JP-7857129-B2 - Light-emitting devices, display devices, photoelectric converters, electronic devices, lighting devices, mobile devices and wearable devices

JP7857129B2JP 7857129 B2JP7857129 B2JP 7857129B2JP-7857129-B2

Inventors

山本哲郎

Assignees

キヤノン株式会社

Dates

Publication Date: 20260512
Application Date: 20220324

Claims (20)

A light-emitting device having a pixel comprising a light-emitting element, a drive transistor whose first main terminal is connected to the light-emitting element and which supplies a current corresponding to a brightness signal to the light-emitting element, a light-emitting control transistor disposed between the second main terminal of the drive transistor and a supply line that supplies a first potential and which controls the light emission or non-emission of the light-emitting element, a write transistor for supplying the brightness signal to the control terminal of the drive transistor, and a capacitive element disposed between the second main terminal and the control terminal, A second potential is supplied to the back gate terminal of the aforementioned drive transistor. One frame period includes a writing period in which the writing transistor conducts and the brightness signal is written to the control terminal, and a light emission period in which, after the writing period, the light emission control transistor changes from a non-conductive state to a conductive state and the light-emitting element emits light according to the brightness signal. A light-emitting device characterized in that, after the start of the writing period and before the end of the writing period, while the brightness signal is input to the control terminal of the drive transistor, the light-emitting control transistor changes from a conductive state to a non-conductive state .
The light-emitting device according to claim 1, characterized in that the length of the period from when the light-emitting control transistor changes from a conductive state to a non-conductive state during the writing period until the end of the writing period is longer than the length of the period during which the light-emitting control transistor is conductive during the writing period.
The light-emitting device according to claim 1 or 2, characterized in that the first potential and the second potential are the same potential.
The light-emitting device according to any one of claims 1 to 3, characterized in that, after the end of the writing period and before the start of the light-emitting period, the writing transistor is again made conductive and the brightness signal is written to the control terminal.
The light-emitting device according to claim 4, characterized in that the length of the period during which the writing transistor conducts again after the end of the writing period and before the start of the light-emitting period is shorter than the length of the writing period.
The light-emitting device according to claim 4 or 5, characterized in that the length of the period during which the writing transistor conducts again after the end of the writing period and before the start of the light-emitting period is shorter than the length of the period from when the light-emitting control transistor changes from a conductive state to a non-conductive state during the writing period until the end of the writing period.
The light-emitting device according to any one of claims 1 to 6, further characterized in that the pixel includes a reset transistor that resets the terminal connected to the first main terminal of the light-emitting element to a third potential.
The light-emitting device according to claim 7, characterized in that the reset transistor is in a conductive state during the aforementioned writing period.
The light-emitting device according to claim 7 or 8, characterized in that the potential supplied to the terminal of the light-emitting element that is not connected to the first main terminal is the same as the third potential.
The light-emitting device according to any one of claims 1 to 9, characterized in that the pixel further includes an additional capacitive element disposed between the capacitive element and a supply line that supplies a fourth potential.
The light-emitting device according to claim 10, characterized in that the first potential and the fourth potential are the same potential.
The light-emitting device according to any one of claims 1 to 11, characterized in that the driving transistor is a p-channel type transistor.
The light-emitting device according to any one of claims 1 to 12, characterized in that the length of the period from the end of the writing period to the start of the light-emitting period is longer than the length of the writing period.
It has a signal line connected to the writing transistor and to which the brightness signal is input, The light-emitting device according to any one of claims 1 to 13, characterized in that only the luminance signal is input to the signal line.
A display device comprising a light-emitting device according to any one of claims 1 to 14 , and an active element connected to the light-emitting device.
It comprises an optical unit having multiple lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays an image. The photoelectric converter is characterized in that the display unit is a display unit that displays an image captured by the image sensor, and has a light-emitting device according to any one of claims 1 to 14 .
It comprises a housing on which a display unit is provided, and a communication unit provided in the housing for communicating with the outside, The display unit is an electronic device characterized by having a light-emitting device according to any one of claims 1 to 14 .
A lighting device having a light source and at least one of a light diffusing section and an optical film, The lighting device is characterized in that the light source has a light-emitting device according to any one of claims 1 to 14 .
A mobile body having an aircraft body and a lighting fixture provided on the aircraft body, The aforementioned light fixture is a mobile body characterized by having a light-emitting device according to any one of claims 1 to 14 .
A wearable device having a display device for displaying images, The wearable device is characterized in that the display device has a light-emitting device according to any one of claims 1 to 14 .

Description

This invention relates to light-emitting devices, display devices, photoelectric conversion devices, electronic devices, lighting devices, mobile devices, and wearable devices. Interest in light-emitting devices using self-luminescent elements such as organic electroluminescent (EL) elements is growing. Patent Document 1 shows a pixel including a drive transistor that supplies current to cause an organic EL element to emit light at a predetermined brightness. Japanese Patent Publication No. 2010-145579 A diagram showing an example configuration of the light-emitting device according to this embodiment.Figure 1 shows an example of the pixel configuration of the light-emitting device.A timing diagram showing an example of the operation of the light-emitting device in Figure 1.Figure 3 illustrates the operation of the light-emitting device at each timing.This figure shows a modified version of the pixels in Figure 2.This figure shows a modified version of the pixels in Figure 2.This figure shows a modified version of the pixels in Figure 2.A timing diagram showing an example of the operation of the light-emitting device in Figure 1.Figure 2 shows the parasitic capacitance of the pixel drive transistor and writing transistor, as well as the gate-source voltage of the drive transistor.A diagram showing an example of a display device using the light-emitting device of this embodiment.A diagram showing an example of a photoelectric conversion device using the light-emitting device of this embodiment.A diagram showing an example of an electronic device using the light-emitting device of this embodiment.A diagram showing an example of a display device using the light-emitting device of this embodiment.A diagram showing an example of a lighting device using the light-emitting device of this embodiment.A diagram showing an example of a mobile body using the light-emitting device of this embodiment.A diagram showing an example of a wearable device using the light-emitting device of this embodiment. The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While multiple features are described in the embodiments, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted. A light-emitting device according to an embodiment of the present disclosure will be described with reference to Figures 1 to 16(a) and 16(b). Figure 1 is a schematic diagram showing an example configuration of the light-emitting device 100 in this embodiment. The light-emitting device 100 includes a pixel array 110 and peripheral circuits arranged around the pixel array 110 to operate the pixel array 110. The pixel array 110 has a plurality of pixels 101 arranged to form a plurality of rows and a plurality of columns. The peripheral circuits that operate (drive) each pixel of the pixel array 110 include, for example, a scanning drive system including a write scanning circuit 201 and a light emission drive scanning circuit 202, and a signal supply system including a signal output circuit 300. In the configuration shown in Figure 1, the write scanning circuit 201 is located on the left side of the pixel array 110, and the light emission drive scanning circuit 202 is located on the right side, but the layout is not limited to this configuration. For example, the arrangement of the write scanning circuit 201 and the light emission drive scanning circuit 202 may be reversed, or the write scanning circuit 201 and the light emission drive scanning circuit 202 may be located on one side of the pixel array 110. Furthermore, a pair of write scanning circuits 201 and light emission drive scanning circuits 202 may be arranged on both the left and right sides, respectively. Here, one "pixel" of the image displayed by the light-emitting device 100 may be composed of multiple subpixels. In this case, the subpixels correspond to the pixels 101 shown in Figure 1. More specifically, one pixel may be composed of three subpixels, for example, a subpixel emitting red light, a subpixel emitting green light, and a subpixel emitting blue light. However, one pixel is not limited to such a combination of three primary color subpixels. In addition to the three primary color subpixels, one pixel may have one or more subpixels of other colors. For example, one pixel may have a subpixel emitting white light in addition to the three primary colors to improve brightness. Also, for example, one pixel may have one or more subpixels emitting complementary color light in addition to the three primary colors to expand the color reproduction range. In the pixel array 110, scan lines 211 and 212 are arranged along the row direction (horizontal direction in Figure 1) for each p