초록 ▼

The present invention is intended to provide an ultrasonic range finder to measure a distance quickly and precisely under different environments. The ultrasonic range finder comprises a casing, an ultrasonic transmitting/receiving unit, a signal processing circuit connected electrically with the ult

The present invention is intended to provide an ultrasonic range finder to measure a distance quickly and precisely under different environments. The ultrasonic range finder comprises a casing, an ultrasonic transmitting/receiving unit, a signal processing circuit connected electrically with the ultrasonic transmitting/receiving unit in the casing, a group of operation buttons on the casing and a display unit. The ultrasonic range finder further comprises a calibration rod to provide a constant reference distance. The calibration rod includes a first end connected to the casing. The calibration rod further includes a second end extendable outwardly relative to the casing and a body between the first and the second ends. By measuring a propagation time of an ultrasonic signal within the constant reference distance an ultrasonic propagation speed can be determined quickly and precisely and thereby perform the distance measurement quickly and precisely without being affected by changes in the environment.

대표청구항 ▼

What is claimed is: 1. An ultrasonic range finder comprising: a housing; an ultrasonic transmitting and receiving unit positioned within the housing; a signal processing circuit, which is mounted in the housing and is connected with the ultrasonic transmitting and receiving unit; a group of operati

What is claimed is: 1. An ultrasonic range finder comprising: a housing; an ultrasonic transmitting and receiving unit positioned within the housing; a signal processing circuit, which is mounted in the housing and is connected with the ultrasonic transmitting and receiving unit; a group of operation buttons on the housing which includes at least a calibration button; a display unit, for displaying the result of a distance measurement; and, a calibration member which has a first end connected to the housing, wherein the calibration member is comprised of a plurality of telescoping members, which when fully extended, extend outwardly from the housing. 2. An ultrasonic range finder comprising: a housing having an ultrasonic transmitting and receiving unit electrically connected to a signal processing unit, the ultrasonic transmitting and receiving unit capable of transmitting and receiving an ultrasonic beam; a calibration member having: a first end mounted in the housing; a second end, wherein the second end is extendable in a direction that an ultrasonic transmitting and receiving unit transmits an ultrasonic relative to the housing; and, a body between the first end and the second end. 3. An ultrasonic range finder according to claim 2, wherein the first end of the calibration member comprises an opening that is configured to fit over a step-shaped protrusion with a bolt hole in the housing. 4. An ultrasonic range finder according to claim 3, wherein an upper portion of the step-shaped protrusion has a smaller radius and passes partially through the opening in the calibration member and a bolt mates with the bolt hole of the step-shaped protrusion causing the first end of the calibration member to firmly press onto the step-shaped protrusion. 5. An ultrasonic range finder according to claim 2, wherein the body is formed by connecting three members one by one. 6. An ultrasonic range finder according to claim 5, wherein a second tube is connected with a first tube and an end of the second tube is exposed out of the first tube which is connected fixedly with the first end of the calibration member. 7. An ultrasonic range finder according to claim 6, wherein a third tube is connected with the second tube and an end of the third tube is exposed out of the second tube which is connected fixedly with the second end of the calibration member. 8. An ultrasonic range finder according to claim 2, wherein one of the calibration member and the housing has at least one stop member to limit the body of the calibration member within a fixed length. 9. An ultrasonic range finder rod according to claim 2, wherein the body of the calibration member is extendable. 10. An ultrasonic range finder according to claim 2, further comprising a laser emitting unit, which is mounted within the housing and can produce a visible mark on a target surface at a distance to be measured. 11. An ultrasonic range finder comprising: a housing; an ultrasonic transmitting and receiving unit mounted within the housing; a control circuit connected to the ultrasonic transmitting and receiving unit; an extendable calibration member; an object target comprising a housing, an ultrasonic transmitting and receiving unit mounted in the object target housing and electrically connected to an object target control circuit, and an indicator electrically connected to the object target control circuit. 12. An ultrasonic range finder according to claim 11, wherein the object target housing has a positioning groove matching one end of the extendable calibration member. 13. An ultrasonic range finder according to claim 11, wherein the indicator is an LED indicating light. 14. An ultrasonic range finder according to claim 11, wherein the ultrasonic range finder has a reflected-type range finding mode that operates without the object target and a feedback-type range finding mode that operates with the object target. 15. An ultrasonic range finder according to claim 14, further comprising an operation button for selectively switching between the reflected-type range finding mode and the feedback-type range finding mode.