Systems and detectors, etc.

Abstract

To provide users with highly convenient features for notifying them of information regarding speed enforcement. [Solution] The communication terminal 20 includes: a communication unit that communicates with an on-board device 30 located in the vehicle 40, which communicates with an external terminal and displays information about the functions of the terminal; and a control unit that performs the process of acquiring a signal indicating the reception result of the enforcement wave from a receiver 10 located in the vehicle 40 that receives enforcement waves indicating the presence of a speed enforcement point, and the process of outputting a notification signal to the on-board device 30 to notify that the vehicle 40 and the speed enforcement point are in a predetermined proximity relationship according to the signal indicating the reception result.

Description

Technical Field

[0001] The present invention relates to, for example, a system and a detector.

Background Art

[0002] There are various types of systems for measuring the speed of a vehicle traveling on a road. In the case of a radar system, a speed measuring device installed along the road emits microwaves in a predetermined frequency band toward the vehicle, receives the reflected wave from the vehicle, and measures the traveling speed of the vehicle.

[0003] For a user such as a driver of a vehicle, it may be useful to be able to grasp in advance the presence of a speed measuring device. Patent Document 1 discloses an electronic device that receives microwaves emitted from a vehicle speed measuring device and outputs an alarm when it detects the presence of the vehicle speed measuring device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One object of the present invention is to provide a system superior to conventional systems, for example, a technique for improving the reception sensitivity of laser light for speed measurement emitted by a speed measuring device.

[0006] The problems described above are presented as independent issues, and the present invention is not necessarily required to solve all of them. The purpose of the present invention is not limited thereto, and the applicant intends to obtain rights through divisional applications, amendments, etc., for configurations that aim to achieve the effects derived from the components disclosed in this specification and the drawings. For example, problems that can be described as "can be done" in this specification are disclosed here if they are reinterpreted as "the problem is...". The problems are presented as independent issues, and the applicant intends to obtain rights through divisional applications, amendments, etc., for configurations that solve these problems individually. Even if a problem is implicitly understood from the description in the specification, the applicant intends to include a part of the configuration described in this specification in the claims through amendment or a divisional application. Problems that combine these independent problems are also disclosed. [Means for solving the problem]

[0007] (1) A system is provided which is installed in a vehicle and has a laser detection function that determines whether or not it has received laser light for speed measurement emitted by a speed measuring device, and comprises a photodetector that outputs a current corresponding to the incident light as a first signal, an integrated circuit that converts and amplifies the first signal into a voltage signal and outputs a second signal, and a control circuit that outputs a determination signal indicating the result of the determination based on the second signal, wherein the integrated circuit is an integrated circuit used for a specific application other than the laser detection.

[0008] The inventors have discovered that by using an integrated circuit, which is typically used for specific applications other than laser detection for speed measurement, for laser detection purposes, the sensitivity of the laser light emitted by the speed measuring device can be improved compared to conventional configurations. This improves the functionality of the laser detection. For example, since the current signal output from the photodetector is applied to an integrated circuit, which has less noise than a transistor amplifier circuit, the noise is reduced, and combined with the gain of the integrated circuit, sensitivity can be improved.

[0009] (2) The integrated circuit may be an integrated circuit designed for the specific application. The inventors have found that by using an integrated circuit designed for a specific application other than laser detection for speed measurement for laser detection purposes, the sensitivity of the laser light emitted by the speed measuring device can be improved compared to conventional configurations. In this way, the function of laser detection can be improved.

[0010] (3) The integrated circuit may be used for optical distance measurement. An integrated circuit for optical distance measurement can handle input signals of relatively high frequencies, and it has the performance necessary to ensure the accuracy of distance measurement. The inventors have found that such an integrated circuit for optical distance measurement is particularly suitable for use in another application, laser detection. In this way, the function of laser detection can be improved. For example, even if the laser light emitted from a speed measuring device has a very narrow pulse width, it can be detected with high accuracy.

[0011] (4) The specific application described above is for receiving laser light for distance measurement, and it is preferable that the integrated circuit does not have the function of emitting laser light for distance measurement. The integrated circuit for receiving laser light for distance measurement is capable of receiving signals of relatively high frequencies, and the integrated circuit for optical distance measurement has the performance necessary to ensure the accuracy of distance measurement. The inventors have found that such an integrated circuit for optical distance measurement is particularly suitable for use in laser detection applications. In this way, the function of laser detection can be improved. For example, even if the laser light emitted from a speed measuring device has a very narrow pulse width, it can be detected with high accuracy.

[0012] (5) The specific application mentioned above is suitable for LiDAR (Light Detection and Ranging). LiDAR is a remote sensing technology that measures distance by irradiating an object with light and detecting the reflected light with an optical sensor, and is also, for example, a high-bandwidth automotive transimpedance amplifier. Such integrated circuits for LiDAR are high-performance, have a high frequency bandwidth, and are designed to accurately detect external laser light rather than reflected light emitted by the integrated circuit itself. Such integrated circuits are also particularly suitable for use in laser detection applications and can improve the functionality of laser detection.

[0013] (6) The integrated circuit may have a transimpedance amplifier. In this way, even a small current output from the photodetector, which is the first signal, can be converted into a second signal which is the voltage signal necessary to determine whether or not the laser light for speed measurement has been received. As a result, the accuracy of the control circuit's determination of whether or not the laser light for speed measurement has been received can be improved.

[0014] (7) The transimpedance amplifier should not be a transimpedance amplifier composed of operational amplifiers. In the case of a transimpedance amplifier composed of operational amplifiers, if the applicable frequency range is relatively low, or if an expensive operational amplifier is required to apply a high frequency range, it is necessary to use an expensive operational amplifier. If the transimpedance amplifier is not composed of operational amplifiers, it is possible to determine whether or not the laser light for speed measurement has been received by using a transimpedance amplifier that corresponds to the frequency of the laser light for speed measurement, without having to construct a transimpedance amplifier with an expensive operational amplifier.

[0015] (8) The resistor that determines the gain of the transimpedance amplifier is preferably in the range of 44kΩ to 77kΩ. The inventors have discovered that by using an integrated circuit in which the resistor that determines the gain of the transimpedance amplifier is in the range of 44kΩ to 77kΩ, the sensitivity of the laser light emitted by the speed measuring device for speed measurement can be improved compared to conventional configurations, and consequently, the function of laser detection can be improved.

[0016] (9) The integrated circuit should be capable of receiving signals with a frequency of at least 10 MHz or higher. For speed measurement, a pulsed laser with a very narrow pulse width, such as 20 ns, may be used. By using an integrated circuit that can receive signals with a frequency of at least 10 MHz or higher, the sensitivity of the laser light for speed measurement can be improved compared to conventional configurations, and consequently, the laser detection function can be improved.

[0017] (10) The integrated circuit is preferably an integrated circuit that is guaranteed to be able to handle input signals of at least 25 MHz or higher as the lower limit of frequency. By using an integrated circuit that is guaranteed to be able to handle input signals of at least 25 MHz or higher as the lower limit of frequency, the sensitivity of the laser light for speed measurement can be improved compared to the conventional configuration, and consequently, the function of laser detection can be improved.

[0018] (11) The laser light emitted by the speed measuring device is a pulsed laser, the photodetector is connected to a higher potential side than the input terminal of the integrated circuit, the integrated circuit outputs a negative pulse as the second signal, the output terminal of the integrated circuit is connected to an emitter-grounded amplifier circuit, the output terminal of the emitter-grounded amplifier circuit is connected to the base side of an emitter follower circuit, and a signal based on a threshold-processed signal of the output signal of the emitter follower circuit is supplied to the control circuit. In this way, when the pulsed laser light emitted by the speed measuring device is received, the integrated circuit outputs a negative pulse, the emitter-grounded amplifier circuit performs inversion and amplification, and the amplified positive pulse is supplied to the emitter follower circuit, high gain can be obtained for the entire system, and the configuration is simplified because the emitter-grounded amplifier circuit can handle both inversion and amplification with one circuit.

[0019] (12) The laser light emitted by the speed measuring device is a pulsed laser, the photodetector is connected to a lower potential side of the input terminal of the integrated circuit, and the integrated circuit outputs a positive pulse as the second signal. In this way, for example, if the gain of the integrated circuit is high, the output of the integrated circuit can be directly input to the emitter follower circuit, which reduces the number of amplification circuits required or eliminates the need for amplification circuits altogether.

[0020] (13) The reference design of the integrated circuit has the photodetector and the coil element connected in series on the input side, but it is preferable to replace the coil element with a resistor. In this way, even if the laser light input to the photodetector is, for example, a very narrow pulse width and high frequency, the ringing can be suppressed by using a resistor.

[0021] (14) It is preferable to place an emitter follower circuit on the output side of the integrated circuit, and to provide the control circuit with a signal based on a threshold-processed signal of the output signal of the emitter follower circuit, and to provide a temperature compensation circuit on the base side of the emitter follower circuit. In this way, although the temperature inside the vehicle changes significantly in a system installed in a vehicle, the base voltage value of the emitter follower circuit is stabilized by providing a temperature compensation circuit. Therefore, the output signal of the emitter follower circuit in relation to the input signal is less likely to fluctuate significantly due to temperature changes, and even if the margin of the set threshold is reduced, it is possible to suppress misjudgment of whether or not the laser light for speed measurement is received.

[0022] (15) In the reference design, the integrated circuit is recommended to have an AD (Analog to Digital) converter on the output side. However, instead of the AD converter, an amplification circuit that amplifies the output of the integrated circuit or an emitter follower circuit to which the output of the integrated circuit is input as a base may be provided. In this way, although the reference design recommends the placement of an AD converter on the output side, by providing an amplification circuit instead, the second signal can be amplified to a level exceeding the capabilities of the integrated circuit, or the emitter follower circuit can be driven based on the second signal from the integrated circuit. As a result, the sensitivity of the laser light for speed measurement can be improved, and consequently, the function of laser detection can be improved.

[0023] (16) A detector is provided which is installed in a vehicle and has a laser detection function that provides notification when it receives laser light for speed measurement emitted by a speed measuring device, and comprises a light receiving element that outputs a current corresponding to the incident light as a first signal, an integrated circuit that converts and amplifies the first signal to a voltage signal and outputs a second signal, a control circuit that outputs a notification signal corresponding to the reception of the laser light based on the second signal, and a notification unit that provides notification according to the notification signal, wherein the integrated circuit is an integrated circuit used for a specific application different from the laser detection.

[0024] As an integrated circuit, by using an integrated circuit used for a specific application different from laser detection for speed measurement in the application of laser detection, the inventor has found that the sensitivity of the laser light for speed measurement emitted by the speed measurement device can be improved compared with the conventional configuration. By doing so, the function of laser detection can be improved. For example, since a current signal output from a light receiving element is applied to an integrated circuit with less noise compared to a transistor amplifier circuit, the noise is reduced, and the sensitivity can be improved with the gain of the integrated circuit combined.

[0025] The system described above may be composed of one device or a plurality of devices.

[0026] A system provided in a vehicle for determining whether or not it has received the laser light for speed measurement emitted by the speed measurement device or a system for giving a notification according to the reception may, for example, have only one light receiving element, but it may have a plurality of the light receiving elements, and based on the reception of the laser light by the plurality of light receiving elements, it may output a signal according to the reception of the laser light. The light receiving element may be, for example, a photodiode, but a phototransistor or the like may also be used.

[0027] (A) The plurality of light receiving elements may be arranged to be arranged in a row along a predetermined direction. In this case, the predetermined direction may be the left - right direction of the electronic device, or the horizontal direction, or the vehicle width direction of the vehicle. By doing so, it is possible to receive laser light from a wide range in the left - right direction, horizontal direction or vehicle width direction and secure a highly sensitive angle in that direction.

[0028] (B) The plurality of light-receiving elements may be arranged along the first direction and the second direction intersecting the first direction. In this case, the first direction may be the left-right direction or horizontal direction of the electronic device, or the vehicle width direction. The second direction may be the up-down direction or vertical direction of the electronic device, or the vehicle height direction. In this way, laser light can be received from a wide range of directions, not only in the left-right direction, horizontal direction or vehicle width direction, but also in the up-down direction, vertical direction or vehicle height direction, and an angle with high sensitivity can be secured in that direction.

[0029] (C) It is preferable to input a first signal to the integrated circuit from each of the multiple photodetectors. Furthermore, it is preferable to make the notification different depending on which photodetector the signal is input from. In this way, the notification regarding the reception of laser light can be made diverse, and convenience for the user can be increased. Not limited to this, at least two of the multiple photodetectors may be connected in parallel so that the first signal is input to the integrated circuit. For example, it is preferable to make the notification a higher level the more photodetectors whose received light intensity exceeds the threshold. Alternatively, a predetermined statistical processing may be performed on the received light intensity input individually from the photodetectors, and if the integrated value exceeds the reference value for each level, a notification for that level may be made. Alternatively, the direction of incidence or emission of the laser light may be notified according to the position of the photodetector that received the laser light, or the direction of the enforcement point (e.g., speed measuring device) may be notified. In this way, it is possible to make it easier for the user to understand the proximity to the enforcement point.

[0030] (D) The device has a focusing lens for focusing laser light, and the plurality of light-receiving elements are arranged in a line along a predetermined direction, and the predetermined direction may be the left-right direction of the electronic device, the horizontal direction, or the width direction of the vehicle. In such cases, the plurality of light-receiving elements are preferably positioned to the left of the vehicle's direction of travel, with respect to the position of the focusing lens. Positioning to the left means that the center of the arrangement direction of the plurality of light-receiving elements is located to the left of the vehicle's direction of travel with respect to the optical axis of the focusing lens. This improves the sensitivity to light reception from the left side of the vehicle's direction of travel, which is the side where enforcement points (e.g., speed measuring devices) are often located.

[0031] (E) It is preferable that multiple light-receiving elements are not all placed on the same straight line.

[0032] (F) It is preferable to position at least one of the multiple photodetectors at an angle from the first and second directions. This ensures that an angle with high sensitivity can be secured in both the first and second directions.

[0033] (G) It is preferable to combine two or more of the above-described arrangements of multiple photodetectors. In this way, the range of angles at which the photodetection sensitivity decreases can be reduced depending on the angle of incidence of the laser light.

[0034] (H) When a lens barrel is positioned between a focusing lens and multiple photodetectors, it is preferable to cut out a portion of the lens barrel. The inside of the lens barrel becomes the optical path of the laser light focused by the focusing lens, and is reflected off the inner wall surface of the lens barrel and guided to the position of the photodetectors. The cutout in the lens barrel should be made to secure the optical path of the laser light. In this way, the range of angles at which the sensitivity of laser light reception from a particular direction decreases can be reduced.

[0035] (I) When a lens barrel is placed between a focusing lens and multiple photodetectors, the lens barrel should have a shape that widens radially on the side with the multiple photodetectors. This makes it easier for the laser light that has passed through the lens barrel to be received by the photodetectors.

[0036] (J) It is preferable to provide a reflective member between two adjacent light-receiving elements that reflects the laser light back to either light-receiving element. Doing so can improve the accuracy of determining the presence of an enforcement point.

[0037] (K) It is preferable that the arrangement of multiple photodetectors be three-dimensional, and in particular, that the photodetectors be arranged at two or more different positions in the front-to-back direction of the electronic device (for example, in the optical axis direction of the focusing lens that focuses light to the positions of the multiple photodetectors). In particular, when the multiple photodetectors include a first photodetector and a second photodetector arranged with a gap between them in a first direction (for example, the left-to-right direction of the electronic device), it is preferable to have a third photodetector on the front side of the electronic device (for example, the rear side of the vehicle) when viewed from the position of the gap. In this way, the range of angles in which the photodetector sensitivity decreases depending on the angle of incidence of the laser light can be reduced.

[0038] (L) When the arrangement of multiple photodetectors is three-dimensional, the first photodetector and the third photodetector, which are located at different positions in the front-to-back direction of the electronic device (for example, in the direction of the optical axis of the focusing lens), may be such that the first photodetector is provided on the first substrate and the third photodetector is provided on the second substrate. In this case, if the first substrate is a transparent substrate that can transmit laser light, the laser light transmitted through the transparent substrate is received by the third photodetector. The first and third photodetectors may be provided on one side and the opposite side of the same substrate. In this way, the area occupied by the substrate within the housing of the electronic device can be reduced, and for example, the thickness of the electronic device in the front-to-back direction can be reduced.

[0039] The inventions described above in (1) to (16) and (A) to (L) can be combined in any way. For example, one may combine all or part of the configuration of the invention shown in (1) with at least part of the configuration of at least one of the inventions from (2) onward. In particular, it is preferable to combine the invention shown in (1) with at least part of the configuration of at least one of the inventions from (2) onward. The applicant intends to obtain patent rights, design rights, etc., for those including these configurations through amendment, divisional application, change application to design registration application, etc. [Effects of the Invention]

[0040] According to the present invention, for example, it is possible to provide a system that is superior to conventional systems. For example, it is possible to improve the receiving sensitivity of the laser light used for speed measurement emitted by the speed measuring device.

[0041] The effects of the present invention are not limited thereto, and the effects produced by the components of the structure disclosed in this specification and drawings are also disclosed. The applicant intends to obtain rights to the components that produce such effects through divisional applications, amendments, etc. For example, the phrases "can do..." in this specification are descriptions that clearly indicate the effects produced, and there are components that produce effects even without such descriptions. Furthermore, there are effects that can be grasped by the component even without such descriptions. [Brief explanation of the drawing]

[0042] [Figure 1] This is a block diagram showing the configuration of the electronic device according to the first embodiment. [Figure 2] This is an external view. [Figure 3] This is a circuit diagram showing an example of the electrical configuration of the light-receiving unit 12. [Figure 4] This graph shows the performance of detection range and detection area. [Figure 5] This is a perspective view showing the first device 800, which constitutes a separate type of electronic device. [Figure 6] This is a perspective view showing another embodiment of the electronic device 900. [Figure 7] This is a perspective view showing a first mounting section for mounting an electronic device 900 of another embodiment onto a vehicle. [Figure 8] This is a perspective view showing an electronic device 900 of another embodiment installed on a dashboard or the like. [Figure 9] This is a perspective view showing a second mounting section for mounting an electronic device 900 of another embodiment onto a vehicle. [Figure 10] This is a perspective view showing a second mounting section for mounting an electronic device 900 of another embodiment onto a vehicle. [Figure 11] This is a perspective view showing an electronic device 900 of another embodiment being mounted or installed on a ceiling or the like. [Figure 12] This is a perspective view showing a third mounting section for mounting the first device 800 of another embodiment onto a vehicle. [Figure 13] This is a perspective view showing the first device 800 of another embodiment attached to the third mounting portion. [Figure 14] This is a perspective view showing an electronic device 900 of another embodiment installed on a ceiling or the like. [Figure 15] This diagram shows the arrangement of the light-receiving elements in the light-receiving unit 12 of another embodiment. [Figure 16] This diagram shows the arrangement of the light-receiving elements in the light-receiving unit 12 of another embodiment. [Figure 17] This diagram shows the arrangement relationship between the light-receiving element and the light-gathering lens of the light-receiving unit 12 in another embodiment. [Figure 18] This graph shows an example of the relationship between the angle of the vehicle relative to its direction of travel and the intensity of the laser beam received. [Figure 19] This diagram shows the arrangement relationship between the light-receiving element and the light-gathering lens of the light-receiving unit 12 in another embodiment. [Figure 20] This diagram shows the arrangement of the light-receiving elements in the light-receiving unit 12 of another embodiment. [Figure 21] This diagram shows the arrangement of the light-receiving elements in the light-receiving unit 12 of another embodiment. [Figure 22] This diagram shows the arrangement of the light-receiving elements in the light-receiving unit 12 of another embodiment. [Figure 23]This diagram shows the arrangement of the light-receiving elements in the light-receiving unit 12 of another embodiment. [Figure 24] This figure shows an example of the three-dimensional arrangement of multiple photodiodes 122 in the light-receiving section 12 of another embodiment. [Figure 25] This figure shows an example of the three-dimensional arrangement of multiple photodiodes 122 in the light-receiving section 12 of another embodiment. [Modes for carrying out the invention]

[0043] Embodiments of the present invention will be described below with reference to the drawings. These drawings are used to illustrate the technical features that the present invention may adopt. The configuration and shape of the described apparatus are merely illustrative examples, and the present invention is not to be construed as being limited thereto. Various changes, modifications, and improvements can be made based on the knowledge of those skilled in the art, as long as they do not depart from the scope of the present invention. In the following description, the labeling using numbers such as 1st, 2nd, ... is for the purpose of identifying each element and does not define the number of elements. In addition, in the figures referenced in the following description, the scale may differ from that of the actual figures in order to make each component, each area, etc., recognizable.

[0044] The laser light emitted by speed measuring devices has the characteristics of having a very narrow pulse width and high frequency, and there is a challenge in increasing the detection sensitivity of such laser light. For example, it has been difficult for commonly used general-purpose amplifier ICs to detect weak laser light. Therefore, the embodiments of the present invention described below propose a technology that can solve this problem.

[0045] [1. Configuration of electronic equipment] The electronic device 10 is, for example, a system installed in a vehicle and having a laser detection function that determines whether or not it has received laser light for speed measurement emitted by a speed measuring device. The laser detection function usually also includes a function that provides notification when laser light for speed measurement is received. In the following, we will describe the case where the electronic device 10 is a detector that provides notification according to the reception when it determines that laser light has been received. The electronic device 10 is a device that is sometimes called a laser detector.

[0046] This section describes a speed measuring device that emits laser light for speed measurement. This speed measuring device is compatible with the laser system and is installed at speed enforcement points where vehicle speeds are enforced. Speed ​​enforcement points are determined by considering factors such as vehicle driving conditions (for example, places where vehicles tend to speed) and the occurrence of traffic accidents (for example, locations with a high number of accidents). Examples of speed enforcement points include general roads, straight roads, curves, and points around curves on routes (roads) that vehicles travel on. Speed ​​measuring devices come in various types, such as fixed, mobile, and semi-fixed, and any type is acceptable.

[0047] A speed measuring device measures the speed of a vehicle, for example, using a laser scanning method. In a specific example, the speed measuring device emits a pulsed laser beam, and when this laser beam reaches the vehicle and reflects, it receives the reflected light. The speed measuring device measures the distance to the vehicle based on the time elapsed from the emission of the laser beam to the reception of the reflected light. The speed measuring device then repeatedly measures the distance to the vehicle and measures the vehicle speed based on the distance traveled per unit time. The laser beam emitted by the speed measuring device has energy concentrated at a specific wavelength. This specific wavelength is preferably the wavelength at which the energy of the light emitted by the speed measuring device peaks. The laser beam has energy at a specific wavelength outside the visible light region, for example. This specific wavelength is imperceptible to humans and belongs to the infrared region. The specific wavelength is, for example, 905 nm, but may be 850 nm, 950 nm, 1900 nm, or other wavelengths. The pulse width of the laser beam is, for example, approximately 20 ns or approximately 15 ns. The pulse interval of the laser light is, for example, approximately 80 ms. The "approximately" part should be within a predetermined range that can be considered to be the same as or substantially the same as the reference value.

[0048] Figure 1 is a block diagram showing the configuration of the electronic device 10. The control unit 11 controls each part of the electronic device 10. The control unit 11 is, for example, a computer including an arithmetic processing circuit and memory. The arithmetic processing circuit is, for example, a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate). The memory includes, for example, RAM (Random Access Memory) or other arithmetic processing circuits. The memory includes, for example, RAM (Random Access Memory) or other volatile memory. The arithmetic processing circuits perform various controls by temporarily reading data into the memory and performing arithmetic processing. The data includes programs for the control unit 11 to execute each function and data for work. In this embodiment, the control unit 11 is a control circuit composed of an integrated circuit separate from the integrated circuit 123 described later.

[0049] The light-receiving unit 12 is a light-receiving unit for receiving the laser light used for speed measurement emitted by the speed measuring device. The configuration of the light-receiving unit 12 will be explained later, but it has sensitivity to the wavelength range to which the laser light used for speed measurement belongs.

[0050] The display unit 13 displays an image. The display unit 13 is, for example, a 3.2-inch color TFT liquid crystal display. However, the display unit 13 may be an organic EL display or other type of display device. The speaker 14 outputs sound. The control unit 11 outputs predetermined sounds from the speaker 14, for example, during alarms and operations. The control unit 11 uses the speaker 14 to announce, for example, operation sounds from the operation unit 19 and various messages (guides, alarms, etc.).

[0051] The microwave receiver 15 includes an antenna and a receiving circuit and receives microwaves. The microwave receiver 15 is an example of a receiver that receives radar waves from a radar-compatible speed measuring device. The GPS (Global Positioning System) receiver 16 includes an antenna and a receiving circuit and receives signals from GPS satellites. The GPS receiver 16 processes the received signals and outputs position information. The position information includes, for example, latitude and longitude information, and may also include altitude information. The GPS receiver 16 is an example of a position information acquisition unit that acquires position information indicating the position of the electronic device 10 (more specifically, the current position). The communication unit 17 communicates with an external device. The communication unit 17 performs wireless communication, for example, Wi-Fi®, Bluetooth®, or other methods.

[0052] The memory unit 18 stores data. For example, the memory unit 18 stores programs for the control unit 11 to perform various controls. The control unit 11 reads the programs from the memory unit 18 into memory and executes them. The memory unit 18 also stores map data showing maps, data showing the types and locations of various facilities, data for notifying the presence of notification targets, data for realizing route guidance functions, data for displaying standby screens, and so on. Targets for notification include, for example, locations of accidents caused by drowsy driving, speed measuring devices (laser type, radar type, loop coil type, H system, LH system, photoelectric tube type, mobile type, etc.), speed limit change points, enforcement areas, checkpoint areas, parking violation monitoring areas, N systems, traffic monitoring systems, intersection monitoring points, red light violation prevention systems, police stations, accident-prone areas, car break-in-prone areas, sharp / consecutive curves (expressways), junction / merging points (expressways), ETC lane advance notice (expressways), service areas (expressways), parking areas (expressways), highway oases (expressways), smart interchanges (expressways), gas stations within PA / SA (expressways), tunnels (expressways), highway radio reception areas (expressways), prefectural border notices, roadside stations, viewpoint parking areas, etc. The memory unit 18 stores the type information of these notification targets, location information indicating their location, image data (for example, a schematic diagram or photograph) to be displayed on the display unit 13, and audio data in association with each other.

[0053] The storage unit 18 may also include a storage medium for permanently storing data. The storage unit 18 may include, for example, an optical recording medium, a magnetic recording medium, a semiconductor recording medium, or other recording media.

[0054] The control unit 19 receives user input. The control unit 19 includes, for example, a touch sensor, volume control buttons, and operation buttons. The touch sensor is provided on the surface of the display unit 13 and detects the position touched by the user. The volume control buttons are operated to adjust the volume of sound output from the speaker 14. The operation buttons are for performing various tasks.

[0055] The sensor unit 20 includes various sensors. For example, the sensor unit 20 includes a geomagnetic sensor, an acceleration sensor, and an illuminance sensor 201 (see Figure 2, etc.). The geomagnetic sensor detects the Earth's magnetic field to determine which direction north is relative to the direction of travel. The acceleration sensor detects the acceleration of the vehicle in the forward, backward, left, right, and up and down directions. The illuminance sensor 201 detects the illuminance, which indicates the brightness inside the vehicle.

[0056] The mounting section 21 is for detachably mounting an external storage medium. The external storage medium is, for example, a memory card. In this case, the mounting section 21 is a memory card slot. The data stored in the storage section 18 may be acquired via the external storage medium. This data may include updated information on new notification targets (location information such as longitude and latitude, type information, etc.).

[0057] The power supply unit 22 supplies power from the power source to each part of the electronic device 10. The power supply unit 22 includes, for example, a power switch 221 and a DC jack 222. The DC jack 222 is for connecting a cigarette lighter plug cord, which is connected to the vehicle's cigarette lighter socket to receive power. The power switch 221 is a switch for turning the electronic device 10 on or off. The light-emitting unit 23 emits light in various colors. The light-emitting unit 23 includes, for example, a light-emitting diode.

[0058] The cable terminal section 24 is a terminal to which an external connection cable is connected. For example, the connection cable is one to which the electronic device 10 connects to the OBD-II connector installed in the vehicle. The OBD-II connector is also called a fault diagnosis connector and is connected to the vehicle's ECU (Engine Control Unit), and various vehicle information is output from it. As will be described later, the control unit 11 creates various standby screens based on the acquired vehicle information and outputs them to the display unit 13.

[0059] In addition to the above, the electronic device 10 may also have functions that are typically found in a laser detector or a radar / laser detector.

[0060] Figure 2 shows a perspective view and a rear view of an example of the external configuration of the electronic device 10. In this example, the housing 100 of the electronic device 10 is divided into a first housing 1001 located on the front side and a second housing 1002 located on the rear side. The front of the first housing 1001 is provided with a display unit 13, a light-emitting unit 23, and an illuminance sensor 201 of the sensor unit 20. The display area of ​​the display unit 13 is located in the opening on the front of the first housing 1001. A speaker 14 is provided to output sound from the upper end surface of the second housing 1002. The right end surface of the housing 100 is provided with a mounting section 21 (i.e., an SD card slot) for inserting an SD card. A condensing lens 121, which forms part of the light-receiving unit 12, is provided in the upper right part of the rear of the housing 100. The power switch 221 and DC jack 222 of the power supply unit 22 are provided in the lower left part of the rear of the housing 100.

[0061] A lens holder 1006 is provided on the rear of the second housing 1002. The lens holder 1006 forms a window, which is an opening that allows the inside and outside of the housing 100 to pass through. When viewed from the rear side of the housing 100, the lens holder 1006 has an elliptical shape with a major axis in the horizontal direction and a minor axis in the vertical direction. When the electronic device 10 is installed in a vehicle, the horizontal direction corresponds to the width direction of the vehicle, and the vertical direction corresponds to the height direction of the vehicle.

[0062] The focusing lens 121 is fitted into the lens holder 1006. The lens holder 1006 and the focusing lens 121 are located on the upper right side of the second housing 1002 when viewed from the rear of the second housing 1002. For example, the focusing lens 121 is positioned on the rear of the housing 100 at least above the center in the vertical direction, and at least to the left of the direction of travel when viewed from the driver's seat side of the vehicle. This is because positioning the focusing lens 121 relatively high on the rear of the second housing 1002 and on the shoulder side where the speed measuring device is likely to be located may make it easier to receive light from the speed measuring device. Pulsed light from the speed measuring device is introduced into the housing 100 via the lens holder 1006 and the focusing lens 121. The focusing lens 121 is formed entirely of a light-transmitting material. The focusing lens 121 is transparent or translucent. The focusing lens 121 has an aspherical surface at the point of light incidence, which may be a parabolic or smooth curved surface, for example. Because the focusing lens 121 is an aspherical lens, spherical aberration can be suppressed when imaging is performed by the photodetector, compared to when a spherical lens is used. The spot size obtained with an aspherical lens can be several orders of magnitude smaller than that obtained with a spherical lens. Based on this idea, the focusing lens 121 may be realized by a combination of multiple lenses that have less spherical aberration than a spherical lens. The focusing lens 121 is at least a lens that transmits pulsed light and is made of a translucent or transparent material.

[0063] The focusing lens 121 guides pulsed light from the speed measuring device to a photodetector (not shown) positioned at a predetermined location behind the focusing lens 121. The position of the focusing lens 121 is set so that the light is focused to the photodetector, according to the characteristics of the focusing lens 121.

[0064] When a speed measuring device is located on the shoulder of the road, pulsed light enters the vehicle almost directly from the front when the distance between the device and the vehicle is large, but as the vehicle approaches, the pulsed light enters from the left. For this reason, the focusing lens 121 is designed so that it can receive light at a wider angle in the vehicle's width direction than in the vehicle's height direction, with a greater horizontal length than a vertical length. For example, the focusing lens 121 should be able to focus light that enters at an incident angle of 40 degrees on both sides in the width direction and 20 degrees on both sides in the height direction. By making the vertical length relatively shorter, the focusing of light other than pulsed light is reduced.

[0065] The focusing lens 121 has characteristics that allow it to detect pulsed light from the speed measuring device even if it is weak. As a result, the electronic device 10 can detect the presence of the speed measuring device over an extremely wide area and long distance, and can quickly notify the device of its presence. Furthermore, it is preferable to provide a visible light cut filter on the incident surface side of the focusing lens 121, or the focusing lens 121 may be formed from a material that has a visible light cut function. This reduces the influence of visible light. The focusing lens 121 may also be an aspheric lens.

[0066] The focusing lens 121 may be positioned so that its optical axis is parallel to the longitudinal direction of the vehicle, but it may also be tilted. In this case, if the optical axis of the focusing lens 121 is tilted to the left front with respect to the longitudinal direction of the vehicle, it may be possible to receive pulsed light from the speed measuring device more easily.

[0067] Under the above configuration, the control unit 11 outputs various warning information to encourage the driver to drive safely. For example, the control unit 11 calculates the distance between the location (latitude and longitude) of the notification target stored as map information in the memory unit 18 and the current location (latitude and longitude) of the vehicle detected by the GPS receiver unit 16, and outputs warning information from the output device when the calculated distance falls below a predetermined distance (GPS warning function). Also, for example, the control unit 11 outputs warning information from the output device when the microwave receiver unit 15 detects a signal corresponding to microwaves in the frequency band emitted from the speed measuring device (radar wave warning function). Also, for example, the control unit 11 outputs warning information from the output device when the light receiver unit 12 receives a predetermined light pulse (laser light warning function). By outputting warning information, the electronic device 10 makes the driver aware of dangerous locations where traffic accidents are likely to occur. In this way, the electronic device 10 can encourage the driver to drive safely. Note that the above-mentioned warning information is just an example, and in reality, various other types of warning information are output to the driver. Alarm information may include, for example, visual information consisting of predetermined images, videos, or characters output to the display unit 13, or sound or voice output to the speaker 14. The output device functions as an alert unit that notifies information by display, sound, light, or other methods perceptible to humans, as exemplified by the display unit 13, speaker 14, and light-emitting unit 23.

[0068] [2. Light receiving section 12] <2-1. Overall Structure> Figure 3 is a circuit diagram showing an example of the electrical configuration of the light-receiving unit 12. The photodiode 122 is an example of a light-receiving element that outputs a current corresponding to the incident light as a first signal. The cathode of the photodiode 122 is connected to the high-potential power line, and the anode of the photodiode 122 is connected to one end of resistor R1. The other end of resistor R1 is grounded. The photodiode 122 is placed, for example, on the back side of the focusing lens 121, receives the light focused by the focusing lens 121, and outputs a current corresponding to the amount of incident light as a first signal. The output of the photodiode 122 should be made to increase in proportion to the amount of incident light. A phototransistor or the like can also be used as a light-receiving element that converts incident light into a current signal.

[0069] An integrated circuit (IC) 123 is placed after the photodiode 122. The input terminal of the integrated circuit 123 is connected in common to the anode of the photodiode 122 and one end of the resistor R1 via a capacitor C1.

[0070] The integrated circuit 123 converts and amplifies the first signal, which is the output of the light receiving unit 12, into a voltage signal and outputs a second signal. The integrated circuit 123 is an integrated circuit used for a specific application different from laser detection. As will be described later in the verification results, the inventors have found that by deliberately using such an integrated circuit 123, which is for a specific application different from laser detection, for the laser detection application of the electronic device 10, the sensitivity of the laser light used for speed measurement emitted by the speed measuring device can be improved compared to the conventional configuration. Such specific applications include optical distance measurement, as will be described later, but more details will be provided later. The integrated circuit 123 should be an integrated circuit designed for a specific application different from laser detection. It can be determined, for example, that an integrated circuit is used for a specific application different from laser detection or is designed for a specific application by looking at the datasheet or package of the integrated circuit, which states that it is suitable for use in that specific application. Thus, it can be determined that an integrated circuit is used for a specific application different from laser detection or is designed for a specific application by looking at the information regarding the specifications of the integrated circuit. Being used for a specific purpose other than laser detection, or being designed for a specific purpose, means that it is not advertised as being for use in laser detection, or that it is not actively advertised as being suitable for use in laser detection.

[0071] The integrated circuit 123 may be used, for example, for optical distance measurement (an optical distance measurement receiver). In this case, unlike general-purpose products that are advertised as being usable for a variety of applications, the integrated circuit 123 is an integrated circuit used for a limited number of specific applications, including optical distance measurement. For example, the MAX3806 from MAXIM Corporation may be used for the integrated circuit 123. Data on the MAX3806 from MAXIM Corporation can be found, for example, at “https: / / www.maximintegrated.com / jp / products / comms / optical-communications / MAX3806.html” and “https: / / datasheets.maximintegrated.com / jp / ds / MAX3806_jp.pdf” (accessed March 31, 2021). This webpage states that the MAX3806 is a high-gain linear preamplifier for distance measurement applications, and only applications other than laser detection are listed. Such optical distance measurement integrated circuits can handle relatively high-frequency signal inputs, and they have the performance necessary to ensure the accuracy of distance measurement. While such integrated circuits for optical distance measurement are designed for applications other than laser detection, they are particularly well-suited for use in laser detection functions.

[0072] The integrated circuit 123 should preferably be an integrated circuit with a transimpedance amplifier (also called a transimpedance amplifier IC). The integrated circuit 123 linearly amplifies the first signal, which is the output of the photodiode 122. According to the above webpage, the MAX3806 is a high-gain linear preamplifier for distance measurement applications using laser beams. Thus, although the MAX3806 is for receiving laser light for distance measurement, it can handle input signals of relatively high frequencies, and integrated circuits for optical distance measurement have the performance necessary to ensure the accuracy of distance measurement. By applying such a MAX3806 as the integrated circuit 123, even if the pulse width of the laser light emitted by the speed measuring device is as narrow as 20 ns and the laser pulse is in the high-frequency range, the integrated circuit 123 processes each of the very narrow pulse widths as a single pulse. Furthermore, a sufficiently large gain can be obtained with the integrated circuit 123 having a transimpedance amplifier.

[0073] The transimpedance amplifier of integrated circuit 123 is not a transimpedance amplifier composed of operational amplifiers. Therefore, using the MAX3806 as integrated circuit 123 is more advantageous in realizing low-cost reception of high-frequency laser light used for speed measurement. The inventor considered that any integrated circuit that can handle input signals with a frequency of at least 10 MHz or higher would be suitable for receiving laser light used for speed measurement. The MAX3806 is an integrated circuit that is guaranteed to handle input signals with a lower frequency limit of at least 25 MHz or higher. The MAX3806 is an integrated circuit 123 that is guaranteed to handle input signals with a lower frequency limit of at least 25 MHz or higher. On the other hand, in the case of a transimpedance amplifier composed of operational amplifiers, the frequency range that can be handled is generally relatively low, making it difficult to improve the reception sensitivity of high-frequency laser light used for speed measurement. Also, to increase the frequency range that can be handled, it is necessary to use expensive operational amplifiers. By not using a transimpedance amplifier composed of operational amplifiers, as in integrated circuit 123, it is possible to improve the reception sensitivity of laser light used for speed measurement without having to construct a transimpedance amplifier with expensive operational amplifiers.

[0074] In the integrated circuit 123 with the above configuration, the input side has the photodiode 122 positioned on the high-potential side. Therefore, in response to the laser light for speed measurement being incident on the photodiode 122 and the first signal being input to the input terminal, the integrated circuit 123 outputs a negative pulse from its output terminal.

[0075] The output terminal of the integrated circuit 123 is connected to an emitter-grounded amplifier circuit 124 using a transistor 1241. The amplifier circuit 124 inverts and further amplifies the output signal of the integrated circuit 123. As a result, a positive pulse is output from the amplifier circuit 124. It is desirable that the amplifier circuit 124 be designed to have a high amplification factor for signals in the specific wavelength range to which the laser light emitted by the speed measuring device belongs. The transistor 1241 can be configured using, for example, an NPN type, and an appropriate type can be used depending on the input signal, etc.

[0076] The output terminal of the amplifier circuit 124 is connected to the emitter follower circuit 125 via capacitor C3. The output terminal of the emitter follower circuit 125 is connected to the input terminal of the comparator 126.

[0077] A thermistor 128 is provided on the base side of the emitter follower circuit 125 as a temperature compensation circuit. The signal from the input side of the emitter follower circuit 125 has its DC component cut by capacitor C3, and only the AC component is input, so the voltage is determined by the voltage divider of resistors R4, R5, etc. surrounding the base side of transistor 1251. A thermistor 128 is placed between capacitor C3, which is connected to the output terminal of the amplifier circuit 124, and the base of transistor 1251, which is the input terminal of the emitter follower circuit 125, and is grounded via resistor R3. One end of thermistor 128 is connected to the input terminal of the emitter follower circuit 125, and the other end is grounded.

[0078] The comparator 126 outputs a high-level signal when the received signal level exceeds a threshold, and a low-level signal when it is below the threshold. The pulse width of the laser light used for speed measurement emitted by the speed measuring device, which is received by the photodiode 122, is short, for example, 20 ns. Therefore, when the laser light is received, the comparator 126 outputs a pulse with a narrow pulse width corresponding to that pulse width.

[0079] The output terminal of the comparator 126 is connected to the waveform shaping circuit 127. The waveform shaping circuit 127 receives a narrow pulse width input to its input terminal in response to the reception of laser light for speed measurement, and generates and outputs a pulse with a predetermined width that can be processed by the control unit 11. As described above, the pulse width of the pulse output from the comparator 126 in response to the reception of laser light for speed measurement is, for example, a very narrow pulse width of 20 ns, and if it is input directly to the microcontroller or the like that makes up the control unit 11, it may be difficult for the control unit 11 to process. Therefore, the waveform shaping circuit 127 is better configured to generate and output a pulse that is widened to, for example, about 50 μs. The waveform shaping circuit 127 is better configured to consist of, for example, an AND gate and a monostable multivibrator, and to output pulse light with a predetermined width defined by the time constant of the monostable multivibrator.

[0080] The output terminal of the waveform shaping circuit 127 is connected to the control unit 11. The control unit 11 determines whether or not it has received the laser light for speed measurement emitted by the speed measuring device and outputs a determination signal indicating the result of that determination. The determination signal is a signal that includes information that can identify whether or not the laser light for speed measurement has been received. The determination signal may also include information for providing notification in response to the reception of the laser light for speed measurement. The determination signal may also be understood as a notification signal for providing this notification. In this embodiment, for example, the control unit 11 may perform control to notify the presence of the speed measuring device when it receives pulse light with a pulse interval of, for example, 80 ms, of the laser light for speed measurement emitted by the speed measuring device. More specifically, this notification is a notification that the vehicle on which the electronic equipment 10 is located and the laser-type speed measuring device are in a predetermined proximity relationship. Alternatively, the control unit 11 may perform control to notify the presence of a speed measuring device when the pulse width (emission time) of the input pulse is, for example, 20 ns, and the pulse width output from the waveform shaping circuit 127 is approximately 50 μs. The control unit 11 may also notify the presence of a speed measuring device when pulse light of a specific wavelength is received at least once. In this way, if there is a possibility that a speed measuring device is present, its presence can be quickly notified and the user can become aware of it. Furthermore, the 80 ms pulse light exemplified above may include a range of less than 80 ms and / or more than 80 ms, which is within a certain range from the reference pulse interval. Similarly, the 20 ns pulse width may include a range of less than 20 ns and / or more than 20 ns, which is within a certain range from the reference pulse width. Accordingly, the pulse width output from the waveform shaping circuit 127 will also fluctuate.

[0081] As described above, by using an integrated circuit 123, which is used for specific applications different from laser detection, in the application of laser detection, the electronic device 10 can improve the sensitivity of receiving the laser light emitted by the speed measuring device for speed measurement compared to conventional configurations, and consequently improve the laser detection function. In this way, for example, compared to using a transistor amplifier circuit instead of the integrated circuit 123, the noise of the second signal is reduced, and the sensitivity can be improved in conjunction with the gain of the integrated circuit 123.

[0082] Since the first stage amplifier, which provides the first signal (a current signal output from the photodiode 122), is an integrated circuit 123 having the aforementioned attributes, high gain can be obtained in a single stage. Furthermore, the noise of the entire amplification circuit is greatly influenced by the noise performance of the amplifier placed in the first stage. By using the low-noise integrated circuit 123 instead of an amplification circuit using transistors in the first stage, noise in the electronic device 10 can be reduced. As a result, the sensitivity of the electronic device 10 to receiving laser light is increased.

[0083] Since the electronic device 10 is installed in a vehicle, it is subject to large temperature fluctuations in its installation environment. In particular, temperature changes inside the vehicle can fluctuate significantly depending on the season and the time of day, such as daytime and nighttime. The voltage drop between the base and emitter of transistor 1251 is temperature-dependent, but by providing the thermistor 128, fluctuations in the voltage drop of the base voltage of the emitter follower circuit 125 due to temperature changes are reduced.

[0084] Setting the threshold value in comparator 126 to a high level with a margin of safety prevents false alarms caused by receiving pulsed light from another device not being emitted by the speed measuring device, but it reduces sensitivity. Setting the threshold value to a low level increases sensitivity, but it may generate false alarms due to picking up noise. In this embodiment, by providing a temperature compensation circuit, temperature changes are reduced, so even if the threshold value is set low, it will not pick up noise, thus increasing sensitivity.

[0085] Figure 4 shows the verification results of the light receiving sensitivity of the laser light for speed measurement when using the light receiving unit 12 having the above configuration. As described above, as an amplification means for amplifying the signal from the photodiode 122, an integrated circuit 123 is used without providing an amplification circuit composed of a transistor circuit in the first stage, an amplification circuit 124 composed of an emitter-grounded transistor circuit is used in the second stage, a thermistor 128 is placed on the input side of the emitter follower circuit 125 and the threshold value of the comparator 126 is set appropriately, and for example, as shown in Figure 4, the detection distance and detection range could be increased. In Figure 4, Comparative Example 2 is an example of the verification results when an amplification circuit consisting of transistors is connected in multiple stages without using an integrated circuit amplifier. Comparative Example 1 is an example of the verification results when using the circuit configuration shown in Figure 25 of Japanese Patent Application Publication No. 2020-169974. According to this embodiment, it was confirmed that the detection distance can be increased compared to Comparative Examples 1 and 2.

[0086] <2-2. Relationship with MAX3806 reference design, etc.> In the reference design for the MAX3806, which constitutes the integrated circuit 123, a coil element is provided at the position of resistor R1 as explained in Figure 3. That is, the connection to the input terminal is the connection point between the photodiode and the coil element. A reference design is a circuit that has been verified to operate reliably if designed according to it. Reference designs are provided, for example, by the method described in the datasheet of the integrated circuit. In this embodiment, although the laser light emitted by the speed measuring device using resistor R1 instead of the coil element shown in such a reference design has a very narrow pulse width and high frequency, ringing can be suppressed by using resistor R1. Although a coil element may be used as in the reference, it is preferable to use resistor R1 because a coil element containing a magnetic material may cause ringing. Also, since the MAX3806 is a transimpedance amplifier, the input impedance is low. The resistance value of resistor R1 is sufficiently large compared to the input impedance, so the input signal flows to the resistor R1 side and the effect of loss is small. Using resistor R1 in this way also contributes to improving the photoreception sensitivity of the laser light for speed measurement.

[0087] The MAX3806 accepts single or burst pulses with a pulse width of 30 ns or more, but it was modified to accept and detect signals with narrower pulse widths (e.g., 20 ns). The inventors confirmed that it can also detect 20 ns signals.

[0088] The integrated circuit 123 is a transimpedance amplifier, and the resistance value that determines its gain is preferably in the range of 44kΩ to 77kΩ, with 60kΩ being preferable. The resistance value of 44kΩ to 77kΩ is the range in the MAX3806 datasheet where operation is guaranteed when a higher gain (GAIN=1) is selected, and 60kΩ is shown as the standard value. In the verification in Figure 4, terminal 7 (GAIN) of the integrated circuit 123 was forced high, resulting in 60kΩ. In this case, the linearity range is guaranteed up to a maximum of 20μAp, and the bandwidth is 49MHz. Furthermore, when terminal 7 is set low, the resistance value that determines the gain becomes 30kΩ, the linearity range is guaranteed up to a maximum of 40μAp, and the bandwidth is 98MHz.

[0089] The integrated circuit 123 has a built-in 14dB attenuator. Asserting terminal 5 (ATT) high enables the attenuator, and forcing it low disables it. It is best to use them depending on the situation. In this embodiment, since it is not used, terminal 5 is connected to the power ground (terminals 3 and 4).

[0090] In the MAX3806 reference design, it is recommended to connect an AD converter to the output side of the MAX3806. However, in this embodiment, instead of an AD converter, an amplification circuit 124 is connected to the output terminal of the integrated circuit 123. For example, if the amplification circuit 124 is omitted when the overall gain of the electronic device 10 meets the specifications due to the gain of the integrated circuit 123, an emitter follower circuit 125 is connected to the output terminal of the integrated circuit 123. For example, by providing the amplification circuit 124, the second signal can be amplified to a level exceeding the capability of the integrated circuit 123, and the emitter follower circuit 125 can be driven based on the second signal, which is the output from the integrated circuit 123. As a result, the sensitivity of the laser light for speed measurement can be improved, and consequently, the function of laser detection can be improved.

[0091] [3. Integrated Circuit 123] The integrated circuit 123 was constructed using the MAX3806, but any integrated circuit with the characteristics described above, including those used or designed for other specific applications, can also be applied to the light-receiving unit 12. Furthermore, the integrated circuit 123 may be an integrated circuit with the following characteristics, for example: The integrated circuit 123 operates from a single +5.0b power supply and converts the current from the AC-coupled photodiode 122 into a single-ended voltage. The integrated circuit 123 is a high-gain linear preamplifier, maintaining linearity over input amplitudes of 42nAp (SNR=3) to 40μAP. It can also withstand overload currents up to 2mAp. As mentioned above, the noise density at a 60kΩ gain is 1.5pA / √Hz, and the input-referred noise at a 60kΩ gain is 14nARMS. Operation is guaranteed over a temperature range of -40℃ to +105℃. Furthermore, as mentioned above, the gain is selectable (60kΩ, 30kΩ), and a 14dB attenuation is also selectable.

[0092] An integrated circuit used for a specific application different from laser detection as an integrated circuit 123 may be a LiDAR (Light Detection and Ranging) sensor. LiDAR is a remote sensing technology that measures distance by irradiating an object with light and detecting the reflected light with an optical sensor, and is also, for example, a high-bandwidth automotive transimpedance amplifier. Such integrated circuits for LiDAR are high-performance, have a high frequency bandwidth, and are designed to accurately detect external laser light rather than reflected light emitted by the sensor itself. The inventors have found that such integrated circuits are also particularly suitable for use in laser detection applications, and have discovered that this can improve the functionality of laser detection. Furthermore, for optical distance measurement, for example, a laser sensor used to measure the distance to a vehicle ahead, or a portable distance measuring laser sensor may be used, and the light-receiving portion of these sensors may be used. Moreover, integrated circuits for specific applications, such as laser sensors for industrial applications, can be used.

[0093] [4. Other embodiments of the light-receiving unit 12] <4-1. Place the photodiode on the low-potential side> It is preferable to arrange the photodiode 122, which is a light-receiving element, in the opposite position to that of the embodiment described above. For example, the photodiode 122 is placed below the input terminal of the integrated circuit 123, and the resistor R1 is placed above the input terminal. This reverses the positive and negative polarity. Consequently, the integrated circuit 123 outputs a positive pulse. As described above, in the common-emitter amplifier circuit 124, the polarity is inverted along with amplification, and a negative pulse is output. Therefore, in such cases, it is preferable to provide an inverting circuit between the amplifier circuit 124 and the emitter follower circuit 125.

[0094] Furthermore, if the gain of the integrated circuit 123 meets the specifications, it is preferable to configure the system so that the output terminal of the integrated circuit 123 is connected to the emitter follower circuit 125 without providing the amplification circuit 124 as in the embodiment described above. In this case, the amplification circuit 124 becomes unnecessary, and the configuration can be simplified. In this case, the output of the integrated circuit 123 has low drive capability. It is preferable to adjust (for example, increase) the input impedance of the emitter follower circuit 125.

[0095] <4-2. Other ICs that make up an integrated circuit> In the embodiment described above, the MAX3806 was used for the integrated circuit 123, but other ICs could also be used.

[0096] The integrated circuit 123 may be best used with a transimpedance amplifier, which offers high-speed operation (90 MHz gain bandwidth [GBW]) along with high accuracy, long-term stability, and extremely low 1 / f noise, making it ideal for high-speed photodiode applications. Recommended applications for this transimpedance amplifier include photodiode monitoring, high-precision current-to-voltage conversion, optical amplifiers, and CAT scanner front-ends.

[0097] Furthermore, the integrated circuit 123 can, for example, be selected to have a closed-rule transimpedance bandwidth of 125 MHz (when the transimpedance gain is 5 kΩ) and 105 MHz (when the transimpedance gain is 20 kΩ), and a transimpedance amplifier with an input-referred noise of 15 nARMS at a 20 kΩ gain is recommended. Recommended applications for this transimpedance amplifier include, for example, photodiode monitoring, high-speed current-to-voltage conversion, optical amplifiers, and CAT scanner front-ends. The operating temperature range is, for example, -40 to +85°C.

[0098] [5. Different forms of electronic devices] <5-1. Separate Type> In the embodiments described above, the electronic device 10 is a monitor-integrated type in which various devices and equipment are mounted in a single housing, but it may also be a separate type divided into multiple housings, for example. Figure 5 is a perspective view showing the external configuration of the first device 800, which constitutes a separate type electronic device, when viewed from the right front side with respect to the direction of travel of the vehicle. The first device 800 is a box-shaped device with a roughly rectangular parallelepiped shape. The first device 800 is divided into a first housing 801 located above and a second housing 802 located below. A cable 810 is pulled out to the outside from the joint between the first housing 801 and the second housing 802. The first device 800 communicates with the second device via the wired cable 810. The first device 800 may have functions such as a control unit 11 and a light receiving unit 12, and may output a judgment signal to the external second device. The second device may provide notification based on this judgment signal. The first device 800 may also communicate with the external device via a wireless communication path.

[0099] <5-2. Variations in mounting positions> Furthermore, the installation location can also be varied; for example, it can be a suspended type attached to the vehicle's dashboard, windshield, rearview mirror, or ceiling using a predetermined mounting component, making it applicable to a wide range of applications.

[0100] <5-2-1. Configuration in which one electronic device 900 can be mounted in different locations (Part 1)> Figure 6 shows the external configuration of the electronic device 900 in another embodiment. Figure 6(a) is a view of the electronic device 900 from the upper right side of the front. Figure 6(b) is a view of the electronic device 900 from the upper right side of the rear. The electronic device 900 has a rectangular parallelepiped shape, with its width being longer than its height. The electronic device 900 is sized and weighted to be easily carried by the user. The housing 900A of the electronic device 900 is divided into a first housing 901 located on the front side and a second housing 902 located on the rear side. The front side of the first housing 901 is provided with a light-emitting unit 911, an operating unit 912, and a sound-emitting unit 913A. This electronic device 900 does not have a display unit 13, and alarms are provided using sound and light. The first electronic device 900 may have at least the functions of the control unit 11 and the light-receiving unit 12 described above. Furthermore, the electronic device 900 may have a function to provide notification based on the determination signal from the control unit 11.

[0101] The light-emitting unit 911 emits a predetermined light. The light-emitting unit 911 includes, for example, a light-emitting diode. The light-emitting unit 911 emits light according to the operating state of the electronic device 900. The light-emitting unit 911 is located slightly to the lower right of the first housing 901 when viewed from the front. The light-emitting unit 911 emits white light when the electronic device 900 is in standby mode. The light-emitting unit 911 emits blue light when the electronic device 900 is being operated. The light-emitting unit 911 emits a flashing red light when the electronic device 900 is receiving pulsed light. Note that the relationship between the operating state and the light-emitting state is not limited to this, and the light-emitting color and timing (for example, the frequency and number of flashes) can be varied in various ways.

[0102] The control unit 912 accepts user input. The control unit 912 is located slightly to the lower right of the first housing 901 when viewed from the front, and is located to the right of the light-emitting unit 911. In this case, the control unit 912 functions as a volume button. The control unit 912 is operated by the user, for example, to adjust the volume of alarm sounds or other sounds, or to mute the alarm sound emitted when pulse light is received. In this case, the control unit 912 accepts a press operation, but it may also be an operation unit that accepts slide, touch, or other operations.

[0103] The sound-emitting unit 913A emits a predetermined sound. The sound-emitting unit 913A has a plurality of holes located slightly to the upper right of the first housing 901 when viewed from the front. The sound-emitting unit 913A outputs sound through these multiple holes. The sound-emitting unit 913A outputs alarm sounds and other sounds.

[0104] A DC jack for receiving power input from a power source is provided on the left side of the housing 900A. For example, a cigarette lighter plug cord or a power cable is connected to the DC jack. A mounting portion 917 for attaching the first mounting member 940 and the second mounting member 950, which will be described later, is provided on the rear of the second housing 902. Thus, the mounting portion 917 is a mounting portion shared by the first mounting member 940 and the second mounting member 950. The mounting portion 917 is located near the center in the width direction of the second housing 902 when viewed from the rear side, and is located near the lower end of the second housing 902. The mounting portion 917 has a pair of grooves 9171 and 9172. The pair of grooves 9171 and 9172 are provided at a predetermined distance from each other in the width direction of the electronic device 900, and each extends in the vertical direction. The first mounting member 940 and the second mounting member 950, which will be described later, can be attached to and detached from the pair of grooves 9171 and 9172. The first mounting member 940 and the second mounting member 950 may be further fixed to the second housing 902 using fasteners such as screws.

[0105] A lens holder 915 is provided on the rear of the second housing 902. The lens holder 915 forms a window, which is an opening that allows the inside and outside of the housing 900A to pass through. The lens holder 915 may have the same shape as the lens holder 1006 described above, and when viewed from the rear side of the housing 900A, it is an elliptical shape with a major axis in the width direction and a minor axis in the vertical direction. When the electronic device 900 is installed in a vehicle, the width direction corresponds to the width direction of the vehicle, and the vertical direction corresponds to the height direction of the vehicle. The second housing 902 is screwed to the first housing 901 using screws at both ends in the width direction when viewed from the rear side.

[0106] The focusing lens 920 is fitted into the lens holder 915. The focusing lens 920 is part of the light receiving section 920A in the electronic device 900 and is positioned at the location corresponding to the light incident section. The focusing lens 920 may have the same configuration as the focusing lens 121. The lens holder 915 and the focusing lens 920 are located on the upper right side of the second housing 902 when viewed from the rear side of the second housing 902. For example, the focusing lens 920 is positioned on the rear side of the housing 900A at least above the center in the vertical direction, and at least to the left of the direction of travel of the vehicle when viewed from the driver's seat side of the vehicle. This is because positioning the focusing lens 920 relatively high on the rear side of the second housing 902 and on the roadside where the speed measuring device is likely to be located may make it easier to receive light from the speed measuring device. Pulsed light from the speed measuring device is introduced into the housing 900A via the lens holder 915 and the focusing lens 920.

[0107] Inside this housing 900A, for example, the electrical circuit, control unit, and other various devices that constitute the light receiving unit 12 of the embodiment described above are mounted. The pulsed light focused by the focusing lens 920 is converted into a pulse signal of a predetermined pulse width by the circuit of the high-sensitivity light receiving unit 920A equipped with the integrated circuit 123 described above and supplied to the control unit. The control unit then provides notification in response to the reception of pulsed light from the speed measuring device in the same manner as the control unit 11 described above. Furthermore, when the control unit 11 receives pulsed light, it may make the light-emitting unit 911 emit red light or emit an alarm sound using the sound-emitting unit 913A. In the illustrated example, there is no display unit 13, but it is preferable to include a display unit 13 and perform display control of the standby screen, etc., in the same manner as in the embodiment described above.

[0108] The electronic device 900 configured as described above is mounted to the vehicle using the first mounting member 940 and the second mounting member 950 selectively. The first mounting member 940 is a member for mounting the electronic device 900 to the dashboard and is also called a dashboard mounting bracket. The second mounting member 950 is also called a suspended mounting stay.

[0109] As shown in Figure 7, the first mounting member 940 includes a base portion 941, a socket portion 942, a ball stud 943, and a mounting portion 944. The base portion 941 is the part that is attached to the dashboard of the vehicle. The bottom surface of the base portion 941 is attached to the dashboard using a fixing member such as an adhesive sheet or double-sided tape as described in Japanese Patent No. 5958927. The base portion 941 includes a socket portion 942 having a space that opens to the front. The ball portion of the ball stud 943 is mounted on the socket portion 942. The socket portion 942 and the ball stud 943 mounted on the socket portion 942 constitute a ball joint mechanism. The ball stud 943 changes its orientation up, down, left, and right when subjected to external force while mounted on the socket portion 942. A mounting portion 944 is provided on the front side of the ball stud 943. The mounting portion 944 is mounted on the mounting portion 917 of the electronic device 900. The mounting portion 944 has a pair of protrusions 9441 and 9442 that protrude to the left and right sides when viewed from the front. Protrusion 9441 protrudes further forward than other parts of the mounting portion 944 and protrudes to the right when viewed from the front. Protrusion 9442 protrudes further forward than other parts of the mounting portion 944 and protrudes to the left when viewed from the front. Protrusion 9441 is inserted into groove 9171, and protrusion 9442 is inserted into groove 9172. When the mounting portion 944 is mounted on the mounting portion 917, it is located between the pair of grooves 9171 and 9172 in the electronic device 900. In this way, the electronic device 900 is attached to the mounting portion 944 of the first mounting member 940 (see Figure 8). The electronic device 900 is installed on the dashboard by attaching the bottom surface of the base portion 941 of the first mounting member 940 to the dashboard using a fixing member as described above.

[0110] Furthermore, as shown in Figure 9, the second mounting member 950 is a plate-shaped member formed from a metal such as aluminum. The second mounting member 950 has a first portion 951, a second portion 952, and a third portion 953. The first portion 951 is a plate-shaped portion. The first portion 951 supports the electronic device 900 by its upper surface contacting the bottom surface of the electronic device 900.

[0111] The second part 952 is a plate-shaped part connected to the first part 951 and substantially perpendicular to the first part 951. The second part 952 supports the electronic device 900 by one side contacting the back of the electronic device 900. The second part 952 has a pair of protrusions 9521 and 9522 that protrude to the left and right sides when viewed from the front, as a part that is attached to the mounting part 917 of the electronic device 900. Protrusion 9521 protrudes further to the front than the other parts of the second part 952 and protrudes to the right when viewed from the front. Protrusion 9522 protrudes further to the front than the other parts of the second part 952 and protrudes to the left when viewed from the front. Protrusion 9521 is attached to the second part 952 by being inserted into the groove 9171, and protrusion 9522 is attached to the groove 9172. As a result, the electronic device 900 is attached to the second mounting member 950, as shown in Figure 10.

[0112] The second portion 952 further has a notch 9523. The notch 9523 is cut out so that it does not overlap with the focusing lens 920 when the second mounting member 950 is attached to the electronic device 900 (see Figure 10(b)).

[0113] The third part 953 is a plate-shaped part connected to the second part 952. The third part 953 is attached (e.g., glued) to the mounting site using a fixing member such as double-sided tape, with its upper surface serving as the mounting surface. When installed by the user, the orientation of the third part 953 relative to the second part 952 should be adjusted according to the shape of the mounting site in the vehicle, in this embodiment, the inclination of the windshield. The third part 953 is attached to the mounting site X1, which is the gap area between the ceiling X2 and the windshield X3 (or the area near the upper edge of the windshield X3), using double-sided tape, as shown in Figures 11(a) and (d), for example. The gap area may be recognizable to the user as a black border area. If the mounting site X1 is, for example, the area behind the rearview mirror, it is desirable for people inside the vehicle that the electronic device 900 will be hidden behind the rearview mirror.

[0114] <5-2-2. Configurations in which one electronic device 900 can be mounted in different locations (Part 2)> The separate-type first device 800 described above can be installed on the dashboard by, for example, attaching a fixing member such as double-sided tape to the bottom surface of the second housing 802. Alternatively, for example, using the third mounting member 960 shown in Figure 12, the first device 800 can be attached to a predetermined position on the third mounting member 960 as shown in Figure 13. Then, as shown in Figure 14, the first device 800 can be suspended by attaching the third mounting member 960 to the windshield using a fixing member such as double-sided tape.

[0115] The circuit configuration of the light-receiving unit 12 described in the above-described embodiment is just one example, and some elements may be omitted or other elements may be added. For example, the thermistor 128 may be removed. Various modifications are possible for the configuration of the light-receiving unit 12 using the integrated circuit 123.

[0116] [6. Configuration with multiple photodiodes 122] Next, a configuration in which the electronic device 10 is equipped with multiple photodiodes 122, which are an example of light-receiving elements, will be described. In the following configuration, the integrated circuit 123 may not be an integrated circuit used for a specific application other than laser detection, but may be, for example, an integrated circuit that has at least voltage signal conversion and amplification, and the following configuration does not necessarily have to be based on the configurations described so far.

[0117] The control unit 11 may output a signal corresponding to the reception of laser light based on the reception of laser light by the multiple photodiodes 122. The signal corresponding to the reception of laser light can be understood as a signal indicating whether or not laser light has been received, or as a signal for notifying (e.g., an alarm) that laser light has been received. The signal for notifying that laser light has been received should be a signal that specifies at least one of the notification method (e.g., sound, voice, light, display) and the notification content (e.g., notification level). In the following description, when distinguishing between the multiple photodiodes 122, they may be represented by adding an alphabet to the end of the code, such as photodiode 122A, 122B, 122C, etc. Note that the number of photodiodes 122 described below is just an example, and the number of photodiodes 122 may be increased or decreased. Also, the following description describes the case in which photodiodes are used as light-receiving elements, but other light-receiving elements such as phototransistors may be used unless otherwise specified.

[0118] <6-1> It is preferable that the multiple photodiodes 122 be arranged in a line along a predetermined direction. In the example shown in Figure 15, four photodiodes 122A, 122B, 122C, and 122D are arranged in a straight line. The predetermined direction may be the left-right direction or the horizontal direction of the electronic device 10. The left-right direction of the electronic device 10 is the width direction of the vehicle 40 (i.e., the vehicle width direction) when the display unit 13 is pointed directly behind the vehicle 40. In this way, the electronic device 10 can receive laser light from a wide range of directions in the left-right or horizontal direction, and secure an angle with high sensitivity in the left-right or horizontal direction. Note that the up-down direction of the electronic device 10 shown in Figure 15 corresponds to the vertical direction (also called the perpendicular direction) or the height direction of the vehicle 40.

[0119] <6-2>The multiple photodiodes 122 are preferably arranged along the first direction and the second direction intersecting the first direction. In the example shown in Figure 16, the first direction is the left-right direction or horizontal direction of the electronic device 10. The left-right direction of the electronic device 10 is the width direction (i.e., the vehicle width direction) of the vehicle 40 when the display unit 13 is facing directly behind the vehicle 40. The second direction corresponds to the up-down direction or vertical direction of the electronic device 10. The up-down direction of the electronic device 10 corresponds to the height direction of the vehicle 40. In the example shown in Figure 16, photodiodes 122A, 122B, and 122C are arranged in the left-right direction of the electronic device 10, and below them, photodiodes 122D, 122E, and 122F are arranged in the left-right direction of the electronic device 10. Photodiodes 122A and 122D are arranged vertically, photodiodes 122B and 122E are arranged vertically, and photodiodes 122C and 122F are arranged vertically. In this way, the electronic device 10 can receive laser light from a wide range of directions, including vertically, in addition to horizontally, and secure an angle of high sensitivity in the vertical direction. For example, when a vehicle 40 is traveling on an inclined surface such as a slope, or when laser light is coming from a low position, securing an angle of high sensitivity in the vertical direction can be advantageous.

[0120] <6-3> It is preferable to have each of the multiple photodiodes 122 input a signal to the integrated circuit 123 (i.e., the integrated circuit having a transimpedance amplifier), but at least two photodiodes 122 may be connected in parallel so that a signal is input to the integrated circuit 123. In the former case, where a signal is input to the integrated circuit 123 from each photodiode 122, the control unit 11 may provide different notifications (e.g., notification content or notification manner) depending on which photodiode 122 the signal is input from. In this way, the electronic device 10 can provide a variety of notifications regarding the reception of laser light, which can increase convenience for the user.

[0121] As an example of such a configuration, the control unit 11 may be configured to provide a higher level of notification as the number of photodiodes 122 whose received light intensity exceeds a threshold increases.

[0122] As another example, the control unit 11 may perform predetermined statistical processing, such as integrating the light intensity input individually from the photodiode 122, and provide notification for that level when the integrated value exceeds the reference value for that level.

[0123] As another example, the control unit 11 may notify the direction of incidence or emission of the laser beam according to the position of the photodiode 122 that receives the laser beam, or it may notify the direction of the enforcement point (e.g., a speed measuring device). For example, if the laser beam is received by the left-side light-receiving element in the direction of travel of the vehicle 40, but not by the right-side light-receiving element, the control unit 11 may notify that the laser beam is coming from the left.

[0124] In this way, based on the laser reception status of multiple photodiodes 122, it becomes easier for the user to understand the proximity relationship between the vehicle 40 and the enforcement point, such as how close the vehicle is to the speed measuring device.

[0125] <6-4>Figure 17 is a diagram showing an example of the arrangement relationship with the focusing lens 121 when the four photodiodes 122A, 122B, 122C, and 122D are arranged in a row as explained in <6-1>.Figure 17(A) is a diagram showing the arrangement relationship between the focusing lens 121 and the photodiodes 122A, 122B, 122C, and 122D when viewed in the direction of the optical axis of the focusing lens 121 (in this embodiment, when the electronic device 10 is viewed from the back side).Figure 17(B) is a diagram showing the arrangement relationship between the focusing lens 121 and the photodiodes 122A, 122B, 122C, and 122D when viewed in a direction perpendicular to the optical axis of the focusing lens 121 (in this embodiment, when the electronic device 10 is viewed from above).

[0126] In the example shown in Figure 17, multiple photodiodes 122A, 122B, 122C, and 122D are arranged in a line on the substrate 130 along the left-right direction of the electronic device 10. A lens barrel 140 (lens barrel portion) is provided between the focusing lens 121 and the photodiodes 122A, 122B, 122C, and 122D. The lens barrel 140 is a cylindrical member with a mirror surface formed on its inside. The inside of the lens barrel 140 becomes the optical path of the laser light that has passed through the focusing lens 121. The light that has passed through the focusing lens 121 is reflected by its mirror surface and guided to one of the positions of the photodiodes 122A, 122B, 122C, and 122D.

[0127] A gap G is formed between photodiode 122A and photodiode 122B, between photodiode 122B and photodiode 122C, and between photodiode 122C and photodiode 122D. Gap G is a region where no photodiodes are present. The size of gap G is preferably smaller than one side of the light-receiving surface of photodiode 122, for example, about 0.3 mm. Of the laser light incident on the focusing lens 121, the light that is incident on the light-receiving surface of any of the photodiodes 122A, 122B, 122C, and 122D becomes the light that is received by the light-receiving unit 12, while the light that is incident on gap G is not received by the light-receiving unit 12.

[0128] In the example shown in Figure 17, the photodiodes 122B, 122C, and 122D are positioned so that their entire light-receiving surfaces overlap with the focusing lens 121 in the front-to-back direction of the electronic device 10. On the other hand, a portion of the light-receiving surface of photodiode 122A overlaps with the focusing lens 121 in the front-to-back direction of the electronic device 10, but the remaining portion does not overlap with the focusing lens 121 and is offset. In this example, photodiode 122A overlaps with the side of the lens barrel 140, etc. For example, such an arrangement may occur if a conventional shield case is reused, or if the second photodiode from the right, 122C, is positioned to overlap with the center of the focusing lens 121 (for example, the optical axis). Furthermore, the inventors have discovered that in such an arrangement, laser light from a predetermined angle from the left side with respect to the direction of travel of the vehicle 40 may enter the gap G, as shown in the graph in Figure 18. As a result, due to the presence of the gap G, a dip (i.e., a region where the laser's light reception sensitivity is low and drops off) may occur depending on the angle of incidence of the laser light. Also, in this example, the angular range in which a constant light reception level is ensured in the vertical direction remains narrow. Therefore, the inventor considered the following configuration.

[0129] When multiple photodiodes 122 are arranged in a line along a predetermined direction, it is preferable to arrange the four photodiodes 122A, 122B, 122C, and 122D to the right, as shown in Figure 19, rather than to the left, as shown in Figure 17(A). In this embodiment, left alignment means aligning the electronic device 10 to the left when viewed from the rear, that is, to the right with respect to the direction of travel of the vehicle 40, and right alignment means aligning the electronic device 10 to the right when viewed from the rear, that is, to the left with respect to the direction of travel of the vehicle 40. Aligning to the left with respect to the direction of travel of the vehicle 40 means aligning the electronic device 10 to the left with respect to the direction of travel of the vehicle 40, with reference to the position of the condensing lens 121, and in particular, it means that the center of the alignment direction (left-right direction of the electronic device 10, etc.) of the four photodiodes 122A, 122B, 122C, and 122D with respect to the optical axis of the condensing lens 121 is located to the left with respect to the direction of travel of the vehicle 40. In this example, the photodiodes 122A, 122B, and 122C are positioned so that their entire light-receiving surfaces overlap with the focusing lens 121 in the front-to-back direction of the electronic device 10. On the other hand, while a portion of the light-receiving surface of the photodiode 122D overlaps with the focusing lens 121 in the front-to-back direction of the electronic device 10, the remaining portion is offset from the focusing lens 121 and overlaps with the lens barrel 140. Considering that the side where the speed measuring device is located is often positioned to the left of the direction of travel of the vehicle 40, the arrangement shown in Figure 19 can improve the sensitivity to light reception from the left side of the direction of travel of the vehicle 40, which is the side where enforcement points (e.g., speed measuring devices) are often located, compared to the arrangement shown in Figure 17.

[0130] <6-5> It is preferable that the multiple photodiodes 122 are not all placed on the same straight line. This ensures that a highly sensitive angle can be secured in the vertical direction of the electronic device 10, and when the same number of photodiodes 122 are used, the dimensions of the lens barrel 140 and the condensing lens 121 can be reduced in the horizontal direction of the electronic device 10.

[0131] <6-6> It is preferable to position at least one side of the photodiode 122 at an angle from the left-right and up-down directions of the electronic device 10. As shown in Figure 21, for example, if the light-receiving surface of the photodiode 122 is rectangular or square, it is preferable to tilt each side of the photodiode 122 at 45 degrees with respect to the left-right and up-down directions of the electronic device 10. In this way, it is possible to secure angles that provide high light-receiving sensitivity of the laser light in both the left-right and up-down directions of the electronic device 10.

[0132] It is preferable to use an arrangement that combines two or more of the arrangements described in <6-7>, <6-4>, and <6-6>. For example, as shown in Figure 22, it is preferable to arrange the photodiode 122A at an angle to the horizontal and vertical directions, as described in <6-6>. Furthermore, it is preferable to arrange the photodiodes 122B, 122C, 122D, and 122E close to the four vertices of the photodiode 122A, with the photodiode 122A at the center. By tilting the central photodiode 122A in this way, the surrounding photodiodes 122B, 122C, 122D, and 122E can be arranged closer to the center, thereby reducing the width of the dip due to the angle of incidence of the laser light (i.e., the angle at which the light receiving sensitivity decreases). It is even better if the dip does not occur at all. The arrangement is not limited to that shown in Figure 22; the multiple photodiodes 122 may be arranged at the center of a circle and at positions on the arc of that circle, or at the center of an ellipse and at positions on the arc of that ellipse. In this way, it is desirable to arrange the multiple photodiodes 122 at the center of a predetermined figure and at the positions of its sides or vertices. The predetermined figure may be a regular n-gon (where n is a natural number of 3 or more). By doing so, the multiple photodiodes 122 can be arranged in close proximity to each other, and the effect of reducing the width of the dip caused by the angle of incidence of the laser light can be expected.

[0133] <6-8> It is preferable that a portion of the lens barrel 140 be notched (i.e., cut). Doing so reduces the range of angles in which the sensitivity to laser light from a specific direction decreases. The notch in the lens barrel 140 should be made to secure the optical path of the laser light. For example, in the configuration described in Figure 17, it is preferable that the portion of the lens barrel 140 closest to the upper part of the leftmost photodiode 122A (for example, the portion that overlaps with the photodiode 122A in the optical axis direction of the focusing lens 121) be notched. Doing so makes it easier to receive light from the left side (light from the right side in Figure 17) relative to the direction of travel of the vehicle 40 on the side where the speed measuring device is located.

[0134] <6-9> The lens barrel 140 is preferably shaped so that the photodiode 122 side (i.e., the front side of the electronic device 10) is wider radially than the condensing lens 121 side (i.e., the back side of the electronic device 10), and is particularly preferably shaped to gradually widen, for example, tapered. This makes it easier for the laser light that has passed through the lens barrel 140 to be received by the photodiode 122.

[0135] <6-10> It is advisable to combine multiple photodiodes 122 with different light-receiving surface areas (i.e., light-receiving areas). For example, it is advisable to combine a photodiode 122 with an outer diameter of 3 x 3 mm and a photodiode 122 with a smaller outer diameter and light-receiving area. Using a photodiode 122 with a larger outer diameter is thought to increase the light-receiving sensitivity because the internal elements are also likely to be larger. Therefore, it is also advisable to combine multiple photodiodes 122 with different outer diameters.

[0136] <6-11>It is preferable to use components that contain multiple light-receiving elements in a single package (hereinafter referred to as "package components"). An example of such a package component is a photodiode array. Package components include those for obtaining images for recording, and for example, a Si photodiode array (reference: https: / / www.hamamatsu.com / jp / ja / product / optical-sensors / photodiodes / si-photodiode-array / si-photodiode-array / index.html) can be used. A Si photodiode array is a sensor in which multiple Si photodiodes are arranged within a single package. An image sensor can be constructed by arranging multiple Si photodiodes. Furthermore, it is preferable to use multiple package components. It is also preferable to use multiple packages with different numbers of internal elements. It is also preferable to use a package that combines a photodiode array and a photodiode.

[0137] <6-12> The focusing lens 121 may be a lens other than an aspheric lens, but it is particularly preferable to use an aspheric lens. In this way, laser light from a wide range of directions in the left and right directions of the electronic device 10 can be received, and an angle with high sensitivity in the left and right directions can be secured. The focusing lens may be configured such that, for example, multiple lenses are combined to focus the light at each of the multiple light-receiving elements located at different positions from each other.

[0138] As a package component as described in <6-13> and <6-11>, it is preferable to use a package component in which light-receiving elements are arranged in two dimensions, and which is not for obtaining images for recording. As a package component not for obtaining images for recording, it is preferable to use an optical mouse sensor (for example, an infrared sensor). In this case, it is significantly cheaper than an image sensor, and therefore the cost of the light-receiving configuration of the electronic device 10 can be reduced. The number of pixels of the optical mouse sensor should be, for example, 16 × 16 pixels. The size of one pixel of the sensor should be, for example, about 60 × 60 μm, which is about an order of magnitude larger than a normal image sensor (reference for optical mouse sensors: http: / / www.infonet.co.jp / ueyama / ip / hardware / optical_mouse.html).

[0139] Furthermore, this sensor may also be used as an object detection sensor (e.g., a gesture sensor). A gesture sensor may be used as a package component not intended for obtaining video for recording. Such a gesture sensor may, for example, have a 30x30 image sensor, receive an image by irradiating it with 940nm light, and have the function of processing information related to gestures and proximity / approach by passing the received result through a DSP. Also, if a package component not intended for obtaining video for recording has a drive unit for a light-emitting element, it is advisable to stop the drive of that light-emitting element. In addition, it may also be equipped with a function to be used for its original purpose, not for obtaining video for recording, in addition to receiving laser light. For example, if it is a gesture sensor, it can also be used as a gesture sensor. It may be used as a gesture sensor when entering the settings screen of the electronic device 10, and as a laser light receiver when the vehicle 40 is in motion.

[0140] <6-14>As shown in Figure 23, it is preferable to provide a reflective member 150 between two adjacent photodiodes 122 that reflects the laser light towards one of the photodiodes 122. The reflective member 150 is, for example, a mirror. The reflective member 150 may have a mirror surface 150A that reflects light toward photodiode 122A and a mirror surface 150B that reflects light toward photodiode 122B. The reflective member 150 may be configured, for example, by setting up a mirror (preferably with the outer mirror surfaces 150A and 150B) in a "Λ" shape between two adjacent photodiodes 122. In this way, the amount of light received by photodiodes 122A and 122B increases, and the accuracy of determining the presence of an enforcement point can be improved.

[0141] <6-15> It is advisable to provide multiple (for example, three) focusing lenses and to position the light-receiving elements differently relative to the optical axis of each focusing lens, such as to the left, center, and right.

[0142] <6-16>Currently, the shape of the focusing lens is often made into a simple shape by cutting a sphere in both the vertical and horizontal directions to facilitate its manufacture. Alternatively, a focusing lens 121 with a shape that prevents light from passing through the dip portion (gap portion) described above may be used.

[0143] <6-17> If the signal from multiple (for example, four) photodiodes 122 is entered into the amplifier in parallel, the frequency response (f-response) may be poor and the configuration may be unusable. This is because if the photodetectors are small, the combined capacitance in parallel is relatively small, but if the photodetectors are large, the combined capacitance may become relatively large. Therefore, it is advisable to use photodetectors that are small to a certain extent or larger.

[0144] In relation to <6-18> and <6-16>, it is advisable to provide multiple sets of configurations in which multiple photodiodes 122 are connected in parallel and fed into the amplifier. The number of photodiodes 122 may be three or two.

[0145] <6-19> It is advisable to diffuse the laser beam by placing a diffuser (sheet, etc.) in part of the laser beam's optical path. In particular, it is advisable to diffuse only the peripheral portion of the focusing lens, while allowing the central portion to pass through undisturbed. Alternatively, the diffuser can be positioned so that half of the laser beam is diffused and the other half is not.

[0146] [7. Three-dimensional arrangement of photodiode 122] <7-1> In order to suppress the occurrence of dips caused by gaps G formed between photodiodes 122, as explained in Figure 17, it is preferable to arrange the photodiodes 122 in a three-dimensional configuration in multiple stages. For example, it is preferable to arrange the photodiodes 122 in a three-dimensional configuration in two stages instead of one. Specifically, it is preferable to arrange the photodiodes 122 at two or more different positions in the front-to-back direction of the electronic device 10 (in other words, in the optical axis direction of the focusing lens 121). In particular, when multiple photodiodes 122 have a first photodetector and a second photodetector arranged with a gap between them in the left-to-right direction of the electronic device 10, it is preferable to have a third photodetector on the front side of the electronic device 10 (for example, the rear side of the vehicle 40) when viewed from the position of the gap. In this way, by eliminating gaps between photodiodes 122 in the left-to-right direction of the electronic device 10, or by further reducing the gaps, it is possible to reduce dips caused by the angle of incidence of light.

[0147] Figure 24 shows an example of a three-dimensional arrangement of multiple photodiodes 122. Figure 24 is a side view of the first substrate 131 and the second substrate 132 of the light-receiving unit 12. Photodiodes 122A (an example of a first light-receiving element) and photodiode 122B (an example of a second light-receiving element) are arranged on the first substrate 131 with gaps between them. The first substrate 131 is preferably made of a material that transmits laser light from one side to the opposite side, and in particular, it is preferable to use a transparent substrate that can transmit laser light. Alternatively, the first substrate 131 may have holes formed at positions that serve as the optical path for the laser light so that photodiodes 122C, 122D, and 122E can receive the laser light. Photodiodes 122C, 122D, and 122E are arranged on the second substrate 132 with gaps between them. Photodiodes 122C, 122D, and 122E are preferably positioned so that they do not overlap at least partially with photodiodes 122A and 122B on the first substrate 131 in the front-to-back direction of the electronic device 10 (for example, in the direction of the optical axis of the focusing lens 121), and more preferably so that they do not overlap at all with photodiodes 122A and 122B on the first substrate 131. In this way, the laser light that passes through the gap between photodiodes 122A and 122B passes through the first substrate 131 and proceeds to the second substrate 132. This laser light is received by one of photodiodes 122C, 122D, and 122E (for example, photodiode 122D, an example of a third light-receiving element). By arranging the photodiodes 122 in a three-dimensional manner in multiple stages in this way, the dip caused by the angle of incidence of light can be reduced compared to when the photodiodes 122 are arranged in a single stage, and the light-receiving sensitivity of the laser light can be improved. The second substrate 132 may be made of the same material as the first substrate 131, but since it does not need to transmit laser light, it may be made of a material that does not transmit laser light.

[0148] <7-2> It is preferable that photodiodes 122A and 122B, and photodiodes 122C, 122D, and 122E be provided on different sides of the same substrate 133. Figure 25 shows an example of a three-dimensional arrangement of multiple photodiodes 122. In Figure 25, photodiodes 122A and 122B are arranged on the first surface 1311 of the substrate 133, and photodiodes 122C, 122D, and 122E are arranged on the second surface 1312, which is opposite to the first surface 1311. The first surface 1311 is the substrate surface on the side of the focusing lens 121 (the back side of the electronic device 10), and the second surface 1312 is the substrate surface on the opposite side of the focusing lens (the front side of the electronic device 10). The photodiodes 122C, 122D, and 122E are preferably provided on the substrate 133 such that the second surface 1312 side becomes the light-receiving surface. The substrate 133 is preferably made of a material that transmits laser light, and is particularly preferably a transparent substrate that can transmit laser light. The substrate 133 may have holes formed at positions that form the optical path of the laser light so that the photodiodes 122C, 122D, and 122E can receive the laser light. In this way, the area occupied by the substrate within the housing of the electronic device 10 can be reduced, and for example, the thickness of the electronic device 10 in the front-to-back direction can be reduced.

[0149] The configurations described in [6. Configurations with Multiple Photodiodes 122] and [7. Three-Dimensional Arrangement of Photodiodes 122] can be applied to the electronic devices described in Figures 5 to 14. Furthermore, the configurations described in [6. Configurations with Multiple Photodiodes 122] and [7. Three-Dimensional Arrangement of Photodiodes 122] may be combined as appropriate.

[0150] Furthermore, the scope of the present invention is not limited to the configurations explicitly described in the specification, but also includes combinations of various aspects of the present invention disclosed herein. While the configurations for which patent protection is sought are specified in the appended claims, we intend to include configurations disclosed herein that are not currently specified in the claims in the future.

[0151] The present invention is not limited to the configuration described in the embodiments above. The components of each embodiment and modification described above can be arbitrarily selected and combined. Furthermore, any component of each embodiment and modification can be arbitrarily combined with any component described in the means for solving the invention, or any component that embodies any component described in the means for solving the invention. The present application intends to obtain rights to these as well through amendments or divisional applications. Even if there is a description such as "in the case of..." or "when...", it is not meant to be a configuration that is limited to that case or time. Configurations that do not fall under these cases or times are also disclosed, and the present application intends to obtain rights to them. Also, even if there is a sequence of descriptions, it is not limited to that order. Configurations with some parts deleted or the order rearranged are also disclosed, and the present application intends to obtain rights to them.

[0152] Furthermore, by converting to a design registration application, we intend to acquire rights to the overall design or a partial design. The drawing depicts the entire device with solid lines, but it is a drawing that includes not only the overall design but also partial designs claimed for parts of the device. For example, it is a drawing that includes not only a partial design for a part of the device's components, but also a partial design for a part of the device regardless of its components. A part of the device may be a component of the device, or a part of that component. We intend to acquire rights not only to the overall design, but also to any part of the drawing that is represented by dashed lines within the solid lines. In addition, all modules, components, and parts inside the device's casing that are shown in the drawing are independently tradable, and we intend to acquire rights to them by converting to a design registration application. [Explanation of symbols]

[0153] 10:Electronic equipment 11: Control Unit 12: Light receiving part 13: Display section 14: Speaker 15: Microwave receiver 16: GPS receiver 17: Communications Department 18: Storage section 19:Operation section 20: Sensor unit 21: Mounting part 22: Power supply section 23: Light-emitting part 24: Cable terminal section 121: Focusing lens 122: Photodiode 123: Integrated Circuits 124: Amplifier Circuit 125: Emitter Follower Circuit 126: Comparator 127: Waveform shaping circuit

Claims

1. An electronic device installed in a vehicle and having a laser detection function that determines whether or not it has received a laser beam for speed measurement emitted by a speed measuring device, A focusing lens that concentrates the laser light, Multiple photodiodes that receive laser light, A control unit that outputs a signal corresponding to the reception of laser light based on the reception of laser light by the plurality of photodiodes, It has, The arrangement of the aforementioned multiple photodiodes is three-dimensional. The plurality of photodiodes include a first photodiode and a second photodiode arranged with a gap between them in the left-right direction of the electronic device. Viewed from the position of the aforementioned gap, the electronic device has a third photodiode on the front side, The first photodiode, the second photodiode, and the third photodiode are arranged at different positions in the optical axis direction of the focusing lens. The third photodiode receives the laser light that has passed through the gap. electronic equipment.

2. The first photodiode is provided on the first substrate, and the third photodiode is provided on the second substrate. The first substrate is a transparent substrate that can transmit laser light. The electronic device according to claim 1.

3. The first photodiode is provided on the first substrate, and the third photodiode is provided on the second substrate. The first substrate has holes formed at positions that serve as the optical path for the laser light, so that the third photodiode can receive the laser light. The electronic device according to claim 1.

4. The first photodiode, the second photodiode, and the third photodiode are provided on one side and the opposite side of the same substrate. The electronic device according to claim 1.

5. The integrated circuit has a signal input based on the reception of laser light by the plurality of photodiodes, The aforementioned integrated circuit is an integrated circuit that performs conversion to and amplification of a voltage signal. The electronic device according to any one of claims 1 to 4.

6. A signal is input to the integrated circuit from each of the plurality of photodiodes. The electronic device according to claim 5.

7. At least two of the aforementioned photodiodes are connected in parallel so that a signal is input to the integrated circuit. The electronic device according to claim 5.

8. The control unit will provide different notification depending on which photodiode the signal is input from. The electronic device according to claim 6.

9. The control unit notifies the direction of the incident or emitted laser light, or the direction of the enforcement point, according to the position of the photodiode that received the laser light. The electronic device according to any one of claims 1 to 8.

10. The control unit, if light is received by the left photodiode in the direction of vehicle travel but not by the right photodiode, provides notification that the laser light is being received from the left. The electronic device according to any one of claims 1 to 9.

11. The control unit provides higher-level notification as the number of photodiodes whose light reception intensity exceeds the threshold increases. The electronic device according to any one of claims 1 to 10.

12. The control unit performs predetermined statistical processing, such as integrating the light intensity input individually from the photodiode, and when the integrated value exceeds the reference value for each level, it provides notification for that level. The electronic device according to any one of claims 1 to 10.

13. The plurality of photodiodes are positioned to the left of the vehicle's direction of travel, with reference to the position of the focusing lens. The arrangement being shifted to the left means that, with respect to the optical axis of the focusing lens, the center of the arrangement direction of the plurality of photodiodes is located to the left of the vehicle's direction of travel. The electronic device according to any one of claims 1 to 12.

14. A lens barrel is positioned between the condensing lens and the plurality of photodiodes. A portion of the aforementioned lens barrel is cut out to secure the optical path for the laser beam. The electronic device according to any one of claims 1 to 13.

15. A lens barrel is positioned between the condensing lens and the plurality of photodiodes. The lens barrel has a shape in which the side with the multiple photodiodes is radially wider than the side with the condensing lens. The electronic device according to any one of claims 1 to 13.

16. The integrated circuit has a signal input based on the reception of laser light by the plurality of photodiodes, The aforementioned integrated circuit is an integrated circuit that performs conversion to and amplification of a voltage signal. The output side of the integrated circuit includes a waveform shaping circuit that widens the pulse width input in response to the reception of laser light into pulses of a predetermined width that can be processed by the control unit. The electronic device according to any one of claims 1 to 15.

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