# US 2024/0201348 A1 · Signal processing device, ultrasonic sensor and vehicle

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- Number: US 2024/0201348 A1
- Document ID: US20240201348A1
- Status: Published application
- Kind: A1
- Application number: 18/537,109
- Filed: 2023-12-12
- Published: 2024-06-20
- Earliest claimed: 2022-12-14
- Assignees: Rohm Co., Ltd.
- Applicants: Rohm Co., Ltd.
- Inventors: Koji Saito
- Web page: https://patentgrep.com/patent/US20240201348A1

## CPC

- G01S 7/52004: {Means for monitoring or calibrating (short-range imaging G01S7/5205)}
- B06B 1/0644: {using a single piezoelectric element (B06B1/0688 takes precedence)}
- G01S 7/527: Extracting wanted echo signals {(Doppler systems G01S15/50)}
- G01S 7/539: using analysis of echo signal for target characterisation; Target signature; Target cross-section
- G01S 15/931: of land vehicles
- B06B 2201/55: Piezoelectric transducer
- G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- B06B: METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, {e.g.} FOR PERFORMING MECHANICAL WORK IN GENERAL (for particular applications, see the relevant subclasses, e.g. B07B1/40, B23Q17/12, B24B31/06; measurement of mechanical vibrations G01H; in direction finding, locating, distance or velocity measuring G01S; {generating seismic energy G01V1/02}; control of mechanical vibrations in general G05D; sound-producing devices, e.g. bells, sirens, whistles G10K, {e.g. methods or devices for transmitting, conducting, or directing sound in general G10K11/00}; generation of electrical oscillations H03B; electromechanical resonators in general H03H; electromechanical transducers {for communication techniques, e.g. microphones, speakers} H04R)

## Abstract

The present disclosure provides a signal processing device. The signal processing device includes a receiving circuit, an envelope detection circuit, a differential amplifier circuit and a selection circuit. The receiving circuit is configured to generate a reflected wave signal based on a reflected wave from an object. The envelope detection circuit is configured to generate an envelope detection signal of the reflected wave signal. The differential amplifier circuit is configured to generate a differentially amplified signal of the envelope detection signal. The selection circuit is configured to select one of a first signal and a second signal. The first signal is the envelope detection signal or a delayed signal of the envelope detection signal. The second signal is the differentially amplified signal or a signal obtained using a difference between the envelope detection signal and the differentially amplified signal.

## Claims

### Claim 1

A signal processing device, comprising:
a receiving circuit, configured to generate a reflected wave signal based on a reflected wave from an object;
an envelope detection circuit, configured to generate an envelope detection signal of the reflected wave signal;
a differential amplifier circuit, configured to generate a differentially amplified signal of the envelope detection signal; and
a selection circuit, configured to select one of a first signal and a second signal, wherein
the first signal is the envelope detection signal or a delayed signal of the envelope detection signal, and
the second signal is the differentially amplified signal or a signal obtained from a difference between the envelope detection signal and the differentially amplified signal.

### Claim 2 (depends on 1)

The signal processing device of claim 1, wherein the differential amplifier circuit is configured to clamp the differentially amplified signal.

### Claim 3 (depends on 1)

The signal processing device of claim 1, wherein the envelope detection signal is
a signal obtained by detecting an upper envelope of the reflected wave signal, or
a signal obtained by subtracting a signal obtained by detecting a lower envelope of the reflected wave signal from the signal obtained by detecting the upper envelope of the reflected wave signal.

### Claim 4 (depends on 3)

The signal processing device of claim 3, wherein the differential amplifier circuit is configured to clamp the differentially amplified signal, such that the differentially amplified signal does not lower than a predetermined value.

### Claim 5 (depends on 1)

The signal processing device of claim 1, wherein the envelope detection signal is
a signal obtained by detecting an lower envelope of the reflected wave signal, or
a signal obtained by subtracting a signal obtained by detecting an upper envelope of the reflected wave signal from the signal obtained by detecting the lower envelope of the reflected wave signal, and
the selection circuit is configured to select a greater one of the first signal and the second signal.

### Claim 6 (depends on 5)

The signal processing device of claim 5, wherein the differential amplifier circuit is configured to clamp the differentially amplified signal, such that the differentially amplified signal does not exceed a predetermined value.

### Claim 7 (depends on 1)

An ultrasonic sensor, comprising:
the signal processing device of claim 1; and
a piezoelectric element configured to receive the reflected wave.

### Claim 8 (depends on 7)

A vehicle comprising the ultrasonic sensor of claim 7.