JP2000052591A - Organic el print head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small and lightweight print head suitable for full-color indication in which power consumption is reduced and optical output is stabilized. SOLUTION: An organic EL element comprises a transparent anode 22 of ITO, an insulating layer 24, a hole implantation transport layer 25 of TPD, a light emission layer 26 of Alq3, and a cathode 27 laminated sequentially on a substrate 21. The light emission layer is sectioned into emission dots 23 by means of holes made in the insulating layer 24 and emits white light including the range of 450-650 nm. Three primary color images of RGB are obtained from the white light b switching color filters R, G, B and a full-color image is formed by exposing it while superposing on a film. As compared with conventional fluorescent light emitting tube, power consumption, thickness and weight of the device are reduced. Furthermore, fluctuation in the emission characteristics is suppressed and the quantity of light is not required to be corrected for every dot.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic EL device for forming a color image using an organic EL device capable of emitting white light.
Regarding the print head.

[0002]

2. Description of the Related Art As a light source of a self-coloring type color printer, a light source using a fluorescent light emitting tube is known. An example of a structure of such a fluorescent light emitting tube for a color print head will be described. The anode light emitting part is R (red), G (green), B
It is divided into three types of light-emitting blocks (blue), and each of the blocks emits ZnO: Zn phosphor. Each block has a structure in which a number of light emitting dots are arranged in parallel at a predetermined pitch. An R (red), G (green), and B (blue) color filter is provided for each block, and is configured to extract red, green, and blue dot-shaped lights, respectively. The dot light of each color is irradiated onto the recording medium in a superimposed manner, and a full-color image (latent image) is formed on the recording medium.

[0003]

A conventional optical print head using a fluorescent arc tube has the following problems. 1) A large amount of energy is consumed in addition to the energy consumed for light emission of the phosphor. That is, the reactive current flows through the hot cathode, the grid, and the like, and energy not directly involved in light emission is consumed, so that the entire power consumption is large.

[0004] 2) The fluorescent light emitting tube is also a kind of a vacuum tube in which various electrodes are housed inside an envelope whose inside is in a high vacuum state. Therefore, a substrate constituting the envelope to ensure a withstand voltage. Cannot be made thinner. Therefore, the weight cannot be reduced.

[0005] 3) A member for supporting the hot cathode is required, and a place for installing the member is required in the envelope. This location is a dead space that does not contribute to light emission, and thus it is difficult to reduce the size of the print head itself.

4) The ZnO: Zn phosphor is apt to change its state on the extreme surface (a range close to the light emitting surface) under the influence of process conditions, gas in the tube, etc., and consequently the light output tends to fluctuate. Therefore, a complicated correction operation for keeping the light output constant must be performed by means such as drive control, which is complicated.

5) ZnO: Zn phosphor has an emission wavelength of 600
Since there is little red component of nm or more and poor matching with the photosensitive agent, red coloring is insufficient. For this reason, there is a case where a head using a red light emitting phosphor is provided in the same device in addition to a head using a red light emitting phosphor in addition to a head using a ZnO: Zn phosphor. This increases the size of the device and increases the manufacturing cost.

SUMMARY OF THE INVENTION An object of the present invention is to provide a print head which consumes less power, is small in size and light in weight, has stable light output, and is suitable for full-color display.

[0009]

According to the present invention, there is provided an organic EL print head (4), wherein at least one of the light-emitting layers (26) is provided between a pair of electrodes (anode 22 and cathode 27) having translucency. ) Comprising an organic EL element (2) for selectively irradiating dot-shaped light obtained by light emission of the light-emitting layer onto a recording medium to form an image.
In the L print head, an emission spectrum of the organic EL element includes a range of 450 nm to 650 nm.

According to a second aspect of the present invention, there is provided the organic EL print head according to the first aspect, wherein the organic EL element is formed of a tris (8- It has a light emitting layer (26) made of (hydroxyquinoline) aluminum.

According to a third aspect of the present invention, there is provided the organic EL print head according to the first aspect, wherein the organic EL element is formed by doping a host material with a dye. It is characterized by having a plurality of layers (36, 37).

An organic EL print head according to a fourth aspect of the present invention is the organic EL print head according to the third aspect, wherein the tris (8-hydroxyquinoline) aluminum shown in the above (Chemical Formula 1) is added to the (Chemical Formula 2). )) And a first light-emitting layer (yellow light-emitting layer 37) doped with rubrene and Al ₂ O (OXZ) ₄ shown in (Chem. 3).
The second light emitting layer (blue light emitting layer 3) doped with TBA shown in FIG.
6).

An organic EL print head according to a fifth aspect of the present invention is the organic EL print head according to the first aspect, wherein the organic EL element (40) is the same as the chemical formula (5).
Luminescent hole transport layer made of TPD shown in (43)
An organic layer (44) made of p-EtTAZ shown in the above (Chem. 6), a luminescent electron transport layer (45) made of tris (8-hydroxyquinoline) aluminum shown in the above (Chem. 1), A light emitting layer (46) made of Nile Red shown in the above (Chemical Formula 7) provided in the middle of an electron transporting layer (45) made of tris (8-hydroxyquinoline) aluminum.

According to a sixth aspect of the present invention, there is provided an organic EL print head according to the first aspect, wherein the organic EL element has a light emitting layer in which a dye is dispersed in a polymer organic substance. (53).

According to a seventh aspect of the present invention, there is provided the organic EL print head according to the sixth aspect, wherein the polymer organic substance is polyvinyl carbazole (PVK) represented by the above formula (8). It is characterized by having.

According to an eighth aspect of the present invention, there is provided the organic EL print head according to the first aspect, wherein the organic EL element comprises a ZnBTZ complex represented by the following chemical formula (9). It is characterized by having a layer (64).

According to a ninth aspect of the present invention, there is provided an organic EL print head according to the first aspect, wherein the hole injection transport layer is made of a material having a transmittance of 70% or more to visible light. 25).

According to a tenth aspect of the present invention, there is provided the organic EL print head according to the first aspect, wherein three colors of red, green and blue are provided outside the organic EL element. Filters (R, G, B)
The color filter switching means is provided, and the type of the color filter through which the dot-shaped light passes can be arbitrarily selected.

According to an eleventh aspect of the present invention, in the organic EL print head according to the first aspect, the recording medium (color film 3) is identical to the recording medium (color film 3) in accordance with image signals of red, green and blue. Controlling the organic EL element (2) so that the red, green, and blue images overlap each other at the position;
A full-color image is formed on the recording medium by performing multiple exposure.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An organic EL print head of the present invention using an organic EL element as a light source and an organic EL printer equipped with the organic EL print head will be described. (1) First Example The organic EL printer 1 shown in FIG.
The light of three primary colors obtained from the L element 2 and the color filters R, G, and B which can be switched is used to write on a color film 3 as a recording medium to form a full-color image.

In order to extract three primary colors by the color filters RGB, the emission color of the organic EL element 2 is white or a color close thereto, or at least the emission spectrum includes a range of 450 nm to 650 nm.

The organic EL printer 1 is driven by a digital color image signal obtained from a video device or the like, and is used as a color video printer for printing an image on a color film 3 in full color. In addition, it can be used for an electrophotographic printer, a silver halide printer, a label printer, and the like.

As shown in FIG. 1, an organic EL printer 1
Has a print head 4 that moves along a sub-scanning direction indicated by an arrow A with respect to a color film 3 as a recording medium set at a predetermined position. Print head 4
Is an organic EL element 2 as a light source and three color filters R, G, B that can be switched with respect to the organic EL element 2.
And a single optical system 8 including a lens 6 and a reflecting mirror 7 provided at a position corresponding to the light emitting section 5 of the organic EL element 2.

As shown in FIG. 1, the print head 4
The color film 3 is moved by the moving mechanism 9 as moving means.
Reciprocates along the sub-scanning direction. Moving mechanism 9
A guide means (not shown) for movably guiding the print head 4 in the sub-scanning direction, a pair of pulleys 11 around which a drive belt 10 is wound, and a drive motor 12 for rotating one of the pulleys 11; have.

If the print head 4 fixed to the drive belt 10 drives the drive motor 12 to circulate the drive belt 10, the print head 4 is guided by guide means (not shown) and moves in the sub-scanning direction. it can.

Next, the configuration of the organic EL element 2 will be described.
As shown in FIGS. 2 and 3, a transparent anode 22 is formed on a transparent substrate 21 made of glass or the like. This anode 2
2 is ITO (composite oxide of indium oxide and tin) or IDIXO (trade name: Idemitsu transparent conductive material, Idemitsu Ind
3. The work function of the surface, such as ium X-Metal Oxide).
It is composed of a transparent substance of 0 eV or more. A plurality of anodes 22 are provided, and one luminescent dot 23 corresponds to each anode.
Each is provided. The anodes 22 are alternately arranged in two rows of odd-numbered and even-numbered light emitting lines parallel to the main scanning direction so that the light emitting dots 23 are arranged in a staggered manner.

The anodes 22 may be arranged so that the light emitting dots 23 are arranged in a line at a predetermined interval. However, in such a case, a space for electrically separating the anodes is required.
It is necessary to substantially reduce the size of the light emitting dots, and when printed, uneven streaks occur. Also, each anode 22
In order to pull out the light emitting dots 23 in a direction perpendicular to the direction in which the light emitting dots 23 are arranged, the width must be narrower than the state shown in FIG. This is not a preferable structure for the anode 22 formed of ITO having high resistance. If the two rows of light emitting lines are arranged in a staggered manner as in this example, the anodes 22 can be easily arranged and the thickness can be doubled as compared with the case of a single row, so that the resistance can be suppressed to a desirable low.

On the anode 22, a photosensitive polyimide, S
spin coating, vapor deposition method of insulating material such as iO ₂ , SiN,
The insulating layer 24 is formed by a method such as a sputtering method.

The insulating layer 2 corresponding to the end of each anode 22
A part of 4 is patterned so as to form a hole having a predetermined light emitting dot shape (square in the illustrated example). Patterning can be performed by photolithography. This square hole substantially defines the shape of the light emitting dot 23.

After the glass substrate 21 is washed and dried,
Is set in a vacuum deposition apparatus ^-FiveIn Torr vacuum
To determine whether the light emitting dots 23 are separated from the holes in the insulating layer 24.
A hole injection transport layer 25 by resistance heating evaporation.
You. At this time, the hole injection / transport layer 25
Transparent material (starburst material, triphenylamid
Derivatives). In this example, the chemical formula (Formula 5)
Was deposited to a thickness of 40 nm.

Further, a light emitting layer 26 is formed thereon. The light-emitting layer 26 is made of a material having a sufficiently wide emission spectrum (at least 450 nm to 650 nm) in the visible region so that a full-color image is formed by the photosensitive agent of the recording medium. In this example, tris (8-hydroxyquinoline) aluminum represented by the chemical formula (Formula 1) was used. The deposition thickness is 50 nm.

FIG. 4 shows the tris (8-hydroxyquinoline) aluminum (Alq ₃ ) employed in this example and the Zn used in a conventional fluorescent arc tube for a print head.
The emission spectra of O: Zn are shown for comparison. As can be seen from this figure, Alq ₃ has an emission spectrum of 450 nm.
650 nm, which has a wider emission spectrum than ZnO: Zn, and in particular, the intensity toward the red region is stronger than ZnO: Zn.

On the light emitting layer 26, Mg: Al or A
l: The cathode 27 is formed of an alloy such as Li. The deposition thickness is 100 nm. A casing is formed by sealing a sealing cap 28 to the peripheral portion of the upper surface of the substrate 21. The inside of the casing may be in a high vacuum state, or may be filled with air or an inert gas from which moisture has been removed. Anode 22
The cathode 27 is hermetically penetrated through the sealing portion between the container 20 and the substrate 13 and is led out to the outside, and is connected to the control means 30 and the power supply 29.

In the organic EL device 2 of the present embodiment thus configured, as shown by a downward arrow in FIG.
Light from the light emitting layer 26 is transmitted to the transparent anode 22 and the transparent substrate 21.
Is applied to the outside of the substrate 21 via the.

The control means 21 includes, for example, a CPU having an internal memory and a drive circuit. The control means 30 controls the light emission of each light emitting dot 23 of the two rows of light emitting lines of the organic EL element 2 in the print head 4, and controls the movement of the moving mechanism 9 in synchronization with the light emission.

More specifically, the control means 30 stores the image data input from the outside in the internal memory, applies a predetermined voltage to the cathodes 27 corresponding to the two columns of the light emitting dots 23, and synchronizes with this. An image signal is output to the anode 22 based on the image data stored in the internal memory. Further, in synchronization with this, the moving mechanism 9 is driven to move the print head 4 in the sub-scanning direction.

As shown in FIG. 1, the print head 4 is provided with color filters R, G, B. The color filters R, G, and B are arranged near the outer surface of the organic EL element 2. Color filter is organic EL element 2
Can be moved in the sub-scanning direction. The color filters R, G, B are arranged such that any one of the filters R, G, or B covers all the light emitting dots 23. And
By switching the positions of the color filters R, G, and B, the type of the color filters R, G, and B through which the light emitted from the light emitting dots 23 passes can be arbitrarily set.

The components described above are housed in a casing (not shown). In this housing, a plurality of color films 3 are stored at predetermined positions as recording media. The color film for which writing by light has been completed is discharged to the discharging mechanism 1.
3 and is discharged out of the housing. By being sandwiched by the discharge mechanism 13, the color film is developed simultaneously with the discharge.

Next, a procedure for forming a full-color image on the color film 3 using the organic EL printer 1 configured as described above will be described.

First, a color filter is selected so that the light emitting dot 23 of each light emitting line of the light emitting section is covered with any of the color filters R, G, or B. In this state,
The control unit 30 controls and drives the organic EL element 2 based on each image signal of an image obtained by color separation into three primary colors.

As a method of driving the organic EL element 2, first, in FIG. 2, a predetermined voltage is applied to a cathode including two rows of light emitting lines, and an image signal is supplied to the anode 22 in synchronization with the application of a predetermined voltage. In synchronization with this, the print head 4 moves at a constant speed in the sub-scanning direction.

When the print head 4 has moved to the end in the sub-scanning direction, the print head 4 is returned to the initial position, the above operation is performed for each of the three primary colors, and the three images separated into the three primary colors are subjected to the photosensitive surface of one color film 3. Write over. That is, a full color image is formed on the color film 3 by performing three scans while switching the color filters R, G, and B.

In the organic EL device 2 of this embodiment, the light from the light emitting layer 26 is irradiated to the outside of the substrate 21 through the transparent anode 22 and the transparent substrate 21. As shown in FIG. 5, on the contrary, a so-called reverse type organic EL element 2a having a structure in which a metal cathode 27, an organic layer 15, and a transparent anode 22 are sequentially stacked on a substrate 21 is also used in this example. Can be used as a light source. In the reverse type organic EL element 2a, the emission of the organic layer 15 is observed from the side opposite to the substrate 21 via the transparent anode 22. A part of the light emitted from the organic layer 15 is reflected by the metal cathode 27 and irradiated in the observation direction.

(2) Second Example The organic EL element 32 of this example will be described with reference to FIGS. The shape and arrangement of the light emitting dots of the organic EL element 32, the configuration when used as a light source in a color printer, the driving method of the entire apparatus, and the like are the same as those in the first example.

The organic EL element 32 of this embodiment has a plurality of light emitting layers formed by doping a host material with a dye. By the light emission from each of these light emitting layers, the light emission color of the organic EL element of this example is white or a color close to it as a whole, or at least the light emission spectrum is 450 nm to 6 nm.
Includes a range of 50 nm.

As shown in FIG. 6, a transparent anode 34 made of ITO is provided on a transparent substrate 33 such as glass.
On the anode 34, there is a hole injection / transport layer 35 made of TPD represented by the chemical formula (Formula 5). On the hole injection transport layer 35 is a blue light emitting layer 36. Blue light emitting layer 36
Represents Al ₂ O (OXZ) ₄ represented by the chemical formula (Formula 3).
Is doped with TBA which is a dye represented by the chemical formula (Formula 4). On this blue light emitting layer 36 is a yellow light emitting layer 37. The yellow light emitting layer 37 is obtained by doping rubrene, a dye represented by the chemical formula (Chemical Formula 2), into Alq ₃ , a dye represented by the chemical formula (Chemical Formula 1). On the yellow light emitting layer 37, an Al: Li cathode 3
There are eight.

The manufacturing process of the organic EL element 32 will be described. After washing and drying the glass substrate with ITO, it is set in a vacuum evaporation apparatus, and the TP is placed in a vacuum of 10 ^-5 Torr.
D is deposited to a thickness of 40 nm, and then T2 is doped with 10 mol% using Al ₂ O (OXZ) ₄ as a host material.
Co-deposited to a film thickness of Further, as the yellow light emitting layer 37, Al
The q ₃ as a host material, rubrene and 0.5 mol% dope, it was co-deposited to a thickness of 40 nm. Once the vacuum was released, an Al: Li alloy was deposited to a thickness of 100 nm as an upper electrode to obtain a device.

A 12 V DC voltage was applied to the organic EL element 32 of the present example, with the ITO side being plus and the Al: Li alloy side being minus. FIG. 7 shows the emission spectrum. The chromaticity of this light emission is x = 0.384, y = 0.412,
Almost white.

(3) Third Example The organic EL element 40 of this example will be described with reference to FIGS. The shape and arrangement of the light emitting dots of the organic EL element 40, the configuration when used as a light source in a color printer, the driving method of the entire apparatus, and the like are the same as in the first example.

In the organic EL element 40 of this example, materials emitting light of red, green, and blue are laminated, and a total of five organic layers are laminated to realize high-luminance white light emission. .

As shown in FIG. 8, on a transparent substrate 41 such as glass, there is a transparent anode 42 made of ITO.
On the anode 42, there is a luminescent hole transport layer 43 made of TPD represented by the chemical formula (Formula 5). On the hole transport layer 43, p-EtT represented by the above chemical formula (Chem. 6) is formed.
There is an organic layer 44 made of AZ. On the organic layer 44, there is a luminescent electron transport layer 45 made of Alq ₃ represented by the above chemical formula (Chemical Formula 1). A light emitting layer 46 of Nile Red, which is a dye represented by the chemical formula (Formula 7), is provided between the electron transport layers 45. That is, the Nile red light emitting layer 46 is sandwiched from above and below by the light emitting electron transport layer 45 made of Alq ₃ . Then, on the upper electron transport layer 45, there is a cathode 47 of Al: Li.

When a DC voltage was applied with the ITO side of the organic EL element 40 of this example as plus and the Al: Li alloy side as minus, white high-luminance light was obtained. FIG. 9 shows the emission spectrum.

In this embodiment, the luminescent hole transport layer 43 made of TPD and the luminescent electron transport layer 4 made of Alq _{3 are used.}
5 and the Nile Red light emitting layer 46 emits light. In the spectrum of FIG. 9, the peak near the wavelength of 400 nm is TP
D, and the peak near the wavelength of 550 nm is A
is due to lq _3, the peak in the vicinity of a wavelength of 600nm is due to the Nile Red. The emission of each of these colors is mixed and observed as white.

(4) Fourth Example The basic structure of the organic EL element 50 of this example will be described with reference to FIGS. The shape and arrangement of the light emitting dots of the organic EL element 50, the configuration when used as a light source in a color printer, the driving method of the entire apparatus, and the like are the same as in the first example.

The organic EL element 50 of this embodiment has an organic layer composed of a single layer of a liquid dye that can be applied, that is, a light-emitting layer in which a dye is dispersed in a polymer organic substance. As an example, polyvinyl carbazole (PVK) represented by the chemical formula (Formula 8) was used as the polymer organic substance.

As shown in FIG. 10, a transparent anode 52 made of ITO is provided on a transparent substrate 51 made of glass or the like. On the anode 52, a light emitting layer 53 in which a dye is mixed with polyvinyl carbazole (PVK) represented by the chemical formula (Formula 8) is applied. A cathode 54 is formed on the polymer light emitting layer 53.

According to the organic EL device 50 of this example having the light emitting layer 53 in which the dye 55 is dispersed in the polymer organic substance,
There are the following advantages. First, the emission color can be easily adjusted by adjusting the type and amount of the dye mixed with the polymer liquid. On the other hand, it is relatively difficult to control the doping amount of the dye by vapor deposition as in the above embodiment. Second, the manufacturing cost is low because the organic layer is a single-layer film of a polymer and can be formed by applying a liquid. On the other hand, the type in which a multilayer film is deposited as in the above embodiment requires relatively much time and cost.
Third, the strength of this single-layer film is high, and it is more durable than a low molecular weight dye-based organic film formed by vapor deposition.

When a DC voltage was applied to the organic EL element 50 of the present example with the ITO side being plus and the Al: Li alloy side being minus, white light with high balance and high luminance was obtained. FIG. 11 shows the emission spectrum. Brightness is several thousand cd / m
²

(5) Fifth Example The organic EL element 60 of this example will be described with reference to FIGS. The shape and arrangement of the light emitting dots of the organic EL element 60, the configuration when used as a light source in a color printer,
The driving method and the like of the entire apparatus are the same as in the first example.

The organic EL element 60 of the present example realizes white light emission with a complex material having high luminance. In this example, ZnBTZ represented by the above-mentioned chemical formula (Formula 9) was used as an example.

As shown in FIG. 12, a transparent anode 62 made of ITO is provided on a transparent substrate 61 such as glass. On the anode 62, the TP represented by the chemical formula (Chem. 5)
There is a hole transport layer 63 made of D. Hole transport layer 63
Above is a light emitting layer 64 made of the ZnBTZ complex represented by the chemical formula (Formula 9). The cathode 6 is provided on the light emitting layer 64.
5 are formed.

When a DC voltage was applied to the organic EL element 60 of the present example with the ITO side being plus and the Al: Li alloy side being minus, white light with good balance and high luminance was obtained. FIG. 13 shows the emission spectrum. The ZnBTZ complex is
It has a molecular structure in which planarity is lost by coordinating S base paper, and various energy levels are taken depending on how the planarity is lost. Therefore, it is considered that the emission spectrum is broadened and white light is emitted.

[0063]

According to the present invention, an organic EL element is used as a light source in the technical field of an optical printer head in which a fluorescent light emitting tube or the like is conventionally used, and its emission color is substantially white. Effect was obtained.

As compared to the conventional fluorescent tube, 1) the power consumption is 1/3 to 1 /
It became 5. 2) The thickness of the substrate material can be reduced to 1.1 mm or less irrespective of the device area, and the thickness of the device is reduced to 1/3 to 1/5 of that of the conventional fluorescent tube. 3) The weight has been reduced by half compared to the conventional fluorescent tube. 4) The dead space is small and miniaturization is possible. 5) Fluctuations in light emission characteristics were reduced, and it became almost unnecessary to correct the light amount for each light emitting dot. 6) The luminescent material can be selected from a variety of organic substances, and the luminescence of the red component, which has been required in the past due to the shortage, can be easily obtained. For example, when tris (8-hydroxyquinoline) aluminum was used, more red components were obtained compared to ZnO: Zn, and good image quality was obtained.

[Brief description of the drawings]

FIG. 1 shows organic E in a first example of an embodiment of the present invention.
FIG. 2 is a structural diagram of an L printer.

FIG. 2 is a schematic plan view of an organic EL element according to a first example.

FIG. 3 is a schematic cross-sectional view of an organic EL element according to a first example.

FIG. 4 is a diagram showing an emission spectrum of the organic EL element in the first example.

FIG. 5 is a schematic cross-sectional view showing another example of the structure of the organic EL element in the first example.

FIG. 6 is a schematic cross-sectional view of an organic EL element according to a second example.

FIG. 7 is a diagram showing an emission spectrum of the organic EL element in the second example.

FIG. 8 is a schematic cross-sectional view of an organic EL element according to a third example.

FIG. 9 is a diagram showing an emission spectrum of the organic EL element in the third example.

FIG. 10 is a schematic cross-sectional view of an organic EL element according to a fourth example.

FIG. 11 is a diagram showing an emission spectrum of an organic EL element in a fourth example.

FIG. 12 is a schematic sectional view of an organic EL element according to a fifth example.

FIG. 13 is a diagram showing an emission spectrum of the organic EL element in the fifth example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Organic EL printer 2, 2a, 32, 40, 50, 60 Organic EL element 3 Color film as a recording medium 4 Print head 22, 34, 42, 52, 62 Anode 23 Light emitting dot 25, 35 Hole injection which is an organic layer Transport layers 26, 46, 53, 64 Light-emitting layers as organic layers 36 Blue light-emitting layers as second light-emitting layers as organic layers 37 Yellow light-emitting layers as first light-emitting layers as organic layers 27, 38, 47 , 54, 65 Cathode 43, 63 Hole transport layer as organic layer 44 Organic layer 45 Electron transport layer as organic layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 11/06 640 C09K 11/06 660 655 680 660 H01L 33/00 M 680 H04N 1/036 A H01L 33 / 00 H05B 33/12 E H04N 1/036 33/14 B H05B 33/12 33/14 (72) Inventor Yukihiko Shimizu 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Corporation (72) Inventor Yoichi Kobori Chiba 629 Oshiba Mobara-shi Futaba Electronics Co., Ltd. F-term (reference) 2C162 AE28 FA17 FA23 3K007 AB00 AB01 AB04 BB06 CA01 CB01 DA00 DB03 EB00 FA01 5C051 AA02 CA06 DB02 DB04 DB06 DB23 EA01

Claims (11)

[Claims] An organic layer including a light emitting layer is provided between a pair of electrodes, at least one of which has a light transmitting property, and a recording medium is selectively irradiated with dot light obtained by light emission of the light emitting layer. Organic EL having an organic EL element for forming an image
In the print head, the emission spectrum of the organic EL device is 450 nm to 6 nm.
Organic EL comprising a range of 50 nm
Print head. 2. The organic EL print head according to claim 1, wherein the organic EL element has a light emitting layer made of tris (8-hydroxyquinoline) aluminum shown in Chemical Formula 1. Embedded image 3. The organic EL print head according to claim 1, wherein the organic EL element has a plurality of light emitting layers in which a host material is doped with a dye. 4. A first light emitting layer in which tris (8-hydroxyquinoline) aluminum shown in Chemical Formula 1 is doped with rubrene shown in Chemical Formula _2, and Al ₂ O shown in Chemical Formula 3
(OXZ) _{4 wherein} TBA shown in (Chem. 4) is doped.
The organic EL print head according to claim 3, further comprising a light emitting layer. Embedded image Embedded image Embedded image 5. The organic EL device according to claim 1, wherein the organic EL device has a T
A light-emitting hole transport layer made of PD, an organic layer made of p-EtTAZ shown in Chemical Formula 6, and a light-emitting electron transport layer made of tris (8-hydroxyquinoline) aluminum shown in Chemical Formula 1; The organic EL print head according to claim 1, further comprising: a light emitting layer made of Nile Red shown in Chemical Formula 7 provided in the middle of the electron transport layer made of tris (8-hydroxyquinoline) aluminum. Embedded image Embedded image Embedded image 6. The organic EL print head according to claim 1, wherein the organic EL element has a light emitting layer in which a dye is dispersed in a polymer organic substance. 7. The polymer organic substance is polyvinyl carbazole (PVK) shown in Chemical formula 8.
The organic EL print head as described in the above. Embedded image 8. The organic EL device according to claim 1, wherein
The organic EL print head according to claim 1, further comprising a light emitting layer made of an nBTZ complex. Embedded image 9. The organic EL print head according to claim 1, further comprising a hole injection / transport layer made of a material having a transmittance of 70% or more with respect to visible light. 10. A color filter comprising three types of red, green, and blue color filters provided outside the organic EL element, and switching means for the color filters, wherein the type of the color filters through which the dot-shaped light passes is arbitrary. 2. The organic EL print head according to claim 1, wherein the organic EL print head is configured to be able to be selected as follows. 11. The organic EL element is controlled so that images of red, green and blue are overlapped at the same position on the recording medium in accordance with image signals of respective colors of red, green and blue, and the recording medium is full-colored by performing multiple exposure. The organic EL print head according to claim 1, wherein an image is formed.