JP5521607B2 - Film thickness measuring method, film thickness measuring apparatus, image forming apparatus having the film thickness measuring apparatus, photoconductive photoreceptor manufacturing method, and photoconductive photoreceptor - Google Patents

Description

  The present invention relates to a film thickness measuring method, a film thickness measuring apparatus, an image forming apparatus having the film thickness measuring apparatus, a photoconductive photoconductor manufacturing method, and a photoconductive manufactured by the photoconductive photoconductor manufacturing method. The present invention relates to a photosensitive photoreceptor.

An image forming apparatus that forms an electrostatic latent image on a photoconductive photosensitive member, transfers a toner image obtained by developing the electrostatic latent image to a sheet-like recording medium, and fixes the image to form an image. It is known as a digital copying machine, facsimile, various optical printers, optical plotters, and the like.
Some photoconductive photoreceptors can fix a toner image as it is, such as zinc oxide photosensitive paper, but the photoconductive photoreceptor used in an image forming apparatus that transfers a toner image onto a sheet-like recording medium. The body can be used repeatedly, and is generally formed into a drum shape or a belt shape with ends and ends, and each step of image formation is performed while moving the peripheral surface in one direction.
A photoconductive photoreceptor that can be used repeatedly is generally formed by forming an intermediate layer in which fine particles are dispersed on a conductive substrate, and forming the photosensitive layer as a “light-transmitting film” on the intermediate layer. It has become.

In an image forming apparatus using a photoconductive photoconductor that can be used repeatedly, various members such as a charging roller, a developing brush, a transfer roller, a cleaning brush, and a cleaning blade are physically disposed on the surface of the photoconductive photoconductor. Due to this physical contact, the surface of the photosensitive layer gradually wears as the image forming process is repeated. In particular, the rubbing force by the cleaning brush and the cleaning blade is large, which is a significant factor in photosensitive layer wear.
When the thickness of the photosensitive layer is reduced to a certain extent due to such wear, the photosensitivity is remarkably reduced, or the charging characteristics are deteriorated so that the surface cannot be uniformly charged to a desired potential. An image cannot be formed. In this way, the life of the photoconductive photoreceptor is exhausted.

In view of such circumstances, research and development have been made on a method for detecting the “life expectancy” of a photoconductive photoreceptor by measuring the thickness of a photosensitive layer of a photoconductive photoreceptor that can be used repeatedly over time.
As a method of measuring the thickness of the photosensitive layer, conventionally, a constant voltage is applied to the charging means to charge the surface of the photosensitive layer to correspond to the thickness of the photosensitive layer, and the change in the charging current with time is sensitized. The thickness of the layer is determined by measuring the amount of infrared absorption by the photosensitive layer from the intensity of the component reflected from the intermediate layer by irradiating the photosensitive layer with infrared light, which is converted to the change in the layer thickness over time. The desired “infrared absorption method” is being considered.

  In the current detection method, the measured current value is easily affected by environmental changes such as temperature and humidity, and it is not always easy to obtain a highly reliable measurement result. In addition, as described above, there are various contacts on the surface of the photosensitive layer, and a certain amount of current leakage inevitably occurs through the contact when the layer thickness is measured. Therefore, the layer thickness of the photosensitive layer is highly accurate (0.5 μm or less). ) Is difficult to measure.

  Since the infrared absorption method is an optical measurement, it has an advantage that the layer thickness can be measured without physical contact. However, in order to reinforce the strength against physical contact, inorganic or organic filler fine particles may be dispersed in the photosensitive layer of the photoconductive photoreceptor. Because there is no "absorption", depending on the mixing ratio between the filler fine particles and the binder resin, the required measurement accuracy cannot be achieved, or the measurement itself becomes impossible, and the types of photosensitive layers that can measure the layer thickness are limited, There is a problem in terms of versatility.

  Although it is conceivable to measure the layer thickness of the photosensitive layer by the conventionally known “light interference film thickness measurement method” as a measurement method for optically measuring the film thickness of the “light transmissive film”, it is conventionally known. In this technology, due to the influence of scattering by filler fine particles and pigment particles dispersed in the photosensitive layer, or scattering due to light diffusion in the intermediate layer, the “spectral spectral intensity maximum and minimum required for film thickness measurement are sufficient. Cannot be obtained.

Therefore, the present applicant has previously prepared a light-transmitting film thickness measuring method and film thickness measuring apparatus using optical interference, an image forming apparatus having a film thickness measuring apparatus, a photoconductive photoreceptor, and a photoconductive photoreceptor. A method has been proposed (see, for example, Patent Document 1).
By this proposal, the film thickness of the light-transmitting film formed on the support substrate via the undercoat layer (intermediate layer) (for example, the photosensitive layer), or the film thickness of the undercoat layer and the light-transmitting film The sum can be measured reliably and accurately.
Some methods for measuring the thickness of the optical interference film thickness have been proposed (see, for example, Patent Documents 2 to 6).

However, in any of the techniques according to Patent Documents 1 to 6, the film thickness of a so-called surface layer containing filler fine particles and the film thickness of the photosensitive layer including the surface layer are simultaneously and accurately measured. That was not enough.
Accordingly, in the present invention, in view of the above-described circumstances, filler fine particles constituting a light-transmitting film in a photoconductive photoreceptor formed by forming a light-transmitting film on a support substrate through an intermediate layer are dispersed. A film thickness measuring method for measuring the film thickness t1 of the surface layer and the film thickness t2 of the photosensitive layer including the surface layer in which the filler fine particles are dispersed, simultaneously and accurately, and for carrying out the film thickness measuring method It aims at providing a film thickness measuring apparatus.
In addition, the present invention is capable of simultaneously measuring the surface layer and the thickness of the photosensitive layer in the photoconductive photoreceptor with extremely high accuracy, effectively avoiding trouble due to the end of the life of the photoconductive photoreceptor, An object of the present invention is to provide an image forming apparatus capable of smoothly performing replacement.
A further object of the present invention is to provide a method for producing a photoconductive photoreceptor that can easily and reliably produce a photoconductive photoreceptor of uniform quality.
Still another object of the present invention is to provide a photoconductive photoreceptor having uniform quality and high reliability.

In order to solve the above problems, a film thickness measuring method, a film thickness measuring apparatus, an image forming apparatus having the film thickness measuring apparatus, a photoconductive photoconductor manufacturing method, and a photoconductive photoconductor manufactured according to the present invention Specifically, the photoconductive photoconductor produced by the method has the technical features described in the following (1) to (35) .
(1): having an intermediate layer in which fine particles are dispersed on the surface of the conductive substrate, and having a photosensitive layer as a light-transmitting film on the intermediate layer, with respect to the conductive substrate of the photosensitive layer A film thickness measuring method for measuring a film thickness of a photoconductive photoreceptor in which a predetermined thickness portion on the opposite side is formed as a surface layer in which reinforcing filler fine particles are dispersed, the film on the photoconductive photoreceptor Light from a light source that emits spectrum light in a wavelength region that enables thickness measurement is guided by an irradiation light guiding fiber included in a fiber probe, and a light beam is emitted from an emission portion of the irradiation light guiding fiber, and the light beam Is incident on the photoconductive photoreceptor in a state of being condensed on the photosensitive layer by the objective lens, and the first reflected light reflected on the surface of the surface layer in the incident light, and the incident light Reflected on the surface of the intermediate layer The first interference light interfered with the second reflected light, and the third reflected light reflected at the optical interface between the surface layer and the lower layer of the first reflected light and the incident light. The second interference light that interferes with the light is returned to the end face of the detection light transmission fiber of the fiber probe through the objective lens, and is guided to the spectroscopic means by the detection light transmission fiber to be spectrally separated. When calculating the reflectance from the spectral intensity, an interference waveform is obtained by enlarging the reflectance to an arbitrary magnitude, and the low-frequency component of the interference waveform (the change in reflectance with respect to wavelength is the first interference light). The film thickness t1 of the surface layer is calculated on the basis of a long period of time), and the photosensitivity is calculated on the basis of the high-frequency component of the interference waveform (the change in reflectance with respect to the wavelength is a short period of the second interference light) Calculate layer thickness t2 A film thickness measuring method, characterized in that the output.

  In the configuration according to the above (1), the “wavelength region enabling film thickness measurement on the photoconductive photoconductor” of spectrum light means a wavelength region that enables film thickness measurement, It is determined by the configuration (presence / absence of dispersion of filler fine particles, particle size of filler fine particles, agglomerated diameter, etc.).

  Since the wavelength width and film thickness have the relationship of the following formula (1), n (where n is the spectral refractive index of the film) is known and adjacent to the interference waveform (periodic change in reflectance). If the wavelength of the peaks and valleys to be detected can be accurately detected, the film thickness can be measured by frequency analysis.

nd = (peak wavelength of peak × peak wavelength of valley) / 4 × (peak wavelength of peak−peak wavelength of valley)
... (1)

  At this time, as is clear from the above formula (1), when calculating the film thickness, the absolute value of the reflectance is not required, and the wavelength that gives the maximum (peak peak) and the minimum (valley peak) has high accuracy. The film thickness d can be measured using the spectral refractive index n registered in advance. Therefore, in order to increase the accuracy of the wavelength that gives the maximum and minimum reflectance, the reflectance is increased to an arbitrary size.

Generally, the spectrophotometer, spectral reflectance meter, optical interference film thickness meter, etc. directly measure the amount of light reflected from the sample, that is, the spectral spectrum intensity, and the reflectance is known in order to obtain the reflectance. It is necessary to measure and calibrate the standard sample in advance.
Thereby, the reflectance R (λ) of the sample can be calculated as the following formula (2).

R (λ) = (Is (λ) −I _d (λ)) / (Ir (λ) −I _d (λ)) · r (λ)
... (2)

Here, Is (λ) is the digital data received in the calculation means by receiving the reflected light from the sample, I _d (λ) is the digital data of the dark current component of the light receiver handled in the calculation means, Ir (Λ) is digital data handled in the calculation means as reflected light from the standard sample, and r (λ) means a known reflectance of the standard sample.
Here, for example, if the reflected light Ir (λ) from the standard sample, which becomes the denominator, is changed to be smaller than the original value and acquired, the reflectance R (λ) can be increased to an arbitrary size.

  The photoconductive photoreceptor is not particularly limited as long as it can detect the first interference light and the second interference light.

(2): the photosensitive layer is formed with a predetermined thickness on the charge generation layer formed in contact with the intermediate layer, the charge transport layer formed on the charge generation layer, and the charge transport layer; The surface layer in which the reinforcing filler fine particles are dispersed, and the distance between the surface layer surface and the intermediate layer surface is measured as the film thickness t2 of the photosensitive layer. This is a film thickness measurement method.

  According to the configuration of (2) above, the distance between the surface layer surface on which the filler fine particles are dispersed and the intermediate layer surface can be measured as the film thickness.

(3): the photosensitive layer is formed with a predetermined thickness on the charge generation layer formed in contact with the intermediate layer, the charge transport layer formed on the charge generation layer, and the charge transport layer; A surface layer in which the reinforcing filler fine particles are dispersed, and the distance between the surface layer surface and the charge transport layer surface is measured as the film thickness t1 of the surface layer ( It is the film thickness measuring method as described in 1).

  According to the configuration of (3) above, the distance between the surface layer surface on which the filler fine particles are dispersed and the charge transport layer surface can be measured as the film thickness.

(4): The photosensitive layer is formed with a predetermined thickness on the charge generation layer formed in contact with the intermediate layer, the charge transport layer formed on the charge generation layer, and the charge transport layer, A surface layer in which the filler fine particles for reinforcement are dispersed, and the thickness t1 of the surface layer provides a wavelength that gives a maximum and a minimum that are adjacent to each other in a low frequency component of an interference waveform, and a surface layer The film thickness t2 of the photosensitive layer is calculated based on a frequency analysis that decomposes a high frequency component of the interference waveform into a cosine wave component. ).

According to the configuration according to the above (4), the distance between the surface layer surface on which the filler fine particles are dispersed and the surface of the charge transport layer and the distance between the surface layer surface on which the filler fine particles are dispersed and the intermediate layer surface are set to the thickness t1, It can be measured as t2.
The frequency conversion method shown here calculates and calculates the thickness of a light-transmitting film based on a frequency analysis method that decomposes an interference waveform into cosine wave components. This frequency analysis method decomposes the interference waveform into cosine wave components and statistically analyzes and analyzes the digital data of the amplitudes, frequencies (wavelengths, periods), or phases of each cosine wave component, There is an advantage that a minute difference in an important part on the chart or graph obtained as a result of the analysis can be amplified and differentiated significantly by function processing. That is, this frequency transformation method is typically a Fourier transformation method,

y (t) = ae ^{j (ωt + φ)} or y (t) = a cos (ωt + φ)

This is also a conversion method for obtaining the frequency ω, amplitude a, and phase φ from the waveform given by (1), in other words, “decomposing into cosine wave (cosine wave) components”. The normal Fourier transform is a signal that changes within various time periods, such as “wall clock pendulum”, “Earth rotation / revolution” or “earthquake occurrence period”, t: time, horizontal axis: (1 / t) = Hz (1 / s) frequency, but in the present invention, between the reflectance: R and the wavelength: λ,

R = A + Bcos (2πnd / λ)

Therefore, the reflectance R is periodically changed by a cosine function every time “light is a fraction of a wavelength” = “1 / λ” (in a certain wavelength range as the thickness of the film increases). The number of changes in reflectance increases). In the case of a thin film, almost no change (vibration) in reflectance occurs in the same wavelength range.

  For example, an interference waveform (periodic change in reflectivity) indicating a film thickness: nd (frequency) is obtained by Fourier transform in a certain wavelength range (t: equivalent to time), and the wavelength width of one period is calculated from this. Is guided.

For wavelength width and film thickness,
Since there is a relationship of nd = (peak wavelength of peak × peak wavelength of valley) / 4 × (peak wavelength of peak−peak wavelength of valley), the wavelength of the peak / valley of the interference waveform (periodic change in reflectance) is accurately determined. If it can be detected, the film thickness can be measured by frequency analysis.

(5): the photosensitive layer is formed with a predetermined thickness on the charge generation layer formed in contact with the intermediate layer, the charge transport layer formed on the charge generation layer, and the charge transport layer; A surface layer in which the filler fine particles for reinforcement are dispersed, and a film thickness t2 obtained by adding a distance between the surface of the intermediate layer and the surface of the charge transport layer to the charge generation layer and the charge transport layer The film thickness measuring method according to the above (1), wherein the film thickness is measured as -t1.

  According to the configuration of (5) above, the distance between the surface of the charge transport layer and the surface of the intermediate layer can be measured as the film thickness t2-t1 obtained by adding the charge transport layer and the charge generation layer.

(6) The film thickness measuring method according to any one of (1) to (5) above, wherein the surface layer has a cross-linked structure having a charge transport function.

(7): The film thickness measurement according to any one of (2) to (6), wherein a difference in refractive index between the surface layer and the charge transport layer is in a range of 0.05 to 0.2. Is the method.

  According to the configuration according to the above (7), the reflection is physically caused by the refractive index difference (complex refractive index difference), so that part of the light is reflected on the surface of the surface layer, and further, air and Because of the small refractive index difference, some light enters the surface layer and is reflected on the surface layer-charge transport layer interface from the refractive index difference between the surface layer and the charge transport layer which is the lower layer, Interference occurs with the light reflected from the surface of the surface layer. An interface where reflection occurs is an optical interface, and the optical interface can be defined as a boundary where a phase having a uniform refractive index is in contact with another phase having a uniform refractive index. Even if an interface between solids (solid phase interface) is formed, if the refractive index (complex refractive index) of the two solids is exactly the same, there will be no optical interface there.

  When the difference in refractive index is less than 0.05, since most of the light that has entered the surface layer does not reflect on the surface of the charge transport layer and reaches the intermediate layer because of the small difference in refractive index, It becomes difficult to measure the distance between the surface layer surface as the film thickness, and it is possible to measure the film thickness between the intermediate layer and the surface layer from the refractive index difference between the intermediate layer, the charge generation layer, and the charge transport layer. However, the thickness of the surface layer cannot be measured.

If the difference between the refractive index of the surface layer and the refractive index of the charge transport layer exceeds 0.2 in such a configuration, the reflection at the interface increases if the refractive index difference between the two media is large. Although light is incident on the charge transport layer, a lot of light is reflected on the surface of the charge transport layer, so that it is possible to measure the distance between the surface of the charge transport layer and the surface layer as the film thickness. However, since the light necessary for interference does not reach the surface of the intermediate layer, the film thickness of the photosensitive layer cannot be measured.
If it is 0.2 or less, a part of light passes through the charge transport layer and reaches the intermediate layer surface as a light beam necessary for interference.

Generally known ice (refractive index: 1.0) in the atmosphere (refractive index: 1.309) has a large difference in refractive index between the two media, and the reflection of light at the interface between ice and air also increases. The presence of water can be well recognized by the human eye, whereas water (refractive index: 1.33) and ice (refractive index: 1.309) have no difference in refractive index. This is equivalent to a phenomenon in which the presence of ice is not known because the reflection becomes weaker and the transmitted light component increases.
In order to be able to measure the thickness of the surface layer by optical interference using the interface reflection on the charge transport layer, the larger the difference in refractive index between the two media, the surface layer and the charge transport layer, is preferable. However, if it exceeds 0.2, as described above, the light component reaching the surface of the intermediate layer is reduced, making it difficult to measure the film thickness of the photosensitive layer by the optical interference method.

  In the present invention, the refractive index of the surface layer and the charge transport layer can be measured with a general spectroscopic ellipsometer by preparing a measurement sample.

(8) The film thickness measuring method according to any one of (1) to (7), wherein the extinction coefficient of the filler fine particles is 0.

  According to the configuration according to the above (8), the extinction coefficient of the filler fine particles contained in the surface layer is 0, so that the presence of light transmitted through the dispersed surface layer can be made possible. In this case, the distance between the surface layer surface where the filler fine particles are dispersed and the surface of the charge transport layer, or the distance between the surface layer surface where the filler fine particles are dispersed and the intermediate layer surface can be measured as the film thickness.

  That is, according to the configuration according to the above (8), the extinction coefficient of the complex refractive index of the filler fine particles becomes 0, so that the light absorption by the filler fine particles basically disappears, and other factors include the filler fine particles. The transmittance of the surface layer decreases due to reflection due to the difference in refractive index between the binder resin and the non-uniformity of the particles, but the transmittance of the surface layer is reduced. The light passes through and reaches the surface of the charge transport layer and the intermediate layer to cause interference.

(9) The film thickness measuring method according to any one of (1) to (8), wherein the filler fine particles are inorganic fillers.

(10) The film thickness measuring method according to any one of (1) to (9), wherein the filler fine particles are a metal oxide.

(11) The film thickness measuring method according to any one of (1) to (9), wherein the filler fine particles are at least one selected from silicon oxide, titanium oxide, and aluminum oxide.

  According to the configuration according to the above (9) to (11), since the filler fine particles contained in the surface layer are inorganic fillers, the hardness of the surface layer in which the filler fine particles are dispersed can be increased, and light In this case as well, the distance between the surface layer surface in which the filler fine particles are dispersed and the surface of the charge transport layer or the distance between the surface layer surface in which the filler fine particles are dispersed and the surface of the intermediate layer can be ensured. Can be measured as the film thickness. As the inorganic filler fine particles, metal oxides are preferable, and silicon oxide, titanium oxide, and aluminum oxide are particularly preferable.

(12) The film thickness measuring method according to any one of (1) to (11) above, wherein a wavelength resolution in the spectroscopic means is 0.4 nm or less.

  According to the configuration of (12) above, the interference waveform having a thin film thickness and a thick film thickness can be obtained simultaneously by a single system of spectroscopic system. The distance between the surface or the distance between the surface layer surface in which filler fine particles are dispersed and the intermediate layer surface can be measured as the film thickness.

(13) The film thickness measuring method according to any one of the above (1) to (12), wherein a wavelength region enabling the film thickness measurement of the photoconductive photoconductor is 600 to 850 nm. It is.

  According to the configuration according to the above (13), a part of the light is transmitted through the surface layer in which the filler fine particles are dispersed and reflected on the surface of the charge transport layer, and a part of the light passes through the charge transport layer. Since the light reaches the intermediate layer surface without being scattered or absorbed by the charge generation layer, the distance between the surface layer surface on which the filler fine particles are dispersed and the surface of the charge transport layer and the filler fine particles are dispersed. The distance between the surface layer surface and the intermediate layer surface can be measured as the film thickness.

(14): The wavelength region enabling the film thickness measurement on the photoconductive photoconductor of the light source is larger than the particle diameter or aggregation diameter of the filler fine particles, and the particle diameter or aggregation diameter of the filler fine particles is 0.6 μm or less. The film thickness measuring method according to (13) above, wherein

According to the configuration according to (14) above, by setting the particle diameter and aggregated diameter of the filler fine particles to 0.6 μm or less, it is possible to avoid the influence of scattering and diffraction caused by the filler fine particles and the aggregated particles and perform a good film thickness measurement. realizable.
If the filler fine particle diameter or the aggregate diameter is 0.6 μm or less, the measurement wavelength range of 600 to 850 nm necessary for film thickness measurement is secured, a good spectral spectrum can be detected, and the surface layer surface on which filler fine particles are dispersed The distance between the surface of the charge transport layer and the distance between the surface of the surface layer in which the filler fine particles are dispersed and the surface of the intermediate layer can be measured as film thicknesses.

(15): the photosensitive layer is formed with a predetermined thickness on the charge generation layer formed in contact with the intermediate layer, the charge transport layer formed on the charge generation layer, and the charge transport layer; A surface layer in which the filler fine particles for reinforcement are dispersed, and the distance between the surface of the surface layer and the surface of the intermediate layer is measured as a film thickness t2 of the photosensitive layer, and the surface of the surface layer and the surface layer The film thickness measuring method according to any one of (1) to (14) above, wherein the distance from the surface of the charge transport layer is simultaneously measured as the film thickness t1 of the surface layer.

  According to the configuration of (15), the surface layer of the photoconductive layer in the photoconductive photoreceptor has a surface layer in which reinforcing filler fine particles are dispersed, and the surface of the intermediate layer and the filler fine particles are dispersed. The distance between the surface layer and the surface of the surface layer thus formed can be simultaneously measured as the photosensitive layer film thickness, and the distance between the surface of the charge transport layer and the surface layer on which the filler fine particles are dispersed can be simultaneously measured as the surface layer film thickness.

(16) The film thickness measuring method according to any one of (1) to (15), wherein the intermediate layer has a layer thickness of 2.5 μm or more.

  According to the configuration of (16), the intermediate layer in which the fine particles are dispersed has a layer thickness of 2.5 μm or more, so that the optical path length can be secured (can be increased), so that the intermediate layer for the measurement wavelength region The opacity of the intermediate layer is increased by the multiple reflection resulting from the difference in refractive index between the fine particles of the binder resin and the binder resin, and the reflected light at the lower interface from the intermediate layer can be suppressed. The distance between the surface layer in which the filler fine particles are dispersed and the distance between the surface of the charge transport layer and the surface of the surface layer in which the filler fine particles are dispersed can be measured as the film thickness. If it is less than .5 μm, the opacity for the measurement wavelength region in the intermediate layer will decrease, and some light will reach the interface below the intermediate layer, and the reflected light from it will return. Surface of the intermediate layer and filler fine particles It is impossible to measure the distance from the surface layer in which the particles are dispersed as the photosensitive layer thickness, and the distance between the surface of the charge transport layer and the surface layer in which the filler fine particles are dispersed as the surface layer thickness.

(17): comprising a conductive substrate, an intermediate layer formed on the surface of the conductive substrate and having fine particles dispersed therein, and a photosensitive layer formed as a light-transmitting film on the intermediate layer, The film thickness of the photoconductive photoreceptor formed as a surface layer in which a predetermined fine thickness portion on the opposite side of the photosensitive substrate to the conductive substrate is dispersed with reinforcing filler fine particles is set to the above (1) to (16). A film thickness measuring apparatus for measuring by the film thickness measuring method according to claim 1, wherein the light source emits spectral light in a wavelength region that enables film thickness measurement of the photoconductive photoreceptor, and the light source. The light from the photoconductive photoconductor is guided to the photoconductive photoconductor side and emitted from the emitting portion toward the photoconductive photoconductor, and the reflected light from the photoconductive photoconductor is received and transmitted. A fiber optic probe comprising: And an objective lens that vertically irradiates the photoconductive photosensitive member in a state where the irradiation light emitted from the emitting portion is condensed toward the photosensitive layer, and on the surface of the surface layer in the incident light The first reflected light reflected by the reflected first reflected light and the second reflected light reflected by the surface of the intermediate layer in the incident light, the first reflected light, and the incident light It consists of second interference light in which the third reflected light reflected at the optical interface between the surface layer and the lower layer in the incident light interferes, from the end face of the detection light transmission fiber via the objective lens. When calculating the reflectance from the spectroscopic means for spectroscopically splitting the incident detection light transmitted, the spectral intensity detection means for detecting the spectroscopic spectral intensity of the detection light split by the spectroscopic means, Arbitrary reflectance The interference waveform is obtained by enlarging to the size, and the film thickness t1 of the surface layer is calculated based on the low frequency component of the interference waveform (a change in reflectance with respect to wavelength is a long period with respect to the first interference light). Calculating means for calculating and calculating the film thickness t2 of the photosensitive layer based on a high-frequency component of the interference waveform (a change in reflectance with respect to wavelength is a short period with respect to the second interference light). This is a characteristic film thickness measuring apparatus.

  According to the configuration relating to (17) above, the film thickness can be measured by the film thickness measuring method described in any of (1) to (16) above.

(18) The film thickness measuring apparatus according to (17), wherein the numerical aperture NA of the objective lens is 0.2 or less.

With the configuration according to (18) above, it is possible to improve the light condensing performance by the objective lens, the amount of the reflected light that can be detected is increased, and the spectral spectrum intensity of the detected light can be detected satisfactorily.
NA is an important value that determines the performance of the objective lens, and is a value related to the depth of focus (spatial resolution) and brightness. It is also called NA (Numerical Aperture), and is expressed by the equation NA = n · sin θ. Here, n represents the refractive index of the medium between the film and the objective lens, and θ represents the angle formed by the optical axis and the light beam entering the outermost side of the objective lens. As NA increases, spatial resolution improves. However, a single objective NA is usually described for a commercially available objective lens.

(19) The film thickness measuring apparatus according to (17) or (18), wherein the objective lens is an achromatic lens.

  According to the configuration of (19) above, it is possible to remove chromatic aberration at the time of light collection and light reception, and it is possible to detect a spectral spectrum intensity with high light collection properties and good wavelength accuracy.

(20) The film thickness measuring apparatus according to any one of (17) to (19), wherein the light source has an emission wavelength of 600 to 850 nm.

  According to the configuration of (20) above, by having an emission wavelength of 600 to 850 nm, some light is transmitted through the surface layer in which filler fine particles are dispersed and reflected on the surface of the charge transport layer. In addition, since some of the light passes through the charge transport layer and reaches the surface of the intermediate layer without being scattered or absorbed by the charge generation layer, the surface layer surface and the charge transport layer in which filler fine particles are dispersed are reflected. The distance between the surface and the distance between the surface layer surface on which the filler fine particles are dispersed and the intermediate layer surface can be measured as film thicknesses.

(21) The film thickness measuring apparatus according to any one of (17) to (20), wherein the light source is a halogen-tungsten lamp.

  The configuration according to (21) is preferable because the emitted light has an extremely wide spectral distribution from the lower limit of the visible range to the near infrared range. In addition, an LED having a light emission distribution at 400 to 1000 nm can be used as the light source.

(22) The film thickness measuring apparatus according to any one of (17) to (21), wherein the spectroscopic means is a diffraction grating, a prism, or a spectral filter.

  According to the configuration of (22) above, as the spectroscopic means such as a diffraction grating, a rotating type that changes the spectral wavelength region by rotation can be used. If the diffraction grating used) is used, a space for rotation and a rotation mechanism are not required, and the film thickness measuring apparatus can be made compact.

(23) The film thickness measuring device according to any one of (17) to (22), wherein the spectrum intensity detecting means is a line sensor or a silicon photodiode array.

As the spectral intensity detection means in the configuration according to the above (23), a line sensor such as a CCD or a “silicon photodiode array” in which silicon photodiodes are arranged at predetermined spectral wavelength positions can be suitably used.
Silicon photodiodes are small, light, and inexpensive, and have a simple circuit configuration even when “a film thickness measuring device is incorporated in an image forming apparatus” as will be described later.

(24) The film thickness measuring apparatus according to any one of (17) to (23), wherein the spectral resolution of the spectroscopic means is 0.4 nm / element or less.

  According to the configuration according to the above (24), the interference waveform having a thin film thickness and a thick film thickness can be simultaneously acquired by a single system of spectroscopic system. The distance from the surface can be measured as the surface layer thickness, or the distance between the surface layer surface in which the filler fine particles are dispersed and the intermediate layer surface can be measured as the photosensitive layer thickness.

(25) The film thickness measuring apparatus according to any one of (17) to (24), wherein a wavelength region of the spectroscopic means is 600 nm or more and 850 nm or less.

  According to the configuration according to the above (25), since the wavelength region is equal to or larger than the particle diameter or the aggregation diameter of the filler fine particles in the surface layer, the charge transport layer that has passed through the surface layer in which the filler fine particles are dispersed without being scattered. Since only reflected light can be dispersed, and only the light transmitted through the surface layer, charge transport layer, and charge generation layer and reflected from the surface of the intermediate layer can be received, the surface of the intermediate layer can be received. The distance between the surface layer where the filler fine particles are dispersed can be measured as the photosensitive layer film thickness, and the distance between the surface of the charge transport layer and the surface layer where the filler fine particles are dispersed can be measured as the surface layer film thickness.

(26): The end of the fiber probe on the objective lens side is centered on the end of the detection light transmission fiber, and the detection light transmission fiber is surrounded by the emission side end of the irradiation light guide fiber. The film thickness measuring apparatus according to any one of (17) to (25), wherein the film thickness measuring apparatus is configured as follows.

(27): The film thickness measuring apparatus according to any one of (17) to (26), further including a filter that cuts light in an unnecessary wavelength region out of light emitted from the light source. .

(28): The film thickness measuring apparatus according to any one of (17) to (27), further including a filter that cuts light of 600 nm or less and 850 nm or more of light in the unnecessary wavelength region.

Light in the “undesired wavelength region” is light in a wavelength region that does not contribute to film thickness measurement (for example, light having a wavelength outside the range of 600 to 850 nm, which causes thermal damage in the light including the ultraviolet region below 600 nm and in the near infrared region. (Including light having a wavelength of more than 850 nm to be applied), and irradiating light in this wavelength region causes damage such as light fatigue to the object to be measured (photoconductive photosensitive member). It is determined by the spectral characteristics of the measurement object (for example, the spectral sensitivity and spectral absorption characteristics of the photoconductive photoreceptor).
When the object to be measured is a photoconductive photoreceptor, the unnecessary wavelength region is preferably a photosensitive layer non-absorption band, and particularly preferably an ultraviolet region or a near infrared region. As a filter in this case, a “sharp cut filter” or the like that transmits light in a wavelength region of “600 to 850 nm” is suitable.

(29): The calculation means stores the refractive index data of any one or more of the intermediate layer surface or the layer interposed on the surface layer surface in a usable manner (17) ) To (28).

  According to the configuration of (29) above, a plurality of spectral refractive index data of each film (surface layer, charge transport layer, and charge generation layer) having different compositions that can be measured by the calculation means can be stored. The distance between the surface layer surface in which the filler fine particles are dispersed and the surface of the charge transport layer and the distance between the surface layer surface in which the filler fine particles are dispersed and the intermediate layer surface can be measured as film thicknesses.

(30): a photoconductive photoreceptor, an electrostatic latent image forming means for forming an electrostatic latent image on the surface of the photoconductive photoreceptor, and developing the toner image by developing the electrostatic latent image with toner. Development means, transfer means for transferring the toner image to a sheet-like recording medium to form an unfixed image, fixing means for fixing the unfixed image on the recording medium, and (17) to (29) above And the photoconductive photoreceptor comprises a conductive substrate, an intermediate layer in which fine particles are dispersed on the surface of the conductive substrate, and the intermediate layer. A photosensitive layer formed as a light transmissive film, and a predetermined thickness portion of the photosensitive layer opposite to the conductive substrate is formed as a surface layer in which reinforcing filler fine particles are dispersed. The film thickness measuring apparatus measures the film thickness t1 of the surface layer. It is an image forming apparatus according to claim.

As the “sheet-shaped recording medium”, a normal transfer paper, an OHP sheet (a plastic sheet for an overhead projector), or the like can be used.
The image forming apparatus of the present invention can be implemented as an analog or digital copying apparatus, facsimile apparatus, optical printer, optical plotter, optical plate making apparatus, or the like, and can also be implemented as a “monochromatic image forming section” in a tandem color image forming apparatus. .

(31) The image forming apparatus according to (30), wherein the image forming apparatus has a function of displaying that the film thickness t1 of the surface layer has become a predetermined value or less.

According to the configuration of (31) above, the “predetermined value” at the film thickness t1 is, for example, “a thickness that allows the photoconductive photoconductor to have a lifetime in about 100 more image forming processes”. In addition, before the photoconductive photoconductor expires, the user can be informed in advance of the timing when the photoconductive photoconductor expires. In such a case, for example, a message to that effect can be displayed on the control display of the image forming apparatus as a message such as “Please replace the photoconductor soon because the photoconductor will be exhausted.” .
Alternatively, the predetermined value can be set to the thickness of the photoconductive photoconductor, and in that case, for example, “The photoconductor has expired. Please replace the photoconductor” on the display. If necessary, the image forming apparatus can be put in an “inoperable state” together with this message display.
By doing so, the photoconductive photoconductor can be exchanged appropriately and smoothly. When the image forming process is executed, the high-quality without image deterioration caused by photoconductive photoconductor deterioration is always obtained. An “image” can be obtained.

(32): The filler particles have a wavelength region in which the particle diameter or aggregation diameter of the filler fine particles is 0.6 μm or less, and the wavelength region enabling the film thickness measurement of the photoconductive photoconductor of the light source of the film thickness measuring device is the filler particles. The image forming apparatus according to (30) or (31), wherein the image forming apparatus has a diameter or an agglomerated diameter or more.

In the image forming apparatus described in (30) or (31) above, the particle diameter or aggregate diameter of the reinforcing filler fine particles dispersed in the surface layer is preferably 0.6 μm or less, and in that case, the film thickness is measured. A measurement wavelength region in the apparatus (a region for specifying a wavelength that gives the maximum / minimum spectral spectrum intensity) is set to a region equal to or larger than the particle diameter or the aggregation diameter.
According to the configuration according to (32) above, it is possible to achieve a favorable film thickness measurement while avoiding the wavelength region in the detection light which is “influence of scattering and diffraction by filler fine particles and condensed particles thereof”.
If the filler fine particle diameter or the aggregate diameter is 0.6 μm or less, a measurement wavelength region of 0.6 to 0.85 μm region suitable for film thickness measurement is secured, a good spectral spectrum can be detected, and the filler is dispersed. The remaining film thickness of the surface layer can be accurately measured.
The “filler fine particles to be dispersed for reinforcement” are not limited to one type, and two or more types (the particle size may be different for each type) may be mixed and dispersed.

(33): Applying an intermediate layer in which fine particles are dispersed on the surface of the conductive substrate, forming an intermediate layer by drying and curing, and applying and drying a photosensitive layer as a light-transmitting film on the intermediate layer A photosensitive layer forming step formed by curing, wherein the photosensitive layer forming step forms a photosensitive film on the intermediate layer; and A spray coating step in which a coating liquid in which reinforcing filler fine particles are dispersed on the photosensitive film is applied by a spray coating method to form a wet coating; and light energy is applied to the wet coating. A wet film curing step for applying and curing, and further drying to form a surface layer, and further using the film thickness measuring device according to any one of (17) to (29) above The film thickness measurement process to measure the film thickness in advance For example, a method for producing a photoconductive member and controlling the spraying conditions in the spray coating steps based on the thickness t1 of the surface layer was measured by the film thickness measuring step.

The “intermediate layer forming step” is a step in which an intermediate layer in which fine particles are dispersed is applied to the surface of a conductive substrate, followed by drying and curing.
The “photosensitive layer forming process” is a process in which a photosensitive film is applied as a light-transmitting film on the intermediate layer and dried and cured. The “photosensitive layer forming step”, “spray coating step”, and “wetting” Film hardening step ".
The “photosensitive layer forming step” is a step of forming a photosensitive layer by applying a photosensitive film as a light-transmitting film on the intermediate layer and drying and curing it.
The “spray coating step” is a step of applying a “coating liquid in which reinforcing filler fine particles are dispersed” by a spray coating method after the photosensitive film forming step. Here, the “reinforcement” in the present invention includes, for example, layer reinforcement or abrasion resistance reinforcement, and the layer reinforcement has a hardness as in the case of the shaping resin composition filled with filler such as FRP. It means improvement of mechanical properties such as enhancement, increase in stress deformation resistance, increase in hardness or increase in toughness, and improvement in thermal properties such as reduction in temperature expansion coefficient or increase in heat resistance. Also, “Coating liquid in which filler fine particles for reinforcement are dispersed” is “spray coating method containing photocrosslinking type polysynthetic resin and solvent that has charge transporting property and is polymerized and cured by application of light energy”. It is applied by.
The “wet film curing step” is a step of forming a surface layer by applying light energy to the wet coating film after the spray coating step and curing it, and further drying.
"Film thickness measurement process" is a film thickness that measures the distance between the surface of the surface layer in which the filler fine particles are dispersed and the surface of the charge transport layer after the coating applied in the spray coating step is cured. This is a measurement step, and is performed using the film thickness measuring apparatus described above.
The spray coating step is executed while controlling the spray coating conditions based on the film thickness measured in the film thickness measurement process.

(34): The conductive substrate is cylindrical or belt-shaped, and the film thickness measurement step measures the film thickness t1 of the surface layer in the axial direction of the conductive substrate, and The method for producing a photoconductive photoconductor according to (33) above, wherein the distribution of the film thickness t1 of the surface layer is measured.

(35): The coating amount is adjusted by controlling the discharge amount of the coating liquid in the spray coating step based on the film thickness t1 of the surface layer measured in the film thickness measurement step. (33) or (34). A method for producing a photoconductive photoreceptor according to (34).

(36) A photoconductive photoreceptor produced by the method for producing a photoconductive photoreceptor according to any one of (33) to (35).

According to the present invention, the film thickness t1 of the surface layer in which filler fine particles are dispersed in the light transmissive film of the photoconductive photoreceptor formed by forming a light transmissive film on the support substrate via the intermediate layer, and To provide a film thickness measuring method for measuring the film thickness t2 of a photosensitive layer including a surface layer in which filler fine particles are dispersed, simultaneously and accurately, and a film thickness measuring apparatus for performing the film thickness measuring method. it can.
In addition, according to the present invention, the thickness of the surface layer and the photosensitive layer in various photoconductive photoreceptors, in particular, the photoconductive photoreceptor having a cross-linked surface layer having a charge transport function in which filler fine particles are dispersed, is extremely accurate. It is possible to provide an image forming apparatus that can measure well, effectively avoid troubles due to the end of the life of the photoconductive photoconductor, and smoothly exchange the photoconductive photoconductor.
Furthermore, according to the present invention, it is possible to provide a method for producing a photoconductive photoreceptor capable of easily and reliably producing a photoconductive photoreceptor of uniform quality.
Furthermore, according to the present invention, a photoconductive photoconductor having a uniform quality and high reliability can be provided by using the photoconductive photoconductor manufactured by the above method for manufacturing a photoconductive photoconductor. .

1 is a schematic diagram for explaining a configuration of a main part in an embodiment of an image forming apparatus according to the present invention. It is a flowchart which shows the operation | movement flow of control based on the film thickness measurement result in the image forming apparatus which concerns on this invention. 1 is a schematic cross-sectional view of a photoconductive photoconductor that is a measurement object in a film thickness measurement method according to the present invention. It is the schematic which shows the structural example (a) of the apparatus which performs the film thickness measuring method of this invention, and the structural example (b) of the objective lens side edge part of a fiber probe. It is a graph which shows an example of the detected spectral spectrum intensity. It is a graph which shows an example of the spectral-spectrum intensity | strength detected when the photosensitive layer is directly irradiated without using an objective lens. It is a graph which shows an example of the spectral-spectrum intensity | strength detected when the thing of wavelength resolution: 0.49nm / element is used as a spectroscopy means. It is the schematic which shows the structural example of the film thickness measuring apparatus provided with the filter. It is a graph which shows an example of the result of film thickness measurement. It is a graph which shows an example of the result of film thickness measurement. It is a schematic diagram which shows roughly an example of the manufacturing apparatus for enforcing the manufacturing method of a photoconductive photoreceptor.

<Image forming apparatus>
Embodiments of the invention will be described below. First, an embodiment of an image forming apparatus will be described.
FIG. 1 is an explanatory view showing only a main part of an embodiment of an image forming apparatus.
In FIG. 1, a photoconductive photosensitive member (hereinafter simply referred to as a photosensitive member (10)) denoted by reference numeral (10) is formed in a “drum shape”, and is driven to rotate clockwise at a predetermined rotational speed during image formation. The

  The image forming process is performed as follows. That is, the peripheral surface of the photosensitive member (10) rotating at a constant speed in the clockwise direction shows the charging means (11) (contact type using a charging roller, but the non-contact charging roller type, the corona discharge type or the charging type) A brush or the like can also be used), and the surface of the charged photoreceptor is exposed.

Reference numeral (12) in FIG. 1 indicates “scanning light” by an optical scanning writing device (not shown). Of course, the exposure can be performed by “optical image irradiation” as in the case of an analog copying machine, or by optical writing by an optical writing device such as an LED array.
The electrostatic latent image formed on the photoreceptor (10) by exposure is developed by the developing device (13) and visualized as a toner image. In the example being described, the electrostatic latent image is formed as a “negative latent image” by scanning with scanning light (12), and becomes a positive “toner image” by reversal development by the developing device (13).

  A sheet-like recording medium (transfer paper, OHP sheet which is a plastic sheet for an overhead projector) S to which a toner image is to be transferred is held on the outer peripheral surface of the transfer belt (14) and conveyed to the left in the figure. While being superposed on the toner image at the transfer portion, the transfer means (15) (illustrated by a transfer brush, but a transfer roller or a corona discharge type can also be used) The toner image is transferred by a transfer bias voltage applied through the toner image.

  The recording medium S to which the toner image is transferred is conveyed to a fixing unit, where the toner image is fixed by a fixing device (not shown), and is discharged outside the device. As described above, the transfer of the toner image onto the sheet-like recording medium may be performed directly from the photosensitive member (10) onto the recording medium S. However, an intermediate transfer such as an intermediate transfer belt may be used. You may make it transfer to a recording medium via a medium.

After the toner image has been transferred, the remaining transfer toner, paper dust, and the like remaining on the surface of the photosensitive layer (described later) are removed by the cleaning device (16). That is, the surface of the photoreceptor (10) is first brushed by the cleaning brush (18) and then rubbed by the contact edge portion of the cleaning blade (17).
The toner removed from the surface of the photoreceptor by the cleaning brush (18) and the cleaning blade (17) is transported to a waste toner storage unit (not shown) by a waste toner transport screw (19). The cleaning blade (17) has a particularly large contact pressure with respect to the photoreceptor (10).

As described above, when the image forming process is executed, the charging means (11), the cleaning brush (18), the cleaning blade (17), and the like come into contact with the surface of the photoconductor (10). The photosensitive layer of the body (10) is gradually scraped and worn.
When the layer thickness of the photosensitive layer becomes a certain value or less due to wear, the photosensitivity is deteriorated and the charging characteristics are deteriorated, so that good image formation cannot be performed. In the embodiment of FIG. 1, when the layer thickness of the surface layer of the photosensitive member (10) is measured by the film thickness measuring device (9), as a result, when the layer thickness becomes a predetermined thickness or less, A message to this effect is displayed.
That is, the film thickness measurement by the film thickness measuring device (9) (the film thickness measurement may be performed constantly, or may be performed intermittently, such as at a rate of once for a plurality of image forming processes. The film thickness as the measurement result is input to the control means (20) constituted by a microcomputer or the like.

  As shown in the flowchart of FIG. 2, the control means (20) stores “predetermined film thickness values: DA, DB”. Film thickness value: DA is, for example, “film thickness that the function of the photoconductor (10) is normal, but the normal function as the photoconductor cannot be achieved after about 100 image forming processes”. Value: DB is the thickness at which the life of the photoreceptor (10) is exhausted.

The control means (20) compares the measured value D of the film thickness (photosensitive layer thickness t2) with the film thickness values DA and DB. When D> DA, the photoconductor (10) functions normally and does not interfere with the image forming process, and “image can be formed”.
When DA ≧ D> DB, the photoconductor (10) functions normally and there is no problem in the image forming process, but the photoconductor (10) will be used up in the near future. For example, the message is displayed on the control display of the image forming apparatus as a message such as “The photoconductor is about to expire, so please replace the photoconductor”.
When D ≦ DB, the life of the photoconductor (10) is exhausted. In this case, the indication: B is displayed on the control display, for example, “The photoconductor has expired. Please replace the message ", and put the image forming apparatus in the" inoperable state ". The message may be displayed by “voice” together with the display on the control display or instead of the display on the control display.
In the above example, the photoconductor (10) is replaced. Of course, a process unit such as a process cartridge can also be replaced.
Further, instead of the photosensitive layer thickness (film thickness) t2, a surface layer thickness (film thickness) t1 to be described later is measured, and an image forming apparatus having the same configuration and operation flow as the case where the photosensitive layer thickness t2 is measured. It is also good.

As the photoreceptor (10), those having various configurations can be used.
A typical example of the structure of the photoreceptor (10) is as shown in FIG. 3 as a conductive substrate having a surface roughness Rmax of 0.4 μm or less or a surface roughness RzJIS: 0.4 to 1.8 μm. An intermediate layer (3) is formed on an aluminum drum (2), a charge generation layer (4) and a charge transport layer (5) are laminated thereon, and a surface layer (6 with reinforcing filler fine particles dispersed therein) ), And the charge generation layer (4), the charge transport layer (5), and the surface layer (6) form a photosensitive layer.
In the present embodiment, the aluminum drum (2) is used as the conductive substrate. However, the present invention is not limited to the aluminum tube, and other various cylindrical conductive substrates may be used, and a nickel belt or a plastic belt may be used. Alternatively, a conductive substrate that has been subjected to aluminum vapor deposition or a conductive resin coating may be used, and various known conductive substrates may be used.

In FIG. 3, the intermediate layer (3) has a function as a binder for adhering and fixing the photosensitive layer to a conductive substrate, and contains “fine pigment particles” in order to suppress adverse effects such as uneven charging.
In FIG. 3, the charge generation layer (4) is a layer that generates “positive and negative charge pairs” by irradiation with a specific wavelength, and the charge transport layer (5) is the charge generated in the charge generation layer (4). It has a function of transporting a predetermined polarity to the surface of the photosensitive layer.
Further, in FIG. 3, the surface layer (6) was formed as “a cross-linked resin having a charge transport function in which reinforcing filler fine particles were dispersed on the surface side of the photosensitive layer (opposite to the conductive substrate)”. Is.

The film thicknesses of the intermediate layer (3), charge generation layer (4), charge transport layer (5), and surface layer (6) are preferably 2 to 6 μm, 1 μm or less, 15 to 35 μm, and 2 to 9 μm, respectively. Therefore, the preferable thickness as the photosensitive layer is 20 to 51 μm.
The layer thickness of the intermediate layer (3) is generally 2 to 6 μm as described above, but has a satisfactory function as the intermediate layer and good optical interference effect between the light-transmitting film surface and the support substrate surface. In order to make it uniform, the thickness of the intermediate layer (3) is preferably 3.5 μm or less.
The layer thickness of the intermediate layer can be measured by a step gauge or a surface roughness meter by partially peeling the film.

  When an “optical scanning device using laser light” is used as an exposure means in an image forming apparatus, depending on the wavelength of the laser light, the photosensitive layer is internally reflected on the surface of the conductive substrate, the surface of the intermediate layer, or the surface of the photosensitive layer. In order to avoid such a problem, the surface of the conductive substrate may be roughened by “cutting” or the like, or fine particles of pigment may be dispersed in the intermediate layer. It may cause irregular reflection.

  As described above, the intermediate layer contains the pigment (fine particles), and the form of the inclusion is a form in which “the fine particles of the pigment are dispersed in the binder resin”. In this case, if the refractive index difference between the pigment fine particles and the binder resin is 1.0 or more, the reflection at the boundary surface between the pigment fine particles and the resin increases, the opacity of the intermediate layer increases, and the light reflectance at the intermediate layer interface increases. As the angle increases, the angle of refraction within the pigment fine particles increases and a lot of light returns in the direction of incidence. Therefore, when measuring the light-transmitting film as the photosensitive layer thickness, It is favorable to obtain “spectral intensity”.

The pigment dispersed in the intermediate layer is preferably rutile or anatase type TiO ₂ having a large refractive index if the difference in refractive index from the photosensitive layer formed thereon is small, and the alkyd having a small refractive index as the binder resin. Resins, melamine resins, acrylic resins, vinyl acetate resins and the like are suitable.
The reflectance of the intermediate layer interface is 50% or more with respect to the wavelength region of 400 to 1100 nm, from the viewpoint of securing the reflectance of the intermediate layer interface with respect to the reflectance at the surface layer surface (surface in contact with air) of the photosensitive layer. It is preferable that it is 90% or less. When the reflectivity at the interface of the intermediate layer exceeds 90%, the difference between the maximum and minimum of the spectral spectrum intensity becomes small, and the sensitivity of measurement decreases. On the other hand, when the reflectance is less than 50%, the spectral spectrum intensity becomes small, and rapid layer thickness measurement becomes difficult.

In addition, as filler fine particles for reinforcement dispersed on the surface portion of the photosensitive layer to form the surface layer of the photosensitive layer, the inorganic filler fine particles are made of a powder of metal such as copper, tin, aluminum or indium, oxidized Metal oxides such as tin, zinc oxide, titanium oxide, indium oxide, and alumina (aluminum oxide), silicon oxide, and potassium titanate are preferable.
One or more filler fine particles of these materials can be dispersed to form a surface layer. The filler fine particles can be dispersed by using a suitable disperser in the state of the surface layer coating solution. The particle diameter or aggregate diameter of filler fine particles to be dispersed is preferably 0.6 μm or less.

  In addition, a charge transport material is added to the surface layer. Examples of such charge transport materials include hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, triarylmethane compounds, and the like. Can be mentioned.

<Film thickness measuring device, film thickness measuring method>
FIG. 4A schematically shows an embodiment of the film thickness measuring device (9).
The film thickness measuring device (9) includes a light source (91) that emits spectral light in a wavelength region determined by the configuration of a light-transmitting film, and light from the light source (91) to be measured (photosensitive member: 10). A fiber probe (93) that guides light to the side, emits light from the emitting part toward the object to be measured, and receives and transmits reflected light from the object to be measured by the detection light transmission fiber (92); An objective lens (94) for condensing the irradiation light emitted from the emitting portion of (93) toward the film (photosensitive layer) of the object to be measured (photosensitive member: 10), and the object lens (reflected by the object to be measured) 94) and a spectral intensity detecting means for detecting the spectral intensity of the detection light spectrally separated by the spectral means (96). (97) And calculating means (98) for calculating and calculating the film thickness t1 of the surface layer (6) from the light spectrum intensity, and calculating and calculating the film thickness t2 of the photosensitive layer, and vertically irradiating the irradiated light to the surface of the object to be measured. It is configured to let you.

Each means which comprises a film thickness measuring apparatus (9) is demonstrated in detail.
The fiber probe (93) guides the light from the light source (91) to the photosensitive member 10, and emits the irradiated light guiding fiber (930) from the emitting portion toward the photosensitive member 10, and the photosensitive member 10. And a detection light transmission fiber (92) for receiving and transmitting the reflected light.
The objective lens (94) is housed and fixed in the lens barrel (95), and vertically irradiates the photosensitive member 10 with the irradiation light emitted from the emitting portion being condensed toward the photosensitive layer described above.
The spectroscopic means (96) includes a first reflected light reflected on the surface of the surface layer (6) in the incident light, and a second reflected light reflected on the surface of the intermediate layer (3) in the incident light. The first interference light, the first reflected light, and the third reflected light reflected at the optical interface between the surface layer (6) and the lower layer in the incident light interfered with each other. The detection light that is incident and transmitted from the end face of the detection light transmission fiber (92) via the objective lens (94) is dispersed.
The spectrum intensity detecting means (97) detects the spectrum intensity of the detection light dispersed by the spectroscopic means (96).
The calculating means (98) calculates an interference waveform by expanding the reflectance to an arbitrary size when calculating the reflectance from the spectral intensity obtained by the spectroscopy, and calculates a low-frequency component (of the reflectance with respect to the wavelength) of the interference waveform. The film thickness t1 of the surface layer (6) is calculated based on the change being a long period with respect to the first interference light, and the high-frequency component of the interference waveform (the change in reflectance with respect to the wavelength is relative to the second interference light). The film thickness t2 of the photosensitive layer is calculated based on the short cycle.
At this time, the arithmetic means (98) stores a plurality of spectral refractive index data of each film (surface layer (6), charge transport layer (5) and charge generation layer (4)) having different compositions that can be measured. Thus, the distance between the surface layer (6) surface in which the filler fine particles are dispersed and the surface of the charge transport layer (5), and the surface layer (6) surface in which the filler fine particles are dispersed and the surface of the intermediate layer (3) Each distance can be measured as a film thickness.

  Here, an interface where reflection occurs is an optical interface, and the optical interface can be defined as a boundary where a phase having a uniform refractive index is in contact with another phase having a uniform refractive index. Even if an interface between solids (solid phase interface) is formed, if the refractive index (complex refractive index) of the two solids is exactly the same, there will be no optical interface there.

Hereinafter, each means which comprises a film thickness measuring apparatus (9) is demonstrated in more detail, giving a specific example.
The objective lens (94) preferably has a numerical aperture (NA) of 0.2 or less. In the example in the description, it is an “achromatic lens” having a lens diameter of 25.4 mm and a focal length of 30 mm. The objective lens (94) is fixed to one end of the lens barrel (95), and the other end of the lens barrel (95) holds the emission side end of the fiber probe (93).
In this example, the distance between the objective lens (94) and the photosensitive layer surface is 70 mm, and the distance between the objective lens (93) and the exit end of the fiber probe (93) is 52.5 mm.

  The light source (91) is a “halogen-tungsten lamp” that emits spectrum light in a wide wavelength range from the visible region to the near infrared region. The emitted light is guided to the emission part of the fiber probe (93) by the irradiation light guiding fiber (930) of the fiber probe (93).

As shown in FIG. 4B, the end of the fiber probe (93) on the objective lens side is centered on the end of the detection light transmission fiber (92), and this is emitted from the irradiation light guide fiber (930). It is comprised so that a side edge part may surround. The light emitted from the emission part is condensed as a light spot having a diameter of 0.53 mm on the surface of the photosensitive layer by the objective lens (94).
That is, the “end face diameter” of the irradiation light guiding fiber (930) is 0.2 mm, and the bundle of fibers (930) shown in FIG. 4B is a circular light source having a diameter of 0.4 mm. Using the imaging magnification (94) (= 70 / 52.5 = 1.33), the diameter of the light spot is 0.53 mm.

  The spectroscopic means (96) in this apparatus example is a “diffraction grating”, specifically, a fixed Zellnitana type diffraction grating (polychromator) having a spectral region of 600 to 850 nm, a spectral resolution of 0.24 nm / element. Is. As the spectroscopic means (96), as described above, a “prism or spectral filter” can be used instead of the diffraction grating.

  The spectral intensity detection means (97) in this apparatus example is a “line sensor”, which has sensitivity in the range from the visible range to 1050 nm and uses the number of light receiving elements: 1024. It goes without saying that the above-described silicon photodiode array can be used in place of such a line sensor.

The step of measuring the layer thickness of the photosensitive layer will be described by taking the case of FIG. 3 as an example of the configuration of the photoconductor (10). That is, in this case, the photosensitive layer includes a charge generation layer (4), a charge transport layer (5), and a surface layer (6). The surface layer (6) is obtained by uniformly dispersing filler fine particles having a particle size of 0.3 μm, that is, 300 nm in the layer.
Part of the collected light is reflected by the surface of the photosensitive layer, that is, the surface of the surface layer (6), and part of the light is incident on the surface layer (6) and is interfaced with the charge transport layer (5). And a part of the light is transmitted through the charge transport layer (5) and reflected from the surface of the intermediate layer (3). These reflected lights are condensed on the “end surface of the detection light transmission fiber (92)” at the exit end of the fiber probe (93) via the objective lens (94), and are dispersed by the optical transmission fiber (92). ) As “detection light”. The transmitted detection light is dispersed by the spectroscopic means (96), and its spectral intensity is detected by the spectral intensity detecting means (97).

  FIG. 5 shows data detected by the spectrum intensity detecting means (97) as described above. In this case, in FIG. 5, when calculating the reflectance from the spectral spectrum intensity obtained by spectroscopy, the reflectance is enlarged to an arbitrary size. As shown in the figure, the spectral spectrum intensity is reflected light reflected by the surface layer surface and the charge transport layer surface and interfered with each other, and reflected light reflected by the surface layer surface and the intermediate layer surface and interfered with each other. The spectral spectral intensity is finite over the wavelength range of 600 nm to 850 nm, and the intensity changes in a vibrational manner with the wavelength in the entire wavelength range.

Such a vibrational change in the spectral spectrum intensity is a result of “interference in the detection light”, but the period of the vibrational change in the spectral spectrum intensity is the low-frequency component of the interference waveform (the reflectance change with respect to the wavelength is , A long period with respect to interference light between the first reflected light reflected on the surface of the surface layer in which the filler fine particles are dispersed and the second reflected light on which the incident light is reflected on the surface of the intermediate layer) and a high-frequency component ( The change of the reflectance with respect to the wavelength is a short period with respect to the interference light between the first reflected light and the third reflected light reflected at the interface between the surface layer in which the filler fine particles are dispersed and the lower layer). Large in the region of 600 nm or more. This is because the filler fine particles dispersed in the surface layer (6) have an aggregate diameter of 600 nm or less in the present embodiment, so that light having a wavelength of 600 nm or less is scattered by the surface layer (6), This is because no significant interference occurs.
When the experiment was conducted under the above conditions, the thickness of the surface layer could be measured with a resolution of 0.1 μm or less with high accuracy.

  As described above, the film thickness measuring device (9) forms a photosensitive layer as a light-transmitting film on the conductive substrate (2) through the intermediate layer (3), and the surface side of the photosensitive member. A method for measuring the film thickness of the surface layer (6) and the film thickness of the photosensitive layer in an object to be measured (photoconductive photoreceptor 10) having a predetermined thickness portion dispersed with reinforcing filler fine particles, Light from a light source (91) that emits spectrum light in a wavelength region defined by the configuration of the light-transmitting film is guided by a fiber probe (93) and emitted from the emission part, and this radiated light beam is used as an objective. A surface layer (6) in which a lens (94) is perpendicularly incident on an object to be measured (10), is condensed and incident on a light-transmitting (photosensitive layer) film, and filler fine particles are dispersed in the incident light. Of the first reflected light reflected on the surface of the light source and the intermediate layer ( The first reflected light that has interfered with the second reflected light reflected on the surface of) and the first reflected light and the incident light are reflected at the optical interface between the surface layer (6) and its lower layer. The second interference light interfered with the third reflected light is returned to the end face of the detection light transmission fiber (92) in the fiber probe (93) via the objective lens (94), and the detection light transmission fiber When the reflectance is calculated from the spectral intensity of the spectrum that is guided to the spectroscopic means (96) by (92) and spectrally divided, an interference waveform is obtained by expanding the reflectance to an arbitrary magnitude, and the spectral intensity The filler fine particles based on the low-frequency component of the interference waveform (the change in reflectance with respect to wavelength is a long period with respect to the interference light (first interference light) between the first reflected light and the second reflected light described above). Surface layer (6) table with dispersed therein The distance between the surface of the charge transport layer 5 and the surface of the charge transport layer 5 (the film thickness t1 of the surface layer) is a high-frequency component (the change in the reflectance with respect to the wavelength is the interference light (first reflection light) 2), the distance (photosensitive layer thickness t2) between the surface layer (6) and the intermediate layer (3) in which the filler fine particles in the object to be measured are dispersed is based on a short period). A film thickness measurement method that calculates and calculates the film thickness is performed.

  As described above, in the film thickness measuring method and film thickness measuring apparatus according to the present invention, the light emitted from the exit end of the fiber probe (93) is transmitted through the object to be measured (10) by the objective lens (94). The light is condensed on a photosensitive film (photosensitive layer).

Thus, instead of focusing using the objective lens (94), the exit end of the fiber probe (95) is brought close to the distance of 0.5 mm from the surface of the photosensitive layer, and the emitted light is directly directed to the photoreceptor (10). When the surface was irradiated, the spectral spectrum intensity of the detection light was as shown in FIG.
As is clear from FIG. 6, the spectrum intensity has a very small vibration amplitude (difference between the maximum value and the minimum value), which makes it difficult to specify the interference waveform and to calculate and calculate the film thickness. A reliable measurement value cannot be calculated.

As a supplementary explanation, in this embodiment, the diffraction grating as a spectroscopic means is a fixed Zellnitana type diffraction grating “spectral wavelength region: 600 to 850 nm, number of elements: 1024, resolution: 0.24 nm / element. Is used for measurement, and the spectral resolution of the diffraction grating is preferably 0.4 nm / element or less, more preferably in the range of 0.4 nm / element to 0.1 nm / element. .
Note that the spectral resolution is defined by dividing the spectral wavelength region by the number of elements to be dispersed.
As a detector capable of increasing the spectral resolution, there is a CCD having a sensitivity higher than that of a photodiode and a maximum number of elements of 5000 pixels. However, there is a problem that noise is superimposed around 900 nm.

  Increasing the spectral resolution of the diffraction grating is the same as increasing the sampling frequency when acquiring electrical signals. In the case of a thickened film, the maximum (peak peak) and minimum (valley peak) wavelengths are used. Since the interval becomes narrow, it is possible to perform discrete sampling without missing information, and it is easy to measure the thickness of a thick photosensitive layer with a surface layer in which reinforcing filler fine particles are dispersed.

As an example, measurement was performed on a photoconductor having the configuration of FIG. 3 using “wavelength resolution: 0.49 nm / element” instead of the diffraction grating (96) in the film thickness measurement apparatus. The interference waveform due to the surface layer thickness that is the low-frequency component is obtained, but the film thickness due to the photosensitive layer thickness that is the high-frequency component is the interference waveform that can withstand the calculation calculation due to insufficient spectral resolution. It was not obtained.
Thus, sufficient spectrum cannot be obtained with a resolution of 0.49 nm / element. On the contrary, the spectral resolution of 0.1 nm / element or less is overspec, the calculation time for calculating the film thickness is long, and the measurement wavelength region cannot be widened.

  Further, as described above, the diffraction grating (96) used in the above embodiment is one having a spectral region of 600 nm to 850 nm. When using a material in such a spectral region, when the filler fine particle diameter or the aggregate diameter is 0.6 μm or less, a measurement wavelength in the 0.6 to 0.85 μm region suitable for film thickness measurement is secured. By setting the spectral region of the diffraction grating in this region, it is possible not only to obtain a highly accurate interference spectrum and to measure the film thickness with an accuracy of 0.1 μm, but also to ensure the wavelength resolution of the diffraction grating. It becomes easy.

  When the spectral region is 600 nm or less, the measurement wavelength region is a wavelength region that is equal to or smaller than the particle size or agglomerated diameter of the filler fine particles, and is affected by “scattering and diffraction by the filler fine particles and the aggregated particles”. (Mechanism of scattering), spectral spectrum intensity for film thickness measurement cannot be acquired. Further, when the spectral region is 850 nm or more, the upper limit of the sensitivity range of the CCD or photodiode array serving as the spectral intensity detection means is about 1000 nm, and in the upper spectral region, the detector of the spectral intensity detection means (97) Since the sensitivity decreases, it becomes difficult to obtain an interference spectrum.

  As for the wavelength region that enables film thickness measurement, in the wavelength region exceeding 850 nm, it passes through the interface of the intermediate layer (3) without being scattered due to the relationship of fine particles dispersed in the intermediate layer (3). Since the component of light reaching the support substrate increases and the reflection component at the interface of the intermediate layer (3) decreases accordingly, the intermediate layer (3) interface and the surface layer (6) interface where filler fine particles are dispersed The interference waveform component corresponding to (light-transmitting film) is reduced, and the film thickness of the photosensitive layer serving as the light-transmitting film cannot be calculated and calculated.

FIG. 8 shows an embodiment of a film thickness measuring apparatus according to the present invention. In order to avoid complication, the same reference numerals as those in FIG. 4A are assigned to the same parts as those of the film thickness measuring apparatus shown in FIG.
The film thickness measuring device (9A) shown in FIG. 8 is different from that shown in FIG. 4 in that the film thickness measuring device (9A) shown in FIG. 8 is in addition to the structure of the film thickness measuring device (9) shown in FIG. A filter (99) is provided on the light source (91) side to cut “light in an unnecessary wavelength region out of light emitted from a light source that emits spectrum light in a wavelength region determined by the configuration of the light-transmitting film”. It is only a point and the other part is the same as what is shown in FIG.
The unnecessary wavelength region preferably includes a wavelength region that generates fluorescence in the photosensitive layer.

As the filter (99), for example, by using the “sharp cut filter” that transmits the light in the “wavelength region of 600 to 850 nm” described above, the photoconductor as a measurement target is not damaged such as light fatigue. Good film thickness measurement can be performed.
In the embodiment described above, the calculation was performed using “values in the wavelength region of 600 nm to 850 nm” as the wavelengths giving the minimum and maximum in the spectral spectrum intensity.

FIG. 9 shows an example of specific measurement results.
In FIG. 9, the horizontal axis represents the position on the photoconductor (the axial position of the drum-shaped photoconductor), the vertical axis represents the film thickness t1 of the surface layer (6), and each black dot represents the film thickness measurement value.
The measured values of the surface layer (6) in FIG. 9 are those in the range of 600 nm to 850 nm as the measurement wavelength region, and this film thickness is expressed as “the surface layer (6) surface in which filler fine particles are dispersed and the charge transport layer ( 5) ”is given. Therefore, the interval between these measured values is “surface layer thickness t1”.
When measured under the above conditions, the thickness of the surface layer (6) and the thickness of the photosensitive layer could be accurately measured with a resolution of 0.1 μm or less.
FIG. 10 also shows the film thickness t1 of the surface layer, the film thickness t2 in which the distance between the surface layer surface and the intermediate layer surface is the photosensitive layer film thickness, and the intermediate layer surface and the charge transport layer surface. (The thickness obtained by adding the charge transport layer and the charge generation layer) is shown as t2-t1. The horizontal axis indicates the position on the photosensitive member (the axial position of the drum-shaped photosensitive member).
Similarly, the film thickness t2-t1 obtained by adding the charge transport layer and the charge generation layer could be accurately measured with a resolution of 0.1 μm or less.

Regarding the measurement of the filler particle diameter, a part of the formed surface layer (6) is sampled, a cross section is prepared using a diamond cutter, and this is photographed with a scanning electron microscope to fill the filler particles in the film. This can be achieved by measuring the diameter.
The embodiment of the image forming apparatus according to the present invention can be obtained by using the film thickness measuring device (9) in the image forming apparatus shown in FIG. 1 as shown in FIG.

<Photoconductive Photoconductor Production Method, Photoconductive Photoconductor>
Hereinafter, embodiments of the method for producing a photoconductive photoreceptor according to the present invention will be described.
In order for the photoreceptor to perform an appropriate function, it is necessary that the photosensitive layer has an appropriate thickness as described above. For this purpose, the thickness of the photosensitive layer accompanying use of the image forming apparatus is required. The case of measuring the “change with time” of was explained. However, the measurement of the thickness of the photosensitive layer is also required when manufacturing the photoreceptor. For example, it is when inspecting whether the photosensitive layer of the manufactured photoreceptor has a predetermined proper thickness.
The film thickness measuring method and film thickness measuring apparatus of the present invention can also be used to adjust the thickness of the photosensitive layer to an appropriate thickness when manufacturing the photoreceptor.
As a means for improving the durability of the photoreceptor, the surface portion of the photosensitive layer is “surface layer in which filler is dispersed” and further “crosslinked surface layer having a charge transport function” has been described above.

In the production of a photoreceptor, as a method for applying a photosensitive layer on a conductive substrate, a dip coating method, a ring coating method, a spray coating method, and the like are known. In the case of “applying a coating liquid containing a photocrosslinking type polysynthetic resin that has charge transporting properties and is polymerized and cured by application of light energy and a solvent”, the dip coating method and the ring coating method are technically difficult.
The “spray coating method” has the advantage that a photosensitive layer coating film can be formed on various substrates with a small amount of coating liquid, and the physical properties of the coating liquid and the maintenance management of the coating apparatus are relatively easy. There is an advantage that a uniform film can be applied and formed even with a coating liquid in which filler fine particles are dispersed.

  If the film thickness of the photosensitive layer of the product after applying the surface layer and drying and curing is fluctuating, the electrical characteristics of the photoreceptor will change and cause abnormal images. If it becomes possible, it becomes possible to grasp the state of the film in the spray coating step, and by adjusting the liquid properties or the coating conditions, it becomes possible to manufacture a high-quality photoconductor having an optimized film thickness.

  In the method for producing a photoconductive photoreceptor according to the present invention, an intermediate layer forming step in which an intermediate layer in which fine particles are dispersed is applied to the surface of a conductive substrate and formed by drying and curing; A photosensitive layer forming step of forming a photosensitive layer as a film by applying and drying and curing the photosensitive layer, wherein the photosensitive layer forming step includes forming a photosensitive film on the intermediate layer. Forming a photosensitive layer, and applying a coating liquid in which reinforcing filler fine particles are dispersed on the photosensitive film by a spray coating method to form a wet coating film; and A wet film curing step in which the wet coating film is cured by applying light energy and then dried to form a surface layer, and the film of the surface layer is further measured using the film thickness measuring apparatus described above. Equipped with a film thickness measurement process to measure thickness in advance , And controlling the spraying conditions in the spray coating steps based on the thickness t1 of the surface layer was measured by the film thickness measuring step.

  That is, in the method for producing a photoconductive photoreceptor according to the present invention, a coating liquid in which reinforcing filler fine particles are dispersed is applied by a spray coating method, and then light energy is applied to the wet coating film to be cured. Furthermore, a film thickness measurement step is provided for measuring the film thickness of the dried surface layer of the filler layer and the surface of the charge transport layer with high accuracy using the above-mentioned film thickness measuring apparatus. Based on the process, the spray coating conditions are controlled to adjust the coating amount, and the film thickness is optimized to obtain a high-quality photoreceptor.

  In other words, “the coating liquid in which the filler is dispersed is applied by a spray coating method to the upper layer of the photosensitive layer including the intermediate layer on the conductive substrate (however, the photosensitive layer here excludes the surface layer) and then dried and cured. In the manufacturing method in which the surface layer is formed ", after the spray-coated coating is heated and dried, the film thickness in the cured state is" the surface of the surface layer in which the filler fine particles are dispersed and the surface of the charge transport layer. , That is, the film thickness t1 is measured by the above-described film thickness measuring apparatus, and the coating amount is adjusted by controlling the coating conditions in the subsequent spray coating step based on the measured film thickness.

  As described above, according to the film thickness measuring apparatus of the present invention, it is possible to measure the film thickness of the photocrosslinking type surface layer having charge transport properties containing the filler fine particles for reinforcement applied by spraying. This can be reflected in the “coating conditions of the spray coating step immediately after”, and the film thickness uniformity of the surface layer of the photoconductor is improved, and a photoconductor having stable image quality can be obtained. In addition, productivity can be improved and the yield rate can be improved.

  Furthermore, in the present invention, when the film thickness is measured at multiple points in the axial direction of the conductive substrate (axial direction of rotation when the image forming apparatus is mounted to form an image), “in general, in the spray coating step, the conductive substrate is used. Since the film thickness in the circumferential direction is almost the same by spin coating, the film thickness profile in the axial direction of the film thickness can be obtained by multipoint measurement. Based on the estimation results, the coating conditions in the subsequent spray coating steps By controlling the coating amount and adjusting the coating amount, it is possible to improve the uniformity of the cross-linked surface layer having a charge transport function containing a filler and obtain a good photoreceptor.

If the physical properties of the coating liquid, the spray coating apparatus, the conductive substrate, and the like are the same, the film thickness in the spray coating step changes according to the discharge amount. Specifically, the film thickness increases as the discharge amount increases and decreases as the discharge amount decreases. Therefore, the spray coating film thickness can be controlled with high accuracy by controlling the discharge amount.
As described above, when the film thickness is measured by the manufacturing method involving the spray coating step, the objective lens used in the film thickness measuring apparatus is 50 mm from the surface of the object to be measured under the condition of the lens diameter: φ25 mm to 30 mm. It is preferable that the incident angle is 70 mm or less.

The objective lens is used to increase the degree of convergence and concentration of light on the object to be measured.
The use of a large-diameter lens can increase the focusing and condensing, but the basic principle of “vertical incidence / perpendicular light reception” necessary for measurement is disrupted, and measurement light enters the film at an angle, resulting in measurement errors. Arise. Objective lens diameter: Under the condition of φ25 mm or more and 30 mm or less, it is possible to ensure sufficient focusing and condensing performance of the measurement light by constructing it so that it is perpendicularly incident with a distance of 50 mm or more and 70 mm or less from the surface of the object to be measured.

Hereinafter, taking the photoconductive photosensitive member shown in FIG. 3 as an example, each layer constituting this will be described in detail.
The intermediate layer (3) has a structure in which particles and fine particles are dispersed in a binder resin, and a binder is added as necessary.
As the binder resin, thermoplastic resins such as polyvinyl alcohol, nitrocellulose, polyamide, and polyvinyl chloride, and thermosetting resins such as polyurethane and alkyd melamine resins can be used.

  As particles dispersed in the intermediate layer (3), titanium oxide, aluminum oxide, tin oxide, zinc oxide, zirconium oxide, magnesium oxide, silica, and surface-treated products thereof can be used. However, in terms of dispersibility and electrical characteristics, titanium oxide is used. Is preferred. As the titanium oxide, any of rutile type and anatase type can be used, but as the colorless transparent pigment, rutile type titanium oxide having a large refractive index is preferable.

  The fine particles dispersed in the intermediate layer (3) are preferably colorless and transparent pigments that are white in a powder state in consideration of increasing the surface reflectance, and have a back surface hiding power (light shielding power against a conductive substrate). If it is transparent, there is no selective wavelength absorption, so surface reflection and internal multiple refraction can be performed in the entire visible region, and at this time, a good interference spectrum can be obtained.

  As the binder resin, an alkyd resin, a melamine resin, an acrylic resin, a vinyl acetate resin or the like having a small refractive index is preferable.

  In order to realize the intermediate layer (3) as described above, for example, the above-mentioned binder resin is dissolved in an organic solvent, and the above-mentioned particles are dispersed in the solution by means of a ball mill, a sand mill or the like. Apply and dry on top.

Moreover, as above-mentioned, although the preferable layer thickness of an intermediate | middle layer (3) is 2-6 micrometers, More preferably, it is 2.5 micrometers or more.
Since the intermediate layer in which the fine particles are dispersed has a layer thickness of 2.5 μm or more, the optical path length can be secured (can be increased), so that the refractive index difference between the fine particles of the intermediate layer and the binder resin with respect to the measurement wavelength range. Since the opacity of the intermediate layer is increased by the multiple reflections coming from and it becomes possible to suppress the reflected light at the lower interface from the intermediate layer, the surface of the intermediate layer and the surface layer in which the filler fine particles are dispersed The distance and the distance between the surface of the charge transport layer and the surface of the surface layer in which the filler fine particles are dispersed can be measured as the film thickness. On the other hand, when the thickness of the intermediate layer is less than 2.5 μm, the opacity of the intermediate layer with respect to the measurement wavelength region is reduced, so that part of the light reaches the interface below the intermediate layer, and the reflected light from there The distance between the surface of the intermediate layer and the surface layer in which the filler fine particles are dispersed is defined as the photosensitive layer thickness, and the surface of the charge transport layer and the surface layer in which the filler fine particles are dispersed. The distance to the surface cannot be measured as the surface layer thickness.

  As described above, the charge generation layer (4) is a “layer that generates positive and negative charge pairs by irradiation with light of a specific wavelength”, and is a layer mainly composed of a charge generation material. Added. As the charge generation material, either an inorganic material or an organic material can be used.

  Examples of the inorganic material include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium compounds such as selenium-arsenic, and amorphous silicon. In amorphous silicon, dangling bonds terminated with hydrogen atoms or halogen atoms, or those doped with boron atoms, phosphorus atoms, or the like can be suitably used.

  Examples of organic materials include phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, and diphenylamine skeletons. Azo pigments, azo pigments having a dibenzothiophene skeleton, azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo pigments having a bis-stilbene skeleton, azo pigments having a distyryl oxadiazole skeleton, distyrylcarbazole skeleton Azo pigments, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and Zomechin pigments, indigoid pigments, vicinal benzimidazole pigments, may be known materials. These charge generation materials can be used alone or as a mixture of two or more.

  Examples of the binder resin used as necessary include polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, polyacrylamide, and the like. be able to. These binder resins can be used alone or as a mixture of two or more.

The method for forming the charge generation layer (4) is roughly classified into a vacuum thin film manufacturing method and a casting method from a solution dispersion system.
Vacuum thin film preparation methods include vacuum deposition, glow discharge decomposition, ion plating, sputtering, reactive sputtering, CVD, etc., and the charge generation layer using the inorganic or organic materials described above Can be formed satisfactorily.
In order to form the charge generation layer (4) by the casting method, the above-described inorganic or organic charge generation material is ball milled with a binder resin, if necessary, using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, or butanone. The dispersion may be dispersed by an attritor, a sand mill, etc., and the dispersion may be appropriately diluted, applied and dried.
As a coating method, a dip coating method, a spray coating method, a beat coating method, or the like can be used. The thickness of the charge generation layer is suitably about 0.01 to 1 μm, and particularly preferably 0.05 to 0.5 μm.

  The charge transport layer (5) comprises a charge transport material as a main component, and the charge transport material and, if necessary, a binder resin in an appropriate solvent such as tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride, cyclohexanone, etc. It can be formed by dissolving or dispersing, and applying and drying the solution or dispersion. A plasticizer, a leveling agent, etc. can also be added to a charge transport layer (5) as needed.

  The charge transport material includes a hole transport material and an electron transport material, and examples of the electron transport material include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2, 4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include known electron accepting substances such as nitrodibenzothiophene-5,5-dioxide, 3,5-dimethyl-3 ′, 5′-ditertiary butyl-4,4′-diphenoquinone. These electron transport materials can be used alone or as a mixture of two or more.

  Examples of hole transport materials include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4-dibenzylaminophenyl) propane, and styrylanthracene. , Styrylpyrazolines, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzfuran derivatives, benzimidazole derivatives, thiophone derivatives, and the like. It can be used alone or as a mixture of two or more.

Binder resins used in the charge transport layer include polycarbonate (bisphenol A type, bisphenol Z type, etc.), polyester, methacrylic resin, acrylic resin, polyethylene, vinyl chloride, vinyl acetate, polystyrene, phenol resin, epoxy resin, polyurethane, Polyvinylidene chloride, alkyd resin, silicon resin, polyvinyl carbazole, polyvinyl butyral, polyvinyl holmar, polyacrylate, polyacrylamide, phenoxy resin, and the like can be used.
These binder resins can be used singly or as a mixture of two or more. The amount of the binder resin used is suitably 0 to 150 parts by weight with respect to 100 parts by weight of the charge transport material.

  As the binder resin, a polymer charge transport material having a function as a binder resin and a function as a charge transport material can also be used. Such polymer charge transport materials include, for example, a polymer having a carbazole ring in the main chain and / or side chain, a polymer having a hydrazone structure in the main chain and / or side chain, a polystyrene polymer, a main chain and Examples thereof include a polymer having a tertiary amine structure in the side chain. As described above, the thickness of the charge transport layer is preferably about 15 to 35 μm, but the allowable range is about 5 to 100 μm.

  An antioxidant may be added to the photoconductive photoreceptor of the present invention for the purpose of preventing a decrease in sensitivity and an increase in residual potential. The antioxidant may be added to any layer containing an organic substance, but a particularly good effect can be obtained by adding it to a layer containing a charge transport material. In this case, even when an antioxidant is added, the detection of the interference spectrum is hardly affected.

  A surface layer obtained by dispersing filler fine particles in a polymer binder and applying it is easy to form and is suitable for forming a smooth surface. The primary particles (particle size or agglomerated size) of the filler fine particles used are those having a particle size of 0.6 μm or less, more preferably 0.3 μm or less in order not to scatter light excessively in the surface layer.

  Examples of inorganic filler fine particles dispersed in the surface layer (6) of the photosensitive layer include metal powders such as copper, tin, aluminum, and indium, and metal oxides such as tin oxide, zinc oxide, titanium oxide, indium oxide, and alumina (aluminum oxide). Inorganic materials such as materials, silicon oxide, and potassium titanate can be used, and a “surface layer” in which one of these materials is used alone or a mixture of two or more of them is also suitable.

The fine filler particles can be dispersed using a suitable disperser in the state of a spray coating solution for the surface layer.
Further, a surface layer (6) in which the amount of wear is suppressed by applying light energy to a wet film formed using a coating liquid containing a photocrosslinking resin having a so-called charge transporting molecular structure and a solvent and curing the film. It has become.

Hereinafter, the spray coating step will be described taking the case of the photoconductor having the configuration shown in FIG. 3 as an example.
Charge transport that is a photosensitive layer even when spray coating is performed using a “photosensitive layer (however, the photosensitive layer is excluded from the surface layer) and containing a solvent that does not dissolve the resin”. Layer (5) and surface layer (6) are not compatible. When the charge transport layer (5) and the surface layer (6) are incompatible, the charge transport layer (5) and the surface layer (6) have a discontinuous layer structure, and a clear interface is formed between the upper layer and the lower layer. The
Even in such a case, the surface layer (6) does not have a large refractive index difference from the charge transport layer (5), so the interface reflection is small, and the measurement light used in the film thickness measurement process reaches the surface of the intermediate layer. it can.

More specifically, the difference in refractive index between the surface layer (6) and the charge transport layer (5) is preferably in the range of 0.05 to 0.2.
When the difference in refractive index is less than 0.05, since most of the light that has entered the surface layer does not reflect on the surface of the charge transport layer and reaches the intermediate layer because of the small difference in refractive index, It becomes difficult to measure the distance between the surface layer surface as the film thickness, and it is possible to measure the film thickness between the intermediate layer and the surface layer from the refractive index difference between the intermediate layer, the charge generation layer, and the charge transport layer. However, the thickness of the surface layer cannot be measured.
When the refractive index difference exceeds 0.2, if the refractive index difference between the two media is large, reflection at the interface increases, so that part of the light enters the charge transport layer, but most of the light is charged. Since the light is reflected on the surface of the transport layer, it is possible to measure the distance between the charge transport layer surface and the surface layer surface as a film thickness. However, since the light necessary for interference does not reach the surface of the intermediate layer, the film thickness of the photosensitive layer cannot be measured.
If it is 0.2 or less, a part of light passes through the charge transport layer and reaches the intermediate layer surface as a light beam necessary for interference.

  When spray coating is carried out using a “photosensitive layer (however, the photosensitive layer is excluded from the surface layer) resin that dissolves the resin”, the charge transport layer (5) and the surface layer (6) Are compatible. When the charge transport layer (5) and the surface layer (6) are compatible, the charge transport layer (5) and the surface layer (6) have a continuous layer structure. When the charge transport layer (5) and the surface layer (6) have a continuous layer structure, a clear interface is not formed between the upper layer and the lower layer, and the surface layer thickness cannot be measured in the film thickness measurement step.

The thickness after curing of the surface layer (6) to be spray-coated is preferably about 3 to 9 μm as described above, but when it is thinned, the limit is about 0.1 μm. When the thickness is less than 0.1 μm, the surface hardness and strength are not sufficient and the durability is poor, and when the thickness exceeds 9 μm, the electrostatic latent image formed by optical scanning or optical writing is developed and visualized. Sometimes dot reproducibility deteriorates.
A more preferable range of the “thickness after curing” of the surface layer formed by spray coating is 0.2 to 8 μm.

  “A charge transporting material” is added to the coating liquid for forming the surface layer (6) as necessary. Examples of charge transport materials include hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triarylmethane compounds.

FIG. 11 conceptually shows an example of an apparatus for carrying out the method for producing a photoconductive photoreceptor.
Reference numeral (100) indicates that the intermediate layer (3), the charge generation layer (4), and the charge transport layer (5) are formed on the conductive substrate (2) in the photoconductive photoreceptor having the configuration shown in FIG. In this state (the state where the photosensitive layer formation step is omitted) (hereinafter referred to as “spray object”) ”, in this state, the portion that becomes the surface layer (6) is formed by the spray coating step. As a result, a photoconductive photoconductor is completed.

  The code | symbol (111) shows the spray gun in a spray coating apparatus. The spray gun (111) is supplied with the coating liquid stored in the liquid tank (113) by the liquid feed pump (112), and performs spray coating on the spray target object (100). At this time, the spray object (100) is rotated at a constant speed around the axis, and the spray gun (111) sprays while moving at a constant speed in the direction of the axis. Spray coating is performed by spraying a plurality of times.

Reference numeral (120) denotes a “film thickness measuring apparatus”, and the film thickness measuring apparatus (9A) shown in FIG. 8 is used here. The configuration of each part excluding the filter (99) is the same as that described above with reference to FIG. The objective lens (94) is an “achromatic lens” having a lens diameter of 25.4 mm and a focal length of 30 mm, and is positioned 70 mm away from the surface of the spray target (100). The filter (99) is a “sharp cut filter” that transmits the light in the above-described “600 to 850 nm wavelength region”.
The film thickness measuring device (120) is movable in the axial direction of the spray target (100).

That is, in the spray coating step, the spray object (100) is rotated while the spray gun (111) is moved in the axial direction to perform spraying, and after the wet film is formed by the spray, the spray object (100 ) Is not shown, but is dried after application of light energy to cure the wet film (wet film curing step), and the film thickness measuring device (120) is moved in the axial direction of the spray object (100), for example, 10 mm. Film thickness measurement (multipoint measurement) is performed at 30 positions at intervals.
The result of the film thickness measurement is input to the calculation means (121). The calculation means (121) determines the discharge amount of the coating liquid according to the film thickness measurement result of the film formed by spraying so that the subsequent spraying can be continued to obtain a desired film thickness.

  The discharge amount determined in this way is input to the control means (122) (configured by a microcomputer together with the calculation means (121)), and the control means (122) is a liquid feed pump when performing the subsequent spraying. (112) is controlled to perform spraying according to the discharge amount.

Specific examples relating to the method for producing a photoconductive photoreceptor will be described below.
For the purpose of manufacturing a photoconductor having the structure shown in FIG. 3, as a conductive substrate (2), a tube diameter: φ30 mm, surface roughness Rmax: 0.3 μm, cut aluminum blank (Tokyo Seimitsu: surface roughness shape measuring machine) Prepared with SURFCOM1400D).

  Examples of the “conductive substrate having a surface roughness Rmax of 0.4 μm or less” include metal substrates such as aluminum tubes and nickel belts (belt-shaped metal substrates formed by the same method as plating), plastic belts (polyester films) Although various well-known things can be used such as aluminum vapor deposition or conductive resin coating to make a conductive belt), the above-mentioned aluminum tube can be subjected to surface processing such as cutting, ironing, drawing, Suitable as a conductive substrate.

70 parts by weight of titanium oxide, which is a colorless transparent pigment, as particles having an average particle size of 0.25 μm, alkyd resin (trade name: Beckolite M6401-50-S (solid content 50%): manufactured by Dainippon Ink & Chemicals, Inc.): 15 parts by weight, melamine resin (trade name: Super Becamine L-121-60 (solid content 60%): manufactured by Dainippon Ink & Chemicals): 10 parts by weight, methyl ethyl ketone: 100 parts by weight, and the mixture was mixed with a ball mill. Dispersed for 72 hours to obtain a “coating solution”.
This coating solution is applied to an aluminum tube having a surface roughness Rmax: 0.3 μm by the “dipping method” and dried at a temperature of 130 ° C. for 20 minutes to obtain an intermediate layer (3) having a thickness of 3.5 μm. It was.
The film thickness was measured with a surface roughness / shape measuring instrument SURFCOM 1400D after removing a part of the intermediate layer of the monitor drum coated under the same conditions.

Next, polyvinyl butyral (BM-2: manufactured by Sekisui Chemical Co., Ltd.): After adding 4 parts by weight of cyclohexanone: 150 parts by weight, a trisazo pigment: 10 parts by weight is added and dispersed in a ball mill for 72 hours. , Cyclohexanone: 210 parts by weight was added and dispersed for 3 hours to obtain a coating liquid having an absorption peak at 900 nm or less, which was applied on the intermediate layer (3) by the “dipping method” and heated at a temperature of 130 ° C. A charge generation layer (4) having a film thickness of 0.2 μm was formed by drying for minutes.
The chemical formula of the “trisazo pigment” is shown below.

Further, charge transport material (compound): 7 parts by weight, polycarbonate resin (Iupilon Z200: manufactured by Mitsubishi Gas Chemical Company): 10 parts by weight, silicone oil (KF-50: manufactured by Shin-Etsu Chemical Co., Ltd.): 0.002 parts by weight Tetrahydrofuran: A coating solution dissolved in 100 parts by weight was applied onto the charge generation layer by a dip method and dried at a temperature of 130 ° C. for 20 minutes to form a charge transport layer (5) having an average film thickness of 22 μm.
The refractive index of the charge transport layer (photosensitive layer) was 1.6 (at 633 nm) (the difference in refractive index from the intermediate layer was 1.1). The refractive index was measured with a spectroscopic ellipsometer (JA Woolam WVASE32) by preparing a thin film formed on Si-Wafer under the same conditions.
The chemical formula of the “charge transport material” is shown below.

As described above, the spray object (100) shown in FIG. 11 is obtained.
The coating liquid for the surface layer includes the charge transport material used in the charge transport layer (5), bisphenol Z-type polycarbonate, and silica fine particles (KMPX100: manufactured by Shin-Etsu Chemical Co., Ltd., particle size: 0.3 μm, part of the surface layer) , Sample a cross-section using a diamond cutter, measure the particle size in the film by taking a photograph with a scanning electron microscope), and <mixing ratio (weight)> charge transport for tetrahydrofuran and cyclohexanone Substance / polycarbonate / silica fine particles / tetrahydrofuran / cyclohexanone = 3/4/2/160/40, and spray coating was performed at a discharge rate of 7 (cc / min). The refractive index of the surface layer was 1.8, the refractive index of the charge transport layer was 1.6, and the refractive index difference was 0.2.

  Regarding the application of the surface layer (6), “data on the surface layer coating liquid” is input to the calculation means (121) in advance. Specifically, the “film thickness after curing after spraying with respect to the discharge amount” was measured, and the correlation between these was grasped and input.

The film thickness of the finally obtained surface layer is set to 2.7 μm, and the dry cured film thickness after spraying the surface layer coating liquid is measured using a film thickness measuring device (9A) with a spectral resolution of 0.24 nm / After expanding the reflectance to an arbitrary size under the condition of the element (spectral wavelength region: 600-850 = 250 nm with 1024 elements), the wavelength region of 600 to 850 nm (filmetrics: measured with a spectral reflectance measuring device F20) ), The “optimum spray discharge amount” was calculated from the measurement results, and the discharge amount in the subsequent spray was controlled. In this way, 50 photoconductors were produced in succession.
After one photoconductor was obtained, the discharge amount data at the time of manufacturing this photoconductor was reflected in the discharge amount on the next photoconductor.

In this way, when the “film thickness of the surface layer” of the photoreceptor having the surface layer (6) cured is extracted, the obtained film thickness is within a range of 2.7 μm ± 0.1 μm and is constant. It was.
Some of the results are shown below. “OK” in the table indicates that there is no problem in quality.

As a comparative example 1, under the same conditions as described above, the result of manufacturing with the spray discharge amount fixed at 10 cc / min is as follows. “OK” in the table indicates that there is no problem in quality, and “NG” indicates that the predetermined quality is not satisfied.

  As described above, when the spray discharge amount is not controlled, the film thickness of the photosensitive layer decreases with an increase in the number of production, and a predetermined quality cannot be achieved after 15 pieces. The coating liquid for spray coating used in the examples and comparative examples changes in physical properties over time, and the quality cannot be maintained unless the discharge amount is increased with the increase in the number of productions. In addition, by providing a film thickness measurement step and adjusting the discharge amount based on the film thickness measurement, it is possible to manufacture a photoconductor of good quality.

  As Comparative Example 2, the refractive index of the surface layer is 1.7, the refractive index of the charge transport layer is 1.74, and the difference in refractive index between the surface layer and the charge transport layer is less than 0.05. In this case, since the amount of light reaching the intermediate layer increases due to a decrease in reflection on the surface of the charge transport layer, an interference waveform due to the film thickness of the photosensitive layer (surface layer + photosensitive layer) can be obtained. However, since the interference waveform due to the film thickness t1 of the surface layer becomes weak, the film thickness t1 of the surface layer cannot be measured.

  Further, as Comparative Example 3, under the same conditions as in Example 1, when calculating the reflectance from the spectral spectrum intensity, the reflectance R (λ) is calculated instead of expanding the reflectance to an arbitrary size. Is measured by the theory method (without magnification), the reflected waveform necessary for optical interference measurement on the surface of the charge transport layer or the intermediate layer is weak, and the interference waveform necessary for the measurement The surface layer is based on the low frequency component of the interference waveform (the change in reflectance with respect to wavelength is a long period with respect to the interference light between the first reflected light and the second reflected light). The film thickness t1 of the photosensitive layer is calculated based on the high-frequency component (the change in reflectance with respect to the wavelength is a short period with respect to the interference light between the first reflected light and the third reflected light described above). I couldn't.

2 conductive substrate 3 intermediate layer 4 charge generation layer 5 charge transport layer 6 surface layer 10 photoconductive photoreceptor 91 light source 92 optical transmission fiber 93 fiber probe 94 objective lens 95 barrel 96 spectroscopic means 97 spectral intensity detection means 98 calculation Means 99 Filter 100 Spray object 111 Spray gun 112 Liquid feed pump 113 Liquid tank 120 Film thickness measuring device 121 Arithmetic means 122 Control means 930 Irradiation light guiding fiber

Patent No. 3958140 JP-A-6-77302 JP-A-11-201730 JP 2000-186916 A JP 2000-356859 A Japanese Patent Laid-Open No. 2001-27815

Claims (35)

Having an intermediate layer in which fine particles are dispersed on the surface of the conductive substrate;
Having a photosensitive layer as a light-transmitting film on the intermediate layer;
A film thickness measuring method for measuring a film thickness of a photoconductive photoreceptor in which a predetermined thickness portion on the opposite side of the conductive layer of the photosensitive layer is formed as a surface layer in which reinforcing filler fine particles are dispersed. There,
The light from a light source that emits spectrum light in a wavelength region that enables film thickness measurement on the photoconductive photoreceptor is guided by an irradiation light guiding fiber that the fiber probe has,
Radiating a light beam from an emission part of the irradiation light guiding fiber,
The light beam is vertically incident on the photoconductive photosensitive member in a state where the light beam is condensed on the photosensitive layer by an objective lens,
A first interference light in which the first reflected light reflected on the surface of the surface layer in the incident light interferes with the second reflected light reflected on the surface of the intermediate layer in the incident light;
And second interference light obtained by interference between the first reflected light and the third reflected light reflected at the optical interface between the surface layer and the lower layer in the incident light,
Return to the end face of the detection light transmission fiber of the fiber probe through the objective lens,
The light is guided to the spectroscopic means by the detection light transmission fiber, and then dispersed.
When calculating the reflectance from the spectral intensity of the spectrum, the interference waveform is obtained by expanding the reflectance to an arbitrary size,
Based on the low-frequency component of the interference waveform (the change in reflectance with respect to wavelength is a long period with respect to the first interference light), the film thickness t1 of the surface layer is calculated and calculated, and the high-frequency component of the interference waveform (with respect to the wavelength) A film thickness measuring method, comprising: calculating and calculating the film thickness t2 of the photosensitive layer based on a change in reflectivity (short period with respect to the second interference light). The photosensitive layer is formed with a charge generation layer formed in contact with the intermediate layer, a charge transport layer formed on the charge generation layer, and a predetermined thickness on the charge transport layer. A surface layer in which filler fine particles are dispersed,
2. The film thickness measuring method according to claim 1, wherein a distance between the surface layer and the intermediate layer is measured as a film thickness t2 of the photosensitive layer. The photosensitive layer is formed with a charge generation layer formed in contact with the intermediate layer, a charge transport layer formed on the charge generation layer, and a predetermined thickness on the charge transport layer. A surface layer in which filler fine particles are dispersed,
The film thickness measuring method according to claim 1, wherein the distance between the surface of the surface layer and the surface of the charge transport layer is measured as a film thickness t1 of the surface layer. The photosensitive layer is formed with a charge generation layer formed in contact with the intermediate layer, a charge transport layer formed on the charge generation layer, and a predetermined thickness on the charge transport layer. A surface layer in which filler fine particles are dispersed,
The thickness t1 of the surface layer is calculated based on the wavelength that gives the maximum and the wavelength that are adjacent to each other in the low-frequency component of the interference waveform, and the refractive index of the surface layer,
2. The film thickness measuring method according to claim 1, wherein the film thickness t2 of the photosensitive layer is calculated based on a frequency analysis that decomposes a high frequency component of an interference waveform into a cosine wave component. The photosensitive layer is formed with a charge generation layer formed in contact with the intermediate layer, a charge transport layer formed on the charge generation layer, and a predetermined thickness on the charge transport layer. A surface layer in which filler fine particles are dispersed,
2. The film thickness according to claim 1, wherein a distance between the surface of the intermediate layer and the surface of the charge transport layer is measured as a film thickness t <b> 2-t <b> 1 obtained by adding the charge generation layer and the charge transport layer. Measuring method.   The film thickness measuring method according to claim 1, wherein the surface layer has a cross-linked structure having a charge transport function.   The film thickness measurement method according to claim 2, wherein a difference in refractive index between the surface layer and the charge transport layer is in a range of 0.05 to 0.2.   The film thickness measuring method according to claim 1, wherein the extinction coefficient of the filler fine particles is 0.   The film thickness measuring method according to claim 1, wherein the filler fine particles are inorganic fillers.   The film thickness measurement method according to claim 1, wherein the filler fine particles are a metal oxide.   The film thickness measuring method according to claim 1, wherein the filler fine particles are at least one selected from silicon oxide, titanium oxide, and aluminum oxide.   The film thickness measuring method according to claim 1, wherein a wavelength resolution in the spectroscopic means is 0.4 nm or less.   The film thickness measuring method according to any one of claims 1 to 12, wherein a wavelength region in which the film thickness of the photoconductive photoconductor can be measured is 600 to 850 nm. The wavelength region that enables film thickness measurement on the photoconductive photoconductor of the light source is larger than the particle diameter or aggregation diameter of the filler fine particles,
The film thickness measuring method according to claim 13, wherein the filler fine particles have a particle diameter or agglomerated diameter of 0.6 μm or less. The photosensitive layer is formed with a charge generation layer formed in contact with the intermediate layer, a charge transport layer formed on the charge generation layer, and a predetermined thickness on the charge transport layer. A surface layer in which filler fine particles are dispersed,
Measure the distance between the surface of the surface layer and the surface of the intermediate layer as the film thickness t2 of the photosensitive layer,
The film thickness measuring method according to claim 1, wherein the distance between the surface layer and the surface of the charge transport layer is measured simultaneously with the time t2 as the film thickness t1 of the surface layer.   The film thickness measuring method according to claim 1, wherein the intermediate layer has a layer thickness of 2.5 μm or more. A conductive substrate, an intermediate layer formed on the surface of the conductive substrate and having fine particles dispersed therein, and a photosensitive layer formed as a light-transmitting film on the intermediate layer, The film according to any one of claims 1 to 16, wherein the film thickness of the photoconductive photoreceptor formed as a surface layer in which a predetermined fine thickness portion on the opposite side to the conductive substrate is dispersed with reinforcing filler fine particles is dispersed. A film thickness measuring device for measuring by a thickness measuring method,
A light source that emits spectral light in a wavelength region that enables film thickness measurement of the photoconductive photoreceptor;
A light guide fiber for guiding the light from the light source to the photoconductive photoconductor side and emitting the light from the emitting portion toward the photoconductive photoconductor side, and the reflected light from the photoconductive photoconductor is received. A fiber probe for detecting light transmission transmitted by
An objective lens that vertically enters the photoconductive photosensitive member in a state where the irradiation light emitted from the emitting portion is condensed toward the photosensitive layer;
A first interference light in which the first reflected light reflected on the surface of the surface layer in the incident light interferes with the second reflected light reflected on the surface of the intermediate layer in the incident light;
And the first reflected light and the second reflected light interfering with the third reflected light reflected at the optical interface between the surface layer and the lower layer in the incident light,
A spectroscopic means for spectroscopically separating the transmitted detection light incident from the end face of the detection light transmission fiber via the objective lens;
Spectral intensity detection means for detecting the spectral intensity of the detection light split by the spectroscopic means;
When calculating the reflectance from the spectral intensity of the spectrum, the interference waveform is obtained by expanding the reflectance to an arbitrary size,
Based on the low-frequency component of the interference waveform (the change in reflectance with respect to wavelength is a long period with respect to the first interference light), the thickness t1 of the surface layer is calculated and calculated, and the high-frequency component of the interference waveform (with respect to the wavelength) A film thickness measuring apparatus comprising: a calculating unit that calculates and calculates the film thickness t2 of the photosensitive layer based on a change in reflectivity based on a short cycle with respect to the second interference light.   The film thickness measuring apparatus according to claim 17, wherein the numerical aperture NA of the objective lens is 0.2 or less.   The film thickness measuring device according to claim 17, wherein the objective lens is an achromatic lens.   The film thickness measuring apparatus according to claim 17, wherein the light source has an emission wavelength of 600 to 850 nm.   21. The film thickness measuring apparatus according to claim 17, wherein the light source is a halogen-tungsten lamp.   The film thickness measuring device according to any one of claims 17 to 21, wherein the spectroscopic means is a diffraction grating, a prism, or a spectral filter.   23. The film thickness measuring apparatus according to claim 17, wherein the spectrum intensity detecting means is a line sensor or a silicon photodiode array.   24. The film thickness measuring apparatus according to claim 17, wherein a spectral resolution of the spectroscopic means is 0.4 nm / element or less.   25. The film thickness measuring apparatus according to claim 17, wherein a wavelength region of the spectroscopic means is 600 nm or more and 850 nm or less.   The objective lens side end of the fiber probe is centered on the end of the detection light transmission fiber, and the detection light transmission fiber is surrounded by the emission side end of the irradiation light guide fiber. The film thickness measuring device according to any one of claims 17 to 25, wherein   27. The film thickness measuring apparatus according to claim 17, further comprising a filter that cuts light in an unnecessary wavelength region out of light emitted from the light source.   28. The film thickness measuring apparatus according to claim 27, further comprising a filter that cuts 600 nm or less and 850 nm or more of light in the unnecessary wavelength region.   29. The refractive index data of any one or more of the intermediate layer surface or the layer interposed on the surface layer surface is stored in an available manner by the calculation means. Film thickness measuring device. A photoconductive photoconductor, an electrostatic latent image forming unit that forms an electrostatic latent image on the surface of the photoconductive photoconductor, a developing unit that develops the electrostatic latent image with toner and develops a toner image; 30. The film according to claim 17, wherein a transfer unit that transfers the toner image to a sheet-like recording medium to form an unfixed image, a fixing unit that fixes the unfixed image on the recording medium, A thickness measuring device,
The photoconductive photoreceptor includes a conductive substrate, an intermediate layer in which fine particles are dispersed on the surface of the conductive substrate, and a photosensitive layer formed as a light transmissive film on the intermediate layer. ,
A predetermined thickness portion of the photosensitive layer opposite to the conductive substrate is formed as a surface layer in which reinforcing filler fine particles are dispersed;
The image forming apparatus, wherein the film thickness measuring device measures a film thickness t1 of the surface layer.   31. The image forming apparatus according to claim 30, wherein the image forming apparatus has a function of displaying that the film thickness t1 of the surface layer has become a predetermined value or less.   The filler particles have a particle diameter or agglomerated diameter of 0.6 μm or less, and the wavelength region enabling the measurement of the film thickness of the photoconductive photoreceptor of the light source of the film thickness measuring device is the filler particle diameter or agglomerated diameter. 32. The image forming apparatus according to claim 30, wherein the image forming apparatus is as described above. Applying an intermediate layer in which fine particles are dispersed on the surface of the conductive substrate, forming an intermediate layer by drying and curing,
Applying a photosensitive layer as a light transmissive film on the intermediate layer, and forming a photosensitive layer by drying and curing, and a method for producing a photoconductive photoreceptor,
In the photosensitive layer forming step, a photosensitive layer forming step for forming a photosensitive film on the intermediate layer, and a coating liquid in which filler fine particles for reinforcement are dispersed on the photosensitive film are applied by a spray coating method. A spray coating step for forming a wet coating film, and applying a light energy to the wet coating film for curing, followed by further drying to form a wet film curing step.
Furthermore, a film thickness measurement step of measuring the film thickness of the surface layer in advance using the film thickness measurement device according to any one of claims 17 to 29,
A method for producing a photoconductive photoreceptor, comprising controlling spray application conditions in the spray coating step based on the film thickness t1 of the surface layer measured in the film thickness measurement step. The conductive substrate is cylindrical or belt-shaped;
The film thickness measuring step measures the film thickness t1 of the surface layer in the axial direction of the conductive substrate at multiple points, and measures the distribution of the film thickness t1 of the surface layer with respect to the axial direction. Item 34. A method for producing a photoconductive photoreceptor according to Item 33.   35. The application amount is adjusted by controlling the discharge amount of the coating liquid in the spray coating step based on the film thickness t1 of the surface layer measured in the film thickness measurement step. A method for producing a photoconductive photoreceptor according to 1.

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