Driving method, light source unit, illumination unit, exposure device, and exposure method

Abstract

The method for driving a light source element is a method for driving a light source element that emits light with a first light emission amount when a current of a first current value is supplied. The driving method includes supplying a current to the light source element at a second current value lower than the first current value, and increasing the current value of the current supplied to the light source element to the first current value. The current value of the current supplied to the light source element at a first time point is a corrected current value obtained by acquiring the current value of the current supplied to the light source element at the first time point on the basis of first information and correcting the acquired current value on the basis of the temperature of the light source element. The first information predetermines the current value of the current to be supplied to the light source element at each point in time during a period in which supply of the current to the light source element is started at a predetermined third current value and the current value of the current to be supplied to the light source element is increased to the first current value.

Description

Technical Field

[0001] It involves driving methods, light source units, illumination units, exposure devices, and exposure methods. Background Technology

[0002] In recent years, liquid crystal display panels have been widely used as display elements for personal computers, televisions, and other devices. Liquid crystal display panels are manufactured by forming circuit patterns of thin-film transistors on a plate (glass substrate) using photolithography. As an apparatus for this photolithography process, an exposure apparatus is used to project the original pattern formed on a mask onto a photoresist layer on the plate via a projection optics system (e.g., Patent Document 1).

[0003] Among the various optical devices, including the aforementioned exposure apparatus, it is required to stabilize the amount of light emitted by the light source.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-207251 Summary of the Invention

[0007] According to the first disclosure, the driving method for the light source element is a method for driving the light source element to emit light with a first luminous intensity when supplied with a first current value. This includes supplying current to the light source element starting with a second current value lower than the first current value and increasing the current value supplied to the light source element to the first current value. The current value supplied to the light source element at a first time point is a corrected current value obtained by acquiring the current value supplied to the light source element at the first time point based on first information and the current value obtained based on temperature correction of the light source element. The first information predetermines the current value supplied to the light source element at each time point during the period when current is supplied to the light source element starting with a predetermined third current value and increasing the current value supplied to the light source element to the first current value.

[0008] According to the second disclosure, the driving method for the light source element is a method for a light source element that emits light with a first luminous intensity when supplied with a first current value and emits light with a second luminous intensity lower than the first luminous intensity when supplied with a fifth current value lower than the first current value. The method includes supplying current to the light source element starting with a sixth current value higher than the fifth current value and decreasing the current value supplied to the light source element from the sixth current value to the fifth current value. The current value supplied to the light source element at a first time point is a corrected current value obtained by acquiring the current value supplied to the light source element at the first time point based on third information and the current value obtained based on temperature correction of the light source element. The third information predetermines the current value supplied to the light source element at each time point during the period when current is supplied to the light source element starting with a predetermined seventh current value and the current value supplied to the light source element changes to the fifth current value.

[0009] According to the third disclosure, the light source unit comprises: a plurality of light source elements arranged in two dimensions on the surface of a fixed object, each emitting light with a first luminous intensity when supplied with a first current value; a detection unit that detects the temperature of the plurality of light source elements; and a control unit that controls the value of the current supplied to the plurality of light source elements. The control unit starts supplying current to the plurality of light source elements with a second current value lower than the first current value, and increases the current value supplied to the plurality of light source elements from the second current value to the first current value. The current value supplied to the plurality of light source elements at a first time point is a corrected current value obtained by acquiring the current value supplied to the plurality of light source elements at the first time point based on first information and the current value obtained based on the temperature correction of the plurality of light source elements. The first information predetermines the current value supplied to the plurality of light source elements at each time point during the period during which current is supplied to the plurality of light source elements starting with a predetermined third current value and the current value supplied to the plurality of light source elements increases to the first current value.

[0010] According to the fourth disclosure, the light source unit comprises: a plurality of light source elements arranged in two dimensions on the surface of a fixed object, each emitting light with a first luminous intensity when supplied with a first current value, and emitting light with a second luminous intensity lower than the first luminous intensity when supplied with a fifth current value lower than the first current value; a detection unit that detects the temperature of the plurality of light source elements; and a control unit that controls the value of the current supplied to the plurality of light source elements, wherein when the plurality of light source elements are in a state of emitting light with the second luminous intensity, the control unit starts supplying current to the plurality of light source elements with a sixth current value higher than the fifth current value, and controls the current supplied to the plurality of light source elements. The current value supplied by the light source element decreases from the 6th current value to the 5th current value. The current value supplied to the plurality of light source elements at the 1st time point is a corrected current value obtained by acquiring the current value supplied to the plurality of light source elements at the 1st time point based on the 3rd information and the current value obtained based on the temperature correction of the plurality of light source elements. The 3rd information predetermines the current value supplied to the plurality of light source elements at each time point during the period when the current is supplied to the plurality of light source elements starting at a predetermined 7th current value and the current value supplied to the plurality of light source elements changes to the 5th current value.

[0011] According to the fifth disclosure, the illumination unit includes the aforementioned light source unit and an illumination optical system that guides light emitted from the light source unit to the irradiated object.

[0012] According to the sixth disclosure, the illumination unit includes a plurality of the aforementioned light source units and an illumination optical system, the illumination optical system including a combining optical element for combining light emitted from the plurality of light source units and guiding the combined light emitted from the combining optical element to the irradiated object.

[0013] According to the seventh disclosure, the exposure apparatus includes the aforementioned illumination unit and a projection optical system that projects a pattern image of a mask illuminated by the illumination unit onto a photosensitive substrate.

[0014] According to the eighth disclosure, the exposure method uses the above-described exposure apparatus, and the exposure method includes: illuminating the mask using the illumination unit; and projecting a pattern image of the mask onto a photosensitive substrate using the projection optics system.

[0015] It should be noted that the structure of the embodiments described below can be appropriately modified, and at least a portion can be replaced with other structures. Furthermore, the constituent elements whose configuration is not particularly limited are not limited to the configuration disclosed in the embodiments, but can be configured in positions that enable their functions. Attached Figure Description

[0016] Figure 1This is a schematic diagram showing the structure of the exposure apparatus according to the first embodiment.

[0017] Figure 2 This is a schematic diagram showing the structure of the lighting unit in the first embodiment.

[0018] Figure 3 (A) is a top view that schematically represents the structure of the light source array. Figure 3 (B) is a diagram that roughly represents the internal structure of the light source unit.

[0019] Figure 4 This is a graph illustrating the relationship between the temperature of an LED package and its luminous output.

[0020] Figure 5 This is a graph showing the measurement results of the light emission of the LED package's light-emitting part when the LED package, which is in a state where the temperature is lower than the first temperature threshold and no current is supplied, is made to emit light with the first light emission amount, and when current is supplied to the LED package at the first current value from the start of current supply.

[0021] Figure 6 It is a graph representing the output relative to the elapsed time.

[0022] Figure 7 This is an example of a one-stage mapping graph.

[0023] Figure 8 (A) is a graph showing the measurement results of the luminous intensity of the light-emitting part of the LED package when the light-emitting part of the LED package, which is in a state where the temperature is lower than the first temperature threshold and no current is supplied, is made to emit light with the first luminous intensity, according to the first stage mapping diagram, the current value supplied to the LED package is controlled. Figure 8 (B) is to Figure 8 The graph in (A) shows the range of light emission deviation rate from 0% to 2% on the vertical axis.

[0024] Figure 9 It is a graph showing the measurement results of the light emission of the LED package's light-emitting part when the light-emitting part of the LED package, which is in a state where the temperature is lower than the first temperature threshold and no current is supplied, is made to emit light with the first light emission amount, and the current value supplied to the LED package is controlled according to the first second-stage mapping diagram.

[0025] Figure 10 It is a graph showing the measurement results of the luminous quantity of the light-emitting part of the LED package when the light-emitting part of the LED package, which is in a state where the temperature is lower than the second temperature threshold and no current is supplied, is made to emit light with the second luminous quantity, and the current value supplied to the LED package is controlled according to the second two-stage mapping diagram.

[0026] Figure 11 (A) and Figure 11 (B) is a graph showing the measurement results of the luminous output of the LED package when the current supplied to the LED package is controlled according to the first two-stage mapping diagram in cases 4 and 5, respectively.

[0027] Figure 12 (A) is a graph showing the measurement results of the luminous output of the LED package when the current supplied to the LED package is controlled according to the second two-stage mapping diagram in case 6. Figure 12 (B) is a graph showing the measurement results of the light-emitting part of the LED package when the current value supplied to the LED package is controlled according to the second phase mapping diagram in case 7.

[0028] Figure 13 This is a top view showing the light source array included in the light source unit of the second embodiment.

[0029] Figure 14 (A) is an example of a temperature mapping diagram. Figure 14 (B) is an example of a second-stage mapping diagram.

[0030] Figure 15 (A) is a graph representing the actual temperature of the LED package relative to the elapsed time since the restart (start) current supply. Figure 15 (B) is a graph representing the actual current value supplied to the LED package by correcting the first-stage mapping based on the actual temperature of the LED package.

[0031] Figure 16 (A) and Figure 16 (B) is a graph showing the measurement results of the luminous output of the LED package when the first two-stage mapping is corrected according to the actual temperature of the LED package and the current supplied to the LED package is controlled in cases 4 and 5, respectively.

[0032] Figure 17 (A) is a graph showing the measurement results of the luminous output of the LED package when the second-stage mapping is corrected according to the actual temperature of the LED package in case 6 and the current value supplied to the LED package is controlled. Figure 17 (B) is a graph showing the measurement results of the luminous output of the LED package when the second-stage mapping is corrected according to the actual temperature of the LED package in case 7 and the current value supplied to the LED package is controlled.

[0033] Figure 18(A) is a graph showing the measurement results of the luminous intensity of the light-emitting part of the LED package when the light-emitting part of the LED package, which is in a state where the temperature is lower than the first temperature threshold and no current is supplied, is emitting light with the first luminous intensity. The graph shows the measurement results of the luminous intensity of the light-emitting part of the LED package when the first two-stage mapping is corrected according to the actual temperature of the LED package and the current value supplied to the LED package 23 is controlled. Figure 18 (B) is a graph showing the measurement results of the luminous intensity of the light-emitting part of the LED package when the light-emitting part of the LED package, which is in a state where the temperature is lower than the second temperature threshold and no current is supplied, is in a state where it emits light with the second luminous intensity, and the current value of the current supplied to the LED package is controlled according to the actual temperature of the LED package after correcting the second two-stage mapping.

[0034] Figure 19 This is a schematic diagram showing the structure of the lighting unit in the third embodiment.

[0035] Figure 20 This is a schematic diagram showing the structure of the exposure apparatus according to the fourth embodiment. Detailed Implementation

[0036] based on Figures 1-10 An exposure apparatus 10 according to one embodiment will be described.

[0037] (Structure of the exposure device)

[0038] First, the structure of the exposure apparatus 10 in this embodiment will be described. Figure 1 This is a diagram that schematically illustrates the structure of the exposure apparatus 10 of this embodiment.

[0039] The exposure apparatus 10 is a stepper scan lithography machine (scanner) that transfers a pattern formed on the mask MSK onto the plate P by driving the mask MSK and the glass substrate (hereinafter referred to as "plate") in the same direction and at the same speed relative to the projection optical system PL. The plate P is, for example, a rectangular glass substrate used in liquid crystal display devices (flat panel displays), with at least one side or diagonal length of 500 mm or more.

[0040] Hereinafter, the direction in which the mask MSK and plate P are driven during scanning exposure (scanning direction) will be set as the X-axis direction, the direction in the horizontal plane orthogonal to it will be set as the Y-axis direction, the direction orthogonal to the X-axis and Y-axis will be set as the Z-axis direction, and the rotation (tilt) directions around the X-axis, Y-axis and Z-axis will be set as θx, θy and θz directions respectively.

[0041] The exposure apparatus 10 includes an illumination system IOP, a mask stage MST for holding the mask MSK, a projection optics system PL, a main body 70 supporting these components, a substrate stage PST for holding the plate P, and control devices (not shown) for these components. The control devices provide unified control over all components of the exposure apparatus 10.

[0042] The main body 70 includes a base (vibration damping platform) 71, columns 72A and 72B, an optical platform 73, a support body 74, and a sliding guide 75. The base (vibration damping platform) 71 is mounted on a floor F, eliminating vibrations from the floor F and supporting columns 72A and 72B. Columns 72A and 72B each have a frame shape, with column 72A positioned inside column 72B. The optical platform 73 has a flat plate shape and is fixed to the top of column 72A. The support body 74 is supported on the top of column 72B via the sliding guide 75. The sliding guide 75 includes an air ball lifter and a positioning mechanism, positioning the support body 74 (i.e., the mask stage MST described later) relative to the optical platform 73 at an appropriate position in the X-axis direction.

[0043] The illumination system IOP is positioned above the main body 70. The illumination system IOP illuminates the mask MSK with illumination light IL. Detailed structure of the illumination system IOP is described later.

[0044] The mask stage MST is supported by a support 74. A patterned surface with a circuit pattern is fixed on the mask stage MST, for example by vacuum adsorption (or electrostatic adsorption). Figure 1 The mask MSK is the lower surface of the mask. The mask stage MST is driven by a drive system including a linear motor in the scanning direction (X-axis direction) with a specified stroke, and is slightly driven in the non-scanning directions (Y-axis direction and θz direction).

[0045] The position information of the mask stage MST in the XY plane (including rotation information in the θz direction) is measured by an interferometer system. The interferometer system illuminates a measuring beam onto a moving mirror (or a mirror-processed reflective surface (not shown)) located at the end of the mask stage MST, and receives the reflected light from the moving mirror, thereby measuring the position of the mask stage MST. The measurement result is supplied to a control device (not shown), which drives the mask stage MST via a drive system based on the measurement result of the interferometer system.

[0046] The projection optical system PL is supported by an optical platform 73 below (on the -Z side) the mask stage MST. The projection optical system PL is configured, for example, identical to the projection optical system disclosed in U.S. Patent Nos. 5,729,331, including multiple (e.g., seven) projection optical units 100 (multi-lens projection optical units) with projection areas of a patterned image of the mask MSK arranged in an alternating pattern, forming an image field with the Y-axis as its length direction. Here, four projection optical units 100 are arranged at predetermined intervals in the Y-axis direction, and the remaining three projection optical units 100 are separated from the four projection optical units 100 towards the +X side and arranged at predetermined intervals in the Y-axis direction. Each of the multiple projection optical units 100 may, for example, use a projection optical unit that forms an upright image using a bi-lateral telecentric equi-multiplication system. It should be noted that the multiple projection areas of the alternatingly arranged projection optical units 100 are collectively referred to as exposure areas. In this embodiment, four projection optical units 100 and three projection optical units 100 are arranged at fixed intervals in the Y-axis direction. However, the number of modules can be less than three or more than four in terms of the number of projection optical units 100 arranged at fixed intervals in the Y-axis direction. In addition, two columns of projection optical units 100 are arranged in the X-axis direction. However, the number of columns of projection optical units 100 arranged in the X-axis direction can be less than one column or more than three columns.

[0047] When the illumination area on the mask MSK is illuminated by the illumination light IL from the illumination system IOP, a projection (partially upright image) of the circuit pattern of the mask MSK is formed in the illumination area (exposure area (conjugate with the illumination area)) of the plate P disposed on the image plane side of the projection optics system PL using the illumination light IL of the transmission mask MSK. Here, a photoresist is coated on the surface of the plate P. The mask stage MST and the substrate stage PST are driven synchronously, that is, the mask MSK is driven in the scanning direction (X-axis direction) relative to the illumination area (illumination light IL), and the plate P is driven in the same scanning direction relative to the exposure area (illumination light IL), thereby exposing the plate P and transferring the pattern of the mask MSK onto the plate P.

[0048] The substrate stage PST is positioned on a base (vibration damping stage) 71 below (on the -Z side) of the projection optical system PL. The substrate P is held on the substrate stage PST by a substrate holding part (not shown).

[0049] The position information (including rotation information (deflection (θz rotation in the θz direction), pitch (θy rotation in the θy direction), and roll (θx rotation in the θx direction))) of the substrate stage PST in the XY plane is measured by an interferometer system. The interferometer system projects a measuring beam from the optical platform 73 onto a moving mirror (or a mirror-finished reflective surface (not shown)) located at the end of the substrate stage PST, and receives the reflected light from the moving mirror, thereby measuring the position of the substrate stage PST. The measurement result is supplied to a control device (not shown), which drives the substrate stage PST based on the measurement result of the interferometer system.

[0050] In the exposure apparatus 10, alignment measurements (e.g., EGA) are performed before exposure, and the results are used to expose the board P according to the following steps. First, the mask stage MST and the substrate stage PST are synchronously driven in the X-axis direction according to the instructions of the control device. This results in scanning exposure of the first exposure area on the board P. When the scanning exposure of the first exposure area is completed, the control device moves the substrate stage PST to a position corresponding to the second exposure area (stepping). Then, the second exposure area is scanned and exposed. The control device similarly repeats the stepping of the board P between exposure areas and the scanning exposure of the exposure areas, thereby transferring the pattern of the mask MSK to all exposure areas on the board P.

[0051] (Structure of the IOP lighting system)

[0052] Next, the structure of the illumination system IOP in this embodiment will be described. The illumination system IOP includes multiple illumination units 90, each corresponding to a plurality of projection optical units 100 included in the projection optical system PL.

[0053] Figure 2 This is a diagram that roughly represents the structure of the lighting unit 90. (For example...) Figure 2 As shown, the lighting unit 90 includes a light source unit OPU and an lighting optical system 80.

[0054] (Structure of the light source unit)

[0055] The light source unit (OPU) includes a light source array 20, a magnifying optical system 30, and a control unit (CTR).

[0056] Figure 3 (A) is a top view schematically showing the structure of the light source array 20. The light source array 20, for example, comprises multiple light sources arranged in an array on the substrate 21 (in... Figure 3In (A), there is a 5×5 LED (Light Emitting Diode) package 23. That is, the light source unit OPU is an LED light source. The number of LED packages 23 can also be changed as needed. Here, the two directions in which the LED packages 23 are arranged are designated as the X1 direction and the Y1 direction. The X1 direction is orthogonal to the Y1 direction. In addition, the direction orthogonal to the X1 direction and the Y1 direction is designated as the Z1 direction. The Z1 direction is approximately parallel to the optical axis OA of the light emitted by the light-emitting part 231 described later.

[0057] Multiple LED packages 23 each have a light-emitting portion 231, and the peak wavelength of the light emitted from the light-emitting portion 231 is, for example, in the range of 360-370 nm, 380-390 nm, or 400-410 nm. That is, the light-emitting portion 231 is an ultraviolet LED (UV LED). The light-emitting surface of the light-emitting portion 231 is square, and the length of one side is L. The LED packages 23 are arranged at a spacing P1. The spacing P1 is the distance between the centers of adjacent LED packages 23. It should be noted that the LED packages 23 may also be arranged, for example, on a heat sink instead of a substrate.

[0058] Figure 3 (B) is a diagram that roughly represents the internal structure of the light source unit (OPU).

[0059] like Figure 3 As shown in (B), the magnifying optical system 30 is a magnifying optical system for forming magnified images of the light-emitting portions 231 of each LED package 23 on a predetermined surface PP. The magnifying optical system 30 includes a plurality of lens portions 31 arranged in a manner corresponding to the arrangement of the LED packages 23. The lens portions 31 are a dual-telecentric optical system that magnifies the projection of the light-emitting portions 231 at a magnification of (the arrangement spacing P1 of the LED packages 23) / (the length L of one side of the light-emitting surface of the light-emitting portion 231) or more.

[0060] In this embodiment, the lens section 31 has four plano-convex lenses, but it is not limited to this. For example, the lens section 31 may also have two biconvex lenses, or even three biconvex lenses. In addition, the lens section 31 may also have both plano-convex lenses and biconvex lenses.

[0061] The control unit CTR controls the current value supplied to the LED package 23 included in the light source array 20.

[0062] Figure 4 This is a diagram illustrating the relationship between the temperature of the LED package 23 and the luminous output of the light-emitting part 231. (Example) Figure 4As shown, when the temperature of the LED package 23 is within the range of temperature T1 to temperature T2 (>T1) (the first temperature range), when a current of the first current value CV1 is supplied, the light-emitting part 231 of the LED package 23 emits light with the first luminous intensity LA1. The first temperature range is, for example, 20°C to 90°C, or it can be 20°C to 50°C.

[0063] Furthermore, when the temperature of the LED package 23 is within the range of temperature T3 to temperature T4 (>T3) (the second temperature range), when a third current value CV3, which is lower than the first current value CV1, is supplied, the light-emitting portion 231 of the LED package 23 emits light with a second luminous intensity LA2. It should be noted that temperature T3 is lower than temperature T1, and temperature T4 is lower than temperature T2.

[0064] In this embodiment, when the control unit CTR causes the light-emitting portion 231 of the LED package 23, which is in a state where the temperature is lower than the first temperature threshold Tth1 (e.g., 15°C) and no current is supplied, to emit light at the first luminous intensity LA1, it starts supplying current to the LED package 23 at a second current value CV2, which is lower than the first current value CV1, and increases the current value supplied to the LED package 23 to the first current value CV1. Therefore, compared to the case where current is supplied to the LED package 23 starting at the first current value CV1, the time until the light-emitting portion 231 of the LED package 23 stably emits light at the first luminous intensity LA1 can be shortened. The first temperature threshold Tth1 is lower than temperature T1, for example, a temperature such that, based on the condition that the state of not supplying current to the LED package 23 has lasted for a predetermined time (e.g., 1 hour), it can be determined that the temperature of the LED package 23 is stable at a temperature lower than temperature T1 (the temperature change within a predetermined period (e.g., 10 seconds) is within a predetermined range (e.g., ±0.1°C)).

[0065] Furthermore, when the control unit CTR causes the light-emitting portion 231 of the LED package 23, which is in a state where the temperature is lower than the second temperature threshold Tth2 (e.g., 15°C) and no current is supplied, to emit light at the second luminous intensity LA2, it starts supplying current to the LED package 23 at a fourth current value CV4, which is lower than the third current value CV3, and increases the current value supplied to the LED package 23 to the third current value CV3. Therefore, compared to the case where current is supplied to the LED package 23 starting at the third current value CV3, the time until the light-emitting portion 231 of the LED package 23 stably emits light at the second luminous intensity LA2 can be shortened. The second temperature threshold Tth2 is lower than temperature T3, for example, a temperature such that, based on the condition that no current is supplied to the LED package 23 for a specified time (e.g., 1 hour), it can be determined that the temperature of the LED package 23 is stable at a temperature lower than temperature T3 (the temperature change within a specified period (e.g., 10 seconds) is within a specified range (e.g., ±0.1°C)). The second temperature threshold Tth2 only needs to be lower than the temperature T3, and it can be the same as or different from the first temperature threshold Tth1.

[0066] Furthermore, when the control unit CTR causes the light-emitting portion 231 of the LED package 23, which is emitting light at a first luminous intensity LA1 and is supplied with a first current value CV1, to emit light at a second luminous intensity LA2, which is lower than the first luminous intensity LA1, the current value supplied to the LED package 23 decreases from the first current value CV1 to a third current value CV3 (< the first current value CV1) over time. Therefore, compared to the case where the current value supplied to the LED package 23 is immediately changed from the first current value CV1 to the third current value CV3, the time until the light-emitting portion 231 of the LED package 23 stably emits light at the second luminous intensity LA2 can be shortened.

[0067] It should be noted that, in this embodiment, "the light-emitting part 231 of the LED package 23 emits light stably with the first luminous intensity LA1" refers to the ratio of the difference between the luminous intensity LAt and the first luminous intensity LA1 at a certain time point t after the current is supplied to the LED package 23, ΔLAt (=LAt-LA1), to the first luminous intensity LA1 (called the luminous intensity deviation rate), that is, ΔLAt / LA1×100 [%] is within the range of ±1%. Furthermore, in this embodiment, "the light-emitting part 231 of the LED package 23 emits light stably with the second luminous intensity LA2" refers to the ratio of the difference between the luminous intensity LAt and the second luminous intensity LA2 at a certain time point t after the current is supplied to the LED package 23, ΔLAt (=LAt-LA2), to the second luminous intensity LA2, that is, ΔLAt / LA2×100 [%] is within the range of ±1%. This is because, within the range of ±1%, the difference in luminous intensity of the light-emitting part 231 of the LED package 23 will not affect the exposure.

[0068] Next, the control of the current value supplied to the LED package 23 by the control unit CTR will be described in detail. The control unit CTR controls the current value supplied to the LED package 23 based on a pre-created two-stage mapping diagram, wherein the two-stage mapping diagram represents the relationship between the elapsed time from the start of supplying current to the LED package 23 and the current value supplied to the LED package 23. The two-stage mapping diagram is created in the following manner.

[0069] Here, as an example, the creation of a two-stage mapping diagram will be explained when the light-emitting part 231 of the LED package 23, which is in a state where the temperature is lower than the first temperature threshold Tth1 and no current is supplied, is made to emit light with the first luminous intensity LA1.

[0070] First, when the light-emitting portion 231 of the LED package 23, which is in a state where its temperature is lower than the first temperature threshold Tth1 and no current is supplied, is made to emit light with a first luminous intensity LA1, current is supplied to the LED package 23 starting with a first current value CV1, and the change in luminous intensity deviation rate is obtained when the first current value CV1 is continuously supplied to the LED package 23. The change in luminous intensity deviation rate can be determined, for example, by actually measuring the luminous intensity of the light-emitting portion 231 of the LED package 23, or by simulation.

[0071] Next, a one-stage mapping is created based on the change in luminous quantity deviation rate, representing the relationship between the elapsed time from the start of current supply to LED package 23 and the current value supplied to LED package 23.

[0072] The creation of the one-stage mapping diagram is explained in more detail. Figure 5 This means that when the light-emitting portion 231 of the LED package 23, which is in a state where the temperature is lower than the first temperature threshold Tth1 and no current is supplied, is made to emit light with the first luminous intensity LA1, such as Figure 6 The graph shown shows the measurement results of the light emission of the light-emitting portion 231 of the LED package 23 when current is supplied to the LED package 23 at the first current value CV1 from the start of current supply. Figure 5 In the diagram, the vertical axis represents the light emission deviation rate, and the horizontal axis represents the elapsed time from the start of current supply.

[0073] Figure 6 This is a graph representing the output relative to elapsed time. Output [%] is the ratio of the current value CVt supplied to the LED package 23 at a given time t to the first current value CV1 (output [%] = CVt / CV1 × 100). For example... Figure 6 As shown, the output is fixed at 100% from the start of current supply.

[0074] When supplying current to the LED package 23 starting with the first current value CV1, such as Figure 5 As shown, the light-emitting portion 231 of the LED package 23 emits light with a higher luminous intensity than the first luminous intensity LA1, and the luminous intensity decreases over time. This is because the luminous intensity of the light-emitting portion 231 of the LED package 23 decreases as the temperature of the LED package 23 increases. More specifically, at the point when current is first supplied to the LED package 23, the luminous intensity of the light-emitting portion 231 of the LED package 23 is high because the temperature of the LED package 23 is low. Subsequently, the luminous intensity decreases as the temperature of the LED package 23 increases.

[0075] After approximately 80 seconds from the start of current supply, the luminous intensity deviation rate became within the range of ±1%, and the luminous intensity of the light-emitting part 231 of the LED package 23 stabilized.

[0076] The one-stage mapping graph is based on Figure 5 The output is determined based on the luminous quantity deviation rate shown. For example, if the luminous quantity deviation rate is approximately +11.2% 100 ms after the start of current supply to LED package 23, the output 100 ms after the start of current supply to LED package 23 is set to 88.8% (100% × 0.888) in a one-stage mapping diagram. Alternatively, if the luminous quantity deviation rate is approximately +1.2% 50 s after the start of current supply, the output 50 s after the start of current supply is set to 98.8% (100% × 0.988) in a one-stage mapping diagram. In this way, by determining the output at each time point from the start of current supply based on the luminous quantity deviation rate, it is possible to obtain, for example,... Figure 7 The one-stage mapping diagram is shown below. Figure 7 As shown, the one-stage mapping predetermines the output at each time point from the start of current supply.

[0077] It should be noted that the output at the start of current supply (0[s]) can be obtained using various interpolation methods. For example... Figure 7 As shown, since the output is less than 100% at the start of current supply (0[s]), the current value when current is supplied to the LED package 23 is lower than the first current value CV1. In the following description, when the light-emitting part 231 of the LED package 23, which is in a state where the temperature is lower than the first temperature threshold Tth1 and no current is supplied, is made to emit light with the first luminous intensity LA1, based on... Figure 6The one-stage mapping diagram created by the change in the luminous quantity deviation rate when current is supplied to the LED package 23 at the first current value CV1 from the start of current supply is called the first stage mapping diagram. In addition, the current value at the start of current supply (0[s]) in the first stage mapping diagram is called the first start current value CVst1.

[0078] It should be noted that, in cases such as Figure 5 When the luminous quantity deviation rate changes as shown, the slope of the luminous quantity deviation rate between time t1 and time t2 can be calculated based on the luminous quantity deviation rate after time t1 and time t2, and the increase ratio (increase) of the output between time t1 and time t2 can be determined based on this slope, creating a one-stage mapping. Alternatively, a one-stage mapping can be created by dividing the change in luminous quantity deviation rate by the time from the start of current supply until the luminous quantity deviation rate enters the ±1% range (the average slope of the luminous quantity deviation rate), such as increasing the output by a fixed ratio. That is, the ratio by which the current value supplied to the LED package 23 increases from the initial current value CVst1 to the first current value CV1 can vary depending on the time from the start of current supply, or it can be fixed.

[0079] A two-stage mapping is created using a first-stage mapping created in this way. The creation of the two-stage mapping will be explained in detail based on a specific example. First, when the light-emitting portion 231 of the LED package 23, which is in a state where the temperature is lower than the first temperature threshold Tth1 and no current is supplied, is made to emit light with a first luminous intensity LA1, based on, for example... Figure 7 The first-stage mapping shown controls the current value supplied to the LED package 23 and obtains the change in luminous intensity deviation rate. The change in luminous intensity deviation rate can be obtained, for example, by actually measuring the luminous intensity of the light-emitting part 231 of the LED package 23, or by simulation.

[0080] Next, a two-stage mapping is created based on the change in luminous quantity deviation rate to represent the relationship between the elapsed time from the start of current supply to LED package 23 and the current value of the current supplied to LED package 23.

[0081] Figure 8 (A) indicates that when the light-emitting portion 231 of the LED package 23, which is in a state where the temperature is lower than the first temperature threshold Tth1 and no current is supplied, is made to emit light with the first luminous intensity LA1, according to Figure 7 The first-stage mapping diagram shown is a graph illustrating the measurement results of the light emission amount of the light-emitting portion 231 of the LED package 23 when the current value supplied to the LED package 23 is controlled according to the first-stage mapping diagram. Figure 8In (A), the vertical axis represents the light emission deviation rate, and the horizontal axis represents the elapsed time from the start of current supply. Figure 8 (B) is to Figure 8 The graph in (A) shows the range of light emission deviation rate from 0% to 2% on the vertical axis.

[0082] from Figure 8 (A) and Figure 8 As can be seen from (B), current is supplied to the LED package 23 starting with a first current value CVst1 that is lower than the first current value CV1, and according to... Figure 7 The first-stage mapping diagram increases the current value supplied to the LED package 23 over time, thereby shortening the time until the light-emitting portion 231 of the LED package 23 stabilizes at the first luminous intensity LA1. However, sometimes it is desirable to further shorten the time from the start of current supply to the LED package 23 until the luminous intensity deviation rate becomes sufficiently small. Therefore, based on... Figure 8 (A) and Figure 8 The luminescence deviation rate shown in (B) creates a two-stage mapping diagram.

[0083] For example, in the first-stage mapping, the output 100 ms after the current is supplied to the LED package 23 is 88.8%. Figure 8 In the graph of luminous quantity deviation rate shown in (B), the luminous quantity deviation rate 100 ms after the start of current supply to LED package 23 is +1%. In this case, the output 100 ms after the start of current supply is set to 87.9% (88.8% × 0.99) in the two-stage mapping diagram. Furthermore, in the first-stage mapping diagram, the output 200 ms after the start of current supply to LED package 23 is 91%. Figure 8 In the graph of luminous quantity deviation rate shown in (B), the luminous quantity deviation rate 200 ms after the start of current supply to LED package 23 is +0.5%. In this case, the output 200 ms after the start of current supply is set to 90.5% (91% × 0.995) in the two-stage mapping diagram. Thus, the two-stage mapping diagram is created based on the change in luminous quantity deviation rate when the current value supplied to LED package 23 is controlled according to the first-stage mapping diagram. That is, the two-stage mapping diagram predetermines the output at each time point from the start of current supply.

[0084] It should be noted that the output at the start of current supply (0[s]) can be obtained using various interpolation methods. Similar to the first-stage mapping, in the second-stage mapping, since the output at the start of current supply (0[s]) is also less than 100%, the current value at the start of current supply to the LED package 23 is also lower than the first current value CV1. In the following explanation, the second-stage mapping created in the following manner is referred to as the first second-stage mapping: it is created based on the change in the luminous intensity deviation rate when the light-emitting portion 231 of the LED package 23, which is in a state where the temperature is lower than the first temperature threshold Tth1 and no current is supplied, is made to emit light with the first luminous intensity LA1. Furthermore, the current value at the start of current supply (0[s]) in the first second-stage mapping is referred to as the second start-up current value CVst2.

[0085] It should be noted that, in cases such as Figure 8 (A) and Figure 8 In the case of the change in luminous quantity deviation rate shown in (B), the slope of the luminous quantity deviation rate between time t1 and time t2 can be calculated based on the luminous quantity deviation rate after time t1 and the luminous quantity deviation rate after time t2, and the increase ratio (increase amount) of the output between time t1 and time t2 can be determined based on this slope to create a first-stage two-phase mapping. Alternatively, a first-stage two-phase mapping can be created based on the value obtained by dividing the change in luminous quantity deviation rate by the time from the start of current supply until the luminous quantity deviation rate enters the range of ±1% (the average slope of the luminous quantity deviation rate), such as increasing the output by a fixed ratio. That is, the ratio by which the current value supplied to the LED package 23 increases from the current value CVst2 at the second start to the current value CV1 at the first start can vary depending on the time from the start of current supply, or it can be fixed.

[0086] Figure 9 This is a graph showing the measurement results of the luminous intensity of the light-emitting portion 231 of the LED package 23 when the light-emitting portion 231 of the LED package 23, which is in a state where the temperature is lower than the first temperature threshold Tth1 and no current is supplied, is made to emit light with the first luminous intensity LA1, and the current value supplied to the LED package 23 is controlled according to the first second-stage mapping diagram. Figure 9 In the diagram, the vertical axis represents the light emission deviation rate, and the horizontal axis represents the elapsed time from the start of current supply.

[0087] like Figure 9As shown, when the current value supplied to the LED package 23 is controlled according to the first-stage mapping diagram, the luminous flux deviation rate is within ±0.5% from the start of current supply. That is, compared with the case where the current value supplied to the LED package 23 is controlled according to the first-stage mapping diagram (see...). Figure 5 Compared to improving the light emission deviation rate, it can be seen that by using the first two-stage mapping map, the time until the light emission of the light-emitting part 231 of the LED package 23 stabilizes can be further shortened.

[0088] This can be attributed to the fact that, by using the first two-stage mapping diagram, an appropriate current value can be supplied to the LED package 23 in order to obtain the first luminous intensity LA1 at various temperatures. It should be noted that after the current value supplied to the LED package 23 becomes the first current value CV1, the LED package 23 continues to emit light with the first luminous intensity LA1.

[0089] Next, the creation of a two-stage mapping diagram used to make the light-emitting part 231 of the LED package 23, which is in a state where the temperature is lower than the second temperature threshold Tth2 and no current is supplied, emit light with the second light emission amount LA2 will be explained.

[0090] First, when the light-emitting portion 231 of the LED package 23, which is in a state where its temperature is lower than the second temperature threshold Tth2 and no current is supplied, is made to emit light with the second luminous intensity LA2, the change in luminous intensity deviation rate when current is supplied to the LED package 23 starting at the third current value CV3 is obtained. Next, based on the obtained change in luminous intensity deviation rate, a one-stage mapping diagram is created representing the relationship between the elapsed time from the start of current supply to the LED package 23 and the current value supplied to the LED package 23. In the following description, the one-stage mapping diagram created in the following manner will be referred to as the second one-stage mapping diagram: when the light-emitting portion 231 of the LED package 23, which is in a state where its temperature is lower than the second temperature threshold Tth2 and no current is supplied, is made to emit light with the second luminous intensity LA2, the change in luminous intensity deviation rate is based on the change in luminous intensity deviation rate when current is supplied to the LED package 23 starting at the third current value CV3 is obtained. In addition, the current value at the start of current supply (0[s]) in the second one-stage mapping diagram is referred to as the third start current value CVst3.

[0091] Next, when the light-emitting portion 231 of the LED package 23, which is in a state where the temperature is lower than the second temperature threshold Tth2 and no current is supplied, is made to emit light with the second luminous intensity LA2, the change in luminous intensity deviation rate is obtained when the current value supplied to the LED package 23 is controlled according to the second first-stage mapping. Then, based on the obtained change in luminous intensity deviation rate, a two-stage mapping is created representing the relationship between the elapsed time from the start of current supply to the LED package 23 and the current value supplied to the LED package 23. In this case, since the output at the start of current supply (0[s]) in the two-stage mapping is less than 100%, the current value at the start of current supply to the LED package 23 becomes a current value lower than the third current value CV3. In the following description, the two-stage mapping diagram created in the following manner will be referred to as the second two-stage mapping diagram: when the light-emitting part 231 of the LED package 23, which is in a state where the temperature is lower than the second temperature threshold Tth2 and no current is supplied, is made to emit light with the second luminous intensity LA2, the diagram is created based on the change in the luminous intensity deviation rate when the current value supplied to the LED package 23 is controlled according to the second one-stage mapping diagram. In addition, the current value at the start of current supply (0[s]) in the second two-stage mapping diagram will be referred to as the fourth start current value CVst4.

[0092] Figure 10 This is a graph showing the measurement results of the luminous intensity of the light-emitting portion 231 of the LED package 23 when the light-emitting portion 231 of the LED package 23 in the light source array 20, which is in a state where the temperature is lower than the second temperature threshold Tth2 and no current is supplied, is made to emit light with the second luminous intensity LA2, and the current value supplied to the LED package 23 is controlled according to the second two-stage mapping diagram created as described above. Figure 10 In the diagram, the vertical axis represents the light emission deviation rate, and the horizontal axis represents the elapsed time from the start of current supply.

[0093] like Figure 10 As shown, even when the light-emitting part 231 of the LED package 23 of the light source array 20, which is in a state where the temperature is lower than the second temperature threshold Tth2 and no current is supplied, is made to emit light with the second luminous intensity LA2, by controlling the current value of the current supplied to the LED package 23 according to the second two-stage mapping, the luminous intensity deviation rate can be reduced and the time until the luminous intensity of the light-emitting part 231 of the LED package 23 stabilizes can be shortened.

[0094] Next, the creation of a two-stage mapping diagram will be explained when the light-emitting part 231 of the LED package 23, which is supplied with a current of the first current value CV1 and emits light with the first light emission amount LA1, becomes a state in which it emits light with the second light emission amount LA2, which is lower than the first light emission amount LA1.

[0095] First, when the light-emitting portion 231 of the LED package 23, which is emitting light at a first luminous intensity LA1 and supplied with a first current value CV1, becomes emitting light at a second luminous intensity LA2, the change in luminous intensity deviation rate is obtained when the current value supplied to the LED package 23 immediately changes from the first current value CV1 to the third current value CV3. Next, based on the obtained change in luminous intensity deviation rate, a one-stage mapping diagram is created representing the relationship between the elapsed time from the start of supplying current to the LED package 23 and the current value supplied to the LED package 23. In the following description, the one-stage mapping diagram created in the following manner will be referred to as the third one-stage mapping diagram: when the light-emitting portion 231 of the LED package 23, which is emitting light at a first luminous intensity LA1 and supplied with a first current value CV1, becomes emitting light at a second luminous intensity LA2, the change in luminous intensity deviation rate is obtained based on the change in luminous intensity deviation rate when the current value supplied to the LED package 23 immediately changes from the first current value CV1 to the third current value CV3. Furthermore, the current value at the start of current supply (0[s]) in the third-stage mapping diagram is referred to as the fifth-start current value CVst5. The start of current supply (0[s]) in the third-stage mapping diagram refers to the timing at which the current value supplied to the LED package 23 is changed from the first current value CV1 to another current value. Since the temperature of the LED package 23, which is emitting light with the first luminous intensity LA1 when supplied with the first current value CV1, is higher than the temperature T4, the light-emitting part 231 of the LED package 23 cannot emit light with the second luminous intensity LA2 unless a current value higher than the third current value CV3 is supplied. Therefore, in the third-stage mapping diagram, the output at the start of current supply (0[s]), that is, the current value at which the current value supplied to the LED package 23 is changed from the first current value CV1 (the fifth-start current value CVst5), is higher than the third current value CV3 and lower than the first current value CV1.

[0096] Next, when the light-emitting portion 231 of the LED package 23, which is emitting light at a first luminous intensity LA1 and supplied with a first current value CV1, becomes emitting light at a second luminous intensity LA2, the change in luminous intensity deviation rate is obtained when the current value supplied to the LED package 23 is controlled according to the third first-stage mapping diagram. Then, based on the obtained change in luminous intensity deviation rate, a two-stage mapping diagram is created representing the relationship between the elapsed time from the start of current supply to the LED package 23 and the current value supplied to the LED package 23. In the following description, the two-stage mapping diagram created in the following manner will be referred to as the third two-stage mapping diagram: created when the light-emitting portion 231 of the LED package 23, which is emitting light at a first luminous intensity LA1 and supplied with a first current value CV1, becomes emitting light at a second luminous intensity LA2, based on the change in luminous intensity deviation rate when the current value supplied to the LED package 23 is controlled according to the third first-stage mapping diagram. Furthermore, the current value at the start of current supply (0[s]) in the third two-stage mapping diagram is referred to as the sixth start current value CVst6. The start of current supply (0[s]) in the third two-stage mapping diagram refers to the timing when the current value supplied to the LED package 23 is changed from the first current value CV1 to another current value. In the third two-stage mapping diagram, the output at the start of current supply (0[s]), that is, the current value when the current value supplied to the LED package 23 is changed from the first current value CV1 (the sixth start current value CVst6), is higher than the third current value CV3 and lower than the first current value CV1.

[0097] By controlling the current value supplied to the LED package 23 according to the third second-stage mapping diagram, when the light-emitting part 231 of the LED package 23, which is emitting light with the first light emission intensity LA1 when supplied with the first current value CV1, becomes emitting light with the second light emission intensity LA2, compared with the case where the current value supplied to the LED package 23 is immediately changed from the first current value CV1 to the third current value CV3, and the case where control is performed according to the third first-stage mapping diagram, the time until the light-emitting part 231 emits light stably with the second light emission intensity LA2 can be shortened.

[0098] (Structure of the illumination optical system 80)

[0099] Refer again Figure 2 The structure of the illumination optical system 80 is described below. The illumination optical system 80 includes an imaging optical system 81, a fly-eye lens (FEL), an aperture stop 85, a focusing optical system 86, and an illuminance correction filter 87.

[0100] The imaging optical system 81 is a bilateral telecentric optical system that projects the image of the light source unit OPU (light source array 20) onto the incident end of the fly-eye lens FEL at an equal magnification.

[0101] A fly-eye lens (FEL) is constructed, for example, by arranging multiple lens elements with positive refractive power in a longitudinal and dense manner, with their optical axes parallel to the reference optical axis AX. Each lens element constituting the fly-eye lens (FEL) has a rectangular cross-section similar to the shape of the illumination field to be formed on the mask MSK (and even the shape of the exposure area to be formed on the plate P).

[0102] Therefore, the light beam incident on the fly-eye lens FEL is wavefront-splitting by multiple lens elements, thereby forming a light source image at or near the back focal plane (emission surface) of each lens element. That is, a substantial surface light source, i.e., a secondary light source, composed of multiple light source images, is formed at or near the back focal plane (emission surface) of the fly-eye lens FEL. The light beam from the secondary light source formed at or near the back focal plane (emission surface) of the fly-eye lens FEL is incident on the aperture stop 85 disposed nearby. It should be noted that, in this embodiment, the back focal plane (emission surface) of the fly-eye lens FEL and the light source array 20 are optically conjugate.

[0103] The aperture stop 85 is positioned approximately conjugate optically to the entrance pupil plane of the projection optical system PL, and has a variable aperture section for defining a range that facilitates illumination by the secondary light source. Furthermore, by changing the aperture of the variable aperture section, the aperture stop 85 sets the σ value (the ratio of the aperture of the secondary light source image on the pupil plane of the projection optical system to the aperture of the pupil plane) that determines the illumination conditions to a desired value. Light from the secondary light source passing through the aperture stop 85 is focused by the focusing optical system 86, and its illuminance is corrected by the illuminance correction filter 87, illuminating the mask MSK, on ​​which a predetermined pattern is formed, in an overlapping manner.

[0104] It should be noted that the wavelength of the light emitted by the light source unit OPU is not limited to the above situation. The light source unit OPU can also be formed by appropriately combining LED packages that emit light with peak wavelengths in the range of 360 to 440 nm.

[0105] (Variation example)

[0106] In the first embodiment described above, the current value supplied to the LED package 23 is controlled according to the first second-stage mapping diagram, the second second-stage mapping diagram, and the third second-stage mapping diagram in three cases. The three cases are: the case in which the light-emitting part 231 of the LED package 23, which is in a state where the temperature is lower than the first temperature threshold Tth1 and no current is supplied, emits light with the first light emission amount LA1 (as described in the first case); the case in which the light-emitting part 231 of the LED package 23, which is in a state where the temperature is lower than the second temperature threshold Tth2 and no current is supplied, emits light with the second light emission amount LA2 (as described in the second case); and the case in which the light-emitting part 231 of the LED package 23, which is supplied with the first current value CV1 and emits light with the first light emission amount LA1, emits light with the second light emission amount LA2 (as described in the third case), but it is not limited to these cases. For example, the current value supplied to the LED package 23 can also be controlled according to the first two-stage mapping diagram, the second two-stage mapping diagram, or the third two-stage mapping diagram in the following four cases (cases 4 to 7).

[0107] (Case 4)

[0108] The fourth case is when the current supply to the LED package 23 is stopped for a predetermined time (e.g., 80 seconds) after the state in which the light-emitting part 231 of the LED package 23 emits light at the first luminous intensity LA1 is stopped, and then the light-emitting part 231 of the LED package 23 is made to emit light at the first luminous intensity LA1 again. In the fourth case, the control unit CTR can control the current value supplied to the LED package 23 according to the first two-stage mapping diagram.

[0109] (Case 5)

[0110] The fifth case is when, after a predetermined time (e.g., 80 seconds) has evicted the current supply to the LED package 23 from a state where the light-emitting portion 231 of the LED package 23 is emitting light at the second luminous intensity LA2, the light-emitting portion 231 of the LED package 23 is then emitting light at the first luminous intensity LA1. In the fifth case, the control unit CTR can control the current value supplied to the LED package 23 according to the first two-stage mapping diagram.

[0111] (Case 6)

[0112] The sixth case is when the current supply to the LED package 23 is stopped for a predetermined time (e.g., 80 seconds) after the state in which the light-emitting part 231 of the LED package 23 emits light at the second luminous intensity LA2 is stopped, and then the light-emitting part 231 of the LED package 23 is made to emit light at the second luminous intensity LA2 again. In the sixth case, the control unit CTR can control the current value supplied to the LED package 23 according to the second two-stage mapping diagram.

[0113] (Case 7)

[0114] The seventh case is when, after a predetermined time (e.g., 80 seconds) has evicted the current supply to the LED package 23 from a state where the light-emitting portion 231 of the LED package 23 emits light at the first luminous intensity LA1, the light-emitting portion 231 of the LED package 23 is then emitting light at the second luminous intensity LA2. In the seventh case, the control unit CTR can control the current value supplied to the LED package 23 according to the second two-stage mapping diagram.

[0115] Situations 1 through 7 are summarized in Table 1.

[0116] [Table 1]

[0117] Regarding cases 4 through 7, the luminous intensity of the light-emitting portion 231 of the LED package 23 was measured when the current value supplied to the LED package 23 was controlled according to the two-stage mapping diagram. Case 4 and 5 used the first two-stage mapping diagram, case 6 used the second two-stage mapping diagram, and case 7 used the third two-stage mapping diagram to control the current value supplied to the LED package 23.

[0118] Figure 11 (A) and Figure 11 (B) is a graph showing the measurement results of the light emission of the light-emitting part 231 of the LED package 23 in cases 4 and 5, respectively. Figure 12 (A) and Figure 12 (B) is a graph showing the measurement results of the light-emitting part 231 of the LED package 23 in cases 6 and 7, respectively.

[0119] like Figure 11 (A) ~ Figure 12 As shown in (B), it can be seen that even if the current supply to the LED package 23 is stopped for a predetermined time from the state in which the light-emitting part 231 of the LED package 23 emits light, and then the light-emitting part 231 of the LED package 23 is made to emit light again, the light emission of the light-emitting part 231 of the LED package 23 can be stabilized in a relatively short time by using the two-stage mapping diagram.

[0120] Implementation Method 2

[0121] like Figure 11 (A) ~ Figure 12 As shown in (B), in cases 4 through 7, compared with cases 1 and 2 (refer to...) Figure 9 and Figure 10Compared to the previous scenario, the luminous intensity deviation rate is larger, and the time until the luminous intensity of the light-emitting portion 231 of the LED package 23 stabilizes is longer. This can be attributed to the fact that, in cases 4 and 5, the temperature of the LED package 23 at the time of restarting current supply to the LED package 23 is above the first temperature threshold Tth1 and is in a state lower than temperature T1. The first two-stage mapping is created for the case where the temperature of the LED package 23 at the time of starting current supply is lower than the first temperature threshold Tth1. Therefore, it can be considered that, when the temperature of the LED package 23 is above the first temperature threshold Tth1, if a current value higher than the current value based on the first two-stage mapping is not supplied, it is impossible to obtain the same luminous intensity as the luminous intensity of the light-emitting portion 231 of the LED package 23 when the temperature of the LED package 23 at the time of starting current supply is lower than the first temperature threshold Tth1.

[0122] Furthermore, in the sixth case, it can be assumed that the temperature of the LED package 23 when current is restarted is above the second temperature threshold Tth2 and lower than the temperature T3. Therefore, it can be assumed that if a current value higher than the current value of the second two-stage mapping created for the case where the temperature of the LED package 23 at the start of current supply is lower than the second temperature threshold Tth2 is not supplied, the same amount of light emission as the light emission of the light-emitting part 231 of the LED package 23 when the temperature of the LED package 23 at the start of current supply is lower than the second temperature threshold Tth2 cannot be obtained.

[0123] Furthermore, in the seventh case, it can be assumed that the temperature of the LED package 23 when current is restarted is above the second temperature threshold Tth2 and higher than the temperature T4. Therefore, it can be assumed that if a current value higher than the current value of the second two-stage mapping created based on the case where the temperature of the LED package 23 at the start of current supply is lower than the second temperature threshold Tth2 is not supplied, the same amount of light emission as the light emission of the light-emitting part 231 of the LED package 23 when the temperature of the LED package 23 at the start of current supply is lower than the second temperature threshold Tth2 cannot be obtained.

[0124] Therefore, in the second embodiment, the temperature correction of the first to third two-stage mapping diagram of the LED package 23 is used to control the current value supplied to the LED package 23.

[0125] Figure 13 This is a top view showing the light source array 20X included in the light source unit OPU-A according to the second embodiment. The light source unit OPU-A includes the light source array 20X and a magnifying optical system 30 (in... Figure 13 (Not shown in the diagram), and the control unit CTR-A.

[0126] The light source array 20X includes a plurality of LED packages 23 arranged in an array on a substrate 21 and a thermistor 25. The thermistor 25 is disposed, for example, near the LED packages 23 on the surface of the substrate 21 and detects the surface temperature of the substrate 21. That is, in this embodiment, the surface temperature of the substrate 21 at a location near the LED packages 23 is used as the temperature of the LED packages 23. It should be noted that, for example, the thermistor may also be mounted on the LED packages 23 and the temperature of the LED packages 23 itself may be measured. In this case, it is sufficient to mount the thermistor at a position that does not obstruct the travel of light emitted from the LED packages 23. Alternatively, for example, the thermistor may be disposed in a portion of the substrate 21 surrounded by the plurality of LED packages 23, and the temperature of this portion may be used as the temperature of the LED packages 23. Since other structures are the same as those in the light source array 20 of the first embodiment, detailed descriptions are omitted.

[0127] The control unit CTR-A controls the initial current value (second current value CV2 or fourth current value CV4) and the proportion by which the current value supplied to the LED package 23 increases to the first current value CV1 or the third current value CV3, based on the temperature of the LED package 23. Furthermore, the control unit CTR-A controls the initial current value supplied to the LED package 23 and the proportion by which the current value supplied to the LED package 23 decreases to the third current value CV3, based on the temperature of the LED package 23. A more detailed explanation of the control performed by the control unit CTR-A will follow.

[0128] As an example, the case where the light-emitting portion 231 of the LED package 23 is brought back to the state of emitting light at the first luminous intensity LA1 after a predetermined time (e.g., 80 seconds) has been stopped from a state in which the light-emitting portion 231 of the LED package 23 emits light at the first luminous intensity LA1 (case 4) will be described. In this case, the temperature of the LED package 23 when the current supply to the LED package 23 is restarted is above the first temperature threshold Tth1 and lower than temperature T1.

[0129] The control unit CTR-A calculates the current value CVact(t) of the current supplied to the LED package 23 at a certain time point t from the start of supplying current to the LED package 23 based on the following equation (1).

[0130] CVact(t) = CVmap(t) × {1.0 + (Tact(t) - Tmap(t)) × (temperature characteristic / 100)} …… (1)

[0131] Here, CVmap(t) represents the current value at a certain time point t from the start of current supply in the first two-stage mapping. Tact(t) represents the actual temperature of the LED package 23 measured by the thermistor 25 at a certain time point t from the start of current supply.

[0132] Tmap(t) represents the temperature of the LED package 23 at a certain time t from the start of current supply in a pre-created temperature map. The temperature map represents the relationship between the elapsed time from the start of current supply and the temperature of the LED package 23 when current is supplied to the LED package 23, which is in a state where its temperature is lower than the first temperature threshold Tth1 and it is not currently receiving current, causing it to emit light at the first luminous intensity LA1, according to the first two-stage map. The temperature map can be created by actually measuring the temperature of the LED package 23 or by simulation.

[0133] The temperature characteristic is a characteristic that represents the relationship between the temperature of the LED package 23 and the light emission of the light-emitting part 231 of the LED package 23. It represents the rate of change (%) of the light emission when the temperature of the LED package 23, which is supplied with a specified current, changes by 1°C. The temperature characteristic can take different values ​​depending on the actual temperature of the LED package 23, or it can be fixed regardless of the temperature of the LED package 23.

[0134] As can be seen from equation (1), when the actual temperature Tact(t) of the LED package 23 and the temperature mapping diagram Tmap(t) are the same at time point t, the control unit CTR-A supplies the current value of the two-stage mapping diagram to the LED package 23. That is, when the actual temperature Tact(t) of the LED package 23 and the temperature mapping diagram Tmap(t) are the same at time point t, the current value supplied to the LED package 23 will not change from the current value of the two-stage mapping diagram.

[0135] Next, the method for determining the current value supplied to the LED package 23 based on the temperature mapping map and the two-stage mapping map executed by the control unit CTR-A will be explained. Figure 14 (A) is an example of a temperature mapping diagram. Figure 14 (B) is an example of a second-stage mapping diagram. It should be noted that in... Figure 14 In (B), the vertical axis is set to the current value for ease of understanding, but the vertical axis can also be the output.

[0136] Here, we will explain the case where the current value supplied to the LED package 23 is determined at a certain time point t11 ​​from the restart (start) of supplying current to the LED package 23.

[0137] like Figure 14As shown in (A), the temperature of LED package 23 at time point t11 ​​obtained from the temperature mapping is Tt11. Additionally, as... Figure 14 As shown in (B), the current value at time point t11 ​​obtained from the first two-stage mapping is CVt11. Furthermore, assume the temperature characteristic is, for example, 2%. In this case, according to equation (1), the current value CVact(t11) supplied to the LED package 23 at time point t11 ​​is CVact(t11) = CVt11 × {1.0 + (Tact(t11) - Tt11) × (2 / 100)}. Here, Tact(t11) is the actual temperature of the LED package 23 measured by the thermistor 25 at time point t11.

[0138] Figure 15 (A) is a graph showing the actual temperature of the LED package 23 relative to the elapsed time since the restart (start) current supply. Figure 15 (B) is a graph representing the actual current value supplied to the LED package 23 by correcting the first-stage mapping based on the actual temperature of the LED package 23. Figure 15 In (A), the solid line represents the actual temperature of LED package 23, and the dashed line represents the temperature mapping value. Additionally, in Figure 15 In (B), the solid line represents the actual current value supplied to the LED package 23, and the dashed line represents the first and second stage mapping value.

[0139] like Figure 15 As shown in (A), the actual temperature of the LED package 23 is higher than the temperature in the temperature map from the time current is supplied to the LED package 23. Therefore, as shown in equation (1), the control unit CTR-A corrects the current value obtained from the first second-stage map based on the actual temperature of the LED package 23 according to equation (1). For example, the control unit CTR-A corrects the second initial current value CVst2 based on the temperature of the LED package 23 when current is supplied to the LED package 23, thereby calculating the second current value CV2 when current is supplied to the LED package 23 again. Thus, as shown in equation (A), the actual temperature of the LED package 23 from the time current is supplied to the LED package 23 is higher than the temperature in the temperature map. Therefore, the actual temperature of ... Figure 15 As shown in (B), the second current value CV2 when the current supply to the LED package 23 is restarted is the corrected second starting current value CVst2' which is higher than the second starting current value CVst2 in the first two-stage mapping.

[0140] Furthermore, the current value supplied to the LED package 23 at each time point during the period from the second corrected current value CVst2' when current is supplied to the LED package 23 again until the current value becomes the first current value CV1 is a corrected current value obtained based on the temperature correction of the LED package 23 at each time point and the current value predetermined for each time point in the first two-stage mapping diagram. Thus, for example, Figure 15 As shown in (B), the control unit CTR-A supplies current to the LED package 23 at a current value greater than the current value in the first second-stage mapping diagram until the current value becomes the first current value CV1.

[0141] Thus, in the second embodiment, the control unit CTR-A controls the current value at the beginning of current supply to the LED package 23, and the current value supplied to the LED package 23 at each time point from the restart of current supply to the LED package 23, based on the temperature of the LED package 23. As a result, current can be supplied to the LED package 23 at a more appropriate current value corresponding to the actual temperature of the LED package 23, thereby shortening the time until the light emission of the light-emitting portion 231 of the LED package 23 stabilizes.

[0142] In the fifth case, that is, after a predetermined time has elapsed since the current supply to the LED package 23 was stopped from the state in which the light-emitting part 231 of the LED package 23 emits light at the second luminous intensity LA2, the control unit CTR-A supplies the LED package 23 with a current value obtained by correcting the first second-stage mapping based on the actual temperature of the LED package 23.

[0143] In addition, in the sixth case, that is, after a predetermined time has elapsed from the state in which the light-emitting part 231 of the LED package 23 emits light at the second light intensity LA2, the control unit CTR-A supplies the LED package 23 with a current value obtained by correcting the second second-stage mapping based on the actual temperature of the LED package 23.

[0144] It should be noted that the temperature mapping used in case 6 is a mapping of the relationship between the elapsed time from the start of current supply and the temperature of the LED package 23 when current is supplied to the LED package 23 which is in a state where the temperature is lower than the second temperature threshold Tth2 and no current is supplied, so that it emits light with the second luminous intensity LA2, according to the second two-stage mapping.

[0145] In addition, in the seventh case, that is, after the current supply to the LED package 23 is stopped for a predetermined time from the state in which the light-emitting part 231 of the LED package 23 emits light at the first light emission level LA1, the control unit CTR-A supplies the LED package 23 with a current value obtained by correcting the second second-stage mapping based on the actual temperature of the LED package 23.

[0146] It should be noted that the temperature mapping used in case 7 is a mapping of the relationship between the elapsed time from the start of current supply and the temperature of the LED package 23 when current is supplied to the LED package 23 which is in a state where the temperature is lower than the second temperature threshold Tth2 and no current is supplied, so that it emits light with the second luminous intensity LA2, according to the second two-stage mapping.

[0147] Furthermore, in the seventh case, the control unit CTR-A can also determine which of the second and third two-stage mapping diagrams to use to control the current value supplied to the LED package 23 based on the temperature of the LED package 23 when the current supply to the LED package 23 is started after a predetermined time has passed since the current supply to the LED package 23 was stopped.

[0148] Figure 16 (A) and Figure 16 (B) is a graph showing the measurement results of the luminous output of the LED package 23 when the first and second stage mapping is corrected according to the actual temperature of the LED package 23 and the current value supplied to the LED package 23 is controlled in cases 4 and 5, respectively. Figure 17 (A) is a graph showing the measurement results of the luminous output of the LED package 23 when the second phase mapping is corrected according to the actual temperature of the LED package 23 in case 6 and the current value supplied to the LED package 23 is controlled. Figure 17 (B) is a graph showing the measurement results of the luminous output of the LED package 23 when the second-stage mapping is corrected according to the actual temperature of the LED package 23 in case 7 and the current supplied to the LED package 23 is controlled. Figure 16 (A) ~ Figure 17 In (B), the vertical axis represents the light emission deviation rate, and the horizontal axis represents the elapsed time from the start of current supply.

[0149] like Figure 16 (A) ~ Figure 17 As shown in (B), it can be seen that: with Figure 11 (A) ~ Figure 12Compared to (B), in the second embodiment, the light emission deviation rate is smaller than that of the variation of the first embodiment, and the time until the light-emitting portion 231 of the LED package 23 emits light at the desired light emission level is shorter. Thus, by correcting the two-stage mapping diagram based on the actual temperature of the LED package 23 and controlling the current value supplied to the LED package 23, the time until the light-emitting portion 231 of the LED package 23 emits light stably at the desired light emission level can be further shortened.

[0150] As detailed above, according to the second embodiment, if the control unit CTR-A supplies a current with a first current value CV1 when the temperature of the LED package 23 is within the range of temperature T1 to temperature T2 (>T1) (the first temperature range), then for the LED package 23 emitting light with a first luminous intensity LA1, it starts supplying current to the LED package 23 with a second current value CV2 that is lower than the first current value CV1, and increases the current value supplied to the LED package 23 from the second current value CV2 to the first current value CV1. The control unit CTR-A controls the second current value CV2 and the ratio of increasing the current value supplied to the LED package 23 from the second current value CV2 to the first current value CV1 based on the temperature of the LED package 23. Specifically, the control unit CTR-A sets the second current value CV2 at the start of supplying current to the LED package 23 as the current value CVst2 obtained based on the second starting current value CVst2 in the first two-stage mapping diagram corrected for the temperature of the LED package 23. Furthermore, the control unit CTR-A increases the proportion when the current value supplied to the LED package 23 increases to the first current value CV1 by using the proportion obtained from the first and second stage mapping based on the temperature correction of the LED package 23. That is, at each time point during the period when the current value supplied to the LED package 23 increases to the first current value CV1, the control unit CTR-A supplies the LED package 23 with a corrected current value obtained by correcting the current value for each time point in the first and second stage mapping based on the temperature of the LED package 23.

[0151] Furthermore, if the control unit CTR-A supplies a current with a third current value CV3 when the temperature of the LED package 23 is within the range of temperature T3 to temperature T4 (>T3) (the second temperature range), then for the LED package 23 emitting light with the second luminous intensity LA2, it starts supplying current to the LED package 23 with a fourth current value CV4, which is lower than the third current value CV3, and increases the current value supplied to the LED package 23 from the fourth current value CV4 to the third current value CV3. The control unit CTR-A controls the fourth current value CV4 and the ratio of increasing the current value supplied to the LED package 23 from the fourth current value CV4 to the third current value CV3 based on the temperature of the LED package 23. Specifically, the control unit CTR-A sets the fourth current value CV4 at the start of supplying current to the LED package 23 to the current value CVst4 obtained based on the fourth starting current value CVst4 in the second two-stage mapping diagram corrected for the temperature of the LED package 23. Furthermore, the control unit CTR-A increases the proportion at which the current value supplied to the LED package 23 increases to the third current value CV3 by using a proportion obtained from the second two-stage mapping based on the temperature correction of the LED package 23. That is, at each time point during the period when the current value supplied to the LED package 23 increases to the third current value CV3, the control unit CTR-A supplies the LED package 23 with a corrected current value obtained by correcting the current value predetermined for each time point in the second two-stage mapping based on the temperature of the LED package 23. This shortens the time until the light emission of the light-emitting portion 231 of the LED package 23 stabilizes.

[0152] Furthermore, in this second embodiment, when a third current value CV3, lower than the first current value CV1, is supplied when the temperature of the LED package 23 is within the temperature range of T3 to T4 (the second temperature range), the LED package 23 emits light with a second luminous intensity LA2, lower than the first luminous intensity LA1. The control unit CTR-A starts supplying current to the LED package 23, which is at a temperature higher than T4, with a current value higher than the third current value CV3, and then reduces the current value supplied to the LED package 23 to the third current value CV3. The control unit CTR-A controls the ratio between the current value at which current is initially supplied to the LED package 23 and the ratio at which the current value supplied to the LED package 23 is reduced to the third current value CV3, based on the temperature of the LED package 23. For example, the control unit CTR-A sets the fourth current value CV4 at which current is initially supplied to the LED package 23 to the current value CVst4 obtained based on the fourth starting current value CVst4 in the second two-stage mapping diagram corrected for the temperature of the LED package 23. Furthermore, at each time point during which the current value supplied to the LED package 23 decreases to the third current value CV3, the control unit CTR-A supplies the LED package 23 with a corrected current value obtained by correcting the current value predetermined for each time point in the second phase mapping based on the temperature of the LED package 23. Therefore, compared to the case where the second phase mapping or the second phase mapping is not corrected according to the temperature of the LED package 23, the time until the light emission of the light-emitting portion 231 of the LED package 23 stabilizes at the second light emission value LA2 can be shortened.

[0153] It should be noted that in the second embodiment described above, the actual temperature of the LED package 23 is measured by the thermistor 25, but this is not a limitation. The control unit CTR-A may, for example, predict the temperature at a certain point in time from the start of current supply to the LED package 23 based on a temperature prediction map, and set this predicted temperature as the actual temperature of the LED package 23. The temperature prediction map can be created, for example, as follows. As an example, the case where, after a predetermined time (e.g., 80 seconds) has elapsed since the current supply to the LED package 23 was stopped from a state where the light-emitting portion 231 of the LED package 23 was emitting light at the first luminous intensity LA1, the case where the light-emitting portion 231 of the LED package 23 is emitting light at the first luminous intensity LA1 is described again, will be explained. In this case, the temperature of the LED package 23 is measured when the current value supplied to the LED package 23 is controlled based on the first second-stage map, and a temperature prediction map is created based on this measurement result. The temperature prediction map is a graph that represents the relationship between the time from the start of current supply to LED package 23 and the actual temperature of LED package 23 when the current value supplied to LED package 23 is controlled based on the first two-stage map.

[0154] The control unit CTR-A only needs to use the temperature of the LED package 23 in the temperature prediction map of the time from the start of current supply to the LED package 23 as the actual temperature of the LED package 23 to correct the first and second stage mapping. Furthermore, in this case, the temperature of the LED package 23 when current supply resumes varies depending on the length of time the current supply to the LED package 23 is stopped. Therefore, a temperature prediction map can be created for each length of time the current supply to the LED package 23 is stopped; for example, a function including the length of time the current supply to the LED package 23 is stopped as a parameter can be used as the temperature prediction map of the LED package 23.

[0155] Furthermore, in the second embodiment described above, a current value obtained based on a two-stage temperature correction mapping of the LED package 23 is supplied to the LED package 23, but this is not a limitation. A current value obtained based on a one-stage temperature correction mapping of the LED package 23 may also be supplied to the LED package 23. In the fourth and fifth cases, the current value at which current is supplied to the LED package 23 (the second current value CV2) becomes the temperature obtained based on the first initial current value CVst1 of the first-stage temperature correction mapping of the LED package 23. In the sixth case, the current value at which current is supplied to the LED package 23 (the fourth current value CV4) becomes the temperature obtained based on the third initial current value CVst3 of the second-stage temperature correction mapping of the LED package 23. In the seventh case, the current value at which current is supplied to the LED package 23 becomes the temperature obtained based on the third initial current value CVst3 of the second-stage temperature correction mapping of the LED package 23.

[0156] It should be noted that, instead of correcting the current value for each time point obtained from the one-stage mapping diagram or the two-stage mapping diagram based on the temperature of the LED package 23 and calculating the current value supplied to the LED package 23 at each time point, the current value for each time point can be corrected based on the temperature of the LED package 23. This correction is based on the current value for each time point calculated according to the formula (approximate formula) representing the current value supplied to the LED package 23 at each time point, which is predetermined in the one-stage mapping diagram or the two-stage mapping diagram.

[0157] In addition, the control unit CTR-A can also use the actual temperature data of the LED package 23, the luminous quantity deviation rate data, and the output data as training data for machine learning, and use the learned model to determine the output.

[0158] Furthermore, in the second embodiment described above, when the current supply to the LED package 23 is stopped for a predetermined time from the state in which the light-emitting portion 231 of the LED package 23 emits light, and then the current supply to the LED package 23 is resumed, the two-stage mapping diagram is corrected based on the actual temperature of the LED package 23 if the temperature of the LED package 23 is above the first temperature threshold Tth1 and lower than temperature T1, or if the temperature of the LED package 23 is above the second temperature threshold Tth2 and lower than temperature T3. However, the two-stage mapping diagram can also be corrected based on the actual temperature of the LED package 23 if the temperature of the LED package 23 is lower than the first temperature threshold Tth1 or lower than the second temperature threshold Tth2.

[0159] Figure 18 (A) is a graph showing the measurement results of the luminous intensity of the light-emitting portion 231 of the LED package 23 when the light-emitting portion 231 of the LED package 23 is emitting light with a first luminous intensity LA1, provided with a current value obtained from the first second-stage mapping map corrected according to the actual temperature of the LED package 23. Additionally, Figure 18 (B) is a graph showing the measurement results of the luminous intensity of the light-emitting part 231 of the LED package 23 when the light-emitting part 231 of the LED package 23 is emitting light with the second luminous intensity LA2, and the current obtained by correcting the second two-stage mapping based on the actual temperature of the LED package 23 is supplied to the LED package 23.

[0160] like Figure 18 (A) and Figure 18 As shown in (B), even when the light-emitting portion 231 of the LED package 23 is in a state where the temperature is lower than the first temperature threshold Tth1 or the second temperature threshold Tth2 and no current is supplied, the time until the light-emitting portion 231 of the LED package 23 emits light at a predetermined amount can be shortened by supplying the LED package 23 with a current value obtained from the two-stage mapping diagram that is corrected according to the actual temperature of the LED package 23.

[0161] In addition, in the second embodiment described above, the current value at which current is supplied to the LED package 23 is started and the ratio of increasing or decreasing the current value supplied to the LED package 23 are controlled according to the temperature of the LED package 23. However, it is sufficient to control at least one of the current value at which current is supplied to the LED package 23 is started and the ratio of increasing or decreasing the current value supplied to the LED package 23 according to the temperature of the LED package 23.

[0162] Third Implementation Method

[0163] The lighting unit for the driving method of the LED package 23 applicable to the first and second embodiments and their variations is not limited to the lighting unit 90. Figure 19 This is a schematic diagram showing the structure of the lighting unit 90A in the third embodiment.

[0164] The illumination unit 90A includes a first light source unit OPU1, a second light source unit OPU2, and an illumination optical system 80A. The first light source unit OPU1 includes a first light source array 20-1, a first magnifying optical system 30-1, and a first control unit CTR-1, and the second light source unit OPU2 includes a second light source array 20-2, a second magnifying optical system 30-2, and a second control unit CTR-2.

[0165] The first light source unit OPU1 emits light with a peak wavelength of 385 nm, for example. The second light source unit OPU2 emits light with a peak wavelength of 365 nm, for example. It should be noted that since the structures of the first light source unit OPU1 and the second light source unit OPU2 are the same as those of the light source unit OPU in the first embodiment or the light source unit OPU-A in the second embodiment, detailed descriptions are omitted.

[0166] The illumination optical system 80A includes a first condensing optical system 83A, a second condensing optical system 83B, a second dichroic mirror DM2, an imaging optical system 81A, a fly-eye lens FEL, an aperture stop 85, a condensing optical system 86, and an illuminance correction filter 87, all of which are configured by a first dichroic mirror DM1.

[0167] The first condensing optical system 83A forms the pupil of the magnified image of the light-emitting part 231 formed by the first magnifying optical system 30-1. That is, the position of the back focal point of the first condensing optical system 83A becomes the position of the pupil. The first condensing optical system 83A has a first dichroic mirror DM1 midway through the optical path, reflecting at least a portion of the light with a peak wavelength of 385nm. Thus, the light beam is incident on the second dichroic mirror DM2. It should be noted that the first condensing optical system 83A can also be configured without the first dichroic mirror DM1. In this case, the configuration of the first light source unit OPU1 and the configuration of each lens in the first condensing optical system 83A can be appropriately adjusted to ensure that the light beam is incident on the second dichroic mirror DM2. Furthermore, the first condensing optical system 83A can be composed of a single lens or a lens group including multiple lenses.

[0168] The second condensing optical system 83B forms the pupil of the magnified image of the light-emitting part 231 formed by the second magnifying optical system 30-2. That is, the position of the back focal point of the second condensing optical system 83B becomes the position of the pupil. The second condensing optical system 83B can be composed of a single lens or a lens group including multiple lenses.

[0169] The second dichroic mirror DM2 transmits at least a portion of light with a peak wavelength of 385 nm and reflects at least a portion of light with a peak wavelength of 365 nm. This forms a composite image formed by the overlap of the pupil image formed by the first focusing optical system 83A and the pupil image formed by the second focusing optical system 83B.

[0170] The imaging optical system 81A is a bi-lateral telecentric optical system that projects the composite image synthesized by the second dichroic mirror DM2 onto the incident end of the fly-eye lens FEL at an equal magnification.

[0171] Since the other structures are the same as those in the above embodiments, detailed descriptions are omitted. Thus, in an exposure apparatus having multiple light source units, any of the light source units in the first and second embodiments and their variations can be applied.

[0172] Implementation Method 4

[0173] Figure 20 This is a schematic diagram showing the structure of the exposure apparatus 10B according to the fourth embodiment.

[0174] In the exposure apparatus 10B, the illumination unit 90B includes a first light source unit OPU1, a second light source unit OPU2, and an illumination optical system 80B. Since the first light source unit OPU1 and the second light source unit OPU2 are the same as in the third embodiment, detailed descriptions are omitted.

[0175] The illumination optical system 80B includes a first condenser optical system 83A1, a second condenser optical system 83B1, a third dichroic mirror DM3, an imaging optical system 81B, a fly-eye lens FEL, an aperture stop 85, a condenser optical system 86B, and an illuminance correction filter 87.

[0176] The first condensing optical system 83A1 is disposed on or near the aforementioned specified surface PP and forms a pupil of the magnified image of the light-emitting portion 231 formed by the first magnifying optical system 30-1. The first condensing optical system 83A1 may be composed of a single lens or a lens group comprising multiple lenses.

[0177] The second focusing optical system 83B1 is disposed on or near the aforementioned specified surface PP and forms a pupil of the magnified image of the light-emitting portion 231 formed by the second magnifying optical system 30-2. The second focusing optical system 83B1 may be composed of a single lens or a lens group comprising multiple lenses.

[0178] The third dichroic mirror DM3 transmits at least a portion of light with a peak wavelength of 385 nm and reflects at least a portion of light with a peak wavelength of 365 nm. Thus, a composite image is formed by superimposing the pupil image formed by the first focusing optical system 83A1 and the pupil image formed by the second focusing optical system 83B1.

[0179] Imaging optical system 81B is a bi-lateral telecentric optical system that projects the composite image synthesized by the third dichroic mirror DM3 onto the incident end of the fly-eye lens FEL at an equal magnification. It should be noted that imaging optical system 81B can also reduce the size of the composite image synthesized by the third dichroic mirror DM3 and project it onto the incident end of the fly-eye lens FEL.

[0180] The light beam incident on the fly-eye lens (FEL) is wavefront-splitting by multiple lens elements, thereby forming a light source image at or near the back focal plane of each lens element. The light beam from the secondary light source formed at or near the back focal plane of the fly-eye lens (FEL) is incident on the aperture stop 85 located nearby.

[0181] Light from the secondary light source passing through the aperture stop 85 is focused by the focusing optical system 86B and its illuminance is corrected by the illuminance correction filter 87, and then illuminates the mask MSK with a prescribed pattern in an overlapping manner.

[0182] Furthermore, in the exposure apparatus 10B, the projection optical system PL is an Offner-type optical system supported by the optical platform 73 below (on the -Z side) the mask stage MST. The projection optical system PL forms, for example, an image field in the shape of an arc with the Y-axis as its length direction.

[0183] When the illumination area on the mask MSK is illuminated by the illumination light IL from the illumination system IOP, the illumination light IL transmits the mask MSK through the projection optics system PL and forms a projection (partially upright image) of the circuit pattern of the mask MSK within the illumination area of ​​the illumination light IL on the plate P located on the image plane side of the projection optics system PL in the illumination area (exposure area (conjugate with the illumination area)). Thus, the plate P is exposed, and the pattern of the mask MSK is transferred onto the plate P.

[0184] As shown in the fourth embodiment, the light source unit of any of the first and second embodiments and their variations can also be applied to an exposure apparatus equipped with an Offner-type projection optical system PL.

[0185] It should be noted that the wavelength of the light emitted by the first light source unit OPU1 and the second light source unit OPU2 is not limited to the above situation. The first light source unit OPU1 and the second light source unit OPU2 can also be formed by appropriately combining LED packages that emit light with peak wavelengths in the range of 360 to 440 nm.

[0186] For example, the first light source unit OPU1 may be configured to emit light with a peak wavelength of 405 nm, and the second light source unit OPU2 may emit light with a peak wavelength of 365 nm. Alternatively, the first light source unit OPU1 may be configured to emit light with a peak wavelength of 395 nm, and the second light source unit OPU2 may emit light with a peak wavelength of 385 nm. The combination of the wavelengths of the light emitted from the first light source unit OPU1 and the second light source unit OPU2 is not limited to these examples. It should be noted that when the combination of the wavelengths of the light emitted from the first light source unit OPU1 and the second light source unit OPU2 is set to a combination other than that in this embodiment, it is preferable to appropriately change the material of the dichroic mirror according to the wavelength used.

[0187] In the above embodiments and their variations, the exposure apparatus is described for manufacturing liquid crystal display devices (flat panel displays), but the exposure apparatus can also be used to expose silicon wafers to manufacture semiconductors.

[0188] The above-described embodiments are preferred embodiments of the present invention, but are not limited thereto. Various modifications can be made without departing from the spirit of the present invention.

[0189] Explanation of reference numerals in the attached figures

[0190] 10, 10B Exposure Device

[0191] 20, 20X light source array

[0192] 20-1 First Light Source Array

[0193] 20-2 Second Light Source Array

[0194] 21 substrate

[0195] 23 LED Packaging

[0196] 25 Thermistor

[0197] 80, 80A, 80B Illumination Optical Systems

[0198] Lighting units 90, 90A, and 90B

[0199] 100 projection optical units

[0200] CTR, CTR-A Control Department

[0201] CTR-1 First Control Unit

[0202] CTR-2 Second Control Unit

[0203] DM2 Second Dichroic Mirror

[0204] FEL fly-eye lens

[0205] MSK mask

[0206] OPU Light Source Unit

[0207] OPU-A Light Source Unit

[0208] OPU1 First Light Source Unit

[0209] OPU2 Second Light Source Unit

[0210] PL projection optical system

[0211] P Glass substrate.

Claims

1. A driving method of a light source element that emits light at a first light emission amount when supplied with a current of a first current value, the driving method of the light source element characterized by, including starting to supply the light source element with a current at a second current value lower than the first current value, and increasing the current value of the current supplied to the light source element to the first current value, the current value of the current supplied to the light source element at a first time point being a corrected current value obtained by correcting a current value acquired at the first time point based on a first information that determines the current value of the current supplied to the light source element at each time point during a period in which the supply of the current to the light source element is started at a predetermined third current value and the current value of the current supplied to the light source element is increased to the first current value, and based on the temperature of the light source element.

2. The driving method of the light source element according to claim 1, characterized by, including: correcting the predetermined third current value based on the temperature of the light source element at the time when the supply of the current to the light source element is started, thereby calculating the second current value; and correcting the current value acquired based on the first information based on the temperature of the light source element at the first time point, thereby calculating the current value of the current supplied to the light source element at the first time point.

3. The driving method of the light source element according to claim 2, characterized by, the current value of the current supplied to the light source element at the first time point being a corrected current value obtained by correcting the current value acquired based on the first information based on a relationship between the elapsed time from the start of the supply of the current to the light source element and the temperature of the light source element that is acquired in advance, and the temperature of the light source element at the first time point.

4. The driving method of the light source element according to any one of claims 1 to 3, characterized in that, the predetermined third current value is a current value at the time when the supply of the current to the light source element is started, which is determined based on a change in the light emission amount of the light source element at the time when the supply of the current to the light source element is started at the first current value in a case where the temperature of the light source element is lower than a first temperature threshold value, the first information is determined based on a change in the light emission amount of the light source element at the time when the supply of the current to the light source element is started at the first current value in a case where the temperature of the light source element is lower than the first temperature threshold value.

5. The driving method of the light source element according to any one of claims 1 to 3, characterized in that, the predetermined third current value is a current value at the start of supplying the current to the light source element, which is determined based on a change in the light emission amount of the light source element when the current is supplied to the light source element at a fourth current value lower than the first current value and the current value of the current supplied to the light source element is increased to the first current value according to second information that determines the current value of the current supplied to the light source element at each time point during a period in which the current is supplied to the light source element at the fourth current value and the current value of the current supplied to the light source element is increased to the first current value, the first information is determined based on a change in the light emission amount of the light source element when the current is supplied to the light source element at the fourth current value and the current value of the current supplied to the light source element is increased to the first current value according to the second information, the fourth current value and the second information are determined based on a change in the light emission amount of the light source element when the current is supplied to the light source element at the first current value.

6. A driving method of a light source element that emits light at a first light emission amount when supplied with a current at a first current value and emits light at a second light emission amount lower than the first light emission amount when supplied with a current at a fifth current value lower than the first current value, the driving method of the light source element characterized by, including supplying the current to the light source element at a sixth current value higher than the fifth current value and decreasing the current value of the current supplied to the light source element from the sixth current value to the fifth current value, the current value of the current supplied to the light source element at the first time point is a corrected current value obtained by correcting the current value of the current supplied to the light source element at the first time point, which is acquired according to third information that determines the current value of the current supplied to the light source element at each time point during a period in which the current is supplied to the light source element at a predetermined seventh current value and the current value of the current supplied to the light source element is changed to the fifth current value, based on the temperature of the light source element.

7. The driving method of the light source element according to claim 6, characterized by, including: correcting the predetermined seventh current value based on the temperature of the light source element at the start of supplying the current to the light source element, thereby calculating the sixth current value; and correcting the current value acquired according to the third information based on the temperature of the light source element at the first time point, thereby calculating the current value of the current supplied to the light source element at the first time point.

8. The driving method of the light source element according to claim 7, characterized by, The current value of the current supplied to the light source element at the first time point is a corrected current value obtained by correcting the current value acquired based on the third information based on a previously acquired relationship between an elapsed time from when the current is started to be supplied to the light source element and the temperature of the light source element, and the temperature of the light source element at the first time point.

9. The driving method of a light source element according to any one of claims 6 to 8, wherein the predetermined seventh current value is a current value at the time when the current is started to be supplied to the light source element, which is determined based on a change in the luminous intensity of the light source element when the current value of the current supplied to the light source element is changed from the first current value to the fifth current value in a state where the light source element that emits light at the first luminous intensity with the current supplied with the first current value emits light at the second luminous intensity, the third information is determined based on a change in the luminous intensity of the light source element when the current value of the current supplied to the light source element is changed from the first current value to the fifth current value.

10. The driving method of a light source element according to any one of claims 6 to 8, wherein the predetermined seventh current value is a current value at the time when the current is started to be supplied to the light source element, which is determined based on a change in the luminous intensity of the light source element when the current is started to be supplied to the light source element with an eighth current value that is higher than the fifth current value, and the current value of the current supplied to the light source element is decreased to the fifth current value according to fourth information that determines the current value of the current supplied to the light source element at each time point during a period in which the current value of the current supplied to the light source element is decreased to the fifth current value from when the current is started to be supplied to the light source element with the eighth current value, the third information is determined based on a change in the luminous intensity of the light source element when the current is started to be supplied to the light source element with the eighth current value, and the current value of the current supplied to the light source element is decreased to the fifth current value according to the fourth information, the eighth current value and the fourth information are determined based on a change in the luminous intensity of the light source element when the current value of the current supplied to the light source element is changed from the first current value to the fifth current value in a state where the light source element that emits light at the first luminous intensity with the current supplied with the first current value emits light at the second luminous intensity.

11. The driving method of a light source element according to any one of claims 6 to 8, wherein the predetermined seventh current value is a current value at the time when the current is started to be supplied to the light source element, which is determined based on a change in the luminous intensity of the light source element when the current is started to be supplied to the light source element with the fifth current value in a case where the temperature of the light source element is lower than a second temperature threshold value, The third information is determined based on a change in the light emission amount of the light source element when current is supplied to the light source element starting with the fifth current value in a case where the temperature of the light source element is lower than the second temperature threshold.

12. The light source element driving method according to any one of claims 6 to 8, wherein The predetermined seventh current value is a current value at the start of the supply of current to the light source element, determined based on a change in the light emission amount of the light source element when current is supplied to the light source element starting with a ninth current value lower than the fifth current value in a case where the temperature of the light source element is lower than the second temperature threshold, and the current value of the current supplied to the light source element is increased to the fifth current value according to fifth information that determines the current value of the current supplied to the light source element at each time point during the period in which current is supplied to the light source element starting with the ninth current value and the current value of the current supplied to the light source element is increased to the fifth current value, The third information is determined based on a change in the light emission amount of the light source element when current is supplied to the light source element starting with the ninth current value in a case where the temperature of the light source element is lower than the second temperature threshold, and the current value of the current supplied to the light source element is increased to the fifth current value according to the fifth information, The ninth current value and the fifth information are determined based on a change in the light emission amount of the light source element when current is supplied to the light source element starting with the fifth current value in a case where the temperature of the light source element is lower than the second temperature threshold.

13. The light source element driving method according to any one of claims 1 to 12, wherein The light source element is an LED element.

14. The light source element driving method according to any one of claims 1 to 13, wherein The peak wavelength of the light emitted from the light source element is in the range of 360 to 370 nm.

15. The light source element driving method according to any one of claims 1 to 13, wherein The peak wavelength of the light emitted from the light source element is in the range of 380 to 390 nm.

16. The light source element driving method according to any one of claims 1 to 13, wherein The peak wavelength of the light emitted from the light source element is in the range of 400 to 410 nm.

17. A light source unit, characterized by provided with: a plurality of light source elements arranged two-dimensionally on the surface of a fixed object, each emitting light at a first light emission amount when supplied with current at a first current value; a detection section that detects the temperature of the plurality of light source elements; and a control section that controls the value of the current supplied to the plurality of light source elements, the control section supplies current to the plurality of light source elements starting with a second current value lower than the first current value, and increases the current value of the current supplied to the plurality of light source elements from the second current value to the first current value, ​ The current value of the current supplied to the plurality of light source elements at the first time point is a corrected current value obtained by correcting a current value of the current supplied to the plurality of light source elements at the first time point, which is acquired based on first information, based on the temperature of the plurality of light source elements, the first information determining the current value of the current supplied to the plurality of light source elements at each time point during a period in which the current is supplied to the plurality of light source elements starting from a predetermined third current value and the current value of the current supplied to the plurality of light source elements is increased to the first current value.

18. The light source unit according to claim 17, wherein the control section corrects the predetermined third current value based on the temperature of the plurality of light source elements at the time when the current is started to be supplied to the plurality of light source elements, thereby calculating the second current value, the control section corrects the current value acquired based on the first information based on the temperature of the plurality of light source elements at the first time point detected by the detection section, thereby calculating the current value of the current supplied to the plurality of light source elements at the first time point.

19. The light source unit according to claim 18, wherein the control section corrects the current value acquired based on the first information based on the temperature of the plurality of light source elements at the first time point and a relationship between an elapsed time from the time when the current is started to be supplied to the plurality of light source elements and the temperature of the plurality of light source elements, which is acquired in advance, thereby calculating the current value of the current supplied to the plurality of light source elements at the first time point.

20. The light source unit according to any one of claims 17 to 19, wherein the predetermined third current value is a current value at the time when the current is started to be supplied to the plurality of light source elements, which is determined based on a change in the light emission amount of the plurality of light source elements at the time when the current is started to be supplied to the plurality of light source elements at the first current value in a case where the temperature of the plurality of light source elements is lower than a first temperature threshold value, the first information is determined based on a change in the light emission amount of the plurality of light source elements at the time when the current is started to be supplied to the plurality of light source elements at the first current value in a case where the temperature of the plurality of light source elements is lower than the first temperature threshold value.

21. The light source unit according to any one of claims 17 to 19, wherein The predetermined third current value is a current value at the start of supplying current to the plurality of light source elements, determined based on a change in the light emission amount of the plurality of light source elements when current is supplied to the plurality of light source elements at a fourth current value lower than the first current value in a case where the temperature of the plurality of light source elements is lower than the first temperature threshold, and the current value of the current supplied to the plurality of light source elements is increased to the first current value according to second information that determines the current value of the current supplied to the plurality of light source elements at each time point during a period in which current is supplied to the plurality of light source elements at the fourth current value and the current value of the current supplied to the plurality of light source elements is increased to the first current value, The first information is determined based on a change in the light emission amount of the plurality of light source elements when current is supplied to the plurality of light source elements at the fourth current value in a case where the temperature of the plurality of light source elements is lower than the first temperature threshold, and the current value of the current supplied to the plurality of light source elements is increased to the first current value according to the second information, The fourth current value and the second information are determined based on a change in the light emission amount of the plurality of light source elements when current is supplied to the plurality of light source elements at the first current value in a case where the temperature of the plurality of light source elements is lower than the first temperature threshold.

22. A light source unit, characterized by provided with: a plurality of light source elements arranged two-dimensionally on a surface of a fixed object, which respectively emit light at a first light emission amount when supplied with current at a first current value, and which respectively emit light at a second light emission amount lower than the first light emission amount when supplied with current at a fifth current value lower than the first current value; a detection unit that detects the temperature of the plurality of light source elements; and a control unit that controls the value of the current supplied to the plurality of light source elements, the control unit starts supplying current to the plurality of light source elements at a sixth current value higher than the fifth current value when the plurality of light source elements are in a state of emitting light at the second light emission amount, and decreases the current value of the current supplied to the plurality of light source elements from the sixth current value to the fifth current value, the current value of the current supplied to the plurality of light source elements at a first time point is a corrected current value obtained by acquiring the current value of the current supplied to the plurality of light source elements at the first time point according to third information that determines the current value of the current supplied to the plurality of light source elements at each time point during a period in which current is supplied to the plurality of light source elements at a predetermined seventh current value and the current value of the current supplied to the plurality of light source elements is changed to the fifth current value, and correcting the acquired current value based on the temperature of the plurality of light source elements.

23. The light source unit according to claim 22, wherein the control unit corrects the predetermined seventh current value based on the temperature of the plurality of light source elements at the start of supplying current to the plurality of light source elements, thereby calculating the sixth current value, ​ The control section corrects the current value obtained from the third information based on the temperature of the plurality of light source elements at the first time point, thereby calculating the current value of the current supplied to the plurality of light source elements at the first time point.

24. The light source unit according to claim 23, wherein The control section corrects the current value obtained from the third information based on the temperature of the plurality of light source elements at the first time point and a relationship between an elapsed time from the start of the supply of the current to the plurality of light source elements and the temperature of the plurality of light source elements, which is obtained in advance, thereby calculating the current value of the current supplied to the plurality of light source elements at the first time point.

25. The light source unit according to any one of claims 22 to 24, wherein The predetermined seventh current value is a current value at the start of the supply of the current to the plurality of light source elements, which is determined based on a change in the luminous quantity of the plurality of light source elements when the current value of the current supplied to the plurality of light source elements is changed from the first current value to the fifth current value in a state where the plurality of light source elements that emit light at the first luminous quantity with the current supplied with the first current value emit light at the second luminous quantity, The third information is determined based on a change in the luminous quantity of the plurality of light source elements when the current value of the current supplied to the plurality of light source elements is changed from the first current value to the fifth current value.

26. The light source unit according to any one of claims 22 to 24, wherein The predetermined seventh current value is a current value at the start of the supply of the current to the plurality of light source elements, which is determined based on a change in the luminous quantity of the plurality of light source elements when the current is supplied to the plurality of light source elements at an eighth current value higher than the fifth current value and the current value of the current supplied to the plurality of light source elements is decreased to the fifth current value in accordance with fourth information that determines the current value supplied to the plurality of light source elements at each time point during a period in which the current is supplied to the plurality of light source elements at the eighth current value and the current value of the current supplied to the plurality of light source elements is decreased to the fifth current value, The third information is determined based on a change in the luminous quantity of the plurality of light source elements when the current is supplied to the plurality of light source elements at the eighth current value and the current value of the current supplied to the plurality of light source elements is decreased to the fifth current value in accordance with the fourth information, The 8th current value and the 4th information are determined based on a change in the light emission amount of the plurality of light source elements when the current value of the current supplied to the plurality of light source elements is changed from the 1st current value to a 5th current value in a state where the plurality of light source elements that emit light at the 1st light emission amount with the current supplied with the 1st current value emit light at a 2nd light emission amount.

27. The light source unit according to any one of claims 22 to 24, wherein The predetermined 7th current value is a current value at the start of the supply of the current to the plurality of light source elements, which is determined based on a change in the light emission amount of the plurality of light source elements when the supply of the current to the plurality of light source elements is started at the 5th current value in a case where the temperature of the plurality of light source elements is lower than a 2nd temperature threshold, The 3rd information is determined based on a change in the light emission amount of the plurality of light source elements when the supply of the current to the plurality of light source elements is started at the 5th current value in a case where the temperature of the plurality of light source elements is lower than the 2nd temperature threshold.

28. The light source unit according to any one of claims 22 to 24, wherein The predetermined 7th current value is a current value at the start of the supply of the current to the plurality of light source elements, which is determined based on a change in the light emission amount of the plurality of light source elements when the supply of the current to the plurality of light source elements is started at a 9th current value lower than the 5th current value and the current value of the current supplied to the plurality of light source elements is increased to the 5th current value in accordance with 5th information that determines the current value of the current supplied to the plurality of light source elements at each time point during a period in which the supply of the current to the plurality of light source elements is started at the 9th current value and the current value of the current supplied to the plurality of light source elements is increased to the 5th current value in a case where the temperature of the plurality of light source elements is lower than a 2nd temperature threshold, The 3rd information is determined based on a change in the light emission amount of the plurality of light source elements when the supply of the current to the plurality of light source elements is started at the 9th current value and the current value of the current supplied to the plurality of light source elements is increased to the 5th current value in accordance with the 5th information in a case where the temperature of the plurality of light source elements is lower than the 2nd temperature threshold, The 9th current value and the 5th information are determined based on a change in the light emission amount of the plurality of light source elements when the supply of the current to the plurality of light source elements is started at the 5th current value in a case where the temperature of the plurality of light source elements is lower than the 2nd temperature threshold.

29. The light source unit according to any one of claims 17 to 28, wherein The plurality of light source elements are a plurality of LED elements.

30. The light source unit according to any one of claims 17 to 28, wherein The peak wavelength of the light emitted from the plurality of light source elements is in a range of 360 to 370 nm.

31. The light source unit according to any one of claims 17 to 28, wherein The peak wavelength of light emitted from the plurality of light source elements is in the range of 380 to 390 nm.

32. The light source unit according to any one of claims 17 to 28, wherein The peak wavelength of light emitted from the plurality of light source elements is in the range of 400 to 410 nm.

33. The light source unit according to any one of claims 17 to 32, wherein The light source unit is a light source unit for an exposure apparatus.

34. A lighting unit characterized by Further comprising: The light source unit according to any one of claims 17 to 33; and An illumination optical system that guides light emitted from the light source unit to an irradiated body.

35. A lighting unit characterized by Further comprising: A plurality of light source units according to any one of claims 17 to 33; and An illumination optical system that includes a synthesis optical element that synthesizes light emitted from a plurality of the light source units, and guides synthesized light emitted from the synthesis optical element to an irradiated body.

36. An exposure apparatus characterized by comprising: Further comprising: The illumination unit according to claim 34 or 35; and A projection optical system that projects a pattern image of a mask illuminated by the illumination unit onto a photosensitive substrate.

37. The exposure apparatus according to claim 36, wherein At least one side of the photosensitive substrate has a length or a diagonal length of 500 mm or more.

38. An exposure method comprising: The exposure method using the exposure apparatus according to claim 36 or 37 includes: Illuminating a mask with the illumination unit; and Projecting a pattern image of the mask onto a photosensitive substrate using the projection optical system.

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