JPH0799541B2 - Image information input device - Google Patents

Description

The present invention relates to an image information input device such as an image reader or an image scanner.

[Conventional technology]

Conventionally, an image reader irradiates the original with light from a light source and guides the reflected light to a CCD (photoelectric conversion element) array to read the information of the original.

By the way, the light amount changes when the light source is not turned on and when a predetermined time has elapsed. Therefore, the reading operation can be performed after the light source is turned on for a predetermined time and the characteristics are stabilized.

[Problems to be solved by the invention]

Therefore, warming up is time-consuming and inconvenient.

Therefore, when preheated or continuously lit, there are problems of power consumption, life, heat generation, and the like.

In addition, the output of CCD is very likely to change due to temperature changes.
For this reason, for example, when high-density reading is performed and the data transfer rate is slow, the reading time inevitably becomes long, and in a compact device, the temperature inside the device easily rises, and the temperature characteristics of the CCD are a problem. Become.

[Object of the Invention]

An object of the present invention is to obtain an image information input device that can perform good reading without being affected by the rising characteristics of the light source and the temperature characteristics of the reading unit such as CCD.

[Means for solving problems]

In order to achieve the above object, in the first embodiment of the present invention, the irradiation light from the light source is applied to the original on the platen, and the reflected light is guided to the information reading section composed of the photoelectric conversion element array to perform main scanning. In an image information input device that performs sub-scanning by relatively moving irradiation light and a document, a white reference reflecting plate arranged in the sub-scanning direction along one of both outer sides in the main scanning direction of the platen area on which the document is placed, Similarly, a black reference reflection plate arranged in the sub-scanning direction along the other outside both ends in the main scanning direction of the platen area on which the original is placed, and the reference information obtained from the white reference reflection plate are input every time one line is read. And a second reference reading section for inputting the reference information obtained from the black reference reflection plate every time one line is read.
Calculation is performed for each reading of one line based on the reference reading section, the read information input to the information reading section, and the reference information input to the first reference reading section and the second reference reading section. And a control unit that corrects the read information (1).

According to another aspect of the present invention, the reference reflection in the main scanning direction is arranged outside the starting end in the sub scanning direction of the platen area on which the document is placed, along the main scanning direction, and so as to be read by the information reading unit. A plate and a control unit that corrects the read information in the main scanning direction using the reference information input to the information reading unit from the reference reflecting plate in the main scanning direction (section 2). .

In the configurations of the first and second aspects, the information reading section is formed in the middle of the photoelectric conversion element array as an effective reading section for inputting the reflected light from the platen area, and the photoelectric conversion element portions on both sides thereof are formed. It is preferable that the first reference reading section and the second reference reading section are formed (section 3).

As still another mode, a white reference reflector is arranged in the sub-scanning direction along one of both outer sides of the platen area in the main scanning direction, and the reference information obtained from the white reference reflector is read every time one line is read. An optical fiber that guides the light of the light source to obtain the white reference, instead of inputting into the first reference reading section,
A first reference reading unit for inputting reference information obtained from the optical fiber is provided, and the read information input to the information reading unit and the first reference reading unit and the second reference reading unit are input. Based on the reference information, the control unit can perform an operation every time one line is read to correct the read information.

[Action]

According to the first to third aspects of the invention, since the white side and the black side reading reference are arranged outside both ends of the platen area in the sub-scanning direction, the reference can be easily obtained, and In all the forms of the first to fourth ranges, since the calculation is performed every time one line is read to correct the read data, for example, the light quantity characteristic / spectral characteristic of the fluorescent lamp as a light source is in the process of rising. Or CCD
Even if the read data is not constant due to a rise in the temperature around the information reading section including the photoelectric conversion element array, the read data is corrected according to the change, and the corrected data becomes constant. Therefore, even in an unstable state where the light quantity characteristic of the fluorescent lamp rises, it is not affected, and fluctuations on both the white side and the black side are accurately corrected, and a good image with excellent gradation is obtained. be able to. Also, the warm-up time of the light source such as a fluorescent lamp is shortened,
The reading time can be shortened, the slice level in the sub-scanning direction becomes uniform, and good gradation reproducibility can be obtained. In addition, a good image can be obtained even if the temperature inside the apparatus increases due to low-speed reading or continuous reading.

According to the second aspect of the invention, since the reference reflection plate in the main scanning direction is provided and the read information is corrected using the reference information from the reference reflection plate in the main scanning direction, the main scanning direction is corrected. Shading correction can be applied to.

According to claim 3, in the same photoelectric conversion element array, an effective reading portion for reflected light from the platen region is formed in the middle thereof, and the first and second effective reading portions are formed on both sides thereof.
It is possible to form the reference reading section of

According to the fourth aspect of the invention, the reading reference on the black side is arranged on one of both outer sides of the platen area in the sub-scanning direction,
Since the optical fiber of the light source guides the light to the first reference reading unit as the white side reading reference, the white reading can be performed without being affected by the rising characteristic of the light source, the temperature characteristic of the reading unit, and the like, as in claim 1. It is possible to obtain an effect such that the fluctuations on the black and white sides are accurately corrected, and a good image having excellent gradation is obtained.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings.

<Structure> As shown in FIG. 1, the image reader 1 includes a main body 3 and an openable / closable document cover 5. The main body 3 is provided with an operation section 7, a platen glass 9 shown in FIG. 2 which is provided under the original cover 5 and sets an original, and a main body 3 provided in parallel with the platen glass 9 to confirm the position of the light source. It has an elongated window 11.

As shown in FIG. 3, the operation unit 7 includes a RESET switch 13 and a DENSI
TY (resolution) switch 15, START switch 17, BRIGHTNESS volume 19, POWER
(Power) lamp 21, ERROR lamp 23, D
ENSITY lamp 25 and READY lamp 2
7 and.

The reset switch 13 is for forcibly returning the system to the initial state. Resolution switch 15 is 50/100/200 DPI
The resolution of (dot / inch) is selected. It is 50 DPI at reset, and 100/200/50 DPI rotates with each subsequent press. The main scanning and the sub scanning have the same resolution. The start switch 17 is a reading start switch when connecting to the printer alone. The shading volume 19 determines the shading of the output image data, and the center position is in a normal state (60% of the threshold).

The power lamp 21 (green) lights up when a power switch (not shown) is turned on. The power switch is used to turn on / off the power supply, and when it is turned on, the system is reset. The error lamp 23 (red) lights up to notify the error. The resolution lamp 25 displays 50/100/200 DPI.
It should be noted that, of the main scanning and the sub scanning, the one with the higher resolution is lit. The ready lamp 27 (green) comes on when the system is ready to read.

The platen glass 9 is placed so as to cover the opening 29 provided in the main body 3, and both ends thereof are pressed by the frames 31 and 33.

As shown in FIG. 8, inside the cover 170 provided with the opening 29 for the contact glass 9, the reference reflection plate 171 in the main scanning direction and the reference acquisition means, for example, the white reference reflection plate 173 in the sub-scanning direction and the black. A reference reflector 175 is provided. The reference scanning plate 171 in the main scanning direction is arranged outside the starting end in the sub scanning direction of the platen area (opening 29) on which the document is placed, along the main scanning direction, and to be read by the CCD 165. It is divided into a 171W and a black reflection part 171B. The white reference reflection plate 173 in the sub-scanning direction is arranged in the sub-scanning direction along one of both outer sides in the main scanning direction of the platen area (opening 29) on which the document is placed, and is arranged to be read by the CCD 165. There is. In addition, the black reference reflector 175 in the sub-scanning direction
Similarly, they are arranged in the sub-scanning direction along the other outside of both ends in the main scanning direction of the platen area (opening 29) on which the document is placed, and are arranged so that they can be read by the CCD 165.

The document cover 5 is hinged to the back of the main body 3 as shown in FIG.
Are joined by. A document retainer 28 using an elastic body such as a sponge is provided at a portion contacting the platen glass 9.

The inside of the main body 3 is configured as shown in FIGS. As shown in FIG. 4, the main body 3 includes two horizontal and parallel rail guides 35 and 37, a light source unit 39 and a mirror unit 41 that move on the rail guides 35 and 37, and the light source unit 39 and the mirror unit 41. Is provided with a drive unit 43 for driving while keeping the optical path length constant with a moving length of 2: 1, an image reading unit 45, a power source 47, a transformer 49, a control unit 177 and the like.

As shown in FIGS. 4 and 5, the light source unit 39 includes a carriage 51 that is passed between the rail guides 35 and 37, and support plates 53 that are provided on both ends of the carriage 51 and that are located on the rail guides 35 and 37. 55, a light source such as a fluorescent lamp 57, a reflection plate 59 of the fluorescent lamp 57, and a mirror 61 that guides the light of the fluorescent lamp 51 reflected by the platen glass 9 to the mirror unit 41.

The support plate 53 is provided with slide spacers 63 and 65 that come into contact with the rail guide 35, wire holding portions 67 and 69, and a leaf spring 68 that serves as an earth and press-contacts the rail guide 35 as shown in FIG. Has been. Similarly, for the support plate 55, slide spacers 71, 73 that contact the rail guide 37 are also provided.
The wire holding portions 75 and 77 and the leaf spring 76 are provided.

In addition, the replacement work of the fluorescent lamp 57 is performed by the frames 31, 33 shown in FIG.
By removing the platen glass 9, the lids 30 and 32 provided on the home position side are removed, and the opening 29 is widened. These lids 30 and 32 are provided with grooves on their side portions, and can be attached and detached by moving in the horizontal direction.

As shown in FIGS. 4 and 6, the mirror unit 41 includes a mirror holding plate 79 passed between the rail guides 35 and 37, and rail guides provided at both ends of the mirror holding plate 79.
And support plates 81 and 83 located above 35 and 37.

The mirror holding plate 79 has a mirror 61 of the light source unit 39.
And the mirror 85 that reflects the light reflected at
Mirror 87 that reflects the light reflected by 85 to the image reading unit 45
And a number of holes 89 for weight reduction.

The support plate 81 is provided with slide spacers 91, 93 that are in contact with the rail guide 35, and pulleys 95, 97, 99.
Further, the support plate 83 is provided with slide spacers 101 and 103 that are in contact with the rail 87 and pulleys 105 and 107.
The pulley 99 supports a flat cable (not shown) connected to the light source unit 39.

As shown in FIG. 4, the drive unit 43 includes a motor 111, a gear 113 attached to the rotation shaft of the motor 111, and a gear 11
Gear 115 meshing with 3 and gear 117 integrated with gear 115
A gear 121 having a winding portion 119 and meshing with the gear 117; a pulley 123 arranged in parallel with the gear 121; and a second position side opposite to the home position (first position). A pulley 129 which is attached to a frame 125 provided and whose position can be adjusted by turning a screw 127, a gear 121 and a pulley 123.
A pulley 131 provided on the extension line of the above, a pulley 133 provided on the home position side, and support pins 135 and 137.

Further, the drive device 43 includes a gear 141 having a winding portion 139 and meshing with the gear 121, and a pulley provided on an extension line of the gears 121, 141.
143 and a pulley 1 which is attached to a frame 145 provided on the second position side and whose position can be adjusted by turning a screw 147.
49, a pulley 151 provided on an extension line of the gear 141 and the pulley 143, and a pulley 153 provided on the home position side.
And support pins 155 and 157.

A condition, for example, a wire 159 is stretched between the support pin 135 and the support pin 137 as follows. That is, the wire 159 having one end attached to the support pin 135 is wound around the pulley 97 from the upper side to the lower side and returned to the support pin 135 side, is wound around the pulley 133 in the clockwise direction and is guided to the second position side, and the pulley 131 makes a right angle. To the second position side by the pulley 123, and the pulley 129 is wound from the bottom to the top and fixed to the support plate 53 via the wire holding portions 67 and 69. Then, the pulley 95 is wound from the upper side to the lower side, returned to the second position side, and fixed to the support pin 137.

Further, a wire 161 is provided between the support pin 155 and the support pin 157.
Is stretched as follows. That is, one end has the support pin 155.
The wire 161 attached to the above is wound around the pulley 107 from the upper side to the lower side, returned to the support pin 155 side, wound around the pulley 153 in the counterclockwise direction and guided to the second position side, and is changed in direction at a right angle by the pulley 151, and wound. Wrap it around the take-up part 139 and use the pulley 143 to
To the second position side by winding the pulley 149 around the pulley 149 from below to above and fixing it to the support plate 55 via the wire holding portions 75 and 77. And is fixed to the support pin 157.

By the way, the wire 1 between the support plate 53 and the pulley 129
59A and wire 161A between support plate 55 and pulley 149
Is extended parallel to the rail guides 35, 37, and the wire 159B between the support pin 135 and the pulley 97 and the wire 161B between the support pin 155 and the pulley 107 are inclined and extended toward the support pins 135, 155. That is, the wires 159A, 161A for driving the light source unit 39 and the mirror unit 41 in the reading direction are stretched in parallel to the rail guides 35, 37, and the wires 159B, 161B for driving in the returning direction are for the rail guides 35, 37. It is stretched diagonally downward.

The image reading unit 45, as shown in FIG.
Sensor consisting of 3 and photoelectric conversion element array, eg CCD165
Is equipped with.

The CCD 165 is a first reference information reading section A (reference reading section) for inputting the reflected light of the white reference reflecting plate 173 as shown in FIG.
, An effective reading section B (information reading section) for inputting the reflected light of the original set on the platen glass 9, and a second reference information reading section C (reference reading for inputting the reflected light of the black reference reflection plate 175). Section) and is connected to the control section 177.

The control unit 177 has, for example, a microcomputer, and has a CCD.
Based on the white reference data, the read data, and the black reference data input to the reading units A, B, and C of the 165, for example, the following formula is calculated and a function (control unit) for correcting the read data is provided. .

(Correction data) = [(read data)-(black reference data)] / [(white reference data)-(black reference data)]
(1) The control unit 177 also has a function of performing shading correction in the main scanning direction, for example, by performing the calculation of the following formula (11th).
(See Figures and 12).

(Correction data) = [(read data Vg)-(black reference data Vb)] / [(white reference data Vw)-(black reference data V
b)] × 100 [%] (2) <Operation> In such a configuration, this device operates as follows.

The state of FIG. 4 is the home position (first position) of the light source unit 39 and the mirror unit 41. When the start switch 17 is pressed in this state, the fluorescent lamp 57 lights up and the motor 111 rotates. At that time, shading correction in the main scanning direction is performed by the reference reflection plate 171.

That is, as shown in FIG. 11, the calculation of equation (2) is performed from the read data Vg of each bit, the white reference data Vw, and the black reference data Vb, and the shading correction by the fluorescent lamp 57 and the lens unit 163 is performed. As a result, uniform output as shown in FIG. 12 is obtained.

By the rotation of the motor 111, the original is read line by line in the second position direction while the mirror unit 41 moves 1/2 of the moving distance of the light source unit 39.

When reading line by line, CCD165 white reference data,
The read data and black reference data are input, and the control unit 177
Then, the calculation of the equation (1) is performed and the read data is corrected. That is, what percentage of the output is calculated with respect to the reference white, and the density of the read data is regulated. When the reading is completed, the fluorescent lamp 57 is turned off and the motor 111 is rotated in the reverse direction to move the light source unit 39 to the Return to the home position from position 2.

<Effects of Embodiment> According to the embodiment described above, the following effects can be obtained.

(1) Since the white reference reflection plate 173 and the black reference reflection plate 175 are provided inside both ends of the opening 29, for example, when a uniform gray-colored original is read, the first reference information reading unit as shown in FIG. The outputs of A, the effective reading section B, and the second reference information reading section C are clearly distinguished.

Since the calculation of the formula (1) is performed every time one line is read to correct the read data, the fluorescent lamp 57
The light intensity characteristics and spectral characteristics of the
Even if the gray read data is not constant as shown in FIG. 10 due to an increase in the temperature around D165, the read data is corrected according to the change, and the correction data becomes constant.

Therefore, even in an unstable state in which the light amount characteristic of the fluorescent lamp 57 rises, the fluorescent lamp 57 is not affected by it and a good image with excellent gradation can be obtained.

Further, the warm-up time of the fluorescent lamp 57 can be shortened, the reading time can be shortened, the slice level in the sub-scanning direction can be made uniform, and good gradation reproducibility can be obtained.

In addition, a good image can be obtained even if the temperature inside the apparatus increases due to low-speed reading or continuous reading.

(2) Since the white reference data and the black reference data are input to the CCD 165 through the same light source unit 39 and mirror unit 41 as the read data, the light amount is attenuated due to fogging and dirt on the light source unit 39 and the mirror unit 41. The read data can be corrected by taking the above into consideration.

[Modification]

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and the following modifications are possible.

(1) In the above-described embodiment, the image reader for black-and-white reading is described, but the invention can be applied to an image reader for color reading. In this case, the reference reflector is white
The color plate is not limited to black or the like, and it is also possible to use a color plate of three colors, for example.

In particular, in an image reader in which reading is performed three times for colorization, improvement in color reproducibility (color balance) can be expected.

(2) Although the reference reflector is provided in the sub-scanning direction in the above embodiment, the correction may be performed using a transmission filter (for example, ND filter) or a light guide.

In other words, the sensor output may be obtained according to the illuminance of the document surface or the light amount, and the read data may be corrected based on the output, or the light source control or the GAIN control may be performed.

(3) In the above embodiment, the reference reflecting plate is used as the reference obtaining means, but the light of the fluorescent lamp 57 may be guided to the reference reading section of the CCD 165 via the optical fiber.

(4) In the above embodiment, the case where the document is fixed and the light source moves has been described, but the document may move and the light source may be fixed.

(5) In the above embodiment, the CCD 165 is used as the first reference reading unit A.
The effective reading section B and the second reference reading section C are separated, but they may be read by different sensors.

By the way, although not directly related to the present invention, instead of providing the black reference reflector, the black reference information reading section C of the CCD 165 is used.
You can put a mask on. That is, The reference information reading portion C of the CCD 165 is masked so as not to be exposed to light, the dark output level is detected, and the read data is corrected.

In the equation (1), when (black reference data) is small,
In other words, when there is no particular temperature rise around the CCD165 inside the device,
The equation (1) becomes (correction data) ≈ (reading data) / (white reference data) (3), and correction of the black reference data is unnecessary. For this reason,
It is not necessary to provide a black reference reflector or mask the CCD 165. For example, as shown in FIG. 13, read data at time T1 and T2 are V1, V2, white reference data is W1,
If W2 is set, the correction outputs P1 and P2 of the CCD 165 are as follows.

P1 = V1 / W1 P2 = V2 / W2 [Effects of the Invention] In summary, according to the present invention, the following effects can be obtained.

(1) In the embodiments of claims 1 to 3, since the white side and the black side reading reference are arranged outside both ends of the platen area in the sub-scanning direction, the reference can be easily obtained. In all the forms of claims 1 to 4, since the calculation is performed every time one line is read and the read data is sequentially corrected, the light source is in the process of starting up or the information reading unit Even if the read data is not constant due to a temperature rise in the periphery, the read data is corrected according to the change, and the corrected data becomes constant. Therefore, fluctuations on the white side and the black side are accurately corrected without being affected by the rising characteristics of the light source, the temperature characteristics of the reading unit, and the like, and a good image with excellent gradation can be obtained.

Further, the warm-up time of the light source such as a fluorescent lamp can be shortened, the reading time can be shortened, the slice level in the sub-scanning direction can be made uniform, and good gradation reproducibility can be obtained.

In addition, a good image can be obtained even if the temperature inside the apparatus increases due to low-speed reading or continuous reading.

(2) In claim 2, the reference reflector in the main scanning direction is provided by a simple method, and the read information is corrected by using the reference information from the reference reflector in the main scanning direction. Also, shading correction can be easily performed in the main scanning direction.

(3) In claim 3, in the same photoelectric conversion element array, an effective reading section for reflected light from the platen area is formed in the middle thereof, and first and second reference reading sections are provided on both sides thereof. Can be formed.

(4) In claim 4, the black side reading reference is arranged on one of both outer sides of the platen area in the sub-scanning direction,
Since the light of the light source is guided to the first reference reading section by the optical fiber as the white side reading reference, the rising characteristics of the light source and the temperature characteristics of the reading section are not affected, as in the case of claim 1. It is possible to obtain the effect that the fluctuations on the white side and the black side are accurately corrected, and a good image having excellent gradation can be obtained.

[Brief description of drawings]

1 to 12 show an embodiment of the present invention.
FIG. 1 is an overall perspective view of an image reader, FIG. 2 is a view showing a structure around a platen glass, FIG. 3 is a view showing an operation part, and FIGS. 4 to 8 are cross-sectional views schematically showing an internal structure. Figure,
9 and 10 are characteristic diagrams for explaining the effect, and FIG.
FIG. 12 and FIG. 12 are characteristic diagrams for explaining the shading correction. Further, FIG. 13 is a characteristic diagram for explaining a modified example. 1 ... Image reader, 3 ... Main body, 5 ... Original cover, 9 ... Platen glass, 29 ... Aperture for contact glass (platen area), 35, 37 ... Rail guide, 39 ... Light source unit , 41 …… Mirror unit, 45…
… Image reading part, 57 …… Fluorescent lamp, 165 …… CCD, 173…
… White reference reflector, 175 …… Black reference reflector, 177 …… Control unit

Claims (4)

[Claims] 1. An irradiation light from a light source is applied to a document on a platen, and the reflected light is guided to an information reading section composed of a photoelectric conversion element array for main scanning, and the irradiation light and the document are relatively moved to make a sub-scan. In an image information input device for scanning, a white reference reflecting plate arranged in the sub-scanning direction along one of both outer sides in the main scanning direction of the platen area on which the original is placed, and a main platen area on which the original is also placed. A black reference reflector arranged in the sub-scanning direction along the other outside of both ends in the scanning direction, a first reference reading unit for inputting reference information obtained from the white reference reflector every time one line is read, and one line A second reference reading unit for inputting reference information obtained from the black reference reflection plate each time the image is read, read information input to the information reading unit, the first reference reading unit, and the first reference reading unit. Image information input apparatus characterized by comprising a control unit for correcting the 1-line the read information for each reading performed operations based on the reference information input to the reference reading of the. 2. The irradiation light from a light source is applied to a document on a platen, and the reflected light is guided to an information reading section composed of a photoelectric conversion element array for main scanning, and the irradiation light and the document are moved relative to each other to make a sub-scan. In the image information input device for scanning, a reference reflection plate in the main scanning direction, which is arranged outside the starting end in the sub scanning direction of the platen area on which the document is placed, along the main scanning direction and so as to be read by the information reading unit, A control unit that corrects the read information in the main scanning direction by using the reference information input from the reference reflector in the main scanning direction to the information reading unit; and a main scanning direction of a platen area on which a document is placed. The white reference reflectors are arranged in the sub-scanning direction along one of the outer sides of both ends, and the white reference reflectors are arranged in the sub-scanning direction along the other of both ends of the platen region on which the original is placed in the main scanning direction. A black reference reflector, a first reference reading unit for inputting reference information obtained from the white reference reflector every time one line is read, and a reference information obtained from the black reference reflector every time one line is read. A second reference reading unit to be input, every read of one line based on the read information input to the information reading unit and the reference information input to the first reference reading unit and the second reference reading unit An image information input device, comprising: a control unit that performs a calculation to correct the read information. 3. The image information input device according to claim 1 or 2, wherein the information reading section is formed in the middle of the photoelectric conversion element array as an effective reading section for inputting reflected light from the platen area. , The first reference reading section and the second photoelectric conversion element section on both sides thereof.
The image information input device, wherein the reference reading unit is formed. 4. An irradiation light from a light source is applied to an original on a platen, and the reflected light is guided to an information reading section composed of a photoelectric conversion element array for main scanning, and the irradiation light and the original are moved relatively to each other to make a sub-scan. In an image information input device for scanning, an optical fiber that guides light from a light source to obtain a white reference, a first reference reading unit that inputs reference information obtained from the optical fiber, and a platen area on which a document is placed. A black reference reflecting plate arranged in the sub-scanning direction along the other outside of both ends in the main scanning direction; a second reference reading unit for inputting reference information obtained from the black reference reflecting plate every time one line is read; Based on the read information input to the information reading unit and the reference information input to the first reference reading unit and the second reference reading unit, calculation is performed for each reading of one line, and Image information input apparatus characterized by comprising a control unit that corrects only take information.