JP3015046B2 - Image reading apparatus and image reading method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image reading apparatus and an image reading method for reading an image on a film.

[Conventional technology]

2. Description of the Related Art There is known an apparatus that photoelectrically reads transmitted light from a transmission type original such as a film using a CCD image sensor or the like.
In addition, reading is performed while automatically transporting a plurality of films to a reading position.

In such a light transmission type document reading apparatus, the presence / absence of the document is determined using a detection sensor for detecting the document.

[Problems to be solved by the invention]

Therefore, a dedicated detection sensor is required to determine the presence or absence of the film. Also, if there are more types of films to be read,
A plurality of detection sensors had to be provided, and the detection control had to be made different depending on the type of film.

[Means for solving the problem]

The present invention has been made in view of the above points, irradiation means for irradiating a film, reading means for reading the image of the film irradiated by the irradiation means, and the film on the optical path of the irradiation means Determining means for determining whether or not the data exists from the output data of the reading means.

Irradiating the film with an irradiating unit; reading an image of the film irradiated by the irradiating unit with a reading unit; and determining whether or not the film exists on an optical path of the irradiating unit. And determining from the output data of (1).

〔Example〕

 Hereinafter, the present invention will be described based on examples.

FIG. 1 is a cross-sectional view of an image reading apparatus to which the present invention is applied. An image sensor 103 such as a CCD having a plurality of light receiving elements arranged in the main scanning direction is used to read image information of a document placed on the platen glass 101. Illumination light from the halogen lamp 104 is reflected from the original on the surface of the original 102, and is imaged by the lens 108 via mirrors 105, 106, and 107.
Imaged on 103. An optical unit 113 including an illumination 104 and a mirror 105, and an optical unit 114 including mirrors 106 and 107.
Moves at a relative speed of 2: 1. The optical unit moves from left to right at a constant speed while performing PLL control by the DC servo motor 109. This moving speed is variable from 22.5 mm / sec to 360 mm / sec depending on the magnification on the outward path, and is always 800 mm / sec on the return path.

The optical unit is read at a resolution of 400 dots / inch by the image sensor 103 in a main scanning direction (hereinafter referred to as Y direction) orthogonal to the sub-scanning direction (hereinafter referred to as X direction) in which the optical unit moves, and the optical unit is moved to the left end home position. After moving to the right to the predetermined position, it is moved back to the home position again to complete one scan.

Thus, the entire area of the original is read and scanned line by line. Reference numeral 111 denotes a light-shielding plate. The light-shielding plate 111 crosses a home position sensor 110 composed of a photo interrupter, thereby detecting that the optical unit is located at the home position.

121 is a projector unit having a built-in lamp, condenser lens, etc., 123 is a halogen lamp, 122 is a reflector for reflecting the light of the halogen lamp 123, 124 is a condenser lens, 126 is a projection lens, and 230 is a projection lens. Film to be read, 12
7 is a reflection mirror, 102 is a Fresnel lens for forming a film image on a reading unit inside the scanner, and 125 is a tray 1.
This is an autocarrier that continuously transports a plurality of films stored in 27 to a reading position while rotating and moving, and pulls out the reading position after reading is completed. The film image is read by the CCD 103 by projecting the transmitted light of the film onto the platen glass 101 by the projector unit 121.

Reference numeral 130 denotes a color printer for printing image data read by the CCD 103.

FIG. 2 is a structural example of a signal processing block in the image reading apparatus shown in FIG.

In this embodiment, the illumination 123 uses a halogen lamp, and is controlled by the light source light amount control unit 201 to control the lighting voltage.

An analog image signal for each line read by the CCD 103 is amplified by an amplifier 203, and then is converted to a multi-valued (8-bit in this embodiment) digital image signal 21 by an A / D converter 204.
It becomes 6.

In this embodiment, the black level of the document is read as "0" and the white level is read as "255". A / D converter 2
A fixed value is given to the black reference level and the white reference level of 04 so that the halogen lamp 123 is completely turned off and the A / D conversion output when no light is incident on the CCD 103 becomes the 0 level which is completely black. The offset of the amplifier 203 is adjusted.

The CCD drive signal generation circuit 205 is a CCD for reset signals, clock signals, horizontal synchronization signals, etc. necessary for driving the CCD 103.
A drive signal 206 is generated, a clock signal 207 to the A / D converter 204 is generated, and a CCD address 208 which is an address signal for identifying each bit of the CCD 103 is generated. In this embodiment, since the CCD 103 is provided with a 5000 pixel line sensor, the CCD address is counted up from 0 to 4999 corresponding to the 5000 pixels read out in synchronization with the horizontal synchronization signal.

A shading data RAM 209 stores digital image signals for two lines of CCD from the A / D converter 204 in all pixels.
And either one of the data for two lines is selected by the bank switching signal 226 from the CPU 212.

The address selector 210 is a shading data RAM 209.
Selector for the address signal 211 given to the CPU circuit
With the address switching signal 213 from 212, the CCD address 208
Switching between the CPU address from the address bus 214 of the CPU circuit unit.

The shading correction table RAM 215 includes the halogen lamp 123, the uneven light distribution included in the Fresnel lens 102 and the lens 108, the uneven sensitivity of each pixel of the CCD 103, and the amplifier 203.
4 is a table for correcting non-uniformity of the read image signal 216 due to an amplification degree setting error or the like of FIG. Prior to the original reading operation, the CPU 212 writes the correction table data into the shading correction table RAM 215, and when reading the original,
By addressing the correction table RAM 215 with the shading data 217 from the shading data RAM 209 and the read image signal 216, an image signal 218 in which the non-uniformity of the read image signal 216 has been corrected is obtained.

Address selector 219 is a shading correction table R
The selector of the address 220 given to the AM 215 selects one of the CPU address 214 and an address obtained by combining the read image signal 216 and the shading data 217 with an address switching signal 221 from the CPU 212.

The motor driver 223 performs forward / reverse control and speed control of the optical system drive motor 109, receives forward / backward / speed data from the data bus 222 of the CPU 212, and receives encoder pulses synchronized with the motor rotation from the DC servo motor 109. The signal 224 controls the drive of the motor 109 using the PLL control. The encoder pulse signal 224 is also provided to the CPU 212, and the CPU 212 detects the scanning position of the optical system by counting the encoder pulse signal 224.

The home position sensor 110 is a sensor composed of a photo interrupter.

The CPU 212 includes a ROM storing a control means program, a working RAM (including a memory area shown in FIG. 14 to be described later), and a microcomputer having a built-in arithmetic unit and the like. The sequence control, image data correction processing,
Controls the illumination light amount and controls the operation unit.

The operation unit 225 includes a display 1001 and switches 1002 to 1005 as shown in FIG.

The auto carrier drive circuit 227 is a control circuit that controls the auto carrier 125 and controls the rotation of the tray 127.

FIG. 4 shows an outline of the shading correction in this embodiment. The horizontal axis corresponds to each pixel of the CCD 103, and the vertical axis is the A / D converter output value corresponding to each pixel. Characteristic a is 1005
This is a shading characteristic corresponding to a standard white original. Here, the standard white original in the case of reading the positive film means an image or the like which is projected without setting the film. Original image signal b read with this shading characteristic
Is output as an image signal c corrected by the shading correction. Here, the output of the CCD 103 is proportional to the amount of light, Is corrected as

Correction data based on this correction formula is written into the shading correction table RAM 215 by the CPU circuit section 212.
That is, as shown in FIG. 5, a shading characteristic a from the shading data RAM 209 is input to the upper address of the RAM 215 in synchronization with each bit of the CCD, and an A / D conversion output by reading a document is input to the lower address. The shading correction table RAM 215 is configured such that a correction output c is output according to a combination of the input a and the input b.

Next, the procedure for setting the shading correction table RAM 215 will be described with reference to the processing flowcharts of FIGS. 6 and 7. FIG. 8 is a display example of a display 1001 relating to a shading data sample.

At 1101 in FIG. 6, after the message 1301 indicates on the display 1001 that the light amount is being controlled, the light amount of the halogen lamp 123 is controlled by the procedure shown in FIG.

After displaying on the display 1001 that the shading data is being taken in by the message 1302 in 1102,
The select switch of the address selector 210 is set to the A side, the image data is taken into the shading RAM 209, and then set to the B side. Thereafter, an operation corresponding to the above equation (1) is performed, and the result is set in the shading correction table RAM 209.

In step 1103, the halogen lamp 123 is turned off, and the message 1303 indicates that copying (reading) is possible.

A description will be given of a process of controlling the lamp light amount of the halogen lamp 123 at the time of capturing the shading data in the seventh part.

In step 1201, an initial value is set in the light source light amount control unit 201.

In step 1202, the driver 223 is controlled to set the reading position at a substantially central position of the Fresnel lens 102.

At 1203, a delay is made for a fixed time (about 0.2 seconds in this embodiment). This delay is caused by the halogen lamp 123
This is because a certain period of time is required after the light source voltage changes until the lamp light amount becomes stable.

In step 1204, the select switch of the address selector 210 is set to the A side, and the image data is transferred to the shading RAM2.
After importing to 09, set to B side.

At 1205, at 1204, the shading RAM 209
Is read out, and the maximum value is calculated.

In step 1206, the maximum value calculated in step 1205 is compared with a predetermined value α (α = 240 in this embodiment), and the maximum value <α (3) is satisfied. Ends the lamp light amount control. Otherwise, the light amount of the lamp is reduced by a predetermined amount in 1207, and then the processing of 1203 to 1206 is repeated.

In step 1208, the lamp light amount value obtained by the above steps 1201 to 1207 is stored in the lamp_r2001 in the internal RAM area of the CPU 212.
(Fig. 14).

As described above, the light quantity control for reading the film image and the loading of the shading correction data are performed.

Next, means for inputting image data and determining the presence / absence of a film will be described with reference to the processing procedure diagram shown in FIG.

In 901, the light amount of the halogen lamp 123 is set based on the lamp light value lamp_r2001 stored when sampling the shading data.

At 902, image data is input from the CCD 103 via the A / D converter 204 and the like, and the shading correction data RAM 215 is input.
The CPU 212 executes the correction calculation represented by the equation (1) based on the data of (1). Based on the correction data, a frequency histogram related to the brightness is created. At this time, multiple image positions are
After performing shading correction on the image data read and input by the above, by creating a histogram related to the degree of volatility, the influence of shading distortion can be removed to make a more accurate determination.

Average value Av from the histogram calculated in 902 at 903
Ask for.

Average value Av calculated in 903 in 904 performs comparison between the values C ₁ determined in advance. Usually, the histogram for most positive photo films is shown in FIG. 10 (A).
Image data is distributed throughout from dark to bright. Therefore, when the film is not present on the lamp optical path of the halogen lamp 123, the light passes through. Therefore, as shown in FIG. 10 (C), the values of the histogram are concentrated on the brightest part and the average value Av is Shows an extremely large value. Therefore, when the determination condition (Av <C ₁ ) indicated by 904 is satisfied, it can be determined that the film exists on the lamp optical path of the halogen lamp 123.

As described above, if it is determined that a film is present, at 908, 1 is set to film_e2002 (FIG. 14) of the internal RAM of the CPU 212.

Next, in 905, the number of low-intensity pixels L indicated by the hatched portions in FIG. 10B is calculated. That is, in the case of a film composed of characters / line drawings, most of the film is bright, and only the image of the characters / line drawings is dark. Therefore, it may not be possible to judge well with the average value Av. Even in this case, low揮度pixel number L is can be determined that there is film if above a certain value C _2, the flow proceeds to 908.

If the judgment formula (L> C ₂ ) shown by 906 is not satisfied,
It can be determined that the film is not present on the lamp light path of the halogen lamp 123, and the CPU 907 sets 0 to film_e2002 of the internal RAM of the CPU 212.

As described above, it is determined from the histogram of the read output data of the CCD 103 whether or not the film exists at the reading position.

By the way, put the film on the tray 127 of the auto carrier 125.
In the case of setting as shown in FIG. 11, it can be set in the vertical direction and the horizontal direction as shown in FIG. In the figure, a hatched portion RD on the lower right is an image projection area when the film is in the horizontal position, and a hatched portion LD on the lower left is an image projection area when the film is in the vertical position.
The portion other than the hatched portion RD or LD corresponds to the frame portion of the film, and is read by the CCD 103 as a black image.

As described above, since the projection image area differs depending on the film setting direction, it is necessary to determine the film length / width.

The vertical / horizontal determination of the film will be described with reference to the processing procedure of FIG.

At 920, the lamp light amount of the halogen lamp 123 is turned on to the maximum.

At 921, the reading position of the reading device is set at the position shown in FIG. 12e.

At 922, the select switch of the address selector 210 is set to the A side, and the output image data from the CCD 103 is taken into the shading RAM 209 via the A / D converter 204 and the like, and then set to the B side.

In 923, the CPU 212 executes a correction operation represented by the equation (1) based on the data of the shading correction data RAM 215 set in the shading data sampling processing,
Based on the correction data, a frequency histogram related to the brightness is created.

From the frequency histogram calculated in 923 at 924,
Number of pixels in shaded areas in Fig. 10 (D) (number of pixels with density close to white)
S calculates the density value P _K of points becomes greater than a given value Cs. If P _K > ε (ε is a constant determined by experiment), that is, since the number of pixels having a density close to white is large, it is determined to be the vertical direction of the film, and the process of 925 is performed (film_j of RAM is set to 0), If not, there are many read signals in the frame (corresponding to black) of the film, so it is determined that the film is in the horizontal direction.
(Film_j of the RAM is set to 1).

As described above, in this embodiment, a plurality of films can be read continuously using the auto carrier 125. Hereinafter, the relationship between the above-described film presence / absence determination, the film length / width determination, and the copy sequence will be described.

The processing procedure in FIG. 15 explains the selection of each mode of 1 frame / continuous frame / all frames.

Here, the one-frame mode is for reading and printing only the film currently present on the optical path of the halogen lamp 123.

In the continuous frame mode, while the film is continuously set on the tray 127 of the auto carrier 125, the film is continuously read while controlling the rotation of the tray every time one frame is read, and the film is placed in the holder having the tray. If it is determined that there is no film, the reading is terminated even if there is a film in another holder.

The all-frames mode is a mode in which all the films set on the tray 127 perform a reading operation.

In step 1401, when the operator presses the switch of the projector 1003, a message 1801 for mode selection shown in FIG. 19 is displayed on the display 1001.

The operator operates the selection key 1005 to select one frame / continuous frame /
Select one of the modes for all frames. Then, in response to the mode selection, 1402 executes the processing procedure of the single frame mode shown in FIG. 16, 1403 executes the processing procedure of the continuous frame mode shown in FIG. 17, and 1404 executes the processing procedure of the continuous frame mode. No.
The processing procedure of the all-frame mode shown in FIG. 18 is executed.

 FIG. 16 shows an operation procedure in the one-frame mode.

In step 1501, the presence / absence of a film is determined according to the procedure shown in FIG. If the film does not exist on the lamp optical path, a warning message (a message indicating that there is no film) shown in FIG. 1803 is displayed for a certain period of time (10 seconds in this embodiment) in 1503.

On the other hand, if the film is on the lamp path, 1504
Then, the film length / width discrimination is performed according to the procedure shown in FIG. 13, and based on the discrimination result, the image data of the corresponding area is read at 1505 and 1506.

Then, after reading is completed, at 1507, a message indicating that further reading is possible is displayed by message 1804 in FIG.

FIG. 17 shows an operation procedure in the continuous frame mode.

At 1601, a film presence / absence determination is made according to the procedure shown in FIG. If the film does not exist on the lamp optical path, it is determined in 1603 whether or not the reading operation is for the first frame. In the case of the reading operation for the first frame, a warning message shown in FIG. (10 seconds in this embodiment). 16 if not the first frame
05 displays message 1804 and ends.

If the film exists on the lamp light path, the film length / width determination shown in FIG.
08 reads the image data of the corresponding area.

After the reading is completed, the auto carrier drive circuit 227 is executed in 1609.
, And the tray 127 is controlled to rotate by one frame, and the above-mentioned processing after 1601 is repeatedly executed on the next holder of the tray 127. If it is determined that there is no film for a certain holder, continuous reading is interrupted at that point, even if a film is set in a further tray, and 1804 in FIG.
Is displayed, and the apparatus enters a standby state for further instructions.

 FIG. 18 shows the operation procedure in the all-frame mode.

When the all-frame mode is selected, the message shown in FIG. 1901 is displayed, and the operator is prompted to select the number of frames.

Tray 127 for commonly used film settings
Is for 80 frames or 140 frames, so the message of 1901 prompts the user to select between 80 and 140 frames.

In 1701, the operator operates the selection key 1005 to select 80 frames or 140 frames.

In 1702, the presence / absence of the film is determined according to the procedure shown in FIG. If the film does not exist on the lamp optical path, the frame advance processing is performed at 1710,
If the film exists on the lamp optical path, the vertical / horizontal determination and reading processing of 1704 to 1709 are performed.

In step 1710, frame advance is performed, and a message 1902 indicates which frame (holder) tray position is currently located from the start point.

At 1711, it is determined whether or not the reading of the selected number of frames has been completed. If the reading has not been completed, the processes after 1702 are repeatedly executed. If the reading has been completed, a message 1804 is displayed at 1712.

〔The invention's effect〕

As described above, according to the present invention, it is possible to reliably determine whether or not a film exists on the optical path of the irradiation unit without providing a dedicated film detection sensor, and to prevent an erroneous reading operation. it can.

[Brief description of the drawings]

1 is an internal configuration diagram of the film reading device, FIG. 2 is a signal processing block diagram of the film reading device, FIG. 3 is an external view of the operation unit, FIG. 4 is an explanatory diagram of shading correction, and FIG. 5 is shading. FIG. 6 and FIG. 7 are flow charts of shading correction and light quantity control, FIG. 8 is a view for explaining a display example, FIG. 9 is a flow chart of film presence / absence determination, FIG. 10 is a diagram showing an example of a histogram of input image data, FIGS. 11 and 12 are explanatory diagrams of film vertical / horizontal determination, FIG. 13 is a flowchart of film vertical / horizontal determination, FIG. The figure shows the contents of the RAM area. Fig. 15 is a flowchart of the mode selection processing procedure when using the auto carrier. Fig. 16 is a flowchart of the processing procedure in the single frame mode. Fig. 17 is the continuous frame mode. Processing procedure FIG. 18 is a flowchart showing the processing procedure in the all-frame mode, FIGS. 19 and 20 are diagrams showing examples of message display, 103 is a CCD, 123 is a halogen lamp, 125 is an auto carrier, 127 is a tray.

Claims (20)

(57) [Claims] An irradiation unit for irradiating the film; a reading unit for reading an image of the film irradiated by the irradiation unit; and a reading unit for determining whether or not the film exists on an optical path of the irradiation unit. An image reading apparatus, comprising: a determination unit that determines from output data. 2. The apparatus according to claim 1, further comprising a creating unit for creating a histogram from output data of said reading unit, wherein said determining unit determines whether a film is present based on said histogram. The image reading device according to claim 1. 3. The image reading apparatus according to claim 1, further comprising a transport unit that transports the film to a reading position of the reading unit. 4. The apparatus according to claim 1, further comprising control means for controlling the reading operation by said reading means to be interrupted when said determination means determines that there is no film. An image reading device according to the item. 5. The apparatus according to claim 1, further comprising control means for controlling the conveyance by said conveyance means when said judgment means judges that there is no film.
The image reading device according to any one of claims 1 to 3. 6. The image reading apparatus according to claim 1, wherein said judging means further judges the vertical and horizontal directions of the film. 7. The apparatus according to claim 6, further comprising a creating means for creating a histogram from output data of said reading means, wherein said determining means determines the vertical and horizontal directions of the film based on said histogram. Image reading device. 8. The image reading apparatus according to claim 6, further comprising a transport unit that transports the film to a reading position of the reading unit. 9. The apparatus according to claim 6, further comprising control means for controlling the reading operation by said reading means to be interrupted when said judgment means judges that there is no film. An image reading device according to the item. 10. The apparatus according to claim 6, further comprising control means for controlling the conveyance by said conveyance means when said judgment means judges that there is no film. The image reading device according to claim 1. 11. A step of irradiating a film with an irradiating unit, a step of reading an image of the film illuminated by the irradiating unit with a reading unit, and determining whether or not the film exists on an optical path of the irradiating unit. Determining from the output data of the reading means. 12. The image reading method according to claim 11, further comprising the step of creating a histogram from output data of said reading means, and determining whether or not a film exists based on said histogram. . 13. An image reading method according to claim 11, further comprising a step of transporting said film to a reading position of said reading means. 14. An image according to claim 11, further comprising a step of interrupting a reading operation by said reading means when said judgment means judges that there is no film. Reading method. 15. The image reading method according to claim 11, wherein the transporting step is performed when the determination unit determines that there is no film. 16. The image reading method according to claim 11, further comprising the step of judging the vertical and horizontal directions of the film. 17. The image reading method according to claim 16, further comprising the step of creating a histogram from output data of said reading means, and judging the vertical and horizontal directions of the film based on the histogram. 18. The image reading method according to claim 16, further comprising the step of transporting said film to a reading position of said reading means. 19. The image reading method according to claim 16, further comprising a step of interrupting a reading operation when it is determined that there is no film. 20. The method according to claim 16, wherein the carrying step is performed when it is determined that there is no film.
19. The image reading method according to any one of claims 18 to 18.