JPH01160659A - Led drive circuit of led printer - Google Patents
Led drive circuit of led printerInfo
- Publication number
- JPH01160659A JPH01160659A JP62320231A JP32023187A JPH01160659A JP H01160659 A JPH01160659 A JP H01160659A JP 62320231 A JP62320231 A JP 62320231A JP 32023187 A JP32023187 A JP 32023187A JP H01160659 A JPH01160659 A JP H01160659A
- Authority
- JP
- Japan
- Prior art keywords
- mos
- led
- circuit
- output
- fet
- 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.)
- Pending
Links
- 239000002131 composite material Substances 0.000 abstract description 2
- 238000005286 illumination Methods 0.000 abstract 2
- 150000001875 compounds Chemical class 0.000 abstract 1
- 238000012423 maintenance Methods 0.000 abstract 1
- 230000000630 rising effect Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 2
- 208000035795 Hypocalcemic vitamin D-dependent rickets Diseases 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 208000033584 type 1 vitamin D-dependent rickets Diseases 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K15/00—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers
- G06K15/02—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers
- G06K15/12—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers
- G06K15/1238—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers simultaneously exposing more than one point
- G06K15/1242—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers simultaneously exposing more than one point on one main scanning line
- G06K15/1247—Arrangements for producing a permanent visual presentation of the output data, e.g. computer output printers using printers by photographic printing, e.g. by laser printers simultaneously exposing more than one point on one main scanning line using an array of light sources, e.g. a linear array
-
- 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
- B41J2/435—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of radiation to a printing material or impression-transfer material
- B41J2/447—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of radiation to a printing material or impression-transfer material using arrays of radiation sources
- B41J2/45—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of radiation to a printing material or impression-transfer material using arrays of radiation sources using light-emitting diode [LED] or laser arrays
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Optics & Photonics (AREA)
- General Engineering & Computer Science (AREA)
- Toxicology (AREA)
- General Health & Medical Sciences (AREA)
- Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Dot-Matrix Printers And Others (AREA)
- Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
- Facsimile Heads (AREA)
- Fax Reproducing Arrangements (AREA)
Abstract
Description
【発明の詳細な説明】
（イ）産業上の利用分野
本発明は、プリンタヘッドに接続移れたＮ個（Ｎは自然
数）のＬＥＤを一定の発光量となすＬＥＤプリンタのＬ
ＥＤ駆動回路に関するものである。DETAILED DESCRIPTION OF THE INVENTION (a) Industrial field of application The present invention relates to an LED printer in which N LEDs (N is a natural number) connected to a printer head emit a constant amount of light.
This relates to an ED drive circuit.
（ロ）従来の技術
従来、Ｎ個のＬＥＤをプリンタヘッドに接読したＬＥＤ
プリンタのＬＥＤ駆動回路は、制御回路から出力される
Ｎ個の各制御信号によってＮ個の各ＭＯＳ−ＦＥＴを駆
動／非駆動状態となし、Ｎ個の各ＭＯＳ−ＦＥＴの駆動
／非駆動状態によってＮ個の各ＬＥＤを駆動／非駆動状
態となし、これよりＮ個の各ＬＥＤの光を感光紙に発光
してドツトを感光紙に印字していた。(b) Conventional technology Conventionally, N LEDs were read directly from the printer head.
The LED drive circuit of the printer drives or non-drives each of the N MOS-FETs according to the N control signals output from the control circuit, and changes the state depending on the drive/non-drive state of each of the N MOS-FETs. Each of the N LEDs was set to a driven/non-driven state, and the light from each of the N LEDs was emitted onto photosensitive paper to print dots on the photosensitive paper.
（八）発明が解決しようとする問題点
しかしながら前記従来の技術において、単に制御回路か
ら出力されるＮ個の各制御信号によってＮ個の各ＭＯＳ
−ＦＥＴを駆動／非駆動状態となし、Ｎ個の各ＭＯＳ−
ＦＥＴの駆動／非駆動状態によってＮ個の各ＬＥＤを駆
動／非駆動状態となすのみでは、Ｎ個の各ＬＥＤの発光
量が、製造上におけるＬＥＤ駆動回路のばらつき及びＮ
個の各ＬＥＤの発光特性のばらつき等に応じて異なるこ
とになり、これよりＮ個の各ＬＥＤの光を感光紙に発光
してドツトを感光紙に印字しても、Ｎ個の各ＬＥＤの発
光量の差異によって、ドツトが濃淡を生ずる問題点があ
った。(8) Problems to be Solved by the Invention However, in the above-mentioned conventional technology, each of the N MOS
-FET is driven/non-driven, each of N MOS-
Simply setting each of the N LEDs to a driving/non-driving state depending on the driving/non-driving state of the FET will result in the amount of light emitted by each of the N LEDs being affected by manufacturing variations in the LED drive circuit and N
Therefore, even if the light from each of the N LEDs is emitted onto photosensitive paper and a dot is printed on the photosensitive paper, the There was a problem in that the dots were shaded due to differences in the amount of light emitted.
（二〉問題点を解決するための手段
本発明は前記問題点を解決するためになされたものであ
り、プリンタヘッドに接続されたＮ個（Ｎは自然数）の
ＬＥＤを駆動／非駆動状態となすＮ個の主ＭＯＳ−ＦＥ
Ｔと、前記Ｎ個の主ＭＯＳ−ＦＥＴを駆動／非駆動状態
となすＮ個の制御信号を出力する制御回路を設け、前記
Ｎ個の各ＬＥＤの光を感光紙に発光してドツトを前記感
光紙に印字するＬＥＤプリンタのＬＥＤ駆動回路におい
て、前記Ｎ個のＬＥＤを一定の発光量となすＮ個の補正
データを保持し、前記Ｎ個の補正データに基いて補正信
号を出力する補正回路と、前記Ｎ個の各主ＭＯＳ−ＦＥ
Ｔに並列接続され、前記補正信号によって駆動される補
助ＭＯＳ−ＦＥＴを設け、前記主ＭＯＳ−ＦＥＴ及び前
記補助ＭＯＳ−ＦＥＴの合成電流によって前記Ｎ個のＬ
ＥＤを一定の発光量となすＬＥＤプリンタのＬＥＤ駆動
回路である。(2) Means for Solving the Problems The present invention has been made to solve the above problems, and it enables N LEDs (N is a natural number) connected to the printer head to be driven/non-driven. N main MOS-FEs
T and a control circuit that outputs N control signals for driving/non-driving the N main MOS-FETs are provided, and the light from each of the N LEDs is emitted onto a photosensitive paper to form a dot on the photosensitive paper. In an LED drive circuit of an LED printer that prints on photosensitive paper, a correction circuit that holds N pieces of correction data for making the N LEDs emit a constant amount of light and outputs a correction signal based on the N pieces of correction data. and each of the N main MOS-FEs.
An auxiliary MOS-FET connected in parallel to T and driven by the correction signal is provided, and a combined current of the main MOS-FET and the auxiliary MOS-FET is used to
This is an LED drive circuit for an LED printer that makes the ED emit a constant amount of light.
（＊）作用
前記構成の本発明によれば、制御回路から出力されるＮ
個の各制御信号によってＮ個の各主ＭＯＳ−ＦＥＴが駆
動／非駆動状態とされ、Ｎ個の各主ＭＯＳ−ＦＥＴの駆
動／非駆動状態によってＮ個の各ＬＥＤが駆動／非駆動
状態とされ、更に補正回路から出力される補正信号によ
って補助ＭＯＳ−ＦＥＴが駆動され、これより並列接続
された主ＭＯＳ−ＦＥＴ及び補助ＭＯＳ−ＦＥＴの合成
電流によってＮ個のＬＥＤが一定の発光量とされ、ドツ
トが均一の濃度で感光紙に印字されることになる。(*) Effect According to the present invention having the above configuration, the N output from the control circuit is
Each of the N main MOS-FETs is set to a driven/non-driven state by each of the control signals, and each of the N LEDs is set to a driven/non-driven state depending on the driven/non-driven state of each of the N main MOS-FETs. Furthermore, the auxiliary MOS-FET is driven by the correction signal output from the correction circuit, and the combined current of the main MOS-FET and the auxiliary MOS-FET connected in parallel causes the N LEDs to emit a constant amount of light. , dots are printed on photosensitive paper with uniform density.
（へ）実施例 本発明の詳細を図示の実施例により具体的に説明する。(f) Example The details of the present invention will be specifically explained with reference to the illustrated embodiments.
第１図は本発明のＬＥＤプリンタのＬＥＤ駆動回路を示
す回路図であって、図番及び構成を説明すると、（１）
は電源電圧ＶＤＤＩ （＞ Ｏ）が入力する電源端子、
（２）は電源電圧Ｖｂｏ＊ （＞ Ｏ）が入力する電源
端子、（３−１）・・・・・・（３−Ｎ）は、基板が前
記電源端子（１）と接続されると共にソースが前記電源
端子（２）と接続された主ＭＯＳ−ＦＥＴとしてのＰチ
ャンネル形ＭＯＳ−ＦＥＴ（以下Ｐ−ＭＯＳと称す）、
（４−１）・・・・・・（４−Ｎ） 、 （５−１）・
・・・・・（５−Ｎ） 、 （６−１）・・・・・・（
６−Ｎ）は、基板が前記電源端子（１）と接続されると
共にソニスが前記電源端子（２）と接続きれた補助ＭＯ
Ｓ−ＦＥＴとしてのＰ−ＭＯＳであって、前記Ｐ−ＭＯ
Ｓ（３−１）・・・・・・（３−１ｉ） 、 （４−１
）・旧・・（４−Ｎ） 、 ＜５−１）・・・・・・（
５−Ｎ） 、 （６−１）・・・・・・（６−Ｎ）の電
流比率は各々、１０：４：２：１とされ、（７−１＞・
・・・・・（７−Ｎ）は各々、前記Ｐ −Ｍ ＯＳ （
３−１）（４−１）（５−１）（６−１） 、・・・・
・・（３−Ｎ）（４−Ｎ）（５−Ｎ）（６−Ｎ）のドレ
インと接続された出力端子、（８−１）・・・・・・（
８−Ｎ）は各々、アノードが前記出力端子（７−１）・
・・・・・（７−Ｎ）と接続されると共にカソードが接
地きれ、プリンタヘッド（図示せず）に接続されたＬＥ
Ｄ、（９）は、前記ＬＥＤ（８−１）・・・・・・（８
−Ｎ）の駆動時に「１」、前記ＬＥＤ（８−１）・・・
・・・（８−Ｎ）の非駆動時に「０．になるＮビットの
制御データが入力するデータ端子、（１０）はクロック
信号Ａが入力するクロック端子、（１１）は前記クロッ
ク信号Ａの立上り（又は立下り）でラッチ移れた前記Ｎ
ビットの制御データを直後の前記クロック信号Ａの立下
り（又は立上り）で順次格納するシフトレジスタ、 （
１２）は、前記ＬＥＤ（８−１＞・・・・・・（８−Ｎ
）の駆動期間に、ハイレベル（以下「１」と称す）の５
ＴＲＯＢＥ信号を発生する５ＴＲＯＢＥ信号発生器、（
１３−１）・・・・・・（１３−Ｎ）は各々、一方の入
力端子が前記シフトレジスタ（１１）の出力端子Ｑ１・
・・・・・Ｑ、と接続されると共に他方の入力端子が前
記５ＴＲＯＢＥ信号発生器（１２）と接続きれたＡＮＤ
回路、（１４−１＞・・・・・・（１４−Ｎ）は各々、
入力端子が前記ＡＮＤ回路（１３−１）・・・・・・（
１３−Ｎ）の出力端子と接続されると共に出力端子が前
記Ｐ−ＭＯＳ（３−１）・・・・−（３−Ｎ）のゲート
と接続されたインバ−夕、（１５）は前記Ｌ Ｅ Ｄ
（８−１）・・・・・・（８−Ｎ）を一定の発光量とな
す３Ｎビツトの補正データが入力するデータ端子、（１
６）はクロック信号Ｂが入力するクロック端子、（１７
−１）（１８−１）（１９−１） 、・・・・・・（１
７−Ｎ）（１８−Ｎ） （１９−Ｎ）はシリアルに接続
され、前記クロック信号Ｂの立上り（又は立下り）でラ
ッチされた前記３Ｎビツトの補正データを直後の前記ク
ロック信号Ｂの立下り（又は立上り）で順次格納するＤ
型フリッププロップ（以下Ｄ−ＦＦと称す）、（２１−
１）（２２−１）（２３−１） 、・・・・・・（２１
−Ｎ）（２２−Ｎ）（２３−Ｎ）は各々、一方の入力端
子が前記ＡＮＤ回路（１３−１）・・・・−（１３−Ｎ
）の出力端子と接続されると共に他方の入力端子が前記
Ｄ −Ｆ Ｆ （１７−１）（１８−１）（１９−１）
、・・・・・・（１７−Ｎ）（１Ｂ−Ｎバｌ９−Ｎ）
の出力端子と接続され、出力端子が前記Ｐ −Ｍ ＯＳ
（４−１）（５−１＞（６−１） 、・・・・・・（
４−Ｎ）（５−Ｎ）（６−Ｎ）のゲートと接続されたＮ
ＡＮＤＡＮＤ回路、尚、Ｌ Ｅ Ｄ （８−１）・・・
・・・（８−Ｎ）を除く第１図の構成は１チツプのＩＣ
に集積化きれる。FIG. 1 is a circuit diagram showing the LED drive circuit of the LED printer of the present invention, and the figure number and configuration are as follows: (1)
is the power supply terminal to which the power supply voltage VDDI (> O) is input,
(2) is the power supply terminal to which the power supply voltage Vbo* (> O) is input, (3-1)... (3-N) is the source terminal to which the board is connected to the power supply terminal (1). is a P-channel type MOS-FET (hereinafter referred to as P-MOS) as a main MOS-FET connected to the power supply terminal (2),
(4-1)...(4-N), (5-1)・
・・・・・・(5-N) , (6-1)・・・・・・(
6-N) is an auxiliary MO in which the board is connected to the power terminal (1) and the SONIS is connected to the power terminal (2).
A P-MOS as an S-FET, the P-MOS
S(3-1)...(3-1i), (4-1
)・Old・・・(4-N), <5-1)・・・・・・(
The current ratios of (5-N), (6-1)... (6-N) are respectively 10:4:2:1, and (7-1>.
...(7-N) are each of the above P-M OS (
3-1) (4-1) (5-1) (6-1) ,...
...Output terminal connected to the drain of (3-N) (4-N) (5-N) (6-N), (8-1) ...... (
8-N), the anodes of which are connected to the output terminals (7-1) and
...LE connected to (7-N) and whose cathode is grounded, and connected to the printer head (not shown)
D, (9) is the LED (8-1) (8
-N) is "1" when the LED (8-1)...
...(8-N) is a data terminal to which N-bit control data that becomes 0 when not driven is input, (10) is a clock terminal to which clock signal A is input, (11) is a terminal of said clock signal A. The above N that was latched at the rising edge (or falling edge)
a shift register that sequentially stores bit control data at the falling edge (or rising edge) of the clock signal A immediately after;
12) is the LED (8-1>...(8-N)
), the high level (hereinafter referred to as "1") 5
5 TROBE signal generator that generates the TROBE signal, (
13-1)...(13-N) each have one input terminal connected to the output terminal Q1 of the shift register (11).
. . . Q, and the other input terminal is connected to the 5 TROBE signal generator (12).
The circuits (14-1>...(14-N) are each
The input terminal is the AND circuit (13-1) (
13-N) and whose output terminal is connected to the gate of the P-MOS (3-1)...-(3-N); (15) is the L E D
(8-1) Data terminal to which 3N-bit correction data that makes (8-N) a constant light emission amount is input;
6) is a clock terminal to which clock signal B is input, (17
-1) (18-1) (19-1) , ...... (1
7-N) (18-N) (19-N) are serially connected, and transmit the 3N bits of correction data latched at the rising edge (or falling edge) of the clock signal B immediately after the rising edge (or falling edge) of the clock signal B. D to be stored sequentially on the downward (or rising)
type flip-prop (hereinafter referred to as D-FF), (21-
1) (22-1) (23-1) , ...... (21
-N) (22-N) (23-N), one input terminal of which is the AND circuit (13-1)...-(13-N)
), and the other input terminal is connected to the output terminal of the D -F F (17-1) (18-1) (19-1).
,...(17-N) (1B-N bar 19-N)
The output terminal is connected to the output terminal of the P-M OS.
(4-1) (5-1>(6-1) , ・・・・・・(
N connected to the gates of 4-N) (5-N) (6-N)
AND circuit, and L E D (8-1)...
...The configuration in Figure 1 except for (8-N) is a 1-chip IC.
It can be integrated into
第２図は本発明のＬＥＤプリンタのＬＥＤ駆動回路に係
る特性を示す図面であって、ｉ、ｉ。FIG. 2 is a diagram showing characteristics related to the LED drive circuit of the LED printer of the present invention, and shows the characteristics of the LED drive circuit of the LED printer of the present invention.
ｉ、ｉｖは各々、Ｐ −Ｍ ＯＳ （３−１＞−−−−
−−（３−Ｎ） 、 Ｐ −Ｍ ＯＳ （４−１）・・
・・・・（４−Ｎ） 、 Ｐ −Ｍ ＯＳ （５−１）
・旧・・（５−Ｎ＞、Ｐ−ＭＯＳ（６−１）・・・・・
・（６−Ｎ）に対応し、ＩはＰ−Ｍ ＯＳ （６−１）
・・・・・・（６−Ｎ）の駆動電流（例えば０゜６３ｍ
Ａ）である。i and iv are each P-M OS (3-1>----
--(3-N), P-MOS (4-1)...
...(4-N), P-M OS (5-1)
・Old...(5-N>, P-MOS(6-1)...
・Corresponds to (6-N), I is P-M OS (6-1)
......(6-N) drive current (e.g. 0°63m
A).
第３図は第２図と同様に本発明のＬＥＤプリンタのＬＥ
Ｄ駆動回路に係る特性を示す図面であって、３ビツトの
補正データで各ＬＥＤの駆動電流を補正することから、
各ＬＥＤの駆動電流を補正する補正データの組合せは２
１−８通りである。FIG. 3 shows the LE of the LED printer of the present invention, similar to FIG. 2.
This is a drawing showing the characteristics related to the D drive circuit, and since the drive current of each LED is corrected using 3-bit correction data,
There are 2 combinations of correction data to correct the drive current of each LED.
There are 1-8 options.
ここで全ＬＥＤを一定の発光量となすには、全ＬＥＤを
一定の発光量となす条件の基で各ＬＥＤの駆動電流を試
験的に測定し、単一のＬＥＤの駆動電流を標準値に設定
しなければならない。具体的には、分類５の補正データ
’ Ｉ Ｊ ｅ ’ ＯＪ ｖｒ□、を各々Ｄ −Ｆ
Ｆ （１７−１）・・・・・・（１７−Ｎ） 、 （１
８−１）・・・・・・（１８−Ｎ） 、 （１９−１）
・・・・・・（１９−Ｎ）に格納し、ＬＥＤ（８−１＞
・・・・・・（８−Ｎ）を一定の発光量となす条件の基
でＬ Ｅ Ｄ （８−１）・・・・・・（８−Ｎ）の駆
動電流を試験的に測定し、例えば単一のＬＥＤの駆動電
流８．８２ｍＡを標準値に設定している。以下、Ｌ Ｅ
Ｄ （８−１＞（８−Ｎ）を用いて具体例を説明する
。In order to make all LEDs emit a constant amount of light, test the drive current of each LED under conditions that make all LEDs emit a constant amount of light, and set the drive current of a single LED to a standard value. must be set. Specifically, the correction data ' I J e ' OJ vr□ of classification 5 are respectively D −F
F (17-1)...(17-N), (1
8-1)...(18-N), (19-1)
...... (19-N), and LED (8-1>
The drive current of L E D (8-1) (8-N) was experimentally measured under the condition that (8-N) had a constant light emission amount. For example, a single LED drive current of 8.82 mA is set as a standard value. Below, L E
A specific example will be explained using D (8-1>(8-N)).
まずＬ Ｅ Ｄ （８−１＞の駆動電流を試験的に測定
した結果、測定データが標準値に比して−１，８９ｍＡ
となり、Ｌ Ｅ Ｄ （８−１）の駆動電流が６．９３
ｍＡとなった場合、Ｌ Ｅ Ｄ （８−１）の駆動電流
６．９３ｍＡは電流比率１１１（−１４Ｉ−３Ｉ）に対
応することから、分類２の補正データ’ＯＪＩ”ＯＪ。First, as a result of experimentally measuring the driving current of LED (8-1), the measured data was -1.89mA compared to the standard value.
Therefore, the drive current of L E D (8-1) is 6.93
mA, the drive current of 6.93 mA of L E D (8-1) corresponds to the current ratio 111 (-14I-3I), so the correction data 'OJI'OJ of classification 2.
「１」をＤ −Ｆ Ｆ （１７−１）（１８−１）（１
９−１＞に順次格納すればよい。モして５ＴＲＯＢＢ信
号発生器（１２）から「１」の５ＴＲＯＢＥ信号が発生
すると共に、シフトレジスタ（１１）の出力端子Ｑ８か
ら「１」の制御信号が出力されると、Ｐ−ＭＯＳ（３−
１＞は、ゲート電圧がＡＮＤ回路（１３）及びインバー
タ（１４）を介して「０」に保持されてオンする。同時
にＤ −Ｆ Ｆ （１７−１）（１ｇ−１）（１９−１
＞の出力端子から補正データ「０」、「０」、「１」に
基く補正信号” Ｊ ｅ ’ ＯＪ ＋ ’ Ｉ Ｊが
出力されると共に、ＡＮＤ回路（１３）の出力端子から
「１」が出力されると、Ｐ −Ｍ ＯＳ （４−１）（
５−１＞は、各ゲート電圧がＮＡＮＤＡＮＤ回路−１）
（２２−１）を介して「１」に保持されてオフし、Ｐ−
ＭＯＳ（６−１）は、ゲート電圧がＮＡＮＤＡＮＤ回路
−１）を介してｒ□、に保持されてオンする。従ってＬ
Ｅ Ｄ （８−１）の駆動電流は、Ｐ−Ｍ ＯＳ （
３−１）（６−１）の合成電流、即ち電流比率１１１（
−１０Ｉ＋Ｉ）の合成電流６．９３ｍＡとなり、ＬＥＤ
（８−１）は一定の発光量とされる。"1" is D -F F (17-1) (18-1) (1
9-1>. When the 5TROBE signal of "1" is generated from the 5TROBB signal generator (12) and the control signal of "1" is output from the output terminal Q8 of the shift register (11), the P-MOS (3-
1> is turned on when the gate voltage is held at "0" via the AND circuit (13) and the inverter (14). At the same time D -F F (17-1) (1g-1) (19-1
A correction signal "J e ' OJ + ' I J" based on the correction data "0", "0", "1" is output from the output terminal of the AND circuit (13), and "1" is output from the output terminal of the AND circuit (13). When output, P -M OS (4-1) (
5-1>, each gate voltage is NANDAND circuit-1)
(22-1) is held at "1" and turned off, and P-
The gate voltage of the MOS (6-1) is held at r□ via the NAND AND circuit (1), and the MOS (6-1) is turned on. Therefore L
The driving current of E D (8-1) is P-M OS (
3-1) (6-1) composite current, that is, the current ratio 111 (
-10I+I), the combined current is 6.93mA, and the LED
(8-1) is a constant amount of light emission.
次にＬ Ｅ Ｄ （８−Ｎ）の駆動電流を試験的に測定
した結果、測定データが標準値に比して＋１．２６ｍＡ
となり、Ｌ Ｅ Ｄ （８−Ｎ）の駆動電流が１０．０
８ｍＡとなった場合、Ｌ Ｅ Ｄ （８−Ｎ）の駆動電
流１０．０８ｍＡは電流比率１６Ｉ（−１４Ｉ＋２Ｉ）
に対応することから、分類７の補正データｒ１」、「１
．。Next, as a result of experimentally measuring the drive current of L E D (8-N), the measured data was +1.26 mA compared to the standard value.
Therefore, the drive current of L E D (8-N) is 10.0
When the current is 8 mA, the driving current of L E D (8-N) is 10.08 mA, and the current ratio is 16 I (-14 I + 2 I).
Therefore, the correction data r1 of classification 7,
．． .
「０」をＤ −Ｆ Ｆ （１７−Ｎ）（１８−Ｎ）（１
９−Ｎ）に順次格納すればよい、そして５ＴＲＯＢＥ信
号発生器（１２）から「１」の５ＴＲＯＢＥ信号が発生
すると共に、シフトレジスタ（１１）の出力端子Ｑ。か
ら「１゜の制御信号が出力されると、Ｐ−ＭＯＳ（３−
Ｎ）は、ゲート重圧がＡＮＤ回路（１３−Ｎ）及びイン
バータ（１４−Ｎ）を介して「０」に保持されてオンす
る。"0" is D -F F (17-N) (18-N) (1
9-N), and a 5TROBE signal of "1" is generated from the 5TROBE signal generator (12) and output terminal Q of the shift register (11). When a 1° control signal is output from P-MOS (3-
N) is turned on when the gate pressure is held at "0" via the AND circuit (13-N) and the inverter (14-N).
同時にＤ −Ｆ Ｆ （１７−Ｎ）（１８−Ｎ）（１９
−Ｎ）の出力端子から補正データ’ Ｉ Ｊ ＊ ’
Ｉ Ｊ ｔ ’ ＯＪに基く補正信号” Ｊ ｖ ’
Ｉ Ｊ ＊ ’ ＯＪが出力されると共に、ＡＮＤ回路
（１３−Ｎ）の出力端子から「１」が出力されると、Ｐ
−Ｍ ＯＳ （４−Ｎ）（５−Ｎ）は、各ゲート電圧
がＮＡＮＤＡＮＤ回路−Ｎ）（２２−Ｎ）を介して１０
」に保持されてオンし、Ｐ−ＭＯＳ（６−Ｎ）は、ゲー
ト電圧がＮＡＮＤＡＮＤ回路−Ｎ）を介して「１」に保
持されてオフする。従ってＬ Ｅ Ｄ （８−Ｎ）の駆
動電流は、Ｐ −Ｍ ＯＳ （３−Ｎ）（４−Ｎ）（５
−Ｎ）の合成電流、即ちｔ流化率１６Ｉ（＝１０Ｉ＋４
Ｉ＋２Ｉ）の合成電流１０．０８ｍＡとなり、Ｉ、 Ｅ
Ｄ （８−Ｎ）はＩ、ＥＤ（８−１）と同様に一定の
発光量ときれる。At the same time D -F F (17-N) (18-N) (19
Correction data 'I J *' from the output terminal of -N)
I J t ' Correction signal based on OJ "J v '
I J * ' When OJ is output and "1" is output from the output terminal of the AND circuit (13-N), P
-MOS (4-N) (5-N), each gate voltage is 10 through the NAND AND circuit -N) (22-N).
The P-MOS (6-N) is held at "1" through the NAND circuit (-N) and turned off. Therefore, the driving current of L E D (8-N) is P -M OS (3-N) (4-N) (5
-N), that is, the current conversion rate is 16I (=10I+4
The combined current of I+2I) is 10.08mA, and
D (8-N) can be determined as a constant amount of light emission similarly to I and ED (8-1).
以上の動作によりＬ Ｅ Ｄ （８−１）・・・・・・
（８−Ｎ）は一定の発光量とされることになる。Through the above operations, L E D (8-1)...
(8-N) is a constant amount of light emission.
尚、３ビツトの補正データで各ＬＥＤの駆動電流を補正
するのみならず、４ビツト以上の補正データで各ＬＥＤ
の駆動電流を補正すれば、各ＬＥＤの駆動電流をより確
実に一定の発光量とできることは言うまでもない。In addition to correcting the drive current of each LED with 3-bit correction data, we also use 4-bit or more correction data to correct the drive current of each LED.
It goes without saying that by correcting the drive current of each LED, the drive current of each LED can be more reliably made to emit a constant amount of light.
（ト）発明の効果
本発明によれば、各ＬＥＤの発光量が、製造上における
ＬＥＤ駆動回路のばらつき及びＮ個の各ＬＥＤの発光特
性のばらつき等に応じて異なっても、補正信号によって
Ｎ個の各ＬＥＤは一定の発光量とされ、これよりＮ個の
各ＬＥＤの光を感光紙に発光してドツトを感光紙に印字
しても、ドツトが一定の濃度で印字される効果が得られ
る。(G) Effects of the Invention According to the present invention, even if the amount of light emitted from each LED differs due to variations in the LED drive circuit during manufacturing and variations in the light emission characteristics of each of the N LEDs, the correction signal Each of the N LEDs is assumed to emit a constant amount of light, so even if the light from each of the N LEDs is emitted onto photosensitive paper and dots are printed on the photosensitive paper, the effect is that the dots are printed at a constant density. It will be done.
第１図は本発明のＬＥＤプリンタのＬＥＤ駆動回路を示
す回路図、第２図及び第３図は本発明のＬＥＤプリンタ
のＬＥＤ駆動回路に係る特性を示す図面である。
（３−１’）・・・・・・（３−Ｎ） 、 （４−１）
・・・・・・（４−Ｎ） 、 （５−１）・・・・・・
（５−Ｎ） 、 （６−１）・・・・・・（６−Ｎ）・
・・Ｐ−ＭＯＳ、 （８−１）・・・・・・（８−Ｎ
）・・・ＬＥＤ、 （１１）・・・シフトレジスフ、
（１２）・−８Ｔ ＲＯＢ Ｅ信号発生器、 （１３−
１）・・・・・・くｌ３−Ｎ）・・・ＡＮＤ回路、 （
１７−１）（１ｇ−１＞（１９−１） 、・・・・・・
（１７−Ｎ）（１ｇ−Ｎ）（ｌ９−Ｎ）・・・Ｄ−ＦＦ
、 （２１−１）（２２−１）（２３−１） 、・・
・・・・（２１−Ｎ）（２２−Ｎ）（２３−Ｎ）・・・
ＮＡＮＤＡＮＤ
回路人 三洋電機株式会社
代理人 弁理士 西野卓嗣 外１名FIG. 1 is a circuit diagram showing an LED drive circuit of an LED printer according to the present invention, and FIGS. 2 and 3 are diagrams showing characteristics related to the LED drive circuit of an LED printer according to the present invention. (3-1')...(3-N), (4-1)
......(4-N), (5-1)...
(5-N), (6-1)...(6-N)・
...P-MOS, (8-1)... (8-N
)...LED, (11)...Shift register,
(12)・-8T ROB E signal generator, (13-
1)......Cl3-N)...AND circuit, (
17-1) (1g-1>(19-1) ,...
(17-N) (1g-N) (l9-N)...D-FF
, (21-1) (22-1) (23-1) ,...
...(21-N) (22-N) (23-N)...
NANDAND Circuit person Sanyo Electric Co., Ltd. agent Patent attorney Takuji Nishino and 1 other person
Claims (1)
のＬＥＤを駆動／非駆動状態となすＮ個の主ＭＯＳ−Ｆ
ＥＴと、前記Ｎ個の主ＭＯＳ−ＦＥＴを駆動／非駆動状
態となすＮ個の制御信号を出力する制御回路を設け、前
記Ｎ個の各ＬＥＤの光を感光紙に発光してドットを前記
感光紙に印字するＬＥＤプリンタのＬＥＤ駆動回路にお
いて、前記Ｎ個のＬＥＤを一定の発光量となすＮ個の補
正データを保持し、前記Ｎ個の補正データに基いて補正
信号を出力する補正回路と、前記Ｎ個の各主ＭＯＳ−Ｆ
ＥＴに並列接続され、前記補正信号によって駆動される
補助ＭＯＳ−ＦＥＴを設け、前記主ＭＯＳ−ＦＥＴ及び
前記補助ＭＯＳ−ＦＥＴの合成電流によって前記Ｎ個の
ＬＥＤを一定の発光量となすことを特徴とするＬＥＤプ
リンタのＬＥＤ駆動回路。(1) N units connected to the printer head (N is a natural number)
N main MOS-Fs that drive/non-drive the LEDs of
ET and a control circuit that outputs N control signals for driving/non-driving the N main MOS-FETs, and emits light from each of the N LEDs onto photosensitive paper to form dots on the photosensitive paper. In an LED drive circuit of an LED printer that prints on photosensitive paper, a correction circuit that holds N pieces of correction data for making the N LEDs emit a constant amount of light and outputs a correction signal based on the N pieces of correction data. and each of the N main MOS-Fs.
An auxiliary MOS-FET connected in parallel to the ET and driven by the correction signal is provided, and a combined current of the main MOS-FET and the auxiliary MOS-FET causes the N LEDs to emit a constant amount of light. LED drive circuit for an LED printer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62320231A JPH01160659A (en) | 1987-12-17 | 1987-12-17 | Led drive circuit of led printer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62320231A JPH01160659A (en) | 1987-12-17 | 1987-12-17 | Led drive circuit of led printer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01160659A true JPH01160659A (en) | 1989-06-23 |
Family
ID=18119190
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62320231A Pending JPH01160659A (en) | 1987-12-17 | 1987-12-17 | Led drive circuit of led printer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01160659A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5990920A (en) * | 1995-08-11 | 1999-11-23 | Oki Data Corporation | Driving apparatus with circuits for efficiently transferring and storing compensation data |
| US6351278B1 (en) * | 1992-03-05 | 2002-02-26 | Rohm Co., Ltd. | Circuit for controlling current for driving printing dot array |
| US7599107B2 (en) | 2006-03-20 | 2009-10-06 | Seiko Epson Corporation | Electro-optical device, electronic apparatus, and driving method |
-
1987
- 1987-12-17 JP JP62320231A patent/JPH01160659A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6351278B1 (en) * | 1992-03-05 | 2002-02-26 | Rohm Co., Ltd. | Circuit for controlling current for driving printing dot array |
| US5990920A (en) * | 1995-08-11 | 1999-11-23 | Oki Data Corporation | Driving apparatus with circuits for efficiently transferring and storing compensation data |
| US7599107B2 (en) | 2006-03-20 | 2009-10-06 | Seiko Epson Corporation | Electro-optical device, electronic apparatus, and driving method |
| US7692842B2 (en) | 2006-03-20 | 2010-04-06 | Seiko Epson Corporation | Electro-optical device, electronic apparatus, and driving method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3296882B2 (en) | Brightness control circuit device | |
| US4734714A (en) | Optical print head with LED diode array | |
| JP2000108407A (en) | Drive circuit and printer using the same | |
| JPH01160659A (en) | Led drive circuit of led printer | |
| JP3256225B2 (en) | LED array printer | |
| JPS62218155A (en) | Led array head | |
| US6498616B1 (en) | Print head having non-volatile memory and means for transmitting correction and inherent data | |
| JPH106554A (en) | Image forming device | |
| JP2849651B2 (en) | Image forming device | |
| JP3136099B2 (en) | Print head of printer device | |
| JPH07144431A (en) | Light-emitting element drive current correction circuit | |
| JP2948446B2 (en) | Integrated circuit device for driving element and light emitting device | |
| US5438346A (en) | Compatible thermal head having strobe signal converting member | |
| JP3058726B2 (en) | Print head and driving method thereof | |
| JPH0649378B2 (en) | Record head | |
| JPH0650195Y2 (en) | Light emitting element drive | |
| JPH10129026A (en) | Integrated circuit for driving element | |
| JPH079394Y2 (en) | Integrated circuit device for driving light emitting element | |
| JPH021983Y2 (en) | ||
| JP3064509B2 (en) | Print head | |
| JPH0650194Y2 (en) | Light emitting element drive | |
| JPH0839861A (en) | Control device of light emitting element | |
| JPH0872296A (en) | Driving circuit for led print head | |
| JP2000335004A (en) | Led drive circuit | |
| JP3453176B2 (en) | LED print head and LED driver IC for print head |