TW202041891A - Lens unit, and light radiating device provided with lens unit - Google Patents

Abstract

The objective of the present invention is to provide a lens unit capable of simultaneously forming images of a plurality of spots of light having a uniform illuminance distribution on an irradiated surface. This lens unit includes a first lens array 25 which uses light flux incident from a light source to form a plurality of secondary light sources, the number thereof corresponding to an array number, a second lens array 27 which guides light flux from the plurality of secondary light sources to an integrator lens 28, and the integrator lens, which collects the light flux that has passed through identical regions in each lens element of the second lens array onto a corresponding identical region on the irradiated surface 29, wherein, in the first lens array, the array number is further divided into units of the lens elements of the second lens array, and the first lens array is disposed on the light source side of the position of a plane that is conjugate with the irradiated surface, in the optical axis direction.

Description

Lens unit and light irradiation device having the lens unit

The present invention relates to a lens unit and a light irradiation device having the lens unit, and more particularly to a lens unit and a light irradiation device having the lens unit. The lens unit and the light irradiation device having the lens unit simultaneously face the irradiation surface Image a plurality of spot lights with uniform illuminance distribution.

For example, Japanese Patent Application Publication No. 2012-3038 discloses a laser annealing device that irradiates laser light to a TFT (thin film transistor) substrate. The laser annealing device is used to anneal and polysilicon a thin film of amorphous silicon in the intersection of the data line and the gate line forming the pixel.

As shown in FIG. 9, in the case of irradiating laser light to the aforementioned TFT substrate, a photomask 60 (top view) is used to selectively irradiate the laser light onto the TFT substrate transported in a predetermined direction (not shown in the figure) Plural positions of. The light shield 60 is provided with a plurality of patterns 61 (formed in two rows in the example shown in the figure) in a matrix with a certain arrangement pitch (pitch) on the surface.

When the laser light is irradiated, a wide area Ar (area enclosed by a dotted line) that covers the entire plurality of patterns 61 formed on the light shield 60 is irradiated.

However, the laser annealing device is not limited to the aforementioned laser annealing device, and any light irradiation device (for example, exposure device) that reforms the material by light irradiation is required to uniformize the illuminance distribution to the entire irradiation area of the light shield.

Therefore, conventional systems use, for example, the irradiation optical unit shown in FIG. 10.

The irradiation optical unit shown in FIG. 10 will be described. In the irradiation optical unit, a first lens array (fly eye) is sequentially arranged along the optical axis from the entrance side (light source side) to the irradiation surface 54 side. 51. A second lens array (fly's eye) 52, an integrator lens 53. The number of arrays (number of lens elements) of the first lens array 51 and the second lens array 52 is the same.

In this configuration, the light beam incident from the light source into the first lens array 51 becomes a secondary light source corresponding to the number of arrays, and the secondary light source is incident on the second lens array 52. The second lens array 52 guides the light beams of the plurality of secondary light sources incident from the first lens array 51 to the integrator lens 53.

Here, the light system emitted from each lens element of the second lens array 52 is concentrated on a point of the irradiation surface 54 by the integrator lens 53 and forms an image (the position of the first lens array 51 and the irradiation surface 54 are conjugation )Relationship).

The light system forming an image on the irradiation surface 54 is formed by superimposing the passing light of a plurality of lens elements formed on the first lens array 51 at one place. Therefore, uneven illuminance is cancelled and the illuminance distribution is made uniform.

As mentioned above, in the light irradiation device, the illuminance distribution of the irradiated light is required to be uniform. The irradiating light system after the illuminance distribution is uniformized is irradiated on a wide area Ar as shown in FIG. The entirety of the plural patterns formed by the cover is covered.

However, the light passing through the pattern opening of the light shield is only a little, and the light shielded by the light shield (most of the irradiated light) becomes useless, so there is a problem of poor light energy efficiency.

In addition, if light is individually irradiated to the opening of the mask in order to improve the energy efficiency of light, the position of the light source side or the irradiation target side needs to be changed every time, so there is a problem that the overall processing takes time.

Based on the above-mentioned reasons, the inventors of the present invention made continuous efforts to achieve the present invention in order to realize a light irradiating device that simultaneously irradiates a plurality of openings of the light shield and has a uniform illuminance distribution.

That is, the object of the present invention is to provide a lens unit and a light irradiation device having the lens unit. The aforementioned lens unit and the light irradiation device having the lens unit can simultaneously image a plurality of point lights with uniform illuminance distribution on the irradiation surface. .

In order to achieve the above-mentioned object, the lens unit of the present invention has a first lens array, a second lens array, and an integrator lens arranged in sequence along the optical axis from the light source side to the irradiation surface side; the lens unit includes: the first lens The array is used to make the light beams emitted from the light source become a plurality of secondary light sources corresponding to the number of the array; the second lens array is used to guide the light beams from the plurality of secondary light sources to the integrator lens; and The integrator lens is used to focus the light beams passing through the same area in each lens element of the second lens array on the corresponding same area on the irradiation surface; the first lens array is formed by the second lens array The lens element has the number of arrays further divided in units, and the position of the surface conjugate with the aforementioned irradiation surface is arranged on the light source side along the optical axis direction.

Furthermore, it is preferable that the number of spot lights forming an image on the irradiation surface is a number obtained by dividing the number of lens elements of the first lens array by the number of lens elements of the second lens array.

In addition, it is preferable to have a lens array moving mechanism that moves the first lens array along the optical axis direction.

In addition, it is preferable that the integrator lens may be a first cylindrical lens that changes the aspect ratio of the image formed on the irradiation surface and a second cylindrical lens that changes the aspect ratio of the image formed on the irradiation surface. Consists of lenses.

As described above, according to the configuration of the present invention, the position of the first lens array is shifted from the position of the surface conjugate with the irradiation surface to the light source side along the optical axis direction, and the lens element of the second lens array is moved The number of arrays of the aforementioned first lens array is further divided. Thereby, it is possible to form a plurality of divided spot lights on the irradiation surface, and the illuminance distribution between and within each spot light can be made uniform.

In addition, with this configuration, it is possible to easily form spot lights corresponding to, for example, a plurality of openings of the light shield, and it is possible to simultaneously irradiate the plurality of openings with spot lights, thereby improving light energy efficiency and work efficiency.

In addition, in order to achieve the above-mentioned object, the light irradiation device of the present invention is characterized by having the aforementioned lens unit.

According to the present invention, a lens unit and a light irradiation device having the lens unit can be provided. The lens unit and the light irradiation device having the lens unit can simultaneously image a plurality of spot lights with uniform illuminance distribution on the irradiation surface.

Hereinafter, embodiments of the lens unit and the light irradiation device of the present invention will be described based on the drawings. FIG. 1 is a cross-sectional view schematically showing an example of a laser annealing device (light irradiation device) to which the lens unit of the present invention is applied. FIG. 2 is a top view showing a part of the TFT substrate processed by the laser annealing device of FIG. 1.

The laser annealing apparatus 1 shown in FIG. 1 is used to selectively irradiate laser light on a TFT substrate 10 having a plurality of pixels (pixels) arranged in a matrix on the surface to anneal a thin film of amorphous silicon formed on the substrate. And polysiliconized devices.

As shown in FIG. 2, the TFT substrate 10 used here has a plurality of pixels 30, and the plurality of pixels 30 are arranged at an arrangement pitch P1 in the substrate conveying direction indicated by arrow A, and are aligned with the substrate conveying direction. The direction of intersection is arranged at the arrangement pitch P2.

In addition, as shown in the figure, a plurality of data lines 31 are formed in a direction parallel to the substrate conveying direction along the edge of each pixel 30 on the substrate surface, and a plurality of gate lines are formed in a direction orthogonal to the substrate conveying direction. 32.

In addition, a cross-shaped lead-in mark 33 is formed outside the display area on the front side in the substrate conveying direction.

The structure of the laser annealing device 1 will be described. The laser annealing device 1 has: a light mask 2 which is correspondingly arranged on the aforementioned TFT substrate 10; a mask stand 3 which holds the aforementioned light mask 2; and a transport mechanism 4 , The TFT substrate 10 is placed and transported in the direction of arrow A at a constant speed.

The mask stand 3 has an opening 3a at the center of the mask stand 3 and grips the peripheral edge of the light mask 2. Then, it can be moved in the directions of arrows B and C as shown in the figure by the drive mechanism 14 such as a motor.

The transport mechanism 4 includes an air stage 5, and the air stage 5 has a plurality of ejection holes for ejecting gas on the upper surface, and a plurality of suction holes for sucking the gas. Then, in a state where the TFT substrate 10 is floated on the air table 5 by a certain amount due to the balance of the gas ejection and suction, the both end edges of the TFT substrate 10 are held by the conveying rollers not shown in the figure. And transport. In addition, it is configured to detect the position of the substrate by a position sensor and a speed sensor not shown in the figure.

In addition, the laser annealing device 1 has a lens unit 6 arranged above the light shield 2 and a laser light source 7 arranged above the lens unit 6 to emit laser light to the lens unit 6. The laser light source 7 is an excimer laser that emits laser light 9 having a wavelength of, for example, 308 nm or 353 nm at a repetitive period of, for example, 50 Hz.

The lens unit 6 is arranged on the optical path of the laser light 9 emitted from the laser light source 7. The lens unit 6 is provided in order to divide the laser light 9 incident from the laser light source 7 into a predetermined plurality of spot lights and to uniformize the illuminance distribution in each of the plurality of divided spot lights. In addition, the lens unit 6 includes a structure that is a characteristic of the present invention, and the details will be described later.

The aforementioned light shield 2 is used to selectively irradiate light to a plurality of predetermined positions (light irradiation target positions) on the TFT substrate 10.

As shown in FIG. 3(a), the light shield 2 is formed with a plurality of openings, that is, in a matrix, at an arrangement pitch equal to the arrangement pitch P1, P2 of the plurality of pixels 30 formed on the TFT substrate 10. Shield pattern 20. In the example shown in the figure, two rows of mask patterns 20A and 20B orthogonal to the substrate conveying direction A are shown.

As shown in (b) of FIG. 3, the aforementioned mask pattern 20 is an opening of a certain shape formed by the light-shielding film 12 provided on the surface of the transparent substrate 11 through which light passes.

In addition, a plurality of micro lenses 17 are provided on the back surface of the transparent substrate 11 (the TFT substrate 10 side). The plurality of micro lenses 17 are arranged to converge light on the convex lens on the TFT substrate 10 and to make the optical axis coincide with the center of each mask pattern 20.

In addition, as shown in FIG. 3(a), the light shield 2 is formed with a first observation window 12A, a second observation window 12B, and a third observation window 12A, a second observation window 12B, and a third observation window 12A, 12B, and 12B, which are long sides in the direction orthogonal to the substrate conveying direction A窗12C.

A first alignment mark is provided in the first observation window 12A, the second observation window 12B, and the third observation window 12C to align a plurality of mask patterns 20 with the light irradiation target positions on the TFT substrate 10 21A, the second alignment mark 21B, and the third alignment mark 21C.

In addition, the laser annealing apparatus 1 includes an alignment mechanism 19 that can move the mask stage 3 in the E and F directions of FIG. 3. The alignment mechanism 19 is constituted by, for example, a linear motor, an electromagnetic actuator, or a track and a motor for aligning the positions of the TFT substrate 10 and the light shield 2.

In addition, the laser annealing apparatus 1 is provided with a line camera (line camera) arranged opposite to one of the aforementioned first observation window 12A, second observation window 12B, and third observation window 12C in the lower part of the TFT substrate 10. camera)15.

The line camera 15 photographs the surface of the TFT substrate 10 and the first alignment mark 21A, the second alignment mark 21B, and the third alignment mark 21C of the light shield 2 through the TFT substrate 10 from below, and combines these first alignment marks 21A, The one-dimensional images of the second alignment mark 21B and the third alignment mark 21C are output to the control mechanism 18 described later.

In addition, a light source 16 for illumination is provided above the mask stage 3 opposite to the line camera 15 and is set as the imaging position of the illumination line camera 15.

Furthermore, the laser annealing apparatus 1 is equipped with the control mechanism 18 which consists of a computer device for performing drive control in the apparatus.

Here, the configuration of the lens unit 6 will be described using FIG. 4. As shown in FIG. 4, the lens unit 6 has a first lens array (fly's eye) 25 and a second lens array (fly's eye) sequentially arranged along the optical axis from the entrance side (laser light source side) to the irradiation surface 29. 27 and an integrator lens 28. In addition, as shown in the figure, there is a surface (referred to as a conjugate surface 26) that is conjugate with the aforementioned irradiation surface 29 on the side closer to the light source than the second lens array 27.

Furthermore, in this embodiment, the aforementioned irradiation surface 29 is set on the surface (back surface) of the light shield 2.

The aforementioned first lens array 25 is used to generate a plurality of secondary light sources corresponding to the number of the array from the light beam incident by the laser light source 7. This secondary light source is generated at the focal point of the first lens array 25 as shown in the figure.

In addition, each lens element of the second lens array 27 is provided to guide light beams from a plurality of secondary light sources to the integrator lens 28.

In addition, the integrator lens 28 is provided for condensing the light beams passing through the same area in each lens element of the second lens array 27 to the corresponding same area on the irradiation surface 29.

In this embodiment, the position of the first lens array 25 is arranged closer to the laser light source 7 than the conjugate surface 26, so it passes through the first lens array 25 and is individually reduced in diameter on the lens elements and is located on the conjugate surface. The image of 26 is formed on the irradiation surface 29.

In addition, the aforementioned first lens array 25 has an array number that further divides the array number of the second lens array 27. That is, the number of arrays (number of lens elements) of the first lens array 25 is formed to be larger than the number of arrays (number of lens elements) of the second lens array 27.

Therefore, the image formed on the irradiation surface 29 is the image obtained by the plurality of lens units of the first lens array 25 corresponding to the lens elements of the second lens array 27, that is, the image formed on the irradiation surface 29 is a plurality of point lights. (The number of spot lights forming an image on the irradiation surface 29 is the number obtained by dividing the number of lens elements of the first lens array 25 by the number of lens elements of the second lens array 27).

Specifically, (a) in FIG. 5 shows a schematic front view of the first lens array 25, and (b) in FIG. 5 shows a schematic front view of the second lens array 27. In addition, (c) in FIG. 5 shows the spot light S formed on the irradiation surface 29.

In addition, in the example shown in FIG. 5, although the number of arrays is simplified for ease of description, the plurality of spot lights S formed on the irradiation surface 29 finally become the same as those shown in FIG. 3(a) in this embodiment. The number and arrangement of the mask patterns 20 shown correspond to each other.

As shown in FIG. 5(b), the second lens array 27 is divided into Mx×My array numbers, and each divided element has lens elements. In this example, Mx=4 and My=4, so there are 4×4 lens elements.

In addition, as shown in FIG. 5(a), the first lens array 25 further divides the area within the Mx×My (4×4) lens elements in the second lens array 27 into Nx×Ny(2 ×3) The number of arrays, and each element of the division has a lens element.

That is, the entire first lens array 25 has (Nx×Mx)×(Ny×My) lens elements. In this example, Nx=2 and Ny=3, so it has (2×4)×(3×4), that is, 8×12 lens elements.

In this case, the optical axes of the plural (8×12) lens elements of the first lens array 25 are respectively reduced in diameter on the conjugate surface 26, and the second lens array 27 is used for each Mx×My The (4×4) lens elements are guided to the integrator lens 28.

Then, the plurality of light systems each incident on the integrator lens 28 of the Mx×My (4×4) lens elements included in the second lens array 27 are collected and formed on the irradiation surface 29. At this time, the light beams passing through the same region in each lens element of the second lens array 27 are collected on the corresponding same region on the irradiation surface 29.

More specifically, for example, as shown in (a) of FIG. 5, the first lens array 25 includes 4×4=16 groups of Nx×Ny (2×3) lens elements. Among the Nx×Ny (2×3) lens elements in each group, for example, the light of the lens element at the upper left position seen through the diagram is set to a ₁₁ , a ₁₂ , a ₁₃ , ... a, respectively ₄₂ , a ₄₃ , a ₄₄ (16 in total).

As shown in (b) of FIG. 5, in the first lens array 25, light a ₁₁ to a ₄₄ passing through the 16 lens elements are respectively incident on the 16 lens elements of the second lens array 27 The upper left area in the view.

In each of the lens elements of the second lens array 27, the light a ₁₁ to a ₄₄ in the same area on the upper left as seen in the figure are made by the integrator lens 28 and the corresponding same area on the irradiation surface 25 is used as point light Sa is overlapped and imaged (Sa=a ₁₁ ＋a ₁₂ ＋...＋a ₄₃ ＋a ₄₄ ).

In the example of FIG. 5, the imaging on the illuminated surface 29 as described above is the Nx×Ny (2×3) point light shown in (c) of FIG. 5 (for the light shield 2 of FIG. In the case of irradiation, it corresponds to the mask pattern 20 of (a) in FIG. 3 and becomes 2×22 spot lights). Here, since the light system of each point is repeated by the light of the Mx×My (4×4) lens elements, the unevenness of the illuminance is cancelled out and the illuminance becomes uniform.

In addition, as shown in FIG. 4, the lens unit 6 may also include a lens array moving mechanism 34 for moving and adjusting the position of the first lens array 25 along the optical axis.

For example, in FIG. 4, in the case where the position of the aforementioned first lens array 25 is aligned with the conjugate surface 26, the diameter of the light S is not reduced because it is divided into Nx×Ny (2×3) points. Therefore, the boundary between the point lights S will disappear (the boundary becomes invisible).

This is because the first lens array 25 is moved closer to the laser light source 7 than the conjugate surface 26 by the lens array moving mechanism 34 as shown in the figure, and the diameter of the optical axis from each lens element is reduced. As a result (the more it moves to the light source side, the more) a thick frame line L appears between the spot lights S as shown in (c) of FIG. 5.

In addition, by changing the position of the first lens array 25 as described above, the size of the spot light S can be changed, so the irradiation area of a plurality of spot lights S can be easily adjusted (that is, it can be formed in accordance with the light shield 2 The opening shape of the mask pattern 20 is adjusted to adjust the irradiation area).

Next, a series of operations performed by the laser annealing apparatus 1 configured as described above will be described.

First, the necessary information is stored in the memory of the control mechanism 18 to perform initial settings. In addition, the driving mechanism 14 of the mask stage 3 is driven according to the instruction of the control mechanism 18, and the mask stage 3 moves in the direction of arrow B by a predetermined distance.

Thereby, for example, the first observation window 12A is positioned above the line camera 15 and the first alignment mark 21A is selected, and the position alignment of the line camera 15 and the first alignment mark 21A is performed.

Next, the transport mechanism 4 starts transport at a constant speed in the direction of arrow A with the TFT substrate 10 placed on the upper surface of the air table 5.

The TFT substrate 10 is transported, and when the lead-in mark 33 marked on the substrate reaches the lower side of the first observation window 12A formed by the light shield 2, the imaging by the line camera 15 is started, and at a certain time interval The captured image is output to the control mechanism 18.

In the control mechanism 18, the alignment mechanism 19 is driven according to the positional relationship between the introduction mark 33 and the alignment mark 21A described above. Then, the alignment mechanism 19 moves the mask stage 3 in the E and F directions indicated by the arrows in FIG. 6, and aligns the TFT substrate 10 and the light mask 2 in a direction orthogonal to the substrate conveying direction A .

Then, the control mechanism 18 is used when the movement distance in the conveying direction of the TFT substrate 10 obtained by calculation reaches the target value, and as shown in FIG. 6, the intersection of the data lines 31 and the gate lines 32 and the light shielding When the centers of the plurality of mask patterns 20 of the mask 2 are the same, the light-emitting instruction of the laser light source 7 is output. Thereby, the laser light emitted from the laser light source 7 is irradiated to the light shield 2 via the lens unit 6 during a predetermined time.

Here, the irradiation surface 29 of the optical system light emitted from the lens unit 6 becomes the surface (back surface) of the light shield 2 and is divided into a plurality of spot lights S as described above, and the illuminance distribution of the spot lights S is uniformized . The plurality of spot lights S correspond to the positions of the plurality of mask patterns 20 formed on the light mask 2 as shown in FIG. 7 and the irradiation area of each spot light S is adjusted to cover the corresponding mask pattern 20 The size of the opening size. Therefore, the light shielded by the light shield 2 is only a little, and the light energy efficiency can be improved.

In this way, the laser light with uniform illuminance is divided into a plurality of spot lights S and irradiated on the back of the light shield 2. The micro lens 17 of the light shield 2 condenses the laser light on the data line 31 of the TFT substrate 10. The intersection with the gate line 32. Then, the amorphous silicon film of the condensing part is annealed to be polysiliconized.

After that, in this embodiment, every time the TFT substrate 10 moves to 2P1, the laser light source is used to control the laser light for a certain period of time, so that the amorphous silicon film at the annealing target position of the entire TFT substrate 10 can be annealed. Processing and polysiliconization.

As described above, according to the embodiment of the present invention, in the lens unit 6 forming the irradiation light, the position of the first lens array 25 is moved from the position of the conjugate surface 26 with the irradiation surface 29 to the light source side along the optical axis direction. The number of arrays of the aforementioned first lens array 25 is further divided by shifting and taking the lens elements of the second lens array 27 as a unit.

Thereby, a plurality of spot lights S can be formed on the irradiation surface 29, and the illuminance distribution between and within each spot light S can be made uniform.

In addition, with this configuration, the spot lights S corresponding to the plurality of openings (mask patterns 20) of the light shield 2 can be easily formed, and the spot lights S can be irradiated to the plurality of openings at the same time, thereby improving light energy efficiency and Operational efficiency.

In addition, in the foregoing embodiment, although the integrator lens 28 is used, the integrator lens 28 forms the spot light S having a shape corresponding to the shape of each lens element of the first lens array 25 on the irradiation surface 29. However, the present invention is not limited to this configuration.

For example, as shown in the perspective view of FIG. 8, a cylindrical lens unit 40 may be arranged as an integrator lens instead of the integrator lens 28.

In the example shown in FIG. 8, the cylindrical lens unit 40 is composed of a pair of cylindrical lenses 41a, 41b (first cylindrical lenses) and a pair of cylindrical lenses 41a, 41b (first cylindrical lenses). The cylindrical lens 42 (second cylindrical lens) between the two, the aforementioned pair of cylindrical lenses 41a, 41b (first cylindrical lens) is used to change the diameter (aspect ratio) of the optical axis in the x direction, the aforementioned cylindrical lens The surface lens 42 (second cylindrical lens) is used to change the diameter (aspect ratio) of the optical axis in the y direction.

The aspect ratio (also called the aspect ratio) of the shape of the spot light imaged on the irradiation surface 29 can be changed by adopting the above-mentioned configuration.

In addition, in the example of the cylindrical lens unit 40 shown in FIG. 8, although the first cylindrical lens for changing the diameter (aspect ratio) of the optical axis in the x direction is composed of two pieces and used to change the optical axis in the y direction The second cylindrical lens with a diameter (aspect ratio) of 1 is composed of one lens, but it is not limited to this structure.

That is, in the example shown in FIG. 8, since the magnification of the optical axis is different in the x direction and the y direction, the lens configuration in the x direction and the y direction are different. In each of the x and y directions, the cylindrical The combination of the number of lenses and the lens shape (convex lens, concave lens) is not limited.

In addition, in the foregoing embodiment, although an example of applying the lens unit of the present invention to a laser annealing device is shown, it is not limited to this, as long as it is a device that modifies materials by irradiation of light, it does not matter. The device can apply the present invention.

For example, in the device shown in FIG. 1, as long as the laser light source 7 is replaced with an exposure light source composed of a xenon lamp that emits ultraviolet light, an ultra-high pressure mercury lamp, or a laser light source that emits ultraviolet light, it is also It can be applied to an exposure device that exposes the photosensitive material coated on the substrate. In this case, the microlens 17 formed on the lower surface of the transparent substrate 11 of the light shield 2 may not be provided, and it may be a device configuration for close exposure.

Alternatively, the present invention can also be applied to the following projection exposure device configuration: a projection lens is provided between the light shield and the exposure object (substrate), and the lens unit of the present invention irradiates the light shield with spot light through The aforementioned projection lens is exposed.

1: Laser annealing device (light irradiation device) 2: Light shield 3: Mask table 3a: Opening 4: Transport mechanism 5: Air table 6: Lens unit 7: Laser light source 9: Laser light 10: TFT substrate 11: Light source 12: Shading film 12A: First observation window 12B: Second observation window 12C: Third observation window 14: Drive mechanism 15: Line camera 16: Light source for lighting 17: Micro lens 18: Control mechanism 19: Alignment mechanism 20, 20A, 20B: mask pattern 21A: first alignment mark 21B: second alignment mark 21C: third alignment mark 25, 51: first lens array 26: conjugate surface 27, 52: second lens array 28, 53: Integrating lens 29, 54: Irradiation surface 30: Pixel 31: Data line 32: Gate line 33: Introducing mark 34: Lens array moving mechanism 40: Cylindrical lens unit 41a, 41b: Cylindrical lens (first cylindrical surface Lens) 42: Cylindrical lens (second cylindrical lens) 60: Light mask 61: Pattern A, B, C: Arrow E, F: Direction L: Frame line P1, P2: Arrangement pitch S, Sa: Point Light Ar: wide area a ₁₁ ~ a ₄₄ : light

Fig. 1 is a cross-sectional view schematically showing an example of a laser annealing device (light irradiation device) to which the lens unit of the present invention is applied. [Fig. 2] A plan view showing a part of a TFT substrate processed by the laser annealing apparatus of Fig. 1. [Fig. In [FIG. 3], (a) is a plan view of the light shield included in the laser annealing apparatus of FIG. 1, and (b) is a cross-sectional view of the light shield. [Fig. 4] A side view showing the configuration of a lens unit included in the laser annealing apparatus of Fig. 1. [Fig. In [FIG. 5], (a) is a front view of the first lens array included in the lens unit of FIG. 4, (b) is a front view of the second lens array included in the lens unit of FIG. 4, and (c) is The front view of the image formed by the lens unit of FIG. 4 on the irradiation surface. [FIG. 6] A plan view for explaining the alignment of the light shield of FIG. 3 with the TFT substrate. [FIG. 7] A plan view showing the spot light irradiated to each pattern of the light mask of FIG. 3. Fig. 8 is a perspective view showing a modification of the lens unit of the present invention. Fig. 9 is a plan view showing the light irradiation area of the light shield in the conventional laser annealing device. [Fig. 10] is a side view showing the structure of a conventional irradiation optical unit.

6: Lens unit

25: The first lens array

26: Conjugate surface

27: The second lens array

28: Integrating lens

29: Irradiated surface

34: Lens array moving mechanism

Claims (7)

A lens unit in which a first lens array, a second lens array and an integrator lens are sequentially arranged along the optical axis from the light source side to the irradiation surface side; The aforementioned lens unit includes: The aforementioned first lens array is used to make the light beam incident from the light source become a plurality of secondary light sources corresponding to the number of the array; The second lens array is used to guide the light beams from the plurality of secondary light sources to the integrator lens; and The aforementioned integrator lens is used for condensing light beams passing through the same area in each lens element of the aforementioned second lens array to the corresponding same area on the aforementioned irradiation surface; The first lens array further divides the number of arrays in units of lens elements included in the second lens array, and is arranged on the light source side along the optical axis direction from the position of the surface conjugate to the irradiation surface. The lens unit according to claim 1, wherein the number of spot lights forming an image on the irradiation surface is obtained by dividing the number of lens elements of the first lens array by the number of lens elements of the second lens array The number obtained. The lens unit according to claim 1, which has a lens array moving mechanism that moves the first lens array along the optical axis direction. The lens unit according to claim 2, which has a lens array moving mechanism that moves the first lens array along the optical axis direction. The lens unit according to any one of claims 1 to 4, wherein the integrator lens is composed of a first cylindrical lens that changes the aspect ratio of the image formed on the irradiation surface and A second cylindrical lens with varying aspect ratio. A light irradiation device has the lens unit as described in any one of claims 1 to 4. A light irradiation device having the lens unit described in claim 5.

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