JP2002164163A - Organic el writing light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL writing light source device that is made in compact size and made to be reduced in the loss of the quantity of light and, further, made to steadily focus the light of each color on the surface of the sensitive material in the case of a color type. SOLUTION: The organic EL writing light source device 10 is constructed to comprise a transparent substrate 11, plural flat micro lenses 12 that are formed in the positions corresponding to the light emitting dots arranged side by side at a prescribed interval on the surface of one side of the transparent substrate, and plural organic EL elements 13 that are formed respectively on each flat micro lens on the surface of one side of this transparent substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an organic EL writing light source device used as a writing head in, for example, a printer or a digital copier.

[0002]

2. Description of the Related Art Conventionally, such an organic EL writing light source device is configured, for example, as shown in FIG. FIG.
1, the organic EL writing light source device 1 includes an organic EL array 2 as a light source, and a lens array 3 disposed below the organic EL array 2.

The organic EL array 2 has a known structure, and as shown in FIG. 13, a plurality of organic EL elements as light emitting dots formed at predetermined intervals in a longitudinal direction on a transparent substrate 2a. And an EL element 2b.

The lens array 3 includes a plurality of refractive index distribution type lenses 3a arranged at a predetermined interval in the longitudinal direction so as to oppose each EL layer 2b as a light emitting dot of the organic EL array 2, for example, It is composed of a lens array that is commercially available under the name Selfoc lens.

[0005] The organic EL writing light source device 1 having such a configuration.
According to the above, each organic EL element 2b of the organic EL array 2
By being driven and controlled by a drive circuit (not shown),
Emit light appropriately. Then, the diffused light emitted from the organic EL element 2b is focused by the corresponding gradient index lens 3a of the lens array 3 and forms an image on the surface of the photosensitive material 4 located thereunder, thereby forming the photosensitive material 4 Is exposed to light.

[0006]

However, in the organic EL writing light source device 1 having such a structure, the focal length of each of the gradient index lenses 3a of the lens array 3 is determined. Organic E to match
Since the L array 2 and the photosensitive material 4 are disposed, the distance from the organic EL array 2 to the photosensitive material 4 cannot be set appropriately. Therefore, the organic EL writing light source device 1
In this case, miniaturization of various devices in which the device is incorporated, such as a printer, a digital copier, and a facsimile machine, is hindered.

Further, the gradient index lens 3a has a large loss of light quantity, and each of the gradient index lenses 3
The light passing through a becomes less than 10% of the light emitted from each organic EL element 2b of the organic EL array 2.

Further, in the case of the color type, for example, R (red), G (green) and B
The three colors of light (blue) are focused on the surface of the photosensitive material 4 via the lens array 3, respectively. The focal length of each of the gradient index lenses 3a of the lens array 3 is determined by the wavelength of the light. It is practically difficult to accurately focus the light of each color on the surface of the photosensitive material 4 when considering the mounting structure, and the exposed portion of the surface of the photosensitive material 4 is widened depending on the color. And the resolution is reduced.

In view of the above, the present invention provides an organic light emitting device which can be made compact, reduces the loss of light amount, and in the case of a color system, surely focuses light of each color on the surface of a photosensitive material. An object of the present invention is to provide an EL writing light source device.

[0010]

According to a first aspect of the present invention, there is provided a transparent substrate and, on a surface on one side of the transparent substrate, positions corresponding to light emitting dots arranged at predetermined intervals. And a plurality of organic EL elements formed on each of the flat microlenses on one side surface of the transparent substrate. This is achieved by the organic EL writing light source device.

In the first aspect, when each organic EL element is driven, light emitted from each organic EL element is focused by the corresponding flat microlens on the transparent substrate, and is distributed to the other side of the transparent substrate. An image is formed on the surface of the provided photosensitive material. As a result, light from each organic EL element as a light emitting dot is irradiated on the surface of the photosensitive material, so that a latent image is formed on the surface of the photosensitive material by exposure to light.

In this case, the light from each organic EL element is focused by a flat microlens formed on the surface of a transparent substrate constituting the organic EL array and forms an image on the surface of a photosensitive material. A lens array including a gradient index lens is not required. Therefore, by appropriately setting the focal length of the flat microlens, the distance from the organic EL element to the photosensitive material can be adjusted to a desired distance, and particularly shortened. This facilitates downsizing of the organic EL writing light source device, and facilitates downsizing of various devices incorporating such an organic EL writing light source device, such as a printer, a digital copier, and a facsimile device. Also, since no gradient index lens is used,
The loss of the amount of light emitted from the organic EL element to the photosensitive material is reduced, and the amount of light emitted from the organic EL element can be used efficiently. Therefore, in order to obtain the same amount of photosensitive light, the amount of light emitted from the organic EL element can be reduced or the photosensitive time can be shortened.

The organic EL writing light source device according to a second aspect of the present invention is the organic EL writing light source device according to the first aspect, wherein each flat microlens corresponds to the corresponding organic EL.
The light emitted from the element is configured to be focused near the surface on the other side of the transparent substrate.

In the second aspect, the light emitted from each organic EL element is focused near the surface on the other side of the transparent substrate by the corresponding flat microlens, so that the photosensitive material is condensed on the other side of the transparent substrate. The photosensitive material can be exposed in a state where the photosensitive material is in contact with the surface. As a result, the height of the organic EL writing light source device from the surface of the photosensitive material is further reduced, so that downsizing of the organic EL writing light source device and various devices incorporating the same is further promoted.

The organic EL writing light source device according to a third aspect of the present invention is the organic EL writing light source device according to the first or second aspect, wherein the organic EL element has a plurality of types of emission colors different from each other. It is composed of an organic EL element.

In the third embodiment, a latent image such as a color image can be formed on the photosensitive material by emitting light of each emission color from the organic EL element.

An organic EL writing light source device according to a fourth aspect of the present invention is the organic EL writing light source device according to any one of the first to third aspects, wherein each of the organic EL elements has a different emission color. A color filter is provided between the organic EL element and the transparent substrate.

In the fourth aspect, the light emitted from each organic EL element passes through a color filter before being incident on the transparent substrate, so that the color is corrected. Therefore,
Light of each emission color can be obtained by using the same emission color, for example, a white organic EL element as the organic EL element of each emission color, and correcting the color by a color filter. Further, only light having a wavelength of a necessary component from light emitted from the organic EL of each color can be transmitted.

The organic EL writing light source device according to a fifth aspect of the present invention is the organic EL writing light source device according to any one of the first to third aspects, wherein each of the organic EL elements has a different emission color. A color filter is provided on the other surface of the transparent substrate corresponding to the organic EL element.

In the fifth aspect, the light emitted from each organic EL element is transmitted through the transparent substrate and then through the color filter, so that the color is corrected. Therefore,
Light of each emission color can be obtained by using the same emission color, for example, a white organic EL element as the organic EL element of each emission color, and correcting the color by a color filter. Further, only light having a wavelength of a necessary component from light emitted from the organic EL of each color can be transmitted.

An organic EL writing light source device according to a sixth aspect of the present invention is the organic EL writing light source device according to any one of the third and fourth aspects, and corresponds to an organic EL element of each emission color. The flat microlenses are configured to have the same focal length with respect to light of each emission color from the organic EL element.

In the sixth aspect, since the focal lengths of the flat microlenses with respect to the light of each emission color are set to be the same, the light of each emission color is focused on the surface of the photosensitive material. Therefore, there is no possibility that the resolution is reduced by the color.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS.
The embodiment described below is a preferred specific example of the present invention, and thus various technically preferable limitations are added. However, the scope of the present invention particularly limits the present invention in the following description. The embodiment is not limited to these embodiments unless otherwise stated.

FIGS. 1 and 2 show the configuration of an embodiment of the organic EL writing light source device according to the present invention. In FIG. 1, an organic EL writing light source device 10 is a monochrome organic EL writing light source device, and is disposed at a position corresponding to a transparent substrate 11 and light emitting dots arranged at predetermined intervals on the upper surface of the transparent substrate 11. A flat microlens array 12 composed of a plurality of flat microlenses 12a formed respectively, and a plurality of organic EL elements 13 formed on each flat microlens 12a on the upper surface of the transparent substrate 11. Have been.

The transparent substrate 11 is composed of a flat glass substrate or the like. The above flat microlens array 1
2 is provided on the upper surface of the transparent substrate
It is formed by a production method utilizing ion exchange disclosed in US Pat. Here, each flat microlens 12 a converges light emitted from the corresponding organic EL element 13, forms an image on the surface of the photosensitive material 20 located below the transparent substrate 11, and forms an adjacent image on the photosensitive material 20. It is configured so that light does not enter the dots to be formed.

The photosensitive material 20 is obtained by applying a photosensitive material to the surface of a sheet-like base member such as a film or photographic paper.

FIG. 3 shows a specific configuration example of the flat microlens 12a. In FIG. 3, the flat microlens 12a has a three-layered structure that is formed in a concave shape with the light-emitting dot as the center, and the transparent substrate 1
The first layer 12b includes a first layer 12b, a second layer 12c, and a third layer 12d sequentially from the top surface. The first layer 12b has, for example, a refractive index n1 = 4, a radius of curvature r1 = 10, and a diameter φ1 = 1.
0 (mm). The second layer 12c has, for example, a refractive index n2 = 3, a radius of curvature r2 = 10, and a diameter φ2 = 12 (m
m). Further, the third layer 12d has, for example, a refractive index n
3 = 2, radius of curvature r3 = 10, diameter φ3 = 15 (mm)
It is. Here, the transparent substrate 11 has a refractive index n0 = 1.
5, the thickness G = 8 mm, and the organic EL element 13 is set to have a diameter of 6 mm.

The flat plate microlens 12 having such a configuration
When light from the organic EL element 13 is incident on a,
As shown in FIG. 3, the light is focused near the lower surface of the transparent substrate 11. Thus, high-resolution exposure is performed on the photosensitive material 20 that is in close contact with the lower surface of the transparent substrate 11 at a distance d = 0. In FIG. 3, the incident light to the flat microlenses 12a is shown as parallel light, but it is actually an organic EL.
Light emitted from the element 13 is diffused light.

The organic EL writing light source device 10 according to the present invention
Is configured as described above, and its operation will be described below. As shown in FIG. 4, the organic EL writing light source device 10 is incorporated in various devices, for example, a printer, a digital copier, a facsimile device, or the like, and is arranged to face a transport roller 21 for transporting the photosensitive material 20. Is established.
Then, the photosensitive material 20 is transported by the transport roller 21 at a predetermined speed while the surface thereof is in close contact with the lower surface of the transparent substrate 11 of the organic EL writing light source device 10. At this time, each organic EL element 13 of the organic EL writing light source device 10 is appropriately driven and controlled by a drive circuit (not shown),
The light emitted from each organic EL element 13 is converged near the lower surface of the transparent substrate 11 by the corresponding flat microlens 12a, and forms an image on the surface of the photosensitive material 20 which is in close contact with the lower surface of the transparent substrate 11. Thereby, the organic EL
The light emitting dots defined by the element 13 emit light, and the photosensitive material 20
Exposure is performed at the corresponding dot position on the surface of.

In this manner, while the photosensitive material 20 is being conveyed by the conveying rollers 21 in the direction indicated by the arrow in FIG.
When the organic EL elements 13 of the organic EL writing light source device 10 are driven and controlled, the organic EL elements 13 arranged substantially in a line on the surface of the photosensitive material 20 prevent each dot spread over the entire surface. The latent image is formed by selectively performing the exposure. Then, by developing the photosensitive material 20, the latent image is fixed, and a dot matrix type image is formed.

In this case, the light emitted from each organic EL element 13 is converged by the corresponding flat microlens 12a, so that the surface of the photosensitive material 20 exhibits the energy distribution by the simulation shown in FIG. And converge within a range of about 8 mm in diameter,
High resolution will be obtained. On the other hand, when there is no flat microlens 12a, the energy distribution by the simulation shown in FIG. 6 is exhibited, and when the flat microlens 12a is present (see FIG. 5).
It can be seen that it is diffused over a wider range as compared with.

Further, in the organic EL writing light source device 10, since a refractive index distribution type lens is not used in order to converge the light emitted from each organic EL element 13, a light quantity loss is reduced. As a result, the amount of photosensitive light on the surface of the photosensitive material 20 increases. As a result, in order to obtain the same amount of photosensitive light, the amount of light emitted from the organic EL element 13 can be reduced, and the cost can be reduced.

FIGS. 7 to 9 show a second embodiment of the organic EL writing light source device according to the present invention. In FIG. 7, an organic EL writing light source device 30 is a color organic EL device.
A writing light source device, comprising: a transparent substrate 31;
A flat microlens array 32 composed of a plurality of flat microlenses 32a formed respectively at positions corresponding to light emitting dots arranged at predetermined intervals for each of the luminescent colors R, G, and B, A plurality of organic EL elements 33 formed on each flat microlens 32a on the upper surface of the substrate 31, and a color filter 34 disposed on the lower surface of the transparent substrate 31 so as to face each flat microlens 32a.
And is composed of

As shown in FIG. 7, the flat plate microlens array 32 of the organic EL writing light source device 10 shown in FIG. 1 and FIG. It is configured similarly to.

As shown in FIG. 8, the color filter 34 includes a red filter 34r, a green filter 34g, and a blue filter 34 corresponding to each of the emission colors R, G, and B, respectively.
b. The color filter 34
Removes unnecessary frequency components from the light (see FIG. 10A) emitted from the organic EL element 33 corresponding to the emission dots of each of the emission colors R, G, and B, as shown in FIG. Thus, only necessary frequency components (see FIG. 10B) are transmitted. Thus, the light emitted from each organic EL element 33 is colored when passing through the corresponding color filter 34, and is configured to have a predetermined emission color.

According to the organic EL writing light source device 30 according to the second embodiment, similarly to the organic EL writing light source device 10 shown in FIG. 1 and FIG. The light emitted from each organic EL element 33 is appropriately controlled and driven by the circuit so that the light emitted from each organic EL element 33 corresponds to the flat microlens array 32r of the corresponding emission color R, G, B.
By 32g and 32b, the light is focused near the lower surface of the transparent substrate 31 and is transmitted through the color filters 34r, 34g and 34b, respectively, and is colored red, green and blue, respectively, and forms an image on the surface of the photosensitive material 20. As a result, light-emitting dots of each light-emitting color defined by the organic EL element 33 emit light, and exposure is performed at a corresponding dot position on the surface of the photosensitive material 20. In this manner, the photosensitive material 20 is selectively conveyed by the organic EL elements 33 at each dot position of the photosensitive material 20 while being conveyed by the conveying roller, so that the color latent image is formed on the entire surface of the photosensitive material 20. Is formed, and the subsequent development forms a dot matrix type color image.

FIG. 11 shows a third embodiment of the organic EL writing light source device according to the present invention. In FIG.
The organic EL writing light source device 40 has substantially the same configuration as the color type organic EL writing light source device 30 shown in FIG. 7, and the same components as those of the organic EL writing light source device 30 are denoted by the same reference numerals. Therefore, the description is omitted. Organic EL writing light source device 4
0, a color filter 41 disposed between the organic EL element 33 and the surface of the transparent substrate 31 instead of the color filter 34, that is, a red filter 41r and a green filter 41.
g, blue filter 41b.

Further, the flat microlens array 32 formed on the surface of the transparent substrate 31 is arranged such that the flat microlens arrays 32r, 32g, and 32b of the respective emission colors respectively transmit red light, green light, and blue light, respectively. It is configured so that it is focused near the lower surface of 31, that is, the focal length is the same for each emission color.
The adjustment of the focal length is performed, for example, by the layers 12b, 12c, and 12d constituting the flat microlens 12a shown in FIG.
By appropriately setting the curvature radii r1 to r3, the refractive indices n1 to n3, and the thickness G of the transparent substrate.

The organic EL writing light source device 4 having such a configuration
According to 0, the light emitted from each organic EL element 33 is colored by a color filter 41 and then focused by the corresponding flat plate microlens arrays 32r, 32g, 32b to form a light near the lower surface of the transparent substrate 31. Image and transparent substrate 3
1 forms an image on the surface of the photosensitive material 20 which is in close contact with the lower surface of the photosensitive material 20. At this time, the flat microlens array 32 corresponding to each emission color
r, 32g, 32b each flat micro lens 32a,
Since the focal length shift due to the color is corrected so that the same focal length is obtained for the light of the corresponding color, the light of each emission color can be accurately transferred to the photosensitive material 20 which is in close contact with the lower surface of the transparent substrate 31. And the resolution of each emission color is improved.

In the above embodiment, the photosensitive material 20
Are disposed in close contact with the lower surfaces of the transparent substrates 11 and 31, thereby providing the organic EL writing light source devices 10, 30 and 4.
Although the height of 0 is suppressed, the present invention is not limited to this, and the photosensitive material 20 may be disposed at a position at a predetermined distance from the lower surfaces of the transparent substrates 11 and 31 and may be conveyed. Is clear. In the embodiment described above,
The case where three colors of R, G, and B are used as the emission colors has been described. However, the present invention is not limited to this, and three colors of yellow Y, magenta M, and cyan C, four colors obtained by adding black and white to these, and furthermore, It is apparent that the present invention can be applied to a plurality of different emission colors such as adding high brightness and low brightness to each color.

[0041]

As described above, according to the present invention, light from each organic EL element is focused by the flat microlenses formed on the surface of the transparent substrate constituting the organic EL array, and the light from the photosensitive material is Since an image is formed on the surface, a conventional lens array including a gradient index lens is unnecessary.
Therefore, by appropriately setting the focal length of the flat microlens, the distance from the organic EL element to the photosensitive material can be adjusted to a desired distance, and particularly shortened. This facilitates downsizing of the organic EL writing light source device, and facilitates downsizing of various devices incorporating such an organic EL writing light source device, such as a printer, a digital copier, and a facsimile device.

Further, since no refractive index distribution type lens is used, the loss of the amount of light emitted from the organic EL element to the photosensitive material is reduced, and the light emission amount of the organic EL element is used efficiently. obtain. Therefore, in order to obtain the same amount of photosensitive light, the amount of light emitted from the organic EL element can be reduced. Furthermore, in the case of the color type, since the focal lengths of the flat microlenses for the light of each emission color are set to be equal to each other, the light of each emission color is focused on the surface of the photosensitive material. An image is formed, and the color does not cause a reduction in resolution.

As described above, according to the present invention, it is possible to reduce the amount of light and reduce the light quantity loss.
Further, in the case of the color system, an extremely excellent organic EL writing light source device in which light of each color is surely focused on the photosensitive material surface can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a part of a configuration of an embodiment of an organic EL writing light source device according to the present invention.

FIG. 2 is a partial cross-sectional view showing a region for one dot in the organic EL writing light source device of FIG.

FIG. 3 is a sectional view showing a specific configuration example of the flat microlens of FIG. 2;

FIG. 4 is a schematic cross-sectional view in a lateral direction showing a use state of the organic EL writing light source device of FIG. 1;

FIG. 5 is a diagram showing a simulation of an energy distribution on a photoconductor for one dot of the organic EL writing light source device of FIG. 1;

FIG. 6 shows the organic E of FIG. 1 without a flat microlens;
FIG. 4 is a diagram illustrating an energy distribution for one dot of the L writing light source device with respect to the photoconductor;

FIG. 7 is a schematic plan view showing a part of the configuration of an organic EL writing light source device according to a second embodiment of the present invention.

8 is a horizontal partial cross-sectional view showing dots of each emission color in the organic EL writing light source device of FIG. 7;

9 is a partial cross-sectional view showing a region for one dot in the organic EL writing light source device of FIG. 7;

10 is a graph showing wavelength characteristics of light before (A) transmission and after (B) transmission of a color filter in the organic EL writing light source device of FIG. 7;

FIG. 11 is a partial cross-sectional view similar to FIG. 9, showing a part of the configuration of an organic EL writing light source device according to a third embodiment of the present invention.

FIG. 12 is a schematic perspective view showing a configuration of an example of a conventional organic EL writing light source device.

13 is a partial cross-sectional view of the organic EL writing light source device of FIG.

[Explanation of symbols]

 1,10,30,40 Organic EL writing light source device 2 Organic EL array 3 Lens array 4,20 Photosensitive material 11,31 Transparent substrate 12,32 Flat plate micro lens array 12a, 32a Flat plate micro lens 13,33 Organic EL element 21 Transport rollers 34, 41 color filter

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H05B 33/14

Claims (6)

[Claims] 1. A transparent substrate, a plurality of microlenses formed on one surface of the transparent substrate at positions corresponding to light emitting dots arranged at a predetermined interval, and a surface on one side of the transparent substrate. 3. An organic EL writing light source device comprising: a plurality of organic EL elements formed on each flat microlens. 2. The method according to claim 1, wherein each flat microlens is configured to focus light emitted from the corresponding organic EL element near a surface on the other side of the transparent substrate. The organic EL writing light source device as described in the above. 3. The organic EL writing light source device according to claim 1, wherein the organic EL element is composed of a plurality of types of organic EL elements of different emission colors. 4. A color filter is provided between the organic EL element and the transparent substrate so that each of the organic EL elements has a different emission color from each other. The organic EL writing light source device according to any one of the above. 5. A color filter is provided on the other surface of the transparent substrate corresponding to the organic EL element so that each of the organic EL elements has a different emission color. Item 4. The organic EL writing light source device according to any one of Items 1 to 3. 6. A flat microlens corresponding to an organic EL element of each emission color is configured to have the same focal length with respect to light of each emission color from the organic EL element. The organic EL writing light source device according to claim 3, wherein: