provided with two conductive electrodes electrically connected to the conductive support of the bulb only at two ends, and the single LED filament structure is the same as the single LED filament structure referred to in this application.

The present application has been described in terms of preferred embodiments, but those skilled in the art will recognize that the embodiments are illustrative of some of the embodiments of the present application and should not be construed as limiting. It should be noted that any reasonable combination of variations and permutations or embodiments equivalent to this embodiment (and in particular the filament embodiment of fig. 1, combined into the bulb embodiment of fig. 2) should be considered to be within the scope of the present specification. Therefore, the protection scope of the present application shall be subject to the scope defined by the appended claims.

Claims

1. An LED filament, comprising:

an electrode electrically connected to the LED segment, an

And the light conversion layer at least covers the LED segment and part of the electrode, so that part of the electrode is exposed, the light conversion layer comprises a top layer and a base layer which are respectively positioned on two sides of the LED chip, the top layer comprises a fluorescent powder composition, the fluorescent powder composition comprises first fluorescent powder with a peak wavelength of 490-500 nm and a FWHM of 29-32 nm under the excitation of blue light, second fluorescent powder with a peak wavelength of 520-540 nm and a FWHM of 110-115 nm under the excitation of blue light, third fluorescent powder with a peak wavelength of 660-672 nm and a FWHM of 15-18 nm under the excitation of blue light, and fourth fluorescent powder with a peak wavelength of 600-612 nm and a FWHM of 72-75 nm under the excitation of blue light.

2. The LED filament according to claim 1, wherein the phosphor composition comprises the following phosphors in percentage by weight: the fluorescent powder comprises 5.45-5.55% of first fluorescent powder, 70-88% of second fluorescent powder, 0.6-7% of third fluorescent powder and the balance of fourth fluorescent powder.

3. The LED filament according to claim 2, wherein D50 of the first phosphor and the fourth phosphor is in a range of 16-20 μm.

4. The LED filament of claim 1, wherein the top layer further comprises a glue, and the weight ratio of the phosphor composition to the glue is 0.2-0.3: 1.

5. The LED filament according to claim 1, wherein the peak wavelength of the blue light chip is 450-500 nm, and the FWHM is 15-18 nm.

6. The LED filament of claim 5, wherein the LED filament is supplied with no more than 8w of electrical energy, and wherein the LED filament emits at least 4lm of white light per millimeter of length of the LED filament when illuminated.

7. An LED bulb lamp, characterized in that, the LED bulb lamp includes:

the lamp holder is connected with the lamp shell;

the core column extends from the lamp holder into the lamp shell; and

a single LED filament as claimed in any one of claims 1 to 6, located within the envelope, the LED bulb located in a spatial coordinate system (X, Y, Z) with the Z axis parallel to the stem, the diameter of the base being R1, the maximum diameter of the envelope being R2, the maximum width of the LED filament in the direction of the Y axis in the YZ plane or in the direction of the X axis in the XZ plane being R3, where R1 < R3 < R2.

8. The LED bulb lamp according to claim 7, wherein the gas contains impurities in an amount of 0.1-5% by volume of the lamp envelope.

9. The LED bulb lamp according to claim 7, wherein the LED filament has at least two first bending points and at least one second bending point when bent, the first bending points and the second bending points are arranged at intervals, and the height of any one of the first bending points on the Z axis is greater than that of the second bending point.

10. The LED bulb lamp of claim 9, wherein the distance between two adjacent first bending points on the Y axis or the X axis has a maximum value D1 and a minimum value D2, wherein D2 is in a range of 0.5D 1-0.9D 1.