JPH04335647A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide the electrophotographic sensitive body capable of operating uniform electric charging at high speed without being affected by the kinds of chargers. CONSTITUTION:The electrophotographic sensitive layer is formed by laminating on a conductive substrate an electrophotographic sensitive layer comprising a first photoconductive layer 14, and on this layer a second photoconductive layer 16 absorbing the light different in the wavelength region from the light that the layer 14 absorbs. This electrophotographic sensitive body is irradiated with the light that the layer 16 absorbs, and at the same time, it is charged by a charger, thus permitting the layer 16 to be made conductive and the carriers to transfer inside the layer 16, accordingly the charge voltage to be evened and uniform charge to be attained, therefore, the obtained electrophotographic sensitive body to be uniformly charged at high speed without being affected by the kinds of the chargers.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor in which a photoconductive layer is formed of a photoconductor, and more specifically, it is charged with a charging device and formed with a latent image by exposure. The present invention relates to an electrophotographic photoreceptor used in an electrophotographic apparatus that performs lithographic printing plates, electrostatic printing, or the like.

0002

[Prior Art] The charging device currently used in most electrophotographic devices is a charging device using a corona discharger, and more specifically, the charging device has a structure in which a control grid is provided on the corona discharger. This is a charging device called a Scorotron charging device. A control grid is not necessary for the sole purpose of realizing a charging device using a corona discharger, and a corotron charging device without a control grid has a fast charging speed but poor uniformity of charging. It has the disadvantage of being sufficient. The Scorotron charging device improves this point by providing a control grid, and can easily uniformly charge a general electrophotographic photoreceptor.

However, since the scorotron charging device requires a control grid, the structure is complicated and a power source is required for charging control, and the charging efficiency decreases due to the influence of the control grid, so the charging speed is insufficient. There is a problem that.

0004

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned conventional problems, and its object is to provide a high-speed, constant charger without being affected by the type of charging device. An object of the present invention is to provide an electrophotographic photoreceptor for an electrophotographic device, which is characterized in that it is uniformly charged.

[0005]

[Means for Solving the Problems] The present invention relates to an electrophotographic photoreceptor for an electrophotographic device that can be uniformly charged at all times without being affected by the type of charging device. Specifically, on an electrophotographic photosensitive layer formed by forming a first photoconductor layer on an electrically conductive support, the first photoconductor layer is exposed to light in a wavelength range different from that in which the first photoconductor layer is exposed. The present invention relates to an electrophotographic photoreceptor for an electrophotographic apparatus, characterized in that it is formed by laminating a second photoconductive layer that exhibits light absorption.

Electrophotographic photoreceptor 1 of the present invention shown in FIG.
is applied to an electrophotographic photosensitive layer 4 formed by forming a first photoconductive layer 3 on a conductive substrate 2 to light having a wavelength range different from that of the light used to expose this electrophotographic photosensitive layer 4. A second photoconductive layer 5 is formed which exhibits light absorption. The electrophotographic photoreceptor 1 thus formed is irradiated with light in a wavelength range that is absorbed by the second photoconductive layer 5, and at the same time is charged by a charging device, and then exposed to light to create an electrostatic latent according to image information. An image is formed, and toner is attracted and formed according to this electrostatic latent image, thereby making it possible to construct electrophotography.

In the above-mentioned present invention, since the second photoconductive layer 5 is irradiated with light absorbed during charging, the second photoconductive layer 5 becomes conductive and the carriers are absorbed. As a result, the charging voltage is averaged, and uniform charging is performed regardless of the type of charging device.

[0008]

[Operation] As described above, on the electrophotographic photosensitive layer formed by forming the first photoconductive layer on the conductive support, a wavelength range different from that in which the first photoconductive layer is exposed is applied. The electrophotographic photoreceptor is characterized in that it is formed by laminating a second photoconductive layer that absorbs light in the wavelength range that the second photoconductive layer absorbs. By irradiating the electrophotographic photoreceptor and simultaneously charging it with a charging device, the electrophotographic photoreceptor can always be uniformly charged without being affected by the type of charging device.

Further, the present invention is characterized in that carriers move in the second photoconductive layer, and as a result, the charging voltage is averaged, and uniform charging is performed regardless of the type of charging device. This effect applies not only to electrophotographic photoreceptors using the Carlson method, but also to electrophotographic photoreceptors using, for example, a capacitive imaging method.

0010

EXAMPLES Examples of electrophotographic photoreceptors to which the present invention is applied will be described below. (Example 1) A polyethylene terephthalate film with a thickness of 100 μm on which ITO was vapor-deposited was used as a conductive support, and the following coating material was applied on it to a thickness of 6 μm as a first photoconductive layer.
An electrophotographic photosensitive layer was obtained.

Zinc oxide
10gε-copper phthalocyanine
2g phthalic anhydride
1g acrylic resin
10g toluene

40g Next, a second layer was applied on top of this electrophotographic photosensitive layer.
The following coating material was applied as a photoconductive layer to a thickness of 1 μm to obtain an electrophotographic photoreceptor.

Poly-N-vinylcarbazole
10g polycarbonate resin
2g dichloromethane
8g toluene

80g pyrylium salt dye (structural formula below)
0.004g

[0013]

[Chemical formula 1]

The obtained electrophotographic photoreceptor was heated for 200 m using a corotron charging device while being irradiated with blue light of around 500 nm, which is absorbed by the pyrylium salt dye represented by the above formula.
When charging was performed at a charging speed of m/sec and development was performed using a black liquid toner, a very uniform black color could be obtained over the entire surface. Next, after charging, the first photoconductive layer was uniformly irradiated with near-infrared light to which it is sensitive, and developed with a black liquid toner, resulting in a very uniform intermediate density over the entire surface.

Further, no particular adverse effects were observed on the electrophotographic properties such as the sensitivity and dark decay properties of the electrophotographic photoreceptor. For comparison, an electrophotographic photoreceptor with only the first photoconductive layer was prepared and similarly charged and developed. As a result, some parts of the surface were sufficiently black, but some parts were black. The results were very non-uniform, with almost no concentration.

[0016] Furthermore, when uniform exposure was carried out after charging and development was carried out, very uneven density was obtained in various parts of the surface, and the film was not suitable for electrophotographic image formation. (Example 2) As shown in FIG. 2, a conductive support 13 made of a 75 μm thick polyethylene terephthalate film 11 laminated with a 5 μm aluminum foil 12 was used.
On top of this, the next coating is applied as the first photoconductive layer 14 to a thickness of 8 μm.
It was applied so that the thickness was m.

Cadmium sulfide
3g styrene-acrylic resin 1
7g acetic acid cellosolve
40g methyl ethyl ketone
Further, on this photoconductive layer 14, a film with a thickness of 1 μm is applied.
A polyethylene terephthalate film 15 was attached to obtain an electrophotographic photosensitive layer that can be used for capacitive imaging.

Next, on this electrophotographic photosensitive layer, the following coating material was applied as a second photoconductive layer 16 to a thickness of 1 μm to obtain an electrophotographic photoreceptor 17. Poly-N-vinylcarbazole
10g polycarbonate resin
2g dichloromethane
8g toluene

80g Heptamethine cyanine dye (structural formula below) 0
．． 001g

[0019]

[Case 2]

The obtained electrophotographic photoreceptor has a wavelength of 760 nm to 760 nm, which is absorbed by the heptamethine cyanine dye represented by the above formula.
Charging was performed at a charging speed of 150 mm/sec using a corotron charging device while simultaneously irradiating near-infrared light around 780 nm and green light to which cadmium sulfide is sensitive. Next, while performing uniform green image exposure, charging is performed with the opposite polarity to the initial charging, and after the entire surface is exposed to green light,
When developed with a black liquid toner, a very uniform intermediate density was obtained over the entire surface.

For comparison, an electrophotographic photoreceptor was prepared with only the first photoconductive layer 14 and an electrophotographic photosensitive layer consisting of a polyethylene terephthalate film 15, and similarly charged and charged.
When image exposure, whole surface exposure, and development were carried out, extremely non-uniform density was obtained in various parts of the surface, and the film was not suitable for electrophotographic image formation.

[0022]

Effects of the Invention As is clear from the above explanation, the wavelength at which the first photoconductive layer is exposed on the electrophotographic photosensitive layer formed by forming the first photoconductive layer on the conductive support is For an electrophotographic photoreceptor characterized in that it is formed by laminating a second photoconductive layer that exhibits light absorption for light in a wavelength range different from that of the second photoconductive layer, To manufacture an electrophotographic photoreceptor for an electrophotographic device that can be charged uniformly at high speed without being affected by the type of charging device by applying light in an absorbing wavelength range and simultaneously charging the photoreceptor. Can be done.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing a cross section of an electrophotographic photoreceptor of the present invention.

FIG. 2 is a schematic sectional view showing a cross section of an electrophotographic photoreceptor according to another embodiment of the present invention.

[Explanation of symbols]

1, 17 Electrophotographic photoreceptor 2, 13 Conductive substrate 3, 14 First photoconductive layer 4 Electrophotographic photosensitive layer 5, 16 Second photoconductive layer 11, 15 Polyethylene terephthalate film 1
2 Aluminum foil

Claims (1)

[Claims] [Claim 1] An electrophotographic photosensitive layer formed by forming a first photoconductive layer on a conductive support is coated with light having a wavelength range different from that in which the first photoconductive layer is exposed. An electrophotographic photoreceptor characterized in that it is formed by laminating a second photoconductive layer that exhibits light absorption.