Casing of electronic calculators

Claim 2

An electronic calculator comprising: a. an upper cover; b. wiring patterns directly formed on an inner surface of the upper cover; c. a display unit mounted on the inner surface of the upper cover and electrically connected to the wiring patterns; d. a computation circuit unit mounted on the inner surface of the upper cover and electrically connected to the wiring patterns; e. key contact patterns formed directly on the inner surface of the upper cover and electrically connected to the wiring patterns; f. key switches electrically associated with the key contact patterns; and g. a bottom and side cover fixed to the upper cover.

Claim 3

The electronic calculator of claim 1, wherein the upper cover is made of glass and the display unit is made of a liquid crystal display unit of which segment electrodes are formed directly on the inner surface of the glass cover.

Claim 4

An electronic calculator comprising an upper cover and a bottom cover, key contact patterns and wiring patterns formed directly on the inner surface of the bottom cover, a computation circuit unit and a display unit mounted on the inner surface of the bottom cover, the computation circuit unit and the display unit being electrically connected to said key contact patterns by said wiring patterns, and a keyboard unit containing a plurality of key contacts mounted on the bottom cover and extending over the key contact patterns between the upper cover and the bottom cover, said key contacts being adapted to contact corresponding key contact patterns when the key contacts are depressed for information entry, said keyboard unit further comprising a plurality of apertures for receiving said key contacts and couplers extending from the bottom surface of the keyboard unit, said bottom cover being provided with through holes which correspond in position to that of said couplers, said couplers extending through said through holes for coupling the keyboard unit with the bottom cover.

Claim 5

An electronic calculator comprising an upper cover and a bottom cover, key contact patterns and wiring patterns formed directly on the inner surface of the bottom cover, a computation circuit unit and a display unit mounted on the inner surface of the bottom cover, the computation circuit unit and the display unit being electrically connected to said key contact patterns by said wiring patterns, and a keyboard unit containing a plurality of key contacts mounted on the bottom cover and extending over the key contact patterns between the upper cover and the bottom cover, said key contacts being adapted to contact corresponding key contact patterns when the key contacts are depressed for information entry, said keyboard unit further comprising a plurality of apertures for receiving said key contacts and couplers extending from the bottom surface of the keyboard unit, said bottom cover being provided with through holes which correspond in position to that of said couplers, said couplers extending through said through holes for coupling the keyboard unit with the bottom cover.

Claim 6

The electronic calculator of claim 3, wherein the circuit element is an LSI circuit element and the display unit is an LED display unit.

Claim 7

The electronic calculator of claim 3, wherein the bottom cover is made of an electrically insulating rigid plate which functions as a substrate.

Claim 8

The electronic calculator of claim 5, wherein the rigid plate is selected from the group consisting of a phenol resin plate and an epoxy resin plate.

Claim 9

The electronic calculator of claim 3, wherein the key contact patterns and wiring pattern are made of a conductive material.

Claim 10

The electronic calculator of claim 3, wherein the upper cover is provided with a plurality of holes and keytops which are attached to the key contacts and adapted to extend through said holes.

Claim 11

The electronic calculator of claim 3, wherein the upper cover is provided with a display window and a rotatable sidewall, said sidewall and bottom cover defining a chamber for housing a power cell.

Claim 12

The electronic calculator of claim 3, wherein a liquid crystal display unit for displaying numeral information is disposed between said upper and bottom covers, and below said display window.

Claim 13

The electronic calculator of claim 10, wherein the liquid crystal display unit comprises a reflection electrode provided on the inner surface of the bottom cover, a glass substrate disposed above and spaced apart from the reflection electrode, said glass substrate being provided on its inner surface with a plurality of transparent segment electrodes and a liquid crystal composition disposed between the glass substrate and the bottom cover.

Claim 14

The electronic calculator of claim 3 wherein the couplers are an integral portion of the keyboard unit and when coupled with the bottom cover becomes integral therewith.

Claim 15

An electronic calculator comprising an upper cover and a bottom cover, key contact patterns and wiring patterns formed directly on the inner surface of the upper cover, a plurality of key switches slidably extending through said upper cover from the outside to the inside thereof, said key switches provided with key contact means, said key contact means being biased for contact with said key contact patterns, wiring patterns formed directly on the bottom cover, electronic elements mounted on the bottom cover and electrically connected to said wiring patterns and means for providing an electrical connection between the wiring patterns on the upper cover and the wiring patterns on the bottom cover.

Claim 16

An electronic calculator comprising an upper cover and a bottom cover, key contact patterns and wiring patterns formed directly on the inner surface of the upper cover, a plurality of key switches slidably extending through said upper cover from the outside to the inside thereof, said key switches provided with key contact means, said key contact means being biased for contact with said key contact patterns, wiring patterns formed directly on the bottom cover, electronic elements mounted on the bottom cover and electrically connected to said wiring patterns and means for providing an electrical connection between the wiring patterns on the upper cover and the wiring patterns on the bottom cover.

Claim 17

The electronic calculator of claim 13, wherein the key switches are biased for contact with said key contact patterns by spring means.

Claim 18

The electronic calculator of claim 13, wherein the key switches are biased for contact with said key contact patterns by an elastic member.

Claim 19

An electronic calculator comprising an upper cover and a bottom cover, key contact patterns and wiring patterns formed directly on the inner surface of the bottom cover, a computation circuit unit and a display unit mounted on the inner surface of the bottom cover, the computation circuit unit and the display unit being electrically connected to said key contact patterns by said wiring patterns, a plurality of key switches mounted on the upper cover and slidably extending through the upper cover from the outside to the inside thereof and provided with key contact means for contacting corresponding key contact patterns when the key switches are depressed for information entry and bias means for causing said key contact means being brought into contact with said key contact patterns by the manual depression of the key switches.

Claim 20

An electronic calculator comprising an upper cover and a bottom cover, key contact patterns and wiring patterns formed directly on the inner surface of the bottom cover, a computation circuit unit and a display unit mounted on the inner surface of the bottom cover, the computation circuit unit and the display unit being electrically connected to said key contact patterns by said wiring patterns, a plurality of key switches mounted on the upper cover and slidably extending through the upper cover from the outside to the inside thereof and provided with key contact means for contacting corresponding key contact patterns when the key switches are depressed for information entry and bias means for causing said key contact means being brought into contact with said key contact patterns by the manual depression of the key switches.

Claim 21

The electronic calculator of claim 16, wherein the bias means is a spring means.