Excimer lamp device

Abstract

Provided are an excimer lamp and an excimer lamp device that have uniform illuminance on an irradiated surface in the longitudinal direction of the excimer lamp, even if the excimer lamp is elongated.　This excimer lamp comprises: a discharge container that has a substantially square shape, the cross-sectional shape of which is flat, and that has a pair of flat walls extending in the longitudinal direction, and a pair of side walls connecting the flat walls; a pair of external electrodes disposed facing each other on the respective outer surfaces of the pair of flat walls; a first internal electrode that is disposed inside the discharge container so as to extend toward the inner surface of the pair of flat walls; and a second internal electrode disposed inside the discharge container at a position separated in the longitudinal direction from the first internal electrode, so as to extend toward the inner surface of the pair of flat walls, wherein the first internal electrode and the second internal electrode are each provided at a position between the ends of the external electrodes and the center in the longitudinal direction.

Description

Technical Field

[0001] The present invention relates to an excimer lamp and an excimer lamp device.

Background Art

[0002] Recently, an excimer lamp (hereinafter also simply referred to as a lamp) has been used for the purpose of irradiating ultraviolet rays onto the surface of a film or building materials (including infrastructure members) to modify the surface. Along with this, various irradiation light amounts are required according to the application or process.

[0003] Conventionally, an excimer lamp has been used to adjust the irradiation light amount by dimming, and frequency dimming is widely used as the dimming method. Frequency dimming is a method of adjusting the pulse emission number of the lamp and controlling the output by changing the frequency of the applied power. In this method, since the input is controlled to light up while fixing the applied voltage at an optimal value, there is an advantage that the starting performance can be maintained well even when the input is lowered. However, if the dimming is lowered too much, partial lighting and discharge cannot be maintained, so there is a problem that the dimming range is limited. In addition, recently, the excimer lamp has been made longer, and a long lamp exceeding 3 m has been developed. However, the problem of frequency dimming becomes more prominent as the lamp becomes longer.

[0004] Another dimming method is a means called Duty dimming. Duty dimming is a technique of generating a light emission On period / Off period by repeating the Duty-On period / Off period at a frequency at which stable discharge (the lamp lights up) occurs, and adjusting the output per unit time. Different from frequency dimming, Duty dimming can be dimmed to a considerably low light amount because it operates at a stable frequency.

[0005] Another dimming method is voltage dimming. Voltage dimming is a technique that adjusts the power to the lamp by increasing or decreasing the voltage at a frequency at which a stable discharge occurs (the lamp lights up). Like duty cycle dimming, voltage dimming operates at a stable frequency, so it can dim to very low light levels.

[0006] However, in duty-shift dimming, the lamp is started each time the duty cycle is turned on, and the lamp's starting characteristics have a significant impact. Typically, excimer lamps have a starting auxiliary electrode at one end in the longitudinal direction, from which the discharge begins (for example, Patent Document 1). If the off time in one cycle is increased to reduce the amount of light emitted, a time difference occurs between the start of the discharge at the starting auxiliary electrode and the propagation of the discharge to the other end. In duty-shift dimming, the lamp is started many times within a unit time, so a difference in light intensity occurs depending on the ON / OFF cycle and the starting delay, resulting in uneven illumination along the length of the lamp. Furthermore, even in duty-shift dimming, as the length of the lamp increases, the starting delay increases, and the uneven illumination becomes even more pronounced. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 5376410 [Overview of the project] [Problems that the invention aims to solve]

[0008] In view of the above problems, the present invention aims to provide an excimer lamp and an excimer lamp apparatus that, even with a long excimer lamp, provides uniform illuminance on the irradiation surface in the longitudinal direction of the excimer lamp. [Means for solving the problem]

[0009] The excimer lamp according to the present invention has a discharge vessel having a flattened, substantially rectangular cross-sectional shape, a pair of flat walls extending in the longitudinal direction, and a pair of side walls connecting these flat walls. A pair of external electrodes are arranged facing each other on the outer surfaces of the pair of flat walls, A first internal electrode is disposed inside the discharge vessel so as to extend toward the inner surface of the pair of flat walls, The discharge container comprises a second internal electrode positioned at a longitudinal distance from the first internal electrode, and extending within the discharge container toward the inner surface of the pair of flat walls, The first internal electrode and the second internal electrode are respectively positioned in the longitudinal direction between the end and the center of the external electrode.

[0010] With this configuration, by positioning the first and second internal electrodes in the longitudinal direction between the end and the center of the external electrode, discharge starts from the respective positions of the first and second internal electrodes, thus shortening the time it takes for the discharge to diffuse throughout the entire discharge chamber. As a result, even when, for example, duty cycle dimming is performed on a long excimer lamp, the illuminance on the irradiation surface in the longitudinal direction of the excimer lamp can be made uniform.

[0011] In the excimer lamp according to the present invention, the first internal electrode may be arranged to connect the inner surfaces of the pair of flat walls, and the second internal electrode may be arranged to connect the inner surfaces of the pair of flat walls.

[0012] With this configuration, the first internal electrode and the second internal electrode can be easily installed inside the discharge vessel.

[0013] In the excimer lamp according to the present invention, the first internal electrode and the second internal electrode may be arranged along the inner surface of the side wall.

[0014] With this configuration, the first internal electrode and the second internal electrode can be easily installed inside the discharge vessel.

[0015] In the excimer lamp according to the present invention, at least a portion of the first internal electrode or the second internal electrode may be configured to face at least one of the pair of external electrodes across the flat wall.

[0016] The first and second internal electrodes face each other across a flat wall from a pair of external electrodes, ensuring that discharge can be reliably initiated near the first and second internal electrodes.

[0017] In the excimer lamp according to the present invention, the first internal electrode and the second internal electrode may be configured such that they do not face either of the pair of external electrodes across the flat wall.

[0018] Even if the first and second internal electrodes do not face both of the pair of external electrodes across a flat wall, it is still possible to initiate discharge from the vicinity of the first and second internal electrodes.

[0019] In the excimer lamp according to the present invention, a third internal electrode may be further provided at a position between the first internal electrode and the second internal electrode in the longitudinal direction, so as to extend into the discharge vessel toward the inner surface of the pair of flat walls.

[0020] This configuration allows for a shorter time for the discharge to diffuse throughout the entire discharge chamber.

[0021] In the excimer lamp according to the present invention, the third internal electrode may be configured to connect the inner surfaces of the pair of flat walls.

[0022] With this configuration, the third internal electrode can be easily installed inside the discharge vessel.

[0023] In the excimer lamp according to the present invention, the first internal electrode and the second internal electrode may be arranged at the positions of the ends of the external electrode in the longitudinal direction, respectively.

[0024] According to this configuration, since the discharges starting at the positions of both ends in the longitudinal direction of the external electrode propagate toward the center respectively, the time until the discharge diffuses over the entire discharge vessel can be shortened.

[0025] In the excimer lamp according to the present invention, n internal electrodes including the first internal electrode and the second internal electrode may be arranged at the central positions of the regions obtained by equally dividing the external electrode into n parts in the longitudinal direction.

[0026] According to this configuration, since the discharges started by the n internal electrodes diffuse in the respective regions of the equally divided discharge spaces, the time until the discharge diffuses over the entire discharge vessel can be made shorter.

[0027] Further, in the excimer lamp device according to the present invention, in the excimer lamp device including any one of the above excimer lamps and a lighting device for lighting the excimer lamp, the lighting device has a dimming means for dimming the excimer lamp.

[0028] According to this configuration, even in the case of a long excimer lamp, the illuminance on the irradiation surface in the longitudinal direction of the excimer lamp becomes uniform.

[0029] In the excimer lamp device according to the present invention, the dimming means may have a duty control unit that changes the time ratio of the on period and the off period of the excimer lamp.

[0030] In the excimer lamp device according to the present invention, the dimming means may have a frequency control unit that changes the lighting frequency of the excimer lamp.

[0031] In the excimer lamp device according to the present invention, the dimming means may also be configured to include a voltage control unit that changes the ignition voltage of the excimer lamp. [Brief explanation of the drawing]

[0032] [Figure 1] Perspective view of an excimer lamp according to the first embodiment [Figure 2A] Plan view of the excimer lamp according to the first embodiment [Figure 2B] Front view of the excimer lamp according to the first embodiment [Figure 2C] Bottom view of the excimer lamp according to the first embodiment [Figure 3] Figure 2B shows a cross-sectional view of the excimer lamp (AA cross-section). [Figure 4] BB cross-section of the excimer lamp shown in Figure 2B. [Figure 5A] This figure shows an example of the voltage waveform applied to a lamp during duty cycle dimming. [Figure 5B] Graph showing experimental results using duty-cycle dimming. [Figure 6A] This figure shows an example of the voltage waveform applied to a lamp during frequency dimming. [Figure 6B] Graph showing experimental results using frequency dimming. [Figure 7A] This figure shows an example of the voltage waveform applied to a lamp during voltage dimming. [Figure 7B] Graph showing experimental results using voltage dimming. [Figure 8A] Plan view of the excimer lamp according to the second embodiment [Figure 8B] Front view of the excimer lamp according to the second embodiment [Figure 8C] Bottom view of the excimer lamp according to the second embodiment [Figure 9A] Plan view of the excimer lamp according to the third embodiment [Figure 9B] Front view of the excimer lamp according to the third embodiment [Figure 9C] Bottom view of the excimer lamp according to the third embodiment [Figure 10] Cross-sectional view of the excimer lamp shown in Figure 9B. [Figure 11A] Plan view of the excimer lamp according to the fourth embodiment [Figure 11B] Front view of the excimer lamp according to the fourth embodiment [Figure 11C] Bottom view of the excimer lamp according to the fourth embodiment [Figure 12] DD cross-sectional view of the excimer lamp shown in Figure 11B [Figure 13A] Front view of the excimer lamp according to the fifth embodiment [Figure 13B] Front view of the excimer lamp according to the fifth embodiment [Figure 13C] Bottom view of the excimer lamp according to the fifth embodiment [Figure 14A] Front view of the excimer lamp according to the sixth embodiment [Figure 14B] Front view of the excimer lamp according to the sixth embodiment [Figure 14C] Bottom view of the excimer lamp according to the sixth embodiment [Figure 15] EE cross-section of the excimer lamp shown in Figure 14B. [Figure 16] Plan view of an excimer lamp according to another embodiment [Figure 17] Plan view of an excimer lamp according to another embodiment [Figure 18] Cross-sectional view of an excimer lamp according to another embodiment [Modes for carrying out the invention]

[0033] Embodiments of the excimer lamp and excimer lamp apparatus according to the present invention will be described with reference to the drawings. Note that the following drawings are schematic illustrations, and the dimensional ratios shown in the drawings do not necessarily correspond to the actual dimensional ratios, nor do the dimensional ratios necessarily correspond between the drawings.

[0034] [First Embodiment] Figure 1 is a perspective view of the excimer lamp according to the first embodiment, and Figures 2A to 2C are views of the excimer lamp shown in Figure 1 from three sides, with Figure 2A being a plan view, Figure 2B a front view, and Figure 2C a bottom view. In the following description, as shown in Figure 1, the direction in which the excimer lamp 1 extends (longitudinal direction) will be the X direction, the direction in which the external electrodes 3 and 4 of the excimer lamp 1 (described in detail later) face each other will be the Y direction, and the direction perpendicular to the X and Y directions will be the Z direction. When expressing directions, if positive and negative directions are to be distinguished, they will be written with positive and negative signs, such as "+X direction" and "-X direction," and if the direction is to be expressed without distinguishing between positive and negative directions, it will simply be written as "X direction."

[0035] Figure 3 is a cross-sectional view AA of the excimer lamp 1 shown in Figure 2B. The excimer lamp 1 includes a discharge container 2. The discharge container 2 is made of a dielectric material (e.g., quartz glass) that is transparent to ultraviolet light. The discharge container 2 has a flattened, approximately rectangular cross-section and has a pair of flat walls 21, 22 and a pair of side walls 23, 23. The discharge container 2 is elongated in the X direction and has a length of 600 mm or more. In the case of a discharge container 2 with a length of 600 mm or more, the uniformity of illumination tends to be poor due to the aforementioned start-up delay.

[0036] The discharge container 2 contains a discharge gas that forms excimer molecules through discharge. In this embodiment, the discharge gas contains xenon (Xe). A more detailed example of the discharge gas is a gas in which xenon (Xe) and neon (Ne) are mixed in a predetermined ratio, and which may also contain trace amounts of oxygen and hydrogen.

[0037] A pair of opposing external electrodes 3 and 4 are provided on the outer surfaces of a pair of flat walls 21 and 22 in the discharge container 2. The external electrode 3 provided on the outer surface of one flat wall 21 is, for example, a high-voltage supply electrode (high-voltage side electrode), and the external electrode 4 provided on the outer surface of the other flat wall 22 is, for example, a ground electrode (low-voltage side electrode). At least one of the external electrodes 3 and 4 is a light-transmitting electrode. In this embodiment, both the external electrodes 3 and 4 are mesh-like, and light passes through the gaps in the mesh.

[0038] A power supply unit 31 extending along the X direction is provided at the -X direction end 3a of the external electrode 3. Similarly, a power supply unit 41 extending along the X direction is provided at the -X direction end 4a of the external electrode 4. The power supply units 31 and 41 are connected to a lighting device 9 (see Figure 2B).

[0039] Although the pair of external electrodes 3 and 4 shown are both light-transmitting electrodes, the design is not limited to this. For example, one of the external electrodes 3 or 4 may be formed in a solid shape. Furthermore, the external electrodes 3 and 4 only need to have a shape that allows light to pass through; for example, they may be electrodes with slits.

[0040] Furthermore, although the external electrodes 3 and 4 in this embodiment are both made of the same material and formed by printing them on the outer surface of the discharge container 2 by clean printing and firing, they may be made of different materials and formed by different methods. In addition, the material used to form the external electrodes 3 and 4 may be, for example, gold or platinum, or alloys containing these.

[0041] Figure 4 is a cross-sectional view of the excimer lamp 1 shown in Figure 2B. Inside the discharge container 2, a first internal electrode 5 and a second internal electrode 6 are provided at positions spaced apart in the longitudinal direction. The first internal electrode 5 and the second internal electrode 6 are arranged to extend into the inner surfaces of a pair of flat walls 21 and 22 inside the discharge container 2. In this embodiment, the first internal electrode 5 and the second internal electrode 6 are arranged to connect the inner surfaces of the pair of flat walls 21 and 22 along the inner surface of the side wall 23 of the discharge container 2.

[0042] The material used to form the internal electrodes 5 and 6 is, for example, platinum. The internal electrodes 5 and 6 are formed by applying a paste-like material to the inner surface of the discharge chamber 2 and then firing it. The width of the internal electrodes 5 and 6 in the X direction is, for example, 1 to 5 mm.

[0043] The first internal electrode 5 and the second internal electrode 6 are positioned in the longitudinal direction between the ends and the center of the external electrodes 3 and 4, respectively. In this embodiment, the first internal electrode 5 and the second internal electrode 6 are positioned at the ends of the external electrodes 3 and 4, respectively, in the longitudinal direction. In this specification, the "ends" of the external electrode 3 in the longitudinal direction include the area within ±30 mm in the ±X direction from the X-direction ends 3a and 3b of the external electrode 3. Similarly, in this specification, the "ends" of the external electrode 4 in the longitudinal direction include the area within ±30 mm in the ±X direction from the X-direction ends 4a and 4b of the external electrode 4.

[0044] In this embodiment, as shown in Figures 2A to C, the first internal electrode 5 is positioned slightly inward (towards the +X direction) from the -X ends 3a and 4a of the external electrodes 3 and 4. Similarly, the second internal electrode 6 is positioned slightly inward (towards the -X direction) from the +X ends 3b and 4b of the external electrodes 3 and 4. However, the distance in the X direction between the first internal electrode 5 and the -X ends 3a and 4a of the external electrodes 3 and 4 is within 30 mm, and the first internal electrode 5 can be said to be positioned at the end of the external electrodes 3 and 4 in the longitudinal direction as described above. Similarly, the distance in the X direction between the second internal electrode 6 and the +X ends 3b and 4b of the external electrodes 3 and 4 is within 30 mm, and the second internal electrode 6 can be said to be positioned at the end of the external electrodes 3 and 4 in the longitudinal direction as described above.

[0045] Generally, when a lamp is started, a decrease in dielectric breakdown voltage occurs near the internal electrodes, and discharge begins from the vicinity of the internal electrodes. Subsequently, the discharge diffuses within the discharge container 2 in a chain reaction, so a delay in the start-up time occurs at positions far from the internal electrodes, albeit for a very short time. The delay in the start-up time is approximately proportional to the distance from the internal electrodes. Therefore, in an excimer lamp 1 having a long discharge container 2, if only one internal electrode is provided at one end in the longitudinal direction of the external electrodes, the problem of the delay in the start-up time becomes significant. As in the present invention, by arranging the first internal electrode 5 and the second internal electrode 6, respectively, between the ends and the center of the external electrodes 3 and 4 in the longitudinal direction, discharge begins from the respective positions of the first internal electrode 5 and the second internal electrode 6, thus shortening the time it takes for the discharge to diffuse throughout the entire discharge container 2. As a result, even when performing duty dimming, such as repeatedly turning the excimer lamp 1 on and off, the illuminance on the irradiation surface in the longitudinal direction of the excimer lamp 1 can be made uniform.

[0046] Preferably, at least a portion of the first internal electrode 5 or the second internal electrode 6 faces at least one of the pair of external electrodes 3 and 4 across the flat walls 21 and 22. By having the internal electrodes 5 and 6 face the external electrodes 3 and 4 across the flat walls 21 and 22, discharge can be reliably initiated from the vicinity of the first internal electrode 5 and the second internal electrode 6.

[0047] In this embodiment, as shown in Figure 4, both ends 6a and 6b of the second internal electrode 6, which extends along the inner surface of the flat walls 21 and 22, face each other with respect to the pair of external electrodes 3 and 4 and the flat walls 21 and 22, respectively. Similarly, as shown in Figures 2A to C, both ends 5a and 5b of the first internal electrode 5, which extends along the inner surface of the flat walls 21 and 22, face each other with respect to the pair of external electrodes 3 and 4 and the flat walls 21 and 22, respectively.

[0048] The excimer lamp device comprises an excimer lamp 1 and a lighting device 9 for lighting the excimer lamp 1. The lighting device 9 has a dimming means for dimming the excimer lamp 1. Methods for dimming the excimer lamp 1 include duty dimming and frequency dimming. The dimming means may have a duty control unit that changes the time ratio of the On period to the Off period of the excimer lamp 1. Alternatively, the dimming means may have a frequency control unit that changes the lighting frequency of the excimer lamp 1.

[0049] Duty-shift dimming is a method of controlling the input to a lamp by keeping the voltage and frequency constant and intermittently supplying power (creating on-off periods). Figure 5A shows an example of the voltage waveform applied to a lamp in duty-shift dimming. Note that Figure 5A is a diagram to explain the duty cycle, and the applied voltage value on the vertical axis and the time value on the horizontal axis are omitted. The duty cycle (%) is calculated using the following formula. Duty ratio (%)=On time / (On time + Off time)×100

[0050] Figure 5B is a graph showing the experimental results of duty cycle dimming. In Figure 5B, the solid line represents illuminance, and the dashed line represents the uniformity of illuminance. The excimer lamp 1 shown in Figures 2A-C is designated as Example 1. Comparative Example 1 is a lamp in which only internal electrode 6 is provided among the internal electrodes 5 and 6 of the excimer lamp 1 shown in Figures 2A-C. As shown in Figure 5B, in Comparative Example 1, the illuminance can be adjusted (dimmed) by adjusting the duty cycle, but when the duty cycle is set to 40% or less, the uniformity exceeds the practical line (shown by the dashed line) and the illuminance becomes uneven. On the other hand, in Example 1, dimming can be performed over a wide range of duty cycles from 10% to 100% without the uniformity exceeding the practical line.

[0051] Frequency dimming is a method of controlling the input to a lamp by increasing or decreasing the frequency of the applied power and adjusting the number of pulses per unit time. Figure 6A shows an example of the voltage waveform applied to a lamp in frequency dimming. Note that Figure 6A shows an example of frequency increase or decrease, and the applied voltage value on the vertical axis and the time value on the horizontal axis are omitted.

[0052] Figure 6B is a graph showing the experimental results of frequency dimming. In Figure 6B, the solid line represents illuminance, and the dashed line represents uniformity. Excimer lamp 1 shown in Figures 2A-C is designated as Example 2. Comparative Example 2 is a lamp in which only internal electrode 6 is provided among the internal electrodes 5 and 6 of excimer lamp 1 shown in Figures 2A-C. As shown in Figure 6B, in Comparative Example 2, illuminance can be adjusted (dimmed) by adjusting the power according to the frequency, but when the power is set to 50% or less, the uniformity exceeds the practical line (shown by the dashed line) and the illuminance becomes uneven. On the other hand, in Example 2, dimming can be performed over a wide range of power from 40% to 100% without the uniformity exceeding the practical line.

[0053] Voltage dimming is a method of controlling the input to a lamp by increasing or decreasing the applied voltage. While frequency dimming adjusts the number of pulses, voltage dimming adjusts the pulse intensity. Figure 7A shows an example of the voltage waveform applied to a lamp in voltage dimming. Note that Figure 7A shows an example of voltage increase or decrease, and the applied voltage value on the vertical axis and the time value on the horizontal axis are omitted.

[0054] Figure 7B is a graph showing the experimental results of voltage dimming. In Figure 7B, the solid line represents illuminance, and the dashed line represents uniformity. Excimer lamp 1 shown in Figures 2A-C is designated as Example 3. Comparative Example 3 is a lamp in which only internal electrode 6 is provided among the internal electrodes 5 and 6 of excimer lamp 1 shown in Figures 2A-C. As shown in Figure 7B, in Comparative Example 3, illuminance can be adjusted (dimmed) by adjusting the power with voltage, but when the power is set to 40% or less, the uniformity exceeds the practical line (shown by the dashed line) and the illuminance becomes uneven. On the other hand, in Example 3, dimming can be performed over a wide range of power from 30% to 100% without the uniformity exceeding the practical line.

[0055] [Second Embodiment] Figures 8A to 8C show the excimer lamp according to the second embodiment viewed from three sides, with Figure 8A being a top view, Figure 8B a front view, and Figure 8C a bottom view.

[0056] In the second embodiment, as shown in Figures 8A-C, the first internal electrode 5 is positioned slightly outside (towards the -X) of the -X ends 3a and 4a of the external electrodes 3 and 4. Similarly, the second internal electrode 6 is positioned slightly outside (towards the +X) of the +X ends 3b and 4b of the external electrodes 3 and 4. However, the distance in the X direction between the first internal electrode 5 and the -X ends 3a and 4a of the external electrodes 3 and 4 is within 30 mm, so it can be said that the first internal electrode 5 is positioned at the end of the external electrodes 3 and 4 in the longitudinal direction. Similarly, the distance in the X direction between the second internal electrode 6 and the +X ends 3b and 4b of the external electrodes 3 and 4 is within 30 mm, so it can be said that the second internal electrode 6 is positioned at the end of the external electrodes 3 and 4 in the longitudinal direction.

[0057] In the present invention, the first internal electrode 5 and the second internal electrode 6 may be configured such that they do not face either of the pair of external electrodes 3 and 4 across the flat walls 21 and 22. In the second embodiment, the first internal electrode 5 is positioned so as not to overlap with the pair of external electrodes 3 and 4 in the X direction, and both ends 5a and 5b of the first internal electrode 5, which extend along the inner surface of the flat walls 21 and 22, do not face the pair of external electrodes 3 and 4 across the flat walls 21 and 22, respectively. Similarly, the second internal electrode 6 is positioned so as not to overlap with the pair of external electrodes 3 and 4 in the X direction, and both ends 6a and 6b of the second internal electrode 6, which extend along the inner surface of the flat walls 21 and 22, do not face the pair of external electrodes 3 and 4 across the flat walls 21 and 22, respectively.

[0058] [Third Embodiment] Figures 9A to 9C show the excimer lamp according to the third embodiment viewed from three sides, with Figure 9A being a top view, Figure 9B a front view, and Figure 9C a bottom view. Figure 10 is a cross-sectional view of the CC of the excimer lamp shown in Figure 9B.

[0059] In the third embodiment, as shown in Figures 9A-C, the first internal electrode 5 is positioned slightly inward (towards the +X) from the -X ends 3a and 4a of the external electrodes 3 and 4. Similarly, the second internal electrode 6 is positioned slightly inward (towards the -X) from the +X ends 3b and 4b of the external electrodes 3 and 4. However, the distance in the X direction between the first internal electrode 5 and the -X ends 3a and 4a of the external electrodes 3 and 4 is within 30 mm, so it can be said that the first internal electrode 5 is positioned at the end of the external electrodes 3 and 4 in the longitudinal direction. Similarly, the distance in the X direction between the second internal electrode 6 and the +X ends 3b and 4b of the external electrodes 3 and 4 is within 30 mm, so it can be said that the second internal electrode 6 is positioned at the end of the external electrodes 3 and 4 in the longitudinal direction.

[0060] The first internal electrode 5 and the second internal electrode 6 may be configured so that they do not face either of the pair of external electrodes 3 and 4 across the flat walls 21 and 22. In the third embodiment, the first internal electrode 5 and the second internal electrode 6 are positioned to overlap with the pair of external electrodes 3 and 4 in the X direction, but the first internal electrode 5 and the second internal electrode 6 do not face either of the pair of external electrodes 3 and 4 across the flat walls 21 and 22. Specifically, as shown in Figure 10, both ends 6a and 6b of the second internal electrode 6 extending along the inner surface of the flat walls 21 and 22 are shorter than in the first embodiment shown in Figure 4, and they do not face either of the pair of external electrodes 3 and 4 across the flat walls 21 and 22. Similarly, as shown in Figures 9A to C, both ends 5a and 5b of the first internal electrode 5 extending along the inner surface of the flat walls 21 and 22 are shorter than in the first embodiment shown in Figures 2A to C, and they do not face either of the pair of external electrodes 3 and 4 across the flat walls 21 and 22. The distance d between the ends 6a, 6b of the internal electrode 6 and the external electrodes 3, 4 (see Figure 10) is preferably 2 mm or less. Here, distance d is the shortest distance in the Z direction between the ends 6a, 6b of the internal electrode 6 and the external electrodes 3, 4. The same applies to the distance d between the ends 5a, 5b of the internal electrode 5 and the external electrodes 3, 4.

[0061] When a voltage is applied to the high-voltage external electrode 3, the glass of the discharge container 2 becomes dielectric, and an electric charge (potential) is generated on the inner surface of the discharge container 2. If the external electrode 3 and the internal electrodes 5 and 6 are not facing each other across the flat wall 21, a large resistance is generated between the area where the potential is generated and the internal electrodes 5 and 6. Similarly, if the low-voltage external electrode 4 and the internal electrodes 5 and 6 are not facing each other across the flat wall 22, a large resistance is generated between the area where the potential is generated and the internal electrodes 5 and 6. When a potential (dielectric breakdown voltage) exceeding these resistances is applied, discharge occurs. The dielectric breakdown voltage increases as the length of the non-overlapping portion of the external electrodes 3 and 4 and the internal electrodes 5 and 6 (the distance d mentioned above) increases.

[0062] [Fourth Embodiment] Figures 11A to 11C show the excimer lamp according to the fourth embodiment viewed from three sides, with Figure 11A being a top view, Figure 11B a front view, and Figure 11C a bottom view. Figure 12 is a DD cross-sectional view of the excimer lamp shown in Figure 11B.

[0063] The external electrode 3 has a main body 30, a root portion 32 extending along the X direction from the -X end of the main body 30, a branch portion 33 extending in the -Z direction from the -X end of the root portion 32, a root portion 34 extending along the X direction from the +X end of the main body 30, and a branch portion 35 extending in the -Z direction from the +X end of the root portion 34. The -X end 3a of the external electrode 3 is the -X end of the branch portion 33, and the +X end 3b of the external electrode 3 is the +X end of the branch portion 35. A power supply portion 31 extending along the X direction is provided at the -X end of the branch portion 33. The distance between the main body 30 and the branch portion 33, and the distance between the main body 30 and the branch portion 35 are both within 20 mm.

[0064] The external electrode 4 has a main body portion 40, a root portion 42 extending along the X direction from the -X direction end of the main body portion 40, a branch portion 43 extending in the -Z direction from the -X direction end of the root portion 42, a root portion 44 extending along the X direction from the +X direction end of the main body portion 40, and a branch portion 45 extending in the -Z direction from the +X direction end of the root portion 44. The -X direction end 4a of the external electrode 4 is the -X direction end of the branch portion 43, and the +X direction end 4b of the external electrode 4 is the +X direction end of the branch portion 45. A power supply portion 41 extending along the X direction is provided at the -X direction end of the branch portion 43. The distance between the main body portion 40 and the branch portion 43, and the distance between the main body portion 40 and the branch portion 45 are both within 20 mm.

[0065] In the fourth embodiment, as shown in Figures 11A-C, the first internal electrode 5 is positioned slightly inward (towards the +X) from the -X ends 3a and 4a of the external electrodes 3 and 4. Similarly, the second internal electrode 6 is positioned slightly inward (towards the -X) from the +X ends 3b and 4b of the external electrodes 3 and 4. However, the distance in the X direction between the first internal electrode 5 and the -X ends 3a and 4a of the external electrodes 3 and 4 is within 30 mm, so it can be said that the first internal electrode 5 is positioned at the end of the external electrodes 3 and 4 in the longitudinal direction. Similarly, the distance in the X direction between the second internal electrode 6 and the +X ends 3b and 4b of the external electrodes 3 and 4 is within 30 mm, so it can be said that the second internal electrode 6 is positioned at the end of the external electrodes 3 and 4 in the longitudinal direction.

[0066] In the fourth embodiment, as shown in Figure 12, both ends 6a and 6b of the second internal electrode 6 extending along the inner surfaces of the flat walls 21 and 22 face each other across the flat walls 21 and 22, with the pair of external electrodes 3 and 4, specifically the branch portions 35 and 45 of the pair of external electrodes 3 and 4 in between. Similarly, as shown in Figures 11A to C, both ends 5a and 5b of the first internal electrode 5 extending along the inner surfaces of the flat walls 21 and 22 face each other across the flat walls 21 and 22, with the pair of external electrodes 3 and 4, specifically the branch portions 33 and 43 of the pair of external electrodes 3 and 4 in between.

[0067] [Fifth Embodiment] Figures 13A to 13C show the excimer lamp according to the fifth embodiment viewed from three sides, with Figure 13A being a top view, Figure 13B a ​​front view, and Figure 13C a bottom view.

[0068] In the fifth embodiment, as shown in Figures 13A-C, the first internal electrode 5 is positioned slightly outside (towards the -X) of the -X-direction ends 3a and 4a of the external electrodes 3 and 4. Similarly, the second internal electrode 6 is positioned slightly outside (towards the +X) of the +X-direction ends 3b and 4b of the external electrodes 3 and 4. However, the distance in the X direction between the first internal electrode 5 and the -X-direction ends 3a and 4a of the external electrodes 3 and 4 is within 30 mm, so it can be said that the first internal electrode 5 is positioned at the end of the external electrodes 3 and 4 in the longitudinal direction. Similarly, the distance in the X direction between the second internal electrode 6 and the +X-direction ends 3b and 4b of the external electrodes 3 and 4 is within 30 mm, so it can be said that the second internal electrode 6 is positioned at the end of the external electrodes 3 and 4 in the longitudinal direction.

[0069] In the fifth embodiment, the first internal electrode 5 is positioned so as not to overlap with the pair of external electrodes 3 and 4 in the X direction, and the first internal electrode 5 is not facing either of the pair of external electrodes 3 and 4 across the flat walls 21 and 22. Similarly, the second internal electrode 6 is positioned so as not to overlap with the pair of external electrodes 3 and 4 in the X direction, and the second internal electrode 6 is not facing either of the pair of external electrodes 3 and 4 across the flat walls 21 and 22.

[0070] [Sixth Embodiment] Figures 14A to 14C show the excimer lamp according to the sixth embodiment viewed from three sides, with Figure 14A being a plan view, Figure 14B a front view, and Figure 14C a bottom view. Figure 15 is an EE cross-sectional view of the excimer lamp shown in Figure 14B.

[0071] In the sixth embodiment, as shown in Figures 14A-C, the first internal electrode 5 is positioned slightly inward (towards the +X) from the -X ends 3a and 4a of the external electrodes 3 and 4. Similarly, the second internal electrode 6 is positioned slightly inward (towards the -X) from the +X ends 3b and 4b of the external electrodes 3 and 4. However, the distance in the X direction between the first internal electrode 5 and the -X ends 3a and 4a of the external electrodes 3 and 4 is within 30 mm, so it can be said that the first internal electrode 5 is positioned at the end of the external electrodes 3 and 4 in the longitudinal direction. Similarly, the distance in the X direction between the second internal electrode 6 and the +X ends 3b and 4b of the external electrodes 3 and 4 is within 30 mm, so it can be said that the second internal electrode 6 is positioned at the end of the external electrodes 3 and 4 in the longitudinal direction.

[0072] In the sixth embodiment, the first internal electrode 5 and the second internal electrode 6 are positioned to overlap with a pair of external electrodes 3 and 4 in the X direction, but the first internal electrode 5 and the second internal electrode 6 do not face either of the pair of external electrodes 3 and 4 across the flat walls 21 and 22. Specifically, as shown in Figure 15, both ends 6a and 6b of the second internal electrode 6 extending along the inner surface of the flat walls 21 and 22 are shorter than in the fourth embodiment shown in Figure 12, and do not face the pair of external electrodes 3 and 4 across the flat walls 21 and 22. Similarly, as shown in Figures 14A to C, both ends 5a and 5b of the first internal electrode 5 extending along the inner surface of the flat walls 21 and 22 are shorter than in the fourth embodiment shown in Figures 11A to C, and do not face the pair of external electrodes 3 and 4 across the flat walls 21 and 22.

[0073] Although embodiments of the present invention have been described above with reference to the drawings, it should be understood that the specific configurations are not limited to these embodiments. The scope of the present invention is indicated not only by the above-described embodiments but also by the claims, and further includes all modifications within the meaning and scope of equivalence to the claims.

[0074] The structures used in each of the above embodiments can be adopted in any other embodiment. The specific configuration of each part is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the present invention.

[0075] (1) In the excimer lamp 1 according to the above embodiment, the first internal electrode 5 and the second internal electrode 6 are positioned at the ends of the external electrodes 3 and 4 in the longitudinal direction, but are not limited to this. The first internal electrode 5 and the second internal electrode 6 may be positioned at any position between the ends and the center of the external electrodes 3 and 4 in the longitudinal direction.

[0076] Furthermore, it is preferable that the n internal electrodes, including the first internal electrode 5 and the second internal electrode 6, are positioned at the center of a region obtained by dividing the external electrodes 3 and 4 into n equal parts in the longitudinal direction. Figure 16 shows an example in which the first internal electrode 5 and the second internal electrode 6 are positioned at the center of a region Ar obtained by dividing the external electrodes 3 and 4 into two equal parts in the longitudinal direction.

[0077] Furthermore, the excimer lamp 1 may further include a third internal electrode 7 positioned between the first internal electrode 5 and the second internal electrode 6 in the longitudinal direction, extending into the inner surfaces of a pair of flat walls 21 and 22 inside the discharge container 2. In this case, as shown in Figure 17, it is preferable that the first internal electrode 5, the second internal electrode 6, and the third internal electrode 7 are each positioned at the center of a region Ar that divides the external electrodes 3 and 4 into three equal parts in the longitudinal direction.

[0078] (2) In the excimer lamp 1 according to the above embodiment, the first internal electrode 5 and the second internal electrode 6 are arranged to connect to the inner surfaces of a pair of flat walls 21 and 22 inside the discharge container 2, but are not limited to this. As shown in Figure 18, if the width of the external electrodes 3 and 4 in the Z direction is wide, the second internal electrode 6 only needs to extend towards the inner surfaces of the pair of flat walls 21 and 22 inside the discharge container 2, and does not necessarily need to be connected to the inner surfaces of the pair of flat walls 21 and 22. The shortest distance between both ends of the second internal electrode 6 and the external electrodes 3 and 4 is preferably 2 mm or less. The same applies to the first internal electrode 5.

[0079] (3) In the excimer lamp 1 according to the above embodiment, the first internal electrode 5 and the second internal electrode 6 are arranged to connect the inner surfaces of a pair of flat walls 21 and 22 along the inner surface of the side wall 23 of the discharge container 2, but the lamp is not limited to this. For example, the first internal electrode 5 and the second internal electrode 6 may have a structure in which a glass plate is held between a pair of flat walls 21 and 22 and a metal wire is wrapped around the glass plate. [Explanation of symbols]

[0080] 1: Excimer lamp 2: Discharge container 3: External electrode 3a:-X direction end 3b:+X direction end 4: External electrode 4a:-X direction end 4b:+X direction end 5: First internal electrode 6: Second internal electrode 7: Third internal electrode 9: Lighting device 21 :Flat wall 22 :Flat wall 23: Side wall 30: Main body 31: Power supply unit 32: Root part 33: Branch 34: Root part 35: Branch 40: Main body 41: Power supply unit 42: Root part 43: Branch 44: Root part 45: Branch Ar: Region divided into n equal parts

Claims

1. An excimer lamp apparatus comprising an excimer lamp and a lighting device for lighting the excimer lamp, The excimer lamp has a roughly rectangular cross-section, and comprises a discharge vessel having a pair of flat walls extending in the longitudinal direction and a pair of side walls connecting these flat walls. A pair of external electrodes are arranged facing each other on the outer surfaces of the pair of flat walls, A first internal electrode is disposed inside the discharge vessel so as to extend toward the inner surface of the pair of flat walls, The discharge container comprises a second internal electrode positioned at a longitudinal distance from the first internal electrode, and extending within the discharge container toward the inner surface of the pair of flat walls, The first internal electrode and the second internal electrode are respectively positioned between the end and the center of the external electrode in the longitudinal direction. The discharge vessel has a longitudinal length of 600 mm or more. The lighting device is an excimer lamp device having a dimming means for dimming the excimer lamp.

2. The first internal electrode is arranged to connect the inner surfaces of the pair of flat walls, The excimer lamp apparatus according to claim 1, wherein the second internal electrode is arranged to connect the inner surfaces of the pair of flat walls.

3. The excimer lamp apparatus according to claim 1, wherein the first internal electrode and the second internal electrode are arranged along the inner surface of the side wall.

4. The excimer lamp apparatus according to claim 1, wherein at least a portion of the first internal electrode or the second internal electrode faces at least one of the pair of external electrodes across the flat wall.

5. The excimer lamp apparatus according to claim 1, wherein the first internal electrode and the second internal electrode do not face either of the pair of external electrodes across the flat wall.

6. The excimer lamp apparatus according to claim 1, further comprising a third internal electrode positioned between the first internal electrode and the second internal electrode in the longitudinal direction, and arranged inside the discharge vessel so as to extend toward the inner surface of the pair of flat walls.

7. The excimer lamp apparatus according to claim 6, wherein the third internal electrode is arranged to connect the inner surfaces of the pair of flat walls.

8. The excimer lamp apparatus according to claim 1, wherein the first internal electrode and the second internal electrode are respectively positioned at the end of the external electrode in the longitudinal direction.

9. The excimer lamp apparatus according to claim 1, wherein the n internal electrodes, including the first internal electrode and the second internal electrode, are each positioned at the center of a region obtained by dividing the external electrode into n equal parts in the longitudinal direction.

10. The excimer lamp apparatus according to claim 1, wherein the dimming means includes a duty control unit that changes the time ratio between the On period and the Off period of the excimer lamp.

11. The excimer lamp apparatus according to claim 1, wherein the dimming means includes a frequency control unit for changing the ignition frequency of the excimer lamp.

12. The excimer lamp apparatus according to claim 1, wherein the dimming means includes a voltage control unit for changing the ignition voltage of the excimer lamp.

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