JP2744631B2 - Thermal stimulation current measurement method and device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for measuring a binding energy state in a homogeneous interior by applying a thermal stimulus as a thermal stimulus current, and in particular, a charge holding medium on which an electrostatic latent image is formed. The present invention relates to a method and a device for measuring a thermal stimulation current for measuring a thermal stimulation current.

[Related Art] Conventionally, in order to measure the binding energy state inside a substance, a test piece is heated at a constant heating rate, and a thermal stimulation current flowing at that time is measured.

FIG. 5 is a diagram showing a schematic configuration of a conventional thermal stimulation current measuring device.

Electrodes 101 and 103 on which aluminum or silver or the like is vacuum-deposited in a disk shape having a diameter of about 20 mm or silver paste is applied are brought into contact with the upper and lower surfaces of the test piece 105. Next, the heater 109 is driven by the temperature controller 110, and the temperature of the test piece 105 is raised to near the softening point.
Put K _1, high voltage direct current between the electrodes 101 and 103, for example, 0-4
The specimen is polarized by applying KV. Next, after cooling to about minus 160 ° C. with liquid nitrogen or the like while applying a voltage, the switch K ₁ is turned off, and then the switch K ₂ is turned on and connected to the high-sensitivity ammeter 107.

Thus, the test piece is heated at a constant heating rate, and the thermal stimulation current flowing at this time is recorded by the recorder 112 as a function of the temperature. At this time, the binding energy of polarization of the test piece 105 is released by heat, and a current showing a peak in a certain temperature region is observed as shown in FIG.

Further, as shown in FIG. 7, a method has been proposed in which one of the electrodes is separated from the test piece and the heat stimulation current is measured.

[Problems to be solved by the invention]

However, in the thermal stimulus current measuring device shown in FIG. 5, since the electrode is brought into direct contact with the test piece, if the thermal stimulus current of the charge storage medium on which an electrostatic latent image is formed is to be measured, for example, Has accumulated charge on the surface, and the electrode comes into direct contact with it,
The state of charge accumulation is disturbed, making it impossible to measure an accurate thermal stimulation current.

On the other hand, if one of the electrodes as shown in FIG. 7 is to be measured away from the surface, the thermal stimulation current to be measured is a very weak value of the order of 10 ^-12 A. Changes in the distance between the two, and it is extremely difficult to keep this constant. Further, in the case of an extremely thin test piece, there is a problem that the deformation is caused by heating and the distance between the electrode and the test piece is similarly changed.

The present invention has been made to solve the above problems, and one of the electrodes is kept out of contact with the test piece, and the distance between the test piece and the electrode is always kept constant, and the expansion and contraction of the test piece accompanied by a temperature rise. It is an object of the present invention to provide a thermal stimulation current measuring method and apparatus capable of accurately measuring a thermal stimulation current while preventing deformation due to heat.

[Means for solving the problem]

For this purpose, the present invention puts a test piece on one electrode,
In the method of measuring the thermal stimulation current flowing in the interelectrode circuit while raising the temperature of the test piece while maintaining the distance between the test piece and the electrode constant, A method for measuring a heat stimulation current provided with a spacer for holding a peripheral portion, and a method in which a first annular hollow ring is fitted to a second annular hollow ring having an outer diameter substantially equal to the inner diameter of the hollow ring, and the first hollow A film-shaped test piece is sandwiched between the ring and the second hollow ring, and is placed on a first electrode having an outer diameter substantially equal to the inner diameter of the second hollow ring to be brought into contact with the film-shaped test piece, A second electrode is disposed opposite to the film-like test piece via a gap,
It is characterized by a thermal stimulation current measuring device for measuring a thermal stimulation current flowing between the first electrode and the second electrode.

[Action]

The present invention is an electrode disposed opposite to the test piece via a gap,
Provide a spacer between the test piece and the spacer, or if the test piece is in the form of a film, keep the distance between the counter electrode and the test piece constant, and furthermore, between the hollow rings where the test pieces fit together. By holding the periphery of the film and fixing it, and preventing deformation of the film-like test piece due to temperature change by evacuation or pressurization, it is possible to always accurately measure the thermal stimulation current.

〔Example〕

 Hereinafter, embodiments will be described with reference to the drawings.

FIG. 1 is a view showing an embodiment of the present invention, in which 100 is a measurement chamber, 101 and 103 are electrodes, 105 is a charge holding medium, 107 is a high-sensitivity ammeter, 109 is a heater, and 111 is a spacer.

The measurement chamber 100 can be heated by a heater 109 driven by a temperature controller (not shown). The electrode 103 has a ring shape, and the charge holding medium 105 is placed thereon. The electrode 101 is opposed to the charge holding medium 105 with a certain gap. The spacer 111 has a hollow ring shape and is fitted or fixed to the electrode 101 with a screw, and presses the periphery of the test piece so that the distance between the electrode and the test piece is constant. . As a material for the spacer, an insulating material such as PTEP may be used.

In such a configuration, the electric charge holding medium 105 in which electric charges are accumulated on the surface or in
While being pressed by 1, the heat stimulation current is measured while the temperature is raised by the heater 109. The charge storage medium 105 stores charges under a voltage applied state of several hundred volts. The stored energy is released in a certain temperature state, and the current at that time is detected by the ammeter 107.

In this case, by keeping the spacer 111 in a fixed state with the electrode 101, the distance between the electrode and the charge holding medium can be kept constant, and a measurement error due to a change in distance can be eliminated.

FIG. 2 is a diagram showing another embodiment of the present invention, and the same numbers as those in FIG. 1 indicate the same contents.

In this embodiment, the charge holding medium is in the form of a film, and the film-like charge holding medium 105 is sandwiched and fixed between the hollow rings 115 and 113. That is,
The outer diameter of the hollow ring 113 is substantially equal to the inner diameter of the hollow ring 115, and the film is fixed by sandwiching and fitting the film between the two. Further, the hollow ring 113 is placed on the electrode 103 having an outer diameter substantially equal to the inner diameter of the hollow ring 113, and is fixed so that its surface is in contact with the film 105. In this way, the electrode 101 is opposed to the film. Of course, in this case, the distance between the electrode 101 and the film is fixed by, for example, a method as shown in FIG. 1, but this is not shown.

In this manner, the heat stimulation current is measured by heating the film-like charge holding medium at a constant temperature rising rate by the heater 109 in the same manner. In the process of heating,
The film 105 may expand and contract under the influence of temperature, and therefore, a film piece on the electrode may undulate, and the distance between the film and the electrode 101 may change. In this case, as shown in FIG. 3, the through-hole 121 is provided in the electrode 103, and a vacuum is drawn by the pump 123 through the through-hole 121, whereby the deformation of the film-like charge holding medium 105 can be prevented. Needless to say, the number of the through holes 121 for evacuating is not one, and a plurality of through holes 121 may be provided, or an annular shape may be provided.

In addition, as shown in FIG. 4, pressurized air may be introduced into the measurement chamber 100 by a pump 127 so that the inside of the measurement chamber 100 is pressurized to prevent deformation of the film-shaped charge holding medium 105.

〔The invention's effect〕

As described above, according to the present invention, in the thermal stimulation current measurement for measuring a very weak current, the distance between the test piece and the electrode can be kept constant, and the deformation of the test piece can be prevented. It is possible to measure the heat stimulation current with high accuracy.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of the present invention, FIG. 2 is a view showing another embodiment of the present invention, FIG. 3 is a view showing an example in which vacuum is drawn in FIG. 2, and FIG. FIG. 2 is a diagram showing an example of pressurization, FIG. 5 is a diagram showing a schematic configuration of a conventional thermal stimulation current measuring device, FIG. 6 is a diagram showing an example of measuring a thermal stimulation current, and FIG.
The figure shows a conventional example in which one of the electrodes is separated from the test piece. 100: measuring chamber, 101, 103: electrodes, 105: charge holding medium, 107: high-sensitivity ammeter, 109: heater, 111: spacer.

Claims (4)

(57) [Claims] 1. A method for measuring a thermal stimulation current flowing between electrodes while placing a test piece on one electrode and disposing the other electrode at a distance from the test piece and increasing the temperature of the test piece. A method for measuring a heat stimulation current, comprising: maintaining a constant distance between the electrode and the electrode; and providing a spacer for pressing a peripheral portion of the test piece. 2. A first annular hollow ring and a second annular hollow ring having an outer diameter substantially equal to the inner diameter of the hollow ring are fitted to each other, and a film is interposed between the first hollow ring and the second hollow ring. While holding the film-shaped test piece, it is placed on a first electrode having an outer diameter substantially equal to the inner diameter of the second hollow ring, and is brought into contact with the film-shaped test piece. A thermal stimulus current measuring device comprising two electrodes arranged opposite to each other and measuring a thermal stimulus current flowing through a circuit between the first electrode and the second electrode. 3. The measuring device according to claim 2, wherein at least one or more through-holes are provided in the first electrode, and a vacuum is drawn through the through-holes. 4. The measuring apparatus according to claim 2, wherein the space where the film-shaped test piece exists is pressurized, and the film-shaped test piece is pressed against the first electrode surface.