JP4640064B2

JP4640064B2 - Image forming apparatus

Info

Publication number: JP4640064B2
Application number: JP2005265961A
Authority: JP
Inventors: 剛瀬戸; 歩小野; 浩良井上; 和俊島
Original assignee: Fuji Xerox Co Ltd; Fujifilm Business Innovation Corp
Current assignee: Fujifilm Business Innovation Corp
Priority date: 2005-09-13
Filing date: 2005-09-13
Publication date: 2011-03-02
Anticipated expiration: 2025-09-13
Also published as: JP2007076797A

Description

本発明は、プリンタや複合機など、用紙上に画像を形成する画像形成装置に関する。 The present invention relates to an image forming apparatus that forms an image on paper, such as a printer or a multifunction peripheral.

プリンタや複合機などの画像形成装置では、形成される画像の質の向上のため、形成先となる用紙種類に応じて画像形成制御を切り替えることが行われている。 In an image forming apparatus such as a printer or a multi-function peripheral, image formation control is switched according to the type of paper as a forming destination in order to improve the quality of an image to be formed.

ここで画像形成装置が用紙種類を判別する方法として、光学式センサーを用いるものがある（特許文献１）。この光学式センサーを用いる場合、光学式センサーである受光部と、発光部とを用紙搬送路を挟んで対向して配置し、発光部にて所定光量の光を放射し、その光が用紙搬送路上を搬送される用紙を透過して受光部に到来し、受光部が当該到達した光の量（受光量）を計測し、この計測で得られたデータと、用紙種類に応じて予め設定された基準データとを比較することによって用紙種類を判定する。 Here, there is a method using an optical sensor as a method for the image forming apparatus to discriminate the paper type (Patent Document 1). When this optical sensor is used, the light receiving unit, which is an optical sensor, and the light emitting unit are arranged to face each other across the paper conveyance path, and a predetermined amount of light is emitted from the light emitting unit, and the light is conveyed by the paper. It passes through the paper transported on the road and arrives at the light receiving unit, and the light receiving unit measures the amount of light that has reached (the amount of received light), and is preset according to the data obtained by this measurement and the paper type The paper type is determined by comparing with the reference data.

なお、汚れや経時変化によってセンサーの感度が変化することに鑑みて、光学式センサーの感度に応じて発光量を調節する技術が例えば特許文献２に開示されている。
特開２００４−２６０３８８号公報特開２００２−２５５３９７号公報 In view of the fact that the sensitivity of the sensor changes due to dirt and changes over time, a technique for adjusting the light emission amount according to the sensitivity of the optical sensor is disclosed in, for example, Patent Document 2.
JP 2004-260388 A Japanese Patent Laid-Open No. 2002-255397

しかしながら、上記従来の光学式センサーを用いた用紙種類の判別方法では、ある特定の光量で放射された光が、どの程度透過するかを検出するものであるため、普通紙と厚紙の識別（一定の光量範囲では光を透過しない）や、トレーシングペーパーとＯＨＰシートの識別（一定の光量範囲では透過する光量の差が小さくなる）が困難になる。 However, in the conventional paper type discrimination method using the optical sensor, it detects how much light emitted with a specific light quantity is transmitted. Light is not transmitted in the light quantity range), and it is difficult to identify the tracing paper and the OHP sheet (the difference in the transmitted light quantity is small in the constant light quantity range).

本発明は上記実情に鑑みて為されたもので、用紙種類の判別精度をより向上できる画像形成装置を提供することを、その目的の一つとする。 SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of further improving the accuracy of discriminating paper types.

上記従来例の問題点を解決するための本発明は、画像形成装置であって、用紙搬送路に関して配置された、発光部及び、当該発光部が放射する光を受ける受光部を備え、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報に基づいて用紙判別処理を実行することを特徴としている。例えば少なくとも１の発光部を互いに異なる光量で複数回にわたり発光制御し、当該発光部が放射する光を少なくとも１の受光部にて受けるようにする。そして、当該互いに異なる光量で複数回にわたり発光させたときの前記受光部での受光量に関する情報を取得し、当該複数回にわたって取得した受光量に関する情報に基づいて用紙判別処理を実行するようにしてもよい。 The present invention for solving the problems of the above-described conventional example is an image forming apparatus, which includes a light emitting unit and a light receiving unit that receives light emitted from the light emitting unit, and is different from each other. The light emitting unit is controlled to emit light with the amount of light, information on the amount of light received by the light receiving unit when the light is emitted with different amounts of light is obtained, and a sheet determination process is performed based on the obtained information about the plurality of received light amounts. It is characterized by executing. For example, at least one light emitting unit is controlled to emit light a plurality of times with different amounts of light so that light emitted from the light emitting unit is received by at least one light receiving unit. Then, information regarding the amount of light received by the light receiving unit when light is emitted a plurality of times with different amounts of light is obtained, and a sheet determination process is executed based on the information regarding the amount of light received over the plurality of times. Also good.

ここで前記発光部と受光部との間の光路内に用紙がない状態において、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報に基づいて用紙判別の基準となる情報を生成することとしてもよい。 Here, when there is no paper in the optical path between the light emitting unit and the light receiving unit, the light emitting unit is controlled to emit light with different light amounts, and the light receiving unit receives light with the different light amounts. Information regarding the amount may be acquired, and information serving as a reference for paper discrimination may be generated based on the acquired information regarding the plurality of received light amounts.

また、画像形成動作停止中の前記発光部、受光部間の光路内に用紙がない状態において、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する停止中情報を取得し、画像形成動作中の前記発光部、受光部間の光路内に用紙がない状態において、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する動作中情報を取得し、前記停止中情報を、前記動作中情報の値に基づいて補正し、当該補正した停止中情報に基づいて、用紙判別の基準となる情報を生成することを特徴としている。 In addition, when there is no paper in the optical path between the light emitting unit and the light receiving unit when the image forming operation is stopped, the light receiving unit is controlled to emit light with different light amounts, and the light reception is performed with the different light amounts. Information on the amount of light received by the light receiving unit is acquired, and when there is no paper in the optical path between the light emitting unit and the light receiving unit during the image forming operation, the light emitting units are controlled to emit light with different light amounts. Acquiring information about the amount of light received by the light receiving unit when light is emitted with a different amount of light, correcting the stopping information based on the value of the operating information, and based on the corrected stopping information The method is characterized in that information serving as a reference for paper discrimination is generated.

さらに前記発光部と受光部との間の光路内に用紙がない状態において、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報に基づいて、用紙判別処理における前記発光部の発光制御を行うことを特徴としている。 Further, when there is no paper in the optical path between the light emitting unit and the light receiving unit, the light emitting unit is controlled to emit light with different amounts of light, and the amount of light received by the light receiving unit when light is emitted with the different amounts of light. Information is acquired, and light emission control of the light emitting unit in the paper discrimination processing is performed based on the acquired information regarding the plurality of received light amounts.

ここで、前記発光部と受光部との間の光路内に用紙がない状態において、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報に基づいて、受光部の動作状態を判別することを特徴としている。 Here, when there is no sheet in the optical path between the light emitting unit and the light receiving unit, the light emitting unit is controlled to emit light with different light amounts, and the light receiving unit emits light with the different light amounts. The information on the amount of received light is acquired, and the operation state of the light receiving unit is determined based on the acquired information on the plurality of received light amounts.

さらに、前記発光部と受光部との間の光路内に用紙が配置されている状態で、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報を、前記配置されている用紙を特定する情報に関連づけて記憶し、当該記憶している情報が、前記用紙判別処理に供されることとしてもよい。 Further, the light receiving unit when the light emitting unit is controlled to emit light with different light amounts and light is emitted with the different light amounts in a state where a sheet is disposed in the optical path between the light emitting unit and the light receiving unit. Information on the received light amount is stored in association with the information specifying the arranged paper, and the stored information is used for the paper discrimination process. It may be provided.

さらに本発明の一態様は、用紙搬送路に関して配置された、発光部及び、当該発光部が放射する光を受ける受光部を備える画像形成装置の制御方法であって、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報に基づいて用紙判別処理を実行することを特徴としている。 Furthermore, one aspect of the present invention is a method of controlling an image forming apparatus that includes a light emitting unit and a light receiving unit that receives light emitted from the light emitting unit, which are arranged with respect to the paper conveyance path, and the light emitting unit emits the light with different light amounts. The information on the amount of light received by the light receiving unit when light is emitted with different light amounts, and paper discrimination processing is executed based on the acquired information on the plurality of received light amounts. It is said.

本発明の実施の形態について図面を参照しながら説明する。本発明の実施の形態に係る画像形成装置は、図１に示すように、給紙トレイ１と、画像形成部２と、転写ロール３と、定着部４と、排出トレイ５と、制御部６と、記憶部７とを含んで構成されている。また本実施の形態の画像形成装置は、図２（ａ），（ｂ）に示すように、この用紙搬送経路に関して配置される、発光部１１と、受光部１２とを備える。すなわち、この発光部１１と受光部１２とは、発光部１１から放射された光が受光部１２に到達するように配置される。具体的な例として、発光部１１と受光部１２とは、用紙搬送路を挟んで対向配置される（図２（ａ））。また、別の例として発光部１１にて放射された光は、用紙搬送路を搬送される用紙にて反射されて受光部１２に到達する（図２（ｂ））。以下の説明では、用紙搬送路を挟んで対向配置される例について述べる。 Embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, an image forming apparatus according to an embodiment of the present invention includes a paper feed tray 1, an image forming unit 2, a transfer roll 3, a fixing unit 4, a discharge tray 5, and a control unit 6. And the storage unit 7. Further, as shown in FIGS. 2A and 2B, the image forming apparatus according to the present embodiment includes a light emitting unit 11 and a light receiving unit 12 that are arranged with respect to the sheet conveyance path. That is, the light emitting unit 11 and the light receiving unit 12 are arranged so that light emitted from the light emitting unit 11 reaches the light receiving unit 12. As a specific example, the light emitting unit 11 and the light receiving unit 12 are disposed to face each other with the paper conveyance path interposed therebetween (FIG. 2A). As another example, the light emitted from the light emitting unit 11 is reflected by the paper conveyed through the paper conveyance path and reaches the light receiving unit 12 (FIG. 2B). In the following description, an example in which the paper conveyance paths are arranged opposite to each other will be described.

給紙トレイ１から搬送された用紙は、用紙搬送経路を通じて、画像形成部２に導かれる。ここで、画像形成部２において形成された像が、転写ロールに到来するタイミングで、用紙が転写ロール３に到達するよう搬送タイミングが制御される。 The sheet conveyed from the sheet feeding tray 1 is guided to the image forming unit 2 through the sheet conveying path. Here, the conveyance timing is controlled so that the sheet reaches the transfer roll 3 at the timing when the image formed in the image forming unit 2 arrives at the transfer roll.

ここで用紙搬送経路には、裏面印刷の際に、用紙を再度転写ロール３へ搬送する反転経路（Ｃ）が設けられている。 Here, the paper conveyance path is provided with a reverse path (C) for conveying the paper to the transfer roll 3 again at the time of backside printing.

なお、この図１に示した画像形成部２は、ドラムＤ上に形成した画像を直接、用紙に転写するものとしているが、ドラムＤから中間転写ベルトに転写し、この中間転写ベルト上の画像を、中間転写ベルトと転写ロール３との間に挟み込んだ用紙に転写することとしてもよい。 Note that the image forming unit 2 shown in FIG. 1 directly transfers the image formed on the drum D onto the sheet, but transfers the image from the drum D to the intermediate transfer belt, and the image on the intermediate transfer belt. May be transferred to a sheet sandwiched between the intermediate transfer belt and the transfer roll 3.

転写ロール３では、ドラムＤに形成されたトナー像を用紙側に引きつける電圧を印加し、トナー像を用紙へ転写する。その後、用紙は定着部４へ搬送され、定着部４にて加熱・加圧されて、像が定着される。像の定着を受けた用紙は、さらに用紙搬送路を介して排出トレイ５に導く。 In the transfer roll 3, a voltage that attracts the toner image formed on the drum D to the sheet side is applied, and the toner image is transferred to the sheet. Thereafter, the sheet is conveyed to the fixing unit 4 and heated and pressed by the fixing unit 4 to fix the image. The sheet on which the image has been fixed is further guided to the discharge tray 5 through the sheet conveyance path.

また、本実施の形態の画像形成装置の制御部６は、ＣＰＵ等であり、記憶部７に格納されているプログラムに従って動作する。この制御部６は、画像形成部２を制御し、また、用紙の搬送を制御する。また、この制御部６は、発光部１１の発光制御を行うとともに、受光部１２にて受けた光量の情報を用いて、搬送している用紙の種類を判別する処理（用紙判別処理）を実行する。この制御部６の具体的な処理の内容については、後に詳しく述べる。 The control unit 6 of the image forming apparatus according to the present embodiment is a CPU or the like, and operates according to a program stored in the storage unit 7. The control unit 6 controls the image forming unit 2 and also controls paper conveyance. In addition, the control unit 6 performs light emission control of the light emitting unit 11 and executes processing for determining the type of paper being conveyed (paper determination processing) using information on the amount of light received by the light receiving unit 12. To do. The specific processing contents of the control unit 6 will be described later in detail.

記憶部７は、ＲＡＭや、ＮＶＲＡＭ（不揮発性ＲＡＭ）等を含んで構成される。この記憶部７は、制御部６のワークメモリとして動作する。また、この記憶部７には、光量制御に係るパラメータや、用紙判別処理の基礎となる受光量に関する情報が格納されている。 The storage unit 7 includes a RAM, an NVRAM (nonvolatile RAM), and the like. The storage unit 7 operates as a work memory for the control unit 6. Further, the storage unit 7 stores parameters relating to the light amount control and information related to the received light amount that is the basis of the paper discrimination process.

ここで、制御部６による用紙判別処理の例について説明する。この処理を実行する制御部６のプログラムは、機能的には図３に示すように、発光部１１の発光光量を制御する光量制御部２１と、受光部１２での受光量の検知レベルをディジタル値に変換する受光量検知部２２と、比較部２３とを含んで構成されている。 Here, an example of the paper discrimination processing by the control unit 6 will be described. As shown in FIG. 3, the program of the control unit 6 that executes this process functionally digitalizes the light amount control unit 21 that controls the amount of light emitted from the light emitting unit 11 and the detection level of the amount of light received by the light receiving unit 12. It is configured to include a received light amount detection unit 22 that converts it into a value and a comparison unit 23.

光量制御部２１は、光量制御に関するパラメータとして予め定められ、記憶部７に格納されている初期光量設定値Ｘと、最終光量設定値Ｙと、光量変化値Ｚとを記憶部７から読み出す。そして、図４に示す処理を実行する。すなわち、発光光量Ｐを初期光量設定値Ｘに設定し（Ｓ１）、発光光量Ｐに対応する光量の光を放射するよう発光部１１を制御する（Ｓ２）。そして受光量検知部２２に検知を実行すべき旨の信号を出力する（Ｓ３）。次に、発光光量Ｐに光量変化値Ｚを加算し（Ｓ４）、加算後の発光光量Ｐが最終光量設定値Ｙを超えたか否かを調べる（Ｓ５）。ここで、加算後の発光光量Ｐが最終光量設定値Ｙを超えていないならば、処理Ｓ２に戻って処理を続ける。また、処理Ｓ５において、加算後の発光光量Ｐが最終光量設定値Ｙを超えた場合は、処理を終了する。 The light quantity control unit 21 reads an initial light quantity setting value X, a final light quantity setting value Y, and a light quantity change value Z, which are predetermined as parameters relating to the light quantity control and stored in the storage unit 7, from the storage unit 7. Then, the process shown in FIG. 4 is executed. That is, the light emission amount P is set to the initial light amount setting value X (S1), and the light emitting unit 11 is controlled to emit light having a light amount corresponding to the light emission amount P (S2). Then, a signal indicating that the detection should be executed is output to the received light amount detection unit 22 (S3). Next, the light amount change value Z is added to the light emission amount P (S4), and it is checked whether or not the light emission amount P after the addition exceeds the final light amount setting value Y (S5). Here, if the light emission amount P after the addition does not exceed the final light amount setting value Y, the process returns to the process S2 to continue the process. In addition, in process S5, when the light emission amount P after the addition exceeds the final light amount setting value Y, the process ends.

受光量検知部２２は、光量制御部２１から検知を実行するべき旨の信号を受信すると、受光部１２が出力している受光量の信号をディジタル値に変換し、その時点で発光部１１が放射している光の光量に係る情報と、当該ディジタル値とを関連づけて、受光光量変化情報として記憶部７に蓄積して格納する。 When the received light amount detection unit 22 receives a signal from the light amount control unit 21 indicating that the detection should be performed, the received light amount detection unit 22 converts the received light amount signal output from the light receiving unit 12 into a digital value. Information relating to the amount of emitted light and the digital value are associated with each other and accumulated and stored in the storage unit 7 as received light amount change information.

これにより、互いに異なる発光光量にて発光部１１を発光制御させたときの受光部１２での受光量に関する情報を取得する。この情報は、発光光量に関する値（ここでは例えば発光部１１の発光させる際のドライブ電流であるとし、発光部１１は、このドライブ電流に比例した光量の光を放射するものとする）に対し、受光部１２にて受けた光のレベルを表した情報であり、模式的に、図５に示すように表すことができる。そこで、このように発光光量の変化に対する受光量の模式的変化量を表す情報を、用紙種類に関連づけて、用紙判別基準情報として記憶部７に格納しておく。 As a result, information on the amount of light received by the light receiving unit 12 when the light emitting unit 11 is controlled to emit light with different amounts of emitted light is acquired. This information corresponds to a value related to the amount of emitted light (here, for example, it is assumed that the light emission unit 11 emits light when the light emission unit 11 emits light, and the light emission unit 11 emits light of a light amount proportional to the drive current). This is information representing the level of light received by the light receiving unit 12, and can be schematically represented as shown in FIG. In view of this, information representing the schematic change amount of the received light amount with respect to the change in the light emission amount is stored in the storage unit 7 as the paper discrimination reference information in association with the paper type.

すなわち、光を透過（あるいは反射）する割合は、光量の変化に応じ、用紙の種類によって例えば、図６に示すように変化する。 That is, the ratio of transmitting (or reflecting) the light changes as shown in FIG. 6 depending on the type of paper according to the change in the amount of light.

比較部２３は、この用紙種類ごとの相違を利用し、発光部１１と受光部１２との光路内に用紙があるときに、上記図４に示した処理により発光光量を変化させながら取得した受光光量変化情報と、記憶部７に格納した用紙判別基準情報と比較し、取得した受光光量変化情報に最も一致する用紙判別基準情報における用紙種類の情報を出力する。この用紙種類の情報は、例えば、画像形成部２に出力され、画像形成部２における画像形成パラメータとして利用される。 The comparison unit 23 uses the difference for each paper type, and when the paper is in the optical path between the light emitting unit 11 and the light receiving unit 12, the light reception acquired while changing the light emission amount by the process shown in FIG. The light quantity change information is compared with the paper discrimination reference information stored in the storage unit 7, and the paper type information in the paper discrimination reference information that most closely matches the acquired received light quantity change information is output. For example, the paper type information is output to the image forming unit 2 and used as an image forming parameter in the image forming unit 2.

ある受光部１２の例では、図６に例示したように、発光部１１から受ける光量が一定の値Ｉminとなるまでは、受け入れた光量に関する情報（例えば抵抗値）はほとんど最大値ＭＡＸに近い状態で推移する。Ｉminを超える光量から、所定のＩmaxまでは、受け入れた光量に略比例し、Ｉmaxを超えると受け入れた光量に関する情報が最小値ＭＩＮとなって飽和する。 In the example of a certain light receiving unit 12, as illustrated in FIG. 6, until the light amount received from the light emitting unit 11 reaches a certain value Imin, information on the received light amount (for example, resistance value) is almost close to the maximum value MAX. It changes in. The light amount exceeding Imin to a predetermined Imax is approximately proportional to the received light amount, and if it exceeds Imax, the information regarding the received light amount becomes the minimum value MIN and is saturated.

本実施の形態の比較部２３は、用紙を透過した後の光量がＩminとなるときの発光部１１の発光量Ｒ１（下限時発光量）と、Ｉmaxとなるときの発光部１１の発光光量Ｒ２（上限時発光量）とを、用紙判別基準情報に含まれる各用紙種類に対応する模式的変化量の情報から見いだしておく。そして、上記図４に示した処理により発光光量を変化させながら取得した受光光量変化情報からも、用紙を透過した後の光量がＩminとなるときの発光部１１の発光光量Ｒ１と、Ｉmaxとなるときの発光部１１の発光光量Ｒ２とを検出する。 The comparison unit 23 of the present embodiment has a light emission amount R1 (light emission amount at the lower limit) of the light emitting unit 11 when the light amount after passing through the paper is Imin, and a light emission amount R2 of the light emitting unit 11 when Imax is reached. (Upper limit light emission amount) is found from the information of the schematic change amount corresponding to each paper type included in the paper discrimination reference information. Then, from the received light amount change information acquired while changing the emitted light amount by the process shown in FIG. 4, the emitted light amount R1 of the light emitting unit 11 when the amount of light after passing through the paper becomes Imin and Imax are obtained. The amount of emitted light R2 of the light emitting unit 11 is detected.

そして、ｊ番目の用紙種類における下限時発光量Ｒj１、上限時発光量Ｒj２を、搬送している用紙における下限時発光量Ｒp１、上限時発光量Ｒp2と比較する。この比較は、下限時発光量の差と、上限時発光量の差とを用い、例えばその和、
｜Ｒj１−Ｒp１｜＋｜Ｒj２−Ｒp２｜
が最小となる用紙種類（ｊ）を、搬送している用紙の種類と判断する。そして、このｊ番目の用紙種類を特定する情報を出力する。 Then, the lower limit light emission amount Rj1 and the upper limit light emission amount Rj2 for the j-th paper type are compared with the lower limit light emission amount Rp1 and the upper limit light emission amount Rp2 for the paper being conveyed. This comparison uses the difference in the light emission amount at the lower limit and the difference in the light emission amount at the upper limit, for example, the sum,
| Rj1-Rp1 | + | Rj2-Rp2 |
The paper type (j) that minimizes is determined as the type of paper being conveyed. Then, information specifying the j-th paper type is output.

なお、光学式センサである発光部１１や受光部１２は、その取り付けの精度や個体差によって上記下限時発光量や、上限時発光量が異なってしまう場合がある。また、用紙搬送時とそうでないときとでは、用紙搬送路近傍に生じる紙による埃や、温度変化の影響によっても、上記下限時発光量や、上限時発光量が異なってしまう場合がある。 The light emitting unit 11 and the light receiving unit 12 that are optical sensors may have different light emission amounts at the lower limit and upper limit light amounts depending on the mounting accuracy and individual differences. Further, the lower limit light emission amount and the upper limit light emission amount may differ between when the paper is conveyed and when it is not, depending on the dust caused by the paper in the vicinity of the paper conveyance path and the influence of temperature change.

そこで、これらの変動を補正するべく、用紙判別基準情報を補正してもよい。例えば、本実施の形態の制御部６は、発光部１１と受光部１２との間の光路内に用紙がない状態において、光量制御部２１の動作（図４に示す処理）を実行して、用紙がない場合での受光光量変化情報を取得する。 Therefore, the paper discrimination reference information may be corrected in order to correct these fluctuations. For example, the control unit 6 according to the present embodiment executes the operation of the light amount control unit 21 (the process shown in FIG. 4) in a state where there is no sheet in the optical path between the light emitting unit 11 and the light receiving unit 12. Received light amount change information when there is no paper is acquired.

そして、ここで取得した用紙がない場合の受光光量変化情報に基づいて、例えば用紙判別基準情報に含まれる、各用紙種類における下限時発光量Ｒj１、上限時発光量Ｒj２を補正する。この補正の具体的な例は、次のようなものである。すなわち、用紙がない場合の受光光量変化情報における下限時発光量をＲo１、上限時発光量をＲo２とする。また用紙種類ごとに、用紙の透過光量に基づいて、下限時発光量Ｒj１、上限時発光量Ｒj２と、この用紙がない場合の受光光量変化情報における下限時発光量をＲo１、上限時発光量をＲo２との間の比ｒj１、ｒj２を、予め定めて記憶部７に格納しておく。そして、
Ｒj１＝ｒj１×Ｒo１
Ｒj２＝ｒj２×Ｒo２
として、ｊ番目の用紙についての下限時発光量Ｒj１、上限時発光量Ｒj２を定め、記憶部７に格納している用紙判別基準情報に含まれる当該情報に置き換えて格納する。 Then, based on the received light amount change information when there is no sheet acquired here, for example, the lower limit light emission amount Rj1 and the upper limit light emission amount Rj2 included in the paper discrimination reference information are corrected. A specific example of this correction is as follows. That is, the lower limit light emission amount and the upper limit light emission amount in the received light amount change information when there is no paper are Ro1 and Ro2, respectively. For each paper type, the lower limit light emission amount Rj1 and the upper limit light emission amount Rj2 based on the transmitted light amount of the paper, and the lower limit light emission amount Ro1 and the upper limit light emission amount in the received light amount change information when there is no paper. Ratios rj1 and rj2 with respect to Ro2 are determined in advance and stored in the storage unit 7. And
Rj1 = rj1 × Ro1
Rj2 = rj2 × Ro2
The lower limit light emission amount Rj1 and the upper limit light emission amount Rj2 for the jth paper are determined and stored in place of the information included in the paper discrimination reference information stored in the storage unit 7.

なお、ここでは、予め定めた比の情報を用いて補正を行なう例を示したが、これに限らず、所定の関数によって演算して求めてもよい。また、ここでは下限時発光量Ｒj１、上限時発光量Ｒj２を定めたが、これに限らず、下限時発光量Ｒj１と、比例変化部分における変化率とを定めてもよい。 Here, an example in which correction is performed using information on a predetermined ratio has been shown, but the present invention is not limited to this, and it may be calculated by a predetermined function. Further, although the lower limit light emission amount Rj1 and the upper limit light emission amount Rj2 are set here, the present invention is not limited thereto, and the lower limit light emission amount Rj1 and the rate of change in the proportional change portion may be determined.

また、ここで用紙搬送中における紙粉の発生や温度変化による受光量の変化を補正するため、画像形成動作停止中（用紙搬送が行なわれていない間）での用紙なし時の受光光量変化情報（停止中情報）と、画像形成動作中（用紙搬送が行なわれている間）での用紙なし時の受光光量変化情報（動作中情報）とを取得し、停止中情報を動作中情報の値に基づいて補正し、この補正後の停止中情報によって、用紙判別基準情報に含まれる各用紙種類における下限時発光量Ｒj１、上限時発光量Ｒj２を補正してもよい。 In addition, in order to correct the change in the amount of received light due to the generation of paper dust and the temperature change during paper conveyance here, the information on the change in the amount of received light when there is no paper while the image forming operation is stopped (while the paper is not being conveyed) (In-stop information) and received light amount change information (in-operation information) when there is no paper during the image forming operation (while the paper is being conveyed), and the in-stop information is the value of the in-operation information The lower limit light emission amount Rj1 and the upper limit light emission amount Rj2 for each paper type included in the paper discrimination reference information may be corrected based on the information during stop after the correction.

ここで動作中情報による停止中情報の補正は、例えば次のようにして行なわれる。すなわち、動作中情報と、停止中情報とのそれぞれから、下限時発光量と上限時発光量とを得ておき（以下、動作中情報について下限時発光量Ｒop１と上限時発光量Ｒop２とし、停止中情報について下限時発光量Ｒnop１と上限時発光量Ｒnop２とする）、動作中情報と停止中情報との差（紙粉などによる光量の変化量に相当する）を求める。すなわち、
ΔＲ１＝Ｒop１−Ｒnop１と、
ΔＲ２＝Ｒop２−Ｒnop２と、
を求める。 Here, the correction of the stopped information by the operating information is performed as follows, for example. That is, the lower limit light emission amount and the upper limit light emission amount are obtained from the operating information and the stopping information (hereinafter, the operating information is referred to as the lower limit light emission amount Rop1 and the upper limit light emission amount Rop2, For the middle information, the lower limit light emission amount Rnop1 and the upper limit light emission amount Rnop2), and the difference between the operating information and the stopping information (corresponding to the amount of change in the amount of light due to paper dust or the like) are obtained. That is,
ΔR1 = Rop1-Rnop1,
ΔR2 = Rop2-Rnop2,
Ask for.

そして、用紙判別基準情報に含まれる各用紙種類における下限時発光量Ｒj１、上限時発光量Ｒj２を、
Ｒj１＝ｒj１×Ｒop１−ΔＲ１
Ｒj２＝ｒj２×Ｒop２−ΔＲ２
として求める。 Then, the lower limit light emission amount Rj1 and the upper limit light emission amount Rj2 for each paper type included in the paper discrimination reference information are expressed as follows:
Rj1 = rj1 × Rop1-ΔR1
Rj2 = rj2 × Rop2-ΔR2
Asking.

これによると、動作中の条件下における受光量の変化に対応した用紙判別基準情報を生成できる。 According to this, the paper discrimination reference information corresponding to the change in the amount of received light under the operating condition can be generated.

また、制御部６は、用紙がない場合の受光光量変化情報における下限時発光量Ｒo１と上限時発光量Ｒo２（これらは動作中のものであっても、停止中のものであってよい）に基づいて、初期光量設定値Ｘと、最終光量設定値Ｙと、光量変化値Ｚとを設定し、発光部１１での発光制御を行なってもよい。例えば、初期光量設定値Ｘを、下限時発光量Ｒo１または、下限時発光量Ｒo１から所定値ΔＬだけ下回る値Ｒo１−ΔＬに設定し、また、最終光量設定値Ｙを、上限時発光量Ｒo２に所定値ΔＨだけ加算した値に設定する。そして、光量変化値Ｚを、用紙の搬送速度に応じて用紙が発光部１１と受光部１２との光路内にある期間に、発光部１１を発光制御可能な回数Ｎを用いて、このＮ以下の値ｎについて、
Ｚ＝（Ｙ−Ｘ）／ｎ
と定める。この発光制御可能な回数Ｎは、用紙サイズ（送り長）と、用紙の搬送速度とに応じて定められる。 Further, the control unit 6 sets the light emission amount Ro1 at the lower limit and the light emission amount Ro2 at the upper limit in the received light amount change information when there is no paper (these may be operating or stopped). Based on this, an initial light amount setting value X, a final light amount setting value Y, and a light amount change value Z may be set, and light emission control in the light emitting unit 11 may be performed. For example, the initial light amount setting value X is set to the lower limit light emission amount Ro1, or a value Ro1-ΔL that is lower than the lower limit light emission amount Ro1 by a predetermined value ΔL, and the final light amount setting value Y is set to the upper limit light emission amount Ro2. A value obtained by adding a predetermined value ΔH is set. Then, the light quantity change value Z is equal to or less than N using the number N of times that the light emitting unit 11 can be controlled to emit light during the period in which the paper is in the optical path between the light emitting unit 11 and the light receiving unit 12 according to the conveyance speed of the paper. For the value n of
Z = (Y−X) / n
It is determined. The number N of times that the light emission can be controlled is determined according to the paper size (feed length) and the paper conveyance speed.

このように検出時の光の制御範囲をなるべく、応答が比例的に変化する区間に近くなるようにして、検出にかかる時間を低減する。なお、用紙がない場合の受光光量変化情報を取得する際、例えば動作中情報や停止中情報を取得する際には、初期光量設定値Ｘを、発光部１１により発光させることのできる最小光量、最終光量設定値Ｙを、発光部１１により発光させることのできる最大光量と設定する。また、光量変化値Ｚは、発光部１１における光量の単位変化量があれば、当該単位変化量としてもよい。 Thus, the time required for detection is reduced by making the control range of light at the time of detection as close as possible to a section in which the response changes proportionally. When acquiring the received light amount change information when there is no paper, for example, when acquiring information during operation or information during stoppage, the initial light amount setting value X is the minimum light amount that can be emitted by the light emitting unit 11; The final light amount setting value Y is set as the maximum light amount that can be emitted by the light emitting unit 11. The light quantity change value Z may be the unit change amount if there is a unit change amount of the light quantity in the light emitting unit 11.

また、停止中情報に比べて動作中情報を取得する際の光量変化値Ｚを大きくして、受光光量変化情報の取得回数を低減してもよい。 Further, the number of acquisitions of the received light amount change information may be reduced by increasing the light amount change value Z when acquiring the in-operation information as compared to the stop information.

また、制御部６は、用紙がない場合の受光光量変化情報（これらは動作中のものであっても、停止中のものであってよい）に基づいて、受光部１２の動作状態を判別する処理を実行してもよい。例えば、その下限時発光量Ｒo１が予め定めた判定基準しきい値を超えている場合などでは、発光部１１ないし受光部１２に何らかの故障があったと判断して、その旨を利用者に報知する。この報知は、例えば表示部（不図示）にその旨を表示することによって行なってもよい。 Further, the control unit 6 determines the operating state of the light receiving unit 12 based on the received light amount change information when there is no paper (they may be operating or stopped). Processing may be executed. For example, when the light emission amount Ro1 at the lower limit exceeds a predetermined determination reference threshold value, it is determined that there is some failure in the light emitting unit 11 or the light receiving unit 12, and this is notified to the user. . This notification may be performed, for example, by displaying that fact on a display unit (not shown).

さらに、ここまでの説明では、用紙判別基準情報は、予め定められているか、または用紙がない場合での受光光量変化情報に基づいて生成されるものとしたが、利用者からの指示に従い、利用者が供した用紙を、用紙搬送経路に沿って搬送させつつ、当該用紙について受光光量変化情報を取得し、利用者から入力される用紙を特定する情報に関連づけて、当該受光光量変化情報に関する情報を、用紙判別基準情報に含めて記憶部７に格納してもよい。この場合、比較部２３では、当該利用者が供した用紙に関する用紙判別基準情報との比較が行なわれることになる。 Further, in the description so far, the paper discrimination reference information is predetermined or generated based on the received light amount change information when there is no paper, but it is used according to instructions from the user. Information relating to the received light amount change information is acquired in association with the information specifying the paper input from the user while the paper provided by the user is conveyed along the paper conveyance path. May be included in the paper discrimination reference information and stored in the storage unit 7. In this case, the comparison unit 23 performs comparison with the sheet determination reference information regarding the sheet provided by the user.

さらに、ここまでの説明における制御部６の動作による用紙判別の処理は、印字が行なわれた後の用紙（裏紙や、既に表面が印刷され裏面を印刷するために画像形成装置内部で再搬送されている用紙）について行なうと、当該印字の内容によって受光光量変化情報に影響が表れる可能性がある。そこで、発光部１１から受光部１２へ至る光路が、用紙の端部など、印字が行なわれない場所となるよう、発光部１１と受光部１２とを、用紙搬送軌跡の端部（用紙の端部側）に近接して設置してもよい。また、画像形成部２の処理内容を参照して、裏面側の印刷中であるか否かを判断し、裏面側の印刷中である場合には、上記処理を行わないこととしてもよい。この場合、表面側の印刷（最初の印刷）である場合にのみ上記処理を行うことになる。 Further, the paper discrimination processing by the operation of the control unit 6 in the above description is performed by re-conveying the paper after printing (the back paper or the inside of the image forming apparatus in order to print the back side and the back side already printed. If this is performed, the received light amount change information may be affected by the contents of the printing. Therefore, the light emitting unit 11 and the light receiving unit 12 are placed at the end of the paper transport path (the end of the paper) so that the optical path from the light emitting unit 11 to the light receiving unit 12 is a place where printing is not performed, such as the end of the paper. It may be installed close to the (part side). In addition, referring to the processing content of the image forming unit 2, it is determined whether or not the back side is being printed. If the back side is being printed, the above processing may not be performed. In this case, the above processing is performed only when printing on the front side (first printing).

このために、本実施の形態の発光部１１と受光部１２とは、裏面印刷時の再搬送経路上に設けないこととしてもよい。具体的な例としては、用紙トレイ近傍に設ければよい（図１のＡの位置）。また、発光部１１からの放射光を反射させて受光部１２に到達させる場合は、ローラによる印字面とは反対側において発光部１１からの光が反射されるよう、用紙搬送経路について印字面とは反対側に発光部１１と受光部１２とを配置することとすればよい（図１のＢの位置）。 For this reason, the light emitting unit 11 and the light receiving unit 12 of the present embodiment may not be provided on the re-conveyance path at the time of back surface printing. As a specific example, it may be provided near the paper tray (position A in FIG. 1). In addition, when the radiated light from the light emitting unit 11 is reflected and reaches the light receiving unit 12, the paper conveyance path and the printing surface are arranged so that the light from the light emitting unit 11 is reflected on the side opposite to the printing surface by the roller. The light emitting unit 11 and the light receiving unit 12 may be arranged on the opposite side (position B in FIG. 1).

また、本実施の形態では、用紙種別を判断した後、当該判断の結果を画像形成部２における画像形成処理に用いることとしているが、これに代えて、利用者がプリントジョブにおいて指定した種類の紙と異なる用紙であるか否かを調べ、その旨警告する処理や、画像形成動作を停止する等の処理に用いてもよい。 In this embodiment, after the paper type is determined, the result of the determination is used for the image forming process in the image forming unit 2, but instead of the type specified by the user in the print job. It may be used for processing such as checking whether the paper is different from the paper and giving a warning to that effect or stopping the image forming operation.

このように本実施の形態では、用紙搬送時に用紙の先端から後端に掛けて、発光光量を段階的ないし連続的に変化させ、当該光量を変化させたときに、用紙を透過（あるいは用紙面で反射）した光量の受光検知結果の変化を取得する。そして、当該受光検知結果の変化に基づいて用紙の種別を判断する。これにより、用紙種類の判別精度をより向上できる。 As described above, in the present embodiment, the amount of emitted light is changed stepwise or continuously from the leading edge to the trailing edge of the sheet during conveyance, and the sheet is transmitted (or the sheet surface) when the amount of light is changed. The change in the light reception detection result of the amount of light reflected by the sensor is acquired. Then, the paper type is determined based on the change in the light reception detection result. As a result, the paper type discrimination accuracy can be further improved.

なお、図４における処理Ｓ４では、発光光量を増加させる方向に変化させているが、これに対して当初の光量を、最終光量よりも大きくして、処理Ｓ４において発光光量を漸減させてもよい。 In step S4 in FIG. 4, the light emission amount is changed in the increasing direction, but the initial light amount may be made larger than the final light amount and the light emission amount may be gradually decreased in step S4. .

本発明の実施の形態に係る画像形成装置の構成例を表す概要図である。1 is a schematic diagram illustrating a configuration example of an image forming apparatus according to an embodiment of the present invention. 本発明の実施の形態に係る画像形成装置における発光部と受光部との配置例を表す説明図である。It is explanatory drawing showing the example of arrangement | positioning of the light emission part and light-receiving part in the image forming apparatus which concerns on embodiment of this invention. 本発明の実施の形態に係る画像形成装置の用紙検知に係る機能ブロック図である。FIG. 3 is a functional block diagram relating to paper detection of the image forming apparatus according to the embodiment of the present invention. 本発明の実施の形態に係る画像形成装置の用紙検知に係る動作を表すフローチャート図である。FIG. 10 is a flowchart illustrating an operation related to sheet detection of the image forming apparatus according to the exemplary embodiment of the present invention. 本発明の実施の形態に係る画像形成装置において設定される用紙判別基準情報の概要例を表す説明図である。FIG. 6 is an explanatory diagram illustrating an outline example of sheet discrimination criterion information set in the image forming apparatus according to the embodiment of the present invention. 本発明の実施の形態に係る画像形成装置において測定する受光光量変化情報の概要例を表す説明図である。It is explanatory drawing showing the example of an outline | summary of the received light amount change information measured in the image forming apparatus which concerns on embodiment of this invention.

符号の説明Explanation of symbols

１給紙トレイ、２画像形成部、３転写ロール、４定着部、５排出トレイ、６制御部、７記憶部、１１発光部、１２受光部、２１光量制御部、２２受光量検知部、２３比較部。 DESCRIPTION OF SYMBOLS 1 Paper feed tray, 2 Image formation part, 3 Transfer roll, 4 Fixing part, 5 Discharge tray, 6 Control part, 7 Storage part, 11 Light emission part, 12 Light reception part, 21 Light quantity control part, 22 Light reception amount detection part, 23 Comparison unit.

Claims

用紙搬送路に関して配置された、発光部及び、当該発光部が放射する光を受ける受光部を備え、
互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報に基づいて用紙判別処理を実行する画像形成装置であって、
前記発光部と受光部との間の光路内に用紙がない状態において、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報に基づいて用紙判別の基準となる情報を生成することを特徴とする画像形成装置。 A light emitting unit disposed with respect to the paper transport path, and a light receiving unit that receives light emitted by the light emitting unit;
The light emitting unit is controlled to emit light with different amounts of light, information on the amount of light received by the light receiving unit when light is emitted with different amounts of light is obtained, and paper determination is performed based on the acquired information about the plurality of received light amounts An image forming apparatus that executes processing,
The amount of light received by the light receiving unit when the light emitting unit is controlled to emit light with different amounts of light in a state where there is no paper in the optical path between the light emitting unit and the light receiving unit. An image forming apparatus characterized in that information is acquired, and information that serves as a reference for paper discrimination is generated based on the acquired information regarding a plurality of received light amounts.

用紙搬送路に関して配置された、発光部及び、当該発光部が放射する光を受ける受光部を備え、
互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報に基づいて用紙判別処理を実行する画像形成装置であって、
画像形成動作停止中の前記発光部、受光部間の光路内に用紙がない状態において、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する停止中情報を取得し、
画像形成動作中の前記発光部、受光部間の光路内に用紙がない状態において、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する動作中情報を取得し、
前記停止中情報を、前記動作中情報の値に基づいて補正し、当該補正した停止中情報に基づいて、用紙判別の基準となる情報を生成することを特徴とする画像形成装置。 A light emitting unit disposed with respect to the paper transport path, and a light receiving unit that receives light emitted by the light emitting unit;
The light emitting unit is controlled to emit light with different amounts of light, information on the amount of light received by the light receiving unit when light is emitted with different amounts of light is obtained, and paper determination is performed based on the acquired information about the plurality of received light amounts An image forming apparatus that executes processing,
In the state where there is no sheet in the optical path between the light emitting unit and the light receiving unit when the image forming operation is stopped, the light receiving unit controls the light emission of the light emitting unit with different light amounts and emits light with the different light amounts. Information about the amount of light received during
In the state where there is no paper in the optical path between the light emitting unit and the light receiving unit during the image forming operation, the light emitting unit is controlled to emit light with different light amounts, and the light receiving unit emits light with the different light amounts. Get information about the amount of light received during operation,
An image forming apparatus, wherein the information during stoppage is corrected based on the value of the information during operation, and information serving as a reference for paper discrimination is generated based on the corrected information during stoppage.

請求項１に記載の画像形成装置であって、
前記発光部と受光部との間の光路内に用紙がない状態において、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報に基づいて、用紙判別処理における前記発光部の発光制御を行うことを特徴とする画像形成装置。 The image forming apparatus according to claim 1 ,
The amount of light received by the light receiving unit when the light emitting unit is controlled to emit light with different amounts of light in a state where there is no paper in the optical path between the light emitting unit and the light receiving unit. An image forming apparatus, wherein information is acquired, and light emission control of the light emitting unit in paper discrimination processing is performed based on the acquired information regarding a plurality of received light amounts.

請求項１から３のいずれか一項に記載の画像形成装置であって、
前記発光部と受光部との間の光路内に用紙がない状態において、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報に基づいて、受光部の動作状態を判別することを特徴とする画像形成装置。 The image forming apparatus according to any one of claims 1 to 3 ,
The amount of light received by the light receiving unit when the light emitting unit is controlled to emit light with different amounts of light in a state where there is no paper in the optical path between the light emitting unit and the light receiving unit. An image forming apparatus characterized by acquiring information and determining an operation state of a light receiving unit based on the acquired information regarding a plurality of received light amounts.

請求項１から４のいずれか一項に記載の画像形成装置であって、
前記発光部と受光部との間の光路内に用紙が配置されている状態で、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報を、前記配置されている用紙を特定する情報に関連づけて記憶し、当該記憶している情報が、前記用紙判別処理に供されることを特徴とする画像形成装置。 An image forming apparatus according to any one of claims 1 to 4 ,
In a state where a sheet is disposed in the optical path between the light emitting unit and the light receiving unit, the light emitting unit is controlled to emit light with different light amounts, and the light receiving unit emits light with the different light amounts. Information on the amount of received light is acquired, information on the acquired plurality of received light amounts is stored in association with information for specifying the placed paper, and the stored information is used for the paper discrimination processing. An image forming apparatus.

用紙搬送路に関して配置された、発光部及び、当該発光部が放射する光を受ける受光部を備える画像形成装置を、  An image forming apparatus including a light emitting unit and a light receiving unit that receives light emitted from the light emitting unit, arranged with respect to the paper conveyance path,
互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報に基づいて用紙判別処理を実行する手段と、  The light emitting unit is controlled to emit light with different amounts of light, information on the amount of light received by the light receiving unit when light is emitted with different amounts of light is obtained, and paper determination is performed based on the acquired information about the plurality of received light amounts Means for performing the process;
前記発光部と受光部との間の光路内に用紙がない状態において、互いに異なる光量にて前記発光部を発光制御させ、当該互いに異なる光量で発光させたときの前記受光部での受光量に関する情報を取得し、当該取得した複数の受光量に関する情報に基づいて用紙判別の基準となる情報を生成する手段と、  The amount of light received by the light receiving unit when the light emitting unit is controlled to emit light with different amounts of light in a state where there is no paper in the optical path between the light emitting unit and the light receiving unit. Means for acquiring information, and generating information serving as a reference for paper discrimination based on the acquired information regarding the plurality of received light amounts;
として機能させることを特徴とするプログラム。  A program characterized by functioning as