JP2002234207A - Exposing unit and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposing unit and an imaging apparatus in which the quantity of light emitted from a light emitting element can be utilized efficiently. SOLUTION: The exposing unit comprises an organic LED 2 disposed at one end of a light guide tube 1 and emitting light depending on desired image information. Light 3 emitted from the organic LED 2 is transmitted through the light guide tube 1 while being reflected or not reflected on the inner surface thereof and guided onto a photosensitive body 10 where the light 3 exposes the surface of the photosensitive body 10 to produce a desired electrostatic latent image. Since the light can be transmitted through the light guide tube 1 efficiently, the quantity of light emitted from the organic LED 2 can be utilized efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for emitting light, and more particularly to an exposure apparatus used as an optical printer head and applied to an electrophotographic image forming apparatus such as a copying machine or a printer. .

[0002]

2. Description of the Related Art Heretofore, as an exposure device for writing a latent image on a photosensitive member of an image forming apparatus, for example, an LED array system has been used.

[0003]

However, in the case of the LED array system as described above, a rod lens array is necessary to form an image on a photoreceptor, but the rod lens array has low light incidence efficiency, The light emitted from the light emitting element cannot be used efficiently. Therefore, in order to obtain a required amount of light on the photoreceptor, the light emitting element must emit more light than necessary.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide an exposure apparatus and an image forming apparatus which can efficiently use the amount of light emitted from a light emitting element. It is in.

[0005]

In order to achieve the above object, an exposure apparatus according to the present invention comprises: a light emitting element which emits light;
A light guide tube for introducing light of the light emitting element to one end and emitting light transmitted from the other end.

The light guide tube is preferably hollow.

The light emitting element and the light guide tube are in a one-to-one correspondence.
It is preferable to provide a plurality of them in correspondence.

Preferably, the light guide tube has a light shielding property.

It is preferable that the light guide tube is formed of a member having a light shielding property.

[0010] The light emitting element is preferably an organic LED.

[0011] It is preferable that a light condensing means for condensing light emitted from the other end of the light guide tube is provided.

It is preferable that the other end of the light guide tube is arranged close to a portion to be exposed.

In the image forming apparatus according to the present invention, the above-described exposure apparatus, a photoconductor exposed by the exposure apparatus,
It is characterized by having.

Therefore, by using the light guide tube,
Since light can be efficiently transmitted inside the light guide tube, the amount of light emitted by the light emitting element can be used efficiently.

Further, by condensing the light emitted from the other end of the light guide tube by the light condensing means, the diffusion of the emitted light can be prevented, and the amount of light emitted from the light emitting element can be used efficiently.

[0016]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The materials, shapes, relative arrangements, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

(First Embodiment) A first embodiment will be described with reference to FIGS. FIG. 1 is a schematic sectional view showing a single exposure apparatus according to the first embodiment. FIG. 2 is a schematic sectional view showing the image forming apparatus according to the first embodiment. FIG. 3 is a perspective view showing an organic LED used in the single exposure apparatus according to the first embodiment.

First, an image forming apparatus to which the exposure apparatus according to the first embodiment is applied will be described with reference to FIG.

FIG. 2 shows a rotary drum type electrophotographic photosensitive member 10 as an image carrier in the center. Around the photoconductor 10, a charging unit 11, an exposure device 12, a developing unit 13, a transfer unit 14, and a cleaning unit 15 are provided. Photoconductor 10, charging means 11, exposure apparatus 1
2. The developing means 13 and the cleaning means 15 are integrally formed into a detachable cartridge to form a process cartridge 16. Further, a fixing unit 17 is provided downstream of the sheet S in the conveying direction.

In the image forming operation, first, the photosensitive member 10
Is uniformly charged by the charging means 11. This photoconductor 1
0 rotates clockwise in the figure, and exposure is performed by light emitted by the exposure device 12 in accordance with a time-series electric digital pixel signal of target image information output to the charged surface of the photoconductor 10. An electrostatic latent image corresponding to the target image information is formed on the peripheral surface of the body 10.

The electrostatic latent image is developed as a toner image by the developing means 13 as the photoreceptor 10 rotates.

On the other hand, a sheet S is supplied from a supply unit (not shown), and the sheet S is conveyed at a predetermined timing to a nip portion between the photoreceptor 10 and the transfer means 14, and a transfer bias voltage is applied to the photoreceptor 10 The toner image formed on the sheet S
Transfer to

The sheet S to which the toner image has been transferred is separated from the surface of the photoreceptor 10 and is conveyed to the fixing means 17, where the toner is fused and fixed by heating and pressing by the fixing means 17, so that the toner image is fixed. Is discharged to the outside of the apparatus.

Here, the surface of the photoreceptor 10 after the transfer of the toner image to the sheet S is cleaned by removing the adhered contaminants such as the residual toner by the cleaning means 15, and is subjected to the image formation again. You.

Next, a single exposure apparatus according to the present embodiment used as the exposure apparatus 12 will be described with reference to FIG.

In FIG. 1, the single exposure apparatus includes a light guide tube 1, an organic LED 2 as a light emitting element, and a driving driver D for emitting the organic LED 2. Reference numeral 3 denotes emitted light emitted from the light guide tube 1.

The light guide tube 1 has an organic LED 2 disposed at one end. Light from the organic LED 2 is introduced from one end, and light transmitted inside the light guide tube 1 is emitted from the other end.

The other end of the light guide tube 1 is arranged close to the surface of the photoreceptor 10 as a portion to be exposed, so that the emitted light reaches the surface of the photoreceptor 10 without being diffused.
The amount of light emitted from the organic LED 2 can be used efficiently.

The light guide tube 1 has a hollow cylindrical shape with both ends opened, and is formed of a member having a light-blocking property such as metal or resin. Has a light-shielding property for preventing leakage to the outside.

As shown in FIG. 3, the organic LED 2 has a translucent reflective layer 32 and a transparent anode layer 3 on a substrate 31.
3, an organic compound layer 36 composed of a hole transport layer 34 and an electron transport layer 35, and a cathode layer 37 are sequentially stacked, and a DC voltage is applied with the anode layer 33 being plus and the cathode layer 37 being minus. Thus, the anode layer 33 and the cathode layer 3
Light is emitted from the portion where 7 intersects toward the surface or side surface of the cathode layer 37.

The translucent reflection layer 32 is not particularly limited as long as it can increase or decrease the reflection transmittance at a specific wavelength. For example, a plurality of layers having different refractive indices depending on the material, thickness and the like are used. Loaded ones are preferred. As a material for forming the translucent reflective layer 32, for example, SiO ₂ ,
TiO _{2 and the} like.

The organic compound layer 36 may have a single-layer structure or a multi-layer structure.
A hole transport layer 34 into which holes are injected from the anode layer 33, and an electron transport layer 35 into which electrons are injected from the cathode layer 37. One of the hole transport layer 34 and the electron transport layer 35 serves as a light emitting layer. Become. Further, a light emitting layer containing a fluorescent material may be provided between the hole transport layer 34 and the electron transport layer 35. Also,
A configuration in which the hole transport layer 34, the electron transport layer 35, and the light emitting layer also serve as a mixed single layer configuration may be employed. The material of the organic compound layer 36 is
It is desirable to select a material that emits light in a spectrum that is sensitive to the photosensitive material of the photosensitive member 10 used.

As a material of the anode layer 33, a material having a large work function is desirable, and for example, ITO, tin oxide, gold, platinum, palladium, selenium, iridium, copper iodide and the like can be used.

The material of the cathode layer 37 is desirably a material having a small work function, for example, Mg / Ag, Mg, A
l, Li, In, or an alloy thereof can be used.

A driver D is connected to the organic LED 2. The driver D adds an anode layer 33 and a cathode layer 3.
A DC voltage having a negative value of 7 is applied.

In the single exposure apparatus having the above configuration, the organic LED 2 disposed at one end of the light guide tube 1 emits light corresponding to desired image information. The light 3 emitted by the organic LED 2 is reflected on the inner surface of the light guide tube 1 or directly transmitted through the inside of the light guide tube 1 without being reflected on the inner surface of the light guide tube 1, and is guided onto the photoconductor 10 to be exposed to light. By exposing the surface of the body 10, a desired electrostatic latent image can be obtained. As described above, since light can be efficiently transmitted inside the light guide tube 1, the amount of light emitted from the organic LED 2 can be used efficiently.

In the present embodiment, the light guide tube 1 is formed to be hollow inside. However, the present invention is not limited to this, and the light guide member 1 may be filled inside. Further, since the light is reflected inside the light guide tube 1 and transmitted inside the light guide tube 1, the light guide tube 1 may be formed by bending the light guide tube 1 in a curved shape, and the installation space can be effectively used.

In the present embodiment, an organic light emitting device
Although the ED 2 is used, the invention is not limited to this, and any light emitting element having a resolution substantially equal to that of the light guide tube 1 can be used.

(Second Embodiment) In a second embodiment, the photoconductor 1 is added to the single exposure apparatus of the first embodiment.
A converging lens 44 is provided as a converging means at the other end of the light guide tube 41 disposed close to the surface 0.

Since other structures and operations are the same as those of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

FIG. 4 is a schematic sectional view showing a single exposure apparatus having a condenser lens 44 according to the second embodiment. 4, the exposure apparatus includes a light guide tube 41, an organic LED 42 as a light emitting element, a driving driver D for emitting the organic LED 42, and a condenser lens 44.
Reference numeral 43 denotes emitted light.

The light guide tube 41 has an organic LED 42 disposed at one end, and introduces the light of the organic LED 42 from one end.
A condenser lens 44 is disposed at the other end, and the light transmitted inside the light guide tube 1 from the other end is condensed by the condenser lens 44 and emitted. As described above, since the light is condensed and emitted by the condenser lens 44, diffusion of the emitted light can be prevented, and the amount of light emitted from the organic LED 42 can be used efficiently.

The other end of the light guide tube 41 is arranged close to the surface of the photoreceptor 10 as a portion to be exposed, so that the emitted light reaches the surface of the photoreceptor 10 without being diffused. Can be used efficiently.

The light guide tube 41 has a hollow cylindrical shape with both ends opened, and is formed of a member having a light-shielding property such as a metal or a resin. Has a light-shielding property for preventing leakage to the outside.

In the single exposure apparatus having the above structure, the organic LED 42 disposed at one end of the light guide tube 41 emits light corresponding to desired image information. Light 4 emitted by the organic LED 42
3 transmits the inside of the light guide tube 41 by reflecting the inner surface of the light guide tube 41 or directly without reflecting on the inner surface of the light guide tube 41;
The light is guided onto the photoconductor 10 and is appropriately condensed by a condensing lens 44 provided at the other end of the light guide tube 41 on the way. Can be obtained. As described above, since the light can be efficiently transmitted inside the light guide tube 41, the amount of light emitted from the organic LED 42 can be efficiently used.

(Third Embodiment) In a third embodiment, n organic LEDs 521 to 52n and light guide tubes 511 to 51n are provided.
51n are provided in a one-to-one correspondence.

Other structures and operations are the same as those of the first embodiment, so that the same components are denoted by the same reference numerals and description thereof will be omitted.

FIG. 5 is a schematic sectional view showing a multi-exposure apparatus according to the third embodiment. In FIG. 5, an exposure apparatus includes light guide tubes 511 to 51n and an organic LE as a light emitting element.
D521 to 52n, and a driver D for driving the organic LEDs 521 to 52n to emit light. 531-5
3n shows the outgoing light emitted from each light guide tube 511-51n.

The light guide tubes 511 to 51n are provided in a line. Each of the light guide tubes 511 to 51n has an organic LED 521 to 52n disposed at one end. Light from the organic LEDs 521 to 52n is introduced from one end, and light transmitted inside the light guide tubes 511 to 51n is emitted from the other end. I do.

The other ends of the light guide tubes 511 to 51n are arranged close to the surface of the photoconductor 10 as a portion to be exposed, so that the emitted light reaches the surface of the photoconductor 10 without being diffused. The amount of light emitted from the organic LEDs 521 to 52n can be used efficiently.

Each of the light guide tubes 511 to 51n has a hollow cylindrical shape with both ends opened, and is formed of a member having a light-shielding property such as a metal or a resin. It has a light-shielding property for preventing light from leaking to the outside.

A driver D is connected to all of the organic LEDs 521 to 52n.
DC voltages are applied with the anode layer of D521 to 52n being plus and the cathode layer being minus.

The multi-exposure apparatus having the above-described configuration includes the light guide tube 5
Organic LEDs 521 to 52 disposed at one end of 11 to 51n
n is emitted by the driver D in accordance with desired image information. The respective lights 531 to 53n emitted by the organic LEDs 521 to 52n reflect the inner surfaces of the light guide tubes 511 to 51n or directly without being reflected to the inner surfaces of the light guide tubes 511 to 51n. To the photoconductor 1
The surface of the photoreceptor 10 is exposed to light and the desired electrostatic latent image can be obtained. Thus, the light guide tubes 511 to 51
n can efficiently transmit light inside the organic LED 521.
５２52n can be used efficiently.

The light guide tubes 511 to 51n have a light-shielding property, and the light inside the light guide tubes 511 to 51n is not leaked to the outside except for the open ends. Good exposure can be performed without crosstalk in which light leaks into the tubes 511 to 51n.

(Fourth Embodiment) In the fourth embodiment, the photoconductor 10 is added to the multi-exposure apparatus of the third embodiment.
Condensing lenses 641 to 64n are provided as condensing means at the other ends of the light guide tubes 611 to 61n arranged close to the surface.

Other configurations and operations are the same as those of the first embodiment, and therefore, the same components will be denoted by the same reference characters and description thereof will be omitted.

FIG. 6 is a schematic sectional view showing a multi-exposure apparatus having a condenser lens according to the fourth embodiment. In FIG. 6, the exposure apparatus includes light guide tubes 611 to 61n, organic LEDs 621 to 62n as light emitting elements, and organic LEDs 62
A driving driver D for emitting light from 1 to 62n and condensing lenses 641 to 64n. Reference numerals 631 to 63n indicate light beams emitted from the light guide tubes 611 to 61n.

The light guide tubes 611 to 61n are provided in a line. Each of the light guide tubes 611 to 61n is provided with one of the organic LEDs 621 to 62n at one end, the light of the organic LED 621 to 62n is introduced from one end, and the condenser lenses 641 to 64n at the other end. Light guide tube 6 from the end
The light transmitted inside 11-61n is collected by condenser lenses 641-6.
The light is condensed and emitted at 4n. Thus, the condenser lens 64
Since the light is collected and emitted at 1 to 64n, diffusion of the emitted light can be prevented, and the amount of light emitted from the organic LEDs 621 to 62n can be used efficiently.

The other ends of the light guide tubes 611 to 61n are arranged close to the surface of the photoreceptor 10 as a portion to be exposed, and the emitted light reaches the surface of the photoreceptor 10 without being diffused. The amount of light emitted from the organic LEDs 621 to 62n can be used efficiently.

Each of the light guide tubes 611 to 61n has a hollow cylindrical shape having both ends opened, and is formed of a member having a light shielding property such as a metal or a resin. It has a light-shielding property for preventing light from leaking to the outside.

A driver D is connected to all of the organic LEDs 621 to 62n.
DC voltages with the anode layer of D621 to 62n being plus and the cathode layer being minus are applied.

The multi-exposure apparatus having the above-described configuration includes the light guide tube 6
Organic LEDs 621-62 arranged at one end of 11-61n
n is emitted by the driver D in accordance with desired image information. Each light 631-63n emitted from the organic LED 621-62n reflects on the inner surface of the light guide tube 611-61n, or directly inside the light guide tube 611-61n without being reflected on the inner surface of the light guide tube 611-61n. To the photoconductor 1
The light is guided to the top of the photoconductor 10 and is appropriately condensed by condensing lenses 641 to 64n provided at the other ends of the light guide tubes 611 to 61n. Thus, a desired electrostatic latent image can be obtained. in this way,
Since light can be efficiently transmitted inside the light guide tubes 611 to 61n, the amount of light emitted from the organic LEDs 621 to 62n can be used efficiently.

The light guide tubes 611 to 61n have a light-shielding property, and the light inside the light guide tubes 611 to 61n is not leaked to the outside except for the open end portions. Good exposure can be performed without crosstalk in which light leaks into the tubes 611 to 61n.

(Fifth Embodiment) A fifth embodiment is directed to an organic LED in which elements are integrated with a multi-exposure apparatus.
An array was used.

Since other configurations and operations are the same as those of the first embodiment, the same components are denoted by the same reference numerals and description thereof will be omitted.

FIG. 7 shows an organic LE according to the fifth embodiment.
FIG. 2 is a schematic sectional view showing a multi-exposure apparatus using a D array. In FIG. 7, the exposure apparatus includes light guide tubes 711-71.
n, an organic LED array 72 in which organic LED elements 721 to 72n are integrally formed, and organic LED elements 721 to 72
n, a driver D that emits light,
74n. Reference numerals 731 to 73n denote emitted lights emitted from the light guide tubes 711 to 71n.

The light guide tubes 711 to 71n are provided in a line. Each of the light guide tubes 711 to 71n has an organic LED element 721 to 72n disposed at one end, and introduces light of the organic LED element 721 to 72n from one end, and a condenser lens 741 to 74n is disposed at the other end. The light transmitted through the inside of the light guide tubes 711 to 71n from the other end is collected by a condenser lens 7
The light is condensed and emitted at 41 to 74n. In this manner, since the light is condensed and emitted by the condenser lenses 741 to 74n, diffusion of the emitted light can be prevented, and the amount of light emitted from the organic LED elements 721 to 72n can be used efficiently.

The other ends of the light guide tubes 711 to 71n are arranged close to the surface of the photoreceptor 10 as a portion to be exposed, and the emitted light reaches the surface of the photoreceptor 10 without being diffused. The amount of light emitted from the organic LED elements 721 to 72n can be used efficiently.

Each of the light guide tubes 711 to 71n has a hollow cylindrical shape having both ends opened, and is formed of a member having a light shielding property such as a metal or a resin. It has a light-shielding property for preventing light from leaking to the outside.

As shown in FIG. 8, the organic LED array 72 is composed of a substrate 81, a translucent reflective layer 82, an anode layer 83 as a transparent electrode, a hole transport layer 84, and an electron transport layer 85. The compound layer 86 and the cathode layer 87 are sequentially stacked, and the anode layer 83 is provided between the organic LED elements 721 to 72n.
Are not stacked and this section does not emit light.

A driver D is connected to all of the organic LED elements 721 to 72n, and a DC voltage is applied from the driver D so that the anode layer 83 of each of the organic LED elements 721 to 72n is plus and the cathode layer 87 is minus. Is done.

The multi-exposure apparatus having the above-described configuration includes the light guide tube 7
Organic LED elements 721 to 721 arranged at one end of 11 to 71n
The driver 72D emits light corresponding to desired image information. The respective lights 731 to 73n emitted from the organic LED elements 721 to 72n reflect the light guide tubes 711 to 71n or directly without being reflected to the light guide tubes 711 to 71n. Transmits inside 71n,
The light is guided on the photoreceptor 10, and is appropriately condensed by condensing lenses 741 to 74 n provided at the other ends of the light guide tubes 711 to 71 n on the way. Exposure can provide a desired electrostatic latent image. As described above, since the light can be efficiently transmitted inside the light guide tubes 711 to 71n, the amount of light emitted from the organic LED elements 721 to 72n can be used efficiently.

The light guide tubes 711 to 71n have a light shielding property, and the light inside the light guide tubes 711 to 71n is not leaked to the outside except for the opening ends. Good exposure can be performed without crosstalk in which light leaks into the tubes 711 to 71n.

[0074]

As described above, according to the present invention, by using a light guide tube, light can be efficiently transmitted inside the light guide tube, and thus the amount of light emitted from the light emitting element can be used efficiently. When used as a plurality of exposure arrays, good exposure without crosstalk can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an exposure apparatus according to a first embodiment.

FIG. 2 is a schematic configuration diagram illustrating an image forming apparatus according to a first embodiment.

FIG. 3 is a perspective view showing an organic LED according to the first embodiment.

FIG. 4 is a schematic sectional view showing an exposure apparatus according to a second embodiment.

FIG. 5 is a schematic sectional view showing an exposure apparatus according to a third embodiment.

FIG. 6 is a schematic sectional view showing an exposure apparatus according to a fourth embodiment.

FIG. 7 is a schematic sectional view showing an exposure apparatus according to a fifth embodiment.

FIG. 8 is a perspective view showing an organic LED according to a fifth embodiment.

[Explanation of symbols]

1,41,511-51n, 611-61n, 711-
71n light guide tube 2,42,521-52n, 621-62n organic LE
D 3,43,531-53n, 631-63n, 731-
73n Outgoing light 10 Electrophotographic photoreceptor 44, 641 to 64n, 741 to 74n Condensing lens 72 Organic LED array 721 to 72n Organic LED element

Continuing on the front page (72) Inventor Ryozo Yanagisawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Seiji Mashita 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F term (reference) 2C162 AE28 FA04 FA17 FA44 FA48 2H076 AB42 AB60 AB61 5F041 AA14 CA45 CA82 CA88 EE25 FF16

Claims (9)

[Claims] 1. An exposure apparatus comprising: a light emitting element that emits light; and a light guide tube that introduces light from the light emitting element to one end and emits light transmitted from the other end. 2. An exposure apparatus according to claim 1, wherein said light guide tube is hollow. 3. A one-to-one correspondence between the light emitting element and the light guide tube.
The exposure apparatus according to claim 1, wherein a plurality of exposure apparatuses are provided. 4. An exposure apparatus according to claim 1, wherein said light guide tube has a light shielding characteristic. 5. An exposure apparatus according to claim 4, wherein said light guide tube is formed of a member having a light shielding property. 6. The exposure apparatus according to claim 1, wherein the light emitting element is an organic LED. 7. The exposure apparatus according to claim 1, further comprising a light collecting means for collecting light emitted from the other end of the light guide tube. 8. The exposure apparatus according to claim 1, wherein the other end of the light guide tube is arranged close to a portion to be exposed. 9. An image forming apparatus, comprising: the exposure apparatus according to claim 1; and a photoconductor exposed by the exposure apparatus.