Patent Application
20240145516
Embodiments of the present disclosure relate to an imaging device, a method for driving the same, and an electronic device.
An imaging device having a structure in which a light receiving layer provided with a photodiode and a layer provided with a pixel transistor are laminated is known (see Patent Document 1, for example). By adopting such a laminated structure, the dynamic range is increased by increasing the area of the photodiode and the transistor area per unit substrate area.
Patent Document 1: Japanese Patent Application Laid-Open No. 2020-88380
Patent Document 2: Japanese Patent Application Laid-Open No. 2018-74268
However, in the imaging device of Patent Document 1, since the pixel area increases, there is a problem that the pixel size cannot be reduced.
The present disclosure provides an imaging device capable of easily increasing the dynamic range without increasing the pixel size, a method for driving the same, and an electronic device.
An imaging device according to a first aspect of the present disclosure includes: a pixel array unit arranged in a matrix in units of a pixel group including a plurality of pixels that performs photoelectric conversion; a pixel transistor provided corresponding to the pixel group and including a plurality of transistors; and a circuit that controls a threshold voltage of at least one transistor of the plurality of transistors.
In the imaging device according to the first aspect, the pixel transistor may include a reset transistor, an amplification transistor, and a selection transistor.
In the imaging device according to the first aspect, the transistor whose threshold voltage is controlled may be at least one of the reset transistor or the selection transistor.
In the imaging device according to the first aspect, the transistor whose threshold voltage is controlled may be arranged in a well region, and the circuit may control a potential applied to the well region.
In the imaging device according to the first aspect, the plurality of transistors constituting the pixel transistor may be n-channel MOS transistors.
In the imaging device according to the first aspect, the plurality of transistors constituting the pixel transistor may be p-channel MOS transistors.
In the imaging device according to the first aspect, each of the plurality of pixels may include a photoelectric conversion element arranged in a first region and a well region arranged in a second region on the first region, and the well regions in the plurality of pixels may be separated by an insulating film.
In the imaging device according to the first aspect, the pixel may include a floating diffusion that accumulates the charge converted by the photoelectric conversion element and a transfer gate that transfers the charge accumulated in the floating diffusion to the pixel transistor, and the floating diffusion and the transfer gate may be arranged in the first region.
In the imaging device according to the first aspect, the pixel may include a floating diffusion that accumulates the charge converted by the photoelectric conversion element and a transfer gate that transfers the charge accumulated in the floating diffusion to the pixel transistor, and the floating diffusion and the transfer gate may be arranged in the second region.
In the imaging device according to the first aspect, each of the plurality of pixels may include a photoelectric conversion element and a well region arranged on the photoelectric conversion element and in which the pixel transistor is arranged, and the well region may be covered with a semiconductor region having a conductivity type different from a conductivity type of the well region.
In the imaging device according to the first aspect, the plurality of transistors of the pixel transistor may be provided corresponding to different pixels.
In the imaging device according to the first aspect, the pixel group may include a first region, a second region, a third region, and a fourth region arranged in a plane direction of the pixel array unit, the first region may include a first pixel group, the second region may include a second pixel group, the third region may be arranged between the first region and the second region and may include a first portion of the pixel transistor, and the fourth region may be arranged on an opposite side of the third region with the second region interposed therebetween and may include a second portion of the pixel transistor.
In the imaging device according to the first aspect, the first pixel group may include a plurality of first pixels, each of the plurality of first pixels may be separated by a first semiconductor region of a first conductivity type, the second pixel group may include a plurality of second pixels, each of the plurality of second pixels may be separated by a second semiconductor region of the first conductivity type, the first portion may be arranged in a first well region of the first conductivity type, the first well region may be separated by a third semiconductor region of a second conductivity type different from the first conductivity type, the second portion may be arranged in a second well region of the first conductivity type, and the second well region may be separated by a fourth semiconductor region of the second conductivity type.
The imaging device according to the first aspect may further include a differential amplification unit. In this imaging device, the pixel array unit may include a first pixel group including a first pixel and a second pixel group including a second pixel, and be configured such that incident light is incident on a photoelectric conversion element included in the first pixel and the incident light is not incident on a photoelectric conversion element included in the second pixel, and the differential amplification unit may cause different currents to flow in the first pixel group and the second pixel in a reset period and a readout period.
In the imaging device according to the first aspect, the pixel transistor may include a reset transistor, an amplification transistor, and a selection transistor, and the differential amplification unit may include a tail current source that causes a constant current to flow through the amplification transistor of each of the first pixel group and the second pixel group, and a current mirror circuit that causes an equal current to flow through the first pixel group and the second pixel group.
In the imaging device according to the first aspect, the differential amplification unit may further include a reset constant current circuit that causes a predetermined current to flow through the second pixel group during a reset period.
A method for driving an imaging device according to a second aspect, the imaging device including a pixel array unit arranged in a matrix in units of a pixel group including a plurality of pixels that performs photoelectric conversion, and a pixel transistor provided corresponding to each pixel group and including a plurality of transistors. The method includes controlling a substrate potential of at least one transistor of the plurality of transistors during a readout period to control a threshold voltage of the transistor.
In the method for driving the imaging device according to the second aspect, the transistor may include an n-channel transistor, and a positive pulse voltage may be applied to the transistor during the readout period.
In the method for driving the imaging device according to the second aspect, the transistor may include an n-channel transistor, and a negative pulse voltage may be applied to the transistor during the readout period.
An electronic device according to a third aspect includes an imaging device, and a signal processing unit that performs signal processing on the basis of a pixel signal imaged by the imaging device. The imaging device includes a pixel array unit arranged in a matrix in units of a pixel group including a plurality of pixels that performs photoelectric conversion, a pixel transistor provided corresponding to each pixel group and including a plurality of transistors, and a circuit that controls a threshold voltage of at least one transistor of the plurality of transistors.
First, circumstances leading to an imaging device of the present disclosure will be described. In Patent Document 1, the dynamic range is increased by increasing the area of a photodiode. However, in a case where only the saturation signal amount of the photodiode is simply increased, the voltage amplitude to be processed in the pixel transistor and the subsequent circuit block also increases. In this case, unless the dynamic range of the subsequent circuit is also further increased, the number of electrons that can be finally handled as an image, that is, the dynamic range of the imaging device does not increase. Therefore, as a result of intensive research, the inventor of the present application has found that it is sufficient to control a threshold value of a pixel transistor by adjusting a well potential applied to a well region of the pixel transistor to further increase the dynamic range. In the following embodiments of the present disclosure, an imaging device in which a well potential of a pixel transistor is adjusted will be described.
Hereinafter, embodiments of the present disclosure are described with reference to the drawings. In the embodiments to be described below, although components of an imaging device and an electronic device will be mainly described, the imaging device and the electronic device may have components and functions that are not illustrated or described. The following description does not exclude components and functions that are not illustrated or described.
Furthermore, the drawings referred to in the following description are drawings for illustrating the embodiments of the present disclosure and promoting understanding thereof, and shapes, dimensions, ratios and the like in the drawings may be different from actual ones for the sake of clarity.
An imaging device according to a first embodiment will be described with reference to
As illustrated in
A pixel transistor 20 includes a reset transistor RST, an amplification transistor AMP, and a selection transistor SEL. Each of these transistors is an n-channel transistor and is formed in a p-well region 26, and each source region and drain region 21 is an n+ region. Each pixel transistor is formed in the p-well region 26. The reset transistor RST is arranged on the pixel 1111, the amplification transistor AMP is arranged on the pixel 1112, and the selection transistor SEL is arranged on the pixel 1122. Note that in
Furthermore, as illustrated in
Furthermore, each of the pixels 11ij (i, j=1, 2) is provided with a floating diffusion FD that accumulates signal charge from the photodiode PD, and the photodiode PD and the floating diffusion FD are connected by a transfer gate TG.
A read operation in the pixel configured as described above will be described with reference to
As described above, by adjusting the substrate potential of the selection transistor SEL at the time of reading, it is possible to expand the range of signals that can be handled without affecting the signal level. That is, the dynamic range can be increased easily.
Next,
A pixel region 251 is a pixel array in which the pixels are two-dimensionally arranged, and converts an optical signal into an electric signal to perform imaging. In the pixel region 251, with respect to pixels, the pixel drive line 252 is provided for every two rows, and the vertical signal line 253 is provided for every two columns. In the present embodiment, the configuration of the pixels constituting the pixel region 251 will be described in detail later.
The vertical drive unit 254 includes a shift register, an address decoder, and the like, and supplies a drive signal to the pixel drive line 252 such that a pixel signal corresponding to charge accumulated in each of imaging elements in the pixel region 251 is read row by row from the top, in order of an odd column and an even column.
The column processing unit 255 includes a signal processing circuit for every two columns of the pixels of the pixel region 251. Each signal processing circuit of the column processing unit 255 performs signal processing, such as A/D conversion processing or correlated double sampling (CDS) processing, on the pixel signal read from the corresponding pixel and supplied through the vertical signal line 253. The column processing unit 255 temporarily holds the pixel signal subjected to the signal processing.
The horizontal drive unit 256 includes a shift register, an address decoder, and the like, and sequentially selects the signal processing circuits of the column processing unit 255. Accordingly, the pixel signals subjected to the signal processing by the signal processing circuits of the column processing unit 255 are sequentially output to the signal processing unit 258.
The system control unit 257 includes a timing generator or the like that generates various timing signals, and controls the vertical drive unit 254, the column processing unit 255, and the horizontal drive unit 256 on the basis of the various timing signals generated by the timing generator.
The signal processing unit 258 performs various kinds of signal processing on the pixel signal output from the column processing unit. At this time, the signal processing unit 258 stores, in the memory unit 259, an intermediate result or the like of the signal processing, as necessary, and refers to the result at a necessary timing. The signal processing unit 258 outputs the pixel signal subjected to the signal processing.
The memory unit 259 includes a dynamic random access memory (DRAM), a static random access memory (SRAM), and the like.
In the pixel region 251 of the imaging device according to the first embodiment, a plurality of two-dimensionally arranged pixels is divided into pixel groups having pixels arranged in two rows and two columns. For example, as illustrated in
In the first embodiment, the substrate potential Vwell is supplied from the vertical drive unit 254 illustrated in
The pulse supplied to the wiring SELi of the i-th (i=1, . . . , m) row and the pulse supplied to the wiring VWlli are sequentially applied from the first row to the m-th row as illustrated in
Furthermore, the larger the amplitude of the pulse supplied to the wiring Vwelli (i=1, . . . , m), the greater the effect of controlling the threshold voltage Vt. However, in a case where the amplitude is increased, the delay of the pulse signal increases and the power consumption increases. Therefore, the amplitude is determined in consideration of the necessary control amount of the threshold voltage Vt, the delay time, and the power consumption.
Note that if the potential Vwell supplied to the well region or the like of the selection transistor SEL is kept high, the effect when the selection transistor SEL is turned off cannot be obtained, and the leak current increases. When the selection transistor SEL is turned off, it is preferable to lower the potential of the well region after the timing at which the selection transistor SEL and the reset transistor RST are turned off.
Furthermore, in the present embodiment, each pixel group has pixels arranged in two rows and two columns. However, a pixel group may include pixels arranged in two rows and four columns, or a pixel group may include one pixel. Moreover, two or more selection transistors may be arranged in each pixel group. In these cases, too, there is no change in the amplitude of a signal VSL (see
As described above, according to the present embodiment, the substrate potential of the selection transistor SEL included in the pixel group can be adjusted at the time of reading, and the dynamic range can be increased easily.
An imaging device according to a second embodiment will be described with reference to
As can be seen from
Next, a read operation of the imaging device according to the second embodiment will be described with reference to
As described above, by adjusting the substrate potential of the reset transistor RST at the time of reading, it is possible to expand the range of signals that can be handled without affecting the signal level. That is, the dynamic range can be increased easily.
In the second embodiment, the substrate potential Vwell is supplied from the vertical drive unit 254 illustrated in
The pulse supplied to the wiring RSTi of the i-th (i=1, . . . , m) row and the pulse supplied to the wiring VWlli are sequentially applied from the first row to the m-th row as illustrated in
Furthermore, as in the case of the first embodiment, the larger the amplitude of the pulse supplied to the wiring Vwelli (i=1, . . . , m), the greater the effect of controlling the threshold voltage Vt. However, in a case where the amplitude is increased, the delay of the pulse signal increases and the power consumption increases. Therefore, the amplitude is determined in consideration of the necessary control amount of the threshold voltage Vt, the delay time, and the power consumption.
Furthermore, in the second embodiment, each pixel group has pixels arranged in two rows and two columns. However, a pixel group may include pixels arranged in two rows and four columns, or a pixel group may include one pixel. Moreover, two or more selection transistors may be arranged in each pixel group. In these cases, too, there is no change in the amplitude of a signal VSL (see
As described above, according to the second embodiment, the substrate potential of the reset transistor RST included in the pixel group can be adjusted at the time of reading, and the dynamic range can be increased easily.
Note that in the imaging device according to the second embodiment, as in the imaging device according to the first embodiment, the adjustment potential Vwell may be supplied to the substrate potential adjustment terminal 25 of the selection transistor SEL of each pixel group at the time of the read operation. That is, the substrate potentials of the selection transistor SEL and the reset transistor RST of each pixel group may be adjusted at the time of reading. As described above, in a case where the substrate potentials of the selection transistor SEL and the reset transistor RST are adjusted together, if it is desired to control the threshold voltages of the reset transistor RST and the selection transistor SEL by the same amount, it is sufficient that the same potential level Vwell is supplied to both well regions. For example, normally, in a case where it is desired to control the threshold voltage Vt of the reset transistor RST and the selection transistor at 0 V in the well region, a potential Vwell of about 0.5 V is supplied to each well region. As a result, the threshold voltages of the reset transistor RST and the selection transistor SEL change by about 0.2 V.
Note that the voltages applied to the gates of the reset transistor RST and the selection transistor SEL are different from each other, and there is no correlation between the gate voltages and the potential Vwell supplied to the well region.
An imaging device according to a third embodiment will be described with reference to
Next, a read operation of the imaging device according to the third embodiment will be described with reference to
As described above, by adjusting the substrate potential of the selection transistor SEL at the time of reading, it is possible to expand the range of signals that can be handled without affecting the signal level. That is, the dynamic range can be increased easily.
In the third embodiment, the substrate potential Vwell is supplied from the vertical drive unit 254 illustrated in
The pulse supplied to the wiring SELi of the i-th (i=1, . . . , m) row and the pulse supplied to the wiring VWlli are sequentially applied from the first row to the m-th row as illustrated in
Furthermore, as in the case of the first embodiment, the larger the amplitude of the pulse supplied to the wiring Vwelli (i=1, . . . , m), the greater the effect of controlling the threshold voltage Vt. However, in a case where the amplitude is increased, the delay of the pulse signal increases and the power consumption increases. Therefore, the amplitude is determined in consideration of the necessary control amount of the threshold voltage Vt, the delay time, and the power consumption.
Furthermore, in the third embodiment, each pixel group has pixels arranged in two rows and two columns. However, a pixel group may include pixels arranged in two rows and four columns, or a pixel group may include one pixel. Moreover, two or more selection transistors may be arranged in each pixel group. In these cases, too, there is no change in the amplitude of a signal VSL (see
As described above, according to the third embodiment, the substrate potential of the reset transistor RST included in the pixel group can be adjusted at the time of reading, and the dynamic range can be increased easily.
An imaging device according to a fourth embodiment will be described with reference to
As can be seen from
Next, the read operation of the imaging device according to the third embodiment is performed similarly to the third embodiment. Note, however, that in the fourth embodiment, the potential Vwell for adjusting the substrate potential is supplied to the reset transistor RST at the time of the read operation. VSS is supplied as the substrate potentials of the amplification transistor AMP and the selection transistor SEL.
As described above, by adjusting the substrate potential of the reset transistor RST at the time of reading, it is possible to expand the range of signals that can be handled without affecting the signal level. That is, the dynamic range can be increased easily.
In the third embodiment, the substrate potential Vwell is supplied from a vertical drive unit 254 illustrated in
The pulse supplied to the wiring RSTi of the i-th (i=1, . . . , m) row and the pulse supplied to the wiring VWlli are sequentially applied from the first row to the m-th row as illustrated in
Furthermore, as in the case of the first embodiment, the larger the amplitude of the pulse supplied to the wiring Vwelli (i=1, . . . , m), the greater the effect of controlling the threshold voltage Vt. However, in a case where the amplitude is increased, the delay of the pulse signal increases and the power consumption increases. Therefore, the amplitude is determined in consideration of the necessary control amount of the threshold voltage Vt, the delay time, and the power consumption.
Furthermore, in the fourth embodiment, each pixel group has pixels arranged in two rows and two columns. However, a pixel group may include pixels arranged in two rows and four columns, or a pixel group may include one pixel. Moreover, two or more selection transistors may be arranged in each pixel group. In these cases, too, there is no change in the amplitude of a signal VSL (see
As described above, according to the fourth embodiment, the substrate potential of the reset transistor RST included in the pixel group can be adjusted at the time of reading, and the dynamic range can be increased easily.
Note that in the imaging device according to the fourth embodiment, as in the imaging device according to the third embodiment, the adjustment potential Vwell may be supplied to a substrate potential adjustment terminal 25 of the selection transistor SEL of each pixel group at the time of the read operation. That is, the substrate potentials of the selection transistor SEL and the reset transistor RST of each pixel group may be adjusted at the time of reading.
An imaging device according to a fifth embodiment will be described with reference to
In the first to fourth embodiments, the well region 26 of the pixels 1111 to 1122 is insulated and separated by the insulating film 27, but in the fifth embodiment, the pixels 1111 to 1122 are separated using a PN junction as illustrated in
An amplification transistor AMP is formed in the p-well region 26 of the pixel 1111, a reset transistor RST is formed in the p-well region 26 of the pixel 1112, and a selection transistor SEL is formed in the p-well region 26 of the pixel 1122. In the fifth embodiment, these transistors are n-channel transistors. Each of the p-well regions 26 of these transistors is provided with a terminal (pad) 25 for adjusting the potential of the p-well region 26, that is, the substrate potential. Furthermore, the n-well region 24 is provided with a terminal 28 that applies a potential VDD to the n-well region.
In the fifth embodiment, as in the case of the first embodiment, at the time of reading, Vwell is applied to the terminal 25 in order to adjust the potential of the p-well region 26 in which the selection transistor SEL is formed. Then, a potential VSS is applied to the terminals 25 of the amplification transistor AMP and the reset transistor RST.
The read operation of the imaging device configured as described above can be performed similarly to the case of the first embodiment. Hence, as in the case of the first embodiment, in the fifth embodiment, too, the substrate potential of the selection transistor SEL included in the pixel group can be adjusted at the time of reading, and the dynamic range can be increased easily. Furthermore, in the present embodiment, the substrate potential of the selection transistor SEL is adjusted, but the substrate potential of the reset transistor RST may be adjusted as in the second embodiment. Moreover, the substrate potentials of the selection transistor SEL and the reset transistor may be adjusted at the time of the read operation.
Furthermore, in the fifth embodiment, the pixel transistor is an n-channel transistor, but even if the pixel transistor is replaced with a p-channel transistor, the dynamic range can be increased easily as in the third embodiment and the fourth embodiment.
An imaging device according to a sixth embodiment will be described with reference to
A region 32 is arranged between the region 31 and the region 33 along the row direction of the pixel groups. The region 32 is provided with a p-well region 43 surrounded by an n-well region 42, and the p-well region 43 is provided with an n-channel selection transistor SEL and a terminal (pad) 25a for adjusting the potential of the p-well region 43. The n-well region 32 is provided with a terminal (pad) 52 to which a potential VDD is applied. Furthermore, a region 34 is arranged on the opposite side of the region 32 with respect to the region 33. In the region 34, a p-well region 47 surrounded by an n-well region 46 is provided, and the p-well region 47 is provided with an n-channel amplification transistor AMP, a reset transistor RST, and a terminal (pad) 25b for adjusting the potential of the p-well region 47. Furthermore, the n-well region 46 is provided with a terminal (pad) 54 to which the potential VDD is applied.
In the imaging device according to the sixth embodiment configured as described above, by adjusting the substrate potential of at least one of the selection transistor SEL or the reset transistor RST via the terminal 25, as in the case of the first embodiment or the second embodiment, the dynamic range can be increased easily at the time of reading.
An imaging device according to a seventh embodiment will be described with reference to
The pixel group 100 includes pixels 1111 to 1122 arranged in two rows and two columns, and these pixels are separated by an insulating film 27 surrounding these pixels. Each pixel 11 (i, j=1, 2) includes a photoelectric conversion element PD and a p-well region 26 provided on the photoelectric conversion element PD (
In the seventh embodiment, in a case where the dynamic range is increased by adjusting the substrate potential of the selection transistor SEL at the time of a read operation, for example, a potential VWll is supplied to the terminal 25 of the p-well region 26 of the pixel 1122, and a potential VSS is supplied to the terminal 25 of the p-well region 26 of the pixels 1111 and 1112, similarly to the case of the first embodiment.
As in the case of the first embodiment, in the seventh embodiment configured as described above, too, the dynamic range can be increased easily at the time of reading.
The pixel group 10S has the same configuration as the pixel group 10 according to the first embodiment, and the dummy pixel group 10D has the same configuration as the pixel group 10 according to the first embodiment except that the dummy pixel group 10D is shielded by a metal film or the like so that incident light does not enter the photoelectric conversion element PD.
The differential amplification unit 140 includes an n-channel MOS tail current source (hereinafter also referred to as tail current source) 150 and a current mirror circuit. The current mirror circuit includes p-channel load transistors (hereinafter also referred to as load transistors) 151 and 152 and a reset-dedicated constant current circuit 153.
The tail current source 150 is connected to the sources of the amplification transistors AMP of the pixel group 10S and the dummy pixel group 10D via a column Vcom line 63. A bias voltage Vbn is applied to the gate of the tail current source 150, and a constant current flows through the amplification transistor AMP.
The drain of one load transistor 151 constituting the current mirror circuit is connected to the drain of the selection transistor SEL of the dummy pixel group 10D via a column signal line 71. The drain of the other load transistor 152 constituting the current mirror circuit is connected to the drain of the selection transistor SEL of the pixel group 10S via a column signal line 61. The sources of the load transistors 151 and 152 are connected to a constant voltage source VDD.
The load transistors 151 and 152 constituting the current mirror circuit cause an equal current to flow through the column signal line 71 on the dummy pixel group 10D side and the column signal line 61 on the pixel group 10S side.
The reset-dedicated constant current circuit 153 is also connected to the column signal line 71 of the dummy pixel group 10D. The reset-dedicated constant current circuit 153 is a circuit that is connected between a constant voltage source Vbrl and the drain of the load transistor 151 and causes a predetermined current value IrstL to flow. Specifically, different currents flow to the reference side of the differential pair in the reset period and the readout period. As a result, different currents flow through the reference side and the signal side of the differential pair during the reset period.
The drain of the reset transistor RST of the dummy pixel group 10D is connected to a column reset line 72, and a reset voltage Vrst is supplied to the column reset line 72.
On the other hand, the drain of the reset transistor RST of the pixel group 10S is connected to a column reset line 62, and the column reset line 62 is connected to the column signal line 41.
The differential amplification unit 140 constitutes a differential amplifier together with the amplification transistor AMP and the selection transistor SEL of the dummy pixel group 10D and the amplification transistor AMP and the selection transistor SEL of the pixel group 10S.
As described above, by providing the dummy pixel group corresponding to each of the pixel groups arranged in each column and the differential amplification unit corresponding to each column in the first embodiment, similarly to Patent Document 2 filed and published by the applicant of the present application, it is possible to change the current flowing through the amplification transistor AMP of each of the pixel group 10S and the dummy pixel group 10D in the reset period and the readout period, and it is possible to adjust the potential of the column signal line 61 to an optimum operating point (operating range) of the differential amplifier above the operating point unique to the differential amplifier. As a result, the conversion efficiency of the amplification transistor of the pixel group 10S can be improved, the linearity can be improved, and the dynamic range can be further increased as compared with the first embodiment.
Note that in the eighth embodiment, as illustrated in
The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may also be realized as a device mounted on any type of mobile body such as an automobile, an electric automobile, a hybrid electric automobile, a motorcycle, a bicycle, a personal mobility, an airplane, a drone, a ship, a robot, a building machine, or an agricultural machine (tractor).
Each of the control units includes: a microcomputer that performs arithmetic processing according to various kinds of programs; a storage section that stores the programs executed by the microcomputer, parameters used for various kinds of operations, or the like; and a driving circuit that drives various kinds of control target devices. Each of the control units further includes: a network interface (I/F) for performing communication with other control units via the communication network 7010; and a communication I/F for performing communication with a device, a sensor, or the like within and without the vehicle by wire communication or radio communication. A functional configuration of the integrated control unit 7600 illustrated in
The driving system control unit 7100 controls the operation of devices related to the driving system of the vehicle in accordance with various kinds of programs. For example, the driving system control unit 7100 functions as a control device for a driving force generating device for generating the driving force of the vehicle, such as an internal combustion engine, a driving motor, or the like, a driving force transmitting mechanism for transmitting the driving force to wheels, a steering mechanism for adjusting the steering angle of the vehicle, a braking device for generating the braking force of the vehicle, and the like. The driving system control unit 7100 may have a function as a control device of an antilock brake system (ABS), electronic stability control (ESC), or the like.
The driving system control unit 7100 is connected with a vehicle state detecting section 7110. The vehicle state detecting section 7110, for example, includes at least one of a gyro sensor that detects the angular velocity of axial rotational movement of a vehicle body, an acceleration sensor that detects the acceleration of the vehicle, and sensors for detecting an amount of operation of an accelerator pedal, an amount of operation of a brake pedal, the steering angle of a steering wheel, an engine speed or the rotational speed of wheels, and the like. The driving system control unit 7100 performs arithmetic processing using a signal input from the vehicle state detecting section 7110, and controls the internal combustion engine, the driving motor, an electric power steering device, the brake device, and the like.
The body system control unit 7200 controls the operation of various kinds of devices provided to the vehicle body in accordance with various kinds of programs. For example, the body system control unit 7200 functions as a control device for a keyless entry system, a smart key system, a power window device, or various kinds of lamps such as a headlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or the like. In this case, radio waves transmitted from a mobile device as an alternative to a key or signals of various kinds of switches can be input to the body system control unit 7200. The body system control unit 7200 receives these input radio waves or signals, and controls a door lock device, the power window device, the lamps, or the like of the vehicle.
The battery control unit 7300 controls a secondary battery 7310, which is a power supply source for the driving motor, in accordance with various kinds of programs. For example, the battery control unit 7300 is supplied with information about a battery temperature, a battery output voltage, an amount of charge remaining in the battery, or the like from a battery device including the secondary battery 7310. The battery control unit 7300 performs arithmetic processing using these signals, and performs control for regulating the temperature of the secondary battery 7310 or controls a cooling device provided to the battery device or the like.
The outside-vehicle information detecting unit 7400 detects information about the outside of the vehicle including the vehicle control system 7000. For example, the outside-vehicle information detecting unit 7400 is connected with at least one of an imaging section 7410 and an outside-vehicle information detecting section 7420. The imaging section 7410 includes at least one of a time-of-flight (ToF) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The outside-vehicle information detecting section 7420, for example, includes at least one of an environmental sensor for detecting current atmospheric conditions or weather conditions and a peripheral information detecting sensor for detecting another vehicle, an obstacle, a pedestrian, or the like on the periphery of the vehicle including the vehicle control system 7000.
The environmental sensor, for example, may be at least one of a rain drop sensor detecting rain, a fog sensor detecting a fog, a sunshine sensor detecting a degree of sunshine, and a snow sensor detecting a snowfall. The peripheral information detecting sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR device (Light detection and Ranging device, or Laser imaging detection and ranging device). Each of the imaging section 7410 and the outside-vehicle information detecting section 7420 may be provided as an independent sensor or device, or may be provided as a device in which a plurality of sensors or devices are integrated.
Here,
Note that
Outside-vehicle information detecting sections 7920, 7922, 7924, 7926, 7928, and 7930 provided to the front, rear, sides, and corners of the vehicle 7900 and the upper portion of the windshield within the interior of the vehicle may be, for example, an ultrasonic sensor or a radar device. The outside-vehicle information detecting sections 7920, 7926, and 7930 provided to the front nose of the vehicle 7900, the rear bumper, the back door of the vehicle 7900, and the upper portion of the windshield within the interior of the vehicle may be a LIDAR device, for example. These outside-vehicle information detecting sections 7920 to 7930 are used mainly to detect a preceding vehicle, a pedestrian, an obstacle, or the like.
Returning to
In addition, on the basis of the received image data, the outside-vehicle information detecting unit 7400 may perform image recognition processing of recognizing a human, a vehicle, an obstacle, a sign, a character on a road surface, or the like, or processing of detecting a distance thereto. The outside-vehicle information detecting unit 7400 may subject the received image data to processing such as distortion correction, alignment, or the like, and combine the image data imaged by a plurality of different imaging sections 7410 to generate a bird's-eye image or a panoramic image. The outside-vehicle information detecting unit 7400 may perform viewpoint conversion processing using the image data imaged by the imaging section 7410 including the different imaging parts.
The in-vehicle information detecting unit 7500 detects information about the inside of the vehicle. The in-vehicle information detecting unit 7500 is, for example, connected with a driver state detecting section 7510 that detects the state of a driver. The driver state detecting section 7510 may include a camera that images the driver, a biosensor that detects biological information of the driver, a microphone that collects sound within the interior of the vehicle, or the like. The biosensor is, for example, disposed in a seat surface, the steering wheel, or the like, and detects biological information of an occupant sitting in a seat or the driver holding the steering wheel. On the basis of detection information input from the driver state detecting section 7510, the in-vehicle information detecting unit 7500 may calculate a degree of fatigue of the driver or a degree of concentration of the driver, or may determine whether the driver is dozing. The in-vehicle information detecting unit 7500 may subject an audio signal obtained by the collection of the sound to processing such as noise canceling processing or the like.
The integrated control unit 7600 controls general operation within the vehicle control system 7000 in accordance with various kinds of programs. The integrated control unit 7600 is connected with an input section 7800. The input section 7800 is implemented by a device capable of input operation by an occupant, such, for example, as a touch panel, a button, a microphone, a switch, a lever, or the like. The integrated control unit 7600 may be supplied with data obtained by voice recognition of voice input through the microphone. The input section 7800 may, for example, be a remote control device using infrared rays or other radio waves, or an external connecting device such as a mobile telephone, a personal digital assistant (PDA), or the like that supports operation of the vehicle control system 7000. The input section 7800 may be, for example, a camera. In that case, an occupant can input information by gesture. Alternatively, data may be input which is obtained by detecting the movement of a wearable device that an occupant wears. Further, the input section 7800 may, for example, include an input control circuit or the like that generates an input signal on the basis of information input by an occupant or the like using the above-described input section 7800, and which outputs the generated input signal to the integrated control unit 7600. An occupant or the like inputs various kinds of data or gives an instruction for processing operation to the vehicle control system 7000 by operating the input section 7800.
The storage section 7690 may include a read only memory (ROM) that stores various kinds of programs executed by the microcomputer and a random access memory (RAM) that stores various kinds of parameters, operation results, sensor values, or the like. In addition, the storage section 7690 may be implemented by a magnetic storage device such as a hard disc drive (HDD) or the like, a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like.
The general-purpose communication I/F 7620 is a communication I/F used widely, which communication I/F mediates communication with various apparatuses present in an external environment 7750. The general-purpose communication I/F 7620 may implement a cellular communication protocol such as global system for mobile communications (GSM (registered trademark)), worldwide interoperability for microwave access (WiMAX (registered trademark)), long term evolution (LTE (registered trademark)), LTE-advanced (LTE-A), or the like, or another wireless communication protocol such as wireless LAN (referred to also as wireless fidelity (Wi-Fi (registered trademark)), Bluetooth (registered trademark), or the like. The general-purpose communication I/F 7620 may, for example, connect to an apparatus (for example, an application server or a control server) present on an external network (for example, the Internet, a cloud network, or a company-specific network) via a base station or an access point. In addition, the general-purpose communication I/F 7620 may connect to a terminal present in the vicinity of the vehicle (which terminal is, for example, a terminal of the driver, a pedestrian, or a store, or a machine type communication (MTC) terminal) using a peer to peer (P2P) technology, for example.
The dedicated communication I/F 7630 is a communication I/F that supports a communication protocol developed for use in vehicles. The dedicated communication I/F 7630 may implement a standard protocol such, for example, as wireless access in vehicle environment (WAVE), which is a combination of institute of electrical and electronic engineers (IEEE) 802.11p as a lower layer and IEEE 1609 as a higher layer, dedicated short range communications (DSRC), or a cellular communication protocol. The dedicated communication I/F 7630 typically carries out V2X communication as a concept including one or more of communication between a vehicle and a vehicle (Vehicle to Vehicle), communication between a road and a vehicle (Vehicle to Infrastructure), communication between a vehicle and a home (Vehicle to Home), and communication between a pedestrian and a vehicle (Vehicle to Pedestrian).
The positioning section 7640, for example, performs positioning by receiving a global navigation satellite system (GNSS) signal from a GNSS satellite (for example, a GPS signal from a global positioning system (GPS) satellite), and generates positional information including the latitude, longitude, and altitude of the vehicle. Incidentally, the positioning section 7640 may identify a current position by exchanging signals with a wireless access point, or may obtain the positional information from a terminal such as a mobile telephone, a personal handyphone system (PHS), or a smart phone that has a positioning function.
The beacon receiving section 7650, for example, receives a radio wave or an electromagnetic wave transmitted from a radio station installed on a road or the like, and thereby obtains information about the current position, congestion, a closed road, a necessary time, or the like. Incidentally, the function of the beacon receiving section 7650 may be included in the dedicated communication I/F 7630 described above.
The in-vehicle device I/F 7660 is a communication interface that mediates connection between the microcomputer 7610 and various in-vehicle devices 7760 present within the vehicle. The in-vehicle device I/F 7660 may establish wireless connection using a wireless communication protocol such as wireless LAN, Bluetooth (registered trademark), near field communication (NFC), or wireless universal serial bus (WUSB). In addition, the in-vehicle device I/F 7660 may establish wired connection by universal serial bus (USB), high-definition multimedia interface (HDMI (registered trademark)), mobile high-definition link (MHL), or the like via a connection terminal (and a cable if necessary) not depicted in the figures. The in-vehicle devices 7760 may, for example, include at least one of a mobile device and a wearable device possessed by an occupant and an information device carried into or attached to the vehicle. The in-vehicle devices 7760 may also include a navigation device that searches for a path to an arbitrary destination. The in-vehicle device I/F 7660 exchanges control signals or data signals with these in-vehicle devices 7760.
The vehicle-mounted network I/F 7680 is an interface that mediates communication between the microcomputer 7610 and the communication network 7010. The vehicle-mounted network I/F 7680 transmits and receives signals or the like in conformity with a predetermined protocol supported by the communication network 7010.
The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 in accordance with various kinds of programs on the basis of information obtained via at least one of the general-purpose communication I/F 7620, the dedicated communication I/F 7630, the positioning section 7640, the beacon receiving section 7650, the in-vehicle device I/F 7660, and the vehicle-mounted network I/F 7680. For example, the microcomputer 7610 may calculate a control target value for the driving force generating device, the steering mechanism, or the braking device on the basis of the obtained information about the inside and outside of the vehicle, and output a control command to the driving system control unit 7100. For example, the microcomputer 7610 may perform cooperative control intended to implement functions of an advanced driver assistance system (ADAS) which functions include collision avoidance or shock mitigation for the vehicle, following driving based on a following distance, vehicle speed maintaining driving, a warning of collision of the vehicle, a warning of deviation of the vehicle from a lane, or the like. In addition, the microcomputer 7610 may perform cooperative control intended for automated driving, which makes the vehicle to travel automatedly without depending on the operation of the driver, or the like, by controlling the driving force generating device, the steering mechanism, the braking device, or the like on the basis of the obtained information about the surroundings of the vehicle.
The microcomputer 7610 may generate three-dimensional distance information between the vehicle and an object such as a surrounding structure, a person, or the like, and generate local map information including information about the surroundings of the current position of the vehicle, on the basis of information obtained via at least one of the general-purpose communication I/F 7620, the dedicated communication I/F 7630, the positioning section 7640, the beacon receiving section 7650, the in-vehicle device I/F 7660, and the vehicle-mounted network I/F 7680. In addition, the microcomputer 7610 may predict danger such as collision of the vehicle, approaching of a pedestrian or the like, an entry to a closed road, or the like on the basis of the obtained information, and generate a warning signal. The warning signal may, for example, be a signal for producing a warning sound or lighting a warning lamp.
The sound/image output section 7670 transmits an output signal of at least one of a sound and an image to an output device capable of visually or auditorily notifying information to an occupant of the vehicle or the outside of the vehicle. In the example of
Note that at least two control units connected to each other via the communication network 7010 in the example illustrated in
Note that the imaging devices according to the first to eighth embodiments can be used as the imaging section 7410 illustrated in
The preferred embodiments of the present disclosure have been described above in detail with reference to the accompanying drawings, but the technical scope of the present disclosure is not limited to such examples. It is clear that one of ordinary skill in the technical field of the present disclosure may conceive of various modifications and corrections within the scope of the technical idea recited in claims. It is understood that they also naturally belong to the technical scope of the present disclosure.
Furthermore, the effects described in the present specification are merely explanatory or exemplary, and are not restrictive. That is, the technology according to the present disclosure may provide other effects that are apparent to those skilled in the art from the description of the present specification, in addition to or instead of the abovementioned effects.
Note that the following configurations also belong to the technical scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-035742 | Mar 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/007608 | 2/24/2022 | WO |
