Abstract: A light source comprises a light combining device for guiding incident light from a first light emitting source (310) and incident light from a second light emitting source (340) with different incident directions to combine two paths of incident light into one path of emission light emitted from a first optical path. The light combining device comprises a guide part (330), for guiding light from the second light emitting source (340) to converge into the first optical path, and hindering a part of light from the first light emitting source (310) from entering the first optical path, the luminous flux of the hindered part of the light being less than the luminous flux of light from the first light emitting source (310) entering the first optical path. This light source can effectively reduce the cost and achieve a better heat dissipation effect and is especially suitable for a projection device.

Abstract: A thread holding mechanism of a sewing machine which holds a thread supplied from a thread supply source includes a thread gripper unit that grips one end of a supplied thread, and a thread presser unit structured in a unified manner with the thread gripper unit and provided between the thread gripper unit and the thread supply source. Provided at the thread-supply-source side is a thread guide that guides another end of the thread, and when the thread gripper unit descends below the thread guide, the thread presser unit abuts the thread.

Abstract: An electronic thread tension control device whereby electrical signals indicating the fabric thickness, the amount of fabric being fed, the needle's amplitude and the size of the thread to be used are transmitted to the control circuitry thereby producing the appropriate output signal that will adjust the tensioning means accordingly.

Abstract: A cylindrical body houses a shaft and is movable with respect thereto. The body carries a first jaw element at one end thereof. A second jaw element is joined to fixed support means connected to the shaft within the body. A compression spring surrounds a portion of the shaft projecting from the opposite end of the body, and the spring urges the jaw elements into clamping relationship. The clamp is opened by moving the body in opposition to the force of the spring.