Light-emitting device

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) for use in image forming devices has been proposed, which uses an OLED as a light source. The OLED-PH has the advantage of being compact and low cost, since the OLED and the transistors for driving it can be formed on the same substrate. In particular, when a silicon wafer is used for the substrate, it is possible to form the driving circuit finely, which results in a high density of the OLED, which serves as the light source. This makes it possible to form images with higher resolution.

[0003] Patent Document 1 discloses an OLED-PH in which a plurality of rectangular light-emitting devices, each of which has a plurality of OLEDs, are arranged in a line. In this OLED-PH, each light-emitting device has a plurality of OLEDs that receive a current through a common power line. Therefore, by reducing the cost of the light-emitting devices, it is possible to further reduce the cost of the OLED-PH.

[0004] Here, a plurality of light emitting devices can be formed on a substrate and cut out to obtain individual light emitting devices, thereby increasing the yield of light emitting devices per substrate and reducing costs.

[0005] In addition, in each OLED of 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, and therefore has a high resistance. Furthermore, the upper electrode is a common electrode, and the driving current of multiple OLEDs flows into it, so the voltage drop is large. As a result, there is a possibility that unevenness in the emission brightness occurs. In order to suppress the voltage drop of the upper electrode, it is desirable to have multiple contact areas between the upper electrode and low-resistance wiring for supplying a potential to the upper electrode.

[0006] In the manufacturing process of OLEDs, electrodes and organic layers are deposited on a substrate by vacuum deposition using a deposition mask to form an OLED. This deposition mask is prone to bending due to its large opening area, and bending of the deposition mask is suppressed by abutting a part of the deposition mask with the substrate. For this reason, columnar structures for abutment, called ribs, are formed on the deposition mask. In the case of a rectangular light-emitting device, the aspect ratio of the opening of the deposition mask becomes large, and the mask is prone to bending in the long side direction of the opening. For this reason, it is necessary to arrange a rib abutment area between adjacent light-emitting devices in the short side direction along the long 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 described 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 abutment area in the long side direction. The contact area must be positioned to avoid interference with the terminal pads and rib contact area, which are used for electrical connection to the outside. For example, the contact area, terminal pads, and rib contact area can be positioned in this order in the short side direction from the OLED placement area. However, such a positioning 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] The first aspect of the present disclosure is A polygonal substrate having a long side direction as a first direction and a short side direction as a second direction; a light-emitting region in which a plurality of light-emitting elements are disposed, the light-emitting elements 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 with respect to the moisture-resistant ring; The light-emitting device is characterized in that

[0011] A second aspect of the present disclosure is A polygonal substrate having a long side direction as a first direction and a short side direction as a second direction; a light-emitting region in which a plurality of light-emitting elements are disposed, the light-emitting elements 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 electrically connected to the second electrode, the first contact region and the second 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, 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 in that Effect of the Invention

[0012] According to the present disclosure, it is possible to improve the yield of light-emitting devices and reduce costs. [Brief description 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. [Diagram 2] FIG. 2 is a cross-sectional view of an example of a light-emitting device according to the first embodiment. [Diagram 3] FIG. 1 is a plan view of an example of a light-emitting device according to a first embodiment. [Figure 4A] FIG. 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 line BB′. [Diagram 5] FIG. 11 is a plan view of an example of a light-emitting device according to a second embodiment. [Figure 6] FIG. 11 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. 11 is a diagram showing a configuration of an image forming apparatus according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Example 1 Examples of the light-emitting device 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 values, shapes, materials, components, arrangements and connection forms of the components, and the like do not limit the present invention.

[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 in which light-emitting devices 002 according to this embodiment are 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 a polygonal (e.g. rectangular) light-emitting device 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. In addition, when a silicon wafer is used as the substrate, it becomes possible to form driving circuits finely. As a result, it becomes possible to increase the density of the OLED. Increasing the density allows for the formation of higher-definition 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 therein, and the openings 004 are arranged at equal intervals to the light-emitting devices 002. After the light-emitting devices 002 on the silicon wafer 001 and the openings 004 of the deposition mask 003 are overlapped in a planar 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] FIG. 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 arranged thereon. 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 with each other. 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 schematic 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). In FIG. 2, an OLED 020 and a transistor 014 are shown.

[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 electrically connecting the drain 012 of the transistor and the OLED 020, and a plurality of metal wirings 016_1 to 016_4, and an insulating layer 019 is provided between each of the wirings. In Fig. 2, the insulating layer 019 is illustrated as a single layer, but it may be 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] 2, the organic compound layer is illustrated as a single layer, but the organic compound layer 021 may be a multi-layer structure. In the OLED 020, the second electrode 022 is a transparent electrode, and light from the organic compound layer 021 can 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 a 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 the 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, amorphous silicon, non-single crystal silicon such as 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 of this embodiment has a rectangular shape having 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 a region adjacent to the light-emitting region in the short side direction among the peripheral regions of the light-emitting region.

[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 a shape with rounded corners. A moisture-resistant ring 100 that plays a role in suppressing and preventing moisture from penetrating into the light-emitting device is arranged on the rectangular substrate 101. In addition, 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 arranged inside the moisture-resistant ring 100. Light-emitting elements are arranged in a row and column direction 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 a region 2. Pads 104_1 and 104_2 are electrically connected to the contact region.

[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 long side direction (first direction) of the narrow portion 100_2. The wide portion here refers to a portion in which the width of the shape of the portion enclosed by the moisture-resistant ring 100 is wider in the short axis direction than the other portions. Similarly, the narrow portion refers to a portion in which the width of the shape of the portion enclosed by the moisture-resistant ring 100 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 (e.g., a side extending in the long side direction or the first direction) of the substrate 101. The distance (first distance) from the side (the side where the first portion and the second portion face each other, the lower side in FIG. 3) of the substrate 101 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 of the long sides of the narrow portion 100_2 and the wide portions 100_1 and 100_3 in the short side direction is the same, and the position of the other long side 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 the 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 a part of a mask for deposition in a film formation 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 of the recess 105 in the short side direction. The first contact region 103_1 and the second contact region 103_2 are disposed in 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 driving circuit for the light-emitting device is formed inside the moisture-resistant ring 100 (not shown). When the OLED is formed, the rib 005 of the deposition mask 003 abuts against the recess 105 of the moisture-resistant ring 100, in other words, the outer side of the moisture-resistant ring 100 at the narrow width portion 100_2, to maintain a certain distance. The rib 005 serves to minimize the surface area where the deposition mask and the light-emitting device come into contact, suppress or prevent the transfer of foreign matter and the occurrence of scratches on the light-emitting device, and suppress or prevent the occurrence of sealing defects. In addition, if the rib 005 abuts against the substrate, scratches may occur in the insulating film on the substrate, and the sealing performance of the light-emitting device may be reduced. In this embodiment, the recess 105, which is the abutment area of ​​the rib 005, is arranged on the outer side of the moisture-resistant ring to ensure the sealing performance of the device.

[0039] The second electrode (upper 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. In addition, since the second electrode 022 is also a common electrode, current flows from multiple OLEDs, and the voltage drop at the second electrode 022 becomes large. Therefore, a difference occurs in the voltage applied to each OLED depending on the distance from the contact region where the potential is supplied. As a result, the actual emission brightness differs between OLEDs to which a voltage for emitting light with the same brightness is applied, and shading, etc. may occur.

[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. The resistance of the second electrode 022 can be reduced by contacting the second electrode 022 at multiple positions in the long side direction with the low-resistance power supply wiring. Therefore, even if multiple OLEDs have a common second electrode 022, it is possible to suppress the position-dependent voltage drop of the second electrode 022 and suppress shading of the 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 with respect to the short side direction of the chip. However, in that case, a region dedicated to the rib is provided between the light emitting devices in the short side direction, and the chip size increases by the amount of the dedicated rib region. 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. Therefore, the number of light emitting devices that can be arranged in the short side direction in one silicon wafer can be increased, thereby increasing the yield.

[0042] 4A is a cross-sectional view of the light-emitting device of FIG. 3 taken along line A-A'. The moisture-resistant ring 040_2 has a layered structure in which contact plugs 045_1-045_4 and metal wirings 046_1-046_4 are layered, and extends from the surface of the light-emitting device to a depth reaching the silicon substrate 010 on which the circuit elements are formed. The contact plugs 045_1-045_4 and metal wirings 046_1-046_4 constituting the moisture-resistant ring 040_2 are formed in the same layer as the contact plugs 015_1-015_4 and metal wirings 016_1-016_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 by 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-resistant rings 040_1-040_2 and the OLED protective layer 025 are not in physical contact with each other. This helps reduce or prevent moisture penetration into the OLED.

[0045] The protective layer 025 of the OLED is removed in the scribe region 041. This can reduce or prevent 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 drawn from the pad 104_1 to directly below the contact region 103_1, and the metal wiring 056_3 and the metal wiring 056_4 are electrically connected with low resistance by the contact plug 055-4. In this embodiment, the pad is in the same layer as the metal wiring 046_3, but it may be in the same layer as the metal wiring 046_4, and the cross-sectional structure of this embodiment is not limited.

[0047] 4B is a cross-sectional view of the light-emitting device of FIG. 3 taken along the line B-B'. The moisture-resistant ring 040_3 has a layered structure in which contact plugs 045_1-045_4 and metal wirings 046_1-046_4 are layered, and extends from the surface of the light-emitting device to a depth reaching the silicon substrate 010 on which the circuit elements are formed. The contact plugs 045_1-045_4 and metal wirings 046_1-046_4 constituting the moisture-resistant ring 040_3 can be formed in the same layer as the contact plugs 015_1-015_4 and metal wirings 016_1-016_4 constituting the wiring 017, for example. 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 by 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] Moreover, 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. In addition, the moisture-resistant ring 040 may have one or more of the contact plugs 045 and the 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 if such a replacement is made.

[0050] The protective layer 025 of the OLED is removed in the scribe region 041. This can reduce or prevent 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_1-020_4 and four transistors 014_1-014_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 made of a metal wiring 056_3 in the same layer as the metal wiring 046_3. A low-resistance power supply wiring 056_3 is drawn from the pad 104_2 to just below the contact region 103_2, and the metal wiring 056_3 and the metal wiring 056_4 are electrically connected with low resistance by the contact plug 055-4. In this embodiment, the pad is in the same layer as the metal wiring 046_3, but may be in the same layer as the metal wiring 046_4, and is not limited to the cross-sectional structure of this embodiment.

[0052] By adopting the configuration described in this embodiment, shading of the brightness of the light-emitting device can be suppressed. 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. Note that only the outline and the parts that are different 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.

[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 region 102 in which light-emitting pixels arranged in rows and columns are arranged, contact regions 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 regions.

[0056] In this embodiment, the moisture-resistant ring 200 is configured by alternately 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 are portions whose short-side widths are shorter than the short-side widths 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 numbers are 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 a plurality of recessed portions. In this embodiment, these portions are referred to as recesses 205_1 to 205_4 of the moisture-resistant ring. The recesses 205_1 to 205_4 are contact regions for contacting ribs that are part of a mask for deposition in a film-forming process. In this embodiment, the recesses 205_1 to 205_4 of the moisture-resistant ring 200 are arranged along the long side of the light-emitting device. Therefore, the arrangement interval of the rib abutment regions on the silicon wafer can be narrowed, and deflection of the deposition mask can be suppressed. Furthermore, by narrowing the arrangement interval of the rib abutment regions, the length of each recess that serves as the abutment region in the long side direction can be shortened, and the interval between the first contact region and the second contact region can be reduced. Therefore, the resistance of the common electrode in the center of the light-emitting device can be further reduced, and the luminance shading of the light-emitting device can be further suppressed. By alternately arranging the contact regions 203_1 to 203_3 between the common electrode and the power supply wiring and the recesses 205_1 to 205_3 of the moisture-resistant ring on the light-emitting device, it is possible to reduce the resistance of the common electrode 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, the yield on the silicon wafer can be increased, and costs can be reduced. 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 surface perpendicular to the first direction.

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

[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 data for each drive is input, a logic circuit for processing data, etc. Regardless of the type of circuit, the length of the light emitting device in the short side direction can be reduced by providing a circuit region in the same position as the contact region and the pad region in the short side direction and arranging the circuit in the circuit region.

[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, the light emitting device has a structure in which a circuit 206_1 is added.

[0062] By adopting the configuration described in this embodiment, shading of the luminance of the light emitting device can be effectively suppressed.

[0063] Example 3 FIG. 8(a) 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. The exposure unit 328 irradiates the photoconductor 327 with light 329, and an electrostatic latent image is formed on the surface of the photoconductor 327. The exposure unit 328 applies the light-emitting device according to the first or second embodiment as an exposure light source. The development unit 331 includes toner and the like. 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 how multiple light emitting devices 336 are arranged in the exposure section 328. Line 337 indicates the direction parallel to the axis of the photoconductor, and represents the direction in which the OLEDs are arranged. This direction is the same as the axis along 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 of 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 column and the second column, 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, the 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-like arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0068] The invention is not limited to the above-described embodiments, and various modifications and variations are possible 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 having a long side direction as a first direction and a short side direction as a second direction; a light-emitting region in which a plurality of light-emitting elements are disposed, the light-emitting elements 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 with respect to 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 with respect to the one long side, The positions of the first narrow portion and the first wide portion in the second direction relative 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 one long side side with respect to the light-emitting region; 4. The light-emitting device according to configuration 3. (Configuration 5) a pad electrically connecting to the first contact region, the pad being disposed in the region adjacent to the second portion and on the light emitting region side with respect to 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 disposed in the region adjacent to the two portions and 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 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 having a long side direction as a first direction and a short side direction as a second direction; a light-emitting region in which a plurality of light-emitting elements are disposed, the light-emitting elements 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 electrically connected to the second electrode, the first contact region and the second 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, 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 configuration 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 configuration 8. (Configuration 11) the first contact region, the recess of the moisture-resistant ring, and the second contact region are arranged in series with respect to the first direction. 9. The light emitting device of configuration 8. (Configuration 12) The recess of the moisture-resistant ring is a region with which a part of a mask for deposition comes into contact when the light-emitting element is formed. The light-emitting device according to configuration 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 disposed between the light-emitting region and one long side end of the substrate; 9. The light emitting device of configuration 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 with respect to 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 region of the substrate; the first contact region, the second contact region, 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 configuration 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 with respect to 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; Further equipped with 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 configuration 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 with respect to the first direction; 18. The light emitting device of claim 17. (Configuration 19) A photoconductor; A charging unit that charges the photoconductor; an exposure section 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 photoconductor; a developing section for developing the electrostatic latent image; a transfer section for transferring 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 having a long side direction as a first direction and a short side direction as a second direction; a light-emitting region in which a plurality of light-emitting elements are disposed, the light-emitting elements 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 with respect to 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; 2. The light emitting device of claim 1.

3. the first narrow portion and the first wide portion are positioned differently in the second direction with respect to the one long side, The positions of the first narrow portion and the first wide portion in the second direction with respect to the other long side are the same.

2. The light emitting device of claim 1.

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

5. a pad electrically connecting to the first contact region, the pad being disposed in the region adjacent to the second portion and on the light emitting region side with respect to the moisture resistant ring; 2. 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 disposed in the region adjacent to the two portions and on the light emitting area side with respect to the moisture resistant ring; 2. 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 is disposed on the first narrow portion and on one of the long sides of the light-emitting region. and the first wide portion is disposed between the first narrow portion and the second narrow portion.

2. The light emitting device of claim 1.

8. A polygonal substrate having a long side direction as a first direction and a short side direction as a second direction; a light-emitting region in which a plurality of light-emitting elements are disposed, the light-emitting elements 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 electrically connected to the second electrode, the first contact region and the second 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, 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:

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

9. The light emitting device of claim 8.

12. The recess of the moisture-resistant ring is a region with which a part of a mask for deposition comes into contact when the light-emitting element is formed.

9. The light emitting device according to claim 8,

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 disposed between the light-emitting region and one long side end of the substrate; 9. The light emitting device of claim 8.

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 with respect to the first direction.

14. The light emitting device of claim 13.

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 region of the substrate; The first contact region is disposed between the light emitting region and one long side end of the substrate. 2 contact area, the circuit area and the recess of the moisture-resistant ring are arranged; 9. The light emitting device of claim 8.

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

16. The light emitting device of claim 15.

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; Further equipped with 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.

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 with respect to the first direction; 20. The light emitting device of claim 17.

19. A photoconductor; A charging unit that charges the photoconductor; an exposure section having the light-emitting device according to claim 1 and forming an electrostatic latent image on a surface of the photoconductor; a developing section for developing the electrostatic latent image; a transfer section for transferring the developed image onto a recording medium; An image forming apparatus comprising:

Images