Excimer lamp and excimer lamp device

Abstract

Even if the excimer lamp is long, an excimer lamp and an excimer lamp device are provided such that the illuminance on the irradiation surface in the longitudinal direction of the excimer lamp is uniform. The excimer lamp has a roughly square shape with a flat cross-section and has a discharge vessel having 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 each positioned opposite the outer surface of the pair of flat walls, a first internal electrode positioned to extend toward the inner surface of the pair of flat walls inside the discharge vessel, and a second internal electrode positioned to extend toward the inner surface of the pair of flat walls inside the discharge vessel at a position spaced apart from the first internal electrode in the longitudinal direction, and the first internal electrode and the second internal electrode are each positioned between the end and the center of the external electrode in the longitudinal direction.

Description

Technology Field

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

[0002] Recently, excimer lamps (hereinafter also simply referred to as lamps) have been used for the purpose of modifying surfaces by irradiating ultraviolet rays onto surfaces such as films or building materials (including infrastructure members), and accordingly, various irradiation light amounts are required to suit the application or process.

[0003] Conventionally, excimer lamps have adopted a usage method of changing the amount of irradiated light by dimming, and frequency dimming is widely used as the dimming method. Frequency dimming is a method of controlling output by adjusting the number of pulses emitted by the lamp by changing the frequency of the applied power. In this method, since the input is controlled to light up while the applied voltage is fixed at an optimal value, there is an advantage that good starting performance can be maintained even when the input is lowered; however, if the dimming is lowered too much, partial lighting and discharge cannot be maintained, which leads to a problem where the dimming range is limited. Furthermore, recently, the length of excimer lamps has been increasing, and long lamps exceeding 3m are being developed; however, the problem of frequency dimming becomes more pronounced as the length of the lamp increases.

[0004] Another dimming method is Duty Dimming. Duty Dimming is a technique that adjusts the output per unit time by generating light-on and light-off periods through the repetition of Duty-On and Duty-Off periods at a frequency of stable discharge (when the lamp lights up). Unlike frequency dimming, Duty Dimming operates at a stable frequency, allowing for dimming down to a considerably low light intensity.

[0005] Another method of dimming is voltage dimming. Voltage dimming is a technique that adjusts the power to the lamp by increasing or decreasing the voltage at the frequency of stable discharge (when the lamp lights up). Like duty cycle dimming, voltage dimming operates at a stable frequency, allowing for dimming down to low light levels.

[0006] However, in duty dimming, since the duty-on / off cycle is repeated, the lamp is started every time the duty-on cycle is turned on, and thus it is significantly affected by the lamp's starting characteristics. Typically, an excimer lamp has a starting auxiliary electrode installed at one end in the longitudinal direction, and discharge is initiated from there (e.g., Patent Document 1). If the off time in one cycle is extended to reduce the amount of irradiated light, a time difference occurs between when the discharge starts from the starting auxiliary electrode side and when the discharge propagates to the other end. Since duty dimming is a method of starting the lamp multiple times within a unit time, a difference in light quantity occurs due to the ON / OFF cycle and the starting delay, resulting in non-uniformity of illumination along the length of the lamp. Furthermore, even in duty dimming, as the lamp length increases, the starting delay increases, and the non-uniformity of illumination becomes even more pronounced. Prior art literature

[0007] Japanese Patent Publication No. 5376410 The problem to be solved

[0008] The present invention aims to provide an excimer lamp and an excimer lamp device in which the illuminance on the irradiation surface along the longitudinal direction of the excimer lamp becomes uniform, even when the excimer lamp is long, in consideration of the above-mentioned problem. means of solving the problem

[0009] An excimer lamp according to the present invention comprises a discharge vessel having a roughly rectangular shape with a flat cross-sectional shape, a pair of flat walls extending in the longitudinal direction, and a pair of side walls connecting the flat walls, and

[0010] A pair of external electrodes each positioned opposite to the outer surface of the above pair of flat walls, and

[0011] A first internal electrode disposed to extend toward the inner surface of the pair of flat walls inside the discharge vessel, and

[0012] A second internal electrode is provided at a position spaced apart in the longitudinal direction from the first internal electrode, and is disposed inside the discharge vessel so as to extend toward the inner surface of the pair of flat walls.

[0013] The first internal electrode and the second internal electrode are each positioned at a location between the end and the center of the external electrode in the longitudinal direction.

[0014] According to this configuration, by placing the first internal electrode and the second internal electrode at positions between the end and the center of the external electrode in the longitudinal direction, respectively, the discharge is initiated from the respective positions of the first internal electrode and the second internal electrode, thereby shortening the time until the discharge spreads throughout the entire discharge vessel. As a result, in a long excimer lamp, even when, for example, duty dimming is performed, the illuminance on the irradiation surface in the longitudinal direction of the excimer lamp can be uniformized.

[0015] In the excimer lamp according to the present invention, the first internal electrode may be configured to be arranged to connect the inner surface of the pair of flat walls, and the second internal electrode may be configured to connect the inner surface of the pair of flat walls.

[0016] According to this configuration, the first internal electrode and the second internal electrode can be easily installed inside the discharge vessel.

[0017] In the excimer lamp according to the present invention, the first internal electrode and the second internal electrode may be configured to be arranged along the inner surface of the side wall.

[0018] According to this configuration, the first internal electrode and the second internal electrode can be easily installed inside the discharge vessel.

[0019] 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 with the flat wall in between.

[0020] By having the first internal electrode and the second internal electrode face each other with a pair of external electrodes and a flat wall in between, discharge can be reliably initiated from the vicinity of the first internal electrode and the second internal electrode.

[0021] 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 each other with the flat wall between them and both sides of the pair of external electrodes.

[0022] Even if the first internal electrode and the second internal electrode do not face each other with a flat wall between them on both sides of a pair of external electrodes, it is possible to initiate a discharge from the vicinity of the first internal electrode and the second internal electrode.

[0023] In the excimer lamp according to the present invention, the configuration may further include a third internal electrode positioned between the first internal electrode and the second internal electrode in the longitudinal direction, extending toward the inner surface of the pair of flat walls inside the discharge vessel.

[0024] According to this configuration, the time required for the discharge to spread throughout the entire discharge vessel can be shortened.

[0025] In the excimer lamp according to the present invention, the third internal electrode may be configured to be arranged to connect the inner surface of the pair of flat walls.

[0026] According to this configuration, a third internal electrode can be easily installed inside the discharge vessel.

[0027] In the excimer lamp according to the present invention, the first internal electrode and the second internal electrode may be configured such that they are each positioned at the end of the external electrode in the longitudinal direction.

[0028] According to this configuration, since the discharge initiated at both ends along the longitudinal direction of the external electrode propagates toward the center, the time until the discharge spreads throughout the entire discharge vessel can be shortened.

[0029] In the excimer lamp according to the present invention, the n internal electrodes, including the first internal electrode and the second internal electrode, may be configured such that each of them is positioned at the center of the area in which the external electrode is divided into n equal parts in the longitudinal direction.

[0030] According to this configuration, since the discharge initiated by n internal electrodes diffuses in each of the n divided discharge spaces, the time until the discharge diffuses throughout the entire discharge vessel can be shortened.

[0031] In addition, the excimer lamp device according to the present invention comprises any one of the excimer lamps and a lighting device for lighting the excimer lamp, wherein

[0032] The above lighting device has a dimming means for dimming the excimer lamp.

[0033] According to this configuration, even with a long excimer lamp, the illuminance on the irradiated surface along the length direction of the excimer lamp becomes uniform.

[0034] In the excimer lamp device according to the present invention, the dimming means may be configured to have a duty control unit that changes the time ratio of the On period and the Off period of the excimer lamp.

[0035] In the excimer lamp device according to the present invention, the dimming means may be configured to have a frequency control unit that changes the lighting frequency of the excimer lamp.

[0036] In the excimer lamp device according to the present invention, the dimming means may be configured to have a voltage control unit that changes the lighting voltage of the excimer lamp. Brief explanation of the drawing

[0037] FIG. 1 is a perspective view of an excimer lamp according to a first embodiment. FIG. 2a is a plan view of an excimer lamp according to a first embodiment. FIG. 2b is a front view of an excimer lamp according to a first embodiment. FIG. 2c is a bottom view of an excimer lamp according to a first embodiment. FIG. 3 is a cross-sectional view AA of the excimer lamp shown in FIG. 2b. Figure 4 is a BB cross-sectional view of the excimer lamp shown in Figure 2b. FIG. 5a is a diagram showing an example of a voltage waveform applied to a lamp in duty dimming. Figure 5b is a graph showing the experimental results by Duty dimming. FIG. 6a is a diagram showing an example of a voltage waveform applied to a lamp in frequency dimming. Figure 6b is a graph showing the experimental results by frequency dimming. FIG. 7a is a diagram showing an example of a voltage waveform applied to a lamp in voltage dimming. Figure 7b is a graph showing the experimental results by voltage dimming. FIG. 8a is a plan view of an excimer lamp according to a second embodiment. FIG. 8b is a front view of an excimer lamp according to a second embodiment. FIG. 8c is a bottom view of an excimer lamp according to a second embodiment. FIG. 9a is a plan view of an excimer lamp according to a third embodiment. FIG. 9b is a front view of an excimer lamp according to a third embodiment. FIG. 9c is a bottom view of an excimer lamp according to a third embodiment. FIG. 10 is a CC cross-sectional view of the excimer lamp shown in FIG. 9b. FIG. 11a is a plan view of an excimer lamp according to a fourth embodiment. FIG. 11b is a front view of an excimer lamp according to a fourth embodiment. FIG. 11c is a bottom view of an excimer lamp according to a fourth embodiment. FIG. 12 is a cross-sectional view of the excimer lamp shown in FIG. 11b. FIG. 13a is a front view of an excimer lamp according to a fifth embodiment. FIG. 13b is a front view of an excimer lamp according to a fifth embodiment. FIG. 13c is a bottom view of an excimer lamp according to a fifth embodiment. FIG. 14a is a front view of an excimer lamp according to a sixth embodiment. FIG. 14b is a front view of an excimer lamp according to a sixth embodiment. FIG. 14c is a bottom view of an excimer lamp according to a sixth embodiment. FIG. 15 is a cross-sectional view of the excimer lamp shown in FIG. 14b. FIG. 16 is a plan view of an excimer lamp according to another embodiment. FIG. 17 is a plan view of an excimer lamp according to another embodiment. FIG. 18 is a cross-sectional view of an excimer lamp according to another embodiment. Specific details for implementing the invention

[0038] Embodiments of the excimer lamp and excimer lamp device according to the present invention will be described with reference to the drawings. In addition, each of the following drawings is schematically illustrated, and the dimensional ratios in the drawings do not necessarily correspond to actual dimensional ratios, nor do the dimensional ratios between the drawings necessarily correspond to each other.

[0039] [First Embodiment]

[0040] FIG. 1 is a perspective view of an excimer lamp according to a first embodiment, FIG. 2a to 2c are drawings of the excimer lamp shown in FIG. 1 viewed from three directions, FIG. 2a is a top view, FIG. 2b is a front view, and FIG. 2c is a bottom view. In the following description, as shown in FIG. 1, the direction in which the excimer lamp (1) extends (length direction) is the X direction, the direction in which the external electrodes (3, 4) of the excimer lamp (1) (described in detail later) face each other is the Y direction, and the direction perpendicular to the X direction and the Y direction is the Z direction. Also, when expressing directions, if positive or negative directions are distinguished, positive or negative signs are attached, such as "+X direction" and "-X direction," and if directions are expressed without distinguishing positive or negative directions, they are simply written as "X direction."

[0041] FIG. 3 is a cross-sectional view AA of the excimer lamp (1) shown in FIG. 2b. The excimer lamp (1) is provided with a discharge vessel (2). The discharge vessel (2) is formed of a dielectric material (e.g., quartz glass) that is transparent to ultraviolet rays. The discharge vessel (2) has a roughly square shape with a flat cross-section and has a pair of flat walls (21, 22) and a pair of side walls (23, 23). The discharge vessel (2) has a long shape in the X direction and has a length of 600 mm or more. In the case of a discharge vessel (2) having a length of 600 mm or more, the uniformity of illumination is prone to deterioration due to the influence of the aforementioned starting delay.

[0042] Inside the discharge vessel (2), a discharge gas that forms excimer molecules by discharge is sealed. In this embodiment, the discharge gas comprises xenon (Xe). As a more detailed example of the discharge gas, it may be composed of a gas in which xenon (Xe) and neon (Ne) are mixed in a predetermined ratio, and additionally may contain trace amounts of oxygen or hydrogen.

[0043] On the outer surface of a pair of flat walls (21, 22) in a discharge vessel (2), a pair of opposing external electrodes (3, 4) are installed. The external electrode (3) installed 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) installed 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 electrode (3) and the external electrode (4) is a light-transmitting electrode. The external electrodes (3, 4) of this embodiment are all shaped like a mesh, and light is allowed to pass through the gaps of the mesh.

[0044] A power supply section (31) extending along the X direction is installed at the -X direction end (3a) of the external electrode (3). Likewise, a power supply section (41) extending along the X direction is installed at the -X direction end (4a) of the external electrode (4). A lighting device (9) (see FIG. 2b) is connected to the power supply section (31) and the power supply section (41).

[0045] Additionally, although the pair of external electrodes (3, 4) are shown as being light-transmitting electrodes, they are not limited to this, and for example, either of the external electrodes (3, 4) may be formed in a solid shape. Also, the external electrodes (3, 4) may be shaped to allow light to pass through, and for example, may be electrodes with slits formed therein.

[0046] In addition, the external electrodes (3, 4) of the present embodiment are all made of the same material and are formed by printing on the outer surface of the discharge vessel (2) by clean printing and firing, but they may each be made of different materials and formed by different methods. Also, the material forming the external electrodes (3, 4) may be, for example, gold or platinum, or an alloy containing these.

[0047] FIG. 4 is a BB cross-sectional view of the excimer lamp (1) shown in FIG. 2b. Inside the discharge vessel (2), a first internal electrode (5) and a second internal electrode (6) are respectively installed at positions spaced apart in the longitudinal direction. The first internal electrode (5) and the second internal electrode (6) are arranged to extend toward the inner surface of a pair of flat walls (21, 22) inside the discharge vessel (2). In this embodiment, the first internal electrode (5) and the second internal electrode (6) are respectively arranged to connect the inner surface of a pair of flat walls (21, 22) along the inner surface of the side wall (23) of the discharge vessel (2).

[0048] The material forming the internal electrodes (5, 6) is, for example, platinum. The internal electrodes (5, 6) are formed by applying a paste-shaped material to the inner surface of the discharge vessel (2) and then firing it. The width of the internal electrodes (5, 6) in the X direction is, for example, 1 to 5 mm.

[0049] The first internal electrode (5) and the second internal electrode (6) are each positioned between the end and the center of the external electrodes (3, 4) in the longitudinal direction. In this embodiment, the first internal electrode (5) and the second internal electrode (6) are each positioned at the end of the external electrodes (3, 4) in the longitudinal direction. Furthermore, in this specification, the "end" of the external electrode (3) in the longitudinal direction includes an area within 30 mm in the ±X direction from the X-direction end (3a, 3b) of the external electrode (3). Likewise, in this specification, the "end" of the external electrode (4) in the longitudinal direction includes an area within 30 mm in the ±X direction from the X-direction end (4a, 4b) of the external electrode (4).

[0050] In this embodiment, as shown in FIGS. 2a to 2c, the first internal electrode (5) is positioned slightly inward (+X side) than the -X direction ends (3a, 4a) of the external electrodes (3, 4). Likewise, the second internal electrode (6) is positioned slightly inward (-X side) than the +X direction ends (3b, 4b) of the external electrodes (3, 4). However, the distance in the X direction between the first internal electrode (5) and the -X direction ends (3a, 4a) of the external electrodes (3, 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, 4) in the longitudinal direction as described above. Likewise, the X-direction distance between the second inner electrode (6) and the +X-direction end (3b, 4b) of the outer electrode (3, 4) is within 30 mm, and the second inner electrode (6) can be said to be positioned at the end of the outer electrode (3, 4) in the longitudinal direction as described above.

[0051] Generally, when starting a lamp, a drop in dielectric breakdown voltage occurs near the internal electrode, and discharge begins from near the internal electrode. Afterward, since the discharge spreads within the discharge vessel (2) in a chain, a delay in the start-up time occurs at a location far from the internal electrode, although it is a very short time. The delay in the start-up time is approximately proportional to the distance from the internal electrode. Therefore, in an excimer lamp (1) having a long discharge vessel (2), if only one internal electrode is installed at one end of the length direction of the external electrode, the problem of delay in the start-up time becomes significant. As in the present invention, by placing the first internal electrode (5) and the second internal electrode (6) respectively at a position between the end and the center of the external electrodes (3, 4) in the length direction, discharge begins from each of the positions of the first internal electrode (5) and the second internal electrode (6), so the time until the discharge spreads throughout the discharge vessel (2) can be shortened. Accordingly, in the case of a long excimer lamp (1), even when duty lighting is performed by repeatedly turning On / Off, for example, the illuminance on the irradiation surface in the longitudinal direction of the excimer lamp (1) can be uniformized.

[0052] It is preferable that 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, 4) with the flat wall (21, 22) in between. By having the internal electrode (5, 6) face the external electrode (3, 4) with the flat wall (21, 22) in between, discharge can be reliably initiated from the vicinity of the first internal electrode (5) and the second internal electrode (6).

[0053] In this embodiment, as shown in FIG. 4, both ends (6a, 6b) of the second internal electrode (6) extending along the inner surface of the flat wall (21, 22) are respectively facing each other with the pair of external electrodes (3, 4) and the flat wall (21, 22) in between. Likewise, as shown in FIG. 2a to c, both ends (5a, 5b) of the first internal electrode (5) extending along the inner surface of the flat wall (21, 22) are respectively facing each other with the pair of external electrodes (3, 4) and the flat wall (21, 22) in between.

[0054] An 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 between the On period and the Off period of the excimer lamp (1). Additionally, the dimming means may have a frequency control unit that changes the lighting frequency of the excimer lamp (1).

[0055] Duty dimming is a method of dimming by controlling the input to a lamp by thinning the power supply (setting the On-Off period) while keeping the voltage and frequency constant. FIG. 5a is a diagram showing an example of a voltage waveform applied to a lamp in duty dimming. FIG. 5a is also a diagram to explain the duty ratio, and the value of the applied voltage on the vertical axis and the value of time on the horizontal axis are omitted. The duty ratio (%) is calculated by the following formula.

[0056] Duty ratio (%)=On time / (On time + Off time)×100

[0057] FIG. 5b is a graph showing experimental results by Duty dimming. The solid line in FIG. 5b represents illuminance, and the dashed line represents the uniformity of illuminance. The excimer lamp (1) shown in FIG. 2a to 2c is designated as Example 1. A lamp in which only the internal electrode (6) among the internal electrodes (5, 6) of the excimer lamp (1) shown in FIG. 2a to 2c is installed is designated as Comparative Example 1. As shown in FIG. 5b, in Comparative Example 1, illuminance can be adjusted (dim) by adjusting the Duty ratio, but if the Duty ratio is 40% or less, the uniformity exceeds the practical line (indicated by the dotted dashed line), and the illuminance becomes non-uniform. On the other hand, in Example 1, dimming can be performed without the uniformity exceeding the practical line over a wide range of Duty ratios from 10% to 100%.

[0058] Frequency dimming is a method of dimming by 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. FIG. 6a is a diagram showing an example of a voltage waveform applied to a lamp in frequency dimming. FIG. 6a is also a diagram showing an example of increasing or decreasing the frequency, where the value of the applied voltage on the vertical axis and the value of time on the horizontal axis are omitted.

[0059] FIG. 6b is a graph showing experimental results by frequency dimming. The solid line in FIG. 6b represents illuminance, and the dashed line represents uniformity. The excimer lamp (1) shown in FIG. 2a to 2c is designated as Example 2. A lamp in which only the internal electrode (6) among the internal electrodes (5, 6) of the excimer lamp (1) shown in FIG. 2a to 2c is installed is designated as Comparative Example 2. As shown in FIG. 6b, in Comparative Example 2, illuminance can be adjusted (dim) by adjusting the power according to the frequency, but if the power is 50% or less, the uniformity exceeds the practical line (indicated by the dotted dashed line), and the illuminance becomes non-uniform. On the other hand, in Example 2, dimming can be performed without the uniformity exceeding the practical line over a wide range of power from 40% to 100%.

[0060] Voltage dimming is a method of controlling the input to a lamp by increasing or decreasing the applied voltage; unlike frequency dimming, which adjusts the number of pulses, voltage dimming adjusts the pulse intensity. FIG. 7a is a diagram showing an example of a voltage waveform applied to a lamp in voltage dimming. FIG. 7a is also a diagram showing an example of voltage increase or decrease, where the value of the applied voltage on the vertical axis and the value of time on the horizontal axis are omitted.

[0061] FIG. 7b is a graph showing experimental results by voltage dimming. The solid line in FIG. 7b represents illuminance, and the dashed line represents uniformity. The excimer lamp (1) shown in FIG. 2a to c is designated as Example 3. A lamp in which only the internal electrode (6) among the internal electrodes (5, 6) of the excimer lamp (1) shown in FIG. 2a to c is installed is designated as Comparative Example 3. As shown in FIG. 7b, in Comparative Example 3, illuminance can be adjusted (dim) by adjusting the power by voltage, but if the power is set to 40% or less, the uniformity exceeds the practical line (indicated by a dotted dashed line), and the illuminance becomes non-uniform. On the other hand, in Example 3, dimming can be performed without the uniformity exceeding the practical line over a wide range of power from 30% to 100%.

[0062] [Second Embodiment]

[0063] FIGS. 8a to 8c are drawings of an excimer lamp according to a second embodiment viewed from three directions, FIG. 8a is a top view, FIG. 8b is a front view, and FIG. 8c is a bottom view.

[0064] In the second embodiment, as shown in FIGS. 8a to 8c, the first internal electrode (5) is positioned slightly outward (-X side) from the -X direction end (3a, 4a) of the external electrode (3, 4). Likewise, the second internal electrode (6) is positioned slightly outward (+X side) from the +X direction end (3b, 4b) of the external electrode (3, 4). However, the X-direction distance between the first internal electrode (5) and the -X direction end (3a, 4a) of the external electrode (3, 4) is within 30 mm, and the first internal electrode (5) can be said to be positioned at the end of the external electrode (3, 4) in the longitudinal direction. Likewise, the X-direction distance between the second inner electrode (6) and the +X-direction ends (3b, 4b) of the outer electrodes (3, 4) is within 30 mm, and the second inner electrode (6) can be said to be positioned at the end of the outer electrodes (3, 4) in the longitudinal direction.

[0065] In the present invention, the first internal electrode (5) and the second internal electrode (6) may be configured such that they do not face each other with the flat walls (21, 22) between them and the pair of external electrodes (3, 4). In the second embodiment, the first internal electrode (5) is positioned so as not to overlap with the pair of external electrodes (3, 4) in the X direction, and the two ends (5a, 5b) of the first internal electrode (5) extending along the inner surface of the flat walls (21, 22) do not face each other with the pair of external electrodes (3, 4) and the flat walls (21, 22) between them. Likewise, the second inner electrode (6) is positioned so as not to overlap with the pair of outer electrodes (3, 4) in the X direction, and the two ends (6a, 6b) of the second inner electrode (6) extending along the inner surface of the flat wall (21, 22) do not face each other with the pair of outer electrodes (3, 4) and the flat wall (21, 22) in between.

[0066] [Third Embodiment]

[0067] FIGS. 9a to 9c are drawings of an excimer lamp according to a third embodiment viewed from three directions, where FIG. 9a is a top view, FIG. 9b is a front view, and FIG. 9c is a bottom view. FIG. 10 is a cross-sectional view of the excimer lamp shown in FIG. 9b.

[0068] In the third embodiment, as shown in FIGS. 9a to 9c, the first internal electrode (5) is positioned slightly inward (+X side) than the -X direction ends (3a, 4a) of the external electrodes (3, 4). Likewise, the second internal electrode (6) is positioned slightly inward (-X side) than the +X direction ends (3b, 4b) of the external electrodes (3, 4). However, the distance in the X direction between the first internal electrode (5) and the -X direction ends (3a, 4a) of the external electrodes (3, 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, 4) in the longitudinal direction. Likewise, the X-direction distance between the second inner electrode (6) and the +X-direction ends (3b, 4b) of the outer electrodes (3, 4) is within 30 mm, and the second inner electrode (6) can be said to be positioned at the end of the outer electrodes (3, 4) in the longitudinal direction.

[0069] The first internal electrode (5) and the second internal electrode (6) may be configured not to face each other with flat walls (21, 22) between both sides of a pair of external electrodes (3, 4). 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, 4) in the X direction, and the first internal electrode (5) and the second internal electrode (6) do not face each other with flat walls (21, 22) between both sides of the pair of external electrodes (3, 4). Specifically, as shown in FIG. 10, the ends (6a, 6b) of the second internal electrode (6) extending along the inner surface of the flat wall (21, 22) are shorter than those of the first embodiment shown in FIG. 4 and do not face each other with the pair of external electrodes (3, 4) and the flat wall (21, 22) in between. Likewise, as shown in FIG. 9a to 9c, the ends (5a, 5b) of the first internal electrode (5) extending along the inner surface of the flat wall (21, 22) are shorter than those of the first embodiment shown in FIG. 2a to 2c and do not face each other with the pair of external electrodes (3, 4) and the flat wall (21, 22) in between. The distance (d) (see FIG. 10) between the ends (6a, 6b) of the internal electrode (6) and the external electrode (3, 4) is preferably 2 mm or less. Here, the distance (d) is the shortest distance in the Z direction between the ends (6a, 6b) of the inner electrode (6) and the outer electrode (3, 4). The same applies to the distance (d) between the ends (5a, 5b) of the inner electrode (5) and the outer electrode (3, 4).

[0070] When voltage is applied to the external electrode (3) on the high voltage side, the glass of the discharge vessel (2) is dielectric, and an electric charge (potential) is generated on the inner surface of the discharge vessel (2). If the external electrode (3) and the internal electrodes (5, 6) do not face each other with the flat wall (21) in between, a large resistance is generated between the part where the potential is generated and the internal electrodes (5, 6). Similarly, if the external electrode (4) on the low voltage side and the internal electrodes (5, 6) do not face each other with the flat wall (22) in between, a large resistance is generated between the part where the potential is generated and the internal electrodes (5, 6). When a potential (dielectric breakdown voltage) exceeding this resistance is applied, a discharge occurs. The dielectric breakdown voltage increases as the length of the non-overlapping part (the distance (d) above) of the external electrodes (3, 4) and the internal electrodes (5, 6) increases.

[0071] [Fourth Embodiment]

[0072] FIGS. 11a to 11c are drawings of an excimer lamp according to a fourth embodiment viewed from three directions, FIG. 11a is a plan view, FIG. 11b is a front view, and FIG. 11c is a bottom view. FIG. 12 is a cross-sectional view DD of the excimer lamp shown in FIG. 11b.

[0073] The external electrode (3) has a main body (30), a source part (32) extending along the X direction from the -X direction end of the main body (30), a branch part (33) extending in the -Z direction from the -X direction end of the source part (32), a source part (34) extending along the X direction from the +X direction end of the main body (30), and a branch part (35) extending in the -Z direction from the +X direction end of the source part (34). The -X direction end (3a) of the external electrode (3) is the -X direction end of the branch part (33), and the +X direction end (3b) of the external electrode (3) is the +X direction end of the branch part (35). A feed part (31) extending along the X direction is installed at the -X direction end of the branch part (33). The distance between the main body (30) and the branch (33), and the distance between the main body (30) and the branch (35) are all within 20 mm.

[0074] The external electrode (4) has a main body (40), a source part (42) extending along the X direction from the -X direction end of the main body (40), a branch part (43) extending in the -Z direction from the -X direction end of the source part (42), a source part (44) extending along the X direction from the +X direction end of the main body (40), and a branch part (45) extending in the -Z direction from the +X direction end of the source part (44). The -X direction end (4a) of the external electrode (4) is the -X direction end of the branch part (43), and the +X direction end (4b) of the external electrode (4) is the +X direction end of the branch part (45). A feed part (41) extending along the X direction is installed at the -X direction end of the branch part (43). The distance between the main body (40) and the branch (43), and the distance between the main body (40) and the branch (45) are all within 20 mm.

[0075] In the fourth embodiment, as shown in FIGS. 11a to 11c, the first internal electrode (5) is positioned slightly inward (+X side) than the -X direction ends (3a, 4a) of the external electrodes (3, 4). Likewise, the second internal electrode (6) is positioned slightly inward (-X side) than the +X direction ends (3b, 4b) of the external electrodes (3, 4). However, the X-direction distance between the first internal electrode (5) and the -X direction ends (3a, 4a) of the external electrodes (3, 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, 4) in the longitudinal direction. Likewise, the X-direction distance between the second inner electrode (6) and the +X-direction ends (3b, 4b) of the outer electrodes (3, 4) is within 30 mm, and the second inner electrode (6) can be said to be positioned at the end of the outer electrodes (3, 4) in the longitudinal direction.

[0076] In the fourth embodiment, as shown in FIG. 12, both ends (6a, 6b) of the second internal electrode (6) extending along the inner surface of the flat wall (21, 22) are respectively facing each other with the flat wall (21, 22) in between, specifically with the branch portion (35, 45) of the pair of external electrodes (3, 4). Likewise, as shown in FIG. 11a to c, both ends (5a, 5b) of the first internal electrode (5) extending along the inner surface of the flat wall (21, 22) are respectively facing each other with the flat wall (21, 22) in between, specifically with the branch portion (33, 43) of the pair of external electrodes (3, 4).

[0077] [Fifth Embodiment]

[0078] FIGS. 13a to 13c are drawings of an excimer lamp according to a fifth embodiment viewed from three directions, FIG. 13a is a top view, FIG. 13b is a front view, and FIG. 13c is a bottom view.

[0079] In the fifth embodiment, as shown in FIGS. 13a to 13c, the first internal electrode (5) is positioned slightly outward (-X side) from the -X direction end (3a, 4a) of the external electrode (3, 4). Likewise, the second internal electrode (6) is positioned slightly outward (+X side) from the +X direction end (3b, 4b) of the external electrode (3, 4). However, the X-direction distance between the first internal electrode (5) and the -X direction end (3a, 4a) of the external electrode (3, 4) is within 30 mm, and the first internal electrode (5) can be said to be positioned at the end of the external electrode (3, 4) in the longitudinal direction. Likewise, the X-direction distance between the second inner electrode (6) and the +X-direction ends (3b, 4b) of the outer electrodes (3, 4) is within 30 mm, and the second inner electrode (6) can be said to be positioned at the end of the outer electrodes (3, 4) in the longitudinal direction.

[0080] In the fifth embodiment, the first internal electrode (5) is positioned so as not to overlap with the pair of external electrodes (3, 4) in the X direction, and the first internal electrode (5) does not face the pair of external electrodes (3, 4) with flat walls (21, 22) in between. Likewise, the second internal electrode (6) is positioned so as not to overlap with the pair of external electrodes (3, 4) in the X direction, and the second internal electrode (6) does not face the pair of external electrodes (3, 4) with flat walls (21, 22) in between.

[0081] [Sixth Embodiment]

[0082] FIGS. 14a to 14c are drawings of an excimer lamp according to a sixth embodiment viewed from three directions, FIG. 14a is a plan view, FIG. 14b is a front view, FIG. 14c is a bottom view, and FIG. 15 is a cross-sectional view of the excimer lamp shown in FIG. 14b.

[0083] In the sixth embodiment, as shown in FIGS. 14a to 14c, the first internal electrode (5) is positioned slightly inward (+X side) than the -X direction ends (3a, 4a) of the external electrodes (3, 4). Likewise, the second internal electrode (6) is positioned slightly inward (-X side) than the +X direction ends (3b, 4b) of the external electrodes (3, 4). However, the X-direction distance between the first internal electrode (5) and the -X direction ends (3a, 4a) of the external electrodes (3, 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, 4) in the longitudinal direction. Likewise, the X-direction distance between the second inner electrode (6) and the +X-direction ends (3b, 4b) of the outer electrodes (3, 4) is within 30 mm, and the second inner electrode (6) can be said to be positioned at the end of the outer electrodes (3, 4) in the longitudinal direction.

[0084] 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, 4) in the X direction, and the first internal electrode (5) and the second internal electrode (6) do not face each other with the flat walls (21, 22) between them and the pair of external electrodes (3, 4). Specifically, as shown in FIG. 15, the ends (6a, 6b) of the second internal electrode (6) extending along the inner surface of the flat walls (21, 22) are shorter than in the fourth embodiment shown in FIG. 12, and do not face each other with the pair of external electrodes (3, 4) and the flat walls (21, 22) between them. Likewise, as shown in FIGS. 14a–c, the two ends (5a, 5b) of the first inner electrode (5) extending along the inner surface of the flat wall (21, 22) are shorter than those of the fourth embodiment shown in FIGS. 11a–c and do not face each other with the pair of outer electrodes (3, 4) and the flat wall (21, 22) in between.

[0085] The embodiments of the present invention have been described above with reference to the drawings, but it should be understood that the specific configuration is not limited to these embodiments. The scope of the present invention is defined by the claims as well as the description of the embodiments above, and includes all modifications within the meaning and scope equivalent to the claims.

[0086] It is possible to adopt the structure employed in each of the above embodiments in any other embodiment. The specific configuration of each part is not limited to the above-described embodiments, and various modifications are possible within the scope of the spirit of the present invention.

[0087] (1) In the excimer lamp (1) according to the above embodiment, the first internal electrode (5) and the second internal electrode (6) are each positioned at the end of the external electrodes (3, 4) in the longitudinal direction, but are not limited thereto. The first internal electrode (5) and the second internal electrode (6) may each be positioned at any position between the end of the external electrodes (3, 4) and the center in the longitudinal direction.

[0088] Additionally, n internal electrodes including the first internal electrode (5) and the second internal electrode (6) are preferably each positioned at the center of an area in which the external electrodes (3, 4) are divided into n equal parts in the longitudinal direction. FIG. 16 shows an example in which the first internal electrode (5) and the second internal electrode (6) are each positioned at the center of an area (Ar) in which the external electrodes (3, 4) are divided into two equal parts in the longitudinal direction.

[0089] Additionally, the excimer lamp (1) may further be provided with a third internal electrode (7) positioned between the first internal electrode (5) and the second internal electrode (6) in the longitudinal direction, extending toward the inner surface of a pair of flat walls (21, 22) inside the discharge vessel (2). In this case, as shown in FIG. 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, 4) into three equal parts in the longitudinal direction.

[0090] (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 the inner surface of a pair of flat walls (21, 22) inside the discharge vessel (2), but are not limited thereto. As shown in FIG. 18, if the width of the external electrodes (3, 4) in the Z direction is wide, the second internal electrode (6) may be extended toward the inner surface of a pair of flat walls (21, 22) inside the discharge vessel (2), and it is not necessary for it to be connected to the inner surface of a pair of flat walls (21, 22). The shortest distance between both ends of the second internal electrode (6) and the external electrodes (3, 4) is preferably 2 mm or less. The same applies to the first internal electrode (5).

[0091] (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, 22) along the inner surface of the side wall (23) of the discharge vessel (2), but are 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, 22) and a metal wire is wrapped around the glass plate. Explanation of the symbols

[0092] 1: Excimer lamp 2: Discharge vessel 3: External electrode 3a : -X direction terminal 3b : +X direction terminal 4: External electrode 4a : -X direction terminal 4b : +X direction terminal 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: Emergency Transfer Section 32: Source 33: Branch 34: Source 35: Branch 40: Main body 41: Emergency Transfer 42: Source 43: Branch 44: Root part 45: Branch Ar: Region divided into n equal parts

Claims

Claim 1 An excimer lamp device comprising an excimer lamp and a lighting device for lighting the excimer lamp, wherein the excimer lamp comprises a discharge vessel having a rectangular cross-sectional shape that is flat and extends in the longitudinal direction, 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 each disposed opposite to the outer surface of the pair of flat walls, a first internal electrode disposed inside the discharge vessel so as to extend toward the inner surface of the pair of flat walls, and a second internal electrode disposed inside the discharge vessel so as to extend toward the inner surface of the pair of flat walls at a position spaced apart from the first internal electrode in the longitudinal direction, wherein the first internal electrode and the second internal electrode are each disposed at a position between the end and the center of the external electrode in the longitudinal direction, and the lighting device comprises a dimming means for dimming the excimer lamp. Device. Claim 2 An excimer lamp device according to claim 1, wherein the first internal electrode is arranged to connect the inner surface of the pair of flat walls, and the second internal electrode is arranged to connect the inner surface of the pair of flat walls. Claim 3 An excimer lamp device according to claim 1, wherein the first internal electrode and the second internal electrode are disposed along the inner surface of the side wall. Claim 4 An excimer lamp device 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 with the flat wall in between. Claim 5 An excimer lamp device according to claim 1, wherein the first internal electrode and the second internal electrode do not face each other with respect to both sides of the pair of external electrodes and the flat wall between them. Claim 6 An excimer lamp device according to claim 1, further comprising a third internal electrode disposed in the interior of the discharge vessel so as to extend toward the inner surface of the pair of flat walls at a position between the first internal electrode and the second internal electrode in the longitudinal direction. Claim 7 An excimer lamp device according to claim 6, wherein the third internal electrode is arranged to connect the inner surface of the pair of flat walls. Claim 8 An excimer lamp device according to claim 1, wherein the first internal electrode and the second internal electrode are each positioned at the end of the external electrode in the longitudinal direction. Claim 9 An excimer lamp device according to claim 1, wherein n internal electrodes, including the first internal electrode and the second internal electrode, are each positioned at the center of a region in which the external electrode is divided into n equal parts in the longitudinal direction. Claim 10 The excimer lamp device according to claim 1, wherein the discharge vessel has a longitudinal length of 600 mm or more. Claim 11 delete Claim 12 The excimer lamp device according to claim 1, wherein the discharge vessel of the excimer lamp has a longitudinal length of 600 mm or more. Claim 13 The excimer lamp device of claim 1, wherein the dimming means comprises a duty control unit that changes the time ratio of the On period and the Off period of the excimer lamp. Claim 14 The excimer lamp device of claim 1, wherein the dimming means comprises a frequency control unit for changing the lighting frequency of the excimer lamp. Claim 15 The excimer lamp device of claim 1, wherein the dimming means comprises a voltage control unit that changes the lighting voltage of the excimer lamp.

Images