JPH09329899A - Production of electrophotographic photoreceptor and producing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a thickness of each functional layer by using an intermediate product or finished product obtd. in the production processes. SOLUTION: An electrophotographic photoreceptor is produced by successively forming plural different functional layers on a conductive base body. In this case, after each functional layer is formed, the absorbance of the formed layer is measured by using the light of such wavelength that is specifically absorbed by the objective layer but is hardly absorbed by the functional layers previously formed under the objective layer. The film thickness is determined by using the measured absorbance and the formula to calculate the film thickness from the obtd. absorbance. When the obtd. film thickness differs from the designed film thickness, the drawing speed of the electrophotographic photoreceptor from a coating tank filled with a coating liquid for the functional layer is changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing an electrophotographic photosensitive member in which a plurality of different functional layers containing an organic material are sequentially laminated on the surface of a conductive substrate.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic photosensitive member used in an electrophotographic apparatus such as a copying machine or a printer, an organic photoconductive material is electrophotographically formed on a conductive substrate made of aluminum, stainless steel or the like. It is known that layers are sequentially laminated according to the function in the process. In such an electrophotographic photoreceptor, a coating liquid in which an organic photoconductive material for forming each functional layer is dissolved or dispersed in an organic solvent together with a binder resin is sequentially coated on a conductive substrate and dried. It is manufactured by Many methods are known as coating methods for this coating liquid, and examples thereof include a spray coating method, a roll coating method, and a dip coating method. Of these, the dip coating method is a method of forming a functional layer by immersing a conductive substrate in a coating tank filled with the above-mentioned coating liquid and then pulling it up at a constant speed, and it is often used because of its high productivity. Are used in the manufacture of the photoconductors.

However, in the dip coating method, since the organic solvent easily evaporates from the coating liquid in the coating tank, the viscosity and the concentration are likely to change, and the coating film thickness changes as the viscosity and the concentration of the coating liquid change. Therefore, it is difficult to form a uniform coating film. Therefore, the variation of the coating film thickness is reduced by adjusting the pulling rate and the coating liquid viscosity for each coating process of each functional layer, and the coating film thickness is measured to check whether or not the desired film thickness is obtained. are doing.

Conventionally, as a method for measuring the coating film thickness, a contact type film thickness measuring method using a step gauge, a surface roughness meter, an eddy current film thickness meter, a color difference meter, a capacitance type film thickness, etc. Total,
Fluorescent X-ray film thickness meter, beta ray film thickness meter, optical interference type film thickness meter, non-contact type film thickness measuring method such as film thickness measuring method using light absorption method, or sample with optical microscope, electron microscope, etc. A photographic method for observing a cross section is known.

Among these, the contact type film thickness measuring method and the photographic method have a drawback that the photoreceptor used for the measurement cannot be used as a product because it damages the photoreceptor itself.
Moreover, even in the non-contact type film thickness method, in the colorimeter,
It is possible to measure the thickness of a pigment dispersion layer such as a charge generation layer, but it is not possible to measure the thickness of a transparent layer that does not contain a pigment such as an undercoat layer or a charge transport layer. Thickness gauges have problems in measurement accuracy and measurement resolution, and fluorescent X-ray film thickness meters and beta ray film thickness meters require special facilities.

On the other hand, the film thickness measuring method using the light interference type film thickness meter which utilizes the interference effect due to the multiple reflection of light can be evaluated relatively easily and in a short time. It is often used when measuring the film thickness of a transparent film such as an undercoat layer or a charge transport layer.
Japanese Patent No. 6540 discloses a method of controlling the coating speed in each coating step by evaluating the film thickness of the undercoat layer and the charge transport layer of the electrophotographic photosensitive member by this method.

Further, a film thickness measuring method using a light absorption method, which utilizes the fact that the absorption of light by the film varies depending on the film thickness, can be evaluated relatively easily and in a short time.
It is often used to measure the film thickness of electrophotographic photoreceptors. Practical characteristic values used in the light absorption method include absorptance, reflectance, etc., each of which represents the ratio of the amount of incident light to the film and the amount of reflected light. In many cases, these characteristic values have a correlation with the film thickness to be measured, and in such a case, the film thickness can be converted from the obtained characteristic value and the conversion formula obtained in advance. For example, JP-A-6-1306
No. 83 discloses that a film of a charge generation layer is directly provided on the surface of a substrate outside the image forming area of an electrophotographic photosensitive member without providing an undercoat layer, and a light absorption spectrum at that position obtained by a spectrophotometer is used. A method of calculating the ratio of the incident light amount and the reflected light amount of a specific single wavelength, that is, the light absorptance and converting the film thickness is disclosed.

However, there are cases where the above two methods cannot be used in the actual manufacturing process of the electrophotographic photosensitive member. For example,
In the case of electrophotographic photoreceptors used in digital color copying machines and printers, which have become mainstream in recent years, honing method, etching method, hard sphere drop / collision method, concavo-convex shape cylindrical body pressure welding method, grinding / cutting method, laser irradiation Method, a method of mechanically roughening the substrate surface such as a high-pressure water jet method, a method of oxidizing the substrate surface such as an anodizing method, a boehmite treatment method, a heat oxidation treatment method, and the like to prevent interference fringes. It is generally practiced to increase the roughness of the conductive substrate surface or the interface of the undercoat layer to prevent the interference fringes of the film by providing an intermediate layer between the photosensitive layer and the substrate surface. When light from an interference-type film thickness meter is projected onto a thin film on a conductive substrate that has been subjected to interference fringe prevention treatment in this way, the method disclosed in Japanese Patent Laid-Open No. 4-336540 discloses a rough substrate surface or The interference spectrum of light cannot be detected due to the scattering at the interface of the undercoat layer. Even when the interference fringe prevention measure is not applied, the sample in which the undercoat layer and the charge generation layer are sequentially stacked, or the sample in which the undercoat layer, the charge generation layer, and the charge transport layer are sequentially stacked is electrically conductive. Since a multiple interference occurs at the surface of each conductive substrate and each layer interface, a special sample for film thickness measurement is used in which only one of the undercoat layer, charge generation layer and charge transport layer is formed on the conductive substrate. Otherwise, the waveform for calculating the film thickness cannot be detected. That is, in this method, the measurement cannot be performed using the intermediate product itself obtained in the manufacturing process.

On the other hand, even in the method using the light absorption spectrum disclosed in Japanese Patent Application Laid-Open No. 6-130683, only the reflected light can be measured only by the spectrophotometer, and only the reflected light amount can be obtained. It is necessary to separately provide a sensor for measuring the amount of incident light, which is essential for calculating the absorption rate. Further, since the film thickness of the electrophotographic photosensitive member is not always uniform, unevenness in the circumferential direction, unevenness in the axial direction,
It is essential to evaluate unevenness such as sagging. In particular, it is generally known that the film of the charge generation layer has large unevenness in thickness, and when the above method is used, only the portion where the undercoat layer is not formed, that is, the film thickness evaluation outside the image forming area is evaluated. It cannot be done and is not practical.

[0010]

SUMMARY OF THE INVENTION The present invention uses an intermediate product or a final product obtained in a manufacturing process to sequentially measure the absorbance of each functional layer of the intermediate product or the final product. It is an object of the present invention to provide a manufacturing method and a manufacturing apparatus capable of preventing the fluctuation of each film thickness and obtaining an electrophotographic photosensitive member having a certain characteristic.

[0011]

The present invention provides a method for manufacturing an electrophotographic photosensitive member comprising a conductive substrate, and a plurality of different functional layers containing an organic material sequentially laminated on the surface of the conductive substrate. An absorbance measurement step of measuring the absorbance at a wavelength at which the absorption of the functional layer formed under each of the functional layers is small and which is characteristically absorbed by each of the functional layers, and each of the functions based on the measured absorbance. A control step of controlling the application of each of the functional layers so that the thickness of the layer becomes constant.

Further, the present invention is an apparatus for manufacturing an electrophotographic photosensitive member comprising a conductive substrate surface on which a plurality of different functional layers containing an organic material are sequentially laminated. Absorbance measuring means for measuring the absorbance at a wavelength that is characteristically absorbed in the layer and is less absorbed by the functional layer formed under each of the functional layers, and the film thickness of each of the functional layers based on the measured absorbance. Control means for controlling the application of each of the functional layers so that the above is constant.

As described above, since the wavelengths that are characteristically absorbed by each functional layer and are less absorbed by the functional layer formed under each functional layer are used for the measurement of the absorbance, the interference fringe prevention treatment is performed. It is possible to measure the film thickness of each functional layer by using the above-mentioned conductive substrate, an intermediate product having a plurality of different functional layers containing an organic material, or the final product itself. In addition, since the film thickness of each functional layer can be measured using the intermediate product or the final product itself, by changing the film thickness measurement position in the same sample, there will be no unevenness in the circumferential direction, unevenness in the axial direction, sagging, etc. Uniformity can be evaluated.

In the above invention, the absorbance at a wavelength characteristically absorbed by each functional layer and less absorbed by the functional layer formed under each functional layer is characteristically absorbed by each functional layer and Measuring the absorbance at a wavelength at which the functional layer formed under each functional layer has a small absorption and the absorbance at a wavelength at which the functional layer formed under each of the functional layers and each of the functional layers has a small absorption. Can be measured by

In the above control process and control means,
It is possible to determine whether or not the theoretical value obtained from the film thickness calculation formula for calculating the film thickness from the absorbance and the measured absorbance is different from the set film thickness.

The wavelength used for measuring the absorbance may be in the infrared region or in the visible wavelength region. When the wavelength used for measuring the absorbance is in the infrared region, the absorbance of a transparent layer containing no pigment such as the undercoat layer or the charge transport layer can be measured. On the other hand, when the wavelength used for measuring the absorbance is in the visible wavelength region, the pigment is dispersed like the charge generation layer, and the functional layer in which the absorption of light by the film appears remarkably in the visible wavelength region. The absorbance of can be measured. A wavelength in the infrared region may be used for measuring the absorbance of the charge generation layer.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

FIG. 9 shows an example of the electrophotographic photosensitive member used in this embodiment. The electrophotographic photosensitive member 1 shown in FIG. 9 is a transparent undercoat layer containing no pigment in order from the conductive substrate 2 side on a cylindrical conductive substrate 2 which has been subjected to interference fringe prevention treatment in advance by honing. 3. A charge generation layer 4 containing a pigment and a transparent charge transport layer 5 containing no pigment are laminated.

For forming each functional layer of such an electrophotographic photosensitive member 1, for example, a coating device 6 shown in FIG. 10 can be used. In FIG. 10, the arrow A direction indicates the upper side of the device, and the arrow B direction indicates the device depth direction.
The coating device 6 includes a bottomed cylindrical coating tank 7, a lift 9 for pulling up the conductive substrate 2 from the coating tank 7, and a lift 9
An operation control unit 1 which is electrically connected to and controls the entire coating device 6.
0 is provided. The coating tank 7 is filled with a coating liquid 11 for forming any one of the undercoat layer 3, the charge generation layer 4, and the charge transport layer 5, and the viscosity of the coating liquid 11 is a viscosity controller (not shown). Is kept constant by. Further, the elevator 9 includes a box-shaped support 9A and a support 9A that are long in a direction orthogonal to both the arrow A direction and the arrow B direction.
From the vertical direction, the plate-shaped standing portion 9B having the longitudinal direction arranged along the longitudinal direction of the support 9A, the longitudinal direction is arranged along the longitudinal direction of the standing portion 9B, An elevating part 9C supported by an upright part 9B so as to be vertically movable along the elevating part 9C and connected to elevating means (not shown), and an elevating part 9C so as to be movable along the longitudinal direction of the elevating part 9C. It has a pair of support arms 9D attached to the side opposite to the standing portion 9B side. The support arm 9D includes a plate-shaped support portion 9E disposed on the side of the elevating portion 9C, and the support portion 9E.
Is provided on the side opposite to the elevating part 9C side, and is provided with a sandwiching part 9F having a substantially semicircular shape when viewed from above, and the sandwiching parts 9F of the pair of support arms 9D project when viewed from above. They are attached to the elevating part 9C so that the side where they are located is outside each other and is arranged above the coating tank 7. The sandwiching portion 9F of the pair of support arms 9D has a cylindrical conductive base 2
The conductive substrate 2 is supported by the support arm 9D by sandwiching the outer periphery thereof and is immersed in the coating tank 7 and pulled up by the elevation of the support arm 9D as the elevation unit 9C moves up and down. When the viscosity of the coating liquid 11 is constant, the pulling speed and the film thickness generally have a linear relationship within a certain range, and the film thickness can be made constant by keeping the pulling speed constant. Then, the film thickness can be adjusted by adjusting the pulling rate. However, even if the viscosity and the pulling rate of the coating liquid 11 are constant, the film thickness may change depending on the aging rate, the roughness of the conductive substrate 2, and the like. Detect changes.

In carrying out the present invention, first, the materials of the undercoat layer 3, the charge generation layer 4 and the charge transport layer 5 are selected, and then the calibration formulas are obtained for each of these functional layers. The calibration formula is a formula expressing the relationship between the actual film thickness (actual film thickness) and the absorbance, and generally the actual film thickness shows a linear relationship with the absorbance.

The actual film thickness can be measured by a known method such as a step method or a photographic method using an optical microscope or an electron microscope.

On the other hand, the absorbance is measured as follows.
The wavelength in the infrared region and the following formula are used for measuring the absorbance of layers containing no pigment such as the undercoat layer 3 and the charge transport layer 5. Absorbance = L (λ ₂ ) − {L (λ ₁ ) + L (λ ₃ )} / 2− (1) In the formula, λ ₂ is the wavelength characteristically absorbed by the layer, and λ ₁
The wavelengths shorter than the absorption is small and lambda ₂ of the layer, lambda ₃
A wavelength longer than λ ₂ with less absorption in the layer is
(Λ) indicates the absorbance at the wavelength λ.

The absorbance calculation method using three wavelengths according to the above absorbance calculation formula (1) can eliminate error factors such as surface reflection, confusion, and internal multiple reflection, and can accurately calculate the absorbance of only the target layer. .

The absorbance of the charge generation layer 4 can be measured in the same manner as the undercoat layer 3 and the charge transport layer 5, but it contains a pigment like the electrophotographic photoreceptor 1 according to the present embodiment. If there is only one layer or if the layers with pigments contain pigments with different absorption wavelengths, the wavelengths in the visible wavelength range and the following formula can be used. Absorbance = L (λ ₄ ) / L (λ ₅ ) −−−−−−−−−−−− (2) In the formula, λ ₄ is the wavelength with the least absorption in the charge generation layer 5, and λ ₅ is the charge. The wavelength with a large absorption in the generation layer 5 is
L (λ) indicates the absorbance at the wavelength λ.

The wavelengths λ ₄ and λ ₅ used for measuring the absorbance of the charge generation layer 4 irradiate the charge generation layer 4 with visible light and measure the amount of visible light, such as a spectrophotometer. Obtained by measuring the absorbance spectrum using
As described above, the wavelength X _{1 having} the least absorption and the wavelength X ₂ having the most absorption are determined as λ ₄ and λ ₅ , respectively.

On the other hand, the absorbance of the undercoat layer 3 and the charge transport layer 5
The wavelength used for measurement is determined as follows. First of all
Organic system used for layer 3, charge generation layer 4 and charge transport layer 5
Infrared absorption of photoconductive materials and substances contained in binder resins
Measure the spectrum. Then these infrared absorption
Absorbance of the undercoat layer 3 and the charge transport layer 5 based on the vector
Select the wavelength used for measurement. Specifically, charge transport
Shows an absorption peak in the infrared absorption spectrum of layer 5
Of the wavelengths, the undercoat layer 3 formed below the charge transport layer 5 and
Wavelength X with little absorption in the charge generation layer 4_FourThe charge transport layer 5
Wavelength λ characteristically absorbed at₂And Also below
Shows an absorption peak in the infrared absorption spectrum of pulling layer 3
Wavelength, wavelength X_FourDifferent wavelength X₇Undercoat layer 3
Wavelength λ characteristically absorbed at₂And Then
The absorption of the undercoat layer 3 is small and the wavelength X ₇Shorter wavelength X₆To
Λ above₁And the absorption of the undercoat layer 3 is small and the wavelength X₇Yo
Longer wavelength X₈Is the above λ_ThreeAnd Similarly, undercoat layer
Waves with little absorption in the charge generation layer 4, the charge generation layer 4, and the charge transport layer 5
Long and wavelength X_FourShorter wavelength X_ThreeThe charge transport layer
Wavelength λ at 5₁And the undercoat layer 3, charge generation layer 4, and
And the wavelength of which the absorption of the charge transport layer 5 is small and the wavelength X
_FourLonger wavelength X_FiveIs the above λ_ThreeAnd The wavelength X
_ThreeAnd wavelength X₆, Wavelength X_FiveAnd wavelength X₈Are the same but different
May be. Figure 7 shows the wavelength λ₁~ Λ_ThreeAnd the absorbance
Is shown.

Next, a calibration formula is determined using these selected wavelengths. When determining the calibration formula, a filter that allows only one specific wavelength used for measuring the absorbance to pass is prepared. The filter is prepared in correspondence to each of the wavelength X ₁ to X ₈ which was selected. In addition, the light source for the infrared region can emit infrared light of the selected wavelengths X _{3 to} X ₅ and the wavelength X.
Those capable of irradiating infrared light of _{6 to} X ₈ or wavelengths X _{3 to} X ₈
Prepare the one that can irradiate the infrared light. As such a light source for the infrared region, for example, a nichrome line light source or the like can be used. Further, the light source for the visible region has wavelengths X _{1 to} X.
Prepare the one that can irradiate ₂ visible light. As such a light source for the visible region, for example, a halogen lamp or the like can be used. Further, an infrared absorbance measuring instrument or a spectrophotometer can be used for measuring the absorbance.

On the other hand, a plurality of samples for determining the calibration formula are prepared using the coating device 6 described above. For example, a plurality of samples in which an undercoat layer 3 having a different film thickness is formed on a conductive substrate 2 having the same material and the same shape, and an undercoat having the same film thickness on the conductive substrate 2 having the same material and the same shape. A plurality of samples each having a layer 3 formed thereon and a charge generation layer 4 having a different film thickness formed thereon, and a conductive substrate 2 made of the same material and having the same shape.
A plurality of samples in which the undercoat layer 3 having the same thickness is formed on the charge generation layer 4, the charge generation layer 4 having the same thickness is formed thereon, and the charge transport layer 5 having the different thickness is further formed thereon. And create. Prior to the preparation of the sample, the relational expression between the actual film thickness and the pulling rate is obtained. Then, the operator inputs the set film thickness to the operation control unit 10 so that the operation control unit 10 selects the pulling speed corresponding to the input set film thickness, and each functional layer is formed at the selected pulling speed. A sample is created.

The absorbance is measured using the sample, the light source and the filter prepared as described above, and the calibration formula is obtained from the actual film thickness measured using the same sample and the measured absorbance. After determining the calibration formula, use intermediate products and final products obtained in the actual manufacturing process, and for each functional layer formation process,
The absorbance of the most recently formed functional layer, that is, the undercoat layer 3 in the process of forming the undercoat layer 3, the charge generation layer 4 in the process of forming the charge generation layer 4, and the charge transport layer 5 in the process of forming the charge transport layer 5. The expected film thickness is obtained from the measured absorbance and the determined calibration formula, and it is determined whether the expected film thickness is the same as the set film thickness. If they are different, the application is controlled so that the film thickness of each functional layer matches the set film thickness by adjusting the pulling rate or the like. For the determination of the calibration formula and the calculation of the expected film thickness, for example, the film thickness measuring device 20 shown in FIG. 1 can be used.

The film thickness measuring device 20 includes a CPU 22 for controlling the film thickness measuring device 20 as a whole, a program for controlling the film thickness measuring device 20 as a whole, a control program which will be described later, and the above two absorbance calculation formulas (1). , (2) and the like stored in ROM 24, RAM 26 as a work area, disk 28, RTC (real-time clock) 30 for synchronizing, keyboard 32 for inputting data and commands, and input data. A display 34 for displaying the calculation result and the like, and a printer 36 for outputting the calculation result and the like are provided, and these are connected to each other via a system bus 38. Further, the film thickness measuring device 20 includes a light source 40 corresponding to a wavelength selected for measuring the absorbance of the functional layer to be measured, and a sample 4
4, a light quantity sensor 42 for measuring the absorbance of the light source 4, and a light source 4
0 and a light amount sensor 42, which irradiates the sample 44 with the light emitted from the light source 40 and guides the light reflected from the sample 44 to the light amount sensor 42;
An SH that is connected to the light amount sensor 42 and the system bus 38 and samples and holds the absorbance data measured by the light amount sensor 42 when an SH (sample hold) signal is output from the CPU 22 via the system bus 38.
A circuit 48 and an A / D (analog-digital) converter 50 connected to the SH circuit 48 and the system bus 38 for converting the absorbance data, which is analog data sampled and held by the SH circuit 48, into digital data. I have it.

2 to 6 show an example of the operation of the CPU 22 of the film thickness measuring device 20.

After turning on the power source of the film thickness measuring device 20 (including the power source of the light source 40 and the light amount sensor 42) and activating the program for preparing the calibration formula and the film thickness measurement, the operator performs the calibration through the keyboard 32. A predetermined key operation for instructing formula formation or film thickness measurement is performed. As an operation procedure, first, a calibration formula is created, and then film thickness measurement is performed. When a calibration formula is created in advance and the calibration formula is already stored in the disk 28, the film thickness measurement may be performed immediately.

In step 100 of FIG. 2, the keyboard 3
It is determined whether or not there is an input from 2, and if there is no input, it waits, and if there is an input, the next step 102
Then, it is determined whether or not the input from the keyboard 32 is an instruction to create a calibration formula.

When the operator performs a predetermined key operation for instructing the preparation of the calibration formula, the determination at step 102 is affirmative, and at the next step 104, the calibration formula is prepared according to the subroutines of FIGS. Exit the routine.

In the calibration formula creating subroutine shown in FIGS. 3 to 4, the display 34 indicates whether to select which of the above formulas (1) and (2) is used to calculate the absorbance at step 110. To display. In the next step 112, the absorbance calculation formula selection data input by the operator via the keyboard 32 is taken in, and in the next step 114, the absorbance calculation formula and its parameters used to create the calibration formula from the taken absorbance calculation formula selection data. Determine the number n. Here, the parameter number n is L (λ ₁ ), L (λ ₂ ) and L (λ ₂ ) in the case of the absorbance calculation formula (1).
₃ ), and L in the case of absorbance calculation formula (2)
(Λ ₄ ) and L (λ ₅ ).

In the next step 116, the sample No.
Is set to 1 and the counter j for measuring the number of parameters is set to 1.

In the next step 118, the sample No.
The display 34 indicates that i should be set at a predetermined position and that a setting completion signal should be input after setting is completed. By this display, the operator can select the sample No. Set i, keyboard 32
A predetermined key operation is performed via.

In the next step 120, the keyboard 32
It is determined whether or not the setting completion signal has been input from the above. If the setting completion signal has not been input, the process returns to step 118. On the other hand, when the setting completion signal is input, in the next step 122, the process shown in FIG.
Calculate the absorbance according to the subroutine.

In the subroutine for calculating the absorbance shown in FIG. The display 34 indicates that j should be set in the light source 40 and that a setting completion signal should be input after the setting is completed.
This display allows the operator to select the selected wavelengths λ ₁ , λ
Filter No. 2 corresponding to either wavelength ₂ or λ ₃ or wavelength λ ₄ or λ ₅ . j is set, and a predetermined key operation is performed via the keyboard 32.

In the next step 148, the keyboard 32
It is determined whether or not the setting completion signal has been input from the above. If the setting completion signal has not been input, the process returns to step 146. On the other hand, when the setting completion signal is input, in the next step 150, the SH signal is output to the SH circuit 48 via the system bus 38. As a result, the SH circuit 48 causes the filter No. is emitted from the light source 40 via the sample No. j. The absorbance data reflected by i and converted into an electric signal by the light amount sensor 42 is sample-held. The sample-held absorbance data is converted from analog data to digital data by the A / D converter 50. In the next step 152, the converted absorbance data is captured via the system bus 38.

In the next step 154, it is judged whether or not the counter j has reached the parameter number n, and if the counter j has not reached the parameter number n, step 156.
Then, j is incremented by 1 and the process returns to step 146. On the other hand, when the counter j reaches the parameter number n, in the next step 158, the sample No. is determined from the selected absorbance calculation formula and the two or three absorbance data. The absorbance of j is calculated, the calculated absorbance is displayed on the display 34 in the next step 160, and the process returns to the routine of FIG.

Since at least two data are required to obtain the calibration formula, after measuring the absorbance, step 124 in FIG.
Then, it is determined whether or not the counter i is 1. When the counter i is 1, the counter i is incremented by 1 in the next step 126, the counter j is set to 1, and the process returns to step 118. On the other hand, if the counter i is not 1, the determination at step 124 is negative and the next step 1
At 28, it is displayed on the display 34 that it is instructed whether or not to continue the operation for calculating the absorbance. With this display, the operator performs a predetermined key operation for instructing the continuation of the operation or the end of the operation via the keyboard 32.

In the next step 130, the keyboard 32
If there is no input from the keyboard 32, it returns to step 128. On the other hand, if there is an input from the keyboard 32, in the next step 132, it is determined whether or not the input from the keyboard 32 is an instruction to continue the operation, and the input from the keyboard 32 continues the operation. If the instruction is for, the process proceeds to step 126. If the input from the keyboard 32 does not indicate that the operation should be continued, then in step 134 (FIG. 4), the sample No. The display 34 indicates that the actual film thicknesses 1 to i should be input. The operator measures the actual film thickness using the same sample before or after the absorbance measurement, and the measured actual film thickness is determined by the keyboard 32.
To enter via.

In the next step 136, the input sample number. The actual film thicknesses from 1 to i are taken in, and in the next step 138, the calibration formula is determined from the calculated absorbance and the corresponding actual film thickness.

At the next step 140, the display 34 indicates that the file name should be input. Thereby, the operator inputs the file name via the keyboard 32. In the next step 142, it is determined whether or not there is an input from the keyboard 32. If there is no input from the keyboard 32, the process returns to step 140, and if there is an input from the keyboard 32, the next step 144
Then, the input file name, calibration formula, and absorbance calculation formula selection data are stored in the disk 28, and the process returns to the routine of FIG.

When the preparation of the calibration formula for each functional layer is completed, the actual product is manufactured, and the film thickness of the functional layer is measured by the film thickness measuring device 20 each time the functional layer is formed. For the film thickness measurement, an intermediate product or final product obtained by actual manufacturing affirmation can be used.

If the input from the keyboard 32 does not instruct the preparation of the calibration formula in step 102 of FIG. 2 described above, in the next step 106, it is determined whether or not the input from the keyboard 32 instructs the film thickness measurement. To determine.
If the input from the keyboard 32 does not instruct the film thickness measurement, the routine ends. On the other hand, when the input from the keyboard 32 is to instruct the film thickness measurement, the film thickness is measured according to the subroutine of FIG. 6 in the next step 108, and the routine ends.

In the film thickness measurement subroutine of FIG. 6, in step 162, the display 34 indicates that a file name should be input. By this display, the operator inputs the file name storing the calibration formula used for measuring the film thickness of the functional layer formed through the keyboard 32. In the next step 164, the input file name is fetched, and in the next step 166, the file having the fetched file name is read from the disk 28.

In the next step 168, the fact that the set film thickness should be input is displayed on the display 34. By this display, the operator inputs the same set film thickness as the set film thickness input to the coating device 6 via the keyboard 32. In addition,
A numerical range may be entered as the set film thickness.

In the next step 170, the input data is fetched and set as the set film thickness t _s . In the next step 172, the counter j for measuring the number of parameters is set to 1.

In the next step 174, the display 34 indicates that the sample intermediate product or final product should be set at a predetermined position and that a setting completion signal should be input after the setting is completed. With this display, the operator sets the sample and performs a predetermined key operation via the keyboard 32.

At the next step 176, the keyboard 32
It is determined whether or not the setting completion signal has been input from the above. If the setting completion signal has not been input, the process returns to step 174. On the other hand, when the setting completion signal is input, in the next step 178, the absorbance is calculated according to the above-mentioned subroutine of FIG.

In the next step 180, the read calibration
Expected film thickness t from the formula and calculated absorbance_cTo calculate. Next
In step 182, the calculated expected film thickness t_cSet membrane
Thickness t _sIt is determined whether or not At this time, the setting film
Thickness t_sIs within the numerical range, the calculated expected film thickness t
_cIs the set film thickness t_sWhether included in the numerical range of
I do. Calculated expected film thickness t_cIs the set film thickness t_sMatches
If so, in the next step 184, display 34
A message that the result is passed is displayed and the process proceeds to step 188. on the other hand,
Calculated expected film thickness t_cIs the set film thickness t_sIf does not match
The display 34 in the next step 186.
The expected film thickness t_cAnd set film thickness t_sTo display
Go to step 188.

In step 188, it is displayed on the display 34 that an instruction as to whether or not to continue the film thickness measurement using another sample should be input. By this display, the operator performs a predetermined key operation for instructing to continue the film thickness measurement or a predetermined key operation for instructing the end of the film thickness measurement via the keyboard 32.

In the next step 190, the keyboard 32
If there is no input from the keyboard 32, the process returns to step 188. If there is an input from the keyboard 32, the next step 192 is performed.
Then, it is determined whether or not the input from the keyboard 32 is an instruction to continue the film thickness measurement. If the input from the keyboard 32 is an instruction to continue the film thickness measurement, the determination in step 192 is affirmative and step 172
Return to On the other hand, if the input from the keyboard 32 does not instruct to continue the film thickness measurement, the process returns to the routine of FIG.

As described above, in the film thickness measuring device 20 according to the present embodiment, after each functional layer is formed, it is characteristically absorbed by the most recently formed functional layer and is formed under this functional layer. The absorption of the functional layer is measured by a small wavelength absorption, without being affected by absorption in the functional layer other than the functional layer to be measured, it is possible to measure the absorbance of the functional layer to be measured, The film thickness can be measured using an intermediate product or a final product obtained in actual manufacturing. Further, the film thickness measuring device 20 according to the present embodiment is
Since the pass / fail of the sample is determined based on the measured absorbance and is displayed, the operator can recognize the pass / fail of the sample, and the expected film thickness t _c and the set film thickness t _s are displayed. Based on this, the pulling rate of the coating device 6 can be adjusted.

In the above embodiment, the set film thickness is input after reading the file. However, the set film thickness is also stored in the file and the set film thickness is read together when the file is read. May be.

In the above embodiment, the completion of setting the sample is confirmed by the setting completion signal from the operator. However, a sensor such as a photo sensor for detecting whether the sample is set at a predetermined position or not. May be arranged to confirm the completion of setting of the sample by the detection signal of this sensor, and the operator's input operation of the setting completion signal may be omitted.

Further, in the above embodiment, the operator is made to input each time whether or not to continue the measurement.
Omit steps 188 and 190 and step 192
Then, it may be determined whether or not the measurement end signal is input, and the measurement may be continuously performed unless the measurement end signal is input, and the measurement may be continuously performed.

A light amount controller for the light source 40 may be provided so that the measured light amount of the light source 40 is constant. In this case, steps 146 and 148 of FIG.
A step for adjusting the light amount of the light source 40 may be provided between and.

Further, in the above embodiment, the speed adjustment after the pass / fail judgment is manually performed, but the coating device 6 and the film thickness measuring device 20 are connected to automatically perform the speed adjustment after the pass / fail judgment. May be. In this case, the CPU 2 of the film thickness measuring device 20
The operation control unit 10 may be omitted by controlling the elevator 9 by means of 2.

Furthermore, in the above embodiment, the film thickness is measured using the intermediate product or the final product after the determination of the calibration formula, but the absorbance can be measured using a special sample for film thickness measurement. Good.

The present invention may be applied to a coating method other than the dip coating method.

[0064]

EXAMPLES The present invention will be specifically described below based on examples, but the present invention is not limited to these examples.

The material of the conductive substrate and the composition of the coating liquid for each functional layer used in the examples of the present invention are as follows. (Conductive Substrate) Aluminum Pipe (Diameter 30 mm, Length 340 mm) Roughened by Honing in advance (Undercoating layer coating liquid) Tributoxyzirconium acetylacetonate 50% toluene solution 90 parts by weight γ-methacryloxypropyltrimethoxysilane 11 Parts by weight i-propyl alcohol 400 parts by weight n-butyl alcohol 200 parts by weight (charge generation layer coating solution) chlorogallium phthalocyanine crystals 1 part by weight vinyl chloride-vinyl acetate copolymer 1 part by weight n-butyl acetate 100 parts by weight (charge Transport Layer) N, N, N ′, N′-Tetraphenylbenzidine Compound {Structural Formula (I)} 2 parts by weight Homopolymer composed of repeating units represented by Structural Formula (II) (weight average molecular weight: 129000) 2 parts by weight Monochrome benzene 20 parts by weight

[0066]

Embedded image

The absorbance calculation formula (1) described above was used to calculate the absorbances of the undercoat layer and the charge transport layer. The wavelength used for the absorbance measurement is a sample in which an undercoat layer, a charge generation layer, and a charge transport layer are each applied as a single layer on the surface of a conductive substrate, and a sample is separately prepared. Total JIR-7000 (made by JEOL Ltd.)
The wavelengths λ ₁ , λ ₂ and λ ₃ were selected from the results. The selected wavelengths are shown in Tables 1 and 2.

[0068]

[Table 1]

[0069]

[Table 2]

In addition, the above-described absorbance calculation formula (2) was used to calculate the absorbance of the charge generation layer. The wavelength used for measuring the absorbance is a visible light reflection / absorption spectrum of a sample in which a single layer of a charge generation layer is coated on the surface of a conductive substrate, and the visible light reflection / absorption spectrum is measured by a spectrophotometer MCPD-200 (manufactured by Otsuka Electronics Co., Ltd.) The wavelengths λ ₄ and λ ₅ were selected from As the wavelength λ ₅ , a wavelength of 570 nm, which has a relatively large absorption and has the best s / n ratio, was used. Table 3 shows the selected wavelengths.

[0071]

[Table 3]

The relationship between these wavelengths and the absorbance is shown in FIG. Next, a sample for preparing the calibration formula was prepared.
The sample for preparing the calibration formula of the undercoat layer was prepared by immersing the conductive substrate in the coating solution for the undercoat layer and then pulling up the conductive substrate to form the undercoat layer on the conductive substrate. At this time, the pulling rate is 150, 190, 230,
270, 310 mm / min. 5 and the set film thicknesses are 1.0, 1.2, 1.3, 1.5 and 1.6 μm. It was set to 1-5.

The sample for preparing the calibration formula for the charge generation layer was prepared by immersing a conductive substrate on which an undercoat layer having a thickness of 1.3 μm was formed in a charge generation layer coating solution. It was prepared by pulling up and forming a charge generation layer on the undercoat layer. At this time, the pulling rate is 100, 150,
200, 250, 300 mm / min. 5 levels,
Moreover, the set film thickness is 0.1, 0.13, 0.15, 0.1.
Sample No. 8 and 0.2 μm, respectively. 6-10
And

The sample for preparing the calibration formula of the charge transport layer is
An undercoating layer having a film thickness of 1.3 μm is formed on the conductive substrate, and a charge generating layer having a film thickness of 0.15 μm is formed on the electroconductive substrate. Was formed by forming a charge transport layer on the charge generation layer. At this time, the pulling rate is 140, 160, 1
80, 200, 220 mm / min. 5 and the set film thickness is 20, 22, 24, 26, 28 μm,
Sample No. It was set to 11-15.

Next, sample No. Absorbances of 1 to 15 were measured using the film thickness measuring device 20 described above. Sample No. 1 to 5 and sample No. The measuring machine used to measure 11 to 15 is an infrared film thickness meter KG-100-CM.
(Manufactured by Kurashiki Spinning Co., Ltd.) and sample No. 6-1
The measuring instrument used to measure 0 is a spectrophotometer MCPD-20.
It was 0 (manufactured by Otsuka Electronics Co., Ltd.). The measuring machine has a light source 40 and a light amount sensor 42 built therein.

Sample No. The absorbances of 1 to 15 are 0.17, 0.20, 0.22, 0.23 and 0.2, respectively.
5, 0.80, 0.77, 0.75, 0.72, 0.6
9, 0.41, 0.46, 0.47, 0.48, 0.5
It was one.

Sample No. The actual film thickness of 1 to 15 was obtained by taking an enlarged photograph of a cut surface of the layer with a transmission microscope to obtain 1.03, 1.18, 1.34 and 1.4 respectively.
8, 1.62, 0.10, 0.13, 0.15, 0.1
8, 0.21, 20.94, 22.39, 24.29,
It was 25.58 and 27.00 μm.

A calibration formula was prepared from these data using a single regression formula. The calibration formula obtained is shown in Table 4.

[0079]

[Table 4]

In the formula, X is the absorbance and Y is the actual film thickness (μm)
Are shown respectively. To measure the accuracy of these calibration formulas,
The correlation coefficient between the expected film thickness converted from each calibration formula and the absorbance of the sample and the actual film thickness of the sample was obtained. The correlation coefficients of the undercoat layer, the charge generation layer, and the charge transport layer were 0.996, 0.990, and 0.942, respectively, and good results were obtained.

Further, a calibration formula showing the relationship between the pulling rate and the absorbance when preparing each sample was also prepared. Table 5 shows the obtained calibration formula.

[0082]

[Table 5]

In the equation, X is the pulling speed (m / s), and Y is
Indicates the absorbance, respectively. In order to measure the accuracy of these calibration formulas, a correlation coefficient between each calibration formula and the expected pulling rate converted from the absorbance of the sample and the actual pulling rate at the time of preparing the sample was determined. The correlation coefficients of the undercoat layer, the charge generation layer, and the charge transport layer are 0.99, respectively.
7, 0.992, 0.953, and good results were obtained.

From the above examples, the absorbance measurement of the intermediate product and final product of the electrophotographic photosensitive member in which the undercoat layer, the charge generation layer and the charge transport layer were sequentially formed on the surface of the electrically conductive substrate which was physically roughened in advance. The results show that it is possible to accurately predict and evaluate the film thickness. Thus, it is possible to promptly detect a change in the manufacturing process such as a change in the concentration or viscosity of the coating liquid or a dip coating speed.

[0085]

According to the present invention, after the formation of each functional layer, a wavelength which is characteristically absorbed by each functional layer and which is less absorbed by the functional layer formed below this functional layer is used. For the measurement, an intermediate product or a final product obtained by actual manufacturing can be used.

Further, according to the present invention, it is possible to accurately predict and evaluate the film thickness from the previously calculated film thickness calculation formula and the measured absorbance, and it is possible to promptly detect the variation in the manufacturing process, And the production of an electrophotographic photosensitive member having an appropriate film thickness can be achieved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a film thickness measuring device according to an embodiment of the present invention.

FIG. 2 is a flowchart of a CPU of the film thickness measuring device of FIG.

FIG. 3 is a flowchart of a CPU of the film thickness measuring device of FIG.

4 is a flowchart of a CPU of the film thickness measuring device in FIG.

5 is a flowchart of a CPU of the film thickness measuring device in FIG.

FIG. 6 is a flowchart of a CPU of the film thickness measuring device of FIG.

FIG. 7 is a graph showing the relationship between wavelengths λ _{1 to} λ ₃ and absorbance.

FIG. 8 is a graph showing the relationship between the wavelength and the absorbance used for measuring the absorbance of the charge generation layer of the example.

FIG. 9 is a sectional view of an electrophotographic photosensitive member used in an embodiment of the present invention.

10 is a schematic configuration diagram of a coating device used for manufacturing the electrophotographic photosensitive member of FIG.

[Explanation of symbols]

 6 Coating Device 9 Elevator 10 Operation Control Unit 20 Film Thickness Measuring Device 22 CPU 24 ROM 40 Light Source 42 Light Quantity Sensor 44 Sample

Claims (15)

[Claims] 1. A method of manufacturing an electrophotographic photosensitive member comprising a plurality of different functional layers containing an organic material sequentially laminated on a surface of a conductive substrate, characterized in that each functional layer is formed after the respective functional layers are formed. Absorbance measurement step of measuring the absorbance at a wavelength at which the absorption of the functional layer formed under each of the functional layers is small, and the film thickness of each of the functional layers becomes constant based on the measured absorbance. And a control step of controlling the coating of each of the functional layers as described above. 2. The control step determines whether or not a theoretical value obtained from a film thickness calculation formula for calculating the film thickness from the absorbance and the measured absorbance matches the set film thickness. The method for producing an electrophotographic photosensitive member according to claim 1, further comprising: 3. The absorbance at a wavelength which is characteristically absorbed by each of the functional layers and which is less absorbed by the functional layers formed under each of the functional layers, and each of the functional layers and each of the functional layers are formed under each of the functional layers. From the absorbance at a wavelength at which both functional layers have low absorption, the absorbance at a wavelength at which the functional layers characteristically absorbed by the functional layers and formed below the functional layers have low absorption is measured. The method for producing an electrophotographic photosensitive member according to claim 1 or 2. 4. A wavelength that is characteristically absorbed by each of the functional layers and is less absorbed by the functional layer formed under each of the functional layers, and a function formed by each of the functional layers and each of the functional layers. The method for producing an electrophotographic photosensitive member according to claim 3, wherein a wavelength at which both layers have a small absorption is in an infrared wavelength region. 5. A wavelength having a small absorption in both the functional layers and the functional layers formed under the functional layers is characteristically absorbed in the functional layers and is formed under the functional layers. The absorption wavelength of the functional layer is longer than the wavelength of less than the absorption wavelength of the functional layer formed under each of the functional layers and shorter than the wavelength of less absorption of the functional layer formed under each of the functional layers. The method for producing an electrophotographic photosensitive member according to claim 4. 6. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the functional layer whose absorbance is measured does not contain a pigment. 7. The method for producing an electrophotographic photosensitive member according to claim 6, wherein the functional layers whose absorbance is measured are an undercoat layer and a charge transport layer. 8. A wavelength characteristically absorbed by each of the functional layers and having less absorption of the functional layer formed under each of the functional layers, and a function formed under each of the functional layers and each of the functional layers. The method for producing an electrophotographic photosensitive member according to claim 3, wherein a wavelength at which both layers have a small absorption is in a visible wavelength region. 9. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the functional layer whose absorbance is measured contains a pigment. 10. The method for producing an electrophotographic photosensitive member according to claim 9, wherein the functional layer whose absorbance is measured is a charge generation layer. 11. An electrophotographic photoconductor manufacturing apparatus comprising a conductive substrate, and a plurality of different functional layers containing an organic material, which are sequentially laminated on the surface of the conductive substrate. Absorbance measuring means for measuring the absorbance at a wavelength at which the absorption of the functional layer formed under each of the functional layers is small, and the film thickness of each of the functional layers becomes constant based on the measured absorbance. An apparatus for manufacturing an electrophotographic photosensitive member, comprising: a control unit that controls coating of each of the functional layers. 12. The control means determines whether or not a theoretical value obtained from a film thickness calculation formula for calculating the film thickness from the absorbance and the measured absorbance matches the set film thickness. The manufacturing apparatus for an electrophotographic photosensitive member according to claim 11, further comprising a determining unit that performs the determination. 13. The absorbance measuring means has an absorbance at a wavelength that is characteristically absorbed by each of the functional layers and is less absorbed by the functional layers formed under each of the functional layers, the functional layers and the respective functions. From the absorbance at a wavelength at which both functional layers formed below the layer absorb less, the absorbance at a wavelength at which the functional layers characteristically absorbed by each functional layer and below the functional layer absorb less The apparatus for manufacturing an electrophotographic photosensitive member according to claim 11, wherein the electrophotographic photosensitive member is measured. 14. A wavelength that is characteristically absorbed by each of the functional layers and is less absorbed by the functional layer formed under each of the functional layers, and a function formed by each of the functional layers and each of the functional layers. 14. The apparatus for manufacturing an electrophotographic photosensitive member according to claim 13, wherein a wavelength at which absorption of both layers is small is in an infrared wavelength region. 15. A wavelength characteristically absorbed by each of the functional layers and having less absorption of the functional layer formed under each of the functional layers, and a function formed by each of the functional layers and each of the functional layers. 14. The electrophotographic photosensitive member manufacturing apparatus according to claim 13, wherein a wavelength at which both layers have a small absorption is in a visible wavelength region.