JPS6215351B2 - - Google Patents
Info
- Publication number
- JPS6215351B2 JPS6215351B2 JP52044139A JP4413977A JPS6215351B2 JP S6215351 B2 JPS6215351 B2 JP S6215351B2 JP 52044139 A JP52044139 A JP 52044139A JP 4413977 A JP4413977 A JP 4413977A JP S6215351 B2 JPS6215351 B2 JP S6215351B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- light
- light receiving
- level
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000001514 detection method Methods 0.000 claims description 12
- 230000003321 amplification Effects 0.000 claims description 7
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 7
- 238000000034 method Methods 0.000 description 10
- 238000010586 diagram Methods 0.000 description 5
- 239000003990 capacitor Substances 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Landscapes
- Exposure Or Original Feeding In Electrophotography (AREA)
- Manufacture Or Reproduction Of Printing Formes (AREA)
- Control Of Exposure In Printing And Copying (AREA)
- Facsimile Image Signal Circuits (AREA)
Description
【発明の詳細な説明】
本発明の複写機、騰写用製版機等における原稿
の濃度検出装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a density detection device for a document in a copying machine, a copying plate-making machine, etc.
原稿には紙面の白いものから複写した原稿のよ
うに灰色がかつたものまで色々あり、したがつて
原稿の地色と文字や図の黒線との間のコントラス
トに色々の状態が存在する。しかも得ようとする
複写や製版した記録紙においてはできるだけ地の
汚れは再現しない白黒のコントラストのはつきり
したものが望まれる。 There are many types of manuscripts, ranging from white paper to gray, like a copy of a manuscript, and therefore there are various contrasts between the background color of the manuscript and the black lines of text and figures. Moreover, it is desired that the copy or plate-made recording paper to be obtained should have a sharp contrast between black and white, without reproducing stains on the background as much as possible.
原稿自体のコントラストとは別に照明するラン
プの劣化やランプ電圧変動によるランプ光量の変
化、光学系のレンズの汚れ等によつても得られる
コントラストすなわち階調性が変化する。 In addition to the contrast of the document itself, the contrast that can be obtained, that is, the gradation, also changes due to deterioration of the illuminating lamp, changes in the amount of light from the lamp due to fluctuations in lamp voltage, dirt on the lenses of the optical system, and the like.
従来謄写用製版機等においては受光回路におい
て光量変化を電圧変化に変換し、その電圧変化に
応じて放電針による記録紙の放電破壊量に変化を
与えている。謄写印刷に際しては放電破壊量に応
じて濃淡が表現される。したがつて電圧変化を制
御することにより得られる階調性を制御すること
ができる。 In conventional mimeograph machines and the like, changes in the amount of light are converted into changes in voltage in a light receiving circuit, and the amount of discharge destruction of recording paper by a discharge needle is changed in accordance with the voltage changes. In mimeograph printing, shading is expressed according to the amount of discharge destruction. Therefore, the gradation obtained can be controlled by controlling the voltage change.
従来原稿の白黒をできるだけ明白に表現し、灰
色部分も白か黒に判別しようとして色々の提案が
されている。 In the past, various proposals have been made to express the black and white of a manuscript as clearly as possible, and to distinguish gray areas as white or black.
例えば原稿よりの反射光量の変化に応じて得ら
れる電圧又は電流変化を半固定抵抗でプリセツト
レベルとして予め一定のレベルをセツトし、その
設定した一定電圧又は電流値以下の電圧又は電流
はカツトして黒として扱う、すなわち一定光量以
下の灰色及び黒を全て黒として判別する直流プリ
セツト方式や、直流成分と交流成分のうち直流成
分をコンデンサでカツトして交流成分のみを取り
出し、あらかじめプリセツトされた値で階調性を
決める方式すなわち交流成分のうちプリセツトさ
れた電圧又は電流値により黒として扱う光量域を
セツトする直流カツト交流プリセツト方式、及び
直流カツト方式ではあるが交流成分の上限又は下
限を一定の直流レベルに固定する交流レベルに固
定方式等がある。 For example, a certain level is set in advance as a preset level using a semi-fixed resistor based on the change in voltage or current obtained in response to changes in the amount of light reflected from the original, and voltages or currents below the set constant voltage or current value are cut off. In other words, the DC preset method treats all gray and black below a certain amount of light as black, and the DC preset method uses a capacitor to cut off the DC component and extract only the AC component, which is then set to a preset value. The DC cut AC preset method sets the light amount range treated as black using a preset voltage or current value of the AC component, and the DC cut method sets the upper or lower limit of the AC component to a constant value. There are methods of fixing the level to the DC level and fixing the level to the AC level.
直流プリセツト方式ではランプの光量変動、レ
ンズのよごれによつて階調性が変動し易いという
欠点があり、直流カツト交流プリセツト方式では
直流成分がカツトされただけ光量変動に強くなる
が原稿上の黒い部分の多い少ないによつて階調性
が変動し、中間調の出かたにむらを生ずるという
欠点があり、光流レベル固定方式は交流成分の上
限又は下限を一定の直流レベルに固定して原稿の
状態による階調性変動を防ぐが直流カツト交流プ
リセツト方式と同様の欠点がある。 The DC preset method has the disadvantage that the gradation tends to fluctuate due to fluctuations in the light intensity of the lamp and dirt on the lens, while the DC cut/AC preset method is more resistant to light intensity fluctuations as the DC component is cut out, but black spots on the document The problem is that the gradation varies depending on the number of parts, and the appearance of intermediate tones is uneven.The light current level fixed method fixes the upper or lower limit of the AC component to a constant DC level. Although this method prevents gradation fluctuations due to the condition of the original, it has the same drawbacks as the DC cut/AC preset method.
本発明は従来の方法の上記の欠点を解消するこ
とを目的としている。 The present invention aims to overcome the above-mentioned drawbacks of the conventional methods.
本発明の詳細を図に示す実施例により説明す
る。 The details of the present invention will be explained with reference to embodiments shown in the figures.
本発明は原稿の最も白い部分と最も黒い部分の
差を検出し、その差によつて製版濃度のスレツシ
ホルドレベルセツトをし、レベルセツト値以下の
光量の部分を黒とし、レベルセツト値以上の光量
の部分についてはその光量変化に応じた出力信号
を取出すことにより光量変動による階調性の変動
をなくすものである。 The present invention detects the difference between the whitest part and the blackest part of the original, sets a threshold level for plate making density based on the difference, and sets the part with the light amount below the level set value as black, and sets the threshold level for the plate making density based on the difference. Regarding the portion of the light amount, by extracting an output signal corresponding to the change in the light amount, fluctuations in gradation due to changes in the light amount are eliminated.
第１図において受光回路１と差動増巾回路２は
たとえばコンデンサC1とダイオードD1よりなる
クランプ回路３とコンデンサC2と抵抗R1，R2と
ダイオードD2からなるピーク検出回路４（第２
図）とにより接続されている。受光回路１の出力
のドリフトが小さい場合はクランプ回路３は省略
されることができる。差動増巾回路２における出
力は変調回路５を経て出力される。 In FIG. 1, a light receiving circuit 1 and a differential amplification circuit 2 include, for example, a clamp circuit 3 consisting of a capacitor C 1 and a diode D 1 , and a peak detection circuit 4 (consisting of a capacitor C 2 , resistors R 1 and R 2 , and a diode D 2) . Second
(Fig.). If the drift of the output of the light receiving circuit 1 is small, the clamp circuit 3 can be omitted. The output from the differential amplification circuit 2 is outputted via the modulation circuit 5.
ピーク検出回路４における抵抗R1とR2の分圧
比により定まる電圧比によりプリセツトレベルが
設定される。 A preset level is set by a voltage ratio determined by a voltage division ratio between resistors R1 and R2 in the peak detection circuit 4.
本発明の一例を示す第２図においては受光回路
１の出力のドリフトが±16mVの例を示し、した
がつて出力レベルの１％以下であるのでクランプ
回路３が省略されている。 FIG. 2, which shows an example of the present invention, shows an example in which the output drift of the light receiving circuit 1 is ±16 mV, which is less than 1% of the output level, so the clamp circuit 3 is omitted.
ピーク検出回路におけるダイオードD2いよる
電圧降下があり光量変動に対して弱いので受光回
路の出力にダイオードの電圧降下分の電圧をダイ
オードD3により上昇する方向にレベルシフトし
て補い、そのレベルシフト分は差動増巾回路にダ
イオードD4を接続することにより下降方向にシ
フトして差引く。 Since the diode D2 in the peak detection circuit has a voltage drop and is vulnerable to changes in light intensity, the voltage of the diode voltage drop is compensated for by shifting the voltage in the upward direction using the diode D3 in the output of the light receiving circuit, and the level shift is performed. The component is shifted downward and subtracted by connecting a diode D4 to the differential amplification circuit.
変調回路には一例として変圧器T1，T2とダイ
オードD5，D6とを有する図に示すダイオード変
調回路を用いる。 As an example of the modulation circuit, a diode modulation circuit shown in the figure is used, which includes transformers T 1 and T 2 and diodes D 5 and D 6 .
差動増巾回路においては受光回路の出力Ａとピ
ーク検出回路の出力Ｂとの差に基いて作動する。
差動増巾回路２への入力Ｂはピーク検出回路によ
り自動的に設定されるが切換スイツチＳによりマ
ニユアルにより設定するように切換ることもでき
る。 The differential amplifier circuit operates based on the difference between the output A of the light receiving circuit and the output B of the peak detection circuit.
The input B to the differential amplification circuit 2 is automatically set by the peak detection circuit, but can also be set manually by the changeover switch S.
変調回路５は第３図に示すような作動特性を有
するのでダイオード１個分のバイアス電圧のとき
変調度が50％になる。したがつて出力ABのいず
れかからダイオード１個分の電圧を差引けば出力
ABの電位が一致したとき変調度が50％になる。
このため第２図では電圧下降手段としてダイオー
ドD7を設けてある。 Since the modulation circuit 5 has operating characteristics as shown in FIG. 3, the degree of modulation becomes 50% when the bias voltage is equivalent to one diode. Therefore, if the voltage of one diode is subtracted from either output AB, the output will be
When the potentials of AB match, the modulation depth becomes 50%.
For this reason, in FIG. 2, a diode D7 is provided as a voltage lowering means.
本発明に係る装置によると第４図に示すように
横軸に原稿面の明暗度を暗を０、明を１として表
示し、縦軸に原紙である記録紙の透過濃度を表示
すると、光量をパラメータとして図のような曲線
が得られ、光量に関係なく原稿明暗度と原紙透過
度との間の関係はほぼ同じである。しかるに直流
プリセツト式では第５図に示すように、光量によ
つて曲線が大きくずれてくることが示されてい
る。 According to the apparatus according to the present invention, as shown in FIG. 4, when the horizontal axis displays the brightness of the document surface with dark as 0 and bright as 1, and the vertical axis displays the transmission density of the recording paper that is the base paper, the amount of light is A curve as shown in the figure can be obtained using the parameter , and the relationship between original brightness and original paper transmittance is almost the same regardless of the amount of light. However, in the case of the DC preset type, as shown in FIG. 5, it has been shown that the curve deviates greatly depending on the amount of light.
本発明によりピーク検出回路において白黒のピ
ーク値を検出し、ピーク値とピーク値の差の値を
基準にしてプリセツトレベルが設定されるのでプ
リセツトレベルを固定すること、下限又は上限を
一定レベルに固定することにより生ずる階調性の
変動が回避されることができる。したがつて光量
の変動により階調性の変動を生ずることが回避さ
れた。 According to the present invention, the peak detection circuit detects the black and white peak values, and the preset level is set based on the difference between the peak values, so it is possible to fix the preset level and set the lower limit or upper limit to a constant level. It is possible to avoid variations in gradation caused by fixing the gradation to . Therefore, variations in gradation due to variations in the amount of light can be avoided.
第１図は本発明に係る装置のブロツク図、第２
図は本発明に係る濃度検出装置の一例の回路図、
第３図は第２図の変調回路の特性図、第４図は本
発明に係る装置による原稿濃度と原紙透過濃度の
関係を示す図、第５図は従来の装置の第４図に対
応する図である。
１……受光回路、２……差動増巾回路、４……
ピーク検出回路、５……変調回路、R1，R2……
ピーク検出回路の抵抗。
FIG. 1 is a block diagram of the device according to the present invention, FIG.
The figure is a circuit diagram of an example of a concentration detection device according to the present invention,
FIG. 3 is a characteristic diagram of the modulation circuit in FIG. 2, FIG. 4 is a diagram showing the relationship between original density and original paper transmission density using the apparatus according to the present invention, and FIG. 5 corresponds to FIG. 4 of the conventional apparatus. It is a diagram. 1... Light receiving circuit, 2... Differential amplifier circuit, 4...
Peak detection circuit, 5...Modulation circuit, R1 , R2 ...
Resistance of peak detection circuit.
Claims (1)
る受光回路と、受光回路に接続されるピーク検出
回路と、受光回路の出力とピーク検出回路の出力
とを入力とする差動増巾回路と、差動増巾回路に
接続される変調回路とを有し、前記差動増巾回路
には両入力が一致したとき変調回路の変調度が50
％になるような電位降下手段が設けられ、原稿の
白黒部のピーク値の差によつて製版濃度のスレツ
シホルドレベルが設定されることを特徴とする原
稿濃度検出装置。1. A light receiving circuit that converts the amount of light reflected from the original into an electrical signal, a peak detection circuit connected to the light receiving circuit, and a differential amplification circuit that receives the output of the light receiving circuit and the output of the peak detection circuit as inputs. , a modulation circuit connected to a differential amplification circuit, and the differential amplification circuit has a modulation degree of 50 when both inputs match.
%, and a threshold level of plate-making density is set based on a difference between peak values of black and white portions of the document.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4413977A JPS53129625A (en) | 1977-04-19 | 1977-04-19 | Original sheet density inspecting system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4413977A JPS53129625A (en) | 1977-04-19 | 1977-04-19 | Original sheet density inspecting system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS53129625A JPS53129625A (en) | 1978-11-11 |
| JPS6215351B2 true JPS6215351B2 (en) | 1987-04-07 |
Family
ID=12683293
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4413977A Granted JPS53129625A (en) | 1977-04-19 | 1977-04-19 | Original sheet density inspecting system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS53129625A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0416679Y2 (en) * | 1987-06-20 | 1992-04-14 |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58163952U (en) * | 1982-04-24 | 1983-11-01 | コピア株式会社 | Control device for diazo copying machine |
| JPS58186737A (en) * | 1982-04-27 | 1983-10-31 | Copyer Co Ltd | Automatic exposure quantity controlling device of copying machine |
| JPS595235A (en) * | 1982-07-01 | 1984-01-12 | Copyer Co Ltd | Automatic printing control device in diazo type copying machine |
| JPS5946353U (en) * | 1982-09-21 | 1984-03-27 | コピア株式会社 | Control device for diazo copying machine |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS492442A (en) * | 1972-04-19 | 1974-01-10 |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5743414Y2 (en) * | 1975-01-09 | 1982-09-24 |
-
1977
- 1977-04-19 JP JP4413977A patent/JPS53129625A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS492442A (en) * | 1972-04-19 | 1974-01-10 |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0416679Y2 (en) * | 1987-06-20 | 1992-04-14 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS53129625A (en) | 1978-11-11 |
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