Patent Application
20080158852
The present invention relates to a display device having a self light emitting type display element such as an electric field light emitting display element, etc.
For example, there are the following patent document 1 and patent document 2 as the display device having the electric field light emitting display element. In the display device described in this patent document 1, for example, as shown in
Further, in the display element described in patent document 2, for example, as shown in
However, in the display device described in the above patent document 1, about the entire range of only the electric field light emitting display element 20 is approximately seen in a uniform color tone, but a display plate 12 having a window portion 21 on a forward side of the electric field light emitting display element 20 is arranged as shown in its
Further, in a character plate 39 shown in
Further, in patent document 2, visibility in a simplex state of the organic EL element 40 is greatly improved. However, for example, when such a display element is used in the display device shown in
Problems that the Invention is to Solve
The present invention is made in consideration of such points, and its object is to provide a display device in which the light emitting display element and its circumference have an oneness appearance while reflection due to external light is restrained in the display device having the light emitting display element.
To achieve the above object, the present invention resides in a display device comprising a light emitting display element; a translucent member arranged on a front face side of this light emitting display element; a circularly polarized light plate arranged on a front face side of this translucent member; and a light interrupting layer arranged on a rear face side of this circularly polarized light plate or arranged in the translucent member, and covering a portion except for a display area of the light emitting display element.
Further, the light emitting display element is constructed by an electric field light emitting display element having a translucent substrate, a transparent electrode, a light emitting layer and a rear face electrode; and a reflecting layer having the same color as a color tone of the rear face electrode or a color approximate to this color is arranged between the circularly polarized light plate and the light interrupting layer.
Further, the translucent member is constructed by a material having an approximately isotropic refractive index.
Further, the present invention resides in a display. device comprising a light emitting display element; a display plate arranged on a front face side of this light emitting display element; and a circularly polarized light plate arranged on a front face side of this display plate; wherein the display plate has a first display area for arranging a display portion of a transmitting property and a ground portion of an untransmitting property in a substrate of a light transmitting property, and a second display area formed by unarranging the display portion and the ground portion correspondingly to the light emitting display element.
Further, the light emitting display element is constructed by an electric field light emitting display element having a translucent substrate, a transparent electrode, a light emitting layer and a rear face electrode; and a reflecting layer having the same color as a color tone of the rear face electrode or a color approximate to this color is arranged between the circularly polarized light plate and the ground portion.
Further, a visible display portion is arranged in a front face side portion of the circularly polarized light plate corresponding to the display portion.
Further, the substrate is constructed by a material having an approximately isotropic refractive index.
It is possible to obtain a display device in which the light emitting display element and its circumference have an oneness appearance while reflection due to external light is restrained in the display device having the light emitting display element.
The present invention will be explained on the basis of each embodiment mode.
The display device in this embodiment mode has the electric field light emitting display element 1, a translucent member 2 arranged on a front face side of the electric field light emitting display element 1, and a circularly polarized light plate 3 arranged on a front face side of the translucent member 2. The display device also has a case member 4 for holding the translucent member 2 and manufactured with synthetic resin, a hard circuit substrate 5 electrically connected to the electric field light emitting display element 1 and mounting a driving circuit, etc. for operating the electric field light emitting display element 1, and a cover 6 for covering a rear face side of the circuit substrate 5. The display device further has a looking-back member 8 arranged on a circumferential edge forward side of the circularly polarized light plate 3 and having an opening portion 7 for determining a visible area of the circularly polarized light plate 3 (translucent member 2) and constructed with e.g., black synthetic resin, and a seeing-through plate 9 for covering the forward side of the circularly polarized light plate 3 and constructed with colorless transparent synthetic resin. The electric field light emitting display element 1 is held in a holder 10 arranged in the case member 4.
For example, the electric field light emitting display element 1 has a display segment of a squarish eight shape, and the display segment is displayed as a display portion by emitting light from an organic layer. For example, when the display device is arranged in a vehicle, a running distance of the vehicle, outside air temperature, etc. are displayed.
It is sufficient for the organic layer 14 to have at least a light emitting layer, but the organic layer 14 may also have a positive hole injecting layer, a positive hole transport layer and an electronic transport layer. Further, it is sufficient for the rear face electrode 15 to be formed in a place corresponding to at least the display segment. However, the glass substrate 11, the transparent electrode 12, the insulating layer 13 and the organic layer 14 are approximately transparent. In contrast to this, the rear face electrode 15 is constructed with a metal such as aluminum, etc. and is seen so as to approximately become a mirror face. Therefore, the rear face electrode 15 is not formed in one portion of the glass substrate 11, but is approximately formed in its entire range, and is set so as to approximately uniformly see an entire face of the electric field light emitting display element 1.
For example, the translucent member 2 is constructed by colorless transparent acrylic resin, polycarbonate resin, etc. constructed by a material having an approximately isotropic refractive index. A reflecting layer 18 of silver color or gray color, etc. (when the rear face electrode 15 is constructed with aluminum) as the same color as a color tone of the above rear face electrode 15 or a color approximate to this color, and a black light interrupting layer 19 are arranged on the rear face side of the translucent member 2. This reflecting layer 18 and the light interrupting layer 19 determine a display area S of the electric field light emitting display element 1, and are arranged in a place of the translucent member 2 except for an area constituting the display area S. Namely, only the display area S is set to be able to be perspective (in a state in which no circularly polarized light plate 3 is arranged), and the display area S is narrower than the range of the rear face electrode 15 formed in the electric field light emitting display element 1. In
The translucent member 2 is set to a colorless transparent material, but may be also colored if the translucent member 2 has a light transmitting property. Further, the light interrupting layer 19 and the reflecting layer 18 may be also arranged on the rear face side of the circularly polarized light plate 3 or the front face side of the translucent member 2. In this case, the light interrupting layer 19 is arranged on the electric field light emitting display element 1 side from the reflecting layer 18. The reflecting layer 18 may be arranged on the rear face side of the circularly polarized light plate 3, and the light interrupting layer 19 may be also arranged on the translucent member 2.
As described in the above patent document 2, the circularly polarized light plate 3 is formed by laminating the linearly polarized light plate and the birefringent plate. Light incident from the birefringent plate side passes the linearly polarized light plate. However, it is restrained that light incident from the linearly polarized light plate side and passing the birefringent plate and reflected on the birefringent plate side is returned to the incident side (reflected light is restrained). In this circularly polarized light plate 3, the birefringent plate is stuck to the front face side of the translucent member 2 such that the birefringent plate locates on the electric field light emitting display element 1 side.
In the display device constructed in this way, the circularly polarized light plate 3 is arranged on the front face side of the translucent member 2 at an on-display time. Therefore, even when external light is incident into the circularly polarized light plate 3 and is reflected within the translucent member 2 and the electric field light emitting display element 1 as mentioned above, its reflected light is Restrained. Thus, the entire face (visible area of the display device) within the opening portion 7 of the looking-back member 8 is uniformly visualized so as to be blackish as well as the display area S of the electric field light emitting display element 1. When a voltage is applied to the electric field light emitting display element 1, the organic layer 14 emits light and a display portion is uniformly transmission-displayed on the blackish face. Further, when the translucent member 2 is a material of a high birefringent property, the reflected light is easily transmitted through the circularly polarized light plate 3 and an effect as the circularly polarized light plate 3 tends to be thinned. However, since the translucent member 2 is constructed with a material having an approximately isotropic refractive index, the reflected light is restrained in the circularly polarized light plate 3.
When strong external light is incident to the visible area of the display device and it is seen from a slanting direction, there is a case in which the translucent member 2 and the electric field light emitting display element 1 are slightly visualized. Namely, the reflected light is slightly emitted. However, the rear face electrode 15 of the electric field light emitting display element 1 is approximately formed on the entire face of the glass substrate 11, and the reflecting layer 18 having the same color as the color tone of the rear face electrode 15 or a color approximate to this color is arranged in the translucent member 2. Therefore, even when it is seen from the slanting direction, the entire face is visualized in a uniform color tone. A reflecting layer 18 may not be require to arrange if there is no bad affect on visibility.
Thus, a boundary (or step difference feeling), a difference of a color tone, etc. between the electric field light emitting display element 1 and its circumference are removed irrespective of a display time and a non-display time, and a display device having an oneness appearance can be obtained. Accordingly, even when large-sized electric field light emitting display element corresponding to the visible area of the display device is not used, the display device having an oneness appearance can be obtained and an increase in cost is also restrained.
The light interrupting layer 19 also has a role for preventing that display light (emitted light) from the electric field light emitting display element 1 is reflected on the reflecting layer 18 and illuminates the glass substrate face 11 of the electric field light emitting display element 1. Accordingly, the light interrupting layer 19 is not limited to black color, but is desirably set to a dark color system such as thick gray, thick blue, thick green, etc. Further, the electric field light emitting display element 1 is used as the light emitting display element, but a self light emitting type display element such as a fluorescent display tube, an inorganic EL element, a light emitting diode display element, etc. may be also applied.
The display device in this embodiment mode has a speed meter 20 and a tachometer 21. An explanation of the tachometer 21 is omitted. The speed meter 20 has an electric field light emitting display element 1, a display plate 23 arranged on the front face side of the electric field light emitting display element 1 and having a display portion 22 of a scale, a number, a character, etc. showing a speed of the vehicle, and a pointer 24 for indicating the display portion 22. The speed meter 20 also has an indicator main body 25 for rotating the pointer 24, a circularly polarized light plate 3 arranged on the front face side of the display plate 23, and a hard circuit substrate 5. The circuit substrate 5 is electrically connected to the indicator main body 25 and the electric field light emitting display element 1. A driving circuit, etc. for operating the indicator main body 25 and the electric field light emitting display element 1 are mounted to the circuit substrate 5. The speed meter 20 also has light emitting diodes 26 and 26A as a light source for illuminating the pointer 24 and the display plate 23.
Further, the display device has a case member 4 arranged between the display plate 23 and the circuit substrate 5, a cover 6 for covering the rear face side of the circuit substrate 5, and a looking-back member 8. The looking-back member 8 is arranged on a circumferential edge forward side of the circularly polarized light plate 3, and has an opening portion 7 determining a visible area of the circularly polarized light plate 3 (display plate 23) and is constructed with e.g., black synthetic resin. The display device also has a seeing-through plate 9 for covering the forward side of the circularly polarized light plate 3 and constructed with colorless transparent synthetic resin. The basic structure of the electric field light emitting display element 1 and the circularly polarized light plate 3 is the same as the above first embodiment mode, and its explanation is therefore omitted. Further, in
The pointer 24 has an indicating portion 27 constructed with e.g., colorless transparent synthetic resin. An unillustrated white foil is hot-stamped on a rear face of the indicating portion 27. For example, when the light emitting diode 26 for illuminating the pointer and emitting light in red is turned on, the red light is reflected on the white foil and the indicating portion 27 is visualized in red color.
The case member 4 is constructed with white synthetic resin having a light interrupting property, and has an outer circumferential wall 28, a placing portion 29 for placing the display plate 23, a sleeve portion 30 for surrounding the light emitting diode 26 for illuminating a pointer, a holder 10, etc. The electric field light emitting display element 1 is held in the holder 10.
The display plate 23 has a first display area S1 for arranging the display portion 22 of a transmitting property and a ground portion 32 of an untransmitting property in a substrate 31 of a light transmitting property, and a second display area S2 formed by arranging no display portion 22 and no ground portion 32. Similar to the above first embodiment mode, the material of the substrate 31 is constructed by e.g., colorless transparent acrylic resin, polycarbonate resin, etc. formed by a material having an approximately isotropic refractive index, but may be also colored. A light interrupting layer 19 of a dark color system (black color, thick gray, thick blue, thick green, etc.) is arranged on a rear face side of the substrate 31 except for a portion forming the display portion 22. The ground portion 32 is formed by arranging this light interrupting layer 19, and a portion where no light interrupting layer 19 is arranged is the display portion 22 of a transmitting property.
Further, the light interrupting layer 19 is arranged in a portion except for an area corresponding to the electric field light emitting display element 1. The area corresponding to this electric field light emitting display element 1 becomes a second display area S2, and is narrower than the range of a rear face electrode 15 formed in the electric field light emitting display element 1. In
Further, a reflecting layer 18 having the same color as the color tone of the rear face electrode 15 of the electric field light emitting display element 1 or a color approximate to this color is arranged between the substrate 31 and the light interrupting layer 19 (ground portion 32). The light interrupting layer 19 and the reflecting layer 18 may be also arranged on the front face side of the substrate 31. In this case, the reflecting layer 18 is arranged closer to the circularly polarized light plate 3 side than the light interrupting layer 19. The reflecting layer 18 may be arranged on the front face side of the substrate 31, and the light interrupting layer 19 may be also arranged on the rear face side of the substrate 31. Further, it is sufficient for the display portion 22 to have a transmitting property. Accordingly, a coloring layer of a transmitting property may be also arranged in a portion corresponding to the display portion 22. Otherwise, if the reflecting layer 18 has a transmitting property, this reflecting layer 18 may be also arranged.
In the display device constructed in this way, only the pointer 24 is visualized within the opening portion 7 of the looking-back member 8, and the circularly polarized light plate 3 is arranged on the front face side of the display plate 23 except for this pointer 24. Therefore, the entire face is uniformly visualized so as to be blackish. For example, when the light emitting diode 26A for illuminating the display plate and emitting light in white color is turned on, the display portion 22 is uniformly transmission-illuminated on the blackish face. Further, when a voltage is applied to the electric field light emitting display element 1, the organic layer 14 emits light and the unillustrated display portion is uniformly transmission-displayed on the blackish face.
Further, even when the speed meter 20 is seen from a slanting direction, the entire face is visualized in a uniform color tone since the reflecting layer 18 arranged on the rear face side of the substrate 31 has the same color as the color tone of the rear face electrode 15 of the electric field light emitting display element 1 or a color approximate to this color. No reflecting layer 18 may be also arranged if a bad influence is exerted on visibility.
Thus, similar to the above first embodiment mode, a display device having an oneness appearance can be obtained irrespective of a display time and a non-display time of the display portion 22 or the electric field light emitting display element 1.
In a front face side portion of the circularly polarized light plate 3 corresponding to the display portion 22 of the display plate 23, for example, a visible display portion 34 is formed by arranging a white transmitting layer 33. This transmitting layer 33 is set to be slightly larger (wider) than the display portion 22 arranged in the display plate 23, but may be also set to be smaller (narrower in width) than the display portion 22.
In the display device constructed in this way, the pointer 24 and the visible display portion 34 are visualized within the opening portion 7 of the looking-back member 8, and the circularly polarized light plate 3 is arranged on the front face side of the display plate 23 except for the pointer 24 and the visible display portion 34. Therefore, the entire face is uniformly visualized so as to be blackish. When the light emitting diode 26A for illuminating the display plate and emitting light in e.g., white color is turned on at a dark time of the circumference such as night time, etc., the visible display portion 34 is uniformly transmission-illuminated on the blackish face. Namely, the visible display portion 34 is always visualized. Effects similar to those of each of the above embodiment modes are obtained by setting such a construction.
For example, the visible display portion 34 may be set to be untransmissive by arranging a white untransmitting layer although this visible display portion 34 is not shown in the drawings. In this case, a light source for illuminating the visible display portion 34 is arranged on the forward side of the circularly polarized light plate 3 instead of the light emitting diode 26A for illuminating the display plate. Further, when the visible display portion 34 is set to be untransmissive, no display portion 22 may be also arranged in the display plate 23.
The display plate 23 has a first display area S1 for arranging an annunciating display portion 35 and a ground portion 32 of an untransmitting property in a substrate 31 of a light transmitting property, and a second display area S2 formed by arranging no annunciating display portion 35 and no ground portion 32. The annunciating display portion 35 is a display portion (e.g., a turn display portion and an engine oil display portion) for displaying an operating state or abnormal contents, etc. of a vehicle. For example, a mark 37 of a turn and engine oil is formed by a black light interrupting layer 19, and a transmitting portion 36 is arranged around the mark 37 (light interrupting layer 19). Further, the ground portion 32 is formed by arranging the black light interrupting layer 19 in the circumference of the annunciating display portion 35. Otherwise, the mark 37 may be also formed by a coloring layer of a transmitting property without arranging the transmitting portion 36. Further, a character display portion for the annunciating display portion 35 may be also added. Thus, the first display area S1 is formed.
The second display area S2 is an area corresponding to the electric field light emitting display element 1, and the annunciating display portion 35 and the ground portion 32 (light interrupting layer 19) are not arranged in this area. In the display device constructed in this way, the entire face uniformly becomes a blackish face unless the electric field light emitting display element 1 or the annunciating display portion 35 is displayed. The transmitting portion 36 of the annunciating display portion 35 is transmission-illuminated by turning-on a light source arranged in the back of the display plate 23 corresponding to each annunciating display portion 35. Further, the electric field light emitting display element 1 is also transmission-displayed similarly to each of the above embodiment modes.
In this embodiment mode, similar to each of the above embodiment modes, a display device having an oneness appearance is obtained. In this embodiment mode, no reflecting layer 18 having the same color as the color tone of the rear face electrode 15 of the electric field light emitting display element 1 or a color approximate to this color is arranged on the rear face side of the substrate 31. However, this reflecting layer 18 may be also arranged. The entire face is also visualized in a uniform color tone by arranging the reflecting layer 18 even when it is seen from a slanting direction as mentioned above. Thus, the display device having a more oneness appearance is attained.
The present invention is applied to the display device in which the circularly polarized light plate is arranged on the front face side of the light emitting display element such as the electric field light emitting display element.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005023682 | Jan 2005 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2005/023301 | 12/20/2005 | WO | 00 | 7/19/2007 |
