TWI779988B - Light source module - Google Patents

Abstract

A light source module includes a light source, a wavelength conversion unit, a diffuser, and reflector. The light source is configured to emit excitation light. The wavelength conversion unit is configured to reflect the excitation light. The diffuser has a first side and a second side opposite to each other, and is configured to allow the excitation light reflected by the wavelength conversion unit to enter the diffuser from the first side and reach the second side. The reflector is configured to reflect the excitation light entering the diffuser, so that the excitation light propagates from the second side to the first side and leaves the diffuser.

Description

Light source module

The present disclosure relates to a light source module.

In recent years, laser light has attracted attention as a light source for projection-type image display devices. Laser light sources have several advantages. First, laser light emitted from a laser light source has excellent directivity and thus has high optical utility. In addition, laser light is monochromatic, so the color reproduction area can be expanded. Laser light sources also feature low power consumption and long life compared to other light sources such as incandescent light bulbs.

When coherent light such as laser light is irradiated onto a rough surface (such as a transmissive or reflective screen) with an unevenness greater than the wavelength of the laser light, a pattern called "spot pattern" or simply "spot" is produced. Dappled light pattern. More specifically, light of a single wavelength scattered at each point on the rough surface overlaps irregularly at each point on the viewing surface to produce complex interference patterns.

In order to eliminate the aforementioned light spots, a conventional technique uses a diffuser to homogenize the laser light. However, this prior art has at least the following deficiencies: (1) when the space is limited, it is necessary to increase the inclination angle of the diffuser, but at the same time it may produce a loss in efficiency; and (2) when there is a cost When considering it, it is necessary to reduce the number of diffusers, but it will make the effect of eliminating speckles worse, and then make the displayed picture uneven.

Therefore, proposing a light source module that can solve the above problems has become one of the current important research and development topics.

In view of this, one purpose of the present disclosure is to propose a light source module that can solve the above problems.

In order to achieve the above object, according to an embodiment of the present disclosure, a light source module includes a light source, a wavelength conversion unit, a diffuser, and a reflector. The light source is configured to emit excitation light. The wavelength conversion unit is configured to reflect excitation light. The diffusion sheet has a first side and a second side opposite, and is configured to allow the excitation light reflected by the wavelength conversion unit to enter the diffusion sheet from the first side and reach the second side. The reflector is configured to reflect excitation light entering the diffuser such that the excitation light travels from the second side to the first side and exits the diffuser.

In one or more embodiments of the present disclosure, the reflector is disposed and contacts the second side of the diffuser.

In one or more embodiments of the present disclosure, a gap is formed between the diffuser and the reflector.

In one or more embodiments of the present disclosure, the light source module further includes a color separation film. The wavelength converting unit is also configured to convert the excitation light into the stimulated light. The dichroic filter is configured to reflect the received light.

In one or more embodiments of the present disclosure, the color separation film is located between the wavelength conversion unit and the diffusion film.

In one or more embodiments of the present disclosure, the dichroic film is also configured to transmit the excitation light.

In one or more embodiments of the present disclosure, the light source module further includes a color wheel and an integrating column. The color wheel is configured to transmit excitation light exiting the diffuser from the first side and stimulated light reflected by the dichroic film. The integrating column is configured to receive excitation light and stimulated light passing through the color wheel.

In one or more embodiments of the present disclosure, the light source module further includes another diffuser and an integrating column. The other diffuser is configured to transmit the exciting light exiting the diffuser from the first side and the stimulated light reflected by the dichroic plate. The integrating column is configured to receive the excitation light and the subject light passing through the other diffuser.

In one or more embodiments of the present disclosure, the light source module further includes a lens. The lens has an optical axis. The excitation light emitted by the light source arrives at the wavelength conversion unit through the lens along the path deviated from the optical axis.

In one or more embodiments of the present disclosure, the light source module further includes another diffusion sheet. The other diffuser is optically coupled between the light source and the wavelength conversion unit.

To sum up, in the light source module of the present disclosure, the reflector can reflect the excitation light that enters the diffusion sheet from the first side of the diffusion sheet and reaches the second side of the diffusion sheet, so that the excitation light propagates through the second side to the first side away from the diffuser. In other words, the excitation light is equivalent to passing through the diffuser twice. Thereby, the light source module of the present disclosure can eliminate the light spots generated by the excitation light with a small number of diffusion sheets.

The above description is only used to explain the problems to be solved by the present disclosure, the technical means to solve the problems, and the effects thereof, etc. The specific details of the present disclosure will be introduced in detail in the following implementation methods and related drawings.

The following will disclose multiple implementations of the present disclosure with diagrams, and for the sake of clarity, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present disclosure. That is to say, in some embodiments of the present disclosure, these practical details are unnecessary. In addition, for the sake of simplifying the drawings, some well-known structures and components will be shown in a simple and schematic manner in the drawings.

Please refer to FIG. 1 , which is a schematic diagram illustrating a light source module 100 according to an embodiment of the present disclosure. As shown in FIG. 1 , in this embodiment, the light source module 100 can be applied to, for example, a three-chip digital light processing projector (DLP; Digital Light Processing), but the disclosure is not limited thereto. The light source module 100 includes a light source 110 , a wavelength conversion unit 120 , diffusers 130 , 131 , 132 , a reflector 140 , a dichroic filter 150 , a color wheel 160 , an integrating column 170 , and lenses 181 , 182 , 183 , 184 , and 185 . The light source 110 is configured to emit excitation light L1. In some embodiments, the light source 110 is a blue laser solid-state light source, so the excitation light L1 is blue laser light, but the present disclosure is not limited thereto. The lenses 181, 182, 183, 184, 185 are configured to adjust the light shape according to the requirement. The lenses 183 , 184 , the diffusion sheet 131 , the dichroic sheet 150 , and the lenses 181 , 182 are sequentially optically coupled to the wavelength conversion unit 120 from the light source 110 . That is, the excitation light L1 emitted by the light source 110 will pass through the lenses 183 , 184 , the diffusion sheet 131 , the dichroic sheet 150 , and the lenses 181 , 182 in order to reach the wavelength conversion unit 120 . It can be seen from this that the dichroic film 150 is configured to transmit the excitation light L1. The wavelength conversion unit 120 is configured to reflect the excitation light L1. Specifically, the lenses 181, 182 have an optical axis A. As shown in FIG. The excitation light L1 emitted by the light source 110 arrives at the wavelength conversion unit 120 along a path deviated from the optical axis A through the lenses 181 and 182 . The excitation light L1 reflected by the wavelength conversion unit 120 will pass through the lenses 182 , 181 and the dichroic film 150 along another path deviated from the optical axis A to reach the diffusion film 130 .

In some implementations, the excitation light L1 transmitted from the light source 110 to the wavelength conversion unit 120 may not pass through the dichroic film 150 .

Please refer to FIG. 2 , which is a schematic diagram illustrating some components of the light source module 100 in FIG. 1 . As shown in FIG. 2, in this embodiment, the diffuser 130 has opposite first sides 130a and second sides 130b, and is configured to allow the excitation light L1 reflected by the wavelength conversion unit 120 to enter and diffuse from the first side 130a. sheet 130 to reach the second side 130b. The reflector 140 is disposed and contacts the second side 130b of the diffusion sheet 130 , and is configured to reflect the excitation light L1 entering the diffusion sheet 130 , so that the excitation light L1 propagates from the second side 130b to the first side 130a and leaves the diffusion sheet 130 .

It can be known from the aforementioned structural configuration that the reflector 140 can reflect the excitation light L1 that enters the diffusion sheet 130 from the first side 130a of the diffusion sheet 130 and reaches the second side 130b of the diffusion sheet 130, so that the excitation light L1 is then transmitted from the second side 130b propagates to the first side 130a out of the diffuser 130 . In other words, the excitation light L1 passes through the diffuser 130 twice. Therefore, the light source module 100 of this embodiment can enhance the effect of eliminating the light spots generated by the excitation light L1 through the combination of the diffuser 130 and the reflector 140 .

In some embodiments, the reflector 140 is a reflective coating disposed on the second side 130b of the diffuser 130, so the reflector 140 does not occupy the internal space of the light source module 100, but this disclosure does not mean that limit.

Please refer to FIG. 3 , which is a schematic diagram illustrating some components of a light source module 100 according to another embodiment of the present disclosure. As shown in FIG. 3 , in this embodiment, a gap G is formed between the diffuser 130 and the reflector 140 . After the excitation light L1 entering the diffuser 130 reaches the second side 130b, it leaves the diffuser 130 from the second side 130b and reaches the reflector 140 through the gap G. The reflector 140 reflects the excitation light L1 back to the diffusion sheet 130 , and the excitation light L1 enters from the second side 130 b of the diffusion sheet 130 and exits from the first side 130 a of the diffusion sheet 130 .

Please refer to FIG. 4 , which is a front view of the wavelength conversion unit 120 in FIG. 1 . As shown in FIG. 4 , in this embodiment, the wavelength conversion unit 120 is also configured to convert the excitation light L1 into the received light L2 . The color separation film 150 is also configured to reflect the received light L2. In detail, the wavelength conversion unit 120 includes a substrate 121 and a plurality of fluorescent blocks 122a, 122b disposed on the substrate 121 . The base plate 121 is disc-shaped, and its center can be engaged with the rotating shaft of a motor (not shown), so as to be rotated by the motor. The substrate 121 includes a reflective portion 121a. The phosphor blocks 122a, 122b and the reflective portion 121a are arranged on the front side of the substrate 121 along a circular path around the center of the substrate 121 . The excitation light L1 emitted by the light source 110 will form a light spot on the substrate 121 . During the rotation of the substrate 121 , the light spot will move sequentially on the fluorescent blocks 122 a , 122 b and the reflective portion 121 a along the aforementioned circular path. When the substrate 121 rotates so that the light spot is located on the reflective portion 121a, the reflective portion 121a will reflect the excitation light L1. When the substrate 121 rotates so that the light spot is located in one of the fluorescent blocks 122a, 122b, the exciting light L1 will be converted into the receiving light L2. The received light L2 substantially travels along the optical axis A to the dichroic film 150 and is reflected by the dichroic film 150 .

For example, the fluorescent block 122a is a yellow fluorescent block, and the converted light L2 is yellow light; the fluorescent block 122b is a green fluorescent block, and the converted light L2 is green. light, but this disclosure is not limited thereto.

As shown in FIG. 1 and FIG. 2 , in this embodiment, the dichroic film 150 is located between the wavelength conversion unit 120 and the diffusion film 130 . The excitation light L1 reflected by the wavelength conversion unit 120 first passes through the dichroic film 150 to reach the diffusion film 130 , and is reflected by the reflector 140 to pass through the dichroic film 150 again. The excitation light L1 passing through the dichroic film 150 again and the receiving light L2 reflected by the dichroic film 150 are transmitted to the integrating column 170 through the lens 185 , the diffuser 132 and the color wheel 160 in sequence along the same optical path.

Please refer to FIG. 5 , which is a front view of the color wheel 160 in FIG. 1 . As shown in FIG. 5 , in this embodiment, the color wheel 160 is configured to transmit the excitation light L1 leaving the diffusion sheet 130 from the first side 130 a and the receiving light L2 reflected by the dichroic sheet 150 . The integrating column 170 is configured to receive the exciting light L1 and the receiving light L2 passing through the color wheel 160 . The color wheel 160 includes a substrate 161 and filters 162a, 162b, 162c, 162d disposed thereon. The base plate 161 is disc-shaped, and its center can be engaged with the rotating shaft of another motor (not shown), so as to be rotated by the motor. The optical filters 162a, 162b, 162c, 162d are arranged around the center of the substrate 161 on the front surface of the substrate 161 . During the rotation of the substrate 161, the exciting light L1 or the receiving light L2 will sequentially pass through the filters 162a, 162b, 162c, 162d.

For example, the filters 162a, 162b, 162c, and 162d are red filters, green filters, blue filters, and yellow filters, respectively, but the disclosure is not limited thereto. With the cooperation of the wavelength conversion unit 120 and the color wheel 160 , the desired color light can be filtered out from the exciting light L1 and the receiving light L2 .

According to the aforementioned structural configuration, since the combination of the diffusion sheet 130 and the reflector 140 improves the effect of eliminating the speckle generated by the excitation light L1 , the light source module 100 of the present disclosure may further consider omitting at least one of the diffusion sheets 131 , 132 .

In some implementations, if the converted light L2 converted by the wavelength conversion unit 120 is a desired color light, the color wheel 160 can be omitted. Please refer to FIG. 6 , which is a schematic diagram illustrating a light source module 100' according to another embodiment of the present disclosure. The difference between this embodiment and the embodiment shown in FIG. 1 is that the light source module 100' of this embodiment omits the color wheel 160.

From the above detailed description of the specific implementation of the present disclosure, it can be clearly seen that in the light source module of the present disclosure, the reflector can enter the diffuser from the first side of the diffuser and reach the second side of the diffuser. The excitation light is reflected, so that the excitation light travels from the second side to the first side and leaves the diffuser. In other words, the excitation light is equivalent to passing through the diffuser twice. Thereby, the light source module of the present disclosure can eliminate the light spots generated by the excitation light with a small number of diffusion sheets.

Although the present disclosure has been disclosed above in terms of implementation, it is not intended to limit this disclosure. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of this disclosure. Therefore, the protection of this disclosure The scope shall be defined by the scope of the appended patent application.

100,100': light source module

110: light source

120: wavelength conversion unit

121,161: Substrate

121a: reflection part

122a, 122b: fluorescent block

130,131,132: Diffusers

130a: first side

130b: second side

140: reflector

150: color separation film

160: color wheel

162a, 162b, 162c, 162d: filter

170: integral column

181, 182, 183, 184, 185: lens

A: optical axis

G: Gap

L1: excitation light

L2: by laser

In order to make the above and other purposes, features, advantages and embodiments of the present disclosure more comprehensible, the accompanying drawings are described as follows: FIG. 1 is a schematic diagram illustrating a light source module according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram illustrating some components of the light source module in FIG. 1 . FIG. 3 is a schematic diagram illustrating some components of a light source module according to another embodiment of the present disclosure. Fig. 4 is a front view showing the wavelength conversion unit in Fig. 1 . Fig. 5 is a front view showing the color wheel in Fig. 1. FIG. 6 is a schematic diagram illustrating a light source module according to another embodiment of the present disclosure.

Domestic deposit information (please note in order of depositor, date, and number) none Overseas storage information (please note in order of storage country, institution, date, and number) none

100: Light source module

110: light source

120: wavelength conversion unit

130,131,132: Diffusers

140: reflector

150: color separation film

160: color wheel

170: integral column

181, 182, 183, 184, 185: lens

A: optical axis

L1: excitation light

L2: by laser

Claims (9)

A light source module, comprising: a light source configured to emit an excitation light; a wavelength conversion unit configured to reflect the excitation light; a diffuser having a first side and a second side opposite to each other and configured to allow The excitation light reflected by the wavelength conversion unit enters the diffusion sheet from the first side and reaches the second side; a reflector is configured to reflect the excitation light entering the diffusion sheet, so that the excitation light passes through the second and a lens with an optical axis, the excitation light emitted by the light source is along a path deviated from the optical axis to reach the wavelength conversion unit through the lens. The light source module as claimed in claim 1, wherein the reflector is disposed on and contacts the second side of the diffuser. The light source module as claimed in claim 1, wherein a gap is formed between the diffuser and the reflector. The light source module according to claim 1, further comprising a color separation chip, wherein the wavelength conversion unit is further configured to convert the excitation light into a subject light, and the color separation film is configured to reflect the subject light. The light source module according to claim 4, wherein the color separation film is located between the wavelength conversion unit and the diffusion film. The light source module as claimed in claim 4, wherein the color separation sheet is further configured to transmit the excitation light. The light source module as described in claim 4, further comprising: a color wheel configured to transmit the excitation light leaving the diffuser from the first side and the received light reflected by the dichroic film; and an integrating column, configured to receive the exciting light and the stimulated light passing through the color wheel. The light source module as described in Claim 4, further comprising: another diffuser configured to transmit the excitation light leaving the diffuser from the first side and the detected light reflected by the color separation plate; and an integrating The column is configured to receive the excitation light and the subject light passing through the other diffusion sheet. The light source module according to claim 1, further comprising another diffusion sheet, the other diffusion sheet is optically coupled between the light source and the wavelength conversion unit.

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