Book holders usually embody a platform having two sets of legs which are hinged near the ends to swing downwardly and straddle a reclining person's stomach with a hinged portion at the front which may be raised upwardly and on which the book is supported. This type of structure was found to be somewhat awkward, quite expensive and is limited to a use as the legs required a support when disposed in substantially vertical position.
USPTO Backgrounds
USPTO Backgrounds