JPH0649378B2 - Record head - Google Patents
Record headInfo
- Publication number
- JPH0649378B2 JPH0649378B2 JP18198685A JP18198685A JPH0649378B2 JP H0649378 B2 JPH0649378 B2 JP H0649378B2 JP 18198685 A JP18198685 A JP 18198685A JP 18198685 A JP18198685 A JP 18198685A JP H0649378 B2 JPH0649378 B2 JP H0649378B2
- Authority
- JP
- Japan
- Prior art keywords
- current
- circuit
- divided
- output
- recording
- 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 - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/315—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material
- B41J2/32—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material using thermal heads
- B41J2/35—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material using thermal heads providing current or voltage to the thermal head
Landscapes
- Fax Reproducing Arrangements (AREA)
- Facsimile Image Signal Circuits (AREA)
- Electronic Switches (AREA)
- Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
- Led Devices (AREA)
- Dot-Matrix Printers And Others (AREA)
- Facsimile Heads (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明はフアクシミリやプリンタ等の印字の用に供さ
れる記録ヘツドに関するものである。Description: FIELD OF THE INVENTION The present invention relates to a recording head used for printing on facsimiles, printers and the like.
この発明の記録ヘツドは、記録素子として発熱抵抗素子
を用いて階調記録を行なうサーマルヘツドや発光素子で
あるＬＥＤを電子写真装置の記録光源とするＬＥＤアレ
イヘツドの駆動方法に関して効果のあるものであるが、
ここでは後者について詳述する。The recording head of the present invention is effective in a method for driving a thermal head for performing gradation recording using a heating resistance element as a recording element and a method for driving an LED array head using an LED, which is a light emitting element, as a recording light source for an electrophotographic apparatus. But,
Here, the latter will be described in detail.
一般に、ＬＥＤアレイヘツドでは、たとえば、１０個／
mmの密度で６４〜１２８個のＬＥＤを形成した複数のＬ
ＥＤアレイチツプを基板上に一列に配設し、これに沿つ
てその駆動回路（ＩＣ）を配列して、ＬＥＤと駆動ＩＣ
とを電流安定化抵抗器を介して接続する構成になつてい
る。Generally, in an LED array head, for example, 10 /
Multiple Ls with 64-128 LEDs formed with a density of mm
The ED array chips are arranged in a line on the substrate, and the drive circuit (IC) is arranged along the line, and the LED and the drive IC are arranged.
And are connected via a current stabilizing resistor.
従来の構成を第２図で説明する。図中、（１００）は駆
動ＩＣの電流増幅部である。(1)はＬＥＤ、Ｒ1はＬＥＤ
(1)への電流を安定化する電流安定化抵抗器である。駆
動ＩＣは通常３２ないし６４個の電流増幅回路を備えて
おり、ここでは図示していないがＬＥＤ(1)を発光させ
る発光信号を転送するシフトレジスタと、出力端が各電
流増幅回路に接続されてその出力を保持するラツチ回路
等から構成されている。A conventional configuration will be described with reference to FIG. In the figure, (100) is a current amplifier of the drive IC. (1) is LED, R 1 is LED
It is a current stabilizing resistor that stabilizes the current to (1). The drive IC is usually provided with 32 to 64 current amplification circuits. Although not shown here, a shift register for transferring a light emission signal for causing the LED (1) to emit light and an output terminal are connected to each current amplification circuit. It is composed of a latch circuit or the like which holds the output of the latch.
ＬＥＤ(1)は駆動特性の１つとして、その内部抵抗が小
さいという欠点がある。電流安定化抵抗器Ｒ1がない場
合には、僅かな印加電圧変動で大きな発光出力変動を生
じる。したがつて、発光出力を安定化するために５０〜
１００Ω程度の負荷抵抗器を接続して電流値を安定化さ
せて定電流駆動に近い駆動方法にしている。One of the driving characteristics of the LED (1) is that it has a small internal resistance. If the current stabilizing resistor R 1 is not provided, a large variation in the light emission output occurs even with a slight variation in the applied voltage. Therefore, in order to stabilize the light emission output,
By connecting a load resistor of about 100Ω to stabilize the current value, a driving method close to constant current driving is adopted.
上記従来の回路構成は、各ＬＥＤ(1)毎の発光出力のば
らつきが小さい場合には、とくに問題のない一般的な構
成である。The above-mentioned conventional circuit configuration is a general configuration with no particular problem when the variation in the light emission output of each LED (1) is small.
しかしながら、実際に製造されるＬＥＤアレイチツプの
発光出力のばらつきには、チツプ内およびチツプ間で２
〜３倍に達する大きなものがある。したがつて、第２図
に示した電流安定化抵抗器Ｒ1を接続しただけの回路構
成では、その発光出力のばらつきはやはり２〜３倍と大
きく、これを補正して均一化することは困難である。However, the variation in the light emission output of the LED array chips actually manufactured is 2 within the chip and between the chips.
There is a big thing that reaches ~ 3 times. Therefore, in the circuit configuration in which only the current stabilizing resistor R 1 shown in FIG. 2 is connected, the variation in the light emission output is still as large as 2-3 times, and it is not possible to correct it and make it uniform. Have difficulty.
ＬＥＤアレイヘツドを記録光源とする電子写真記録装置
では、高品質な記録画像を得るために発光量の均一性が
求められ、その範囲は±１５％以内にする必要がある。
したがつて、ＬＥＤアレイヘツドに用いるＬＥＤアレイ
チツプは、製造したＬＥＤアレイチツプから適正なもの
だけを選別して使用しなければならない。ＬＥＤアレイ
チツプの主な材料は通常の半導体に用いるＳｉに比べて
高価なＧaＡsであり、ばらつきの少ないＬＥＤアレイチ
ツプだけ選別して用いるための、ＬＥＤアレイチツプや
ＬＥＤアレイヘツドの価格は極めて高価なものとなって
いる。In an electrophotographic recording apparatus using an LED array head as a recording light source, the uniformity of the light emission amount is required to obtain a high quality recorded image, and the range must be within ± 15%.
Therefore, for the LED array chips used for the LED array head, only the proper one should be selected from the manufactured LED array chips before use. The main material of the LED array chip is GaAs, which is more expensive than Si used for ordinary semiconductors, and the price of the LED array chip and the LED array head for selecting and using only the LED array chip with little variation becomes extremely expensive. There is.
この発明は上記問題点を解決するためになされたもの
で、小形かつ安価に構成できながら、記録素子の出力効
率に応じた駆動電流が得られて記録エネルギーの均一化
が図れ、また、記録電流の変動に対して的確に対応させ
て記録素子の記録効率に応じた駆動電流の供給を維持す
ることができる記録ヘッドを提供することを目的とす
る。The present invention has been made to solve the above-mentioned problems, and it is possible to obtain a drive current according to the output efficiency of a recording element to make the recording energy uniform while achieving a small size and a low cost. It is an object of the present invention to provide a recording head capable of maintaining the supply of a drive current according to the recording efficiency of a recording element by appropriately responding to the fluctuation of
この発明に係る記録ヘッドは、複数の記録素子と、第１
の分割電流回路及びこの第１の分割電流回路と並列接続
された出力電流値が異なる複数の第２の分割電流回路か
ら構成され上記各記録素子に上記第１及び第２の分割電
流回路の電流が加算された駆動電流を出力する電流増幅
回路と、上記第１の分割電流回路の出力電流値を検出す
る電流検出回路と、上記電流検出回路の検出信号に基づ
き上記各記録素子の出力効率に応じた上記第２の分割電
流回路を選択する電流制御回路とを備え、上記電流増幅
回路は上記第１の分割電流回路の電流と選択された第２
の分割電流回路の電流とが加算された駆動電流を出力す
るように構成したことを特徴とする。A recording head according to the present invention includes a plurality of recording elements and a first recording element.
Current of each of the first and second divided current circuits, which is composed of a plurality of divided current circuits and a plurality of second divided current circuits connected in parallel with the first divided current circuit and having different output current values. A current amplifier circuit that outputs a drive current to which is added, a current detection circuit that detects the output current value of the first divided current circuit, and the output efficiency of each recording element based on the detection signal of the current detection circuit. And a current control circuit for selecting the second divided current circuit according to the first divided current circuit.
It is characterized in that it is configured so as to output a drive current obtained by adding the current of the divided current circuit of.
この発明によれば、記録素子の出力効率に応じて、電流
増幅回路におけるベースとなる第１の分割電流増幅回路
と、その他の第２の電流増幅回路の中から選択された１
つまたは複数の第２の電流増幅回路とを駆動することに
より、記録素子の出力効率に対応した値の駆動電流が得
られ、記録エネルギーの均一化が図れる。According to the present invention, according to the output efficiency of the recording element, one selected from the first divided current amplification circuit which is the base of the current amplification circuit and the other second current amplification circuit is selected.
By driving one or a plurality of second current amplifier circuits, a drive current having a value corresponding to the output efficiency of the recording element can be obtained, and the recording energy can be made uniform.
また、電流増幅回路への供給電源電圧の変動等により記
録素子の駆動電流が変動した場合、その電流が電流検出
回路により検出され、その検出信号に応じて電流制御回
路が動作されて、第１の分割電流増幅回路および選択さ
れた第２の分割電流増幅回路の出力電流値が制御され
て、所定の電流値が出力されることになる。これによっ
て、記録素子の駆動電流に変動がある場合、その変動に
対して的確に対応させて、記録素子の記録効率に応じた
駆動電流の供給が維持されることになる。Further, when the drive current of the recording element fluctuates due to fluctuations in the power supply voltage supplied to the current amplifier circuit, the current is detected by the current detection circuit, and the current control circuit is operated according to the detection signal, so that the first The output current value of each of the divided current amplification circuits and the selected second divided current amplification circuit is controlled, and a predetermined current value is output. As a result, when there is a change in the drive current of the recording element, the supply of the drive current according to the recording efficiency of the recording element is maintained by accurately responding to the change.
第１図はこの発明の一実施例の記録ヘツドの構成を示す
ものである。ここでは、記録ヘツドにおける複数の駆動
ＩＣおよびＬＥＤのうち、３２ビツト構成にした１個の
駆動ＩＣについて示してある。FIG. 1 shows the structure of a recording head according to an embodiment of the present invention. Here, of the plurality of drive ICs and LEDs in the recording head, one drive IC having a 32-bit configuration is shown.
同図において、(1)は記録素子としてのＬＥＤ、(2)は互
に並列接続の４つの分割電流増幅回路(21)，(22)，(2
3)，(24)からなる電流増幅回路、(3)は記録ヘツドに入
力された発光信号Ｓで電流増幅回路(2)の動作を制御
し、かつ電流増幅回路(2)の出力電流値を制御する電流
制御回路、(4)は分割電流増幅回路(21)，(22)，(23)，
(24)のうち発光信号Ｓにより必ず駆動されるベースとな
る第１の分割電流増幅回路(21)の出力電流を、電流値検
出抵抗器Ｒ２の両端にかかる電圧値で検出する電圧比較
回路からなる電流検出回路としての比較回路、(5)は発
光信号Ｓを順次クロツク信号に同期して転送するシスト
レジスタを含むメモリ回路、(6)，(7)，(8)はそれぞれ
第２の分割電流増幅回路(22)，(23)，(24)の駆動をあら
かじめ設定する駆動選択信号ａ，ｂ，ｃのメモリ回路で
ある。(9)は発光信号Ｓと発光時間を設定する時限信号
Ｔのアンド回路である。(10)は駆動ＩＣ自体の温度を検
知する感温センサであり、検出した温度信号を各電流制
御回路(3)に伝達し、温度に応じてＬＥＤ(1)への電流値
を制御するようになつている。In the figure, (1) is an LED as a recording element, and (2) is four divided current amplification circuits (21), (22), (2
3), a current amplification circuit consisting of (24), (3) controls the operation of the current amplification circuit (2) by the light emission signal S input to the recording head, and controls the output current value of the current amplification circuit (2). Current control circuit to control, (4) is divided current amplification circuit (21), (22), (23),
A voltage comparison circuit for detecting the output current of the first divided current amplification circuit (21) which is a base which is always driven by the light emission signal S among (24) by the voltage value applied across the current value detection resistor R 2. Comparing circuit as a current detecting circuit, (5) is a memory circuit including a cyst register for transferring the light emission signal S sequentially in synchronization with the clock signal, and (6), (7), and (8) are second memory circuits, respectively. This is a memory circuit for the drive selection signals a, b, c for presetting the drive of the divided current amplifier circuits (22), (23), (24). (9) is an AND circuit of the light emission signal S and the time limit signal T for setting the light emission time. (10) is a temperature sensitive sensor that detects the temperature of the drive IC itself, and transmits the detected temperature signal to each current control circuit (3) so that the current value to the LED (1) is controlled according to the temperature. It has become.
つぎに、動作について説明する。Next, the operation will be described.
まず、各ＬＥＤ(1)に対応して発光信号Ｓと駆動選択信
号ａ，ｂ，ｃがクロツク信号と同期して順次各メモリ回
路(5)，(6)，(7)，(8)に入力される。First, the light emission signal S and the drive selection signals a, b, c corresponding to each LED (1) are sequentially provided to the respective memory circuits (5), (6), (7), (8) in synchronization with the clock signal. Is entered.
発光信号Ｓはアンド回路(9)で発光時間を設定する時限
信号Ｔと論理積がとられて電流制御回路(3)に入力さ
れ、これにより電流増幅回路(2)が駆動される。電流増
幅回路(2)における分割電流増幅回路(21)は電流検出抵
抗器Ｒ2を介して、ＬＥＤ(1)に接続され、その他の回路
(22)〜(24)は直接ＬＥＤ(1)に接続されている。各分割
電流増幅回路(21)，(22)，(23)，(24)は電流制御回路
(3)から伝達される信号量の大きさ、たとえば電圧値等
で駆動する電流値が設定されている。The light emission signal S is ANDed with the time signal T for setting the light emission time by the AND circuit (9) and input to the current control circuit (3), which drives the current amplification circuit (2). The divided current amplification circuit (21) in the current amplification circuit (2) is connected to the LED (1) through the current detection resistor R 2 and other circuits
(22) to (24) are directly connected to the LED (1). Each divided current amplifier circuit (21), (22), (23), (24) is a current control circuit
The magnitude of the signal transmitted from (3), for example, the current value to be driven by the voltage value or the like is set.
また、分割電流増幅回路(21)は発光信号Ｓｎにより必ず
駆動されるが、その他のもの(22)〜(24)は負荷であるＬ
ＥＤ(1)の発光効率、すなわち駆動電流で所定範囲の発
光出力となるように、その駆動が駆動選択信号ａn，
ｂn，ｃnで任意に選択される。電流増幅回路（２）の出
力電流は、その供給電源電圧Ｖ１の電圧値に依存するの
で、電流検出抵抗器Ｒ２の両端にかかる電圧を電圧比較
回路からなる電流検出回路（４）で検出し、ＬＥＤ
（１）への供給電流が一定になるように、検出値を電流
制御回路（３）に伝達する。ＬＥＤ(1)の発光効率はＬ
ＥＤ自身の温度に依存して変化する。したがつて、ＬＥ
Ｄ(1)の温度を検出するためＬＥＤ(1)とほぼ同様の条件
下にある駆動ＩＣに設けた感温センサ(10)の出力信号を
各電流制御回路(3)に伝達し、温度に応じた出力電流と
なるように電流増幅回路(2)が制御される。すなわち、
上記分割電流増幅回路(21)をベースとして、他の分割電
流増幅回路(22)〜(24)のうちのいずれかが選択されて駆
動され、ＬＥＤ(1)に対して発光効率に応じた駆動電流
が供給される。これによつて各ＬＥＤ(1)の発光出力が
均一化され、換言すればＬＥＤアレイチツプを選別使用
しなくてよいため、コスト安となる。Further, the divided current amplifier circuit (21) is always driven by the light emission signal Sn, but the others (22) to (24) are loads L
Luminous efficiency of ED (1), i.e. such that the light output in a predetermined range in the driving current, the driving driving selection signal a n,
It is arbitrarily selected by b n and c n . Since the output current of the current amplification circuit (2) depends on the voltage value of the power supply voltage V 1 thereof, the voltage applied across the current detection resistor R 2 is detected by the current detection circuit (4) including a voltage comparison circuit. And LED
The detected value is transmitted to the current control circuit (3) so that the supply current to (1) becomes constant. The luminous efficiency of LED (1) is L
It changes depending on the temperature of the ED itself. Therefore, LE
In order to detect the temperature of D (1), the output signal of the temperature sensor (10) provided in the drive IC under almost the same conditions as the LED (1) is transmitted to each current control circuit (3) to detect the temperature. The current amplifier circuit (2) is controlled so that the output current will be the corresponding output current. That is,
Based on the divided current amplification circuit (21), one of the other divided current amplification circuits (22) to (24) is selected and driven, and the LED (1) is driven according to the luminous efficiency. Electric current is supplied. As a result, the light emission output of each LED (1) is made uniform, in other words, it is not necessary to select and use the LED array chips, which results in cost reduction.
ここでは、電流増幅回路(2)を４分割構成として説明し
たが、分割数が多い程、駆動電流値を細密化でき、ＬＥ
Ｄ(1)の発光出力を均一化できる。たとえば、各分割電
流増幅回路(21)，(22)，(23)，(24)の出力電流値が同様
の場合、負荷ＬＥＤ(1)への駆動電流は４種類である
が、この発明の構成において、第２の分割電流増幅回路
(22),(23),(24)のすべての出力電流値を異ならせた場
合、８種類にすることができる。Here, the current amplifier circuit (2) is described as a 4-division configuration, but the larger the number of divisions, the finer the drive current value, and
The light emission output of D (1) can be made uniform. For example, when the output current values of the divided current amplifier circuits (21), (22), (23) and (24) are the same, there are four types of drive currents to the load LED (1). Second divided current amplifier circuit in the configuration
When all the output current values of (22), (23) and (24) are made different, there can be eight kinds.
また、第１の分割電流増幅回路(21)も駆動選択制御した
場合、１６種類と多種類化制御が可能となる。さらに、
第２の分割電流増幅回路は異なる出力電流値のものをそ
れぞれ複数個ずつ具備してもよい。In addition, when the first divided current amplifier circuit (21) is also drive-selectively controlled, 16 types and multiple types can be controlled. further,
The second divided current amplifier circuit may be provided with a plurality of output current values.
ところで、上記のものは、各ＬＥＤ(1)毎に発光信号Ｓ
と３つの駆動選択信号ａ，ｂ，ｃで駆動制御しているの
で、メモリ回路としては従来の発光信号Ｓのみを入力す
る場合の４倍必要となり、駆動ＩＣも大きくなる。By the way, in the above, the light emission signal S is set for each LED (1).
Since the drive is controlled by the three drive selection signals a, b, and c, the memory circuit needs to be four times as large as the conventional case where only the light emission signal S is input, and the drive IC becomes large.
しかるに、ＬＥＤアレイチツプにおいて、チツプ内やチ
ツプ間の発光出力（効率）のばらつきは大きなものがあ
るが、複数のＬＥＤ(1)のうちで互に隣接するＬＥＤ(1)
間では通常の場合大差はない。この現象を利用して、隣
接する複数のＬＥＤ(1)に同一の駆動選択信号ａn，
ｂn，ｃnを入力して駆動するようにしているので、ＬＥ
Ｄアレイヘツドとしての発光出力のばらつきを記録画像
に支障のない程度に抑制することができる。その結果、
駆動選択信号ａ，ｂ，ｃのメモリ回路(5)，(6)，(7)の
数を減少させ、駆動ＩＣを小形にでき、かつ一層安価な
ＬＥＤアレイヘツドを提供できる。However, in the LED array chip, there are large variations in the light emission output (efficiency) within the chip or between the chips, but among the plurality of LEDs (1), the LEDs (1) adjacent to each other.
There is usually no great difference between the two. By utilizing this phenomenon, the same drive selection signal a n ,
Since b n and c n are input and driven, LE
It is possible to suppress variations in the light emission output of the D array head to such an extent that the recorded image is not hindered. as a result,
The number of memory circuits (5), (6), (7) for the drive selection signals a, b, c can be reduced, the drive IC can be downsized, and an inexpensive LED array head can be provided.
上記実施例は、記録素子としてＬＥＤ(1)を用いた場合
であるが、この発明の記録ヘツドは、これに限定される
ものではなく、発熱素子を用いたものにも適用可能であ
る。In the above-mentioned embodiment, the LED (1) is used as the recording element, but the recording head of the present invention is not limited to this, and can be applied to the one using the heating element.
たとえば、熱記録ヘツドで階調記録を行なう場合、発熱
抵抗素子への供給電力を制御し、高濃度画像を得るに伴
ない供給電力を大きくし発熱温度を高くしている。この
供給電力の制御として２つの方法があつた。第１の方法
は単位時間当りの電力供給量を一定とし、電力供給時間
を複数段階設け、所望の記録画像濃度を得るために必要
な発熱体温度を得ている。第２の方法は駆動回路の電源
電圧を制御することで、発熱抵抗素子への供給電力を制
御するものである。For example, when performing gradation recording with a thermal recording head, the electric power supplied to the heating resistor element is controlled to increase the electric power supplied to obtain a high density image and raise the heat generation temperature. There are two methods for controlling the supplied power. In the first method, the amount of power supply per unit time is constant, the power supply time is set in multiple stages, and the temperature of the heating element necessary to obtain a desired recorded image density is obtained. The second method is to control the power supply voltage of the drive circuit to control the power supplied to the heating resistance element.
これらの方法は、よく知られているので、ここでは詳述
しないが、いずれにしても階調記録の場合には、白黒の
みの２値記録に比べて表現階調数が多くなるほど同一ラ
インの記録走査回数の増大や記録走査の時間が長くな
り、１枚の記録画像を得るのに長時間を必要としてい
た。Since these methods are well known, they will not be described in detail here, but in any case, in the case of gradation recording, as the number of expressed gradations increases as compared with binary recording of black and white only, the same line is reproduced. Since the number of print scans increases and the print scan time becomes long, it takes a long time to obtain one print image.
この発明の熱記録ヘツドの場合、発熱抵抗素子の所定時
間内の駆動において、前述したようにすでに駆動電流値
を設定できるので、所定記録時間内で発熱素子枚に発熱
温度を制御でき、表現階調数が多くなつても１枚の記録
画像を得る時間は２値画像を得る場合と変わらない。In the case of the thermal recording head of the present invention, since the driving current value can be already set as described above when the heating resistance element is driven within the predetermined time, the heating temperature can be controlled on the heating element sheet within the predetermined recording time, and Even if the number of tones is large, the time for obtaining one recorded image is the same as that for obtaining a binary image.
以上のように、この発明によれば、電流増幅回路の複数
の分割電流増幅回路のうち、ベースとなる第１の分割電
流増幅回路と第２の分割電流増幅回路の１つまたは複数
を選択して、その合成電流により各記録素子を駆動させ
ることにより、各記録素子間での出力のばらつきを補正
して、複数の記録素子の出力をそれぞれ、高品質画像を
得るための許容範囲内に制御することが可能となる。As described above, according to the present invention, of the plurality of divided current amplification circuits of the current amplification circuit, one or more of the first divided current amplification circuit and the second divided current amplification circuit to be the base are selected. Then, by driving each recording element with the combined current, the output variation between each recording element is corrected and each output of multiple recording elements is controlled within the allowable range for obtaining a high quality image. It becomes possible to do.
その結果、例えばＬＥＤアレイヘッドの場合、各ＬＥＤ
として製造時にその発光出力にばらつきがあっても、実
用時には各ＬＥＤの発光出力を均一化することができ、
したがって、ＬＥＤなどの記録素子として、ばらつきの
少ないものを選別するという作業を必要としない。As a result, for example, in the case of an LED array head, each LED
As a result, even if there are variations in the light emission output during manufacturing, the light emission output of each LED can be made uniform in practical use,
Therefore, it is not necessary to select a recording element such as an LED having a small variation.
また、第１および第２の複数の分割電流増幅回路の各出
力電流値を互いに異なるように設定することも可能であ
り、その結果、分割電流増幅回路の分割数に比して駆動
電流値の制御段数を多くとることが可能になり、各記録
素子の駆動電流値の制御の細密化を達成することができ
るという格別な効果を奏するものである。It is also possible to set the output current values of the first and second plurality of divided current amplifier circuits to be different from each other, and as a result, the drive current value of the divided current amplifier circuit is smaller than that of the divided current amplifier circuits. The number of control steps can be increased, and the particular effect of being able to achieve fine control of the drive current value of each recording element can be achieved.
第１図はこの発明に係る記録ヘツドが適用されたＬＥＤ
アレイヘツドの駆動回路の一例を示す構成図、第２図は
従来の記録ヘツドにおける駆動回路の構成図、第３図は
第１図における要部の拡大図である。 (1)……記録素子、(2)……電流増幅回路、(3)……電流
制御回路、(4)……電流検出回路、(5)，(6)，(7)，(8)
……メモリ回路、(21)，(22)，(23)，(24)……分割電流
増幅回路。 なお、図中同一符号は同一もしくは相当部分を示す。FIG. 1 shows an LED to which a recording head according to the present invention is applied.
FIG. 2 is a block diagram showing an example of a drive circuit for an array head, FIG. 2 is a block diagram of a drive circuit for a conventional recording head, and FIG. 3 is an enlarged view of a main part in FIG. (1) …… Recording element, (2) …… Current amplification circuit, (3) …… Current control circuit, (4) …… Current detection circuit, (5), (6), (7), (8)
...... Memory circuit, (21), (22), (23), (24) …… Split current amplifier circuit. The same reference numerals in the drawings indicate the same or corresponding parts.
フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｂ４１Ｊ 2/455 Ｈ０１Ｌ 33/00 Ｊ 7376−4Ｍ Ｈ０４Ｎ 1/23 １０３ Ａ 9186−5Ｃ Continuation of front page (51) Int.Cl. 5 Identification number Office reference number FI Technical display location B41J 2/455 H01L 33/00 J 7376-4M H04N 1/23 103 A 9186-5C
Claims (2)
びこの第１の分割電流回路と並列接続された出力電流値
が異なる複数の第２の分割電流回路から構成され上記各
記録素子に上記第１及び第２の分割電流回路の電流が加
算された駆動電流を出力する電流増幅回路と、上記第１
の分割電流回路の出力電流値を検出する電流検出回路
と、上記電流検出回路の検出信号に基づき上記各記録素
子の出力効率に応じた上記第２の分割電流回路を選択す
る電流制御回路とを備え、上記電流増幅回路は上記第１
の分割電流回路の電流と選択された第２の分割電流回路
の電流とが加算された駆動電流を出力するように構成し
たことを特徴とする記録ヘッド。1. A recording element comprising a plurality of recording elements, a first divided current circuit, and a plurality of second divided current circuits connected in parallel with the first divided current circuit and having different output current values. A current amplifier circuit that outputs a drive current to which the currents of the first and second divided current circuits are added,
A current detection circuit for detecting the output current value of the divided current circuit, and a current control circuit for selecting the second divided current circuit according to the output efficiency of each recording element based on the detection signal of the current detection circuit. The current amplification circuit includes the first
And a current of the selected second divided current circuit is added to output a drive current.
数の上記発光素子毎に供給電力を制御することを特徴と
する特許請求の範囲第１項記載の記録ヘッド。2. The recording head according to claim 1, wherein the recording element is a light emitting element, and the supply power is controlled for each of a plurality of adjacent light emitting elements.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18198685A JPH0649378B2 (en) | 1985-08-19 | 1985-08-19 | Record head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18198685A JPH0649378B2 (en) | 1985-08-19 | 1985-08-19 | Record head |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6241056A JPS6241056A (en) | 1987-02-23 |
| JPH0649378B2 true JPH0649378B2 (en) | 1994-06-29 |
Family
ID=16110326
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18198685A Expired - Fee Related JPH0649378B2 (en) | 1985-08-19 | 1985-08-19 | Record head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0649378B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1988007729A1 (en) * | 1987-04-01 | 1988-10-06 | Eastman Kodak Company | Printer apparatus |
| JPS6469369A (en) * | 1987-09-11 | 1989-03-15 | Stanley Electric Co Ltd | Light quantity controller for light-emitting element |
| JPH01125251A (en) * | 1987-11-11 | 1989-05-17 | Seiko Epson Corp | Thermal head drive device |
| JPH05270052A (en) * | 1992-01-31 | 1993-10-19 | Kyocera Corp | Image forming apparatus |
| US8866410B2 (en) * | 2007-11-28 | 2014-10-21 | Cree, Inc. | Solid state lighting devices and methods of manufacturing the same |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57126678A (en) * | 1981-01-30 | 1982-08-06 | Oki Electric Ind Co Ltd | Controlling method for driving of thernal recoding device |
| JPS59201876A (en) * | 1983-04-30 | 1984-11-15 | Fuji Xerox Co Ltd | Recorded density correcting device |
| JPS59202879A (en) * | 1983-05-06 | 1984-11-16 | Canon Inc | Optical printer |
| JPS59222368A (en) * | 1983-06-01 | 1984-12-14 | Mitsubishi Electric Corp | Driving circuit of thermal head |
| JPS6092880A (en) * | 1983-10-27 | 1985-05-24 | Fujitsu Ltd | Driving circuit for led array |
-
1985
- 1985-08-19 JP JP18198685A patent/JPH0649378B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6241056A (en) | 1987-02-23 |
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