Light-emitting devices

Abstract

To provide a low-cost light-emitting device having high yield.SOLUTION: A light-emitting device includes a polygon substrate, a light-emitting region where a plurality of light emitting elements are arranged, the light-emitting element having a light-emitting layer, and first electrodes and a second electrode that sandwich the light-emitting layer, and a first contact region electrically connected to the second electrode, and a moisture-resistant ring surrounding the light-emitting region and the first contact region. The first electrode is provided in each of the plurality of light-emitting elements, and the second electrode is a common electrode shared by a plurality of light-emitting elements. When the long side direction is a first direction and the short side direction of the substrate is a second direction, the moisture-resistant ring has a fist part arranged on one long side of the light-emitting region on the substrate and at a first distance from the long side in the second direction, and a second part arranged at a second distance from the long side in the second direction. The first distance is longer than the second distance. The first contact region is arranged in an area adjacent to the second part of the moisture-resistance ring on the light-emitting region side with respect to the moisture-resistant ring.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to light emitting devices, for example, light emitting devices having light emitting elements. [Background technology]

[0002] Organic Light Emitting Diode (OLED) An optical writing device (OLED-PH: OLED Print Head) has been proposed for use in image forming devices, which uses an OLED (OLED) as a light-emitting source. OLED-PH has the advantage of being compact and low-cost, since the OLED and the transistors that drive it can be formed on the same substrate. In particular, when a silicon wafer is used as the substrate, it is possible to form the drive circuitry finely, which results in a higher density of OLEDs, which serve as light-emitting sources. This makes it possible to form higher-resolution images.

[0003] Patent Document 1 discloses an OLED-PH in which a plurality of rectangular light-emitting devices, each equipped with a plurality of OLEDs, are arranged in a line. In this OLED-PH, each light-emitting device has a plurality of OLEDs that receive current through a common power line. Therefore, by reducing the cost of the light-emitting devices, further cost reductions for the OLED-PH can be achieved.

[0004] Here, multiple light-emitting devices can be formed on a substrate and then cut out to obtain individual light-emitting devices. Therefore, increasing the yield of light-emitting devices per substrate can reduce costs.

[0005] Furthermore, in each OLED in Patent Document 1, the lower electrode is an independent electrode, and the upper electrode is a common electrode. The upper electrode is generally made of a material that is transparent to the emission wavelength of the light-emitting layer, resulting in high resistance. Furthermore, since the upper electrode is a common electrode, the drive current for multiple OLEDs flows into it, resulting in a large voltage drop. As a result, unevenness in the luminance of emitted light may occur. To suppress the voltage drop in the upper electrode, it is desirable to have multiple contact areas between the upper electrode and low-resistance wiring that supplies potential to the upper electrode.

[0006] In the OLED manufacturing process, OLEDs are formed by depositing electrodes and organic layers on a substrate using a vacuum deposition method using a deposition mask. Because the opening area of ​​this deposition mask is large, it is prone to bending. By abutting a portion of the deposition mask against the substrate, the bending of the deposition mask is suppressed. For this reason, columnar structures called ribs are formed on the deposition mask for abutment. For rectangular light-emitting devices, the aspect ratio of the opening in the deposition mask is large, making the mask more likely to bend in the long-side direction of the opening. Therefore, a rib abutment region must be positioned along the long-side direction between adjacent light-emitting devices in the short-side direction. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-30565 Summary of the Invention [Problem to be solved by the invention]

[0008] As mentioned above, in order to suppress the voltage drop of the upper electrode (common electrode), it is effective to arrange the contact area between the upper electrode and the low resistance wiring for supplying a potential to the upper electrode along the long side direction. On the other hand, it is necessary to arrange the rib contact area along the long side direction. The contact area must be positioned to avoid interference with the terminal pads and rib contact areas that are used for external electrical connection. For example, the contact area, terminal pads, and rib contact areas can be positioned in this order along the short side from the OLED placement area. However, such a placement increases the chip size, reducing the yield of light-emitting devices per substrate and hindering cost reduction.

[0009] An object of the present disclosure is to provide a light-emitting device that can improve yield and reduce costs. [Means for solving the problem]

[0010] A first aspect of the present disclosure is a polygonal substrate whose long side direction is a first direction and whose short side direction is a second direction; a light-emitting region in which a plurality of light-emitting elements are disposed, each having a light-emitting layer provided on the substrate and a first electrode and a second electrode sandwiching the light-emitting layer; a first contact region electrically connected to the second electrode, the first contact region being disposed in a peripheral region of the light emitting region of the substrate; a moisture-resistant ring provided on the substrate and surrounding the light-emitting region and the first contact region; Equipped with the first electrode is provided for each of the plurality of light-emitting elements, and the second electrode is a common electrode shared by the plurality of light-emitting elements; the moisture-resistant ring has a first portion disposed on one long side of the substrate with respect to the light-emitting region at a first distance from the long side in the second direction, and a second portion disposed at a second distance from the long side in the second direction, the first distance is greater than the second distance; the first contact region is adjacent to the second portion of the moisture-resistant ring and is disposed in a region on the light-emitting region side of the moisture-resistant ring; The light-emitting device is characterized by:

[0011] A second aspect of the present disclosure is a polygonal substrate whose long side direction is a first direction and whose short side direction is a second direction; a light-emitting region in which a plurality of light-emitting elements are disposed, each having a light-emitting layer provided on the substrate and a first electrode and a second electrode sandwiching the light-emitting layer; a first contact region and a second contact region that are arranged in a peripheral region of the light-emitting region of the substrate and electrically connect to the second electrode; a moisture-resistant ring provided on the substrate and surrounding the light-emitting region, the first contact region, and the second contact region; Equipped with the first electrode is provided for each of the plurality of light-emitting elements, and the second electrode is a common electrode shared by the plurality of light-emitting elements; the moisture-resistant ring includes a first recess on one long side; the recess of the moisture-resistant ring is disposed between the first contact region and the second contact region. The light-emitting device is characterized by: [Effects of the Invention]

[0012] According to the present disclosure, it is possible to improve the yield of light-emitting devices and reduce costs. [Brief explanation of the drawings]

[0013] [Figure 1] 1 shows the arrangement of a substrate and a deposition mask of a light-emitting device according to Example 1. [Figure 2] FIG. 1 is a cross-sectional view of an example of a light-emitting device according to a first embodiment. [Figure 3] FIG. 1 is a plan view of an example of a light-emitting device according to a first embodiment. [Figure 4A] 4 is a cross-sectional view of an example of the light-emitting device of FIG. 3 taken along the AA' plane. [Figure 4B] FIG. 4 is a cross-sectional view of an example of the light-emitting device of FIG. 3 taken along the BB′ plane. [Figure 5] FIG. 10 is a plan view of an example of a light-emitting device according to a second embodiment. [Figure 6] FIG. 10 is a plan view of an example of a light-emitting device according to a second embodiment. [Figure 7]FIG. 7 is a cross-sectional view of an example of the light-emitting device of FIG. 6 taken along plane CC'. [Figure 8] FIG. 10 is a diagram showing the configuration of an image forming apparatus according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Example 1 Examples of light-emitting devices according to the present disclosure will be described with reference to Figures 1, 2, 3, 4A, and 4B. Note that the following embodiments are merely examples of the present invention, and the present invention is not limited to the numerical values, shapes, materials, components, arrangements and connection forms of the components, etc.

[0015] In the following, an OLED will be described as an example of a light-emitting element, but the present disclosure is not limited to OLEDs and can be applied to current-driven light-emitting devices in general.

[0016] FIG. 1(a) shows an example of light-emitting devices 002 according to this embodiment formed on a silicon wafer 001. The light-emitting devices 002 are formed in a matrix on the silicon wafer 001. In the case of polygonal (e.g., rectangular) light-emitting devices having long and short sides, the yield per silicon wafer varies greatly depending on the size of the short side, so making the short side as short as possible is effective in reducing costs. Furthermore, when a silicon wafer is used as the substrate, it becomes possible to form driving circuits with fine detail. As a result, it becomes possible to increase the density of OLEDs. Increasing the density enables the formation of higher-resolution images.

[0017] Figure 1(b) shows an example of a deposition mask 003 for forming an OLED on a light-emitting device 002. The deposition mask 003 has multiple openings 004 arranged at equal intervals between the openings 004 and the light-emitting devices 002. After the light-emitting devices 002 on the silicon wafer 001 and the openings 004 in the deposition mask 003 are overlapped in plan view, the silicon wafer 001 and the deposition mask 003 are brought into close contact, and electrodes and organic layers are deposited on the light-emitting devices by vacuum deposition to form an OLED.

[0018] Figure 1(c) shows an example of the cross-sectional structure of the silicon wafer 001 and the deposition mask 003 when they are in close contact. The deposition mask 003 has ribs 005. These ribs 005 make it possible to maintain a constant distance between the silicon wafer 001 and the deposition mask 003 when they are in close contact. The ribs 005 also minimize the area where the deposition mask 003 comes into contact with the light-emitting device 002, thereby suppressing or preventing the transfer of foreign matter and scratches to the light-emitting device 002 and suppressing or preventing the occurrence of sealing defects.

[0019] FIG. 2 is a cross-sectional view showing an example of an OLED and a transistor connected to the OLED.

[0020] A transistor is an example of an active element. The transistor may be a thin film transistor (TFT). Figure 2 shows an OLED 020 and a transistor 014.

[0021] The transistor 014 is disposed on a silicon substrate 010 and is composed of a transistor gate 013 , a transistor drain 012 , and a transistor source 011 .

[0022] There are a plurality of contact plugs 015_1 to 015_4 that electrically connect the drain 012 of the transistor and the OLED 020, and a plurality of metal wirings 016_1 to 016_4 that form wiring 017, and an insulating layer 019 is provided between each wiring. In Fig. 2, the insulating layer 019 is illustrated as a single layer, but it may also have a laminated structure of multiple layers.

[0023] The OLED 020 is composed of a first electrode 016-4, an organic compound layer 021 having a light-emitting layer, and a second electrode 022.

[0024] Although the organic compound layer 021 is illustrated as a single layer in FIG. 2, the organic compound layer 021 may be multiple layers. In the OLED 020, the second electrode 022 is a transparent electrode, allowing light from the organic compound layer 021 to be extracted to the outside. A protective layer 025 is provided on the second electrode 022 to reduce deterioration of the OLED. The second electrode 022 of the OLED 020 is shared by multiple OLEDs 020 and serves as a common electrode.

[0025] In the light-emitting device 002, the combination of the OLED 020 and the transistor 014 is repeatedly arranged in the row and column directions.

[0026] Between each OLED 020, a structure 027 having a large step is formed in the layer immediately below the organic compound layer 021. The structure 027 electrically separates the organic compound layers 021 while the second electrode 022 is formed to achieve electrical connection.

[0027] The method of electrical connection with the electrodes (source electrode, drain electrode) included in the transistor is not limited to the embodiment shown in Fig. 2. Either the source electrode or the drain electrode of the transistor may be electrically connected in accordance with the polarity of the first electrode 016_4 or the polarity of the transistor.

[0028] Although transistors are used as switching elements in FIG. 2, other switching elements may be used instead.

[0029] The transistor is not limited to a transistor using a single crystal silicon wafer, but may be a thin film transistor having an active layer on an insulating surface of a substrate, and examples of the active layer include single crystal silicon, non-single crystal silicon such as amorphous silicon and microcrystalline silicon, and non-single crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide.

[0030] 3 is a schematic diagram showing one form of a light-emitting device according to this embodiment. The light-emitting device according to this embodiment has a rectangular shape with long sides parallel to a first direction and short sides parallel to a direction intersecting the first direction.

[0031] In a light-emitting device, when the light-emitting region is formed along the long side direction, components other than the light-emitting region, such as a contact region, can be arranged in the peripheral region of the light-emitting region, adjacent to the light-emitting region in the short side direction.

[0032] The substrate 101 has a polygonal shape, and an example of a rectangular substrate 101 will be described here. In this specification, the long side direction of the rectangular substrate 101 is referred to as a first direction, and the short side direction perpendicular to the long side direction is referred to as a second direction. In addition, the polygon in this specification also includes shapes with rounded corners. A moisture-resistant ring 100 that serves to suppress and prevent moisture from penetrating into the light-emitting device is disposed on the rectangular substrate 101. Furthermore, a light-emitting region 102, a first contact region 103_1 and a second contact region 103_2, and pads 104_1 and 104_2 are disposed inside the moisture-resistant ring 100. Light-emitting elements are arranged in a matrix in the light-emitting region 102. The first contact region 103_1 and the second contact region 103_ A wiring electrically connected to a common electrode of the OLED is disposed in an area 2. Pads 104_1 and 104_2 are electrically connected to the contact area.

[0033] A plurality of light-emitting elements are arranged in a matrix in light-emitting region 102. As described above, each light-emitting element is composed of a light-emitting layer and a first electrode and a second electrode that sandwich the light-emitting layer, the first electrode being an independent electrode provided for each light-emitting element, and the second electrode being a common electrode provided for all light-emitting elements.

[0034] The first contact region 103_1 and the second contact region 103_2 are adjacent to the light-emitting region 102 of the substrate 101 and are provided inside the moisture-resistant ring 100. The recess 105, the first contact region 103_1 and the second contact region 103_2, and the pads 104_1 and 104_2 are arranged between the light-emitting region 102 and one long side end of the substrate 101. In other words, the recess 105, the first contact region 103_1 and the second contact region 103_2, and the pads 104_1 and 104_2 are arranged on the same side in the short side direction with respect to the light-emitting region 102. The recess 105 is arranged between the first contact region 103_1 and the second contact region 103_2. The recess 105, the first contact region 103_1 and the second contact region 103_2, and the pads 104_1 and 104_2 are arranged in series in the long side direction. In the example of FIG. 3, the pad 104_1, the first contact region 103_1, the recess 105, the second contact region 103_2, and the pad 104_2 are arranged in series in this order along the long side.

[0035] The moisture-resistant ring 100 is a guard ring made of a wiring layer and is provided to surround the light-emitting region 102, the first contact region 103_1, the second contact region 103_2, and the pads 104_1 and 104_2. The moisture-resistant ring 100 has one or more recesses 105 on one of the long sides of the substrate. The moisture-resistant ring 100 has a narrow portion 100_2 and wide portions 100_1 and 100_3 provided on both sides of the narrow portion 100_2 in the long side direction (first direction). The wide portion here refers to a portion of the shape of the portion enclosed by the moisture-resistant ring 100 that is wider in the short axis direction than the other portions. Similarly, the narrow portion refers to a portion of the shape of the portion enclosed by the moisture-resistant ring 100 that is narrower in the short axis direction than the other portions. Therefore, the width of the narrow portion 100_2 in the short side direction (second direction) is shorter than the width of the wide portions 100_1 and 100_3 in the short side direction, and the width of the wide portions 100_1 and 100_3 in the short side direction is longer than the width of the narrow portion 100_2 in the short side direction.

[0036] In other words, the moisture-resistant ring 100 has a first portion and a second portion extending along one side of the substrate 101 (for example, a side extending in the long side direction or the first direction). The distance (first distance) from the side of the substrate 101 (the side where the first and second portions face each other, the lower side in FIG. 3) to the first portion is greater than the distance (second distance) from the side of the substrate 101 to the second portion. That is, the distance from the side of the substrate 101 to the first portion is greater than the distance from the side of the substrate to the second portion. Thus, for example, the narrow portion 100_2 may have the first portion. Also, the wide portion 100_1 or 100_3 may have the second portion.

[0037] The position of one long side of the narrow portion 100_2 and the wide portions 100_1 and 100_3 in the short side direction is the same, but the position of the other long side of the narrow portion 100_2 in the short side direction is different. Due to the presence of the narrow portion 100_2, the moisture-resistant ring 100 has a concave portion on its outer periphery. This portion is referred to as a recess 105 in this embodiment. The recess 105 is an abutment region for abutting a rib that is part of a mask for vapor deposition in a film-forming process. The narrow portion 100_2 has a shorter width in the short side direction than the wide portions 100_1 and 100_3 by the width in the short side direction of the recess 105. The first contact region 103_1 and the second contact region 103_2 are disposed within the wide portions 100_1 and 100_3 of the moisture-resistant ring 100, respectively. In other words, the first contact region 103_1 and the second contact region 103_2 are adjacent to the second portion of the moisture-resistant ring 100 and are disposed in regions on the light-emitting region side of the moisture-resistant ring 100.

[0038] A drive circuit for the light-emitting device is formed inside the moisture-resistant ring 100 (not shown). During OLED formation, the rib 005 of the deposition mask 003 abuts against the recess 105 of the moisture-resistant ring 100—in other words, the outer surface of the moisture-resistant ring 100 at the narrow portion 100_2—maintaining a certain distance. The rib 005 minimizes the contact area between the deposition mask and the light-emitting device, suppressing or preventing the transfer of foreign matter and scratches to the light-emitting device and suppressing or preventing sealing defects. Furthermore, if the rib 005 abuts against the substrate, scratches may occur in the insulating film on the substrate, potentially reducing the sealing performance of the light-emitting device. In this embodiment, the recess 105, which serves as the abutment area for the rib 005, is positioned on the outer surface of the moisture-resistant ring to ensure the sealing performance of the device.

[0039] The second electrode (top electrode / common electrode) 022 of the OLED in this embodiment is made of a transparent electrode material, and therefore has a relatively high wiring resistance. Furthermore, because the second electrode 022 also serves as a common electrode, current flows from multiple OLEDs, resulting in a large voltage drop across the second electrode 022. Therefore, differences in the voltage applied to each OLED occur depending on the distance from the contact region where the potential is supplied. This can result in differences in actual light emission brightness between OLEDs to which a voltage is applied to emit light with the same brightness, potentially resulting in shading and other issues.

[0040] The light-emitting device of this embodiment has at least two contact regions (103_1, 103_2) between the second electrode (upper electrode / common electrode) 022 and the power supply wiring along the long side edge of the light-emitting device. By contacting the second electrode 022 at multiple positions in the long side direction with the low-resistance power supply wiring, the resistance of the second electrode 022 can be reduced. Therefore, even if multiple OLEDs have a common second electrode 022, it is possible to suppress position-dependent voltage drop of the second electrode 022 and suppress shading of light emission brightness.

[0041] It is also possible to arrange the first contact region 103_1 or the second contact region 103_2 and the abutment region of the rib 005 of the deposition mask 003 in series along the short side of the chip. However, in that case, a dedicated rib area would be provided between the light-emitting devices in the short side direction, and the chip size would increase by the amount of the dedicated rib area. In the light-emitting device of this embodiment, the recess 105 of the moisture-resistant ring, which is the rib abutment region, is arranged between the first contact region 103_1 and the second contact region 103_2, thereby reducing the distance between the light-emitting devices in the short side direction. This increases the number of light-emitting devices that can be arranged in the short side direction on a single silicon wafer, thereby improving yield.

[0042] 4A is a cross-sectional view taken along the line A-A' of the light-emitting device of FIG. 3. The moisture-resistant ring 040_2 has a layered structure in which contact plugs 045_1 to 045_4 and metal wirings 046_1 to 046_4 are stacked, and extends from the surface of the light-emitting device to a depth reaching the silicon substrate 010 on which circuit elements are formed. The contact plugs 045_1 to 045_4 and metal wirings 046_1 to 046_4 constituting the moisture-resistant ring 040_2 are formed in the same layer as the contact plugs 015_1 to 015_4 and metal wirings 016_1 to 016_4 constituting the wiring 017. In this way, the moisture-resistant ring 040 has the same layer structure as the multilayer wiring structure of the internal circuit, and can be formed simultaneously with the internal circuit using a common process.

[0043] The cross-sectional structure of the moisture-resistant ring 100 is the same as that of the moisture-resistant ring 040_2 at any point in the light-emitting device, so that the moisture-resistant ring 040_2 and the moisture-resistant ring 040_1 have the same cross-sectional structure.

[0044] In addition, the moisture-proof rings 040_1 to 040_2 and the OLED protective layer 025 are not in physical contact with each other. This reduces or prevents moisture penetration into the OLED.

[0045] The protective layer 025 of the OLED is removed in the scribe area 041. This reduces or prevents chipping of the protective layer 025 when cutting the light-emitting device from the silicon wafer.

[0046] In the contact region 103_1, the second electrode (common electrode) 022 of the OLED and the metal wiring 056-4 are in physical contact. The pad 104_1 is composed of the metal wiring 056_3 in the same layer as the metal wiring 046_3. A low-resistance power supply wiring is laid from the pad 104_1 to directly below the contact region 103_1, and the contact plug 055-4 provides low-resistance electrical conduction between the metal wiring 056_3 and the metal wiring 056_4. In this embodiment, the pad is in the same layer as the metal wiring 046_3, but it may also be in the same layer as the metal wiring 046_4, and the cross-sectional structure of this embodiment is not limited to this.

[0047] 4B is a cross-sectional view taken along the line B-B' of the light-emitting device of FIG. 3. The moisture-resistant ring 040_3 has a layered structure in which contact plugs 045_1 to 045_4 and metal wirings 046_1 to 046_4 are stacked, and extends from the surface of the light-emitting device to a depth reaching the silicon substrate 010 on which circuit elements are formed. The contact plugs 045_1 to 045_4 and metal wirings 046_1 to 046_4 constituting the moisture-resistant ring 040_3 can be formed, for example, in the same layer as the contact plugs 015_1 to 015_4 and metal wirings 016_1 to 016_4 constituting the wiring 017. In this way, the moisture-resistant ring 040 has the same layer structure as the multilayer wiring structure of the internal circuit, and can be formed simultaneously with the internal circuit using a common process.

[0048] The cross-sectional structure of the moisture-resistant ring 100 may be the same as that of the moisture-resistant ring 040_1 at any point in the light-emitting device. In this case, the moisture-resistant ring 040_1, the moisture-resistant ring 040_3, and the moisture-resistant ring 040_4 have the same cross-sectional structure.

[0049] The moisture-resistant rings 040_1 to 040_4 are in physical contact with the protective layer 025 of the OLED, and serve to reduce or prevent moisture penetration into the OLED. The moisture-resistant ring 040 may have one or more of the contact plugs 045 and metal wiring 046 partially replaced with a layer made of the same material as the protective layer 025. Since the protective layer 025 is made of a material that can reduce moisture penetration, the moisture resistance of the moisture-resistant ring 040 can be maintained even with such a replacement.

[0050] The protective layer 025 of the OLED is removed in the scribe area 041. This reduces or prevents chipping of the protective layer 025 when cutting the light-emitting device from the silicon wafer.

[0051] Along the B-B' cross section, the light-emitting region 102 is provided with four light-emitting elements 020_1 to 020_4 and four transistors 014_1 to 014_4 electrically connected to the light-emitting elements. In the contact region 103_2, the second electrode (common electrode) 022 of the OLED and the metal wiring 056-4 are physically in contact with each other. The pad 104_2 is formed by a metal wiring 056_3 in the same layer as the metal wiring 046_3. A low-resistance power supply wiring 056_3 is routed from the pad 104_2 to directly below the contact region 103_2, and a contact plug 055-4 provides low-resistance electrical continuity between the metal wiring 056_3 and the metal wiring 056_4. In this embodiment, the pad is in the same layer as the metal wiring 046_3, but it may also be in the same layer as the metal wiring 046_4, and the cross-sectional structure is not limited to this embodiment.

[0052] By adopting the configuration described in this example, it is possible to suppress shading of the brightness of the light-emitting device. In addition, the yield can be improved and production can be carried out at low cost.

[0053] Example 2 A second embodiment of the light-emitting device according to the present disclosure will now be described in detail. Only the outline and differences from the first embodiment will be described, and the same or similar parts will be denoted by the same reference numerals and will not be described again.

[0054] FIG. 5 is a schematic diagram showing one form of a light-emitting device according to this embodiment.

[0055] Arranged on a rectangular substrate 101 are a moisture-resistant ring 200, a light-emitting area 102 in which light-emitting pixels arranged in rows and columns are arranged, contact areas 203_1 to 203_5 electrically connected to a common electrode of the OLED, and pads 204_1 to 204_3 electrically connected to the contact areas.

[0056] In this embodiment, the moisture-resistant ring 200 is configured by alternatingly arranging five wide portions 200_1, 200_3, 200_5, 200_7, and 200_9 and four narrow portions 200_2, 200_4, 200_6, and 200_8. The narrow portions 200_2, 200_4, 200_6, and 200_8 have widths in the short side direction that are shorter than the widths in the short side direction of the wide portions 200_1, 200_3, 200_5, 200_7, and 200_9. As in the first embodiment, the wide portions 200_1, 200_3, 200_5, 200_7, and 200_9 may have second portions, and the narrow portions 200_2, 200_4, 200_6, and 200_8 may have first portions. Here, an example is shown in which there are five wide portions and four narrow portions, but the number is not particularly limited.

[0057] Due to the presence of the wide portions 200_1, 200_3, 200_5, 200_7, and 200_9, the outer peripheral shape of the moisture-resistant ring 200 includes multiple recessed portions. In this embodiment, these recessed portions are referred to as recessed portions 205_1 to 205_4 of the moisture-resistant ring. The recessed portions 205_1 to 205_4 are contact areas for contacting ribs, which are part of a vapor deposition mask used in the film formation process. In this embodiment, multiple recessed portions 205_1 to 205_4 of the moisture-resistant ring 200 are arranged along the long sides of the light-emitting device. This reduces the spacing between the rib contact areas on the silicon wafer, thereby suppressing deflection of the vapor deposition mask. Furthermore, by reducing the spacing between the rib contact areas, the length of each recessed portion, which serves as a contact area, along the long side can be shortened, thereby reducing the distance between the first and second contact regions. This reduces the resistance of the common electrode in the center of the light-emitting device, thereby further suppressing brightness shading in the light-emitting device. By alternately arranging the contact regions 203_1 to 203_3 of the common electrode and power supply wiring and the recesses 205_1 to 205_3 of the moisture-resistant ring on the light-emitting device, the resistance of the common electrode can be reduced at a plurality of locations.

[0058] By arranging components other than the light-emitting region, such as the contact region of the light-emitting device, in series in the long side direction, the light-emitting device can be further miniaturized, increasing the yield on the silicon wafer and reducing costs. In this specification, "component A and component B are arranged in series in a first direction" means that component A and component B have an overlapping portion when viewed in plan from the first direction on a plane perpendicular to the first direction.

[0059] 6 is a schematic diagram showing another embodiment of the light-emitting device according to the present invention. Compared with the light-emitting device of FIG. 5, some circuits 206_1 to 206_2 for driving the light-emitting devices are added. The circuits 206_1 to 206_2 are arranged in series in the long side direction. In other words, the circuits 206_1 to 206_2 are arranged in series in the long side direction. 2are additionally arranged so as to overlap in a plan view with respect to a surface perpendicular to the long side direction. The circuits 206_1 to 206_2 are also arranged in series with the contact regions 203_1 to 203_3 and the pads 204_1 to 204_3 in the long side direction.

[0060] Specific examples of the circuits 206_1 to 206_2 include, but are not limited to, an input protection circuit, an input circuit to which each driving data is input, a logic circuit for processing data, etc. Regardless of the type of circuit, by providing a circuit region in the same position in the short side direction as the contact region and the pad region and arranging the circuit in the circuit region, it becomes possible to reduce the length in the short side direction of the light-emitting device.

[0061] Fig. 7 is a cross-sectional view taken along the line CC' of the light emitting device of Fig. 6. Compared to Fig. 4A, this device has a structure in which a circuit 206_1 is added.

[0062] By adopting the configuration described in this example, it is possible to effectively suppress shading of the brightness of the light-emitting device.

[0063] Example 3 FIG. 8A is a schematic diagram of an image forming apparatus 340 according to an embodiment of the present disclosure. The image forming apparatus 340 includes a photoconductor 327, an exposure unit 328, a development unit 331, a charging unit 330, a transfer unit 332, a transport unit 333, and a fixing unit 335. Light 329 from the exposure unit 328 is irradiated onto the photoconductor 327, forming an electrostatic latent image on the surface of the photoconductor 327. The light-emitting device according to the first or second embodiment is used as an exposure light source for the exposure unit 328. The development unit 331 includes toner, etc. The charging unit 330 charges the photoconductor 327. The transfer unit 332 transfers the developed image to a recording medium 334. The transport unit 333 transports the recording medium 334. The recording medium 334 is, for example, paper. The fixing unit 335 fixes the image formed on the recording medium.

[0064] 8(b) and 8(c) are schematic diagrams showing the arrangement of multiple light-emitting devices 336 in the exposure section 328. Line 337 indicates the direction parallel to the axis of the photoconductor, representing the direction in which the OLEDs are arranged. This direction is the same as the direction of the axis about which the photoconductor 327 rotates. This direction can also be called the long axis direction of the photoconductor 327. In FIG. 8(b), the OLEDs are arranged along the long axis direction of the photoconductor 327.

[0065] FIG. 8(c) shows an arrangement of light-emitting devices 338 different from that shown in FIG. 8(b). In this example, the light-emitting devices are arranged in four columns in a direction (row direction) intersecting the long axis direction. The light-emitting devices 338 are arranged to form a first column, a second column, a third column, and a fourth column in that order. In each of the first and second columns, the light-emitting portions are arranged alternately in the column direction. In other words, the light-emitting devices 338 in the first column and the light-emitting devices 338 in the second column are arranged at different positions in the row direction.

[0066] In the first column, a plurality of light-emitting devices 338 are arranged at intervals. In the second column, light-emitting devices are arranged at positions corresponding to the spaces between the light-emitting devices 338 in the first column. That is, a plurality of light-emitting units are also arranged at intervals in the row direction.

[0067] The arrangement in FIG. 8(c) can also be described as a grid arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0068] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention.

[0069] The disclosure of this embodiment includes the following configuration. (Configuration 1) a polygonal substrate whose long side direction is a first direction and whose short side direction is a second direction; a light-emitting region in which a plurality of light-emitting elements are disposed, each having a light-emitting layer provided on the substrate and a first electrode and a second electrode sandwiching the light-emitting layer; a first contact region electrically connected to the second electrode, the first contact region being disposed in a peripheral region of the light emitting region of the substrate; a moisture-resistant ring provided on the substrate and surrounding the light-emitting region and the first contact region; Equipped with the first electrode is provided for each of the plurality of light-emitting elements, and the second electrode is a common electrode shared by the plurality of light-emitting elements; the moisture-resistant ring has a first portion disposed on one long side of the substrate with respect to the light-emitting region at a first distance from the long side in the second direction, and a second portion disposed at a second distance from the long side in the second direction, the first distance is greater than the second distance; the first contact region is adjacent to the second portion of the moisture-resistant ring and is disposed in a region on the light-emitting region side of the moisture-resistant ring; A light-emitting device characterized by: (Configuration 2) the moisture-resistant ring has a first narrow portion having the first portion on the one long side and a first wide portion having the second portion on the one long side, the first wide portion and the second wide portion are provided on both sides of the first narrow portion of the moisture-resistant ring in the first direction, the first contact region is provided in the first wide portion; a second contact region electrically connected to the second electrode is provided in the second wide portion; 2. The light-emitting device according to claim 1. (Configuration 3) the first narrow portion and the first wide portion are positioned differently in the second direction relative to the one long side, The positions of the first narrow width portion and the first wide width portion in the second direction with respect to the other long side are the same. 3. The light-emitting device according to claim 1 or 2. (Configuration 4) the first contact region is disposed on the first wide portion of the moisture-resistant ring on the side of the one long side with respect to the light-emitting region; 4. The light-emitting device according to configuration 3. (Configuration 5) a pad electrically connected to the first contact region, the pad being disposed adjacent to the second portion and on the light-emitting region side of the moisture-resistant ring; 5. The light-emitting device according to any one of configurations 1 to 4. (Configuration 6) a circuit region in which a part of a circuit for driving the light-emitting element is formed, the circuit region being adjacent to the two portions and located on the light-emitting area side with respect to the moisture-resistant ring; 6. The light-emitting device according to any one of configurations 1 to 5. (Configuration 7) the moisture-resistant ring has a first narrow portion having the first portion on the one long side and a first wide portion having the second portion on the one long side, The moisture-resistant ring includes the first narrow portion, a second narrow portion disposed on the one long side of the light-emitting region, and the first wide portion disposed between the first narrow portion and the second narrow portion. 2. The light-emitting device according to claim 1. (Configuration 8) a polygonal substrate whose long side direction is a first direction and whose short side direction is a second direction; a light-emitting region in which a plurality of light-emitting elements are disposed, each having a light-emitting layer provided on the substrate and a first electrode and a second electrode sandwiching the light-emitting layer; a first contact region and a second contact region that are arranged in a peripheral region of the light-emitting region of the substrate and electrically connect to the second electrode; a moisture-resistant ring provided on the substrate and surrounding the light-emitting region, the first contact region, and the second contact region; Equipped with the first electrode is provided for each of the plurality of light-emitting elements, and the second electrode is a common electrode shared by the plurality of light-emitting elements; the moisture-resistant ring includes a first recess on one long side; the recess of the moisture-resistant ring is disposed between the first contact region and the second contact region. A light-emitting device characterized by: (Configuration 9) the moisture-resistant ring further includes a second recess on the one long side, the second recess, the first contact region, the first recess, and the second contact region are arranged in this order; 9. The light-emitting device of claim 8. (Configuration 10) the first contact region, the second contact region, and the recess of the moisture-resistant ring are disposed between the light-emitting region and one long side end of the substrate; 9. The light-emitting device of claim 8. (Configuration 11) the first contact region, the recess of the moisture-resistant ring, and the second contact region are arranged in series in the first direction. 9. The light-emitting device of claim 8. (Configuration 12) the recessed portion of the moisture-resistant ring is a region with which a part of a vapor deposition mask comes into contact when the light-emitting element is formed; 9. The light-emitting device of claim 8, (Configuration 13) a first pad and a second pad disposed in a peripheral region of the light emitting region of the substrate and electrically connected to the first contact region and the second contact region, respectively; the first contact region, the first pad, the recess of the moisture-resistant ring, the second contact region, and the second pad are arranged between the light-emitting region and one long side end of the substrate; 9. The light-emitting device of claim 8. (Configuration 14) the first pad, the first contact region, the recess of the moisture-resistant ring, the second contact region, and the second pad are arranged in series in the first direction. 14. The light-emitting device of claim 13. (Configuration 15) a circuit region in which a part of a circuit for driving the light emitting element is formed, the circuit region being disposed in a peripheral region of the light emitting area of ​​the substrate; the first contact region, the second contact region, the circuit region, and the recessed portion of the moisture-resistant ring are disposed between the light-emitting region and one long side end of the substrate; 9. The light-emitting device of claim 8. (Configuration 16) the first contact region, the circuit region, the recess of the moisture-resistant ring, and the second contact region are arranged in series in the first direction. 16. The light-emitting device of claim 15. (Configuration 17) a first pad and a second pad disposed in a peripheral region of the light emitting region of the substrate and electrically connected to the first contact region and the second contact region, respectively; a circuit region disposed in a peripheral region of the light-emitting region of the substrate, the circuit region forming a part of a circuit for driving the light-emitting element; Furthermore, the first contact region, the second contact region, the first pad, the second pad, the circuit region, and the recess of the moisture-resistant ring are disposed between the light-emitting region and one long side end of the substrate; 9. The light-emitting device of claim 8. (Configuration 18) the first pad, the first contact region, the circuit region, the recess of the moisture-resistant ring, the second contact region, and the second pad are arranged in series in the first direction; 18. The light-emitting device of claim 17. (Configuration 19) A photoreceptor; a charging unit that charges the photosensitive member; an exposure unit having the light-emitting device according to any one of configurations 1 to 18 and forming an electrostatic latent image on the surface of the photoreceptor; a developing unit that develops the electrostatic latent image; a transfer unit that transfers the developed image onto a recording medium; An image forming apparatus comprising: [Explanation of symbols]

[0070] 100: Moisture-resistant ring 101: Substrate 102: Light-emitting region 103: Contact region 105: Recess 203: Contact region 204: Pad 205: Recess

Claims

1. a polygonal substrate whose long side direction is a first direction and whose short side direction is a second direction; a light-emitting region in which a plurality of light-emitting elements are disposed, each having a light-emitting layer provided on the substrate and a first electrode and a second electrode sandwiching the light-emitting layer; a first contact region electrically connected to the second electrode, the first contact region being disposed in a peripheral region of the light emitting region of the substrate; a moisture-resistant ring provided on the substrate and surrounding the light-emitting region and the first contact region; Equipped with the first electrode is provided for each of the plurality of light-emitting elements, and the second electrode is a common electrode shared by the plurality of light-emitting elements; the moisture-resistant ring has a first portion disposed on one long side of the substrate with respect to the light-emitting region at a first distance from the long side in the second direction, and a second portion disposed at a second distance from the long side in the second direction, the first distance is greater than the second distance; the first contact region is adjacent to the second portion of the moisture-resistant ring and is disposed in a region on the light-emitting region side of the moisture-resistant ring; A light-emitting device characterized by:

2. the moisture-resistant ring has a first narrow portion having the first portion on the one long side and a first wide portion having the second portion on the one long side, the first wide portion and the second wide portion are provided on both sides of the first narrow portion of the moisture-resistant ring in the first direction, the first contact region is provided in the first wide portion; a second contact region electrically connected to the second electrode is provided in the second wide portion; 10. The light emitting device of claim 1.

3. The first narrow width portion and the first wide width portion are positioned differently in the second direction relative to the one long side. And the first narrow portion and the first wide portion are positioned in the same position in the second direction relative to the other long side; 3. The light-emitting device of claim 2.

4. the first contact region is disposed on the first wide portion of the moisture-resistant ring on the side of the one long side with respect to the light-emitting region; 4. The light-emitting device according to claim 3.

5. a pad electrically connected to the first contact region, the pad being disposed adjacent to the second portion and on the light emitting region side of the moisture-resistant ring; 10. The light emitting device of claim 1.

6. a circuit region in which a part of a circuit for driving the light-emitting element is formed, the circuit region being adjacent to the second portion and disposed in the region on the light-emitting area side with respect to the moisture-resistant ring; 10. The light emitting device of claim 1.

7. the moisture-resistant ring has a first narrow portion having the first portion on the one long side and a first wide portion having the second portion on the one long side, The moisture-resistant ring includes the first narrow portion, a second narrow portion disposed on the one long side of the light-emitting region, and the first wide portion disposed between the first narrow portion and the second narrow portion.

10. The light emitting device of claim 1.

8. a polygonal substrate whose long side direction is a first direction and whose short side direction is a second direction; a light-emitting region in which a plurality of light-emitting elements are disposed, each having a light-emitting layer provided on the substrate and a first electrode and a second electrode sandwiching the light-emitting layer; a first contact region and a second contact region that are arranged in a peripheral region of the light-emitting region of the substrate and electrically connect to the second electrode; a moisture-resistant ring provided on the substrate and surrounding the light-emitting region, the first contact region, and the second contact region; Equipped with the first electrode is provided for each of the plurality of light-emitting elements, and the second electrode is a common electrode shared by the plurality of light-emitting elements; the moisture-resistant ring includes a first recess on one long side; the first recess of the moisture-resistant ring is disposed between the first contact region and the second contact region; A light-emitting device characterized by:

9. the moisture-resistant ring further includes a second recess on the one long side, the second recess, the first contact region, the first recess, and the second contact region are arranged in this order; 9. The light emitting device of claim 8.

10. the first contact region, the second contact region, and the first recess of the moisture-resistant ring are disposed between the light-emitting region and one long side end of the substrate; 9. The light emitting device of claim 8.

11. The first contact region, the first recess of the moisture-resistant ring, and the second contact The regions are arranged in series with respect to the first direction.

9. The light emitting device of claim 8.

12. a first pad and a second pad disposed in a peripheral region of the light emitting region of the substrate and electrically connected to the first contact region and the second contact region, respectively; the first contact region, the first pad, the first recess of the moisture-resistant ring, the second contact region, and the second pad are arranged between the light-emitting region and one long side end of the substrate; 9. The light emitting device of claim 8.

13. the first pad, the first contact region, the first recess of the moisture-resistant ring, the second contact region, and the second pad are arranged in series in the first direction.

13. The light emitting device of claim 12.

14. a circuit region in which a part of a circuit for driving the light emitting element is formed, the circuit region being disposed in a peripheral region of the light emitting area of ​​the substrate; the first contact region, the second contact region, the circuit region, and the first recess of the moisture-resistant ring are disposed between the light-emitting region and one long side end of the substrate; 9. The light emitting device of claim 8.

15. the first contact region, the circuit region, the first recess of the moisture-resistant ring, and the second contact region are arranged in series in the first direction.

15. The light emitting device of claim 14.

16. a first pad and a second pad disposed in a peripheral region of the light-emitting region of the substrate and electrically connected to the first contact region and the second contact region, respectively; a circuit region disposed in a peripheral region of the light-emitting region of the substrate, the circuit region forming a part of a circuit for driving the light-emitting element; Furthermore, the first contact region, the second contact region, the first pad, the second pad, the circuit region, and the first recess of the moisture-resistant ring are disposed between the light-emitting region and one long side end of the substrate; 9. The light emitting device of claim 8.

17. the first pad, the first contact region, the circuit region, the first recess of the moisture-resistant ring, the second contact region, and the second pad are arranged in series in the first direction; 17. The light emitting device of claim 16.

18. A photoreceptor; a charging unit that charges the photosensitive member; an exposure unit having the light-emitting device according to claim 1 and forming an electrostatic latent image on the surface of the photoreceptor; a developing unit that develops the electrostatic latent image; a transfer unit that transfers the developed image onto a recording medium; An image forming apparatus comprising:

Images