JP5020580B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus that reads an image of a document.

  In recent years, there has been a demand from the user to reduce the first copy output time (FCOT), which is the time from when the image reading apparatus starts reading a document to when it is output by an image forming apparatus such as a printer.

  On the other hand, it takes time for the image reading apparatus to prepare for reading, for example, it takes time to stabilize the light amount necessary for reading after the lamp for illuminating the original is turned on, but such time is becoming difficult to ignore. .

  In view of user convenience, an image reading apparatus has been proposed that turns on a lamp as soon as it is detected that a document is set (see, for example, Patent Document 1).

In addition, an image forming apparatus that shortens the FCOT by performing automatic document size detection when detecting the pressure plate opening / closing operation and waiting the reading optical system at the shading position after the size detection is completed (for example, Patent Document 2). reference.).
JP-A-9-163137 JP 2001-285583 A

  However, the above-mentioned Patent Document 1 does not consider automatic document size detection that improves user usability when the user cannot specify the document size well. For this reason, since it can be assumed that it takes time to specify the size of the document placed by the user, it cannot be said that an inexperienced user can obtain a really fast copy output.

  In Patent Document 2, the reading optical system is moved to the shading position in order to realize FCOT shortening in consideration of automatic document size detection. However, as described above, since it takes time for the light quantity to stabilize after the lamp is turned on, it cannot be said that sufficient FCOT reduction can be realized only by moving the reading optical system to the shading position.

  On the other hand, since the lamp lighting time also affects the lamp life, there is a demand that the user does not want to turn on the lamp unless the user really intends to start reading a document.

  Therefore, an object of the present invention is to provide an image reading apparatus that improves user convenience and realizes shortening of FCOT during image reading.

  In order to achieve the above object, an image reading apparatus according to the present invention includes a document table on which a document is placed, a pressure plate that presses the document on the document table and that can be opened and closed with respect to the document table, and the pressure plate includes the pressure plate. An open state that is open with respect to the document table, a closed state in which the pressure plate is closed with respect to the document table, and a closed state in which the pressure plate is between the open state and the closed state A pressure plate detecting means for detecting an image, an operation unit for manually inputting an instruction to the image reading apparatus, a reading means for reading an image of a document on the document table, and an illumination means for irradiating light on the document on the document table And a moving means for moving the illumination position of the illumination means and the reading position of the reading means in the sub-scanning direction orthogonal to the main scanning direction of the reading means, and the size of the original on the original table in the sub-scanning direction. Document for detection The detection result of the pressure plate detecting means is changed from the open state to the closing state in a state where the illumination position and the reading position are moved to the position where the original should be placed on the original table by the knowledge means and the moving means. The illumination unit is turned on in response to the transition to the state, the size of the document in the main scanning direction on the document table is detected based on the reading result of the reading unit, and the size in the main scanning direction and the size of the document The size of the document on the document table is determined based on the size in the sub-scanning direction according to the detection result of the document detection means, and the detection result of the pressure plate detection means transitions from the open state to the closing state. Whether or not there has been an input from the operation unit until the size of the document is confirmed, and in the case of a negative determination, if the size of the document is determined, the illumination means is turned off and an affirmative determination is made. When the input from the operation unit is a start instruction to start reading the document, the illumination unit is continuously turned on, the reading unit is caused to read the image of the document on the document table, an affirmative determination, and the If the input from the operation unit is not the start instruction, a control unit that waits for the start instruction on the document table from the operation unit by continuously lighting the illumination unit for a predetermined time after the size of the document is determined. It is characterized by having.

According to the present invention, when there is a possibility that Yoo over The inputs an instruction to start immediately reading can postpone the turning off of the lighting means light intensity stabilization time of the illuminating means is required. As a result, it is possible to provide an image reading apparatus that improves the user-friendliness and shortens the FCOT during image reading.

Example 1
Embodiment 1 will be described below with reference to the drawings. FIG. 1 is a front view of the image reading apparatus 200, and FIGS. 2 to 4 are side views of the image reading apparatus.

  In FIG. 1, the image reading apparatus 200 includes a reference white plate 201 for shading and a platen glass 202. The original placed on the platen glass 202 is irradiated with light by the lamp 203, and the irradiated light is reflected by the first mirror 204, the second mirror 205, and the third mirror 206, passes through the lens 207, and the CCD 208. Is incident on. The scanner unit 209 has a lamp 203 and a first mirror 204. In addition, a pressure plate 210 that covers the platen glass 202 is provided on the upper portion of the image reading apparatus 200.

  Next, a method for detecting whether or not the pressure plate 210 has been opened will be described with reference to FIGS. 2 shows a state in which the pressure plate 210 is closed, FIG. 3 shows a closed state, and FIG. 4 shows a state in which the platen is completely opened.

  As shown in FIG. 2, when both of the two sensors 213 and 214 provided in the image reading apparatus 200 detect a flag 215 that moves as the pressure plate is opened and closed, the pressure plate is closed by a CPU 230 described later. It is determined that the state has been set. Further, as shown in FIG. 3, when only the sensor 213 detects the flag 215, it is determined that the pressure plate is in a closed state. Furthermore, as shown in FIG. 4, when neither of the sensors 213 and 214 detect the flag 215, it is determined that the pressure plate is in a fully opened state.

  Next, an outline of automatic document size detection will be described with reference to FIG. FIG. 5 is an arrangement diagram of sensors for automatic document size detection.

  The length of the document in the main scanning direction (main scanning length) is detected by the scanner unit 209 illuminating the document placed on the platen glass 202 and reading it by the CCD 208. The length of the document in the sub-scanning direction (sub-scanning length) is detected by the outputs of the reflective sensors 220 and 221.

  The reason why the sub-scanning length is detected to such an extent that it can be classified into the approximate length is that the main scanning length can be detected with a certain degree of precision. For example, when the main scanning length corresponding to the A4 size can be detected as the main scanning length, if the reflection type sensors 220 and 221 in the sub-scanning direction both detect the reflected light from the document, A3, the reflection type sensor If both 220 and 221 are not detected, it is possible to determine the size of A4.

  FIG. 6 is a block diagram illustrating a configuration of a control system of the image reading apparatus and the image forming apparatus. The control system of the image reading apparatus 200 has a configuration in which a CPU 230, a ROM 231, a RAM 232, an image processing unit 233, sensors 213, 214, 220, 221, a lamp 203, a motor 234, an operation unit 235 are connected.

  Here, the motor 234 is an optical motor that drives the scanner unit 209 in the sub-scanning direction along the document. The CCD 208 is connected to the image processing unit 233 via an A / D conversion circuit (not shown).

  CPU 230 detects the open / close state of the pressure plate based on the outputs of sensors 213 and 214. The CPU 230 detects the sub-scanning length of the document based on the outputs of the sensors 220 and 221, and detects the main scanning length of the document based on the output of the image processing unit 233.

  When the start key provided on the operation unit 235 is pressed, the CPU 230 turns on the lamp 203 and drives the motor 234 to move the scanner unit 209 along the document 101 in the sub-scanning direction.

  By scanning the original, the optical output read by the CCD 208 is converted into a digital signal by an A / D conversion circuit (not shown) and then transferred to the image processing unit 233 as image data. The image data processed by the image processing unit 233 is transferred to the controller 110 of the image forming apparatus 100, and an image is formed on the sheet by the image forming apparatus based on the image data.

  Next, an automatic document size detection sequence and a document image reading sequence will be described with reference to the flowcharts of FIGS. These flows are executed by the CPU 230 of the image reading apparatus 200.

  The CPU 230 detects the open state of the pressure plate 210 (the state shown in FIG. 4) when the user sets a document on the platen glass 202 (S701). Then, the CPU 230 moves the scanner unit 209 to a position (original size detection position) where a part of the original document set on the platen glass 202 can be read (S702).

  Next, with the lamp 203 turned off, external light is detected by reading a part of one line of the document in the main scanning direction with the CCD 208 (S703). That is, the pressure plate 210 is open, and the document blocks external light such as an indoor fluorescent lamp, so that the external light is determined by detecting the edge of the document in the main scanning direction. The area is determined to be a no-document area.

  In addition, as described with reference to FIG. 5, infrared light from the light emitting units of the reflective sensors 220 and 221 is emitted from the lower side of the document table, and reflected light from the original is received by the light receiving units of the reflective sensors 220 and 221. As a result, the CPU 230 detects the approximate length in the sub-scanning direction (S704).

  Next, when the CPU 230 detects the pressure plate closing state (the state shown in FIG. 3) (S705), the CPU 230 turns on the lamp 203 (S706). Then, the CPU 230 causes the CCD 208 to read one line of the document in the main scanning direction and detects the main scanning length of the document (S707).

  Here, a portion where the light from the lamp 203 is blocked and reflected by the document and a portion where the reflected light does not return because there is no document are detected, and the edge of the document is detected based on the detection result. Is done. Thus, a precise main scanning length is detected based on the external light detection result by the CCD 208 executed in step S703 and the document edge detection result by the CCD 208 executed in step S707.

  Further, since the sub-scanning direction length is determined to some extent in step S704, the CPU 230 can determine the standard document size, and the document size is determined when the pressure plate is completely closed (S708).

  Conventionally, the lamp 203 is turned off when the document size is determined. However, as described above, it takes time to stabilize the light amount of the lamp 203, and in order to shorten the FCOT, the stabilization time of the lamp 203 can be ignored. It is gone. On the other hand, if the lamp is simply left on standby from the beginning, the lamp life is lost, so it is necessary to appropriately control the lighting and extinguishing of the lamp 203.

  Therefore, in this embodiment, the CPU 230 determines whether or not the user inputs a key on the operation unit 235 before the pressure plate 210 is closed and the document size is determined (S709). If the key information has not been acquired, the flow proceeds to the flow of FIG. 8, and the CPU 230 turns off the lamp 203 (S801). This is because there is no key input from the user, so there is no need to start reading an image of the original immediately, and the lamp 203 is extinguished to extend the lamp life.

  Thereafter, the CPU 230 turns off the CCD 208 (S802) and waits until the start key is pressed (S803). When the start key is pressed, the CPU 230 moves the scanner unit 209 to the shading position (directly below the reference white plate 201) (S804), and performs black shading sampling based on the output from the CCD 208 (S805).

  Black shading sampling is a process of reading the reference white plate 201 by the CCD 208 with the lamp 203 turned off. The result of black shading sampling is used for black level offset processing during shading correction. When the black shading sampling is completed, the CPU 230 turns on the lamp 203 (S806), and performs white shading sampling (S807).

  White shading sampling is sampling for illuminating the lamp 203 on the reference white plate 201 and detecting the white level in the main scanning direction. From the result of performing black shading sampling and white shading sampling, a step or a drop in the reading level in the main scanning direction is detected, and the reading level is adjusted by a gain. As a result, the reading level of the white level in the main scanning direction is corrected uniformly.

  After executing the shading correction, the CPU 230 detects dust on the reference white plate 201 (S808). When dust is detected on the reference white plate 201, the change singularity is detected to identify the dust position, and the white level of the dust-detected area is corrected by the image processing unit 233.

  When the dust on the reference white plate 201 is detected, the CPU 230 moves the scanner unit 209 to the image reading start standby position (S809). The image reading start standby position starts moving so that the scanner unit 209 can take an acceleration distance so that the scanner unit 209 can read from the leading edge of the image of the document in a state where the scanner unit 209 starts scanning and reaches a stable reading speed. Position.

  Next, the CPU 230 starts to move the scanner unit 209 and starts a document image reading operation in accordance with the reading timing of the leading edge of the image (S810). After the reading operation is completed, the CPU 230 turns off the lamp 203 (S811), moves the scanner unit 209 to the shading position (S812), and ends the image reading control.

  On the other hand, when any key information is acquired in step S709, the CPU 230 moves the scanner unit 209 to the shading position (S710). Then, the CPU 230 determines whether or not the key information acquired in step S709 is a start key (S711). That is, the CPU 230 determines whether or not the user has input a start key before the platen 210 is closed and the document size is determined.

  If it is determined in step S711 that the key is the start key, the flow proceeds to the flow of FIG. 8, and the CPU 230 starts reading the original image from the white shading sampling in step 807 without turning off the lamp 203.

  In this way, by not turning off the lamp 203, it is possible to start reading a document with the minimum necessary preparation before reading without waiting for the lamp light amount stabilization time that normally requires the most time for preparation before reading. Become. As a result, the FCOT can be shortened as compared with the conventional case where the preparation before reading is performed with the lamp turned off.

  In addition, since fluctuations in the amount of light that occur when the lamp 203 is held in a lit state can be corrected again by shading correction processing by starting from white shading sampling, stable document reading is possible.

  On the other hand, if it is not determined in step S711 that the key is a start key, the flow proceeds to the flow of FIG. 8, and the CPU 230 starts time measurement while the lamp 203 is lit (S813). If the start key is pressed, the document image reading operation is started from the white shading sampling in step 807.

  As described above, when a key other than the start key is pressed, for example, when the number of copies is input using the numeric keypad, it is considered that the user immediately gives an instruction to start image formation (press the start key). Therefore, the lamp 203 is not turned off. As a result, the FCOT can be shortened as described above.

  Then, the CPU 230 determines whether or not a predetermined time has elapsed from the start of time measurement in step S813 (S815). If the predetermined time has elapsed, the CPU 230 proceeds to step S801 and turns off the lamp. Accordingly, it is possible to prevent the life of the lamp 203 from being shortened by keeping the lamp 203 lit.

(Example 2)
Next, Example 2 will be described. The configuration of the second embodiment is basically the same as the configuration of the first embodiment. However, in the second embodiment, not only the automatic document size detection process but also the manual setting is performed by the operation unit 235 in the read document size detection process. Is possible. Therefore, the procedure of control processing from document size determination to image reading is different from that in the first embodiment.

  The image reading apparatus 200 of the first embodiment always performs automatic document size detection processing immediately after the pressure plate 210 is closed. However, if the user knows the document size to be read in advance, the user can manually set the document size and omit the automatic document size detection process to further shorten the FCOT.

  Therefore, in the second embodiment, until the document size is determined, the CPU 230 monitors whether key information from the operation unit 235 is input. If the key information is input, whether the key information is manual document size information. Judging. If it is determined that the key information is manual document size information, the automatic document size detection sequence process is interrupted, and the process proceeds to step S708 in FIG. 7 to determine the document size based on the contents input by the user. Subsequent processing after step S709 is as described in the first embodiment.

It is a front view of an image reading apparatus. FIG. 3 is a side view of the image reading apparatus in a state where a pressure plate is closed. FIG. 3 is a side view of the image reading apparatus in a state where the pressure plate is being closed. FIG. 3 is a side view of the image reading apparatus in a state where a pressure plate is completely opened. FIG. 6 is a layout diagram of sensors for automatic document size detection. 2 is a block diagram illustrating a configuration of a control system of the image reading apparatus and the image forming apparatus. FIG. 6 is a flowchart illustrating an image reading operation. 6 is a flowchart illustrating an image reading operation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 110 Controller 200 Image reading apparatus 201 Reference | standard white board 202 Platen glass (transparent stand)
203 lamp (lighting means)
204, 205, 206 Mirror 207 Lens 208 CCD (reading means)
209 Scanner unit 210 Pressure plate 213, 214 Sensor (pressure plate detection means)
215 Flag 220, 221 Sensor 230 CPU (control means)
231 ROM
232 RAM
233 Image processing unit 234 Motor 235 Operation unit

Claims (3)

An original table on which an original is placed;
A pressure plate that presses the document on the document table and is openable and closable with respect to the document table;
An open state in which the pressure plate is open with respect to the platen; a closed state in which the pressure plate is closed with respect to the platen; and a state in which the pressure plate is between the open state and the closed state. A pressure plate detecting means for detecting a certain closing state;
An operation unit for manually inputting an instruction to the image reading device;
Reading means for reading an image of a document on the document table;
Illumination means for irradiating light on the original on the original table;
Moving means for moving the illumination position of the illumination means and the reading position of the reading means in the sub-scanning direction orthogonal to the main scanning direction of the reading means;
Document detection means for detecting the size of the document on the document table in the sub-scanning direction;
The detection result of the pressure plate detection means transits from the open state to the closing state in a state in which the moving position moves the illumination position and the reading position to a position where the document should be placed on the document table. Accordingly, the illumination unit is turned on, and the size of the document on the document table in the main scanning direction is detected based on the reading result of the reading unit, and the size in the main scanning direction and the size of the document detection unit are detected. The size of the document on the document table is determined based on the size in the sub-scanning direction according to the detection result, and the document is detected after the detection result of the pressure plate detection means transitions from the open state to the closing state. It determined before determining the size whether the input from the operation unit is performed, in the case of negative determination turns off the illuminating means when the size of the document is accepted, an affirmative determination, and the operation unit If the input is a start instruction to start reading the original, the illumination unit is continuously turned on, the reading unit is caused to read an image of the original on the original table, an affirmative determination is made, and the operation unit If the input is not the start instruction that before Symbol the operating unit size from stable continues to light the illumination means a predetermined time of a document having control means for waiting the start instruction on the document table An image reading apparatus. A reference white plate for performing shading correction of the reading means;
The moving means moves the illumination position and the reading position to either the document table or the reference white plate,
The control means receives the document size from the operation unit after the detection result of the pressure plate detection means transitions from the open state to the closing state until the document size is determined. The detection of the size in the main scanning direction is interrupted, and the reference white plate is moved from the position where the document should be placed on the document table by the moving unit while the illumination unit is lit. The image reading apparatus according to claim 1, wherein the image reading apparatus is moved to the position. A reference white plate for performing shading correction of the reading means;
The moving means moves the illumination position and the reading position to either the document table or the reference white plate,
In the case of the affirmative determination, the control means moves the illumination position and the reading position from the position where the document should be placed on the document table by the moving means while the illumination means is lit. 2. The image reading apparatus according to claim 1, wherein

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