JP3429499B2 - Physical quantity measurement device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning force microscope, a high-resolution surface potential profile measuring device, and a physical quantity measuring device used for measuring a surface potential of a photosensitive drum, a toner profile, and a toner potential distribution. Regarding

[0002]

2. Description of the Related Art Conventionally, the state of the sample surface (potential, shape, etc.)
Various types of physical quantity measuring devices have been proposed. FIG. 14 shows a basic configuration for measuring the bending of the cantilever 1 by using an optical method based on the so-called optical lever method. In this case, the light emitted from the light source 4 is applied to the reflection mirror 5 on the surface opposite to the surface on which the probe 2 is formed at the tip of the cantilever 1, and the light reflected by the reflection mirror 5 is received. It is led to the element 6. In such a state, the bending or vibration of the spring changes according to the force acting between the probe 2 and the surface of the sample 3. Then, according to the change, it is reflected by the reflection mirror 5 on the cantilever 1,
The position of the light reaching the light receiving element 6 moves, and the light receiving element 6 detects this movement, whereby the force acting on the cantilever 1 can be measured. As described above, the optical lever optical system including the light source 4, the reflection mirror 5, and the light receiving element 6 requires a certain optical path length, and the entire optical system tends to be large. Therefore, when the two-dimensional distribution of the sample surface state is measured, the optical system itself is not scanned, but the stage 7 side on which the sample 3 is installed is scanned to perform the measurement. .

The example of FIG. 15 (see Japanese Patent Laid-Open No. H5-256641) shows a highly sensitive and compact cantilever displacement detector using the optical lever method. In this case, the light source 4 is arranged in the vicinity of the cantilever 1 and the optical path length is increased by the mirrors 8 and 9 to reduce the size of the entire optical system. As a result, measurement of a large sample such as a photosensitive drum can be supported.

The example of FIG. 16 (see Japanese Patent Application No. 5-93499) shows an example of an apparatus for measuring the potential and shape of the surface of the sample 3 (photosensitive drum). In this case, the light emitted from the light source 4 (semiconductor laser) is reflected by the reflection mirror 5 attached to the rear surface of the tip of the cantilever 1 and detected by the light receiving element 6 by the so-called optical lever method. The detected signal is output as the output Vo by the preamplifier 10. After that, the voltage V ₂₁ that is the output value from the integrator 12 and the AC voltage V of the sine wave AC power supply 13 are added to the adder 11.
₃₁ and the AC voltage V ₃₂ of the sine wave AC power supply 14 are applied. The voltage V ₄₁ from the adder 11 is the power amplifier 1
5, the voltage V ₅₁ from the power amplifier 15 is applied to the probe 2 of the cantilever 1. The voltage V ₅₁ is cantilever 1 of the resonance frequency omega ₀ and its half frequency omega _0/2
AC voltage Va {= G (V ₃₁ + V ₃₂ )} having the following and DC bias voltage Vb (= GV ₂₁ ) are superimposed. By applying this voltage V ₅₁ to the cantilever 1, the resonance frequency ω
₀ detects a difference between the (potential with respect to the ground potential) voltage Vs of the DC bias voltage Vb and the sample surface from the amplitude of the resonant oscillation of the cantilever 1 caused by, controlling the DC bias voltage Vb so that this difference becomes 0 By doing so, the surface potential of the sample 3 is measured from the value of Vb. On the other hand, the frequency ω ₀
The distance d between the tip of the probe 2 and the surface of the sample 3 is measured from the vibration amplitude generated by / 2, and the Z-axis actuator 16 is driven by the voltage from the power amplifier 17 so as to keep the value of this distance d constant. The surface shape of the sample 3 is measured from the voltage V ₂₂ which is the control signal of the Z-axis actuator 16 by controlling the drive with V ₅₂ . In this way, the surface potential and the surface shape of the sample 3 can be measured simultaneously and independently.

[0005]

In the apparatus of FIG. 15, the light source 4 (laser diode or the like) is arranged near the cantilever 1 to reduce the size of the entire optical system. In this case, the light source 4 always needs to be driven by a stable constant current, and therefore a laser drive circuit (not shown) for driving this.
Is required on the optical system side. However, disposing such a laser driving circuit on the side of the optical system increases the size of the entire optical system and makes it heavy. Especially, for scanning a large sample by moving the cantilever 1 and the optical system. It will be a disadvantage.
Therefore, there is a method in which the laser drive circuit is not directly arranged on the optical system side but is arranged at another distant place and electric power is supplied from that place to the light source 4 through electric wiring. However, such a method causes a serious problem when measuring a high-voltage surface potential with a scanning force microscope. That is, during measurement of a high-voltage surface potential, spark-induced discharge may occur between the probe 2 and the surface of the sample 3 or between the probe 2 and a peripheral device (not shown). Electromagnetic noise is generated by such spark discharge, and a surge current flows in the electric wiring between the laser drive circuit and the light source 4 due to the electromagnetic noise, and in the worst case, the light source 4 is destroyed.

When force detection is performed by the optical lever method as in the example of FIG. 16, not all the light emitted from the light source 4 is guided to the light receiving element 6, but a part of the light is scattered. , The surface of the sample 3 is irradiated. When a photosensitive material (photosensitive drum) is used as the sample 3 as in this example, the surface of the drum is discharged due to the leaked light, and the surface charge is discharged. Electric latent image)
Will be disturbed.

Further, in order to accurately measure the bending and vibration of the cantilever 1 by using an optical method, the light emitted from the light source 4 is accurately applied to the tip position of the cantilever 1. It is necessary to adjust the position where light is irradiated before the measurement. However, the wavelength of light used for the light source 4 is not in the visible region but in the infrared or ultraviolet region.
Therefore, it is impossible for the naked eye to align the light emitted from the light source 4. In addition, although an infrared image converter that visualizes the emission of infrared light is also commercially available,
The sensitivity is low and it is not enough for practical use.

Further, in FIG. 16, the probe 2 and the sample 3
An electrostatic attraction acts on the surface of the (photosensitive drum), the potential difference is V ₁ , the distance is d ₁ , and an equivalent area facing the drum surface at the tip of the probe 2. the When S _1, the force F ₁ acting between the probe 2 and the drum _{surface, F 1 = S 1 ε 0} (V 1 2 / d 1 2) ... (1) However, epsilon _0: dielectric air It can be expressed as a rate. On the other hand, the cantilever 1 having the same potential as the probe 2 is supported by the base 18,
A support mechanism (peripheral device) for supporting these parts is provided around the, and such a support mechanism is at ground potential for noise shielding. Therefore, electrostatic attraction acts between the cantilever 1 and the supporting mechanism around the cantilever 1. Now, assuming that the potential difference between the _two is V ₂ , the equivalent distance is d ₂ , and the equivalent area is S ₂ , the force F _{2 in} this case is F ₂ = S ₂ ε ₀ (V ₂ ² / d ₂ ² ) It can be expressed as (2). Here, comparing F ₁ and F ₂ in the equations (1) and (2), d ₁ << d ₂ , but the area S ₂ is 1
It is the back side of, and S ₂ >> S ₁ . Further, since the potential of the probe 2 and the potential of the drum surface are substantially equal to each other in structure, the potential of the supporting mechanism in the periphery is always the ground potential, so that the value of V ₂ is high when the potential of the drum surface is high. Becomes larger, which results in V ₁ << V ₂ . Therefore, from such a fact, the force F ₂ may be the force F ₁ depending on the environmental conditions of the peripheral devices.
However, this value causes a measurement error.

[0009]

[0010]

[0011]

According to a first aspect of the present invention, there is provided a spring to which a probe is attached, and the force is exerted between the probe and a surface of a sample arranged opposite thereto. In a physical quantity measuring device for measuring the physical quantity of the sample by detecting the bending or vibration of the spring or the change of the vibration using an optical method, a light source for measurement that emits light of a wavelength that the sample does not sensitize, and the sample is A light receiving element having sensitivity to a wavelength which is not exposed to light is provided, and a wavelength conversion member for converting light emitted from the measurement light source into visible light is provided in a portion other than a portion of the spring irradiated with the light emitted from the measurement light source. .

According to the first aspect of the present invention, the light emitted from the light source and having a wavelength at which the sample is not sensitized is applied to the wavelength conversion member on the cantilever so that the irradiated position is visible. The physical quantity can be measured without disturbing the state of the sample, and the irradiation position of the cantilever can be easily adjusted.

According to the second aspect of the invention, the probe has a spring attached thereto, and the spring bends or vibrates due to the force acting between the probe and the surface of the sample arranged opposite thereto. In a physical quantity measuring device for measuring a physical quantity of the sample by detecting a change in vibration using an optical method, a measuring light source that emits light of a wavelength that the sample does not sensitize, and a sensitivity to a wavelength that the sample does not sensitize. A light-receiving element having a shield member that covers a part or the entire region of the spring except the probe region, and a wavelength conversion member that converts the light of the measurement light source into visible light is provided on the shield member. Provided.

According to the second aspect of the present invention, the light emitted from the light source and having a wavelength at which the sample is not sensitized is applied to the wavelength conversion member on the shielding member arranged above the cantilever. The irradiated position can be illuminated with visible light, which allows the physical quantity to be measured without disturbing the state of the sample, and the irradiation position of the cantilever can be adjusted easily. Furthermore, it is possible to eliminate the constraint on the design and manufacture of the cantilever.

According to the third aspect of the present invention, the probe has a spring attached thereto, and the bending or vibration of the spring is caused by the force acting between the probe and the surface of the sample arranged opposite thereto. In a physical quantity measuring device for measuring a physical quantity of the sample by detecting a change in vibration using an optical method, a measuring light source that emits light of a wavelength that the sample does not sensitize, and a sensitivity to a wavelength that the sample does not sensitize. A shield member formed of a conductive material having a rigidity higher than that of the spring, which covers a part or the whole of the spring excluding the probe region of the spring, A wavelength conversion member for converting the light of the measurement light source into visible light was provided in the, and the shielding member having this wavelength conversion member was set to the same potential as the spring and the probe.

In the invention according to claim 3 , the light emitted from the light source and having a wavelength that the sample does not sensitize is applied to the wavelength conversion member on the shielding member arranged above the cantilever, The irradiated position can be illuminated with visible light, which allows the physical quantity to be measured without disturbing the state of the sample, and the irradiation position of the cantilever can be adjusted easily. Since the cantilever can be designed and manufactured without restrictions, the shielding member is made of a conductive material having high rigidity, and the cantilever and the shielding member are set to the same potential. It is possible to reduce the electrostatic attractive force that acts between the cantilever and the peripheral equipment.

In the invention according to claim 4, the invention according to claim 1, 2 or
In the invention described in 3 above, the emission wavelength of the light source to which the sample is not exposed is set to a value of 400 nm or less, or a value of 600 nm or more.

In the fourth aspect of the invention, it is frequently used as the light-sensitive material of the sample that the light-sensitive sensitivity is 400.
Since it is around 600 nm and around 600 nm, it is 600 for a sample of a light-sensitive material near 400 nm.
By using a light source having an emission wavelength of nm or more and a light source having an emission wavelength of 400 nm or less for a sample of a photosensitive material near 600 nm, the state of the sample may be disturbed by the light of the light source. Disappear.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A reference example of the present invention will be described with reference to FIGS. In addition, the above-mentioned conventional example (FIGS. 14 to 1)
The description of the same portions as 6) is omitted, and the same reference numerals are used for the same portions.

[Overall Configuration] A probe 2 is attached to the tip of a cantilever 1 as a spring, and a sample 3 (photoreceptor) used for high-voltage surface potential measurement is provided at a position facing the probe 2. Drums etc.) are arranged. On the back surface side of the probe 2 of the cantilever 1, an optical system and a measuring circuit using the optical lever method similar to the above-described conventional example (see FIG. 16) are provided.
An optical fiber 19 (single mode fiber) as an optical waveguide is arranged on the back surface side of the probe 2 of the cantilever 1. A SELFOC lens 20 as an emitting portion is attached to one end of the optical fiber 19, and the SELFOC lens 20 is arranged to face the reflection mirror 5 provided on the back surface of the cantilever 1 so as to face it. There is.
In this case, the optical fiber 19 and the Selfoc lens 20 form an optical transmission unit 21.

The other end of the optical fiber 19 is inserted into the shield box 22 and connected to the optical fiber coupler 23. A selfoc collimating lens 24 and a laser diode 25 (hereinafter referred to as an LD) as a measurement light source are sequentially arranged on the optical path of the optical fiber coupler 23, and a driving laser drive circuit 26 ( Hereinafter, the LD drive circuit) is connected. In this case, the LD drive circuit 26, the LD 25, the SELFOC collimator lens 24, and the optical fiber coupler 2
3 constitutes a laser diode unit 27 as a light source unit.

The operation of this structure will be described. The light emitted from the LD 25 in the shield box 22 is condensed by the SELFOC collimator lens 24, passes through the optical fiber coupler 23, and passes through the optical fiber 19.
Optically coupled in. The combined light travels through the optical fiber 19 and is then guided to the external space, where it is emitted from the SELFOC lens 20 at the end of the optical fiber 19 toward the reflection mirror 5 on the back surface of the cantilever 1. It The light reflected by the reflection mirror 5 is detected by the light receiving element 6 (PSD) by the so-called optical lever method, and is output as the output Vo by the preamplifier 10. Subsequent processing is performed similarly to FIG.

As described above, by using the optical fiber 19, the distance between the cantilever 1 and the LD 25 can be separated by at least 1 m or more. Therefore, the probe 2
Even if a spark discharge or the like occurs between the high voltage measuring sample 3 and the peripheral device, the electromagnetic noise generated by the spark discharge is not transmitted to the LD 25 side through the optical fiber 19 and the laser diode unit. Since 27 is away from the place where the spark is generated, a surge current does not flow in the current that drives the LD 25, and the LD 25 itself is hardly destroyed. As a result, highly reliable measurement can be performed. in this case,
By covering the entire circumference of the LD 25 with a shield box (not shown), the influence of electromagnetic noise can be further reduced.

Further, the optical fiber 19 is excellent in flexibility. The SELFOC lens 20 generally has a diameter of 3 to
Since the length is about 5 mm and the length is about 10 mm, it is made of a very light material. From the above, by moving the SELFOC lens 20, the cantilever 1 and the light receiving element 6 as a unit, it is possible to perform scanning while the sample 3 is fixed. Can also be measured.

The lens used in the shield box 22 is not limited to the SELFOC collimating lens 24, and any lens having characteristics equivalent to this may be used. The SELFOC lens 20 attached to the optical fiber 19 may be a general lens as long as it is small. Further, the optical fiber 19 is not limited to the single mode fiber, and may be a multimode fiber.

[Photosensitive Drum] In the present embodiment, the case where the sample 3 is made of a photosensitive material such as a photosensitive drum used in an electrophotographic apparatus will be described. The light source for measurement (LD25 or the like) emits light in a wavelength region where the sample 3 is not exposed. In addition, the light receiving element (light receiving element 6)
Has a sensitivity of a wavelength at which the sample 3 is not exposed. Hereinafter, specific numerical values will be described.

FIG. 2 shows the spectral sensitivity of a well-known typical photosensitive drum used in an electrophotographic apparatus. Thus, near 400 nm, Se and the mixture of zinc sulfide and cadmium sulfide have particularly high sensitivity. In the vicinity of 600 nm, LPC (Layere
d Photo Conductor) {Approximately 0.1 μm thick chlorodiane b
Membrane CGL (Char of mixture of lue and diphenylhydrazone
The CTL (Cha of about 15 μm on the ge Generation Layer)
rge transport layer) has a particularly high sensitivity. In addition, an organic photoconductor (polyvinylcarba
A positively charged mixture of 1: 1 mixture of zole and trinitrofluorenone) has sensitivity around 600 nm,
Organic photoconductor (a substance similar to that charged negatively)
Has a sensitivity in the range of 400 nm to 600 nm.

This shows that the photosensitive drum has no sensitivity to light having a wavelength of 600 nm or more. Therefore, for this reason, the measurement light source that emits the light having the wavelength of 600 nm or more and the light receiving element having the sensitivity of the wavelength of 600 nm or more are used. Further, from the viewpoint of providing a certain degree of margin with respect to the spectral sensitivity, it is preferable to use a light source and a light receiving element made of a material corresponding to light having a wavelength of 900 nm or more. Materials for the light source and the light receiving element corresponding to the wavelength of 900 nm or more include those shown in Tables 1 and 2 below.

[0029]

[Table 1]

[0030]

[Table 2]

Further, as the material of the light source and the light receiving element corresponding to the wavelength of 600 nm or more, in addition to the light source and the light receiving element corresponding to the wavelength of 900 nm or more, the materials shown in Tables 3 and 4 below are available. is there.

[0032]

[Table 3]

[0033]

[Table 4]

Further, in FIG. 2, since the substance (1) has a low sensitivity to a wavelength of 400 nm or less, a light source having a wavelength of 400 nm or less and a light receiving element having sensitivity to this wavelength are used. Materials for the light source and the light receiving element corresponding to the wavelength of 400 nm or less include those shown in Tables 5 and 6 below.

[0035]

[Table 5]

[0036]

[Table 6]

As described above, the light-emitting element and the light-receiving element in which the light emission wavelength and the wavelength having the spectral sensitivity match from the various materials of the light source and the light-receiving element are used by using the light having the wavelength which does not have the spectral sensitivity of the photoconductor. On the photoconductor drum 44, the optical lever optical system (in FIG. 1, the LD 25, the optical fiber 19 having the SELFOC lens 20, the reflection mirror 5, and the light receiving element 6) is configured by combining The state of the electrostatic latent image is not disturbed, so that the measurement of the surface potential and the like can be accurately performed without the measurement error. In addition, although the optical lever optical system was described,
It can also be applied when measuring the state of the sample by detecting the deformation and vibration of the cantilever by the optical interference method.

[Outline of Light Source] As shown in FIG. 3, an infrared laser diode having an emission wavelength of 1310 nm is used for the LD 25 as a measurement light source. Also here
Laser diode 2 as a light source for adjustment that emits visible light
8 (hereinafter, referred to as LD) is provided. This LD2
As 8, a visible light laser diode having a wavelength of 670 nm is used. The LD 28 is driven by a laser drive circuit 29.

Collimating lenses 30 and 31 are arranged on the optical paths of these two LDs 25 and 28, respectively. An optical coupler 32 is provided at a position where these two optical paths intersect. A focus lens 33 is arranged between the optical coupler 32 and the optical fiber coupler 23 to which the optical fiber 19 is connected. In this case, LD
The drive circuits 26 and 29, the LDs 25 and 28, the collimator lenses 30 and 31, the optical coupler 32, the focus lens 33, and the optical fiber coupler 23 constitute a laser diode unit 27.

FIG. 4 shows a state in which this device is constructed using the laser diode unit 27 of FIG. A stage 34 for adjusting the irradiation position is attached to the SELFOC lens 20 at the tip of the optical fiber 19. Further, the light receiving element 6 includes an X stage 3 that can move the element in the X direction.
5 is attached.

The operation of this apparatus will be described below. First, the laser drive circuit 26 is turned off, and the laser drive circuit 2
9 is turned on so that only the LD 28 emits visible light.
This visible light is collimated by the collimator lens 31,
It is condensed by the focus lens 33 via the optical coupler 32, and is introduced into the optical fiber 19 from the optical fiber coupler 23. The introduced light passes through the inside of the optical fiber 19, is emitted from the cell-fox lens 20 at the tip, and is irradiated to the reflection mirror 5 at the tip of the cantilever 1. The wavelength of the radiated light is 670 nm, which is within the region of the luminosity factor 36 as shown in FIG. 5, so the irradiation position can be confirmed with the naked eye or using an optical microscope. Therefore, from the above, using the stage 34 attached to the SELFOC lens 20,
The light emitted onto the cantilever 1 can be adjusted to a desired position of the reflection mirror 5. In addition, the light reflected from the cantilever 1 goes toward the light receiving element 6. Also in this case, while observing the reflected light with the naked eye, the light receiving element 6 is aligned using the X stage 35 so that the light enters the predetermined position of the light receiving element 6.

In this way, after adjusting the positions of the cantilever 1 and the light receiving element 6 where the light is irradiated using visible light, the laser drive circuit 29 is turned off at the time of actual measurement.
The laser drive circuit 26 is turned on to emit infrared light only from the LD 25. As a result, the infrared light is guided to the optical fiber 19 as in the case of visible light, is emitted from the SELFOC lens 20, and is irradiated to a predetermined position of the reflection mirror 5 on the cantilever 1, and The light is reflected by the cantilever 1 and guided to a predetermined position of the light receiving element 6 by a so-called optical lever method. At this time, the selfoc lens 20 and the cantilever 1
And the light receiving element 6 are set in the same state as when they are aligned with visible light, the optical axis through which infrared light passes becomes equal to the optical axis through which visible light passes,
Infrared light is emitted to the position aligned with visible light. By the method as described above, the alignment of the infrared light onto the cantilever 1 and the alignment of the light incident on the light receiving element 6 can be easily performed with visible light that can be visually confirmed. Thus, the displacement and vibration of the probe 2 can be accurately measured without including a measurement error.

[Details of Light Source] Here, the above-mentioned optical fiber 19 is not used, and the light for measurement from the LD 25 or the visible light from the LD 28 is transmitted to the emission side of the optical coupler 32. An exit window 37a is provided for
A focus lens 37 is attached to the exit window 37a. As a result, the laser diode unit 27
Is composed of LD drive circuits 26 and 29, LDs 25 and 28, collimator lenses 30 and 31, an optical coupler 32, an emission window 37a, and a focus lens 37. Further, here, the measuring LD 25 emits light having a wavelength that the sample 3 does not sensitize. The light receiving element 6 also has a sensitivity of a wavelength at which the sample 3 is not exposed.

FIG. 7 shows a state in which this device is constructed using the laser diode unit 27 of FIG. The operation of this device will be described below. First, the LD 28 is turned on, and the visible light emitted from the LD 28 is used to adjust the irradiation position on the cantilever 1 with the naked eye. The irradiation position can be adjusted by moving an irradiation position adjusting stage (not shown) mounted on the laser diode unit 27 (similar to the stage 34 in FIG. 4). Further, the light receiving element 6 also performs position adjustment using the X stage 35. After finishing the adjustment in this way,
By turning on the LD 25 and turning off the LD 28 and irradiating a predetermined position on the cantilever 1 with light having a wavelength that the sample 3 does not sensitize, the bending of the beam can be accurately measured by the optical lever method. .

As described above, the present apparatus is based on the optical fiber 1
9 is not used, and the light emitted from the laser diode unit 27 is directly guided onto the cantilever 1. Therefore, it is particularly applied to the measurement of a low-voltage surface potential or the like in which spark discharge or the like is not a problem. be able to. Also, LD
25, the light-receiving element 6 has its emission wavelength and light-receiving sensitivity wavelength in a wavelength that the sample 3 does not sensitize, so that the state of the sample surface is not disturbed by the light of the light source, and the measurement accuracy can be improved. The LD 2 that emits infrared light when performing alignment using visible light from the LD 28
5 may also be turned on at the same time, and after the alignment, only visible light may be turned off to perform actual measurement.

Next, FIG. 8 shows an example in which the laser diode unit 27 is applied to an apparatus adopting the so-called photothermal method (PT method). This PT
The method refers to irradiating the sample 3 with modulated light or pulsed light from a light source that emits a pump beam, and performing thermoelastic effects generated thereby to perform nondestructive evaluation of the composition of the material, coating layer, and measurement with a photoacoustic microscope. Say.

Sample 3 is made of a photosensitive material. An LD 38 (semiconductor laser) as a light source that emits a pump beam, and an optical system such as a lens 39 are arranged above the sample 3. This LD38 is a modulation power source 4
Driven by 0. An interference filter 41 and a light receiving element 42 (PSD) are arranged diagonally above the sample 3. This light receiving element 42 is connected to an amplifier 43,
This amplifier 43 sends the measurement signal a to the lock-in amplifier 44. A reference signal b is sent from the modulated light source 40 to the lock-in amplifier 44.

The operation of the device adopting the PT method will be described. By applying a pump beam from the LD 38 to the surface of the photosensitive sample 3, the sample surface periodically causes thermal expansion and vertical movement. The vertical movement of the sample surface is detected by the optical lever method using the light (probe beam) from the LD 25 of the laser diode unit 27 and the light receiving element 42, and the detected measurement signal a is detected by the lock-in amplifier 4
4, the surface shape of the sample 3 and the specific heat distribution can be examined. Even in such a measuring device, the position where the infrared light from the LD 38 is irradiated on the sample surface can be specified by using the LD 28 that emits visible light.

Next, one mode of implementation of the present invention will be described with reference to FIGS. In addition, the above-mentioned reference example (Fig. 1
8) and the description of the same parts is omitted, and the same parts are denoted by the same reference numerals.

As shown in FIG. 9, a wavelength converting member 45 for converting incident light into visible light is provided on the surface of the cantilever 1 opposite to the surface on which the probe 2 is formed. However,
The wavelength conversion member 45 exists in a region other than a region (hereinafter, probe region A) irradiated with light for detecting the bending of the cantilever 1.

FIG. 10 shows an example in which the cantilever 1 having such a wavelength conversion member 45 is paired with the laser diode unit 27 connected to the optical fiber 19. The laser diode unit 27 includes a laser drive circuit 26, an LD 25, a selfoc collimating lens 24, and an optical fiber coupler 23. A light receiving element 6 is arranged on the reflected light path of the cantilever 1 using the optical lever method. In this case, participants described above
Similar to Reference Example, the LD25 and the light receiving element 6, there is a wavelength of the emission wavelength and the light receiving sensitivity to the wavelength where the sample 3 is not sensitive.

Here, the function of the wavelength converting member 45 will be described. The infrared light emitted from the LD 25 is emitted from the SELFOC lens 20 via the optical fiber 19 and travels toward the cantilever 1. At this time, there is no problem if the infrared light is radiated into the probe area A which is a normal measurement position, but the infrared light is radiated onto the area outside the probe area A, that is, the wavelength conversion member 45. If so, infrared light is converted into visible light and shines at the irradiation position. Since such a glow means that the infrared light is out of the normal irradiation position, the position of the SELFOC lens 20 is searched for the bright position on the wavelength conversion member 45 using a stage (not shown). It is adjusted so that it is guided into the needle area A. In this way, since the infrared light used for measurement can be easily aligned on the cantilever 1 with the naked eye or using an optical microscope, an infrared scope or visible light is emitted. There is no need to separately provide a light source for adjustment. As a result, it is possible to provide a small and lightweight device that can be easily aligned.

Next, the material of the wavelength conversion member 45 will be described. The material of the wavelength conversion member 45 is selected according to the emission wavelength of the LD 25 used as the light source. First,
LD25 is in the ultraviolet range, especially the emission wavelength is 185n
In the case of m and 254 nm, the wavelength conversion member 45 is shown in Table 7,
It is formed by the composition (fluorescent material) as shown in Table 8.

[0054]

[Table 7]

[0055]

[Table 8]

When the LD 25 is in the ultraviolet light region, particularly when the emission wavelengths are 297 nm, 313 nm and 365 nm,
In the case of 400 nm or less, the wavelength conversion member 45 has a composition (fluorescent material) as shown in Table 9.

[0057]

[Table 9]

When the LD 25 is in the infrared light region, particularly when the emission wavelength is 800 nm or more, the wavelength conversion member 45 is shown in Table 1.
0 (fluorescent material).

[0059]

[Table 10]

When the LD 25 is in the infrared light region, particularly when the emission wavelength is 800 nm or more, the wavelength conversion member 45 is shown in Table 1.
It is composed of a composition (nonlinear optical material) as shown in FIG.

[0061]

[Table 11]

As can be seen from Tables 7 to 11 above,
By appropriately selecting the material of the wavelength conversion member 45 according to the emission wavelength of the LD 25, it is possible to efficiently emit light. In addition to such materials, organic nonlinear optical materials may be used.

Next, another embodiment of the present invention will be described with reference to FIG. Incidentally, the description of the embodiments the same parts as the implementation described above is omitted, using the same reference numerals for the same parts.

On the upper part of the cantilever 1, a shielding plate 46 as a shielding member is arranged with a constant interval. A hole 47 is formed in the tip region of the shielding plate 46. The area of the cantilever 1 immediately below the hole 47 is a probe area A to which light for detecting the bending of the beam is irradiated. In addition, a wavelength conversion member 45 that converts incident light into visible light is provided in a region of the shield plate 46 excluding the hole 47.

By thus disposing the shielding plate 46 having the wavelength conversion member 45 on the upper portion of the cantilever 1,
Similar to the implementation of embodiment described above (see FIG. 10), when the infrared light for the force detection is irradiated onto the wavelength converting member 45 is that portion for shining a visible light, the cantilever 1 Alignment can be done with the naked eye. In addition, the wavelength conversion member 45
Is not directly formed on the cantilever 1, but is formed on the shielding plate 46 that is separately arranged.
There are less restrictions on the design and production of the product, and the degree of freedom can be increased. In addition, in the present embodiment, the shielding member is the shielding plate 46 that covers only the upper portion of the cantilever 1, but the present invention is not limited to this, and the entire area of the cantilever 1 may be covered. .

Next, still another embodiment of the present invention will be described with reference to FIGS. It should be noted that description of the same parts as those in the above-described respective embodiments will be omitted, and the same reference numerals will be used for the same parts.

The periphery of the cantilever 1 is covered with a shield box 48 as a shielding member. The shield box 48 is made of a conductive material and has a large plate thickness and high rigidity. Hole 4 at the end of the shield box 48
7 is formed, and the wavelength conversion member 45 is provided on the upper surface side except the hole 47. Also, the shield box 48
The cantilever 1 and the cantilever 1 are connected by a lead wire 49, so that the shield box 48, the cantilever 1, and the probe 2 are set to the same potential.

By providing the wavelength converting member 45 in this way, the positioning is made with the naked eye so that the infrared light for force detection should be positioned in the probe area A on the cantilever 1 to be originally irradiated. can do. Further, since the shield box 48 has high rigidity, the shield box 48 does not vibrate even if an electrostatic force acts between the shield box 48 and peripheral devices (not shown). Along with this, the cantilever 1 does not vibrate either. Further, since the shield box 48, the cantilever 1 and the probe 2 are set to the same potential, the back surface of the cantilever 1 (the surface opposite to the surface on which the probe 2 is formed) and peripheral devices. The electrostatic attraction does not act between them, and as a result, the electrostatic attraction acts only between the probe 2 and the sample surface, so that no measurement error occurs. Since the wavelength conversion member 45 is not directly formed on the cantilever 1, the degree of freedom in design and manufacture can be increased.

FIG. 13 shows a modification of FIG. A transparent conductive film 50 made of a transparent conductive material is provided in the region of the hole 47 formed in the shield box 48 to close the upper surface side. The transparent conductive film 50 has the same potential as the shield box 48. By closing the probe region A in this way, the electrostatic force acting between the back surface of the cantilever 1 and the peripheral device can be further reduced, thereby further improving the measurement accuracy. You can

[0070]

[0071]

According to the first aspect of the present invention, the light source and the light receiving element are formed of a material corresponding to a wavelength that the sample does not sensitize, so that the state of the sample surface is not disturbed by the light of the light source. The accuracy can be further improved, and the light emitted from the light source is irradiated to the wavelength conversion member on the cantilever to convert it to visible light, so the irradiation position of the light emitted from the measurement light source can be adjusted. Can be performed much more easily.

According to the second aspect of the present invention, the light source and the light receiving element are arranged such that the wavelength at which the sample does not sensitize has the emission wavelength and the light receiving sensitivity wavelength, so that the state of the sample surface is disturbed by the light from the light source. It is possible to further improve the measurement accuracy and to convert the light emitted from the light source into visible light by irradiating it with the wavelength conversion member provided on the shielding member. The light irradiation position can be adjusted more easily, and since the wavelength conversion member is provided on the shielding member instead of on the cantilever, it is possible to design and manufacture the probe and cantilever. You can increase the degree.

According to the third aspect of the present invention, the light source and the light receiving element are formed of the material corresponding to the wavelength that the sample does not sensitize, so that the state of the sample surface is not disturbed by the light of the light source and the measurement accuracy is improved. Can be further increased,
Further, since the light emitted from the light source is irradiated onto the wavelength conversion member provided on the shielding member to be converted into visible light, it is possible to more easily adjust the irradiation position of the light emitted from the measurement light source. Moreover, since the wavelength conversion member is provided on the shielding member instead of on the cantilever,
The degree of freedom in designing and manufacturing the probe and cantilever can be increased, and the electrostatic attraction that acts between the cantilever and peripheral equipment can be reduced. The error can be eliminated and the measurement accuracy can be improved.

The invention according to claim 4 is 600 nm for a sample having a photosensitivity of about 400 nm.
The light source having the above emission wavelength is used, and the light source having the emission wavelength of 400 nm or less is used for the photosensitive material of the sample having a photosensitivity of around 600 nm. As a result, more accurate measurement can be performed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a physical quantity measuring device that is a reference example of the present invention.

FIG. 2 is a characteristic diagram showing the spectral sensitivity of a photoconductor.

FIG. 3 is a configuration diagram showing a light source unit.

4 is a configuration diagram showing a physical quantity measuring device including the light source unit of FIG.

FIG. 5 is a characteristic diagram showing the luminosity in the wavelength region that humans perceive.

FIG. 6 is a configuration diagram showing a light source unit.

7 is a configuration diagram showing a physical quantity measuring device including the light source unit of FIG.

FIG. 8 is a configuration diagram showing a physical quantity measuring device to which a photothermal method is applied.

9 show one embodiment of the implementation of the present invention,
(A) is sectional drawing of a cantilever, (b) is the top view.

FIG. 10 is a configuration diagram showing a physical quantity measuring device including the cantilever of FIG.

FIG. 11 shows another embodiment of the present invention,
(A) is sectional drawing of a cantilever, (b) is the top view.

12A and 12B show still another embodiment of the present invention, in which FIG. 12A is a sectional view of a cantilever, and FIG. 12B is a top view thereof.

13A and 13B show a modified example of FIG. 12, where FIG. 13A is a sectional view of a cantilever beam, and FIG. 13B is a top view thereof.

FIG. 14 is a sectional view showing a basic detection principle by a conventional optical lever method.

15 is a cross-sectional view showing a conventional example to which the detection optical system by the optical lever method of FIG. 14 is applied.

FIG. 16 is a circuit diagram showing a conventional physical quantity measuring device.

[Explanation of symbols]

1 cantilever (spring) 2 probe 3 samples 6 Light receiving element 25 Measurement light source 28 Light source for adjustment 45 Wavelength conversion member 46, 48 Shielding member

Continuation of front page (56) Reference JP-A-7-260806 (JP, A) JP-A-3-71001 (JP, A) JP-A-4-319607 (JP, A) JP-A-5-118843 (JP , A) JP 5-273276 (JP, A) JP 5-340718 (JP, A) JP 5-340723 (JP, A) JP 7-43372 (JP, A) JP 7-167808 (JP, A) JP-A-7-333234 (JP, A) JP-A-8-170906 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01N 13/00 -13/24 G01N 27/00-27/92 G01R 29/00-29/26 G01B 7/00-7/34 G01B 11/00-11/30 G01B 21/00-21/32

Claims (4)

(57) [Claims] 1. A spring having a probe attached thereto, wherein bending or vibration of the spring or a change in vibration is optically caused by a force acting between the probe and a surface of a sample arranged opposite thereto. In a physical quantity measuring device for measuring the physical quantity of the sample by detecting using a method, a light source for measurement that emits light having a wavelength that the sample does not sensitize, and a light receiving element having sensitivity to a wavelength that the sample does not sensitize A physical quantity measuring device characterized in that a wavelength conversion member for converting the light emitted from the measurement light source into visible light is provided in a portion other than the portion of the spring irradiated with the light emitted from the measurement light source. 2. A spring having a probe attached thereto, wherein bending or vibration of the spring or a change in vibration is optically caused by a force acting between the probe and a surface of a sample arranged opposite thereto. In a physical quantity measuring device for measuring the physical quantity of the sample by detecting using a method, a measurement light source that emits light of a wavelength that the sample does not sensitize, and a light receiving element that has sensitivity to a wavelength that the sample does not sensitize And a shielding member that covers a part or the whole of the spring except the probe region, and a wavelength conversion member that converts the light of the measurement light source into visible light is provided on the shielding member. Physical quantity measuring device. 3. A spring having a probe attached thereto, wherein the bending or vibration of the spring or a change in vibration is optically caused by a force acting between the probe and a surface of a sample arranged opposite thereto. In a physical quantity measuring device for measuring the physical quantity of the sample by detecting using a method, a measurement light source that emits light of a wavelength that the sample does not sensitize, and a light receiving element that has sensitivity to a wavelength that the sample does not sensitize However, a shield member formed of a conductive material having a rigidity higher than that of the spring, which covers a part or the entire region of the spring except the probe region of the spring, is provided, and the shield of the measurement light source is provided on the shield member. A physical quantity measuring device characterized in that a wavelength conversion member for converting light into visible light is provided, and a shielding member having this wavelength conversion member is set to the same potential as the spring and the probe. 4. The emission wavelength of a light source to which a sample is not exposed is set to 4
00nm or less, or, the physical quantity measuring device of claim 1, 2 or 3, wherein it has a value of more than 600 nm.