Print head
AssigneeCitizen Watch Co., Ltd.
InventorsTakuro Kohyama, Kazumi Hasegawa, Yasuo Iwata
Life of this patent
Estimating the term…
Abstract
A needle guide (5) is composed of a first guide wall (5a) and a second guide wall (5b) arranged at a distance x from each other. Each of these guide walls is formed with through holes through which needles penetrate and which extends parallel to the longitudinal direction of a needle bunch, the through holes of the first guide wall and the second guide wall for one needle is shifted from each other in the convergence direction of the needles with a shift amount δn determined by the distance x and a convergence angle θn of the needle.
Claims9
A print head for selectively projecting a plurality of needles to perform printing, characterized in that
- the respective proximal ends of the plurality of needles on the drive side are arranged on the circumference of a circle, so that the needles constitute a cone-shaped needle bunch converged in a manner such that tip ends for forming dots are arranged straight in a dotting position,
- the needle bunch is kept in the cone-shaped configuration by a needle guide,
- the needle guide is composed of a first guide wall and a second guide wall arranged in the longitudinal direction of the needle bunch, the first guide wall being placed on the tip end side of the needle bunch and the second guide wall being spaced from the first guide wall by the distance (x), and
- the first guide wall and the second guide wall are walls perpendicular to the longitudinal direction of the needle bunch and are formed into an integral block, the guide walls having through holes penetrated parallel to the longitudinal direction of the needle bunch by the needles, the through holes of the first guide wall and the second guide wall for one needle (No. n) being shifted from each other in the convergence direction of the needles by a shift amount (δn) determined by the distance (x) and a convergence angle (θn) of the needle.
A print head for selectively projecting a plurality of needles to perform printing, comprising:
- a needle guide of resin located on the respective tip ends of the needles and configured to guide the needles, wherein
- the needle guide has a first guide wall located on the tip end side of the needles and a second guide wall integral with the first guide wall and located at a given distance from the first guide wall,
- the first guide wall and the second guide wall are formed with first through holes and second through holes penetrated individually by the needles, the center of each of the first holes is shifted by a distance from the center of the corresponding one of the second through hole,
- the needle guide is hollow and having a rectangular cross section, and
- at least two of the first through holes in the first wall communicating with each other and all the second through holes in the second wall are elliptic.
A print head comprising:
- a plurality of straight needles having proximal ends located on the circumference of a circle or an ellipse and tip end portions converged by being passed through needle holes of a guide member;
- and
- a drive mechanism for driving the proximal end of a selected one of the plurality of needles in the axial direction of the needle, wherein
- the guide member is composed of a front guide wall and a rear guide wall spaced from each other by a fixed distance and having surfaces parallel to a plane containing the circumference of the circle or the ellipse,
- the front guide wall and the rear guide wall are formed with needle inserting holes having inside faces perpendicular to the surfaces of the guide walls, respectively, in the regions where the respective axes of the individual needles intersect, and
- the needle inserting holes have a cross-sectional shape and a size such as to be able to guide the needles driven by the drive mechanism without changing the postures of the needles.
Dependencies are inferred from the claim text.