JPH0390244U

JPH0390244U -

Info

Publication number: JPH0390244U
Application number: JP15179489U
Authority: JP
Priority date: 1989-12-28
Filing date: 1989-12-28
Publication date: 1991-09-13

Description

[Brief explanation of drawings]

第１図は本考案の画像濃度制御装置が適用され
た画像形成装置の概略図、第２図は本考案の画像
濃度制御装置において使用される基準濃度パツチ
の一例を示す説明図、第３図は第２図に示す基準
濃度パツチを形成するためのパツチパターン信号
の波形図、第４図は画像面積率をパラメータとし
たベタ部トナー量と光センサ出力との関係を示す
グラフ、第５図はベタ部トナー量をパラメータと
した画像面積率と濃度との関係を示すグラフ、第
６図は画像面積率と光センサ感度との関係を示す
グラフ、第７図、第８図は基準濃度パツチの他の
例を示す説明図、第９図は光センサによるトナー
量測定の原理を示す説明図、第１０図は単位面積
当たりのトナー量と光センサ出力との関係を示す
グラフ、第１１図は従来の画像濃度制御装置の動
作を説明するための模式図、第１２図はコントラ
スト電位と濃度との関係を示すグラフである。１……感材、２……帯電器、３……現像器、３
ａ……トナー供給装置、４……転写器、５……パ
ツチ濃度検知用光センサ、５ａ……発光素子、５
ｂ……受光素子、６……クリーナ、７……除電ラ
ンプ、８……レーザ光源、９……画像情報発生器
、１０……パツチパターン発生器、１１……レー
ザ駆動回路、１２……ＣＰＵ、３１……トナー、
３２……発光素子、３３……感材、３４……受光
素子、３５……光センサ、３６……基準濃度パツ
チ、３７……画像、Ｐ……画像生成領域、Ｑ……
濃度検知領域。 FIG. 1 is a schematic diagram of an image forming apparatus to which the image density control device of the present invention is applied, FIG. 2 is an explanatory diagram showing an example of a reference density patch used in the image density control device of the present invention, and FIG. is a waveform diagram of the patch pattern signal for forming the reference density patch shown in FIG. 2, FIG. 4 is a graph showing the relationship between the amount of solid toner and the optical sensor output using the image area ratio as a parameter, and FIG. A graph showing the relationship between image area ratio and density using the amount of solid toner as a parameter. Figure 6 is a graph showing the relationship between image area ratio and photosensor sensitivity. Figures 7 and 8 are graphs showing the relationship between image area ratio and photosensor sensitivity. An explanatory diagram showing another example, Fig. 9 is an explanatory diagram showing the principle of toner amount measurement using an optical sensor, Fig. 10 is a graph showing the relationship between the toner amount per unit area and the optical sensor output, and Fig. 11 is an explanatory diagram showing the principle of toner amount measurement using an optical sensor. FIG. 12, a schematic diagram for explaining the operation of a conventional image density control device, is a graph showing the relationship between contrast potential and density. 1...Sensitive material, 2...Charger, 3...Developer, 3
a... Toner supply device, 4... Transfer device, 5... Optical sensor for detecting patch density, 5a... Light emitting element, 5
b... Light receiving element, 6... Cleaner, 7... Static elimination lamp, 8... Laser light source, 9... Image information generator, 10... Patch pattern generator, 11... Laser drive circuit, 12... CPU, 31... Toner,
32...Light emitting element, 33...Sensitive material, 34...Light receiving element, 35...Photo sensor, 36...Reference density patch, 37...Image, P...Image generation area, Q...
Concentration detection area.

Claims

[Scope of utility model registration request]

means for forming a binary electrostatic latent image pattern on a specific area of a photosensitive material uniformly charged in advance so that the image area ratio after development is less than 100%; and a means for developing the electrostatic latent image pattern. An image density control device comprising: a means for forming a reference density patch; a means for detecting an average density of the reference density patch; and a means for adjusting an image density based on the detected density. .