Abstract: An optical beam scanning apparatus includes a beam-to-beam distance adjuster (300) for rotationally displacing a beam splitter (301). The beam-to-beam distance adjuster (300) comprises three arm members (312, 313, 314) which are linked to each other through notch portions (323, 324). A member (315) is linked to the arm member (313). The beam splitter (301) is secured on the member (315) from which a plate spring (316) extends. A projection member (317) is provided between a leading edge portion of the plate spring (316) and the arm member (314). A rotation angle of the beam splitter (301) can be changed by actuating three arm members (312, 313, 314) in link motion, whereby a beam-to-beam distance between two beams (B.sub.a, B.sub.b) can be also changed.

Abstract: N-(.alpha.,.alpha.-dialkylbenzyl)-phenylacetamide compounds represented by the following general formula: ##STR1## wherein each of X.sub.1 and X.sub.2 is a halogen atom, an alkyl group containing from 1 to 3 carbon atoms, an alkoxyl group containing from 1 to 3 carbon atoms or a hydrogen atom; R.sub.1 is an alkoxyl group containing from 1 to 3 carbon atoms or a hydrogen atom; R.sub.2 is an alkyl group containing from 1 to 3 carbon atoms, and alkoxyalkyl group containing from 2 to 6 carbon atoms, an allyl group or a hydrogen atom; each of R.sub.3 and R.sub.4 is an alkyl group containing from 1 to 4 carbon atoms; and each of m and n is an integer of 1-3. This invention also provides herbicidal compositions comprising at least one of said compounds and a carrier.

Abstract: N-(.alpha.,.alpha.-dimethylbenzyl)-phenylacetamide compounds represented by the following general formula: ##STR1## wherein X is a chlorine atom or a bromine atom. This invention also provides herbicidal compositions comprising at least one of said compounds and a herbicidal carrier.

Abstract: N-(.alpha.,.alpha.-dialkylbenzyl)-phenylacetamide compounds represented by the following general formula: ##STR1## wherein each of X.sub.1 and X.sub.2 is a halogen atom, an alkyl group containing from 1 to 3 carbon atoms, an alkoxyl group containing from 1 to 3 carbon atoms or a hydrogen atom; R.sub.1 is an alkoxyl group containing from 1 to 3 carbon atoms or a hydrogen atom; R.sub.2 is an alkyl group containing from 1 to 3 carbon atoms, and alkoxyalkyl group containing from 2 to 6 carbon atoms, an allyl group or a hydrogen atom; each of R.sub.3 and R.sub.4 is an alkyl group containing from 1 to 4 carbon atoms; and each of m and n is an integer of 1-3. This invention also provides herbicidal compositions comprising at least one of said compounds and a carrier.