CN211741715U

CN211741715U - Optical lens

Info

Publication number: CN211741715U
Application number: CN201922448947.XU
Authority: CN
Inventors: 张柯; 张雷
Original assignee: Advanced Micro Intelligent System & Creative Optics Inc
Current assignee: Yuanzhuo Micro Nano Technology Suzhou Co ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-10-23
Anticipated expiration: 2029-12-31

Abstract

The utility model provides an optical lens, its includes the light source, light loop through first optical system, TIR prism to digital micro mirror device, through the projection light that digital micro mirror device reflects through TIR prism and second optical system project, through the deflection light that digital micro mirror device reflects deviate from second optical system, digital micro mirror device with be provided with protection device between the TIR prism, protection device includes the shielding piece, be equipped with the unthreaded hole on the shielding piece, light passes through the unthreaded hole and jets into digital micro mirror device and from the digital micro mirror array jets out, the shielding piece blocks the deflection light reflects to digital micro mirror device through TIR prism. The protection device is arranged to protect the digital micromirror device from being irradiated by light reflected by the TIR prism, so that the working temperature of the digital micromirror device is prevented from rising due to stray light, the damage probability of the digital micromirror device is reduced, and the service life of the digital micromirror device is prolonged.

Description

Optical lens

Technical Field

The invention relates to the technical field of laser direct writing, in particular to an optical lens in laser direct writing.

Background

In the field of laser direct writing technology, a commonly used spatial light modulator is a Digital Micromirror Device (DMD), which includes a plurality of micromirrors with two deflection angles. As shown in fig. 1, in practical application, a light source is guided to a digital micromirror device after being subjected to a light uniformizing effect, a micromirror in the digital micromirror device has two deflection angles α and- α, when the deflection angle of the micromirror is α, the micromirror guides light to a subsequent optical system, which corresponds to turning on of a digital circuit, when the deflection angle of the micromirror is- α, the micromirror deflects light out of the subsequent optical system, which corresponds to turning off of the digital circuit, and a desired pattern is formed by controlling the deflection angle of the micromirror in the digital micromirror device, where α is usually equal to 12 degrees. The digital micromirror device is a micro-electro-mechanical system with electronic input and optical output, when the digital micromirror device works, the digital micromirror device can generate heat, meanwhile, light of a light source led to the digital micromirror device can also cause the temperature of the digital micromirror device to rise, the digital micromirror device needs to work at a proper temperature, the digital micromirror device is prevented from being damaged due to overhigh temperature, although an external heat dissipation device is usually adopted to help the digital micromirror device to dissipate heat at present, the digital micromirror array can still be damaged or even fail due to overhigh working temperature.

Disclosure of Invention

The present invention is directed to an optical lens for reducing the temperature of a digital micromirror device, which is directed to the problems of the prior art.

In order to solve the above problems, the present invention provides an optical lens, which includes a light source, wherein light from the light source sequentially passes through a first optical system and a TIR prism to a digital micromirror device, projection light reflected by the digital micromirror device is projected by the TIR prism and a second optical system, deflection light reflected by the digital micromirror device is deflected out of the second optical system, a protection device is disposed between the digital micromirror device and the TIR prism, the protection device includes a blocking member, a light passing hole is disposed on the blocking member, light is emitted into the digital micromirror device through the light passing hole and emitted from the digital micromirror array, and the blocking member blocks the deflection light from being reflected to the digital micromirror device through the TIR prism.

Further, the peripheral edge of the protection device is not smaller than the edge of the digital micromirror device.

Further, a gap is arranged between the shielding piece and the digital micro-mirror device, and the distance of the gap is calculated according to the using area of the digital micro-mirror device and the distance between the TIR prism and the digital micro-mirror device.

Further, the size of the light passing hole is calculated according to the distance between the shielding piece and the digital micro-mirror device.

Further, the shielding piece is 1-3mm away from the digital micro-mirror device.

Further, the shielding piece is 2mm away from the digital micro-mirror device.

Further, the size of the light passing hole is larger than 20mm multiplied by 4 mm.

Further, the size of the light passing hole is 24mm multiplied by 10 mm.

Further, the surface of the shielding piece close to the digital micromirror device is a rough surface.

Further, the surface of the shielding piece close to the digital micromirror device is a black light absorbing layer.

Further, the surface of the shielding piece close to the TIR prism is a smooth surface.

Compared with the prior art, the protection device is arranged between the digital micromirror device and the TIR prism to protect the digital micromirror device from being irradiated by the light reflected by the TIR prism, so that the working temperature of the digital micromirror device is prevented from being increased due to stray light, the probability of damage of the digital micromirror device is reduced, and the service life of the digital micromirror device is prolonged.

Drawings

Fig. 1 illustrates the operation of the digital micromirror device.

Fig. 2 is a schematic view of an optical lens.

Fig. 3 is a schematic diagram of the optical path of the projection light.

Fig. 4 is a schematic diagram of the path of deflected light.

Fig. 5 is a schematic diagram of a digital micromirror device.

Fig. 6 is a schematic side view of a protective device.

Fig. 7 is a schematic front view of the protection device.

Detailed Description

In order that the objects, aspects and advantages of the invention will become more apparent, the invention will be described by way of example only, and in connection with the accompanying drawings.

As shown in fig. 2, which is a schematic view of an optical lens in the field of laser direct writing, light emitted by a laser enters a first optical system 2 through an optical fiber 1, light is homogenized in the first optical system 2, the light passing through the first optical system 2 is reflected to a digital micromirror device 4 through a TIR (Total Internal Reflection) prism 3, the first optical system 2 and the TIR prism 3 form an illumination light path, the light is reflected by a coded digital micromirror device 4, projection is realized by the projection light through the TIR prism 3 and a second optical system 5, the deflection light reflected by the digital micromirror device 4 is deflected out of the second optical system 5, and the TIR prism 3 and the second optical system 5 form an imaging light path.

The illumination light path and the imaging light path share the TIR prism 3, in the illumination light path, the TIR prism 3 is used for turning the illumination light path by utilizing the total reflection of light, and enters the digital micromirror device 4 at a proper angle, for example, 24-degree angle incidence digital micromirror device 4, in the imaging light path, the TIR prism 3 is used for enabling the imaging light path to penetrate.

It is found that, as shown in fig. 3, it is an optical path diagram of the micromirror in the dmd 4 directing the projected light to the subsequent optical system, as shown in fig. 4, it is an optical path diagram of the micromirror in the dmd 4 deflecting the deflected light out of the subsequent optical system, and the deflection angle of the dmd 4 is- α, and since the light reflected by the dmd 4 enters the TIR prism 3 at twice the incident angle when the dmd is at- α, the light is reflected on the surface of the TIR prism 3, and thus the reflected light is reflected to the dmd 4, including the active region 40 and the peripheral region 41 (peripheral mechanical device electronics) of the dmd 4, as shown in fig. 4-5. Since the light reflected by the TIR prism 3 is stray light for the optical system, it will be absorbed by the peripheral region 41 of the digital micromirror device 4, resulting in thermal effect, causing temperature rise, exceeding the operating temperature of the digital micromirror device 4, reducing the service life of the digital micromirror device 4 and even destroying the digital micromirror device.

Aiming at the problem of temperature rise of the digital micromirror device 4 caused by stray light reflected by the TIR prism 3, the invention provides a protection device 6 of the digital micromirror device, as shown in FIGS. 6-7, wherein the protection device 6 is positioned between the digital micromirror device 4 and the TIR prism 3, can be integrated with a mounting base of the digital micromirror device 4, and can also be mounted on the mounting base of the digital micromirror device 4 as an accessory. Fig. 5 shows a side view of the protection device 6, the protection device 6 includes a shielding member 60, a light passing hole 61 is formed on the shielding member 60, light enters the dmd 4 and exits from the dmd array 4 through the light passing hole 61, and the shielding member 60 blocks the deflected light from being reflected to the dmd 4 through the TIR prism 3.

The protection device needs to ensure that all incident light is reflected to the digital micromirror device 4, the light reflected by the digital micromirror device 4 is not blocked, and meanwhile, stray light is prevented from being reflected back to the digital micromirror device 4 through the TIR prism 3. According to the above requirements, the distance between the protection device 6 and the digital micromirror device 4 is calculated according to the using area of the digital micromirror device and the distance between the TIR prism 3 and the digital micromirror device 4, and further the size of the protection device light passing hole 61 is calculated. For the commonly used DMD 4 area of 20mm x 4mm with a prism to DMD gap of 7mm, the preferred location of the shield 60 is 1-3mm, preferably 2mm, in front of the DMD. The size of the light passing hole must be larger than 20mm multiplied by 4mm, and the preferred size of the light passing hole is 24mm multiplied by 10mm, so that the protection effect is best.

The peripheral edge of the shade 60 is not smaller than the edge of the digital micromirror device 4. The material of the shielding member 60 is preferably a material with good heat conductivity, such as copper, and the shielding member 60 is used to guide the heat generated by the light to the wall of the lens as soon as possible.

The surface of the protection device 6 is treated, and the surface close to the digital micromirror device 4 is a surface with large roughness, and is preferably a black light absorption layer. And a smooth surface is adopted near the mirror side of the TIR prism 3, so that the reflected light of the TIR prism 3 is favorably reflected again.

When the digital micromirror device 4 is matched with the TIR prism 3 for use, the protection device 6 protects the digital micromirror device 4 from being irradiated by light reflected by the TIR prism 3, so that the phenomenon that the working temperature of the digital micromirror device 4 is increased due to stray light is avoided, the probability of damage of the digital micromirror device 4 is reduced, and the service life of the digital micromirror device is prolonged.

Claims

1. An optical lens assembly comprising a light source, wherein the light source passes through a first optical system and a TIR prism in sequence to a digital micromirror device, the projection light reflected by the digital micromirror device is projected through the TIR prism and a second optical system, and the deflection light reflected by the digital micromirror device is deflected out of the second optical system, the optical lens assembly comprising: the digital micromirror device is characterized in that a protection device is arranged between the digital micromirror device and the TIR prism and comprises a shielding piece, a light passing hole is formed in the shielding piece, light rays are emitted into the digital micromirror device and emitted from the digital micromirror array through the light passing hole, and the shielding piece blocks the deflected light rays from being reflected to the digital micromirror device through the TIR prism.

2. An optical lens according to claim 1, characterized in that: the peripheral edge of the protective device is not smaller than the edge of the digital micromirror device.

3. An optical lens according to claim 1, characterized in that: the distance between the blocking piece and the digital micro-mirror device is calculated according to the using area of the digital micro-mirror device and the distance between the TIR prism and the digital micro-mirror device.

4. An optical lens according to claim 3, characterized in that: the size of the light passing hole is calculated according to the distance between the shielding piece and the digital micromirror device.

5. An optical lens according to claim 1, characterized in that: the distance between the shielding piece and the digital micro-mirror device is 1-3 mm.

6. An optical lens according to claim 1, characterized in that: the shielding piece is 2mm away from the digital micromirror device.

7. An optical lens according to claim 1, characterized in that: the size of the light passing hole is larger than 20mm multiplied by 4 mm.

8. An optical lens according to claim 1, characterized in that: the size of the light passing hole is 24mm multiplied by 10 mm.

9. An optical lens according to claim 1, characterized in that: the surface of the shielding piece close to the digital micromirror device is a rough surface.

10. An optical lens according to claim 1 or 9, characterized in that: the surface of the shielding piece close to the digital micromirror device is a black light absorption layer.

11. An optical lens according to claim 1, characterized in that: the surface of the shielding piece close to the TIR prism is a smooth surface.