JP6678294B2 - UV sterilizer - Google Patents

Description

  The present invention relates to an ultraviolet sterilizer for sterilizing the surface of a target article by irradiating the surface of the target article with ultraviolet light by emitting light from a xenon flash discharge tube.

  2. Description of the Related Art Conventionally, an ultraviolet sterilizer that sterilizes a target article by irradiating ultraviolet rays from a xenon flash discharge tube is known.

For example, by supplying charge energy stored in a capacitor to a very small xenon-enclosed discharge tube at a high current density, powerful ultraviolet light is instantaneously generated, and this ultraviolet light has a strong sterilizing effect. An ultraviolet instant sterilization apparatus characterized by the following is known. The above high current density means 2000 A / cm 2 or more, preferably about 3100 A / cm 2. (Patent Document 1)
Further, the supply energy per pulse of the flash pulse having spectral characteristics including a wavelength range of 300 nm or less is set to 0.5 to 20 J, the number of flash pulses per second is set to 10 to 400, and the flash lamp is moved to move. A disinfection method and a disinfection device characterized by irradiating a flash pulse to the object to be sterilized by approaching the object to be sterilized are also known. (Patent Document 2).

  Such a xenon flash discharge tube can generate and irradiate powerful ultraviolet light instantaneously, has no physical effect on the target article, and sterilizes the target article in a short time and without contact. Can be helpful.

Japanese Patent Publication No. 6-77596 JP 2005-143706 A

  In the sterilizers of Patent Documents 1 and 2, the charge energy stored in the condenser is supplied to a xenon-enclosed discharge tube or a flash lamp, for example, a xenon flash lamp, so-called xenon flash discharge tube, and has a spectral characteristic including ultraviolet rays. A flash is generated instantaneously.

  Therefore, looking at the actual light emission operation of the xenon flash tube, it is needless to say that the condenser must be charged first, and the sterilization operation by the xenon flash tube is only performed after the capacitor has been charged. In the case where the light emitting operation is repeatedly performed, the next light emitting operation cannot be performed until the charging operation is completed. Therefore, the repetition interval of the light emitting operation is limited by the charging operation time. Had a problem to be solved.

  Further, as shown in the above documents, the spectral characteristics of the xenon flash tube include not only the ultraviolet region but also the visible light region. Although it is possible to increase the amount of ultraviolet light by increasing the amount of energy, it is necessary to use a condenser for ultraviolet light. There was a problem that the efficiency of using the accumulated charge energy was not good.

  An object of the present invention is to provide an ultraviolet sterilizer using a xenon flash discharge tube, which has a high use efficiency of charge electric energy of a condenser with respect to ultraviolet rays.

  In addition, the present invention reduces the amount of energy used to generate ultraviolet light by increasing the efficiency of using energy with respect to ultraviolet light, thereby shortening the charging time of the amount of energy required for the next light emission. An object of the present invention is to provide an ultraviolet sterilizer using a xenon flash discharge tube, which can shorten a light emitting operation interval and reduce the charge / discharge energy amount of a capacitor to improve the durability performance of the capacitor.

  The ultraviolet disinfection device according to the present invention uses a xenon flash discharge tube that emits light by consuming the charge of the condenser and emits ultraviolet light emitted from the xenon flash tube to sterilize the target article. A sterilization apparatus, which is provided in a charge circuit for charging the capacitor with electric charge consumed by the xenon flash discharge tube, and provided in a discharge loop of the charged electric charge via the xenon flash tube of the capacitor; Switch means for controlling the supply state of the charged charges to the xenon flash discharge tube by turning off and controlling the light emitting operation of the xenon flash discharge tube; and operating the xenon flash light when the switch means is turned on. A trigger circuit for exciting a discharge tube to start a light emitting operation, and controlling the on / off operation of the switch means; Means for outputting an on signal for turning on the switch means, outputting an off signal for turning off the switch means near a peak value including a peak value of a light emission waveform, and performing the on / off operation. Control means for performing a specified number of times of light emission capable of obtaining at least the amount of ultraviolet light necessary for sufficient sterilization of the target article, wherein the light emission waveform of the xenon flash discharge tube was cut off near the peak value. It is characterized in that control is performed so as to obtain a light emission waveform.

  According to this configuration, the light emission operation of the xenon flash discharge tube is controlled so as to end when the light emission waveform reaches the vicinity of the peak value including the peak value. In other words, the tube current is cut off at a point near the time including the point at which the so-called tube current value flowing through the xenon flash discharge tube by consuming the charged charge of the capacitor becomes a peak.

  For this reason, it is possible to increase the efficiency of using the charge electric energy of the capacitor with respect to the ultraviolet rays, thereby reducing the amount of energy used to generate the ultraviolet rays, and thereby shortening the charging time of the energy amount required for the next light emission. It is possible to provide an ultraviolet sterilizer using a xenon flash discharge tube, which can shorten the interval between repeated light emission operations, and can reduce the charge / discharge energy of the capacitor to improve the durability performance of the capacitor.

  As one mode of the ultraviolet sterilizer having the control means, the control means includes a light receiving element for receiving the emitted light of the xenon flash discharge tube, and using the light reception output of the light receiving element to control the xenon flash discharge tube. Waveform detection means for detecting that the emission waveform has reached the vicinity of the peak value including the peak value and forming peak arrival information; and forming the off signal based on the peak arrival information to emit light of the xenon flash discharge tube. An emission time setting means for setting a time from the start to the formation of the peak arrival information as an emission time of the xenon flash discharge tube thereafter.

  According to this configuration, first, the xenon flash discharge tube is caused to emit light, so that the subsequent light emission time is set to end when the light emission waveform reaches the vicinity of the peak value including the peak value. For this reason, in the subsequent light emission operation, it is possible to increase the utilization efficiency of the charge electric energy of the capacitor with respect to the ultraviolet light, thereby reducing the amount of energy used to generate the ultraviolet light, and thus required for the next light emission. An ultraviolet sterilizer using a xenon flash discharge tube that can shorten the charging time of energy amount, shorten the repetitive light emission operation interval, and reduce the charge and discharge energy amount of the capacitor and improve the durability performance of the capacitor. Can be provided.

  As one mode of the ultraviolet sterilizer having the control means, the control means measures and sets in advance the time from the start of light emission of the xenon flash discharge tube until the light emission waveform reaches a peak value including a peak value. Light-emitting time information to be input, and a light-emitting time storage means for outputting an on / off signal for controlling a light-emitting operation of the xenon flash discharge tube based on the light-emitting time information.

  According to this configuration, the light emission time of the xenon flash discharge tube is set in advance so as to end when the light emission waveform reaches the vicinity of the peak value including the peak value. For this reason, in the light emission operation of the xenon flash discharge tube, it is possible to increase the efficiency of using the charge electric energy of the condenser with respect to the ultraviolet light, thereby reducing the amount of energy used to generate the ultraviolet light, and thus for the next light emission. Ultraviolet light using a xenon flash discharge tube that can shorten the charging time of the required energy, shorten the repetitive light emission operation interval, and reduce the charge and discharge energy of the capacitor to improve the durability of the capacitor A sterilization device can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, there exists the outstanding effect that the utilization efficiency of the charge electric charge of a capacitor with respect to ultraviolet-rays can be provided and the ultraviolet-ray sterilization apparatus using a xenon flash discharge tube can be provided.

  Also, by increasing the efficiency of energy utilization for ultraviolet light, the amount of energy used for generating ultraviolet light can be reduced, thereby shortening the charging time for the amount of energy required for the next light emission. In addition, it is possible to provide an ultraviolet sterilizer using a xenon flash discharge tube, which can shorten the charge and discharge energy of the condenser and improve the durability of the condenser.

Schematic circuit block diagram of the ultraviolet sterilizer according to the first embodiment of the present invention Schematic operation flowchart of the sterilizer Schematic light emission waveform diagram of the sterilizer Schematic charging voltage diagram of the condenser during sterilization operation of the sterilizer Schematic graph showing other ratio values when the maximum value of the ratio values in Table 1 is set to 100. Schematic light emission waveform diagram when charging voltage is 270V, 300V Schematic circuit block diagram of an ultraviolet sterilizer according to a second embodiment of the present invention

(First embodiment)
A first embodiment of an ultraviolet sterilizer 1 according to the present invention will be described with reference to FIGS.

  FIG. 1 is a schematic circuit block diagram of an ultraviolet sterilizer 1 according to a first embodiment of the present invention. As shown in FIG. As a source.

  The charging circuit 2 is a circuit for charging the capacitor 3 with electric charge consumed by the xenon flash tube 4, and includes, for example, a DC-DC converter circuit using a battery as a power supply, an AC-DC converter circuit using a commercial power supply as a power supply, and the like. It is well known.

  In the discharge loop of the charge via the xenon flash tube 4 of the condenser 3, the supply state of the charge to the xenon flash tube 4 is controlled by turning on and off to control the xenon flash tube 4. A switch means 6 including, for example, an IGBT which is a switch element for controlling a light emitting operation is provided.

  The trigger circuit 5 is a circuit that operates when the switch means 6 is turned on to excite the xenon flash discharge tube 4 to start a light emitting operation, and is composed of, for example, a trigger capacitor 5a, a trigger coil 5b, and the like.

  The control means 7 is a means for controlling the on / off operation of the switch means 6, outputs an ON signal for turning on the switch means 6, and controls the switch means 6 in the vicinity of the peak value including the peak value of the emission waveform. By outputting an off signal for turning off the light, the light emission waveform of the xenon flash tube 4 is controlled to be a light emission waveform cut off near the peak value including the peak value, and at least the on / off operation is not shown. Control is performed such that light emission is performed at a prescribed number of times of light emission to obtain a necessary amount of ultraviolet light necessary for sufficient sterilization of the article to be sterilized.

  For example, using the light receiving element 7a for receiving the light emitted from the xenon flash discharge tube 4 and using the light receiving output of the light receiving element 7a, the light emission waveform of the xenon flash discharge tube 4 reaches the vicinity of the peak value including the peak value. A waveform detecting means 7b for detecting and forming and outputting arrival information, and outputs an ON signal of the switch means 6 in response to the completion of charging of the capacitor 3 as an example, and outputs an OFF signal of the switch means 6 based on the arrival information. By doing so, the time from the start of light emission of the xenon flash discharge tube 4 to the formation of the arrival information is set as the light emission time of the xenon flash discharge tube 4 from the next time, and the number of times of output of the on / off signal is required. A light emission time setting means 7c for setting based on the amount of ultraviolet light.

  Hereinafter, regarding the operation of the first embodiment of the ultraviolet sterilizer 1 according to the present invention having the above-described configuration, the schematic operation flowchart shown in FIG. 2, the schematic light emission waveform diagram shown in FIG. Prior to that, description will be given with reference to the schematic charging voltage diagram of the condenser 3 during the sterilization operation, but before that, the results of confirming the output state of ultraviolet rays in the wavelength range of 200 to 300 nm, which are necessary and beneficial for sterilization and sterilization operations, will be described. Keep it.

  The confirmation was performed on the ultraviolet output state according to the emission time and the ultraviolet output state according to the discharge energy of the xenon flash tube.

  First, regarding the ultraviolet output state by light emission time, the emission energy by light emission time when the same light emitting portion configuration is used, and the capacitor having a capacitance value of 200 μF is set to two charging voltages of 270 V and 300 V to emit light. The quantity was determined by measuring the two wavelength ranges.

  Next, regarding the ultraviolet output state for each discharge energy, the first condition (standard condition) and the second condition under which the area of the emission waveform is substantially equal, that is, the second condition under which the discharge energy of the xenon flash discharge tube is substantially equal, The third condition under which the light emission waveform area was almost doubled was measured by measuring the respective amount of emitted energy.

  Specifically, the standard conditions are 400 μF, a charging voltage of 280 V, and a light emission time of 70 μs, in which the capacitance value of the capacitor 3 in FIG.

  The second condition is such that the same xenon flash tube and capacitor as the above standard conditions are used, the charging voltage is 230 V, and the emission time is 110 μs, so that the discharge energy of the xenon flash tube is substantially equal.

  The third condition is such that the same xenon flash tube and capacitor as in the above standard conditions were used, the charging voltage was increased to 280 V, and the emission time was increased to 95 μs so that the emission waveform area of the xenon flash tube was almost doubled. I have.

  The emission energy was measured using a multi-channel spectrometer (MCPD-3000; Otsuka Electronics Co., Ltd.), and the distance between the xenon flash discharge tube and the measuring instrument was determined by the output of the spectroscope during the checking operation. The measurement was performed by setting each of the distances so as not to be saturated.

  Table 1 shows the results of confirming the emission energy amount (μW / cm 2) obtained when the emission time was set to 50 μs, 100 μs, 200 μs, 400 μs, 1000 μs, 2000 μs, and 5000 μs. The measurement results of the emission energy amount (μW / cm 2) in the wavelength range of 200 to 800 nm including the ultraviolet range necessary and useful for sterilization of 300 nm and the same ultraviolet range are shown.

  As is clear from Table 1, in the present confirmation configuration example, regardless of the charging voltage value of the capacitor, the cumulative absolute value of the emission energy increases in any wavelength range as the emission time becomes longer. Was confirmed.

  Also, looking at the ratio of the emission energy amount in the wavelength range of 200 to 300 nm (ultraviolet light) to the emission energy amount in the wavelength range of 200 to 800 nm, when the charging voltage of the capacitor is 270 V, 7.4% to 9.7%. , And when the charging voltage is 300 V, it varies between 7.8% and 12.1%.

  Considering again the ratio of the amount of emitted energy in the wavelength range of 200 to 300 nm (ultraviolet light) to the amount of emitted energy in the wavelength range of 200 to 800 nm, it shows that it exhibits a kind of ultraviolet light generation efficiency. Needless to say, it is desirable to use energy in a high state.

  However, considering the original operation as an ultraviolet sterilizer, it is of course preferable to use the apparatus in a state where the ultraviolet ray generation efficiency is high, but the absolute value of the amount of ultraviolet rays obtained cannot be neglected. If the amount of ultraviolet light obtained is low even with high efficiency, it is possible that sufficient sterilization performance may not be obtained.When using it as an actual device, both the efficiency of ultraviolet light generation and the amount of ultraviolet light obtained should be considered. It is necessary and desirable to set such a light emitting operation.

  FIG. 5 is a schematic graph in which other ratio values are plotted with the maximum value of the ratio values in Table 1 as 100, and fluctuations of the ratio values are estimated. As is clear from FIG. Due to the difference, the ultraviolet light generation efficiency itself and the light emission time at which the efficiency increases become different.

  Considering the height of only the ultraviolet ray generation efficiency from a practical point of view, 80 or more in FIG. 5 is desirable, and 90 or more is more desirable. That is, considering only the ultraviolet ray generation efficiency, it is practically desirable that the light emitting operation condition achieves an efficiency of 80% or more with respect to the obtained maximum efficiency, and more preferably 90% or more.

  Here, the relationship between the above-mentioned ultraviolet generation efficiency and the light emission time of the xenon flash discharge tube is apparent from FIG. 5, but in this confirmation example, the light emission time is independent of the charging voltage of the capacitor. When the peak of the ultraviolet ray generation efficiency exists between 50 μs and 100 μs, and the charging voltage value of the capacitor is 270 V, it becomes 90% or less when it exceeds about 300 μs, and it becomes 80% or less when it exceeds about 400 μs. When the voltage is 300 V, the efficiency becomes 90% or less when the light emission time exceeds about 100 μs, and 80% or less when the light emission time exceeds about 150 μs. From the above, it can be seen that, when considering only the ultraviolet light emission efficiency, the ultraviolet light emission efficiency after exceeding the peak decreases in a shorter light emission time as the charging voltage of the capacitor is higher.

  Further, looking at the emission waveform of the xenon flash discharge tube in this confirmation example, as shown in the schematic emission waveform diagram of FIG. 6, the image steeply rises and reaches a peak, and then gradually falls. Specifically, the emission waveform reached a peak in about 65 μs at 270 V and about 55 μs at 300 V, and then gradually decreased thereafter.

  The present invention provides a xenon flash tube having the above-described characteristics to be useful as an ultraviolet light source of an ultraviolet sterilizer, in which the emission waveform has a high emission efficiency and a large emission amount. For example, in the present example, when the capacitor is operated at a charging voltage value of 270 V, the capacitor is operated at a charging voltage value of 300 V between 55 μs and 400 μs. Is set as a light emission time of 65 μs to 150 μs, and the light emission time is set.

  Therefore, the actual light emission operation of the xenon flash discharge tube is an operation in which light emission is stopped when a light emission waveform near the peak value including the peak value is obtained.

  In other words, by controlling the light emission operation of the xenon flash discharge tube so that the light emission waveform becomes a waveform cut off near the peak value including the peak value, not only high efficiency and good ultraviolet light generation efficiency can be realized, but also ultraviolet light emission efficiency can be realized. As for the absolute value of the amount, a good amount of ultraviolet light can be obtained.

  In the time region until the emission waveform reaches the vicinity of the peak value including the peak value, there is also a region where the efficiency of the ultraviolet ray generation is increased only by looking at the ultraviolet ray generation efficiency. As described above, application to an ultraviolet sterilizer is not preferable, and therefore, in the present invention, as described above, the emission waveform has a peak value in consideration of both the ultraviolet generation efficiency and the amount of ultraviolet light obtained. A light emitting operation that is cut off in the vicinity of the included peak value is realized.

  Table 2 shows the results of confirming the emission energy (μW / cm 2) obtained when the xenon flash tube was made to emit light under the above three conditions. Specifically, the wavelength range was 200 to 300 nm and the wavelength range was 300 to 300 μm. The measurement result of the emission energy amount (μW / cm 2) at 800 nm is shown.

  As is clear from Table 2, under the second condition, in which the light emission time is increased while the charging voltage is lowered and the discharge energy is substantially equal to the standard condition, the emission energy amount in the range of 300 to 800 nm is reduced under the standard condition. In contrast to the injection energy of about 1.08 times that obtained, the energy amount in the range of 200 to 300 nm useful for sterilization and the like is 0 even though the discharge energy amount is almost the same. It was confirmed that the injection energy amount was greatly reduced to .79 times.

  Further, in the case of the third condition in which the emission time was lengthened so that the discharge energy was almost double that of the standard condition, the emission energy in the range of 300 to 800 nm was 2.08 times, which was based on the discharge energy. However, the emission energy amount in the range of 200 to 300 nm is 1.87 times even though the discharge energy amount is almost doubled, and the emission energy amount is greatly reduced as in the case of the second condition. Was confirmed.

  Here, when the above measurement results are viewed from the viewpoint of obtaining ultraviolet rays necessary and useful for sterilization in a wavelength range of 200 to 300 nm in combination with the confirmation results described in Table 1 above and the schematic graph shown in FIG. When the discharge energy is increased, the ultraviolet rays can be increased in absolute value, but the increase in the ultraviolet rays in proportion to the increase in the discharge energy cannot be expected. For example, the discharge energy is twice as large as the standard condition in this confirmation example. Is consumed, the light emission operation under the standard condition is performed twice from the light emission operation under the third condition, in which twice the discharge energy is consumed at a time and the amount of ultraviolet light is 1.87 times the standard condition. Obtaining twice the amount of ultraviolet light results in obtaining a larger amount of ultraviolet light.

  In other words, performing the light emission operation with a small discharge energy a plurality of times until the light emission waveform reaches the vicinity of the peak value including the peak value is performed more than performing the light emission operation with the large discharge energy exceeding the vicinity of the peak once. Therefore, it is effective for obtaining ultraviolet rays necessary and useful for sterilization in a wavelength range of 200 to 300 nm. In other words, the light emission operation until the light emission waveform reaches the vicinity of the peak value including the peak value is nothing but improvement in the ultraviolet ray generation efficiency.

  It should be noted that it is needless to say that the application to the ultraviolet sterilizer needs to consider the absolute value of the amount of ultraviolet rays in consideration of the contribution to the sterilization action. Needless to say, the light emission operation of the xenon flash discharge tube is controlled so that the light emission waveform becomes a waveform cut off near the peak value including the peak value while taking the value into consideration.

  Hereinafter, the operation of the first embodiment of the ultraviolet sterilizer 1 according to the present invention will be described.

  As shown in FIG. 2, when the ultraviolet sterilizer 1 is started in step 201 to perform sterilization, the apparatus 1 first resets an internal counter in step 202, and then resets the internal counter in step 203 by the charging circuit 2. The charging of the capacitor 3 is started, and when the charging is completed in step 204, the control unit 7 outputs an ON signal of the switch unit 6 in step 205.

  When the ON signal is output, the switch means 6 performs an ON operation, whereby the trigger circuit 5 also starts operating, and the xenon flash discharge tube 4 consumes the charge of the capacitor 3 and starts emitting light. . At the time of the output of the ON signal, the control means 7 simultaneously turns on a built-in timer to start time measurement.

  The light emitted from the xenon flash discharge tube 4 is received by the light receiving element 7a of the control means 7, and the received light output is input to the waveform detection means 7b.

  For example, during the light emission operation of the xenon flash discharge tube 4, the waveform detecting means 7b AD-converts the light-receiving output of the light-receiving element 7a in step 206, and determines whether or not the AD-converted value has reached a nearby value including the maximum value. Is determined in step 207, and the determination result is output to the light emission time setting means 7c.

  If the A / D conversion value is not determined to be a neighborhood value including the maximum value, the flow counts the number of executed A / D conversions by the internal counter in step 209 in order to perform the A / D conversion again. In step 210, a comparison is made with a predetermined number of times set in advance based on the time until the count result and the preceding A / D conversion value surely exceed the nearby value including the Max value. Since the number of times has not been reached, the flow returns to AD conversion (step 206), and the above-described operation including AD conversion is performed again.

  If it is determined that the AD conversion value is a near value including the maximum value, the flow stops the time measurement started in step 205, and the time measurement is changed to the emission time T of the xenon flash discharge tube 4 from the next time. Is set in step 208. Specifically, it outputs the clock time signal to the light emission time setting means 7c, and the light emission time setting means 7c receives the clock time signal and sets a point in time at which the off signal is output to the switch means 6; Is set as the emission time T of the xenon flash discharge tube 4 from the next time until the off signal is output.

  Thereafter, the flow passes through the previous steps 209 and 210, and when the number of AD conversions reaches the predetermined number, an off signal is output from the light emission time setting means 7c as shown in the flow 211, and the xenon flash discharge tube 4 Stops emitting light. During this operation, it goes without saying that the preceding A / D conversion value is lower than the neighboring value including the maximum value, so that the flow is executed without going through the step 208.

  Next, the apparatus 1 restarts charging of the condenser 3 at step 212 to start the next light emission of the xenon flash discharge tube 4, that is, the original sterilization operation, and when the charging of the condenser 3 is completed at step 213. At step 214, the control means 7 outputs an ON signal of the switch means 6 to turn on the switch means 6, thereby operating the trigger circuit 5 to cause the xenon flash discharge tube 4 to emit light.

  The xenon flash tube 4 that has started emitting light receives the off signal of the switch means 6 output from the control means 7 when the elapse of the light emission time T set in the previous step 208 is confirmed in step 215, and proceeds to step 216. To stop the light emission.

  Therefore, looking at the light emission operation of the above-described xenon flash discharge tube 4, as shown in the schematic waveform diagram in FIG. 3, the previous light emission time T when the light emission waveform reaches the vicinity value including the peak value is obtained. When the time elapses, the light emission operation becomes the interrupted waveform shown by the solid line. That is, in FIG. 3, it is needless to say that the light emission waveform is significantly different from the light emission waveform during the light emission operation in which almost all of the charging energy of the capacitor 3 is consumed, which is partially indicated by the broken line. Note that the above-described light emission operation, which is interrupted when the light emission time T when the light emission waveform reaches the vicinity value including the peak value, elapses when the so-called tube current flowing through the xenon flash discharge tube 4 has the vicinity value including the peak value. It can also be referred to as a blocked light emitting operation.

  If the light emission operation of the xenon flash discharge tube 4 is stopped after the elapse of the light emission time T, the flow then counts the number of light emission operations of the xenon flash discharge tube 4 by the internal counter in step 217, and then in step 218. A comparison is made between the counting result and the specified number of times of light emission, that is, the number of times of light emission that can sufficiently sterilize the sterilization target, and in such a case, the sterilization operation is the first light emission and the number of times of specified light emission has not been reached. Therefore, the flow returns to step 212, and the above-described operation is performed again from the charging of the capacitor 3. Thereafter, the operation is continued until the count result in step 217 exceeds the specified number of times of light emission.

  When the number of times of the light emission operation of the xenon flash discharge tube 4 described above, in which the light emission waveform becomes a waveform cut off near the peak value including the peak value, reaches the above-mentioned specified number of light emission, the flow judges the arrival in step 218. To step 219, thereby ending the current sterilization operation.

  Here, the charging / discharging operation of the capacitor 3 during the sterilization operation after step 212 described above will be described with reference to a charge voltage image diagram shown in FIG.

  The charging of the capacitor 3 is started at time t0, which is the time of step 212, and the charging voltage is gradually increased as shown in FIG.

  When the charging voltage value of the capacitor 3 rises and reaches the charging completion voltage value Vmax at the time point t1 and charging is completed (step 213), an on signal is output in step 214, and the charged charge is transferred to the xenon flash discharge tube. 4, the xenon flash discharge tube 4 starts to emit light, and at the same time, the charging voltage of the capacitor 3 drops sharply.

  The discharge operation, which is also the light emission operation of the xenon flash discharge tube 4, is stopped by the off signal output at time t2 when the previous light emission time T has elapsed, that is, at the same time as the light emission operation of the xenon flash discharge tube 4 stops. The drop of the charging voltage of the capacitor 3 also stops. Further, when the total number of times of light emission of the current light emitting operation does not reach the above-mentioned specified number of times of light emission, the charging is started again after the determination in step 218 (step 212), and the charging voltage of the capacitor 3 is shown in FIG. Will rise again as shown after time t2.

  Thereafter, when the charging is completed at the time point t3, the light emission operation of the xenon flash discharge tube 4 is performed again by the ON signal. Therefore, the charging voltage of the capacitor 3 drops sharply again until the previous light emission time T elapses. If the cumulative number of times of light emission including the light emitting operation has not reached the prescribed number of times of light emission, the above-described operation is repeated from the charging operation in step 212 again.

  That is, as shown after the time point t3 in FIG. 4, the capacitor 3 repeatedly performs the so-called charge / discharge operation including the rise and fall of the charging voltage based on the light emission operation of the xenon flash discharge tube 4 during the light emission time T. Will be.

  Here, the charge voltage of the capacitor 3 during the repetition of the charge / discharge operation is re-examined with reference to FIG. 4, and the light emission operation is performed when the tube current value approaches the peak value including the peak value. Since the light emitting operation is cut off and is different from the light emitting operation in which all the charge stored in the capacitor 3 is released, the amount of energy consumed in one light emitting operation is small. Therefore, the voltage that decreases in one light emitting operation is completely charged. It decreases from the voltage value Vmax to the voltage value Vs at which light emission stops.

  As a result, the charging operation for the next light emission operation is started from this voltage value Vs. Naturally, the repetitive light emission indicated by Tb in FIG. 4 until reaching the charge completion voltage value Vmax is reached. The so-called charging time during the operation can be made shorter than the charging time Ta from the time point t0 when all the charge has been released to the time point t1 when the charging is completed, and the interval of the preceding repeated light emission operation, which is the sterilization operation, can be shortened.

As described above, according to the first embodiment of the ultraviolet sterilizer 1 according to the present invention, the light emission time of the xenon flash discharge tube is set to end when the light emission waveform reaches the vicinity including the peak value. The setting makes it possible to increase the use efficiency of the charge electric energy of the condenser with respect to the ultraviolet light in the light emission operation of the xenon flash discharge tube, thereby making it possible to reduce the amount of energy used to generate the ultraviolet light, and thus for the next light emission. In addition, the charging time for the energy required for the power supply can be shortened, the repetitive light emission operation interval can be shortened, and the charge / discharge energy of the capacitor can be reduced to improve the durability performance of the capacitor.
(Second embodiment)
Next, a second embodiment according to the ultraviolet sterilizer of the present invention will be described with reference to FIG.

  FIG. 7 is a schematic block diagram showing an ultraviolet sterilizer 8 according to the second embodiment of the present invention. As shown, the ultraviolet sterilizer 8 according to the second embodiment, as shown in FIG. It has a control means 9 different from the ultraviolet sterilizer 1 of the embodiment.

  That is, the control means 9 of the ultraviolet sterilizer 8 of the second embodiment controls the on / off operation of the switch means 6 like the control means 7 of the first embodiment. The emission signal of the xenon flash discharge tube 4 is cut off near the peak value by outputting an ON signal for turning ON and outputting an OFF signal for turning OFF the switch means 6 near the peak value including the peak value of the emission waveform. This is a means for controlling the light emission waveform so as to have a predetermined number of times so as to obtain an amount of ultraviolet light necessary for sufficient sterilization of an article (not shown) to be sterilized at least.

  However, as is apparent from FIG. 7, the light receiving element 7a, the waveform detecting means 7b, and the like provided in the first embodiment shown in FIG. 1 are not provided. The operation of setting the light emission time T by the light emission operation of the xenon flash discharge tube 4 described in 211 is not performed, and in the second embodiment, the light emission time information is used, for example, in the manufacturing process of the device 8. The light emission time T is supplied through the input terminal 9X of the storage means 9A, whereby the light emission time T is previously set in the light emission time storage means 9A.

  In other words, the ultraviolet sterilizer 8 according to the second embodiment sets the light emission time T by the light emission time storage means 9A that controls the operation of the switch means 6, and controls the light emission operation of the xenon flash discharge tube after the operation starts. This is different from the first embodiment in that the process is performed in advance without performing the process.

  According to this configuration, the light emission time T of the xenon flash discharge tube 4 is set in advance so as to end when the light emission waveform reaches the vicinity of the peak value including the peak value. In the light emitting operation, the use efficiency of the charge electric energy of the capacitor with respect to the ultraviolet rays can be increased, and thus, similarly to the first embodiment described above, the amount of energy used to generate the ultraviolet rays can be reduced, and thus the next time. A xenon flash discharge tube that can shorten the charging time of the amount of energy required for light emission, shorten the interval between repeated light emission operations, and reduce the amount of charge and discharge energy of the capacitor to improve the durability of the capacitor Can be provided.

  Note that the sterilizing apparatus according to the present invention is not limited to the above-described embodiment. It goes without saying that various changes can be made without departing from the spirit of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be effectively used for an ultraviolet sterilizer that irradiates an ultraviolet ray to a sterilization target using a flash discharge tube.

DESCRIPTION OF SYMBOLS 1 Ultraviolet sterilizer 2 Charging circuit 3 Capacitor 4 Xenon flash discharge tube 5 Trigger circuit 5a Trigger capacitor 5b Trigger coil 6 Switching means 7 Control means 7a Light receiving element 7b Waveform detecting means 7c Emission time setting means 8 Ultraviolet sterilizer 9 Control means 9A Light emission Time storage means

Claims (3)

A xenon flash discharge tube that emits light by consuming the charged charge of the condenser is a light source, and is an ultraviolet sterilization device that sterilizes a target article with emission light in an ultraviolet region emitted from the xenon flash discharge tube. A charging circuit for charging the electric charge consumed by the xenon flash discharge tube, and a charging circuit provided in a discharge loop of the charged electric charge via the xenon flash discharge tube of the condenser, and performing the on / off operation to perform the xenon flash discharge. Switch means for controlling the state of supply of the charged charges to the tube to control the light emission operation of the xenon flash discharge tube; and operating when the switch means is turned on to excite the xenon flash discharge tube to emit light. A trigger circuit for starting, and means for controlling the on / off operation of the switch means, wherein the switch means And an off signal for turning off the switch means near the peak value including the peak value of the light emission waveform, and performing the on / off operation at least sufficiently sterilizing the target article. And control means for performing a specified number of times of light emission capable of obtaining a necessary amount of ultraviolet light for controlling the light emission waveform of the xenon flash discharge tube to be a light emission waveform cut off near the peak value. An ultraviolet sterilizer characterized by the above-mentioned. The control means includes a light receiving element for receiving the emitted light of the xenon flash discharge tube, and the light emission waveform of the xenon flash discharge tube reaches near a peak value including a peak value using a light receiving output of the light receiving element. Waveform detection means for detecting the fact that the peak reaching information is formed, and the time from the start of light emission of the xenon flash discharge tube to the formation of the peak reaching information by forming the off signal based on the peak reaching information. The ultraviolet sterilization apparatus according to claim 1, further comprising: a light emission time setting means for setting the following as a light emission time of the xenon flash discharge tube. The control means receives luminescence time information which is set by measuring in advance the time from the start of luminescence of the xenon flash discharge tube until the luminescence waveform reaches the vicinity of a peak value including a peak value, and the luminescence time information is input. 2. The ultraviolet sterilizer according to claim 1, further comprising: a light emission time storage unit that outputs an on / off signal for controlling a light emission operation of the xenon flash discharge tube based on the condition.