# US 5,689,290 A · Liquid level detecting mechanism and ink jet recording apparatus having the mechanism > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,689,290 A - Document ID: US5689290A - Status: Granted - Kind: A - Application number: 08/647,285 - Filed: 1996-05-09 - Granted: 1997-11-18 - Earliest claimed: 1992-06-11 - Assignees: Canon Kabushiki Kaisha - Inventors: Atsushi Saito; Akio Okubo; Yasuhiko Ikeda - Web page: https://patentgrep.com/patent/US5689290A ## CPC - B41J 2/17513: {Inner structure} - B41J 2/17566: {Ink level or ink residue control} - G01F 23/2921: {for discrete levels} - B41J 2002/17573: {using optical means for ink level indication} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME ## Abstract A liquid level detecting mechanism for detecting the liquid level in a vessel for storage of liquid, includes a light emitting unit and a light receiving unit disposed opposite to the vessel for storage of liquid or a chamber communicating with the vessel. The light receiving unit detects the liquid level in the vessel in accordance with the quantity of received light from the light emitted from the light emitting unit, and members in contact with liquid which are arranged between the light emitting unit and the light receiving unit, the members being formed of a material having high wettability relative to the liquid. ## Claims ### Claim 1 A liquid remaining detecting mechanism for detecting a remaining amount of liquid in a container for storing the liquid, comprising: a light emitting section and a light receiving section provided within the container or a member communicating with the container, said light receiving section detecting the presence or absence of a predetermined liquid in the container based on an amount of light received from said light emitting section; and light permeable liquid guiding means, having a directional component, for guiding the liquid in a direction of liquid level change in the container as the liquid in the container is reduced, said liquid guiding means having high wettability relative to the liquid in a light path from said light emitting section to said light receiving section. ### Claim 2 (depends on 1) The liquid level detecting mechanism according to claim 1, wherein said liquid guiding means is formed of fibrous material. ### Claim 3 (depends on 1) The liquid level detecting mechanism according to claim 1, wherein said liquid guiding means is formed of porous material. ### Claim 4 (depends on 1) The liquid level detecting mechanism according to claim 1, wherein said liquid guiding means is formed of a member having minute grooves on its surface. ### Claim 5 (depends on 1) The liquid remaining detecting mechanism according to claim 1, wherein the presence of the predetermined amount of liquid is detected when a droplet of the liquid is present on said liquid guiding means and the absence of the predetermined amount of liquid is detected when a droplet of the liquid is not present on said liquid guiding means. ### Claim 6 An ink jet recording apparatus for recording by discharging ink comprising: ink jet recording means, including discharging orifices for discharging ink; an ink storage unit, in fluid communication with said ink jet recording means, for storing the ink and supplying the ink to said ink jet recording means; a light emitting section and a light receiving section provided within said ink storage unit or a member communicating with said ink storage unit, said light receiving section detecting the presence or absence of a predetermined liquid in said ink storage unit based on an amount of light received from said light emitting section; and light permeable liquid guiding means, having a directional component, for guiding the liquid in a direction of liquid level change in said ink storage unit as the liquid in said ink storage unit is reduced, said liquid guiding means having high wettability relative to the liquid in a light path from said light emitting section to said light receiving section. ### Claim 7 (depends on 6) The ink jet recording apparatus according to claim 6, wherein said liquid guiding means is formed of fibrous material. ### Claim 8 (depends on 6) The ink jet recording apparatus according to claim 6, wherein said liquid guiding means is formed of porous material. ### Claim 9 (depends on 6) The ink jet recording apparatus according to claim 6, wherein said liquid guiding means is formed of a member having minute grooves on its surface. ### Claim 10 (depends on 6) The ink jet recording apparatus according to claim 6, wherein said ink jet recording means comprises electricity-heat converters for generating heat energy for use to discharge the ink. ### Claim 11 (depends on 10) The ink jet recording apparatus according to claim 10, wherein said ink jet recording means discharges the ink through the discharge orifices by the use of film boiling occurring in the ink due to heat energy generated by the electricity-heat converters. ### Claim 12 (depends on 6) The ink jet recording apparatus according to claim 6, wherein the presence of the predetermined amount of liquid is detected when a droplet of the liquid is present on said liquid guiding means and the absence of the predetermined amount of liquid is detected when a droplet of the liquid is not present on said liquid guiding means. ### Claim 13 (depends on 6) The ink jet recording apparatus according to claim 6, wherein said liquid guiding means comprises first and second members disposed on an interior surface of said ink storage unit. ### Claim 14 (depends on 6) The ink jet recording apparatus according to claim 6, wherein said liquid guiding means is formed by an interior surface of said ink storage unit. ### Claim 15 An ink jet recording apparatus for recording ink onto a recording medium, comprising: ink jet recording means, including discharge orifices, for recording ink on the recording medium; a mounting unit for mounting said ink jet recording means thereon; an ink storage unit, in fluid communication with said ink jet recording means, for storing the ink to be supplied to said ink jet recording means; an ink supply mechanism, cooperating with said ink storage unit, for supplying the ink within said ink storage unit to said ink jet recording means; a light emitting section and a light receiving section provided within said ink storage unit or a member communicating with said ink storage unit, said light receiving section detecting the presence or absence of a predetermined liquid in said ink storage unit based on an amount of light received from said light emitting section; and light permeable liquid guiding means, having a directional component, for guiding the liquid in a direction of liquid level change in said ink storage unit as the liquid in said ink storage unit is reduced, said liquid guiding means having high wettability relative to the liquid in a light path from said light emitting section to said light receiving section. ### Claim 16 (depends on 15) The ink jet recording apparatus according to claim 15, wherein said liquid guiding member is formed of fibrous material. ### Claim 17 (depends on 15) The ink jet recording apparatus according to claim 15, wherein said liquid guiding member is formed of porous material. ### Claim 18 (depends on 15) The ink jet recording apparatus according to claim 15, wherein said liquid guiding member is formed of a member having minute grooves on its surface. ### Claim 19 (depends on 15) The ink jet recording apparatus according to claim 15, wherein said ink jet recording means comprises electricity-heat converters for generating heat energy for use to discharge the ink. ### Claim 20 (depends on 19) The ink jet recording apparatus according to claim 19, wherein said ink jet recording means discharges the ink through the discharge orifices by the use of film boiling occurring in the ink due to heat energy generated by said electricity-heat converters. ### Claim 21 (depends on 15) The ink jet recording apparatus according to claim 15, wherein the presence of the predetermined amount of liquid is detected when a droplet of the liquid is present on said liquid guiding member and the absence of the predetermined amount of liquid is detected when a droplet of the liquid is not present on said liquid guiding member. ### Claim 22 (depends on 15) The ink jet recording apparatus according to claim 15, wherein said liquid guiding member comprises first and second members disposed on an interior surface of said ink storage unit. ### Claim 23 (depends on 15) An ink jet recording apparatus according to claim 15, wherein said liquid guiding member is formed by an interior surface of said ink storage unit. ### Claim 24 A liquid level detecting mechanism for detecting the liquid level in a container for storing the liquid, the mechanism comprising: a light emitting section and a light receiving section provided within the container or a member communicating with the container, said light receiving section detecting the level of liquid in the container based on an amount of light received from said light emitting section; and a liquid guiding member, having a directional component, for guiding the liquid in a direction of liquid level change in the container as the liquid in the container is reduced, said liquid guiding member having high wettability relative to the liquid in a light path from said light emitting section to said light receiving section. ### Claim 25 (depends on 24) The liquid level detecting mechanism according to claim 24, wherein said liquid guiding member is formed of fibrous material. ### Claim 26 (depends on 24) The liquid level detecting mechanism according to claim 24, wherein said liquid guiding member is formed of porous material. ### Claim 27 (depends on 24) The liquid level detecting mechanism according to claim 24, wherein said liquid guiding member is formed of a member having minute grooves on its surface. ### Claim 28 (depends on 24) The liquid remaining detecting mechanism according to claim 24, wherein the presence of liquid is detected when a droplet of the liquid is present on said liquid guiding member and the absence of liquid is detected when a droplet of the liquid is not present on said liquid guiding member. ### Claim 29 A liquid level detecting device for detecting the liquid level in a container for storing the liquid, the device comprising: a light emitting section and a light receiving section provided within the container or a member communicating with the container, said light receiving section detecting the level of liquid in the container based on an amount of light received from said light emitting section; and a transparent window disposed in an optical path in said container between said light emitting section and said light receiving section or in a member communicating with said container between said light emitting section and said light receiving section, said transparent window having a portion for preventing a liquid droplet from attaching thereto in said optical path. ### Claim 30 (depends on 29) The liquid level detecting device according to claim 29, wherein said transparent window is formed of fibrous material. ### Claim 31 (depends on 29) The liquid level detecting device according to claim 29, wherein said transparent window is formed of porous material. ### Claim 32 (depends on 29) The liquid level detecting device according to claim 29, wherein said transparent window is formed of a member having minute grooves on a surface thereof. ### Claim 33 (depends on 29) The liquid level detecting device according to claim 29, wherein the presence of liquid is detected when the liquid droplet is present on said transparent window and the absence of liquid is detected when the liquid droplet is not present on said transparent window. ### Claim 34 An ink jet recording apparatus for recording by using an ink jet recording head, the apparatus comprising: an ink storage unit, in fluid communication with said ink jet recording means, for storing the ink an supplying the ink to said ink jet recording means; a light emitting section and a light receiving section provided within said ink storage unit or a member communicating with said ink storage unit, said light receiving section detecting the level of ink in said ink storage unit based on an amount of light received from said light emitting section; and a transparent window disposed in an optical path in said ink storage unit between said light emitting section and said light receiving section or in a member communicating with said ink storage between said light emitting section and said light receiving section, said transparent window having a portion for preventing an ink droplet from attaching thereto in said optical path. ### Claim 35 (depends on 34) The ink jet recording apparatus according to claim 34, wherein said transparent window is formed of fibrous material. ### Claim 36 (depends on 34) The ink jet recording apparatus according to claim 34, wherein said transparent window is formed of porous material. ### Claim 37 (depends on 34) The ink jet recording apparatus according to claim 34, wherein said transparent window is formed of a member having minute grooves on its surface. ### Claim 38 (depends on 34) The ink jet recording apparatus according to claim 34, wherein the presence of liquid is detected when the ink droplet is present on said transparent window and the absence of ink is detected when the ink droplet is not present on said transparent window. ### Claim 39 (depends on 34) The ink jet recording apparatus according to claim 34, wherein said transparent window comprises first and second members disposed on an interior surface of said ink storage unit. ### Claim 40 (depends on 34) The ink jet recording apparatus according to claim 34, wherein said transparent window is formed by an interior surface of said ink storage unit.