JPH0619244Y2 - Image scanner - Google Patents

Description

Detailed Description of the Invention A. Purpose of the Invention (1) Industrial Application Field The present invention relates to an image scanner.

(2) Conventional Technology Conventionally, there is known an image scanner that scans an original by an image sensor that converts reflected light from the original into an electric signal and reads an image of the original.

As such an image scanner, an optical sensor member of the image scanner (a light source for illuminating an original, a light source for illuminating the original, is disposed on a carriage which is arranged to face an original fed in the sub-scanning direction and is reciprocally driven along the main scanning direction. An original is formed by supporting a member composed of a light receiving element array and an image pickup optical system for forming an image of reflected light from the original on the light receiving element (hereinafter referred to as “image sensor”), and reciprocally driving the carriage a plurality of times. There are known serial type image scanners for reading a document, image scanners for reading the entire surface of a document in one scan by an image sensor having a length from one end to the other like a facsimile. . Also known is a serial image scanner (that is, a serial image scanner printer) in which a print head is supported on a carriage of the serial image scanner.

As shown in FIG. 7, such a conventional image scanner Im has an image sensor G that converts reflected light from an original into an electric signal, an amplifier Q that amplifies a read signal of the image sensor G, and this amplifier. Gain adjusting means R for adjusting the gain of Q, ADC (analog-digital converter) for AD-converting (analog-digital conversion) the output signal of the amplifier Q, and storing or shading correction of the digital signal output by this ADC. It is composed of a microcomputer or the like for performing calculations.

The image scanner Im shown in FIG. 7 has the output signal of the amplifier, that is, A, based on the variation of the characteristics of the image sensor or the amplifier when it is assembled.
There are variations in the input signal to DC. Therefore, when the product is assembled, the gain adjusting means is used to appropriately set the input signal level to the ADC.

When adjusting the gain of the amplifier Q of the read signal output from the image sensor, an adjustment terminal is provided between the amplifier Q and the ADC on the printed circuit board (not shown),
A gain was adjusted by connecting a measuring instrument such as an oscilloscope to this adjustment terminal.

However, the above-described conventional gain adjustment method requires an expensive measuring instrument such as an oscilloscope, and the time required to arrange the measuring instrument and the image scanner close to each other and connect or disconnect them. It took a lot of work.

By the way, in conventional copiers and facsimiles,
There is a model in which a number (or figure) display section is provided on those operation panels. A number display section of such a copying machine and a facsimile is usually provided at one place, and the one number display section has a number having a different meaning in various different operation modes of the copying machine and the facsimile. It is supposed to be displayed.

Therefore, by using the numeral display unit capable of displaying different meanings in the different operation modes, without using the expensive measuring device,
An image information reading device capable of gain adjustment is proposed in Japanese Patent Laid-Open No. 62-262560.

The gain adjustment method described in the above publication uses a numeric display unit (that is, a display unit that displays different meaning numbers in different operation modes) conventionally provided in devices such as copying machines and facsimiles. This is convenient because gain adjustment can be performed without adding a new configuration.

(3) Problems to be Solved by the Invention However, the display unit capable of displaying numbers (or figures) having different meanings in various different operation modes as described above is used in high-end models such as copying machines and facsimiles. Has been adopted a lot, but not so low-end models. It is impossible to perform the gain adjusting method of the above-mentioned Japanese Patent Laid-Open No. 62-262560 with a model which does not have such a numerical display portion. In particular,
For serial type image scanners or serial type image scanner printers that are not so luxurious,
Since many models do not have a numerical display, it is often impossible to perform the gain adjustment method described in the above publication.

However, even if the device does not have a numeral display section that can display different meanings in different operation modes as described above,
In many cases, a plurality of inexpensive indicator lights such as LEDs are provided.

In view of the above circumstances, the present invention makes it possible to perform gain adjustment in an image scanner provided with a plurality of indicator lights by using the plurality of indicator lights without using an expensive measuring instrument. Is an issue.

B. Configuration of the Invention (1) Means for Solving the Problems In order to solve the above problems, the image scanner of the invention has the structure shown in the claim correspondence diagram of FIG. That is, the image scanner of the present invention includes an image sensor G, an amplifier Q output signal of the image sensor G is inputted, the gain adjustment unit R for adjusting the gain of the amplifier Q, a plurality of indicator lamps LED ₄ ~ LED ₉
The indicator lamps LED _{4 to} LED ₉ when used in the normal mode
Means for generating a normal display lighting signal s _n for lighting
In the image scanner having the above, the maximum value storage means V for storing the maximum value l _imax of the output signal l _i of the amplifier Q, and the plurality of indicator lamps LED _{4 to} LE.
Means W for outputting a plurality of indicator lamp lighting level set values L ₁ , L ₂ , ... Established corresponding to each of D ₉ and the maximum value l
_i is compared with the plurality of indicator lamp lighting level setting values L ₁ , L ₂ , ... And the maximum value l _imax is the respective indicator lamp lighting level setting values L 1.
Comparing means CP which detects which level among ₁ , ₁ , L ₂ , ... And generates a gain display lighting signal s _g for lighting the indicator lamps LED _{4 to} LED ₉ corresponding to the detected level, the normal display lighting signal s _n and mode selecting means J with gains display lighting signal s _g is input
Depending on the signal from that a signal selection means N for outputting one of the inputted normal display lighting signal s _n or gain for display lighting signal s _g on the indicator LED ₄ ~LED ₉ Characterize.

(2) Operation In the image scanner of the present invention having the above-mentioned configuration, when the gain adjusting mode is selected by the mode selecting means J, the signal selecting means N is turned on for gain display input from the comparing means CP. The signal s _g is _sent to the indicator LE
D _4, LED _5, so that the output ... to. In this state, the maximum value g _imax of the output signal g _i from the amplifier Q of the read signal of the image sensor G is stored in the maximum value storage means V. Then, the output signal of the maximum value storage means V is converted by the comparison means CP into a plurality of indicator lamp lighting level set values L ₁ , L
₂ , it is detected which level the maximum value g _imax is with respect to each indicator lamp lighting level set value L ₁ , L ₂ ,. Then, the comparison means CP generates a gain display lighting signal s _g for lighting the indicator lights LED ₄ , LED ₅ , ... Corresponding to the detected level. The gain display lighting signal s _g lights the indicator lamp corresponding to the detected level among the indicator lamps LED ₄ , LED ₅ , ... Via the signal selecting means N. The operator operates the gain adjusting means R while looking at the lit indicator light, and when the indicator light corresponding to a predetermined level is lit, the gain of the amplifier Q is set to an appropriate value and the gain adjustment work is performed. finish.

(3) Embodiment An embodiment in which the image scanner of the present invention is applied to a serial type image scanner printer will be described below with reference to the drawings.

In FIG. 2, a serial type image scanner printer 1 is provided with a sheet inlet 3 and a sheet outlet 4 extending in the left-right direction with a roller cover 2 interposed in the center of the upper surface thereof. A sheet guide 5 is attached to the rear side of the sheet inlet 3, and a detachable canopy 6 is provided to the front side of the sheet outlet 4.

A gain adjustment window 1a (see FIG. 2) and an operation panel Pa (see FIGS. 2 and 3) that can be opened and closed are provided on the front surface of the serial type image scanner printer 1, and inside the gain adjustment window 1a. Is provided with a gain adjustment volume R described later. Further, on the operation panel Pa, a select switch SW ₀ , a line feed switch SW ₁ , a page break switch SW ₂ , a speed selection switch SW ₃ , for selecting whether to accept a signal from the outside such as a computer, a font of a font card. A font changeover switch SW ₄ , a line density changeover switch SW ₅ , a gradation mode selection switch SW _{6 and the} like for selecting which of the built-in fonts to use are provided.

The select switch SW ₀ is provided with a green light emitting diode for display (that is, a “select lamp”) LED ₁ that lights up in a state of receiving a signal from the outside, and the speed select switch SW ₃ lights up in a medium speed print mode. green display light-emitting diodes (i.e., "print mode display lamp") LED ₂ is juxtaposed, the font changeover switch SW ₄ is mode printing is selected using a font of font card and turned off at a high speed print mode A green display light emitting diode (that is, a “font display lamp”) LED _{3 that} is sometimes lit is also provided. Further, the linear density changeover switch SW ₅ has a linear density reading mode 180 dp of the selected image sensor.
i, green display light-emitting diodes (i.e., "reading mode _indicators") LED 4, LED ₅ or LED ₆ to light up in response to 160dpi or 90dpi are juxtaposed. Further, the gradation mode selection switch SW ₆
Is the gradation reading mode of the selected image sensor (2-gradation mode, dither mode, or multi-gradation mode)
A green light emitting diode for display (that is, a “gradation mode display lamp”) LED ₇ , LED ₈ or LED ₉ is additionally provided.

On the upper right side of the operation panel Pa, a red light emitting diode for display (that is, a "power lamp") LED ₁₀ which lights up when the power is turned on, and a red light which lights up when the printing paper or the document A is not set. Display light-emitting diode (ie "paper detection indicator lamp") LED ₁₁
Also provided is a red indicator light emitting diode (or "ribbon empty indicator lamp") LED _{12 which} is illuminated when the print ribbon is exhausted. The power lamp LED ₁₀ is turned on when a power switch (not shown) disposed on the lower part of the left side wall of the serial type image scanner printer 01 in FIG. 2 is turned on and the power is turned on. It has become.

Further, a reset switch SW _R is arranged on the lower left side of the operation panel Pa, and a font card insertion port Pa ₁ is arranged on the lower right side thereof.

In FIG. 4, a carriage driving device D ₁ of the serial type image scanner printer 1 includes a carriage driving step motor M ₁ and an endless carriage driving belt 7 reciprocally driven by the carriage driving step motor M ₁ . Has been done. The carriage B, whose lower surface is fixed to the carriage drive belt 7 and is guided along a guide bar 8 extending in the main scanning direction X, includes a print head support member B ₁ and an image sensor support member B. ₂ and. The carriage B
Are reciprocally driven along the main scanning direction X along the surface of the platen P provided along the main scanning direction X.

A correction plate F is fixed to the left end side of the platen P, and the surface of the correction plate F is colored uniformly white.
Further, the front surface and the surface of the document A to be read and scanned are arranged so as to be substantially on the same plane.

A recording paper such as a thermal transfer paper or an original A is fed by a paper feed stepping motor M ₂ and a paper feed roller 9 rotated by the stepping motor M ₂ .
Then, the sheet is driven to the surface of the platen P extending in the main scanning direction X by a sheet driving device D _{2 including} a guide member (not shown). Then, each time the carriage B is moved along one scanning line of the recording paper, the original A, etc., the recording paper, the original A, etc. are fed at a predetermined pitch in the sub-scanning direction Y by the paper drive device D ₂ . .

A thermal transfer type print head 10 is supported on the print head support member B ₁ of the carriage B, and an upper surface of the print head support member B ₁ is an ink ribbon cassette 11.
Is configured to be detachably attached.

The image sensor support member B _z of the carriage B includes
An image sensor composed of a light source for illuminating an original document (not shown), an imaging optical system having a mirror, a SELFOC lens, etc., and a reflected light amount detecting means having a plurality of light receiving element rows is supported, and the reflected light amount detecting means is supported. Is arranged so that the reflected light from the original A or the correction plate F illuminated by the light source is received via the imaging optical system. Further, a mark 12 for indicating the left-right direction reading start position and a mark 13 for indicating the up-down direction reading start position are provided at appropriate positions on the image sensor supporting member B ₂ .

The print head 10 is connected to the print head drive circuit 2 of the control unit U via an appropriate connecting cable.
It is driven by 0. The read signal detected by the reflected light amount detecting means is input to the buffer amplifier 21 of the control unit U via an appropriate connecting cable.

The output of the buffer amplifier 21 is input to the shading correction circuit 22 via the operational amplifier Q whose gain is adjusted by the gain adjustment volume R. The shading correction circuit 22 is a conventionally known appropriate shading correction circuit including an ADC (analog-digital converter) that converts an input signal into a 6-bit digital signal and outputs the 6-bit digital signal. It's working. In this embodiment, since the ADC of the shading correction circuit 22 outputs a 6-bit signal as described above,
The minimum value is "000000" (0 in decimal system) and the maximum value is "111111" (63 in decimal system), which is 0 in the end.
It is possible to output a total of 64 levels of signals up to 63 levels. In this embodiment, the ADC in the shading correction circuit 22 converts the input signal into a 6-bit digital signal, but outputs another number of bits, for example, an 8-bit digital signal. It is also possible to adopt one.

The microcomputer 23 includes a central processing unit CPU, a random access memory RAM, a read only memory RO.
The input / output interface 10 and the like.

Then, the shading correction circuit 22 calculates the dark correction data d _i from the dark output output by the image sensor G in a state where the light source for illuminating the original is turned off at a position where the image sensor G faces the correction plate F. The dark correction data d _i is stored in the RAM of the microcomputer 23. Further, the shading correction circuit 22 calculates bright correction data from the bright output detected by the image sensor G with the light source turned on (that is, the detection signal of the reflected light amount from the correction plate F),
The bright correction data l _{i is} also stored in the RAM of the microcomputer 23. As described above, in this embodiment, the ADC of the shading correction circuit 22 outputs a 6-bit digital signal, so the maximum values of the dark correction data d _i and the bright correction data l _i stored are “11111”.
1 ”(= 63 in decimal).

Further, the shading correction circuit 22 performs shading correction on the original read output detected by the image sensor G by using the dark correction data d _i and the bright correction data l _i stored in the RAM when reading the original. It is configured.

A control unit U is composed of the print head drive circuit 20, the buffer amplifier 21, the operational amplifier Q, the gain adjusting volume (that is, the gain adjusting means) R, the shading correction circuit 22 and the microcomputer 23.

Further, as shown in FIG. 4, the control unit U includes:
The output signal I _h of the home position sensor S _H for the carriage B is detected to be located in the home _position, the output signal I _p of the paper detection sensor S _P for detecting the presence or absence of the document _A, and, first and second FIG Input signals from various switches SW _i (i = 0 to 6) of the operation panel Pa shown in are input.

The control unit U then drives the carriage-driving step motor M ₁ to drive the drive signal O _m1 , drives the paper-feeding step motor M ₂ to drive O _m2 , and drives the carriage B to detect reflected light amount _Oim. Is being output.

Further, the control unit U is configured to be connectable to the personal computer 26 via the Centronics connection cable 24 for controlling the printing section and the RS232-C connection cable 25 for controlling the image sensor section.

The serial-type image scanner sprinter 1 described above has a gain adjustment mode, and when the power switch is pressed with the font changeover switch SW ₄ and the line density changeover switch SW ₅ turned on, the microcomputer 2
No. 2, the gain adjustment mode stored in the ROM is executed. The ROM stores the following values as the LED lighting level setting values L _{1 to} L ₆ .

L ₁ = 60 L ₂ = 59 L ₃ = 58 L ₄ = 57 L ₅ = 56 Then, as described later in detail, the microcomputer 23 sets the maximum value of the bright correction data l _i stored in its RAM. l
_imax is compared with the LED lighting level set values L _{1 to} L _6, and the LEDs _{4 to} LE are selected according to the level of the maximum value l _imax.
It is configured to light any one of D ₉ .

Next, the operation of the embodiment of the serial type image scanner printer having the above-mentioned configuration when the gain adjustment mode is executed will be described with reference to the flowcharts of FIGS. 5A to 5B.

In step 31, the font changeover switch SW ₄
When the power is turned on while simultaneously pressing and the line density changeover switch SW ₅ , the gain adjustment mode is stoled.

When the gain adjustment mode starts, in step 32, the carriage B is moved to the operation start point.

Next, in step 33, the carriage B is moved to the correction data writing position (the position where the image sensor G faces the correction plate F).

Next, in step 34, the light receiving amount detection circuit of the image sensor G is activated.

Next, in step 35, the correction data d _i is written (stored) in the RAM of the microcomputer 22. The dark correction data d _i is obtained by amplifying and AD converting the detection value (dark output) of the reflected light amount from the correction plate F by the operational amplifier Q and the shading correction circuit 22 in a state where the light source for illuminating the original is turned off. 6-bit digital data obtained by

Next, in step 36, the light source for illuminating the original is turned on.

Next, in step 37, the bright correction data l _i is written (stored) in the RAM of the microcomputer 22. The bright correction data l _i is obtained by amplifying and AD converting the detection value (bright output) of the reflected light amount from the correction plate F by the operational amplifier Q and the shading correction circuit 22 in a state where the light source for illuminating the original is turned on. 6-bit digital data obtained by Then, this bright correction data l
The maximum value of _i (6-bit digital data) is "111
111 ”(= 63, decimal number).

Next, in step 38, the RAM of the microcomputer 22
The maximum value l _imax of the bright correction data l _i stored in is retrieved and stored in the register of the CPU of the microcomputer 22.

Next, in step 39, L _i (= 60) ≦ l _imax
It is determined whether or not. If yes, the LED ₇ is turned on in step 40, and if no, the LED ₇ is turned off in step 41 and then the process proceeds to step 42.

Next, in step 42, L ₂ (= 59) ≦ l _imax
It is determined whether or not <L ₁ (= 60).

If yes, the LED ₈ is turned on in step 43, and if no, the LED ₈ is turned off in step 44 and then the process proceeds to step 45.

Next, in step 45, L ₃ (= 58) ≦ l _imax
It is determined whether or not <L ₂ (= 59). If yes, the LED ₉ is turned on in step 46, and if no, the LED ₉ is turned off in step 47 and then the process proceeds to step 48.

Next, in step 48, L ₄ (= 57) ≦ l _imax
It is determined whether or not <L ₃ (= 58). If yes, the LED ₄ is turned on in step 49, and if no, the LED ₄ is turned off in step 50 and the process proceeds to step 51.

Next, in step 51, L ₅ (= 56) ≦ l _imax
It is determined whether or not <L ₄ (= 57). If yes, the LED ₅ is turned on in step 52, and if no, the LED ₅ is turned off in step 53 and then the process proceeds to step 54.

Next, in step 54, L ₅ (= 56)> l _imax
It is determined whether or not. If yes, the LED ₆ is turned on in step 55, and if no, the LED ₅ is turned off in step 56 and the process returns to step 37.

Next, referring to FIG. 6, a work flow performed by a person will be described.

In step 61, the gain adjustment work is started.

Next, in step 62, it is confirmed which of the LEDs _{4 to 9} is turned on. Then, in step 63, it is determined whether the gain is appropriate. This determination is determined to be appropriate when the LED ₄ is lit, and is determined to be inappropriate when the other LEDs are lit. If no, go to step 64.

In step 64, the gain adjustment volume R is adjusted, and the process returns to step 62. Then, the step 6
Steps 62 to 64 are repeated until the answer in step 3 is YES.

When the result of step 63 is YES (when the LED ₄ is lit), the process proceeds to step 65, and the gain adjustment work is completed.

Although the embodiment of the serial type image scanner printer according to the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and deviates from the invention described in the scope of claims for utility model registration. It is possible to make various design changes without the need.

For example, in the above embodiment, the maximum value l _imax of the bright correction data l _i stored in the RAM of the microcomputer 22 is adopted as the maximum value of the output of the amplifier Q, and the CPU of the microcomputer 22 is a means for storing the maximum value. The maximum value of the output of the amplifier Q is the amplifier Q.
An analog signal maximum value detector that detects the maximum value of the signal (analog signal) that appears at the output terminal of is provided, and the detected maximum value and the set LED lighting level setting values L ₁ , L ₂ , ... LED _{4 to} L are compared according to the comparison result.
It is also possible to configure the ED ₉ to be illuminated.

Further, the control unit U for realizing various means of the present invention shown in FIG. 1 can be configured by using a wired logic instead of using the microcomputer 22.

C. Effect of the Invention According to the serial type image scanner having the above-mentioned gain adjustment mode, what level is the maximum value of the output of the amplifier of the read signal by using the plurality of indicator lights used in the normal mode of the image scanner? Is displayed, and the gain of the amplifier can be adjusted while observing this display. Therefore, gain adjustment can be performed without using an expensive measuring instrument.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing the structure of a serial type image scanner according to the present invention, and FIG. 2 is an external view of an embodiment of the serial type image scanner. FIG. View of
An enlarged view of the III portion, FIG. 4 is an explanatory view of the configuration of an embodiment of the serial image scanner, and FIGS. 5A and 5B show processing of the machine (serial image scanner) in the gain adjustment mode of the embodiment. FIG. 6 is a flow chart, FIG. 6 is a flow chart showing the processing of the worker in the same mode, and FIG. 7 is an explanatory diagram of a conventional serial type image scanner. CP ... Comparison means, G ... Image sensor, J ... Mode selection means, L ₁ , L ₂ , ... Indicator light lighting level set value, LEDs _{4 to} L
ED ₉ ... Indicator light, l _i ... (Amplifier Q) output signal (that is, bright correction data), l _imax ... Maximum value of l _i , N ... Signal selecting means, Q ... Amplifier, R ... Gain adjusting means, s _g ...
Gain for display lighting signal, s n _... lighting signal for normal display, V
... maximum value storage means, W ... means for outputting the indicator lamp lighting level set value

Continued Front Page (72) Takeo Tamura, Inventor, 210 Hisamoto, Takatsu-ku, Kawasaki-shi, Kanagawa NEC Electric Home Electronics Co., Ltd. 2nd Factory (72) Hiroo Togashi, Hisamoto 210, Takatsu-ku, Kawasaki-shi, Kanagawa NEC Home Electronics Co., Ltd. In the second factory

Claims (1)

[Scope of utility model registration request] 1. An image sensor (G), an amplifier (Q) to which an output signal of the image sensor (G) is input, and a gain adjusting means (R) for adjusting the gain of the amplifier (Q). the indicator and _(LED 4 _{~LED 9),} said indicator when used in normal mode _(LED 4 _~LE
D ₉ ), a means for generating a normal display lighting signal (s _n ) for lighting the D ₉ ), and the maximum value (l _imax ) of the output signal (l _i ) of the amplifier (Q) stored in the image scanner. A plurality of indicator lamp lighting level set values (L ₁ , L ₂ , ...) Determined corresponding to each of the value storage means (V) and the plurality of indicator lamps (LED _{4 to} LED ₉ ).
And a means (W) for outputting the maximum value (l _imax ) and the plurality of indicator lamp lighting level set values (L ₁ , L ₂ , ...) For comparing the maximum value (l _imax ) with each display. Which of the lamp lighting level set values (L ₁ , L ₂ , ...) Is detected, and the indicator lamp (LED ₄ ...
A gain display lighting signal for lighting the LED _{9) (s g)} comparing means for generating (CP), together with the normal display lighting signal _{(s n)} and the gain for display lighting signal _{(s g)} is input Depending on the signal from the mode selection means (J), either the input normal display lighting signal (s _n ) or gain display lighting signal (s _g ) is input to the indicator lamp (L).
An image scanner provided with a signal selection means (N) for outputting to ED _{4 to} LED ₉ .