Claims
- 1. An image forming apparatus, comprising:
- a toner density sensor including a light emitting element which emits light toward a toner pattern image formed on an image carrier, and a light receiving element which receives a resulting reflection from said toner pattern image in order to allow an image forming condition to be controlled based on an output of said light receiving element,
- said light emitting element and said light receiving element positioned such that a line connecting said light emitting element and said toner pattern image and a line connecting said light receiving element and said toner pattern image lie in a plane inclined a preselected angle relative to a normal extending from a surface of said image carrier through said toner pattern image.
- 2. The apparatus as claimed in claim 1, further comprising:
- a support element on which said light emitting element and said light receiving element are mounted to form a unit.
- 3. The apparatus as claimed in claim 1, wherein:
- said light emitting element and said light receiving element each has a directivity, and
- said light emitting element and said light receiving element are positioned to satisfy either one of the following relations:
- .phi.>.phi.1+tan.sup.-1 (D2/2.rho.)
- .phi.>.phi.2+tan.sup.-1 (D1/2.rho.)
- where .phi.1 is the directivity or spread of a beam issuing from said light emitting element, .phi.2 is the directivity or spread of a beam incident to said light receiving element, .phi. is the preselected angle, D1 is a diameter of a light emitting surface of said light emitting element, D2 is a diameter of a light receiving surface of said light receiving element, and .rho. is an optical path length between a center of said light emitting surface and a center of said light receiving surface.
- 4. The apparatus as claimed in claim 1, further comprising:
- a support element on which said light emitting element and said light receiving element are mounted to form a unit.
- 5. A toner density sensor, comprising:
- a light emitting element which emits light toward a toner pattern image formed on an image carrier, and
- a light receiving element which receives a resulting reflection from said toner pattern image in order to allow an image forming condition to be controlled based on an output of said light receiving element,
- wherein said light emitting element and said light receiving element are positioned such that a line connecting said light emitting element and said toner pattern image and a line connecting said light receiving element and said toner pattern image lie in a plane inclined a preselected angle relative to a normal extending from a surface of said image carrier through said toner pattern image.
- 6. The toner density sensor as claimed in claim 5, further comprising:
- a support element on which said light emitting element and said light receiving element are mounted to form a unit.
- 7. The toner density sensor as claimed in claim 5, wherein:
- said light emitting element and said light receiving element each has a directivity, and
- said light emitting element and said light receiving element are positioned to satisfy either one of the following relations:
- .phi.>.phi.+ tan.sup.-1 (D2/2.rho.)
- .phi.>.phi.2+tan.sup.-1 (D1/2.rho.)
- where .phi.1 is the directivity of spread of a beam issuing from said light emitting element, .phi.2 is the directivity or spread of a beam incident to said light receiving element, .phi. is the preselected angle, D1 is a diameter of a light emitting surface of said light emitting element, D2 is a diameter of a light receiving surface of said light receiving element, and .rho. is an optical path length between a center of said light emitting surface and a center of said light receiving surface.
- 8. The apparatus as claimed in claim 7, comprising:
- a support element on which said light emitting element and said light receiving element are mounted to form a unit.
- 9. An image forming apparatus, comprising:
- a toner density sensor including a light emitting element which emits light toward a toner pattern image formed on an image carrier, and a light receiving element which receives a resulting reflection from said toner pattern image in order to allow an image forming condition to be controlled based on an output of said light receiving element,
- said light emitting element and said light receiving element are positioned such that a line connecting said light emitting element and said toner pattern image and a line connecting said light receiving element and said toner pattern image are inclined at a preselected angle relative to a normal extending from a surface of said image carrier through said toner pattern image.
- 10. The apparatus as claimed in claim 9, wherein:
- said light emitting element and said light receiving element each has a directivity, and
- said light emitting element and said light receiving element are positioned to satisfy either one of the following relations:
- .phi.>.phi.1+tan.sup.-1 (D2/2.rho.)
- .phi.>.phi.2+tan.sup.-1 (D1/2.rho.)
- where .phi.1 is the directivity or spread of a beam issuing from said light emitting element, .phi.2 is the directivity or spread of a beam incident to said light receiving element, .phi. is the preselected angle, D1 is a diameter of a light emitting surface of said light emitting element, D2 is a diameter of a light receiving surface of said light receiving element, and .rho. is an optical path length between a center of said light emitting surface and a center of said light receiving surface.
- 11. A toner density sensor comprising:
- a light emitting element for emitting light toward a toner pattern image formed on an image carrier, and
- a light receiving element for receiving a resulting reflection from said toner pattern image in order to allow an image forming condition to be controlled based on an output of said light receiving element,
- said light emitting element and said light receiving element are positioned such that a line connecting said light emitting element and said toner pattern image and a line connecting said light receiving element and said toner pattern image are inclined a preselected angle relative to a normal extending from a surface of said image carrier through said toner pattern image.
- 12. The toner density sensor as claimed in claim 11, wherein:
- said light emitting element and said light receiving element each has a directivity, and
- said light emitting element and said light receiving element are positioned to satisfy either one of the following relations:
- .phi.>.phi.1+tan.sup.-1 (D2/2.rho.)
- .phi.>.phi.2+tan.sup.-1 (D1/2.rho.)
- where .phi.1 is the directivity or spread of a beam issuing from said light emitting element, .phi.2 is the directivity or spread of a beam incident to said light receiving element, .phi. is the preselected angle, D1 is a diameter of a light emitting surface of said light emitting element, D2 is a diameter of a light receiving surface of said light receiving element, and .rho. is an optical path length between a center of said light emitting surface and a center of said light receiving surface.
- 13. A toner density sensing method, comprising the steps of:
- positioning a light emitting element and a light receiving element such that a line connecting said light emitting element and a toner pattern image formed on an image carrier and a line connecting said light receiving element and said toner pattern image lie in a plane inclined a preselected angle relative to a normal extending from a surface of said image carrier through said toner pattern image;
- emitting light from said light emitting element toward said toner pattern image,
- receiving a resulting reflection from said toner pattern image with a light receiving element, and
- controlling an image forming condition based on an output of said light receiving element.
- 14. The method according to claim 13, further comprising the steps of:
- positioning said light emitting element such that a line connecting said light emitting element and said toner pattern image is inclined a first predetermined angle relative to a normal extending from a surface of said image carrier through said toner pattern image; and
- causing the reflection to be incident to said light receiving element positioned such that a line connecting said light receiving element and said toner pattern image is inclined at a second predetermined angle relative to said normal.
Priority Claims (2)
Number |
Date |
Country |
Kind |
7-114480 |
May 1995 |
JPX |
|
7-342647 |
Dec 1995 |
JPX |
|
Parent Case Info
This is a Continuation of application Ser. No. 08/584,443 filed on Jan. 11, 1996, U.S. Pat. No. 5,630,195.
US Referenced Citations (4)
Continuations (1)
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Number |
Date |
Country |
Parent |
584443 |
Jan 1996 |
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