JP2013015823A - Electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic device suppressing generation of interference fringes, maintaining image formation with little image defects and showing high reproducibility of thin lines.SOLUTION: An electrophotographic photoreceptor includes a charge generating layer and a charge transporting layer on a conductive support. The conductive support has such a surface profile that in a graph showing the dependency of an average local height difference (Rmk) on a calculation length, the maximum (Rmk,max) of (Rmk) satisfies expression (1):Rmk,max≥0.15λT, where Trepresents a transmittance until a laser beam reaches the conductive support, and that in the graph, a Rmk equal to or larger than (Rmk,max) and 2/3 or more of (Rmk,max) appears in a calculation length apart from the calculation length where the maximum (Rmk,max) appears, by 0.1 time or less or 10 times or more. An interfacial profile between the i-th layer and the (i+1)-th layer of the photoreceptor satisfies expression (2), where Trepresents a transmittance until a laser beam reaches the i-th layer on the conductive support; and nand nrepresent refractive indices of the i-th layer and (i+1)-th layer on the conductive support, respectively.

Description

  The present invention relates to an electrophotographic apparatus.

  As an image holding member used in an electrophotographic apparatus, there is a laminated type organic electrophotographic photosensitive member. In a laminated type photoconductor, when laser light is used as an image exposure light source, there arises a problem that interference fringes are generated in a latent image due to multiple reflection of exposure light inside the photoconductor.

In order to solve this problem, Patent Document 1 describes a method of roughening a photosensitive substrate serving as a reflective surface.
On the other hand, Patent Document 2 describes a method for evaluating a roughened substrate that prevents interference fringes.
Patent Document 3 describes a method for measuring the interference fringe prevention capability of a photoreceptor using a roughened substrate.

Japanese Patent Laid-Open No. 2000-075528 JP 2004-117454 A JP 2008-122999 A

  In order to cope with higher image quality of electrophotographic apparatuses, the diameter of the exposure beam spot has been reduced. For this reason, the roughening of the substrate to prevent interference fringes affects the fine line reproducibility. In addition, in order to improve fine line reproducibility, it is required to use a photoreceptor having a thinner photosensitive layer. Furthermore, in the case where an intermediate layer is provided between the photosensitive layer and the substrate, it is required to use a photoconductor having a thinner intermediate layer from the viewpoint of the repeated stability of the photoconductor.

  For this reason, when a conventionally used substrate is used for a thin film photoreceptor, there is a problem that black spots caused by roughening of the substrate and fogging caused by hole injection from the substrate cannot be suppressed. .

  In view of preventing interference fringes by roughening the substrate of the photosensitive layer, it is necessary to search for a more efficient rough shape. However, in order to search for or define an efficient rough shape, the parameters related to roughening that have been used in the past have been insufficient, leaving room for improvement.

  The object of the present invention has been made in view of the above-mentioned problems, while maintaining the image formation with less image defects such as black spots and fog, while suppressing the generation of interference fringes from the beginning of use until the end of the durable life. An object is to provide an electrophotographic apparatus with high reproducibility.

According to one aspect of the present invention, there is provided an electrophotographic apparatus having an exposure unit, a charging unit, a developing unit, a transfer unit, and an electrophotographic photosensitive member having a laser light source for oscillating a laser beam having a wavelength λ. The photoconductor has at least a charge generation layer and a charge transport layer in this order on a conductive support, and the conductive support has a surface shape with a calculated length of an average local height difference (Rmk). In the graph showing the dependency, the maximum value (Rmk, max) of the average local height difference (Rmk) is the following formula (1) (in formula (1), T ₁ indicates that the laser beam is the conductive support). Show the transmittance to reach
When the layer provided in contact with the conductive support is a first layer and the layer provided in contact with the conductive support is named as a second layer up to the charge generation layer, the average local In the graph showing the dependency of the height difference (Rmk) on the calculated length, the maximum value (Rmk, max) of the average local height difference (Rmk) is 0.1 times or less or 10 times or more away from the calculated length. In the calculated length, Rmk that is not more than the maximum value (Rmk, max) and more than two-thirds of the maximum value (Rmk, max) is expressed, and the i-th layer and the i + 1-th layer (i is an integer of 1 or more) The shape of the interface with the following formula (2)
(In Formula (2), T _{i + 1} indicates the transmittance until the laser beam reaches the i-th layer on the conductive support, and n _i and n _{i + 1} are respectively on the conductive support. An electrophotographic apparatus characterized by satisfying the refractive indices of the i-th layer and the (i + 1) -th layer provided in contact with each other is provided.

According to another aspect of the present invention, there is provided an electrophotographic apparatus having an exposure means having a laser light source for oscillating a laser beam having a wavelength λ, a charging means, a developing means, a transfer means, and an electrophotographic photosensitive member. The electrophotographic photoreceptor has at least a charge generation layer and a charge transport layer in this order on a conductive resin support, and the conductive resin support is the 0th layer. When the layer provided in contact with the first layer is named as the first layer and the layer provided in contact with the second layer is named as the second layer up to the charge generation layer, the conductive resin support is In the graph where the surface shape shows the calculation length dependence of the average local height difference (Rmk), the maximum value (Rmk, max) of the average local height difference (Rmk) is 0.1 times or less from the calculated length. Alternatively, in the calculated length more than 10 times away, Rmk that is less than a large value (Rmk, max) and more than two-thirds of the maximum value (Rmk, max) is expressed, and the shape of the interface between the i-th layer and the i + 1-th layer (i is an integer of 1 or more) The following formula (2)
(In Formula (2), T _{i + 1} represents the transmittance until the laser beam reaches the i-th layer on the conductive resin support, and n _i and n _{i + 1} represent the conductive resin support, respectively. An electrophotographic apparatus characterized by satisfying the refractive index of the i-th layer and the (i + 1) -th layer provided in contact with each other is provided.

Furthermore, according to another aspect of the present invention, there is provided an electrophotographic apparatus having an exposure unit having a laser light source for oscillating a laser beam having a wavelength λ, a charging unit, a developing unit, a transfer unit, and an electrophotographic photosensitive member. The electrophotographic photosensitive member has a charge generation layer provided in contact with a conductive support and a charge transport layer provided on the charge generation layer. In a graph whose shape shows the calculation length dependence of the average local height difference (Rmk), 0.1 times or less from the calculated length at which the maximum value (Rmk, max) of the average local height difference (Rmk) is expressed or Rmk that is less than the maximum value (Rmk, max) and half or more of the maximum value (Rmk, max) is expressed at a calculated length that is 10 times or more apart, and the maximum of the average local height difference (Rmk) The value (Rmk, max) is Serial formula (1)
There is provided an electrophotographic apparatus characterized by satisfying (in formula (1), T ₁ represents a transmittance until the laser beam reaches the conductive support).

  According to the present invention, while suppressing the generation of interference fringes from the initial use to the end of the durable life, image formation with less image defects such as ghosts and black spots can be achieved not only under normal temperature and normal humidity but also under low temperature and low humidity. An electrophotographic apparatus with high fine line reproducibility can be provided while maintaining.

(I) is a diagram showing mesh division of the three-dimensional surface shape data when calculating Rmk (L), (ii) is the calculated Rmk (L) data, and the horizontal axis is the logarithm of L This is an example of a graph. (I) is a graph of two-dimensional and three-dimensional surface roughening shapes in five types of artificial roughness shapes (a) to (e) prepared for examining the effect of randomness, and (ii) is randomness. 5 is an Rmk (L) graph of five types of artificial roughness shapes (a) to (e) prepared for examining the effect of (iii), and (iii) is five types of artificial roughness shapes prepared for examining the effect of randomness. (a) is a graph showing the interference fringes level determined by numerical calculation using Fresnel coefficient at ~ (e), (iv) the (b) and the shape of (e), Rmod (λ / (2n i) ) On the horizontal axis and frequency of occurrence on the vertical axis, showing that there is a difference in bias between the two. (I) is a figure which shows the content of 3D surface shape data, and the concept of a variable, (ii) is a figure explaining the detail when mesh-dividing 3D surface shape data. It is a figure which shows the definition of a photoreceptor layer structure and a variable for demonstrating the outline of the numerical calculation using a Fresnel coefficient. (I) is a figure which shows the concept of the weighted average of Rmk (L) data when calculating Rmk, ave, (ii) is the weighting of Rmk (L) data when calculating Rmk, ave, s It is a figure which shows the concept of an average, (iii) is a figure which shows the concept of the weighted average of Rmk (L) data when calculating Rmk, ave, l. (I) is a figure which shows the example (partial enlarged view) of the arrangement | sequence mask pattern used in the laser ablation in this invention, (ii) is the example (partial enlarged view) of the arrangement | sequence mask pattern used in the laser ablation in this invention. (Iii) is a figure which shows the example of the outermost surface cross-sectional shape of the electrophotographic photoreceptor in this invention, (iv) is a figure which shows the outline of the example of the laser processing apparatus in this invention. 1 is a diagram schematically showing a configuration of an example of an electrophotographic apparatus according to the present invention. (I) is a figure which shows the example (partial enlarged view) of the arrangement | sequence mask pattern used in the laser ablation in this invention, (ii) is the example (partial enlarged view) of the arrangement | sequence mask pattern used in the laser ablation in this invention. FIG. (I) is a graph of Rmk (L) data calculated from the surface shape of the roughened support, with the horizontal axis representing the logarithm of L, and (ii) is a roughened and conductive surface. It is the figure which plotted the Rmk (L) data calculated from the surface shape of the layer, making the horizontal axis logarithm of L. (I) is a diagram in which a horizontal axis represents the exposure laser wavelength and a vertical axis represents Rmk, max / T ₁ , and a part of the example / comparative example is plotted, and (ii) represents the horizontal axis √ (n _i − _{n i + 1) / (n} i + n i + 1) (i = 1), is a plot of some examples / comparative examples and the vertical axis is the _{(Rmk, max) / T 1} λ.

The present inventors have intensively studied to achieve the above object.
In order to realize an efficient rough shape, the calculation length (L) dependence of the average local height difference (Rmk) was devised as an appropriate evaluation parameter. The electrophotographic apparatus of the present invention has an electrophotographic photosensitive member having a rough shape defined by Rmk between a support and a charge generation layer, thereby effectively eliminating interference fringes (or generating interference fringes). And the above-mentioned purpose is achieved.

That is, the electrophotographic apparatus of the present invention is an electrophotographic apparatus having, for example, an exposure unit having a laser light source for oscillating a laser beam having a wavelength λ, a charging unit, a developing unit, a transfer unit, and an electrophotographic photosensitive member. When the electrophotographic photosensitive member has at least a charge generation layer and a charge transport layer in this order on the conductive support, the surface shape of the conductive support is calculated as an average local height difference (Rmk (μm)). In the graph showing the length (L (μm)) dependency,
(1): Calculation that is 0.1 times or less or 10 times or more away from the calculated length (Lm (μm)) in which the maximum value (Rmk, max (μm)) of the average local height difference (Rmk (μm)) is expressed In length, Rmk is expressed not more than the maximum value (Rmk, max) and not less than two thirds of the maximum value (Rmk, max), and
(2): The maximum value (Rmk, max) of the average local height difference (Rmk) is expressed by the following formula (1).
(In formula (1), T ₁ indicates the transmittance until the laser beam reaches the conductive support).

Here, the dependence of the average local height difference Rmk on the calculated length L will be described. This parameter is calculated by the following procedures (1) to (5). After measuring the three-dimensional surface shape data z (x, y) of the roughness shape,
(1): The obtained surface shape data is divided into meshes whose side length is L (see the left figure in FIG. 1 (i)).
(2): The height z (x, y) is averaged within each mesh having a length L of one side (see the right diagram in FIG. 1 (i)).
(3): In each mesh, the local height difference is calculated from the difference in height from surrounding meshes.
(4): The obtained local height difference is averaged over all meshes. This is called the average local height difference Rmk.
(5): The procedure of (1) to (4) is repeated while changing L to obtain the calculation locality L of the average local height difference Rmk, that is, the function Rmk (L).

  When the obtained Rmk (L) is graphed with the horizontal axis representing the logarithm of the calculated length L (μm) and the vertical axis representing the average local height difference Rmk (μm), for example, FIG. 1 (ii) is obtained.

  In FIG. 1 (ii), the maximum value of Rmk refers to the value of Rmk = 0.206 at L = Lm = 18.3 (μm). This is written as Rmk, max = 0.206. Also, a calculated length of L = Lm · 0.1 = 18.3 · 0.1 = 1.83 (μm) or less and a calculated length of L = Lm · 10 = 18.3 · 10 = 183 (μm) or more In this case, Rmk of Rmk, max × 2/3 = 0.14 (μm) or more is not expressed. That is, this example does not satisfy the conditions of the electrophotographic photosensitive member according to the present invention.

  According to the present invention, an averaging effect by generating a large number of micro interference fringes can be efficiently expressed, generation of macro interference fringes can be suppressed, and a high-resolution electrostatic latent image can be obtained. .

  “In the calculated length (Lmk, μm)) where the maximum value of the average local height difference (Rmk (μm)) is expressed (Lm (μm) is 0.1 times or less or 10 times or more away from the calculated length, Interference fringes can be effectively prevented with a rough surface shape such that Rmk is less than or equal to the maximum value (Rmk, max) and more than two-thirds of the maximum value (Rmk, max). The term “preventing” means that the interference fringe levels that are expressed differ depending on whether or not the above features are satisfied when surface shapes having the same ten-point average roughness Rz are compared.

A mechanism that can effectively prevent interference fringes will be described. For this purpose, first, the concept of “randomness” of the rough surface shape is introduced.
Randomness means the irregularity of the rough surface shape. When the rough shape has the same period and amplitude (height), the randomness shape is not. It is called a certain shape. This can be easily understood by superimposing sine waves (cosine waves).

  The following formula shows an artificial two-dimensional surface rough shape consisting of a sine wave (cosine wave) with various periods and amplitudes (heights) and combinations thereof, and a three-dimensional surface that naturally expands it. Five types of rough shapes are shown. A graph of each of the five types is shown in FIGS. 2 (i), (a) to (e).

From the above formula and FIG. 2 (i), the shape of FIGS. 2 (i), (b), and (c) is a simple sine wave (cosine wave), and has no very regular randomness. You can see that
On the other hand, FIG. 2 (i) (a), (d), and (e) is not a simple sine wave (cosine wave), but has a shape in which those having different periods and amplitudes (heights) are superimposed. . However, when sine waves (cosine waves) having greatly different amplitudes such as 0.4 (μm) and 0.1 (μm) are superimposed as shown in FIGS. As can be seen from FIGS. 2 (i) and 2 (a), the regularity is high and the randomness is small compared to FIGS. 2 (i), (d) and (e).

  Rmk (L) can more objectively quantify the above-mentioned “randomness”. FIG. 2 (ii) is a graph showing the results of calculating Rmk (L) for the five types of artificial roughing shapes.

  As shown in FIG. 2 (ii), the Rmk (L) graphs of FIGS. 2 (i), (a), (b), and (c) have sharp peaks, whereas FIG. 2 (i) The graphs (d) and (e) have two peaks, and it can be seen that these peaks are broad. In other words, the magnitude of randomness corresponds to the peak sharpness (shape) of the Rmk (L) graph.

  Here, it should be noted that the shapes of FIGS. 2 (i), (a) to (e) all have the same overall amplitude. That is, all of the shapes in FIGS. 2 (i), (a) to (e) have the same ten-point average roughness Rz = 1.0 (μm). Nevertheless, the fact that the graphs of Rmk (L) have different shapes for each of the five types means the large amount of information that Rmk (L) has.

  The above is understood from the fact that Rmk (L) is a parameter reflecting how much height difference exists in which scale (calculated length). That is, in the case of a rough shape with a small randomness whose characteristics of the substrate surface shape are almost determined by a single sine wave (cosine wave), the period of the sine wave (cosine wave) and the calculated length of Rmk (L) When the lengths L match, Rmk (L) has a large value. On the other hand, in the case of a rough shape with a large randomness, since a plurality of sine waves (cosine waves) having different periods are superimposed, there are a plurality of peaks of Rmk (L). As a result, the shape of the graph is It will be broad.

  Therefore, in order to know the magnitude of the randomness of the substrate surface roughness shape, it is only necessary to look at the sharpness of the peak in the Rmk (L) graph. When this is objectively converted into a numerical value, “the maximum value (Rmk, max (μm)) of the average local height difference (Rmk (μm)) is 0.1 times or less from the calculated length (Lm (μm)) or In a calculated length that is 10 times or more away, Rmk that is less than the maximum value (Rmk, max) and more than two-thirds of the maximum value (Rmk, max) is expressed. That is, a roughness shape having this feature is defined as having a large randomness, and a roughness shape not having this feature is defined as having a low randomness.

  Next, it will be described that the interference fringe prevention capability is high when the randomness is large and the interference fringe prevention capability is low when the randomness is small.

  The graph shown in FIG. 2 (iii) shows the interference fringes in the shapes of FIGS. 2 (i), (a) to (e), which are numerically calculated by obtaining the Fresnel coefficient from the film thickness and refractive index of each layer of the photoreceptor. Level (potential difference contrast). The larger the value on the vertical axis, the more interference fringes are generated. According to this result, the interference fringe level is higher in the shapes of FIGS. 2 (i), (d), and (e) having a large randomness than in the shapes of FIGS. 2 (i), (a) to (c) having a small randomness. Low.

  2 (i) (a) to (e), the Rz is the same, but the rough shapes of FIGS. 2 (i), (d) and (e) with large randomness interfere with each other. It has been shown by numerical calculation that the fringe prevention effect is high. This can be understood as follows.

The mechanism by which the interference fringes disappear due to the rough shape is that a large number of micro interference fringes appear due to the formation of a micro optical path difference, and the macro interference fringes are made invisible by averaging the contrast. . At this time, from the viewpoint of providing an optical path difference, it is important that two height differences differing by an integer multiple of λ / (2n _i ) (i is an integer of 1 or more) perform the same function. That is, the local height difference of R (μm) and the local height difference of R + λ / (2n _i ) (μm) are different from each other in terms of the optical phase difference by a phase of 2π (rad). The contribution to the weak interference condition is the same.

Now, the difference in height that is shifted by an integral multiple of λ / (2n _i ) means that the optical phase difference is the same, even if the height difference of the rough shape is large, even if the height difference is R In the case where the deviation is made only by a magnitude shifted by an integral multiple of λ / (2n _i ), the bright and dark portions of the generated micro interference fringes are biased, and a sufficient averaging action cannot be obtained.

In other words, if the rough height frequency distribution P (R) is biased in Rmod (λ / (2n _i )), sufficient interference fringe prevention capability is obtained. It will not be possible. And such a small bias corresponds to a large randomness. Actually, FIG. 2 (iv) shows a graph with Rmod (λ / (2n _i )) on the horizontal axis and appearance frequency on the vertical axis for the shapes of FIGS. 2 (i), (b) and (e). However, it can be seen that the appearance frequencies in FIGS. 2 (i) and 2 (e) are not biased and the distribution is flat.

However, even if the shape has no randomness, a large interference fringe prevention effect can be obtained if the relationship between the laser wavelength λ and the roughening amplitude R is set well. However, in an actual photoreceptor, it is difficult to prevent Rz from changing by about λ / (2n _i ) to 0.2 (μm) at the upper and lower ends of the photoreceptor drum. Therefore, considering that it is required to prevent interference fringes over the entire surface of the photosensitive drum, such a pinpoint design is not practical. The rough shape with randomness can stably exhibit the interference fringe prevention effect even for Rz fluctuation of about 0.2 (μm), and has a wider latitude than the shape without randomness.

  Based on these findings, the present invention has been completed by further studies and provides the following invention.

An electrophotographic apparatus having an exposure means having a laser light source for oscillating a laser beam having a wavelength λ (μm), a charging means, a developing means, a transfer means, and an electrophotographic photosensitive member. The support has at least a charge generation layer and a charge transport layer in this order, and the conductive support has a surface shape with an average length difference (Rmk (μm)) calculated length (L ( μm)) In the graph showing the dependence, the maximum value (Rmk, max (μm)) of the average local height difference (Rmk (μm)) is expressed by the following formula (1) (in formula (1), T ₁ is Satisfying the transmittance until the laser beam reaches the conductive support)
When the layer provided in contact with the conductive support is a first layer and the layer provided in contact with the conductive support is named as a second layer up to the charge generation layer, the average local In the graph showing the dependency of the height difference (Rmk) on the calculated length, the maximum value of the average local height difference (Rmk) ((Rmk, max) is 0.1 times or less or 10 times or more away from the calculated length. In the calculated length, Rmk that is equal to or less than the maximum value (Rmk, max) and more than two-thirds of the maximum value (Rmk, max) is expressed, and the i-th layer and the i + 1-th layer (i is an integer of 1 or more) The shape of the interface with the following formula (2)
(In Formula (2), T _{i + 1} indicates the transmittance until the laser beam reaches the i-th layer on the conductive support, and n _i and n _{i + 1} are respectively on the conductive support. An electrophotographic apparatus characterized by satisfying a refractive index of an i-th layer and an i + 1-th layer provided in contact with each other).

An electrophotographic apparatus having an exposure means having a laser light source for oscillating a laser beam having a wavelength λ (μm), a charging means, a developing means, a transfer means, and an electrophotographic photosensitive member. A layer having at least a charge generation layer and a charge transport layer in this order on a resin support, the conductive resin support being the 0th layer, and a layer provided in contact with the conductive resin support Is the first layer, and the layer provided in contact therewith is named as the second layer up to the charge generation layer, the conductive resin support has a surface shape with an average local height difference ( In the graph showing the calculation length dependency of Rmk), the calculation length is 0.1 times or less or 10 times or more away from the calculation length in which the maximum value (Rmk, max) of the average local height difference (Rmk) is expressed. The maximum value (Rmk, max) or less Rmk below 2/3 of the maximum value (Rmk, max) is expressed, and the shape of the interface between the i-th layer and the i + 1-th layer (i is an integer of 1 or more) is expressed by the following formula (2)
(In Formula (2), T _{i + 1} represents the transmittance until the laser beam reaches the i-th layer on the conductive resin support, and n _i and n _{i + 1} represent the conductive resin support, respectively. An electrophotographic apparatus characterized by satisfying a refractive index of an i-th layer and an i + 1-th layer provided in contact with each other).

An electrophotographic apparatus having an exposure means having a laser light source for oscillating a laser beam having a wavelength λ (μm), a charging means, a developing means, a transfer means, and an electrophotographic photosensitive member. A charge generation layer provided in contact with the support and a charge transport layer provided on the charge generation layer, wherein the conductive support has an average local height difference (Rmk) ) In the graph showing the calculation length dependence, in the calculation length that is 0.1 times or less or 10 times or more away from the calculation length in which the maximum value (Rmk, max) of the average local height difference (Rmk) is expressed Rmk that is less than or equal to the maximum value (Rmk, max) and more than half of the maximum value (Rmk, max) is expressed, and the maximum value (Rmk, max) of the average local height difference (Rmk) is Formula (1)
An electrophotographic apparatus characterized by satisfying (in formula (1), T ₁ represents a transmittance until the laser beam reaches the conductive support).

  The concept of Rmk (L) has been already described, but here, it will be described in more detail along with a method when actual calculation is performed. However, the specific calculation method of Rmk (L) is not limited to the one described below.

First, three-dimensional surface shape data as shown in FIG. 3 (i) is obtained using an atomic force microscope or a laser microscope. In the three-dimensional surface shape data, one coordinate in the horizontal direction (indicated as (x, y) for a continuous variable, (i, j) for a discrete variable) is designated. Corresponding height data (z (x, y) for continuous variables, Z _{i, j for} discrete variables) is determined. In actual measurement, all variables are discrete variables. The horizontal quantization scale is set to p _xy (μm). Further, FIG. 3 (i) shows a case of a square lattice, but a triangular lattice or a hexagonal lattice may be used.

(1) The obtained three-dimensional surface shape data is divided into meshes having a side length of L (μm). L is larger than the quantization scale in the horizontal direction, and the region length of the three-dimensional surface shape data (assuming that the region of the three-dimensional surface shape data is a rectangle, the region lengths in the x direction and the y direction are respectively Λ _x and Λ L is smaller than _y ). In addition, L is selected as an integral multiple of p _xy for calculation. M (M is an integer of 1 or more) is defined by L = p _xy M. Further, N _i and N _j (N _i and N _j are integers of 1 or more) are defined by Λ _x = p _xy N _i and Λ _y = p _xy N _j .

(2) In each divided mesh, the height data is arithmetically averaged. The height data is processed as shown in the following formula if the case of discrete variables and the case of continuous variables are written together.

As shown in FIG. 3 (ii), this process is performed by shifting the calculation area by M / 2 squares (or by L / 2 (μm)), while shifting the entire area p _xy N _i × p _xy N _j (Λ _x XΛ _y (μm ² )). The possible values of the discrete variables (i, j) are as follows:

(3) A local height difference at the point of interest (i, j) (or (x, y)) is obtained from the arithmetic average value of the height data obtained for each mesh as shown in the following equation.

  The integral in the continuous conversion of the equation (6) is a cycle integral along the circumference of the diameter L (μm). In the discrete transformation, the difference in height between the target mesh and surrounding meshes is calculated. The surrounding meshes mentioned here are meshes having a circumference of a diameter L (μm) sharing the center with the target mesh, and there are eight in the case of a square lattice.

(4) The obtained local height difference is referred to as the whole mesh p _xy N _i × p _xy N _j (Λ _x × Λ _y (μm ² )) (in the discrete case, the entire mesh) Average).

The value obtained in this way is called the average local height difference, and in both cases of discrete and continuous, it depends on the length L (μm) of the mesh (from L = p _xy M, M is associated with L. ). This is rewritten as Rmk (L) (μm).

(5) The average local height difference Rmk (L) obtained in this way changes by first setting the mesh length L (μm). Therefore, by changing L to various values and calculating Rmk (L) each time, Rmk (L) is obtained as a function of L. The change width of L may be arbitrarily selected as long as Rmk (L) is sufficiently smooth. However, for the purpose of the present invention that captures interference fringe prevention capability, the value of L is expressed by the following equation: n _s = 0, 1, It is suitable to change as follows. However, when β = 2, s is preferably 1 or less, and more preferably 0.25 or less.

  An outline of numerical calculation performed by obtaining the Fresnel coefficient from the film thickness and refractive index of each layer of the photoreceptor will be described.

  FIG. 4 shows a conceptual diagram of a model used for performing numerical calculation. In FIG. 4, the structure of the photoreceptor is such that five layers are formed on the lowermost substrate. However, the present invention is not limited to this structure, and two or more layers including at least a charge generation layer and a charge transport layer are included. Any photoreceptor may be used.

4, n _i (i = 1, 2,...) Is the refractive index of each layer, d _i (i = 1, 2,...) Is the film thickness of each layer, and r _i (i = 0, 1,...). Means the amplitude reflectivity between the layers. Here, the refractive index may be a complex number in consideration of absorption. The amplitude reflectance is expressed by the following formula using the refractive index. However, since r ₀ is the amplitude reflectivity of the substrate, it cannot be determined from the above equation when the substrate is a metal.

  From only these parameters and the laser wavelength λ, the ratio of the light amount in the charge generation layer to the incident light amount can be obtained. Since the ratio changes depending on the film thickness of each layer, the ratio of the amount of light is calculated using the rough shape data of the layer corresponding to the fifth layer in FIG. 4, that is, the outermost surface layer of the photoreceptor. The roughness changes along the shape, and the degree of occurrence of micro interference fringes can be numerically calculated. From the degree of occurrence, the effect of preventing macro interference fringes, that is, the interference fringe level is obtained.

An image quality deterioration factor different from the interference fringes caused by the roughness shape will be described. In the roughness shape formed on the outermost surface layer, when the size of the uneven domain in the horizontal direction is increased, sensitivity unevenness corresponding to the unevenness appears as image quality deterioration in the drawn image. In order to estimate the degree quantitatively, as another parameter obtained from the Rmk (L) data, the weighted average values Rmk, ave, Rmk, ave, s and Rmk, ave of Rmk (L) represented by the following formula: , L.

  Rmk, ave, Rmk, ave, s, and Rmk, ave, l are Rmk (L) graphs obtained by logarithmically plotting the calculated length L on the horizontal axis, respectively, in FIGS. 5 (i), (ii), and (iii). The average value of Rmk (L) obtained by weighting as shown in FIG. Further, parameters Rmk, ave, and mdr represented by the following formulas are defined from these three values.

  The smaller the Rmk, ave, and mdr, the worse the fine line reproducibility. As a result of the examination, the values of Rmk, ave, and mdr are preferably 0.065 μm or less, and more preferably 0.050 μm or less.

  Further, since the fine line reproducibility depends on the horizontal size of the concavo-convex shape, in addition to the conditions of the Rmk, ave, and mdr values described above, the calculated length Lm that expresses the maximum value Rmk, max of Rmk is 7 ( It is more preferable that it is below (micrometer).

  In the present invention, not only the horizontal size of the concavo-convex shape but also the vertical size, that is, the height difference affects the fine line reproducibility. This corresponds to the Rz value and is preferably 1.3 (μm) or less. In addition, when considering the balance between the vertical size of the uneven shape and its density, it can be seen that the size of the Rmk, max value is also related to the image quality. From the viewpoint of preventing image quality deterioration due to sensitivity unevenness, Rmk, max is preferably 0.18 (μm) or less, and more preferably 0.15 (μm) or less.

  A method for measuring the three-dimensional surface shape data of the outermost surface in the present invention will be described. There are no particular restrictions on the measurement of the three-dimensional surface shape data. For example, a commercially available atomic force microscope, electron microscope, laser microscope, optical microscope, or optical interference type three-dimensional surface shape measuring instrument can be used.

  Examples of the atomic force microscope include a scanning probe microscope Neos (manufactured by Bruker Nano), a nanoscale hybrid microscope (VN-8000, manufactured by Keyence Corporation), and a scanning probe microscope (NanoNavi station (SII). -Nanotechnology Co., Ltd.), a scanning probe microscope (SPM-9600, Shimadzu Corporation Co., Ltd.), etc. can be used.

  Examples of the electron microscope include a 3D real surface view microscope (VE-9800, manufactured by Keyence Corporation), a 3D real surface view microscope (VE-8800, manufactured by Keyence Corporation), and a scanning electron microscope conventional / variable. Pressure SEM (manufactured by SII Nanotechnology Co., Ltd.), scanning electron microscope (SUPERSCAN SS-550, Shimadzu Corporation Co., Ltd.) and the like can be used.

  Examples of the laser microscope include an ultradeep shape measuring microscope (VK-8550, manufactured by Keyence Corporation), an ultradeep shape measuring microscope (VK9500, manufactured by Keyence Corporation), and an ultradeep shape measuring microscope (VK- 9700, manufactured by Keyence Corporation), surface shape measurement system (Surface Explorer SX-520DR model, manufactured by Ryoka System Co., Ltd.), scanning confocal laser microscope (OLS4000, manufactured by Olympus Corporation), A real color confocal microscope OPTEX (C130, manufactured by Lasertec Corporation) can be used.

  As an optical microscope, for example, a digital microscope (VHX-500, manufactured by Keyence Corporation) and a digital microscope (VHX-1000, manufactured by Keyence Corporation), a 3D digital microscope (VC-7700, OMRON ( Etc.) can be used.

  Examples of the optical interference type three-dimensional surface shape measuring instrument include a white interference measuring system (R6500H, manufactured by Ryoka System Co., Ltd.), a non-contact three-dimensional surface property / level difference measuring device Tarisurf (CCI6000, Ametech Co., Ltd.). Can be used.

  Using the measuring device, vertical height data z (x, y) corresponding to the horizontal coordinate (x, y) can be measured to obtain three-dimensional surface shape data. The procedure for deriving Rmk (L) from the obtained three-dimensional surface shape data is as described above.

Next, the configuration of the electrophotographic photosensitive member according to the present invention will be described.
The photoreceptor used in the electrophotographic apparatus of the present invention can have the following three types of configurations.
1: An intermediate layer, a charge generation layer, and a charge transport layer are formed in this order on a metal support.
2: An intermediate layer, a charge generation layer, and a charge transport layer are formed in this order on the resin conductive support.
3: A charge generation layer and a charge transport layer are formed in this order on the metal support.

  Each item will be described below.

<Metal support>
Examples thereof include aluminum, copper, iron, nickel, titanium, and alloys thereof. Among these, aluminum or an aluminum alloy of 3000 (Al—Mn), 5000 (Al—Mg), or 6000 (Al—Mg—Si) is preferable.

A rough surface satisfying the conditions of the present invention can be obtained by performing multiple times of laser ablation on the metal support.
On the other hand, a rough surface shape that satisfies the conditions of the present invention cannot be obtained by single-time machining or honing of laser ablation, which is a conventional technique.

  When the surface roughness shape is formed by laser ablation processing, the laser oscillation pulse width used is preferably 1 (ps) or more and 100 (ns) or less. When the oscillation pulse width is shorter than 1 (ps), it is easy to form a rough shape having a large rate of change in vertical height with respect to a change in horizontal coordinate. However, in the present invention, such a sharp (sharp) roughness shape is not preferable from the viewpoint of increasing the randomness, and the production cost increases. On the other hand, if the oscillation pulse width is longer than 100 (ns), surface damage due to heat increases, and it becomes difficult to obtain a desired roughness shape. As the laser having an oscillation pulse width of 1 (ps) or more and 100 (ns) or less, an excimer laser can be suitably used.

  The excimer laser used in the present invention is obtained by exciting a gas mixture of a rare gas such as Ar, Kr, and Xe and a halogen gas such as F and Cl by applying energy by discharge, electron beam or X-ray, and then combining them. It is a laser beam emitted when dissociating by falling into a state.

  Examples of the gas used in the excimer laser include ArF, KrF, XeCl, and XeF. Particularly preferred is KrF or ArF. As a method for forming the concavo-convex shape, a mask in which laser light transmitting portions a and laser light shielding portions b are appropriately arranged as shown in FIGS. 6 (i) and (ii) is used. Only the laser beam that has passed through the mask is collected by the lens, and the workpiece is irradiated with the collected laser beam, so that an uneven shape having a desired shape and arrangement can be formed. However, the thicknesses of the masks of the transmissive part and the shielding part are continuously changed, so that a smooth concavo-convex shape can be formed as shown in the cross-sectional view of the concavo-convex shape shown in FIG. 6 (iii). . Since a large number of irregularities within a certain area can be formed instantaneously at the same time regardless of the shape and area of the irregularities, such a process can be completed in a short time.

In the laser irradiation using the mask in FIG. 6 (iv), processing of several mm ² to several cm ² is performed per irradiation with the excimer laser beam irradiator c. In laser processing, as shown in FIG. 6 (iv), the laser irradiation position of the support is moved in the axial direction of the support by the work moving device e while the support f is rotated by the work rotation motor d. Thus, it is possible to efficiently form the concavo-convex portion over the entire surface of the support. According to the present invention, rough surface processing with high controllability of the size, shape and arrangement of the concavo-convex portions and high accuracy and high flexibility can be realized.

  Further, after performing laser irradiation using the mask pattern as shown in FIG. 6 (i), the mask pattern having a light transmission area different from that in FIG. 6 (i) as shown in FIG. 6 (ii). If the laser irradiation is performed using, an uneven shape in which two periods are superimposed can be formed. For example, the two-dimensional roughness shape shown in FIGS. 2 (i) and (d) can be produced by superimposing twice, and the two-dimensional roughness shape shown in FIGS. 2 (i) and (e) can be produced by superposing four times. .

<Resin conductive support>
A plastic obtained by conducting a conductive treatment may be used alone, or a conductive layer obtained by conducting a conductive treatment on a plastic may be provided on a metal support to provide a resin conductive support.

  The rough surface shape of the present invention can be obtained by performing a plurality of times of processing by laser ablation as described above also on the resin conductive support.

  In the case of providing a coating-type conductive layer, conventionally, a surface roughening agent for roughening the conductive layer has been added to the conductive layer, but the known method satisfies the conditions of the present invention. A rough surface shape cannot be obtained.

In order to ensure that the rough surface shape of the conductive layer satisfies the conditions of the present invention by performing laser ablation multiple times, that is, without additional processing, the following process combinations are precisely performed at a level that has not been performed conventionally. It must be made. This is because the rough surface state of the present invention requires roughness having various lateral scales.
1: Control of roughness formation by only conductive particles and binder resin 2: Control of degree of roughening by rough particles (hereinafter also referred to as “surface roughening material”)

<Control of roughness formation using only conductive particles and binder resin>
Examples of the conductive material used for the conductive layer include various metals and metal oxides. Among them, tin oxide (hereinafter, also referred to as “SnO ₂ ”) having a powder resistivity in a range of 10 ^{4 to} 10 ⁶ Ω · cm is preferable because it has excellent resistance characteristics. In addition, when the conductive material of SnO ₂ is manufactured, a metal compound having a valence different from tin, such as antimony oxide, a nonmetallic element, or the like is mixed (doped) to reduce the powder resistivity to 1/1000 or more. A conductive material reduced to 1/100000 can also be used. Further, the resistance of the SnO ₂ conductive material of the oxygen-deficient SnO ₂ was reduced to the same extent as antimony-doped can be suitably used in non-doped without increasing constituent elements. Furthermore, TiO ₂ particles coated with oxygen-deficient SnO ₂ are more preferably used.

When TiO ₂ particles coated with oxygen-deficient SnO ₂ are used as conductive particles, the mass ratio of oxygen-deficient SnO ₂ -coated TiO ₂ particles (P) and binder resin (B) in the coating liquid for the conductive layer (P: B) is preferably in the range of 2.3: 1.0 to 3.3: 1.0. If the amount of oxygen-deficient SnO ₂ -coated TiO ₂ particles is too small, it will be difficult to adjust the volume resistivity of the conductive layer. When oxygen-deficient SnO ₂ coated TiO ₂ particles is too large, the binding of the oxygen-deficient SnO ₂ coated TiO ₂ particles is difficult in the conductive layer, cracks are likely to occur.

  Conventionally, conductive particles having a particle size of several tens of nanometers to several hundreds of nanometers have been suitably used. However, in the present invention, those having a thickness of 100 nm to 500 nm are preferable from the viewpoint of forming a rough surface shape.

Moreover, when the base surface of a conductive layer is a mirror surface, it is preferable to scatter incident light in this conductive layer. The particle diameter (D) of the conductive particles when the maximum scattering output shows a high refractive index can be obtained by the following Weber equation. Note that n ₃ represents the refractive index of the conductive particles, and n ₄ represents the refractive index of the binder resin.

  That is, when the conductive particles are rutile titanium oxide (refractive index 2.7), the binder resin is phenol resin (refractive index 1.62), and the image exposure λ is 655 nm, Most preferably, the average particle size of the conductive particles is 386 nm and the particle size distribution is sharp.

Conventionally, resins such as phenol resin, polyurethane resin, polyamide, polyimide, polyamideimide, polyvinyl acetal, epoxy resin, acrylic resin, melamine resin, and polyester have been used as the binder resin for the conductive layer. However, when using TiO ₂ particles coated with oxygen-deficient SnO ₂ as the conductive particles, if a polyurethane resin is used, minute roughness is not formed on the surface of the conductive layer after coating and drying. It is not preferable.

When TiO ₂ particles coated with oxygen-deficient SnO ₂ are used as the conductive particles, the surface of the conductive layer after coating and drying is made fine by using a thermosetting phenol resin as the binder resin. Can be formed.

  Moreover, it is preferable to add a leveling agent to the coating liquid for the conductive layer in order to control the formation of roughness.

<Control of degree of roughening by roughening particles>
In order to obtain Rmk, max necessary for the present invention and to obtain roughness having various lateral scales, a surface roughening material for roughening the surface of the conductive layer is used for the conductive layer. It is preferable to add to the coating solution.

  At this time, as described above, it is preferable for the fine line reproducibility to add the surface roughening material to the coating liquid for the conductive layer so that the values of Rmk, ave, and mdr are 0.065 μm or less. , Rmk, ave, mdr are more preferably 0.050 μm or less.

  Conventionally, resin particles having an average particle diameter of 1 μm or more and 3 μm or less have been used as the surface roughening material. For example, curable resin particles such as curable rubber, polyurethane, epoxy resin, alkyd resin, phenol resin, polyester, silicone resin, and acryl-melamine resin have been suitably used.

However, when TiO ₂ particles coated with oxygen-deficient SnO ₂ are used as the conductive particles and a thermosetting phenol resin is used as the binder resin, when the silicone resin is used as the surface roughening agent, the above Rmk , Ave, mdr cannot be obtained. This is because the silicone particles tend to aggregate in the TiO ₂ particles / phenol resin solution.

When TiO ₂ particles coated with oxygen-deficient SnO ₂ are used as the conductive particles and thermosetting phenol resin is used as the binder resin, polymethyl methacrylate particles are used as the surface roughening agent, and the conductive layer By controlling the film thickness, it is possible to obtain a conductive layer having Rmk, ave, mdr of 0.065 μm or less while ensuring necessary Rmk, max.

  At this time, the average particle diameter of the polymethyl methacrylate particles is preferably 5 μm or less, and more preferably two or more kinds of particles having different average particle diameters are mixed and used.

<Combination of control of roughness formation with only conductive particles and binder resin and control of surface roughness with rough particles>
However, it will be repeated, but it will be described again because it is important. For example, even when two types of polymethyl methacrylate particles having an average particle diameter of 2 μm and polymethyl methacrylate particles having an average particle diameter of 4 μm are used as a surface roughness imparting material (hereinafter also referred to as “roughening imparting particles”), When the roughness formation only by the conductive particles and the binder resin is not controlled, the photoconductor according to the present invention cannot be produced (insufficient randomness).

  At this time, in order to solve the lack of randomness, if the conventionally known particles as described above are used as the roughening particles, it is necessary to add particles having a larger average particle diameter. However, when large-diameter particles are introduced, Rmk, ave and mdr are larger than 0.065 μm, and fine line reproduction is deteriorated.

  Therefore, the combination of the control of roughness formation using only the conductive particles and the binder resin and the control of the degree of roughening using the roughening particles is important for achieving a shape that satisfies the conditions of the present invention without post-processing. is there.

<Intermediate layer>
The intermediate layer can be formed by applying an intermediate layer coating solution containing a binder resin on a support and drying it.
As the binder resin for the intermediate layer, water-soluble resins such as polyvinyl alcohol, polyvinyl methyl ether, polyacrylic acids, methyl cellulose, ethyl cellulose, polyglutamic acid, casein, and starch, polyamide resins, polyimide resins, polyamideimide resins, polyamide acids Examples thereof include resins, melamine resins, epoxy resins, polyurethane resins, and polyglutamic acid ester resins. In view of coating properties, adhesion, solvent resistance, resistance, etc. in addition to effectively expressing the electrical barrier properties, the binder resin of the intermediate layer is preferably a thermoplastic resin. Specifically, a thermoplastic polyamide resin is preferable. The polyamide resin is preferably a low crystalline or non-crystalline copolymer nylon that can be applied in a solution state. The thickness of the intermediate layer is preferably 0.1 μm to 3 μm, and more preferably 0.1 μm to 0.5 μm from the viewpoint of suppressing potential fluctuation.

Furthermore, when an electric field is applied in the stacking direction of the sample in which the conductive layer and the intermediate layer are stacked, and the current value at the electric field application time t (sec) is I (t), the range of 0 ≦ t ≦ 300 is satisfied. It is preferable that the current value I (t) has a characteristic of 0.2 ≦ I _min / I (0) ≦ 5 when the minimum value of the current value I (t) is I _min .
Further, in order to prevent the flow of electric charges (carriers) in the intermediate layer, the intermediate layer may contain an electron transport material (electron accepting material such as an acceptor).

<Charge generation layer>
Examples of the charge generation material used in the charge generation layer of the electrophotographic photosensitive member in the present invention include azo pigments such as monoazo, disazo and trisazo, phthalocyanine pigments such as metal phthalocyanine and nonmetal phthalocyanine, indigo and thioindigo. Indigo pigments such as perylene acid anhydrides, perylene pigments such as perylene imide, polycyclic quinone pigments such as anthraquinone and pyrenequinone, squarylium dyes, pyrylium salts, thiapyrylium salts, and triphenylmethane dyes And inorganic substances such as selenium, selenium-tellurium, amorphous silicon, quinacridone pigments, azulenium salt pigments, cyanine dyes, xanthene dyes, quinoneimine dyes, styryl dyes, cadmium sulfide, and zinc oxide. Can be mentioned. These charge generation materials may be used alone or in combination of two or more.

  Among the above various charge generation materials, azo pigments and phthalocyanine pigments are preferable because they are highly sensitive and the present invention works more effectively. In addition, considering that the ghost is likely to occur when the sensitivity is increased by increasing the thickness of the charge transport layer, the present invention is utilized to the maximum when the phthalocyanine pigment is used. is there. When the phthalocyanine pigment is used in combination with another charge generation material, the phthalocyanine pigment is preferably 50% by mass or more based on the total mass of the charge generation material.

  Among the phthalocyanine pigments, metal phthalocyanine pigments are preferable, and oxytitanium phthalocyanine, chlorogallium phthalocyanine, dichlorotin phthalocyanine, and hydroxygallium phthalocyanine are more preferable, and among these, hydroxygallium phthalocyanine is particularly preferable.

  Examples of oxytitanium phthalocyanine include crystalline oxytitanium having strong peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction. Phthalocyanine crystals and 9.5 °, 9.7 °, 11.7 °, 15.0 °, 23.5 °, 24.1 ° and 27 with Bragg angles 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction Crystalline oxytitanium phthalocyanine crystals having a strong peak at 3 ° are preferred.

  As chlorogallium phthalocyanine, a crystalline form of chlorogallium having strong peaks at 7.4 °, 16.6 °, 25.5 ° and 28.2 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction Phthalocyanine crystals and crystal forms of chlorogallium phthalocyanine crystals having strong peaks at 6.8 °, 17.3 °, 23.6 ° and 26.9 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction In addition, it has strong peaks at 8.7 to 9.2 °, 17.6 °, 24.0 °, 27.4 ° and 28.8 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction. Crystalline chlorogallium phthalocyanine crystals are preferred.

  As dichlorotin phthalocyanine, Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction is 8.3 °, 12.2 °, 13.7 °, 15.9 °, 18.9 ° and 28.2 °. Crystalline dichlorotin phthalocyanine crystal having strong peaks, and strong peaks at 8.5, 11.2 °, 14.5 ° and 27.2 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction Dichlorotin phthalocyanine crystals having a crystal form of 8.7 °, 9.9 °, 10.9 °, 13.1 °, 15.2 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction , 16.3 °, 17.4 °, 21.9 °, and 25.5 ° in the form of dichlorotin phthalocyanine crystals having a strong peak, or 9 with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction .2 °, 12.2 °, 13. °, 14.6 °, preferably crystalline form of dichlorotin phthalocyanine crystal having strong diffraction peaks at 17.0 ° and 25.3 °.

  Examples of hydroxygallium phthalocyanine include a hydroxygallium phthalocyanine crystal having a crystal form having strong peaks at 7.3 °, 24.9 °, and 28.1 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction, and CuKα Strong against 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 ° with Bragg angle 2θ ± 0.2 ° in characteristic X-ray diffraction Crystalline hydroxygallium phthalocyanine crystals having a peak are preferred.

In the present invention, the Bragg angle in CuKα characteristic X-ray diffraction of the crystal form of the phthalocyanine crystal was measured under the following conditions.
Measuring device: Fully automatic X-ray diffractometer manufactured by Mac Science (trade name: MXP18)
X-ray tube: Cu, tube voltage: 50 kV, tube current: 300 mA,
Scan method: 2θ / θ scan, scan speed: 2 deg. / Min, sampling interval: 0.020 deg. ,
Start angle (2θ): 5 deg. Stop angle (2θ): 40 deg. ,
Divergence slit: 0.5 deg. Scattering slit: 0.5 deg. , Receiving slit: 0.3 deg. ,
Uses curved monochromator

  The particle size of the charge generation material is preferably 0.01 μm to 0.5 μm, more preferably 0.01 μm to 0.3 μm, and even more preferably 0.01 μm to 0.2 μm. Even more preferred.

  Examples of the binder resin used for the charge generation layer include acrylic resin, allyl resin, alkyd resin, epoxy resin, diallyl phthalate resin, silicone resin, styrene-butadiene copolymer, cellulose resin, nylon, phenol resin, butyral resin, benzal. Resin, Melamine resin, Polyacrylate resin, Polyacetal resin, Polyamideimide resin, Polyamide resin, Polyallyl ether resin, Polyarylate resin, Polyimide resin, Polyurethane resin, Polyester resin, Polyethylene resin, Polycarbonate resin, Polystyrene resin, Polysulfone resin, Polyvinyl Acetal resin, polyvinyl methacrylate resin, polyvinyl acrylate resin, polybutadiene resin, polypropylene resin, methacrylic resin, urea resin, Vinyl - vinyl acetate copolymer, vinyl acetate resins, and vinyl chloride resins. In particular, a butyral resin is preferable. These can be used alone or as a mixture or copolymer of two or more.

  Such a charge generation layer can be formed by applying a charge generation layer coating solution containing a charge generation material, a binder resin, and a solvent in advance on a support and drying it. The coating liquid containing the charge generating substance, the binder resin and the solvent is obtained by dispersing the charge generating substance together with the binder resin and the solvent. Examples of the dispersion method include a method using a homogenizer, an ultrasonic disperser, a ball mill, a sand mill, a roll mill, a vibration mill, an attritor, a liquid collision type high-speed disperser, and the like. The ratio between the charge generating material and the binder resin is preferably in the range of 1: 0.3 to 1: 4 (mass ratio).

  The solvent used in the coating solution for the charge generation layer is selected from the viewpoints of the solubility and dispersion stability of the binder resin, charge generation material and electron transport material used. Examples of the organic solvent include alcohols, sulfoxides, ketones, ethers, esters, aliphatic halogenated hydrocarbons, and aromatic compounds.

  The film thickness of the charge generation layer is preferably 0.05 μm to 2.00 μm. When a phthalocyanine pigment is used as the charge generation material, it is 0.05 μm to 0.18 μm from the viewpoint of preventing image deterioration due to ghost. It is more preferable.

  In addition, various sensitizers, antioxidants, ultraviolet absorbers, plasticizers, and the like can be added to the charge generation layer as necessary.

  Phthalocyanine particles having a particle diameter of 0.01 μm to 0.2 μm are dispersed in a solvent in a ratio of 1: 0.3 to 1: 4 (mass ratio) as a ratio to the binder resin, and the film is dried after coating and drying. In order to obtain a charge generation layer having a thickness of 0.18 μm or less, the charge generation layer coating solution has a viscosity of preferably 2 cP to 20 cP, and more preferably 2 cP to 5 cP.

In the electrophotographic photosensitive member in which the charge generation layer is produced as described above, the shape of the interface between the conductive support or the layer between the conductive support and the charge generation layer and the charge generation layer is Rmk, ave. , Mdr is preferably 0.065 μm or less in order to ensure fine line reproducibility, and more preferably 0.050 or less.
This is because the charge generation layer coating liquid having the above-described composition is uniformly applied by setting the values of Rmk, ave, and mdr as 0.065 μm or less as the base shape of the interface with the charge generation layer. .

<Charge transport layer>
Examples of the charge transport material used in the charge transport layer of the electrophotographic photoreceptor of the present invention include a triarylamine compound, a hydrazone compound, a styryl compound, a stilbene compound, a pyrazoline compound, an oxazole compound, a thiazole compound, and a triarylmethane compound. Is mentioned. These hole transport materials may be used alone or in combination of two or more.

  Examples of the binder resin used for the charge transport layer include acrylic resin, acrylonitrile resin, allyl resin, alkyd resin, epoxy resin, silicone resin, nylon, phenol resin, phenoxy resin, butyral resin, polyacrylamide resin, polyacetal resin, Polyamideimide resin, polyamide resin, polyallyl ether resin, polyarylate resin, polyimide resin, polyurethane resin, polyester resin, polyethylene resin, polycarbonate resin, polystyrene resin, polysulfone resin, polyvinyl butyral resin, polyphenylene oxide resin, polybutadiene resin, polypropylene resin Methacrylic resin, urea resin, vinyl chloride resin, vinyl acetate resin and the like. Among these, polyarylate resin and polycarbonate resin are preferable, and polyarylate resin is particularly preferable. These resins can be used alone or as a mixture or copolymer of two or more.

Among the polyarylate resins, polyarylate resins having a repeating structural unit represented by the following formula (15) are preferable.

R _{31 to} R ₃₄ each independently represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a phenyl group, or an alkoxy group having 1 to 3 carbon atoms, and at least one site has an alkyl group. X is an oxygen atom, a sulfur atom,
Indicates. R ₃₅ and R _{36 each} represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an aryl group, an alkylidene group or a fluorenylidene group formed by combining R ₃₅ and R ₃₆ . Y represents a divalent organic group.

  The weight average molecular weight of the binder resin is preferably 50,000 to 200,000, and more preferably 100,000 to 180,000.

  In the present invention, the weight average molecular weight was determined by measuring the molecular weight distribution using gel permeation chromatography HLC-8120 manufactured by Tosoh Corporation and calculating in terms of polystyrene. Tetrahydrofuran (THF) was used as a developing solvent. The sample to be measured was a 0.1% by mass solution. As the column, a column with exclusion limit molecular weight (polystyrene conversion) of 4 × 10 6 (trade name: TSKgel SuperHM-N, manufactured by Tosoh Corporation) was used. RI was used as a detector. The column temperature was 40 ° C. The injection volume was 20 μl. The flow rate was 1.0 ml / min.

The charge transport layer is a charge transport layer coating solution (hereinafter also referred to as “hole transport layer coating solution”) obtained by dissolving a hole transport material, which is a charge transport material, and a binder resin in a solvent. It can be formed by applying and drying it.
The ratio of the hole transport material is preferably in the range of 30% by weight to 70% by weight with respect to the total mass of the charge transport layer (hereinafter also referred to as “hole transport layer”).

  Solvents used in the charge transport layer coating solution include acetone, ketones such as methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, aromatic hydrocarbons such as toluene and xylene, 1,4-dioxane, and tetrahydrofuran. Such ethers, chlorobenzene, chloroform, hydrocarbons substituted with halogen atoms such as carbon tetrachloride are used.

  The thickness of the charge transport layer is preferably 5 μm to 40 μm, and more preferably 10 μm to 30 μm.

  Note that a protective layer for protecting the charge transport layer may be provided on the charge transport layer. The protective layer can be formed by applying a coating liquid for a protective layer obtained by dissolving a binder resin in a solvent to the charge transport layer and drying it. Alternatively, the protective layer may be formed by applying a coating solution for a protective layer obtained by dissolving a monomer / oligomer of a binder resin in a solvent to the charge transporting layer and curing and / or drying it. For curing, light, heat, or radiation (such as an electron beam) can be used.

  The various resins described above can be used as the binder resin for the protective layer. Further, conductive particles such as conductive tin oxide and conductive titanium oxide may be dispersed in the protective layer for the purpose of resistance control. The thickness of the protective layer is preferably 0.2 μm to 10 μm, and particularly preferably 1 μm to 5 μm.

  When applying the coating liquid for each of the above layers, for example, an application method such as dip coating (dip coating), spray coating, spinner coating, roller coating, Meyer bar coating, or blade coating is used. be able to.

  In addition, the surface layer of the electrophotographic photosensitive member is made of polytetrafluoroethylene, polyvinylidene fluoride, fluorine-based graft polymer, silicone-based graft polymer, fluorine for the purpose of improving the cleaning property and abrasion resistance of the electrophotographic photosensitive member. A lubricant such as a block polymer, a silicone block polymer, or a silicone oil may be contained. Moreover, you may add antioxidants, such as a hindered phenol and a hindered amine, in order to improve a weather resistance. Furthermore, a film strength reinforcing agent such as silicone particles may be added to reinforce the strength.

  When a protective layer is provided on the electrophotographic photoreceptor, the protective layer is a surface layer of the electrophotographic photoreceptor, and when a protective layer is not provided, the hole transport layer is a surface layer of the electrophotographic photoreceptor.

  FIG. 7 shows an example of a schematic configuration of an electrophotographic apparatus provided with a process cartridge having an electrophotographic photosensitive member according to the present invention.

  In FIG. 7, reference numeral 1 denotes a cylindrical electrophotographic photosensitive member, which is driven to rotate about a shaft 2 in the direction of an arrow at a predetermined peripheral speed.

  The surface of the electrophotographic photoreceptor 1 to be rotationally driven is uniformly charged to a predetermined positive or negative potential by a contact charging means 3 having a contact charging member (charging roller or the like), and then exposed by laser beam scanning exposure. Exposure light (image exposure light) 4 output from (not shown) is received. In this way, electrostatic latent images corresponding to the target image are sequentially formed on the surface of the electrophotographic photosensitive member 1.

  The electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is developed with toner contained in the developer of the developing means 5 to become a toner image. Next, the toner image formed and supported on the surface of the electrophotographic photoreceptor 1 is transferred from a transfer material supply means (not shown) to the electrophotographic photoreceptor 1 and the transfer means by a transfer bias from a transfer means (transfer roller or the like) 6. 6 (contact portion) is sequentially transferred onto a transfer material (paper or the like) P taken out and fed in synchronization with the rotation of the electrophotographic photosensitive member 1.

  The transfer material P that has received the transfer of the toner image is separated from the surface of the electrophotographic photosensitive member 1 and introduced into the fixing means 8 to receive the image fixing, and is printed out as an image formed product (print, copy). Is done.

  The surface of the electrophotographic photoreceptor 1 after the transfer of the toner image is cleaned by removing the developer (toner) remaining after the transfer by a cleaning means (cleaning blade or the like) 7 and further output from a pre-exposure means (not shown). After being subjected to charge removal processing by pre-exposure light (not shown), it is repeatedly used for image formation. In addition, when the charging unit is a contact charging unit as in the present invention, pre-exposure is not always necessary.

  The above-described electrophotographic photosensitive member 1 and contact charging means 3 are housed in a container and integrally combined as a process cartridge. The process cartridge is attached to a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. You may comprise so that attachment or detachment is possible. In FIG. 7, the electrophotographic photosensitive member 1, the contact charging unit 3, the developing unit 5, and the cleaning unit 7 are integrally supported to form a cartridge, and electrophotographic using a guide unit 10 such as a rail of an electrophotographic apparatus main body. The process cartridge 9 is detachable from the apparatus main body.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to these. In the examples, “part” means “part by mass”.

(Example of production of electrophotographic photoreceptor)
(Preparation of electrophotographic photoreceptor A-1)
-Support body A mirror-finished aluminum cylinder (JIS-A3003, aluminum alloy) having a length of 357.5 mm and a diameter of 30 mm was used as a support body.

-Surface roughening and evaluation of the support An uneven portion was formed on the support using a KrF excimer laser (wavelength 248 (nm), pulse width 17 (ns)). At this time, laser processing was performed twice using different arrangement mask patterns, and roughness shapes having different periods were superimposed.

In the first laser processing, as shown in FIG. 8 (i), the laser light transmission parts a are arranged at intervals of 60 (μm), and the thicknesses of the masks of the transmission part a and the shielding part b continuously change. A chrome mask having an array pattern is used. The laser irradiation energy was 2.2 (J / cm ² ), and the irradiation area per irradiation was 1.4 (mm) square. As shown in FIG. 6 (iv), the support was rotated, and laser irradiation was performed while shifting the laser irradiation position in the axial direction of the support.

In the second laser processing, a mask similar to that used in the first laser processing was used except that the arrangement period of the laser light transmitting portions was 12 (μm) as shown in FIG. 8 (ii). . The laser irradiation energy was 2.1 (J / cm ² ), and the irradiation area per irradiation was 1.4 (mm) square. As shown in FIG. 6 (iv), the support photoconductor was rotated, and laser irradiation was performed while shifting the laser irradiation position in the axial direction of the support.

  When the rough surface shape of the obtained support was enlarged and observed with an operation type probe microscope Neos (manufactured by Bruker Nano), the same shape as shown in FIGS. 2 (i) and (d) was formed. I was able to confirm. When Rmk (L) was calculated, the same graph as shown in FIGS. 2 (ii) and 2 (d) was obtained. The results are shown in FIG. 9 (i). Rmk has a maximum value of 0.057 μm at the calculated length Lm = 6.0 μm. Next, since Rmk of 0.038 μm is obtained at Lm = 0.6 μm, Rmk is calculated at a distance of 0.1 times or less or 10 times or more from the calculated length at which Rmk, max is expressed. , Max or less, and Rmk, which is 2/3 or more of Rmk, max, is expressed. That is, it was a roughness shape with randomness. Rmk, ave, l, Rmk, ave, s, Rmk, ave, Rmk, ave, mdr are 0.034 (μm), 0.058 (μm), 0.047 (μm), and 0.027, respectively. (Μm).

  When the ten-point average roughness Rz of the rough surface shape of the obtained support and the average length Rsm of the roughness curve element were measured, they were 0.73 (μm) and 4 (μm), respectively. Measurement is in accordance with JIS-B0601 (1994), using a surface roughness meter Surfcoder SE3500 (manufactured by Kosaka Laboratory), feed rate 0.1 (mm / s), cutoff λc 0.08 (mm), The measurement length was set to 2.50 (mm). The surface shape data of the support is summarized in Table 1.

  The total reflectivity of the obtained support was 0.91 at a wavelength of 780 nm.

Formation and Evaluation of Intermediate Layer Next, 4.5 parts of N-methoxymethylated nylon (trade name: Toresin EF-30T, manufactured by Teikoku Chemical Industry Co., Ltd.) and copolymer nylon resin (Amilan) were formed on the support. CM8000 (manufactured by Toray Industries, Inc.) 1.5 parts in a mixed solvent of 65 parts methanol / 30 parts n-butanol was dip-coated, and this was applied at 100 ° C. for 10 minutes. By drying, an intermediate layer having a film thickness of 0.4 μm was formed.

  When the surface shape of the obtained intermediate layer is enlarged and observed with a scanning probe microscope Neos (manufactured by Bruker Nano), the same shape as that shown in FIGS. 2 (i) and 2 (d) is formed. I was able to confirm that. When Rmk (L) is calculated, the same graph as that shown in FIGS. 2 (ii) and (d) is obtained, and the maximum value Rmk, max of Rmk is 0.1 times or less from the calculated length or 10 At a calculated length that is more than twice as far away, Rmk, max or less, and Rmk that is 1/2 or more of Rmk, max were expressed. That is, it was a roughness shape with randomness. Rmk, max and Rmk, max are calculated lengths Lm, Rmk, ave, l, Rmk, ave, s, Rmk, ave, mdr are 0.51 (μm), 6.0 (μm), respectively. They were 0.031 (μm), 0.052 (μm), 0.042 (μm), and 0.024 (μm). Table 2 summarizes the surface shape data of the intermediate layer.

  When the ten-point average roughness Rz and the average length Rsm of the roughness curve element of the surface shape of the obtained intermediate layer were measured, they were 0.66 (μm) and 4 (μm), respectively. Measurement is in accordance with JIS-B0601 (1994), using a surface roughness meter Surfcoder SE3500 (manufactured by Kosaka Laboratory), feed rate 0.1 (mm / s), cutoff λc 0.08 (mm), The measurement length was set to 2.50 (mm).

  Separately, this intermediate layer coating solution was applied onto a quartz substrate to a thickness of 3 μm and dried to prepare a sample for refractive index measurement. When the refractive index of this coating film was measured by Abbe's refractive index, the refractive index n was 1.53.

Charge generation layer Next, a crystalline hydroxygallium phthalocyanine crystal having a strong peak at 7.3 °, 24.9 °, and 28.1 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction (charge) (Generating material) 20 parts, polyvinyl butyral resin (trade name: BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 350 parts of cyclohexanone were dispersed in a sand mill using glass beads having a diameter of 1 mm for 3 hours. Then, 1200 parts of ethyl acetate was added (dispersed particle size measured by CAPA-700 of charge generation material at this time (manufactured by Horiba, Ltd.) was 0.15 μm) to prepare a coating solution for charge generation layer.

This charge generation layer coating solution was dip-coated on the intermediate layer and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.14 μm.
A sample for refractive index measurement was prepared in the same manner as the intermediate layer, and the refractive index was measured. The refractive index n at a wavelength of 780 nm was 1.65.

-Charge transport layer Next, 9 parts of a compound (hole transport material) having a structure represented by the following formula (16),
1 part of a compound represented by the following formula (17) (hole transport material),
And 5 parts of a polyarylate resin having a repeating structural unit (bisphenol C type) represented by the following formula (18) (mass ratio of terephthalic acid skeleton to isophthalic acid skeleton: terephthalic acid / isophthalic acid = 50/50)
Was dissolved in a mixed solvent of 50 parts of monochlorobenzene / 10 parts of dichloromethane to obtain a coating solution for a hole transport layer.

This hole transport layer coating solution was dip-coated on the charge generation layer and dried at 110 ° C. for 1 hour to form a hole transport layer having a thickness of 18 μm.
Thus, an electrophotographic photosensitive member having a support, a conductive layer, an intermediate layer, a charge generation layer, and a hole transport layer in this order, and the hole transport layer being a surface layer was produced.

Preparation and evaluation of transmittance measurement sample A polyethylene terephthalate film having a thickness of 125 μm is wound on a mirror-finished aluminum cylinder having a length of 357.5 mm and a diameter of 30 mm, and the above-described intermediate layer, charge generation layer, and charge transport The layers were coated in the same manner to obtain a transmittance measurement sample.
The wound film was peeled off from the aluminum cylinder, and the transmittance of the coating film was measured with reference to a film on which nothing was applied. The transmittance (T ₁ ) at a wavelength of 780 nm was 0.484. Similarly, when a charge generation layer and a charge transport layer were coated on a polyethylene terephthalate film and the transmittance of the coating film was measured, the transmittance (T ₂ ) at a wavelength of 780 nm was 0.494.

(Preparation of electrophotographic photoreceptor A-2)
An electrophotographic photosensitive member A-2 was produced in the same manner as the electrophotographic photosensitive member A-1, except that the roughening of the support was changed as follows.

-Roughening of the support The uneven part was formed on the support using a KrF excimer laser (wavelength 248 (nm), pulse width 17 (ns)). At this time, laser processing was performed three times using different arrangement mask patterns, and roughness shapes having different periods were superimposed.

In the first laser processing, as shown in FIG. 8 (i), the laser light transmission parts a are arranged at intervals of 60 (μm), and the thicknesses of the masks of the transmission part a and the shielding part b continuously change. A chrome mask having an array pattern is used. The irradiation energy of the laser was 3.0 (J / cm ² ), and the irradiation area per irradiation was 1.4 (mm) square. As shown in FIG. 6 (iv), the support was rotated, and laser irradiation was performed while shifting the laser irradiation position in the axial direction of the support.

In the second laser processing, the same mask as that used in the first laser processing was used except that the arrangement period of the laser light transmitting portions was 30 (μm). The irradiation energy of the laser was 3.0 (J / cm ² ), and the irradiation area per irradiation was 1.4 (mm) square. As shown in FIG. 6 (iv), the support was rotated, and laser irradiation was performed while shifting the laser irradiation position in the axial direction of the support.

In the third laser processing, the same mask as that used in the first laser processing was used except that the arrangement period of the laser light transmitting portions was 6 (μm). The irradiation energy of the laser was 3.0 (J / cm ² ), and the irradiation area per irradiation was 1.4 (mm) square. As shown in FIG. 6 (iv), the support was rotated, and laser irradiation was performed while shifting the laser irradiation position in the axial direction of the support.

  The surface shape of the obtained support was magnified and observed with an operational probe microscope Neos (manufactured by Bruker Nano), and the result of calculating Rmk (L) is shown in FIG. 9 (ii). Rmk, max was 0.094, and the calculated length Lm at which Rmk, max was expressed was 3.9 μm. From FIG. 9 (ii), it can be seen that Rmk, which is two thirds or more of Rmk, max, is expressed at a calculated length that is 0.1 times or less away from the calculated length where Rmk, max is expressed. That is, it was a roughness shape with randomness.

  Table 2 shows the evaluation values of the surface shape of the support, and Table 3 shows the evaluation values of the surface shape of the intermediate layer. The unit of the numerical values in the table is [μm].

(Preparation of electrophotographic photoreceptor A-3)
An electrophotographic photosensitive member A-3 was produced in the same manner as the electrophotographic photosensitive member A-1, except that the roughening of the support and the formation of the intermediate layer were changed as follows.

-Roughening of the support KrF excimer laser (wavelength 248 (nm), pulse width 17 (ns)) as in the electrophotographic photosensitive member A-1, except that the irradiation energy was set to 3.0 (J / cm ² ) An uneven portion was formed on the substrate using

-Formation of intermediate layer An intermediate layer was formed in the same manner as in the electrophotographic photosensitive member A-1, except that the film thickness was 1.0 µm.

(Preparation of electrophotographic photoreceptor A-4)
An electrophotographic photosensitive member A-4 was produced in the same manner as the electrophotographic photosensitive member A-1, except that the roughening of the support and the formation of the intermediate layer were changed as follows.

-Roughening of the support KrF excimer laser (wavelength 248 (nm), pulse width 17 (ns)) as in the electrophotographic photosensitive member A-1, except that the irradiation energy was set to 3.0 (J / cm ² ) An uneven portion was formed on the substrate using

-Formation of intermediate layer An intermediate layer was formed in the same manner as in the electrophotographic photosensitive member A-1, except that the film thickness was 1.8 µm.

(Preparation of electrophotographic photoreceptor A-5)
An electrophotographic photosensitive member A-5 was produced in the same manner as the electrophotographic photosensitive member A-1, except that the irradiation energy for roughening the support was changed to 1.9 (J / cm ² ).

(Preparation of electrophotographic photoreceptor A-6)
An electrophotographic photosensitive member A-6 was produced in the same manner as the electrophotographic photosensitive member A-1, except that the formation of the charge transport layer was changed as follows.

-Charge transport layer The following components were dissolved in a mixed solvent of 600 parts of monochlorobenzene and 200 parts of methylal to prepare a charge transport layer coating solution.
-Hole transport compound represented by the above chemical formula (16): 70 parts
Polycarbonate resin (Iupilon Z400, manufactured by Mitsubishi Engineering Plastics): 100 parts

  Using the charge transport layer coating solution thus prepared, the charge transport layer coating solution is dip-coated on the charge generation layer and dried by heating in an oven at a temperature of 120 ° C. for 60 minutes. A (μm) charge transport layer was formed.

(Preparation of electrophotographic photoreceptor A-7)
An electrophotographic photosensitive member A-7 was produced in the same manner as the electrophotographic photosensitive member A-6, except that the irradiation energy for roughening the support was changed to 1.3 (J / cm ² ).

(Preparation of electrophotographic photoreceptor A-8)
An electrophotographic photoreceptor A-8 was produced in the same manner as the electrophotographic photoreceptor A-6, except that the irradiation energy for roughening the support was changed to 2.8 (J / cm ² ).

(Preparation of electrophotographic photoreceptor A-9)
The electrophotographic photosensitive member except that the mask used for roughening the support was changed to the following, and the laser irradiation energy for roughening was changed to 1.9 (J / cm ² ). In the same manner as in A-1, an electrophotographic photoreceptor A-9 was produced.
First laser processing: a shape similar to that shown in FIG. 8 (i), in which the interval between the laser beam transmitting portions a is changed from 60 μm to 150 (μm).
Second laser processing: the shape shown in FIG. 8 (i) (interval 60 (μm) between laser beam transmitting portions).

(Preparation of electrophotographic photoreceptor A-10)
The electrophotographic photosensitive member except that the mask used for roughening the support was changed to the following, and the laser irradiation energy for roughening was changed to 1.9 (J / cm ² ). In the same manner as A-2, an electrophotographic photoreceptor A-10 was produced.
First laser processing: a shape similar to that shown in FIG. 8 (i), in which the interval between the laser beam transmitting portions a is changed from 60 μm to 150 (μm).
Second laser processing: the shape shown in FIG. 8 (i) (interval 60 (μm) between laser beam transmitting portions).
Third laser processing: the shape shown in FIG. 8 (ii) (laser light transmission part interval 12 (μm)).

(Preparation of electrophotographic photoreceptor A-11)
An electrophotographic photoreceptor A-11 was produced in the same manner as the electrophotographic photoreceptor A-9 except that the roughening of the support and the formation of the intermediate layer were changed as follows.

-Roughening of the support KrF excimer laser (wavelength 248 (nm), pulse width 17 (ns)) as in the electrophotographic photosensitive member A-9 except that the irradiation energy was 2.7 (J / cm ² ) An uneven portion was formed on the substrate using

-Formation of intermediate layer An intermediate layer was formed in the same manner as in the electrophotographic photoreceptor A-9 except that the film thickness was changed to 1.0 m.

(Preparation of electrophotographic photoreceptor A-12)
An electrophotographic photosensitive member A-12 was produced in the same manner as the electrophotographic photosensitive member A-9 except that the roughening of the support and the formation of the intermediate layer were changed as follows.

-Roughening of the support KrF excimer laser (wavelength 248 (nm), pulse width 17 (ns)) as in the electrophotographic photosensitive member A-9 except that the irradiation energy was 2.7 (J / cm ² ) An uneven portion was formed on the substrate using

-Formation of intermediate layer An intermediate layer was formed in the same manner as in the electrophotographic photoreceptor A-9 except that the film thickness was changed to 1.8 m.

(Preparation of electrophotographic photoreceptor A-13)
An electrophotographic photosensitive member A-13 was produced in the same manner as the electrophotographic photosensitive member A-1, except that the irradiation energy for roughening the support was changed to 1.7 (J / cm ² ).

(Preparation of electrophotographic photoreceptor A-14)
The electrophotographic photosensitive member except that the mask used for roughening the support was changed to the following, and the laser irradiation energy for roughening was changed to 1.9 (J / cm ² ). In the same manner as in A-6, an electrophotographic photoreceptor A-14 was produced.
First laser processing: a shape similar to that shown in FIG. 8 (i), in which the interval between the laser beam transmitting portions a is changed from 60 μm to 150 (μm).
Second laser processing: the shape shown in FIG. 8 (i) (interval 60 (μm) between laser beam transmitting portions).

(Preparation of electrophotographic photoreceptor A-15)
An electrophotographic photoreceptor A-15 was produced in the same manner as the electrophotographic photoreceptor A-14, except that the irradiation energy for roughening the support was changed to 1.2 (J / cm ² ).

(Preparation of electrophotographic photoreceptor A-16)
An electrophotographic photosensitive member A-16 was produced in the same manner as the electrophotographic photosensitive member A-14 except that the irradiation energy for roughening the support was changed to 2.5 (J / cm ² ).

(Preparation of electrophotographic photoreceptor A-17)
An electrophotographic photosensitive member A-17 was produced in the same manner as the electrophotographic photosensitive member A-1, except that the irradiation energy for roughening the support was changed to 2.9 (J / cm ² ).

(Preparation of electrophotographic photoreceptor A-18)
An electrophotographic photosensitive member A-18 was produced in the same manner as the electrophotographic photosensitive member A-1, except that the irradiation energy for roughening the support was changed to 2.8 (J / cm ² ).

(Preparation of electrophotographic photoreceptor A-19)
An electrophotographic photoreceptor A-19 was produced in the same manner as the electrophotographic photoreceptor A-1, except that no intermediate layer was formed.

(Preparation of electrophotographic photoreceptor A-20)
An electrophotographic photoreceptor A-20 was produced in the same manner as the electrophotographic photoreceptor A-2 except that no intermediate layer was formed.

(Preparation of electrophotographic photoreceptor C-1)
An electrophotographic photosensitive member C-1 was produced in the same manner as the electrophotographic photosensitive member A-1, except that the roughening of the support was changed as follows.

-Roughening of the support The uneven part was formed on the support using a KrF excimer laser (wavelength 248 (nm), pulse width 17 (ns)). At this time, laser processing was performed only once using a single array mask pattern, and a roughness shape having a single period was superimposed.

In laser processing, as shown in FIG. 8 (i), the laser light transmitting portions a are arranged at intervals of 60 (μm), and the mask thicknesses of the transmitting portion a and the shielding portion b are continuously changed. A chrome mask having an array pattern was used. The laser irradiation energy was 3.6 (J / cm ² ), and the irradiation area per irradiation was 1.4 (mm) square. As shown in FIG. 6 (iv), the support was rotated, and laser irradiation was performed while shifting the laser irradiation position in the axial direction of the support.

  The surface shape of the obtained support was magnified and observed with an operational probe microscope Neos (manufactured by Bruker Nano), and the result of calculating Rmk (L) is shown in FIG. 9 (iii). Rmk, max was 0.110, and the calculated length Lm at which Rmk, max was expressed was 6.7 μm. From the graph shown in FIG. 9 (iii), in the calculated length that is 0.1 times or less or 10 times or more away from the calculated length in which the maximum value Rmk, max of Rmk is expressed, it is more than two thirds of Rmk, max. It can be seen that Rmk is not expressed. That is, it was a roughness shape without randomness.

(Preparation of electrophotographic photoreceptor C-2)
An electrophotographic photosensitive member C-2 was produced in the same manner as the electrophotographic photosensitive member C-1, except that the mask used for roughening the support was changed to that shown in FIG. 8 (ii).

(Preparation of electrophotographic photoreceptor C-3)
Except that the mask used for roughening the support is similar to that shown in FIG. 8 (ii), and the interval of the laser beam transmitting part a is changed from 12 μm to 150 μm, the electrophotographic photosensitive C- In the same manner as in Example 1, an electrophotographic photoreceptor C-3 was produced.

(Preparation of electrophotographic photoreceptor C-4)
An electrophotographic photoreceptor C-4 was produced in the same manner as the electrophotographic photoreceptor A-1, except that the roughening of the support was changed as follows.

-Roughening of the support Using a wet honing apparatus (Fuji Seiki Seisakusho Co., Ltd.), a concavo-convex part was formed on the support under the following conditions.

・ Liquid honing condition Abrasive grains: Spherical alumina beads (trade name: CB-A30S, manufactured by Showa Denko KK)
Suspension medium: water abrasive / suspension medium: 1/9 (volume ratio)
Number of rotations of aluminum tube: 1.67 s-1
Air blowing pressure: 0.165 MPa
Gun moving speed: 13.3 mm / s
Distance between gun nozzle and aluminum tube: 190mm
Honing abrasive grain discharge angle: 45 °
Number of polishing liquid projections: 1 time

  The surface shape of the obtained support was magnified and observed with an operational probe microscope Neos (manufactured by Bruker Nano), and the result of calculating Rmk (L) is shown in FIG. 9 (iV). Rmk, max was 0.171, and the calculated length Lm at which Rmk, max was expressed was 5.9 μm. From the graph shown in FIG. 9 (iV), in the calculated length that is 0.1 times or less or 10 times or more away from the calculated length in which the maximum value Rmk, max of Rmk is expressed, it is more than two thirds of Rmk, max. It can be seen that Rmk is not expressed. That is, it was a roughness shape without randomness.

(Preparation of electrophotographic photoreceptor C-5)
An electrophotographic photosensitive member C-5 was produced in the same manner as the electrophotographic photosensitive member C-4 except that the distance between the gun nozzle and the aluminum tube was changed to 150 mm.

(Preparation of electrophotographic photoreceptor C-6)
An electrophotographic photosensitive member C-6 was produced in the same manner as the electrophotographic photosensitive member C-5 except that the air blowing pressure was changed to 0.02 MPa.

(Preparation of electrophotographic photoreceptor B-1)
-Support body A mirror-finished aluminum cylinder (JIS-A3003, aluminum alloy) having a length of 357.5 mm and a diameter of 30 mm was used as a support body.

-Conductive layer The following materials were dispersed with a sand mill using glass beads having a diameter of 1 mm for 8 hours to prepare a dispersion.
Oxygen-deficient SnO ₂ -coated TiO ₂ particles (SnO ₂ coverage (mass ratio) is 35%): 73 parts
・ Phenolic resin (Brand name: Priorofen J-325, manufactured by Dainippon Ink & Chemicals, Inc., resin solid content 60%): 27 parts
1-methoxy-2-propanol: 45 parts

The following materials were added to the dispersion as roughening particles.
Polymethylmethacrylate resin particles (trade name: SSX-102, manufactured by Sekisui Plastics Co., Ltd., average particle size 2 μm): 5 parts
・ 5 parts of polymethyl methacrylate resin particles (trade name: SSX-104, manufactured by Sekisui Plastics Co., Ltd., average particle size: 4 μm)

  Furthermore, 0.001 part of silicone oil (trade name: SH28PA, manufactured by Toray Dow Corning Co., Ltd.) was added and stirred to prepare a coating solution for a conductive layer.

  This conductive layer coating solution was dip-coated on a support, dried and thermally cured at a temperature of 140 ° C. for 30 minutes to form a conductive layer having an average film thickness of 15 μm at a position of 130 mm from the upper end of the support.

  The rough surface shape of the obtained conductive layer was enlarged and observed with an operational probe microscope Neos (manufactured by Bruker Nano), and the result of calculating Rmk (L) is shown in FIG. 9 (V). From the graph, Rmk, which is less than Rmk, max and more than two thirds of Rmk, max, is expressed in a calculated length which is 0.1 times or less or 10 times or more away from the calculated length where Rmk, max is expressed. I understand that. That is, it was a roughness shape with randomness.

  As described above, the Rz of the surface of the conductive layer was measured and found to be 0.85 μm. Table 3 summarizes the surface shape data of the intermediate layer.

-Formation of an intermediate | middle layer, a charge generation layer, and a charge transport layer Next, the intermediate | middle layer, the charge generation layer, and the charge transport layer were formed on the said conductive layer similarly to the photoreceptor A-1.

(Preparation of electrophotographic photoreceptor B-2)
Photosensitive member B-2 was prepared in the same manner as photosensitive member B-1, except that the roughening imparting particles used in the conductive layer were changed as follows when manufacturing photosensitive member B-1.
Polymethylmethacrylate resin particles (trade name: SSX-103, manufactured by Sekisui Plastics Co., Ltd., average particle size: 3 μm): 6 parts
-Polymethylmethacrylate resin particles (trade name: SSX-104, manufactured by Sekisui Plastics Co., Ltd., average particle size: 4 μm): 6 parts

(Preparation of electrophotographic photoreceptor B-3)
Photoreceptor B-3 was produced in the same manner as Photoreceptor B-2 except that the thickness of the conductive layer was 18 μm at the time of production of Photoreceptor B-2.

(Preparation of electrophotographic photoreceptor B-4)
Photoreceptor B-4 was produced in the same manner as Photoreceptor B-3, except that the thickness of the conductive layer was changed to 21 μm when producing Photoreceptor B-3.

(Preparation of electrophotographic photoreceptor B-5)
Photoreceptor B-5 was produced in the same manner as Photoreceptor B-2, except that the roughening imparting particles used in the conductive layer were changed as follows when producing Photoreceptor B-2.
-Polymethylmethacrylate resin particles (trade name: SSX-102, manufactured by Sekisui Plastics Co., Ltd., average particle size 2 μm): 10 parts

(Preparation of electrophotographic photoreceptor B-6)
Photoreceptor B-6 was produced in the same manner as Photoreceptor B-5, except that the thickness of the conductive layer was changed to 10 μm when producing Photoreceptor B-5.

(Preparation of electrophotographic photoreceptor B-7)
Photoconductor B-7 was produced in the same manner as photoconductor B-4, except that the method for adjusting the dispersion before adding the roughening imparting particles was changed as follows.
Oxygen-deficient SnO ₂ -coated TiO ₂ particles (SnO ₂ coverage (mass ratio) is 35%): 68 parts
-Phenol resin (trade name: Priorofen J-325, manufactured by Dainippon Ink & Chemicals, Inc., resin solid content 60%): 32 parts
1-methoxy-2-propanol: 45 parts

(Preparation of electrophotographic photoreceptor B-8)
At the time of preparation of the photoreceptor B-7, the method for adjusting the dispersion before adding the roughening imparting particles was changed as follows, and the thickness of the conductive layer was changed to 15 μm. Similarly, Photoconductor B-8 was produced.
Oxygen deficient SnO ₂ -coated TiO ₂ particles (SnO ₂ coverage (mass ratio) is 35%): 34 parts
Oxygen-deficient SnO ₂ -coated BaSO ₄ particles (SnO ₂ coverage (mass ratio) is 40%): 34 parts
-Phenol resin (trade name: Priorofen J-325, manufactured by Dainippon Ink & Chemicals, Inc., resin solid content 60%): 32 parts
1-methoxy-2-propanol: 45 parts

(Preparation of electrophotographic photoreceptor B-9)
Photoreceptor B-9 was produced in the same manner as Photoreceptor B-8, except that the thickness of the conductive layer was changed to 21 μm when producing Photoreceptor B-8.

(Preparation of electrophotographic photoreceptor B-10)
Photosensitive member B-10 was prepared in the same manner as photosensitive member B-9, except that the preparation method of the dispersion before adding the roughening imparting particles was changed as follows when preparing photosensitive member B-9. .
Oxygen deficient SnO ₂ coated BaSO ₄ particles (SnO ₂ coverage (mass ratio) is 40%): 68 parts
-Phenol resin (trade name: Priorofen J-325, manufactured by Dainippon Ink & Chemicals, Inc., resin solid content 60%): 32 parts
1-methoxy-2-propanol: 45 parts

(Preparation of electrophotographic photoreceptor B-11)
Photosensitive member B-11 was prepared in the same manner as photosensitive member B-10, except that the thickness of the conductive layer was changed to 26 μm at the time of manufacturing photosensitive member B-10.

(Preparation of electrophotographic photoreceptor B-12)
Photoreceptor B-12 was produced in the same manner as Photoreceptor B-7, except that the thickness of the conductive layer was changed to 20 μm when producing Photoreceptor B-7.

(Preparation of electrophotographic photoreceptor B-13)
Photoreceptor B-1 is the same as Photoreceptor B-1, except that the support is changed to a conductive resin cylinder and the roughening imparting particles used in the conductive layer are changed as follows. -13 was produced.
Polymethylmethacrylate resin particles (trade name: SSX-105, manufactured by Sekisui Plastics Co., Ltd., average particle size 5 μm): 10 parts

(Preparation of electrophotographic photoreceptor B-14)
A photoconductor B-14 was produced in the same manner as the photoconductor B-13 except that the thickness of the conductive layer was 20 μm.

(Preparation of electrophotographic photoreceptor B-15)
A photoconductor B-15 was produced in the same manner as the photoconductor B-14 except that the roughening particles used for the conductive layer were changed as follows.
Silicone resin particles (trade name: KMP-590, manufactured by Shin-Etsu Silicone Co., Ltd., average particle size 2 μm): 10 parts

(Preparation of electrophotographic photoreceptor D-1)
Photoconductor D-1 was prepared in the same manner as Photoreceptor B-1, except that when the photoconductor B-1 was prepared, the conductive layer was roughened and no imparted particles were used.

  The surface shape of the obtained support was magnified and observed with an operational probe microscope Neos (manufactured by Bruker Nano), and the result of calculating Rmk (L) is shown in FIG. 9 (Vi). Rmk, max was 0.041, and the calculated length Lm at which Rmk, max was expressed was 0.9 μm. From the graph shown in FIG. 9 (iV), Rmk more than two-thirds of Rmk, max is expressed at a calculated length that is 10 times or more away from the calculated length where the maximum value Rmk, max of Rmk is expressed. It turns out that there is no. That is, it was a roughness shape without randomness.

(Preparation of electrophotographic photoreceptor D-2)
A photoconductor D-2 was prepared in the same manner as the photoconductor B-1, except that the roughening imparting particles used in the conductive layer were changed as follows when the photoconductor B-1 was manufactured.
Silicone resin particles (trade name: Tospearl 120, manufactured by Momentive Performance Materials Japan GK, average particle size 2 μm): 10 parts

(Preparation of electrophotographic photoreceptor D-3)
Photoconductor D-3 was prepared in the same manner as Photoconductor B-1, except that the roughening imparting particles used in the conductive layer were changed as follows when Photoconductor B-1 was prepared.
Silicone resin particles (trade name: Tospearl 120, manufactured by Momentive Performance Materials Japan Godo Kaisha, average particle size 2 μm): 1.5 parts

(Preparation of electrophotographic photoreceptor D-4)
Photoconductor D-4 was prepared in the same manner as Photoconductor B-1, except that the roughening imparting particles used in the conductive layer were changed as follows when Photoconductor B-3 was prepared.
Polymethylmethacrylate resin particles (trade name: SSX-103, manufactured by Sekisui Plastics Co., Ltd., average particle size 2 μm): 12 parts

(Preparation of electrophotographic photoreceptor D-5)
Photoreceptor D-5 was produced in the same manner as Photoreceptor B-5, except that the dispersion time of the oxygen-deficient SnO ₂ -coated TiO ₂ particles was changed from 8 hours to 24 hours when producing Photoreceptor B-5. .

(Preparation of electrophotographic photoreceptor D-6)
A photoconductor D-6 was prepared in the same manner as the photoconductor D-5 except that the conductive layer was changed as follows when the photoconductor B-1 was manufactured.

-Conductive layer The following material was disperse | distributed for 2 hours with the sand mill using the glass bead of diameter 1mm, and the dispersion liquid was prepared.
-Zinc oxide that has been surface-treated with a silane coupling agent (the coverage (mass ratio) of the silane coupling agent is 1.5%): 60 parts
-Butyral resin (trade name: BM-1, manufactured by Sekisui Chemical Co., Ltd.): 15 parts
Blocked isocyanate (trade name: Sumijour 3175, manufactured by Sumika Bayer Urethane Co., Ltd.): 15 parts
1-methoxy-2-propanol: 200 parts

The following materials were added to the dispersion as roughening particles.
Silicone resin particles (trade name: Tospearl 120, manufactured by Momentive Performance Materials Japan Godo Kaisha, average particle size 2 μm): 9 parts

  Furthermore, 0.023 part of dibutyltin dilaurate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and stirred to prepare a coating solution for a conductive layer.

  This conductive layer coating solution was dip-coated on a support, dried and thermally cured at a temperature of 170 ° C. for 40 minutes to form a conductive layer having an average film thickness of 18 μm at a position 130 mm from the upper end of the support.

(Preparation of electrophotographic photoreceptor D-7)
The photoconductor D-6 was prepared except that the following alizarin dyed zinc oxide was used instead of zinc oxide surface-treated with a silane coupling agent, and the addition amount of silicone resin particles was 12 parts. A photoconductor D-7 was produced in the same manner as B-5.

  Preparation of alizarin-stained zinc oxide is as follows.

The following materials were mixed and stirred at 50 ° C. for 5 hours to prepare a dispersion.
-A mixed solution in which 500 parts of tetrahydrofuran was subjected to surface treatment with a silane coupling agent and 100 parts of zinc oxide (the coverage (mass ratio) of the silane coupling agent was 1.5%) was stirred.
A solution in which 1 part of alizarin is dissolved in 50 parts of tetratrahydrofuran

  The dispersion was filtered under reduced pressure to filter out alizarin-stained zinc oxide, followed by drying under reduced pressure at 60 ° C. to prepare alizarin-stained zinc oxide.

(Examples 1-38 and Comparative Examples 1-18)
The produced electrophotographic photosensitive member was mounted on the following evaluation apparatus and image output was performed.

-Image output device For image output, a modified machine of a copy machine “image RUNNER ADVANCEiR-ADV C5051” manufactured by Canon Inc. (modified so that one line of 1200 DPI can be written on the photoreceptor as image exposure) was used. The charging unit for the color image output drum of the copying machine is a contact charging unit including a charging roller, and a voltage obtained by superimposing an AC voltage on a DC voltage is applied to the charging roller. As the exposure light (image exposure light), a semiconductor laser having an oscillation wavelength of 780 nm, 655 nm, 405 nm, and 850 nm was used so that the amount of light was variable.

・ Interference fringe evaluation
The presence or absence of interference fringes was determined from visual evaluation of the Keima pattern halftone image output from the image output device and the reflection spectrum of the photoreceptor. A reflection spectral film thickness meter FE-3000 (manufactured by Otsuka Electronics Co., Ltd.) was used for the reflection spectrum measurement. Interference fringe evaluation was ranked in the following five stages a to e. The evaluation results are shown in Table 4 and Table 5.

a: No interference fringes on the image are confirmed, and no wavelength fluctuation is observed in the reflection spectrum intensity in the wavelength range of image exposure b: No interference fringes on the image are confirmed, and wavelength fluctuation is confirmed in the reflection spectrum intensity Is done. c: A slight interference fringe is observed on the image d: An interference fringe is observed and the image is not preferable for practical use e: An interference fringe is generated severely and the image is not practical

FIG. 10 (i) shows graphs plotted with the horizontal axis representing the exposure laser wavelength and the vertical axis representing Rmk, max / T ₁ for Examples 1 to 3, 5 to 9, and Comparative Examples 7 to 8. In FIG. 10 (i), a, b, and d are ranks of interference fringe evaluation defined above. In addition, the straight line in FIG.
In this case, n = 0.15 is substituted.

From FIG. 10 (i), the following formula
When the electrophotographic apparatus having the electrophotographic photosensitive member satisfies the above, it can be seen that image quality deterioration due to the generation of interference fringes does not occur.

Moreover, about Example 10-23 and Comparative Examples 17-18 in FIG.10 (ii),
The horizontal axis
(I = 1) and the vertical axis
The graph plotted as. In FIG. 10 (ii), a, b, and d are the ranks of interference fringe evaluation defined above. In addition, the straight line in FIG.
In this case, n = 0.62 is substituted.

From FIG. 10 (ii), the following formula
When the electrophotographic apparatus having the electrophotographic photosensitive member satisfies the above, it can be seen that image quality deterioration due to the generation of interference fringes does not occur.

-Fogging / Pochi Evaluation Fogging / pochi evaluation was performed by outputting a solid white image from the image output device and visually evaluating the fog / pochi on paper. The fog and spot evaluation was ranked in the following five grades A to E. The evaluation results are shown in Table 4 and Table 5.

A: Excellent image with no fog or spots B: Slight fog or spots, but good image.
C: fog and spots are observed D: generation of fog and spots is large E: fog and spots are generated very severely, and this is not practically preferable.

-Thin line reproduction evaluation The fine line reproducibility was evaluated according to the following procedure.
First, in the environment of a temperature of 23 ° C./relative humidity of 50%, the electrophotographic photosensitive member is set to have a potential condition such that the dark portion potential (Vd) is −700 V and the light portion potential (Vl) is −200 V. The initial potential of the photoreceptor was adjusted.

  Next, development settings were made so that the solid black image output density was D = 1.4, and the chart of each image below with an output resolution of 1200 dpi was output from the external controller.

1 line-2 space image (1L2S)
2-line-4 space image (2L4S)

  The output image thus obtained was magnified 100 times with an optical microscope, and the fine line reproducibility was evaluated according to the following criteria. The evaluation results are shown in Table 4 and Table 5.

5: Line width of (1L2S) does not change 4: Line width of (1L2S) changes moderately 3: Line width of (1L2S) changes and appears to be missing 2 : Discontinuity is observed in the line width of (1L2S), and moderate fluctuations are observed in the line width of (2L4S) 1: Variations are observed in the line width of (2L4S), and it appears to be missing

  As described above, in an electrophotographic apparatus having a photoreceptor having a rough shape defined by Rmk (L) below the charge generation layer, image defects such as fogging and black spots are suppressed while suppressing generation of interference fringes. It can be seen that it is possible to provide an electrophotographic apparatus that maintains an image with a small number of images and has high fine line reproducibility.

a ··· laser beam transmitting portion b ··· laser beam shielding portion c ··· excimer laser beam irradiator d ··· workpiece rotating motor e ··· workpiece moving device f ··· Support 1 ... Electrophotographic photosensitive member 2 ... Shaft 3 ... Contact charging means 4 ... Exposure light (image exposure light)
5 ... Development means 6 ... Transfer means 7 ... Cleaning means 8 ... Fixing means 9 ... Process cartridge 10 ... Guide means P ... Transfer material

Claims (3)

An electrophotographic apparatus having an exposure means having a laser light source for oscillating a laser beam having a wavelength λ, a charging means, a developing means, a transfer means, and an electrophotographic photosensitive member,
The electrophotographic photoreceptor has at least a charge generation layer and a charge transport layer in this order on a conductive support,
In the conductive support, in the graph in which the surface shape shows the calculated length dependency of the average local height difference (Rmk),
The maximum value (Rmk, max) of the average local height difference (Rmk) is the following formula (1) (in formula (1), T ₁ is the transmittance until the laser beam reaches the conductive support. Show)
When the layer provided in contact with the conductive support is a first layer and the layer provided in contact with the conductive support is named as a second layer up to the charge generation layer,
In the graph showing the calculation length dependence of the average local height difference (Rmk),
In the calculated length that is 0.1 times or less or 10 times or more away from the calculated length in which the maximum value (Rmk, max) of the average local height difference (Rmk) is expressed, the maximum value (Rmk, max) or less and Rmk more than two thirds of the maximum value (Rmk, max) is expressed,
The shape of the interface between the i-th layer and the i + 1-th layer (i is an integer of 1 or more) is expressed by the following formula (2)
(In Formula (2), T _{i + 1} indicates the transmittance until the laser beam reaches the i-th layer on the conductive support, and n _i and n _{i + 1} are respectively on the conductive support. Refractive index of the i-th layer and the i + 1-th layer provided in contact with each other)
An electrophotographic apparatus characterized by satisfying the above. An electrophotographic apparatus having an exposure means having a laser light source for oscillating a laser beam having a wavelength λ, a charging means, a developing means, a transfer means, and an electrophotographic photosensitive member,
The electrophotographic photoreceptor has at least a charge generation layer and a charge transport layer in this order on a conductive resin support,
The conductive resin support is the 0th layer, the layer provided in contact with the conductive resin support is the first layer, and the layer provided in contact with the conductive resin support is the second layer. If you name the generation layer,
In the conductive resin support, the surface shape is a graph showing the calculation length dependence of the average local height difference (Rmk),
In the calculated length that is 0.1 times or less or 10 times or more away from the calculated length in which the maximum value (Rmk, max) of the average local height difference (Rmk) is expressed, the maximum value (Rmk, max) or less and Rmk more than two thirds of the maximum value (Rmk, max) is expressed,
The shape of the interface between the i-th layer and the i + 1-th layer (i is an integer of 1 or more) is expressed by the following formula (2)
(In Formula (2), T _{i + 1} represents the transmittance until the laser beam reaches the i-th layer on the conductive resin support, and n _i and n _{i + 1} represent the conductive resin support, respectively. (The refractive indices of the i-th layer and the (i + 1) -th layer provided in contact with each other are shown.)
An electrophotographic apparatus characterized by satisfying the above. An electrophotographic apparatus having an exposure means having a laser light source for oscillating laser light having a wavelength λ, a charging means, a developing means, a transfer means, and an electrophotographic photosensitive member,
The electrophotographic photoreceptor has a charge generation layer provided in contact with a conductive support and a charge transport layer provided on the charge generation layer,
The conductive support is a graph in which the surface shape shows the calculated length dependence of the average local height difference (Rmk),
In the calculated length that is 0.1 times or less or 10 times or more away from the calculated length in which the maximum value (Rmk, max) of the average local height difference (Rmk) is expressed, the maximum value (Rmk, max) or less and Rmk more than half of the maximum value (Rmk, max) is expressed,
The maximum value (Rmk, max) of the average local height difference (Rmk) is expressed by the following formula (1).
(In the formula (1), T ₁ represents a transmittance of up to the laser light reaches the conductive support)
An electrophotographic apparatus characterized by satisfying the above.