JP3173954B2 - Reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading device using a solid-state image sensor, and more particularly to a reading device used in the fields of design, CAD, and filing.

[0002]

2. Description of the Related Art A conventional reading apparatus disclosed in Japanese Patent Application No. 2-219362 has a cross section of a main part as shown in FIG. A reading surface of a reflective document 17 is placed with its reading surface facing down, and this reading surface is illuminated by the light source 11, while light irregularly reflected on the reflecting document 17 is reflected by 12 mirrors 1,
The light is condensed by a lens 1 of 13 and a linear CCD sensor 14
Thus, an image information signal of the reflection document 17 is obtained. In addition, 22
An optical option unit 20 including a mirror 2, a lens 2 of 23, and a CCD 2 of 24 is mounted for transmission reading. At the time of transparent reading, reference numeral 17 denotes a transparent original such as a film. Reference numeral 18 denotes a scattering plate for converting light from the light source 11 into scattered light. Reference numeral 19 denotes a transparent glass pressing plate for bringing the transparent original 17 into close contact with the glass table 16. The light emitted from the light source 11 becomes uniform light by the scattering plate 18, passes through the transmission original 17 and the glass pressing plate 19, bends the optical path by the mirror 2, is condensed by the lens 2, and It reaches the CCD sensor CCD2.

In a conventional reading apparatus, 30
0 dpi reflective originals can be read. A 600 dpi transparent original can be read on the option unit side.
i, a 1200 dpi transparent original can be read.

In a conventional reading apparatus, the option unit has an optical system with a higher resolution than the main body. The option unit allows switching to an optical system with a plurality of different resolutions. The CCD signal of the optional unit is amplified more than the CCD signal of the main unit to make it more resistant to noise received in the transmission path from the optional unit to the main unit. Therefore, to return the signal level on the main unit side,
There is a damping circuit.

[0005]

In the prior art,
By adding the option, a scanner that can read a transparent original (film) with high resolution and high S / N was realized, but the user of the scanner sometimes needs to read a reflective original (such as a logo mark) with high resolution. . In the prior art, a reflection original could not be read at 600 dpi. At times, it may be necessary to read a reflection document in a large area (for example, A3). If it becomes necessary to read the A3 reflection document, conventionally, the user needs to purchase a new A3 scanner in addition to the A4 scanner,
Alternatively, only the A3 scanner needs to be purchased. In this case, the originals of most scanners are A4 size or smaller, and it is necessary to always increase the installation area of the scanner. In addition, since it is necessary to set a large-size document downward, it is difficult to adjust the reading position.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a reading apparatus capable of reading a reflection original at 600 dpi, reading an A3-size reflection original, and turning the reading surface of the reflection original upward.

[0007]

According to the present invention, an object of the present invention is to obtain an image information signal of a document from a first light source for illuminating a reading surface of the document and light irregularly reflected on the document. A reading device having a first optical system, a second light source for illuminating a reading surface of the document, and a second optical device for obtaining an image information signal of the document from light diffusely reflected on the document. And an optical option unit having a first light source and a second light source. When reading a transparent original, at least one of the reading area and the resolution of the second optical system is different from that of the first optical system. The reading apparatus according to claim 1, wherein the reading is performed using an optical system, and when reading a reflection original, the reading is selectively performed using the second optical system and the second light source or the first optical system and the first light source. Achieved.

[0008] According to the present invention, the above object is achieved by the second aspect.
The reading area of the first optical system is wider than the reading area of the first optical system.

According to the present invention, the aforementioned object is achieved by using the second optical system in the optical option unit for reading, so that when reading a transmissive original, the optical option unit is placed between the optical option unit and the main body. This is achieved by the reading device according to claim 3, further comprising a scattering plate, and a light shielding plate for reading the reflection original.

[0010]

According to the first aspect of the present invention, the reading device includes a first light source and a first optical system, and optionally includes a second light source and a second optical system. At least one of the resolutions is different from the first optical system. Therefore, it is possible to read a reflection original at 600 dpi and an A3-size original at 300 dpi. An optional unit that is cheaper than the conventional technology and can be read more widely than the main body can be supplied. At least the power supply control circuit can be shared with the main unit. Since this optional unit is removable,
The installation area can be reduced.

According to the reading device of the second aspect, the reading area of the second optical system is wider than the reading area of the first optical system, so that an A3-size original can be read at 300 dpi.

According to the reading device of the third aspect, since the reading is performed by using the second optical system in the optical option unit, when reading the transmissive original, scattering occurs between the optical option unit and the main body. A light-shielding plate for reading a reflection original. Therefore, it is possible to read the transmission original and the reflection original.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a reading apparatus according to an embodiment of the present invention.

In this embodiment, 21 light sources and 25 pulse motors are attached to the conventional reader shown in FIG. 1D. FIGS. 1a to 1c respectively show the three readings of the present invention.
Indicates the mode. FIG. 1A shows reading of a transparent original using the optional unit. Since this is the same as the case of reading a conventional transparent original, the description is omitted. FIG. 1C is a diagram showing reading of the reflection original 28 whose reading surface is set downward with the optical unit of the main body. This mode is also the same as the conventional example, and the description is omitted. FIG. 1B is a diagram illustrating reading of a reflection original with the reading surface facing upward using the option unit. 26 is a reflection original set upward, 2
Reference numeral 7 denotes a light-shielding plate serving as a table for 26 originals.

While the reading surface is illuminated by the light source 21, the light irregularly reflected by the reflection original 26 is reflected by the mirror 2, is condensed by the lens 2, and is reflected by the linear CCD sensor 24. Obtain an image information signal.

In this case, if the 20 optical units decompose the A4 size at 600 dpi, it is possible to read an A4 size reflection original at a resolution of 600 dpi. Also, 20 optical units have 300 A3 size.
With an optical system that resolves in dpi, it is possible to read an A3-size reflective original at a resolution of 300 dpi.

Next, the operation of the CCD sensor will be described with reference to FIGS.

FIG. 2 is a block diagram of the CCD sensor.
25 is a sensor portion of the CCD sensor of N charge coupled device _{S 1, S 2 ...... S N} . 26 is a transfer gate, 27 is an N-bit analog shift register S
R ₁ , SR ₂ ,..., SR _N , and 28 is an output buffer. CCD of S ₁ of the sensor unit 25, S ₂ ...... S analog register SR ₁ of the photoelectric charge stored in the _N by a transfer pulse phi _T to the transfer gate 26 27, SR _2, ...... SR
_N, and are sequentially shifted to the output buffer 28 by the shift clocks φ ₁ and φ ₂ after the transfer pulse φ _T , where they are photoelectrically converted and output a voltage VO according to each charge.

The reset pulse φ _R is output from the output buffer 28.
That is, the photocharge shifted to the pixel is reset each time, that is, the voltage output VO of the CCD is changed to the sensor unit 26 before one scan.
S ₁ of the CCD, a S ₂ ...... S _N voltage corresponding to the photoelectric charge stored in the output.

FIG. 3 shows a driving pulse for the CCD and the CCD.
It is a timing chart with output. phi _T transfer pulse, phi _1, phi ₂ is the shift clock, the phi _R is a reset pulse. Vo is an output obtained by sampling and holding the voltage output VO of the CCD with the sample and hold signal SH. T
_CLAMP is a clamp signal described later.

The number N of the CCD sensors in FIGS.
When the optical unit of 0 or 20 is A4 size 300 dpi, N ≧ 2550 (8.5 inch × 300 /
Inch) When A4 size is 600 dpi, N ≧ 5100 (8.5 inch × 600 /
A3 size 300dpi N ≧ 3508 (297mm x 1 inch /
25.4 mm x 300 / inch).

FIG. 4 is a block diagram of a reading apparatus according to an embodiment of the present invention. 14 is a CC for reading a reflection original
This is a CCD 1 of a D sensor, which receives drive pulse signals φ _T , φ ₁ , φ ₂ , φ _R from the control circuit 38, and outputs 30 S
The CCD voltage VO1 is output to H1 (sample hold 1). SH1 of 30 receives the sample and hold signal SH from the control circuit 38, samples and holds the CCD voltage output VO1, and sends it to the AMP1 of 31 as the output vo1. 31 AMP1 is the sample hold output vo1
And convert the analog signal VIDEO1 to RLY of 34
(Switching circuit). Optional unit CCD
The CCD2 of the sensor 24 outputs the CCD voltage output VIDEO2 amplified in the same manner as the CCD1 through the signal cable and the connector 32 on the main body side, and the ATN (attenuator) 33 of the CCD24.
Send to Here, the width of VIDEO2 is larger than that of VIDEO1. RLY (switching circuit) 34 switches the output VIDEO1 output VIDEO2 'and 31 of the AMP1 33 of ATN (attenuators) in the switching signal T _GATE from the control circuit 38, the output VIDEO 3
5 to the CLAMP (level clamp circuit).

The input range of the ADC of T _GATE = '1' VIDEO2 when '= VIDEO T _GATE =' 0 of VIDEO1 = VIDEO 35 when 'CLAMP (clamp circuit) the voltage level of the VIDEO 36 (AD conversion circuit) Level shift. The AD timing is converted at the rising edge of the inverted signal of the signal SH. 36 ADC of (AD converter) is AD converter 8bit, the output _{D 7, D 6, ...... D} 0 is 37 DATA
PROCESS (data processing circuit). 39
LAMPCONT1 (lighting circuit 1) is the light source 1 on the main body side.
1 is turned on when TLON1 = '1'. 43 LAM
PCONT2 (lighting circuit 2) is an optional light source 21
Is turned on when TLON2 = '1'. 42 is DRIV
E1 (pulse motor drive circuit 1) receives the signal FORWA
When the pulse signal _TPM1 is given once when RD1 = '1', the 15 PM1 (pulse motor 1) rotates one step clockwise to advance the 10 optical units by 1/600 inch in the scanning direction. 45 DRIVE2 (pulse motor drive circuit 2) also outputs the signal FOWARD.
When the pulse signal _TPM2 is given once when 2 = '1', the PM2 44 (pulse motor 2) rotates one step clockwise, and advances the 20 optical units in the scanning direction by 1/600 inch. 46 is a host computer. DA of this host computer 46 and 37
TA PROCESS (data processing circuit) is SCSI
Data is transmitted and received via an IF (SCSI interface). Also 37 DATA PROCESS
The (data processing circuit) is connected to the CONTROL (control circuit) by a data bus line, and enables the removal of commands from the host or information on the state of the scanner (whether there is an option or not, etc.). .

FIG. 5 is a specific circuit diagram of the block diagram of FIG. Symbol ASW in the figure is an analog switch, VO
F represents a voltage follower, OP represents an operational amplifier, RLY represents a relay, and ADC represents an AD converter.

Analog switch ASW1, capacitor C
1. The voltage follower VOF1 constitutes the sample-and-hold circuit (SH1) 30. The value of the time constant C ₃ × R ₁ in AMP1 31 is sufficiently larger than the period T of the transfer pulse phi _T. Output v capacitor C ₃ and resistor R ₁
As shown in FIG. 6, the level of o1 is shifted down from about 7V to about 0V, inverted and amplified by about 3.6 times by an operational amplifier OP1, and a signal VIDEO1 is output. That is, R
₅ / R ₃ = 3.6 is set.

[0026] 34 RLY of when the T _GATE = "0" when the _{VIDEO = VIDEO1 T GATE = "1} " switches the VIDEO = VIDEO2 words, the control circuit 38 and the optional unit is set in the reading apparatus unit _TGATE is set to "1".

The level clamping circuit (CLAMP) 35 of C ₅ and ASW3 clamp signal T from the control circuit 38
_CLAMP is supplied and the signal VIDEO (approximately +
0.8V) is level-shifted from 0V to a correctly measured signal,
AD converter A as VIN (1.8V from 0V)
Input to DC36.

The AD converter 36 converts the input signal level from 0 V to 2 V into 256 gradations.
This timing is performed at the rising edge of the inverted signal of the signal SH.

Next, the operation of reading a transparent original in which the optical option unit for reading the transparent original is set will be described.

By reading a transparent original, the CCD sensor 2
The voltage output VO2 of the CCD 2 is sampled and held by the sample and hold 2 and becomes the output vo2. In this case, as shown in FIG. 7, the output vo2 of about 7V is shifted down to near 0V, inverted and amplified by the operational amplifier OP2, and becomes the signal VIDEO2. The GAIN at this time is set to 7.2 times, which is twice as large as that at the time of reflection reading. That relationship R6 and R4 in AMP2 of Fig. 5 R ₆ / R ₄ =
It is set to 7.2.

The reason is that a signal cable for transmitting a signal from the optical option unit to the main body of the reading apparatus becomes long, and the signal VIDEO2 is easily affected by noise.

Then, the output VID from 41 AMP2
EO2 is sent to an attenuator (ATN) 33. Since the resistance values of the resistors R ₇ and R ₈ of the attenuator (ATN) 33 are set to be equal, the output signal V
IDEO2 'is attenuated to 1/2 of the input signal VIDEO2. The attenuator (ATN) 33 is provided as standard equipment in the main body of the reader.

The output signal from the attenuator 33 is sent to a level clamp circuit (CLAMP) 35 by a switching circuit (RLY) 34 as a signal VIDEO. Capacitor C ₅ and the analog switch ASW3 of the level clamping circuit (CLAMP) 35 is from the control circuit 38, FIG. 3, given a clamp signal T _CLAMP as shown in FIGS. 6 and 7, about -1V to + 0. The level of the 8 V signal VIDEO is shifted from 0 V to a signal on the positive side.
BR> to the converter 36. This AD converter 3
Numeral 6 converts the input signal level from 0 V to 2 V into 256 gradations. This timing is performed at the rising edge of the inverted signal of the signal SH.

When the optional unit is installed, T
_GATE = "1" and the switching circuit of 34 is VIDEO
2 'is automatically selected, and then HOST C of 46
OMPUTER to SCSI interface (SCS
When the reflection original is designated by a command via the I IF), the control circuit 38 sets T _LON2 = “1” and _turns on the light source 21. If you specify a transparent original,
The control circuit 8 sets T _LON1 = “1” and _turns on the light source 11.

FIG. 8A shows the relationship between T _PM1 and φ _T when reading a reflected original at 300 dpi with the scanner of the main body, as shown in FIG. 1C. FIG. 8B shows T _PM1 , T _PM2 , and T _PM2 when reading a transparent original at 600 dpi using the option as shown in FIG.
shows the relationship between the φ _T. FIG. 8C shows the relationship between T _PM2 and φ _T when reading an upward reflecting original at 300 dpi using the option as shown in FIG. 1B.

1) At least an optional unit that can be read more widely than the conventional technology can be supplied at a lower cost than the main body.
The power supply and control circuit can be shared with the main unit. This option is detachable, so if you don't need it, you can remove it and use the small footprint of the scanner.

2) Since the reflection original can be used upward, the reading position can be easily adjusted.

3) A high-resolution reflection original can be read. In this case, it would be good to have a high-resolution A4 scanner body, but for example, using a 300 dpi A4 scanner at 300 dpi rather than using a 600 dpi A4 scanner at a much faster scanning speed. A reflection area / dot of 300 dpi is four times faster than 600 dpi, and it can be basically said that the speed is four times faster. Therefore, the scanner having the configuration of the present invention (the main body is 300 dpi, the option is 600 dpi) has an advantage that the scanner of the main body can be used at high speed when used at a low resolution (300 dpi or less).

[0039]

According to the first aspect of the present invention, the first light source and the first optical system are provided, the second light source and the second optical system are optionally provided, and the reading of the second optical system is performed. At least one of the area and the resolution is different from the first optical system. Therefore, it is possible to read a reflection original at 600 dpi and an A3-size original at 300 dpi. An optional unit that is cheaper than the conventional technology and can be read more widely than the main body can be supplied. At least the power supply control circuit can be shared with the main unit. Since this optional unit is detachable, the installation area can be reduced.

According to the reading apparatus of the second aspect, the reading area of the second optical system is wider than the reading area of the first optical system, so that an A3-size original can be read at 300 dpi.

According to the reading device of the third aspect, since the reading is performed by using the second optical system in the optical option unit, when reading the transmissive original, scattering occurs between the optical option unit and the main body. A light-shielding plate for reading a reflection original. Therefore, it is possible to read the transmission original and the reflection original.

[Brief description of the drawings]

FIG. 1a is a sectional view of a main part of an embodiment of a reading apparatus of the present invention.

FIG. 1b is a sectional view of a main part of an embodiment of the reading apparatus of the present invention.

FIG. 1c is a sectional view of an essential part of an embodiment of the reading apparatus of the present invention.

FIG. 1d is a sectional view of a main part of a conventional example of a reading apparatus.

FIG. 2 is a block diagram for explaining the operation of the CCD sensor.

FIG. 3 is a time chart for explaining the operation of the CCD sensor.

FIG. 4 is a block diagram of a reading apparatus according to the embodiment of the present invention.

FIG. 5 is a circuit diagram of a reading apparatus according to the embodiment of the present invention.

FIG. 6 is a signal waveform diagram in the circuit of FIG. 5;

FIG. 7 is a signal waveform diagram in the circuit of FIG. 5;

FIG. 8 is an explanatory diagram of a pulse signal for driving a pulse motor and a transfer pulse.

[Explanation of symbols]

 11, 21 Light source 14, 24 CCD 15, 44 Pulse motor 30, 40 Sample hold 31, 41 AMP 33 Attenuator 34 Switching circuit 35 Level clamp circuit 36 AD circuit 37 Data processing circuit 38 Control circuit

Claims (3)

(57) [Claims] A first light source for illuminating a reading surface of a document;
A first optical system for obtaining an image information signal of the document from light diffusely reflected on the document, further comprising: a second light source for illuminating a reading surface of the document; An optical option unit having a second optical system that obtains an image information signal of the document from light that is diffusely reflected, wherein at least one of a reading area and a resolution of the second optical system is different from that of the first optical system. When reading a transparent original, reading is performed using the first light source and the second optical system, and when reading a reflective original, the second optical system and the second light source or the first optical system and the second optical system are used. 1
A reading device for selectively reading using the light source. 2. The reading device according to claim 1, wherein a reading area of the second optical system is wider than a reading area of the first optical system. 3. When reading a transmissive original to read using the second optical system in the optical optional unit, a scattering plate is provided between the optical optional unit and the main body to read a reflective original. The reading device according to claim 1, further comprising a light-shielding plate.