Light emitting device, light emitting module, and image forming device

Abstract

To provide a technique advantageous for stable operation of a light-emitting device.SOLUTION: There is provided a light emitting device including a substrate on which a light emitting region in which a plurality of light emitting elements are disposed, extending in a first direction as a longitudinal direction, a processing circuit for processing a data signal for controlling the light emitting brightness of the plurality of light emitting elements according to a clock signal, and a plurality of terminals aligned in the first direction for receiving supply of the clock signal, the data signal, and electric power are disposed. The plurality of terminals include a first terminal, and a second terminal and a third terminal disposed so as to be adjacent to each other. The processing circuit is disposed in the first direction with respect to the plurality of terminals. One of the clock signal and the data signal is supplied to the second terminal, and the other of the clock signal and the data signal is supplied to the third terminal.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a light-emitting device, a light-emitting module, and an image-forming apparatus. [Background technology]

[0002] A print head for an image forming apparatus has been proposed that uses an organic light-emitting diode (OLED) as a light source. Patent Document 1 discloses a light-emitting device in which an OLED and a driving transistor for driving the OLED are formed on a single substrate. Forming the OLED and the driving transistor on the same substrate enables miniaturization and cost reduction. Patent Document 1 also discloses that the light-emitting device receives a plurality of signals, such as clock signals and data signals, and performs signal processing within the device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-174522 Summary of the Invention [Problem to be solved by the invention]

[0004] In a light-emitting device such as that shown in Patent Document 1, it is conceivable to arrange multiple terminals that receive multiple signals and a processing circuit that processes the signals in a single direction in order to reduce the size of the device. In this case, the distance between each terminal and the processing circuit becomes long, so a layout that takes into account the signal delay between the terminal and the processing circuit is required.

[0005] An object of the present invention is to provide a technique that is advantageous for stable operation of a light-emitting device. [Means for solving the problem]

[0006] In view of the above problems, a light-emitting device according to an embodiment of the present invention is a light-emitting device including a substrate on which a plurality of light-emitting elements are arranged, a light-emitting region extending in a first direction as its longitudinal direction, a processing circuit that processes a data signal for controlling the light-emitting brightness of the plurality of light-emitting elements in accordance with a clock signal, and a plurality of terminals arranged in the first direction for receiving the clock signal, the data signal, and power, wherein the plurality of terminals include a first terminal, a second terminal, and a third terminal arranged adjacent to each other, and the processing circuit is arranged in the first direction relative to the plurality of terminals, and one of the clock signal and the data signal is supplied to the second terminal, and the other of the clock signal and the data signal is supplied to the third terminal. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a technique that is advantageous for stable operation of a light-emitting device. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a light-emitting device according to an embodiment of the present invention. [Figure 2] FIG. 3 is a timing chart showing an example of signals input to the light-emitting device of the present embodiment. [Figure 3] FIG. 2 is a layout diagram showing a configuration example of the light-emitting device of the present embodiment. [Figure 4] FIG. 2 is a layout diagram showing a configuration example of the light-emitting device of the present embodiment. [Figure 5] FIG. 3 is a timing chart showing an example of signals input to the light-emitting device of the present embodiment. [Figure 6] FIG. 1 is a block diagram showing an example of the configuration of a light-emitting device according to an embodiment of the present invention. [Figure 7] FIG. 2 is a layout diagram showing a configuration example of the light-emitting device of the present embodiment. [Figure 8] 3A and 3B are diagrams showing examples of layouts of light-emitting devices on a wafer according to the present embodiment; [Figure 9] 5A to 5C are diagrams showing an example of a wire bonding process for the light emitting device of the present embodiment. [Figure 10] FIG. 2 is a layout diagram showing a configuration example of the light-emitting device of the present embodiment. [Figure 11] FIG. 2 is a layout diagram showing an example of an exposure head using the light-emitting device of the present embodiment. [Figure 12] FIG. 2 is a cross-sectional view showing an example of the configuration of a pixel of the light-emitting device of the present embodiment. [Figure 13] FIG. 1 is a diagram showing an example of an image forming apparatus using a light-emitting device according to an embodiment of the present invention. [Figure 14] FIG. 1 is a diagram showing an example of a display device using the light-emitting device of the present embodiment. [Figure 15] FIG. 1 is a diagram showing an example of a photoelectric conversion device using the light-emitting device of the present embodiment. [Figure 16] 1A and 1B are diagrams showing examples of electronic equipment using the light-emitting device of the present embodiment. [Figure 17] FIG. 1 is a diagram showing an example of a display device using the light-emitting device of the present embodiment. [Figure 18] FIG. 1 is a diagram showing an example of a lighting device using the light-emitting device of the present embodiment. [Figure 19] FIG. 1 is a diagram showing an example of a moving object using the light-emitting device of the present embodiment. [Figure 20] FIG. 1 is a diagram showing an example of a wearable device using the light-emitting device of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0010] 1 to 11, a light-emitting device according to an embodiment of the present disclosure will be described. In the following description, an example will be described in which an organic light-emitting diode (OLED) is used as a light-emitting element disposed in the light-emitting device. However, the present disclosure is not limited to light-emitting devices using OLEDs, and can be applied to light-emitting devices in general.

[0011] FIG. 1 is a block diagram showing an example of the configuration of a light-emitting device 100 according to this embodiment. The light-emitting device 100 includes a light-emitting region 105 in which multiple light-emitting elements are arranged, a scanning circuit 107, a processing circuit 104, and a substrate 106 on which multiple terminals 101 to 103 for receiving signals and power are arranged. As examples of signals supplied to the multiple terminals 101 to 103, FIG. 1 shows that a clock signal is supplied to terminal 102, and a data signal for controlling the light emission brightness and timing of the multiple light-emitting elements arranged in the light-emitting region 105 is supplied to terminal 103. Terminal 101 may also be supplied with other control signals, or may function as a power supply terminal. Processing circuit 104 receives the data signal in synchronization with the clock signal. Processing circuit 104 processes the data signal in accordance with the clock signal and outputs the signal to scanning circuit 107. Scanning circuit 107 scans the multiple light-emitting elements in accordance with the signal supplied from processing circuit 104. This sequentially scans a plurality of light emitting elements arranged in light emitting area 105, controlling whether each light emitting element emits light or not. In light emitting area 105, light emitting elements are arranged one-dimensionally or two-dimensionally.

[0012] FIG. 2 illustrates the timing relationship between a clock signal and a data signal input from an external device to the light-emitting device 100. The clock signal and data signal input to the light-emitting device 100 are input to the processing circuit 104 and processed. In the example illustrated in FIG. 2, the data signal is input into the processing circuit 104 at the rising edge of the clock signal. That is, after the nth data item is input at the nth rising edge of the clock signal, the n+1th data item is input by the next n+1th rising edge of the clock signal. Therefore, data corresponding to each light-emitting element of the data signal transitions in one clock signal cycle. Furthermore, if the data signal transitions simultaneously with the rising edge of the clock signal, a slight difference between the rising edge of the clock signal and the transition of the data signal may change the data that is input. Therefore, as illustrated in FIG. 2, data transitions at the falling edge of the clock signal. Therefore, the pulse width of the clock signal is shorter than the period of data transition corresponding to each light-emitting element of the data signal. The period of the data signal is one clock signal cycle, which can be more than twice the minimum pulse width of the clock signal.

[0013] The data input into processing circuit 104 is processed within processing circuit 104 and output from processing circuit 104 to scanning circuit 107 as signals that determine the amount of current required for the light-emitting elements to emit light and whether or not to emit light. Scanning circuit 107 sequentially scans the light-emitting elements arranged in light-emitting area 105, and the light-emitting elements emit light at an amount that corresponds to the amount of current.

[0014] FIG. 3 shows an example layout of the light-emitting device 100 of this embodiment. The light-emitting device 100 used in a print head for an image forming apparatus using an OLED as a light source can be mounted on a rectangular substrate 106 having long and short sides, depending on its intended use. In the configuration shown in FIG. 3, the long side of the substrate 106 corresponds to a first direction, and the short side corresponds to a second direction. Here, the substrate 106 may be a rectangle having four sides in a planar view, as shown in FIG. 3. Furthermore, for example, the substrate 106 may be a polygon, such as an octagon, with chamfered corners in a planar view. The chamfered corners of the substrate 106 may be curved rather than straight. In other words, the substrate 106 may be a substantially rectangular shape having long and short sides from a macroscopic perspective. Here, the planar view refers to an orthogonal projection onto the surface of the substrate 106 on which the light-emitting region 105, the processing circuit 104, the scanning circuit 107, and the multiple terminals 101 to 103 are arranged.

[0015] Light-emitting region 105 is arranged on substrate 106 with its longitudinal direction being a first direction along the long side of substrate 106. Multiple terminals 101 to 103 are arranged to be aligned in the first direction. Processing circuit 104 is arranged in the first direction relative to multiple terminals 101 to 103. Light-emitting region 105 is arranged in a second direction intersecting the first direction relative to processing circuit 104 and multiple terminals 101 to 103. Scanning circuit 107 is arranged between processing circuit 104 and light-emitting region 105. It can also be said that scanning circuit 107 is arranged between multiple terminals 101 to 103 and light-emitting region 105.

[0016] In the configuration shown in FIG. 3, the multiple terminals 101 to 103 and the processing circuit 104 are arranged side by side in the first direction. It is possible to arrange the multiple terminals 101 to 103 adjacent to the processing circuit 104 in the second direction. However, in that case, it is necessary to increase the length of the short side of the substrate 106 (the second direction). This increases the layout area of ​​the light-emitting device 100, and reduces the number of light-emitting devices 100 that can be arranged on a single silicon wafer when manufacturing the light-emitting devices 100. In order to increase the number of light-emitting devices 100 obtained from a single silicon wafer, the processing circuit 104 and the multiple terminals 101 to 103 are arranged side by side in the first direction, thereby shortening the length of the short side of the substrate 106. For this reason, the layout shown in FIG. 3 is often adopted. In this case, the distance between the processing circuit 104 and the terminals to which clock signals and data signals are input becomes longer.

[0017] When a control signal such as a clock signal is transmitted within the light-emitting device 100, delays in signal transmission occur due to the resistance of the signal line and parasitic capacitance with other wiring patterns. As described above, in a configuration in which a data signal is acquired at the falling edge of a clock signal, the phase relationship between the clock signal and the data signal is important. The operation timing is designed to ensure a time margin between the transition timing of the data signal and the rising edge of the clock signal. However, signal transmission delays can cause the phase relationship between the clock signal and the data signal input to the light-emitting device 100 to shift, resulting in, for example, a shorter time between the rising edge of the clock signal and the transition timing of the data signal. This can result in a malfunction in which data cannot be acquired correctly. In addition, the phase relationship can be affected by manufacturing variations in the devices used in the circuits within the light-emitting device and the temperature at which the device is used.

[0018] To mitigate such problems, the clock signal and data signal are supplied to adjacent terminals among the multiple terminals 101 to 103. This reduces the difference in wiring length from the terminal to which the clock signal is supplied and the terminal to which the data signal is supplied to the processing circuit 104. This reduces the difference in the amount of delay in signal transmission caused by wiring resistance and parasitic capacitance. This makes it easier to lay out the light-emitting device 100 so that the delay amounts of the clock signal and the data signal are the same, even if a transmission delay occurs within the light-emitting device 100. As a result, data acquisition failures due to signal delays are suppressed, and the operation of the light-emitting device 100 is stabilized.

[0019] For example, in adjacent terminals 102 and 103, one of a clock signal and a data signal is supplied to terminal 102, and the other of the clock signal and the data signal is supplied to terminal 103. In this case, a signal whose transition period is longer than the transition period of data corresponding to each light-emitting element of the data signal may be supplied to terminal 101. For example, terminal 101 may be supplied with a signal whose signal value transitions more slowly than the data signal, such as a signal for causing processing circuit 104 to start or end the acquisition of the data signal into the clock signal. Furthermore, for example, terminal 101 may be a terminal for supplying power. For example, terminal 101 may be supplied with a power supply potential, a ground potential, or the like.

[0020] For example, a clock signal may be supplied to terminal 102, a data signal to terminal 103, and a signal or power whose transition is slower than that of the data signal to terminal 101. Also, for example, a data signal may be supplied to terminal 102, a clock signal to terminal 103, and a signal or power whose transition is slower than that of the data signal to terminal 101. In the configuration shown in FIG. 3, terminals 101 and 103 are adjacent to each other. Therefore, for example, a signal or power whose transition is slower than that of the data signal may be supplied to terminal 102, a data signal to terminal 103, and a clock signal to terminal 101. Furthermore, for example, a signal or power whose transition is slower than that of the data signal may be supplied to terminal 102, a clock signal to terminal 103, and a data signal to terminal 101.

[0021] As shown in FIG. 2, the pulse width of the clock signal is shorter than the data transition period of the data signal. Therefore, the clock signal is susceptible to signal quality influences such as the distance of the wiring pattern it passes through, device variations, and temperature changes. Therefore, the clock signal may be supplied to terminal 102, of the multiple terminals 101 to 103, which is closest to processing circuit 104. This reduces data acquisition errors due to timing deviations. That is, as shown in FIG. 3, terminals 102 and 103 are arranged between processing circuit 104 and terminal 103, and terminal 102 is arranged between processing circuit 104 and terminal 103. In this case, a clock signal may be supplied to terminal 102, a data signal to terminal 103, and a signal or power whose transition is slower than that of the data signal to terminal 101. That is, a signal with a faster period may be supplied to a terminal of the multiple terminals 101 to 103 closer to processing circuit 104. This achieves stable operation of light-emitting device 100.

[0022] Fig. 4 shows a modified example of the light-emitting device 100 shown in Fig. 3. In the configuration shown in Fig. 4, terminals 108 and 109 are arranged in addition to the above-mentioned terminals 101 to 103. The terminals 108 and 109 are terminals arranged between the terminal 101 and the terminal 103. Furthermore, similar to the configuration shown in Fig. 3, the terminals 101 to 103, 108, and 109 are arranged to line up in the first direction.

[0023] For example, a clock signal is supplied to terminal 102, a data signal 1 is supplied to terminal 103, and a data signal 2 is supplied to terminal 108. As described above, the pulse width of the clock signal is shorter than the data transition period of data signals 1 and 2. Furthermore, data signal 2 supplied to terminal 108 is a signal that transitions with a period equal to or longer than the data transition period of data signal 1 supplied to terminal 103, that is, a period equal to or longer than the data transition period of data signal 1. In this embodiment, the transition periods of data signals 1 and 2 are assumed to be the same. Furthermore, terminals 101 and 109 may be, for example, terminals for supplying power. Furthermore, signals whose transitions are slower than those of data signals 1 and 2 may be supplied to terminals 101 and 109. In the example shown in FIG. 4, two terminals for supplying data signals are provided, but the number is not limited to two, and three or more terminals may be provided. For example, a data signal similar to data signals 1 and 2 may be supplied to terminal 109.

[0024] Fig. 5 shows an example of the operation of the light-emitting device 100 shown in Fig. 4. As in the operation shown in Fig. 2, data signals 1 and 2 are captured at the falling edge of the clock signal, and two pieces of data are captured simultaneously. As in the above, data signal 1 and data signal 2 are captured using the same clock, so it is necessary to design the device so that the difference in delay between the clock signal and data signals 1 and 2 is small.

[0025] In the configuration shown in FIG. 4 , timing discrepancies between the clock signal and the data signal due to signal delays within the light-emitting device 100, manufacturing variations in the circuit devices, temperature during use, and the like are taken into consideration. Specifically, the terminal 102 to which a clock signal having a pulse width shorter than the data fiber period of data signals 1 and 2 is input is located closer to the processing circuit 104. The terminals 103 and 108 to which data signals 1 and 2 are input are located farther from the processing circuit 104 than the terminal 102. Meanwhile, the terminal 102 to which the clock signal is input and the terminal 103 to which data signal 1 is input are located adjacent to each other, and the terminal 103 to which data signal 1 is input and the terminal 108 to which data signal 2 is input are located adjacent to each other. This reduces the difference in delay between the clock signal and the data signal, thereby stabilizing the operation of the light-emitting device 100. This achieves stable operation of the light-emitting device 100. 4, the period of the signals supplied to each of the multiple terminals 101 to 103, 108, and 109 may become slower continuously or stepwise as the terminals are further away from the processing circuit 104. Here, the terminal receiving the power supply can be said to be the terminal receiving the signal with the slowest period when the inclusion of noise or the like is not taken into consideration.

[0026] Fig. 6 is a block diagram showing an example of the configuration of light-emitting device 100. Fig. 7 is a diagram showing an example of the layout of light-emitting device 100. Below, differences from the configuration of light-emitting device 100 described above will be described, and descriptions of configurations that may be similar will be omitted as appropriate.

[0027] As shown in FIGS. 6 and 7 , the processing circuit 104 includes an acquisition circuit 501 to which a clock signal and a data signal are input. The processing circuit 104 described above may also include the acquisition circuit 501, but the illustration is omitted. Within the processing circuit 104, the acquisition circuit 501 acquires data of the data signal at the rising edge of the clock signal. Considering signal delays and the like, it is considered preferable to have a short distance between the terminal to which the clock signal or data signal is input and the acquisition circuit 501 of the processing circuit 104 to which the clock signal or data signal is input. Therefore, as shown in FIG. 7 , in a plan view of the substrate 106, the acquisition circuit 501 may be positioned closer to the multiple terminals 101 to 103 and 108 than the center of the processing circuit 104. This allows the length of the wiring pattern between the terminal to which the clock signal or data signal is supplied and the acquisition circuit 501. Here, the center of the processing circuit 104 may be, for example, the position of the geometric center of gravity of the processing circuit 104 in a plan view with respect to the substrate 106. The geometric shape of the processing circuit 104 may be defined, for example, by the outer edges of the transistors arranged on the outermost periphery of the transistors constituting the processing circuit 104 and the imaginary lines connecting the outer edges. The shape of the acquisition circuit 501 may also be defined in the same way as the processing circuit 104.

[0028] 6 and 7, two data signals 1 and 2 are also input. The number of data signals supplied is not limited to two and may be one, or three or more. It is sufficient that the number of terminals provided for inputting the data signals is greater than the number of data signals supplied. In the configuration shown in FIG. 7, for example, a clock signal may be supplied to terminal 102, data signals 1 and 2 may be supplied to terminals 103 and 108, and a signal whose transition is slower than that of the data signals or power may be supplied to terminal 101.

[0029] FIG. 7 also shows the arrangement of a moisture-resistant ring 551. The moisture-resistant ring 551 may be a guard ring formed of a conductive pattern arranged on a wiring layer on a semiconductor substrate to protect components such as the processing circuit 104, the light-emitting region 105, and the scanning circuit 107 from moisture in the atmosphere. In an orthogonal projection onto the substrate 106, the moisture-resistant ring 551 may be arranged along the outer edge of the substrate 106, surrounding the light-emitting region 105, the scanning circuit 107, the processing circuit 104, and the plurality of terminals 101 to 103, 108, as shown in FIG. 7. In a plan view of the substrate 106, the moisture-resistant ring 551 may have a recess 552 recessed into the substrate 106 between the plurality of terminals 101 to 103, 108 and the processing circuit 104. The recess 552 of the moisture-resistant ring 551 is a necessary part in the process of depositing an OLED on the light-emitting device 100, as will be described later.

[0030] FIG. 8( a) shows an example in which the light-emitting device 100 is formed on a silicon wafer 601. As shown in FIG. 8( a), the light-emitting device 100 may be formed on a semiconductor substrate such as silicon, or on a semiconductor layer formed on a substrate such as plastic, glass, ceramic, or metal. The semiconductor substrate and semiconductor layer are not limited to silicon, and other semiconductor materials may be used. For example, the material of the semiconductor substrate and semiconductor layer may be germanium or a compound semiconductor. Compound semiconductors include gallium arsenide, indium phosphide, indium arsenide, and indium gallium arsenide phosphide, and these semiconductor materials may further contain aluminum. In this embodiment, the light-emitting devices 100 may be formed in multiple rows and columns on a single silicon wafer 601. For rectangular light-emitting devices 100, the number of light-emitting devices 100 obtained from a single silicon wafer 601 varies significantly depending on the size of the short side. Therefore, shortening the short side as much as possible is effective in reducing the cost of the light-emitting devices 100. Furthermore, when a silicon wafer 601 is used as the substrate (which becomes the substrate 106 when the light-emitting device 100 is completed), it becomes possible to finely form each component such as a driving circuit. As a result, it becomes possible to increase the density of light-emitting elements, and to form higher-resolution images.

[0031] 8(b) shows an example of a deposition mask 602 for forming an OLED on a light-emitting device 100 by vapor deposition. The deposition mask 602 has a plurality of openings 603 arranged therein, and the openings 603 and the light-emitting devices 100 (e.g., light-emitting regions 105) are arranged at equal intervals. The light-emitting devices 100 on the silicon wafer 601 are aligned with the openings 603 in the deposition mask 602. Next, the silicon wafer 601 and the deposition mask 602 are brought into close contact with each other, and electrodes, organic layers, and the like are vapor-deposited on the light-emitting devices using a vacuum deposition method, thereby forming an OLED.

[0032] 8(c) shows an example of a cross-sectional structure when the silicon wafer 601 and the deposition mask 602 are in close contact with each other. The deposition mask 602 has ribs 604. The ribs 604 maintain a constant distance between the silicon wafer 601 and the deposition mask 602 when the silicon wafer 601 and the deposition mask 602 are in close contact with each other. This minimizes the area where the deposition mask 602 comes into contact with the light-emitting device 100, suppressing the transfer of foreign matter to the light-emitting device 100 and the occurrence of scratches, and suppressing the occurrence of sealing defects. The portion where the ribs 604 are arranged becomes the recessed portion 552 of the moisture-resistant ring 551 shown in FIG. 7.

[0033] It is possible to provide a portion where the rib 604 is disposed in the second direction relative to the terminals 101-103, 108 and the processing circuit 104 without providing the recesses 552 of the moisture-resistant ring 551 between the terminals 101-103, 108 and the processing circuit 104. However, in that case, a region dedicated to the rib 604 is provided between the light-emitting devices 100 on the silicon wafer 601 in the second direction (short side direction), and the substantial chip size increases by the amount of the dedicated rib region. In this embodiment, the recesses 552 of the moisture-resistant ring 551, which is a region where the rib 604 abuts, are provided between the terminals 101-103, 108 and the processing circuit 104. This allows the distance between the light-emitting devices 100 on the silicon wafer 601 in the short side direction (second direction) of the substrate 106 of the light-emitting devices 100 to be reduced. Therefore, the number of light emitting devices 100 that can be arranged in the short side direction within one silicon wafer 601 can be increased, and the number of light emitting devices 100 that can be obtained from one silicon wafer 601 can be increased.

[0034] 9(a) to 9(e) show the steps for mounting the light-emitting device 100 on the control board 701. The terminals 101 to 103 (shown as terminals 101 to 103 in FIGS. 9(a) to 9(e) but other terminals such as the above-mentioned terminals 108 and 109 may also be provided) provided on the light-emitting device 100 are electrically connected to the wiring pattern 702 on the control board 701 by wire bonding. This allows the light-emitting device 100 to be mounted as an electronic component. FIGS. 9(a) to 9(e) show side views of the light-emitting device 100.

[0035] As shown in Fig. 9(a), a capillary 704 with a ball 703 formed thereon is moved directly above the wiring pattern 702 using a wire bonding device (not shown). Next, as shown in Fig. 9(b), the capillary 704 is lowered using a wire bonding device (not shown), and the ball 703 melted by the capillary 704 is pressed against the wiring pattern 702, and the wire 705 and the wiring pattern 702 are connected by, for example, an ultrasonic thermocompression bonding method. Thereafter, as shown in Fig. 9(c), the wire 705 is pulled out from the tip of the capillary 704 using a wire bonding device (not shown), and is moved toward the terminals 101 to 103 of the light-emitting device 100. 9(d) and 9(e), a wire bonding device (not shown) is used to press a capillary 704 against the terminals 101 to 103, and wires 705 are connected to the terminals 101 to 103 by ultrasonic thermocompression bonding, and at the same time, the wires 705 are cut. Using this wire bonding method, wire bonding is performed on the plurality of light-emitting devices 100 arranged on the control board 701.

[0036] 10 is a schematic diagram showing one form of a light-emitting device 100 according to this embodiment. The light-emitting device 100 of this embodiment can be used, for example, as a light source for an image forming apparatus. The light-emitting device 100 of 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. For example, the first direction may be a direction along the rotation axis of a photosensitive member of the image forming apparatus.

[0037] The substrate 1701 has a polygonal shape, and an example of a rectangular substrate 1701 will be described here. In this specification, the direction of the long sides of the rectangular substrate 1701 is referred to as a first direction, and the direction of the short sides perpendicular to the long side is referred to as a second direction. In addition, the polygon in this specification also includes shapes with rounded corners. A moisture-resistant ring 1700 that suppresses and prevents moisture from penetrating into the light-emitting device 100 is disposed on the rectangular substrate 1701. The moisture-resistant ring 1700 can be, for example, a guard ring formed of a wiring layer.

[0038] A light-emitting region 1702, a contact region 1703, pads 1704, and a circuit 1706 are arranged inside the moisture-resistant ring 1700. The circuit 1706 is a part of the circuit for driving each light-emitting device, and specific examples thereof include, but are not limited to, an input protection circuit, an input circuit to which drive data is input, and a logic circuit for processing data. The light-emitting elements EL are arranged in a matrix within the light-emitting region 1702. The contact region 1703 is an area where wiring electrically connecting to a common electrode of the light-emitting elements EL is arranged. The pads 1704 correspond to the terminals 101 to 103, 108, and 109 described above. The positional relationship between the pads 1704 and processing circuits within the circuit 1706, such as a logic circuit that receives clock signals and data signals and processes the data signals in accordance with the clock signals, is as described above.

[0039] The outer periphery of the moisture-resistant ring 1700 may include a plurality of recessed portions, which can be used as contact areas for contacting ribs that are part of a mask for vapor deposition in a film-forming process, for example.

[0040] Each of the plurality of light-emitting elements EL arranged in a matrix in the light-emitting region 1702 is composed of a light-emitting layer and a first electrode and a second electrode that sandwich the light-emitting layer. In this embodiment, the first electrode may be an independent electrode provided for each light-emitting element EL, and the second electrode may be a common electrode provided for all the light-emitting elements EL.

[0041] For example, in the case where light-emitting region 1702 has four rows of light-emitting elements EL, the initial positions of the light-emitting elements EL in the first row and the initial positions of the light-emitting elements EL in the second row may be shifted in the first direction by ¼ of the X-direction dimension of the light-emitting elements EL, as illustrated in Fig. 10. In the case of n rows, where n is an integer of 2 or greater, the initial positions of the light-emitting elements EL in the first row and the initial positions of the light-emitting elements EL in the second row may be shifted in the X direction by 1 / n of the X-direction dimension of the light-emitting elements EL. Such a configuration is advantageous for improving resolution.

[0042] The contact region 1703 is an area adjacent to the light emitting region 1702 of the substrate 1701, and is disposed inside the moisture-resistant ring 1700. At least one of the contact region 1703, the pad 1704, and the circuit 1706, together with the recess of the moisture-resistant ring 1700, may be disposed between the light emitting region 105 and one long side end of the substrate 1701, and may be disposed in series in the long side direction (first direction).

[0043] In this way, by arranging the contact region 1703, the pad 1704, the circuit 1706, etc. in the same position in the short side direction, the length of the light-emitting device 100 in the short side direction (second direction) can be reduced, making it possible to make the light-emitting device 100 smaller.

[0044] The light-emitting device 100 of this embodiment has multiple contact regions 1703 between the common electrode of the light-emitting element EL and the power supply wiring along the long side edge of the light-emitting device. If the common electrode is made of, for example, a transparent electrode material with relatively high electrical resistance, the amount of voltage drop in the long side direction may be large. Therefore, the voltage applied to each OLED varies depending on the distance from the contact region to which the potential is supplied. This can result in differences in actual emission brightness between OLEDs to which a voltage is applied to emit light with the same brightness, resulting in shading and other problems. By having multiple contact regions 1703 along the long side edge of the light-emitting device, as in this embodiment, the voltage drop in the common electrode along the long side direction can be reduced, thereby preventing shading and other problems.

[0045] In this embodiment, an example in which the light emitting device 100 is used in a head substrate 1800 of an exposure head, which is a light emitting module provided in an image forming apparatus, will be described with reference to Figures 11(a) to 11(c). Figure 11(a) is a schematic perspective view of the head substrate 1800. Figure 11(b) shows an arrangement of a plurality of light emitting elements EL provided on the head substrate 1800, and Figure 11(c) shows an enlarged view of a portion of Figure 11(b).

[0046] An LED chip 1803 is mounted on the head substrate 1800. As the LED chip 1803, for example, the above-described light emitting device 100 can be used.

[0047] 11(a), an LED chip 1803 is provided on one surface of a head substrate 1800, and a long flexible flat cable (FFC) connector 1807 is provided on the other surface. The one surface of the head substrate 1800 here refers to the surface (upper surface, front surface) on which the LED chip 1803 is provided. The other surface of the substrate refers to the surface (lower surface, back surface) opposite to the side on which the LED chip 1803 is provided.

[0048] The FFC connector 1807 is attached to the other surface (bottom surface, back surface) of the head substrate 1800 so that its longitudinal direction follows the longitudinal direction of the head substrate 1800. The long FFC connector 1807 is provided to input a control signal (drive signal) from a control circuit section of the main body of the image forming apparatus, and the control signal is transferred to each LED chip 1803. The LED chips 1803 are driven (to emit light or turn off) by the control signal input to the head substrate 1800.

[0049] The LED chips 1803 mounted on the head substrate 1800 will now be described. As shown in Fig. 11(b) and Fig. 11(c), a plurality of light-emitting elements EL are arranged on one surface of the head substrate 1800. For example, a plurality of LED chips 1803-1 to 1803-17 (17 chips) are arranged. Fig. 11(b) illustrates LED chips 1803_1, 1803_7, 1803_8, 1803_9, 1803_10, and 1803_17. Each of the LED chips 1803_1 to 1803_17 has a plurality of light-emitting elements EL arranged in its longitudinal direction, and for example, 516 light-emitting elements EL are arranged.

[0050] In the longitudinal direction of the LED chip 1803, the center-to-center distance k2 between adjacent light-emitting elements EL corresponds to the resolution of the image forming device. For example, when the resolution of the image forming device in this embodiment is 1200 dpi, the light-emitting elements EL are arranged so that the center-to-center distance k2 between adjacent light-emitting elements EL is 21.16 μm in the longitudinal direction of the LED chips 1803_1 to 1803_17. Therefore, the exposure range of the exposure head in this embodiment is approximately 314 mm.

[0051] The photosensitive layer of the photosensitive drum is formed with a width of 314 mm or more. Since the long side of A4 size recording paper and the short side of A3 size recording paper are 297 mm, the exposure head of this embodiment has an exposure range that can form images on A4 size recording paper and A3 size recording paper. While Figure 11(c) shows an example in which multiple light-emitting elements EL are arranged in the longitudinal direction, light-emitting elements EL may be arranged in the lateral direction as well as the longitudinal direction.

[0052] A plurality of LED chips 1803_1 to 1803_17 are arranged in the axial direction of the photosensitive drum. Specifically, the LED chips 1803_1 to 1803_17 are alternately arranged in two rows along the axial direction of the photosensitive drum. That is, as shown in FIG. 11(b), counting from the left, the odd-numbered LED chips 1803_1, 1803_3, ..., 1803_17 are mounted in a row in the longitudinal direction of the head substrate 1800. Also, counting from the left, the even-numbered LED chips 1803_2, 1803_4, ..., 1803_16 are mounted in a row in the longitudinal direction of the head substrate 1800. The LED chips 1803 are arranged in this manner. As a result, as shown in FIG. 11(c), the center-to-center distance k1 of the light-emitting elements EL can be made equal to the center-to-center distance k2 of the light-emitting elements EL in the longitudinal direction of the LED chip 1803. Here, the center-to-center distance k1 of the light-emitting elements EL indicates the center-to-center distance between the light-emitting elements EL arranged at one end of the LED chip 1803_7 and the other end of the LED chip 1803_8. Also, the center-to-center distance k2 of the light-emitting elements EL indicates the center-to-center distance k2 between adjacent light-emitting elements EL in the LED chip 1803_8.

[0053] In other words, the center-to-center distance k1 between adjacent light-emitting elements EL arranged on one end of an LED chip 1803 and the other end of another LED chip 1803 can be made equal to the center-to-center distance k2 between adjacent light-emitting elements EL on one LED chip 1803.

[0054] In this embodiment, the light-emitting element EL is an organic light-emitting element that is a current-driven light-emitting element. The organic light-emitting elements are arranged in a line along the main scanning direction (the axial direction of the photosensitive drum) on a TFT substrate, for example, and are electrically connected in parallel by power supply wiring that is also provided along the main scanning direction.

[0055] When the light-emitting device is used in an exposure head, linear exposure is performed, and therefore the ratio of the longitudinal direction (first direction) to the lateral direction (second direction) of the shape of the light-emitting region 1702 is larger than when the light-emitting device is used in a display device, etc. The ratio of the longitudinal direction (first direction) to the lateral direction (second direction) of the shape of the LED chip substrate is also larger.

[0056] Specifically, for example, the length of the long side of LED chip 1803 (or light-emitting region 1702) is at least five times the length of the short side of LED chip 1803 (or light-emitting region 1702), and may be at least ten times the length. For example, the length of the long side of LED chip 1803 (or light-emitting region 1702) can be at least 20 times the length of the short side of LED chip 1803 (or light-emitting region 1702).

[0057] The length of the long side of the LED chip 1803 is determined by the axial length of the photosensitive drum, the number of LED chips arranged in the axial direction, and the arrangement of the LED chips 1803. The length of the short side of the LED chip 1803 is determined by whether the light-emitting element EL is arranged in the light-emitting region 1702 in the direction perpendicular to the axis of the photosensitive drum, and the arrangement of the pad 1704 and the contact region 1703.

[0058] Furthermore, the organic layer may be configured to have a red-emitting layer, taking into account the wavelength dependency of the photosensitive drum's photosensitivity. The LED chip 1803 may have a color filter. By including a color filter, the amount of normal light incident on the photosensitive drum is not reduced, and stray light from unintended directions can be absorbed, improving print quality.

[0059] Here, application examples in which the light-emitting device 100 of this embodiment is applied to an image forming apparatus, a display device, a photoelectric conversion device, an electronic device, a lighting device, a mobile object, and a wearable device will be described with reference to Figs. 12(a) and 12(b) to Figs. 20(a) and 20(b). The description will be made assuming that a light-emitting element such as an organic light-emitting element (OLED) using an organic light-emitting material is arranged in the pixel arranged in the light-emitting device 100. First, details of each component arranged in the pixel of the light-emitting device 100 will be shown, and then application examples will be described.

[0060] The organic light-emitting device according to this embodiment includes a first electrode, a second electrode, and an organic compound layer disposed between these electrodes. One of the first electrode and the second electrode is an anode, and the other is a cathode. In the organic light-emitting device according to this embodiment, the organic compound layer may be a single layer or a laminate consisting of multiple layers, as long as it includes an emitting layer. When the organic compound layer is a laminate consisting of multiple layers, the organic compound layer may include a hole injection layer, a hole transport layer, an electron blocking layer, a hole / exciton blocking layer, an electron transport layer, an electron injection layer, and the like, in addition to the emitting layer. The emitting layer may also be a single layer or a laminate consisting of multiple layers. When the emitting layer is a multilayer, a charge generation layer may be disposed between the emitting layers. The charge generation layer may be composed of a compound having a lower LUMO than the hole transport layer, and the LUMO of the charge generation layer may be lower than the HOMO of the hole transport layer. Here, the molecular orbital energy of the organic compound layer may be the molecular orbital energy of the organic compound having the largest weight ratio in the organic compound layer.

[0061] In the organic light-emitting device of this embodiment, when an organic compound is contained in the light-emitting layer, the light-emitting layer may be a layer consisting of only the organic compound, or may be a layer consisting of an organometallic complex and other compounds. Here, when the light-emitting layer is a layer consisting of an organometallic complex and other compounds, the organic compound may be used as a host or a guest of the light-emitting layer. It may also be used as an assist material contained in the light-emitting layer. Here, the host is the compound with the largest mass ratio among the compounds constituting the light-emitting layer. The guest is a compound with a mass ratio smaller than that of the host among the compounds constituting the light-emitting layer, and is responsible for the main emission of light. The assist material is a compound with a mass ratio smaller than that of the host among the compounds constituting the light-emitting layer, and assists the emission of the guest. The assist material may also be called a second host. The host material may also be called a first compound, and the assist material may also be called a second compound.

[0062] Here, the organic compound may be used together with conventionally known low-molecular-weight and high-molecular-weight hole-injecting or hole-transporting compounds, host compounds, light-emitting compounds, electron-injecting or electron-transporting compounds, etc., as needed.

[0063] As the hole injection / transport material, a material with high hole mobility is suitable so that holes can be easily injected from the anode and the injected holes can be transported to the light-emitting layer. In addition, a material with a high glass transition temperature is suitable to reduce deterioration of film quality such as crystallization in organic light-emitting devices. The electron transporting material can be arbitrarily selected from those capable of transporting electrons injected from the cathode to the light-emitting layer, and is selected in consideration of the balance with the hole mobility of the hole transporting material, etc. The electron transporting material can also be used in the hole blocking layer.

[0064] The electron injection material can be arbitrarily selected from those that allow easy injection of electrons from the cathode, and is selected in consideration of the balance with hole injection properties, etc. The electron injection material can also be used in combination with an electron transport material.

[0065] Structure of organic light-emitting element The organic light-emitting element is provided by forming an insulating layer, a first electrode, an organic compound layer, and a second electrode on a substrate. A protective layer, a color filter, a microlens, etc. may be provided on the cathode. When a color filter is provided, a planarizing layer may be provided between the protective layer and the color filter. The planarizing layer may be made of an acrylic resin, etc. The same applies when a planarizing layer is provided between the color filter and the microlens.

[0066] substrate Examples of the substrate include quartz, glass, silicon wafer, resin, and metal. Furthermore, the substrate may be provided with switching elements such as transistors and wiring patterns, with an insulating layer thereon. When a silicon wafer is used as the substrate, the active layer, source region, and drain region of the transistor are formed within the substrate. Furthermore, it is suitable because it allows transistors to be densely arranged. The insulating layer may be made of any material, as long as it allows contact holes to be formed so that a wiring pattern can be formed between the first electrode and the substrate, and insulation from unconnected wiring patterns is ensured. For example, the insulating layer may be made of a resin such as polyimide, silicon oxide, silicon nitride, or the like.

[0067] electrode A pair of electrodes can be used as the electrodes. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a higher potential is the anode, and the other is the cathode. It can also be said that the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode.

[0068] The anode may be made of a material with a high work function. For example, simple metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten, mixtures containing these metals, alloys of these metals, and metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and zinc indium oxide can be used. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used as the anode.

[0069] These electrode materials may be used alone or in combination of two or more. The anode may be composed of one layer or multiple layers.

[0070] When the electrode is used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys thereof, or laminates thereof can be used. The above materials can also function as a reflective film without functioning as an electrode. Furthermore, when a transparent electrode is used as the electrode, a transparent conductive oxide layer such as indium tin oxide (ITO) or indium zinc oxide can be used, but is not limited to these. Photolithography technology can be used to form the electrode.

[0071] On the other hand, a material with a low work function may be selected as the cathode material. Examples include simple metals such as alkali metals (e.g., lithium), alkaline earth metals (e.g., calcium), aluminum, titanium, manganese, silver, lead, and chromium, as well as mixtures containing these metals. Alternatively, alloys combining these simple metals may be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver may be used. Metal oxides such as indium tin oxide (ITO) may also be used. These electrode materials may be used alone or in combination. The cathode may have a single-layer or multi-layer structure. Silver may be used as the cathode, and a silver alloy may be used to reduce silver aggregation. The alloy ratio is not important as long as silver aggregation is reduced. For example, the silver:other metal ratio may be 1:1 or 3:1.

[0072] The cathode may be a top-emission element using an oxide conductive layer such as ITO, or a bottom-emission element using a reflective electrode such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but using a DC or AC sputtering method, for example, can provide good coverage of the formed film and reduce the resistance of the cathode.

[0073] Pixel isolation layer The pixel separation layer may be formed of silicon oxides such as silicon nitride (SiN), silicon oxynitride (SiON), or silicon oxide (SiO) formed using a chemical vapor deposition (CVD) method. To increase the in-plane resistance of the organic compound layer, the thickness of the organic compound layer, particularly the hole transport layer, may be thinned on the sidewalls of the pixel separation layer. Specifically, the thickness of the organic compound layer on the sidewalls can be thinned by increasing the taper angle of the sidewalls of the pixel separation layer or the thickness of the pixel separation layer, thereby increasing vignetting during deposition.

[0074] On the other hand, the sidewall taper angle and film thickness of the pixel separation layer can be adjusted to the extent that voids are not formed in the protective layer formed thereon. By preventing voids from being formed in the protective layer, the occurrence of defects in the protective layer can be reduced. Since the occurrence of defects in the protective layer is reduced, deterioration of reliability such as the occurrence of dark spots and poor conduction of the second electrode can be reduced.

[0075] According to this embodiment, charge leakage to adjacent pixels can be effectively suppressed even if the taper angle of the sidewall of the pixel separation layer is not steep. As a result of this study, it was found that charge leakage can be sufficiently reduced if the taper angle is between 60 degrees and 90 degrees. The thickness of the pixel separation layer may be between 10 nm and 150 nm. Similar effects can also be achieved even if the pixel separation layer is composed only of pixel electrodes without a pixel separation layer. However, in this case, short circuits in organic light-emitting elements can be reduced by making the thickness of the pixel electrode less than half that of the organic layer or by making the edge of the pixel electrode forward tapered at less than 60 degrees.

[0076] Furthermore, even when the first electrode is a cathode and the second electrode is an anode, a wide color gamut and low-voltage operation are possible by forming an electron transport material and a charge transport layer, and an emitting layer on the charge transport layer.

[0077] organic compound layer The organic compound layer may be formed as a single layer or as multiple layers. When multiple layers are present, they may be called hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc., depending on their functions. The organic compound layer is mainly composed of organic compounds but may also contain inorganic atoms or inorganic compounds. The organic compound layer may contain, for example, copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, etc. The organic compound layer may be disposed between the first electrode and the second electrode, or may be disposed in contact with the first electrode and the second electrode.

[0078] When multiple light-emitting layers are present, a charge-generating portion may be present between the first and second light-emitting layers. The charge-generating portion may have an organic compound with a lowest unoccupied molecular orbital energy (LUMO) of -5.0 eV or less. The same applies when a charge-generating portion is present between the second and third light-emitting layers.

[0079] protective layer A protective layer may be provided on the cathode. For example, by adhering glass with a moisture absorbent on the cathode, the penetration of moisture and other contaminants into the organic compound layer can be reduced, thereby reducing the occurrence of display defects. In another embodiment, a passivation layer such as silicon nitride may be provided on the cathode to reduce the penetration of moisture and other contaminants into the organic compound layer. For example, after forming the cathode, the cathode may be transferred to another chamber without breaking the vacuum, and a 2 μm-thick silicon nitride may be formed by CVD to serve as a protective layer. After forming the protective layer by CVD, a protective layer may be formed by atomic layer deposition (ALD). The material of the protective layer formed by ALD is not limited, and may be silicon nitride, silicon oxide, aluminum oxide, or the like. Silicon nitride may be further formed by CVD on the protective layer formed by ALD. The protective layer formed by ALD may have a thickness smaller than that of the protective layer formed by CVD. Specifically, the thickness of the protective layer formed by ALD may be 50% or less, or even 10% or less, of the protective layer formed by CVD.

[0080] Color filters A color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element may be provided on another substrate, and the substrate on which the color filter is formed may be bonded to the substrate on which the organic light-emitting element is provided. Alternatively, for example, a color filter may be patterned on the above-mentioned protective layer using photolithography technology. The color filter may be made of a polymer.

[0081] planarization layer A planarization layer may be disposed between the color filter and the protective layer. The planarization layer is provided for the purpose of reducing the unevenness of the layers below the planarization layer. It may also be called a material resin layer without limiting the purpose. The planarization layer may be composed of an organic compound, and may be a low molecular weight or a high molecular weight. In consideration of reducing the unevenness, a high molecular weight organic compound may be used for the planarization layer.

[0082] The planarization layers may be provided above and below the color filter. In this case, the constituent materials of the planarization layers may be the same or different. Specific examples of the material for the planarization layer include polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0083] Microlenses The organic light-emitting device may have an optical component such as a microlens on its light-emitting side. The microlens may be made of acrylic resin, epoxy resin, or the like. The microlens may be intended to increase the amount of light extracted from the organic light-emitting device or to control the direction of the extracted light. The microlens may have a hemispherical shape. When the microlens has a hemispherical shape, among the tangents to the hemisphere, there is a tangent that is parallel to the insulating layer, and the point of contact between this tangent and the hemisphere is the vertex of the microlens. The vertex of the microlens can be determined in the same way in any cross-sectional view. In other words, among the tangents to the semicircle of the microlens in the cross-sectional view, there is a tangent that is parallel to the insulating layer, and the point of contact between this tangent and the semicircle is the vertex of the microlens.

[0084] It is also possible to define the midpoint of a microlens. In the cross section of the microlens, a line segment is imagined from the point where an arc shape ends to the point where another arc shape ends, and the midpoint of this line segment can be called the midpoint of the microlens. The cross section for determining the vertex and midpoint may be a cross section perpendicular to the insulating layer.

[0085] The microlens has a first surface having a convex portion and a second surface opposite the first surface. The second surface can be disposed closer to the functional layer (light-emitting layer) than the first surface. To achieve this configuration, it is necessary to form the microlens on the light-emitting device. If the functional layer is an organic layer, high-temperature processes can be avoided in the microlens manufacturing process. Furthermore, if the second surface is disposed closer to the functional layer than the first surface, the glass transition temperatures of the organic compounds constituting the organic layer may all be 100°C or higher, and are preferably, for example, 130°C or higher.

[0086] Counter substrate An opposing substrate may be disposed on the planarization layer. The opposing substrate is called an opposing substrate because it is provided at a position corresponding to the aforementioned substrate. The opposing substrate may be made of the same material as the aforementioned substrate. When the aforementioned substrate is defined as a first substrate, the opposing substrate may be a second substrate.

[0087] organic layer The organic compound layers (hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) constituting the organic light-emitting element according to an embodiment of the present disclosure may be formed by the following method.

[0088] The organic compound layer constituting the organic light-emitting device according to the embodiment of the present disclosure can be formed by dry processes such as vacuum deposition, ionization deposition, sputtering, plasma, etc. Alternatively to the dry process, a wet process can be used in which the compound is dissolved in an appropriate solvent and a layer is formed by a known coating method (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.).

[0089] Here, when a layer is formed by a vacuum deposition method or a solution coating method, crystallization is unlikely to occur and the layer has excellent stability over time. When a film is formed by a coating method, the film can be formed by combining it with an appropriate binder resin.

[0090] Examples of the binder resin include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0091] These binder resins may be used singly or in combination as homopolymers or copolymers, and may further contain known additives such as plasticizers, antioxidants, and ultraviolet absorbers, as needed.

[0092] Pixel circuit The light-emitting device may have a pixel circuit connected to the light-emitting element. The pixel circuit may be an active matrix type that controls the emission of the first light-emitting element and the second light-emitting element independently. The active matrix type circuit may be voltage-programmed or current-programmed. The drive circuit has a pixel circuit for each pixel. The pixel circuit may have a light-emitting element, a transistor that controls the emission brightness of the light-emitting element, a transistor that controls the emission timing, a capacitor that holds the gate voltage of the transistor that controls the emission brightness, and a transistor for connecting to GND without going through the light-emitting element.

[0093] The light-emitting device has a display region and a peripheral region arranged around the display region. The display region has pixel circuits, and the peripheral region has a display control circuit. The mobility of a transistor constituting the pixel circuit may be lower than the mobility of a transistor constituting the display control circuit.

[0094] The slope of the current-voltage characteristics of the transistors that make up the pixel circuit may be smaller than the slope of the current-voltage characteristics of the transistors that make up the display control circuit. The slope of the current-voltage characteristics can be measured using the so-called Vg-Ig characteristics.

[0095] The transistors that make up the pixel circuit are transistors connected to the light-emitting elements, such as the first light-emitting element.

[0096] pixel An organic light emitting device includes a plurality of pixels, each of which includes sub-pixels that emit different colors, for example, RGB colors.

[0097] A pixel has an area called a pixel aperture that emits light. The pixel aperture may be 15 μm or less, or 5 μm or more. More specifically, it may be 11 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc.

[0098] The spacing between the subpixels may be 10 μm or less, and specifically may be 8 μm, 7.4 μm, or 6.4 μm.

[0099] The pixels may be arranged in a known manner in a plan view. For example, they may be in a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the subpixels in a plan view may be any known shape. For example, they may be rectangular, quadrilaterals such as diamonds, or hexagons. Of course, a shape that is close to a rectangle, rather than an exact shape, is included in the rectangle. The shape of the subpixels and the pixel arrangement may be used in combination.

[0100] Uses of the organic light-emitting device according to embodiments of the present disclosure The organic light-emitting device according to the embodiment of the present disclosure can be used as a component of a display device or a lighting device, and can also be used as an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, or a light-emitting device having a white light source and a color filter.

[0101] The display device may be an image information processing device that has an image input unit that inputs image information from an area CCD, linear CCD, memory card, etc., has an information processing unit that processes the input information, and displays the input image on the display unit.

[0102] The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of this touch panel function may be an infrared method, a capacitance method, a resistive film method, or an electromagnetic induction method, and is not particularly limited. The display device may also be used in the display unit of a multifunction printer.

[0103] Next, further explanation will be given with reference to the drawings. Fig. 12(a) shows an example of a pixel arranged in the light-emitting region 105 of the light-emitting device 100. The pixel has sub-pixels 810. The sub-pixels are divided into 810R, 810G, and 810B based on the light emitted from the sub-pixels. The emitted colors may be distinguished by the wavelength of light emitted from the light-emitting layer, or the light emitted from the sub-pixels may be selectively transmitted or color-converted using a color filter or the like. Each sub-pixel has a reflective electrode 802 as a first electrode on an interlayer insulating layer 801, an insulating layer 803 covering the edge of the reflective electrode 802, an organic compound layer 804 covering the first electrode and the insulating layer, a transparent electrode 805 as a second electrode, a protective layer 806, and a color filter 807.

[0104] A transistor and a capacitor may be disposed below or inside the interlayer insulating layer 801. The transistor and the first electrode may be electrically connected via a contact hole (not shown) or the like.

[0105] The insulating layer 803 may also be called a bank or a pixel separation film. The insulating layer 803 covers the edges of the first electrodes and is disposed to surround the first electrodes. The portions of the first electrodes not covered by the insulating layer 803 come into contact with the organic compound layer 804 and become light-emitting regions.

[0106] The organic compound layer 804 includes a hole injection layer 841 , a hole transport layer 842 , a first light-emitting layer 843 , a second light-emitting layer 844 , and an electron transport layer 845 .

[0107] The second electrode may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0108] The protective layer 806 reduces the penetration of moisture into the organic compound layer. Although the protective layer is illustrated as a single layer, it may be a multi-layer structure. Each layer may be an inorganic compound layer and an organic compound layer.

[0109] The color filters 807 are divided into 807R, 807G, and 807B depending on their colors. The color filters may be formed on a planarization film (not shown). A resin protective layer (not shown) may be disposed on the color filters. The color filters may be formed on a protective layer 806. The color filters may be provided on an opposing substrate such as a glass substrate and then bonded thereto.

[0110] A display device 800 (corresponding to the light-emitting device 100 described above) in FIG. 12(b) includes an organic light-emitting element 826 and a TFT 818 as an example of a transistor. A substrate 811 made of glass, silicon, or the like is provided with an insulating layer 812 on top of it. An active element such as the TFT 818 is disposed on the insulating layer, and a gate electrode 813, a gate insulating film 814, and a semiconductor layer 815 of the active element are disposed on top of the insulating layer. The TFT 818 also includes the semiconductor layer 815, a drain electrode 816, and a source electrode 817. An insulating film 819 is provided on top of the TFT 818. An anode 821 constituting the organic light-emitting element 826 and the source electrode 817 are connected via a contact hole 820 provided in the insulating film.

[0111] The electrical connection between the electrodes (anode, cathode) included in the organic light-emitting element 826 and the electrodes (source electrode, drain electrode) included in the TFT is not limited to the embodiment shown in Figure 12(b). In other words, it is sufficient that either the anode or the cathode is electrically connected to either the TFT source electrode or the drain electrode. TFT stands for thin film transistor.

[0112] 12(b), the organic compound layer is illustrated as a single layer, but the organic compound layer 822 may be a multi-layer structure. A first protective layer 824 and a second protective layer 825 are provided on the cathode 823 to reduce deterioration of the organic light-emitting element.

[0113] In the display device 800 of FIG. 12(b), a transistor is used as the switching element, but another switching element may be used instead.

[0114] Also, the transistor used in the display device 800 of FIG. 12(b) is not limited to a transistor using a single crystal silicon wafer, and may be a thin film transistor having an active layer on an insulating surface of a substrate. Examples of the active layer include non-single crystal silicon such as single crystal silicon, amorphous silicon, and microcrystalline silicon, and non-single crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Note that a thin film transistor is also called a TFT element.

[0115] The transistor included in the display device 800 of FIG. 12(b) may be formed in a substrate such as a silicon substrate. Here, forming in the substrate means manufacturing a transistor by processing the substrate itself such as a silicon substrate. That is, having a transistor in the substrate can also be regarded as the substrate and the transistor being integrally formed.

[0116] The organic light emitting element according to this embodiment has its emission luminance controlled by a TFT which is an example of a switching element, and an image can be displayed by the respective emission luminances by providing a plurality of organic light emitting elements in a plane. Here, the switching element according to this embodiment is not limited to a TFT, and may be a transistor formed of low temperature polysilicon or an active matrix driver formed on a substrate such as a silicon substrate. Forming on the substrate can also mean forming in the substrate. Whether to provide a transistor in the substrate or use a TFT is selected according to the size of the display portion. For example, if the size is about 0.5 inches, an organic light emitting element may be provided on a silicon substrate.

[0117] 13(a) to 13(c) are schematic diagrams illustrating an example of an image forming apparatus using the light-emitting device 100 of this embodiment. The image forming apparatus 926 shown in FIG. 13(a) includes a photoconductor 927, an exposure light source 928, a developing unit 931, a charging unit 930, a transfer unit 932, a transport unit 933 (the transport roller in the configuration of FIG. 13(a)), and a fixing unit 935. The exposure light source 928 corresponds to the head substrate 1800 shown in FIG. 11(a). Therefore, the above-described light-emitting device 100 (LED chip 1803) can be used as the exposure light source 928 of the image forming apparatus 926.

[0118] Light 929 is emitted from an exposure light source 928, and an electrostatic latent image is formed on the surface of a photoconductor 927. The light-emitting device 100 can be applied to this exposure light source 928. A developing unit 931 contains toner or the like as a developer and can function as a developing device that applies the developer to the exposed photoconductor 927. A charging unit 930 charges the photoconductor 927. A transfer unit 932 transfers the developed image to a recording medium 934. A transport unit 933 transports the recording medium 934. The recording medium 934 can be, for example, paper or film. A fixing unit 935 fixes the image formed on the recording medium.

[0119] 13(b) and 13(c) are schematic diagrams showing an exposure light source 928 in which a plurality of light-emitting sections 936 are arranged along the longitudinal direction of a long substrate. The light-emitting device 100 can be applied to this light-emitting section 936. In other words, a plurality of pixels are arranged along the longitudinal direction of the substrate. A direction 937 is parallel to the axis of the photosensitive member 927. This column direction is the same as the axial direction of the photosensitive member 927 when it rotates. This direction 937 can also be called the long axis direction of the photosensitive member 927.

[0120] FIG. 13(b) shows a configuration in which the light-emitting units 936 are arranged along the longitudinal direction of the photoconductor 927. FIG. 13(c) shows a modified configuration of the arrangement of the light-emitting units 936 shown in FIG. 13(b), in which the light-emitting units 936 are arranged alternately in the column direction in the first and second columns. The light-emitting units 936 are arranged at different positions in the row direction in the first and second columns. In the first column, multiple light-emitting units 936 are arranged at intervals, and in the second column, light-emitting units 936 are arranged at positions corresponding to the gaps between the light-emitting units 936 in the first column. Multiple light-emitting units 936 are also arranged at intervals in the row direction. The arrangement of the light-emitting units 936 shown in FIG. 13(c) can be described as, for example, a grid-like arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0121] FIG. 14 is a schematic diagram illustrating an example of a display device using the light-emitting device 100 of this embodiment. The display device 1000 may include a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. The touch panel 1003 and the display panel 1005 are connected to flexible printed circuits FPCs 1002 and 1004. An active element such as a transistor is disposed on the circuit board 1007. The battery 1008 may not be disposed if the display device 1000 is not a portable device, and even if it is a portable device, it does not need to be disposed in this position. The light-emitting device 100 can be applied to the display panel 1005. Light-emitting elements disposed in the light-emitting device 100 functioning as the display panel 1005 are connected to active elements such as transistors disposed on the circuit board 1007 and operate.

[0122] The display device 1000 shown in FIG. 14 may be used as a display unit of a photoelectric conversion device (which may also be called an imaging device) that has an optical unit with multiple lenses and an imaging element that receives light that has passed through the optical unit and photoelectrically converts it into an electrical signal. The photoelectric conversion device may have a display unit that displays information acquired by the imaging element. The display unit may be a display unit exposed to the outside of the photoelectric conversion device or a display unit located within a viewfinder. The photoelectric conversion device may be a digital camera or a digital video camera.

[0123] FIG. 15 is a schematic diagram illustrating an example of a photoelectric conversion device using the light-emitting device 100 of this embodiment. The photoelectric conversion device 1100 may include a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The photoelectric conversion device 1100 may also be called an imaging device. The light-emitting device 100 of this embodiment can be applied to the viewfinder 1101 or the rear display 1102, which are display units. In this case, the light-emitting device 100 may display not only an image to be captured, but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the moving speed of a subject, the possibility that the subject will be blocked by an obstruction, and the like.

[0124] Since the timing suitable for capturing an image is often very short, it is better to display information as soon as possible. Therefore, a light-emitting device 100 in which pixels including light-emitting elements using an organic light-emitting material such as an organic EL element are arranged may be used in a viewfinder 1101 or a rear display 1102. This is because organic light-emitting materials have a fast response speed. A light-emitting device 100 using an organic light-emitting material is more suitable than a liquid crystal display device for these devices, which require a high display speed.

[0125] The photoelectric conversion device 1100 has an optical section (not shown). The optical section has multiple lenses, which form an image on a photoelectric conversion element (not shown) housed in a housing 1104 that receives light that has passed through the optical section. The focus of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically.

[0126] The light-emitting device 100 may be applied to a display unit of an electronic device. In this case, the light-emitting device 100 may have both a display function and an operation function. Examples of the portable terminal include a mobile phone such as a smartphone, a tablet, and a head-mounted display.

[0127] FIG. 16 is a schematic diagram showing an example of an electronic device using the light-emitting device 100 of this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit 1202 may be a biometric recognition unit that recognizes a fingerprint to perform unlocking, etc. A portable device having a communication unit can also be called a communication device. The light-emitting device 100 of this embodiment can be applied to the display unit 1201.

[0128] 17(a) and 17(b) are schematic diagrams illustrating an example of a display device using the light-emitting device 100 of this embodiment. FIG. 17(a) illustrates a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The light-emitting device 100 of this embodiment can be applied to the display unit 1302. The display device 1300 may have a base 1303 that supports the frame 1301 and the display unit 1302. The base 1303 is not limited to the form shown in FIG. 17(a). For example, the bottom edge of the frame 1301 may also serve as the base 1303. The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0129] FIG. 17(b) is a schematic diagram illustrating another example of a display device using the light-emitting device 100 of this embodiment. The display device 1310 of FIG. 17(b) is configured to be bendable and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The light-emitting device 100 of this embodiment can be applied to the first display unit 1311 and the second display unit 1312. The first display unit 1311 and the second display unit 1312 may be a single display unit without any joints. The first display unit 1311 and the second display unit 1312 can be separated by the bending point. The first display unit 1311 and the second display unit 1312 may display different images, or the first display unit and the second display unit 1312 may display a single image.

[0130] FIG. 18 is a schematic diagram illustrating an example of a lighting device using the light-emitting device 100 of this embodiment. The lighting device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusion unit 1405. The light-emitting device 100 of this embodiment can be applied to the light source 1402. The optical film 1404 may be a filter that improves the color rendering of the light source. The light diffusion unit 1405 can effectively diffuse light from the light source, such as for lighting, and deliver the light over a wide area. If necessary, a cover may be provided on the outermost part. The lighting device 1400 may include both the optical film 1404 and the light diffusion unit 1405, or only one of them.

[0131] The lighting device 1400 is, for example, a device that illuminates a room. The lighting device 1400 may emit white, daylight white, or any other color from blue to red. It may have a dimming circuit that adjusts the light intensity. The lighting device 1400 may have a power supply circuit connected to the light-emitting device 100 that functions as the light source 1402. The power supply circuit is a circuit that converts AC voltage into DC voltage. White has a color temperature of 4200K, and daylight white has a color temperature of 5000K. The lighting device 1400 may also have a color filter. The lighting device 1400 may also have a heat sink. The heat sink dissipates heat from within the device to the outside, and examples of the heat sink include metal with a high specific heat, liquid silicon, etc.

[0132] FIG. 19 is a schematic diagram of an automobile having a tail lamp, which is an example of a vehicle lamp using the light-emitting device 100 of this embodiment. The automobile 1500 may have a tail lamp 1501 that is turned on when the brakes are applied, for example. The light-emitting device 100 of this embodiment may be used as a headlamp as a vehicle lamp. An automobile is an example of a mobile body, and the mobile body may be a ship, a drone, an aircraft, a railcar, an industrial robot, or the like. The mobile body may have a body and a lamp provided thereon. The lamp may indicate the current location of the body.

[0133] The light emitting device 100 of this embodiment can be applied to a tail lamp 1501. The tail lamp 1501 may have a protective member that protects the light emitting device 100 functioning as the tail lamp 1501. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, and may be made of polycarbonate or the like. The protective member may also be made by mixing a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like with polycarbonate.

[0134] The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window may be a window for checking the front and rear of the automobile, or may be a transparent display such as a head-up display. The light-emitting device 100 of this embodiment may be used in the transparent display. In this case, the constituent materials of the electrodes and the like of the light-emitting device 100 are made of transparent materials.

[0135] 20(a) and 20(b), a further application example of the light-emitting device 100 of this embodiment will be described. The light-emitting device 100 can be applied to systems that can be worn as a wearable device, such as smart glasses, a head-mounted display (HMD), or smart contact lenses. An image capturing and displaying device used in such an application example has an image capturing device capable of photoelectrically converting visible light and a light-emitting device capable of emitting visible light.

[0136] 20(a) illustrates glasses 1600 (smart glasses) according to one application example. An imaging device 1602 such as a CMOS sensor or a SPAD is provided on the front side of a lens 1601 of the glasses 1600. In addition, the light-emitting device 100 of this embodiment is provided on the back side of the lens 1601.

[0137] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the image capture device 1602 and the light emitting device 100 according to each embodiment. The control device 1603 also controls the operations of the image capture device 1602 and the light emitting device 100. The lens 1601 is formed with an optical system for focusing light onto the image capture device 1602.

[0138] FIG. 20(b) illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 include a control device 1612, which is equipped with an imaging device corresponding to the imaging device 1602 and a light-emitting device 100. A lens 1611 includes an optical system for projecting light emitted from the imaging device in the control device 1612 and the light-emitting device 100, and an image is projected onto the lens 1611. The control device 1612 functions as a power source for supplying power to the imaging device and the light-emitting device 100 and controls the operation of the imaging device and the light-emitting device 100. The control device 1612 may also include a gaze detection unit that detects the gaze of the wearer. Infrared light may be used for gaze detection. The infrared light emitter emits infrared light toward the eyeball of a user gazing at a displayed image. An imaging unit having a light-receiving element detects the emitted infrared light reflected from the eyeball, thereby obtaining an image of the eyeball. By providing a reduction means for reducing the amount of light from the infrared light emitting section to the display section in a plan view, degradation of image quality is reduced.

[0139] The gaze of the user relative to the displayed image is detected from an image of the eyeball obtained by capturing infrared light. Any known method can be used for gaze detection using the image of the eyeball. As an example, a gaze detection method based on the Purkinje image formed by reflection of irradiated light on the cornea can be used.

[0140] More specifically, gaze detection processing is performed based on the pupil-corneal reflex method, which calculates a gaze vector representing the direction (rotation angle) of the eyeball based on the pupil image and Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0141] The light emitting device 100 according to the embodiment of the present disclosure may include an imaging device having a light receiving element, and may control the display image based on user line of sight information from the imaging device.

[0142] Specifically, based on the line-of-sight information, the light-emitting device 100 determines a first field of view area where the user gazes and a second field of view area other than the first field of view area. The first field of view area and the second field of view area may be determined by a control device of the light-emitting device 100, or may be determined by an external control device and received. In the display area of ​​the light-emitting device 100, the display resolution of the first field of view area may be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area may be lower than that of the first field of view area.

[0143] The display area includes a first display area and a second display area different from the first display area, and a high-priority area is determined from the first display area and the second display area based on line-of-sight information. The first display area and the second display area may be determined by a control device of the light-emitting device 100, or may be determined by an external control device and received. The resolution of the high-priority area may be controlled to be higher than the resolution of areas other than the high-priority area. In other words, the resolution of an area with a relatively low priority may be lowered.

[0144] Note that AI may be used to determine the first field of view area and areas with high priority. The AI ​​may be a model configured to estimate the angle of gaze and the distance to an object in the line of sight from the image of the eyeball, using as training data an image of the eyeball and the actual direction in which the eyeball in the image was looking. The AI ​​program may be included in the light-emitting device 100, the imaging device, or an external device. If included in an external device, it is transmitted to the light-emitting device 100 via communication.

[0145] When display control is performed based on visual recognition detection, the smart glasses can be applied to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured outside information in real time.

[0146] The disclosure of the present specification includes the following light emitting device, light emitting module, and image forming apparatus.

[0147] (Item 1) A light-emitting device including a substrate on which a plurality of light-emitting elements are arranged, a light-emitting region extending in a first direction as a longitudinal direction, a processing circuit that processes a data signal for controlling the light emission brightness of the plurality of light-emitting elements in accordance with a clock signal, and a plurality of terminals arranged in the first direction for receiving the clock signal, the data signal, and power, the plurality of terminals include a first terminal, and a second terminal and a third terminal arranged adjacent to each other; the processing circuit is disposed in the first direction relative to the plurality of terminals; A light-emitting device, characterized in that one of the clock signal and the data signal is supplied to the second terminal, and the other of the clock signal and the data signal is supplied to the third terminal.

[0148] (Item 2) 2. The light-emitting device according to item 1, wherein the second terminal and the third terminal are disposed between the processing circuit and the first terminal.

[0149] (Item 3) the second terminal is supplied with the data signal, and the third terminal is supplied with the clock signal; 3. The light-emitting device according to item 2, wherein the third terminal is disposed between the processing circuit and the second terminal.

[0150] (Item 4) 4. The light-emitting device according to any one of items 1 to 3, wherein the pulse width of the clock signal is shorter than the period of data transitions of the data signal corresponding to each light-emitting element.

[0151] (Item 5) the plurality of terminals further includes a fourth terminal disposed between the first terminal and the second terminal; a pulse width of the clock signal is shorter than a period of transition of data corresponding to each light-emitting element of the data signal; 4. The light-emitting device according to item 3, wherein the fourth terminal is supplied with a signal that transitions at a period equal to or greater than the period of transition of data corresponding to each light-emitting element of the data signal.

[0152] (Item 6) the plurality of terminals further includes a fourth terminal disposed between the first terminal and the second terminal; a pulse width of the clock signal is shorter than a period of transition of data corresponding to each light-emitting element of the data signal; a signal that transitions at a period longer than a period of transition of data corresponding to each light emitting element of the data signal is supplied to the first terminal; 4. The light-emitting device according to item 3, wherein the fourth terminal is a terminal for supplying power.

[0153] (Item 7) 6. The light-emitting device according to any one of items 1 to 5, wherein the first terminal is a terminal for supplying power.

[0154] (Item 8) A light-emitting device described in any one of items 1 to 5, characterized in that a signal that transitions at a period longer than the period of data transitions corresponding to each light-emitting element of the data signal is supplied to the first terminal.

[0155] (Item 9) the substrate has a rectangular shape with long and short sides; 9. The light-emitting device according to any one of items 1 to 8, wherein the first direction is a direction along the long side.

[0156] (Item 10) 10. The light-emitting device according to any one of items 1 to 9, wherein the light-emitting region is arranged in a second direction intersecting the first direction relative to the processing circuit and the plurality of terminals.

[0157] (Item 11) 11. The light-emitting device according to any one of items 1 to 10, further comprising a scanning circuit that scans the plurality of light-emitting elements according to a signal supplied from the processing circuit.

[0158] (Item 12) 12. The light-emitting device of claim 11, wherein the scanning circuit is disposed between the processing circuit and the light-emitting area.

[0159] (Item 13) the processing circuit includes an acquisition circuit to which the clock signal and the data signal are input; 13. The light-emitting device according to any one of items 1 to 12, wherein, in a plan view of the substrate, the acquisition circuit is disposed closer to the plurality of terminals than the center of the processing circuit.

[0160] (Item 14) a moisture-resistant ring is disposed along an outer edge of the substrate, surrounding the light-emitting region, the processing circuit, and the plurality of terminals; A light-emitting device described in any one of items 1 to 13, characterized in that, when viewed in a plane relative to the substrate, the moisture-resistant ring has a recess that is recessed into the inside of the substrate between the multiple terminals and the processing circuit.

[0161] (Item 15) A light emitting module comprising a plurality of light emitting devices, each of which is the light emitting device according to any one of claims 1 to 14.

[0162] (Item 16) a photoreceptor, an exposure light source for exposing the photoreceptor, a developing device for applying a developer to the exposed photoreceptor, and a transfer device for transferring an image developed by the developing device onto a recording medium, 15. An image forming apparatus, wherein the exposure light source comprises the light emitting device according to any one of items 1 to 14.

[0163] 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. [Explanation of symbols]

[0164] 100: Light-emitting device, 101 to 103, 108, 109: Terminals, 104: Processing circuit, 105: Light-emitting region, 106: Substrate

Claims

1. A light-emitting device including a substrate on which a plurality of light-emitting elements are arranged, a light-emitting region extending in a first direction as a longitudinal direction, a processing circuit that processes a data signal for controlling the light emission brightness of the plurality of light-emitting elements in accordance with a clock signal, and a plurality of terminals arranged in the first direction for receiving the clock signal, the data signal, and power, the plurality of terminals include a first terminal, and a second terminal and a third terminal arranged adjacent to each other; the processing circuit is disposed in the first direction relative to the plurality of terminals; A light-emitting device, characterized in that one of the clock signal and the data signal is supplied to the second terminal, and the other of the clock signal and the data signal is supplied to the third terminal.

2. The light-emitting device according to claim 1 , wherein the second terminal and the third terminal are disposed between the processing circuit and the first terminal.

3. the second terminal is supplied with the data signal, and the third terminal is supplied with the clock signal; The light-emitting device of claim 2 , wherein the third terminal is disposed between the processing circuit and the second terminal.

4. 2. The light-emitting device according to claim 1, wherein the pulse width of the clock signal is shorter than the period of data transitions of the data signal corresponding to each light-emitting element.

5. the plurality of terminals further includes a fourth terminal disposed between the first terminal and the second terminal; a pulse width of the clock signal is shorter than a period of transition of data corresponding to each light-emitting element of the data signal; 4. The light-emitting device according to claim 3, wherein the fourth terminal is supplied with a signal whose transition period is equal to or greater than the period of transition of the data corresponding to each light-emitting element of the data signal.

6. the plurality of terminals further includes a fourth terminal disposed between the first terminal and the second terminal; a pulse width of the clock signal is shorter than a period of transition of data corresponding to each light-emitting element of the data signal; a signal that transitions at a period longer than a period of transition of data corresponding to each light emitting element of the data signal is supplied to the first terminal; 4. The light-emitting device according to claim 3, wherein the fourth terminal is a terminal for supplying power.

7. 2. The light-emitting device according to claim 1, wherein the first terminal is a terminal for supplying power.

8. The light-emitting device according to claim 1 , wherein the first terminal is supplied with a signal whose transition period is longer than the transition period of the data corresponding to each light-emitting element of the data signal.

9. the substrate has a rectangular shape with long and short sides; The light-emitting device according to claim 1 , wherein the first direction is a direction along the long side.

10. The light-emitting device of claim 1 , wherein the light-emitting region is disposed in a second direction intersecting the first direction relative to the processing circuit and the plurality of terminals.

11. The light emitting device according to claim 1 , further comprising a scanning circuit that scans the plurality of light emitting elements in accordance with a signal supplied from the processing circuit.

12. 12. The light emitting device of claim 11, wherein the scanning circuitry is disposed between the processing circuitry and the light emitting area.

13. the processing circuit includes an acquisition circuit to which the clock signal and the data signal are input; The light-emitting device according to claim 1 , wherein, in a plan view of the substrate, the acquisition circuit is disposed at a position closer to the plurality of terminals than the center of the processing circuit.

14. a moisture-resistant ring is disposed along an outer edge of the substrate, surrounding the light-emitting region, the processing circuit, and the plurality of terminals; 2. The light-emitting device according to claim 1, wherein, in a plan view of the substrate, the moisture-resistant ring has a recess recessed into the inside of the substrate between the plurality of terminals and the processing circuit.

15. A light emitting module comprising a plurality of light emitting devices, each of which is a light emitting device according to any one of claims 1 to 14.

16. a photoreceptor, an exposure light source for exposing the photoreceptor, a developing device for applying a developer to the exposed photoreceptor, and a transfer device for transferring an image developed by the developing device onto a recording medium, 15. An image forming apparatus, wherein the exposure light source comprises the light emitting device according to claim 1.

Images