JPH1052944A - Image-recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive and compact image-recording apparatus by greatly simplifying circuits and a control mechanism inside a printer controller part with the effective utilization of characteristics of devices in an image controller part. SOLUTION: A means 20 for outputting a timing control signal (/UNBL signal) is provided in a counter/memory 6a in an image controller part 6. A signal line outputting dot data (/VDO signal) from the counter/memory 6a is shared to output the timing control signal. A circuit constitution in a printer controller part 7 is hence simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus such as a laser printer, and more particularly to a scanning timing control for a horizontal scanning of a laser beam.

[0002]

2. Description of the Related Art A laser printer will be described as an example of a conventional image recording apparatus. FIG. 5 shows a configuration of a laser scanning unit of the laser printer. Reference numeral 1 denotes a semiconductor laser, and an image controller 6 (see FIG. 6 described later)
ON / OFF modulation is performed based on the dot data from. Reference numeral 2 denotes a polygon scanner which horizontally scans a laser beam A emitted from the semiconductor laser 1. Reference numeral 3 denotes a beam detector (synchronization detector) which generates a horizontal synchronization signal when the laser beam A scanned by the polygon scanner 2 is incident. 4 is an fθ lens. Reference numeral 5 denotes a photosensitive drum, which performs fθ correction on the scanned laser beam A and irradiates the photosensitive drum 5 charged by a charger (not shown). Thus, the electrostatic latent image formed on the photosensitive drum 5 is recorded as an image on a recording sheet by a well-known electrophotographic process.

FIG. 6 shows an example of a configuration of a control unit of the laser printer. 6 is an image controller,
7, a printer controller; and 8, a laser driver. FIG. 7 shows a simplified signal exchange between the image controller 6, the printer controller 7, and the laser driver 8. FIG. 8 shows the timing from the start of printing to the printing of one page of data. FIG. 9 shows the exchange of data for each horizontal scan.

[0004] The operation of each unit related to laser scanning of a laser printer will be described below. Reference numeral 6a in FIG. 6 denotes a counter and a memory (hereinafter, referred to as a counter / memory) in the image controller unit 6. This counter / memory 6
a creates dot data based on the image data from the external device 10 and develops it on the memory, and then sends a / PRN to the printer controller 7 to start the printing operation.
Outputs T signal. Reference numeral 7a denotes a CPU that controls the printer controller unit 7. This CPU 7a has a / PRN
After receiving the T signal, the recording paper (not shown) is fed and the electrophotographic process is initialized. After the polygon scanner 2 rises to a predetermined number of rotations, a horizontal synchronizing signal (hereinafter, referred to as a / BD signal) is generated.
Generate N signal.

Reference numeral 9 denotes a logic control unit. The logic control unit 9 generates the semiconductor laser 1 at a predetermined timing by the counter 9a to generate the / BD signal of the next scan every scan based on the / BD signal generated by the / LON signal. To generate an unblanking signal (hereinafter, referred to as a / UNBL signal) that causes the laser beam A to be incident on the laser beam.

The image controller 6 outputs dot data for one scan as a / VDO signal at a predetermined frequency after a predetermined time by the counter / memory 6a based on the / BD signal from the printer controller 7 as a reference. 9b is an OR circuit in the logic control unit 9. This OR circuit 9b
Is a / VDO signal from the image controller unit 6,
The OR of the / LON signal from the CPU 7a for printer control and the / UNBL signal from the counter 9a is performed, and a laser drive signal / LD is output to the laser driver unit 8.

[0007]

However, in the above-mentioned prior art, the printer controller 7 has a counter 9a which operates based on the / BD signal in order to generate a / UNBL signal. In order to output the / VDO signal to the counter 6, a counter / memory 6a which operates based on the / BD signal as in the counter 9a is provided.

As described above, since devices having the same function and operating on the basis of the / BD signal are provided in the same system in duplicate, the circuit scale is increased and the cost is extremely high. Further, the CPU 7a for controlling the printer is / L
In order to generate an ON signal, it is necessary to control the timing, and the control mechanism has become very complicated.

Therefore, an object of the present invention is to make use of the characteristics of the devices in the image controller unit to greatly simplify the circuit and control mechanism in the printer controller unit, and to provide an inexpensive and compact configuration. An image recording apparatus is provided.

[0010]

SUMMARY OF THE INVENTION The present invention relates to an image controller for creating dot data based on image data, and a printer for controlling on / off modulation of a light source based on the created dot data. The controller unit and the light generated by the light source unit are incident on a synchronization detector to generate a horizontal synchronization signal serving as a reference for scanning on the photoconductor, and the on / off modulation is performed in synchronization with the horizontal synchronization signal. A printer unit for scanning the controlled light to record an image on the photoconductor, provided in the image controller unit, wherein the synchronization detector detects the horizontal synchronization signal as 1 By providing a timing control signal output unit for outputting a timing control signal for controlling the timing of light emission of the light source unit so as to periodically generate each scan, image recording is performed. And characterized in that it constitutes a location.

The present invention also provides an image controller unit for creating dot data based on image data, a printer controller unit for performing on / off modulation control of a light source unit based on the created dot data, The light generated by the light source unit is incident on a synchronization detector to generate a horizontal synchronization signal serving as a reference for scanning on the photoconductor, and the ON / OFF modulated light is synchronized with the horizontal synchronization signal. A printer unit that scans the photosensitive member to record an image on the photoconductor, provided in the image controller unit, and the image controller unit sends a print start signal to the printer controller unit. Output from the light source unit so as to start the horizontal synchronizing signal generation operation. By comprising the forced timing control signal output means for outputting a timing control signal, characterized in that it constitutes an image recording apparatus.

The following components may be added. Forcibly controlling the light emission timing of the light source unit so that the synchronization detector starts the operation of generating a horizontal synchronization signal after the image controller unit outputs a print start signal to the printer controller unit. A forced timing control signal output unit that outputs a timing control signal may be provided in the image controller.

Further, the timing control signal output means is constituted by a counter circuit, and the light emission timing of the light source section is counted by the counter circuit, and a timing control signal is output when the count value reaches a certain value. You may do so. In this case, the counter circuit includes:
The counting operation can be started based on a horizontal synchronizing signal sent via the printer controller.

Further, the timing control signal output means may output the timing control signal after transmitting one line of dot data. Further, the timing control signal may be output from the image controller using a signal line for transmitting the dot data. Further, the forced timing control signal may be output from the image controller using a signal line for transmitting the dot data. Further, a laser light source or a light emitting diode can be used as the light source unit.

[0015]

Embodiments of the present invention will be described below. A first embodiment of the present invention will be described with reference to FIGS. In addition, the conventional example described above (FIGS.
The same parts as those shown in FIG. 7 are denoted by the same reference numerals, and the description thereof is omitted. In this example, the laser printer shown in FIG. 6 will be described as an example of the image recording apparatus.

FIG. 1 shows an example of the configuration of a laser scanning unit of a laser printer. The counter / memory 6a in the image controller unit 6 outputs dot data for one scan as a / VDO signal at a predetermined frequency, and outputs the next scan line at a predetermined timing based on the / BD signal as a horizontal synchronization signal. Output means 20 is provided for outputting a / UNBL signal as a timing control signal for controlling the light emission timing of the semiconductor laser 1 so as to periodically generate the / BD signal.

FIG. 2 shows a case where the / V signal is output from the counter / memory 6a in the image controller unit 6 using the same signal line.
5 shows timings of waveforms at which the DO signal and the / UNBL signal are output. In FIG. 1, a counter / memory 6a in the image controller unit 6 starts a counting operation based on the / BD signal from the printer controller unit 6, and after a predetermined time, outputs dot data for one line into /
Output as a VDO signal. At the same time, the counter / memory 6a generates a / BD signal for generating the / BD signal of the next line at a predetermined timing (for example, when the count value of the counter reaches a certain value) with reference to the / BD signal.
The UNBL signal is output after outputting dot data for one line.

As described above, the counter / memory section 6a in the image controller section 6 counts and outputs the timing of the / UNBL signal, so that the counter / memory section 6a in the printer controller section 6 as in the conventional example (FIG. 6). It is not necessary to provide the counter 9a, so that the printer controller 6 can be configured to be very inexpensive.

Next, a second embodiment of the present invention will be described with reference to FIGS. The image controller 6 in this example outputs a / VDO signal,
The image controller 6 is a printer controller 7
Outputs a / PRINT signal as a print start signal, and then outputs a / LON signal as a forced timing control signal for forcibly controlling the emission timing of the semiconductor laser 1 in order to generate a / BD signal. Means 30 are provided.

FIG. 4 shows a signal / V from the counter / memory 6a in the image controller 6 using the same signal line.
5 shows timings of waveforms at which a DO signal and a / LON signal are output. In FIG. 3, the image controller 6 outputs the / PRINT signal to the printer controller 7, and then generates the / BD signal. Therefore, the / LON signal is generated from the signal line of the / VDO signal at the timing shown in FIG. I do.

As described above, the / LO signal is output from the / VDO signal line in the image controller 6 at a predetermined timing.
Outputting the N signal eliminates the need for the printer controller 6 to perform timing management, thereby enabling the printer controller 6 to have a very simplified configuration.

By combining the above two examples,
The signals of both the / UNBL signal and the / LON signal are changed to / V
A similar effect can be obtained even if the image controller unit 6 is configured to output from the same signal line as the DO signal. Although the image recording apparatus has been described using the laser printer of FIG. 5 as an example, the present invention is not limited to this.

[0023]

As described above, according to the present invention, the horizontal synchronizing signal (/ BD signal) is periodically generated for each scanning line by effectively utilizing the counter / memory in the image controller. The timing control signal (/ UNBL)
Since the means for outputting the signal is provided in the counter / memory, it is not necessary to provide a separate counter in the printer controller unit as in the prior art, and the circuit configuration can be greatly reduced. Further, since means for outputting a forced timing control signal (/ LON signal) for controlling the start of generation of the horizontal synchronizing signal is provided in the image controller, the configuration of the controller in the printer controller can be simplified. it can. Therefore, an image recording apparatus having a very low cost and a simplified configuration can be obtained as compared with the conventional apparatus.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a timing chart showing the operation timing of each unit for the printing scan of FIG.

FIG. 3 is a block diagram showing a second embodiment of the present invention.

FIG. 4 is a timing chart showing operation timings of the respective units for the printing scan in FIG. 3;

FIG. 5 is a perspective view illustrating a configuration of a scanning unit of the laser printer.

FIG. 6 is a block diagram showing a conventional example.

FIG. 7 is a block diagram showing a further simplified configuration of FIG. 6;

FIG. 8 is a timing chart showing the operation timing of each unit at the start of a printing operation.

FIG. 9 is a timing chart showing the operation timing of each unit during print scanning.

[Description of Signs] 1 light source unit (semiconductor laser) 3 synchronization detector 5 photoconductor 6 image controller unit 6a counter circuit 7 printer controller unit 20 timing control signal output unit 30 forced timing control signal output unit

Claims (11)

[Claims] An image controller for generating dot data based on image data; a printer controller for controlling on / off modulation of a light source based on the generated dot data; The generated light is incident on the synchronization detector to generate a horizontal synchronization signal serving as a reference for scanning on the photoconductor, and the on / off modulation-controlled light is scanned in synchronization with the horizontal synchronization signal. An image recording apparatus comprising: a printer unit for recording an image on the photoconductor; provided in the image controller unit, wherein the synchronization detector periodically generates the horizontal synchronization signal for each scan. An image recording apparatus comprising a timing control signal output means for outputting a timing control signal for controlling the light emission timing of the light source unit. 2. The image processing apparatus according to claim 1, wherein the synchronization controller is provided in the image controller, and the synchronization detector starts a horizontal synchronization signal generation operation after the image controller outputs a print start signal to the printer controller. 2. The image recording apparatus according to claim 1, further comprising a forced timing control signal output unit for outputting a forced timing control signal for forcibly controlling light emission timing of the light source unit. 3. The timing control signal output means includes a counter circuit, and counts the light emission timing of the light source unit by the counter circuit, and outputs a timing control signal when the count value reaches a certain value. The image recording apparatus according to claim 1, wherein: 4. The image recording apparatus according to claim 3, wherein the counter circuit starts a counting operation based on a horizontal synchronization signal sent via the printer controller. 5. The timing control signal output means includes:
The image recording apparatus according to claim 3, wherein the timing control signal is output after transmitting dot data for a line. 6. The image recording apparatus according to claim 1, wherein the timing control signal is output from the image controller using a signal line for transmitting the dot data. 7. The image recording apparatus according to claim 2, wherein the forced timing control signal is output from the image controller using a signal line for transmitting the dot data. . 8. An image controller for creating dot data based on image data, a printer controller for controlling on / off modulation of a light source based on the created dot data, and The generated light is incident on the synchronization detector to generate a horizontal synchronization signal serving as a reference for scanning on the photoconductor, and the on / off modulation-controlled light is scanned in synchronization with the horizontal synchronization signal. An image recording apparatus comprising: a printer unit that records an image on the photoconductor, provided in the image controller unit, after the image controller unit outputs a print start signal to the printer controller unit. A forced timing control signal for forcibly controlling the light emission timing of the light source unit so that the synchronization detector starts the operation of generating a horizontal synchronization signal. An image recording apparatus comprising a forced timing control signal output means for outputting a signal. 9. The image recording apparatus according to claim 8, wherein the forced timing control signal is output from the image controller using a signal line for transmitting the dot data. 10. The image recording apparatus according to claim 1, wherein a laser light source is used as said light source unit. 11. The image recording apparatus according to claim 1, wherein a light emitting diode is used as the light source.