KR20110005127A - Lens for flash module - Google Patents

Abstract

PURPOSE: A lens for a flash module is provided to increasing uniformity and illuminance on an image surface from light is irradiated. CONSTITUTION: A lens(12) for a flash module includes a lens unit(12b) and a coupling unit(12a). The top of the lens unit is flat. The lens unit has a cone shape downward. The coupling unit is expanded from the lens unit. The lens unit additionally includes reflecting units(12c,12d). The reflecting units are protruded downward with a screw thread shape. The lens is slid horizontally for insertion.

Description

Lens for flash module {Lens for flash module}

The present invention relates to a lens for a flash module, and more particularly, to a lens employed in a flash module of a mobile terminal such as a mobile phone.

Recently, as the use of portable terminals has increased and user demands have been diversified, portable terminal technologies have been developing toward miniaturizing their sizes while being equipped with various functions.

In particular, among the functions mounted in the portable terminal, the camera function is now established as an essential function rather than an additional function.

Thanks to the recent rapid development of camera technology, the camera module is gradually miniaturized to meet the needs of users.

In the case of a camera module mounted on a portable terminal, a camera module including a lens module and an imaging device is mounted on one surface of a portable terminal such as a mobile phone or a PDA. The flash module is disposed around the camera module to irradiate light forward when the image is captured.

Therefore, when shooting at night or in a dark room, a flash module can be used to obtain a clearer and better quality shot image, and can be used as a light at night to provide convenience to the user.

As such, the flash module includes a lens. As the user's eye level increases day by day, lens technology must be developed accordingly, but it is greatly limited by material and processing limitations and mechanical constraints.

In the lens used in the flash module of the existing mobile phone, the key point is the uniformity in the image surface to which light is irradiated based on the resolution of the angle of view of the camera mounted on the phone.

However, only existing lenses, for example Fresnel lenses, have revealed a limitation in improving the uniformity based on illuminance and the angle of view of the camera mounted on the mobile phone.

The present invention has been proposed to solve the above-described problems, and an object of the present invention is to provide a lens for a flash module, which is capable of obtaining a uniformity and an improvement in illuminance compared to a conventional lens.

In order to achieve the above object, a lens for a flash module according to a preferred embodiment of the present invention includes a lens portion having an upper surface flat and conical in a downward direction, and a coupling portion extending from the lens portion. The case is installed by the coupling portion but is opposed to the LED package of the lower and is installed spaced apart from the LED package.

The lens unit further includes a reflector on the outer edge.

The reflecting portion protrudes downward in the form of a thread.

The lens is installed in a form that is fitted from the upper direction to the downward direction, or is installed in a form that is fitted by sliding horizontally.

The upper surface of the lens is rectangular.

Flash module lens according to another embodiment of the present invention, the upper surface is flat and is formed in a conical shape in the downward direction from the bottom of the upper surface, is installed in the case of the portable terminal opposite to the lower LED package and spaced apart from the LED package It is installed.

The upper surface of the lens is circular or square.

The lens is installed in such a way that the lens is fitted in the downward direction.

According to the present invention having such a configuration, the uniformity is also approximately 50 to 50% compared to the existing Fresnel lens type by improving the center lux of about 40 to 50% compared to the existing Fresnel lens type by using the prism characteristic of focusing and dispersion. ~ 60% improvement is achieved.

As such, when the lens for the flash module of the present invention is employed, the uniformity and illuminance of the image plane to which light is irradiated is improved.

In addition, it is possible to realize miniaturization and light weight, so that any field whose purpose is to improve the uniformity according to the illuminance and the field of view (FOV) of the field using the LED as an auxiliary light source (or light source) It has the advantage of being applicable.

Hereinafter, a flash module lens according to an embodiment of the present invention will be described with reference to the accompanying drawings. Prior to the detailed description of the present invention, the terms or words used in the specification and claims described below should not be construed as being limited to the ordinary or dictionary meanings. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

(First embodiment)

1 is an exploded perspective view schematically showing an example of an assembly in which a lens for a flash module according to a first embodiment of the present invention is installed. 2 is a cross-sectional view of the combination of FIG.

The lens 12 is installed in the lens installation space of the mobile phone case 10. The lens installation space is formed to be concave, but is formed to match the edge shape of the lens 12. The central portion of the lens installation space is drilled to form the perforation portion 16, and the jaw portion 18 serving as a cradle is formed to be flat inwardly on the edge of the lens installation space. The coupling part 12a of the lens 12 is fitted into the lens installation space. That is, the distance from one outermost side of the jaw portion 18 to the outermost side of the other side opposite thereto is almost similar to the distance from one outermost side of the coupling portion 12a to the outermost side of the other side opposite thereto. That is, it is preferable that the interval between the outermost one side of the jaw portion 18 and the outermost side of the other side opposite thereto is slightly larger. This is to make the fitting possible. That is, in order to install the lens 12 in the lens installation space of the mobile phone case 10, when the lens 12 is inserted from the upper direction downwards, the lens 12 is fitted in the concave lens installation space. The bottom surface of the engaging portion 12a of the lens 12 is in close contact with the upper surface of the jaw portion 18 of the installation space.

On the other hand, the lens 12 is installed to be spaced apart from the LED package 14 of the lower. The LED package 14 is installed on the base substrate 30. The lens 12 and the LED package 14 are centered. That is, the center of the lower portion of the lens 12 is opposed to the center of the upper portion of the LED package 14 (that is, the center of the upper surface of the mounted light emitting device (not shown)). The distance between the lens 12 and the LED package 14 is about 0.2 to 0.5 mm. Here, the illustrated 0.2 mm may be interpreted as a numerical value meaning that the lens 12 should not contact the LED package 14. If the distance between the lens 12 and the LED package 14 is greater than 0.5 mm, some of the light emitted from the LED package 14 may not be incident to the lens 12.

In FIGS. 1 and 2, the lens 12 is press-fitted from the upward direction to the downward direction. On the other hand, the shape of the lens mounting space of the mobile phone case 10 may be changed (for example, the jaw portion 18 may be changed into a "c" shape) to couple the lens 12 in a horizontal sliding manner.

3 is a perspective view of a lens for a flash module according to a first embodiment of the present invention. 4 is a bottom view of FIG. 3. 5 is a cross-sectional view taken along the line A-A of FIG.

The lens 12 includes a lens portion 12b having a flat top surface and a conical shape downward and a coupling portion 12a surrounding the lens portion 12b. The coupling part 12a refers to a rectangular shape protruding outward while contacting the lens part 12b. The coupling portion 12a has a shape of a rectangle or a rectangle. The lens 12 is made of synthetic resin such as polycarbonate or polymethyl methacrylate (PMMA), and is transparent or translucent material.

A conical lens portion 12b is formed at the center of the bottom surface of the lens 12. A vertex 12e is formed at the center of the lens portion 12b. The vertex 12e is opposed to the center of the upper portion of the LED package 14 (that is, the center of the upper surface of the mounted light emitting element (not shown)). In the specification of the present invention, reference numeral 12e is expressed as a vertex, but may be expressed in other terms (eg, vertex, etc.).

The portion where the coupling portion 12a and the lens portion 12b abut form the reflective surface 13. Reflecting material may be formed on the reflecting surface 13. The reflecting surface 13 reflects the light reflected by hitting the surface of the lens portion 12b to be incident again to the lens portion 12b side. Reflecting portions 12c and 12d are further formed on the left and right sides of the outer edge of the lens portion 12b. The reflecting portions 12c and 12d reflect light reflected on the surface of the lens portion 12b so as to be incident again to the lens portion 12b side. The reflecting portions 12c and 12d protrude downward in the form of threads.

The lens 12 has a larger thickness from the top surface to the bottom vertex 12e than the thickness of the coupling portion 12a. And in order to distribute | disperse and collect light in the lens part 12b well, the vertex 12e is exposed under the coupling part 12a.

Since the refractive index of the lens 12 is different from that of air, it performs a function like a prism. That is, the light emitted from the lower LED package is collected by the lens 12 and dispersed while passing through the lens 12.

In the first embodiment of the present invention, the lens mounting space in which the lens 12 is provided is rectangular, and the lens 12 is rectangular. By the way, if the lens installation space is square or circular, the lens 12 may be square or circular. When the lens 12 is square or circular, the illuminance and uniformity are improved as compared with the case where the lens 12 is rectangular. On the other hand, in the case where the shape of the lens 12 is a rectangular shape, reflecting portions 12c and 12d are additionally formed only on the left and right sides of the outer edge of the lens portion 12b due to mechanical limitations. When the lens 12 is square or circular, the same reflective portion can be formed as a whole along the outer edge of the lens portion 12b. That is, the square or circular lens 12 may be formed with a reflecting portion having the same size and shape along the outer edge of the lens portion 12b. Compared with 12), roughness and uniformity are improved.

The illuminance measurement simulation result (unit; Lux) of the conventional LED package which does not employ the existing Fresnel lens or the lens of the first embodiment of the present invention is shown in Table 1 below.

(Table 1)

Image area     -400     -200       0      200      400      400      76      99      64      105      79      200      74      100      108      106      81       0      75      101      114      106      83     -200      72      102      112      105      82     -400      75      100      65      106      81

In addition, the illuminance measurement simulation result (unit: Lux) of the conventional LED package employing a conventional Fresnel lens is shown in Table 2 below.

(Table 2)

Image area     -400     -200       0      200      400      400      94      104      110      107      93      200      106      113      113      114      108       0      119      114      122      118      111     -200      108      112      109      121      109     -400      96      108      106      104      97

On the other hand, the illuminance measurement simulation results (unit: Lux) for the conventional LED package employing the flash module lens of the first embodiment of the present invention are shown in Table 3 below. The simulation results in Table 3 are almost the same values regardless of which of the flash module lenses of the first to third embodiments of the present invention is employed.

(Table 3)

Image area     -400     -200       0      200      400      400      139      147      148      148      138      200      144      157      155      153      143       0      145      158      171      155      147     -200      142      157      154      156      145     -400      138      155      146      148      137

The simulation results of Tables 1 to 3 simulate the illuminance of about 1m away from the LED light source (not shown) of the LED package, but enter each cell after dividing the area irradiated with light by 400 × 400 at a distance of 1m. The amount of light generated was simulated. The illuminometer used in the illuminance measurement simulation is the TES-1335 model.

The simulation results of Tables 1 to 3 show that the case of employing the flash module lens of the first embodiment of the present invention in the same LED package has the best optical characteristics. In particular, the simulation results show that the existing Fresnel lens type (see Table 2) has a center lux of 122 and roughness of about 400 mm away from the center is less than about 100, whereas the first embodiment of the present invention In the case of the flash module lens of the example, the center lux is 171 and the roughness at about 400 mm from the center is approximately 138. That is, when the flash module lens of the first embodiment of the present invention is adopted, the uniformity is also about 50 to 50% compared to the existing Fresnel lens type, with the center lux improved by about 40 to 50% compared to the existing Fresnel lens type. It can be seen that an improvement of ~ 60% can be achieved.

6 is a view showing the results of actually measuring the roughness of the conventional LED package that does not employ a conventional Fresnel lens or the lens of the first embodiment of the present invention, Figure 7 is a flash of the first embodiment of the present invention The diagram shows the results of actually measuring the illuminance of the conventional LED package employing the module lens. The illuminometer used for the illuminance measurement was a TES-1335 model. The illuminance was measured about 1 m away from the LED light source (not shown) of the LED package, and the illuminance was measured about 445.95 mm away from the center.

When measuring the illuminance of the conventional LED package (for example, 5038 size, 1.92T) that does not employ the existing Fresnel lens or the flash module lens according to the first embodiment of the present invention and The same result was obtained. That is, the illuminance at the center is about 105.6 kPa, and the illuminance at about 445.95 mm away from the center is about 60 kPa.

Looking at the uniformity of the illuminance at the center and the illuminance of about 445.95 mm away from the center, the assumption that the illuminance at the center is 100% as shown in FIG. 6 (b) is about 445.95 mm away from the center. Roughness is less than 60%.

However, when the flash module lens according to the first embodiment of the present invention is adopted, as shown in Fig. 7A, that is, the illuminance at the center is about 172.6 ㏓, and is about 445.95 mm away from the center. Roughness is approximately 100 Hz or more. Looking at the uniformity of the illuminance at the center measured as shown in (a) of FIG. 7 and the roughness of about 445.95 mm away from the center, it is assumed that the illuminance at the center is 100% as shown in FIG. In the case of roughness 445.95 mm away from the center, the illuminance is more than 60%. In terms of uniformity, roughness of about 445.95 mm away from the center is more than 60%, indicating that the overall improvement compared to the existing.

That is, comparing FIG. 6 with FIG. 7 shows that the case of employing the flash module lens according to the first embodiment of the present invention is relatively improved in terms of illuminance and uniformity. More specifically, the center lux is approximately equal to the case where the lens for the flash module according to the first embodiment of the present invention is not used compared to the case for not using the lens for the flash module according to the first embodiment of the present invention. A 33% improvement was achieved, and roughness about 445.95 mm away from the center was improved by about 43%. This is about 28% higher than the existing Fresnel lens type and roughness of 445.95m is also increased by about 31% compared to the existing Fresnel lens type, so it can be seen that the optical characteristics are excellent.

As such, when the lens for the flash module according to the first embodiment of the present invention is adopted, the uniformity and illuminance of the image plane to which light is irradiated is improved.

(Second embodiment)

8 is a perspective view of a lens for a flash module according to a second embodiment of the present invention. 9 is a bottom view of FIG. 8. 10 is a cross-sectional view taken along the line B-B in FIG. 9.

The flash module lens 22 of the second embodiment of the present invention is almost the same as compared with the lens 12 of the first embodiment described above. The differences can vary in size. In the lens 12 of the first embodiment, each reflecting portion is formed on the left and right sides of the lens portion 12b, but the lens 22 of the second embodiment has two reflecting portions formed on the left and right sides of the lens portion 22b. Is different. For example, one reflecting portion 12c is formed on the left side of the lens portion 12b and one reflecting portion 12d is formed on the right side, while two reflecting portions (2) are formed on the left side of the lens portion 22b. 22c) is formed and two reflecting portions 22d are formed on the right side. In Fig. 9, reference numeral 22e is a vertex, and reference numeral 23 is a reflecting surface.

Even if the detailed description of the lens 22 of the second embodiment is not given, those skilled in the art can sufficiently understand the description of the lens 12 of the first embodiment described above.

Although a separate drawing is not provided for the installation form of the lens 22 of the second embodiment, those skilled in the art can easily grasp how the lens 22 of the second embodiment is installed by FIG. 1 and FIG. 2. It is to be understood that the installation form of the lens 22 is the same as the installation form of the lens 12.

11 is a view showing the results of actually measuring the roughness of the conventional LED package that does not employ the existing Fresnel lens or the lens of the second embodiment of the present invention, Figure 12 is a flash of the second embodiment of the present invention The diagram shows the results of actually measuring the illuminance of the conventional LED package employing the module lens. The illuminometer used for the illuminance measurement was a TES-1335 model. The illuminance was measured about 1 m away from the LED light source (not shown) of the LED package, and the illuminance was measured about 445.95 mm away from the center.

When measuring the illuminance of the conventional LED package (for example, 5038 size, 1.92T) that does not employ the existing Fresnel lens or the flash module lens according to the second embodiment of the present invention as shown in Figure 11 (a) The result was obtained. That is, the illuminance at the center is about 110.2 kPa, and the illuminance at about 445.95 mm away from the center is about 61 to 64 kPa.

Looking at the uniformity of illuminance at the center and illuminance of about 445.95 mm away from the center, assuming that the illuminance at the center is 100% as shown in (b) of FIG. 11, it is about 445.95 mm away from the center. The maximum value of roughness is about 58.3%.

However, when the flash module lens according to the second embodiment of the present invention is adopted, as shown in FIG. 12 (a), that is, the illuminance at the center is about 161.3 ㏓ and about 445.95 mm away from the center. Roughness is approximately 95 dB or more. Looking at the uniformity of illuminance at the center measured as shown in (a) of FIG. 12 and about 445.95 mm away from the center, it is assumed that the illuminance at the center is 100% as shown in (b) of FIG. In this case, the maximum value of illuminance about 445.95 mm from the center is about 69%. In terms of uniformity, it can be seen that the maximum value of roughness at about 445.95 mm away from the center is approximately 69%, which is an overall improvement.

That is, comparing FIG. 11 and FIG. 12 shows that the case of employing the flash module lens according to the second embodiment of the present invention is relatively improved in terms of illuminance and uniformity. More specifically, the case where the lens for the flash module according to the second embodiment of the present invention is adopted is improved in center lux compared to the case where the lens for the flash module according to the second embodiment of the present invention is not used. In addition, the roughness at about 445.95 mm away from the center is also improved, indicating that the optical characteristics are excellent.

As such, when the lens for the flash module according to the second embodiment of the present invention is adopted, the uniformity and illuminance of the image plane to which light is irradiated is improved.

(Third Embodiment)

13 is a perspective view of a lens for a flash module according to a third embodiment of the present invention. 14 is a cross-sectional view of a lens for a flash module according to a third embodiment of the present invention. 15 is a view for explaining a form in which a lens for a flash module according to a third embodiment of the present invention is installed.

The flash module lens 40 according to the third embodiment has a flat top surface and is formed in a conical shape downward from the bottom of the top surface. Lens 40 has a vertex 40a.

Although not shown in the drawings, the lens installation space of the mobile phone case 10 in which the lens 40 is to be installed is formed as shown in FIGS. 1 and 2, but has a circular shape. Therefore, the lens 40 of the third embodiment has an image surface circular. On the other hand, the upper surface of the lens 40 may be square instead of circular.

As illustrated in FIG. 15, the lens 40 of the third embodiment is installed in the lens installation space of the mobile phone case 10 in a fitting manner. That is, in order to install the lens 40 in the lens installation space of the mobile phone case 10, when the lens 40 is inserted from the upper direction downwards, the lens 40 is fitted into the concave lens installation space. The vertex 40a faces the center of the upper portion of the lower LED package (not shown) (that is, the center of the upper surface of the mounted light emitting device (not shown)).

Although the actual illuminance measurement result for the case where the lens 40 and the LED package of the third embodiment are combined is not shown, the center lux is compared with the conventional one based on the simulation result as shown in Table 3 above. It will be apparent that the illumination is improved and the illuminance at some distance from the center is also improved, so that it has a considerably superior optical characteristic.

As such, when the lens for the flash module according to the third embodiment of the present invention is adopted, the uniformity and illuminance of the image plane to which light is irradiated is improved.

FIG. 16 illustrates that light emitted from an LED package in a structure not employing a flash module lens according to embodiments of the present invention and a structure employing a flash module lens according to embodiments of the present invention may be converged to a detector. A chart showing the light intensity of a case.

FIG. 16A is a chart when a conventional Fresnel lens is used, and the light intensity of the Y axis is about 130 to 140 candelas (cd). FIG. 16B is a chart in which any of the lenses of the first to third embodiments described above is used, and the intensity of light on the Y axis is about 180 to 220 candelas (cd).

That is, the case of using any of the lenses of the first to third embodiments described above is about 80 candelas higher than the case of using the conventional Fresnel lens. In terms of roughness, the result is approximately 80 to 90 Lux.

FIG. 17 illustrates that light emitted from an LED package in a structure not employing a lens for a flash module according to embodiments of the present invention and a structure employing a lens for a flash module according to embodiments of the present invention may be converged to a detector. It is a chart showing the intensity of light according to the area of the case. FIG. 17A is a chart when a conventional Fresnel lens is used, and FIG. 17B is a chart when any of the lenses of the first to third embodiments described above is used. In the case of using the Fresnel lens, it can be seen that the intensity of light of the focused chart outermost angle is a slightly reduced dark chart color compared to the case of using any of the lenses of the first to third embodiments described above. This means that when one of the lenses of the first to third embodiments of the present invention is used, the light is well focused up to the outermost level. In addition, it can be seen that the roughness of the outermost angle with respect to the illuminance of the center derives a uniformity of about 70% or more.

18 is a view illustrating a structure in which a flash module lens according to an exemplary embodiment of the present invention is not adopted and a light emitted from an LED package in a structure employing a flash module lens according to embodiments of the present invention is connected by lines. It is a chart shown in 3D, Figure 19 is emitted from the LED package in a structure that does not employ a flash module lens according to embodiments of the present invention and a structure employing a lens for a flash module according to embodiments of the present invention. It is a chart shown in 2D by connecting light with lines.

In the case of using a Fresnel lens, it is also seen that the intensity of light at the outermost angle is higher than that of the center. However, as compared with the case of using any of the lenses of the first to third embodiments described above, the rising width is somewhat lower, and it can be seen that there is a marked difference in the uniformity measurement.

On the other hand, the present invention is not limited only to the above-described embodiments and can be carried out by modifications and variations within the scope not departing from the gist of the present invention, the technical idea that such modifications and variations are also within the scope of the claims Must see

1 is an exploded perspective view schematically showing an example of an assembly in which a lens for a flash module according to a first embodiment of the present invention is installed.

2 is a cross-sectional view of the combination of FIG.

3 is a perspective view of a lens for a flash module according to a first embodiment of the present invention.

4 is a bottom view of FIG. 3.

5 is a cross-sectional view taken along the line A-A of FIG.

6 is a view showing the results of actually measuring the roughness of the conventional LED package that does not employ the existing Fresnel lens or the lens of the first embodiment of the present invention.

7 is a view showing the results of actually measuring the illuminance of the LED package employing the flash module lens of the first embodiment of the present invention.

8 is a perspective view of a lens for a flash module according to a second embodiment of the present invention.

9 is a bottom view of FIG. 8.

10 is a cross-sectional view taken along the line B-B in FIG. 9.

11 is a view showing the results of actually measuring the roughness of the conventional LED package that does not employ the existing Fresnel lens or the lens of the second embodiment of the present invention.

12 is a view showing the results of actually measuring the illuminance of the LED package employing the flash module lens of the second embodiment of the present invention.

13 is a perspective view of a lens for a flash module according to a third embodiment of the present invention.

14 is a cross-sectional view of a lens for a flash module according to a third embodiment of the present invention.

15 is a view for explaining a form in which a lens for a flash module according to a third embodiment of the present invention is installed.

FIG. 16 illustrates that light emitted from an LED package in a structure not employing a flash module lens according to embodiments of the present invention and a structure employing a flash module lens according to embodiments of the present invention may be converged to a detector. A chart showing the light intensity of a case.

FIG. 17 illustrates that light emitted from an LED package in a structure not employing a lens for a flash module according to embodiments of the present invention and a structure employing a lens for a flash module according to embodiments of the present invention may be converged to a detector. It is a chart showing the intensity of light according to the area of the case.

18 is a view illustrating a structure in which a flash module lens according to an exemplary embodiment of the present invention is not adopted and a light emitted from an LED package in a structure employing a flash module lens according to embodiments of the present invention is connected by lines. 3D chart.

19 is a view illustrating a structure in which a flash module lens according to an exemplary embodiment of the present invention is not employed and a light emitted from an LED package in a structure employing a flash module lens according to embodiments of the present invention is connected by lines. Chart in 2D.

Claims (9)

The upper surface includes a lens portion formed flat and conical in the downward direction, and a coupling portion formed to extend from the lens portion, The flash module lens, characterized in that installed in the case of the portable terminal by the coupling portion, opposing the lower LED package and spaced apart from the LED package. The method according to claim 1, The lens unit for a flash module, characterized in that further comprising a reflector on the outer edge. The method according to claim 2, The reflector is a lens for a flash module, characterized in that protruding downward in the form of a thread. The method according to claim 1, The lens is a flash module lens, characterized in that installed in the form of being fitted in the downward direction. The method according to claim 1, The lens is a flash module lens, characterized in that installed in the form of sliding horizontally fitted. The method according to any one of claims 1 to 5, The upper surface of the lens is a lens for a flash module, characterized in that made of a rectangle. The upper surface is flat and is formed in a conical shape downward from the lower surface of the upper surface, The flash module lens installed in the case of the portable terminal, characterized in that opposed to the LED package of the lower and installed away from the LED package. The method of claim 7, The upper surface of the lens is a lens for a flash module, characterized in that consisting of a circular or square. The method according to claim 7 or 8, The lens is a flash module lens, characterized in that installed in the form of being fitted in the downward direction.

Images