JP3478683B2 - Image reading apparatus and control method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates irradiates light from the light source to the document image reading equipment AND ITS control reads an image
Regarding the method .

Further, the present invention relates to an image reading apparatus in an image scanner, a facsimile machine, etc., and in particular,
Regarding a document which is illuminated by a linear light source composed of an LED (light emitting diode) array and a linear CCD (charge-coupled device) image pickup device captures the linear image, the white reference value is related to the rise of the light quantity immediately after the LED is turned on. The data is measured, the optimum wait time until the light amount stabilizes is calculated, and the white reference value is calculated from the mathematical formula before the actual reading is started.

Further, the present invention relates to an image reading device such as an image scanner or a facsimile device, and in particular, LE
A document is illuminated with a linear light source composed of a D (light emitting diode) array, and the linear image is picked up by a one-dimensional image sensor such as a CCD (charge coupled device). Image information can be output.

[0004]

2. Description of the Related Art Conventionally, in a general scanner device, an image to be scanned is irradiated with light, the light reflected by the image is incident on a scanner optical section, and the level of the incident light is converted from analog to digital and converted. The digital value can be obtained as a scanned image.

Contrast information is an important factor that determines the image quality of a scanner image, which is defined as the range of shading from the darkest pixel to the brightest pixel in the image. The scanner device performs A / D conversion for each pixel based on this contrast information.

Since each scanner device has variations in optical characteristics and electrical characteristics, the contrast information is different. Therefore, it is necessary to perform the operation of setting the contrast information and store the result before the reading operation of the scanner device.

Specifically, the contrast information includes reference data (white reference value) that defines the value of the whitest data that is actually read by the scanner device and reference data (offset data that defines the value of the blackest data). Value) can be expressed as. When the optical signal of each pixel is A / D converted, the white reference value and the offset value are referred to.

When the scanner device reads the white reference value and the offset value, the output depends on the hardware environment of the light source, the optical sensor, the A / D conversion circuit, the amplifier, etc., and the position accuracy and individual difference. When reading a specific pixel, it is required that the variation ratio due to this degree of dependence is low in order to realize a stable high image quality by keeping the output constant. Therefore, in addition to adopting highly accurate parts, increasing the amount of light from the light source and stabilizing the amount of light, and increasing the reading time per pixel, the white reference value and offset value measurement cycle that serve as a reference during A / D conversion are also measured. Measures are taken such as to perform every time the document is read.

On the other hand, recently, some serial printers used for word processors have an image reading function by mounting a scanner head cartridge of the same shape instead of the print head cartridge.

Further, conventionally, as a general image reading apparatus used in a scanner, a facsimile apparatus, etc., one using a reduction optical system is known. FIG. 31 is a diagram showing an optical configuration of an image reading apparatus using a reduction optical system.

The image reading apparatus includes a light source 105a extending in the longitudinal direction for irradiating the original 106a, a mirror 104a for bending an optical path to downsize the entire apparatus, and a mirror 104.
A lens 102a for focusing the light reflected by a, a white reference correction plate (shading plate) 103a for correcting the lens cos 4th power law of the white output waveform, and a line CCD image pickup device 101a for converting optical information into an electric signal. Has been done.

This image reading apparatus is provided with an IC such as an A / D converter (not shown) that performs analog-digital conversion before the voltage waveform output from the line CCD image pickup device 101a is transferred to the image processing system. There is.

In the above image reading apparatus, an inexpensive Xe lamp or LED is often used as a light source in order to reduce the cost.

[0014]

However, when the LED is used as the light source of the former, when the scanner reads the white reference value and the offset value, the LED is turned on in advance in order to avoid a change in the light amount due to the temperature characteristic of the LED. LE
It is necessary to preheat until the temperature of D stabilizes. The occurrence of waiting time for this preheating significantly lowers work efficiency.

Further, in order to avoid the occurrence of a waiting time for preheating, it is necessary to turn on the LED and keep the heat in order to prevent the temperature drop of the LED even when the scanner device does not perform the image reading operation.

However, the LED deteriorates with the accumulation of the lighting time, and continuing to light the LED shortens the life of the LED. In addition, when driven by a battery, a large amount of power is consumed for lighting the LED, which shortens the life of the battery.

On the other hand, a temperature sensor is provided and the LED
It is desirable to manage the temperature of the device in detail and perform optimum control, but there are cases where it cannot be used because the parts used are limited due to size reduction and cost reduction.

Further, in the case of a printer device in which the printer can function as a document reading device by mounting the scanner head cartridge on the carriage of the serial printer, the circuit of the scanner head cartridge becomes complicated and the number of contacts of the connector is increased. Problems such as increase will occur.

On the other hand, the latter conventional image reading apparatus has the following problems. That is, Xe lamp and LED
Since the light source such as has a small absolute light quantity, it is necessary to lengthen the accumulation time of image reading or to increase the sensitivity of the light receiving unit in order to obtain stable image information.

At present, although the development of high-speed driving of the CCD device is in progress, there is a limit to the sensitivity characteristic of the light receiving portion for photoelectrically converting the optical information of the document, and in order to obtain a stable S / N. It was necessary to illuminate the document with a sufficient amount of light.

Therefore, when the drive current of the LED or the like is increased to increase the amount of light, there is a change in the wavelength of light due to heat generation of the LED itself and a change in current due to a change in forward voltage.
There was a problem that a stable light quantity could not be obtained immediately after lighting and the white reference value could not be measured or an actual image could not be read (stable output image could not be obtained) until it became stable.

Further, even if the light amount is almost stable after a predetermined time has passed from the lighting, the white reference value continues to change slightly due to the heat generation of the LED itself and the change of the environmental temperature. Therefore, the white reference value before the actual reading is started. It is appropriate to re-measure the value,
Since it takes time, the white reference value is often represented by a single measurement value when a predetermined time has elapsed after lighting (when the light amount is almost stable).

Further, since the actual white reference value measurement and image reading after the light amount is stabilized are performed after a predetermined time (fixed time), which is considered to be sufficiently stable, changes over time and circuit elements specific In many cases, it is waiting for an extra time in anticipation of errors.

Further, the latter conventional image reading apparatus has the following problems. That is, Xe lamp and LED
Since the light source such as has a small absolute light intensity, in order to obtain stable image information, the accumulation time of image reading is lengthened,
Alternatively, it was necessary to increase the sensitivity of the light receiving section.

At present, although the development of high-speed driving of CCD devices is in progress, there is a limit to the sensitivity characteristic of the light receiving portion for photoelectrically converting the optical information of the original, and in order to obtain a stable S / N. It was necessary to illuminate the document with a sufficient amount of light.

Therefore, when the drive current of the LED or the like is increased to increase the amount of light, there is a change in the wavelength of light due to heat generation of the LED itself and a change in current due to a change in forward voltage.
There is a problem that a stable light amount cannot be obtained.

On the other hand, when the removable print head cartridge is detachably mounted on the printer mounted on the portable personal computer, there is a problem that the scanner circuit must be simplified due to the restriction of the small external size. there were.

Further, since the portable personal computer has a specification that it can be driven by a secondary battery, there is a problem that power consumption should be reduced as much as possible.

Therefore, the present invention relates to the environmental temperature.
Read the original image with the light source always stable.
It is an object of the present invention to provide an image reading apparatus and a control method therefor.

[0030]

[0031]

[0032]

[0033]

In order to achieve the above object, the image reading apparatus of the present invention includes a scanner cartridge.
In an image reading device that reads an image by irradiating an original with light from a light source built in the scanner cartridge while reciprocally moving a mounted carriage, an environmental temperature detecting unit for detecting an environmental temperature, and an original temperature reading unit before reading an original image. The light source is turned on for preheating only for a time corresponding to the ambient temperature, and the light source is mainly used for reading the original image.
It is controlled so that it is turned on when the carriage is moving forward and turned off when the carriage is moving backward,
And a control means for setting the lighting ratio at that time according to the ambient temperature. The control method of the image reading apparatus of the present invention is a scanner cartridge.
A control method for an image reading apparatus equipped with a carriage of Tsu di from a light source incorporated in the scanner cartridge while round trip motion by irradiating light to the document to read an image, detects the environmental temperature, before reading the original image Turns on the light source for preheating only for a time corresponding to the ambient temperature, and mainly reads the light source when reading an original image.
It is characterized in that it is controlled so that it is turned on when the carriage is moving forward and turned off when the carriage is moving backward, and the lighting ratio at that time is set according to the ambient temperature.

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[Embodiment Referring] of images reader and its of the present invention
It will be described an embodiment of the control method. Image reading equipment according to the present embodiment is applied to a portable personal computer.

[First Embodiment] FIG. 1 is a perspective view showing the outer appearance of a portable personal computer according to the first embodiment. FIG. 2 is a block diagram showing the hardware configuration of the personal computer.

This personal computer 1 is equipped with an ink jet type serial printer 2, and a scanner head cartridge having the same shape as the print head cartridge is mounted on a carriage for moving the print head cartridge to read an original from the serial printer. It can function as a device.

The personal computer is a host unit 200 and a printer scanner unit unit 219.
Composed of. In the host unit 200, a central processing unit (CPU) 201 controls the whole. The BIOS 202 that instructs the basic control of the CPU 201 is written in the ROM.

The CPU 201 is a writable nonvolatile memory device such as a floppy disk drive (FD).
D) 203 and hard disk drive (HDD) 204
To floppy disk controller (FDC) 205
The application program is read out via the hard disk controller (HDC) 206, expanded in the main memory 207, and the program is executed using the main memory 207.

The video graphic array controller (VGAC) 208 is a liquid crystal display (LCD) 20.
A character or the like written in the video memory (VRAM) 210 is displayed at 9. In addition, key input from the keyboard 211 is performed by the keyboard controller (KBC) 21.
It is done via 2.

The numerical processor (FPU) 213 is a C
It supports arithmetic processing executed by the PU 201. A real-time clock (RTC) 214 indicates the elapsed time at the present time, and operates with a dedicated battery even when the entire system is powered off. Static RAM (SRA
M) 214A stores system information such as the operating state of the system. This memory also holds its contents by the dedicated battery 221 when the power is not turned on.

The DMA controller (DMAC) 215 is for memory-memory, memory-I / O, I / O-I / O.
CPU 20 for high-speed data transfer between
Data transfer is performed without intervention of 1.

The interrupt controller (IRQC) 216 accepts interrupts from each I / O and performs processing according to the priority order. A timer (not shown) has a free running timer of several channels and manages various times. In addition, a serial interface (SIO) that connects to the outside
217, an expansion port (PORT) 218, and an LED (not shown) for notifying a user of an operation status are provided in the host unit 200.
It is provided in.

On the other hand, the printer scanner unit section 219
Is connected to the host unit 200 via a parallel interface. In the printer-scanner unit section 219, the printing function or the scanner function is realized by mounting either the removable print head cartridge or the scanner head cartridge on the carriage of the printer body as described above. The printer controller of the host unit 200 and the printer scanner unit unit 219 transmits / receives status data, print data, and scan data using the registers of the I / O port.

[Printer Scanner Unit 219] FIG. 3 is a perspective view showing the appearance of the printer scanner unit 219. FIG. 4 shows the printer scanner unit section 219.
FIG. 3 is a block diagram showing the hardware configuration of the above. The printer scanner unit 219 is a CPU for controlling the printer.
401, a ROM 40 that stores a printer scanner control program, printer emulation, and print fonts
2. RAM 403 for storing development data for printing, image data captured by a scanner, data received from the host unit 200, printer scanner head 40
4. A motor driver 405 for driving the motor, a printer scanner controller 406 for controlling access to the memory, exchanging data with the host unit 200, and sending a control signal to the motor driver 405. A thermistor 407 is provided to manage the temperature of the printer scanner unit 219.

The CPU 401 controls the main body 200 mechanically and electrically according to the control program stored in the ROM 402, and the printer unit 2 from the host unit 200.
The emulation command sent to the printer scanner controller 406 is read from the I / O data register in the printer scanner controller 406, and writing / reading is controlled in the I / O register or I / O port in the controller corresponding to the emulation command.

[Printer Scanner Controller 406]
FIG. 5 is a block diagram showing the configuration of the printer scanner controller 406. Printer scanner controller 4
The function block 06 includes an I / O data register 501 for exchanging data at the command level with the host unit 200, and a reception buffer controller 502 for directly writing reception data from the I / O data register 501 to the RAM 403. .

When printing, the print data is read from the print data buffer of the RAM 403 and sent to the print head. When the scanner is used, the data sent from the scan head is also sent to the RAM 403.
Print scan buffer controller 503 that writes data to the print data buffer, a memory controller 504 that controls memory access to the RAM 403 from three directions, a sequence controller 505 that controls a print scan sequence, and a host that controls communication with the host unit 200. A functional block including the interface 506 is provided.

FIG. 6 is an explanatory diagram showing a map of the I / O data register 501. Motor control port 60
By directly rewriting the register value of 1, each port is controlled and each motor is driven.

The recording data buffer area 602 is for setting a data area necessary for a printing or scanning operation. By setting a start address 6021 and an end address (only a start address at the time of scanning) 6022, The print scan buffer controller 503 reads and writes the print data from the start address of the RAM 403 to the end address in order.

At this time, the recording data address pointer indicates the data address which is currently being sent or written. In the print mode, the read data is transferred to the print head, and the head driver in the head sends a control signal. In the scan mode, the data sent from the scan head is written in this buffer.

Similarly, the reception data buffer area 603 also sets a data area required for reception, and by setting a start address 6031 and an end address 6032 (only the start address at the time of scanning), reception is performed within that range. RAM 403 by the buffer controller 503
The received data is written from the start address to the end address in order. At this time, the reception data address pointer indicates the data address which has already been received. FIG. 7 is an explanatory diagram showing address areas of the recording data buffer and the receiving buffer on the RAM 403 in the writing operation of the receiving data.

[Scanner Unit] FIG. 8 is a perspective view showing the outer appearance of the scanner head cartridge. The scanner head cartridge 800 of the printer scanner unit section 219 shown in FIG.
The connector 80 has the same shape as that of 02, and the electrical connection portion with the printer unit is also common to the print head cartridge.
Has 1. The connector 801 of the scanner head cartridge 800 is provided with a contact portion 802 for transmitting / receiving a read control signal from the main body.

The carriage 30 is driven by the head guide 303.
1 and the scanner head cartridge 800 are connected. The read signal and the control signal are transmitted / received to / from the printer scanner controller 406 via the contact portion 802 and the flexible cable 304.

FIG. 9 is a block diagram showing the construction of parts in the scanner head cartridge. In the cartridge body, a flexible board on which electric components are mounted is arranged in a substantially box-shaped interior so as to enclose the optical system components.

In the figure, reference numeral 901 is a document for reading. An LED (light emitting element) 902 serves as a light source,
It emits light when connected to a power source via the connector 801.
Reference numeral 903 is a mirror that reflects the reflected light of the light emitted by the LED 902 toward the CCD sensor 904.

The analog output of the reflected light detected by the CCD sensor 904 is amplified by the amplifier 905. 9
A scanner controller IC 06 transmits and receives data and commands to and from the main body. Also, it outputs control signals relating to the scanner operation such as the LED 902 and the CCD 904 according to the command from the main body. Further, control such as amplifying an analog signal read from the CCD 904 and sending it to the A / D conversion block 9061 and the main body is performed.

Reference numeral 907 denotes a work SRAM for performing two A / D reference values including a white reference value and an offset value, the operation state of the scanner, and expansion of read data. The scanner controller 906 sends and receives commands from the main body.
Is performed at the register level of the I / O port inside.

FIG. 10 is an explanatory diagram showing a map of the I / O port register. FIG. 11 is an explanatory diagram showing a dedicated status port used for exchanging information between the host unit 200 and the printer scanner unit unit 219. 1
The status port 1 indicated by 101 is composed of 8 bits and is used for exchanging information regarding the status of the other status ports and the printer scanner unit section 219. The status port 2 indicated by 1102 is composed of 16 bits and is used for exchanging commands and data. The status port 3 indicated by 1103 is composed of 16 bits,
It is used to send image data for printing from the host unit 200 to the printer scanner unit unit 219.

FIG. 12 is a diagram showing the bit contents of the status port 1 1101. Each bit is host part 2
00 and the printer scanner unit section 219.

Bit 0 indicated by 1201 has a value of 1 when data is sent from the host section 200 to the printer scanner unit section 219 via the status port 2 indicated by 1102, and has a value of 0 when not sent. Bit 1 indicated by 1202 is transmitted from the printer scanner unit section 219 to the host section 20 via the status port 2 indicated by 1102.
The value is 1 when data is sent to 0, and the value is 0 when data is not sent.

Bit 2 indicated by 1203 has a value 0 when data can be sent from the host unit 200 to the printer scanner unit 219 via the status port 3 indicated by 1103, and has a value 1 when the data cannot be sent. 1
Bit 3 indicated by 204 is the printer scanner unit section 2
When the power of 19 is turned on, the value becomes 0, and when it is not turned on, the value becomes 1. Bit 4 indicated by 1205 has a value of 1 when the printer scanner unit section 219 is in a busy state, and has a value of 0 when it is in a ready state. Bit 5 indicated by 1206
Has a value of 1 when the status ports 1 to 1103 of 1101 to 1103 are being initialized, and has a value of 0 when they have been initialized.

FIG. 13 is a diagram showing a list of commands sent from the host section 200 to the printer scanner unit section 219 via the status port 2 indicated by 1102.
The host unit 200 writes these commands to the status port 2 indicated by 1102 and then sets the bit 0 indicated by 1201. The printer scanner unit section 219 is 1
When it is detected that bit 0 indicated by 201 is set,
Processing is performed according to the command written in the status port 2 indicated by 1102, and bit 0 indicated by 1201 is dropped. When this process ends, the result is written to the status port 2 indicated by 1102 and the bit 1 indicated by 1202
Stand up. When the host unit 200 detects that bit 1 indicated by 1202 is set, it reads the contents of the status port 2 indicated by 1102, and returns 1 when the reading is completed.
Bit 1 shown at 202 is dropped.

The details of each command will be described below. 1000H shown at 1301 initializes the status ports 1, 2, and 3. Reference numeral 4000H shown at 1302 is a command for transferring a print image. After writing this command, by writing the image data itself to the status port 3 of 1103, printing can be performed.

Reference numerals 8000H to 8F78 shown in 1303 are commands for reading the scanner, and the lower 12 bits indicate the feed amount after the image scanning operation. When this command is written, the read image data will be
02 from the printer scanner unit section 219 to the host section 200 via the status port 2. After the transfer of the image data, the feed amount indicated by the value of the lower 12 bits is fed, and the operation ends. Here, the unit of the feed amount is 1/360 inch.

9000H to 9F78H shown in 1304
Is a command for instructing the feed, and the lower 12
The feed amount is specified by the bit value. The unit of feed amount is 1/360 inch. 9FF0 shown in 1305
H is a command for instructing paper discharge. 9FF1H shown at 1306 is a command for instructing paper feeding. 1307
A801H shown in is a command for acquiring the information of the head unit currently mounted in the printer scanner unit section 219. When this command is activated,
1-byte head unit information is sent from the printer scanner unit section 219 to the host section 200 via the status port 2 of 1102. FIG. 14 is a diagram showing 1-byte head unit information sent from the printer scanner unit section 219 to the host section 200.

Bit 0 indicated by 1401 indicates the type of the head unit currently installed in the printer scanner unit section 219. If the value is 0, the scanner head is installed, and if the value is 1, the print head is installed. Means that. Bit 1 indicated by 1402 indicates whether or not a head unit is currently installed in the printer scanner unit section 219. A value 0 means no head unit, and a value 1 means head unit.

Bit 2 indicated by 1403 is a bit which is effective only when the scanner head is mounted, and indicates whether or not it can be read after being preheated. If the value is 0, it can be preheated or turned off. That it is unreadable,
A value of 1 means that it is preheated and readable.

A 805H shown at 1308 is a command for acquiring the setting value of the reading resolution currently set in the printer scanner unit section 219. When this command is issued, the printer scanner unit section 21
Read resolution information of 1 to 9 bytes is stored in the host unit 200.
Will be sent to. FIG. 15 is a diagram showing 1-byte read resolution information sent from the printer scanner unit section 219 to the host section 200.

36 when bit 0 indicated by 1501 has a value of 1
180 when bit 1 shown by 0dpi and 1502 has a value of 1
means dpi. No more than one of these bits can have the value 1 at the same time.

AD00H to AD3FH shown at 1309 are commands for acquiring the white reference value detected at the accumulation time of 512 microseconds, and the lower 8 bits correspond to dots 0 to 127 of the head in order. Upon receiving this command, the printer scanner unit section 219 sends back the 1-byte white reference value set to the corresponding dot to the host section 200 via the status port 2 of 1102.

AD40H to AD7FH shown at 1310 are commands for acquiring the white reference value detected at the accumulation time of 256 microseconds, and the lower 8 bits correspond to dots 0 to 127 of the head in order. Upon receiving this command, the printer scanner unit section 219 sends back the 1-byte white reference value set to the corresponding dot to the host section 200 via the status port 2 of 1102.

AD80H indicated by 1311 is a command for acquiring the ID of the mounted head unit. Upon receiving this command, the printer scanner unit section 219 sends this ID back to the host section 200 via the status port 2 of 1102.

AD81H shown at 1312 is a command for acquiring the in-machine temperature information of the printer scanner unit section 219. Upon receiving this command, the printer scanner unit section 219 sends 1 byte of this in-machine temperature information to the host section 20 via the status port 2 of 1102.
Send back to 0.

ADF0H indicated by 1313 is a command for performing a white reference value detection actual operation. Upon receiving this command, the printer scanner unit section 219 performs a white reference value detection operation for each of the accumulation times of 512 microseconds and 256 microseconds.

B805H shown at 1314 is a command for setting a new reading resolution in the printer scanner unit section 219. After this command is activated, the printer scanner unit section 219 is continuously operated as shown in FIG.
By sending the 1-byte read resolution information shown in
You can set a new reading resolution.

In BD00H to BD3FH indicated by 1315, the white reference value at the accumulation time of 512 microseconds is set to the host unit 20.
0 to RAM4 in the printer scanner unit section 219
03, and the lower 8 bits sequentially correspond to the dots 0 to 127 of the head. After issuing this command, the printer scanner unit section 2 continues.
By sending the 1-byte white reference value to 19, the white reference value of the corresponding dot can be set. This RAM40
The white reference value in 3 is written in the scanner head immediately before the actual scan operation.

BD40H to BD7FH indicated at 1316 are the white reference values at the accumulation time of 256 microseconds, which are set to the host unit 20.
0 to RAM4 in the printer scanner unit section 219
The command is sent to H.03, and the lower 8 bits sequentially correspond to the dots 0 to 127 of the head. After issuing this command, the white reference value of the corresponding dot can be set by continuously sending the 1-byte white reference value to the printer scanner unit section 219. The white reference value in the RAM 403 is written in the scan head immediately before the actual scan operation is performed.

BDF0H shown at 1317 is a command for writing the white reference value set in the RAM 403 in the printer scanner unit section 219 into the scanner head.

D000H shown at 1318 is a command for moving the carriage to the head replacement position. When this command is received, the printer scanner unit section 2
19 moves the carriage to the head replacement position.

D100H shown at 1319 is a command for returning the carriage from the head replacement position to the home position. When this command is received, the printer scanner unit section 219 carries out initialization processing of the head unit and then moves the carriage to the home position. To move.

Reference numeral 1320 designates the left offset of the carriage position, and the lower 12 bits designate the offset amount. The unit of the offset amount is 1/360 inch.

16 and 17 are flowcharts showing the processing procedure of the basic scanner operation according to the command transmitted by the host section 200. When the scanner operation starts, the command 1301 is transmitted to initialize the status port (step S1601). 120
It is detected by referring to bit 5 shown by 6 whether or not the initialization processing is completed (step S1602). If the initialization process is completed, bits 0 and 1 indicated by 1401
By referring to bit 1 indicated by 402, it is detected whether or not the scanner head cartridge 800 is attached to the carriage 301 (step S1603).

If it is already mounted, the process proceeds to step S1607, and if it is not mounted, a command 1318 is transmitted to start head replacement. Carriage 301 by this command
Moves to the head replacement position, so the user mounts the scanner head cartridge 800 (step S160).
5). When the mounting is completed, the command 1319 is transmitted to complete the head replacement (step S1606), and the step S
The processing moves to 1603.

In step S1607, by referring to the bit indicated by 1403, it is detected whether or not the scanner head cartridge 800 is preheated (step S1607). If it is preheated, the user sets the white reference paper, A command 1306 is transmitted to feed paper (step S16).
08). The white reference value detection operation is performed by the command 1313 (step S1609). The command 1305 is transmitted and the paper is written (step S1610).

The user sets the document sheet to be read and sends a command 1306 to feed the sheet (step S161).
1). The original is read (step S1612)
However, its details are omitted here. Step S
When the reading of the original is completed in 1612, the original is discharged (step S1613).

Waiting for the next request (step S161)
4) If there is a read request, the process returns to step S1607 to perform the next read. If there is a print request, command 1
301 is transmitted to initialize the status port (step S1615).

It is determined whether or not the initialization processing is completed by referring to the bit 1206 (step S1616), and if it is completed, the bits 1401 and 1402.
It is detected whether or not the print head cartridge 302 is attached to the carriage 301 by referring to (step S1617). If it is already mounted, the process ends. If it is not mounted, the command 1318 is transmitted to start head replacement.

Since the carriage 301 is moved to the head replacement position by this command, the user mounts the print head cartridge 302 (step S161).
9). When the mounting is completed, the command 1319 is transmitted to complete the head replacement (step S1620). When the mounting of the print head cartridge 302 is confirmed, the scanner operation ends.

FIG. 18 is a flow chart showing a preheat treatment procedure executed by the CPU 401 for controlling the printer. When the scanner head cartridge 800 is mounted, bit 2 (bit 14) of the current head unit information is
(Corresponding to 03) is set to a value of 0 and the preheat treatment is started.

First, the temperature inside the printer is read (step S1701). Next, the time required for preheating is calculated based on the correspondence between the temperature inside the printer and the preheating time stored in advance in the ROM 402 (step S).
1702). Then, the LED 902 is turned on for preheating (step S1703).

It is determined whether or not the preheating time calculated in step S1702 has elapsed (step S1704).
When the time has elapsed, the LED 902 is switched to the heat retention lighting (step S1705), the value 1 is set to the bit 2 (corresponding to the bit 1403) of the current head unit information, and the preheat treatment is ended.

19 and 20 are C for printer control.
It is a flow chart which shows the heat treatment procedure performed by PU401. When the value 1 is set in bit 2 (corresponding to bit 1403) of the current head unit information,
Start the heat treatment.

The temperature inside the printer is read (step S
1801). The type of power source is detected to determine whether it is a commercial alternating current (AC) power source or a battery (step S1802). A lighting / lighting cycle for heat retention and a lighting current are calculated according to the in-machine temperature and the type of power source (step S1803). In the case of battery drive, the duration is also calculated. Then, a flag instructing lighting is set (step S180).
4).

The flag is discriminated (step S1805),
When the flag is set, the LED 902 is turned on (step S1806), and when the flag is not set, the LED 902 is turned off (step S180).
7).

Whether or not there is a request from the host unit 200 is detected (step S1808), and if there is a request, the heat treatment is terminated, and if there is no request, it is determined whether or not the cycle time has elapsed (step S1808). S1809). If the cycle time has not elapsed, the process returns to step S1808, and if the cycle time has elapsed, the flag is inverted (step S181).
0).

It is determined whether or not the continuation time has elapsed (step S1811). If not, step S1
Returning to 805, if the time has elapsed, the LED 902 is turned off (step S1812), and the bit 2 (corresponding to the bit 1403) of the current head unit information is set to the value 0. Subsequently, it is detected whether or not there is a request from the host unit 200 (step S1813), and if there is a request, the heat treatment is terminated, and if there is no request, the process of step S1813 is repeated and waits.

[Second Embodiment] The external appearance of a portable personal computer according to the second embodiment is the same as that shown in FIG. The hardware configuration of the personal computer is similar to that shown in FIG.

This personal computer 1 is equipped with an ink jet type serial printer 2, and a scanner head cartridge having the same shape as the print head cartridge is mounted on a carriage for moving the print head cartridge to read an image from the serial printer. It can function as a device.

The liquid crystal display device 3 can be opened and closed by a TFT color liquid crystal. The keyboard 4 can be operated when the liquid crystal display device 3 is opened. Although not visible in the figure, the serial inkjet printer 2 is housed in the rear of the main body.

The personal computer (personal computer) includes a host section 200 and a printer scanner unit section 219.
Composed of. In the host unit 200, a central processing unit (CPU) 201 controls the whole. The BIOS 202 that instructs the basic control of the CPU 201 is written in the ROM.

The CPU 201 is a writable nonvolatile memory device such as a floppy disk drive (FD).
D) 203 and hard disk drive (HDD) 204
To floppy disk controller (FDC) 205
The application program is read out via the hard disk controller (HDC) 206, expanded in the main memory 207, and the program is executed using the main memory 207.

The video graphic array controller (VGAC) 208 is a liquid crystal display (LCD) 20.
A character or the like written in the video memory (VRAM) 210 is displayed at 9. In addition, key input from the keyboard 211 is performed by the keyboard controller (KBC) 21.
It is done via 2.

The numerical processor (FPU) 213 is a C
It supports arithmetic processing executed by the PU 201. A real-time clock (RTC) 214 indicates the elapsed time at the present time, and operates with a dedicated battery even when the entire system is powered off. Real time clock 214
Static RAM (SRAM) 214 provided inside
System information such as the operating state of the system is stored in A. This memory also holds the contents by a dedicated battery when the power is not turned on.

The DMA controller (DMAC) 215 is used for memory-memory, memory-I / O, I / O-I / O.
CPU 20 for high-speed data transfer between
Data transfer is performed without intervention of 1.

The interrupt controller (IRQC) 216 accepts interrupts from each I / O and performs processing according to the priority order. A timer (not shown) has a free running timer of several channels and manages various times. In addition, a serial interface (SIO) that connects to the outside
217, an expansion port (PORT) 218, and an LED (not shown) for notifying a user of an operation status are provided in the host unit 200.
It is provided in.

The drive source for these is the AC adapter 2
20 (rated voltage 20V, 54W) and nickel-hydrogen secondary battery (battery) 221 (rated voltage 12V, 2700mA)
/ H).

On the other hand, the printer scanner unit section 219
Is connected to the host unit 200 via a parallel interface. In the printer-scanner unit section 219, the printing function or the scanner function is realized by mounting either the removable print head cartridge or the scanner head cartridge on the carriage of the printer body as described above. The printer controller of the host unit 200 and the printer scanner unit unit 219 transmits / receives status data, print data, and scan data using the registers of the I / O port.

FIG. 21 shows a printer scanner unit section 21.
It is a block diagram which shows the structure of 9. The printer scanner unit unit 219 stores a printer control CPU (printer CPU) 401, a printer scanner control program, a printer emulation, and a print font.
An OM (printer side ROM) 2302, a developed data for printing, an image data captured by a scanner, a RAM (printer side RAM) 403 for storing received data from the host unit 200, a printer driver 2304 for driving a motor, 2305, a controller 2306 that controls access to the memory, exchanges data with the host unit 200, and sends a control signal to the printer driver.

The printer CPU 401 and the controller 2306 have three motors (carriage motor 2307, auto sheet feeder (ASF) motor 2308, line feed motor 2309) via the motor drivers 2304 and 2305 according to the control program in the ROM 2302. Control, 4 sensors (home position detection, ASF position detection, paper feed detection, paper discharge detection)
While performing electromechanical control of the scanner heads and print heads 2310 to 2313, the emulation command sent from the host unit 200 to the printer scanner unit unit 219 is input / output in the controller 2306.
The control corresponding to the command read from the data register and the I / O data register in the controller 2306, I
Write to and read from the / O port.

One of the scanner head cartridge 800 and the print head cartridge 302 is attached to and detached from the printer section. Carriage 301 of printer unit
Has a contact portion (electrode) 2316, which is connected by pressure when the cartridge is mounted on the carriage 301.

As a method for discriminating the cartridge to be mounted on the carriage 301, each head has 2-bit head IDs 317 and 318 in a part of the line connected to the contact portion 2316.
The contents of the control pins are made to correspond by reading 317 and 318 and discriminating the scanner head cartridge 800 or the print head cartridge 302.

When the head IDs 317 and 318 recognize the print head cartridge 302, the bubble (BJ) head 320 is ejected through the head driver 319 to perform printing. When the scanner head cartridge 800 is recognized, the reading operation is performed. [Printer Scanner Controller 406] The configuration of the printer scanner controller 406 is the same as in FIG. Printer scanner controller 40
6 includes an I / O data register 501 for exchanging data at the command level with the host unit 200 as a functional block, and a reception buffer controller 502 for directly writing reception data from the I / O data register 501 to the RAM 403. .

When printing, the print data is read from the print data buffer of the RAM 403 and sent to the print head. When the scanner is used, the data sent from the scan head is also sent to the RAM 403.
Print scan buffer controller 503 that writes data to the print data buffer, a memory controller 504 that controls memory access to the RAM 403 from three directions, a sequence controller 505 that controls a print scan sequence, and a host that controls communication with the host unit 200. A functional block including the interface 506 is provided.

[Scanner Unit] The appearance of the scanner head cartridge is the same as that shown in FIG. The scanner head cartridge 800 is the print head cartridge 30.
The connector 801 has the same shape as that of the printer head unit 2 and has the same electrical connection with the printer unit as the print head cartridge.
Have. The connector 801 of the scanner head cartridge 800 is provided with a contact portion (connector portion) 802 for transmitting and receiving a read control signal from the main body via the contact portion 2316.

The carriage 30 is driven by the head guide 303.
1 and the scanner head cartridge 800 are connected. The read signal and the control signal are transmitted / received to / from the printer scanner controller 406 via the contact portion 802 and the flexible cable 304.

A positioning hole 811B and a positioning groove 811C for positioning when mounted on the carriage 301 are provided. The reference wall 811 determines the posture in the reading direction, and the mounting position is determined by being biased to the carriage side.

FIG. 22 shows the printer scanner unit section 21.
9 is a perspective view showing the outer appearance of FIG. The scanner head cartridge 800 has the same shape as the print head cartridge 302 that performs recording on a recording medium, and the scanner head cartridge 800 and the print head cartridge 30.
Both of the two are detachable and replaceable with respect to the printer unit. The carriage 301 is provided with a carriage contact portion 316 that transmits and receives a read signal from the main body via the connector portion 802 of the scanner head cartridge 800.

The read signal is sent to the CPU 40 on the printer side via the contact portion 802 and the flexible cable 304.
1 is processed.

The carriage 301 has a frame side plate portion 45.
Reading is performed by reciprocating along the slider shaft and the slide plate 47 between A and 45B. A carriage drive motor (CR motor) 307 moves the carriage 301 via a belt.

FIG. 23 is a perspective view showing the optical arrangement inside the scanner head cartridge. A plurality of LEDs 902 (λ = 570 nm) that are light sources are arranged longer than the reading width direction. A cylindrical rod lens 912 is installed in parallel with and close to the LED 902. LE
The irradiation center of D902 passes through the center of the lens working surface of the rod lens 912, and the original surface is obliquely irradiated.

The light reflected from the document surface passes through the field lens 913 which is the first image forming system lens whose optical axis center is provided in the direction substantially perpendicular to the document, and is provided in parallel with the reading width direction. The mirror 903 changes the direction of the optical axis to 9
It is bent by 0 ° to form a light beam that is substantially parallel to the original.

Reference numeral 918 denotes an aperture, which is the position of the image forming surface of the field lens 913 which is the first image forming system lens. An image forming lens (not shown) that is a second image forming system lens is provided behind the aperture 918.

The image forming position of the image forming lens is the position of the CCD 904 as the line image pickup device. The imaging system lens is arranged at a reduction ratio of 0.45158.

The structure of parts inside the scanner head cartridge is the same as that shown in FIG. In the cartridge body, a flexible board on which electric components are mounted is arranged in a substantially box-shaped interior so as to enclose the optical system components.

In the figure, reference numeral 901 is a document for reading. An LED (light emitting element) 902 serves as a light source,
It emits light when connected to a power source via the connector 801.
Reference numeral 903 is a mirror that reflects the reflected light of the light emitted by the LED 902 toward the CCD sensor 904.

The analog output of the reflected light detected by the CCD sensor 904 is amplified by the amplifier 905. 9
A scanner controller IC 06 transmits and receives data and commands to and from the main body. Also, it outputs control signals relating to the scanner operation such as the LED 902 and the CCD 904 according to the command from the main body. Further, control such as amplifying an analog signal read from the CCD 904 and sending it to the A / D conversion block 9061 and the main body is performed.

Reference numeral 907 denotes a work SRAM for performing two A / D reference values including a white reference value and an offset value, the operation state of the scanner, and expansion of read data. The scanner controller 906 sends and receives commands from the main body.
Is performed at the register level of the I / O port inside.

24 and 25 are flowcharts showing the processing procedure of the basic scanner operation. When the scanner operation is started, a port initialization command is transmitted to initialize the status port (step S902).
It is determined whether or not the initialization process is completed by referring to the status initialized bit (step S903).

When the initialization process is completed, the head mounting bit and the scanner bit (the head ID 317 of the scanner head cartridge 800 or the head ID 318 of the print head cartridge 302) are referred to,
It is determined whether or not the head is mounted on the carriage 301 and the head is the scanner head cartridge 800 (step S904).

If the carriage 301 has already been mounted and it is the scanner head cartridge 800, the process proceeds to step S908. On the other hand, when the print head cartridge 302 is not mounted or is mounted, a head replacement start command is transmitted to start head replacement (step S905). This command causes the carriage 302
Moves to the head replacement position, so the user mounts the scanner head cartridge 800 (step S90).
6). When the mounting is completed, the head replacement processing is ended by the head replacement end command (step S907).

It is checked in step S908 if the LED 902 is already on (step S90).
8). If the LED is not lit, the reference value (black reference value) in the LED off state is read (step S909). The read black reference value is temporarily held in the RAM 403.

After that, the LED 902 is turned on, the current lighting time is set to the lighting start time tON, and the data is read from the real time clock 214 (step S910). The read lighting start time tON is temporarily stored in the RAM 403. The user sets white reference paper and sends a paper feed command to feed paper (step S911).

A white reference detection command is transmitted to perform a white reference value detection operation (step S912). When the white reference value detection operation ends, the white reference paper is discharged by the paper discharge command (step S913).

On the other hand, if the LED 902 is already lit in step S908, the time is read from the real time clock 214, and the white reference value is calculated from the difference from the lighting start time tON using equation 3 which is an approximate expression described later. , RA
The M403 is reset (step S914).

When the white reference value is determined, the actual reading operation is started. Select the scanning resolution (step S
915). If 360 dpi is selected, 360 dpi
i bit = 0 is set (step S917), 180d
When pi is selected, 360 dpi bit = 1 is set (step S916), and a resolution setting command is transmitted to set the reading resolution (step S918).

The user sets the read original paper (step S919) and sends a paper feed command to feed the paper. A document reading operation is performed (step S920), and after the document reading operation is completed, the document sheet is discharged by a paper discharge command (step S921).

FIG. 26 is a flow chart showing the procedure for measuring the white reference value in step S912. RAM403
The measurement number counter i assigned to the area is set to 1 and the actual measurement is started (step S1001). It is checked whether or not the measurement counter i is larger than 3 (step S1002). Since i = 1 at the beginning, the white reference value Li (i = 1) is measured (step S100).
3). The measured white reference value Li is temporarily stored in the area of the RAM 403.

The elapsed time t (i =
1) is read (step S1004). The elapsed time t after lighting is temporarily stored in the area of the RAM 403. The measurement counter i is incremented (i = i + 1) (step S1005), and waits for t0 time (step S1006).

After waiting, the process returns to step S1002 to check the measurement number counter i. Start with step S1002 after measuring three times until i> 3.
When the condition of> 3 is satisfied, the measurement is terminated, and step S100
Move to 7.

In step S1007, an approximate expression, which will be described later, is determined from the three measured values. The saturation time of the white reference value is calculated from the approximate expression (step S1008). The system waits until the current time read from the real-time clock 214 matches the saturation time (step S1009). As a result, the reading operation can be prohibited for the minimum necessary time until the light amount becomes stable and the actual reading can be started.

After the end of the standby, the real time clock 214
Based on the elapsed time tm read from, the white reference value is calculated from the above-mentioned approximate expression and reset (step S10).
10).

FIG. 27 is a diagram showing changes in the actual white reference value L according to the elapsed time t after the light source is turned on. LED902
Generates heat after lighting, so that the relative emission intensity decreases. If the white reference value L is sampled immediately after lighting with the decrease in the relative light emission intensity, the white reference value decreases with heat generation. LED 902 in the present embodiment
In the case of, on average, LED90 is turned on after lighting for about 60 seconds.
The temperature of 2 is saturated, and the amount of light is almost stable.

Further, in the case of the present embodiment, the white reference value is sampled at equal time intervals three times immediately after lighting, and the data is approximated by a mathematical expression to saturate the temperature after lighting the LED and stabilize the light quantity. Is calculated, and the white reference value is recalculated at the start of actual reading thereafter.

FIG. 28 is a diagram showing the Lagrange interpolation method for approximating the time variation curve of the light quantity immediately after the light source is turned on shown in FIG. Generally, several methods are known for approximating a function, but here, Lagrange interpolation (m-th order polynomial approximation) is used. In FIG. 28, generally m +
When data from y0 to ym is obtained at one point from x0 to xm, the interpolation polynomial P (x) is P (x) = y0N0 (x) + y1N1 (x) + using these data.
... + mNm (x) here,

[0164]

[Equation 1] In the present embodiment, since interpolation is performed with m = 2 (second-order polynomial), N0, N1 and N2 are expressed by Equation 2.

[0165]

## EQU2 ## N0 (x) = (x-x1) (x-x2) / (x0-
x1) (x0-x2) N1 (x) = (x-x0) (x-x2) / (x1-x0)
(X1-x2) N2 (x) = (x-x0) (x-x1) / (x2-x0)
(X2-x1) Therefore, the interpolation polynomial P (x) is expressed by Expression 3.

[0166]

## EQU00003 ## P (x) = y0N0 (x) + y1N1 (x) + y2N2 (x) FIG. 29 is a flowchart showing the procedure for calculating the saturation time (LED light amount stable time) of the white reference value in step S1008. The calculation number counter n is set to a value of 1 (step S1301), and the actual calculation is started.

The white reference value Ln is calculated by substituting the tn value in Expression 3 (step S1302). t after t0 time from tn
The n + 1 value is substituted into Equation 3 to calculate Ln + 1 (step S1303).

| (Ln-Ln + 1) | / t0 (= gradient of approximate expression) is calculated, and it is determined whether the absolute value is 0.05 or more (step S1304). When the absolute value of the slope of the approximate expression is 0.05 or more, the calculation number counter n =
It is set to n + 1 and the next time interval is calculated again (step S1305).

On the other hand, when the absolute value of the slope of the approximate expression is smaller than 0.05, tn + 1 is set as the saturation time, and that value is stored in the RAM.
The area is temporarily held in the area above 403, and the processing ends. FIG. 30 is a diagram showing the change over time of the white reference value when calculating the saturation time (LED light amount stabilization time) of the white reference value.

In the present embodiment, the white reference value measurement during preheating is performed at regular intervals, but it is sufficient to know the elapsed time after lighting the LED, and the measurements may be performed at irregular time intervals. . Although the Lagrange interpolation is performed by the quadratic polynomial approximation, it may be performed by the cubic or higher multi-order approximation. Furthermore, the interpolation method is not limited to the Lagrange interpolation, and other methods (such as the least square method and the spline interpolation method) may be used.

Also, while preheating, the white reference measuring paper is fed,
Although the white reference value is measured, it is also possible to provide a white reference surface on a part of the printer without feeding the paper and read the reference surface at the time of measurement.

[Third Embodiment] An embodiment of the image reading apparatus of the present invention will be described. The external appearance of the portable personal computer according to the third embodiment is the same as that shown in FIG. The hardware configuration of the personal computer is the same as in FIG.

This personal computer 1 is equipped with an ink jet type serial printer 2, and a scanner head cartridge having the same shape as the print head cartridge is mounted on a carriage for moving the print head cartridge to read an image from the serial printer. It can function as a device.

The liquid crystal display device 3 is a 11.8 inch TFT.
It is a color liquid crystal and can be opened and closed freely. The keyboard 4 can be operated when the liquid crystal display device 3 is opened. Although not visible in the figure, the serial inkjet printer 2 is housed in the rear of the main body.

The personal computer is a host unit 200 and a printer scanner unit unit 219.
Composed of. In the host unit 200, a central processing unit (CPU) 201 controls the whole. The BIOS 202 that instructs the basic control of the CPU 201 is written in the ROM.

The CPU 201 is a writable nonvolatile memory device such as a floppy disk drive (FD).
D) 203 and hard disk drive (HDD) 204
To floppy disk controller (FDC) 205
The application program is read out via the hard disk controller (HDC) 206, expanded in the main memory 207, and the program is executed using the main memory 207.

The video graphic array controller (VGAC) 208 is a liquid crystal display (LCD) 20.
A character or the like written in the video memory (VRAM) 210 is displayed at 9. In addition, key input from the keyboard 211 is performed by the keyboard controller (KBC) 21.
It is done via 2.

The numerical processor (FPU) 213 is a C
It supports arithmetic processing executed by the PU 201. A real-time clock (RTC) 214 indicates the elapsed time at the present time, and operates with a dedicated battery even when the entire system is powered off. Real time clock 214
Static RAM (SRAM) 214 provided inside
System information such as the operating state of the system is stored in A. This memory also holds the contents by a dedicated battery when the power is not turned on.

The DMA controller (DMAC) 215 is used for memory-memory, memory-I / O, I / O-I / O.
CPU 20 for high-speed data transfer between
Data transfer is performed without intervention of 1.

The interrupt controller (IRQC) 216 accepts interrupts from each I / O and performs processing according to the priority order. A timer (not shown) has a free running timer of several channels and manages various times. In addition, a serial interface (SIO) that connects to the outside
217, an expansion port (PORT) 218, and an LED (not shown) for notifying a user of an operation status are provided in the host unit 200.
It is provided in.

The drive source for these is the AC adapter 2
20 (rated voltage 20V, 54W) and nickel-hydrogen secondary battery (battery) 221 (rated voltage 12V, 2700mA)
/ H).

On the other hand, the printer scanner unit section 219
Is connected to the host unit 200 via a parallel interface. In the printer-scanner unit section 219, the printing function or the scanner function is realized by mounting either the removable print head cartridge or the scanner head cartridge on the carriage of the printer body as described above. The printer controller of the host unit 200 and the printer scanner unit unit 219 transmits / receives status data, print data, and scan data using the registers of the I / O port.

FIG. 32 is a block diagram showing the arrangement of the scanner head cartridge, printer head cartridge and printer unit. The printer CPU 401 and controller 2306 control three motors (for carriage, line feed, and auto sheet feed), four sensors (home position detection, ASF position detection, paper feed detection, paper discharge detection), scanner, and print. The drive control of the head and the temperature detection control by the thermistor circuit are performed.

As a method of discriminating the cartridge mounted on the carriage, a 2-bit head ID is provided in each carriage contact portion (not shown), the head ID is read after mounting the carriage, and the scanner head cartridge and the print head cartridge are read. Determine and match the contents of the control pin.

The appearance of the scanner head cartridge is shown in FIG.
Is the same as. The scanner head cartridge 800 is
It has the same shape as the print head cartridge 302, and also has an electrical connection portion with the printer unit that has a connector 801 common to the print head cartridge. The connector 801 of the scanner head cartridge 800 is provided with a contact portion (connector portion) 802 for transmitting and receiving a read control signal from the main body via the contact portion 2316.

The carriage 30 is driven by the head guide 303.
1 and the scanner head cartridge 800 are connected. The read signal and the control signal are transmitted / received to / from the printer scanner controller 406 via the contact portion 802 and the flexible cable 304.

A positioning hole 811B and a positioning groove 811C for positioning when mounted on the carriage 301 are provided. The reference wall 811 determines the posture in the reading direction, and the mounting position is determined by being biased to the carriage side.

The external appearance of the printer scanner unit section 219 is the same as that shown in FIG. Scanner head cartridge 8
Reference numeral 00 has the same shape as the print head cartridge 302 for recording on the recording medium, and both the scanner head cartridge 800 and the print head cartridge 302 are detachably replaceable with respect to the printer unit. The carriage 301 has a scanner head cartridge 800.
A carriage contact portion 316 for transmitting and receiving a read signal from the main body via the connector portion 802 is provided.

The read signal is sent to the CPU 40 on the printer side via the contact portion 802 and the flexible cable 304.
1 is processed.

The carriage 301 has a frame side plate portion 45.
Reading is performed by reciprocating along the slider shaft and the slide plate 47 between A and 45B. A carriage drive motor (CR motor) 307 moves the carriage 301 via a belt.

The optical arrangement inside the scanner head cartridge is the same as in FIG. Multiple LEDs that are light sources
902 (λ = 570 nm) is arranged longer than the reading width direction. A cylindrical rod lens 912 is installed in parallel with and close to the LED 902. LED90
The irradiation center of 2 passes through the center of the lens action surface of the rod lens 912, and irradiates the surface of the document obliquely.

The light reflected from the document surface passes through the field lens 913 which is the first imaging system lens whose optical axis center is provided in a direction substantially perpendicular to the document, and is provided parallel to the reading width direction. The mirror 903 changes the direction of the optical axis to 9
It is bent by 0 ° to form a light beam that is substantially parallel to the original.

Reference numeral 918 denotes an aperture, which is the position of the image forming surface of the field lens 913 which is the first image forming system lens. An image forming lens (not shown) that is a second image forming system lens is provided behind the aperture 918.

The image forming position of the image forming lens is the position of the CCD 904 as the line image pickup device. The imaging system lens is arranged at a reduction ratio of 0.45158.

The operation of the image reading apparatus having the above configuration will be described. First, the electrical characteristics of the LED serving as the scanner light source will be described. FIG. 33 is a graph showing the relationship between the ambient temperature Ta and the relative light emission intensity Iv. It is shown that the relative emission intensity Iv of the LED decreases as the ambient temperature Ta increases.

FIG. 34 is a graph showing the relationship between ambient temperature Ta and forward voltage Vf. It is shown that when the ambient temperature Ta rises, the LED forward voltage Vf decreases.

FIG. 35 shows an LED used in this embodiment.
It is a block diagram of a drive circuit. In order to reduce the size of the circuit, the circuit is simplified and a constant voltage drive system is adopted. In this LED drive circuit, seven LEDs serving as a light source are arranged in series (LED array), the LED drive current can be switched in two steps, and control is performed by the signal levels of drive signals S1 and S2.

That is, when the drive signal S1 is at high level and the drive signal S2 is at low level, a strong current (about 20 [mA]) flows through the LED array. Further, when the drive signal S1 is at the low level and the drive signal S2 is at the high level, a weak current (about 10 [mA]) flows through the LED array.

FIG. 36 shows a scanner head cartridge having five environmental temperatures (0 ° C., 10 ° C., 20 ° C., 30 ° C., 40 ° C.).
It is a graph which shows the data at the time of changing into (° C) and reading a white standard value. In FIG. 36, the horizontal axis represents 128 dots when reading by the scanner. The vertical axis represents the numerical value received by the printer unit when the scanner output is expressed in 256 steps. It can be seen that the scanner output decreases as the environmental temperature rises. The change in the scanner output value due to the ambient temperature is not preferable for inputting a stable image, and therefore needs to be corrected.

FIG. 37 is a graph showing the relationship between the white reference value and the elapsed time. Fig. 37 shows the ambient temperature of 25 ° C (room temperature)
Then, the white reference value sheet fed from the printer unit is stored in a strong current state (drive signal S1 is H
The data read at 20 [mA] at the high level is shown. The horizontal axis represents the elapsed time (unit: seconds) after the LED, which is the light source, is turned on. The vertical axis is the scanner output 2
When expressed in 56 levels, it is a numerical value received by the printer unit. The scanner head cartridge 800 according to the present embodiment is configured with a reading width of 128 pixels, but the data is shown with a typical value of 63-
It has 66 pixels.

After the LED is turned on, the relative light emission intensity Iv decreases as it heats up. The relative light emission intensity Iv does not decrease in proportion to the elapsed time but shows a sharp change immediately after light emission.

In addition, the LED during reading selectively emits a strong current (20 [mA]) in the case of a storage time of 256 [μsec] depending on the reading resolution, but during the return operation in which the carriage returns to the home position, We want to suppress the power consumption of the main body and the LED and prohibit the lighting of the LED as the light source as much as possible.

The temperature condition when the LED temperature is saturated in this continuous reading operation is the most stable state for obtaining stable image quality. Therefore, the white reference read value here is “110”.

According to the data shown in FIG. 37, the case where the scanner output value reaches "110" which is the stable state at the time of reading means that after the light emission with the strong current (20 [mA]), it is about 60 [se].
c] After a lapse of time.

In order to obtain the above-mentioned stable state, first, it is necessary to eliminate the influence of the change in the output of the scanner due to the ambient temperature. The printer CPU 401 detects the environmental temperature from the thermistor circuit 2401 which is a temperature sensor.

FIG. 38 is a diagram showing the preheating time required until the white reference value "110" is reached. The scanner head cartridge is preheated using the preheating time according to each environmental temperature. The reading operation is prohibited during the preheating operation. Since the preheating time is different, the temperature rise amount at each environmental temperature is different.

Next, the saturation temperature of the LED being read is
In order not to be affected by the environmental temperature, it is necessary to set the lighting ratio of the LED according to the environmental temperature. FIG. 39
FIG. 4 is a diagram showing a lighting ratio of LEDs set according to an ambient temperature.

Even if the lighting ratio is selected, the printer CPU 401
If the temperature information from the host unit 200 or the temperature detection circuit in the scanner is used,
You may judge by the temperature information.

Since the reciprocating speed of the carriage 301 is 3.9 Khz (651 PPS), L
The average current consumption during the reading operation by the ED is as shown in Formula 4 at the environmental temperature of 25 ° C.

[0210]

[Formula 4] 20 × 0.52 + 0 × 0.48 = 10.4 [mA] In order to maintain this state in the interval until the next reading operation starts after the original reading becomes stable, It is necessary to consume the same power consumption as the state in the LED as the light source. That is, 10 [mA] is set as the weak current (S1 “LOW”, S2 “High”) LE
It is necessary to feed D.

Further, when the average current consumption in a low temperature environment such as 0 ° C. is large, it is possible to drive the LEDs at a specific ratio by blinking with a strong current (20 [mA]) to obtain the average current.

FIG. 40 is a flow chart showing the control processing procedure of the image reading apparatus. The printer CPU 401 detects the ambient temperature from the thermistor circuit 2401 (step S101) and selects the preheating time (see FIG. 38) corresponding to each ambient temperature (step S102). The drive signal S1 is set to the high level, the drive signal S2 is set to the low level, and the preheating operation of the scanner unit is performed (step S
103).

The reading operation is prohibited during the preheating operation (step S104), and the white reference value is read after the preheating is completed (step S105). It is determined whether or not there is a read command (step S106), and if there is a read command, LE
Select the D lighting ratio (see FIG. 39) (step S10).
7), the image is read (step S108).

If there is no read command in step S106, the drive signal S1 is set to low level and the drive signal S2 is set to H level to perform the heat retention operation (step S109).
It is determined whether or not there is an end command (step S110),
If there is an end command, the process ends, and if there is no end command, the process returns to step S106.

In this embodiment, the time is used for controlling the preheating temperature of the LED. However, when it is possible to dispose the temperature sensor near the LED light source inside the scanner at the time of preheating, the temperature is controlled by the temperature management. You can

[0216]

Effect of the Invention The present onset light by the lever, regardless of the environment temperature
Read the original image with the light source always stable.
You can

[0217]

[0218]

[0219]

[0220]

[0221]

[0222]

[0223]

[0224]

[0225]

[0226]

[0227]

[0228]

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235]

[Brief description of drawings]

FIG. 1 is a perspective view showing the external appearance of a portable personal computer according to a first embodiment.

FIG. 2 is a block diagram showing a hardware configuration of a personal computer.

FIG. 3 is a perspective view showing an appearance of a printer scanner unit section 219.

FIG. 4 is a block diagram showing a hardware configuration of a printer scanner unit section 219.

FIG. 5 is a block diagram showing a configuration of a printer scanner controller 406.

FIG. 6 is an explanatory diagram showing a map of an I / O data register 501.

FIG. 7 is a RAM 40 in an operation of writing received data.
FIG. 3 is an explanatory diagram showing address areas of a recording data buffer and a receiving buffer on No. 3.

FIG. 8 is a perspective view showing an appearance of a scanner head cartridge.

FIG. 9 is a block diagram showing a configuration of parts inside the scanner head cartridge.

FIG. 10 is an explanatory diagram showing a map of an I / O port register.

11 is an explanatory diagram showing a dedicated status port used for exchanging information between the host unit 200 and the printer scanner unit unit 219. FIG.

12 is a diagram showing bit contents of status port 1 of 1101. FIG.

FIG. 13 illustrates a printer scanner unit unit 219 from a host unit 200 via a status port 2 shown by 1102.
It is a figure which shows the list of the commands sent to.

14 is a diagram showing 1-byte head unit information sent from the printer scanner unit section 219 to the host section 200. FIG.

FIG. 15 is a diagram showing 1-byte read resolution information sent from the printer scanner unit section 219 to the host section 200.

16 is a flowchart showing a processing procedure of a basic scanner operation according to a command transmitted by the host unit 200. FIG.

17 is a flowchart showing a processing procedure of a basic scanner operation according to a command transmitted by the host unit 200 continued from FIG. 16;

FIG. 18 is a flowchart showing a preheat treatment procedure executed by a printer control CPU 401.

FIG. 19 is a flowchart showing a heat treatment procedure executed by the CPU 401 for controlling the printer.

FIG. 20 is a printer control CPU 40 that follows FIG. 19;
It is a flow chart which shows the heat treatment procedure performed by 1.

FIG. 21 is a block diagram showing a configuration of a printer scanner unit section 219.

FIG. 22 is a perspective view showing the outer appearance of a printer scanner unit section 219.

FIG. 23 is a perspective view showing an optical arrangement inside the scanner head cartridge.

FIG. 24 is a flowchart showing a processing procedure of a basic scanner operation.

FIG. 25 is a flowchart showing a processing procedure of a basic scanner operation subsequent to FIG. 24.

FIG. 26 is a flowchart showing a white reference value measurement procedure in step S912.

FIG. 27 is a diagram showing changes in the actual white reference value L according to the elapsed time t after the light source is turned on.

28 is a diagram showing a Lagrange interpolation method for approximating the time variation curve of the light amount immediately after the light source is turned on shown in FIG. 27.

FIG. 29 is a flowchart showing a procedure for calculating a white reference value saturation time (LED light amount stable time) in step S1008.

FIG. 30: White reference value saturation time (LED light quantity stabilization time)
It is a figure which shows the time change of the white reference value at the time of calculation.

FIG. 31 is a diagram showing an optical configuration of an image reading apparatus using a reduction optical system.

FIG. 32 is a block diagram showing configurations of a scanner head cartridge, a printer head cartridge, and a printer unit.

FIG. 33 is a graph showing the relationship between ambient temperature Ta and relative emission intensity Iv.

FIG. 34 is a graph showing the relationship between ambient temperature Ta and forward voltage Vf.

FIG. 35 is a configuration diagram of an LED drive circuit used in the present embodiment.

FIG. 36: The ambient temperature is set to 5 with the scanner head cartridge.
It is a graph which shows the data at the time of changing a kind (0 degreeC, 10 degreeC, 20 degreeC, 30 degreeC, 40 degreeC), and reading a white reference value.

FIG. 37 is a graph showing a relationship between a white reference value and elapsed time.

FIG. 38 is a diagram showing a preheating time required until the white reference value “110” is reached.

FIG. 39 is a diagram showing a lighting ratio of LEDs set according to the ambient temperature.

FIG. 40 is a flowchart showing a control processing procedure of the image reading apparatus.

[Explanation of symbols]

2 Serial printer 200 host department 219 Printer Scanner Unit 301 carriage 401 CPU 406 Printer Scanner Controller 800 scanner head cartridge 902 LED 2401 Thermistor circuit

Continuation of the front page (56) References JP-A-8-87076 (JP, A) JP-A-5-276319 (JP, A) JP-A-5-212587 (JP, A) JP-A-1-300668 (JP , A) JP 61-255366 (JP, A) JP 5-12212 (JP, A) JP 2-25159 (JP, A) JP 61-133766 (JP, A) JP 8-149301 (JP, A) JP-A-7-122374 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 1/04 101 G06T 1/00 430 B41J 2/01

Claims (8)

(57) [Claims] 1. A carrier carrying a scanner cartridge.
An image reading apparatus for reading an image by irradiating light to the original from the built-in light source before Symbol scanner cartridge while the Tsu di is reciprocated, and the ambient temperature detecting means for detecting the environmental temperature, the prior document image reading The light source is turned on for preheating only for a time period according to the ambient temperature, and the light source is mainly used when reading the original image and when the carriage is moving forward.
The image reading apparatus is provided with: a control unit that controls to turn on the light and turn off the light when the carriage is returning, and sets a lighting ratio at that time according to the environmental temperature. 2. The image reading apparatus according to claim 1, wherein the control unit turns on the light source for keeping heat when the original image reading is not performed after the preheating is turned on. 3. The image reading apparatus according to claim 1, wherein the control unit prohibits the reading of the original image until the lighting time for the preheating elapses. 4. The image reading device according to claim 1, wherein the light source is an LED. 5. A carrier equipped with a scanner cartridge.
The control method of the previous SL image reading apparatus from a light source incorporated in the scanner cartridge by irradiating light to the original document to read an image while the Tsu di is reciprocated, to detect the environmental temperature, the environmental temperature before document image reading for a time corresponding to the light the light source for the preheating,
When reading an original image, the light source is mainly used as the carrier.
Tsu controlled to turn off at the time of backward movement of the carriage causes lit during di forward movement, the control method of the image reading apparatus characterized by setting accordingly the lighting ratio at that time to the environmental temperature . 6. The method of controlling an image reading apparatus according to claim 5, wherein the light source is turned on for keeping heat when a document image is not read after the preheating is turned on. 7. The method of controlling an image reading apparatus according to claim 5, wherein reading of the original image is prohibited until a lighting time for the preheating elapses. 8. The method of controlling an image reading apparatus according to claim 5, wherein the light source is an LED.