Electrostatic attracting device

[Detailed Description of the Invention]

(Field of the Invention) The present invention relates to an electrostatic adsorption device. (PRIOR ART) An electrostatic adsorption device is arranged on the upper surface of an insulator layer, and is provided with a pair of comb dentate electrodes made from electric conduction material, an adsorption layer arranged on it, and a power supply which impresses direct-current voltage among an above-mentioned pair of electrodes. By an electrostatic field which occurs at the time of impression of voltage to the above-mentioned electrode, adsorption maintenance of the covering objects, such as paper and a plastic film, is carried out on the surface of the above-mentioned adsorption layer. An above-mentioned pair of comb dentate electrodes are arranged in the state where it set its teeth mutually. (Object of the Invention) However, when the plastic material which has the electric resistivity more than 10'3 Oh 1 Da omegacm especially is used as the above-mentioned adsorption layer in an electrostatic adsorption device which was described above, When fixed time passes after the impression start of voltage, the adsorption power declines gradually and there is a problem of it becoming impossible to achieve the operation of Suction device 5. Then, an object of the present invention is to provide the electrostatic adsorption device which can maintain adsorption power, even if it uses the plastic material which has the electric resistivity more than 10'3 Oh 1 Da omegacm as an adsorption layer. (Means for solving problem) In the electrostatic adsorption device provided with a pair of comb dentate electrodes which the present invention has been arranged on the upper surface of an insulator layer, and were made from electric conduction material, the adsorption layer arranged on it, and the power supply which impresses direct-current voltage between the above-mentioned electrodes, The above-mentioned power supply is provided with the polarity-reversals function which reverses the polarity of the voltage impressed to an above-mentioned pair of comb dentate electrodes for every predetermined time. (An operation and effect of an invention) The power supply provided with the above-mentioned voltage-poles reversal (pulse reversal voltage may be called hereafter) function in the electrostatic adsorption device of the present invention, Impress the voltage which polarity reverses for every predetermined time to an above-mentioned pair of comb dentate electrodes, they are made to generate an electrostatic field, and adsorption maintenance of the covering object is carried out by the electrostatic adsorption power by this electrostatic field. This holding power made from adsorption increases with time, or is maintained at least by reversal of the polarity of the above-mentioned voltage. Such an operation and an effect are notably revealed, when electric resistivity forms an adsorption layer with the plastic material beyond 10" order 0cm. When electric resistivity forms an adsorption layer with the plastic material which is 108 orders thru/or 1012 order omegacm, even if it does not reverse the polarity of voltage, there is sufficient adsorption holding power, but adsorption holding power can be made to further increase from the time of direct-current voltage impression by reversal impression of the polarity of voltage. That is, in the present invention, holding power increases compared with the time of the same voltage impression as the conventional flowed-in one direction type static electricity adsorption device. Therefore, when making holding power of the same level profitably like, impressed electromotive force of pulse reversal voltage can be dropped. In the electrostatic adsorption device of the present invention, it was unsuitable as a material of an adsorption layer conventionally, It becomes usable [ what has the electric resistivity more than 1013 order omegacm ], and it becomes Kanmon to also use the polyester film or sorting in which it has the electric resistivity about 1016 and 10'?omegacm especially as an adsorption layer material. It is although reversing the polarity of the voltage impressed between electrodes is indicated in the electrostatic adsorption device also in JP,47-39392,B in order to reinforce adsorption power, Reversal of the polarity of the impressed electromotive force in the electrostatic adsorption device indicated by this publication of examined patent applications is [ only being carried out temporarily at the time of voltage impression, and ], and the present invention performed during an adsorbing action by repeating reversal of the polarity of impressed electromotive force for every predetermined time completely differs in thought. It is completely different also from the thing of form which impresses exchange to the adsorption supporting structure. (EXAMPLE) Hereinafter, the electrostatic adsorption device by the desirable example of the present invention is explained, referring to an accompanying drawing. Drawing 1 is a top view of the electrostatic adsorption device by the example of the present invention, and Drawing 2 is a sectional view in alignment with line A-A of Drawing 1. The electrostatic adsorption device is provided with electrostatic fixing disc 1 and electric power unit 10. The above-mentioned electrostatic fixing disc 1 has insulating supporters 2, a pair of comb dentate electrodes 3.4 arranged on these insulating supporters 2, and adsorption layer 5 arranged on these. It is mutually joined, for example with double-sided adhesion sheet 6, and the above-mentioned insulating supporters 2, electrode 3.4, and adsorption layer 5 are really stopped, and constitute electrostatic fixing disc 1. What could print the above-mentioned electrode 3.4 to electrode pattern form directly on insulating supporters' 2 upper surface or the undersurface ° of adsorption layer 5 using conductive ink, or formed metal, such as copper foil, in electrode pattern form may be pasted up with adhesives on the above-mentioned insulating supporters 2. The above-mentioned adsorption layer 5 is mainly formed by a plastic, and the semi-conductive thing in which the electric resistivity is 10B Oh 1 Da omegacm thru/or a 102 order omegacm grade to its electric resistivity is usable to the thing of the rate of high electrical resistivity more than 10'3 Oh 1 Da omegacm. This electric resistivity is JIS. K According to 6911, it should be measured under the same measurement voltage as the operating voltage of an electrostatic adsorption device. The thickness of the above-mentioned adsorption layer is set as the range of 0.02 mm to 2.5 mm, preferably 0.05 mm to 2.Qmm. The above-mentioned electric power unit 10 is provided with direct-current power supply 11 whose generating voltage is 100OV thru/or about 500 OV, and polarity-reversals circuit 12 which reverses automatically the polarity of the voltage impressed to the above-mentioned electrode 3.4 for every predetermined time. a time check of a timer for this polarity-reversals circuit 12 to measure the above-mentioned predetermined time, a time constant circuit, etc. -- it has device 13. this time check -- change]1? which is clocked by device 13 and which comprises a relay etc. for every predetermined time is operated, and the polarity of voltage impressed to the above-mentioned electrode 3.4 is automatically reversed for every predetermined time. For a predetermined period [ above-mentioned ], it is set up in the unit for tens of minutes from several seconds. When an adsorption layer is formed by the plastic of the rate of high electrical resistivity more than 1013 order omegacm, adsorption power decreases this time, but it needs to be before that adsorption holding power reaches below a value satisfactory as an adsorption device. In the electrostatic adsorption device of the above composition, they are dielectric constant 6 and electric resistivity 5X10"omegacm about an adsorption layer, It formed with thickness Q and a 5-mm plastic dielectric sheet, and to electrode 3.4, direct current 1000V was impressed, where polarity is reversed every 10 seconds, and the change of adsorption power to a record paper was measured in Example 1 and this state. Adsorption power made the record paper (A4 size and weight 67g/M2) adsorb, pulled this horizontally with the spring balance, and measured the power at the time of moving. The result of the above-mentioned measurement was shown in the 1st table. The thing which makes it reversed once immediately after impressing the polarity of comparative example 1 and impressed electromotive force for what does not reverse the polarity of impressed electromotive force was made into comparative example 2 using the electrostatic adsorption device of the same structure, change of each adsorption power was measured, and it was shown in the 1st table of the above. The above-mentioned adsorption layer is formed with dielectric constant 3, electric resistivity 2 XIO"omega cm, and a 100-micrometer-thick polyester film, To electrode 3.4, direct current 2000V was impressed, where polarity is reversed every 10 seconds, and the change of adsorption power to a record paper was measured like the above in the state of [ this ] Example 2. The result of this measurement was shown in the 2nd table. The thing which makes it reversed once immediately after impressing the polarity of comparative example 3 and impressed electromotive force for what does not reverse the polarity of impressed electromotive force was made into comparative example 4 using the electrostatic adsorption device of the same structure, change of each adsorption power was measured, and it was shown in the 2nd table of the above. (Hereinafter, space) 1st Table 60 7.80 5.10 5.10 In addition The above-mentioned measurement is temperature 25degreeC and 70% of humidity. It carried out under conditions. 312 Table 1 1.70 The above-mentioned measurement was performed under temperature 24degreeC and the conditions of 70% of humidity. While adsorption power increased gradually, in Example 1, adsorption power was stabilizing at 5 kg according to both comparative examples 1 and 2, so that the above result might show. While adsorption power increased gradually after voltage impression and was mostly stabilized after 10 minutes in Example 2, it is at comparative example 3.4, In comparative example 4, although adsorption power increased temporarily immediately after impression of voltage, in comparative examples 3 and 4, adsorption power is about 0 in Woven little and 5 minutes with progress of time. Thus, in the electrostatic adsorption device of the present invention, the adsorption power increases with time by reversal of the polarity of the above-mentioned voltage, or is maintained at least, and it becomes possible to use a wide material as an adsorption layer.

[Brief Description of the Drawings]

Drawing 1 is a top view of the electrostatic adsorption device by the example of the present invention, Drawing 2 is a sectional view in alignment with line A-A of Drawing 1. 1 Electrostatic Fixing Disc 2 Insulating Supporters 3.4 Electrode 5 Adsorption Layer Electric power unit Direct-current power supply ■ Polarity-reversals circuit ■ a time check -- a device