JP2001339578A - Image reader, image reading method and computer- readable storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader that gives no adverse effect on image quality of a read image without revising a structure of an external electrode type fluorescent discharge tube itself and without decreasing the service life of the external electrode type fluorescent discharge tube and to provide a lighting control method and a storage medium. SOLUTION: The image reader is characteristically configured to solve tasks above such that, that is, the image reader has a lamp that lights up an original, an image read means that reads an image of the lighted original by the lamp, an original platen glass plate on which the original is placed, a member that presses the original, a detection means that detects that the member exists on the original platen glass, a measurement means that measures a time when the detection means detects that the member exists on the original platen glass, and a control means that controls start timing of image reading depending on the time measured by the measurement means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus for reading an image, such as a copying machine or a scanner, an image reading method, and a computer-readable storage medium.

[0002]

2. Description of the Related Art Conventionally, in an image reading apparatus mounted on a copying machine, a halogen lamp or a hot cathode fluorescent lamp has been used as illumination for exposing a document. In recent years, an external electrode-type fluorescent discharge tube in which a plurality of linear or band-shaped external electrodes are arranged on the outer surface of a glass bulb and a high-frequency voltage is applied to these external electrodes to light the external electrodes is often used. It is becoming.

This external electrode type fluorescent discharge tube is obtained by applying a high frequency voltage from the external electrodes to an internal discharge space sandwiched between a plurality of external electrodes disposed on the outer surface of a dielectric glass bulb. , Which causes a discharge in the glass bulb. When this discharge is generated, the discharge current can be increased by setting the high-frequency voltage to a predetermined value. This discharge current can effectively excite the entire phosphor on the inner surface of the bulb, thereby greatly increasing the light output.

In a conventional image reading apparatus using such an external electrode type fluorescent discharge tube, a reflected light obtained by turning on a lamp composed of the external electrode type fluorescent discharge tube and scanning an original is used. An image is read by being reflected by a plurality of mirrors mounted on an optical bench and passing through a lens to form an image on a CCD.

[0005]

However, such an image reading apparatus has problems in the following cases.
That is, for example, the case where the inside of the housing of the image reading apparatus is left for a long time in a dark state where the predetermined brightness is insufficient, such as at night. In this case, it takes time to start the external electrode type fluorescent discharge tube until it is turned on. FIG. 14 is a diagram showing the relationship between the lamp darkness leaving time and the starting time, and the horizontal axis represents the lamp leaving time in the dark state,
The starting time is plotted on the vertical axis. As shown in FIG. 2, the longer the time the lamp is left in the dark state, the more the lighting start timing changes, that is, the longer the time required for the start. The starting here means a period from when the lighting switch is pressed to when the light amount of the lamp reaches a desired value. Such a delay in starting the lamp is generally referred to as a dark starting characteristic.

The following measures have been taken to improve such dark start characteristics. FIG. 15 is a diagram showing a configuration of an external electrode type fluorescent discharge tube for improving dark starting characteristics. In FIG. 1A, an LED, a miniature bulb, and other luminous bodies b are arranged near an external electrode type fluorescent discharge tube a as a xenon lamp, and the external electrode type fluorescent discharge tube a is left in a dark state for a long time. Not to be. Further, in FIG. 3B, a conductive chip c for promoting discharge is arranged in the discharge tube, so that the characteristic of delaying start-up when left in a dark state for a long time can be improved. But,
LED, in addition to lamp a comprising an external electrode type fluorescent discharge tube,
A luminous body b such as a miniature bulb is installed, or an external electrode d
Since the structure of the external electrode type fluorescent discharge tube itself is changed when the conductive tip c is provided, there is a problem in terms of manufacturing cost and reliability.

[0007] Further, in order to improve the dark start characteristics, the lamp may be turned on at certain intervals. However, if the lamp is turned on every fixed time to improve the dark start characteristics, the life of the lamp is shortened.

[0008]

The present invention is configured as follows to solve the above-mentioned problems. That is, the image reading device according to claim 1 of the present invention includes: a light source that illuminates a document; an image reading unit that reads an image of the document illuminated by the light source; a member that presses the document; Detecting means for detecting that the member is in the closed state; measuring means for measuring the time in the closed state when the detecting means detects that the member is in the closed state; and time measured by the measuring means. And control means for controlling the start timing of image reading by the image reading means according to

[0009] The image reading device according to the second aspect of the present invention provides
A light source for illuminating the original, image reading means for reading an image of the original illuminated by the light source, a measuring means for measuring a time during which the light source is in a state where the brightness is lower than a predetermined brightness, and measurement by the measuring means Control means for controlling an image reading start timing by the image reading means in accordance with the set time.

[0010] The image reading device according to the fifth aspect of the present invention provides
A light source for illuminating a document, first and second measuring means for measuring a time during which the light source is in a state where the brightness is insufficient, and a light source which satisfies the predetermined brightness by the first measuring means. Starting to measure the time in the absence state, and controlling the second measurement means to measure the time in the state where the light source is insufficient for the predetermined brightness when the predetermined mode is selected thereafter, Control means for controlling an image reading start timing by the image reading means according to the time measured by the first or second measuring means;
It is characterized by having.

Further, the image reading apparatus according to the present invention is characterized in that:
A light source that illuminates the subject, a photoelectric conversion unit that reads an image of the subject illuminated by the light source and converts the read image into an electric signal, and a detection unit that detects an electric signal obtained by reading a reference image with the photoelectric conversion unit, A measuring unit that measures a time until the level of the electric signal reaches the predetermined value when the level of the electric signal detected by the detecting unit does not reach a predetermined value; and a time measured by the measuring unit. And control means for controlling the image reading start timing in accordance with the timing.

The image reading method according to claim 11, wherein the step of reading an image of the document illuminated by a light source, the step of detecting that a member for pressing the document is in a closed state, and the detecting step When detecting that the member is in the closed state, measuring the time in the closed state, and controlling the image reading start timing according to the time measured by the measurement, characterized by having I do.

The image reading method according to a twelfth aspect of the present invention provides a method for reading an image of a document illuminated by a light source, a step of measuring a time during which the light source is in a state where a predetermined brightness is insufficient, and Controlling the start timing of image reading according to the time measured in the step.

The image reading method according to claim 15 is a step of measuring a time during which a light source illuminating the original is in a state where the brightness is insufficient for a predetermined brightness, and the first measuring means determines that the light source is in a predetermined state. The time when the light source is in a state where the brightness is insufficient is started by a second mode when the predetermined mode is selected. Controlling the image reading start timing in accordance with the time measured in the measuring step.

Further, according to the image reading method of the present invention, a photoelectric conversion step of converting an image of a subject illuminated by a light source into an electric signal, and an electric signal obtained by reading a reference image in the photoelectric conversion step. Detecting a level, measuring the time until the level of the electric signal reaches the predetermined value when the level of the electric signal detected by the detecting step has not reached a predetermined value, and the measuring step Controlling the image reading start timing in accordance with the time measured by the method.

The storage medium according to claim 21, wherein the processing of reading the image of the document illuminated by the light source, the processing of detecting that the member for pressing the document is in a closed state, and the detecting step A program for executing a process of measuring the time in the closed state when detecting that the device is in the closed state, and a process of controlling an image reading start timing according to the time measured by the measurement. I remember.

In the storage medium according to the present invention, a process for reading an image of an original illuminated by a light source, a process for measuring a time when the light source is in a state where the brightness is insufficient for a predetermined brightness; And a program for executing the process of controlling the image reading start timing in accordance with the time measured by the program.

Further, the storage medium according to the twenty-fifth aspect measures the time during which the light source for illuminating the original is in a state where the brightness is insufficient for the predetermined brightness, and the first measuring means determines whether the light source has a predetermined brightness. Start measuring the time during which the brightness is insufficient, and then control the second measuring means to measure the time during which the light source is under the predetermined brightness when the predetermined mode is selected. In addition, a program for executing the process of controlling the image reading start timing according to the time measured in the measurement step is stored.

A storage medium according to a twenty-seventh aspect of the present invention includes a detecting process for detecting a level of an electric signal obtained by reading a reference image by photoelectric conversion for converting an image of a subject illuminated by a light source into an electric signal; When the level of the electric signal detected by the detection processing has not reached a predetermined value, the measurement processing for measuring the time until the level of the electric signal reaches the predetermined value, and the time measured by the measurement processing A control process for controlling the image reading start timing in accordance therewith, and a program for executing the control process are stored.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention shows a case where an image reading apparatus is applied to a copying machine.

FIG. 1 is a diagram showing a configuration of a main part of an image reading section in an image reading apparatus using an external electrode type fluorescent discharge tube according to the first embodiment. In this image reading apparatus, reflected light from a document 101 obtained by turning on an external electrode type fluorescent discharge tube (hereinafter, also simply referred to as a “lamp”) 105 and scanning the document 101 is reflected on an optical table 10.
7 and the mirrors 108 and 109 mounted on the optical bench 110 and reflected by the lens 11
1 to form an image on the CCD 112.

In the first embodiment, a xenon lamp is used as the external electrode type fluorescent discharge tube (lamp) 105. As shown in FIG. It is stored.

FIG. 2 is a block diagram showing a configuration of a control system of the image reading apparatus. The scanner controller 203 includes a well-known CPU 131, a ROM 132, a RAM 133, an I / O
An O interface 134, an image processing unit 135, a timer 137, and the like are connected via a bus 136. The optical table 10 is connected to the I / O interface 134.
7 and 110 in the sub-scanning direction along the document, a lamp 105 whose lighting is controlled by a scanner controller 203, a pressure plate open / close detection sensor 10
4. The operation unit 113 having the copy button 113a is connected. The CCD 112 is connected to a bus 136 in the scanner controller 203 via an A / D conversion circuit 201.

The scanner controller 203 recognizes that the original has been replaced by the pressure plate open / close detection sensor 104 when reading the image of the original, and when the copy button 113a is pressed, turns on the lamp 105 to turn on the optical motor 202.
To move the optical tables 107 and 110 along the original 101 in the sub-scanning direction.

The reflected light from the original 101 obtained by scanning the original 101 passes through the lens
An image is formed on D112. The light output read by the CCD 112 is converted into a digital signal by the A / D conversion circuit 201 and then sent to the scanner controller 203 as image data. The scanner controller 203 transfers the input image data to the image processing unit 135 in the scanner controller, and outputs an output image by a printer (not shown) based on the image data processed by the image processing unit 135.

FIG. 3 is a flowchart showing a process for delaying the image reading start timing. This processing program is stored in the ROM 13 in the scanner controller 203.
2 and is executed by the CPU 131.

First, the scanner controller 203 scans the document 101 to turn off the lamp 105 (step S1), and then monitors the state of the pressure plate open / close detection sensor 104 to identify whether the pressure plate 103 has been opened or closed (step S1). S2). When the pressure plate 103 is opened and closed and it is detected that the pressure plate 103 is closed, that is, closed, the timer 137 is started (step S3).
It is determined whether a predetermined time has elapsed since the timer 137 was started, that is, 4 hours or more in the present embodiment (step S4). If four hours or more have not elapsed, it is determined whether or not the copy button 113a has been pressed (step S).
5). If the copy button 113a has not been pressed, the process returns to step S4. On the other hand, the copy button 113a
Is pressed, the process returns to step S1, and the lamp 105 is turned on. Then, an image reading operation is performed at a normal image reading start timing, and the lamp 105 is turned off at the same time when the image reading operation is completed. The timer 137 keeps measuring unless the pressure plate 103 is opened after the pressure plate 103 is closed. If the timer 137 has reached 4 hours in step S4, the image reading start timing is delayed. As a result, the time from when the copy button 113a is pressed and the lamp 105 is turned on to when the image reading operation is started is lengthened.

As described above, the longer the time the lamp 105 is left in a state where the brightness is not enough for a predetermined brightness such as a dark state, the longer the start time of the lamp 105, that is, the time until the illuminance rises to the predetermined illuminance. Becomes longer (see FIG. 14). Therefore, when operating in a normal sequence not according to the present embodiment, the read image has the following problem. In other words, the amount of light emitted at the start of reading is not enough to read the image sufficiently, and as a result, the printed image is covered. On the other hand, in the present embodiment, the time from when the normal copy button 113a is pressed and the lamp 105 is turned on to when the image reading operation is started is normally 200 mS. If the image is left in a state where the brightness is insufficient, the time from when the copy button 113a is pressed and the lamp 105 is turned on to when the image reading operation is started is set to one second. As a result, the illuminance of the lamp 105 rises to the amount of light necessary to read the image at the start of the image reading, and the resulting output image is not fogged.

As described above, in the present embodiment, the image quality of the read image is adversely affected without changing the structure of the external electrode type fluorescent discharge tube itself and without shortening the life of the external electrode type fluorescent discharge tube. It is possible to provide an image reading device, a lighting control method, and a storage medium that do not affect the image reading.

In the present embodiment, the start of the time measurement in the dark state of the lamp is performed by detecting that the pressure plate is closed. However, the present invention is not limited to this. For example, it is detected that the lamp is turned off. The same effect can be obtained by setting this as the beginning of the time measurement in the dark state of the lamp.

Further, in the present embodiment, the case where the time of being left in the dark state has reached 4 hours is a reference, but it goes without saying that the reference time is not limited to 4 hours. Further, as shown in FIG. 4, the same effect as that of the present embodiment can be obtained by calculating the timing of starting reading according to the time of being left in the dark state.

(Second Embodiment) FIG. 5 shows a second embodiment of the present invention.
FIG. 3 is a diagram showing a configuration of an image reading device according to the embodiment. The image reading apparatus according to the second embodiment is applied to a copying machine as in the first embodiment. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

The image reading apparatus according to the second embodiment has an automatic document feeder 115. In the case where the image reading is performed by using the automatic document feeder 115 by the so-called flowing scanning of the document, the automatic document feeder 115 is kept closed. Therefore, it may be difficult to predict that the inside of the housing 114 is in a dark state from the detection output of the pressure plate detection sensor 104. Therefore, in the present embodiment, the image is not affected by the dark start characteristic of the lamp 105 even when performing so-called original scanning.

FIG. 6 is a flowchart showing a processing procedure for setting the document reading start timing in the second embodiment. Here, the same step processes as those in the first embodiment are denoted by the same step numbers.

First, the scanner controller 203 drives the automatic document feeder 115 to read the original (step S1A). It waits until the reading of the original is completed and the lamp 105 is turned off (step S2A). When the lamp 105 is turned off, the timer 137 is started by detecting a lighting / light-off control signal at the time of turning off the lamp 105 (step S3).

Then, it is determined whether or not a predetermined time has elapsed since the timer 137 was started, in this embodiment, 4 hours or more (step S4). If not more than four hours have elapsed at this time, it is determined whether the copy button 113a has been pressed (step S5). Copy button 113
If a has not been pressed, the process returns to step S4 and the same processing is repeated. On the other hand, when the copy button 113a is pressed, the process returns to step S1A, the lamp 105 is turned on at a normal reading start timing, an image is read by scanning the original, and the lamp 105 is turned on simultaneously with the end of the scanning. Turn off the light.

Here, the timer 137 keeps counting unless the copy button 113a is pressed after turning off the lamp 105. When the timer 137 reaches 4 hours in step S4, the reading start timing is delayed, and the time from when the copy button 113a is pressed until the lamp 105 is turned on to when the image reading is started by the flow reading operation is lengthened. .

As described above, the ON / OFF control signal of the lamp 105 is used as a trigger for starting the measurement of the timer 137. Normally, the time from when the copy button 113a is pressed until the lamp 105 is turned on and the reading operation is started is 200 ms. However, when the copy button 113a is left in a dark state for more than 4 hours, the copy button 113a is pressed. Is set to 1 second from turning on the lamp 105 to starting the reading operation. As a result, the illuminance of the lamp 105 rises to the required illuminance at the start of image reading, so that the image is not affected.

In the second embodiment, as in the first embodiment, the case where the time of being left in the dark state is 4 hours is used as a reference. Needless to say, this reference time is not limited to 4 hours. Further, as shown in FIG. 4, the same effect as that of the present embodiment can be obtained by calculating the timing of starting reading according to the time of being left in the dark state.

(Third Embodiment) In recent years, power saving has been achieved in copiers and the like used as image reading apparatuses. For example, power saving mode, sleep mode, and other power saving settings are possible. The power of the predetermined section in which such a mode is set is turned off. Therefore, for example, when the power supply of the scanner controller 207 shown in FIG. 2 is in a cut-off state, the lamp 105 is not turned on and is left for a long time. When the power of the image reading unit is cut off, the timer 137 and the CPU 131 are turned off.
Also does not work. Thus, in the third embodiment, in such a power saving mode, the image is not affected even if the start of the lamp (rise of the illuminance) is delayed as a result of the lamp 105 being left in a dark state for a long time. Control to delay the read start timing is performed.

FIG. 7 shows the configuration of the main part of the third embodiment, in which a CPU 138 is provided outside the scanner controller 203.

FIG. 8 is a flowchart showing a procedure of a process for setting a start timing of image reading according to the third embodiment. The procedure of this processing is stored in the ROM 132 in the scanner controller 203 as a program. The CPU 138 is a CPU for monitoring a state in a power saving mode, a sleep mode, and other power saving settings.
It is. As the CPU 138, a CPU of a predetermined unit operable even in the power saving mode or the like may be used as a CPU for state monitoring. The lighting time of the lamp 105 is controlled by a timer 1 controlled by the CPU 138 for monitoring the state.
37. Note that the CPU 138 may directly measure time without using a timer.

First, it is confirmed whether or not the apparatus has entered the power saving mode (step S11). If the apparatus is not in the power saving mode, it operates according to the sequence in the first embodiment or the second embodiment.

When entering the power saving mode, the timer 137
Is transmitted to the state monitoring CPU 138. Hereafter, the CPU 1 for status monitoring is used instead of the CPU 131.
At 38, the time of the dark state is measured (step S1).
2).

Then, it is determined whether the count time of the state monitoring CPU has passed a predetermined time, for example, 4 hours or more (step S13). If not more than four hours, it is determined whether or not the power ON key has been pressed (step S14). If the power ON key has not been pressed, the process returns to step S13 and the same processing is repeated. On the other hand, when the power ON key is pressed, the power supply of the predetermined section, which has been turned off, is restored. Then, when the copy button 113a is pressed, the image reading operation is started (Step S).
15) Return to the process of step S11.

On the other hand, in step S13, the state monitoring CPU
If the count time of 138 becomes 4 hours or more, it is determined whether the document reading start timing has already been delayed (step S16). If the start timing has already been delayed, the process proceeds to step S14 to determine whether the power ON key has been pressed. On the other hand, if the document reading start timing has not been delayed, the document reading operation start timing is delayed (step S17), and the process returns to step S14 to determine whether the power ON key has been pressed.

FIG. 9 shows the timing for measuring the time during which the lamp is in the dark state in consideration of the power saving mode as described above. When the power saving mode is set as shown in FIG. 9, the process shifts from the measurement of the dark state time by the CPU 131 to the measurement of the dark state time by the CPU 138.

As described above, in the power saving mode, the lamp 10
When the time when the number 5 disappears becomes a predetermined time, for example, 4 hours or more, the document reading start timing is delayed from the normal timing when the document is returned next time. Here, the time from the pressing of the copy button 113a to the lighting of the lamp 105 to the start of the operation of reading an image is set to one second. As a result, even when the rise of the lamp due to the dark start characteristic is delayed, when the document reading is started, the light has risen to a sufficient amount, and the apparatus can be operated without affecting the image.

Most of recent copying machines have not only a copying function but also a composite function such as a printer and a facsimile. Under these circumstances, it is conceivable that the frequency of use in other modes such as a printer and a facsimile is higher than the frequency of use as a copier.

In such a case, depending on the predetermined mode, the state where the lamp 105 is left in a dark state may be continued. For example, the lamp 105 is turned on in the facsimile transmission mode, while the lamp 10 is turned on in the printer output, facsimile reception and other modes in which image reading is not performed.
5 is not turned on. Therefore, the lamp 105
Is often left in a dark state for a long time.

In the printer output mode or the FAX reception mode, the power of the scan control unit 207 may be cut off. In this case, the CPU 131 and the timer 137
Does not work.

The count time of the timer 137 is transmitted to the status monitoring CPU 138 when the printer output / fax reception mode is entered or when other modes are switched. Thereafter, the time of the dark state is measured not by the CPU 131 but by the state monitoring CPU 138 (step S12). The start timing of image reading is controlled as follows according to the measurement result of this time. In other words, in the normal case where the dark start characteristic does not occur, the time from turning on the lamp 105 to starting the reading operation is 200 mS, and if the lamp is left in the dark state for more than 4 hours, the copy button is pressed. The time from when the lamp 113 is pressed to when the lamp 105 is turned on to when the image reading operation is started is set to 1
Seconds. As a result, the illuminance of the lamp 105 rises to an illuminance sufficient to read the image at the start of the image reading, and the image is not affected.

In this embodiment, the case where the time of being left in the dark state is 4 hours is a reference, but it goes without saying that the reference time is not limited to 4 hours. Further, as shown in FIG. 4, the same effect as that of the present embodiment can be obtained by calculating the timing of starting reading according to the time of being left in the dark state.

(Fourth Embodiment) In the fourth embodiment, the start timing of image reading is controlled by directly detecting the lamp lighting delay (see FIG. 14) due to the dark start characteristics of the lamp. This is to prevent the delay in the rise of the illuminance of the lamp from affecting the image. Specifically, first, the signal level of the image of the white board read by the CCD 112 is stored for shading correction that also serves as gain adjustment of the CCD output performed when the power is turned on or when the apparatus is initially adjusted. . Then, the lamp 105 is controlled under the control of the initially set reading start timing.
Lights up. At this time, the signal level of the white plate, which is a reference member for correcting the unevenness of the illuminated image reading due to the lighting of the lamp 105, is read, and the reading start timing of the document is set according to the read signal level of the white plate. It is. Therefore, in this embodiment, the reference member for correcting the non-uniformity of the image reading is used. However, such a member is not limited to the white plate. The same effect in the present embodiment can be obtained by using a member capable of predicting the occurrence of the dark start characteristic of the lamp from the difference from the current signal level.

FIG. 10 is a diagram showing the white board level at the time of shading correction and the signal level of the white board after the lamp is left in a dark state. Here, if the initial setting of the document reading start time is not appropriate, that is,
If the signal level of the white plate is lower than the signal level of the white plate read at the time of shading adjustment, it will affect image reading of the document.

Then, the signal level of the white board read at the time of the initial setting is compared with the signal level of the white board after the lamp is put in the dark state after the light is turned off. The timing is controlled so as to be later than the initially set time.

FIG. 11 is a flowchart showing a procedure for setting a document reading start timing according to the fourth embodiment. This processing program is stored in the ROM 132 in the scanner controller 203,
1 is performed.

First, the lamp 105 is turned on, and the image of the white plate is read by the CCD 112 (step S21).
It is determined whether the read signal level is significantly different from the signal level at the time of shading correction (initial) (step S22). If the read signal level is not significantly different from the signal level at the time of shading adjustment (initial), the initially set time (data) is used as the document reading start timing (step S2).
3), end the process.

On the other hand, if the read signal level is significantly different from the signal level at the time of shading adjustment (initial), a time longer than the initially set time is set as the document reading start timing (step S2).
4), end the process.

By adopting such a configuration, it is possible to automatically determine the optimum time for delaying the document reading start timing, and to realize a configuration in which the image is not affected by the dark start characteristic. it can.

(Fifth Embodiment) Next, a case in which the time for delaying the document reading start timing is set more accurately will be described. In the fifth embodiment, the signal level of the white board read by the CCD 112 at the time of shading adjustment performed when the power is turned on or at the time of initial adjustment of the apparatus is stored. The lamp 105 only for the initially set extinguishing time
Is turned off, the lamp 105 is turned on, and the CCD 112 is turned off.
The timer 137 measures the time until the signal level of the white board read in step (1) approaches the signal level of the initial white board. FIG. 12 is a timing chart showing a time T from when the lamp ON signal rises to when the signal level of the white board read reaches the initial signal level of the white board.

FIG. 13 is a flowchart showing a procedure of a process for setting a time for delaying the document reading start timing according to the fifth embodiment. This processing program is stored in the ROM 132 in the scanner controller 203 and is executed by the CPU 131.

First, after turning on the lamp 105 (step S31), the timer 137 is started (step S32). It waits until the signal level of the white board read by the CCD 112 approaches the initial signal level of the white board (step S33).

When the signal level of the white board approaches the initial signal level of the white board, the time measured by the timer 137 is read (step S34). Then, based on the time measured by the timer 137, a time for delaying the document reading start timing is calculated (step S35), and the process ends.

By adopting such a configuration, it is possible to further optimally determine the time for automatically delaying the document reading start timing, and to realize a configuration in which the image is not affected by the dark start characteristic without fail. can do.

According to the embodiment described above, the structure of the external electrode type fluorescent discharge tube itself is not changed, and the life of the external electrode type fluorescent discharge tube is not shortened. An inexpensive and highly reliable image reading device that is not affected by images can be realized.

Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations of the embodiments, but has the functions described in the claims or the configurations of the embodiments. Any configuration that can achieve the function is applicable.

In the present embodiment, the case where the time of being left in the dark state is 4 hours is used as a reference. Needless to say, this reference time is not limited to 4 hours. Further, the same effect as in the present embodiment can be obtained by calculating the timing of starting reading according to the difference in signal level when reading the reference member, and controlling the timing of starting reading based on the calculation result. Can be.

In this embodiment, the CDD is used as the photoelectric conversion means for outputting the image reading signal.
The present invention is not limited to D, and the same effect in the present embodiment can be obtained by using other photoelectric conversion elements such as MOS.

The present embodiment may be applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.) or to an apparatus composed of one device. Is also good.

It is needless to say that the present invention can also be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus using a storage medium storing software program modules for realizing the functions of the above-described embodiments. Absent. In this case, the program module itself read from the storage medium implements the novel function of the present invention, and the storage medium storing the program constitutes the present invention.

In the above embodiment, the program modules shown in the flowcharts of FIGS. 3, 6, 8, 11 and 13 are stored in the ROM 132 as a storage medium. The storage medium for supplying the program module is not limited to the ROM, and may be, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, DVD, magnetic tape, nonvolatile memory card, or the like. Can be used.

In the above embodiment, the light source is not limited to the external electrode type fluorescent discharge tube, but also includes the internal electrode type fluorescent discharge tube and the like. Similar effects can be obtained when used in an apparatus.

[0074]

As described above, according to the present invention, it is possible to realize an image reading with a high reliability that the image quality is affected by the delay of the rise of the lamp illuminance due to the dark start without changing the structure of the lamp itself.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a document reading apparatus according to a first embodiment.

FIG. 2 is a block diagram illustrating a configuration of a control system of the image reading apparatus.

FIG. 3 is a flowchart illustrating a document reading start timing setting procedure;

FIG. 4 is a diagram illustrating an example of a reading start timing according to a dark start leaving time.

FIG. 5 is a diagram illustrating a configuration of a second embodiment.

FIG. 6 is a flowchart illustrating a document reading start timing setting procedure according to a second embodiment.

FIG. 7 is a block diagram illustrating a configuration of a control system of the image reading apparatus.

FIG. 8 is a flowchart illustrating a document reading start timing setting procedure according to a fourth embodiment;

FIG. 9 is a diagram illustrating a timing chart of time measurement in a dark state in the CPU.

FIG. 10 is a diagram showing signal levels of a white plate at the time of shading adjustment and after being left for a light-off time.

FIG. 11 is a flowchart illustrating a document reading start timing setting procedure according to a fifth embodiment;

FIG. 12 is a timing chart showing a time T from when the lamp ON signal rises to when the signal level of the read white board reaches the initial signal level of the white board.

FIG. 13 is a flowchart illustrating a document reading start timing setting procedure according to a sixth embodiment.

FIG. 14 is a diagram illustrating a relationship between a lamp leaving time in a dark state and a starting time.

FIG. 15 is a diagram showing an example of a conventional measure for improving dark start.

[Explanation of symbols]

 101 Document 102 Document Platen Glass 103 Pressure Plate 104 Pressure Plate Open / Close Detection Sensor 105 Lamp 111 Lens 112 CCD 113 Operation Unit 113a Copy Button 114 Housing 115 Automatic Document Feeder 131 CPU 136 Bus 137 Timer 138 CPU

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06T 1/00 430 G06T 1/00 430J 5C072 H04N 1/00 H04N 1/00 C (72) Inventor Nori Matsui Akira 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Tsunao Honho 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Satoru Kijima Tokyo No. 3-30-2 Shimomaruko, Ota-ku Canon Inc. (72) Inventor Nobuo Matsuoka Within No. 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Akihiro Kashihara 3 Shimomaruko, Ota-ku, Tokyo C term 30-2 Canon Inc. F term (reference) 2H012 CA01 CB01 2H108 AA01 CA01 CB01 FA05 JA06 2H109 AA02 AA15 AA23 AB02 AB22 CA17 5B047 AA01 BC11 CA05 CB04 CB11 5C062 AB17 AB41 AB42 AC58 AC61 AD02 BA00 5C072 AA01 CA04 EA05 FB23 LA07 RA16 UA11 UA13

Claims (30)

[Claims] 1. A light source for illuminating a document, image reading means for reading an image of the document illuminated by the light source, a member for pressing the document, and a detecting means for detecting that the member is in a closed state. Measuring means for measuring the time in the closed state when the detecting means detects that the member is in the closed state; and starting image reading by the image reading means in accordance with the time measured by the measuring means. An image reading apparatus comprising: a control unit that controls timing. 2. A light source for illuminating a document, image reading means for reading an image of the document illuminated by the light source, and measuring means for measuring a time when the light source is in a state where the brightness is lower than a predetermined value. An image reading apparatus comprising: a control unit that controls an image reading start timing by the image reading unit according to a time measured by the measurement unit. 3. The apparatus according to claim 1, further comprising: a signal detecting unit configured to detect a signal associated with turning on / off, wherein the measuring unit sets a state in which the light source does not have a predetermined brightness according to the detection of the signal by the signal detecting unit. The image reading apparatus according to claim 2, wherein a certain time is measured. 4. The apparatus according to claim 1, further comprising: a member for pressing the document; a detecting unit for detecting that the member is in a closed state; and a signal detecting unit for detecting a signal associated with turning on / off. The detection means detects that the member is in the closed state, and measures a time during which the light source is in a state where the brightness is insufficient for a predetermined brightness in accordance with detection of a signal by the signal detection means. The image reading device according to claim 2. 5. A light source for illuminating a document, first and second measuring means for measuring a time period during which the light source is in a state where the brightness is insufficient for a predetermined brightness, and the first light source determines that the light source is a predetermined light source. Starts measuring the time during which the brightness of the light source is insufficient, and then, when the predetermined mode is selected, measures the time during which the light source is insufficient for the predetermined brightness by the second measuring means. Control means for controlling the image reading by the image reading means in accordance with the time measured by the first or second measuring means. 6. The image processing apparatus according to claim 1, wherein the control unit controls the image reading start timing to be later than a normal image reading start timing when the time measured by the measuring unit reaches a predetermined time. 6. The image reading device according to any one of 1 to 5. 7. A light source for illuminating a subject, photoelectric conversion means for reading an image of the subject illuminated by the light source and converting the read image into an electric signal, and detecting an electric signal obtained by reading a reference image by the photoelectric conversion means. Detecting means for
A measuring unit that measures a time until the level of the electric signal reaches the predetermined value when the level of the electric signal detected by the detecting unit does not reach a predetermined value; and a time measured by the measuring unit. Control means for controlling an image reading start timing according to the image reading apparatus. 8. The control unit controls the image reading start timing to be later than the normal image reading start timing when the level of the electric signal detected by the detecting unit has not reached a predetermined value. The image reading device according to claim 7, wherein 9. The image reading apparatus according to claim 7, wherein the reference image is a reference image for correcting non-uniformity of image reading by the photoelectric conversion unit. 10. The image reading apparatus according to claim 1, wherein a lighting start timing of the light source varies according to a time period in which the light source is left in a state where brightness is insufficient. . 11. A step of reading an image of a document illuminated by a light source, a step of detecting that a member that presses the document is in a closed state, and a step of detecting that the member is in a closed state by the detecting step. Measuring the time in the closed state, and controlling the image reading start timing according to the time measured by the measurement. 12. A step of reading an image of a document illuminated by a light source, a step of measuring a time during which the light source is in a state where a predetermined brightness is insufficient, and reading an image according to the time measured in the measuring step. Controlling the start timing. 13. A signal detecting step of detecting a signal accompanying lighting / turning off, wherein the measuring step includes the step of: setting the light source to a predetermined brightness with the detection of the signal by the signal detecting step. 13. The image reading method according to claim 12, wherein a time during which the state is insufficient is measured. 14. The apparatus according to claim 1, further comprising: a step of detecting that the member that presses the document is in a closed state; and a signal detecting step of detecting a signal accompanying lighting / light-off. Detecting that the member is in the closed state, and measuring a time during which the light source is in a state where the brightness is insufficient for a predetermined brightness in accordance with the detection of the signal in the signal detecting step. The image reading method according to claim 12. 15. A step of measuring a time during which a light source for illuminating a document is insufficient for a predetermined brightness, and measuring a time during which the light source is insufficient for a predetermined brightness by first measuring means. And when the predetermined mode is selected thereafter, the second measuring means controls to measure the time during which the light source is in a state where the brightness is insufficient for the predetermined brightness, and the time measured in the measuring step is controlled. Controlling the image reading start timing according to the image reading method. 16. The image forming apparatus according to claim 16, wherein the control step controls the image reading start timing to be later than a normal image reading start timing when the time measured by the measurement reaches a predetermined time. Item 11 to 1
5. The image reading method according to any one of 5. 17. A photoelectric conversion step of converting an image of a subject illuminated by a light source into an electric signal, a step of detecting a level of an electric signal obtained by reading a reference image in the photoelectric conversion step, and a step of detecting the level of the electric signal. Measuring the time until the level of the electric signal reaches the predetermined value when the level of the detected electric signal has not reached the predetermined value; and starting image reading according to the time measured in the measuring step. Controlling the timing. 18. The method according to claim 18, wherein the control step controls the image reading start timing to be later than a normal image reading start timing when the electric signal detected by the detection means has not reached a predetermined value. The image reading method according to claim 17. 19. The image reading method according to claim 17, wherein the reference image is a reference image for correcting non-uniformity of image reading by the photoelectric conversion unit. 20. The lighting device according to claim 11, wherein a lighting start timing of the light source varies in accordance with a time when the light source is left in a state where the brightness is insufficient.
2. The image reading method according to 1. 21. A process for reading an image of a document illuminated by a light source, a process for detecting that a member that presses the document is in a closed state, and a case where the detecting step detects that the member is in a closed state. A computer-readable storage medium storing a program for executing a process of measuring the time in the closed state and a process of controlling an image reading start timing according to the time measured by the measurement. 22. A process for reading an image of a document illuminated by a light source, a process for measuring a time during which the light source is in a state where a predetermined brightness is insufficient, and an image reading process according to the time measured in the measuring process. A computer-readable storage medium storing a process for controlling a start timing and a program for executing the process. 23. The apparatus according to claim 23, further comprising: a signal detecting process for detecting a signal associated with turning on / off, wherein the measuring process is performed so that the light source has a predetermined brightness in accordance with the signal detection in the signal detecting step. 23. The computer readable storage medium according to claim 22, wherein a time during which the state is insufficient is measured. 24. The image processing apparatus further comprises: a process of detecting that a member for pressing the document is in a closed state; and a signal detection process of detecting a signal associated with lighting / light-off. Detecting that the member is in the closed state, and measuring a time during which the light source is in a state where the brightness is insufficient for a predetermined brightness in accordance with the detection of the signal in the signal detecting step. A computer-readable storage medium according to claim 22. 25. A process for measuring a time during which a light source for illuminating a document is in a state where a predetermined brightness is insufficient, and measuring a time when a light source is in a state where the brightness is insufficient for a predetermined brightness by first measuring means. And when the predetermined mode is selected thereafter, the second measuring means controls to measure the time during which the light source is in a state where the brightness is insufficient for the predetermined brightness, and the time measured in the measuring step is controlled. And a computer-readable storage medium storing a program for executing a process of controlling an image reading start timing according to the program. 26. The control method according to claim 26, wherein when the time measured by the measurement has reached a predetermined time, the image reading start timing is controlled to be later than the normal image reading start timing. Item 21 to 2
6. The computer-readable storage medium according to any one of 5. 27. A detection process for detecting a level of an electric signal obtained by reading a reference image by photoelectric conversion for converting an image of a subject illuminated by a light source into an electric signal, and a level of the electric signal detected by the detection process A measuring process for measuring a time until the level of the electric signal reaches the predetermined value when the predetermined value is not reached, and a control for controlling an image reading start timing according to the time measured by the measuring process. And a computer-readable storage medium storing a program for executing the processing. 28. The control process, wherein when the electric signal detected by the detection process does not reach a predetermined value, control is performed such that the image reading start timing is later than the normal image reading start timing. An image reading method according to claim 27. 29. A computer-readable image according to claim 27, wherein said reference image is a reference image for correcting non-uniformity of image reading by said photoelectric conversion means. Storage media. 30. The light-emitting device according to claim 21, wherein the lighting start timing of the light source is changed according to a time when the light source is left in a state where the brightness is insufficient.
A computer-readable storage medium according to claim 1.