Abstract: An ultrasonic transducer includes a piezoceramic element with a first surface and a second surface opposite to each other through the piezoceramic element and a lateral surface connecting the first surface and the second surface, an acoustic matching layer with a third surface and a fourth surface opposite to each other through the acoustic matching layer and the third surface connecting with the second surface of the piezoceramic element, a first damping element with a fifth surface and a sixth surface opposite to each other through the first damping element and the sixth surface connecting with the first surface of the piezoceramic element, and a second damping element encapsulating the first damping element and the lateral surface of the piezoceramic element.

Abstract: A displaying device adapted to a screen is provided. The displaying device includes a transparent pyramid, a movable support, and an image conversion unit. The movable support is connected to the transparent pyramid to move the transparent pyramid between a first location and a second location which is different from the first location. The first location is the position on the screen. The image conversion unit is configured to receive image data. When the transparent pyramid moves to the first location, the image conversion unit converts the image data to a holographic image displayed on the screen, and the transparent pyramid generates a 3D hologram based on the holographic image.

Abstract: A shoemaking machine includes a sewing device having a cantilever unit, a work platform and a clamping frame unit. The cantilever unit has a sewing needle extending toward the clamping frame unit. A driving device is disposed on the cantilever unit, and includes a movable seat that is movable toward and away from the clamping frame unit. An ultrasonic positioning device is connected to the cantilever unit, and includes a welding head facing the clamping frame unit. The clamping device is connected to the movable seat and has a clamping space. The ultrasonic positioning device is inserted into the clamping space and is clamped by the clamping device.

Abstract: A displaying device adapted to a screen is provided. The displaying device includes a transparent pyramid, a movable support, and an image conversion unit. The movable support is connected to the transparent pyramid to move the transparent pyramid between a first location and a second location which is different from the first location. The first location is the position on the screen. The image conversion unit is configured to receive image data. When the transparent pyramid moves to the first location, the image conversion unit converts the image data to a holographic image displayed on the screen, and the transparent pyramid generates a 3D hologram based on the holographic image.

Abstract: A shoemaking machine includes a sewing device having a cantilever unit, a work platform and a clamping frame unit. The cantilever unit has a sewing needle extending toward the clamping frame unit. A driving device is disposed on the cantilever unit, and includes a movable seat that is movable toward and away from the clamping frame unit. An ultrasonic positioning device is connected to the cantilever unit, and includes a welding head facing the clamping frame unit. The clamping device is connected to the movable seat and has a clamping space. The ultrasonic positioning device is inserted into the clamping space and is clamped by the clamping device.