Disclosed is a thermochromic writing tool which includes a writing element including a reservoir in which thermochromic ink is retained, and a writing point portion which is disposed on a front end portion of the reservoir and from which the thermochromic ink is dischargeable; a barrel which is made of a resin and in which the writing element is accommodated so as to be movable in a longitudinal direction; a protruding and retracting mechanism including a push element made of a resin and disposed on a rear end portion of the barrel so as to be tiltable in a radial direction relative to an axis of the barrel; and a rub portion disposed on a rear end portion of the push element 5.

A side-knock type mechanical pencil comprising a body with a side-mounted knock button coupled to the body of the mechanical pencil and adapted to slidingly engage with a lead tube with a frustoconical hub for translating the motion of the knock button actuation to linear extension of the lead.

An eraser assembly is provided that includes a housing, a tray, a coupler, and an eraser insert. The housing has a concave shape including an interior portion. The tray has a retaining portion disposed in the interior portion of the housing and a mounting portion disposed opposite the retaining portion. The coupler is configured to releasably hold the tray to the housing. The eraser insert is configured to be mounted to the mounting portion. An eraser insert is also provided that includes a first side and a second side, an eraser pad, and a coupler. The first side includes a mounting surface and an eraser pad is disposed on the second side. The coupler is disposed on or about the mounting surface and is configured to detachably connect the eraser insert to an eraser assembly at the mounting surface.

A side-knock type mechanical pencil comprising a body with a side-mounted knock button coupled to the body of the mechanical pencil and adapted to slidingly engage with a lead tube with a frustoconical hub for translating the motion of the knock button actuation to linear extension of the lead.

An eraser case includes a cylindrical container in which an eraser with a cylindrical hole is stored to be extendable and retractable. A twist-up base is slidable in an axial direction inside the cylindrical container, and an end part of an eraser stored in the cylindrical container is fixed to the twist-up base. A screw shaft body can be inserted into the cylindrical hole of the eraser and can push the twist-up base out by being inserted into and threadedly engaged with a screw hole piercing through the twist-up base to convert an axial rotational motion into an axial motion of the twist-up base. The twist-up base includes a convex locking portion protruding toward the eraser. The convex locking portion fixes the eraser to the twist-up base by being locked to a concave locking portion provided on an inner wall surface of the cylindrical hole of the eraser.

A whiteboard cleaning system includes a user movement sensor that determines when a user is inactive; a whiteboard capture camera that makes an image of the whiteboard when the user movement sensor detects that the user is inactive; a classification module that classifies the image with a pre-trained image data set using an augmentation technique to enhance the size of the image data set and determines whether the whiteboard needs to be cleaned based on the classification, through transfer learning, using the image data set; and a wiper that cleans the whiteboard when the classification module determines that the whiteboard needs to be cleaned.

A soft-member attachment structure includes an attachment hole provided through a rear end portion of a barrel. The barrel configures a thermochromic writing instrument, along a longitudinal central axis and having an inner circumferential surface between two openings located at an upper end and a lower end; an attachment portion located under a large diameter portion of a soft member used for a thermochromic change and having a diameter being smaller than a diameter of the large diameter portion and allowing insertion into the attachment hole; a straight internal hole provided along a longitudinal central axis of the soft member and opening at least at a lower end of the soft member; and a rod-like inner core having an outer diameter allowing insertion into the internal hole, a length to be placed within the internal hole, and an outer circumferential surface contacting an inner circumferential surface of the internal hole.

The present disclosure relates to a friction body for discoloring handwriting written with a thermochromic ink with frictional heat, wherein the friction body comprises a surface portion configured to generate frictional heat when manually rubbed on a porous substrate and wherein the surface portion has a thermal effusivity of less than about 300 J K.sup.1 m.sup.2 s.sup.1/2.

The present disclosure relates to a friction body for discoloring handwriting written with a thermochromic ink with frictional heat, wherein the friction body comprises a surface portion configured to generate frictional heat when manually rubbed on a porous substrate and wherein 5 the friction body comprises a first thermal conductivity in a first direction substantially parallel to the surface plane which is greater than a second thermal conductivity in a second direction which is substantially perpendicular to the surface plane.

A manual device including a first portion and a second portion. The second portion being at least partially fitted into the first portion and being moveable in translation relative to the first portion. The first portion having a first distal end while the second portion has a second distal end opposite the first distal end. The second portion also includes a locking device designed to prevent the first portion from moving in translation relative to the second portion only when, considered in the direction of gravity. The first distal end is arranged above the second distal end, and the locking device includes a chamber and a ball or equivalent accommodated in the chamber. The chamber is provided only in the second portion.