JP2995483B2 - Image reading device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a SCSI (Small Computer System Interface).
e) An image reading apparatus using the interface.

[Conventional technology]

SCSI standardized by the American National Standards Institute (ANSI) in 1986
Are magnetic disks, magnetic tapes, optical disks, printers,
This is a general-purpose input / output interface for small and medium-sized computer systems that can operate not only in common with various peripheral devices such as scanners, but also enables communication between systems. With the progress of standardization, the momentum to adopt SCSI in various systems such as personal computers, minicomputers, and OA systems is increasing.

Up to eight host computers and peripheral devices can be connected to the SCSI bus. Various peripheral devices such as a magnetic disk, a magnetic tape, a printer, an optical disk, an image reading device, and a CD / ROM can be connected to the SCSI bus by the same control means. Usually, a host computer is called an initiator and peripheral devices are called a target, and communication between the initiator and the target is the basis of interface operation in SCSI. Here, the initiator obtains the right to use the SCSI bus, and other SCSI devices (targets)
This is a SCSI device that has requested some kind of operation. In a normal interface operation, the host computer becomes an initiator. The target is a SCSI device that performs an operation requested by the initiator, and usually a peripheral device operates as the target.

In many cases, an image reading apparatus also has a function of only a target for outputting image data to an initiator serving as a host computer.

Here, an operation sequence until the image reading apparatus reads an image by communicating with the personal computer via the SCSI bus will be described.

In the operation sequence shown in FIG.
101 is a state where all the SCSI devices are not using the bus. Next, it enters the arbitration phase 102. This is the phase in which the SCSI device acquires the right to use the bus, and the phase in which the personal computer, which is the initiator, also acquires the right to use the bus.

Next, the selection phase 103 is entered. The selection phase 103 is a phase for selecting the SCSI device (in this case, an image input device) that operates as a target by the initiator (personal computer) having acquired the right to use the bus. Next, the command phase 104 is entered. At this time, various parameters are output from the initiator to the target.
Finally, a read command is sent, and the data phase 105 is entered. The data phase 105 outputs image data from a target image reading device to a personal computer (initiator).

When the image reading device finishes outputting the image data, the process enters the status phase 106. In the status phase 106, the result of determining whether the output image data is in accordance with the command parameter is output as a status. Next, the process enters the message-in phase 107. In this phase, the content of the error in the status phase 106 is output. If no error occurs, the process enters the bus free phase 101, and the sequence ends.

Conventionally, at this time, the fluorescent lamp is preheated after a read command is input in the command phase 104 and then enters the data phase 105, and is turned on three seconds later.

In addition, since the amount of light of the fluorescent lamp fluctuates at the environmental temperature as shown in FIG. 6, it has been necessary to preliminarily turn on the fluorescent lamp until the light amount becomes constant particularly at low temperatures.

[Problems to be solved by the invention]

However, as shown in FIG. 6, the amount of light of a fluorescent lamp fluctuates depending on the environmental temperature. When a personal computer with a slow processing speed is used, the phase moves between the arbitration, selection, and command phases, or processing time is particularly required for a command phase having many setting commands. Since the fluorescent lamp was turned on in the data phase following this command phase, especially when the temperature is low, after the fluorescent lamp is turned on after 3 seconds of preheating,
Preliminary lighting is required until the light amount of the fluorescent lamp increases, and the time until image reading starts is longer than necessary because a high-speed SCSI bus is used.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the conventional example, and has as its object to provide an image reading apparatus capable of shortening the time until image reading starts.

[Means for solving the problem]

In order to achieve the above object, in the present invention, the image reading apparatus is configured as described in (1), (2), and (3) below.

(1) A light source for illuminating a document, imaging means for receiving light from the document and converting the signal into an electric signal, and an interface for transmitting the electric signal to an external device. An image reading apparatus further comprising lighting control means connected to the external device for preheating the light source and lighting the light source.

(2) The image reading device according to (1), wherein the lighting control unit is provided with a command to turn on the light source at an early stage of a command phase of the interface.

(3) The image reading device according to (1) or (2), wherein the light source is a fluorescent lamp.

[Action]

With the above configuration, the image reading apparatus according to the present invention is connected to an external device from the selection phase before the data phase provided in the interface to preheat the light source for illumination, and then is turned on. Since the control can be performed, the image reading start time can be reduced.

Further, a light source lighting command is output to the lighting control means at the beginning of the command phase, and the fluorescent lamp can be turned on immediately after the command is input, so that the processing speed can be increased.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a control unit of an image reading apparatus according to an embodiment of the present invention. FIG. 2 is an operation sequence of the image reading apparatus according to the embodiment of the present invention until an image is read by a SCSI bus. FIG. 4 is an explanatory view showing a connection with an external device according to the embodiment of the present invention, FIG. 4a is a cross-sectional view of the image reading device of the embodiment according to the present invention, and FIG. 4b is a top view of the same. Note that the same (corresponding) components as those in the conventional example shown in FIG. 5 are denoted by the same reference numerals, and redundant description will be omitted.

In FIG. 1, reference numeral 1 denotes a platen glass for placing a document;
Reference numeral 2 denotes an imaging lens that forms an image of reflected light from the original, and 3 denotes a lens 2
Sensor (CCD), which is an image sensor that converts an image formed by the CCD into an electric signal, 4 is an amplifier that amplifies the output signal of the CCD 3, and 5 is an A / D (analog / digital) that quantizes the amplified analog image signal. Digital) conversion device. 6 is A
A selector for selecting a digital output from the A / D converter 5; an image processing circuit 7 for switching the resolution of the digital output from the A / D converter 5; A SCSI interface circuit for transmitting signals to and from the CPU 9, a CPU (Central Processing Unit) 10 such as a microprocessor for controlling the entire image reading apparatus (hereinafter referred to as a scanner), and a CPU 10 for a program Built-in ROM etc. Reference numeral 11 denotes a fluorescent lamp for illuminating a document, and 12 denotes a fluorescent lamp control circuit for controlling the fluorescent lamp 11. In addition,
Reference numeral A denotes lighting control means formed by the SCSI interface circuit 8, the CPU 10, and the fluorescent lamp control circuit 12.

FIG. 3 shows the scanner and the external device 9 according to the embodiment of the present invention.
(For example, LBP, personal computer).

Here, 13 is a scanner, 14 is a personal computer as an initiator, 15 is an LBP (laser beam printer), and 16 is a CRT (CRT display device).
The scanner 13, the personal computer 14, and the LBP 15 are connected by a SCSI bus. As shown in the figure, a scanner 13 and a personal computer 14, an LBP 15, and a CRT
The output of the image signal to 16 is performed via the SCSI interface circuit 8 described above.

FIG. 4a shows the internal configuration of the above-mentioned scanner 13, and FIG. 4b shows the document placing position of the scanner 13.

Here, 17 is a reference density subject, 18 is a control unit,
19 is a CCD driver (drive circuit), 20 is a fluorescent lamp unit for illuminating the original, 21 is a reflection mirror, 22 is an original, and 23 is a platen cover.

Next, the overall operation of the embodiment of the present invention will be described with reference to FIGS.

First, as shown in FIGS. 1 and 4a, an original 22 on a platen glass (original platen glass) 1 is irradiated by a fluorescent lamp 11 in a fluorescent lamp unit 20 for illuminating the original, and reflected light of the original 22 is reflected. Is guided onto the CCD 3 by the imaging lens 2 to form an original image.
At this time, the original 22 is placed on the platen glass 1 so that the right end is the leading end of the original as shown in FIG. 4b. In FIG. 4a, the right end of the fluorescent lamp unit 20 for document illumination, which is a scanning optical system, has an initial value, and the initial position is confirmed by an optical position sensor (not shown). While the original 22 is placed on the platen glass 1, instructions of various processing modes are input to the scanner 13 from the personal computer 14 as the external device 9. The instruction of this mode is, for example, content of whether the pixel density is 300 dpi (dot / inch), 200 dpi, or 150 dpi, or whether the image signal is binary or multi-level.

The CPU 10 that has received the instructions of the various processing modes via the SCSI interface circuit 8 issues a control signal for mode switching in advance and sets the pixel density and image signal processing to the image processing circuit 7 in accordance with the instructions. deep.

Next, when a document reading start command is input from the personal computer 14, the CPU 10 is scanned by a motor (not shown) for driving the fluorescent lamp unit 20. When the CPU 10 reaches the document leading end position, the CPU 10 A control signal for permitting image signal output is output to the personal computer 14, and the image signal read by the CCD 3 by scanning the original is sent to the personal computer 14. The number of scans of the optical system is uniquely determined by the number of pulses by which the CPU 10 drives an optical system drive motor (not shown). When the CPU 10 outputs the required number of pulses according to the size of the document to the motor, the CPU 10 determines that the reading of the document is completed, turns off the fluorescent lamp via the fluorescent lamp control circuit 12, and controls the image signal output to be disabled. It outputs a signal to the SCSI interface circuit 8 and controls the reversal of the motor, and outputs a document reading end signal to the personal computer 14 via the SCSI interface circuit 8.

Due to the motor reversal control of the CPU 10 described above, the original illumination fluorescent lamp unit 20 advances in the direction of arrow 1A in FIG. Stop when detected. If the next document reading start command is not received from the personal computer 14 in the return section of the optical system, the fluorescent lamp unit 20 stops at the initial position and the document reading operation ends.

Next, the operation of the embodiment of the image reading apparatus according to the present invention shown in FIG. 2 will be described with reference to the sequence of the SCSI phase.
Note that steps 101 to 102 in the sequence are the same as in the conventional example shown in FIG.

The personal computer 14, which is the external device 9 that has acquired the right to use the bus of the SCSI interface 8, enters a selection phase 103 for selecting the scanner 13 as a target. Here, when the scanner 13 is selected, the fluorescent lamp 11 is preheated and then turned on. Next, the command phase 104 is entered. The command phase 104 sets various parameters from the personal computer 14 as an initiator to the target scanner 13. At this time, a fluorescent lamp lighting command is sent at the beginning of the command phase 104, and the fluorescent lamp 11 is turned on immediately after entering the command phase 104.

After setting the parameters, the process enters the data phase 105. Here, the personal computer from the scanner 13
At 14, image data is transferred.

Next, the status phase 106 is entered. The status phase 106 is a phase in which the result of determining whether or not the image data as set in the command phase 104 has been transmitted is transmitted from the scanner 13.

The message in phase 107 is a phase for receiving a message from the scanner 13, and the status phase 106
When the NG comes out of the scanner 13, the content is output. After passing through the message-in phase 107, the process returns to the bus-free phase 101, and the sequence ends.

In the above embodiment, the optical system moving type has been described. Similarly, the optical system fixed type device, that is, a document moving type such as a facsimile for moving a document can be similarly implemented, and the same effect as described above can be obtained. it can.

〔The invention's effect〕

As described above, since the light source is controlled to be turned on when connected to the external device in the selection phase provided in the interface, it is possible to reduce the time until the start of image reading as compared with turning on the light source in the conventional data phase.

Further, since the light source lighting command is provided at the beginning of the command phase, the time until image reading starts can be similarly reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a control unit of an embodiment of an image reading apparatus according to the present invention, and FIG. 2 reads an image via a SCSI bus of the image reading apparatus of the embodiment of the present invention. FIG. 3 is an explanatory diagram showing connection with an external device according to the embodiment of the present invention, FIG. 4a is a sectional view of the image reading device according to the embodiment of the present invention, and FIG. FIG. 5 is a top view, FIG. 5 is an operation sequence until an image is read by a SCSI bus of a conventional image reading device, and FIG. 6 is a diagram showing a temperature characteristic of a fluorescent lamp. In the drawings, the same reference numerals indicate the same (corresponding) components. 3. Image sensor (CCD) 8. SCSI interface circuit 9. External device 11. Fluorescent light 22. Document A. Lighting control means

Claims (3)

(57) [Claims] A light source for illuminating the original; an image pickup unit for receiving light from the original and converting the light into an electric signal; and an interface for transmitting the electric signal to an external device. An image reading apparatus, comprising: lighting control means for connecting to the external device from a selection phase to preheat and light the light source. 2. An image reading apparatus according to claim 1, wherein said lighting control means includes a command for turning on said light source at an early stage of a command phase of said interface. 3. The image reading apparatus according to claim 1, wherein said light source is a fluorescent lamp.