JP2000156285A - Exposure device, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure device in which resolution can be improved for a column direction of light emitting elements without changing element constitution of a light emitting body array, which is advantageous with relation to cost, and which can be favorably applied to an exposure part in an electrophotography method. SOLUTION: A light emitting body array 101 comprising plural light emitting elements 2 disposed in a column direction is connected to a position shift means 102, and its control part 103 is composed of a CPU 104, a ROW 105, a RAM 106, and an input/output port 107. By means of the position shift means 102, the position of the light emitting body array 101 is shifted for a specified quantity (d/2) in the column direction in a range of an arrangement pitch (d) of the light emitting elements 2, when light emission (solid scan) is conducted at the original position before shifting and at the position after shifting. Resolution can thus be improved to at least twice for a scan direction, and since feed control (auxiliary scan) of photosensitive recording material is conducted in accordance with it, an exposed image of a high resolution can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus and an image forming apparatus serving as a light source for exposing a photosensitive member in an electrophotographic apparatus, and more particularly to a light emitting element in which a plurality of light emitting elements are arranged in a line. The present invention relates to an exposure apparatus and an image forming apparatus configured as an array.

[0002]

2. Description of the Related Art As is well known, an electrophotographic method is a process in which an image is exposed on a photoconductor, developed with toner, transferred to a transfer material (paper), fixed, and the photoconductor is cleaned. Therefore, use for an image forming apparatus is active.

In such an image forming apparatus, a laser optical system that scans a laser beam with a polygon mirror is widely used as an exposure unit for writing a latent image on the surface of a photosensitive member because of its high resolution and high speed. ing.
However, in the case of a laser optical system, a space for arranging optical components such as a polygon mirror and a lens is required, which makes it difficult to reduce the size of the apparatus. However, there is a problem that it is difficult to increase the speed.

[0004] Therefore, a light-emitting array in which an organic light-emitting element, an inorganic light-emitting element, and the like are arranged in a plurality of rows and arranged in an array has been attracting attention. Since an element can be electrically selected for scanning, which is a so-called solid-state scanning and an optical system is simplified, application to an electrophotographic exposure unit has been advanced. For example, as a linear light-emitting array, a transparent anode layer, an organic compound layer, and a cathode layer are sequentially laminated on a long-strip light-transmitting substrate, and the front and back of the strip-shaped organic compound layer are formed in a predetermined pattern of electrodes. A proposal has been made in which an array of light-emitting elements that individually emit light is sandwiched between layers.

[0005]

However, in the case of such a linear luminous element array, the direction of the arrangement of the luminous elements is preferable in terms of electric scanning, but the resolution (resolution) in the scanning direction is low. There is a problem that is determined by the arrangement pitch of, the high resolution can be obtained by increasing the number of light emitting elements and narrowing the arrangement pitch,
Increasing the degree of integration increases the difficulty of fabrication and has limitations. When the number of light emitting elements is increased and the arrangement pitch is reduced, there is a problem that the manufacturing cost is significantly increased.

Therefore, the present invention has been made in view of such a conventional problem, and it is possible to improve the resolution in the direction of the arrangement of the light emitting elements without changing the element configuration of the light emitting element array. It is an object of the present invention to provide an exposure apparatus which is advantageous in cost and can be preferably applied to an electrophotographic exposure unit.

[0007]

In order to achieve the above object, an exposure apparatus according to the present invention comprises a plurality of light-emitting elements arranged in a row to form a light-emitting array, and the light-emitting array is made to correspond to input data. An exposure apparatus that drives and exposes a medium by emitting light thereof includes a position shift unit that shifts a position of the light emitting array by a predetermined amount in a direction along a row of light emitting elements.

With the above arrangement, the position of the light emitting element array in which a plurality of light emitting elements are arranged in a row is shifted by a predetermined amount in the direction along the row of the light emitting elements by the position shifting means. Therefore, if the light emission (solid-state scanning) of the light emitting array is performed at the original position where the light emitting element is not shifted and the position where the light emitting element is shifted by a predetermined amount within the range of the arrangement pitch of the light emitting elements, the light emission is at least doubled in the scanning direction. Since the resolution (resolution) can be improved and the feeding control (sub-scanning) of the photosensitive recording material is performed in correspondence with the resolution, a high-resolution exposure image can be obtained. In this position shift control, the resolution can be further improved by reducing the shift amount and increasing the number of movement steps within the range of the arrangement pitch of the light emitting elements.

The present invention also includes an image forming apparatus having at least the above-described exposure apparatus and a photoconductor exposed by the exposure apparatus.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an exposure apparatus according to the present invention will be described below with reference to the accompanying drawings.

1 to 7 show a first embodiment of the present invention. FIG. 1 is a structural view of an exposure apparatus according to the present invention, FIG. 2 is a perspective view of a luminous body array portion thereof, and FIG. FIG. 4 is a cross-sectional view showing the layer configuration of the element, FIG. 4 is a chart showing timing of light emission control, and FIGS. 5 to 7 are schematic diagrams showing a storage arrangement of input data such as image information.

The exposure apparatus includes a light emitting array 101,
The light emitting element array 101 includes a plurality of light emitting elements 2 and a driver 3 for the light emitting element 2.
104, ROM 105, RAM 106, input / output port 1
07. Then, the CPU 104, the ROM 105,
A RAM 106 and an input / output port 107 are connected by a control line, and a CP that captures input data such as image information.
Various data, addresses, and the like are transmitted to each unit via the control line by the U104, and the input / output port 107 is connected to the position shift means 102 and the driver 3 of the light emitting element 2 by the input / output line. A drive signal or the like corresponding to input data such as information is transmitted.

As shown in FIG. 2, the luminous body array 101 has a large number of luminous elements 2 on a long-strip light-transmitting substrate 21.
Are arranged in a row (array), and a driver 3 for causing the light emitting elements 2 in the row to emit light in accordance with image information is formed in a circuit pattern adjacent to the row. The luminous body array 101 has a position shift means 102 connected to one end thereof.
Is shifted by a predetermined amount in the direction in which the light emitting elements 2 are arranged. That is, the position shift means 102 is provided with an actuator for shift driving, and repeats shift and return in synchronization with a shift signal described later. Here, the shift amount is set to の of the arrangement pitch d of the light emitting elements 2.

When the exposure apparatus is applied, a selfoc lens array 32 is provided between the photoconductor 211 as a light irradiation medium, and the light emission of the light emitting elements 2 arranged in a row is controlled by a long band selfoc lens. The array 32 guides and irradiates the surface of the rotating drum type photoconductor 211.

The light-emitting elements 2 in a row are so-called organic light-emitting elements, which are collectively formed by lamination, and as shown in FIG.
2. An organic compound layer 203 and a cathode layer 204 are sequentially stacked, and a row of light-emitting elements that individually emit light is collectively formed by sandwiching the front and back of the band-shaped organic compound layer 203 between electrode layers 202 and 204 having a predetermined pattern. The configuration is as follows.

As the substrate 201, any substrate capable of holding a light emitting element on its surface may be used. For example, a transparent insulating substrate made of glass such as soda lime glass or a resin film is preferably used.

As a material of the anode layer 202, a material having a large work function is desirable. For example, ITO, tin oxide, gold, platinum, palladium, selenium, iridium, copper iodide and the like can be used. On the other hand, the material of the cathode layer 204 is desirably a material having a small work function, for example, Mg / A
g, Mg, Al, In, or an alloy thereof can be used.

The organic compound layer 203 may have a single-layer structure or a multi-layer structure. For example, the organic compound layer 203 may include a hole transport layer into which holes are injected from the anode layer 202 and a cathode layer 204. It consists of an electron transport layer into which electrons are injected, and one of the hole transport layer and the electron transport layer becomes a light emitting layer. Also,
A phosphor layer containing a phosphor may be provided between the hole transport layer and the electron transport layer. Further, a configuration in which a hole transport layer, an electron transport layer, and a fluorescent layer are also used in a mixed single layer configuration is also possible.

As the hole transport layer, for example, N, N'-
Bis (3-methylphenyl) -N, N'-diphenyl-
(1,1′-biphenyl) -4,4′-diamine (TPD) can be used, and the following organic materials can also be used.

[0020]

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[0021]

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[0022]

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[0023]

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[0024]

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Further, inorganic materials such as a-Si and a-SiC may be used.

As the electron transporting layer, for example, Tris (8
-Quinolinol) aluminum (hereinafter Alq ₃ ), and the following materials can also be used.

[0027]

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[0028]

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[0029]

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[0030]

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Further, a dopant as shown below can be doped into the electron transporting layer or the hole transporting layer.

[0032]

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Further, it is preferable to provide a dielectric layer between the anode layer 202 and the substrate 201. The dielectric layer is Si
By laminating layers having different refractive indexes such as O ₂ and SiO, it is possible to increase (lower) the reflectance and transmittance at a specific wavelength. Alternatively, it is also possible to simply use a half mirror.

It is preferable that a protective layer (sealing layer) is provided on the upper surface of the cathode layer 204 by laminating an insulating moisture-proof material to protect the surface layer and prevent deterioration and prevent short-circuit of the electrodes. .

In the CPU 104, the luminous body array 101 and the position shift means 102 according to input data such as image information.
Is controlled.

That is, light emission (solid-state scanning) of the light emitting elements 2 arranged in a line is performed in synchronization with the rotation of the photosensitive member 211, and as shown in FIG. The light emission timing S2 is synchronized with the accompanying feed signal S. At this time, the luminous body array 101 outputs the sending signal S
The shift and the return are repeated by the shift signal S1 which is shifted by a predetermined amount in the direction of the arrangement row in synchronization with the shift signal S and inverted at the rise of the feed signal S. This shift amount is の of the arrangement pitch d of the light emitting elements 2 as described above, and therefore, the feed signal S has a cycle of 周期 of the feed signal S0 in the conventional configuration without using the position shift means 102. The light emitter array 101 is shifted in synchronization with this, and the solid-state scanning is performed at both the original position and the position shifted by d / 2.

Input data such as image information is decomposed into pixels by A / D conversion and stored in the RAM 106. Digital data corresponding to the number of pixels is converted into light-emitting elements as shown in FIG. The table is a two-dimensional table of the row direction of 2 (solid-state scanning direction) and the moving direction of the photoconductor. The number of pixels of this two-dimensional table is two times larger in the solid-state scanning direction than in the conventional configuration in which the position shift means 102 is not used.
Since the position shift control is performed in the direction of the solid-state scanning, odd-numbered pixels and even-numbered pixels are separated and extracted from the two-dimensional table shown in FIG. 5, and the odd-numbered pixel data is as shown in FIG. As shown in FIG. 7, the even-numbered pixel data is stored in the RAM 106 as a two-dimensional table similar to FIG.

Therefore, in the light emission (solid-state scanning) of the light emitting elements 2 arranged in a line, the data of the odd-numbered pixel table shown in FIG. 6 is sequentially read out at the original position where the light emitting array 101 is not shifted, and d / 2 Figure 7 in the shifted position
Are sequentially read out.

In this embodiment, the odd-numbered pixel data and the even-numbered pixel data are separated into two-dimensional tables. However, these data tables are not necessarily provided, and the two-dimensional tables shown in FIG. During the position shift control, the odd-numbered pixel data and the even-numbered pixel data may be appropriately read.

With the above configuration, in the exposure apparatus of this embodiment, the position of the luminous body array 101 in which the plurality of light emitting elements 2 are arranged in a row is shifted by the position shift means 102 in the direction along the row of the light emitting elements 2. It is shifted by a predetermined amount (d / 2). Then, light emission of the light emitting array 101 (solid-state scanning)
Is performed at an original position where the light-emitting elements 2 are not shifted and at a position where the light-emitting elements 2 are shifted by a predetermined amount within the range of the arrangement pitch d, so that the resolution (resolution) can be improved at least twice in the scanning direction. Since the feed control (sub-scan) of the photoconductor 211 is performed in correspondence with this, a high-resolution exposure image can be obtained. In this case, there is no need to change the element configuration of the light emitting array 101, which is advantageous in terms of cost. As a result, it can be preferably applied to an electrophotographic exposure unit.

In this embodiment, the light emitting array 10
Since the shift amount of 1 is set to の of the arrangement pitch d of the light emitting elements 2, the number of pixels for A / D conversion is also reduced by the position shift unit 102.
Although the direction of solid-state scanning is doubled as compared with the conventional configuration using no light emitting element, the present invention is not limited to this, and the shift amount is reduced and the number of moving steps is increased within the range of the arrangement pitch d of the light emitting elements 2. Thereby, the resolution can be further improved. For example, assuming that the shift amount is d / 3, the shift operation is a two-step shift of d / 3 shift, 2d / 3 shift, and return.
The number of pixels for the / D conversion may be tripled in the direction of solid-state scanning, thereby improving the resolution three times as compared with the conventional configuration in which no position shift is performed.

In this embodiment, as shown in FIG. 8A, the light emitting array 101 is provided in the position shift means 102.
8 are connected, and the shift movement is performed. However, the present invention is not limited to this. For example, FIG.
As shown in (B), the luminous body array 101 and the selfoc lens array 32 are integrated by a structure 615,
This may be connected to the position shifting means 102 to shift the Selfoc lens array 32 also.

FIG. 9 shows a second embodiment of the present invention, which is an example of an image forming apparatus using the exposure apparatus according to the present invention. FIG. 9 is a block diagram of an electrophotographic image forming apparatus. is there.

In this image forming apparatus, a charging means 212 and a rotating drum type photoreceptor 211 are provided around an image bearing member.
Developing means 213, transfer means 214, cleaning means 2
16 are arranged in order, an exposing unit 217 is arranged between the charging unit 212 and the developing unit 213, and a fixing unit 215 is arranged in a discharge path of the transfer material P such as recording paper.

Exposure means 217 is one to which the exposure apparatus of the present invention is applied. A selfoc lens array 32 is provided in front of the light emitter array 101, and the light emission output of the light emitter array 101 is provided by the selfoc lens array 32. Is appropriately guided as the exposure L.
Exposure L can be formed on the image 11 and a good latent image can be obtained.

In the exposure means 217, the selfoc lens array 32 is housed in the main body 31 of the exposure apparatus and integrally formed, but the invention is not limited to this. For example, FIG. 10 is a configuration diagram showing another example of the exposure unit. As shown in FIG. 10, the SELFOC lens array 32 is separated without being housed in the main body 41 of the exposure apparatus, and is separated from the photoconductor 211. They may be provided as appropriate.

In the image formation, first, the photosensitive member 211 is uniformly charged by the charging means 212. Exposure L is performed on the charged surface of the photoconductor 211 by exposure means 217 in accordance with a time-series electric digital pixel signal as image information, and an electrostatic latent image corresponding to the image information is formed on the peripheral surface of the photoconductor 211. Is formed. The electrostatic latent image is developed as a toner image by developing means 213 using insulating toner. On the other hand, a transfer material P as a recording material is supplied from a paper feeding unit (not shown),
The photoconductor 211 is introduced at a predetermined timing into a pressure contact nip (transfer portion) T pressed against the photoconductor 211 with a predetermined pressure, and performs a transfer by applying a predetermined transfer bias voltage.

The transfer material P which has undergone the transfer of the toner image is separated from the surface of the photoconductor 211, and is introduced into a fixing means 215 such as a heat fixing system, where the toner image is fixed to form a print (image). It is discharged outside the device. Further, the surface of the photoconductor 211 after the transfer of the toner image to the transfer material P is cleaned by a cleaning unit 216 to remove adhered contaminants such as residual toner, and is repeatedly used for forming a latent image.

In this case, the exposure means 217 for performing the electrophotographic exposure process comprises the exposure apparatus of the present invention. Therefore, the resolution can be improved by position shift control in the direction of the row of the light emitting elements 2. Since the feed control (sub-scanning) of the photosensitive member 211 is performed in correspondence with this, a high-resolution exposure image can be obtained, and the element configuration of the light emitting array 101 does not need to be changed. In terms of advantages. As a result, it is preferable for the exposure section of the electrophotographic system, and high image quality can be achieved.

FIG. 11 shows a third embodiment of the present invention.
This is another example of an image forming apparatus using the exposure apparatus according to the present invention. FIG. 1 is a configuration diagram of a multicolor image forming apparatus using an electrophotographic method.

In this image forming apparatus, in order to form a multi-color image, four process components up to electrophotographic transfer are arranged in a row, and the transfer material P passes through the four consecutive process components in order. Thus, the sheet is conveyed to the fixing unit F1.

That is, the photosensitive drums 301 to 301 of the rotating drum type
04 are arranged in order from the upstream side of the transfer belt TF1 passed between the two rollers TR1 and TR2.
1 to C4, exposure means E1 to which the exposure apparatus of the present invention is applied
E4, developing means D1 including developing sleeves S1 to S4
D4, transfer blades T1 to T4 are arranged, and a fixing means F1 is provided in a discharge path of the transfer material P.

The transfer material P is transported in the direction of the arrow,
The transfer belt TF1 guides the transfer belt TF1 onto the transfer belt TF1 suspended on R1 and TR2, and moves to a black transfer position set between the photosensitive member 301 and the transfer blade T1. At this time, the photoreceptor 301 has a predetermined black toner image by an electrophotographic process using a charging means C1, an exposing means E1, and a developing sleeve S1 of a developing means D1 arranged on the periphery of the drum. The transfer of the black toner image is performed.

Further, the transfer material P is conveyed by the transfer belt TF1, and is set to a cyan transfer position set to be sandwiched between the photosensitive member 302 and the transfer blade T2, and set to be set to be sandwiched between the photosensitive member 303 and the transfer blade T3. Sequentially moves to the magenta transfer position and the yellow transfer position set between the photosensitive member 304 and the transfer blade T4. At each transfer position, the cyan toner image and the magenta The transfer of the toner image and the yellow toner image is performed.

In this case, since each of the photoconductors 301 to 304 is rotating favorably, the image registration can be favorably performed between the transfer recordings. The transfer material P on which the multicolor recording has been performed by the above process is guided to the fixing unit F1 to be fixed, whereby a multicolor image can be obtained.

In such a multi-color image forming apparatus, since there are a plurality of electrophotographic processes, there is a problem with the light emitting element array in the conventional exposure means (exposure apparatus), that is, the direction of the arrangement of the light emitting elements. The problem that the resolution (resolution) is limited also affects a plurality of or multiplexes, but here, since the exposure units E1 to E4 by the exposure apparatus of the present invention are provided, each of the exposure units has a light emitting element. The resolution can be improved by the position shift control in the direction of the arrangement of the photoconductors, and the feed control (sub-scanning) of the photoconductor is performed in correspondence with this, so that a high-resolution exposure image can be obtained. Since the element configuration of the light emitting array does not need to be changed, there is an advantage in cost. As a result, the influence of the problem can be mitigated even with a plurality of configurations, so that a high-quality multicolor image which is preferable for an exposure unit of a multicolor electrophotographic system can be obtained.

[0057]

As described above, according to the exposure apparatus of the present invention, the position of the light emitting element array in which a plurality of light emitting elements are arranged in a line is adjusted by a predetermined amount in the direction along the line of the light emitting elements by the position shift means. Will be shifted. For this reason, the light emission (solid-state scanning) of the light emitter array is not shifted to the original position.
If the scanning is performed at a position shifted by a predetermined amount within the range of the arrangement pitch of the light emitting elements, the resolution (resolution) can be improved at least twice in the scanning direction. Since control (sub-scanning) is performed, a high-resolution exposure image can be obtained. In this case, the element configuration of the light emitter array does not need to be changed,
There is a cost advantage. As a result, it can be preferably applied to an electrophotographic exposure unit.

In the position shift control, the resolution can be further improved by reducing the shift amount and increasing the number of moving steps within the range of the arrangement pitch of the light emitting elements.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an exposure apparatus showing a first embodiment of the present invention.

FIG. 2 is a perspective view of a luminous body array portion of FIG.

FIG. 3 is a cross-sectional view illustrating a layer configuration of the light emitting device of FIG.

FIG. 4 is a chart showing timing of light emission control.

FIG. 5 is a schematic diagram showing a storage arrangement of input data such as image information.

FIG. 6 is a schematic diagram showing a storage arrangement of input data such as image information.

FIG. 7 is a schematic diagram showing a storage arrangement of input data such as image information.

FIG. 8 is a side view illustrating the connection between the position shift means and the light emitting array.

FIG. 9 is a configuration diagram of an example of an electrophotographic image forming apparatus according to a second embodiment of the present invention.

FIG. 10 is a configuration diagram illustrating another example of the exposure unit of FIG. 9;

FIG. 11 is a configuration diagram of another example of an electrophotographic image forming apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

 2 Light-emitting element 101 Light-emitting body array 102 Position shift means 104 CPU 211 Photoconductor 217 Exposure means (exposure apparatus) E1, E2, E3, E4 Exposure means (exposure apparatus)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Mashimo 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yukio Nagase 3-30-2 Shimomaruko, Ota-ku, Tokyo Non-corporation F term (reference) 2C162 AE02 AE12 AE21 AE28 AE47 AE50 AF13 AF19 FA04 FA17 FA19 FA45 3K007 AB00 AB17 AB18 BB05 CA01 CA06 CB01 DA00 DB03 EB00 FA01

Claims (9)

[Claims] 1. An exposure apparatus, wherein a plurality of light emitting elements are arranged in a row to form a light emitting array, the light emitting array is driven in accordance with input data, and the medium is exposed by the light emission. An exposure apparatus comprising: a position shift unit that shifts a position of a body array by a predetermined amount in a direction along a row of light emitting elements. 2. The exposure apparatus according to claim 1, wherein the shift amount is set to be smaller than the arrangement pitch of the light emitting elements. 3. The exposure apparatus according to claim 1, wherein the luminous body array and the image forming means are integrated, and both are simultaneously shifted. 4. The exposure apparatus according to claim 1, wherein at least the light emitting array repeats shift and return. 5. The exposure apparatus according to claim 1, wherein the exposure is performed according to a shift timing. 6. The exposure apparatus according to claim 1, wherein image data is sequentially read according to shift timing. 7. The exposure apparatus according to claim 1, wherein image data separated and extracted according to a shift amount is stored in a memory. 8. The light-emitting device according to claim 1, wherein the substrate comprises at least an anode layer and a cathode layer, and one or more organic compound layers sandwiched therebetween. 3. The exposure apparatus according to claim 1. 9. An image forming apparatus comprising at least the exposure apparatus according to claim 1 and a photoconductor exposed by the exposure apparatus.