JP2008010317A - ORGANIC ELECTROLUMINESCENCE ELEMENT AND Finder DEVICE EQUIPPED WITH THE SAME - Google Patents

Abstract

When an organic EL element is disposed as a light-emitting display unit in a finder device, the number of parts of the finder device is reduced and the transmittance is improved.
An organic EL element is provided on an optical path through which light from a subject in a finder device passes. The organic EL element 20 includes a transparent substrate 21, a sealing member 22 provided to face the transparent substrate 21, and an organic EL layer 27 disposed between the transparent substrate 21 and the sealing member 22. The upper surface 22U of the sealing member 22 is formed as a diffusion surface. The lower surface 22D of the sealing member 22 has a Fresnel lens structure. Thereby, the organic EL element 20 is provided with functions of a focusing screen and a Fresnel lens.
[Selection] Figure 2

Description

  The present invention relates to an organic electroluminescent element suitably used for a finder apparatus.

Conventionally, in a finder device such as a single-lens reflex camera, an organic electroluminescence element (hereinafter referred to as an organic EL device) is located near a subject imaging position between a pentagonal prism and a focusing plate having a diffusing surface and a Fresnel lens structure formed on each surface. It is known that a light-emitting display unit composed of an element) is arranged. In this apparatus, the organic EL element is caused to emit light, whereby a frame frame can be displayed in the finder, and character information such as shutter speed, film sensitivity, aperture value, etc. can be displayed (Patent Document 1, 2).
Japanese Patent No. 3539251 JP 2000-221578 A

  However, if the light emitting display unit is disposed between the pentaprism and the focus plate, the distance between the pentaprism and the focus plate becomes long, and the viewfinder device may be enlarged.

  Moreover, the organic EL element requires a transparent substrate for laminating the organic light emitting layer and a sealing member for sealing the organic light emitting layer. When the transparent substrate and the sealing member are inserted on the optical path, There is a risk that the transmission efficiency of light incident on the finder is lowered, and the amount of light of the subject image observed with the finder is reduced. Furthermore, since the distance between the diffusing surface on which the subject image is formed and the light emitting point of the organic EL element becomes longer, the focus position of the eye for observing it is different for both, so either the subject image or the display information May be observed out of focus (out of focus).

  Therefore, the present invention has been made in view of these problems, and is an organic EL element disposed on the optical path of a finder device, and the size of the finder device is increased, and the amount of light of the subject image observed by the finder An object is to provide an organic EL element capable of preventing shortage and blurring of display information.

  The organic EL element according to the present invention includes a transparent substrate, an organic light emitting material, an organic EL layer disposed on one surface of the transparent substrate, and a transparent material, and is provided to face the transparent substrate. In addition, the organic electroluminescence device includes an organic EL layer disposed between the transparent substrate and a sealing member that seals the organic EL layer, and is capable of transmitting a light beam through the sealing member and the transparent substrate. Then, one of the surface opposite to the one surface of the transparent substrate, the surface facing the transparent substrate of the sealing member, and the surface opposite to the surface facing the sealing member condenses the light flux. Therefore, it has a positive power and the other surface is a diffusion surface for diffusing the light beam.

  Any one surface is preferably formed as a Fresnel lens structure, which can reduce the thickness of the organic EL element. Each of the one surface and the other surface is preferably formed by, for example, molding or etching, formed by bonding an optical member, or integrally formed by bonding a transparent material.

  An organic EL element according to the present invention is disposed on one surface of a prism, and is formed of an organic EL layer containing an organic light emitting material and a transparent material, and is provided to face one surface of the prism. And a sealing member that seals the organic EL layer with an organic EL layer interposed therebetween, and the light beam can be incident on one surface of the prism through the sealing member.

  Of the opposing surface facing the one surface of the prism of the sealing member and the surface opposite to the opposing surface of the sealing member, one surface has a positive power for condensing the light beam, and the other surface is A diffusing surface for diffusing the light beam is preferable.

  The finder apparatus according to the present invention is characterized in that the organic EL element is arranged so as to intersect an optical path that allows a light beam reflected from a subject to pass therethrough and guides it to a finder window.

  In the present invention, since the organic EL element has a function as a focusing screen and a Fresnel lens, when the organic EL element is applied to a finder device, it is not necessary to provide a focus plate as a separate member, and the number of parts of the finder device Can be reduced and downsizing can be achieved. Further, in the finder device, the number of optical members through which the light beam observed by the observer passes is reduced, so that it is possible to suppress a decrease in the amount of light in the observation image. Further, the focus shift in the viewfinder can be reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a finder device of a single-lens reflex camera to which the present embodiment is applied. In the following description, a case where the present invention is applied to a single-lens reflex camera will be described. However, the present invention can also be applied to other optical devices such as a microscope and a compact camera.

  In the finder device 10, the light emitting display unit 16 is disposed on a transverse region that faces the lower surface 14 </ b> D (that is, the incident surface) of the pentaprism 14 and intersects the optical path through which the light beam from the subject passes. The light-emitting display unit 16 is composed of an organic EL element, and also functions as a focusing screen and a Fresnel lens, as will be described later. The eyepiece 15 is opposed to the emission surface 14B formed on the back surface of the pentaprism 14. The quick return mirror 12 is provided below the light emitting display unit 16, and the photographing optical system 11 is provided in front of the quick return mirror 12.

  The light beam reflected by the subject is reflected by the quick return mirror 12 via the photographing optical system 11, guided to the light emitting display unit 16, transmitted through the light emitting display unit 16, and via the pentaprism 14 and the eyepiece 15. The light enters the finder window 17. Similarly, the light emitted from the light emitting display unit 16 is guided into the finder window 17 through the pentaprism 14 and the objective lens 15. When a release switch (not shown) is pressed, the quick return mirror 12 is retracted from the optical path, and the light beam guided by the photographing optical system 11 is an image pickup surface 19 of an image pickup device provided behind the quick return mirror 12. (Or film surface) etc., and these are exposed.

  FIG. 2 is a cross-sectional view of the light emitting display unit 16. As shown in FIG. 2, the light emitting display unit 16 includes an organic EL element 20, and the organic EL element 20 includes a transparent substrate 21, a sealing member 22 provided so as to face the transparent substrate 21, and a transparent substrate. An organic EL layer 27 that is sandwiched between an anode 26 and a cathode 28 is provided between 21 and the sealing member 22. The transparent substrate 21 and the sealing member 22 are transparent members formed of a transparent material such as glass, plastic, or a composite material thereof. In FIG. 2, the transparent substrate 21 side is disposed on the eyepiece side, and the sealing member 22 side is disposed on the objective side.

  An anode 26, an organic EL layer 27, and a cathode 28 are laminated in this order on the lower surface 21D of the transparent substrate 21 facing the sealing member 22, and the sealing member 22 is provided below the cathode 28 in FIG. . The anode 26, the organic EL layer 27, and the cathode 28 are formed of a transparent material, and can transmit the light beam incident on the organic EL element 20. The organic EL layer 27 includes, for example, a hole transport layer made of a hole transport material, an organic light emitting layer made of an organic light emitting material, and an electron transport layer made of an electron transport material in order from the anode 26 side. Configured. The organic EL layer 27 emits light of a color such as red, green, blue, or white when a voltage is applied between the anode 26 and the cathode 28.

  The sealing member 22 is formed in a plate shape, and a protruding portion 23 protruding toward the transparent substrate 21 is formed on the outer peripheral portion thereof. The protrusion 23 is bonded to the transparent substrate 21 via an adhesive (not shown), thereby forming a sealed space 29 between the transparent substrate 21 and the sealing member 22, and the anode 26, the cathode 28, and the organic The EL layer 27 is disposed in the sealed space 29 and is sealed by the sealing member 22.

  The upper surface 22U of the sealing member 22 facing the lower surface 21D of the transparent substrate 21 is formed as a diffusion surface. The lower surface 22D of the sealing member 22 that is the surface opposite to the upper surface 22U is formed in a Fresnel lens structure that swells downward, and is formed as a lens having positive power.

  The light beam incident from the subject is refracted so as to be condensed by the lower surface 22D of the sealing member 22, and forms an image on the upper surface 22U of the sealing member 22 which is a diffusion surface. The upper surface 22U is disposed at a position optically conjugate with the imaging surface 19 (or film surface), and diffuses the imaged light to enter the photographer's eyes.

  The diffused light exiting from the upper surface 22U of the sealing member 22 passes through the anode 28, the organic EL layer 27, the cathode 26, and the transparent substrate 21, and is emitted from the upper surface 21U of the transparent substrate 21. The light emitted from the organic EL layer 27 is also emitted from the upper surface 21U of the organic EL element 20 through the anode 26 and the transparent substrate 21.

  In the present embodiment, one surface through which the luminous flux of the sealing member 22 transmits is formed as a Fresnel lens structure, and the other surface is used as a diffusing surface, so that the organic EL element 20 can be used as a focusing screen and a Fresnel lens. Functions can be added. This eliminates the need to provide a focus plate as a separate member in the finder device 10, thereby reducing the number of members of the finder device and reducing the size. In addition, since the number of members through which the light flux from the subject passes is reduced in the finder device 10, the transmittance of the finder device 10 as a whole can be improved, and the insufficient light quantity of the observation image can be solved.

  The diffusion surface of the upper surface 22U of the sealing member 22 is formed, for example, by adhering a focusing plate (optical member) having a diffusion surface to the sealing member with an adhesive or the like. Further, for example, a transparent material such as glass, UV curable resin, or thermosetting resin may be fixed to the sealing member, and thereby the diffusion surface may be formed integrally with the sealing member. When fixing a transparent material such as resin or glass to a sealing member, for example, a mold is disposed so as to overlap the sealing member, and a fluidized resin or glass is filled between the mold and the sealing member. Thereafter, the resin is cured or the glass is solidified to form a diffusion surface. In this case, when the resin is a UV curable resin, it is preferable to cure by applying UV light from the sealing member side. Similarly, the lower surface 22D of the sealing member 22 may be formed by, for example, bonding a Fresnel lens (optical member) to the sealing member, or fixing a transparent material such as resin or glass. The material of the sealing member and the optical member bonded to the sealing member is not particularly limited as long as it is a transparent member such as glass or plastic.

  As shown in FIG. 3, the upper surface 22U and the lower surface 22D of the sealing member 22 may be integrally formed with the sealing member 22 by molding (for example, glass mold) or etching. Of course, either one of the upper surface 22U and the lower surface 22D is formed by molding or etching, formed by adhering an optical member, or formed by adhering a transparent material, and the other is different among these methods. It may be formed by a method.

  FIG. 4 is a sectional view showing an organic EL element according to the second embodiment of the present invention. In the present embodiment, the upper surface 22U of the sealing member 22 is formed as a Fresnel lens structure that swells upward, and the lower surface 22D is formed as a diffusion surface. Other configurations are the same as those of the first embodiment.

  5 to 8 show third to sixth embodiments, respectively. In the first and second embodiments, both the diffusing surface and the Fresnel lens structure are formed on the sealing member 22, but in the third to sixth embodiments, one of the diffusing surface or the Fresnel lens structure is transparent. The other surface is formed on the lower surface 22 </ b> D or the upper surface 22 </ b> U of the sealing member 22 while being formed on the upper surface 21 </ b> U of the substrate 21.

  Specifically, in the third embodiment, as shown in FIG. 5, the upper surface 21U of the transparent substrate 21 is formed as a diffusion surface, and the lower surface 22D of the sealing member is formed in a Fresnel lens structure that swells downward. The In the fourth embodiment, as shown in FIG. 6, the diffusion surface is formed on the upper surface 21U of the transparent substrate 21, and is formed on the upper surface 22U of the sealing member in a Fresnel lens structure that swells upward.

  Furthermore, in the fifth embodiment, as shown in FIG. 7, the upper surface 21U of the transparent substrate 21 is formed as a Fresnel lens structure that swells upward, and the lower surface 22D of the transparent substrate 22 is formed as a diffusion surface. Further, in the sixth embodiment, as shown in FIG. 8, the upper surface 21U of the transparent substrate 21 is formed as a Fresnel lens structure that swells upward, and the upper surface 22U of the sealing member 22 is formed as a diffusion surface.

  Also in the second to sixth embodiments described above, the light beam incident from the subject is refracted so as to be condensed by the Fresnel lens structure and imaged on the diffusion surface. The diffusing surface is disposed at a position optically conjugate with the imaging surface 19 (or film surface), and diffuses the imaged light beam to enter the photographer's eye. Therefore, since the organic EL element 20 in the second to sixth embodiments can also function as a focusing screen and a Fresnel lens as in the first embodiment, the same effects as in the first embodiment can be obtained. Can play.

  In the third to sixth embodiments, the diffusing surface or Fresnel lens structure provided on the upper surface 21U of the transparent substrate 21 is formed by, for example, molding or etching similarly to the upper surface 22U or the lower surface 22D of the sealing member 22. It is formed by adhering an optical member, or by adhering a transparent material.

  FIG. 9 is a cross-sectional view of an organic EL element according to the seventh embodiment of the present invention. In the first to sixth embodiments, the organic EL element 20 is provided separately from the pentaprism 14, but in the seventh embodiment, the organic EL element 20 is formed integrally with the pentaprism. Hereinafter, the seventh embodiment will be described in detail.

  In the present embodiment, the anode 26, the organic EL layer 27, and the cathode 28 are laminated in this order on the lower surface 14D (that is, the incident surface) of the pentaprism 14, and the pentaprism prism is disposed below the cathode 28 in FIG. The organic EL element 20 is configured by providing the sealing member 22 facing the lower surface 14D. The protruding portion 23 of the sealing member 22 is bonded to the lower surface 14D of the pentaprism via an adhesive, whereby a sealed space 29 is formed between the pentaprism 14 and the sealing member 22, and an anode 26, a cathode 28, The organic EL layer 27 is disposed in the sealed space 29 and sealed by the sealing member 22.

  Similar to the first embodiment, the upper surface 22U of the sealing member 22 is formed as a diffusing surface, and the lower surface 22D of the sealing member 22 is formed in a Fresnel lens structure that bulges downward, and has a positive power. It is formed as a lens having Therefore, also in this embodiment, the functions as a focusing screen and a Fresnel lens can be imparted to the organic EL element 20, and the same effects as in the first embodiment can be obtained. Of course, in the seventh embodiment, a Fresnel lens structure may be formed on the upper surface 22U, and a diffusion surface may be formed on the lower surface 22D.

  In the first to seventh embodiments, the surface formed in the Fresnel lens structure may be formed so as to have a positive power, and may be formed in a convex lens shape, for example. However, when the convex lens shape is used, the thickness of the sealing member 22 is increased. Therefore, the Fresnel structure is preferable.

  Further, in the first to seventh embodiments, as shown in FIGS. 2 to 9, the organic EL layer 27 is provided over almost the entire lower surface 21D of the transparent substrate 21 (or the lower surface 14D of the pentaprism). Of course, it may be partially provided.

  Further, part or all of the anode 26 and / or the cathode 28 may be formed as a non-transparent electrode. In this case, it is better that the non-transparent electrode portion is provided outside the optical path through which light from the subject passes, that is, the non-transparent electrode portion observes the subject when the light-emitting display unit 16 is observed from the finder window 17. It should be provided outside the possible field of view.

  Furthermore, in the present invention, for example, as shown in FIG. 2, it is preferable to provide a Fresnel lens structure on the lower side (that is, the objective side) and a diffusion surface on the upper side (that is, the eyepiece side). This is because the concentric circles of the Fresnel lens are not easily observed by the observer according to such a configuration. However, if the diffusing surface is provided on the objective side and the Fresnel lens structure is provided on the eyepiece side, the light beam diffused on the diffusing surface can be efficiently guided to the pentaprism, so that a brighter subject image can be observed. .

  In the first to seventh embodiments, the prism provided on the upper side of the light emitting display unit 16 is not limited to the pentaprism 14 and may be another prism. In the first and sixth embodiments, an optical member other than a prism such as a pentamirror or a side swing mirror may be used.

It is a top view of the finder apparatus of a camera. It is sectional drawing of the organic EL element in 1st Embodiment. It is sectional drawing in the case of manufacturing the organic EL element in 1st Embodiment with another manufacturing method. It is sectional drawing of the organic EL element in 2nd Embodiment. It is sectional drawing of the organic EL element in 3rd Embodiment. It is sectional drawing of the organic EL element in 4th Embodiment. It is sectional drawing of the organic EL element in 5th Embodiment. It is sectional drawing of the organic EL element in 6th Embodiment. It is sectional drawing for showing the organic EL element in 7th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Finder apparatus 14 Penta prism 16 Light emission display part 20 Organic EL element 21 Transparent substrate 21D The lower surface (one surface) of a transparent substrate
21U Top surface of transparent substrate (opposite surface)
22 Sealing member 22D Bottom surface of sealing member (opposite surface)
22U Top surface (opposite surface) of sealing member
27 Organic EL layer

Claims (6)

A transparent substrate, an organic EL layer that includes an organic light emitting material and is disposed on one surface of the transparent substrate; and is formed of a transparent material and is provided to face the transparent substrate; An organic electroluminescence element capable of transmitting a light beam through the sealing member and a transparent substrate, comprising: a sealing member that seals the organic EL layer by disposing the organic EL layer therebetween;
Any one of a surface opposite to the one surface of the transparent substrate, a surface facing the transparent substrate of the sealing member, and a surface opposite to the surface facing the sealing member is the light flux. An organic electroluminescence element having positive power for condensing light and having another surface as a diffusion surface for diffusing the light flux.   The organic electroluminescence device according to claim 1, wherein the one surface is formed as a Fresnel lens structure.   Each of the one surface and the other surface is formed by molding or etching, formed by adhering an optical member, or integrally formed by adhering a transparent material. 2. The organic electroluminescent element according to 1.   An organic EL layer including an organic light emitting material disposed on one surface of the prism and a transparent material provided to face the one surface of the prism, and the organic EL layer disposed between the one surface and the surface. An organic electroluminescence device comprising a sealing member for sealing the organic EL layer, and capable of transmitting a light beam to one surface of the prism through the sealing member.   One of the opposing surface of the sealing member facing the one surface of the prism and the surface opposite to the opposing surface of the sealing member has positive power for condensing the luminous flux. 5. The organic electroluminescence element according to claim 4, wherein the other surface is a diffusion surface for diffusing the light beam. 6. A finder apparatus, wherein the organic electroluminescent element according to claim 1 is disposed so as to cross an optical path that allows a light beam reflected from a subject to pass therethrough and guides it to a finder window. .

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