JPH04362858A - Picture reader - Google Patents

Abstract

PURPOSE:To reduce power consumption and to improve the picture quality with safety by reducing a read time in the case of consecutive read. CONSTITUTION:A fluorescent light 2 and a mirror 6 are supported by a 1st carriage 10 and mirrors 7, 8 are supported by a 2nd carriage 11. The 1st carriage 10 and the 2nd carriage 11 are stretched by a wire or belt 12 and moved in the left direction A from a home position by a motor (M) 13 and then restores in the right direction A' and the state is detected by a home position sensor 9. Upon the receipt of a read start command from an external device, a CPU lights the fluorescent light 2 and starts the movement of the carriages 10, 11 in the read direction A after lapse of a time t1 for which the luminous quantity of the fluorescent light 2 is made stable, When the read is finished, the fluorescent light 2 goes off, and the movement in the return direction A' of the carriages 10, 11 is started. The fluorescent light 2 is lighted again after lapse of a prescribed time t2 or after the carriages 10, 11 pass a prescribed position P1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device in an image forming apparatus such as a copying machine or a facsimile machine.

0002

[Prior Art] Generally, in image forming apparatuses such as PPC (plain paper copy), fluorescent lamps are used as light sources to illuminate the document surface due to reasons such as stability of light amount, ease of control, lifespan, and cost. Halogen lamps and the like are widely used. Image forming apparatuses using this light source are configured so that the light source is turned on in response to an instruction to start reading, and is turned off after reading is completed to return the reading optical system (carriage) such as the light source to the initial position.However, continuous reading is not possible. In this case, the total time of the lighting time of the light source and the stabilization time of the light amount is important. Note that this time takes, for example, several tens to several hundreds of milliseconds depending on the light source and power source, and cannot be ignored as the number of readings increases.

In order to solve these problems, a conventional image reading device is disclosed in Japanese Patent Application Laid-Open No. 2-109462.
As shown in the publication, there is a mode in which the illumination lamp turns off immediately after reading is completed, and a mode in which the illumination lamp waits for the next reading instruction until a predetermined time has elapsed after reading is completed, and turns off if there is no such instruction. Devices that shorten the reading time when reading are known are known.

0004

However, in the conventional image reading apparatus described above, the light source is not turned off when continuous reading is performed, so there is a problem that the power consumption of the light source and the like increases while the carriage returns. Incidentally, if the same power source is used for the light source and the motor for driving the carriage, this problem becomes noticeable because the power consumption when the carriage returns is large.

Furthermore, when reading a thick original such as a book original, the operator opens the original holding plate and presses the original with his/her hand, which has an adverse effect on the eyes. Furthermore, since digital image forming apparatuses perform image processing by holding the black data output signal of the CCD when the light source is turned off, there is a problem that the black data cannot be updated during reading, resulting in deterioration of image quality. There is a point.

In view of the above conventional problems, the present invention can shorten the reading time when performing continuous reading, reduce power consumption, and improve safety and image quality. The purpose is to provide an image reading device.

[0007]

[Means for Solving the Problems] In order to achieve the above object, a first means includes a light source for illuminating the document surface, a carriage for moving the light source in the sub-scanning direction of the document surface, and a light source for illuminating the document surface. After the light source is turned on and the light intensity of the light source becomes stable, the carriage is controlled to move from the home position in the sub-scanning direction, and after scanning is completed, the light source is turned off and the carriage is controlled to return to the home position. The present invention is characterized by comprising a control means for controlling the light source so that the amount of light from the light source is stabilized by turning on the light source again before scanning is started.

[0008] The second means is such that the control means of the first means:
The present invention is characterized in that black data for shading correction when the light source is turned off is held regardless of whether the next scan is started or not.

The third means is characterized in that, in the first and second means, the light source is turned on again after a predetermined time has elapsed after the end of scanning, and this time is variable depending on the size and magnification of the read image. shall be.

[0010] In the fourth means, in the first to third means, the light source is lit again when the carriage reaches a predetermined position after scanning, and this position is variable depending on the size and magnification of the read image. It is characterized by

The fifth means is characterized in that the time for relighting the light source in the third means can be set from the outside.

The sixth means is characterized in that the position of the carriage at which the light source is turned on again in the fourth means can be set from the outside.

[0013]

[Operation] In the first means, with the above configuration, the light source is turned off after scanning is completed and turned on again before the start of the next scan to stabilize the light intensity of the light source, so that the reading time when performing continuous reading is reduced. It is possible to shorten the time, reduce power consumption, and realize a safe image reading device.

[0014] In the second means, black data for shading correction when the light source is turned off is retained, so that the quality of the image can be improved.

In the third means, since the time to turn on the light source again is variable depending on the size and magnification of the read image,
It is possible to set an optimal relighting time with little power fluctuation while the carriage returns.

[0016] In the fourth means, since the return distance of the carriage for re-lighting the light source is variable depending on the size and magnification of the read image, an optimal re-lighting time is set that minimizes power fluctuations while the carriage returns. be able to.

In the fifth means, since the time for relighting the light source can be set from the outside, the optimum relighting time can be set in accordance with variations in components of the carriage drive system.

In the sixth means, since the position of the carriage at which the light source is re-lit can be set from the outside, the optimum re-lighting time can be set in accordance with variations in parts of the carriage drive system.

[0019]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the image reading device according to the present invention, FIG. 2 is a side view showing the configuration of the optical system of the image reading device shown in FIG. 1, and FIG. 3 shows the operation of the image reading device shown in FIG. It is a flow chart for explanation.

First, the configuration of the optical system 1 to which the image reading apparatus of this embodiment is applied will be explained with reference to FIG. A reference white plate 21 for white level correction is provided around the home position side (right side in the figure) of the contact glass 3, which is moved horizontally to A'.

The reflected light from the original and the reference white plate 21 is reflected by the mirror 6.
After being reflected by .about.8, an image is formed by the lens 4 on the light receiving surface of the CCD 5. Fluorescent lamp 2 and mirror 6 are in the first carriage 1
0, the mirrors 7, 8 are supported by the second carriage 11
Supported by The first carriage 10 and the second carriage 11 are supported by a wire or belt 12,
Left direction A from the home position by motor (M) 13
After moving to , it returns to the right direction A' and is detected by the home position sensor 9 .

In FIG. 1, an image signal read by a CCD 5 is amplified by an amplifier (AMP) 15, and then converted to a digital signal of approximately 6 to 8 bits by an A/D converter 16, and then subjected to black correction. Shading correction is performed by a circuit 17 and a white correction circuit 19. The black correction circuit 17 and the white correction circuit 19 perform shading based on the black level when the fluorescent lamps 2 are turned off and the white level of the reference white board 21 when the fluorescent lamps 2 are turned on, which are stored in RAMs (random access memories) 18 and 20, respectively. In order to perform the correction and, therefore, to correct the black level, it is important to update the black data in the RAM 18 as needed.

The shading-corrected signal is subjected to MTF and smoothing correction by the filter 21, and then
The zooming circuit 22 changes the magnification in the main scanning direction, the image processing circuit 23 performs γ correction and halftone processing, and the image is sent to an external device 35 such as a printer via an interface (I/F) 24.
is output to. Incidentally, the magnification change in the sub-scanning direction is performed optically by changing the driving speeds of the first carriage 10 and the second carriage 11 of the optical system 1.

A CPU (central processing unit) 25 communicates with an external device 35 via a bidirectional buffer 26.
The filter 21, the scaling circuit 22, and the image processing circuit 23 are controlled by various parameters given from the external device 35. The CPU 25 also controls the fluorescent lamp 2 via the driver 27.
The lighting signal is turned on and off, and the fluorescent lamp 2 is turned on or off by the fluorescent lamp ballast 28. The CPU 25 also takes in the detection signal of the home position sensor 9, and rotates the motor 13 in the forward or reverse direction according to the motor drive signal 29 to rotate the motor 13 in the first direction.
The carriage 10 and the second carriage 11 are moved back and forth. The timing signal generation circuit 32 includes a reference oscillator (OSC).
) 34 reference clock to generate the image reading clock and various gate signals, and the CPU 25 controls the CC
It is applied to the CCD 5 via the D drive circuit 33.

Next, referring to FIG. 3, the operation of the above embodiment,
In particular, the operation of the CPU 25 will be explained. First, the external device 35
When image parameters and control data are received from (step S1), commands for the filter 21, variable magnification circuit 22, and image processing circuit 23 are set, and the carriage 1
Driving conditions such as speed and distance of 0 and 11 are determined (step S2). In this embodiment, in the case of continuous reading,
An instruction is given from the external device 35 before starting the first reading.

Next, upon receiving an instruction to start reading from the external device 35 (step S3), the fluorescent lamp 2 is turned on (step S4), and a time t1 is reached during which the light intensity of the fluorescent lamp 2 becomes stable.
After lapse of , the carriages 10 and 11 start moving in the reading direction A (steps S5 and S6). Next, when the reading is completed (step S7), the fluorescent lamp 2 is turned off (step S8), and the carriages 10 and 11 start moving in the return direction A' (step S9).

Next, it is determined whether or not continuous reading is instructed by the external device 35 before starting the first reading (
step S10), a predetermined time t2 in the case of continuous reading;
(step S11), or the carriage 10,
11 passes the predetermined position P1 (step S12
), the fluorescent lamp 2 is turned on again (step S13). When the time t1 in which the light amount of the fluorescent lamp 2 becomes stable has elapsed (step S14), it is determined whether the carriages 10, 11 have returned to their home positions (step S15), and if they have returned, the process returns to step S6, and the carriages 10, 11 and moves in the reading direction A again. When the image reading is completed, the process branches from step S10 to step S16 without turning on the fluorescent lamp 2 again, and when the carriages 10 and 11 return to their home positions, the process returns to step S1.

Therefore, according to the above embodiment, the re-lighting time of the fluorescent lamp 2 and the stabilization time of the light amount are determined by the carriages 10 and 1.
1 when the carriages 10 and 11 return, it is possible to shorten the reading time and reduce power consumption when performing continuous reading, and it is safe because the fluorescent lamp 2 is turned off when the carriages 10 and 11 return.

Next, a second embodiment will be explained with reference to FIG. FIG. 4 is a flowchart for explaining the operation of the image reading apparatus of the second embodiment. In the first embodiment described above, continuous reading was instructed by the external device before the start of the first reading, but in this second embodiment, the instruction was not given before the start of the first reading. First, in steps S21 to S29, the fluorescent lamp 2 is turned on and the carriages 10 and 11 are moved in the reading direction A.
, 11 until they start moving in the return direction A' are the same as those shown in steps S1 to S9 above, so detailed explanation thereof will be omitted.

Next, after a predetermined time t2 has elapsed (step S30) or after the carriages 10 and 11 have passed the predetermined position P1 (step S31), the fluorescent lamp 2 is turned on again (step S32). Then, a predetermined time t3
If the next reading is instructed before the elapse of (steps S33, S36), the carriage 10
, 11 have returned to their home positions (step S35), and if they have returned, the process returns to step S26 to perform continuous reading. On the other hand, if the next reading is not instructed before the predetermined time t3 has elapsed (steps S33, S36), the fluorescent lamp 2 is turned off (step S37).
), the process returns to step S21.

Therefore, according to this second embodiment,
Even if continuous reading is not instructed by an external device before starting the first reading, the re-lighting time of the fluorescent lamp 2 and the stabilization time of the light amount are secured when the carriages 10 and 11 return, so that when performing continuous reading, It is possible to shorten reading time and reduce power consumption, and it is safe because the fluorescent lamp 2 is turned off.

Next, a third embodiment will be described with reference to FIG. FIG. 5 is a flowchart for explaining the operation of the image reading apparatus of the third embodiment. Step S4
1 to S49, the fluorescent lamp 2 is turned on and the carriage 10
, 11 in the reading direction A, and the carriages 10, 1
1 until it starts moving in the return direction A' is the same as the operation shown in steps S1 to S9 of the first embodiment, so a detailed explanation thereof will be omitted.

When the carriages 10 and 11 return to their home positions (step S50), the fluorescent lamp 2 is turned on again (step S51), and if the next reading is instructed before the predetermined time t4 has elapsed (step S50), the fluorescent lamp 2 is turned on again (step S51). S52, S53)
, the process returns to step S45, and after the elapse of time t1 during which the light amount of the fluorescent lamp 2 becomes stable, the carriages 10 and 11 start moving in the reading direction A again (step S46). On the other hand, if the next reading is not instructed before the predetermined time t4 has elapsed (steps S52, S53), the fluorescent lamp 2 is turned off (step S54), and the process returns to step S41.

Therefore, in this third embodiment, the fluorescent lamp 2 is not lit again while the carriages 10 and 11 are returning, but is lit again after returning to the home position.
The peak value of power consumption can be reduced, and high speed during continuous reading can be ensured.

Next, a fourth embodiment will be described with reference to FIG. FIG. 6 is a flowchart for explaining the operation of the image reading device of the fourth embodiment. First, when image parameters and control data are received from an external device (step S61), commands for the filter 21, variable magnification circuit 22, and image processing circuit 23 are set, and the speed and distance of the carriages 10 and 11 are set. Driving conditions are determined (step S62). Next, upon receiving a reading start instruction from the external device (step S63), the black level of the fluorescent lamp 2 when it is turned off is read (step S64).

Next, the fluorescent lamp 2 is turned on (step S6).
5) After the elapse of time t1 during which the light amount of the fluorescent lamp 2 becomes stable, the carriages 10 and 11 start moving in the reading direction A (steps S66 and S67). Next, when the reading is completed (step S68), the fluorescent lamp 2 is turned off (step S69), and the carriages 10 and 11 are moved in the return direction A.
' (step S70).

Next, when the carriages 10 and 11 return to their home positions (step S71), the black level of the fluorescent lamp 2 when it is turned off is read again (step S72), and then the fluorescent lamp 2 is turned on again (step S73). . Next, as in steps S52 to S54 of the third embodiment, if the next reading is instructed before the predetermined time t4 has elapsed (steps S74, S75), the process returns to step S66, and the fluorescence Time t1 when the light amount of lamp 2 becomes stable
After lapse of , the carriages 10 and 11 start moving in the reading direction A again. On the other hand, if the next reading is not instructed before the predetermined time t4 has elapsed (steps S74, S75), the fluorescent lamp 2 is turned off (step S75).
76), the process returns to step S61.

Therefore, in this fourth embodiment, since the black level is read when the fluorescent lamp 2 is turned off, the quality of the image can be improved. Since the fluorescent lamp 2 is turned on again after returning to the home position, the peak value of power consumption can be reduced, and high speed during continuous reading can be ensured.

Next, a fifth embodiment will be explained with reference to FIG. FIG. 7 is a flowchart for explaining the operation of the image reading device of the fifth embodiment. First, Pu S8
1 to S90, the fluorescent lamp 2 is turned on and the carriage 10
, 11 in the reading direction A, and the carriages 10, 1
1 until it starts moving in the return direction A' is the same as the operation shown in steps S61 to S70 of the fourth embodiment, so a detailed explanation thereof will be omitted.

In step 91 and subsequent steps, as in the first embodiment, after the predetermined time t2 has elapsed (step S91) or after the carriages 10 and 11 have passed the predetermined position P1 (step S92), the fluorescent lamp is turned off. The black level is read when the fluorescent lamp 2 is turned off (step S93), and then the fluorescent lamp 2 is turned on (step S94). If the next reading is instructed before the predetermined time t4 has elapsed (step S
95, S96), the process returns to step S86, and the carriages 10 and 1 are
1 starts moving in the reading direction A again. On the other hand, if the next reading is not instructed before the predetermined time t4 has elapsed (steps S95, S96), the fluorescent lamp 2 is turned off (step S97), and the process returns to step S81.

Therefore, in this fifth embodiment, the sampling time for black data, the time for relighting the fluorescent lamp 2, and the time for stabilizing the light amount are secured when the carriages 10 and 11 return, so that the time required for continuous reading is reduced. It is possible to shorten reading time and reduce power consumption, and since the fluorescent lamp 2 is turned off, it is possible to improve safety and image quality.

Next, a sixth embodiment will be explained. FIG. 8 is an explanatory diagram showing the operation panel of the image reading device of the sixth embodiment, FIG. 9 is a block diagram schematically showing the image reading device of the sixth embodiment, and FIG. 10 is an explanatory diagram showing the operation panel of the image reading device of the sixth embodiment. It is a flowchart for explaining the operation of the reading device. As shown in FIG. 8, this image reading device includes a high-speed mode key 35 for selecting the high-speed mode, and an LED (light-emitting diode) that lights up when the high-speed mode is selected.
36, and as shown in FIG. 9, when the high speed mode is selected by the high speed mode key 35, the CPU 25 turns on the LED 36.

In FIG. 10, first, step S101
- In S110, the fluorescent lamp 2 is turned on and the carriage 1 is turned on.
0 and 11 in the reading direction A, and move the carriages 10 and 11 in the reading direction A.
The operations until 11 returns to the home position are the same as those in steps S41 to S50 of the third embodiment. Next, in step S111, the high speed mode key 35 is pressed.
If the high speed mode is not selected, the process returns to step S101 and the normal light-off mode is executed. On the other hand,
When the high speed mode is selected by the high speed mode key 35, an unconditional lighting mode similar to steps S51 to S54 of the third embodiment is executed (steps S112 to S54).
S115).

Therefore, according to this sixth embodiment,
Since the user can select between the high speed mode and the normal mode, it is possible to select conditions according to the number of times and type of document to be read.

Next, a seventh embodiment will be explained. FIG. 11 is an explanatory diagram showing the operation panel of the image reading apparatus according to the seventh embodiment, and FIG. 12 is a flowchart for explaining the operation of the image reading apparatus according to the seventh embodiment. As shown in FIG. 11, this image reading device includes keys 37 to 39 for selecting ultra high speed mode, high speed high image quality mode, and high image quality mode, respectively, and an LED 40 that lights up when each mode is selected. ~42.

Steps S121 to S130 shown in FIG.
The operation of turning on the fluorescent lamp 2 after reading the black level when the fluorescent lamp 2 is turned off, turning off the fluorescent lamp 2 after reading is completed, and returning the carriages 10 and 11 to the home position is shown in FIG. The operation is the same as that shown in steps S61 to S70. In the seventh embodiment, in the subsequent step S131, the mode selected by the keys 37 to 39 is determined.

In the fifth embodiment shown in FIG. 7, the carriages 10 and 11 read the black level while returning and stabilize the light amount of the fluorescent lamp 2, so it is the fastest, but Since a large current flows through the motor 12, the sampled black data is disturbed due to noise, and the image quality deteriorates (ultra high speed mode). On the other hand, in the fourth embodiment shown in FIG. 6, the black level is read after the carriages 10 and 11 return to their home positions, so the image quality is good but the speed is a little slow (high-speed, high-quality mode). Furthermore, when the black level is not read, the speed is the slowest, but the power consumption is the lowest, and the image quality is the best (high image quality mode).

Therefore, in this seventh embodiment, when the high image quality mode is selected by the key 39, step S
Returning to step 121, if the ultra high speed mode is selected by the key 37, the process branches to steps S132 to S138, the black level is read while the carriages 10 and 11 are returning, and the high speed high image quality mode is selected by the key 38. If so, the process branches to steps S139 to S143, and after the carriages 10 and 11 return to their home positions, the black level is read.

Therefore, according to this seventh embodiment,
The user can select three types of reading modes in consideration of image quality, reading speed, and economy.

Here, the size and reading magnification of the image data to be output to the external device are determined in the form of the distance in the sub-scanning direction, that is, the driving distance of the motor 13, based on both parameters given to the CPU 25 from the external device. If the image size is A4 horizontal size and the magnification is 50%, the scanning distance is 420 mm {= 210 mm x (100/50)
} becomes.

Therefore, in the first, second and fifth embodiments, the predetermined time t2 for re-lighting the fluorescent lamp 2 can be determined according to the scanning distance using a table as shown in FIG. . Further, the position P1 of the carriages 10 and 11 at which the fluorescent lamp 2 is to be turned on again can be determined according to the scanning distance using a table as shown in FIG. In this case, time t2 and position P1 are
, 11, the time when the power supply fluctuation is the least can be set in advance, so that the lifespan of the power supply and the fluorescent lamp ballast 28 can be extended and costs can be reduced.

Note that this position P1 may be determined using Equation 1, or it may be configured to be settable via the numeric keypad 44 and displayed on the screen 43 of the LCD panel, as shown in FIGS. 15 and 16. or may be configured to be settable from the outside. In this case, the carriages 10, 11
The position P1 can be set according to the following equation depending on variations in the drive system. P1 = S-100 (S: scanning distance) However, if S<0, S=0

[0053] Furthermore, in the second to fourth embodiments,
It is preferable that the times t3 and t4 for turning on the fluorescent lamp 2 and turning it off again in the case of not continuous reading are variable depending on conditions such as the processing speed of the external device.
It may also be configured to be configurable as shown in . In this case, it is possible to change the times t3 and t4 for turning off the light again according to the conditions of the external device, so it is possible to speed up the reading time depending on the external device, and also to prevent wasted time for turning off the light again. can improve economic efficiency.

[0054]

As described above, the invention according to claim 1 provides a light source for illuminating a document surface, a carriage for moving the light source in the sub-scanning direction of the document surface, and a light source for illuminating the document surface. After the light intensity of the light source is stabilized, the carriage is controlled to move from the home position in the sub-scanning direction, and after scanning is completed, the light source is turned off and the carriage is controlled to return to the home position, and the next scan starts. The control means controls the light source so that the amount of light from the light source is stabilized by re-lighting the light source before the reading is performed.
Power consumption can be reduced and a safe image reading device can be realized.

[0055] In the invention according to claim 2, the control means according to claim 1 controls whether or not the next scan is started.
Since black data for shading correction when the light source is turned off is retained, image quality can be improved.

[0056] The invention according to claim 3 is the invention according to claims 1 and 2, wherein the light source is lit again after a predetermined time has elapsed after the end of scanning;
Since this time is variable depending on the size and magnification of the read image, it is possible to set the optimum re-lighting time with less power fluctuation while the carriage returns.

According to a fourth aspect of the invention, in the first to third aspects, the light source is lit again when the carriage reaches a predetermined position after scanning, and this positional distance is determined according to the size and magnification of the read image. Since it is variable, it is possible to set the optimum relighting time with less power fluctuation while the carriage returns.

According to the fifth aspect of the invention, in the third aspect, the time for relighting the light source can be set from the outside.
The optimum relighting time can be set according to variations in parts of the carriage drive system.

[0059] According to the invention as claimed in claim 6, in claim 4, the position of the carriage at which the light source is re-lit can be set from the outside, so that the optimum re-lighting time can be set in accordance with variations in parts of the drive system of the carriage. Can be set.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an image reading device according to the present invention.

FIG. 2 is a side view showing the configuration of an optical system of the image reading device shown in FIG. 1;

FIG. 3 is a flowchart for explaining the operation of the image reading device in FIG. 1;

FIG. 4 is a flowchart for explaining the operation of the image reading device of the second embodiment.

FIG. 5 is a flowchart for explaining the operation of the image reading device of the third embodiment.

FIG. 6 is a flowchart for explaining the operation of the image reading device of the fourth embodiment.

FIG. 7 is a flowchart for explaining the operation of the image reading device of the fifth embodiment.

FIG. 8 is an explanatory diagram showing an operation panel of an image reading device according to a sixth embodiment.

FIG. 9 is a block diagram schematically showing an image reading device according to a sixth embodiment.

FIG. 10 is a flowchart for explaining the operation of the image reading device of the sixth embodiment.

FIG. 11 is an explanatory diagram showing an operation panel of an image reading device according to a seventh embodiment.

FIG. 12 is a flowchart for explaining the operation of the image reading device according to the seventh embodiment.

FIG. 13 is an explanatory diagram showing a table of times for relighting fluorescent lamps.

FIG. 14 is an explanatory diagram showing a table of carriage positions for relighting a fluorescent lamp.

FIG. 15 is an explanatory diagram showing input means for inputting the position of the carriage for relighting the fluorescent lamp.

16 is a perspective view showing the input means of FIG. 15. FIG.

FIG. 17 is an explanatory diagram showing a table of times for turning off fluorescent lamps again.

[Explanation of symbols]

2. Fluorescent light 10,11 Carriage 25 CPU (Central Processing Unit)

Claims (6)

[Claims] 1. A light source for illuminating a document surface; a carriage for moving the light source in the sub-scanning direction of the document surface; The carriage is controlled to move in the scanning direction, the light source is turned off after the scan is completed, and the carriage returns to the home position, and the light source is turned on again before the start of the next scan to adjust the light intensity of the light source. An image reading device comprising: a control means for controlling the image so that the image is stabilized; 2. The image according to claim 1, wherein the control means holds black data for shading correction when the light source is turned off, regardless of whether or not the next scan is started. reading device. 3. The light source is turned on again after a predetermined time has elapsed after the end of scanning, and this time is variable depending on the size and magnification of the read image.
The image reading device described. 4. The light source is turned on again when the carriage reaches a predetermined position after scanning, and this position is variable depending on the size and magnification of the read image. 3. The image reading device according to any one of 3. 5. The image reading device according to claim 3, wherein the time for re-lighting the light source can be set from the outside. 6. The image reading device according to claim 4, wherein the position of the carriage at which the light source is turned on again can be set from the outside.