KR19990027302U - Writing pressure measuring instrument using multilayer piezoelectric element - Google Patents

Abstract

The present invention relates to a writing pressure measuring device using a multilayer piezoelectric element, which means that the writing pressure sensing means is made of a multilayer piezoelectric element having a polarization direction opposite to each other and has a quick response.

In the writing pressure measuring device equipped with a sensor unit for detecting the writing pressure in the frame 10 that accommodates the writing instrument 20 to measure the writing pressure, the user can inquire the user, while having elasticity inside the frame 10. A pair of parallel pressure plates 30 are fixed as possible, and the piezoelectric elements 41 stacked between the pressure plates 30 in a plurality of layers via electrodes 45, 46, 47, 48, and 49. Position the pressure sensor unit 40 consisting of (42) (43) (44), the upper and lower ends of the pressure sensor unit 40 is in close contact with the pressure plate (30) (30 '), the electrode via a wire It is connected to the amplifier 80, the amplifier is characterized in that the writing pressure is measured by being connected to the signal processor (82).

Description

Handwriting pressure measuring instrument using multilayer piezoelectric element

The present invention relates to a handwriting pressure measuring device for determining whether the person is the same by detecting the writing with different pressure characteristics, more specifically, the multi-layer piezoelectric means in which the direction for writing pressure sensing is opposite to each other The present invention relates to a handwriting pressure meter using a multilayer piezoelectric element, which is made of a device and has a quick response.

In modern society, the use of various credit cards is becoming more common due to the rapid progress of informatization. These credit cards record personal information and passwords in digital numbers on the magnetic media attached to the back, thereby maintaining the differentiation and confidentiality of the credit cards.

Recently, however, due to the frequent loss and theft of these credit cards and the development of cryptographic decryption technology, various personal information recorded on the credit card is leaked and illegally distributed. Are skyrocketing.

In order to prevent illegal distribution of various credit cards and to protect credit card users, we have developed a method for identifying credit card users using fingerprint identification and eye identification, as well as preventing others from using passwords of credit cards. However, due to the complexity and economical aspects of the device, its use is avoided.

The present invention is to solve such a conventional problem, to determine whether the same by sensing the writing with different pressure characteristics for each person, and the means for detecting the multilayer piezoelectric element is made of a multilayer piezoelectric element The purpose is to provide a writing pressure meter used.

1 is a schematic configuration diagram showing a writing pressure meter using a multilayer piezoelectric element according to the present invention.

Explanation of symbols on the main parts of the drawings

10 ... frame

20 ... writing instruments

30,30 '... pressure plate

31 ... Home

41,42,43,44 ... Piezoelectric Element

45,46,47,48,49 ... electrode

50 ... support

52 ... turning

54 ... Home

71,72 ... wires

80 ... amplifier

82 ... signal processor

As a technical configuration for achieving the above object, the present invention is provided with a sensor unit for detecting the writing pressure in the frame containing the writing instrument in the writing pressure measuring device to be able to query the user by measuring the writing pressure, the inside of the frame Fixing a pair of deformable parallel pressure plate having elasticity, and positioned between the pressure plate between the pressure sensor portion consisting of a piezoelectric element stacked in a plurality of layers via an electrode, the upper and lower ends of the pressure sensor portion is in close contact with the pressure plate, The electrode is connected to the amplifier via a wire, and the amplifier is connected to the signal processor by writing pressure measurement by using a multi-layer piezoelectric element characterized in that the writing pressure is measured.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a writing pressure measuring instrument using a multilayer piezoelectric element according to the present invention as a whole, having a frame 10 having a shape for accommodating a conventional writing implement, and writing inside the frame 10. A writing instrument 20 containing an ink solution or the like and having a writing ball 22 is accommodated.

A pair of pressure plates 30 and 30 ′ parallel to each other are fixed to the inner upper end of the frame 10, and the lower pressure plate 30 is deformed by receiving the pressure applied to the writing instrument 20 at the center of the writing unit. The writing instrument 20 is held in close contact with the upper end of the writing instrument 20 so that the position of the writing instrument 20 can be fixed, and the upper side pressure plate 30 'accommodates the multilayered piezoelectric elements to be described later with the pressure plate 30. Provide space to do so. In addition, concave grooves 31 are formed in the centers of the surfaces of the pressure plates 30 and 30 'facing each other. Of course, the pressing plate 30, 30 ′ may be a member forming the upper and lower ends of a polyhedron or a cylinder having a hollow portion, as shown in the figure formed of separate plate shapes separated from each other to be fixed to the frame 10 It may be.

A plurality of piezoelectric elements 41, 42, 43, 44 in the shape of coins are provided between the plurality of electrode plates 30, 30 ′, and a plurality of electrodes 45, 46, 47, 48, and 49. The pressure sensor unit 40 is formed to be stacked via a medium), wherein the piezoelectric elements 41, 42, 43, and 44 have polarization directions opposite to each other. Both ends of the 40 are held in close contact by a support 50 having a projection 52 fitted into the grooves 31 of the pressure plates 30 and 30 '. This means that the pressure sensor unit 40 side end of the support 50 is in close contact with the outermost electrodes 45 and 49, respectively, more preferably, the pressure sensor unit 40 side of the support 50. In the center of the end is formed a concave semicircular groove 54.

The piezoelectric element is a Pb (Zr, Ti) O ₃ -based piezoelectric element, the electrode is a metal such as silver (Ag), nickel (Ni), the support is relatively excellent elasticity and not corrosive well. Metals such as titanium (Ti) and stainless steel are used. In addition, when the pressure plates 30 and 30 'are made of a ceramic material such as alumina and zirconia having excellent insulation and elasticity or a metal such as titanium or stainless steel, the pressure plates 30 and 30' are preferably coated with insulation. .

In the space formed between the pressure plates 30 and 30 ', the pressure plate 30 and 30 are protected when the writing pressure is not applied by protecting the pressure sensor unit 40 from external impact and having an appropriate elasticity. ') Is filled with a sensor protector 60 to provide a restoring force to return to the original position, the sensor protector 60 is a pressure sensor unit (silicon rubber, polyurethane, natural rubber, etc.) Use a very flexible material compared to the elements that make up 40).

In addition, the first, third and fifth electrodes 45, 47 and 49 are connected to the amplifier 80 via the first wire 71 and the second and fourth electrodes 46 and 48. ) Is connected to the amplifier 80 via the second wire 72, the amplifier 80 is connected to the signal processor 82 for signal analysis and display.

In such a configuration, when writing, the pressure is transmitted to the lower pressure plate 30 and the support 50 through the writing ball 22 and the writing instrument 20, so that the lower pressure plate 30 and the support 50 are While deforming, the piezoelectric elements 41, 42, 43, 44 of the piezoelectric sensor unit 40 are deformed. Accordingly, the piezoelectric elements 41, 42, 43, 44 output an electrical signal corresponding to the writing pressure, and thus, the piezoelectric elements 41, 42, 43, 44 are generated at the respective piezoelectric elements 41, 42, 43, 44. The electrical signal is transmitted to the external amplification unit 80 and the signal processing unit 82 through the electrode and the wire, so that the writing pressure can be measured.

The writing pressure measured in the above appears differently depending on the thickness of the piezoelectric element used, the number of stacked piezoelectric elements, and the shape of the support 50, and the electric signal V generated by the writing pressure is represented by Equation 1 below. .

V = n (d ₃₃ -Dν / t⋅d ₃₁ ) P + δ

Here, d ₃₃ and d ₃₁ are the piezoelectric element constants, ν is the Poisson's ratio of the piezoelectric elements, n is the number of stacked piezoelectric elements, and t and D represent the thickness and diameter of the piezoelectric element, respectively. In addition, P is the pressure delivered to the piezoelectric element when writing, δ means an electrical signal amplified by the shape and material of the support 50.

According to Equation 1, the larger the number of stacked piezoelectric elements, the larger the electric signal, that is, the more sensitive it is.

That is, the writing pressure transmitted through the writing instrument 20 is easily changed to the piezoelectric elements 41, 42, 43, 44 of the pressure sensor unit 40 through the pressure plate 30 and the support 50. The piezoelectric element is deformed to correspond to the writing pressure, so that the piezoelectric element transmits an electrical signal to the amplifier 80 through an electrode and an electric wire, and the transmitted signal is transmitted by the signal processor 82. It is possible to determine whether the writing pressure characteristics of the person who is processed and taking the current writing are the same by comparing the writing pressure characteristics with a previously input pressure characteristic.

In particular, by stacking a plurality of piezoelectric elements, it has an output sensitivity of approximately 1 Hz to a pressure of 1 mPa, has a very fast response of 0.1 · 10 ^-3 sec, and a writing pressure of 1000 Hz or more. Very accurate and fast response can be measured.

As described above, the writing pressure measuring device using the multilayer piezoelectric element according to the present invention transmits the writing pressure so that the piezoelectric elements stacked in multiple layers can be deformed, and analyzes the electrical signal caused by the deformation of the piezoelectric element. Writing pressure has the effect of being able to measure accurately while having very fast response.

Claims (3)

In the writing pressure measuring device is provided with a sensor unit for detecting the writing pressure in the frame 10 that accommodates the writing instrument 20 to measure the writing pressure to query the user, A pair of parallel pressure plates 30, 30 ′ that are elastic and deformable are fixed to the inside of the frame 10, and electrodes 45, 46, 47 are disposed between the pressure plates 30, 30 ′. Positioning the pressure sensor unit 40 consisting of piezoelectric elements 41, 42, 43, 44, which are stacked in a plurality of layers via (48) (49), the upper and lower ends of the pressure sensor unit 40 The part is in close contact with the pressure plate 30, 30 ', the electrode is connected to the amplifier 80 via a wire, the amplifier is connected to the signal processor 82, the multi-layer type, characterized in that the writing pressure is measured Handwriting pressure measuring instrument using piezoelectric element. According to claim 1, wherein the support plate 50 is located between the pressure plate 30, 30 'and the pressure sensor unit 40, the support 50 is a projection on the pressure plate 30, 30' side, respectively And a groove 31 for accommodating the protrusions 52 in the pressure plates 30 and 30 ', and ends of the pressure plates 30 and 30' side of the support 50 are formed. A writing pressure measuring instrument using a multilayer piezoelectric element, characterized by forming a concave semicircular groove (54). The writing pressure measuring device using a multilayer piezoelectric element according to claim 1, wherein the piezoelectric elements (41) (42) (43) (44) have a polarization direction opposite to that of their neighbors to improve sensitivity.